National Library of Energy BETA

Sample records for middle piney cr

  1. Piney Point Village, Texas: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    is a stub. You can help OpenEI by expanding it. Piney Point Village is a city in Harris County, Texas. It falls under Texas's 7th congressional district.12 References ...

  2. BR UFF BIG PINEY WILD ROSE BLU E GAP BR UFF UNIT WAMSUT TER

    U.S. Energy Information Administration (EIA) Indexed Site

    The boundaries are not informed by subsurface structural information. The data and methods ... BIG PINEY TIP TOP BIR D CANYON SWAN FONTEN ELL E LABARGE HOGSBACK CHIMNEY BUT TE BIG PINEY ...

  3. BR UFF BIG PINEY WILD ROSE BLU E GAP BR UFF UNIT WAMSUT TER

    U.S. Energy Information Administration (EIA) Indexed Site

    BIG PINEY TIP TOP BIR D CANYON SWAN FONTEN ELL E LABARGE HOGSBACK CHIMNEY BUT TE BIG PINEY AREA TIP TOP UNI T LINCOLN ROAD BLU E FOREST DEER HILL FOGART Y CREEK GREEN RIVER BEND ...

  4. BR UFF BIG PINEY WILD ROSE BLU E GAP BR UFF UNIT WAMSUT TER

    Gasoline and Diesel Fuel Update (EIA)

    (1) and Robert King (2) (1) Z, Inc., (2) Energy Information Administration BIG PINEY TIP ... BLU E FOREST SWAN DEER HILL FOGART Y CREEK GREEN RIVER BEND DRY PINEY SWAN S HOGSBACK AREA ...

  5. Middle East

    SciTech Connect (OSTI)

    Hemer, D.O.; Mason, J.F.; Hatch, G.C.

    1981-10-01

    Petroleum production in Middle East countries during 1980 totaled 6,747,719,000 bbl or an average rate of 18,436,390,000 bbl/d, down 13.9% from 1979. Increases were in Saudi Arabia and Syria. Significant decreases occurred in Iraq, Iran, Kuwait, and Turkey. New discoveries were made in Abu Dhabi, Iran, Saudi Arabia, Sharjah, and Oman. New areas were explored in Bahrain, Oman, Syria, and Yemen. 9 figures, 16 tables.

  6. Middle School Science Bowl

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

    2015 February Middle School Science Bowl Middle School Science Bowl WHEN: Feb 28, 2015 8:00 AM - 4:00 PM WHERE: Highland High School 4700 Coal Ave SE, Albuquerque, NM...

  7. Longfellow Middle School Wins Virginia Middle School Science...

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

    Wins Virginia Middle School Science Bowl on March 7 2014 Virginia Middle School Science Bowl At the end of the day, the team from Longfellow Middle School, Falls Church, won the...

  8. Tennessee: Bringing Jobs and Economic Development to Piney Flats...

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

    DPI employees Computer-aided design, accounting, and safety training Produce product installation training videos. ... DPI is expanding its engineering, development, and manufacturing ...

  9. Tennessee: Bringing Jobs and Economic Development to Piney Flats

    Broader source: Energy.gov [DOE]

    By tooling up a manufacturing line in Tennessee, where jobs are created, Diversified Power International, LLC is able to manufacture its product in the United States instead of Taiwan.

  10. Microsoft Word - CR.doc

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

    in XAS studies a. Porewater Na and Nitrate b. Water Extractable and Sorbed Cr c. In-situ Temperature Depth Below Ground Surface (m) Figure 1. Solute concentration profiles in core...

  11. Minnesota Regional Science Bowl for Middle School Students |...

    Office of Science (SC) Website

    Minnesota Regions Minnesota Regional Science Bowl for Middle School Students National Science Bowl (NSB) NSB Home About High School Middle School Middle School Students Middle ...

  12. Bohnam Middle School wins Pantex Middle School Science Bowl ...

    National Nuclear Security Administration (NNSA)

    Thursday, February 12, 2015 - 4:13pm NNSA Blog Teams from 17 area Texas schools competed for a regional title Saturday at the Pantex Middle School Science Bowl at West Texas A&M ...

  13. Middle Georgia Biofuels | Open Energy Information

    Open Energy Info (EERE)

    Georgia Biofuels Jump to: navigation, search Name: Middle Georgia Biofuels Place: East Dublin, Georgia Zip: 31027 Product: Georgia-based biodiesel producer. References: Middle...

  14. Process for depositing Cr-bearing layer

    DOE Patents [OSTI]

    Ellis, Timothy W.; Lograsso, Thomas A.; Eshelman, Mark A.

    1995-05-09

    A method of applying a Cr-bearing layer to a substrate, comprises introducing an organometallic compound, in vapor or solid powder form entrained in a carrier gas to a plasma of an inductively coupled plasma torch or device to thermally decompose the organometallic compound and contacting the plasma and the substrate to be coated so as to deposit the Cr-bearing layer on the substrate. A metallic Cr, Cr alloy or Cr compound such as chromium oxide, nitride and carbide can be provided on the substrate. Typically, the organometallic compound is introduced to an inductively coupled plasma torch that is disposed in ambient air so to thermally decompose the organometallic compound in the plasma. The plasma is directed at the substrate to deposit the Cr-bearing layer or coating on the substrate.

  15. Process for depositing Cr-bearing layer

    DOE Patents [OSTI]

    Ellis, T.W.; Lograsso, T.A.; Eshelman, M.A.

    1995-05-09

    A method of applying a Cr-bearing layer to a substrate, comprises introducing an organometallic compound, in vapor or solid powder form entrained in a carrier gas to a plasma of an inductively coupled plasma torch or device to thermally decompose the organometallic compound and contacting the plasma and the substrate to be coated so as to deposit the Cr-bearing layer on the substrate. A metallic Cr, Cr alloy or Cr compound such as chromium oxide, nitride and carbide can be provided on the substrate. Typically, the organometallic compound is introduced to an inductively coupled plasma torch that is disposed in ambient air so to thermally decompose the organometallic compound in the plasma. The plasma is directed at the substrate to deposit the Cr-bearing layer or coating on the substrate. 7 figs.

  16. Nucleation of Cr precipitates in Fe-Cr alloy under irradiation

    SciTech Connect (OSTI)

    Dai, Y. Y.; Ao, L.; Sun, Qing- Qiang; Yang, L.; Nie, JL; Peng, SM; Long, XG; Zhou, X. S.; Zu, Xiaotao; Liu, L.; Sun, Xin; Terentyev, Dimtry; Gao, Fei

    2015-04-01

    The nucleation of Cr precipitates induced by overlapping of displacement cascades in Fe-Cr alloys has been investigated using the combination of molecular dynamics (MD) and Metropolis Monte Carlo (MMC) simulations. The results reveal that the number of Frenkel pairs increases with the increasing of overlapped cascades. Overlapping cascades could promote the formation of Cr precipitates in Fe-Cr alloys, as analyzed using short range order (SRO) parameters to quantify the degree of ordering and clustering of Cr atoms. In addition, the simulations using MMC approach show that the presence of small Cr clusters and vacancy clusters formed within cascade overlapped region enhance the nucleation of Cr precipitates, leading to the formation of large Cr dilute precipitates.

  17. Conneaut Middle School Wind Turbine | Open Energy Information

    Open Energy Info (EERE)

    Conneaut Middle School Wind Turbine Jump to: navigation, search Name Conneaut Middle School Wind Turbine Facility Conneaut Middle School Wind Turbine Sector Wind energy Facility...

  18. Natural Gas Study Guide - Middle School | Department of Energy

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

    Middle School Natural Gas Study Guide - Middle School PDF icon Natural Gas Study Guide - Middle School More Documents & Publications Natural Gas Study Guide - High School What is ...

  19. National Science Bowl Update: Middle School Teams from Maryland...

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

    The teams remaining are: Indiana Creekside Middle School, Carmel Maryland Takoma Park Middle School, Silver Spring The top eight middle school teams in the academic competition ...

  20. Middle East oil and gas

    SciTech Connect (OSTI)

    Not Available

    1984-12-01

    The following subjects are covered in this publication: (1) position of preeminence of the Middle East; (2) history of area's oil operations for Iran, Iraq, Bahrain, Kuwait, Saudi Arabia, neutral zone, Qatar, United Arab Emirates, Oman and Egypt; (3) gas operations of Saudi Arabia, Iran, Kuwait, Qatar, Iraq and United Arab Emirates; (4) changing relationships with producing countries; (5) a new oil pricing environment; (6) refining and other industrial activities; and (7) change and progress. 10 figs., 12 tabs.

  1. Middle School Rules, Forms, and Resources | U.S. DOE Office of...

    Office of Science (SC) Website

    Resources National Science Bowl (NSB) NSB Home About High School Middle School Middle School Students Middle School Coaches Middle School Regionals Middle School Rules, Forms,...

  2. Longfellow Middle School Edges Out Gildersleeve to Win 2011 Virginia Middle

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

    School Science Bowl | Jefferson Lab Edges Out Gildersleeve to Win 2011 Virginia Middle School Science Bowl Longfellow Middle School Edges Out Gildersleeve to Win 2011 Virginia Middle School Science Bowl 1st_place_Longfellow.jpg The team from Longfellow Middle School, Falls Church, won the 2011 Virginia Regional Middle School Science Bowl held March 5 at Jefferson Lab. Pictured, left to right, are Ryan Golant, Kunal Naik, Keaton Lee, Tarun Kamath, Ross Dempsey and Coach James Bradford. Photo:

  3. Structural analysis of Cr aggregation in ferromagnetic semiconductor (Zn,Cr)Te

    SciTech Connect (OSTI)

    Kobayashi, H.; Yamawaki, K.; Nishio, Y.; Kanazawa, K.; Kuroda, S.; Mitome, M.; Bando, Y.

    2013-12-04

    The Cr aggregation in a ferromagnetic semiconductor (Zn,Cr)Te was studied by performing precise analyses using TEM and XRD of microscopic structure of the Cr-aggregated regions formed in iodine-doped Zn{sub 1?x}Cr{sub x}Te films with a relatively high Cr composition x ? 0.2. It was found that the Cr-aggregated regions are composed of Cr{sub 1??}Te nanocrystals of the hexagonal structure and these hexagonal precipitates are stacked preferentially on the (111)A plane of the zinc-blende (ZB) structure of the host ZnTe crystal with its c-axis nearly parallel to the (111){sub ZB} plane.

  4. Longfellow Middle School Wins Virginia Middle School Science Bowl on March

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

    7 | Jefferson Lab Wins Virginia Middle School Science Bowl on March 7 Longfellow Middle School Wins Virginia Middle School Science Bowl on March 7 2014 Virginia Middle School Science Bowl At the end of the day, the team from Longfellow Middle School, Falls Church, won the Virginia Regional Middle School Science Bowl on March 7. The team of (back row, left to right) Coach Jim Bradford, Fred Zhang and Benjamin Xu, and (front, l. to r.) Christopher Bi, Wenbo Wu and Aaditya Singh pose for a

  5. Midea: ENERGY STAR Referral (MWF-08CR)

    Broader source: Energy.gov [DOE]

    DOE referred the matter of Westpointe-brand room air conditioner model MWF-08CR to the EPA for appropriate action after DOE testing showed that the model does not meet the ENERGY STAR specification.

  6. Emerson: ENERGY STAR Referral (CR289E)

    Broader source: Energy.gov [DOE]

    DOE referred the matter of Emerson-brand refrigerator, model CR289E, to the EPA for appropriate action after DOE testing showed that the model does not meet the ENERGY STAR specification.

  7. West KY Regional Middle School Science Bowl

    Broader source: Energy.gov [DOE]

    Deegan Lawrence (far right) from Henderson County North Middle School gives an answer as teammates D.J. Banks (middle) and Alex Chandler look on during DOE’s West Kentucky Regional Middle School Science Bowl in Paducah February 6. Henderson North won the competition and will compete in DOE’s National Science Bowl® in Washington, D.C. April 30 through May 4.

  8. Are You Smarter Than a Middle Schooler?

    Broader source: Energy.gov [DOE]

    Test your knowledge of math and science against the middle school finalists in the National Science Bowl with these 10 questions.

  9. Microstructural and mechanical characteristics of Ni–Cr thin films

    SciTech Connect (OSTI)

    Petley, Vijay; Sathishkumar, S.; Thulasi Raman, K.H.; Rao, G.Mohan; Chandrasekhar, U.

    2015-06-15

    Highlights: • Ni–Cr thin films of varied composition deposited by DC magnetron co-sputtering. • Thin film with Ni–Cr: 80–20 at% composition exhibits most distinct behavior. • The films were tensile tested and exhibited no cracking till the substrate yielding. - Abstract: Ni–Cr alloy thin films have been deposited using magnetron co-sputtering technique at room temperature. Crystal structure was evaluated using GIXRD. Ni–Cr solid solution upto 40 at% of Cr exhibited fcc solid solution of Cr in Ni and beyond that it exhibited bcc solid solution of Ni in Cr. X-ray diffraction analysis shows formation of (1 1 1) fiber texture in fcc and (2 2 0) fiber texture in bcc Ni–Cr thin films. Electron microscopy in both in-plane and transverse direction of the film surface revealed the presence of columnar microstructure for films having Cr upto 40 at%. Mechanical properties of the films are evaluated using nanoindentation. The modulus values increased with increase of Cr at% till the film is fcc. With further increase in Cr at% the modulus values decreased. Ni–Cr film with 20 at% Ni exhibits reduction in modulus and is correlated to the poor crystallization of the film as reflected in XRD analysis. The Ni–Cr thin film with 80 at% Ni and 20 at% Cr exhibited the most distinct columnar structure with highest electrical resistivity, indentation hardness and elastic modulus.

  10. Middle School Science Bowl | The Ames Laboratory

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

    Science Bowl Middle School Science Bowl February 20, 2016 Mark your calendars Be a part of the Ames Laboratory/Iowa State University Middle School Science Bowl! Form a team and show you've got what it takes to compete against the best teams in the Midwest. This event is guaranteed to excite and challenge the Midwest's brightest middle school students. The basics - For students in grades 6, 7, and 8 - One-day academic competition - Held on the beautiful Iowa State University campus in Ames, Iowa

  11. Virginia Middle School Science Bowl | Jefferson Lab

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

    Virginia Middle School Science Bowl Twenty Teams to Compete in Virginia Middle School Science Bowl on March 5 NEWPORT NEWS, Va., March 3, 2016 - Some of the brightest young minds in the Commonwealth will meet at the U.S. Department of Energy's Jefferson Lab on March 5, to compete in the Virginia Regional Middle School Science Bowl. Teams from 20 schools are registered for this year's academic competition. The U.S. Department of Energy (DOE) National Science Bowl® is an annual academic

  12. East Middle School and Cayuga Community College Space Heating...

    Open Energy Info (EERE)

    Middle School and Cayuga Community College Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name East Middle School and Cayuga Community College Space...

  13. Media Advisory: Virginia Middle School Science Bowl Set For March...

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

    Virginia Middle School Science Bowl Set For March 5 at Jefferson Lab What: The Department of Energy's 2011 Virginia Regional Middle School Science Bowl When: Saturday, March 5,...

  14. Media Advisory: March 7 Virginia Middle School Science Bowl Tournament...

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

    March 7 Virginia Middle School Science Bowl Tournament What: The 2009 Virginia Regional Middle School Science Bowl When: Saturday, March 7, 2009. Round-robin competition will run...

  15. Henderson County North Middle School wins 2015 DOE West Kentucky...

    Energy Savers [EERE]

    Henderson County North Middle School wins 2015 DOE West Kentucky Regional Science Bowl Henderson County North Middle School wins 2015 DOE West Kentucky Regional Science Bowl ...

  16. Secretary Chu Announces Middle and High School Finalists Set...

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

    ... Lincolnshire Daniel Wright Middle School Indiana Carmel Creekside Middle School West Lafayette Harrison High School Iowa Cedar Rapids Home Schools of Eastern Iowa (MS) West Des ...

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

    SciTech Connect (OSTI)

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

    1992-12-31

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

  18. Kinetics and Mechanism of the Hydrogenation of CpCr(CO)3/[CpCr(CO)3]2 Equilibrium to CpCr(CO)3H

    SciTech Connect (OSTI)

    Norton, Jack R.; Spataru, Tudor; Camaioni, Donald M.; Lee, Suh-Jane; Li, Gang; Choi, Jongwook; Franz, James A.

    2014-05-26

    The kinetics of the hydrogenation of 2 CpCr(CO)3/[CpCr(CO)3]2 to CpCr(CO)3H has been investigated. The reaction is second-order in Cr and first-order in H2, with a rate constant of 45 M 2s 1 at 25 C in benzene. DFT calculations rule out an H2 complex as an intermediate, and suggest (a) end-on approach of H2 to one Cr of [CpCr(CO)3]2 as the Cr-Cr bond undergoes heterolytic cleavage, (b) heterolytic cleavage of the coordinated H2 between O and Cr, and (c) isomerization of the resulting O-protonated CpCr(CO)2(COH) to CpCr(CO)3H. The work at Pacific Northwest National Laboratory (PNNL) was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences; Battelle operates PNNL for DOE.

  19. Hazard Evaluation for 244-CR Vault

    SciTech Connect (OSTI)

    GRAMS, W.H.

    1999-08-19

    This document presents the results of a hazards identification and evaluation performed on the 244-CR Vault to close a USQ (USQ No.TF-98-0785, Potential Inadequacy in Authorization Basis (PIAB): To Evaluate Miscellaneous Facilities Listed In HNF-2503 And Not Addressed In The TWRS Authorization Basis) that was generated as part of an evaluation of inactive TWRS facilities.

  20. BR UFF BIG PINEY WILD ROSE BLU E GAP BR UFF UNIT WAMSUT TER

    U.S. Energy Information Administration (EIA) Indexed Site

    BOE Reserve Class No 2001 reserves 0.1 - 10 MBOE 10.1 - 100 MBOE 100.1 - 1,000 MBOE 1,000.1 - 10,000 MBOE 10,000.1 - 100,000 MBOE > 100,000 MBOE Basin Outline ID The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by Section 604 of the Energy Policy and Conservation Act Amendments of 2000 (P.L. 106-469). The boundaries are not informed by subsurface structural

  1. BR UFF BIG PINEY WILD ROSE BLU E GAP BR UFF UNIT WAMSUT TER

    U.S. Energy Information Administration (EIA) Indexed Site

    Gas Reserve Class No 2001 gas reserves 0.1 - 10 MMCF 10.1 - 100 MMCF 100.1 - 1,000 MMCF 1,000.1 - 10,000 MMCF 10,000.1 - 100,000 MMCF > 100,000 MMCF Basin Outline ID The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by Section 604 of the Energy Policy and Conservation Act Amendments of 2000 (P.L. 106-469). The boundaries are not informed by subsurface

  2. BR UFF BIG PINEY WILD ROSE BLU E GAP BR UFF UNIT WAMSUT TER

    U.S. Energy Information Administration (EIA) Indexed Site

    Liquids Reserve Class No 2001 liquids reserves 0.1 - 10 Mbbl 10.1 - 100 Mbbl 100.1 - 1,000 Mbbl 1,000.1 - 10,000 Mbbl 10,000.1 - 100,000 Mbbl Basin Outline ID The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by Section 604 of the Energy Policy and Conservation Act Amendments of 2000 (P.L. 106-469). The boundaries are not informed by subsurface structural

  3. Attachment I CHPRC CONDITION REPORT FORM Status: Analysis CR NUMBER: CR-2011I 2037

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

    CHPRC CONDITION REPORT FORM Status: Analysis CR NUMBER: CR-2011I 2037 Issue Identification and Processing Initiator: Initiating IDetifed Bannister, Roland J Document: 6/23/2011d Title of Issue: Extent of Condition review for S3000 containers Description of Issue: Extent of Condition Review arose from the Causal Analysis regarding the breached drum found in 2404WB on April 26, 2011. The scope of the review was to assess all other known S3000 (homogenous solids) waste streams to identify

  4. Dual-phase Cr-Ta alloys for structural applications

    DOE Patents [OSTI]

    Liu, Chain T.; Brady, Michael P.; Zhu, Jiahong; Tortorelli, Peter F.

    2001-01-01

    Dual phase alloys of chromium containing 2 to 11 atomic percent tantalum with minor amounts of Mo, Cr, Ti, Y, La, Cr, Si and Ge are disclosed. These alloys contain two phases including Laves phase and Cr-rich solid solution in either eutectic structures or dispersed Laves phase particles in the Cr-rich solid solution matrix. The alloys have superior mechanical properties at high temperature and good oxidation resistance when heated to above 1000.degree. C. in air.

  5. Texas Middle School Wins National Science Competition - News Releases |

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

    NREL Texas Middle School Wins National Science Competition June 27, 2003 Golden, CO. - Four middle school students from College Station Middle School in College Station, Texas, showed their mastery of science today, winning the National Middle School Science Bowl by a landslide (geologic phenomena). Winners in the model solar car competition also were announced today. Andrew Jackson Middle School from Titusville, Fla., will take home the trophy for the fastest car powered by sunlight. Each

  6. Cr-doped scandium borate laser

    DOE Patents [OSTI]

    Chai, Bruce H.; Lai, Shui T.; Long, Margaret N.

    1989-01-01

    A broadly wavelength-tunable laser is provided which comprises as the laser medium a single crystal of MBO.sub.3 :Cr.sup.3+, where M is selected from the group of Sc, In and Lu. The laser may be operated over a broad temperature range from cryogenic temperatures to elevated temperatures. Emission is in a spectral range from red to infrared, and the laser is useful in the fields of defense, communications, isotope separation, photochemistry, etc.

  7. Temporal evolution of ion energy distribution functions and ion charge states of Cr and Cr-Al pulsed arc plasmas

    SciTech Connect (OSTI)

    Tanaka, Koichi; Anders, André

    2015-11-15

    To study the temporal evolution of ion energy distribution functions, charge-state-resolved ion energy distribution functions of pulsed arc plasmas from Cr and Cr-Al cathodes were recorded with high time resolution by using direct data acquisition from a combined energy and mass analyzer. The authors find increases in intensities of singly charged ions, which is evidence that charge exchange reactions took place in both Cr and Cr-Al systems. In Cr-Al plasmas, the distributions of high-charge-state ions exhibit high energy tails 50 μs after discharge ignition, but no such tails were observed at 500 μs. The energy ratios of ions of different charge states at the beginning of the pulse, when less neutral atoms were in the space in front of the cathode, suggest that ions are accelerated by an electric field. The situation is not so clear after 50 μs due to particle collisions. The initial mean ion charge state of Cr was about the same in Cr and in Cr-Al plasmas, but it decreased more rapidly in Cr-Al plasmas compared to the decay in Cr plasma. The faster decay of the mean ion charge state and ion energy caused by the addition of Al into a pure Cr cathode suggests that the mean ion charge state is determined not only by ionization processes at the cathode spot but also by inelastic collision between different elements.

  8. Middle Rio Grande Cooperative Water Model

    Energy Science and Technology Software Center (OSTI)

    2005-11-01

    This is computer simulation model built in a commercial modeling product Called Studio Expert, developed by Powersim, Inc. The simulation model is built in a system dynamics environment, allowing the simulation of the interaction among multiple systems that are all changing over time. The model focuses on hydrology, ecology, demography, and economy of the Middle Rio Grande, with Water as the unifying feature.

  9. Cr segregation at the FeCr surface and the origin of corrosion resistance in ferritic steels

    SciTech Connect (OSTI)

    De Caro, M S; Morse, B; Egiebor, N; Farmer, J; Caro, A

    2008-11-22

    Structural materials in Gen-IV nuclear reactors will face severe conditions of high operating temperatures, high neutron flux exposure, and corrosive environment. Radiation effects and corrosion and chemical compatibility issues are factors that will limit the materials lifetime. Low-chromium (9-12 Cr wt.%) ferritic martensitic (F/M) steels are being considered as possible candidates because they offer good swelling resistance and good mechanical properties under extreme conditions of radiation dose and irradiation temperature. The surface chemistry of FeCr alloys, responsible for the corrosion properties, is complex. It exists today a controversy between equilibrium thermodynamic calculations, which suggest Cr depletion at the surface driven by the higher surface energy of Cr, and experimental data which suggest the oxidation process occurs in two stages, first forming a Fe-rich oxide, followed by a duplex oxide layer, and ending with a Cr-rich oxide. Moreover, it has been shown experimentally that corrosion resistance of F/M steels depends significantly on Cr content, increasing with increasing Cr content and with a threshold around 10% Cr, below which, the alloy behaves as pure Fe. In an attempt to rationalize these two contradicting observations and to understand the physical mechanism behind corrosion resistance in these materials we perform atomistic simulations using our FeCr empirical potential and analyze Cr equilibrium distributions at different compositions and temperatures in single and polycrystalline samples. We analyze the controversy in terms of thermodynamic and kinetic considerations.

  10. NREL: Workforce Development and Education Programs - Middle School

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

    Learn about fun and exciting middle school programs and competitions that will put student's science and math skills to the test. National Middle School Science Bowl NREL Model Car ...

  11. Media Advisory - The Virginia Middle School Science Bowl Is Set...

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

    The Virginia Middle School Science Bowl Is Set For March 6 at Jefferson Lab What: The 2010 Virginia Regional Middle School Science Bowl When: Saturday, March 6, 2010. Round-robin...

  12. Longfellow Middle School Edges Out Gildersleeve to Win 2011 Virginia...

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

    Edges Out Gildersleeve to Win 2011 Virginia Middle School Science Bowl 1stplaceLongfellow.jpg The team from Longfellow Middle School, Falls Church, won the 2011 Virginia Regional...

  13. STEM Volunteer Training: Engaging Middle School Students | Department...

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

    STEM Volunteer Training: Engaging Middle School Students STEM Volunteer Training: Engaging Middle School Students August 13, 2015 3:00PM to 4:00PM EDT Register: https:...

  14. SF6432-CR (02-01-13) Cost Reimbursement

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

    labor are authorized as direct charges Control : SF 6432-CR Title: Standard Terms & Conditions for Cost Reimbursement Owner: Procurement Policy Department Release Date: 11...

  15. SF6432-CR (02-01-12) Cost Reimbursement

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

    as direct charges to this contract Control : SF 6432-CR Title: Standard Terms & Conditions for Cost Reimbursement Owner: Procurement Policy & Quality Dept Release Date:...

  16. SF6432-CR (02-01-13) Cost Reimbursement

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

    by Part 931 of the DEAR by a Sandia audit. Control : SF 6432-CR Title: Standard Terms & Conditions for Cost Reimbursement Owner: Procurement Policy Department Release Date: 04...

  17. SF6432-CR (02-01-13) Cost Reimbursement

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

    ... prior to any attempts to enter a government site as shown ... premises are subject to search. (e) Contractor shall ... SF 6432-CR Title: Standard Terms & Conditions for Cost ...

  18. SF6432-CR (02-01-12) Cost Reimbursement

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

    ... prior to any attempts to enter a government site as shown ... premises are subject to search. (e) Contractor will ... SF 6432-CR Title: Standard Terms & Conditions for Cost ...

  19. Development of Surface Complexation Models of Cr(VI) Adsorption...

    Office of Scientific and Technical Information (OSTI)

    Cr(VI) Adsorption on Soils, Sediments and Model Mixtures of Kaolinite, Montmorillonite, ... into aquifers and shallow sediments and soils via many anthropogenic activities. ...

  20. SF6432-CR (02-01-13) Cost Reimbursement

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

    a Government site to perform work shall have Control : SF 6432-CR Title: Standard Terms & Conditions for Cost Reimbursement Owner: Procurement Policy & Quality Dept Release...

  1. Microsoft Word - chapter FeCrMo_ver2.doc

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

    Low-Alloy Ferritic Steels Fe-Cr-Mo Tempered December 8, 2005 ... strength level, material processing, and heat treatment 1. ... yield strength, hydrogen gas pressure, and temperature. ...

  2. Mines Welcomes Middle School Students | Critical Materials Institute

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

    Mines Welcomes Middle School Students Denver middle school students at Mines. Denver middle school students at Mines museum. Denver middle school students watch chemistry show at Mines. CMI partner Colorado School of Mines welcomed 180 sixth and seventh grade students from the Denver School of Science and Technology. The students spent the day at Mines to learn about Earth, energy, the environment, critical materials and mining. The students enjoyed a chemistry show by professor Jim Horan, and

  3. EnergySmart Schools Case Study: Northern Guilford Middle School

    SciTech Connect (OSTI)

    2009-09-01

    An EnergySmart Schools Case Study on the Northern Guilford Middle School in Greensboro, North Carolina

  4. Virginia, Maryland teams prepare for Regional Middle School Science Bowl |

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

    Jefferson Lab Virginia, Maryland teams prepare for Regional Middle School Science Bowl Virginia, Maryland teams prepare for Regional Middle School Science Bowl March 3, 2005 The Department of Energy's Jefferson Lab, in Newport News, Va., hosts the Virginia/Maryland Regional Middle School Science Bowl tomorrow (Saturday, March 5). A dozen schools have registered teams for the event, according to Jan Tyler, Science Education program manager. This is JLab's second year hosting the Middle School

  5. V.P. Biden Hosts the Middle Class Task Force

    Broader source: Energy.gov [DOE]

    Secretary Chu will join Vice President Biden at the White House as he hosts a Middle Class Task Force event.

  6. Spin-driven ordering of Cr in the equiatomic high entropy alloy NiFeCrCo

    SciTech Connect (OSTI)

    Niu, C.; Zaddach, A. J.; Oni, A. A.; Sang, X.; LeBeau, J. M.; Koch, C. C.; Irving, D. L.; Hurt, J. W.

    2015-04-20

    Spin-driven ordering of Cr in an equiatomic fcc NiFeCrCo high entropy alloy (HEA) was predicted by first-principles calculations. Ordering of Cr is driven by the reduction in energy realized by surrounding anti-ferromagnetic Cr with ferromagnetic Ni, Fe, and Co in an alloyed L1{sub 2} structure. The fully Cr-ordered alloyed L1{sub 2} phase was predicted to have a magnetic moment that is 36% of that for the magnetically frustrated random solid solution. Three samples were synthesized by milling or casting/annealing. The cast/annealed sample was found to have a low temperature magnetic moment that is 44% of the moment in the milled sample, which is consistent with theoretical predictions for ordering. Scanning transmission electron microscopy measurements were performed and the presence of ordered nano-domains in cast/annealed samples throughout the equiatomic NiFeCrCo HEA was identified.

  7. Oil Study Guide - Middle School | Department of Energy

    Energy Savers [EERE]

    Middle School Oil Study Guide - Middle School PDF icon Oil Study Guide - Middle School More Documents & Publications Oil Study Guide - High School evaluation_egs_tech_2008.pdf A History of Geothermal Energy Research and Development in the United States: Reservoir Engineering 1976-2006

  8. STEM: Volunteer Training Engaging Middle School Students

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

    STEM: Volunteer Training Engaging Middle School Students August 13, 2015 Erin Twamley Education Project Manager Department of Energy Nimisha Ghosh Roy Network Manager National Girls Collaborative Project Rabiah Mayas, Ph.D. Director of Science and Integrated Strategies Museum of Science and Industry Chicago 2 Agenda You are on mute! Use your webinar bar to fill out poll, send a chat or send in a question. Please tell us via chat if you cannot see or hear. Overview of STEM Training Key Outcomes

  9. Middle Urals` pollution prevention priorities assessment project

    SciTech Connect (OSTI)

    Gonzalez, M.; Ott, R.L.; Chukanov, V.

    1995-09-13

    The Middle Urals is an important Russian industrial region. The key industries are also the most environmentally damaging: mining, metallurgical and chemical industries. There are some 600 large-sized and medium-sized enterprises located within the Middle Urals` region. Their annual solid and gaseous chemical releases have led to exceeding some maximum permissible contaminant concentrations by factors of tens and hundreds. The environmental problems of the Middle Urals are of such magnitude, seriousness, and urgency that the limited available resources can be applied only to the problems of the highest priority in the most cost-effective way. By the combined efforts of scientists from Lawrence Livermore National Laboratory (USA), Institute of Industrial Ecology (Ekaterinburg, Russia) and Russian Federal Nuclear Center (Snezhinsk, Russia) the project on Environmental Priorities Assessment was initiated in 1993. Because the project will cut across a spectrum of Russian environmental, social, and political issues, it has been established as a genuine Russian effort led by Russian principals. Russian participants are the prime movers and decision-makers, and LLNL participants are advisors. A preliminary project has been completed to gather relevant environmental data and to develop a formal proposal for the full priorities assessment project for submittal to the International Science and Technology Center. The proposed priorities assessment methodology will be described in this paper. The specific objectives of this project are to develop and to implement a methodology to establish Russian priorities for future pollution prevention efforts in a limited geographic region of the Middle Urals (a part of Chelyabinsk and Sverdlovsk Oblasts). This methodology will be developed on two geographic levels: local (town scale) and regional (region scale). Detailed environmental analysis will be performed on a local scale and extrapolated to the regional scale.

  10. Magnetic properties and hyperfine interactions in Cr8, Cr7Cd, and Cr7Ni molecular rings from 19F-NMR

    SciTech Connect (OSTI)

    Bordonali, L; Garlatti, E; Casadei, C M; Furukawa, Y; Lascialfari, A; Carretta, S; Troiani, F; Timco, G; Winpenny, R E; Borsa, F

    2014-04-14

    A detailed experimental investigation of the 19F nuclear magnetic resonance is made on single crystals of the homometallic Cr8 antiferromagnetic molecular ring and heterometallic Cr7Cd and Cr7 Ni rings in the low temperature ground state. Since the F? ion is located midway between neighboring magnetic metal ions in the ring, the 19F-NMR spectra yield information about the local electronic spin density and 19F hyperfine interactions. In Cr8, where the ground state is a singlet with total spin S T = 0, the 19F-NMR spectra at 1.7 K and low external magnetic field display a single narrow line, while when the magnetic field is increased towards the first level crossing field, satellite lines appear in the 19F-NMR spectrum, indicating a progressive increase in the Boltzmann population of the first excited state S T = 1. In the heterometallic rings, Cr7Cd and Cr7 Ni, whose ground state is magnetic with S T = 3/2 and S T = 1/2, respectively, the 19F-NMR spectrum has a complicated structure which depends on the strength and orientation of the magnetic field, due to both isotropic and anisotropic transferred hyperfine interactions and classical dipolar interactions. From the 19F-NMR spectra in single crystals we estimated the transferred hyperfine constants for both the F?-Ni2+ and the F?-Cd2+ bonds. The values of the hyperfine constants compare well to the ones known for F?-Ni2+ in KNiF3 and NiF2 and for F?-Cr3+ in K2NaCrF6. The results are discussed in terms of hybridization of the 2s, 2p orbitals of the F? ion and the d orbitals of the magnetic ion. Finally, we discuss the implications of our results for the electron-spin decoherence.

  11. Characterization of Cr-rich Cr-Sb multilayer films: Syntheses of a new metastable phase using modulated elemental reactants

    SciTech Connect (OSTI)

    Regus, Matthias; Mankovsky, Sergiy; Polesya, Svitlana; Kuhn, Gerhard; Ditto, Jeffrey; Schürmann, Ulrich; Jacquot, Alexandre; Bartholomé, Kilian; Näther, Christian; Winkler, Markus; König, Jan D.; Böttner, Harald; Kienle, Lorenz; Johnson, David C.; Ebert, Hubert; Bensch, Wolfgang

    2015-10-15

    The new metastable compound Cr{sub 1+x}Sb with x up to 0.6 has been prepared via a thin film approach using modulated elemental reactants and investigated by in-situ X-ray reflectivity, X-ray diffraction, differential scanning calorimetry, energy dispersive X-ray analysis as well as transmission electron microscopy and atomic force microscopy. The new Cr-rich antimonide crystallizes in a structure related to the Ni{sub 2}In-type structure, where the crystallographic position (1/3, 2/3, 3/4) is partially occupied by excess Cr. The elemental layers of the pristine material interdiffused significantly before Cr{sub 1+x}Sb crystallized. A change in the activation energy was observed for the diffusion process when crystal growth starts. First-principles electronic structure calculations provide insight into the structural stability, magnetic properties and resistivity of Cr{sub 1+x}Sb. - Graphical abstract: 1 amorphous multilayered film 2 interdiffused amorphous film 3 metastable crystalline phase 4 thermodynamic stable phase (and by-product). - Highlights: • Interdiffusion of amorphous Cr and Sb occurs before crystallization. • Crystallization of a new metastable phase Cr{sub 1.6}Sb in Ni{sub 2}In-type structure. • The new Cr-rich phase shows half-metallic behavior.

  12. 244-CR Vault Interim Stabilization Project Plan

    SciTech Connect (OSTI)

    PARKMAN, D.B.

    2000-04-25

    The 244-CR Vault is a two-level, multi-cell structure of reinforced concrete constructed below grade. The lower cell contains four individual compartments, each containing a steel process storage tank and equipped with a concrete sump. The upper cell contains the piping and support equipment, and has two compartments for each of the tanks. The ''pump pit'' is accessed by the removal of concrete cover blocks, while the smaller ''riser pit'' is accessed by steel cover plates. The facility most recently was used as a double-contained receiver tank (DCRT). A DCRT is a type of waste transfer tank that together with its related equipment constitutes a short-term storage area for liquid waste and has a pump pit for waste transfer operations. This vault most recently was used for short-term storage and waste routing for saltwell liquid pumped from the 241-C Tank Farm in the 200 East Area. Waste transfer lines are connected inside the pump pit by a jumper installed between connecting nozzles. An active ventilation system is in operation at the 244-CR vault. Ventilation supply air enters the upper vault section through an inlet header with some leakage through the spaces between the cell cover blocks. The upper and lower vaults are connected by exhauster ports, which allow airflow between the two sections. Normal flow moves air from the upper cell to the lower cell where it is removed and routed into a filter plenum; there the air is treated by a bank of four prefilters and two banks of high-efficiency particulate air (HEPA) filters (each containing four HEPAs). The air is exhausted to the atmosphere through the 296-C-05 Stack. The stack is equipped with a record sampler and continuous air monitor. Two fans (each rated at 4,200 cubic feet per minute) installed downstream of the filtration system provide the motive force for exhausting the vaults and the tanks. As an active system, it is operated continuously with only one of the two fans required to operate at a time. A continuous beta-gamma air monitor is interlocked to the operating fan. Loss of power to the fans will activate an alarm at the 244-AR facility.

  13. Interlayer coupling in Fe/Cr/Gd multilayer structures

    SciTech Connect (OSTI)

    Drovosekov, A. B. Kreines, N. M.; Savitsky, A. O.; Kravtsov, E. A.; Blagodatkov, D. V.; Ryabukhina, M. V.; Milyaev, M. A.; Ustinov, V. V.; Pashaev, E. M.; Subbotin, I. A.; Prutskov, G. V.

    2015-06-15

    The effect of the chromium layer thickness on the magnetic state of an [Fe/Cr/Gd/Cr]{sub n} multilayer structure is studied. A series of Fe/Cr/Gd structures with Cr spacer thicknesses of 4–30 Å is studied by SQUID magnetometry and ferromagnetic resonance in the temperature range 4.2–300 K. The obtained experimental results are described in terms of an effective field model, which takes into account a biquadratic contribution to the interlayer coupling energy and a nonuniform magnetization distribution inside the gadolinium layer (which was detected earlier). Depending on the magnetic field and temperature, the following types of magnetic ordering are identified at various chromium layer thicknesses: ferromagnetic, antiferromagnetic, and canted ordering. A comparison of the experimental and calculated curves allowed us to determine the dependence of the bilinear (J{sub 1}) and biquadratic (J{sub 2}) exchange constants on chromium layer thickness t{sub Cr}. Weak oscillations at a period of about 18 Å are detected in the J{sub 1}(t{sub Cr}) dependence in the range 8–30 Å. The interlayer coupling oscillations in the system under study are assumed to be related to the RKKY exchange interaction mechanism via the conduction electrons of Cr.

  14. Effects of Cr and Ni on Interdiffusion and Reaction between U and Fe-Cr-Ni Alloys

    SciTech Connect (OSTI)

    K. Huang; Y. Park; L. Zhou; K.R. Coffey; Y.H. Sohn; B.H. Sencer; J. R. Kennedy

    2014-08-01

    Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe–15 wt.%Cr or Fe–15 wt.%Cr–15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U6Fe and thin UFe2 phases were observed to develop with solubilities: up to 2.5 at.% Ni in U6(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr)2, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni)2. The interdiffusion and reactions in the U vs. Fe and U vs. Fe–Cr–Ni exhibited a similar temperature dependence, while the U vs. Fe–Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases – lower growth rate at lower temperature but higher growth rate at higher temperature.

  15. Middle East and African Partnerships and Projects | Department of Energy

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

    Middle East and African Partnerships and Projects Middle East and African Partnerships and Projects The Office of Energy Efficiency and Renewable Energy (EERE) engages bilaterally with individual countries in the Middle East and Africa. Bilateral Partnerships Israel EERE collaborates with the Israeli Ministry of Energy and Water Resources (MEW) to conduct jointly-funded research, development, and demonstration projects that aim to successfully commercialize cutting-edge clean energy

  16. Media Advisory - Virginia Regional Middle School Science Bowl | Jefferson

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

    Lab Middle School Science Bowl Media Advisory - Virginia Regional Middle School Science Bowl What: Virginia Regional Middle School Science Bowl When: Saturday, March 1, 2014. Round robin competition runs from 9 a.m. - noon. The double elimination, semi-final and finalist rounds run from 1:30 - ~ 4 p.m. Awards presentations will be made immediately after the final round. Where: CEBAF Center Auditorium, Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, Va.

  17. 2016 Middle School Science Bowl | The Ames Laboratory

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

    2016 Middle School Science Bowl Check out video highlights of the 2016 Ames Laboratory Regional Middle School Science Bowl, held Feb. 20. Twenty-four teams from across the state competed in the event, with Ames Middle School winning the championship over LeMars and a trip to the U.S. Department of Energy's National Science Bowl, April 28-May 2 in Washington DC

  18. Greeley's Maplewood Middle School Stellar in Solar Car Race

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

    Greeley's Maplewood Middle School Stellar in Solar Car Race For more information contact: Sarah Holmes Barba, 303-275-3023 email: Sarah Barba Golden, Colo., May. 12, 2001 - Students from Greeley's Maplewood Middle School built the fastest model solar car and won the Junior Solar Sprint at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) today. A team from Lyons Middle School won top honors for design. Thirty-seven teams from across Colorado entered the 20-meter race,

  19. Middle Tennessee EMC- Residential Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Middle Tennessee Electric Membership Corporation (MTEMC) and the Tennessee Valley Authority (TVA) offer incentives for residential customers through the In-Home Energy Evaluation Program. This...

  20. Middle Tennessee E M C | Open Energy Information

    Open Energy Info (EERE)

    Tennessee E M C Place: Tennessee Website: www.mtemc.com Twitter: @MidTnElectric Facebook: https:www.facebook.comMiddleTennesseeElectric?refts Outage Hotline:...

  1. Middle School | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Attending National Event Volunteers 2015 Competition Results News Media WDTS Home ... Middle School Print Text Size: A A A FeedbackShare Page 2015 National Science Bowl 2015 ...

  2. Middle School Academic Competition - Double Elimination | U.S...

    Office of Science (SC) Website

    NSB Home About High School Middle School Attending National Event Volunteers 2015 ... School Double Elimination Top Teams for 2015 News Media WDTS Home Contact Information ...

  3. Students Sharpen Science and Math Skills at Middle School Science...

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

    Students Sharpen Science and Math Skills at Middle School Science Bowl March 8, 2004 ... questions about earth science, physical science, life science, math, and general science. ...

  4. Past Middle School National Science Bowl Winners (2002 - 2015...

    Office of Science (SC) Website

    ... Davis (Coach) 2003 First Place Team: College Station Middle School, College Station, Texas Team Members: Jeffrey Chen, Sean Lau, Brian Liu, Alex Liu, Becca Yasskin, and Cathy ...

  5. Stoller Middle School of Beaverton, Ore., emerges undefeated...

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

    Wash. Shahala Middle School, Vancouver, Wash. Pierce County Home School Club, Milton, Wash. BPA sponsors the science bowl to showcase students' talents in science,...

  6. Middle School Academic Competition - Double Elimination | U.S...

    Office of Science (SC) Website

    FAQ's Alumni Past National Science Bowl Winners Past National Science Bowl Photos and Videos National Science Bowl Logos High School Middle School Attending National Event...

  7. Ames wins 2015 Middle School Science Bowl | The Ames Laboratory

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

    championship round. Complete results from the afternoon can be found HERE. Champion - Ames Middle School Seated (left to right): Brennan Seymour, Andres Cordorba,...

  8. Training Manual for Senior and Middle Level Managers in Energy...

    Open Energy Info (EERE)

    Agency for International Developments (USAID) Energy Small Grants Program developed a training manual in order to build the knowledge base of senior and middle level managers...

  9. Coal Study Guide - Middle School | Department of Energy

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

    PDF icon Coal Study Guide - Middle School More Documents & Publications Coal Study Guide for Elementary School Coal Study Guide - High School Guide to Low-Emission Boiler and ...

  10. Maryland team wins Virginia/Maryland Regional Middle School Science...

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

    There are two competitions at the National Middle School Science Bowl - an academic math and science competition and a model fuel-cell car competition. The academic competition...

  11. Honey Creek Middle School Wins U.S. Department of Energy National Science

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

    Competition - News Releases | NREL Honey Creek Middle School Wins U.S. Department of Energy National Science Competition June 24, 2006 Photo of students from Honey Creek Middle School standing with their trophy from the National Middle School Science Bowl. Students from Honey Creek Middle School traveled from Terre Haute, Ind., to take first place at the National Middle School Science Bowl in Denver, Colo. Five middle school students from Honey Creek Middle School in Terre Haute, Ind.,

  12. Middle School Coaches | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Coaches National Science Bowl® (NSB) NSB Home About High School Middle School Middle School Students Middle School Coaches Middle School Regionals Attending the National Finals Volunteers 2016 Competition Results News Media WDTS Home Contact Information National Science Bowl® U.S. Department of Energy SC-27/ Forrestal Building 1000 Independence Ave., SW Washington, DC 20585 E: Email Us Middle School Middle School Coaches Print Text Size: A A A FeedbackShare Page Welcome Middle School Coaches

  13. 9 Cr-- 1 Mo steel material for high temperature application

    DOE Patents [OSTI]

    Jablonski, Paul D; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-11-27

    One or more embodiments relates to a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The 9 Cr-1 Mo steel has a tempered martensite microstructure and is comprised of both large (0.5-3 .mu.m) primary titanium carbides and small (5-50 nm) secondary titanium carbides in a ratio of. from about 1:1.5 to about 1.5:1. The 9 Cr-1 Mo steel may be fabricated using exemplary austenizing, rapid cooling, and tempering steps without subsequent hot working requirements. The 9 Cr-1 Mo steel exhibits improvements in total mass gain, yield strength, and time-to-rupture over ASTM P91 and ASTM P92 at the temperature and time conditions examined.

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

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2000-01-01

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

  15. SF6432-CR (02-01-13) Cost Reimbursement

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

    CR xx-xxxx) Initial release SANDIA CORPORATION SF 6432-CR (04/2015) SECTION II STANDARD TERMS AND CONDITIONS FOR COST-REIMBURSEMENT CONTRACTS THE FOLLOWING CLAUSES APPLY TO THIS CONTRACT AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY IDENTIFIED AS BEING CHANGED, SUPPLEMENTED, OR AMENDED IN WRITING ISSUED BY THE SANDIA CONTRACTING REPRESENTATIVE. (CTRL+CLICK ON A LINK BELOW TO ADVANCE DIRECTLY TO THAT SECTION) ACCEPTANCE OF TERMS AND CONDITIONS (Ts&Cs)

  16. Phase stability and elastic properties of Cr-V alloys

    SciTech Connect (OSTI)

    Gao, M. C.; Suzuki, Y.; Schweiger, H.; Do?an, .N.; Hawk, J.; Widom M.

    2013-02-20

    V is the only element in the periodic table that forms a complete solid solution with Cr and thus is particularly important in alloying strategy to ductilize Cr. This study combines first-principles density functional theory calculations and experiments to investigate the phase stability and elastic properties of CrV binary alloys. The cluster expansion study reveals the formation of various ordered compounds at low temperatures that were not previously known. These compounds become unstable due to the configurational entropy of bcc solid solution as the temperature is increased. The elastic constants of ordered and disordered compounds are calculated at both T = 0 K and finite temperatures. The overall trends in elastic properties are in agreement with measurements using the resonant ultrasound spectroscopy method. The calculations predict that addition of V to Cr decreases both the bulk modulus and the shear modulus, and enhances the Poissons ratio, in agreement with experiments. Decrease in the bulk modulus is correlated to decrease in the valence electron density and increase in the lattice constant. An enhanced Poissons ratio for bcc CrV alloys (compared to pure Cr) is associated with an increased density of states at the Fermi level. Furthermore, the difference charge density in the bonding region in the (110) slip plane is highest for pure Cr and decreases gradually as V is added. The present calculation also predicts a negative Cauchy pressure for pure Cr, and it becomes positive upon alloying with V. The intrinsic ductilizing effect from V may contribute, at least partially, to the experimentally observed ductilizing phenomenon in the literature.

  17. Influence of Cr on the nanoclusters formation and superferromagnetic behavior of Fe-Cr-Nb-B glassy alloys

    SciTech Connect (OSTI)

    Chiriac, H.; Whitmore, L.; Grigoras, M.; Ababei, G.; Stoian, G.; Lupu, N.

    2015-05-07

    High resolution imaging and electron diffraction confirm that in the as-quenched state the structure of Fe{sub 79.7−x}Cr{sub x}Nb{sub 0.3}B{sub 20} (x = 11–13 at. %) melt-spun ribbons is completely amorphous, independent of the Cr content. Energy-dispersive X-ray spectroscopy mapping emphasizes clearly the presence of Fe and Cr clusters varying from approximately 1 to 2–3 nm in size with the increase of Cr content from 11 to 13 at. %. The Fe and Cr atoms segregate the atomic scale to form nanometer sized clusters, influencing strongly the macroscopic magnetic behavior. The Curie temperature of the system, T{sub C}{sup system}, confirmed by the magnetic susceptibility versus temperature measurements, gives the strength of the magnetic interactions between clusters. The inter-cluster interactions are much stronger for lower contents of Cr, the microstructure is less uniform, and T{sub C}{sup system} increases from 290 K for 13 at. % Cr to 330 K for 11.5 at. % Cr. The whole system transforms to a ferromagnetic state through interactions between the clusters. Zero-field cooling and field cooling curves confirm the cluster behavior with a blocking temperature, T{sub b}, of about 250 K. Above T{sub b}, the ribbons behave as a superferromagnetic system, whilst below the blocking temperature a classical ferromagnetic behavior is observed.

  18. EM participates in local middle school’s career week

    Broader source: Energy.gov [DOE]

    OREM recently participated in Vine Middle School’s 6th Annual College and Career Week. OREM sends employee representatives to the Knoxville-based middle school every year to educate children about the value of education and the diverse jobs that are possible through the sciences.

  19. Surface structure of ?-Cr2O3(0001) after activated oxygen exposure

    SciTech Connect (OSTI)

    Kaspar, Tiffany C.; Chamberlin, Sara E.; Chambers, Scott A.

    2013-09-13

    The surface structure of a-Cr2O3(0001) before and after exposure to activated oxygen from an ECR plasma source was investigated by x-ray photoelectron spectroscopy (XPS) and x-ray photoelectron diffraction (XPD). Epitaxial Cr2O3(0001) thin films were deposited on Al2O3(0001) substrates by oxygen-plasma-assisted molecular beam epitaxy (OPA-MBE). When cooled or annealed in vacuum, strong evidence for a Cr-Cr-O3- termination was obtained by comparing the Cr3+ XPD azimuthal scan to single scattering simulations. However, after plasma exposure, a high binding energy feature was observed in the Cr 2p XPS spectrum that possesses an ordered structure distinct from the underlying Cr3+ of Cr2O3, which remains Cr-Cr-O3-like. Investigation of this new surface structure with simulations of various candidate structures tentatively rules out CrO2-like configurations. The high binding energy feature likely arises from a higher oxidation state of Cr. One possibility is the oxidation of the surface layer of Cr to Cr6- with a double chromyl structure (O=Cr=O).

  20. Chromium Isotope Fractionation During Reduction of Cr(VI) Under Saturated Flow Conditions

    SciTech Connect (OSTI)

    Jamieson-Hanes, Julia H.; Gibson, Blair D.; Lindsay, Matthew B.J.; Kim, Yeongkyoo; Ptacek, Carol J.; Blowes, David W.

    2012-10-25

    Chromium isotopes are potentially useful indicators of Cr(VI) reduction reactions in groundwater flow systems; however, the influence of transport on Cr isotope fractionation has not been fully examined. Laboratory batch and column experiments were conducted to evaluate isotopic fractionation of Cr during Cr(VI) reduction under both static and controlled flow conditions. Organic carbon was used to reduce Cr(VI) in simulated groundwater containing 20 mg L{sup -1} Cr(VI) in both batch and column experiments. Isotope measurements were performed on dissolved Cr on samples from the batch experiments, and on effluent and profile samples from the column experiment. Analysis of the residual solid-phase materials by scanning electron microscopy (SEM) and by X-ray absorption near edge structure (XANES) spectroscopy confirmed association of Cr(III) with organic carbon in the column solids. Decreases in dissolved Cr(VI) concentrations were coupled with increases in {delta}{sup 53}Cr, indicating that Cr isotope enrichment occurred during reduction of Cr(VI). The {delta}{sup 53}Cr data from the column experiment was fit by linear regression yielding a fractionation factor ({alpha}) of 0.9979, whereas the batch experiments exhibited Rayleigh-type isotope fractionation ({alpha} = 0.9965). The linear characteristic of the column {delta}{sup 53}Cr data may reflect the contribution of transport on Cr isotope fractionation.

  1. Gamma-ray decay of levels in /sup 53/Cr

    SciTech Connect (OSTI)

    Dickens, J.K.; Larson, D.C.

    1987-11-01

    Gamma-ray decay of levels in the stable isotope /sup 53/Cr has been studied using /sup 53/Cr(n,n'..gamma..) reactions for incident neutron energies between threshold and 10 MeV. Of the 65 gamma rays or gamma-ray groups observed for neutron interactions with /sup 53/Cr, 50 have been placed or tentatively placed among 34 levels in /sup 53/Cr up to an excitation energy of 4.36 MeV. Deduced branching ratios are in reasonable agreement with previous measurements except for decay of the E/sub x/ = 1537-keV level. For the decay of the E/sub x/ = 1537-keV level we are unable to explain variations in the branching ratios of the transition gamma rays as a function of incident neutron energy within the framework of the presently known level structure of /sup 53/Cr and suggest the possibility of a second energy level at E/sub x/ = 1537 keV. 59 refs., 13 figs., 2 tabs.

  2. DOE - NNSA/NFO -- Nevada Science Bowl - MIDDLE SCHOOL

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

    Bowl NNSA/NFO Language Options U.S. DOE/NNSA - Nevada Field Office Nevada Science Bowl - Middle School March 4-5, 2016 Middle School Competition On behalf of the National Nuclear Security Administration Nevada Field Office (NNSA/NFO), we are pleased to announce the 2016 Nevada Science Bowl for middle school competition will take place March 4-5, 2016 at the National Atomic Testing Museum and the Henderson International School campus. We would be honored to have your school field a team for this

  3. DOE - NNSA/NFO -- Science Bowl - Middle School Registration

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

    Bowl > Nevada Middle School Science Bowl Registration NNSA/NFO Language Options U.S. DOE/NNSA - Nevada Field Office Welcome to the Annual Nevada Middle School Science Bowl! March 4-5, 2016 Registration is due on January 27, 2016 Thirty-two teams from middle schools in Southern Nevada are welcome to participate in this round-robin double-elimination competition. Monetary awards are given to the first through fourth place teams for use in their school's mathematics/science departments. Although

  4. Middle School Science Bowl 2003 - News Releases | NREL

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

    Middle School Science Bowl 2003 June 18, 2003 Golden, CO. - Middle School Science Students to Face Off in Battle of Brains Teams from around the nation to test their science skills and knowledge Sixteen teams of some of the brightest sixth through eighth grade students from around the United States will test their mental agility in the National Middle School Science Bowl June 25-28. The teams, all winners of regional contests, will build and race solar-powered model cars and compete in

  5. Secretary Bodman Travels to the Middle East | Department of Energy

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

    the Middle East Secretary Bodman Travels to the Middle East November 10, 2005 - 2:22pm Addthis Four-nation swing to emphasize domestic energy needs and goals WASHINGTON, DC - Secretary of Energy Samuel W. Bodman embarked upon a four-nation tour through the Middle East to enhance the United States' relationship with major oil-producing nations, promote economic liberalization and increased foreign investment in the region, and reaffirm U.S. energy policy goals. "Both consumers and producers

  6. Media Advisory: March 7 Virginia Middle School Science Bowl Tournament |

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

    Jefferson Lab 7 Virginia Middle School Science Bowl Tournament Media Advisory: March 7 Virginia Middle School Science Bowl Tournament What: The 2009 Virginia Regional Middle School Science Bowl When: Saturday, March 7, 2009. Round-robin competition will run from 10 a.m. - noon. The double-elimination, semi-final and finalist rounds will run from 1:30 - 5 p.m. Awards will be presented immediately after the final round. Where: CEBAF Center Auditorium at the Thomas Jefferson National

  7. 2010 DOE National Science Bowl® Photos - Smith Middle School...

    Office of Science (SC) Website

    Smith Middle School National Science Bowl (NSB) NSB Home About National Science Bowl ... 2010 DOE National Science Bowl Photos - Smith Middle School Print Text Size: A A A ...

  8. Secretary Bodman to Travel to the Middle East to Advance International...

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

    Travel to the Middle East to Advance International Energy Cooperation Secretary Bodman to Travel to the Middle East to Advance International Energy Cooperation January 10, 2008 - ...

  9. Room-temperature ferromagnetism in Cr-doped Si achieved by controlling atomic structure, Cr concentration, and carrier densities: A first-principles study

    SciTech Connect (OSTI)

    Wei, Xin-Yuan; Yang, Zhong-Qin; Zhu, Yan; Li, Yun

    2015-04-28

    By using first-principles calculations, we investigated how to achieve a strong ferromagnetism in Cr-doped Si by controlling the atomic structure and Cr concentration as well as carrier densities. We found that the configuration in which the Cr atom occupies the tetrahedral interstitial site can exist stably and the Cr atom has a large magnetic moment. Using this doping configuration, room-temperature ferromagnetism can be achieved in both n-type and p-type Si by tuning Cr concentration and carrier densities. The results indicate that the carrier density plays a crucial role in realizing strong ferromagnetism in diluted magnetic semiconductors.

  10. Grain boundary depletion and migration during selective oxidation of Cr in a Ni-5Cr binary alloy exposed to high-temperature hydrogenated water

    SciTech Connect (OSTI)

    Schreiber, Daniel K.; Olszta, Matthew J.; Bruemmer, Stephen M.

    2014-10-01

    High-resolution microscopy of a high-purity Ni-5Cr alloy exposed to 360C hydrogenated water reveals intergranular selective oxidation of Cr accompanied by local Cr depletion and diffusion-induced grain boundary migration (DIGM). The corrosion-product oxide consists of a porous, interconnected network of Cr2O3 platelets with no further O ingress into the metal ahead. Extensive grain boundary depletion of Cr (to <0.05at.%) is observed typically 20100 nm wide as a result of DIGM and reaching depths of many micrometers beyond the oxidation front.

  11. Importance of Doping and Frustration in Itinerant Fe-doped Cr2Al

    SciTech Connect (OSTI)

    Susner, Michael A; Parker, David S; Safa-Sefat, Athena

    2015-01-01

    We have performed an experimental and theoretical study comparing the effects of Fe-doping of Cr2Al, an antiferromagnet with a N el temperature of 670 K, with known results on Fe-doping of antiferromagnetic bcc Cr. (Cr1-xFex)2Al materials are found to exhibit a rapid suppression of antiferromagnetic order with the presence of Fe, decreasing TN to 170 K for x=0.10. Antiferromagnetic behavior disappears entirely at x 0.125 after which point increasing paramagnetic behavior is exhibited. This is unlike the effects of Fe doping of bcc antiferromagnetic Cr, in which TN gradually decreases followed by the appearance of a ferromagnetic state. Theoretical calculations explain that the Cr2Al-Fe suppression of magnetic order originates from two effects: the first is band narrowing caused by doping of additional electrons from Fe substitution that weakens itinerant magnetism; the second is magnetic frustration of the Cr itinerant moments in Fe-substituted Cr2Al. In pure-phase Cr2Al, the Cr moments have an antiparallel alignment; however, these are destroyed through Fe substitution and the preference of Fe for parallel alignment with Cr. This is unlike bulk Fe-doped Cr alloys in which the Fe anti-aligns with the Cr atoms, and speaks to the importance of the Al atoms in the magnetic structure of Cr2Al and Fe-doped Cr2Al.

  12. Importance of Doping and Frustration in Itinerant Fe-doped Cr2Al

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

    Susner, Michael A; Parker, David S; Safa-Sefat, Athena

    2015-01-01

    We have performed an experimental and theoretical study comparing the effects of Fe-doping of Cr2Al, an antiferromagnet with a N el temperature of 670 K, with known results on Fe-doping of antiferromagnetic bcc Cr. (Cr1-xFex)2Al materials are found to exhibit a rapid suppression of antiferromagnetic order with the presence of Fe, decreasing TN to 170 K for x=0.10. Antiferromagnetic behavior disappears entirely at x 0.125 after which point increasing paramagnetic behavior is exhibited. This is unlike the effects of Fe doping of bcc antiferromagnetic Cr, in which TN gradually decreases followed by the appearance of a ferromagnetic state. Theoretical calculationsmore » explain that the Cr2Al-Fe suppression of magnetic order originates from two effects: the first is band narrowing caused by doping of additional electrons from Fe substitution that weakens itinerant magnetism; the second is magnetic frustration of the Cr itinerant moments in Fe-substituted Cr2Al. In pure-phase Cr2Al, the Cr moments have an antiparallel alignment; however, these are destroyed through Fe substitution and the preference of Fe for parallel alignment with Cr. This is unlike bulk Fe-doped Cr alloys in which the Fe anti-aligns with the Cr atoms, and speaks to the importance of the Al atoms in the magnetic structure of Cr2Al and Fe-doped Cr2Al.« less

  13. Metastable bcc phase formation in the Nb-Cr system

    SciTech Connect (OSTI)

    Thoma, D.J.; Schwarz, R.B.; Perepezko, J.H.; Plantz, D.H.

    1993-08-01

    Extended metastable bcc solid solutions of Nb-Xat.%Cr (X = 35, 50, 57, 77, 82, and 94) were synthesized by two-anvil splat-quenching. In addition, bcc (Nb-67at.%Cr) was prepared by mechanically alloying mixtures of niobium and chromium powders. The lattice parameters were measured by X-ray diffraction and the Young`s moduli were measured by low-load microindentation. The composition dependence of the lattice parameters and elastic moduli show a positive deviation with respect to a rule of mixtures. During continuous heating at 15C/min., the metastable precursor bcc phases decomposed at temperatures above 750C to uniformly refined microstructures.

  14. Teachers and JLab scientists help middle-school science instructors...

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

    scientists help middle-school science instructors prepare to teach physics in the 21st century By John Anderson, II, JLab Public Affairs intern August 11, 2003 As part of Jefferson...

  15. Local Middle School Receives School-to-Career Grant

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

    Grant For more information contact: e:mail: Public Affairs Golden, Colo., December 24, 1997 - Deer Creek Middle School in Littleton received a 10,000 grant from the ...

  16. Middle School Energy and Nuclear Science Curriculum Now Available

    Broader source: Energy.gov [DOE]

    A new middle school science, technology, engineering, and math (STEM) curriculum called The Harnessed Atom is now available on the Office of Nuclear Energy website. This new curriculum offers...

  17. Middle Georgia El Member Corp | Open Energy Information

    Open Energy Info (EERE)

    El Member Corp Place: Georgia Phone Number: 1-800-342-0144 Website: www.mgemc.com Facebook: https:www.facebook.comMiddleGeorgiaEMC Outage Hotline: 229-268-2671; 800-342-0144...

  18. Massachusetts Middle School Goes Local for PV Solar Energy System...

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

    New 26 kW solar energy system to be part of curriculum at Norton Middle School. | Photo ... that displays the data on the amount of energy being generated by the solar energy system. ...

  19. Record 18 teams prepare for Virginia Regional Middle School Science...

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

    MEDIA ADVISORY: News Media invited to cover the March 10 Virginia Regional Middle School Science Bowl at Jefferson Lab; Record turnout with bright young minds from 18 teams vying...

  20. Record 18 teams prepare for Virginia Regional Middle School Science...

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

    of Energy's Jefferson Lab, in Newport News, Va., hosts the Virginia Regional Middle School Science Bowl on Saturday, March 10, with a record 18 teams competing. This is the...

  1. Middle School Science Bowl Registration | Argonne National Laboratory

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

    one team. A team is made up of 4-5 middle school students. All teams should have a coach mentoring and managing the team. Teams are selected on a first come first serve basis....

  2. EECBG Success Story: Massachusetts Middle School Goes Local for...

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

    Massachusetts Middle School Goes Local for PV Solar Energy System EECBG Success Story: ... roof. | U.S. Department of Energy EECBG Success Story: Learning is Now Much 'Cooler' for ...

  3. Middle Schoolers Face-Off in Model Car Challenge

    Broader source: Energy.gov [DOE]

    Forty-four teams entered the middle school Lithium-Ion Battery Powered Model Car Competition, and two teams distinguished themselves, one for speed and the other for design.

  4. EECBG Success Story: Massachusetts Middle School Goes Local for...

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

    New 26 kW solar energy system to be part of curriculum at Norton Middle School. | Photo courtesy of Norton Public Schools. New 26 kW solar energy system to be part of curriculum at...

  5. Media Advisory: March 1 Middle School Science Bowl Tournament | Jefferson

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

    Lab 1 Middle School Science Bowl Tournament Media Advisory What: Virginia Regional Middle School Science Bowl When: Saturday, March 1, 2008. Round robin competition runs from 10 a.m. - noon. The double elimination, semi-final and finalist rounds run from 1:30 - 5 p.m. Awards presentations will be made immediately after the final round. Where: CEBAF Center Auditorium, Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA Details: Twenty teams, representing

  6. Shell model description of band structure in 48Cr

    SciTech Connect (OSTI)

    Vargas, Carlos E.; Velazquez, Victor M.

    2007-02-12

    The band structure for normal and abnormal parity bands in 48Cr are described using the m-scheme shell model. In addition to full fp-shell, two particles in the 1d3/2 orbital are allowed in order to describe intruder states. The interaction includes fp-, sd- and mixed matrix elements.

  7. Magnetization reversal in TmCrO{sub 3}

    SciTech Connect (OSTI)

    Yoshii, Kenji

    2012-11-15

    Highlights: ► We observed two magnetization reversals in TmCrO{sub 3}. ► The reversal at 28 K is attributed to antiparallel coupling between Cr{sup 3+} and Tm{sup 3+}. ► The other reversal originates from spin reorientation. ► Magnetocaloric effect is observed at the spin reorientation temperature. ► Characteristic magnetization switching is demonstrated. -- Abstract: The perovskite chromite TmCrO{sub 3} shows magnetization reversal at two temperatures. The reversal at ∼28 K is attributed to the antiparallel coupling between Tm{sup 3+} and Cr{sup 3+} moments, while that at the lower temperature (∼6–7 K) is rooted in a rotation of the magnetic moments. Magnetocaloric measurements offer a relatively large entropy change (∼4–5 J kg{sup −1} K{sup −1}) at the lower temperature. The reversal at ∼28 K is accompanied by a sign change of an exchange-bias-like field. The absence of the training effect suggests that this behavior is rooted in unidirectional magnetic anisotropy. The existence of the two magnetization reversals offers the characteristic switching of magnetization. For example, the magnetization is flipped without changing the direction of the applied magnetic field.

  8. Audit Report: CR-FS-99-01

    Energy Savers [EERE]

    MANAGEMENT REPORT AUDIT OF THE DEPARTMENT OF ENERGY'S CONSOLIDATED FINANCIAL STATEMENTS FOR FISCAL YEAR 1998 Report Number: CR-FS-99-01 Capital Regional Audit Office Date of Issue: June 15, 1999 Germantown, MD 20874 MANAGEMENT REPORT AUDIT OF THE DEPARTMENT OF ENERGY'S CONSOLIDATED FINANCIAL STATEMENTS FOR FISCAL YEAR 1998 TABLE OF CONTENTS Page SUMMARY.................................................................................. 1 PART I - APPROACH AND

  9. CR-39 track etching and blow-up method

    DOE Patents [OSTI]

    Hankins, Dale E. (Livermore, CA)

    1987-01-01

    This invention is a method of etching tracks in CR-39 foil to obtain uniformly sized tracks. The invention comprises a step of electrochemically etching the foil at a low frequency and a "blow-up" step of electrochemically etching the foil at a high frequency.

  10. Audit Report: CR-B-01-01 | Department of Energy

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

    Audit Report: CR-B-01-01 May 9, 2001 Issues Regarding Fee Structure for Three Environmental Management Contracts PDF icon Audit Report: CR-B-01-01 More Documents & Publications ...

  11. Audit Report: CR-B-96-01 | Department of Energy

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

    Audit Report: CR-B-96-01 May 24, 1996 The Federal Energy Regulatory Commission Leased Warehouse Space PDF icon Audit Report: CR-B-96-01 More Documents & Publications Semiannual ...

  12. Audit Report: CR-B-97-02 | Department of Energy

    Office of Environmental Management (EM)

    2 Audit Report: CR-B-97-02 April 4, 1997 Audit of Department of Energy's Contractor Salary Increase Funds Audit Report: CR-B-97-02 More Documents & Publications Inspection Report:...

  13. Audit Report: CR-FS-97-02 | Department of Energy

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

    FS-97-02 Audit Report: CR-FS-97-02 May 1, 1997 Audit of the Department of Energy's Consolidated Financial Statements for Fiscal Year 1996 Audit Report: CR-FS-97-02 More Documents &...

  14. Audit Report: CR-B-95-03 | Department of Energy

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

    Audit Report: CR-B-95-03 February 6, 1995 Audit of the Department of Energy's Security Police Officer Training PDF icon Audit Report: CR-B-95-03 More Documents & Publications Type...

  15. Pressure dependence of the magnetic order in CrAs: A neutron...

    Office of Scientific and Technical Information (OSTI)

    Pressure dependence of the magnetic order in CrAs: A neutron diffraction investigation Citation Details In-Document Search Title: Pressure dependence of the magnetic order in CrAs:...

  16. Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized...

    Office of Scientific and Technical Information (OSTI)

    Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter deposition Title: Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter ...

  17. The Preparation of an Ultrastable Mesoporous Cr(III)-MOF via...

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

    labilization of the Fe(III)-O coordination bond in a mesoporous metal-organic framework, PCN-333-Fe(III), is realized by the reduction of Fe(III) by Cr(II). The Fe(II)-Cr(II)...

  18. Technology Implimentation Plan - ATF FeCrAl Cladding for LWR Application

    SciTech Connect (OSTI)

    Snead, Mary A.; Snead, Lance; Terrani, Kurt A.; Field, Kevin G.; Worrall, Andrew; Robb, Kevin R.; Yamamoto, Yukinori; Powers, Jeffrey J.; Dryepondt, Sebastien N.; Pint, Bruce A.; Hu, Xunxiang

    2015-06-01

    Technology implimentation plan for FeCrAl development under the FCRD Advanced Fuel program. The document describes the activities required to get FeCrAl clad ready for LTR testing

  19. The crystal and magnetic structure of Ti-substituted LaCrO{sub...

    Office of Scientific and Technical Information (OSTI)

    On account of a miscibility gap, a higher degree of Ti-substitution at the Cr site cannot be achieved; as a consequence the solid state solubility of Ti in LaCrOsub 3 at 1573 K ...

  20. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

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

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; et al

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reachmore »the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.« less

  1. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

    SciTech Connect (OSTI)

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; Rory Kennedy, J.

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reach the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.

  2. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

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

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; et al

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reachmore » the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.« less

  3. Non-classical nuclei and growth kinetics of Cr precipitates in FeCr alloys during ageing

    SciTech Connect (OSTI)

    Li, Yulan; Hu, Shenyang Y.; Zhang, Lei; Sun, Xin

    2014-01-10

    In this manuscript, we quantitatively calculated the thermodynamic properties of critical nuclei of Cr precipitates in FeCr alloys. The concentration profiles of the critical nuclei and nucleation energy barriers were predicted by the constrained shrinking dimer dynamics (CSDD) method. It is found that Cr concentration distribution in the critical nuclei strongly depend on the overall Cr concentration as well as temperature. The critical nuclei are non-classical because the concentration in the nuclei is smaller than the thermodynamic equilibrium value. These results are in agreement with atomic probe observation. The growth kinetics of both classical and non-classical nuclei was investigated by the phase field approach. The simulations of critical nucleus evolution showed a number of interesting phenomena: 1) a critical classical nucleus first shrinks toward its non-classical nucleus and then grows; 2) a non-classical nucleus has much slower growth kinetics at its earlier growth stage compared to the diffusion-controlled growth kinetics. 3) a critical classical nucleus grows faster at the earlier growth stage than the non-classical nucleus. All of these results demonstrate that it is critical to introduce the correct critical nuclei in order to correctly capture the kinetics of precipitation.

  4. Global Threat Reduction Initiative Africa and Middle East Project Plan 2012

    SciTech Connect (OSTI)

    Jamison, Jeremy D.

    2012-02-01

    GTRI Africa and Middle East Project Plan submitted for school project to American Graduate University.

  5. Surface half-metallicity of CrS thin films and perfect spin filtering and spin diode effects of CrS/ZnSe heterostructure

    SciTech Connect (OSTI)

    Gao, G. Y. Yao, K. L.

    2014-11-03

    Recently, ferromagnetic zinc-blende Mn{sub 1−x}Cr{sub x}S thin films (above x = 0.5) were fabricated experimentally on ZnSe substrate, which confirmed the previous theoretical prediction of half-metallic ferromagnetism in zinc-blende CrS. Here, we theoretically reveal that both Cr- and S-terminated (001) surfaces of the CrS thin films retain the half-metallicity. The CrS/ZnSe(001) heterogeneous junction exhibits excellent spin filtering and spin diode effects, which are explained by the calculated band structure and transmission spectra. The perfect spin transport properties indicate the potential applications of half-metallic CrS in spintronic devices. All computational results are obtained by using the density functional theory combined with nonequilibrium Green's function.

  6. Los Alamos Middle School team wins regional MathCounts competition

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

    Los Alamos Middle School team wins Regional MathCounts competition Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit Los Alamos Middle School wins regional MathCounts event Competes against 60 other middle schools for the title. March 1, 2013 Los Alamos Middle School won the regional MathCounts competition. Los Alamos Middle School won the regional MathCounts competition. Contacts Editor Linda

  7. Middle School Academic Question Resources | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Academic Question Resources National Science Bowl® (NSB) NSB Home About High School Middle School Middle School Students Middle School Coaches Middle School Regionals Middle School Rules, Forms, and Resources Strategies For Success Sample Questions Academic Question Resources Attending the National Finals Volunteers 2016 Competition Results News Media WDTS Home Contact Information National Science Bowl® U.S. Department of Energy SC-27/ Forrestal Building 1000 Independence Ave., SW Washington,

  8. Cr.sup.3+ -doped colquiriite solid state laser material

    DOE Patents [OSTI]

    Payne, Stephen A.; Chase, Lloyd L.; Newkirk, Herbert W.; Krupke, William F.

    1989-01-01

    Chromium doped colquiriite, LiCaAlF.sub.6 :Cr.sup.3+, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr.sup.3+ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slop efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd.sup.3+ or Tm.sup.3+ for use in a multimegajoule single shot fusion research facility.

  9. Cr/sup 3 +/-doped colquiriite solid state laser material

    DOE Patents [OSTI]

    Payne, S.A.; Chase, L.L.; Newkirk, H.W.; Krupke, W.F.

    1988-03-31

    Chromium doped colquiriite, LiCaAlF/sub 6/:Cr/sup 3 +/, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr/sup 3 +/ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slope efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd/sup 3 +/ or Tm/sup 3 +/ for use in a multimegajoule single shot fusion research facility. 4 figs.

  10. Cr{sub 2}Nb-based alloy development

    SciTech Connect (OSTI)

    Liu, C.T.; Horton, J.A.; Carmichael, C.A.

    1996-05-01

    This paper summarizes recent progress in developing Cr{sub 2}Nb/Cr(Nb) alloys for structural use in advanced fossil energy conversion systems. Alloy additions were added to control the microstructure and mechanical properties. Two beneficial elements have been identified among all alloying additions added to the alloys. One element is effective in refining the coarse eutectic structure and thus substantially improves the compressive strength and ductility of the alloys. The other element enhances oxidation resistance without sacrificing the ductility. The tensile properties are sensitive to cast defects, which can not be effectively reduced by HIPping at 1450-1580{degrees}C and/or directionally solidifying via a floating zone remelting method.

  11. Transport signatures of quantum critically in Cr at high pressure.

    SciTech Connect (OSTI)

    Jaramillo, R.; Feng, Y.; Wang, J.; Rosenbaum, T. F.

    2010-08-03

    The elemental antiferromagnet Cr at high pressure presents a new type of naked quantum critical point that is free of disorder and symmetry-breaking fields. Here we measure magnetotransport in fine detail around the critical pressure, P{sub c} {approx} 10 GPa, in a diamond anvil cell and reveal the role of quantum critical fluctuations at the phase transition. As the magnetism disappears and T {yields} 0, the magntotransport scaling converges to a non-mean-field form that illustrates the reconstruction of the magnetic Fermi surface, and is distinct from the critical scaling measured in chemically disordered Cr:V under pressure. The breakdown of itinerant antiferromagnetism only comes clearly into view in the clean limit, establishing disorder as a relevant variable at a quantum phase transition.

  12. SF6432-CR (02-01-13) Cost Reimbursement

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

    Department Release Date: 11/17/15 Page 1 of 25 Printed copies of this document are uncontrolled. Retrieve latest version electronically. SANDIA CORPORATION SF 6432-CR (11/2015) SECTION II STANDARD TERMS AND CONDITIONS FOR COST-REIMBURSEMENT CONTRACTS THE FOLLOWING CLAUSES APPLY TO THIS CONTRACT AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY IDENTIFIED AS BEING CHANGED, SUPPLEMENTED, OR AMENDED IN WRITING ISSUED BY THE SANDIA CONTRACTING REPRESENTATIVE.

  13. SF6432-CR (02-01-13) Cost Reimbursement

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

    7/31/13 Page 1 of 24 Printed copies of this document are uncontrolled. Retrieve latest version electronically. SANDIA CORPORATION SF 6432-CR (07/2013) SECTION II STANDARD TERMS AND CONDITIONS FOR COST-REIMBURSEMENT CONTRACTS THE FOLLOWING CLAUSES APPLY TO THIS CONTRACT AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY IDENTIFIED AS BEING CHANGED, SUPPLEMENTED, OR AMENDED IN WRITING ISSUED BY THE SANDIA CONTRACTING REPRESENTATIVE. (CTRL+CLICK ON A LINK BELOW

  14. AmeriFlux CR-Lse La Selva

    SciTech Connect (OSTI)

    Loescher, Hank

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site CR-Lse La Selva. Site Description - Site was occupied by Native Americans since 3000 B.P. practicing shifting cultivation. Some selective cutting along rivers (heart of palm). Charcoal dating indicate fires 2400 B.P. and 1100 B.P. Some clearing for pasture/cocoa production, second growth, humid tropical rain forest. Site resides on land presently owned by the Organization for Tropical Studies.

  15. Watermelon-like iron nanoparticles: Cr doping effect on magnetism and magnetization interaction reversal

    SciTech Connect (OSTI)

    Kaur, Maninder; Dai, Qilin; Bowden, Mark E.; Engelhard, Mark H.; Wu, Yaqiao; Tang, Jinke; Qiang, You

    2013-06-26

    Chromium (Cr) forms a solid solution with iron (Fe) lattice when doped in core-shell iron -iron oxide nanocluster (NC) and shows a mixed phase of sigma (?) FeCr and bcc Fe. The Cr dopant affects heavily the magnetization and magnetic reversal process, and causes the hysteresis loop to shrink near the zero field axis. Dramatic transformation happens from dipolar interaction (0 at. % Cr) to strong exchange interaction (8 at. % of Cr) is confirmed from the Henkel plot and delta M plot, and is explained by a water-melon model of core-shell NC system.

  16. Nysmith School Wins Virginia Middle School Science Bowl | Jefferson Lab

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

    Nysmith School Wins Virginia Middle School Science Bowl Nysmith School for the Gifted, Herndon, finished in first place at the Virginia Regional Middle School Science Bowl. Nysmith will now represent Virginia at the National Science Bowl® (NSB) finals to be held in Washington, D.C., April 28-May 2. Team members (front row, left to right) Ajit Kadeveru, Vaibhav Sharma, and Kaien Yang, and (back row, l.-r.) Anusha Allamsetty and Ishaan Sharma are pictured with their team trophy and Beau Tyler,

  17. Middle School Science Bowl Registration | Argonne National Laboratory

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

    Middle School Science Bowl Registration Regional champions of the Academic Science Bowl win a trip to Washington, D.C.! We encourage all eligible participants to apply to the National Science Bowl. All applicants must be enrolled for the current school year in grades sixth, seventh, or eighth at the team's school. Each school is only allowed to submit one team. A team is made up of 4-5 middle school students. All teams should have a coach mentoring and managing the team. Teams are selected on a

  18. Oil and gas developments in Middle East in 1986

    SciTech Connect (OSTI)

    Hemer, D.O.; Gohrbandt, K.H.A.

    1987-10-01

    Petroleum production in Middle East countries during 1986 totaled 4,493,973,000 bbl (an average rate of 12,312,254 BOPD), up 22.3% from the revised 1985 total of 3,673,729,000 bbl. Iraq, Kuwait, Saudi Arabia, Abu Dhabi, and Oman had significant increased; Iran was the only Middle East country with a significant decrease. New fields went on production in Oman and Yemen Arab Republic, and significant discoveries were reported in Iraq, Yemen Arab Republic, Oman, and Syria. However, exploration was generally down in most countries. Exploration and production operations continued to be affected by war in Iraq and Iran. 8 figures, 7 tables.

  19. Greeley's Maplewood Middle School Stellar in Solar Car Race

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

    Greeley's Maplewood Middle School Stellar in Solar Car Race Media may contact: George Douglas, 303-275-4096 email: George Douglas Golden, Colo., May. 13, 2000 - Students from Greeley's Maplewood Middle School built the fastest model solar car and won the Junior Solar Sprint at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) today. A team from Monarch K-8 School in Louisville won top honors for design. Forty-one teams from across Colorado entered the 20-meter race,

  20. Low temperature spin dynamics in Cr{sub 7}Ni-Cu-Cr{sub 7}Ni coupled molecular rings

    SciTech Connect (OSTI)

    Bordonali, L.; Furukawa, Y.; Mariani, M.; Sabareesh, K. P. V.; Garlatti, E.; Borsa, F.

    2014-05-07

    Proton Nuclear Magnetic Resonance (NMR) relaxation measurements have been performed down to very low temperature (50 mK) to determine the effect of coupling two Cr{sub 7}Ni molecular rings via a Cu{sup 2+} ion. No difference in the spin dynamics was found from nuclear spin lattice relaxation down to 1.5 K. At lower temperature, the {sup 1}H-NMR line broadens dramatically indicating spin freezing. From the plot of the line width vs. magnetization, it is found that the freezing temperature is higher (260 mK) in the coupled ring with respect to the single Cr{sub 7}Ni ring (140 mK)

  1. Oil and gas developments in Middle East in 1981

    SciTech Connect (OSTI)

    Hemer, D.O; Mason, J.F.; Hatch, G.C.

    1982-11-01

    Petroleum production in Middle East countries during 1981 totaled 5,741,096,000 bbl, or an average rate of 15,729,030 BOPD, down 14.9% from 1980. Increases were in Oman, Dubai, and Turkey. Significant decreases occurred in Iraq, Iran, Kuwait, Divided Neutral Zone, Qatar, and Abu Dhabi. New discoveries were made in Oman, Saudi Arabia, and Abu Dhabi.

  2. Cr(OH)₃(s) Oxidation Induced by Surface Catalyzed Mn(II) Oxidation

    SciTech Connect (OSTI)

    Namgung, Seonyi; Kwon, M.; Qafoku, Nikolla; Lee, Gie Hyeon

    2014-09-16

    This study examined the feasibility of Cr(OH)₃(s) oxidation mediated by surface catalyzed Mn(II) oxidation under common groundwater pH conditions as a potential pathway of natural Cr(VI) contaminations. Dissolved Mn(II) (50 μM) was reacted with or without synthesized Cr(OH)₃(s) (1.0 g/L) at pH 7 – 9 under oxic or anoxic conditions. In the absence of Cr(OH)₃(s), homogeneous Mn(II) oxidation by dissolved O₂ was not observed at pH ≤ 8.0 for 50 d. At pH 9.0, by contrast, dissolved Mn(II) was completely removed within 8 d and precipitated as hausmannite. When Cr(OH)₃(s) was present, this solid was oxidized and released substantial amounts of Cr(VI) as dissolved Mn(II) was added into the suspension at pH ≥ 8.0 under oxic conditions. Our results suggest that Cr(OH)₃(s) was readily oxidized by a newly formed Mn oxide as a result of Mn(II) oxidation catalyzed on Cr(OH)₃(s) surface. XANES analysis of the residual solids after the reaction between 1.0 g/L Cr(OH)₃(s) and 204 μM Mn(II) at pH 9.0 for 22 d revealed that the product of surface catalyzed Mn(II) oxidation resembled birnessite. The rate and extent of Cr(OH)₃(s) oxidation was likely controlled by those of surface catalyzed Mn(II) oxidation as the production of Cr(VI) increased with increasing pH and initial Mn(II) concentrations. This study evokes the potential environmental hazard of sparingly soluble Cr(OH)₃(s) that can be a source of Cr(VI) in the presence of dissolved Mn(II).

  3. Oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, Ken (Naperville, IL); Baxter, David J. (Woodridge, IL)

    1984-01-01

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1-8 wt. % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500.degree.-1000.degree. C.

  4. Improved oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, K.; Baxter, D.J.

    1983-07-26

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1 to 8 wt % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500 to 1000/sup 0/C.

  5. Characterization of modified 9 Cr-1 Mo steel extruded pipe

    SciTech Connect (OSTI)

    Sikka, V.K.; Hart, M.D.

    1985-04-01

    The fabrication of hot-extruded pipe of modified 9 Cr-1 Mo steel at Cameron Iron Works is described. The report also deals with the tempering response; tensile, Charpy impact, and creep properties; and microstructure of the hot-extruded pipe. The tensile properties of the pipe are compared with the average and average -1.65 standard error of estimate curves for various product forms of several commercial heats of this alloy. The creep-rupture properties are compared with the average curve for various product forms of the commercial heats.

  6. 2010 DOE National Science Bowl® Photos - Will James Middle School...

    Office of Science (SC) Website

    The Will James Middle School team competes in the Solar Car Challenge at the National Science Bowl in Washington, DC. Will James Middle School won the Best Design Document award. ...

  7. 2010 DOE National Science Bowl® Photos - Will James Middle School...

    Office of Science (SC) Website

    Will James Middle School Team as they compete in the Solar Car Challenge at the National Science Bowl for middle school students in Washington DC. Left to right: Evan Quarles, ...

  8. Henderson County North Middle School wins 2015 DOE West Kentucky Regional Science Bowl

    Broader source: Energy.gov [DOE]

    PADUCAH, Ky. – Henderson County North Middle School won the U.S. Department of Energy’s West Kentucky Regional Science Bowl February 6, 2015 during competition among 12 middle school teams. The...

  9. The response of CR-39 nuclear track detector to 1-9 MeV protons

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

    Sinenian, N.; Rosenberg, M. J.; Manuel, M.; McDuffee, S. C.; Casey, D. T.; Zylstra, A. B.; Rinderknecht, H. G.; Johnson, M. Gatu; Seguin, F. H.; Frenje, J. A.; et al

    2011-10-28

    The response of CR-39 nuclear track detector (TasTrak®) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. The effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather thanmore » the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.« less

  10. Irradiation-enhanced α' precipitation in model FeCrAl alloys

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

    Edmondson, Philip D.; Briggs, Samuel A.; Yamamoto, Yukinori; Howard, Richard H.; Sridharan, Kumar; Terrani, Kurt A.; Field, Kevin G.

    2016-02-17

    Model FeCrAl alloys with varying compositions (Fe(10–18)Cr(10–6)Al at.%) have been neutron irradiated at ~ 320 to damage levels of ~ 7 displacements per atom (dpa) to investigate the compositional influence on the formation of irradiation-induced Cr-rich α' precipitates using atom probe tomography. In all alloys, significant number densities of these precipitates were observed. Cluster compositions were investigated and it was found that the average cluster Cr content ranged between 51.1 and 62.5 at.% dependent on initial compositions. This is significantly lower than the Cr-content of α' in binary FeCr alloys. As a result, significant partitioning of the Al from themore » α' precipitates was also observed.« less

  11. Ferromagnetism at room temperature in Cr-doped anodic titanium dioxide nanotubes

    SciTech Connect (OSTI)

    Liao, Yulong E-mail: hwzhang@uestc.edu.cn; Zhang, Huaiwu E-mail: hwzhang@uestc.edu.cn; Li, Jie; Yu, Guoliang; Zhong, Zhiyong; Bai, Feiming; Jia, Lijun; Zhang, Shihong; Zhong, Peng

    2014-05-07

    This study reports the room-temperature ferromagnetism in Cr-doped TiO{sub 2} nanotubes (NTs) synthesized via the electrochemical method followed by a novel Cr-doping process. Scanning electron microscopy and transmission electron microscopy showed that the TiO{sub 2} NTs were highly ordered with length up to 26 ?m, outer diameter about 110 nm, and inner diameter about 100 nm. X-ray diffraction results indicated there were no magnetic contaminations of metallic Cr clusters or any other phases except anatase TiO{sub 2}. The Cr-doped TiO{sub 2} NTs were further annealed in oxygen, air and argon, and room-temperature ferromagnetism was observed in all Cr-doped samples. Moreover, saturation magnetizations and coercivities of the Cr-doped under various annealing atmosphere were further analyzed, and results indicate that oxygen content played a critical role in the room-temperature ferromagnetism.

  12. Effects of Cr doping on the magnetic properties of multiferroic YMnO{sub 3}

    SciTech Connect (OSTI)

    Han, Tai-Chun Wu, I-Chu; Hsu, Hsin-Kai

    2014-05-07

    We have synthesized a series of YMn{sub 1?x}Cr{sub x}O{sub 3} (0???x???0.1) samples and study the effect of Cr-doping on their magnetic properties. The magnetic characterization indicates that with increasing Cr-content up to 0.1, the antiferromagnetic (AFM) transition temperature increases from 73 to 89?K. Our experiment results also indicate that the Cr-doped samples exhibit the characteristics of spin-glass state at low temperature. Moreover, the magnetic hysteresis curves of the doped samples show a weak ferromagnetic (FM) behavior. It is found that the spin-glass state of the Cr-doped samples is due to the competition between AFM superexchange and FM double-exchange interaction, induced by the Cr doping.

  13. Jefferson Lab Hosts 23 Teams for Middle School Science Bowl on March 7 |

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

    Jefferson Lab Hosts 23 Teams for Middle School Science Bowl on March 7 Jefferson Lab Hosts 23 Teams for Middle School Science Bowl on March 7 NEWPORT NEWS, Va., March 2, 2009 - The nation's future scientists, engineers and mathematicians may be found testing their mental skills at the Department of Energy's Virginia Regional Middle School Science Bowl taking place at Jefferson Lab on Saturday, March 7. Twenty-three teams, representing middle schools from across the region are registered for

  14. Teachers and JLab scientists help middle-school science instructors prepare

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

    to teach physics in the 21st century | Jefferson Lab and JLab scientists help middle-school science instructors prepare to teach physics in the 21st century Valerie Bicouvaris, Berkeley MIddle School, Williamsburg Valerie Bicouvaris, Berkeley Middle School, Williamsburg, uses magnetism to conduct a "magic" trick during the course section on magnetism. Teachers and JLab scientists help middle-school science instructors prepare to teach physics in the 21st century By John Anderson,

  15. Highly tunable magnetism in silicene doped with Cr and Fe atoms under

    Office of Scientific and Technical Information (OSTI)

    isotropic and uniaxial tensile strain (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Highly tunable magnetism in silicene doped with Cr and Fe atoms under isotropic and uniaxial tensile strain Citation Details In-Document Search Title: Highly tunable magnetism in silicene doped with Cr and Fe atoms under isotropic and uniaxial tensile strain We have investigated the magnetic properties of silicene doped with Cr and Fe atoms under isotropic and uniaxial

  16. EXTENDED ANALYSIS OF THE SPECTRUM OF SINGLY IONIZED CHROMIUM (Cr II)

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect EXTENDED ANALYSIS OF THE SPECTRUM OF SINGLY IONIZED CHROMIUM (Cr II) Citation Details In-Document Search Title: EXTENDED ANALYSIS OF THE SPECTRUM OF SINGLY IONIZED CHROMIUM (Cr II) We have made new observations of the spectrum of singly ionized chromium (Cr II) in the region 2850-37900 Å with the National Institute of Standards and Technology 2 m Fourier transform spectrometer. These data extend our previously reported observations in the

  17. Origin of spin gapless semiconductor behavior in CoFeCrGa: Theory...

    Office of Scientific and Technical Information (OSTI)

    behavior in CoFeCrGa: Theory and Experiment This content will become publicly available on July 8, 2016 Title: Origin of spin gapless semiconductor behavior in ...

  18. Structural studies and band gap tuning of Cr doped ZnO nanoparticles

    SciTech Connect (OSTI)

    Srinet, Gunjan Kumar, Ravindra Sajal, Vivek

    2014-04-24

    Structural and optical properties of Cr doped ZnO nanoparticles prepared by the thermal decomposition method are presented. X-ray diffraction studies confirmed the substitution of Cr on Zn sites without changing the wurtzite structure of ZnO. Modified form of W-H equations was used to calculate various physical parameters and their variation with Cr doping is discussed. Significant red shift was observed in band gap, i.e., a band gap tuning is achieved by Cr doping which could eventually be useful for optoelectronic applications.

  19. Microsoft Word - chapter FeNiCrMo_ver4.doc

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

    Low-Alloy Ferritic Steels Fe-Ni-Cr-Mo Tempered December 8, ... strength level, material processing, and heat treatment 1. ... steel composition, hydrogen gas pressure, and temperature. ...

  20. Honey Creek Middle School Wins National Science Competition - News Releases

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

    | NREL Honey Creek Middle School Wins National Science Competition July 13, 2005 Golden, Colo. - Solar concentrators using highly efficient photovoltaic solar cells will reduce the cost of electricity from sunlight to competitive levels soon, attendees were told at a recent international conference on the subject. Herb Hayden of Arizona Public Service (APS) and Robert McConnell and Martha Symko-Davies of the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) organized

  1. AmeriFlux US-SuM Maui Sugarcane Middle

    SciTech Connect (OSTI)

    Anderson, Ray; Wang, Dong

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-SuM Maui Sugarcane Middle. Site Description - Continuous, irrigated, sugarcane cultivation for >100 years. Practice is to grow plant sugarcane for 2 years, drydown, burn leaves, harvest cane, and then till and replant very shortly after harvest. Site differs from Sugarcane Windy and Sugarcane Lee/sheltered in soil and meteorology.

  2. Sandia California Regional Middle and High School Science Bowl winners |

    National Nuclear Security Administration (NNSA)

    National Nuclear Security Administration Regional Middle and High School Science Bowl winners Thursday, March 3, 2016 - 2:00pm San Ramon's Dougherty Valley High School won the high school division for the third year in a row. More than 240 students and 48 teams competed in the Sandia California Regional Science Bowls at Las Positas College, in Livermore, California. Hopkins Junior High School (Fremont, California) and Dougherty Valley High School (San Ramon, California) defended their titles

  3. Oil and gas developments in Middle East in 1982

    SciTech Connect (OSTI)

    Hemer, D.O.; Hatch, G.C.

    1983-10-01

    Petroleum production in Middle East countries during 1982 totaled 4,499,464,000 bbl (an average rate of 12,162,915 BOPD), down 21.5% from 1981. Increases were in Iraq, Iran, and Oman. Significant decreases occurred in Kuwait, Divided Neutral Zone, Saudi Arabia, Qatar, and Abu Dhabi. New discoveries were reported in Oman, Syria, Abu Dhabi, Dubai, Iran, and Saudi Arabia.

  4. Readout of Secretary Chu's Middle East trip: Thursday, February 25 |

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

    Department of Energy Thursday, February 25 Readout of Secretary Chu's Middle East trip: Thursday, February 25 February 25, 2010 - 12:00am Addthis Today, Secretary Chu was in Doha, Qatar, where he began the day by signing a Memorandum of Understanding on Renewable and Alternative Energy with Deputy Prime Minister and Energy & Industry Minister Abdullah bin Hamad Al-Attiyah. The agreement provides a framework for bilateral cooperation with the Ministry and other Qatari institutions on

  5. Hood River Middle School Music and Science Building

    High Performance Buildings Database

    Hood River, Oregon The Hood River Middle School Music and Science Building is includes music and science classroom, music practice rooms, teacher offices, a greenhouse, an adjacent recycling and storage building, and outdoor spaces including an amphitheater and garden. The building is integrated with the school's progressive sustainability and permaculture curriculum. Students can track and create experiments using data from the buildings net zero energy system and rainwater harvesting system, and learn about the building's innovative and integrated use of materials and systems.

  6. DOE New Jersey Regional Middle School Science Bowl | Princeton Plasma

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

    Physics Lab 0, 2015, 9:00am to 3:00pm Science Education Lab-wide DOE New Jersey Regional Middle School Science Bowl Contact Information Website: New Jersey Regional Science Bowl Coordinator(s): Deedee Ortiz-Arias, Science Education Department Program Administraor dortiz@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under heightened security measures because of the events of

  7. Magnetic Interaction Reversal In Watermelon Nanostructured Cr-doped Fe Nanoclusters

    SciTech Connect (OSTI)

    Kaur, Maninder; Dai, Qilin; Bowden, Mark E.; Engelhard, Mark H.; Wu, Yaqiao; Tang, Jinke; Qiang, You

    2013-11-11

    Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (<10 at. %) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr2O3 and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (rv25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of r-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs. The giant magnetoresistance (GMR) effect,1,2 where an antiferromagnetic (AFM) exchange coupling exists between two ferromagnetic (FM) layers separated by a certain type of magnetic or non-magnetic spacer,3 has significant potential for application in the magnetic recording industry. Soon after the discovery of the GMR, the magnetic properties of multilayer systems (FeCr) became a subject of intensive study. The application of bulk iron-chromium (Fe-Cr) alloys has been of great interest, as these alloys exhibit favorable prop- erties including corrosion resistance, high strength, hardness, low oxidation rate, and strength retention at elevated temper- ature. However, the structural and magnetic properties of Cr-doped Fe nanoclusters (NCs) have not been investigated in-depth. Of all NCs, Fe-based clusters have unique magnetic properties as well as favorable catalytic characteristics in reactivity, selectivity, and durability.4 The incorporation of dopant of varied type and concentration in Fe can modify its chemical ordering, thereby optimizing its electrical, optical, and magnetic properties and opening up many new applications. The substitution of an Fe atom (1.24 A˚ ) by a Cr atom (1.25 A˚ ) can easily modify the magnetic properties, since (i) the curie temperature (Tc ) of Fe is 1043 K, while Cr is an itinerant AFM with a bulk Neel temperature TN =311 K, and (ii) Fe and Cr share the same crystal structure (bcc) with only 0.5% difference between their lattice constants.

  8. Improving thermostability of CrO{sub 2} thin films by doping with Sn

    SciTech Connect (OSTI)

    Ding, Yi; Wang, Ziyu; Liu, Shuo; Shi, Jing; Yin, Di; Yuan, Cheng; Lu, Zhihong; Xiong, Rui

    2014-09-01

    Chromium dioxide (CrO{sub 2}) is an ideal material for spin electronic devices since it has almost 100% spin polarization near Fermi level. However, it is thermally unstable and easily decomposes to Cr{sub 2}O{sub 3} even at room temperature. In this study, we try to improve the thermal stability of CrO{sub 2} thin films by doping with Sn whose oxide has the same structure as CrO{sub 2}. High quality epitaxial CrO{sub 2} and Sn-doped CrO{sub 2} films were grown on single crystalline TiO{sub 2} (100) substrates by chemical vapor deposition. Sn{sup 4+} ions were believed to be doped into CrO{sub 2} lattice and take the lattice positions of Cr{sup 4+}. The magnetic measurements show that Sn-doping leads to a decrease of magnetocrystalline anisotropy. The thermal stabilities of the films were evaluated by annealing the films at different temperatures. Sn-doped films can withstand a temperature up to 510 °C, significantly higher than what undoped films can do (lower than 435 °C), which suggests that Sn-doping indeed enhances the thermal stability of CrO{sub 2} films. Our study also indicates that Sn-doping may not change the essential half metallic properties of CrO{sub 2}. Therefore, Sn-doped CrO{sub 2} is expected to be very promising for applications in spintronic devices.

  9. Metastable bcc phase formation in the Nb-Cr-Ti system

    SciTech Connect (OSTI)

    Thoma, D.J.; Perepezko, J.H.

    1994-08-01

    Metastable disordered bcc phases have been formed from the melt in the Nb-Cr-Ti system where primary Laves phases would develop under equilibrium solidification conditions. Three vertical temperature-composition sections in the ternary system incorporating NbCr, were evaluated: the Nb-Cr binary, the TiCr{sub 2}-NbCr{sub 2} isoplethal section, and the NbCr{sub 2}-Ti plethal section. In the rapid solidification of NbCr{sub 2}, metastable bcc phase formation was not observed, but deviations from NbCr{sub 2} stoichiometry or alloying with Ti was found to promote bcc phase formation by decreasing the required liquid undercooling to reach the metastable bcc liquidus and solidus. The metastable phases were characterized through x-ray diffraction (XRD), and systematic deviations from Vegard`s Rule have been defined in the three plethal sections. The metastable bcc phases decompose at temperatures >800{degrees}C to uniformly refined microstructures. As a result, novel microstructural tailoring schemes are possible through the metastable precursor microstructures.

  10. Audit Report: CR-B-95-06 | Department of Energy

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

    5-06 Audit Report: CR-B-95-06 June 30, 1995 Audit of Department of Energy Support Service Contracting PDF icon Audit Report: CR-B-95-06 More Documents & Publications Audit Report: IG-0427 Inspection Report: IG-0377 Chapter 16 - Types of Contracts

  11. Audit Report: CR-FS-96-03 | Department of Energy

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

    6-03 Audit Report: CR-FS-96-03 April 15, 1996 Report on Matters Identified at Strategic Petroleum Reserve During Audit of Statement of Financial Position PDF icon Audit Report: CR-FS-96-03 More Documents & Publications Audit Report: IG-0370 Inspection Report: INS-9502 Audit Report: ER-FS-99-04

  12. Audit Report: CR-B-95-02 | Department of Energy

    Energy Savers [EERE]

    5-02 Audit Report: CR-B-95-02 November 10, 1994 Audit of Management Controls Over Selected Energy Research Major System Acquisitions PDF icon Audit Report: CR-B-95-02 More Documents & Publications Audit Report: ER-B-95-04 Audit Report: IG-0389 Audit Report: IG-0543

  13. Computational prediction and characterization of single-layer CrS{sub 2}

    SciTech Connect (OSTI)

    Zhuang, Houlong L.; Blonsky, Michael N.; Hennig, Richard G.; Johannes, Michelle D.

    2014-01-13

    Using first-principles calculations, we predict a previously unreported bulk CrS{sub 2} phase that is stable against competing phases and a low energy dynamically stable single-layer CrS{sub 2} phase. We characterize the electronic, optical, and piezoelectric properties of this single-layer material. Like single-layer MoS{sub 2}, CrS{sub 2} has a direct bandgap and valley polarization. The optical bandgap of CrS{sub 2} is 1.3?eV, close to the ideal bandgap of 1.4?eV for photovoltaic applications. Applying compressive strain increases the bandgap and optical absorbance, transforming it into a promising photocatalyst for solar water splitting. Finally, we show that single-layer CrS{sub 2} possesses superior piezoelectric properties to single-layer MoS{sub 2}.

  14. NEUTRON-INDUCED SWELLING OF Fe-Cr BINARY ALLOYS IN FFTF AT ~400 DEGREES C

    SciTech Connect (OSTI)

    Garner, Francis A.; Greenwood, Lawrence R.; Okita, Taira; Sekimura, Naoto; Wolfer, W. G.

    2002-12-31

    The purpose of this effort is to determine the influence of dpa rate, He/dpa ratio and composition on the void swelling of simple binary Fe-Cr alloys. Contrary to the behavior of swelling of model fcc Fe-Cr-Ni alloys irradiated in the same FFTF-MOTA experiment, model bcc Fe-Cr alloys do not exhibit a dependence of swelling on dpa rate at approximately 400 degrees C. This is surprising in that an apparent flux-sensitivity was observed in an earlier comparative irradiation of Fe-Cr binaries conducted in EBR-II and FFTF. The difference in behavior is ascribed to the higher helium generation rates of Fe-Cr alloys in EBR-II compared to that of FFTF, and also the fact that lower dpa rates in FFTF are accompanied by progressively lower helium generation rates.

  15. Middle East fuel supply & gas exports for power generation

    SciTech Connect (OSTI)

    Mitchell, G.K.; Newendorp, T.

    1995-12-31

    The Middle East countries that border on, or are near, the Persian Gulf hold over 65% of the world`s estimated proven crude oil reserves and 32% of the world`s estimated proven natural gas reserves. In fact, approximately 5% of the world`s total proven gas reserves are located in Qatar`s offshore North Field. This large natural gas/condensate field is currently under development to supply three LNG export projects, as well as a sub-sea pipeline proposal to export gas to Pakistan. The Middle East will continue to be a major source of crude oil and oil products to world petroleum markets, including fuel for existing and future base load, intermediate cycling and peaking electric generation plants. In addition, as the Persian Gulf countries turn their attention to exploiting their natural gas resources, the fast-growing need for electricity in the Asia-Pacific and east Africa areas offers a potential market for both pipeline and LNG export opportunities to fuel high efficiency, gas-fired combustion turbine power plants. Mr. Mitchell`s portion of this paper will discuss the background, status and timing of several Middle Eastern gas export projects that have been proposed. These large gas export projects are difficult and costly to develop and finance. Consequently, any IPP developers that are considering gas-fired projects which require Mid-East LNG as a fuel source, should understand the numerous sources and timing to securing project debt, loan terms and conditions, and, restrictions/credit rating issues associated with securing financing for these gas export projects. Mr. Newendorp`s section of the paper will cover the financing aspects of these projects, providing IPP developers with additional considerations in selecting the primary fuel supply for an Asian-Pacific or east African electric generation project.

  16. NJ Regional Middle School Science Bowl | Princeton Plasma Physics Lab

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

    2, 2013, 8:00am Science Education Lab-wide Event NJ Regional Middle School Science Bowl Teams of students are invited to participate in the Department of Energy's National Science Bowl Competition. Each year PPPL hosts the New Jersey Regional Science Bowl which decides which teams from the local area can continue onto the national competition in Washington, D.C. The Science Bowl is a double elimination contest with oral question and answer rounds in the fields of chemistry, biology, physics,

  17. 2016 Middle School Science Bowl Results | The Ames Laboratory

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

    2016 Middle School Science Bowl Results News release Championship Results Bracket First Place - Ames Front row (l-r) Rishabh Swamy, Hannah Huang, Nitzan Friedberg; Back (l-r) Coach Collin Reichert, Andres Cordoba, David Kim, Ames Laboratory Director Adam Schwartz. Second Place - LeMars Front row (l-r) Ethan Hulinsky, Alex Meier, Jake Francksen-Small; Back row (l-r) Coach Ryan Zittritsch, Tate Hogrefe, Kyle Herbst, Ames Laboratory Director Adam Schwartz. Third Place - Madrid Front (l-r) Jason

  18. Oil and gas developments in Middle East in 1984

    SciTech Connect (OSTI)

    Hemer, D.O.; Lyle, J.H.

    1985-10-01

    Petroleum production in Middle East countries during 1984 totaled 4,088,853,000 bbl (an average rate of 11,144,407 BOPD), down less than 1.0% from the revised total of 4,112,116,000 bbl produced in 1983. Iraq, Kuwait, Qatar, and Oman had significant increases; Iran and Dubai had significant decreases. Jordan produced oil, although a minor amount, for the first time ever, and new production facilities were in the planning stage in Syria, North Yemen, and Oman, which will bring new fields on stream when completed.

  19. Oil and gas developments in Middle East in 1985

    SciTech Connect (OSTI)

    Hemer, D.O.; Gohrbandt, K.H.A.

    1986-10-01

    Petroleum production in Middle East countries during 1985 totaled 3,837,580,000 bbl (an average rate of 10,513,917 BOPD), down 2.2% from the revised 1984 total of 3,924,034,000 bbl. Iran, Iraq, Dubai, Oman, and Syria had significant increases; Kuwait, Kuwait-Saudi Arabia Divided Neutral Zone, Saudi Arabia, and Qatar had significant decreases. New fields went on production in Iraq, Abu Dhabi, Oman, and Syria. In North Yemen, the first ever oil production in that country was nearing the start-up stage at year end. 9 figures, 9 tables.

  20. Oil and gas developments in Middle East in 1984

    SciTech Connect (OSTI)

    Hemer, D.O.; Lyle, J.H.

    1985-10-01

    Petroleum production in Middle East countries during 1984 totaled 4,088,853,000 bbl (an average rate of 11,144,407 BOPD), down less than 1.0% from the revised total of 4,112,116,000 bbl produced in 1983. Iraq, Kuwait, Qatar, and Oman had significant increases; Iran and Dubai had significant decreases. Jordan produced oil, although a minor amount, for the first time ever, and new production facilities were in the planning stage in Syria, North Yemen, and Oman, which will bring new fields on stream when completed. 4 figures, 9 tables.

  1. Development of ODS FeCrAl alloys for accident-tolerant fuel cladding

    SciTech Connect (OSTI)

    Dryepondt, Sebastien N.; Hoelzer, David T.; Pint, Bruce A.; Unocic, Kinga A.

    2015-09-18

    FeCrAl alloys are prime candidates for accident-tolerant fuel cladding due to their excellent oxidation resistance up to 1400 C and good mechanical properties at intermediate temperature. Former commercial oxide dispersion strengthened (ODS) FeCrAl alloys such as PM2000 exhibit significantly better tensile strength than wrought FeCrAl alloys, which would alloy for the fabrication of a very thin (~250 m) ODS FeCrAl cladding and limit the neutronic penalty from the replacement of Zr-based alloys by Fe-based alloys. Several Fe-12-Cr-5Al ODS alloys where therefore fabricated by ball milling FeCrAl powders with Y2O3 and additional oxides such as TiO2 or ZrO2. The new Fe-12Cr-5Al ODS alloys showed excellent tensile strength up to 800 C but limited ductility. Good oxidation resistance in steam at 1200 and 1400 C was observed except for one ODS FeCrAl alloy containing Ti. Rolling trials were conducted at 300, 600 C and 800 C to simulate the fabrication of thin tube cladding and a plate thickness of ~0.6mm was reached before the formation of multiple edge cracks. Hardness measurements at different stages of the rolling process, before and after annealing for 1h at 1000 C, showed that a thinner plate thickness could likely be achieved by using a multi-step approach combining warm rolling and high temperature annealing. Finally, new Fe-10-12Cr-5.5-6Al-Z gas atomized powders have been purchased to fabricate the second generation of low-Cr ODS FeCrAl alloys. The main goals are to assess the effect of O, C, N and Zr contents on the ODS FeCrAl microstructure and mechanical properties, and to optimize the fabrication process to improve the ductility of the 2nd gen ODS FeCrAl while maintaining good mechanical strength and oxidation resistance.

  2. Progress in the material development of LiCaAlF sub 6 :Cr sup 3+ laser crystals

    SciTech Connect (OSTI)

    Michelle D. Shinn.; Chase, L.L.; Caird, J.A.; Payne, S.A.; Atherton, L.J.; Kway, W.L.

    1990-03-01

    High Cr{sup 3+} doping levels, up to 8 mole percent, and low losses have been obtained with the tunable solid-state laser material LiCaAlF{sub 6}:Cr{sup 3+} (Cr:LiCAF). Measurements and calculations show that high pumping and extraction efficiencies are possible with the improved material. 13 refs., 4 figs., 1 tab.

  3. Magnetic properties and hyperfine interactions in Cr{sub 8}, Cr{sub 7}Cd, and Cr{sub 7}Ni molecular rings from {sup 19}F-NMR

    SciTech Connect (OSTI)

    Bordonali, L.; Borsa, F.; Consorzio INSTM, Via Giusti 9, I-50121 Firenze; Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 ; Garlatti, E.; Dipartimento di Fisica e Scienze della Terra, Università di Parma, Viale G. P. Usberti 7 Casadei, C. M.; Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 ; Furukawa, Y.; Lascialfari, A.; Consorzio INSTM, Via Giusti 9, I-50121 Firenze; Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano ; Carretta, S.; Timco, G.; Winpenny, R. E. P.

    2014-04-14

    A detailed experimental investigation of the {sup 19}F nuclear magnetic resonance is made on single crystals of the homometallic Cr{sub 8} antiferromagnetic molecular ring and heterometallic Cr{sub 7}Cd and Cr{sub 7}Ni rings in the low temperature ground state. Since the F{sup −} ion is located midway between neighboring magnetic metal ions in the ring, the {sup 19}F-NMR spectra yield information about the local electronic spin density and {sup 19}F hyperfine interactions. In Cr{sub 8}, where the ground state is a singlet with total spin S{sub T} = 0, the {sup 19}F-NMR spectra at 1.7 K and low external magnetic field display a single narrow line, while when the magnetic field is increased towards the first level crossing field, satellite lines appear in the {sup 19}F-NMR spectrum, indicating a progressive increase in the Boltzmann population of the first excited state S{sub T} = 1. In the heterometallic rings, Cr{sub 7}Cd and Cr{sub 7}Ni, whose ground state is magnetic with S{sub T} = 3/2 and S{sub T} = 1/2, respectively, the {sup 19}F-NMR spectrum has a complicated structure which depends on the strength and orientation of the magnetic field, due to both isotropic and anisotropic transferred hyperfine interactions and classical dipolar interactions. From the {sup 19}F-NMR spectra in single crystals we estimated the transferred hyperfine constants for both the F{sup −}-Ni{sup 2+} and the F{sup −}-Cd{sup 2+} bonds. The values of the hyperfine constants compare well to the ones known for F{sup −}-Ni{sup 2+} in KNiF{sub 3} and NiF{sub 2} and for F{sup −}-Cr{sup 3+} in K{sub 2}NaCrF{sub 6}. The results are discussed in terms of hybridization of the 2s, 2p orbitals of the F{sup −} ion and the d orbitals of the magnetic ion. Finally, we discuss the implications of our results for the electron-spin decoherence.

  4. Oil and gas development in Middle East in 1987

    SciTech Connect (OSTI)

    Hemer, D.O.; Gohrbandt, K.H.A.; Phillips, C.B.

    1988-10-01

    Petroleum production in Middle East countries during 1987 totaled an estimated 4,500,500,000 bbl (an average rate of 12,330,137 b/d), up slightly from the revised 1986 total of 4,478,972,000 bbl. Iran, Iraq, Syria, and Yemen Arab Republic had significant increases; Kuwait and Saudi Arabia had significant decreases. Production was established for the first time in People's Democratic Republic of Yemen. New fields went on production in Iraq, Oman, People's Democratic Republic of Yemen, and Syria, and significant oil discoveries were reported in Iraq, Oman, People's Democratic Republic of Yemen, Syria, and Yemen Arab Republic. The level of exploration increased in 1987 with new concessions awarded in some countries, drilling and seismic activities on the increase, new regions in mature areas explored for the first time, and significant reserve additions reported in new and old permits. The Iraq-Iran war still had a negative impact in some regions of the Middle East, particularly in and around the Gulf. 11 figs., 4 tabs.

  5. Ferromagnetic superexchange in insulating Cr2MoO6 by controlling orbital hybridization

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

    Zhu, M.; Do, D.; Dela Cruz, Clarina R.; Dun, Zhiling; Cheng, J. -G.; Goto, H.; Uwatoko, Yoshiya; Zou, T.; Zhou, Haidon D.; Mahanti, Subhendra D.; et al

    2015-09-11

    We report the magnetic and electronic structures of the newly synthesized inverse-trirutile compound Cr2MoO6. Despite the same crystal symmetry and similar bond-lengths and bond-angles to Cr2TeO6, Cr2MoO6 possesses a magnetic structure of the Cr2MoO6 type, different from that seen in Cr2TeO6. Ab-initio electronic structure calculations show that the sign and strength of the Cr-O-Cr exchange coupling is strongly influenced by the hybridization between Mo 4d and O 2p orbitals. This result further substantiates our recently proposed mechanism for tuning the exchange interaction between two magnetic atoms by modifying the electronic states of the non-magnetic atoms in the exchange path throughmore » orbital hybridization. This approach is fundamentally different from the conventional methods of controlling the exchange interaction by either carrier injection or through structural distortions.« less

  6. Probe Mssbauer spectroscopy of mechanical alloying in binary Cr?{sup 57}Fe(1 at%) system

    SciTech Connect (OSTI)

    Elsukov, Evgeny P. Kolodkin, Denis A. Ul'yanov, Alexander L. Porsev, Vitaly E.

    2014-10-27

    Solid state reactions during mechanical alloying (MA) in a binary mixture of powdered Cr and {sup 57}Fe in atomic ratio of 99:1 have been studied using {sup 57}Fe Mssbauer spectroscopy, X-ray diffraction and Auger spectrometry. The proposed model of MA includes formation of Cr(Fe){sub x}O{sub y} oxides at the contact places of Cr and Fe particles, formation of nanostructure with simultaneous dissolution of the oxides, penetration of Fe atoms along grain boundaries in close-to-boundary distorted zones of interfaces in a substitutional position, formation of the substitutional solid solution of Fe in Cr in the body of grains. It was shown that the increase in the BCC lattice parameter on increasing the milling time is due to the dissolution of oxides and formation of interstitial solid solution of O in Cr. There were established substantial differences in consumption of BCC Fe in a Mg ? Al ? Si ? Cr sequence due to the major role of chemical interaction of Mg(Al,Si,Cr) with Fe.

  7. Effects of competing magnetic interactions on the electronic transport properties of CuCrSe{sub 2}

    SciTech Connect (OSTI)

    Tewari, Girish C.; Jawaharlal Nehru University, New Delhi 110067 ; Karppinen, Maarit; Rastogi, Ashok K.

    2013-02-15

    We have synthesized single-phase samples of the CuCrSe{sub 2} phase that exhibits hexagonal-rhombohedral layered crystal structure with space group R3m. Here we present a detailed study of electronic transport and magnetic properties of CuCrSe{sub 2}. We moreover investigate the heat capacity of CuCrSe{sub 2} in comparison to that of CuCrS{sub 2}. The electrical resistivity of CuCrSe{sub 2} shows metallic-like behavior down to 2 K, while the thermoelectric power is large around 100 {mu}V K{sup -1} at 300 K. A weak anomaly in resistivity and a rounded maximum in magnetic susceptibility are observed around 55 K. No sharp transition at 55 K is observed in the heat capacity of CuCrSe{sub 2}, rather a visible maximum is seen. At low temperatures from 2 to 14 K, the magnetic heat capacity follows T{sup 2}-dependence. We tentatively believe this behavior of CuCrSe{sub 2} to be due to competing magnetic interactions between intralayer Cr atoms. The ferromagnetic Cr-Se-Cr indirect exchange among intralayer Cr atoms is enhanced in the selenide compound (that is more metallic than the sulfide compound), and competes with the antiferromagnetic Cr-Cr direct interactions. The interlayer antiferromagnetic exchange through Cu atoms leads to magnetic ordering at low temperature at T{sub N}=55 K. - Graphical abstract: Comparison of magnetic properties of CuCrSe{sub 2} and CuCrS{sub 2} indicates a sharp cusp-like anomaly in magnetic susceptibility at the antiferromagnetic transition of CuCrS{sub 2} while the maximum of CuCrSe{sub 2} is well rounded. Magnetization is reversible after field-cooling (FC) and zero-field-cooling (ZFC) for both compounds. Highlights: Black-Right-Pointing-Pointer Layered CuCrSe{sub 2} can be synthesized in both fully and partially cation-ordered forms. Black-Right-Pointing-Pointer Contrary to previously believed insulating nature the cation-ordered phase is metallic. Black-Right-Pointing-Pointer Magnetic property of CuCrSe{sub 2} is somewhat different from that of CuCrS{sub 2}. Black-Right-Pointing-Pointer Magnetization and heat capacity data suggest complex short-range ordering for CuCrSe{sub 2}.

  8. Nanoscale Phase Separation In Epitaxial Cr-Mo and Cr-V Alloy Thin Films Studied Using Atom Probe Tomography: Comparison Of Experiments And Simulation

    SciTech Connect (OSTI)

    Devaraj, Arun; Kaspar, Tiffany C.; Ramanan, Sathvik; Walvekar, Sarita K.; Bowden, Mark E.; Shutthanandan, V.; Kurtz, Richard J.

    2014-11-21

    Tailored metal alloy thin film-oxide interfaces generated using molecular beam epitaxial (MBE) deposition of alloy thin films on a single crystalline oxide substrate can be used for detailed studies of irradiation damage response on the interface structure. However presence of nanoscale phase separation in the MBE grown alloy thin films can impact the metal-oxide interface structure. Due to nanoscale domain size of such phase separation it is very challenging to characterize by conventional techniques. Therefor laser assisted atom probe tomography (APT) was utilized to study the phase separation in epitaxial Cr0.61Mo0.39, Cr0.77Mo0.23, and Cr0.32V0.68 alloy thin films grown by MBE on MgO(001) single crystal substrates. Statistical analysis, namely frequency distribution analysis and Pearson coefficient analysis of experimental data was compared with similar analyses conducted on simulated APT datasets with known extent of phase separation. Thus the presence of phase separation in Cr-Mo films, even when phase separation was not clearly observed by x-ray diffraction, and the absence of phase separation in the Cr-V film were thus confirmed.

  9. Nanoscale phase separation in epitaxial Cr-Mo and Cr-V alloy thin films studied using atom probe tomography: Comparison of experiments and simulation

    SciTech Connect (OSTI)

    Devaraj, A.; Ramanan, S.; Walvekar, S.; Bowden, M. E.; Shutthanandan, V.; Kaspar, T. C.; Kurtz, R. J.

    2014-11-21

    Tailored metal alloy thin film-oxide interfaces generated using molecular beam epitaxy (MBE) deposition of alloy thin films on a single crystalline oxide substrate can be used for detailed studies of irradiation damage response on the interface structure. However, the presence of nanoscale phase separation in the MBE grown alloy thin films can impact the metal-oxide interface structure. Due to nanoscale domain size of such phase separation, it is very challenging to characterize by conventional techniques. Therefore, laser assisted atom probe tomography (APT) was utilized to study the phase separation in epitaxial Cr{sub 0.61}Mo{sub 0.39}, Cr{sub 0.77}Mo{sub 0.23}, and Cr{sub 0.32}V{sub 0.68} alloy thin films grown by MBE on MgO(001) single crystal substrates. Statistical analysis, namely frequency distribution analysis and Pearson coefficient analysis of experimental data was compared with similar analyses conducted on simulated APT datasets with known extent of phase separation. Thus, the presence of phase separation in Cr-Mo films, even when phase separation was not clearly observed by x-ray diffraction, and the absence of phase separation in the Cr-V film were confirmed.

  10. Thermodynamic Modeling and Experimental Study of the Fe-Cr-Zr System

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Bei, Hongbin; Busby, Jeremy T

    2013-01-01

    Wide applications of zircaloys, stainless steels and their interactions in nuclear reactors require the knowledge on phase stability and thermodynamic property of the Fe-Cr-Zr system. This knowledge is also important to develop new Zr-contained Fe-Cr ferritic steels. This work aims at developing thermodynamic models for describing phase stability and thermodynamic property of the Fe-Cr-Zr system using the Calphad approach coupled with experimental study. Thermodynamic descriptions of the Fe-Cr and Cr-Zr systems were either directly adopted or slightly modified from literature. The Fe-Zr system has been remodeled to accommodate recent ab-initio calculation of formation enthalpies of various Fe-Zr compounds. Reliable ternary experimental data and thermodynamic models were mainly available in the Zr-rich region. Therefore, selected ternary alloys located in the vicinity of the eutectic valley of (Fe,Cr,Zr) and (Fe,Cr)2Zr laves phase in the Fe-rich region have been experimentally investigated in this study. Microstructure has been examined by using scanning electron microscope, energy-dispersive Xray spectroscopy and X-ray diffraction. These experimental results, along with the literature data were then used to develop thermodynamic models for phases in the Fe-Cr-Zr system. Calculated phase equilibria and thermodynamic properties of the ternary system yield satisfactory agreements with available experimental data, which gives the confidence to use these models as building blocks for developing a Zr, Fe and Cr contained multicomponent thermodynamic database for broader applications in nuclear reactors.

  11. Tucson and Colorado Springs Middle Schools Win Science Bowl Hydrogen Fuel

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

    Cell Model Car Competitions - News Releases | NREL Tucson and Colorado Springs Middle Schools Win Science Bowl Hydrogen Fuel Cell Model Car Competitions National "Battle of the Brains" continues June 19 with academic face off June 18, 2004 Golden, Colo. - Doolen Middle School from Tucson, Ariz., captured top place in the model hydrogen fuel cell stock competition and Jenkins Middle School from Colorado Springs, Colo., captured top place in the open class model car competitions on

  12. Secretary Bodman to Travel to the Middle East to Advance International

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

    Energy Cooperation | Department of Energy to Travel to the Middle East to Advance International Energy Cooperation Secretary Bodman to Travel to the Middle East to Advance International Energy Cooperation January 10, 2008 - 10:23am Addthis WASHINGTON, DC - U.S. Secretary of Energy Samuel W. Bodman next week will embark on a five-nation tour through the Middle East to enhance the United States' relationship with oil-producing nations, promote sustained investment in conventional and

  13. Clinton Middle School wins CNS-sponsored Dream It. Do It. competition |

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

    Y-12 National Security Complex Press Releases / Clinton Middle School wins ... Clinton Middle School wins CNS-sponsored Dream It. Do It. competition Posted: May 12, 2016 - 5:12pm Clinton Middle School wins the inaugural Dream It. Do It. Competition May 2016. Front row (left to right): Janet Hawkins, Paige Cooper, Sierra Patrick, Anthony Burkett Hundley and Kristin Waldschlager of CNS. Back row (left to right): Anderson County Chamber President Rick Meredith, Jack Spangler, Jonathan Lewis,

  14. Photo of the Week: Students from Roosevelt Middle School win Argonne's 2013

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

    Regional Science Bowl | Department of Energy Students from Roosevelt Middle School win Argonne's 2013 Regional Science Bowl Photo of the Week: Students from Roosevelt Middle School win Argonne's 2013 Regional Science Bowl February 25, 2013 - 11:49am Addthis Each year, the National Science Bowl brings together thousands of middle and high school students from across the country to compete in a range of science disciplines, including biology, chemistry, earth science, physics, astronomy and

  15. Princeton High School and Grover Middle School Win Top Prizes at Regional

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

    Science Bowls | Princeton Plasma Physics Lab Princeton High School and Grover Middle School Win Top Prizes at Regional Science Bowls Princeton Plasma Physics Laboratory Hosts Competitions February 27, 2012 Tweet Widget Google Plus One Share on Facebook Thomas Grover Middle School took home the top prize Feb. 24 during the middle school Science Bowl® competition at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL). Grover team members (from left) are Coach Rae

  16. Electrochemical Testing of Ni-Cr-Mo-Gd Alloys

    SciTech Connect (OSTI)

    T. E. Lister; R. E. Mizia; H. Tian

    2005-10-01

    The waste package site recommendation design specified a boron-containing stainless steel, Neutronit 976/978, for fabrication of the internal baskets that will be used as a corrosion-resistant neutron-absorbing material. Recent corrosion test results gave higher-than-expected corrosion rates for this material. The material callout for these components has been changed to a Ni-Cr-Mo-Gd alloy (ASTM-B 932-04, UNS N06464) that is being developed at the Idaho National Laboratory. This report discusses the results of initial corrosion testing of this material in simulated in-package environments that could contact the fuel baskets after breach of the waste package outer barrier. The corrosion test matrix was executed using the potentiodynamic and potentiostatic electrochemical test techniques. The alloy performance shows low rates of general corrosion after initial removal of a gadolinium-rich second phase that intersects the surface. The high halide-containing test solutions exhibited greater tendencies toward initiation of crevice corrosion.

  17. Steamside Oxidation Behavior of Experimental 9%Cr Steels

    SciTech Connect (OSTI)

    Dogan, O.N.; Holcomb, G.R.; Alman, D.E.; Jablonski, P.D.

    2007-10-01

    Reducing emissions and increasing economic competitiveness require more efficient steam power plants that utilize fossil fuels. One of the major challenges in designing these plants is the availability of materials that can stand the supercritical and ultra-supercritical steam conditions at a competitive cost. There are several programs around the world developing new ferritic and austenitic steels for superheater and reheater tubes exposed to the advanced steam conditions. The new steels must possess properties better than current steels in terms of creep strength, steamside oxidation resistance, fireside corrosion resistance, and thermal fatigue resistance. This paper introduces a series of experimental 9%Cr steels containing Cu, Co, and Ti. Stability of the phases in the new steels is discussed and compared to the phases in the commercially available materials. The steels were tested under both the dry and moist conditions at 650C for their cyclical oxidation resistance. Results of oxidation tests are presented. Under the moist conditions, the experimental steels exhibited significantly less mass gain compared to the commercial P91 steel. Microstructural characterization of the scale revealed different oxide compositions.

  18. Magnetic properties of granular CoCrPt:SiO{sub 2} films as tailored by

    Office of Scientific and Technical Information (OSTI)

    Co{sup +} irradiation (Journal Article) | SciTech Connect Magnetic properties of granular CoCrPt:SiO{sub 2} films as tailored by Co{sup +} irradiation Citation Details In-Document Search Title: Magnetic properties of granular CoCrPt:SiO{sub 2} films as tailored by Co{sup +} irradiation We report on an approach to tailor the magnetic exchange in a conventional granular CoCrPt:SiO{sub 2} recording medium by irradiation with Co{sup +} ions. Irradiation at low fluences enhances the intergranular

  19. Sign reversal of transformation entropy change in Co{sub 2}Cr(Ga,Si) shape

    Office of Scientific and Technical Information (OSTI)

    memory alloys (Journal Article) | SciTech Connect Sign reversal of transformation entropy change in Co{sub 2}Cr(Ga,Si) shape memory alloys Citation Details In-Document Search Title: Sign reversal of transformation entropy change in Co{sub 2}Cr(Ga,Si) shape memory alloys In situ X-ray diffraction (XRD) measurements and compression tests were performed on Co{sub 2}Cr(Ga,Si) shape memory alloys. The reentrant martensitic transformation behavior was directly observed during the in situ XRD

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

    SciTech Connect (OSTI)

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

    2012-01-30

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

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

    SciTech Connect (OSTI)

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

    2012-01-30

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

  2. Hydrothermal synthesis and magnetic properties of ErCrO{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Sundarayya, Y. Kumar, K. Ashwini Sondge, Rajesh Srinath, S. Kaul, S. N.

    2014-04-24

    Homogeneous single phase ErCrO{sub 4} nanoparticles have been synthesized by a modified sol-gel followed by hydrothermal method. X-ray diffraction reveals that the compound crystallizes into tetragonal structure with space group I41/amd. The average crystallite size was estimated to be 21(1) nm. Morphological analysis of the sample confirms uniform particles of size 20 nm. DC magnetic measurements show that ErCrO{sub 4} undergoes a paramagnetic-antiferromagnetic transition at 16 K, due to the superexchange Er-O-Cr-O-Er antiferromagnetic interactions.

  3. CASL - Mixing and non-stoichiometry in Fe-Ni-Cr-Zn-O spinel compounds:

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

    Density functional theory calculations Mixing and non-stoichiometry in Fe-Ni-Cr-Zn-O spinel compounds: Density functional theory calculations Mixing and non-stoichiometry in Fe-Ni-Cr-Zn-O spinel compounds: Density functional theory calculations D.A. Andersson and C.R. Stanek Materials Science and Technology Division Los Alamos National Laboratory Density functional theory (DFT) calculations have been employed to better understand the thermodynamic properties of AB2O4 (where A=Fe2+, Ni2+ or

  4. Jefferson Lab Hosts Virginia Middle School Science Bowl on March 1 |

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

    Jefferson Lab Middle School Science Bowl on March 1 Jefferson Lab Hosts Virginia Middle School Science Bowl on March 1 NEWPORT NEWS, Va., Feb. 26, 2014 - Some of the brightest young minds in the Commonwealth will meet at the Department of Energy's Jefferson Lab on Saturday, March 1, to compete in the Virginia Regional Middle School Science Bowl. Teams from 16 middle schools are registered for this year's academic competition. The National Science Bowl® - sponsored and managed by the U.S.

  5. Nine teams compete in Virginia Middle School Science Bowl competition at

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

    Jefferson Lab on March 11 | Jefferson Lab Nine teams compete in Virginia Middle School Science Bowl competition at Jefferson Lab on March 11 Nine teams compete in Virginia Middle School Science Bowl competition at Jefferson Lab on March 11 March 17, 2006 Peasley Middle School The Peasley Middle School Team from Gloucester, Va., is coached by Ray Yoh (far right). The team (from left to right) includes Tavis Sparrier, Sayer Fisher, William Wei-Xi Wang and Caleb Dyke. Photo by Steve Gagnon,

  6. D.C. Middle and High School Students Get a Chance to Experience...

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

    Are you a teacher or a middle or high school student looking for ways to test your ... The mock competition allows students to experience the competition, practice answering ...

  7. Middle School Academic Competition - Round Robin | U.S. DOE Office...

    Office of Science (SC) Website

    NSB Home About High School Middle School Attending National Event Volunteers 2015 ... School Double Elimination Top Teams for 2015 News Media WDTS Home Contact Information ...

  8. Middle School Students | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Attending National Event Volunteers 2015 Competition Results News Media WDTS Home ... Click to view the 2015 Middle School National Science Bowl Final Matches YouTube link: ...

  9. Middle School Electric Car Competition | U.S. DOE Office of Science...

    Office of Science (SC) Website

    NSB Home About High School Middle School Attending National Event Volunteers 2015 ... School Double Elimination Top Teams for 2015 News Media WDTS Home Contact Information ...

  10. 2010 DOE National Science Bowl® Photos - Roosevelt Middle School...

    Office of Science (SC) Website

    Roosevelt Middle School National Science Bowl (NSB) NSB Home About National Science Bowl Contacts Regional Science Bowl Coordinators National Science Bowl FAQ's Alumni Past ...

  11. 2010 DOE National Science Bowl® Photos - 2010 Middle School...

    Office of Science (SC) Website

    2010 Middle School Teams National Science Bowl (NSB) NSB Home About National Science Bowl Contacts Regional Science Bowl Coordinators National Science Bowl FAQ's Alumni Past ...

  12. LOS ALAMOS, New Mexico, April 26, 2011-Los Alamos Middle School...

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

    the Challenge Process Special Judges Award for their project "Contributing Factors to Obesity, Part 2." - 3 - * Los Alamos Middle School team members Madeline Lockhart, Sean...

  13. Forum on Enhancing the Delivery of Energy Efficiency to Middle Income Households: Discussion Summary

    SciTech Connect (OSTI)

    none,

    2012-09-20

    Summarizes discussions and recommendations from a forum for practitioners and policymakers aiming to strengthen residential energy efficiency program design and delivery for middle income households.

  14. The effect of f[subscript O2] on the partitioning and valence of V and Cr

    Office of Scientific and Technical Information (OSTI)

    in garnet/melt pairs and the relation to terrestrial mantle V and Cr content (Journal Article) | SciTech Connect Journal Article: The effect of f[subscript O2] on the partitioning and valence of V and Cr in garnet/melt pairs and the relation to terrestrial mantle V and Cr content Citation Details In-Document Search Title: The effect of f[subscript O2] on the partitioning and valence of V and Cr in garnet/melt pairs and the relation to terrestrial mantle V and Cr content Chromium and vanadium

  15. Audit Report: CR-B-97-01 | Department of Energy

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

    1 Audit Report: CR-B-97-01 October 22, 1996 Audit of Department of Energy's Warehouse Space The downsizing of Department of Energy (Department) facilities as a result of the end of ...

  16. Audit Report: CR-B-95-05 | Department of Energy

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

    of the Federal Enegy Regulatory Commission's Office of Chief Accountant Audit Report: CR-B-95-05 More Documents & Publications Audit Report: IG-0811 Audit Manual Audit Report:...

  17. Ultrathin nanosheets of CrSiTe3. A semiconducting two-dimensional...

    Office of Scientific and Technical Information (OSTI)

    In this work we for the first time exfoliate the CrSiTe3, a bulk ferromagnetic semiconductor, to mono- and few-layer 2D crystals onto a SiSiO2 substrate. The Raman spectra show ...

  18. Microstructural Stability of 9-12 Cr Steels at Elevated Temperatures

    SciTech Connect (OSTI)

    Dogan, Omer N.; Hawk, Jeffrey A.

    2005-09-01

    The objective of this report is to explore new substitutional solute solution (Cu, Co) and precipitate (TiC) hardening mechanisms for improved strength of 9-12 Cr martensitic steels.

  19. Audit Report: CR-B-97-04 | Department of Energy

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

    Audit Report: CR-B-97-04 More Documents & Publications Audit of Selected Hazardous Waste Remedial Actions Program Costs, ER-B-97-04 Audit Report: IG-0443 Inspection Report: IG-0369

  20. Effects of Cr/Zn Substitutions on Dielectric Properties of CaCu{sub

    Office of Scientific and Technical Information (OSTI)

    3}Ti{sub 4}O{sub 12}(CCTO) Ceramics (Journal Article) | SciTech Connect Effects of Cr/Zn Substitutions on Dielectric Properties of CaCu{sub 3}Ti{sub 4}O{sub 12}(CCTO) Ceramics Citation Details In-Document Search Title: Effects of Cr/Zn Substitutions on Dielectric Properties of CaCu{sub 3}Ti{sub 4}O{sub 12}(CCTO) Ceramics Effects of Zn and Cr substitutions on dielectric properties of CaCu{sub 3-x}Zn{sub x}Ti{sub 4-y}Cr{sub y}O{sub 12} ceramics are reported. Dielectric measurements at room

  1. In Situ Long-Term Reductive Bioimmobilization of Cr(VI) in Groundwater...

    Office of Scientific and Technical Information (OSTI)

    injection into Cr(VI)-contaminated groundwater stimulates an average increase in biomass by up to 50 times, from-5105 to 2.5107 cellsmL. The results also show a...

  2. Half-metallic ferromagnetism in Cr-doped semiconducting Ge-chalcogenide: Density functional approach

    SciTech Connect (OSTI)

    Saini, Hardev S.; Singh, Mukhtiyar; Thakur, Jyoti; Kashyap, Manish K.

    2014-04-24

    A supercell approach has been used to calculate the electronic and magnetic properties of Cr-doped Ge chalcogenide, Ge{sub 1−x}Cr{sub x}Te (x = 0.25 and 0.125). The calculations have been performed using full potential Linear Augmented Plane Wave (FPLAPW) method within generalized gradient approximation (GGA) as exchange-correlation (XC) potential. The calculated results show that the doping of Cr induces the 100% spin polarization at Fermi level (EF) and showed the robust half metallic ferromagnetism in this compound. Thus, the compound at both dopant concentrations behave as dilute magnetic semiconductor (DMS) showing metallic property in majority and semiconducting for minority spin channels which is best suited for spintronic applications. The total magnetic moments of this compound are mainly due to Cr-d states present at E{sup F} with negligible contribution from electronic states of other atoms.

  3. Demonstration of a Full-core Reactivity Equivalence for FeCrAl...

    Office of Scientific and Technical Information (OSTI)

    Demonstration of a Full-core Reactivity Equivalence for FeCrAl Enhanced Accident Tolerant Fuel in BWRs Citation Details In-Document Search Title: Demonstration of a Full-core ...

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

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2002-01-01

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

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

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2001-01-01

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

  6. A pseudo binary y-Gd solidification diagram for Ni-Cr-Mo-Gd alloys...

    Office of Scientific and Technical Information (OSTI)

    Title: A pseudo binary y-Gd solidification diagram for Ni-Cr-Mo-Gd alloys. No abstract prepared. Authors: Dupont, John Neuman 1 ; Minicozzi, Michael J. 1 ; Robino, Charles ...

  7. A Doppler lidar for measuring winds in the middle atmosphere

    SciTech Connect (OSTI)

    Chanin, M.L.; Garnier, A.; Hauchecorne, A.; Porteneuve, J. )

    1989-11-01

    The possibility of measuring winds in the middle atmosphere with a Doppler lidar has just been demonstrated. It is aimed at studying the wave-mean flow interaction, when used is association with the Rayleigh lidar providing density and temperature profiles and their fluctuations. The new Doppler lidar relies on the Rayleigh scattering from air molecules is designed to cover the height range 25-60 km, a region where radars cannot operate. The Doppler shift to the backscattered echo is measured by inter-comparing the signal detected through each of the two high-resolution, narrow band-pass Fabry-Perot interferometers tuned on either side of the emitted laser line.

  8. Annual Energy Consumption Analysis Report for Richland Middle School

    SciTech Connect (OSTI)

    Liu, Bing

    2003-12-18

    Richland Middle School is a single story, 90,000 square feet new school located in Richland, WA. The design team proposed four HVAC system options to serve the building. The proposed HVAC systems are listed as following: (1) 4-pipe fan coil units served by electrical chiller and gas-fired boilers, (2) Ground-source closed water loop heat pumps with water loop heat pumps with boiler and cooling tower, and (3) VAV system served by electrical chiller and gas-fired boiler. This analysis estimates the annual energy consumptions and costs of each system option, in order to provide the design team with a reasonable basis for determining which system is most life-cycle cost effective. eQuest (version 3.37), a computer-based energy simulation program that uses the DOE-2 simulation engine, was used to estimate the annual energy costs.

  9. 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 supplied to Fe(III)-reducing bacteria.

  10. Heat treatment of NiCrFe alloy to optimize resistance to intergrannular stress corrosion

    DOE Patents [OSTI]

    Steeves, Arthur F.; Bibb, Albert E.

    1984-01-01

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprising heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cool the alloy body, and heat the cooled body to a temperature between 1100.degree. to 1500.degree. F. for about 1 to 30 hours.

  11. Audit Report: CR-B-97-03 | Department of Energy

    Energy Savers [EERE]

    3 Audit Report: CR-B-97-03 May 6, 1997 Followup Audit on the Procurement of Support Services for the Energy Information Administration PDF icon Audit Report: CR-B-97-03 More Documents & Publications Aligning Contract Incentives & Contract Mgt Trends - David Leotta, Director, Office of Contract Management, OAPM Update on Procurement Opportunities and Acquisition Process OPAM Policy Acquisition Guides

  12. Surface modification to improve fireside corrosion resistance of Fe-Cr ferritic steels

    DOE Patents [OSTI]

    Park, Jong-Hee (Clarendon Hills, IL); Natesan, Krishnamurti (Naperville, IL); Rink, David L. (Mokena, IL)

    2010-03-16

    An article of manufacture and a method for providing an Fe--Cr ferritic steel article of manufacture having a surface layer modification for corrosion resistance. Fe--Cr ferritic steels can be modified to enhance their corrosion resistance to liquid coal ash and other chemical environments, which have chlorides or sulfates containing active species. The steel is modified to form an aluminide/silicide passivating layer to reduce such corrosion.

  13. Ultrathin nanosheets of CrSiTe3. A semiconducting two-dimensional

    Office of Scientific and Technical Information (OSTI)

    ferromagnetic material (Journal Article) | SciTech Connect Ultrathin nanosheets of CrSiTe3. A semiconducting two-dimensional ferromagnetic material Citation Details In-Document Search This content will become publicly available on November 27, 2016 Title: Ultrathin nanosheets of CrSiTe3. A semiconducting two-dimensional ferromagnetic material Finite range ferromagnetism and antiferromagnetism in two-dimensional (2D) systems within an isotropic Heisenberg model at non-zero temperature were

  14. Heat treatment of NiCrFe alloy 600 to optimize resistance to intergranular stress corrosion

    DOE Patents [OSTI]

    Steeves, A.F.; Bibb, A.E.

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprises heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cooling the alloy body, and heating the cooled body to a temperature between 1100 to 1500/sup 0/F for about 1 to 30 hours.

  15. Ultrathin nanosheets of CrSiTe3. A semiconducting two-dimensional ferromagnetic material

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

    Lin, Ming -Wei; Zhung, Houlong L.; Yan, Jiaqiang; Ward, Thomas Zac; Puretzky, Alexander A.; Rouleau, Christopher M.; Gai, Zheng; Liang, Liangbo; Meunier, Vincent; Ganesh, Panchapakesan; et al

    2015-11-27

    Finite range ferromagnetism and antiferromagnetism in two-dimensional (2D) systems within an isotropic Heisenberg model at non-zero temperature were originally proposed to be impossible. However, recent theoretical studies using an Ising model have recently shown that 2D magnetic crystals can exhibit magnetism. Experimental verification of existing 2D magnetic crystals in this system has remained elusive. In this work we for the first time exfoliate the CrSiTe3, a bulk ferromagnetic semiconductor, to mono- and few-layer 2D crystals onto a Si/SiO2 substrate. The Raman spectra show the good stability and high quality of the exfoliated flakes, consistent with the computed phonon spectra ofmore » 2D CrSiTe3, giving a strong evidence for the existence of 2D CrSiTe3 crystals. When the thickness of the CrSiTe3 crystals is reduced to few-layers, we observed a clear change in resistivity at 80~120 K, consistent with the theoretical calculations on the Curie temperature (Tc) of ~80 K for the magnetic ordering of 2D CrSiTe3 crystals. As a result, the ferromagnetic mono- and few-layer 2D CrSiTe3 indicated here should enable numerous applications in nano-spintronics.« less

  16. Radiation tolerance of neutron-irradiated model Fe-Cr-Al alloys

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

    Field, Kevin G.; Hu, Xunxiang; Littrell, Kenneth C.; Yamamoto, Yukinori; Snead, Lance Lewis

    2015-07-14

    The Fe Cr Al alloy system has the potential to form an important class of enhanced accident-tolerant cladding materials in the nuclear power industry owing to the alloy system's higher oxidation resistance in high-temperature steam environments compared with traditional zirconium-based alloys. However, radiation tolerance of Fe Cr Al alloys has not been fully established. In this study, a series of Fe Cr Al alloys with 10 18 wt % Cr and 2.9 4.9 wt % Al were neutron irradiated at 382 C to 1.8 dpa to investigate the irradiation-induced microstructural and mechanical property evolution as a function of alloy composition.more » Dislocation loops with Burgers vector of a/2 111 and a 100 were detected and quantified. Results indicate precipitation of Cr-rich is primarily dependent on the bulk chromium composition. Mechanical testing of sub-size-irradiated tensile specimens indicates the hardening response seen after irradiation is dependent on the bulk chromium composition. Furthermore, a structure property relationship was developed; it indicated that the change in yield strength after irradiation is caused by the formation of these radiation-induced defects and is dominated by the large number density of Cr-rich α' precipitates at sufficiently high chromium contents after irradiation.« less

  17. Networks of ultrasmall Pd/Cr bilayer nanowires as high performance hydrogen sensors.

    SciTech Connect (OSTI)

    Zeng, X.-Q.; Wang, Y.-L.; Deng, H.; Latimer, M. L.; Xiao, Z.-L.; Pearson, J.; Xu, T.; Wang, H.-H.; Welp, U.; Crabtree, G. W.; Kwok, W.-K.

    2011-01-01

    The newly developed hydrogen sensor, based on a network of ultrasmall pure palladium nanowires sputter-deposited on a filtration membrane, takes advantage of single palladium nanowires' characteristics of high speed and sensitivity while eliminating their nanofabrication obstacles. However, this new type of sensor, like the single palladium nanowires, cannot distinguish hydrogen concentrations above 3%, thus limiting the potential applications of the sensor. This study reports hydrogen sensors based on a network of ultrasmall Cr-buffered Pd (Pd/Cr) nanowires on a filtration membrane. These sensors not only are able to outperform their pure Pd counterparts in speed and durability but also allow hydrogen detection at concentrations up to 100%. The new networks consist of a thin layer of palladium deposited on top of a Cr adhesion layer 1-3 nm thick. Although the Cr layer is insensitive to hydrogen, it enables the formation of a network of continuous Pd/Cr nanowires with thicknesses of the Pd layer as thin as 2 nm. The improved performance of the Pd/Cr sensors can be attributed to the increased surface area to volume ratio and to the confinement-induced suppression of the phase transition from Pd/H solid solution ({alpha}-phase) to Pd hydride ({beta}-phase).

  18. Radiation tolerance of neutron-irradiated model Fe-Cr-Al alloys

    SciTech Connect (OSTI)

    Field, Kevin G.; Hu, Xunxiang; Littrell, Kenneth C.; Yamamoto, Yukinori; Snead, Lance Lewis

    2015-07-14

    The Fe Cr Al alloy system has the potential to form an important class of enhanced accident-tolerant cladding materials in the nuclear power industry owing to the alloy system's higher oxidation resistance in high-temperature steam environments compared with traditional zirconium-based alloys. However, radiation tolerance of Fe Cr Al alloys has not been fully established. In this study, a series of Fe Cr Al alloys with 10 18 wt % Cr and 2.9 4.9 wt % Al were neutron irradiated at 382 C to 1.8 dpa to investigate the irradiation-induced microstructural and mechanical property evolution as a function of alloy composition. Dislocation loops with Burgers vector of a/2 111 and a 100 were detected and quantified. Results indicate precipitation of Cr-rich is primarily dependent on the bulk chromium composition. Mechanical testing of sub-size-irradiated tensile specimens indicates the hardening response seen after irradiation is dependent on the bulk chromium composition. Furthermore, a structure property relationship was developed; it indicated that the change in yield strength after irradiation is caused by the formation of these radiation-induced defects and is dominated by the large number density of Cr-rich α' precipitates at sufficiently high chromium contents after irradiation.

  19. Microstructure and Mechanical Properties of n-irradiated Fe-Cr Model Alloys

    SciTech Connect (OSTI)

    Matijasevic, Milena; Al Mazouzi, Abderrahim

    2008-07-01

    High chromium ( 9-12 wt %) ferritic/martensitic steels are candidate structural materials for future fusion reactors and other advanced systems such as accelerator driven systems (ADS). Their use for these applications requires a careful assessment of their mechanical stability under high energy neutron irradiation and in aggressive environments. In particular, the Cr concentration has been shown to be a key parameter to be optimized in order to guarantee the best corrosion and swelling resistance, together with the least embrittlement. In this work, the characterization of the neutron irradiated Fe-Cr model alloys with different Cr % with respect to microstructure and mechanical tests will be presented. The behavior of Fe-Cr alloys have been studied using tensile tests at different temperature range ( from -160 deg. C to 300 deg. C). Irradiation-induced microstructure changes have been studied by TEM for two different irradiation doses at 300 deg. C. The density and the size distribution of the defects induced have been determined. The tensile test results indicate that Cr content affects the hardening behavior of Fe-Cr binary alloys. Hardening mechanisms are discussed in terms of Orowan type of approach by correlating TEM data to the measured irradiation hardening. (authors)

  20. Middle School Academic Competition - Round Robin | U.S. DOE Office...

    Office of Science (SC) Website

    ... Team 1 2 3 4 5 6 7 8 Total Points 1. Hopkins Junior High School 2 2 2 2 2 0 2 12 2. Sycamore School 0 2 2 2 0 0 2 8 3. Norris Middle School 0 0 2 2 0 0 2 6 4. Commack Middle School ...

  1. Electronic structure, magnetism, and antisite disorder in CoFeCrGe and CoMnCrAl quaternary Heusler alloys

    SciTech Connect (OSTI)

    Enamullah, .; Venkateswara, Y.; Gupta, Sachin; Varma, Manoj Raama; Singh, Prashant; Suresh, K. G.; Alam, Aftab

    2015-12-10

    In this study, we present a combined theoretical and experimental study of two quaternary Heusler alloys CoFeCrGe (CFCG) and CoMnCrAl (CMCA), promising candidates for spintronics applications. Magnetization measurement shows the saturation magnetization and transition temperature to be 3 μB, 866 K and 0.9 μB, 358 K for CFCG and CMCA respectively. The magnetization values agree fairly well with our theoretical results and also obey the Slater-Pauling rule, a prerequisite for half metallicity. A striking difference between the two systems is their structure; CFCG crystallizes in fully ordered Y-type structure while CMCA has L21 disordered structure. The antisite disorder adds a somewhat unique property to the second compound, which arises due to the probabilistic mutual exchange of Al positions with Cr/Mn and such an effect is possibly expected due to comparable electronegativities of Al and Cr/Mn. Ab initio simulation predicted a unique transition from half metallic ferromagnet to metallic antiferromagnet beyond a critical excess concentration of Al in the alloy.

  2. Electronic structure, magnetism, and antisite disorder in CoFeCrGe and CoMnCrAl quaternary Heusler alloys

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

    Enamullah, .; Venkateswara, Y.; Gupta, Sachin; Varma, Manoj Raama; Singh, Prashant; Suresh, K. G.; Alam, Aftab

    2015-12-10

    In this study, we present a combined theoretical and experimental study of two quaternary Heusler alloys CoFeCrGe (CFCG) and CoMnCrAl (CMCA), promising candidates for spintronics applications. Magnetization measurement shows the saturation magnetization and transition temperature to be 3 μB, 866 K and 0.9 μB, 358 K for CFCG and CMCA respectively. The magnetization values agree fairly well with our theoretical results and also obey the Slater-Pauling rule, a prerequisite for half metallicity. A striking difference between the two systems is their structure; CFCG crystallizes in fully ordered Y-type structure while CMCA has L21 disordered structure. The antisite disorder adds amore » somewhat unique property to the second compound, which arises due to the probabilistic mutual exchange of Al positions with Cr/Mn and such an effect is possibly expected due to comparable electronegativities of Al and Cr/Mn. Ab initio simulation predicted a unique transition from half metallic ferromagnet to metallic antiferromagnet beyond a critical excess concentration of Al in the alloy.« less

  3. LLNL Middle East and North Africa research database

    SciTech Connect (OSTI)

    Dodge, D; Hauk, T; Moore, R M; O'Boyle, J; Ruppert, S

    1999-07-23

    The Lawrence Livermore National Laboratory (LLNL) Comprehensive Nuclear-Test-Ban Treaty Research and Development (CTBT R and D) program has made significant progress populating a comprehensive seismic research database (RDB) for seismic events and derived research products in the Middle East and North Africa (MENA). Our original ME/NA study region has enlarged and is now defined as an area including the Middle East, Africa, Europe, Southwest Asia, the Former Soviet Union and the Scandinavian/Arctic region. The LLNL RDB will facilitate calibration of all International Monitoring System (IMS) stations (primary and auxiliary) or their surrogates (if not yet installed) as well as a variety of gamma stations. The RDB provides not only a coherent framework in which to store and organize large volumes of collected seismic waveforms and associated event parameter information, but also provides an efficient data processing/research environment for deriving location and discrimination correction sur faces and capabilities. In order to accommodate large volumes of data from many sources with diverse formats the RDB is designed to be flexible and extensible in addition to maintaining detailed quality control information and associated metadata. Station parameters, instrument responses, phase pick information, and event bulletins were compiled and made available through the RDB. For seismic events in the MENA region occurring between 1976 and 1999, we have systematically assembled, quality checked and organized event waveforms; continuous seismic data from 1990 to present are archived for many stations. Currently, over 11,400 seismic events and 1.2 million waveforms are maintained in the RDB and made readily available to researchers. In addition to open sources of seismic data, we have established collaborative relationships with several ME/NA countries that have yielded additional ground truth and broadband waveform data essential for regional calibration and capability studies. Additional data and ground truth from other countries are also currently being sought. Research results, along with descriptive metadata are stored and organized within the LLNL RDB and prepared for delivery and integration into the Department of Energy (DOE) Knowledge Base (KB). Deliverables consist of primary data products (raw materials for calibration) and derived products (distilled from the organized raw seismological data). By combining travel-time observations, event characterization studies, and regional wave-propagation studies of the LLNL CTBT research team for ground truth events and regional events, we have assembled a library of ground truth information, event location correction surfaces, tomographic models and mine explosion histories required to support the ME/NA regionalization program. Corrections and parameters distilled from the LLNL RDB provide needed contributions to the KB for the MENA region and will enable the United States National Data Center (NDC) to effectively verify CTBT compliance. The LLNL portion of the DOE KB supports critical NDC pipeline functions in detection, location, feature extraction, discrimination, and analyst review in the Middle East and North Africa.

  4. Enhancing Middle East climate change monitoring and indexes

    SciTech Connect (OSTI)

    Sensoy, S.; Peterson, T.C.; Zhang, X.

    2007-08-15

    Extreme climate events can have significant impacts on both natural and human systems, and therefore it is important to know if and how climate extremes are changing. Analysis of extremes requires long-term daily station data and, unfortunately, there are many regions in the world where these data are not internationally exchanged. The Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (Folland et al. 2001) relied heavily on the multinational analysis of Frich et al (2002). However, Frich et al. had no results from all of Central and South America, and most of Africa and southern Asia, including the Middle East. To remedy this situation for the IPCC Fourth Assessment Report, the joint World Meteorological Organization Commission for Climatology/World Climate Research Programme (WCRP) project on Climate Variability and Predictability (CLIVAR) Expert Team on Climate Change Detection, Monitoring, and Indices (Zwiers et al. 2003) internationally coordinated a series of five regional climate change workshops and a set of indices for analyses of extremes. Two workshops covered the Americas, one in Brazil and one in Guatemala. One workshop addressed southern Africa. A workshop in India involved south and central Asia, while the workshop for the Middle East sought to address the region from Turkey to Iran and from Georgia to the southern tip of the Arabian Peninsula. The key to a successful workshop is a collaborative approach between outside experts and regional participants. The participants here broght long-term daily precipitation and maximum and minimum temperature data, station history information, an understanding of their country's climate, and a willingness to analyze thse data under the tutelage of outside experts. The outside experts brought knowledge of the crucial data and climate change issues, presentations to explain these issues, and user-friendly software to aid the analyses. Xuebin Zhang of Environment Canada wrote the workshop software to perform quality control (QC) on the data, tst the time series homogeneity, and calculate the indices. The participants created presentations on how extremes were changing in their countries. The workshop is making a direct contribution to climate change research by initiating a peer-review paper on how extremes are changing in a region never before analyzed and where data exchange is rare.

  5. Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

    SciTech Connect (OSTI)

    Jagannadham, Kasichainula

    2015-05-15

    Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600?C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600?C. TiN film deposited at 600?C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600?C on Si(111) wafer but the film deposited at 500?C showed cubic CrN and hexagonal Cr{sub 2}N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600?C. Nitride film of tungsten deposited at 600?C on Si(100) wafer was nitrogen deficient, contained both cubic W{sub 2}N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500?C were nonstoichiometric and contained cubic W{sub 2}N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600?C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films.

  6. National Science Bowl Update: Middle School Teams from Maryland and Indiana to Compete for National Championship on Monday

    Broader source: Energy.gov [DOE]

    The field of middle school finalists in the Department of Energy (DOE) National Science Bowl has narrowed once more, and now only two middle school teams remain in the competition.

  7. Influence of the hydration by the environmental humidity on the metallic speciation and the photocatalytic activity of Cr/MCM-41

    SciTech Connect (OSTI)

    Elías, Verónica R.; Sabre, Ema V.; Winkler, Elin L.; Andrini, Leandro; Requejo, Félix G.; Casuscelli, Sandra G.; Eimer, Griselda A.

    2014-05-01

    The influence of the environmental humidity on the Cr species deposited on inorganic supports like MCM-41 silicates was analyzed by UV–vis Diffuse Reflectance (UV–vis RD), Electronic Spin Resonance (ESR) and X-ray near-edge (XANES) spectroscopy. Metal speciation could be inferred, finding that prolonged exposure periods under environmental humidity provoked the reduction of the active Cr{sup 6+} species and thus, the decrease of the Cr/MCM-41 photoactivity. After the Ti loading over the Cr modified samples, Cr species and the photoactivity were not notably influenced by the humidity exposure. Thus, it could be concluded that the presence of Ti is important because the TiO{sub 2} cover protects the oxidized Cr species, stabilizing them. - Graphical abstract: The load of Ti on the Cr modified MCM-41 produces a TiO{sub 2} cover that protects the active Cr species from their reduction by the environmental humidity. - Highlights: • Spectroscopic analysis shows presence of Cr{sup 6+}/Cr{sup 5+} in calcined/re-calcined samples. • Cr{sup 3+} species increase for hydrated samples causing their photoactivity decrease. • Samples with high Cr loadings are more sensitive to environmental humidity presence. • TiO{sub 2} cover protects oxidized Cr species from their reduction by the water. • Ti is important to allow a synergistic effect and to stabilize active Cr{sup 6+}/Cr{sup 5+}.

  8. Kinetic and reactor models for HDT of middle distillates

    SciTech Connect (OSTI)

    Cotta, R.M.; Filho, R.M.

    1996-12-31

    Hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of middle distillates over a commercial Ni-Mo/y-Al{sub 2}O{sub 3} has been studied under wide operating conditions just as 340 to 380{degrees}C and 38 to 98 atm. A Power Law model was presented to each one of those reactions. The parameters of kinetic equations were estimated solving the ordinary differential equations by the 4 order Runge-Kutta-Gill algorithm and Marquardt method for searching of set of kinetic parameters (kinetic constants as well as the orders of reactions). An adiabatic diesel hydrotreating trickle-bed reactor packed with the same catalyst was simulated numerically in order to check up the behavior of this specific reaction system. One dimensional pseudo-homogeneous model was used in this work. For each feed, the mass and energy balance equations were integrated along the length of the catalytic bed using the 4th Runge-Kutta-Gill method. The performance of two industrial reactors was checked. 5 refs., 2 tabs.

  9. Irradiation-induced formation of a spinel phase at the FeCr/MgO interface

    SciTech Connect (OSTI)

    Xu, Yun; Yadav, Satyesh Kumar; Aguiar, Jeffery A.; Anderoglu, Osman; Baldwin, Jon Kevin; Wang, Yongqiang; Misra, Amit; Luo, Hongmei; Uberuaga, Blas P.; Li, Nan

    2015-04-27

    Oxide dispersion strengthened ferritic/martensitic alloys have attracted significant attention for their potential uses in future nuclear reactors and storage vessels, as the metal/oxide interfaces act as stable high-strength sinks for point defects while also dispersing helium. Here, in order to unravel the evolution and interplay of interface structure and chemistry upon irradiation in these types of materials, an atomically sharp FeCr/MgO interface was synthesized at 500 °C and separately annealed and irradiated with Ni3+ ions at 500 °C. After annealing, a slight enrichment of Cr atoms was observed at the interface, but no other structural changes were found. However, under irradiation, sufficient Cr diffuses across the interface into the MgO to form a Cr-enriched transition layer that contains spinel precipitates. First-principles calculations indicate that it is energetically favorable to incorporate Cr, but not Fe, substitutionally into MgO. Furthermore, our results indicate that irradiation can be used to form new phases and complexions at interfaces, which may have different radiation tolerance than the pristine structures.

  10. Production of Ni-Cr-Ti-natural fibres composite and investigation of mechanical properties

    SciTech Connect (OSTI)

    Pesmen, G.; Erol, A.

    2015-03-30

    Intermetallic materials such as Ni{sub 2}Ti, Cr{sub 2}Ti are among advanced technology materials that have outstanding mechanical and physical properties for high temperature applications. Especially creep resistance, low density and high hardness properties stand out in such intermetallics. The microstructure, mechanical properties of (%50Ni-%48Cr-%2Ti)-%10Naturel Fibres and (%64Ni-%32Cr-%4Ti)-%10Naturel Fibres powders were investigated using specimens produced by tube furnace sintering at 1000-1200-1400C temperature. A composite consisting of ternary additions, a metallic phase, Ti,Cr and Ni have been prepared under Ar shroud and then tube furnace sintered. XRD, SEM (Scanning Electron Microscope), were investigated to characterize the properties of the specimens. Experimental results carried out for composition (%64Ni-%32Cr-%4Ti)-%10Naturel at 1400C suggest that the best properties as 112.09HV and 5,422g/cm{sup 3} density were obtained at 1400C.

  11. Enhanced piezoelectric output voltage and Ohmic behavior in Cr-doped ZnO nanorods

    SciTech Connect (OSTI)

    Sinha, Nidhi; Ray, Geeta; Godara, Sanjay; Gupta, Manoj K.; Kumar, Binay

    2014-11-15

    Highlights: • Low cost highly crystalline Cr-doped ZnO nanorods were synthesized. • Enhancement in dielectric, piezoelectric and ferroelectric properties were observed. • A high output voltage was obtained in AFM. • Cr-doping resulted in enhanced conductivity and better Ohmic behavior in ZnO/Ag contact. - Abstract: Highly crystalline Cr-doped ZnO nanorods (NRs) were synthesized by solution technique. The size distribution was analyzed by high resolution tunneling electron microscope (HRTEM) and particle size analyzer. In atomic force microscope (AFM) studies, peak to peak 8 mV output voltage was obtained on the application of constant normal force of 25 nN. It showed high dielectric constant (980) with phase transition at 69 °C. Polarization vs. electric field (P–E) loops with remnant polarization (6.18 μC/cm{sup 2}) and coercive field (0.96 kV/cm) were obtained. In I–V studies, Cr-doping was found to reduce the rectifying behavior in the Ag/ZnO Schottky contact which is useful for field effect transistor (FET) and solar cell applications. With these excellent properties, Cr-doped ZnO NRs can be used in nanopiezoelectronics, charge storage and ferroelectric applications.

  12. Ablation and cone formation mechanism on CR-39 by ArF laser irradiation

    SciTech Connect (OSTI)

    Shakeri Jooybari, B. E-mail: hafarideh@aut.ac.ir; Afarideh, H. E-mail: hafarideh@aut.ac.ir; Lamehi-Rachti, M.; Ghergherehchi, M.

    2015-03-07

    In this work, chemical properties, surface modification, and micro structures formation on ablated polyallyl di-glycol carbonate (CR-39) polymer by ArF laser irradiation (λ = 193 nm) at various fluences and pulse number were investigated. CR-39 samples have been irradiated with an ArF laser (193 nm) at a repetition rate of 1 Hz. Threshold fluence of ablation and effective absorption coefficient of CR-39 were determined. Conical microstructures (Taylor cone) formed on laser-ablated CR-39 exhibit: smooth, Taylor cone shape walls and sharp tips together with interference and well defined fringe-structure with a period of 230 nm, around cone base. Mechanism of cone formation and cone evolution of CR-39 ablated surface were investigated by change of fluences (at a given pulse number) and pulse number (at a given fluence). Cone height, cone base, and region of interface were increased in micrometer steps by increasing the total fluence. Depression on the base of the cone and the circular fringe were simulated. FTIR spectra were measured and energy dispersive x-ray analysis of irradiated and un-irradiated samples was performed.

  13. Irradiation-induced formation of a spinel phase at the FeCr/MgO interface

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

    Xu, Yun; Yadav, Satyesh Kumar; Aguiar, Jeffery A.; Anderoglu, Osman; Baldwin, Jon Kevin; Wang, Yongqiang; Misra, Amit; Luo, Hongmei; Uberuaga, Blas P.; Li, Nan

    2015-04-27

    Oxide dispersion strengthened ferritic/martensitic alloys have attracted significant attention for their potential uses in future nuclear reactors and storage vessels, as the metal/oxide interfaces act as stable high-strength sinks for point defects while also dispersing helium. Here, in order to unravel the evolution and interplay of interface structure and chemistry upon irradiation in these types of materials, an atomically sharp FeCr/MgO interface was synthesized at 500 °C and separately annealed and irradiated with Ni3+ ions at 500 °C. After annealing, a slight enrichment of Cr atoms was observed at the interface, but no other structural changes were found. However, undermore » irradiation, sufficient Cr diffuses across the interface into the MgO to form a Cr-enriched transition layer that contains spinel precipitates. First-principles calculations indicate that it is energetically favorable to incorporate Cr, but not Fe, substitutionally into MgO. Furthermore, our results indicate that irradiation can be used to form new phases and complexions at interfaces, which may have different radiation tolerance than the pristine structures.« less

  14. STEM Middle School Mentoring Cafés Take it on the Road | Department of

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

    Energy STEM Middle School Mentoring Cafés Take it on the Road STEM Middle School Mentoring Cafés Take it on the Road November 12, 2015 - 3:00pm Addthis STEM Mentoring Cafes - sponsored in part by the Energy Department - engage middle schoolers with science and technology professionals at local science centers and museums nationwide to inspire them to learn about a broad spectrum of energy-related career fields. source: Matty Greene/US DOE STEM Mentoring Cafes - sponsored in part by the

  15. U.S. Energy Secretary Bodman Completes Middle East Trip | Department of

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

    Energy Bodman Completes Middle East Trip U.S. Energy Secretary Bodman Completes Middle East Trip November 20, 2005 - 2:51pm Addthis WASHINGTON, DC - U.S. Secretary of Energy Samuel W. Bodman concluded his four-nation swing through the Middle East this weekend, by attending the inauguration of the New Permanent Headquarter Office Building of the International Energy Forum (IEF) Secretariat and participating in a number of bilateral meetings in Riyadh, Saudi Arabia. "This trip allowed me

  16. Media Advisory - The Virginia Middle School Science Bowl Is Set For March 6

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

    at Jefferson Lab | Jefferson Lab The Virginia Middle School Science Bowl Is Set For March 6 at Jefferson Lab Media Advisory - The Virginia Middle School Science Bowl Is Set For March 6 at Jefferson Lab What: The 2010 Virginia Regional Middle School Science Bowl When: Saturday, March 6, 2010. Round-robin competition will run from 10 a.m. - noon. The double-elimination, semi-final and finalist rounds will run from 1:30 to approximately 4 p.m. Awards will be presented immediately after the

  17. Media Advisory: Virginia Middle School Science Bowl Set For March 5 at

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

    Jefferson Lab | Jefferson Lab Advisory: Virginia Middle School Science Bowl Set For March 5 at Jefferson Lab Media Advisory: Virginia Middle School Science Bowl Set For March 5 at Jefferson Lab What: The Department of Energy's 2011 Virginia Regional Middle School Science Bowl When: Saturday, March 5, 2011. Round-robin competition will run from 9 a.m. - noon. The double-elimination, semi-final and finalist rounds will run from 1 p.m. to approximately 4 p.m. Awards will be presented

  18. Halls Middle School students get a taste of science at Y-12 | Y-12 National

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

    Security Complex Halls Middle School ... Halls Middle School students get a taste of science at Y-12 Posted: May 21, 2013 - 12:40pm Engineering, science and history experts give Halls Middle School students a taste of science past and present at Y-12. During a visit to the Y-12 National Security Complex on May 20, eighth graders Miller Sullivan, center, and Tyler Young, right, learn what happens to a banana when it is submerged in liquid nitrogen. Darryl Smith, left, was one of four

  19. Smith Middle School Takes First Place at Science Bowl Hydrogen Fuel Cell

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

    Car Competition - News Releases | NREL Smith Middle School Takes First Place at Science Bowl Hydrogen Fuel Cell Car Competition National "Battle of the Brains" continues June 25 with academic face off June 24, 2005 Golden, Colo. - Smith Middle School from Chapel Hill, N.C., captured top place in the model hydrogen fuel cell competition on the first day of the National Middle School Science Bowl. St. Andrew's Episcopal School, from Amarillo, Texas, took second and Robert Frost

  20. Latitudinal survey of middle atmospheric water vapor revealed by shipboard microwave spectroscopy. Master's thesis

    SciTech Connect (OSTI)

    Schrader, M.L.

    1994-05-01

    Water vapor is one of the most important greenhouse gases and is an important tracer of atmospheric motions in the middle atmosphere. It also plays an important role in the chemistry of the middle atmosphere and through its photodissociation by solar radiation, it is the major source of hydrogen escaping to space. Ground-based microwave measurements conducted in the 1980s have provided a fair understanding of the seasonal variation of mesospheric water vapor in the northern hemisphere mid-latitudes, but the global distribution of water vapor in the middle atmosphere is only beginning to be revealed by space-based measurements.

  1. Fourteen Teams to Compete in Virginia Middle School Science Bowl on March 7

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

    | Jefferson Lab Fourteen Teams to Compete in Virginia Middle School Science Bowl on March 7 Fourteen Teams to Compete in Virginia Middle School Science Bowl on March 7 NEWPORT NEWS, Va., March 3, 2015 - Some of the brightest young minds in the Commonwealth will meet at the U.S. Department of Energy's Jefferson Lab on March 7, to compete in the Virginia Regional Middle School Science Bowl. Teams from 14 schools are registered for this year's academic competition. The National Science Bowl® -

  2. Atom probe study of irradiation-enhanced α' precipitation in neutron-irradiated Fe–Cr model alloys

    SciTech Connect (OSTI)

    Chen, Wei -Ying; Miao, Yinbin; Wu, Yaqiao; Tomchik, Carolyn A.; Mo, Kun; Gan, Jian; Okuniewski, Maria A.; Maloy, Stuart A.; Stubbins, James F.

    2015-07-01

    Atom probe tomography (APT) was performed to study the effects of Cr concentrations, irradiation doses and irradiation temperatures on a' phase formation in Fe-Cr model alloys (10-16 at.%) irradiated at 300 and 450°C to 0.01, 0.1 and 1 dpa. For 1 dpa specimens, α' precipitates with an average radius of 1.0-1.3 nm were observed. The precipitate density varied significantly from 1.1x10²³ to 2.7x10²⁴ 1/m³, depending on Cr concentrations and irradiation temperatures. The volume fraction of α' phase in 1 dpa specimens qualitatively agreed with the phase diagram prediction. For 0.01 dpa and 0.1 dpa, frequency distribution analysis detected slight Cr segregation in high-Cr specimens, but not in Fe-10Cr specimens. Proximity histogram analysis showed that the radial Cr concentration was highest at the center of a' precipitates. For most precipitates, the Cr contents were significantly lower than that predicted by the phase diagram. The Cr concentration at precipitate center increased with increasing precipitate size.

  3. Multiband Optical Absorption Controlled by Lattice Strain in Thin-Film LaCrO3

    SciTech Connect (OSTI)

    Sushko, Peter; Qiao, Liang; Bowden, Mark E.; Varga, Tamas; Exarhos, Gregory J.; Urban, III, Frank K.; Barton, David; Chambers, Scott A.

    2013-02-11

    Experimental measurements and ab initio modeling of the optical transitions in strained G-type antiferromagnetic LaCrO3 resolve two decades of debate regarding the magnitude of the optical band gap and the character of the corresponding transitions in this material. Using time-dependent density functional theory and accounting for thermal disorder effects, we demonstrate that the fourmost prominent low-energy absorption features are due to intra-Cr t2g {eg (2.4, 3.6 eV), inter-Crt2g {t2g (4.4 eV), and inter-ion O 2p { Cr 3d (from ?5 eV) transitions and show that the excitation energies of the latter type can be strongly affected by the lattice strain.

  4. Electronic and magnetic properties of epitaxial perovskite SrCrO3(001)

    SciTech Connect (OSTI)

    Zhang, Hongliang; Du, Yingge; Sushko, Petr; Bowden, Mark E.; Shutthanandan, V.; Qiao, Liang; Cao, Guixin; Gai, Zheng; Sallis, Shawn; Piper, L.F.J.; Chambers, Scott A.

    2015-06-24

    We have investigated the intrinsic properties of SrCrO3 epitaxial thin films synthesized by molecular beam epitaxy. We find compelling evidence that SrCrO3 is a correlated metal. X-ray photoemission valence band and O K-edge x-ray absorption spectra indicate a strongly hybridized Cr3d-O2p state crossing the Fermi level, leading to metallic behavior. Comparison between valence band spectra near the Fermi level and the densities of states calculated using density functional theory (DFT) also suggests the presence of coherent and incoherent states and points to a strong electron-electron correlation effects. The magnetic susceptibility can be described by Pauli paramagnetism at temperatures above 100 K, but reveals antiferromagnetic behavior at lower temperatures resulting from orbital ordering as suggested by Ortega-San-Martin et al. [Phys. Rev. Lett. 99, 255701 (2007)].

  5. Response of 9Cr-ODS Steel to Proton Irradiation at 400 °C

    SciTech Connect (OSTI)

    Jianchao He; Farong Wan; Kumar Sridharan; Todd R. Allen; A. Certain; Y. Q. Wu

    2014-09-01

    The stability of Y–Ti–O nanoclusters, dislocation structure, and grain boundary segregation in 9Cr-ODS steels has been investigated following proton irradiation at 400 °C with damage levels up to 3.7 dpa. A slight coarsening and a decrease in number density of nanoclusters were observed as a result of irradiation. The composition of nanoclusters was also observed to change with a slight increase of Y and Cr concentration in the nanoclusters following irradiation. Size, density, and composition of the nanoclusters were investigated as a function of nanocluster size, specifically classified to three groups. In addition to the changes in nanoclusters, dislocation loops were observed after irradiation. Finally, radiation-induced enrichment of Cr and depletion of W were observed at grain boundaries after irradiation.

  6. Design of 3D eye-safe middle range vibrometer

    SciTech Connect (OSTI)

    Polulyakh, Valeriy; Poutivski, Iouri

    2014-05-27

    Laser Doppler Vibrometer and Range Meter (3D-MRV) is designed for middle range distances [1100 meters]. 3D-MRV combines more than one laser in one device for a simultaneous real time measuring the distance and movement of the targets. The first laser has a short pulse (t?30psec) and low energy (E?200nJ) for distance measurement and the second one is a CW (continuous wave) single frequency laser for the velocity measurement with output power (P?30mW). Both lasers perform on the eye-safe wavelength 1.5 ?m. 3D-MRV uses the same mono-static optical transmitting and receiving channel for both lasers including an output telescope and a scanning angular system. 3D-MRV has an optical polarization switch to combine linear polarized laser beams from two lasers into one optical channel. The laser beams from both lasers by turns illuminate the target and the scattered laser radiation is collected by the telescope on a photo detector. The electrical signal from photo detector is used for measuring the distance to the target and its movement. For distance measurement the time of flight method is employed. For targets movement the optical heterodyne method is employed. The received CW laser radiation is mixed on a photo detector with the frequency-shifted laser radiation that is taken from CW laser and passed through an acousto-optic cell. The electrical signal from a photo detector on the difference frequency and phase has information about movement of the scattered targets. 3D-MVR may be used for the real time picturing of vibration of the extensive targets like bridges or aircrafts.

  7. The Preparation of an Ultrastable Mesoporous Cr(III)-MOF via Reductive

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

    Labilization | Center for Gas SeparationsRelevant to Clean Energy Technologies | Blandine Jerome The Preparation of an Ultrastable Mesoporous Cr(III)-MOF via Reductive Labilization Previous Next List Lian, Xizhen; Feng, Dawei; Chen, Ying-Pin; Liu, Tian-Fu; Wang, Xuan; and Zhou, Hong-Cai. The Preparation of an Ultrastable Mesoporous Cr(III)-MOF via Reductive Labilization. Chem. Sci., 6, 7044-7048 (2015). DOI: 10.1039/c5sc02587g preparation.ultrastable Abstract: Kinetic labilization of the

  8. Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect SciTech Connect Search Results Journal Article: Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system Citation Details In-Document Search Title: Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system Authors: Dhar, S. K. [1] ; Provino, A. [2] ; Manfrinetti, P. [2] ; Kulkarni, R. [1] ; Goyal, Neeraj [1] ; Paudyal, D. [3] + Show Author Affiliations Department of Condensed Matter Physics & Materials Science, T.I.F.R., Homi Bhabha Road, Colaba,

  9. AB INITIO PHASE STABILITY AT HIGH TEMPERATURES AND PRESSURES IN THE V-Cr

    Office of Scientific and Technical Information (OSTI)

    SYSTEM (Journal Article) | SciTech Connect AB INITIO PHASE STABILITY AT HIGH TEMPERATURES AND PRESSURES IN THE V-Cr SYSTEM Citation Details In-Document Search Title: AB INITIO PHASE STABILITY AT HIGH TEMPERATURES AND PRESSURES IN THE V-Cr SYSTEM Authors: Landa, A ; Soderlind, P ; Yang, L H Publication Date: 2013-10-29 OSTI Identifier: 1116979 Report Number(s): LLNL-JRNL-645443 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal Name: Physical Review

  10. Advanced ODS FeCrAl alloys for accident-tolerant fuel cladding

    SciTech Connect (OSTI)

    Dryepondt, Sebastien N; Unocic, Kinga A; Hoelzer, David T; Pint, Bruce A

    2014-09-01

    ODS FeCrAl alloys are being developed with optimum composition and properties for accident tolerant fuel cladding. Two oxide dispersion strengthened (ODS) Fe-15Cr-5Al+Y2O3 alloys were fabricated by ball milling and extrusion of gas atomized metallic powder mixed with Y2O3 powder. To assess the impact of Mo on the alloy mechanical properties, one alloy contained 1%Mo. The hardness and tensile properties of the two alloys were close and higher than the values reported for fine grain PM2000 alloy. This is likely due to the combination of a very fine grain structure and the presence of nano oxide precipitates. The nano oxide dispersion was however not sufficient to prevent grain boundary sliding at 800 C and the creep properties of the alloys were similar or only slightly superior to fine grain PM2000 alloy. Both alloys formed a protective alumina scale at 1200 C in air and steam and the mass gain curves were similar to curves generated with 12Cr-5Al+Y2O3 (+Hf or Zr) ODS alloys fabricated for a different project. To estimate the maximum temperature limit of use for the two alloys in steam, ramp tests at a rate of 5 C/min were carried out in steam. Like other ODS alloys, the two alloys showed a significant increase of the mas gains at T~ 1380 C compared with ~1480 C for wrought alloys of similar composition. The beneficial effect of Yttrium for wrought FeCrAl does not seem effective for most ODS FeCrAl alloys. Characterization of the hardness of annealed specimens revealed that the microstructure of the two alloys was not stable above 1000 C. Concurrent radiation results suggested that Cr levels <15wt% are desirable and the creep and oxidation results from the 12Cr ODS alloys indicate that a lower Cr, high strength ODS alloy with a higher maximum use temperature could be achieved.

  11. Demonstration of a Full-core Reactivity Equivalence for FeCrAl Enhanced

    Office of Scientific and Technical Information (OSTI)

    Accident Tolerant Fuel in BWRs (Conference) | SciTech Connect Demonstration of a Full-core Reactivity Equivalence for FeCrAl Enhanced Accident Tolerant Fuel in BWRs Citation Details In-Document Search Title: Demonstration of a Full-core Reactivity Equivalence for FeCrAl Enhanced Accident Tolerant Fuel in BWRs Authors: George, Nathan M [1] ; Powers, Jeffrey J [1] ; Maldonado, G Ivan [1] ; Worrall, Andrew [1] ; Terrani, Kurt A [1] + Show Author Affiliations ORNL Publication Date: 2015-01-01

  12. Development of a Full-core Reactivity Equivalence for FeCrAl Enhanced

    Office of Scientific and Technical Information (OSTI)

    Accident Tolerant Fuel in BWRs (Conference) | SciTech Connect Development of a Full-core Reactivity Equivalence for FeCrAl Enhanced Accident Tolerant Fuel in BWRs Citation Details In-Document Search Title: Development of a Full-core Reactivity Equivalence for FeCrAl Enhanced Accident Tolerant Fuel in BWRs Authors: George, Nathan M [1] ; Powers, Jeffrey J [1] ; Maldonado, G Ivan [1] ; Worrall, Andrew [1] ; Terrani, Kurt A [1] + Show Author Affiliations ORNL Publication Date: 2015-01-01 OSTI

  13. Elastic Modulus Measurement of ORNL ATF FeCrAl Alloys

    SciTech Connect (OSTI)

    Thompson, Zachary T.; Terrani, Kurt A.; Yamamoto, Yukinori

    2015-10-01

    Elastic modulus and Poissons ratio for a number of wrought FeCrAl alloys, intended for accident tolerant fuel cladding application, are determined via resonant ultrasonic spectroscopy. The results are reported as a function of temperature from room temperature to 850C. The wrought alloys were in the fully annealed and unirradiated state. The elastic modulus for the wrought FeCrAl alloys is at least twice that of Zr-based alloys over the temperature range of this study. The Poissons ratio of the alloys was 0.28 on average and increased very slightly with increasing temperature.

  14. Development and quality assessments of commercial heat production of ATF FeCrAl tubes

    SciTech Connect (OSTI)

    Yamamoto, Yukinori

    2015-09-01

    Development and quality assessment of the 2nd generation ATF FeCrAl tube production with commercial manufacturers were conducted. The manufacturing partners include Sophisticated Alloys, Inc. (SAI), Butler, PA for FeCrAl alloy casting via vacuum induction melting, Oak Ridge National Laboratory (ORNL) for extrusion process to prepare the master bars/tubes to be tube-drawn, and Rhenium Alloys, Inc. (RAI), North Ridgeville, OH, for tube-drawing process. The masters bars have also been provided to Los Alamos National Laboratory (LANL) who works with Century Tubes, Inc., (CTI), San Diego, CA, as parallel tube production effort under the current program.

  15. Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | DOE PAGES Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system Title: Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system Authors: Dhar, S. K. [1] ; Provino, A. [2] ; Manfrinetti, P. [2] ; Kulkarni, R. [1] ; Goyal, Neeraj [1] ; Paudyal, D. [3] + Show Author Affiliations Department of Condensed Matter Physics & Materials Science, T.I.F.R., Homi Bhabha Road, Colaba, Mumbai, 400005, India Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146

  16. Uniform Corrosion of model FeCrAl Alloys in LWR Coolants (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Conference: Uniform Corrosion of model FeCrAl Alloys in LWR Coolants Citation Details In-Document Search Title: Uniform Corrosion of model FeCrAl Alloys in LWR Coolants Authors: Terrani, Kurt A [1] ; Kim, Young-Jin [2] ; Pint, Bruce A [1] + Show Author Affiliations ORNL General Electric (GE) Publication Date: 2015-01-01 OSTI Identifier: 1185956 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Conference Resource Relation: Conference: 2015 American Nuclear Society Annual

  17. EECBG Success Story: Massachusetts Middle School Goes Local for PV Solar Energy System

    Broader source: Energy.gov [DOE]

    When the school buses pull up to Norton Middle School this year, students will see more than just their friends and teachers, they'll get a view of new - 126 solar panels on the school's roof. Learn more.

  18. 2010 DOE National Science Bowl® Photos - Falcon Cove Middle...

    Office of Science (SC) Website

    Text Size: A A A FeedbackShare Page Falcon Cove Middle School students from Weston, FL tour the National Mall in Washington, DC as they participate in the National Science Bowl. ...

  19. Standard's Guide to Learning Middle School Hands-On Science Elective...

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

    Guide to Learning Middle School Hands-On Science Elective Class Student: Grade: Date: Math B Proficiency Levels PP P A Collect, organize, analyze, and graph (e.g., line plots,...

  20. EPR and optical investigations of LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor

    SciTech Connect (OSTI)

    Singh, Vijay; Sivaramaiah, G.; Rao, J.L.; Kim, S.H.

    2014-12-15

    Graphical abstract: The EPR spectrum of as-prepared LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor at 110 K. - Highlights: • Using the combustion synthesis, LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor has been prepared in a few minutes. • Optical investigation indicates that Cr{sup 3+} ions are present in octahedral symmetry. • The EPR signals indicate that exchange coupled Cr{sup 3+}–Cr{sup 3+} ion pairs in weakly distorted sites. - Abstract: The LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor has been prepared by a low-temperature combustion synthesis method. As-prepared combustion synthesized powder was characterized using powder X-ray diffraction (XRD), diffuse reflectance (DRS), electron paramagnetic resonance (EPR) and photoluminescence (PL) studies. The X-ray diffraction pattern reveals crystalline hexagonal phases. The UV–vis diffuse reflectance spectrum exhibits three broad bands characteristic of Cr{sup 3+} ions in octahedral symmetry. The EPR spectrum exhibits several resonance signals. The signals with the effective g values at g = 4.84, 3.64 and 2.26 have been attributed to the isolated Cr{sup 3+} ions. The signal with the effective g value at g = 1.94 has been attributed to exchange coupled Cr{sup 3+}–Cr{sup 3+} ion pairs. The PL studies exhibit several bands characteristic of Cr{sup 3+} ions in octahedral symmetry.

  1. Jefferson Lab Hosts 20 Teams for Middle School Science Bowl on March 1 |

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

    Jefferson Lab Middle School Science Bowl on March 1 NEWPORT NEWS, Va., Feb. 25, 2008 - Tomorrow's scientists, engineers and mathematicians may be found testing their mental skills at the Department of Energy's Virginia Regional Middle School Science Bowl taking place at Jefferson Lab on Saturday, March 1. Twenty teams, representing high schools from across the region are registered for this year's academic competition. The National Science Bowl® tournament - sponsored by the U.S. Department

  2. D.C. Middle and High School Students Get a Chance to Experience the

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

    Regional Science Bowl Competition Setting | Department of Energy D.C. Middle and High School Students Get a Chance to Experience the Regional Science Bowl Competition Setting D.C. Middle and High School Students Get a Chance to Experience the Regional Science Bowl Competition Setting March 26, 2014 - 1:07pm Addthis Annie Whatley Annie Whatley Deputy Director, Office of Minority Education and Community Development Have you ever heard of the Washington, D.C. regional science bowl competition?

  3. Aspen Elementary, Los Alamos Middle School students take top award in 26th

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

    New Mexico Supercomputing Challenge 26th New Mexico Supercomputing Challenge Aspen Elementary, Los Alamos Middle School students take top award in 26th New Mexico Supercomputing Challenge Andy Corliss, Phillip Ionkov and Ming Lo of Aspen Elementary, and Max Corliss of Los Alamos Middle School won first place in the New Mexico Supercomputing Challenge. April 27, 2016 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop

  4. Solar Energy Education. Renewable energy activities for junior high/middle

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

    school science (Technical Report) | SciTech Connect junior high/middle school science Citation Details In-Document Search Title: Solar Energy Education. Renewable energy activities for junior high/middle school science × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy

  5. Delgado-Aparicio urges middle school students to pursue careers in science

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

    and join the quest for fusion energy | Princeton Plasma Physics Lab Delgado-Aparicio urges middle school students to pursue careers in science and join the quest for fusion energy By Jeanne Jackson DeVoe June 16, 2015 Tweet Widget Google Plus One Share on Facebook Physicist Luis Delgado-Aparicio (with a photo of Einstein behind him) speaks to middle school students at the Hispanics Inspiring Students' Performance and Achievement (HISPA) Conference at Princeton University. (Photo by Elle

  6. Calling Science Stars in Middle and High Schools | Department of Energy

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

    Science Stars in Middle and High Schools Calling Science Stars in Middle and High Schools November 10, 2010 - 10:03am Addthis 2010 Science Bowl national champions: North Carolina School of Science and Mathematics from Durham, NC | Department of Energy Photo | Public Domain | 2010 Science Bowl national champions: North Carolina School of Science and Mathematics from Durham, NC | Department of Energy Photo | Public Domain | Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office

  7. Dual and Triple Ion-Beam Irradiations of Fe, Fe(Cr) and Fe(Cr)-ODS Final Report: IAEA SMoRE CRP

    SciTech Connect (OSTI)

    Fluss, M J; Hsiung, L L; Marian, J

    2011-11-20

    Structures of nanoparticles in Fe-16Cr-4.5Al-0.3Ti-2W-0.37Y2O3 (K3) and Fe-20Cr-4.5Al-0.34Ti-0.5Y2O3 (MA956) oxide dispersion strengthened (ODS) ferritic steels produced by mechanical alloying (MA) and followed by hot extrusion have been studied using high-resolution transmission electron microscopy (HRTEM) techniques to gain insight about the formation mechanism of nanoparticles in MA/ODS steels. The observations of Y-Al-O complex-oxide nanoparticles in both ODS steels imply that decomposition of Y2O3 in association with internal oxidation of Al occurred during mechanical alloying. While the majority of oxide nanoparticles formed in both steels is Y4Al2O9, a few oxide particles of YAlO3 are also occasionally observed. These results reveal that Ti (0.3 wt %) plays an insignificant role in forming oxide nanoparticles in the presence of Al (4.5 wt %). HRTEM observations of crystalline nanoparticles larger than {approx}2 nm and amorphous or disordered cluster domains smaller than {approx}2 nm provide an insight into the formation mechanism of oxide nanoparticle in MA/ODS steels, which we believe from our observations involves a solid-state amorphous precursor followed by recrystallization. Dual ion-beam irradiations using He{sup +} + Fe{sup +8} ions were employed to gain more detailed insight about the role of nanoparticles in suppressing radiation-induced swelling. This is elaborated through TEM examinations of cavity distributions in ion-irradiated Fe-14Cr and K3-ODS ferritic steels. HRTEM observations of helium-filled cavities (helium bubbles) preferably trapped at nanoscale oxide particles and clusters in ion-irradiated K3-ODS are presented. Finally, we describe the results from triple ion-beam irradiations using H{sup +} + He{sup +} + Fe{sup +8} ions to emulate fusion first wall radiation effects. Preliminary work is reported that confirms the existence of significant hydrogen synergistic effects described earlier by Tanaka et al., for Fe(Cr) and by Wakai et al., for F82H reduced activation ferritic martensitic (RAF/M) steel. These previous results combined with our data suggest a complex new 'catalytic' mechanism whereby H interacts with the steady state population of defects and the embryonic cavities so as to accelerated cavity (void) growth in both Fe(Cr) and under special conditions in ODS steels.

  8. Ab initio study of structural stability and electronic properties of Ti{sub 1-x}Mg{sub x}Cr{sub 2} and TiMg{sub x}Cr{sub 2-x} laves phase

    SciTech Connect (OSTI)

    Sari, A. Merad, G.

    2015-03-30

    The structural stability and electronic properties of TiMgCr{sub 2} laves phase have been calculated and compared. It is found that Mg prefer to substitutes titanium than chromium. The values of entalpies of formation show that Ti{sub 1-x}Mg{sub x}Cr{sub 2} may exist for only one concentration x=0.125 and the more favorable alloy is Ti{sub 0.875}Mg{sub 0.125}Cr{sub 2}. For TiCr{sub 2}, the optimized structural parameters were in good agreement with experimental values, while for TiMgCr{sub 2}, there is not experimental data. The electronic densities of states (DOS) are given and the nature of bonds are also discussed.

  9. Understanding the solidification and microstructure evolution during CSC-MIG welding of FeCrB-based alloy

    SciTech Connect (OSTI)

    Sorour, A.A. Chromik, R.R. Gauvin, R. Jung, I.-H. Brochu, M.

    2013-12-15

    The present is a study of the solidification and microstructure of Fe28.2%Cr3.8%B1.5%Si1.5%Mn (wt.%) alloy deposited onto a 1020 plain carbon steel substrate using the controlled short-circuit metal inert gas welding process. The as-solidified alloy was a metal matrix composite with a hypereutectic microstructure. Thermodynamic calculation based on the ScheilGulliver model showed that a primary (Cr,Fe){sub 2}B phase formed first during solidification, followed by an eutectic formation of the (Cr,Fe){sub 2}B phase and a body-centered cubic Fe-based solid solution matrix, which contained Cr, Mn and Si. Microstructure analysis confirmed the formation of these phases and showed that the shape of the (Cr,Fe){sub 2}B phase was irregular plate. As the welding heat input increased, the weld dilution increased and thus the volume fraction of the (Cr,Fe){sub 2}B plates decreased while other microstructural characteristics were similar. - Highlights: We deposit FeCrB-based alloy onto plain carbon steel using the CSC-MIG process. We model the solidification behavior using thermodynamic calculation. As deposited alloy consists of (Cr,Fe){sub 2}B plates embedded in Fe-based matrix. We study the effect of the welding heat input on the microstructure.

  10. Changes induced in a ZnS:Cr-based electroluminescent waveguide structure by intrinsic near-infrared laser radiation

    SciTech Connect (OSTI)

    Vlasenko, N. A. Oleksenko, P. F.; Mukhlyo, M. A.; Veligura, L. I.

    2013-08-15

    The causes of changes that occur in a thin-film electroluminescent metal-insulator-semiconductor-insulator-metal waveguide structure based on ZnS:Cr (Cr concentration of {approx}4 Multiplication-Sign 10{sup 20} cm{sup -3}) upon lasing ({lambda} Almost-Equal-To 2.6 {mu}m) and that induce lasing cessation are studied. It is established that lasing ceases because of light-scattering inhomogeneities formed in the structure and, hence, optical losses enhance. The origin of the inhomogeneities and the causes of their formation are clarified by studying the surface topology and the crystal structure of constituent layers of the samples before and after lasing. The studies are performed by means of atomic force microscopy and X-ray radiography. It is shown that a substantial increase in the sizes of grains on the surface of the structure is the manifestation of changes induced in the ZnS:Cr film by recrystallization. Recrystallization is initiated by local heating by absorbed laser radiation in existing Cr clusters and quickened by a strong electric field (>1 MV cm{sup -1}). The changes observed in the ZnS:Cr film are as follows: the textured growth of ZnS crystallites, an increase in the content of Cr clusters, and the appearance of some CrS and a rather high ZnO content. Some ways for improving the stability of lasing in the ZnS:Cr-based waveguide structures are proposed.

  11. Ion irradiation testing and characterization of FeCrAl candidate alloys

    SciTech Connect (OSTI)

    Anderoglu, Osman; Aydogan, Eda; Maloy, Stuart Andrew; Wang, Yongqiang

    2014-10-29

    The Fuel Cycle Research and Development program’s Advanced Fuels Campaign has initiated a multifold effort aimed at facilitating development of accident tolerant fuels. This effort involves development of fuel cladding materials that will be resistant to oxidizing environments for extended period of time such as loss of coolant accident. Ferritic FeCrAl alloys are among the promising candidates due to formation of a stable Al₂O₃ oxide scale. In addition to being oxidation resistant, these promising alloys need to be radiation tolerant under LWR conditions (maximum dose of 10-15 dpa at 250 – 350°C). Thus, in addition to a number of commercially available alloys, nuclear grade FeCrAl alloys developed at ORNL were tested using high energy proton irradiations and subsequent characterization of irradiation hardening and damage microstructure. This report summarizes ion irradiation testing and characterization of three nuclear grade FeCrAl cladding materials developed at ORNL and four commercially available Kanthal series FeCrAl alloys in FY14 toward satisfying FCRD campaign goals.

  12. Cr-doped TiSe2 - A layered dichalcogenide spin glass

    SciTech Connect (OSTI)

    Luo, Huixia; Tao, Jing; Krizan, Jason W.; Seibel, Elizabeth M.; Xie, Weiwei; Sahasrabudhe, Girija S.; Bergman, Susanna L.; Phelan, Brendan F.; Wang, Zhen; Zhang, Jiandi; Cava, R. J.

    2015-09-17

    We report the magnetic characterization of the Cr-doped layered dichalcogenide TiSe2. The temperature dependent magnetic susceptibilities are typical of those seen in geometrically frustrated insulating antiferromagnets. The Cr moment is close to the spin-only value, and the Curie–Weiss temperatures (θcw) are between –90 and –230 K. Freezing of the spin system, which is glassy, characterized by peaks in the ac and dc susceptibility and specific heat, does not occur until below T/θcw = 0.05. The CDW transition seen in the resistivity for pure TiSe2 is still present for 3% Cr substitution but is absent by 10% substitution, above which the materials are metallic and p-type. Structural refinements, magnetic characterization, and chemical considerations indicate that the materials are of the type Ti1–xCrxSe2-x/2 for 0 ≤ x ≤ 0.6.

  13. Oxidation resistance of 9-12% Cr steels: effect of rare earth surface treatment

    SciTech Connect (OSTI)

    Dogan, Omer N.; Alman, David A.; Jablonski, Paul D.

    2005-02-01

    Medium Cr steels have been used in fossil fired power plants for many years because of their excellent high temperature stability and mechanical properties. The environment in a fossil fired power plant is extremely aggressive in terms of corrosion, especially oxidation. This is only accelerated as the operating temperature increases to 650C and beyond. For any new steel to be qualified for power plant use, in addition to adequate strength at the operating temperature, material wastage from all corrosion processes must be kept to a minimum acceptable level. The use of medium Cr steels provides a means to improve overall corrosion resistance. Three medium Cr are under development for use as high temperature power plant steels: 0.08C-(9-12)Cr-1.2Ni-0.7Mo-3.0Cu-3.0Co-0.5Ti. Oxidation tests were performed on the steels for times greater than 1000 hours in order to determine the oxidation kinetics and extent of material wastage. Also, rare earth oxides were incorporated into the outer surface layers of the steels to see if the oxidation resistance could be improved. These results will be compared to current power plant steels.

  14. Zinc protects human peripheral blood lymphocytes from Cr(III)(phenanthroline){sub 3}-induced apoptosis

    SciTech Connect (OSTI)

    Sankaramanivel, Sundararaj; Rajaram, Anantanarayanan; Rajaram, Rama

    2010-03-15

    We have studied the effect of Cr(III)(phen){sub 3} [(tris(1,10-phenanthroline) chromium(III) chloride)] on lymphocytes in order to find out if metallothioneins (MTs) are produced in the process. We also investigated whether zinc pretreatment is able to protect cells from apoptosis reported to occur for this compound. Our results indicate that MT synthesis is induced by Cr(III)(phen){sub 3}, and it has been identified as the MT-3 isoform through RT-PCR which has not been reported earlier. By zinc pretreatment, this apoptosis is reversed as inferred from cytotoxicity studies, Annexin-V/PI staining, ethidium bromide/acridine orange staining and DNA fragmentation pattern and ultrastructural investigations using TEM and SEM. The zinc pretreatment reduces the amount of ROS produced by Cr(III)(phen){sub 3} . The MT-1a and 1b synthesized by zinc (also evidenced through RT-PCR experiments) is possibly able to scavenge ROS which is one of the early signaling molecules that lead to apoptosis. Zinc pretreatment also reverses the changes in downstream signaling events such as mitochondrial membrane potential, ATP levels and the activation of caspase-3. This is the first report on the induction of MT-3 in lymphocytes due to a metal stress or any other stimuli. Even though MT-3 is synthesized here, apoptosis still occurs due to ROS production on Cr(III)(phen){sub 3} exposure when the cells have not been primed with zinc.

  15. Investigation on growth and laser properties of GGG:(Nd,Cr) single crystals

    SciTech Connect (OSTI)

    Zhang; Lin; Liu; Liu; Zhu

    1986-04-04

    Investigation on the growth and laser properties of gadolinium gallium garnet crystal doped with neodymium and chromium is reported. As the segregation coefficient of Nd in GGG is less than 1 and that of Cr is greater than 1, a modified Czochralski method for growth is adopted in order to keep the dopants being uniform in the grown crystal.

  16. Computational discovery of ferromagnetic semiconducting single-layer CrSnTe3

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

    Zhuang, Houlong L.; Xie, Yu; Kent, P. R. C.; Ganesh, P.

    2015-07-06

    Despite many single-layer materials being reported in the past decade, few of them exhibit magnetism. Here we perform first-principles calculations using accurate hybrid density functional methods (HSE06) to predict that single-layer CrSnTe3 (CST) is a ferromagnetic semiconductor, with band gaps of 0.9 and 1.2 eV for the majority and minority spin channels, respectively. We determine the Curie temperature as 170 K, significantly higher than that of single-layer CrSiTe3 (90K) and CrGeTe3 (130 K). This is due to the enhanced ionicity of the Sn-Te bond, which in turn increases the superexchange coupling between the magnetic Cr atoms. We further explore themore » mechanical and dynamical stability and strain response of this single-layer material for possible epitaxial growth. Lastly, our study provides an intuitive approach to understand and design novel single-layer magnetic semiconductors for a wide range of spintronics and energy applications.« less

  17. Microstructures and Mechanical Properties of Compositionally Complex Co-free FeNiMnCr18 FCC Solid Solution Alloy

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

    Wu, Zhenggang; Bei, Hongbin

    2015-01-01

    Recently,a structurally-simplebutcompositionally-complex FeNiCoMnCr highentropyalloywasfoundto haveexcellentmechanicalproperties(e.g.,highstrengthandductility).Tounderstandthepotentialof using highentropyalloysasstructuralmaterialsforadvancednuclearreactorandpowerplants,itis necessary tohaveathoroughunderstandingoftheirstructuralstabilityandmechanicalpropertiesde- gradation underneutronirradiation.ThisrequiresustodevelopasimilarmodelalloywithoutCobe- cause materialwithCowillmakepost-neutron-irradiationtestingdifficult duetotheproductionofthe 60Co radioisotope.Toachievethisgoal,aFCC-structuredsingle-phasealloywithacompositionof FeNiMnCr18 wassuccessfullydeveloped.Thisnear-equiatomicFeNiMnCr18 alloy hasgoodmalleability and itsmicrostructurecanbecontrolledbythermomechanicalprocessing.Byrollingandannealing,the as-cast elongated-grained-microstructureisreplacedbyhomogeneousequiaxedgrains.Themechanical properties (e.g.,strengthandductility)oftheFeNiMnCr18 alloy arecomparabletothoseoftheequiatomic FeNiCoMnCr highentropyalloy.Bothstrengthandductilityincreasewithdecreasingdeformation temperature,withthelargestdifferenceoccurringbetween293and77K.Extensivetwin-bandswhich are bundlesofnumerousindividualtwinsareobservedwhenitistensile-fracturedat77K.Notwin bands aredetectedbyEBSDformaterialsdeformedat293Kandhigher.Theunusualtemperature-de- pendencies ofUTSanduniformelongationcouldbecausedbythedevelopmentofthedensetwin substructure, twin-dislocationinteractionsandtheinteractionsbetweenprimaryandsecondarytwin- ning systemswhichresultinamicrostructurerefinement andhencecauseenhancedstrainhardening and postponednecking.

  18. Analysis of the FeCrAl Accident Tolerant Fuel Concept Benefits during BWR Station Blackout Accidents

    SciTech Connect (OSTI)

    Robb, Kevin R

    2015-01-01

    Iron-chromium-aluminum (FeCrAl) alloys are being considered for fuel concepts with enhanced accident tolerance. FeCrAl alloys have very slow oxidation kinetics and good strength at high temperatures. FeCrAl could be used for fuel cladding in light water reactors and/or as channel box material in boiling water reactors (BWRs). To estimate the potential safety gains afforded by the FeCrAl concept, the MELCOR code was used to analyze a range of postulated station blackout severe accident scenarios in a BWR/4 reactor employing FeCrAl. The simulations utilize the most recently known thermophysical properties and oxidation kinetics for FeCrAl. Overall, when compared to the traditional Zircaloy-based cladding and channel box, the FeCrAl concept provides a few extra hours of time for operators to take mitigating actions and/or for evacuations to take place. A coolable core geometry is retained longer, enhancing the ability to stabilize an accident. Finally, due to the slower oxidation kinetics, substantially less hydrogen is generated, and the generation is delayed in time. This decreases the amount of non-condensable gases in containment and the potential for deflagrations to inhibit the accident response.

  19. Solute redistribution and phase stability at FeCr/TiO2–x interfaces under ion irradiation

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

    Xu, Y.; Aguiar, J. A.; Yadav, S. K.; Anderoglu, O.; Baldwin, J. K.; Wang, Y. Q.; Valdez, James A.; Misra, A.; Luo, H. M.; Uberuaga, B. P.; et al

    2015-02-26

    Cr diffusion in trilayer thin films of 100 nm Fe–18Cr/125 nm TiO2–x/100 nm Fe–18Cr deposited on MgO substrates at 500 °C was studied by either annealing at 500 °C or Ni3+ ion irradiation at 500 °C. Microchemistry and microstructure evolution at the metal/oxide interfaces were investigated using (high-resolution) transmission electron microscopy, energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy. Diffusion of Cr into the O-deficient TiO2 layer, with negligible segregation to the FeCr/TiO2–x interface itself, was observed under both annealing and irradiation. Cr diffusion into TiO2–x was enhanced in ion-irradiated samples as compared to annealed. Irradiation-induced voids and amorphization ofmore » TiO2–x was also observed. The experimental results are rationalized using first-principles calculations that suggest an energetic preference for substituting Ti with Cr in sub-stoichiometric TiO2. Furthermore, the implications of these results on the irradiation stability of oxide-dispersed ferritic alloys are discussed.« less

  20. Ferromagnetic superexchange in insulating Cr2MoO6 by controlling orbital hybridization

    SciTech Connect (OSTI)

    Zhu, M.; Do, D.; Dela Cruz, Clarina R.; Dun, Zhiling; Cheng, J. -G.; Goto, H.; Uwatoko, Yoshiya; Zou, T.; Zhou, Haidon D.; Mahanti, Subhendra D.; Ke, Xianglin

    2015-09-11

    We report the magnetic and electronic structures of the newly synthesized inverse-trirutile compound Cr2MoO6. Despite the same crystal symmetry and similar bond-lengths and bond-angles to Cr2TeO6, Cr2MoO6 possesses a magnetic structure of the Cr2MoO6 type, different from that seen in Cr2TeO6. Ab-initio electronic structure calculations show that the sign and strength of the Cr-O-Cr exchange coupling is strongly influenced by the hybridization between Mo 4d and O 2p orbitals. This result further substantiates our recently proposed mechanism for tuning the exchange interaction between two magnetic atoms by modifying the electronic states of the non-magnetic atoms in the exchange path through orbital hybridization. This approach is fundamentally different from the conventional methods of controlling the exchange interaction by either carrier injection or through structural distortions.

  1. Anisotropic magnetic properties of Dy{sub 6}Cr{sub 4}Al{sub 43} single

    Office of Scientific and Technical Information (OSTI)

    crystal (Journal Article) | SciTech Connect Anisotropic magnetic properties of Dy{sub 6}Cr{sub 4}Al{sub 43} single crystal Citation Details In-Document Search Title: Anisotropic magnetic properties of Dy{sub 6}Cr{sub 4}Al{sub 43} single crystal We have studied the anisotropic magnetic behavior of the rare earth intermetallic compound Dy{sub 6}Cr{sub 4}Al{sub 43}. This compound crystallizes in the hexagonal symmetry and orders ferromagnetically at 8.3 K as confirmed by the magnetic

  2. Record 18 teams prepare for Virginia Regional Middle School Science Bowl on

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

    March 10 at Jefferson Lab | Jefferson Lab Newport News, Va. -- The Department of Energy's Jefferson Lab, in Newport News, Va., hosts the Virginia Regional Middle School Science Bowl on Saturday, March 10, with a record 18 teams competing. This is the largest turnout we've had for the Middle School Science Bowl in the four years we have hosted it at Jefferson Lab, according to Jan Tyler, JLab's Science Education program manager and Science Bowl coordinator. "The Science Bowl is an

  3. Secretary Chu Announces Middle and High School Finalists Set to Compete in

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

    the 2012 National Science Bowl in Washington, D.C. | Department of Energy Middle and High School Finalists Set to Compete in the 2012 National Science Bowl in Washington, D.C. Secretary Chu Announces Middle and High School Finalists Set to Compete in the 2012 National Science Bowl in Washington, D.C. April 12, 2012 - 2:12pm Addthis Washington D.C. - Demonstrating the Obama Administration's commitment to improving the participation and performance of America's students in science, technology,

  4. Néel temperature of Cr{sub 2}O{sub 3} in Cr{sub 2}O{sub 3}/Co exchange-coupled system: Effect of buffer layer

    SciTech Connect (OSTI)

    Pati, Satya Prakash E-mail: phy-satya@yahoo.co.in; Shimomura, Naoki; Nozaki, Tomohiro; Sahashi, Masashi; Shibata, Tatsuo

    2015-05-07

    The lattice parameter dependence of the Néel temperature T{sub N} of thin Cr{sub 2}O{sub 3} in a Cr{sub 2}O{sub 3}/Co exchange-coupled system is investigated. Lattice-mismatch-induced strain is generated in Cr{sub 2}O{sub 3} by using different buffer layers. The lattice parameters are determined from out-of-plane and in-plane X-ray diffraction measurements. The Néel temperature is detected by direct temperature-dependent magnetization measurement as well as the temperature-dependent interface exchange coupling energy. It is observed that in-plane lattice contraction can enhance T{sub N} in Cr{sub 2}O{sub 3}, which is consistent with theoretical calculations.

  5. The MSFR as a flexible CR reactor: the viewpoint of safety

    SciTech Connect (OSTI)

    Fiorina, C.; Cammi, A.; Franceschini, F.; Krepel, J.

    2013-07-01

    In this paper, the possibility has first been discussed of using the liquid-fuelled Molten Salt Fast Reactor (MSFR) as a flexible conversion ratio (CR) reactor without design modification. By tuning the reprocessing rate it is possible to determine the content of fission products in the core, which in turn can significantly affect the neutron economy without incurring in solubility problems. The MSFR can thus be operated as U-233 breeder (CR>1), iso-breeder (CR=1) and burner reactor (CR<1). In particular a 40 year doubling time can be achieved, as well as a considerable Transuranics and MA (minor actinide) burning rate equal to about 150 kg{sub HN}/GWE-yr. The safety parameters of the MSFR have then been evaluated for different fuel cycle strategies. Th use and a softer spectrum combine to give a strong Doppler coefficient, one order of magnitude higher compared to traditional fast reactors (FRs). The fuel expansion coefficient is comparable to the Doppler coefficient and is only mildly affected by core compositions, thus assisting the fuel cycle flexibility of the MSFR. ?eff and generation time are comparable to the case of traditional FRs, if a static fuel is assumed. A notable reduction of ?eff is caused by salt circulation, but a low value of this parameter is a limited concern in the MSFR thanks to the lack of a burnup reactivity swing and of positive feedbacks. A simple approach has also been developed to evaluate the MSFR capabilities to withstand all typical double-fault accidents, for different fuel cycle options.

  6. Scaling Effects of Cr(VI) Reduction Kinetics. The Role of Geochemical Heterogeneity

    SciTech Connect (OSTI)

    Wang, Li; Li, Li

    2015-10-22

    The natural subsurface is highly heterogeneous with minerals distributed in different spatial patterns. Fundamental understanding of how mineral spatial distribution patterns regulate sorption process is important for predicting the transport and fate of chemicals. Existing studies about the sorption was carried out in well-mixed batch reactors or uniformly packed columns, with few data available on the effects of spatial heterogeneities. As a result, there is a lack of data and understanding on how spatial heterogeneities control sorption processes. In this project, we aim to understand and develop modeling capabilities to predict the sorption of Cr(VI), an omnipresent contaminant in natural systems due to its natural occurrence and industrial utilization. We systematically examine the role of spatial patterns of illite, a common clay, in determining the extent of transport limitation and scaling effects associated with Cr(VI) sorption capacity and kinetics using column experiments and reactive transport modeling. Our results showed that the sorbed mass and rates can differ by an order of magnitude due to of the illite spatial heterogeneities and transport limitation. With constraints from data, we also developed the capabilities of modeling Cr(VI) in heterogeneous media. The developed model is then utilized to understand the general principles that govern the relationship between sorption and connectivity, a key measure of the spatial pattern characteristics. This correlation can be used to estimate Cr(VI) sorption characteristics in heterogeneous porous media. Insights gained here bridge gaps between laboratory and field application in hydrogeology and geochemical field, and advance predictive understanding of reactive transport processes in the natural heterogeneous subsurface. We believe that these findings will be of interest to a large number of environmental geochemists and engineers, hydrogeologists, and those interested in contaminant fate and transport, water quality and water composition, and natural attenuation processes in natural systems.

  7. Audit Report: CR-B-97-04 | Department of Energy

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

    5, 1997 Audit OF Controls Over The ADP Support Services Contract The Federal Acquisition Regulation requires the Department of Energy (Department) to ensure that efficient methods and effective cost controls are used over its cost-reimbursement contracts. Our objective was to determine whether the program offices at the Department's Headquarters were managing their Automated Data Processing (ADP) support services contract costs. PDF icon Audit Report: CR-B-97-04 More Documents & Publications

  8. Audit Report: CR-B-98-02 | Department of Energy

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

    2 Audit Report: CR-B-98-02 November 14, 1997 Audit of Management of the Laboratory Directed Research and Development Program at the Lawrence Livermore National Laboratory The Department's national laboratories, since their establishment, have been permitted to conduct a limited amount of discretionary research activities. The Department's Defense Program laboratories, such as the Lawrence Livermore National Laboratory, generate funding for Laboratory Directed Research and Development (LDRD)

  9. Audit Report: CR-B-99-01 | Department of Energy

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

    1 Audit Report: CR-B-99-01 October 1, 1998 Department's Working Capital Fund The Department established the Working Capital Fund (Fund) in January 1996 as a financial management tool for charging the costs of common services provided at Headquarters to Departmental program offices. The objectives in establishing the Fund were to increase efficiency of the Department's operations, improve management of administrative services through the use of flexible and business-like finance methods, and

  10. Audit Report: CR-FS-99-01 | Department of Energy

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

    9-01 Audit Report: CR-FS-99-01 June 15, 1999 Management Report Audit of the Department of Energy's Consolidated Financial Statements for Fiscal Year 1998 As required by the Government Management Reform Act of 1994, we audited the U.S. Department of Energy's (Department) consolidated financial statements as of and for the years ended September 30, 1998 and 1997 to determine whether they presented fairly, in all material respects, the Department's financial position, net cost, changes in net

  11. Audit Report: CR-L-01-06 | Department of Energy

    Energy Savers [EERE]

    L-01-06 Audit Report: CR-L-01-06 February 8, 2001 Federal Managers' Financial Integrity Act Audit Report We reviewed the Department of Energy's (Department) progress in implementing the Federal Managers' Financial Integrity Act (FMFIA) of 1982. The review was made to assist you in determining whether the evaluations of the systems of management, accounting, and administrative controls were carried out in a reasonable and prudent manner by the Department for Fiscal Year 2000. PDF icon Audit

  12. First-principles study of the structural and elastic properties of Cr{sub 2}AlX (X=N, C) compounds

    SciTech Connect (OSTI)

    Cui Shouxin; Wei Dongqing; Hu Haiquan; Feng Wenxia; Gong Zizheng

    2012-07-15

    The structural, electronic and elastic properties of Cr{sub 2}AlX, with X=N, C, have been investigated at the density functional theory level by applying a plane-wave pseudopotential approach. The band structure and density of states reveal the metallic features of Cr{sub 2}AlX. The total and projected density of states indicate that the bonding is achieved through a hybridization of Cr 3d states with Al and X-atom p states. The Cr 3d-X2p bonds are lower in energy and are stiffer than Cr 3d-Al 3p bonds. The charge density distributions indicate that there exist soft Cr-Al and relatively strong Cr-X covalent bonds, which might be responsible for their hardness. The elastic constants were obtained in the pressure range 0-100 GPa, and satisfy the stability conditions for hexagonal crystal, which indicates that these two compounds are stable in the pressure regime studied. By analyzing bulk modulus to shear modulus ratio and Cauchy pressure, Cr{sub 2}AlC is predicted to be brittleness and Cr{sub 2}AlN is ductile. The Debye temperature was obtained from the average sound velocity. - Graphical abstract: The heterogeneity of chemical bonds in Cr{sub 2}AlX (X=N, C) is observed: soft Cr-Al and relatively strong Cr-X covalent bonds might be contributed to their hardness. Highlights: Black-Right-Pointing-Pointer Cr 3d-X2p (X=N, C) bonds are lower in energy and stiffer than Cr 3d-Al 3p bonds for Cr{sub 2}AlX. Black-Right-Pointing-Pointer The hardness of Cr{sub 2}AlX might be ascribed to soft Cr-Al and relatively strong Cr-X covalent bonds. Black-Right-Pointing-Pointer The predicted brittleness of Cr{sub 2}AlC and ductility of Cr{sub 2}AlN originated from their novel structure.

  13. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed into the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.

  14. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

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

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; et al

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20more » mA cm–2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.« less

  15. Rapid preparation and magnetodielectric properties of trirutile Cr{sub 2}WO{sub 6}

    SciTech Connect (OSTI)

    Gaultois, Michael W.; Kemei, Moureen C.; Harada, Jaye K.; Seshadri, Ram

    2015-01-07

    Dense pellets of > 99% purity trirutile Cr{sub 2}WO{sub 6} were prepared in one step from starting oxides using spark plasma sintering, leading to simultaneous reaction and consolidation in 3 min at 1473 K. The reducing environment during processing may be partly responsible for the rapid reaction time in these oxides, with partial reduction of Cr{sup 3+} and the associated oxygen vacancies allowing rapid diffusion of cations. The low-temperature physical properties of Cr{sub 2}WO{sub 6} were examined, and a new transition at T = 5.9 K was observed as an anomaly in the temperature-dependent dielectric permittivity and a corresponding anomaly in the specific heat. A strong enhancement of the magnetocapacitance is observed below this transition temperature at T = 5.9 K and may be associated with a change from collinear spin order to more complex spin order.

  16. Redox Dynamics of Mixed Metal (Mn, Cr, and Fe) Ultrafine Particles

    SciTech Connect (OSTI)

    Nico, Peter S.; Kumfer, Benjamin M.; Kennedy, Ian M.; Anastasio, Cort

    2008-08-01

    The impact of particle composition on metal oxidation state, and on changes in oxidation state with simulated atmospheric aging, are investigated experimentally in flame-generated nanoparticles containing Mn, Cr, and Fe. The results demonstrate that the initial fraction of Cr(VI) within the particles decreases with increasing total metal concentration in the flame. In contrast, the initial Mn oxidation state was only partly controlled by metal loading, suggesting the importance of other factors. Two reaction pathways, one reductive and one oxidative, were found to be operating simultaneously during simulated atmospheric aging. The oxidative pathway depended upon the presence of simulated sunlight and O{sub 3}, whereas the reductive pathway occurred in the presence of simulated sunlight alone. The reductive pathway appears to be rapid but transient, allowing the oxidative pathway to dominate with longer aging times, i.e. greater than {approx}8 hours. The presence of Mn within the particles enhanced the importance of the oxidative pathway, leading to more net Cr oxidation during aging implying that Mn can mediate oxidation by removal of electrons from other particulate metals.

  17. Stability of precipitate phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T

    2015-01-01

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the and phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. Two key findings resulted from this work. One is that the phase is stable at high temperature and transformed into the phase at lowmoretemperature. The other is that both the and phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.less

  18. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed intomore » the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  19. Ferromagnetic ordering of Cr and Fe doped p-type diamond: An ab initio study

    SciTech Connect (OSTI)

    Benecha, E. M.; Lombardi, E. B.

    2014-02-21

    Ferromagnetic ordering of transition metal dopants in semiconductors holds the prospect of combining the capabilities of semiconductors and magnetic systems in single hybrid devices for spintronic applications. Various semiconductors have so far been considered for spintronic applications, but low Curie temperatures have hindered room temperature applications. We report ab initio DFT calculations on the stability and magnetic properties of Fe and Cr impurities in diamond, and show that their ground state magnetic ordering and stabilization energies depend strongly on the charge state and type of co-doping. We predict that divacancy Cr{sup +2} and substitutional Fe{sup +1} order ferromagnetically in p-type diamond, with magnetic stabilization energies (and magnetic moment per impurity ion) of 16.9 meV (2.5 μ{sub B}) and 33.3 meV (1.0 μ{sub B}), respectively. These magnetic stabilization energies are much larger than what has been achieved in other semiconductors at comparable impurity concentrations, including the archetypal dilute magnetic semiconductor GaAs:Mn. In addition, substitutional Fe{sup +1} exhibits a strong half-metallic character, with the Fermi level crossing bands in only the spin down channel. These results, combined with diamond’s extreme properties, demonstrate that Cr or Fe dopedp-type diamond may successfully be considered in the search for room temperature spintronic materials.

  20. Cr-doped TiSe2 - A layered dichalcogenide spin glass

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

    Luo, Huixia; Tao, Jing; Krizan, Jason W.; Seibel, Elizabeth M.; Xie, Weiwei; Sahasrabudhe, Girija S.; Bergman, Susanna L.; Phelan, Brendan F.; Wang, Zhen; Zhang, Jiandi; et al

    2015-09-17

    We report the magnetic characterization of the Cr-doped layered dichalcogenide TiSe2. The temperature dependent magnetic susceptibilities are typical of those seen in geometrically frustrated insulating antiferromagnets. The Cr moment is close to the spin-only value, and the Curie–Weiss temperatures (θcw) are between –90 and –230 K. Freezing of the spin system, which is glassy, characterized by peaks in the ac and dc susceptibility and specific heat, does not occur until below T/θcw = 0.05. The CDW transition seen in the resistivity for pure TiSe2 is still present for 3% Cr substitution but is absent by 10% substitution, above which themore » materials are metallic and p-type. Structural refinements, magnetic characterization, and chemical considerations indicate that the materials are of the type Ti1–xCrxSe2-x/2 for 0 ≤ x ≤ 0.6.« less

  1. Sintered Cr/Pt and Ni/Au ohmic contacts to B12P2

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

    Frye, Clint D.; Kucheyev, Sergei O.; Edgar, James H.; Voss, Lars F.; Conway, Adam M.; Shao, Qinghui; Nikolic, Rebecca J.

    2015-04-09

    With this study, icosahedral boron phosphide (B12P2) is a wide-bandgap semiconductor possessing interesting properties such as high hardness, chemical inertness, and the reported ability to self-heal from irradiation by high energy electrons. Here, the authors developed Cr/Pt and Ni/Au ohmic contacts to epitaxially grown B12P2 for materials characterization and electronic device development. Cr/Pt contacts became ohmic after annealing at 700 °C for 30 s with a specific contact resistance of 2×10–4 Ω cm2, as measured by the linear transfer length method. Ni/Au contacts were ohmic prior to any annealing, and their minimum specific contact resistance was ~l–4 × 10–4 Ωmore » cm2 after annealing over the temperature range of 500–800 °C. Rutherford backscattering spectrometry revealed a strong reaction and intermixing between Cr/Pt and B12P2 at 700 °C and a reaction layer between Ni and B12P2 thinner than ~25 nm at 500 °C.« less

  2. Effect of lattice deformation on exchange coupling constants in Cr{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Kota, Yohei; Imamura, Hiroshi; Sasaki, Munetaka

    2014-05-07

    We studied lattice deformation effect on exchange interaction in the corundum-type Cr{sub 2}O{sub 3} theoretically. First-principles electronic structure calculations were performed to evaluate the total energy and exchange coupling constants of Cr{sub 2}O{sub 3} under lattice deformation. We found that a few percent elastic deformation is expected via misfit strain and that the first- and second-nearest neighbor exchange coupling constants of Cr{sub 2}O{sub 3} strongly depend on the lattice deformation. These results imply a possibility for improving the thermal stability of Cr{sub 2}O{sub 3} based magnetoelectric devices by lattice deformation.

  3. LaCrO{sub 3} heteroepitaxy on SrTiO{sub 3}(001) by molecular beam epitaxy

    SciTech Connect (OSTI)

    Qiao, L.; Droubay, T. C.; Bowden, M. E.; Shutthanandan, V.; Kaspar, T. C.; Chambers, S. A.

    2011-08-08

    Stoichiometric, epitaxial LaCrO{sub 3} films have been grown on SrTiO{sub 3}(001) by molecular beam epitaxy using O{sub 2} as the oxidant. Films grew in a layer-by-layer fashion, giving rise to coherently strained, structurally excellent films and surfaces which preserve the step-terrace structure of the substrate. The critical thickness is in excess of 500 A. Cr(III) near the surface is easily oxidized to Cr(V) upon exposure to atomic oxygen and reduction back to Cr(III) is readily achieved by vacuum annealing, resulting in tunability of the charge state at the B-site cation.

  4. LaCrO3 heteroepitaxy on SrTiO3(001) by molecular beam epitaxy

    SciTech Connect (OSTI)

    Qiao, Liang; Droubay, Timothy C.; Bowden, Mark E.; Shutthanandan, V.; Kaspar, Tiffany C.; Chambers, Scott A.

    2011-08-09

    Stoichiometric, epitaxial LaCrO3 films have been grown on TiO2-terminated SrTiO3(001) substrates by molecular beam epitaxy using O2 as the oxidant. Film growth occurred in a layer-by-layer fashion, giving rise to structurally excellent films and surfaces which preserve the step-terrace structure of the substrate. The critical thickness is in excess of 500 . Near-surface Cr(III) is highly susceptible to further oxidation to Cr(V), leading to the formation of a disordered phase upon exposure to atomic oxygen. Recovery of the original epitaxial LaCrO3 phase is readily achieved by vacuum annealing.

  5. Cr-W-V bainitic/ferritic steel with improved strength and toughness and method of making

    DOE Patents [OSTI]

    Klueh, Ronald L.; Maziasz, Philip J.

    1994-01-01

    A high strength, high toughness Cr-W-V ferritic steel composition suitable for fast induced-radioactivity (FIRD) decay after irradiation in a fusion reactor comprises 2.5-3.5 wt % Cr, 2. This invention was made with Government support under contract DE-AC05-840R21400 awarded by the U.S. Department of Energy to Martin Marietta Energy Systems, Inc. and the Government has certain rights in this invention.

  6. Strain induced ferromagnetism in epitaxial Cr{sub 2}O{sub 3} thin films integrated on Si(001)

    SciTech Connect (OSTI)

    Punugupati, Sandhyarani Narayan, Jagdish; Hunte, Frank

    2014-09-29

    We report on the epitaxial growth and magnetic properties of antiferromagnetic and magnetoelectric (ME) Cr{sub 2}O{sub 3} thin films deposited on cubic yttria stabilized zirconia (c-YSZ)/Si(001) using pulsed laser deposition. The X-ray diffraction (2ϴ and Φ) and TEM characterizations confirm that the films were grown epitaxially. The Cr{sub 2}O{sub 3}(0001) growth on YSZ(001) occurs with twin domains. There are four domains of Cr{sub 2}O{sub 3} with in-plane rotation of 30° or 150° from each other about the [0001] growth direction. The epitaxial relation between the layers is given as [001]Si ‖ [001]YSZ ‖ [0001]Cr{sub 2}O{sub 3} and [100]Si ǁ [100]YSZ ǁ [101{sup ¯}0] Cr{sub 2}O{sub 3} or [112{sup ¯}0] Cr{sub 2}O{sub 3}. Though the bulk Cr{sub 2}O{sub 3} is an antiferromagnetic with T{sub N} = 307 K, we found that the films exhibit ferromagnetic like hysteresis loops with high saturation and finite coercive field up to 400 K. The thickness dependent magnetizations together with oxygen annealing results suggest that the ferromagnetism (FM) is due to oxygen related defects whose concentration is controlled by strain present in the films. This FM, in addition to the intrinsic magneto-electric properties of Cr{sub 2}O{sub 3}, opens the door to relevant spintronics applications.

  7. CR108, a novel vitamin K3 derivative induces apoptosis and breast tumor inhibition by reactive oxygen species and mitochondrial dysfunction

    SciTech Connect (OSTI)

    Yang, Chun-Ru; Liao, Wei-Siang; Wu, Ya-Hui; Murugan, Kaliyappan; Chen, Chinpiao; Chao, Jui-I

    2013-12-15

    Vitamin K3 derivatives have been shown to exert anticancer activities. Here we show a novel vitamin K3 derivative (S)-2-(2-hydroxy-3-methylbutylthio)naphthalene-1,4-dione, which is named as CR108 that induces apoptosis and tumor inhibition through reactive oxygen species (ROS) and mitochondrial dysfunction in human breast cancer. CR108 is more effective on the breast cancer cell death than other vitamin K3 derivatives. Moreover, CR108 induced apoptosis in both the non-HER-2-overexpressed MCF-7 and HER-2-overexpressed BT-474 breast cancer cells. CR108 caused the loss of mitochondrial membrane potential, cytochrome c released from mitochondria to cytosol, and cleaved PARP proteins for apoptosis induction. CR108 markedly increased ROS levels in breast cancer cells. N-acetylcysteine (NAC), a general ROS scavenger, completely blocked the CR108-induced ROS levels, mitochondrial dysfunction and apoptosis. Interestingly, CR108 increased the phosphorylation of p38 MAP kinase but conversely inhibited the survivin protein expression. NAC treatment prevented the activation of p38 MAP kinase and rescued the survivin protein levels. SB202190, a specific p38 MAP kinase inhibitor, recovered the survivin protein levels and attenuated the cytotoxicity of CR108-treated cells. Furthermore, CR108 inhibited the xenografted human breast tumor growth in nude mice. Together, we demonstrate that CR108 is a novel vitamin K3 derivative that induces apoptosis and tumor inhibition by ROS production and mitochondrial dysfunction and associates with the phosphorylation of p38 MAP kinase and the inhibition of survivin in the human breast cancer. - Highlights: CR108 is more effective on the cell death than other vitamin K3 derivatives. CR108 induces apoptosis and tumor inhibition by ROS and mitochondrial dysfunction. CR108 induces apoptosis by p38 kinase activation and survivin inhibition. CR108 is a potent vitamin K3 analog that can develop for breast cancer therapy.

  8. Ultrathin nanosheets of CrSiTe3. A semiconducting two-dimensional ferromagnetic material

    SciTech Connect (OSTI)

    Lin, Ming -Wei; Zhung, Houlong L.; Yan, Jiaqiang; Ward, Thomas Zac; Puretzky, Alexander A.; Rouleau, Christopher M.; Gai, Zheng; Liang, Liangbo; Meunier, Vincent; Ganesh, Panchapakesan; Kent, Paul R. C.; Sumpter, Bobby G.; Mandrus, David G.; Geohegan, David B.; Xiao, Kai

    2015-11-27

    Finite range ferromagnetism and antiferromagnetism in two-dimensional (2D) systems within an isotropic Heisenberg model at non-zero temperature were originally proposed to be impossible. However, recent theoretical studies using an Ising model have recently shown that 2D magnetic crystals can exhibit magnetism. Experimental verification of existing 2D magnetic crystals in this system has remained elusive. In this work we for the first time exfoliate the CrSiTe3, a bulk ferromagnetic semiconductor, to mono- and few-layer 2D crystals onto a Si/SiO2 substrate. The Raman spectra show the good stability and high quality of the exfoliated flakes, consistent with the computed phonon spectra of 2D CrSiTe3, giving a strong evidence for the existence of 2D CrSiTe3 crystals. When the thickness of the CrSiTe3 crystals is reduced to few-layers, we observed a clear change in resistivity at 80~120 K, consistent with the theoretical calculations on the Curie temperature (Tc) of ~80 K for the magnetic ordering of 2D CrSiTe3 crystals. As a result, the ferromagnetic mono- and few-layer 2D CrSiTe3 indicated here should enable numerous applications in nano-spintronics.

  9. Hole-induced insulator-to-metal transition in La1-xSrxCrO3 epitaxial films

    SciTech Connect (OSTI)

    Zhang, Hongliang; Du, Yingge; Sushko, Petr; Bowden, Mark E.; Shutthanandan, V.; Sallis, Shawn; Piper, Louis F. J.; Chambers, Scott A.

    2015-04-01

    We have investigated the evolution of the structural and electronic properties of La1-xSrxCrO3 (0 ? x ? 1) epitaxial films deposited by molecular beam epitaxy (MBE) using x-ray diffraction, x-ray photoemission spectroscopy, x-ray absorption spectroscopy, electrical transport, and ab initio modeling. LaCrO3 is an antiferromagnetic Mott insulator whereas stoichiometric SrCrO3 is a metal. Substituting Sr2+ for La3+ in LaCrO3 effectively dopes holes into the top of valence band, leading to Cr4+ (3d2) local electron configurations. Core-level and valence-band features monotonically shift to lower binding energy with increasing x, indicating downward movement of the Fermi level toward the valence band maximum. An insulator-to-metal like transition is observed at x ? 0. 65 even as the material becomes a p-type semiconductor at lower doping level and eventually becomes degenerately doped. Valence band x-ray photoemission spectroscopy reveals diminution of electronic state density at the top of the valence band while O K-edge x-ray absorption spectroscopy shows the development of a new unoccupied state above the Fermi level as holes are doped into LaCrO3. These results indicate a pronounced redistribution of electronic state density of states upon hole doping, a result that is also obtained by density functional theory with a Hubbard U correction.

  10. Synthesis and characterization of Cr-doped ZnO nanorod-array photocatalysts with improved activity

    SciTech Connect (OSTI)

    Chang, Chi-Jung Yang, Tsung-Lin; Weng, Yu-Ching

    2014-06-01

    Immobilized photocatalysts with high catalytic activity under UV light were prepared by growing Cr-doped ZnO nanorods on glass substrates by a hydrothermal method. The effects of Cr dopant on the surface texture, crystallinity, surface chemistry, and photoinduced charge separation and their relation with the photocatalytic degradation of Cr-doped ZnO were investigated by scanning electron microscopy, diffuse reflectance spectra, photoelectrochemical scanning electrochemical microscopy, and X-ray photoemission spectroscopy. Adding the appropriate amount of Cr dopant is a powerful way to enhance the separation of charge carriers in ZnO photocatalyst. The photocatalytic activity was improved due to the increase in surface oxygen vacancies, the separation of charge carriers, modification of the band gap, and the large surface area of the doped ZnO nanorod photocatalyst. - Graphical abstract: Photoinduced charge separation and its relation with the photocatalytic degradation activity of Cr-doped ZnO were investigated by photoelectrochemical scanning electrochemical microscopy. - Highlights: Cr dopant enhances separation of charge carries in ZnO nanorod photocatalyst. Photoinduced charge carries separation monitored by PEC-SECM. The higher the photocurrent is, the higher the photocatalytic activity is. Degradation of DB86 dye solutions under visible light finished within 50 min. Higher activity due to more oxygen vacancy, tuned band gap and more surface area.

  11. Characterization of Cr poisoning in a solid oxide fuel cell cathode using a high-energy x-ray microbeam.

    SciTech Connect (OSTI)

    Liu, D. J.; Almer, J.; Cruse, T.

    2010-01-01

    A key feature of planar solid oxide fuel cells (SOFCs) is the feasibility of using metallic interconnects made of high temperature ferritic stainless steels, which reduce system cost while providing excellent electric conductivity. Such interconnects, however, contain high levels of chromium, which has been found to be associated with SOFC cathode performance degradation at SOFC operating temperatures; a phenomenon known as Cr poisoning. Here, we demonstrate an accurate measurement of the phase and concentration distributions of Cr species in a degraded SOFC, as well as related properties including deviatoric strain, integrated porosity, and lattice parameter variation, using high energy microbeam X-ray diffraction and radiography. We unambiguously identify (MnCr){sub 3}O{sub 4} and Cr{sub 2}O{sub 3} as the two main contaminant phases and find that their concentrations correlate strongly with the cathode layer composition. Cr{sub 2}O{sub 3} deposition within the active cathode region reduces porosity and produces compressive residual strains, which hinders the reactant gas percolation and can cause structural breakdown of the SOFC cathode. The information obtained through this study can be used to better understand the Cr-poisoning mechanism and improve SOFC design.

  12. Calloway Middle School Honored at DOE National Science Bowl, Lone Oak Competes Among High Schools

    Broader source: Energy.gov [DOE]

    PADUCAH, KY – Calloway County Middle School won the Civility Award and was named one of the top six battery-powered model car design teams at the Department of Energy’s National Science Bowl in Washington, D.C.

  13. Middle School Academic Competition - Round Robin | U.S. DOE Office...

    Office of Science (SC) Website

    ... Team 1 2 3 4 5 6 7 Total Points 1. Mahtomedi Middle School 2 0 2 0 0 0 4 2. Edward Hurley Elementary School 0 0 2 0 0 0 2 3. Treasure Valley Math & Science Center 2 2 2 2 2 2 12 4. ...

  14. Gas projects surge in the Middle East as governments seek new revenue sources

    SciTech Connect (OSTI)

    Williams, M.D.

    1997-02-24

    The rapid development of natural gas and condensate reserves in the Middle East results from a simple motivation: the desire of governments to earn revenues. For the past decade, Middle East governments have run budget deficits, which they funded by drawing down foreign assets and issuing debt. Now in the process of structural economic reform, they have begun to use an under-utilized resource--natural gas, of which Middle East governments own about one third of the world`s reserves. Governments receive revenues from several sources in natural gas developments, which makes the projects very attractive. Revenue comes from the sale of the natural gas in the domestic market and, if exported, the international market; the sale of associated condensates; the additional exports of crude oil or refined products if natural gas is substituted for refined products in domestic markets; the increased sale of crude oil if natural gas is injected into reservoirs to maintain pressure; and the sale of petrochemicals where natural gas is used as feedstock. Large projects under way in the Middle East highlight the consequences of multiple revenue sources and interlinked costs of natural gas and condensate development. Other countries in the region are undertaking similar projects, so examples cited represent only a portion of what is occurring. The paper describes Abu Dhabi, Qatar, Saudi Arabia, and Iran.

  15. Correlation between morphology, chemical environment, and ferromagnetism in the intrinsic-vacancy dilute magnetic semiconductor Cr-doped Ga2Se3/Si(001)

    SciTech Connect (OSTI)

    Yitamben, E.N.; Arena, D.; Lovejoy, T.C.; Pakhomov, A.B.; Heald, S.M.; Negusse, E.; Ohuchi, F.S.; Olmstead, M.A.

    2011-01-28

    Chromium-doped gallium sesquiselenide, Cr:Ga{sub 2}Se{sub 3}, is a member of a new class of dilute magnetic semiconductors exploiting intrinsic vacancies in the host material. The correlation among room-temperature ferromagnetism, surface morphology, electronic structure, chromium concentration, and local chemical and structural environments in Cr:Ga{sub 2}Se{sub 3} films grown epitaxially on silicon is investigated with magnetometry, scanning tunneling microscopy, photoemission spectroscopy, and x-ray absorption spectroscopy. Inclusion of a few percent chromium in Ga{sub 2}Se{sub 3} results in laminar, semiconducting films that are ferromagnetic at room temperature with a magnetic moment 4{micro}{sub B}/Cr. The intrinsic-vacancy structure of defected-zinc-blende {beta}-Ga{sub 2}Se{sub 3} enables Cr incorporation in a locally octahedral site without disrupting long-range order, determined by x-ray absorption spectroscopy, as well as strong overlap between Cr 3d states and the Se 4p states lining the intrinsic-vacancy rows, observed with photoemission. The highest magnetic moment per Cr is observed near the solubility limit of roughly one Cr per three vacancies. At higher Cr concentrations, islanded, metallic films result, with a magnetic moment that depends strongly on surface morphology. The effective valence is Cr{sup 3+} in laminar films, with introduction of Cr{sup 0} upon islanding. A mechanism is proposed for laminar films whereby ordered intrinsic vacancies mediate ferromagnetism.

  16. Effect of annealing treatment on the electrical characteristics of Pt/Cr-embedded ZnO/Pt resistance random access memory devices

    SciTech Connect (OSTI)

    Chang, Li-Chun; Kao, Hsuan-Ling; Liu, Keng-Hao

    2014-03-15

    ZnO/Cr/ZnO trilayer films sandwiched with Pt electrodes were prepared for nonvolatile resistive memory applications. The threshold voltage of a ZnO device embedded with a 3-nm Cr interlayer was approximately 50% lower than that of a ZnO monolayer device. This study investigated threshold voltage as a function of Cr thickness. Both the ZnO monolayer device and the Cr-embedded ZnO device structures exhibited resistance switching under electrical bias both before and after rapid thermal annealing (RTA) treatment, but resistive switching effects in the two cases exhibited distinct characteristics. Compared with the as-fabricated device, the memory cell after RTA demonstrated remarkable device parameter improvements, including a lower threshold voltage, a lower write current, and a higher R{sub off}/R{sub on} ratio. Both transmission electron microscope observations and Auger electron spectroscopy revealed that the Cr charge trapping layer in Cr-embedded ZnO dispersed uniformly into the storage medium after RTA, and x-ray diffraction and x-ray photoelectron spectroscopy analyses demonstrated that the Cr atoms lost electrons to become Cr{sup 3+} ions after dispersion. These results indicated that the altered status of Cr in ZnO/Cr/ZnO trilayer films during RTA treatment was responsible for the switching mechanism transition.

  17. Thermal aging modeling and validation on the Mo containing Fe-Cr-Ni alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-04-01

    Thermodynamics of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys is critical knowledge to understand thermal aging effect on the phase stability of Mo-containing austenitic steels, which subsequently facilitates alloy design/improvement and degradation mitigation of these materials for reactor applications. Among the intermetallic phases, Chi (χ), Laves, and Sigma (σ) are often of concern because of their tendency to cause embrittlement of the materials. The focus of this study is thermal stability of the Chi and Laves phases as they were less studied compared to the Sigma phase. Coupled with thermodynamic modeling, thermal stability of intermetallic phases in Mo containing Fe-Cr-Ni alloys was investigated at 1000, 850 and 700 C for different annealing times. The morphologies, compositions and crystal structures of the precipitates of the intermetallic phases were carefully examined by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and transmission electron microscopy. Three key findings resulted from this study. First, the Chi phase is stable at high temperature, and with decreasing temperature it transforms into the Laves phase that is stable at low temperature. Secondly, Cr, Mo, Ni are soluble in both the Chi and Laves phases, with the solubility of Mo playing a major role in the relative stability of the intermetallic phases. Thirdly, in situ transformation from Chi phase to Laves phase was directly observed, which increased the local strain field, generated dislocations in the intermetallic phases, and altered the precipitate phase orientation relationship with the austenitic matrix. The thermodynamic models that were developed and validated were then applied to evaluating the effect of Mo on the thermal stability of intermetallic phases in type 316 and NF709 stainless steels.

  18. Effects of Partial Phase Transformation on Characteristics of 9Cr Nanostructured Ferritic Alloy

    SciTech Connect (OSTI)

    Ji Hyun, Yoon; Byun, Thak Sang; Hoelzer, David T

    2014-01-01

    The core structures of future nuclear systems require tolerance to extreme irradiation, and some critical components, for example, the fuel cladding in Sodium-cooled Fast Reactors (SFRs), have to maintain mechanical integrity to very high doses of 200 -400 dpa at high temperatures up to 700 degrees C. The high Cr nanostructured ferritic alloys (NFAs) are under intense research worldwide as a candidate core material. Although the NFAs have some admirable characteristics for high-temperature applications, their crack sensitivity is very high at high temperatures. The fracture toughness of high strength NFAs is unacceptably low above 300 degrees C. The objective of this study is to develop processes and microstructures with improved high temperature fracture toughness and ductility. To optimize the afterextrusion heat treatment condition, both the computational simulation technique on phase equilibrium and the basic microstructural and mechanical characterization have been carried out. 9 Cr-NFA was produced by the mechanical alloying of pre-alloyed Fe-9Cr base metallic powder and yttria particles, and subsequent extrusion. The post-extrusion heat-treatments of various conditions were applied to the asextruded NFA. The tensile and fracture toughness tests were conducted for as-extruded and heat-treated samples at up to 700 degrees C. Fracture toughness of the NFA has increased by more than 40% at every testing temperature after heat-treatment in the inter-critical temperature range. The increment of fracture toughness of the NFA after post-extrusion heat-treatment is attributed to the increased strength at below 500 degrees C, and an increased ductility at 700 degrees C.

  19. Alloy Design and Development of Cast Cr-W-V Ferritic Steels for Improved High-Temperature Strength for Power Generation Applications

    SciTech Connect (OSTI)

    Klueh, R.L.; Maziasz, P.J.; Vitek, J.M.; Evans, N.D.; Hashimoto, N.

    2006-09-23

    Economic and environmental concerns demand that the power-generation industry seek increased efficiency for gas turbines. Higher efficiency requires higher operating temperatures, with the objective temperature for the hottest sections of new systems {approx} 593 C, and increasing to {approx} 650 C. Because of their good thermal properties, Cr-Mo-V cast ferritic steels are currently used for components such as rotors, casings, pipes, etc., but new steels are required for the new operating conditions. The Oak Ridge National Laboratory (ORNL) has developed new wrought Cr-W-V steels with 3-9% Cr, 2-3% W, 0.25% V (compositions are in wt.%), and minor amounts of additional elements. These steels have the strength and toughness required for turbine applications. Since cast alloys are expected to behave differently from wrought material, work was pursued to develop new cast steels based on the ORNL wrought compositions. Nine casting test blocks with 3, 9, and 11% Cr were obtained. Eight were Cr-W-V-Ta-type steels based on the ORNL wrought steels; the ninth was COST CB2, a 9Cr-Mo-Co-V-Nb cast steel, which was the most promising cast steel developed in a European alloy-development program. The COST CB2 was used as a control to which the new compositions were compared, and this also provided a comparison between Cr-W-V-Ta and Cr-Mo-V-Nb compositions. Heat treatment studies were carried out on the nine castings to determine normalizing-and-tempering treatments. Microstructures were characterized by both optical and transmission electron microscopy (TEM). Tensile, impact, and creep tests were conducted. Test results on the first nine cast steel compositions indicated that properties of the 9Cr-Mo-Co-V-Nb composition of COST CB2 were better than those of the 3Cr-, 9Cr-, and 11Cr-W-V-Ta steels. Analysis of the results of this first iteration using computational thermodynamics raised the question of the effectiveness in cast steels of the Cr-W-V-Ta combination versus the Cr-Mo-V-Nb combination in COST CB2. To explore this question, nine more casting test blocks, four 3Cr steels and five 11Cr steels were purchased, and microstructure and mechanical properties studies similar to those described above for the first iteration of test blocks were conducted. Experimental results from the second iteration indicated that 11 Cr steels with excellent properties are possible. The 11Cr-1.5Mo-V-Nb steels were superior to 11Cr-2W-V-Ta steels, and it appears the former class of steels can be developed to have tensile and creep properties exceeding those of COST CB2. The W-Nb combination in an 11Cr-2W-V-Nb steel had tensile and short-time creep properties at 650 C better than the 11Cr-1.5Mo-V-Nb steels, although long-time low-stress properties may not be as good because of Laves phase formation. Based on the results, the next step in the development of improved casting steels involves acquisition of 11Cr-1.5Mo-V-Nb-N-B-C and 11Cr-2W-V-Nb-N-B-C steels on which long-term creep-rupture tests (>10,000 h) be conducted. For better oxidation and corrosion resistance, development of 11Cr steels, as opposed to a 9Cr steels, such as COST CB2, are important for future turbine designs that envision operating temperatures of 650 C.

  20. Creep and oxidation behavior of modified CF8C-plus with W, Cu, Ni, and Cr

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

    Unocic, Kinga A.; Dryepondt, Sebastien N.; Yamamoto, Yukinori; Maziasz, Philip J.

    2016-02-01

    Here, the microstructures of modified CF8C-Plus (Fe-19Cr-12Ni-0.4W-3.8Mn-0.2Mo-0.6Nb-0.5Si-0.9C) with W and Cu (CF8CPWCu) and CF8CPWCu enhanced with 21Cr + 15Ni or 22Cr + 17.5Ni were characterized in the as-cast condition and after creep testing. When imaged at lower magnifications, the as-cast microstructure was similar among all three alloys as they all contained a Nb-rich interdendritic phase and Mn-based inclusions. Transmission electron microscopy (TEM) analysis showed the presence of nanoscale Cu-rich nanoprecipitates distributed uniformly throughout the matrix of CF8CPWCu, whereas in CF8CPWCu22/17, Cu precipitates were found primarily at the grain boundaries. The presence of these nanoscale Cu-rich particles, in addition to W-richmore » Cr23C6, nanoscale Nb carbides, and Z-phase (Nb2Cr2N2), improved the creep strength of the CF8CPWCu steel. Modification of CF8CPWCu with Cr and Ni contents slightly decreased the creep strength but significantly improved the oxidation behavior at 1073 K (800 °C). In particular, the addition of 22Cr and 17.5Ni strongly enhanced the oxidation resistance of the stainless steel resulting in a 100 degrees or greater temperature improvement, and this composition provided the best balance between improving both mechanical properties and oxidation resistance.« less

  1. Nanostructured Cu-Cr alloy with high strength and electrical conductivity

    SciTech Connect (OSTI)

    Islamgaliev, R. K. Nesterov, K. M.; Bourgon, J.; Champion, Y.; Valiev, R. Z.

    2014-05-21

    The influence of nanostructuring by high pressure torsion (HPT) on strength and electrical conductivity in the Cu-Cr alloy has been investigated. Microstructure of HPT samples was studied by transmission electron microscopy with special attention on precipitation of small chromium particles after various treatments. Effect of dynamic precipitation leading to enhancement of strength and electrical conductivity was observed. It is shown that nanostructuring leads to combination of high ultimate tensile strength of 790–840 MPa, enhanced electrical conductivity of 81%–85% IACS and thermal stability up to 500 °C. The contributions of grain refinement and precipitation to enhanced properties of nanostructured alloy are discussed.

  2. Corrosion and degradation of a polyurethane/Co-Ni-Cr-Mo pacemaker lead

    SciTech Connect (OSTI)

    Sung, P.; Fraker, A.C.

    1987-12-01

    An investigation to study changes in the metal surfaces and the polyurethane insulation of heart pacemaker leads under controlled in vitro conditions was conducted. A polyurethane (Pellethane 2363-80A)/Co-Ni-Cr-Mo (MP35N) wire lead was exposed in Hanks' physiological saline solution for 14 months and then analyzed using scanning electron microscopy, x-ray energy dispersive analysis, and small angle x-ray scattering. Results showed that some leakage of solution into the lead had occurred and changes were present on both the metal and the polyurethane surfaces.

  3. GLADY CASSIT Y VANDALIA MURPHY CR EEK BU CKHN-CENT URY CLAY

    U.S. Energy Information Administration (EIA) Indexed Site

    GLADY CASSIT Y VANDALIA MURPHY CR EEK BU CKHN-CENT URY CLAY GLENVILLE N MINNORA JARVISVILLE FAR MINGTON PH ILIPPI BELIN GT ON WAYN ESBUR G PR UNT Y GLENVILLE S CAVE RUN TAYLOR DRAIN ROSEDALE ST MPT-N RMNT-SHK WESTON-JAN E LEW SWN DL-WID EN VADIS STANL EY DEKALB UNION TALLM AN SVILL E ASPINALL-FIN ST ER ZOLLARSVILLE WILBU R RAMSEY HEATER S BR IDGEPORT-PRUNT YTOWN ALEXAND ER LILLY FORK SH ERMAN HIRAM ST FK-BLST N CK BU RNS CH APEL S BR WN -LUM BER PORT CON INGS PR ATT BOSWELL REVEL ELK C REEK

  4. Audit Report: CR-B-02-01 | Department of Energy

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

    1 Audit Report: CR-B-02-01 October 15, 2001 Fixed-Price Contracting for Department of Energy Cleanup Activities As part of its Contract Reform effort, the Department of Energy (Department) acted to increase its use of fixed-price contracts. This shift was designed to increase the cost-effectiveness of operations. Since October 1994, the Office of Environmental Management (EM) has awarded a number of fixed-price contracts for environmental cleanup activities. In so doing, EM expected significant

  5. Audit Report: CR-B-98-01 | Department of Energy

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

    1 Audit Report: CR-B-98-01 October 8, 1997 Audit of the Internal Control Structure of the Department of Energy's Working Capital Fund The Subcommittee on Energy and Water Development of the Committee on Appropriations, in its report dated July 16, 1996, approved the implementation of a Working Capital Fund (Fund) at the U.S. Department of Energy. The Subcommittee also directed the Office of Inspector General to conduct periodic audits of the Fund. This audit was conducted to determine if the

  6. Audit Report: CR-B-99-02 | Department of Energy

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

    2 Audit Report: CR-B-99-02 September 30, 1999 Management of Unneeded Materials and Chemicals For more than 50 years, the U.S. Department of Energy (Department) and its contractors operated large production facilities and laboratories that acquired and produced directly or as by-products enormous amounts of non-nuclear materials such as sodium, lead, chemicals, and scrap metal. However, a mission change resulting from the end of the Cold War called into question the need for continued stockpiling

  7. Testing Novel CR-39 Detector Deployment System For Identification of Subsurface Fractures, Soda Springs, ID

    SciTech Connect (OSTI)

    McLing, Travis; Carpenter, Michael; Brandon, William; Zavala, Bernie

    2015-06-01

    The Environmental Protection Agency (EPA) has teamed with Battelle Energy Alliance, LLC (BEA) at Idaho National Laboratory (INL) to facilitate further testing of geologic-fracture-identification methodology at a field site near the Monsanto Superfund Site located in Soda Springs, Idaho. INL has the necessary testing and technological expertise to perform this work. Battelle Memorial Institute (BMI) has engaged INL to perform this work through a Work for Others (WFO) Agreement. This study continues a multi-year collaborative effort between INL and EPA to test the efficacy of using field deployed Cr-39 radon in soil portals. This research enables identification of active fractures capable of transporting contaminants at sites where fractures are suspected pathways into the subsurface. Current state of the art methods for mapping fracture networks are exceedingly expensive and notoriously inaccurate. The proposed WFO will evaluate the applicability of using cheap, readily available, passive radon detectors to identify conductive geologic structures (i.e. fractures, and fracture networks) in the subsurface that control the transport of contaminants at fracture-dominated sites. The proposed WFO utilizes proven off-the-shelf technology in the form of CR-39 radon detectors, which have been widely deployed to detect radon levels in homes and businesses. In an existing collaborative EPA/INL study outside of this workscope,. CR-39 detectors are being utilized to determine the location of active transport fractures in a fractured granitic upland adjacent to a landfill site at the Fort Devens, MA that EPA-designated as National Priorities List (NPL) site. The innovative concept of using an easily deployed port that allows the CR-39 to measure the Rn-222 in the soil or alluvium above the fractured rock, while restricting atmospheric Rn-222 and soil sourced Ra from contaminating the detector is unique to INL and EPA approach previously developed. By deploying a series of these inexpensive detector-casing combinations statistical samples of the Rn-222 flux can be measured, elucidating the most communicative fractures (i.e. fractures that are actively transporting water and gasses). The Rn-222 measurements can then be used as an input to create a more accurate conceptual model to be used for transport modeling and related cleanup activities. If the team’s approach is demonstrated to be applicable to a wide variety of rock types and soil conditions it might potentially offer significant cost saving without a reduction in data quality at Monsanto Superfund and other sites underlain by fracture-dominated bedrock.

  8. Model independent interpretation of recent CR lepton data after AMS-02

    SciTech Connect (OSTI)

    Gaggero, Daniele; Maccione, Luca E-mail: luca.maccione@lmu.de

    2013-12-01

    We model the CR leptonic fluxes above 20 GeV in terms of a superposition of a standard and a charge symmetric extra component, which we generically describe as power-laws in momentum. We investigate under these hypotheses the compatibility between AMS-02, Fermi-LAT and PAMELA datasets on positron fraction, electron+positron spectrum and electron spectrum respectively. We find that it is possible to reconcile AMS and Fermi-LAT data within uncertainties, if energy-dependent effects are present in Fermi-LAT systematics. We also study possible deviations from charge symmetry in the extra component and find no compelling evidence for them.

  9. Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3β/β-catenin signaling

    SciTech Connect (OSTI)

    Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo; Lee, Jeong-Chae; Shi, Xianglin

    2013-09-01

    Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3β/β-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active β-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3β, β-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3β/β-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3β/β-catenin signaling involved in Cr(VI) carcinogenesis. • The inhibition of apoptosis and autophagy contributes to Cr(VI) carcinogenesis.

  10. Highly tunable magnetism in silicene doped with Cr and Fe atoms under isotropic and uniaxial tensile strain

    SciTech Connect (OSTI)

    Zheng, Rui; Ni, Jun; Chen, Ying

    2015-12-28

    We have investigated the magnetic properties of silicene doped with Cr and Fe atoms under isotropic and uniaxial tensile strain by the first-principles calculations. We find that Cr and Fe doped silicenes show strain-tunable magnetism. (1) The magnetism of Cr and Fe doped silicenes exhibits sharp transitions from low spin states to high spin states by a small isotropic tensile strain. Specially for Fe doped silicene, a nearly nonmagnetic state changes to a high magnetic state by a small isotropic tensile strain. (2) The magnetic moments of Fe doped silicene also show a sharp jump to ∼2 μ{sub B} at a small threshold of the uniaxial strain, and the magnetic moments of Cr doped silicene increase gradually to ∼4 μ{sub B} with the increase of uniaxial strain. (3) The electronic and magnetic properties of Cr and Fe doped silicenes are sensitive to the magnitude and direction of the external strain. The highly tunable magnetism may be applied in the spintronic devices.

  11. Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

    SciTech Connect (OSTI)

    Rinderknecht, H. G. Rojas-Herrera, J.; Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; Sio, H.; Sinenian, N.; Rosenberg, M. J.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Filkins, T.; Steidle, Jessica A.; Traynor, N.; Freeman, C.; Steidle, Jeffrey A.

    2015-12-15

    The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protons with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.

  12. Room temperature ferromagnetism in epitaxial Cr{sub 2}O{sub 3} thin films grown on r-sapphire

    SciTech Connect (OSTI)

    Punugupati, Sandhyarani Narayan, Jagdish; Hunte, Frank

    2015-05-21

    We report on the epitaxial growth and magnetic properties of Cr{sub 2}O{sub 3} thin films grown on r-sapphire substrate using pulsed laser deposition. The X-ray diffraction (XRD) (2θ and Φ) and TEM characterization confirm that the films are grown epitaxially. The r-plane (011{sup ¯}2) of Cr{sub 2}O{sub 3} grows on r-plane of sapphire. The epitaxial relations can be written as [011{sup ¯}2] Cr{sub 2}O{sub 3} ‖ [011{sup ¯}2] Al{sub 2}O{sub 3} (out-of-plane) and [1{sup ¯}1{sup ¯}20] Cr{sub 2}O{sub 3} ‖ [1{sup ¯}1{sup ¯}20] Al{sub 2}O{sub 3} (in-plane). The as-deposited films showed ferromagnetic behavior up to 400 K but ferromagnetism almost vanishes with oxygen annealing. The Raman spectroscopy data together with strain measurements using high resolution XRD indicate that ferromagnetism in r-Cr{sub 2}O{sub 3} thin films is due to the strain caused by defects, such as oxygen vacancies.

  13. On the peculiar properties of triangular-chain EuCr{sub 3}(BO{sub 3}){sub 4} antiferromagnet

    SciTech Connect (OSTI)

    Gondek, ?.; Szytu?a, A.; Przewo?nik, J.; ?ukrowski, J.; Prokhorov, A.; Chernush, L.; Zubov, E.; Dyakonov, V.; Tyvanchuk, Yu.

    2014-02-15

    In this paper we report studies on EuCr{sub 3}(BO{sub 3}){sub 4} compound, that is a member of newly discovered family of huntite-related specimens for non-linear optics. For the first time, the uncommon temperature dependence of the EuCr{sub 3}(BO{sub 3}){sub 4} lattice parameters is reported. Additionally, the magnetism of this compound is extremely interesting. Namely, a possible interplay in between potentially magnetic rare-earth ions and 3d metal stacked within quasi-1D chain that can lead to a great variety of magnetic behaviour. Indeed, in our studies we have found 3D-long range ordering with metamagnetic behaviour, while at higher temperature the magnetic chains become uncoupled. - Graphical abstract: Torsion-like vibrations are the key to understand negative thermal expansion along the a-axis. Display Omitted - Highlights: EuCr{sub 3}(BO{sub 3}){sub 4} is a peculiar triangular-chain antiferromagnet. Rare earth sublattice is non-magnetic with Eu{sup 3+} configuration. Cr{sup 3+} magnetic moments show 1-D behaviour along with spin fluctuations. Torsion vibrations of Cr triangular tubes lead to anomalous expansion of unit cell.

  14. Localized Corrosion of a Neutron Absorbing Ni-Cr-Mo-Gd Alloy

    SciTech Connect (OSTI)

    R.E. Mizia; T. E. Lister; P. J. Pinhero; T. L. Trowbridge

    2005-04-01

    The National Spent Nuclear Fuel Program, located at the Idaho National Laboratory (INL), has developed a new nickel-chromium-molybdenum-gadolinium structural alloy for storage and long-term disposal of spent nuclear fuel (SNF). The new alloy will be used for SNF storage container inserts for nuclear criticality control. Gadolinium has been chosen as the neutron absorption alloying element due to its high thermal neutron absorption cross section. This alloy must be resistant to localized corrosion when exposed to postulated Yucca Mountain in-package chemistries. The corrosion resistance properties of three experimental heats of this alloy are presented. The alloys performance are be compared to Alloy 22 and borated stainless steel. The results show that initially the new Ni-Cr-Mo-Gd alloy is less resistant to corrosion as compared to another Ni-Cr-Mo-Gd alloy (Alloy 22); but when the secondary phase that contains gadolinium (gadolinide) is dissolved, the alloy surface becomes passive. The focus of this work is to qualify these gadolinium containing materials for ASME code qualification and acceptance in the Yucca Mountain Repository.

  15. Origin of spin gapless semiconductor behavior in CoFeCrGa: Theory and Experiment

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

    Bainsla, Lakhan; Mallick, A. I.; Raja, M. Manivel; Coelho, A. A.; Nigam, A. K.; Johnson, D. D.; Alam, Aftab; Suresh, K. G.

    2015-07-08

    Despite a plethora of materials suggested for spintronic applications, a new class of materials has emerged, namely spin gapless semiconductors (SGS), which offers potentially more advantageous properties than existing ones. These magnetic semiconductors exhibit a finite band gap for one spin channel and a closed gap for the other. Supported by electronic-structure calculations, we report evidence of SGS behavior in equiatomic quaternary CoFeCrGa, having a cubic Heusler (prototype LiMgPdSn) structure but exhibiting chemical disorder (DO3 structure). CoFeCrGa is found to transform from SGS to half-metallic phase under pressure, which is attributed to unique electronic-structure features. The saturation magnetization (MS) wasmore » obtained at 8K agrees with the Slater-Pauling rule and the Curie temperature (TC) is found to exceed 400K. Carrier concentration (up to 250K) and electrical conductivity are observed to be nearly temperature independent, prerequisites for SGS. The anomalous Hall coefficient is estimated to be 185S/cm at 5K. Considering the SGS properties and high TC, this material appears to be promising for spintronic applications.« less

  16. Magnetic Correlations in the Quasi-2D Semiconducting Ferromagnet CrSiTe3

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

    Williams, Travis J.; Aczel, Adam A.; Lumsden, Mark D.; Nagler, Stephen E.; Stone, Matthew B.; Yan, Jiaqiang; Mandrus, D.

    2015-10-02

    Intrinsic, two-dimensional ferromagnetic semiconductors are an important class of materials for overcoming the limitations of dilute magnetic semiconductors for spintronics applications. CrSiTe3 is a particularly interesting member of this class, since it can likely be exfoliated down to single layers, where Tc is predicted to increase dramatically. Establishing the nature of the magnetism in the bulk is a necessary precursor to understanding the magnetic behavior in thin film samples and the possible applications of this material. In this work, we use elastic and inelastic neutron scattering to measure the magnetic properties of single crystalline CrSiTe3. We find that there ismorea very small single ion anisotropy favoring magnetic ordering along the c-axis and that the measured spin waves fit well to a model where the moments are only weakly coupled along that direction. Finally, we find that both static and dynamic correlations persist within the ab-plane up to at least 300 K, strong evidence of this material's two-dimensional characteristics that are relevant for future studies on thin film and monolayer samples.less

  17. Subtask 12B1: Welding development for V-Cr-Ti alloys

    SciTech Connect (OSTI)

    King, J.F.; Goodwin, G.M.; Grossbeck, M.L.; Alexander, D.J.

    1995-03-01

    Development of the metallurgical and technological basis for the welding of thick sections of V-Cr-Ti alloys. The weldability and weldment properties of the V-5Cr-5Ti alloy have been evaluated. Results for the Sigmajig test of the vanadium alloy were similar to the cracking resistance of stainless steels, and indicates hot-cracking is unlikely to be a problem. Subsize Charpy test results for GTA weld metal in the as-welded condition have shown a significant reduction in toughness compared to the base metal. The weld metal toughness properties were restored to approximately that of the base metal after exposure to a PWHT 950{degrees}C. The subsize Charpy toughness results for the EB weld metal from this same heat of vanadium alloy has shown significant improvement in properties compared to the GTA weld metal and the base metal. Further testing and analysis will be conducted to more fully characterize the properties of weld metal for each welding process and develop a basic understanding of the cause of the toughness decrease in the GTA welds. 5 figs., 1 tab.

  18. Influence of fatigue on the nanohardness of NiTiCr-wires

    SciTech Connect (OSTI)

    Frotscher, M.; Young, M. L.; Bei, Hongbin; George, Easo P; Neuking, K.; Eggeler, G.

    2009-01-01

    Testing parameters, such as rotational speed and bending radius, have a strong influence on the fatigue life of pseudoelastic NiTi shape-memory alloys during bending rotation fatigue (BRF) experiments [M. F. X. Wagner, Int. J. Mat. Res. 97 (2006), p. 1687-1696. and M. Frotscher, et al., Thermomechanical processing, microstructure and bending rotation fatigue of ultra-fine grained NiTiCr-wires, Proceedings of the International Conference for Shape Memory and Superelastic Technologies (SMST 2007), Tsukuba, Japan, ASM International, (2008), p. 149-158.]. Previous studies showed a decrease in the fatigue life for smaller bending radius (i.e. higher equivalent strain) and larger rotational speed. This observation is associated with an increase of dislocation density, the stabilization of stressinduced martensite during cycling, and an increase of the plateau stresses due to self-heating. In the present study, we examine the influence of these fatigue parameters on the nanohardness and shape recovery of pseudoelastic NiTiCr shape-memory alloy wires by nanoindentation. We show that nanoindentation is a suitable method for the characterization of fatigue-related microstructural changes, which affect the mechanical properties.

  19. Magnetic Correlations in the Quasi-Two-Dimensional Semiconducting Ferromagnet CrSiTe3

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

    Williams, Travis J.; Aczel, Adam A.; Lumsden, Mark D.; Nagler, Stephen E.; Stone, Matthew B.; Yan, Jiaqiang -Q.; Mandrus, D.

    2015-10-02

    Intrinsic, 2D ferromagnetic semiconductors are an important class of materials for overcoming dilute magnetic semiconductors’ limitations for spintronics. CrSiTe3 is a particularly interesting material of this class, since it can likely be exfoliated to single layers, for which Tc is predicted to increase dramatically. Establishing the nature of the bulk material’s magnetism is necessary for understanding the thin-film magnetic behavior and the material’s possible applications. In this work, we use elastic and inelastic neutron scattering to measure the magnetic properties of single crystalline CrSiTe3. We find a very small single ion anisotropy that favors magnetic ordering along the c-axis andmore » that the measured spin waves fit well to a model in which the moments are only weakly coupled along that direction. Then, we find that both static and dynamic correlations persist within the ab-plane up to at least 300 K, which is strong evidence of the material's 2D characteristics that are relevant for future studies on thin film and monolayer samples.« less

  20. Oxidation Resistant, Cr Retaining, Electrically Conductive Coatings on Metallic Alloys for SOFC Interconnects

    SciTech Connect (OSTI)

    Vladimir Gorokhovsky

    2008-03-31

    This report describes significant results from an on-going, collaborative effort to enable the use of inexpensive metallic alloys as interconnects in planar solid oxide fuel cells (SOFCs) through the use of advanced coating technologies. Arcomac Surface Engineering, LLC, under the leadership of Dr. Vladimir Gorokhovsky, is investigating filtered-arc and filtered-arc plasma-assisted hybrid coating deposition technologies to promote oxidation resistance, eliminate Cr volatility, and stabilize the electrical conductivity of both standard and specialty steel alloys of interest for SOFC metallic interconnect (IC) applications. Arcomac has successfully developed technologies and processes to deposit coatings with excellent adhesion, which have demonstrated a substantial increase in high temperature oxidation resistance, stabilization of low Area Specific Resistance values and significantly decrease Cr volatility. An extensive matrix of deposition processes, coating compositions and architectures was evaluated. Technical performance of coated and uncoated sample coupons during exposures to SOFC interconnect-relevant conditions is discussed, and promising future directions are considered. Cost analyses have been prepared based on assessment of plasma processing parameters, which demonstrate the feasibility of the proposed surface engineering process for SOFC metallic IC applications.

  1. Origin of spin gapless semiconductor behavior in CoFeCrGa: Theory and Experiment

    SciTech Connect (OSTI)

    Bainsla, Lakhan; Mallick, A. I.; Raja, M. Manivel; Coelho, A. A.; Nigam, A. K.; Johnson, D. D.; Alam, Aftab; Suresh, K. G.

    2015-07-08

    Despite a plethora of materials suggested for spintronic applications, a new class of materials has emerged, namely spin gapless semiconductors (SGS), which offers potentially more advantageous properties than existing ones. These magnetic semiconductors exhibit a finite band gap for one spin channel and a closed gap for the other. Supported by electronic-structure calculations, we report evidence of SGS behavior in equiatomic quaternary CoFeCrGa, having a cubic Heusler (prototype LiMgPdSn) structure but exhibiting chemical disorder (DO3 structure). CoFeCrGa is found to transform from SGS to half-metallic phase under pressure, which is attributed to unique electronic-structure features. The saturation magnetization (MS) was obtained at 8K agrees with the Slater-Pauling rule and the Curie temperature (TC) is found to exceed 400K. Carrier concentration (up to 250K) and electrical conductivity are observed to be nearly temperature independent, prerequisites for SGS. The anomalous Hall coefficient is estimated to be 185S/cm at 5K. Considering the SGS properties and high TC, this material appears to be promising for spintronic applications.

  2. Middle School Academic Competition - Double Elimination | U.S. DOE Office

    Office of Science (SC) Website

    of Science (SC) Academic Competition - Double Elimination National Science Bowl® (NSB) NSB Home About National Science Bowl Contacts Regional Science Bowl Coordinators National Science Bowl FAQ's Alumni Past National Science Bowl Winners Past National Science Bowl Photos and Videos National Science Bowl Logos High School Middle School Attending the National Finals Volunteers 2016 Competition Results News Media WDTS Home Contact Information National Science Bowl® U.S. Department of Energy

  3. Students and Parents at Carver Middle School Explore STEM with Jefferson

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

    Lab (Newport News Public Schools TV Media Center,This Just In program) | Jefferson Lab Students and Parents at Carver Middle School Explore STEM with Jefferson Lab (Newport News Public Schools TV Media Center,This Just In program) External Link: http://nnpstv.com/mediacenter/video/1326/This-Just-In-110-Week-of-April-2-2012 By jlab_admin on Mon, 2012-04-02

  4. Method for enriching a middle isotope using vibration-vibration pumping

    DOE Patents [OSTI]

    Rich, Joseph W.; Homicz, Gregory F.; Bergman, Richard C.

    1989-01-01

    Method for producing isotopically enriched material by vibration-vibration excitation of gaseous molecules wherein a middle mass isotope of an isotopic mixture including lighter and heavier mass isotopes preferentially populates a higher vibrational mode and chemically reacts to provide a product in which it is enriched. The method can be used for vibration-vibration enrichment of .sup.17 O in a CO reactant mixture.

  5. INFLUENCE OF CARBON AND DPA RATE ON NEUTRON-INDUCED SWELLING OF Fe-15Cr-16Ni-0.25Ti IN FFTF AT ~400 DEGREES C

    SciTech Connect (OSTI)

    Okita, Taira; Sekimura, Naoto; Garner, Francis A.; Wolfer, W. G.

    2002-12-31

    The purpose of this effort is to determine the influence of dpa rate and composition on the void swelling of simple austenitic Fe-Cr-Ni alloys. Contrary to the swelling behavior of fcc Fe-15Cr-16Ni and Fe-15Cr-16Ni-0.25Ti alloys irradiated in the same FFTF-MOTA experiment, Fe-15Cr-16Ni-0.25Ti-0.04C does not exhibit a dependence of swelling on dpa rate at approximately 400 degrees C. The transient regime of swelling is prolonged by carbon addition, however.

  6. Magnetic and Structural Phase Transitions in the Spinel Compound Fe1+xCr2 xO4

    SciTech Connect (OSTI)

    Ma, Jie; Garlea, Vasile O; Rondinone, Adam Justin; Aczel, Adam A; Calder, Stuart A; Dela Cruz, Clarina R; Sinclair, R.; Tian, Wei; Chi, Songxue; Kiswandhi, Andhika; Brooks, James S.; Zhou, Haidong; Matsuda, Masaaki

    2014-01-01

    Neutron diffraction, X-ray diffraction, magnetic susceptibility, and specific heat measurements have been used to investigate the magnetic and structural phase transitions of the spinel system Fe1+xCr2 xO4 (0.0 x 1.0). The temperature versus Fe concentration (x) phase diagram contains two magnetically ordered phases and four structural phases below 420 K. The complicated transitions are closely related to the change in the spin and orbital degrees of freedom induced by substitution of Fe ions for Cr ions. The systematic change in the crystal structure is explained by the combined effects of Jahn-Teller distortion, spin-lattice interaction, Fe2+-Fe3+ hopping, and disorder among Fe2+, Fe3+, and Cr3+ ions.

  7. Ab initio study on noncompensated CrO codoping of GaN for enhanced solar energy conversion

    SciTech Connect (OSTI)

    Pan, Hui; Gu, Baohua; Eres, Gyula; Zhang, Zhenyu

    2010-03-01

    We describe a novel photocatalyst obtained by codoping GaN with CrO, according to a new "noncompensated" codoping concept based on first-principles calculations. The approach enables controllable narrowing of the GaN band gap with significantly enhanced carrier mobility and photocatalytic activity in the visible light region and thus offers immense potential for application in solar energy conversion, water splitting, and a variety of solar-assisted photocatalysis. Our calculations indicate that the formation energy for the cation doping is greatly reduced by noncompensated codoping with an anion. Although Cr doping alone can split the band gap with the formation of an intermediate band, the mobility is low due to carrier trapping by the localized states. The first-principles calculations also demonstrate that CrO codoping of GaN shifts the Fermi level into the conduction band resulting in high carrier density and mobility.

  8. Total Reducing Capacity in Aquifer Minerals and Sediments: Quantifying the Potential to Attenuate Cr(VI) in Groundwater

    SciTech Connect (OSTI)

    Sisman, S. Lara

    2015-07-20

    Hexavalent chromium, Cr(VI), is present in the environment as a byproduct of industrial processes. Due to its mobility and toxicity, it is crucial to attenuate or remove Cr(VI) from the environment. The objective of this investigation was to quantify potential natural attenuation, or reduction capacity, of reactive minerals and aquifer sediments. Samples of reduced-iron containing minerals such as ilmenite, as well as Puye Formation sediments representing a contaminated aquifer in New Mexico, were reacted with chromate. The change in Cr(VI) during the reaction was used to calculate reduction capacity. This study found that minerals that contain reduced iron, such as ilmenite, have high reducing capacities. The data indicated that sample history may impact reduction capacity tests due to surface passivation. Further, this investigation identified areas for future research including: a) refining the relationships between iron content, magnetic susceptibility and reduction capacity, and b) long term kinetic testing using fresh aquifer sediments.

  9. Weldability of Fe-Al-Cr Overlay Coatings for CorrosionProtection in Oxidizing/Sulfidizing Environments

    SciTech Connect (OSTI)

    Regina, JR

    2003-03-04

    The effect of chromium additions to the weldability of Fe-Al based overlay claddings are currently being investigated for the corrosion protection of boiler tubes in Low NOx furnaces. The primary objective of this research is to identify weldable (crack-free) Fe-Al-Cr weld overlay coating compositions that provide corrosion resistance over long exposure times. During the current project phase, preliminary corrosion testing was conducted on several ternary Fe-Al-Cr alloys in two types of gaseous corrosion environments. These long-term corrosion tests were used to develop a target weld composition matrix and serve as a base line for future corrosion tests. Preliminary Fe-Al based welds with various aluminum concentrations and one ternary Fe-Al-Cr weld overlay were successfully deposited using a Gas Tungsten Arc Welding (GTAW) process and cracking susceptibility was evaluated on these coatings.

  10. Low voltage tunneling magnetoresistance in CuCrO{sub 2}-based semiconductor heterojunctions at room temperature

    SciTech Connect (OSTI)

    Li, X. R.; Han, M. J.; Shan, C.; Hu, Z. G. Zhu, Z. Q.; Chu, J. H.; Wu, J. D.

    2014-12-14

    CuCrO{sub 2}-based heterojunction diodes with rectifying characteristics have been fabricated by combining p-type Mg-doped CuCrO{sub 2} and n-type Al-doped ZnO. It was found that the current for the heterojunction in low bias voltage region is dominated by the trap-assisted tunneling mechanism. Positive magnetoresistance (MR) effect for the heterojunction can be observed at room temperature due to the tunneling-induced antiparallel spin polarization near the heterostructure interface. The MR effect becomes enhanced with the magnetic field, and shows the maximum at a bias voltage around 0.5 V. The phenomena indicate that the CuCrO{sub 2}-based heterojunction is a promising candidate for low-power semiconductor spintronic devices.

  11. MASS MEASUREMENT OF {sup 45}Cr AND ITS IMPACT ON THE Ca-Sc CYCLE IN X-RAY BURSTS

    SciTech Connect (OSTI)

    Yan, X. L.; Xu, H. S.; Litvinov, Yu. A.; Zhang, Y. H.; Tu, X. L.; Zhou, X. H.; He, J. J.; Sun, Y.; Wang, M.; Yuan, Y. J.; Xia, J. W.; Yang, J. C.; Jia, G. B.; Hu, Z. G.; Ma, X. W.; Mao, R. S.; Schatz, H.; Blaum, K.; Sun, B. H.; Audi, G.; and others

    2013-03-20

    Masses of neutron-deficient {sup 58}Ni projectile fragments have been measured at the HIRFL-CSR facility in Lanzhou, China employing the isochronous mass spectrometry technique. Masses of a series of short-lived T{sub z} = -3/2 nuclides including the {sup 45}Cr nucleus have been measured with a relative uncertainty of about 10{sup -6}-10{sup -7}. The new {sup 45}Cr mass turned out to be essential for modeling the astrophysical rp-process. In particular, we find that the formation of the predicted Ca-Sc cycle in X-ray bursts can be excluded.

  12. Stress-corrosion cracking and surface-pitting tests of NiCrFe alloy bolts (LWBR development program)

    SciTech Connect (OSTI)

    Keller, K.L.

    1983-02-01

    Accelerated corrosion tests confirmed the adequate resistance to stress corrosion cracking (SCC) of the specific heats of NiCrFe X-750 and NiCrFe 600 used as bolts in the LWBR. SCC acceleration was achieved by running autoclave corrosion tests at 680/sup 0/F (well above the LWBR core operating temperatures of approximately 525/sup 0/F to 560/sup 0/F). Component stress levels were representative of maximum service stresses. No specimens from heats of either alloy suffered SCC.

  13. Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets

    SciTech Connect (OSTI)

    Kodaira, S. Kurano, M.; Hosogane, T.; Ishikawa, F.; Kageyama, T.; Sato, M.; Kayano, M.; Yasuda, N.

    2015-05-15

    A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

  14. EERE Success Story-Tennessee: Bringing Jobs and Economic Development to

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

    Piney Flats | Department of Energy Bringing Jobs and Economic Development to Piney Flats EERE Success Story-Tennessee: Bringing Jobs and Economic Development to Piney Flats May 1, 2014 - 2:35pm Addthis With grants from the Tennessee Solar Institute (TSI) and Recovery Act funding from EERE's State Energy Program (SEP), Diversified Power International, LLC (DPI) has successfully realized its vision of retaining its technology at home, while also verifiably providing an increase of more than

  15. Letter Report Documenting Progress of Second Generation ATF FeCrAl Alloy Fabrication

    SciTech Connect (OSTI)

    Yamamoto,, Y.; Yang, Y.; Field, K. G.; Terrani, K.; Pint, B. A.; Snead, L. L.

    2014-06-10

    Development of the 2nd generation ATF FeCrAl alloy has been initiated, and a candidate alloy was selected for trial tube fabrication through hot-extrusion and gun-drilling processes. Four alloys based on Fe-13Cr-4.5Al-0.15Y in weight percent were newly cast with minor alloying additions of Mo, Si, Nb, and C to promote solid-solution and second-phase precipitate strengthening. The alloy compositions were selected with guidance from computational thermodynamic tools. The lab-scale heats of ~ 600g were arc-melted and drop-cast, homogenized, hot-forged and -rolled, and then annealed producing plate shape samples. An alloy with Mo and Nb additions (C35MN) processed at 800°C exhibits very fine sub-grain structure with the sub-grain size of 1-3μm which exhibited more than 25% better yield and tensile strengths together with decent ductility compared to the other FeCrAl alloys at room temperature. It was found that the Nb addition was key to improving thermal stability of the fine sub-grain structure. Optimally, grains of less than 30 microns are desired, with grains up to and order of magnitude in desired produced through Nb addition. Scale-up effort of the C35MN alloy was made in collaboration with a commercial cast company who has a capability of vacuum induction melting. A 39lb columnar ingot with ~81mm diameter and ~305mm height (with hot-top) was commercially cast, homogenized, hot-extruded, and annealed providing 10mm-diameter bar-shape samples with the fine sub-grain structure. This commercial heat proved consistent with materials produced at ORNL at the lab-scale. Tubes and end caps were machined from the bar sample and provided to another work package for the ATF-1 irradiation campaign in the milestone M3FT-14OR0202251.

  16. Luteolin inhibits Cr(VI)-induced malignant cell transformation of human lung epithelial cells by targeting ROS mediated multiple cell signaling pathways

    SciTech Connect (OSTI)

    Pratheeshkumar, Poyil; Son, Young-Ok; Divya, Sasidharan Padmaja; Roy, Ram Vinod; Hitron, John Andrew; Wang, Lei; Kim, Donghern; Dai, Jin; Asha, Padmaja; Zhang, Zhuo; Wang, Yitao; Shi, Xianglin

    2014-12-01

    Hexavalent chromium [Cr(VI)] is a well-known human carcinogen associated with the incidence of lung cancer. Inhibition of metal induced carcinogenesis by a dietary antioxidant is a novel approach. Luteolin, a natural dietary flavonoid found in fruits and vegetables, possesses potent antioxidant and anti-inflammatory activity. We found that short term exposure of human bronchial epithelial cells (BEAS-2B) to Cr(VI) (5 μM) showed a drastic increase in ROS generation, NADPH oxidase (NOX) activation, lipid peroxidation, and glutathione depletion, which were significantly inhibited by the treatment with luteolin in a dose dependent manner. Treatment with luteolin decreased AP-1, HIF-1α, COX-2, and iNOS promoter activity induced by Cr(VI) in BEAS-2B cells. In addition, luteolin protected BEAS-2B cells from malignant transformation induced by chronic Cr(VI) exposure. Moreover, luteolin also inhibited the production of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α) and VEGF in chronic Cr(VI) exposed BEAS-2B cells. Western blot analysis showed that luteolin inhibited multiple gene products linked to survival (Akt, Fak, Bcl-2, Bcl-xL), inflammation (MAPK, NF-κB, COX-2, STAT-3, iNOS, TNF-α) and angiogenesis (HIF-1α, VEGF, MMP-9) in chronic Cr(VI) exposed BEAS-2B cells. Nude mice injected with BEAS-2B cells chronically exposed to Cr(VI) in the presence of luteolin showed reduced tumor incidence compared to Cr(VI) alone treated group. Overexpression of catalase (CAT) or SOD2, eliminated Cr(VI)-induced malignant transformation. Overall, our results indicate that luteolin protects BEAS-2B cells from Cr(VI)-induced carcinogenesis by scavenging ROS and modulating multiple cell signaling mechanisms that are linked to ROS. Luteolin, therefore, serves as a potential chemopreventive agent against Cr(VI)-induced carcinogenesis. - Highlights: • Luteolin inhibited Cr(VI)-induced oxidative stress. • Luteolin inhibited chronic Cr(VI)-induced malignant transformation. • Luteolin inhibited chronic Cr(VI)-induced inflammation. • Luteolin inhibited chronic Cr(VI)-induced angiogenesis.

  17. Heat treated 9 Cr-1 Mo steel material for high temperature application

    DOE Patents [OSTI]

    Jablonski, Paul D.; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-08-21

    The invention relates to a composition and heat treatment for a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The novel combination of composition and heat treatment produces a heat treated material containing both large primary titanium carbides and small secondary titanium carbides. The primary titanium carbides contribute to creep strength while the secondary titanium carbides act to maintain a higher level of chromium in the finished steel for increased oxidation resistance, and strengthen the steel by impeding the movement of dislocations through the crystal structure. The heat treated material provides improved performance at comparable cost to commonly used high-temperature steels such as ASTM P91 and ASTM P92, and requires heat treatment consisting solely of austenization, rapid cooling, tempering, and final cooling, avoiding the need for any hot-working in the austenite temperature range.

  18. Properties and features of structure formation CuCr-contact alloys in electron beam cladding

    SciTech Connect (OSTI)

    Durakov, Vasiliy G.; Dampilon, Bair V. E-mail: gnusov@rambler.ru; Gnyusov, Sergey F. E-mail: gnusov@rambler.ru

    2014-11-14

    The microstructure and properties of the contact CuCr alloy produced by electron-beam cladding have been investigated. The effect of the electron beam cladding parameters and preheating temperature of the base metal on the structure and the properties of the coatings has been determined. The bimodal structure of the cladding coating has been established. The short circuit currents tests have been carried out according to the Weil-Dobke synthetic circuit simulating procedure developed for vacuum circuit breakers (VCB) test in real electric circuits. Test results have shown that the electron beam cladding (EBC) contact material has better breaking capacity than that of commercially fabricated sintered contact material. The application of the technology of electron beam cladding for production of contact material would significantly improve specific characteristics and reliability of vacuum switching equipment.

  19. Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel

    SciTech Connect (OSTI)

    Hsiung, L; Fluss, M; Kimura, A

    2010-04-06

    Oxide nanoparticles in Fe-16Cr ODS ferritic steel fabricated by mechanical alloying (MA) method have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. A partial crystallization of oxide nanoparticles was frequently observed in as-fabricated ODS steel. The crystal structure of crystalline oxide particles is identified to be mainly Y{sub 4}Al{sub 2}O{sub 9} (YAM) with a monoclinic structure. Large nanoparticles with a diameter larger than 20 nm tend to be incoherent and have a nearly spherical shape, whereas small nanoparticles with a diameter smaller than 10 nm tend to be coherent or semi-coherent and have faceted boundaries. The oxide nanoparticles become fully crystallized after prolonged annealing at 900 C. These results lead us to propose a three-stage formation mechanism of oxide nanoparticles in MA/ODS steels.

  20. Thermo-mechanical processing (TMP) of Ti-48Al-2Nb-2Cr based alloys

    SciTech Connect (OSTI)

    Fuchs, G.E.

    1995-02-01

    The effects of heat treatment and deformation processing on the microstructures and properties of {gamma}-TiAl based alloys produced by ingot metallurgy (I/M) and powder metallurgy (P/M) techniques were examined. The alloy selected for this work is the second generation {gamma}-TiAl based alloy -- Ti-48Al-2Nb-2Cr (at %). Homogenization of I/M samples was performed at a variety of temperatures, followed by hot working by isothermal forging. P/M samples were prepared from gas atomized powders, consolidated by both HIP and extrusion and some of the HIPed material was then hot worked by isothermal forging. The effects of processing, heat treatment and hot working on the microstructures and properties will be discussed.

  1. The Russian-American Gallium Experiment (SAGE) Cr Neutrino Source Measurement

    SciTech Connect (OSTI)

    Abdurashitov, J.; Gavrin, V.; Girin, S.; Gorbachev, V.; Ibragimova, T.; Kalikhov, A.; Khairnasov, N.; Knodel, T.; Kornoukhov, V.; Mirmov, I.; Shikhin, A.; Veretenkin, E.; Vermul, V.; Yants, V.; Zatsepin, G.; Bowles, T.; Nico, J.; Teasdale, W.; Wark, D.; Cherry, M.; Karaulov, V.; Levitin, V.; Maev, V.; Nazarenko, P.; Shkolnik, V.; Skorikov, N.; Cleveland, B.; Daily, T.; Davis, R. Jr.; Lande, K.; Lee, C.; Wildenhain, P.; Khomyakov, Y.; Zvonarev, A.; Elliott, S.; Wilkerson, J.

    1996-12-01

    The solar neutrino capture rate measured by SAGE is well below that predicted by solar models. To check the overall experimental efficiency, we exposed 13tonnes of Ga metal to a reactor-produced 517kCi source of {sup 51}Cr. The ratio of the measured production rate to that predicted from the source activity is 0.95{plus_minus}0.11(stat)+0.05/{minus}0.08(syst). This agreement verifies that the experimental efficiency is measured correctly, establishes that there are no unknown systematic errors at the 10{percent} level, and provides considerable evidence for the reliability of the solar neutrino measurement. {copyright} {ital 1996 The American Physical Society.}

  2. Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

  3. Thermomechanical treatment for improved neutron irradiation resistance of austenitic alloy (Fe-21Cr-32Ni)

    SciTech Connect (OSTI)

    L. Tan; J. T. Busby; H. J. M. Chichester; K. Sridharan; T. R. Allen

    2013-06-01

    An optimized thermomechanical treatment (TMT) applied to austenitic alloy 800H (Fe-21Cr-32Ni) had shown significant improvements in corrosion resistance and basic mechanical properties. This study examined its effect on radiation resistance by irradiating both the solution-annealed (SA) and TMT samples at 500 degrees C for 3 dpa. Microstructural characterization using transmission electron microscopy revealed that the radiation-induced Frank loops, voids, and y'-Ni3(Ti,Al) precipitates had similar sizes between the SA and TMT samples. The amounts of radiation-induced defects and more significantly y' precipitates, however, were reduced in the TMT samples. These reductions would approximately reduce by 40.9% the radiation hardening compared to the SA samples. This study indicates that optimized-TMT is an economical approach for effective overall property improvements.

  4. 2011 HONDA CR-Z 2982 - HYBRID ELECTRIC VEHICLE BATTERY TEST RESULTS

    SciTech Connect (OSTI)

    Gray, Tyler; Shirk, Matthew; Wishart, Jeffrey

    2014-09-01

    The U.S. Department of Energy’s Advanced Vehicle Testing Activity Program consists of vehicle, battery, and infrastructure testing on advanced technology related to transportation. The activity includes tests on hybrid electric vehicles, including testing traction batteries when both the vehicles and batteries are new and at the conclusion of 160,000 miles of on-road fleet testing. This report documents battery testing performed for the 2011 Honda CR-Z (VIN JHMZF1C64BS002982). Battery testing was performed by Intertek Testing Services NA. The Idaho National Laboratory and Intertek collaborate on the Advanced Vehicle Testing Activity for the Vehicle Technologies Office of the U.S. Department of Energy.

  5. Ion polished Cr/Sc attosecond multilayer mirrors for high water window reflectivity

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

    Guggenmos, Alexander; Radünz, Stefan; Rauhut, Roman; Hofstetter, Michael; Venkatesan, Sriram; Wochnik, Angela; Gullikson, Eric M.; Fischer, Stefan; Nickel, Bert; Scheu, Christina; et al

    2014-01-20

    Recent advances in the development of attosecond soft X-ray sources ranging into the water window spectral range, between the 1s states of carbon and oxygen (284 eV–543 eV), are also driving the development of suited broadband multilayer optics for steering and shaping attosecond pulses. The relatively low intensity of current High Harmonic Generation (HHG) soft X-ray sources calls for an efficient use of photons, thus the development of low-loss multilayer optics is of uttermost importance. Here, we report about the realization of broadband Cr/Sc attosecond multilayer mirrors with nearly atomically smooth interfaces by an optimized ion beam deposition and assistedmore » interface polishing process. This yields to our knowledge highest multilayer mirror reflectivity at 300 eV near normal incidence. The results are verified by transmission electron microscopy (TEM) and soft/hard X-ray reflectometry.« less

  6. Bose-Einstein condensation of triplons in Ba3Cr2O8

    SciTech Connect (OSTI)

    Jaime, Marcelo [Los Alamos National Laboratory; Kohama, Y [Los Alamos National Laboratory; Aczel, A [MCMASTER UNIV; Ninios, K [UNIV OF FL; Chan, H [UNIV OF FL; Balicas, L [NHMFL; Dabkowska, H [MCMASTER UNIV; Like, G [MCMASTER UNIV

    2009-01-01

    By performing heat capacity, magnetocaloric effect, torque magnetometry and force magnetometry measurements up to 33 T, we have mapped out the T-H phase diagram of the S = 1/2 spin dimer compound Ba{sub 3}Cr{sub 2}O{sub 8}. We found evidence for field-induced magnetic order between H{sub cl} = 12.52(2) T and H{sub c2} = 23.65(5) T, with the maximum transition temperature T{sub c} {approx} 2.7 K at H {approx} 18 T. The lower transition can likely be described by Bose-Einstein condensation of triplons theory, and this is consistent with the absence of any magnetization plateaus in our magnetic torque and force measurements. In contrast, the nature of the upper phase transition appears to be quite different as our measurements suggest that this transition is actually first order.

  7. Mn-Fe base and Mn-Cr-Fe base austenitic alloys

    DOE Patents [OSTI]

    Brager, Howard R.; Garner, Francis A.

    1987-01-01

    Manganese-iron base and manganese-chromium-iron base austenitic alloys designed to have resistance to neutron irradiation induced swelling and low activation have the following compositions (in weight percent): 20 to 40 Mn; up to about 15 Cr; about 0.4 to about 3.0 Si; an austenite stabilizing element selected from C and N, alone or in combination with each other, and in an amount effective to substantially stabilize the austenite phase, but less than about 0.7 C, and less than about 0.3 N; up to about 2.5 V; up to about 0.1 P; up to about 0.01 B; up to about 3.0 Al; up to about 0.5 Ni; up to about 2.0 W; up to about 1.0 Ti; up to about 1.0 Ta; and with the remainder of the alloy being essentially iron.

  8. Ion polished Cr/Sc attosecond multilayer mirrors for high water window reflectivity

    SciTech Connect (OSTI)

    Guggenmos, Alexander; Radünz, Stefan; Rauhut, Roman; Hofstetter, Michael; Venkatesan, Sriram; Wochnik, Angela; Gullikson, Eric M.; Fischer, Stefan; Nickel, Bert; Scheu, Christina; Kleineberg, Ulf

    2014-01-20

    Recent advances in the development of attosecond soft X-ray sources ranging into the water window spectral range, between the 1s states of carbon and oxygen (284 eV–543 eV), are also driving the development of suited broadband multilayer optics for steering and shaping attosecond pulses. The relatively low intensity of current High Harmonic Generation (HHG) soft X-ray sources calls for an efficient use of photons, thus the development of low-loss multilayer optics is of uttermost importance. Here, we report about the realization of broadband Cr/Sc attosecond multilayer mirrors with nearly atomically smooth interfaces by an optimized ion beam deposition and assisted interface polishing process. This yields to our knowledge highest multilayer mirror reflectivity at 300 eV near normal incidence. The results are verified by transmission electron microscopy (TEM) and soft/hard X-ray reflectometry.

  9. Super-High Temperature Alloys and Composites from NbW-Cr Systems

    SciTech Connect (OSTI)

    Shailendra Varma

    2008-12-31

    Nickel base superalloys must be replaced if the demand for the materials continues to rise for applications beyond 1000{sup o}C which is the upper limit for such alloys at this time. There are non-metallic materials available for such high temperature applications but they all present processing difficulties because of the lack of ductility. Metallic systems can present a chance to find materials with adequate room temperature ductility. Obviously the system must contain elements with high melting points. Nb has been chosen by many investigators which has a potential of being considered as a candidate if alloyed properly. This research is exploring the Nb-W-Cr system for the possible choice of alloys to be used as a high temperature material.

  10. Photo-transport properties of Pb{sub 2}CrO{sub 5} single crystals

    SciTech Connect (OSTI)

    Mondal, P. S.; Okazaki, R. Taniguchi, H.; Terasaki, I.

    2014-11-21

    We report photo-thermoelectric transport phenomena in Pb{sub 2}CrO{sub 5} single crystals. Without illumination, this material exhibits an insulating behavior characterized by an activation-type temperature variation of the electrical conductivity. The Seebeck coefficient contrastingly shows a crossover from high-temperature insulating to low-temperature metallic behavior, which is attributed to degenerate carriers in a donor level. We have found that under illumination, both the conductivity and the Seebeck coefficient increase in magnitude with increasing photon flux density in the degenerate-conduction regime. This result is difficult to understand within a simple photo-doping effect, which usually leads to a decrease in the Seebeck coefficient under illumination. The observed phenomenon is discussed in terms of a two-carrier contribution to the transport properties.

  11. 2011 Honda CR-Z 4466 - Hybrid Electric Vehicle Battery Test Results

    SciTech Connect (OSTI)

    Tyler Gray; Matthew Shirk; Jeffrey Wishart

    2014-09-01

    The U.S. Department of Energy’s Advanced Vehicle Testing Activity Program consists of vehicle, battery, and infrastructure testing on advanced technology related to transportation. The activity includes tests on hybrid electric vehicles, including testing traction batteries when both the vehicles and batteries are new and at the conclusion of 160,000 miles of on-road fleet testing. This report documents battery testing performed for the 2011 Honda CR-Z (VIN JHMZF1C67BS004466). Battery testing was performed by Intertek Testing Services NA. The Idaho National Laboratory and Intertek collaborate on the Advanced Vehicle Testing Activity for the Vehicle Technologies Office of the U.S. Department of Energy.

  12. Feasibility of correlating V-Cr-Ti alloy weld strength with weld chemistry. CRADA final report

    SciTech Connect (OSTI)

    Grossbeck, M.L.; Odom, R.W.

    1998-06-01

    The mechanical properties of refractory metals such as vanadium are determined to a large extent by the interstitial impurities in the alloy. In the case of welding, interstitial impurities are introduced in the welding process from the atmosphere and by dissolution of existing precipitates in the alloy itself. Because of the necessity of having an ultra-pure atmosphere, a vacuum chamber or a glove box is necessary. In the V-Cr-Ti system, the titanium serves as a getter to control the concentration of oxygen and nitrogen in solid solution in the alloy. In this project the secondary ion mass spectrometry (SIMS) technique was used to detect, measure, and map the spacial distribution of impurity elements in welds in the alloy V-4Cr-4Ti. An attempt was then made to correlate the concentrations and distributions of the impurities with mechanical properties of the welds. Mechanical integrity of the welds was determined by Charpy V-notch testing. Welds were prepared by the gas-tungsten-arc (GTA) method. Charpy testing established a correlation between weld impurity concentration and the ductile to brittle transition temperature (DBTT). Higher concentrations of oxygen resulted in a higher DBTT. An exception was noted in the case of a low-oxygen weld which had a high hydrogen concentration resulting in a brittle weld. The concentrations and distributions of the impurities determined by SIMS could not be correlated with the mechanical properties of the welds. This research supports efforts to develop fusion reactor first wall and blanket structural materials.

  13. Microstructural characterization of as-cast biocompatible Co-Cr-Mo alloys

    SciTech Connect (OSTI)

    Giacchi, J.V.; Morando, C.N.; Fornaro, O.; Palacio, H.A.

    2011-01-15

    The microstructure of a cobalt-base alloy (Co-Cr-Mo) obtained by the investment casting process was studied. This alloy complies with the ASTM F75 standard and is widely used in the manufacturing of orthopedic implants because of its high strength, good corrosion resistance and excellent biocompatibility properties. This work focuses on the resulting microstructures arising from samples poured under industrial environment conditions, of three different Co-Cr-Mo alloys. For this purpose, we used: 1) an alloy built up from commercial purity constituents, 2) a remelted alloy and 3) a certified alloy for comparison. The characterization of the samples was achieved by using optical microscopy (OM) with a colorant etchant to identify the present phases and scanning electron microscopy (SE-SEM) and energy dispersion spectrometry (EDS) techniques for a better identification. In general the as-cast microstructure is a Co-fcc dendritic matrix with the presence of a secondary phase, such as the M{sub 23}C{sub 6} carbides precipitated at grain boundaries and interdendritic zones. These precipitates are the main strengthening mechanism in this type of alloys. Other minority phases were also reported and their presence could be linked to the cooling rate and the manufacturing process variables and environment. - Research Highlights: {yields}The solidification microstructure of an ASTM-F75 type alloy were studied. {yields}The alloys were poured under an industrial environment. {yields}Carbides and sigma phase identified by color metallography and scanning microscopy (SEM and EDS). {yields}Two carbide morphologies were detected 'blocky type' and 'pearlite type'. {yields}Minority phases were also detected.

  14. Sublette County, Wyoming: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Big Piney, Wyoming Bondurant, Wyoming Boulder, Wyoming Calpet, Wyoming Cora, Wyoming Daniel, Wyoming Marbleton, Wyoming Pinedale, Wyoming Retrieved from "http:en.openei.orgw...

  15. HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3...

    Office of Scientific and Technical Information (OSTI)

    ...6Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel Citation Details In-Document Search Title: HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel You are accessing a ...

  16. Investigations of the optical and EPR properties of LiGa{sub 5}O{sub 8}:Cr{sup 3+} phosphor

    SciTech Connect (OSTI)

    Singh, Vijay; Ravikumar, R.V.S.S.N.; Sivaramaiah, G.; Rao, J.L.; Kim, S.H.

    2015-01-15

    Highlights: • Cr{sup 3+} doped LiGa{sub 5}O{sub 8} phosphor was synthesized by solution combustion synthesis. • Morphological studies show the non-uniform distribution of particles. • Photoluminescence spectra of Cr{sup 3+} doped LiGa{sub 5}O{sub 8} showed the characteristic Cr{sup 3+} peaks. • EPR spectrum showed Cr{sup 3+} ions in tetragonally distorted octahedral symmetry. - Abstract: Red emitting LiGa{sub 5}O{sub 8} doped with Cr{sup 3+} ions has been prepared by a low temperature solution combustion route. The as-prepared phosphor was studied using X-ray diffraction and scanning electron microscopic techniques. The optical spectrum exhibits two broad bands characteristic of Cr{sup 3+} ions in an octahedral symmetry. Upon excitation at 590 nm, the material displays narrow red emission line centered at 715 nm due to the {sup 2}E{sub g} → {sup 4}A{sub 2g} transition of Cr{sup 3+} ions. Electron paramagnetic resonance analyses of the sample confirm the presence of Cr{sup 3+} in the LiGa{sub 5}O{sub 8} matrix.

  17. Reversible nano-structuring of SrCrO3-? through oxidization and reduction at low temperatures

    SciTech Connect (OSTI)

    Zhang, Hongliang; Sushko, Petr; Colby, Robert J.; Du, Yingge; Bowden, Mark E.; Chambers, Scott A.

    2014-08-18

    Oxygen vacancies are often present in complex oxides as point defects and their effect on the electronic properties of the oxides is typically uniform and isotropic. Exploiting oxygen deficiency in order to generate controllably, novel structures and functional properties remains a challenging goal. We show that epitaxial strontium chromite films can be transformed, reversibly and at low temperature, from the cubic metallic perovskite SrCrO3-? to the rhombohedral semiconducting SrCrO2.8. Oxygen vacancies aggregate and give rise to ordered arrays of {111}-oriented SrO2 planes interleaved between layers of tetrahedrally-coordinated Cr4+ and separated by ~1 nm. First-principle calculations provide insight into the origin of the stability of such nanostructures and, consistent with the experimental data, predict that the barrier for oxide ion diffusion along these quasi-2D nanostructures is ~5 times lower than that in the cubic SrCrO3-? a property of considerable importance in, for example, solid oxide fuel cells.

  18. Effect of Austenization Temperature on the Microstructure and Strength of 9% and 12% Cr Ferritic-Martensitic Steels

    SciTech Connect (OSTI)

    Terry C. Totemeier

    2004-10-01

    The effect of reduced-temperature austenization on the microstructure and strength of two ferritic-martensitic steels was studied. Prototypic 9% and 12% Cr steels, grade 91 (9Cr-1MoVNb) and type 422 stainless (12Cr-1MoVW), respectively, were austenized at 925C and 1050C and tempered at 760C. The reduced austenization temperature was intended to simulate potential inadequate austenization during field construction of large structures and also the thermal cycle experienced in the Type IV region of weld heat affected zones (HAZ). The microstructure, tensile behavior, and creep strength were characterized for both steels treated at each condition. The reduced austenization temperature resulted in general coarsening of carbides in both steels and polygonization of the tempered martensite structure in type 422. For this steel, a marked reduction in microhardness was observed, while there was little change in microhardness for grade 91. Slight reductions in tensile strength were observed for both steels at room temperature and elevated temperatures of 450 and 550C. The strength reduction was greater for type 422 than for grade 91. At 650C the tensile strength reduction was minimal for both steels. Marked reductions in creep rupture lives were observed for both steels at 650C; the reductions were less at 600C and minimal at 550C. Overall, the higher Cr content steel was observed to be more sensitive to variations in heat treatment conditions.

  19. Giant magnetocaloric effect and temperature induced magnetization jump in GdCrO{sub 3} single crystal

    SciTech Connect (OSTI)

    Yin, L. H.; Yang, J.; Kan, X. C.; Song, W. H.; Dai, J. M.; Sun, Y. P.

    2015-04-07

    We report on a systematic study of the single-crystal GdCrO{sub 3}, which shows various novel magnetic features, such as temperature-induced magnetization reversal (TMR), temperature-induced magnetization jump (TMJ), spin reorientation, and giant magnetocaloric effect (MCE). In the field-cooled cooling process with modest magnetic field along the c axis, GdCrO{sub 3} first shows a TMR at T{sub comp}∼120−130 K and then an abrupt TMJ with a sign change of magnetization at T{sub jump}∼52−120 K, and finally a spin reorientation at T{sub SR}∼4−7 K. Interestingly, the remarkable TMJ behavior, which was not reported ever before, persists at higher fields up to 10 kOe even when TMR disappears. In addition, giant MCE with the maximum value of magnetic entropy change reaching ∼31.6 J/kg K for a field change of 44 kOe was also observed in GdCrO{sub 3} single crystal, suggesting it could be a potential material for low-T magnetic refrigeration. A possible mechanism for these peculiar magnetic behaviors is discussed based on the various competing magnetic interactions between the 3d electrons of Cr{sup 3+} ions and 4f electrons of Gd{sup 3+} ions.

  20. Measuring the activity of a {sup 51}Cr neutrino source based on the gamma-radiation spectrum

    SciTech Connect (OSTI)

    Gorbachev, V. V. Gavrin, V. N.; Ibragimova, T. V.; Kalikhov, A. V.; Malyshkin, Yu. M.; Shikhin, A. A.

    2015-12-15

    A technique for the measurement of activities of intense β sources by measuring the continuous gamma-radiation (internal bremsstrahlung) spectra is developed. A method for reconstructing the spectrum recorded by a germanium semiconductor detector is described. A method for the absolute measurement of the internal bremsstrahlung spectrum of {sup 51}Cr is presented.

  1. Modulation of physical and photocatalytic properties of (Cr, N) codoped TiO{sub 2} nanorods using soft solution processing

    SciTech Connect (OSTI)

    Lu, Wen-Chung; Nguyen, Hoang-Diem; Wu, Chun-Yi; Chang, Kao-Shuo Yoshimura, Masahiro

    2014-04-14

    Facile polymerized complex reactions together with a hydrothermal reaction were implemented to make single crystalline TiO{sub 2} nanorods for the first time. Chromium (Cr) and nitrogen (N{sub 2}) co-doping was performed to tailor the physical properties. Transmission electron microscopy and x-ray diffraction study illustrated that highly reactive facets of (101), (111), and (001) dominated rutile TiO{sub 2} nanorods. A growth model, based on formation of complex species, was proposed to elucidate effectiveness of the soft solution processing in making TiO{sub 2} nanorods. X-ray photoelectron spectroscopy analysis and consideration of fundamentals of charge neutrality showed N{sub 2} doping could inhibit formation of Cr{sup 6+} and oxygen vacancies (V{sub O}{sup 2+}). An investigation of the photocatalytic properties exhibited high efficiency of photodegradation of methylene blue in 15 min under pH = 10, using a nanocomposite of (7% Cr, 0.0021% N) codoped and 3% Cr doped TiO{sub 2} nanorods.

  2. Magnetic behavior in Cr{sub 2}@Ge{sub n} (1?n?12) clusters: A density functional investigation

    SciTech Connect (OSTI)

    Dhaka, Kapil Trivedi, Ravi Bandyopadhyay, Debashis

    2014-04-24

    With a goal to produce magnetic moment in Cr{sub 2} Doped Ge{sub n} clusters which will be useful for practical applications, we have considered the structure and magnetic properties of Pure Germanium clusters and substitutionally doped it with Cr dimer to produce Cr{sub 2}@Ge{sub n} clusters. As the first step of calculation, geometrical optimizations of the nanoclusters have been done. These optimized geometries have been used in calculate the average binding energy per atom (BE), HOMO-LUMO gap and hence the relative stability of the clusters. These parameters have been demonstrated as structural and electronic properties of the clusters. Gap between highest occupied molecular orbital and lowest unoccupied molecular orbital indicate cluster to be a potential motif for generating magnetic cluster assembled materials. Based on these values a comparative study on different sized clusters has been done in order to understand the origin of structures, electronic and magnetic properties of Cr{sub 2}@Ge{sub n} nanoclusters.

  3. Re-Evaluation of Results in NUREG/CR-6674 for Carbon and Low-Alloy Steel Components (MRP-76)

    SciTech Connect (OSTI)

    A. Deardorff; D. Harris; D. Dedhia

    2002-11-30

    This report evaluates the conservatisms and uncertainties reported in NUREG/CR-6674 that lead to high probabilities of cracking in carbon and low-alloy steel for reactor piping. The report uses additional data generated since the completion of the report to eliminate uncertainties and show lower probabilities of cracking.

  4. Petroleum potential of lower and middle Paleozoic rocks in Nebraska portion of Mid-Continent

    SciTech Connect (OSTI)

    Carlson, M.P. )

    1989-08-01

    Central North America during the Paleozoic was characterized by northern (Williston) and southern (Anadarko) depositional regimes separated by a stable Transcontinental arch. Nebraska lies on the southern flank of this arch and contains the northern zero edges of the lower and middle Paleozoic rocks of the southern regime. Most of these rocks are secondary dolomites with zones of excellent intercrystalline porosity. The Reagan-LaMotte Sandstones and the overlying Arbuckle dolomites are overlapped by Middle Ordovician rocks toward the Transcontinental arch. Rocks equivalent to the Simpson consist of a basal sand (St. Peter) and overlying interbedded gray-green shales and dolomitic limestones. An uppermost shale facies is present in the Upper Ordovician (Viola-Maquoketa) eastward and southward across Nebraska. The dolomite facies extends northward into the Williston basin. The Silurian dolomites, originally more widely deposited, are overlapped by Devonian dolomites in southeastern Nebraska. Upper Devonian rocks exhibit a regional facies change from carbonate to green-gray shale to black shale southeastward across the Mid-Continent. Mississippian carbonates overlap the Devonian westward and northward across the Transcontinental arch. Pennsylvanian uplift and erosion were widespread, producing numerous stratigraphic traps. Sands related to the basal Pennsylvanian unconformity produce along the Cambridge arch. Arbuckle, Simpson, Viola, and Hunton production is present in the Forest City basin and along the Central Kansas uplift. Although source rocks are scarce and the maturation is marginal, current theories of long-distance oil migration encourage exploration in the extensive lower and middle Paleozoic reservoirs in this portion of the Mid-Continent.

  5. West Windsor-Plainsboro South High School &amp; William Annin Middle School

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

    Virginia win N.J. Regional Science Bowl at PPPL | Princeton Plasma Physics Lab

    West Windsor-Plainsboro South High School & William Annin Middle School win N.J. Regional Science Bowl at PPPL Top science whizzes will go to national contest in Washington, D.C. By Jeanne Jackson DeVoe February 23, 2016 Tweet Widget Google Plus One Share on Facebook The West Windsor-Plainsboro South High School team buzzes in an answer as they compete against Millburn High School in Round 12 of the New

  6. 50 middle-schoolers are wowed by science at PPPL's My Brother's Keeper

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

    program | Princeton Plasma Physics Lab 50 middle-schoolers are wowed by science at PPPL's My Brother's Keeper program By Jeanne Jackson DeVoe March 8, 2016 Tweet Widget Google Plus One Share on Facebook Students use a compass to map the magnetic field lines of the electromagnet they created during a workshop at PPPL's My Brother's Keeper event March 4. (Photo by Elle Starkman/PPPL Office of Communications) Students use a compass to map the magnetic field lines of the electromagnet they

  7. 50 middle-schoolers are wowed by science at PPPL's My Brother's Keeper

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

    program | Princeton Plasma Physics Lab 50 middle-schoolers are wowed by science at PPPL's My Brother's Keeper program By Jeanne Jackson DeVoe March 8, 2016 Tweet Widget Google Plus One Share on Facebook Students use a compass to map the magnetic field lines of the electromagnet they created during a workshop at the My Brother's Keeper event at PPPL March 4. (Photo by Elle Starkman/PPPL Office of Communications) (Photo by Photo by Elle Starkman/PPPL Office of Communications) Students use a

  8. Cr-doped Ge{sub 2}Sb{sub 2}Te{sub 5} for ultra-long data retention phase change memory

    SciTech Connect (OSTI)

    Wang, Qing; Xia, Yangyang; Zheng, Yonghui; Zhang, Qi; Liu, Bo Song, Sannian; Cheng, Yan; Song, Zhitang; Feng, Songlin; Huo, Ruru

    2015-11-30

    Phase change memory is regarded as one of the most promising candidates for the next-generation non-volatile memory. Its storage medium, phase change material, has attracted continuous exploration. Ge{sub 2}Sb{sub 2}Te{sub 5} (GST) is the most popular phase change material, but its thermal stability needs to be improved when used in some fields at high temperature (more than 120 °C). In this paper, we doped Cr atoms into GST and obtained Cr{sub 10}(Ge{sub 2}Sb{sub 2}Te{sub 5}){sub 90} (labeled as Cr-GST) with high thermal stability. For Cr-GST film, the sheet resistance ratio between amorphous and crystalline states is high up to 3 orders of magnitude. The crystalline Cr-GST film inherits the phase structure of GST, with metastable face-centered cubic phase and/or stable hexagonal phase. The doped Cr atoms not only bond with other atoms but also help to improve the anti-oxidation property of Cr-GST. As for the amorphous thermal stability, the calculated temperature for 10-year-data-retention of Cr-GST film, based on the Arrhenius equation, is about 180 °C. The threshold current and threshold voltage of a cell based on Cr-GST are about 6 μA and 2.7 V. The cell could be operated by suitable voltages for more than 40 000 cycles. Thus, Cr-GST is proved to be a promising phase change material with ultra-long data retention.

  9. Structure and physical properties of single crystal PrCr{sub 2}Al{sub 20} and CeM{sub 2}Al{sub 20} (M=V, Cr): A comparison of compounds adopting the CeCr{sub 2}Al{sub 20} structure type

    SciTech Connect (OSTI)

    Kangas, Michael J.; Schmitt, Devin C.; Sakai, Akito; Nakatsuji, Satoru; Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 ; Chan, Julia Y.

    2012-12-15

    Crystal growth and full structure determination of compounds adopting the CeCr{sub 2}Al{sub 20} structure type, LnTi{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), LnV{sub 2}Al{sub 20} (Ln=La-Pr, and Sm), and LnCr{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), are reported. Resistivity, magnetic susceptibility, and heat capacity of flux grown single crystals of the nonmagnetic CeM{sub 2}Al{sub 20} (Ln=Ce, Yb; M=Ti, V) compounds are compared to PrCr{sub 2}Al{sub 20}. Of particular interest is PrCr{sub 2}Al{sub 20} which does not show any phase transition down to the lowest temperature of the measurement (400 mK in resistivity measurement and 1.8 K for magnetic susceptibility measurements) and exhibits Kondo behavior at low temperatures. - Graphical abstract: Crystal structure of SmV{sub 2}Al{sub 20} showing the interpenetrating diamond-like samarium network and pyrochlore-like vanadium network. Highlights: Black-Right-Pointing-Pointer Single crystals of LnM{sub 2}Al{sub 20} were grown from a molten aluminum flux. Black-Right-Pointing-Pointer Magnetic, electrical, and specific heat of single crystal LnM{sub 2}Al{sub 20} are presented. Black-Right-Pointing-Pointer PrCr{sub 2}Al{sub 20} exhibits evidence of Kondo effect.

  10. Evaluation of American Indian Science and Engineering Society Intertribal Middle School Science and Math Bowl Project

    SciTech Connect (OSTI)

    AISES, None

    2013-09-25

    The American Indian Science and Engineering Society (AISES) has been funded under a U.S. Department of Energy (DOE) grant (Grant Award No. DE-SC0004058) to host an Intertribal Middle-School Science and Math Bowl (IMSSMB) comprised of teams made up of a majority of American Indian students from Bureau of Indian Education-funded schools and public schools. The intent of the AISES middle school science and math bowl is to increase participation of American Indian students at the DOE-sponsored National Science Bowl. Although national in its recruitment scope, the AISES Intertribal Science and Math Bowl is considered a regional science bowl, equivalent to the other 50 regional science bowls which are geographically limited to states. Most regional bowls do not have American Indian student teams competing, hence the AISES bowl is meant to encourage American Indian student teams to increase their science knowledge in order to participate at the national level. The AISES competition brings together teams from various American Indian communities across the nation. Each team is provided with funds for travel to and from the event, as well as for lodging and meals. In 2011 and 2012, there were 10 teams participating; in 2013, the number of teams participating doubled to 20. Each Science and Math Bowl team is comprised of four middle school grades 6 through 8 students, one alternate, and a teacher who serves as advisor and coach although in at least two cases, the coach was not a teacher, but was the Indian Education Coordinator. Each team member must have at least a 3.0 GPA. Furthermore, the majority of students in each team must be comprised of American Indian, Alaska Native or Native Hawaiian students. Under the current DOE grant, AISES sponsored three annual middle school science bowl competitions over the years 2011, 2012 and 2013. The science and math bowls have been held in late March concurrently with the National American Indian Science and Engineering Fair (NAISEF) and EXPO at the Albuquerque, NM Convention Center. Albuquerque is also the home of the AISES national office. The AISES staff also recruits volunteers to assist with implementation of the science and math bowl event. In 2011, there were 7 volunteers; in 2012, 15 volunteers, and in 2013, 19 volunteers. Volunteers are recruited from a variety of local sources, including Sandia Laboratories, Southwest Indian Polytechnic Institute students, Department of Defense, as well as family members of AISES staff. For AISES, the goals of the Intertribal Middle School Science and Math Bowl project are to have more Native students learn science, for them to gain confidence in competing, and to reward their effort in order to motivate them to pursue studies in the sciences and engineering. For DOE, the goals of the project are to get more Native students to compete at the National Science Bowl, held in Washington, DC.

  11. Corrosion and Stress Corrosion Cracking of High Cr Ferritic-Martensitic Steels in Supercritical Water

    SciTech Connect (OSTI)

    Jinsung, Jang; Seong Sik, Hwang; Chang Hee, Han; Byung Hak, Lee

    2006-07-01

    Corrosion behavior of the F-M (ferritic-martensitic) steels (T91, T92, T122) and Fe-base ODS (oxide dispersion strengthened) alloy (MA956{sup TM}) were evaluated in an aerated (8 ppm D.O.) SCW (supercritical water) at the temperature range between 300 and 627 deg C under 25 MPa. In aerated SCW the weight change of the F-M steel specimens became greater as the test temperature increased. However, the extent of the weight change at 350 deg C, just below the critical temperature appeared not to be less than those at 550 deg C. And the weight changes of all the F-M steel specimens in the deaerated SCW (for 347 hrs in 100 ppb D.O. for 347 hrs, and in 10 ppb D.O. for 432 hrs) tended to converge to about 1 mgcm{sup -2}. In aerated or deaerated conditions 20Cr Fe-base ODS alloy appeared to be very resistant to a SCW corrosion at all the test temperatures up to 500 hrs. Stress corrosion cracking (SCC) behavior of 9Cr F-M steels (T91 and T92) was investigated by CERT (Constant Extension Rate Test) in SCW at various temperatures and D.O. levels with different strain rates. T91 did not show any evidence of a SCC in a fully deaerated (below 10 ppb D.O.) SCW at 500, 550, and 600 deg C at the test conditions. T92 specimens were tested at 500 deg C in SCW with different D.O. levels. The strain rate did not seem to affect the SCC behavior of the T92 steel, but D.O. in SCW seems to affect the SCC behavior to some extent. The total elongation of T92 in SCW of 100 ppb or of 500 ppb D.O. was significantly smaller than that at a fully deaerated (below 10 ppb D.O.) SCW (about 15 vs. 20%), and it appears to provide a clue to a SCC on the fracture surface after the CERT test. (authors)

  12. Microstructural evolution during solution treatment of Co-Cr-Mo-C biocompatible alloys

    SciTech Connect (OSTI)

    Giacchi, J.V.; Fornaro, O.; Palacio, H.

    2012-06-15

    Three different Co-Cr-Mo-C alloys conforming to ASTM F75 standard were poured in an industrial environment and subjected to a conventional solution treatment at 1225 Degree-Sign C for several time intervals. The microstructural changes and transformations were studied in each case in order to evaluate the way in which treatment time influences the secondary phase fraction and clarify the microstructural changes that could occur. To assess how treatment time affects microstructure, optical microscopy and image analyzer software, scanning electron microscopy and energy dispersion spectrometry analysis were employed. The main phases detected in the as-cast state were: {sigma}-phase, M{sub 6}C, and M{sub 23}C{sub 6} carbides. The latter presented two different morphologies, blocky type and lamellar type. Despite being considered the most detrimental feature to mechanical properties, {sigma}-phase and lamellar carbides dissolution took place in the early stages of solution treatment. M{sub 23}C{sub 6} carbides featured two different behaviors. In the alloy obtained by melting an appropriate quantity of alloyed commercial materials, a decrease in size, spheroidization and transformation into M{sub 6}C carbides were simultaneously observed. In the commercial ASTM F75 alloy, in turn, despite being the same phase, only a marked decrease in precipitates size was noticed. These different behaviors could be ascribed to the initial presence of other phases in the alloy obtained from alloyed materials, such as {sigma}-phase and 'pearlitic' carbides, or to the initial precipitate size which was much larger in the first than in the commercial ASTM F75 alloy studied. M{sub 6}C carbides dissolved directly in the matrix as they could not be detected in samples solution-treated for 15 min. - Highlights: Black-Right-Pointing-Pointer Three different Co-Cr-Mo alloys were poured under an industrial environment. Black-Right-Pointing-Pointer Transformation of existing phases followed during conventional solution treatment. Black-Right-Pointing-Pointer In as-cast/treated samples, phases were identified by color metallography, SEM and EDS. Black-Right-Pointing-Pointer M{sub 23}C{sub 6} {yields} M{sub 6}C transformation was corroborated by SEM and EDS analysis. Black-Right-Pointing-Pointer Carbide spheroidization was also detected prior a noticeably carbide size decreasing.

  13. Investigation of structural changes in chiral magnet Cr{sub 1?3}NbS{sub 2} under application of pressure

    SciTech Connect (OSTI)

    Mito, M. Tsuruta, K.; Deguchi, H.; Tajiri, T.; Kishine, J.; Inoue, K.; Kousaka, Y.; Nakao, Y.; Akimitsu, J.

    2015-05-14

    We perform structural analysis experiments on the chiral magnet Cr{sub 1?3}NbS{sub 2}, in which Cr{sup 3+} ions are inserted between hexagonal NbS{sub 2} layers. The noncentrosymmetrical nature of the inserted Cr{sup 3+} appears as a distorted CrS{sub 6} octahedron. Under the application of hydrostatic pressure, the lattice shrinks significantly along the c-axis rather than the a-axis. However, at a pressure P of approximately 34?GPa, a kink in the rate of decrease in the lattice parameters is observed, and the slight movement of a Nb atom along the c-axis brings about a decrease in the distortion of the CrS{sub 6} octahedron. This structural change qualitatively suggests a decrease in the strength of the Dzyaloshinskii-Moriya (D-M) interaction. Under hydrostatic pressure, the magnetic ordering temperature T{sub C} decreases, and dT{sub C}/dP exhibits a slight change at around 3?GPa. A series of experiments indicates that the change in the structural symmetry of the CrS{sub 6} octahedron influences the exchange network between Cr{sup 3+} ions as well as the D-M interaction.

  14. Synthesis and Luminescence Characteristics of Cr3+ doped Y3Al5O12 Phosphors

    SciTech Connect (OSTI)

    Smith, Brenda A.; Dabestani, Reza T.; Lewis, Linda A.; Thompson, Cyril V.; Collins, Case T.; Aytug, Tolga

    2015-10-01

    Luminescence performance of yttrium aluminum garnet (Y3Al5O12) phosphors as a function of Cr3+ concentration has been investigated via two different wet-chemical synthesis techniques, direct- (DP) and hydrothermal-precipitation (HP). Using either of these methods, the red-emitting phosphor [Y3Al5-xCrxO12 (YAG: Cr3+)] showed similar photoluminescence (PL) intensities once the dopant concentration was optimized. Specifically, the YAG: Cr3+ PL emission intensity reached a maximum at Cr3+ concentrations of x = 0.02 (0.4 at.%) and x = 0.13 (2.6 at.%) for DP and HP processed samples, respectively. The results indicated the strong influence of the processing method on the optimized YAG: Cr3+ performance, where a more effective energy transfer rate between a pair of Cr3+ activators at low concentration levels was observed by using the DP synthesis technique. Development of a highly efficient phosphor, using a facile synthesis approach, could significantly benefit consumer and industrial applications by improving the operational efficiency of a wide range of practical devices.

  15. Impact of x-ray dose on the response of CR-39 to 1–5.5 MeV alphas

    SciTech Connect (OSTI)

    Rojas-Herrera, J. Rinderknecht, H. G.; Zylstra, A. B.; Gatu Johnson, M.; Orozco, D.; Rosenberg, M. J.; Sio, H.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2015-03-15

    The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray fluences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-K{sub α} and K{sub β} x-rays. The CR-39 detectors were then exposed to 1–5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.

  16. Synthesis and mechanical properties of CrMoC{sub x}N{sub 1-x} coatings deposited by a hybrid coating system

    SciTech Connect (OSTI)

    Yun, Ji Hwan; Heo, Su Jeong; Kim, Kwang Ryul; Kim, Kwang Ho

    2008-01-15

    Quaternary CrMoC{sub x}N{sub 1-x} coatings were deposited on steel substrates (AISI D2) and Si wafers by a hybrid coating system combining an arc-ion plating technique and a dc reactive magnetron sputtering technique using Cr and Mo targets in an Ar/N{sub 2}/CH{sub 4} gaseous mixture. The carbon content of CrMoC{sub x}N{sub 1-x} coatings was linearly increased with increasing CH{sub 4}/(CH{sub 4}+N{sub 2}) gas flow rate ratio. The maximum hardness of 44 GPa was obtained from the CrMoC{sub x}N{sub 1-x} coatings containing a carbon content of x=0.33 with a residual stress of -4.4 GPa. The average friction coefficient of Cr-Mo-N coatings was 0.42, and it is decreased to 0.31 after applying CrMoC{sub x}N{sub 1-x} coatings. This result was caused by the formation of a carbon-rich transfer layer that acted as a solid lubricant to reduce contact between the coating surface and steel ball. The microstructure of the coatings was investigated by x-ray diffraction, scanning electron microscopy, and x-ray photoelectron spectroscopy. In this work, the microstructure and mechanical properties of the CrMoC{sub x}N{sub 1-x} coatings were systematically investigated with the instrumental analyses.

  17. Impact of x-ray dose on the response of CR-39 to 1–5.5 MeV alphas

    SciTech Connect (OSTI)

    Rojas-Herrera, J.; Rinderknecht, H. G.; Zylstra, A. B.; Gatu Johnson, M.; Orozco, D.; Rosenberg, M. J.; Sio, H.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2015-03-01

    The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray uences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-Kα and Kβ x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.

  18. Impact of x-ray dose on the response of CR-39 to 1–5.5 MeV alphas

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

    Rojas-Herrera, J.; Rinderknecht, H. G.; Zylstra, A. B.; Gatu Johnson, M.; Orozco, D.; Rosenberg, M. J.; Sio, H.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; et al

    2015-03-01

    The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray uences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-Kα and Kβ x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed tomore » x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.« less

  19. Impact of x-ray dose on the response of CR-39 to 15.5 MeV alphas

    SciTech Connect (OSTI)

    Rojas-Herrera, J.; Rinderknecht, H. G.; Zylstra, A. B.; Gatu Johnson, M.; Orozco, D.; Rosenberg, M. J.; Sio, H.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2015-03-01

    The CR-39 nuclear track detector is used in many nuclear diagnostics #12;fielded at inertial con#12;nement fusion (ICF) facilities. Large x-ray uences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-K?#11; and K#12;? x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0#6; 0.1 Gy causes a decrease of (19 #6;2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 #6;1.3 Gy results in a decrease of (45 #6;5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual eff#11;ect depending on alpha particle energy is characterized using an empirical formula.

  20. High field magnetotransport and point contact Andreev reflection measurements on CuCr{sub 2}Se{sub 4} and CuCr{sub 2}Se{sub 3}BrDegenerate magnetic semiconductor single crystals

    SciTech Connect (OSTI)

    Borisov, K. Coey, J. M. D.; Stamenov, P.; Alaria, J.

    2014-05-07

    Single crystals of the metallically degenerate fully magnetic semiconductors CuCr{sub 2}Se{sub 4} and CuCr{sub 2}Se{sub 3}Br have been prepared by the Chemical Vapour Transport method, using either Se or Br as transport agents. The high-quality, millimetre-sized, octahedrally faceted, needle- and platelet-shaped crystals are characterised by means of high field magnetotransport (?{sub 0}H? 14?T) and Point Contact Andreev Reflection. The relatively high spin polarisation observed |P|>0.56, together with the relatively low minority carrier effective mass of 0.25 m{sub e}, and long scattering time 10{sup ?13}?s, could poise these materials for integration in low- and close-to-room temperature minority injection bipolar heterojunction transistor demonstrations.

  1. Formation of less-known structurally complex ?{sub b} and orthorhombic quasicrystalline approximant ?{sub n} on solidification of selected AlPdCr alloys

    SciTech Connect (OSTI)

    Adamech, M.; ?erni?kov, I.; ?urika, L.; Kolesr, V.; Drienovsk, M.; Bednar?k, J.; Svoboda, M.; Janovec, J.

    2014-11-15

    The evolution of phases was investigated on cooling of Al{sub 71}Pd{sub 24}Cr{sub 5}, Al{sub 73}Pd{sub 20}Cr{sub 7}, and Al{sub 73}Pd{sub 23}Cr{sub 4} alloys from 1350 C down to ambient temperature with the rate of 10 Cmin{sup ?1}. To perform the investigation, differential thermal analysis, synchrotron X-ray powder diffraction, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy were used. In all the investigated alloys structurally complex phases ?{sub n} (?{sub 6} + ?{sub 28}) and ?{sub b}, as well as the ?-phase were identified. Based on the results of differential thermal analysis, sequences of phase transformations were determined. The Al{sub 71}Pd{sub 24}Cr{sub 5} alloy started to solidify at 1031.4 C through ?. Primary dendrites of ?{sub b} were observed in Al{sub 73}Pd{sub 20}Cr{sub 7} and Al{sub 73}Pd{sub 23}Cr{sub 4} alloys. In the second step of solidification ? and/or ?{sub b} were formed. The peritectic reaction, liquid + ?{sub b} + ? ? ?{sub n} + ?{sub b} + ?, leading to the formation of the quasicrystalline approximant ?{sub n} (?{sub 6} + ?{sub 28}) took place in the final step of solidification at approximately 792 C. - Highlights: Structurally complex ?{sub n} (?{sub 6} + ?{sub 28}), ?{sub b} and ?-phases were identified. The Al{sub 71}Pd{sub 24}Cr{sub 5} alloy started to solidify at 1031.4 C through the primary ? phase. The Al{sub 73}Pd{sub 20}Cr{sub 7} and Al{sub 73}Pd{sub 23}Cr{sub 4} alloys solidified in the same way. The quasicrystalline approximant ?{sub n} (?{sub 6} + ?{sub 28}) was formed at approximately 792 C.

  2. High-temperature phase transformation in Cr added TiAl base alloy

    SciTech Connect (OSTI)

    Abe, E.; Niinobe, K.; Nobuki, M.; Nakamura, M.; Tsujimoto, T.

    1999-07-01

    The authors have investigated a microstructure evolution of a Ti-48Al-3.5Cr (in at.%) alloy at high-temperatures ({gt} 1,473K). In the alloy annealed at 1673K for 1.8ks, followed by air-cooling, a characteristic microstructure with a feathery fashion was uniformly formed. From a cooling-rate-controlling study, it was found that formation of the feathery structure is accomplished during continuous cooling from 1673K to 1573K, within the {alpha} + {gamma} two-phase region. Transmission electron microscopy revealed that the feathery structure is composed of lamellar colonies (5--10{micro}m) which are crystallographically tilted slightly (a few degree) with their neighbors. A surprising fact is that lamellae in each colony are mostly the {gamma} phase with few {alpha}{sub 2} phase less than 5% in volume. This suggests that the feathery structure is a metastable product and has not resulted from the {alpha} {r{underscore}arrow} {alpha} + {gamma} transformation above 1,573 K. Instead, the feathery structure formation should be attributed to the non-equilibrium {alpha} {r{underscore}arrow} {gamma} transformation which occurs at high-temperatures with a small degree of supercooling. The authors discuss this interesting phase transformation in terms of the {alpha} {r{underscore}arrow} {gamma} massive transformation, based on the continuous-cooling-transformation (CCT) diagram constructed for the present alloy.

  3. Study on the influence of CR-39 detector size on radon progeny detection in indoor environments

    SciTech Connect (OSTI)

    Pereira, L. A.; Hadler, J. C.; Lixandro F, A. L.; Guedes, S.; Takizawa, R. H.

    2014-11-11

    It is well known that radon daughters up to {sup 214}Po are the real contaminants to be considered in case of indoor radon contamination. Assemblies consisting of 6 circular bare sheets of CR-39, a nuclear track detector, with radius varying from 0.15 to 1.2 cm were exposed far from any material surface for periods of approximately 6 months in 13 different indoor rooms (7 workplaces and 6 dwellings), where ventilation was moderate or poor. It was observed that track density was as greater as smaller was the detector radius. Track density data were fitted using an equation deduced based on the assumption that the behavior of radon and its progeny in the air was described by Fick's Law, i.e., when the main mechanism of transport of radon progeny in the air is diffusion. As many people spend great part of their time in closed or poorly ventilated environments, the confirmation they present equilibrium between radon and its progeny is an interesting start for dosimetric calculations concerning this contamination.

  4. Preliminary Results on FeCrAl Alloys in the As-received and Welded State Designed to Have Enhanced Weldability and Radiation Tolerance

    SciTech Connect (OSTI)

    Field, Kevin G.; Gussev, Maxim N.; Hu, Xunxiang; Yamamoto, Yukinori

    2015-09-30

    The present report summarizes and discusses the recent results on developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability. The alloys used for these investigations are modern FeCrAl alloys based on a Fe-13Cr-5Al-2Mo-0.2Si-0.05Y alloy (in wt.%, designated C35M). Development efforts have focused on assessing the influence of chemistry and microstructure on the fabricability and performance of these newly developed alloys. Specific focus was made to assess the weldability, thermal stability, and radiation tolerance.

  5. Nature of =~SiOCrO(2)CI And (=~SiO)(2)CrO(2) Sites Prepared By Grafting CrO(2)CI(2) Onto Silica

    SciTech Connect (OSTI)

    Demmelmaier, C.A.; White, R.E.; Bokhoven, J.A.van; Scott, S.L.

    2009-05-14

    The room-temperature reaction between chromyl chloride and Sylopol 952 silicas pretreated at 200, 450, and 800 C was investigated using IR, XANES, and EXAFS spectroscopy, as well as by DFT modeling. On the silicas pretreated at 200 and 450 C, the structurally uniform sites formed by the reaction with one surface hydroxyl group are described as {triple_bond}SiOCrO{sub 2}Cl. Unreacted silanols persist on these silicas even in the presence of excess CrO{sub 2}Cl{sub 2}, and on the silica pretreated at 200 C some participate in hydrogen bonding with the grafted monochlorochromate sites. On the silica pretreated at 800 C, both {triple_bond}SiOCrO{sub 2}Cl and ({triple_bond}SiO){sub 2}CrO{sub 2} sites are formed. The latter are produced despite the absence of hydrogen-bonded hydroxyl pairs on the support. The origin of the chromate sites is proposed to be the reaction between CrO{sub 2}Cl{sub 2} and hydroxyl-substituted siloxane 2-rings. These rings are likely formed at 800 C by condensation between a pair of vicinal silanols in which one of the silanols is also a member of a geminal pair.

  6. Photocatalytic H{sub 2} production from spinels ZnGa{sub 2−x}Cr{sub x}O{sub 4} (0≤x≤2) solid solutions

    SciTech Connect (OSTI)

    Xu, Xiaoxiang; Xie, Yinghao; Ni, Shuang; Azad, Abul K.; Cao, Tongcheng

    2015-10-15

    Solid solutions of ZnGa{sub 2−x}Cr{sub x}O{sub 4} (0≤x≤2) were successfully prepared by solid state reactions. Introducing Cr into ZnGa{sub 2}O{sub 4} crystal structure significantly improves its light absorption and greatly enhances its photocatalytic activity. An optimized Cr content (x=1.5 for ZnGa{sub 0.5}Cr{sub 1.5}O{sub 4}) was found for the solid solutions with the highest photocatalytic hydrogen production rate (~775 μmol/h). Compositional analysis suggests there is a strong enrichment of Cr at the surface of sample ZnGa{sub 0.5}Cr{sub 1.5}O{sub 4} compared with other samples. Theoretical calculations suggest their electronic structures involve spin-polarized conduction band (CB) and valence band (VB) that are mainly composed of Cr 3d orbitals. The highest photocatalytic activity observed in ZnGa{sub 0.5}Cr{sub 1.5}O{sub 4} is probably due to the higher Cr content at the surface that favors the Cr 3d orbital overlapping. - Graphical abstract: Electronic structure and density of states of ZnGa{sub 2}O{sub 4} after partially substituting Ga with Cr. - Highlights: • Complete solid solution can be formed between ZnGa{sub 2}O{sub 4} and ZnCr{sub 2}O{sub 4}. • Optical properties and catalytic activity are improved by adding Cr into ZnGa{sub 2}O{sub 4}. • An optimized Cr content exists for the highest activity. • Enrichment of Cr in the surface is beneficial for a better performance.

  7. Formation of a regular domain structure in TGS–TGS + Cr crystals with a profile impurity distribution

    SciTech Connect (OSTI)

    Belugina, N. V. Gainutdinov, R. V.; Tolstikhina, A. L.; Ivanova, E. S.; Kashevich, I. F.; Shut, V. N.; Mozzharov, S. E.

    2015-07-15

    A complex investigation of TGS–TGS + Cr crystals with a profile impurity distribution of chromium ions Cr{sup 3+} has been carried out at the macrolevel (measurement of dielectric properties by the method of nematic liquid crystals) and microlevel (domain structure according to atomic force microscopy data). It is established that periodic doped layers are formed only in individual growth pyramids in the regions where the polarization vector has a nonzero component along the normal to the growth faces rather than throughout the entire crystal volume. The domain configuration at the boundary of growth layers with different impurity compositions has been studied by piezoelectric force microscopy. The static unipolarity of layers with and without chromium impurity is approximately identical, whereas the domain-wall density in doped regions is higher than that in undoped ones by a factor of about 7.

  8. Measurement of the {sup 208}Pb({sup 52}Cr,n){sup 259}Sg excitation function

    SciTech Connect (OSTI)

    Folden III, C. M.; Dragojevic, I.; Garcia, M. A.; Gates, J. M.; Nelson, S. L.; Hoffman, D. C.; Nitsche, H.; Duellmann, Ch. E.; Sudowe, R.; Gregorich, K. E.; Eichler, R.

    2009-02-15

    The excitation function for the {sup 208}Pb({sup 52}Cr,n){sup 259}Sg reaction has been measured using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. The maximum cross section of 320{sub -100}{sup +110} pb is observed at a center-of-target laboratory-frame energy of 253.0 MeV. In total, 25 decay chains originating from {sup 259}Sg were observed and the measured decay properties are in good agreement with previous reports. In addition, a partial excitation function for the {sup 208}Pb({sup 52}Cr,2n){sup 258}Sg reaction was obtained, and an improved {sup 258}Sg half-life of 2.6{sub -0.4}{sup +0.6} ms was calculated by combining all available experimental data.

  9. AN UNBIASED SPECTRAL LINE SURVEY TOWARD R CrA IRS7B IN THE 345 GHz WINDOW WITH ASTE

    SciTech Connect (OSTI)

    Watanabe, Yoshimasa; Sakai, Nami; Yamamoto, Satoshi; Lindberg, Johan E.; Bisschop, Suzanne E.; Jorgensen, Jes K.

    2012-02-01

    We have conducted a spectral line survey in the 332-364 GHz region with the Atacama Submillimeter Telescope Experiment 10 m telescope toward R CrA IRS7B, a low-mass protostar in the Class 0 or Class 0/I transitional stage. We have also performed some supplementary observations in the 450 GHz band. In total, 16 molecular species are identified in the 332-364 GHz region. Strong emission lines of CN and CCH are observed, whereas complex organic molecules and long carbon-chain molecules, which are characteristics of hot corino and warm carbon-chain chemistry (WCCC) source, respectively, are not detected. The rotation temperature of CH{sub 3}OH is evaluated to be 31 K, which is significantly lower than that reported for the prototypical hot corino IRAS 16293-2422 ({approx}85 K). The deuterium fractionation ratios for CCH and H{sub 2}CO are obtained to be 0.038 and 0.050, respectively, which are much lower than those in the hot corino. These results suggest a weak hot corino activity in R CrA IRS7B. On the other hand, the carbon-chain related molecules, CCH and c-C{sub 3}H{sub 2}, are found to be abundant. However, this source cannot be classified as a WCCC source, since long carbon-chain molecules are not detected. If WCCC and hot corino chemistry represent the two extremes in chemical compositions of low-mass Class 0 sources, R CrA IRS7B would be a source with a mixture of these two chemical characteristics. The UV radiation from the nearby Herbig Ae star R CrA may also affect the chemical composition. The present line survey demonstrates further chemical diversity in low-mass star-forming regions.

  10. Phase diagram and magnetocaloric effects in Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15} and (Mn{sub 1?x}Cr{sub x})NiGe{sub 1.05} alloys

    SciTech Connect (OSTI)

    Quetz, Abdiel Muchharla, Baleeswaraiah; Dubenko, Igor; Talapatra, Saikat; Ali, Naushad; Samanta, Tapas; Stadler, Shane

    2014-05-07

    The magnetocaloric and thermomagnetic properties of Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15} and (Mn{sub 1?x}Cr{sub x}) NiGe{sub 1.05} systems for 0???x???0.105 and 0???x???0.1, respectively, have been studied by x-ray diffraction, differential scanning calorimetry, and magnetization measurements. Partial substitution of Cr for Mn in (Mn{sub 1?x}Cr{sub x})NiGe{sub 1.05} results in a first order magnetostructural transition from a hexagonal paramagnetic to an orthorhombic paramagnetic phase near T{sub M}???380?K (for x?=?0.07). Partial substitution of Cr for In in Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15} shifts the magnetostructural transition to a higher temperature (T?=?T{sub M}???450?K) for x?=?0.1. Large magnetic entropy changes of ?S?=??12 (J/(kgK)) and ?S?=??11 (J/(kgK)), both for a magnetic field change of 5?T, were observed in the vicinity of T{sub M} for (Mn{sub 1?x}Cr{sub x})NiGe{sub 1.05} and Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15}, respectively.

  11. Assessing middle school students` understanding of science relationships and processes: Year 2 - instrument validation. Final report

    SciTech Connect (OSTI)

    Schau, C.; Mattern, N.; Weber, R.; Minnick, K.

    1997-01-01

    Our overall purpose for this multi-year project was to develop an alternative assessment format measuring rural middle school students understanding of science concepts and processes and the interrelationships among them. This kind of understanding is called structural knowledge. We had 3 major interrelated goals: (1) Synthesize the existing literature and critically evaluate the actual and potential use of measures of structural knowledge in science education. (2) Develop a structural knowledge alternative assessment format. (3) Examine the validity of our structural knowledge format. We accomplished the first two goals during year 1. The structural knowledge assessment we identified and developed further was a select-and-fill-in concept map format. The goal for our year 2 work was to begin to validate this assessment approach. This final report summarizes our year 2 work.

  12. Science and Technology to Advance Regional Security in the Middle East and Central Asia

    SciTech Connect (OSTI)

    Tompson, A F B; Richardson, J H; Ragaini, R C; Knapp, R B; Rosenberg, N D; Smith, D K; Ball, D Y

    2002-10-09

    This paper is concerned with the promotion and advancement of regional security in the Middle East and Central Asia through the development of bilateral and multilateral cooperation on targeted scientific and technical projects. It is widely recognized that increasing tensions and instability in many parts of the world emphasize--or reemphasize--a need to seek and promote regional security in these areas. At the Lawrence Livermore National Laboratory (LLNL), a national security research facility operated for the US Department of Energy, we are pursuing an effort to use science and technology as a ''low risk'' means of engagement in regions of strategic importance to the United States. In particular, we are developing collaborations and cooperative projects among (and between) national laboratory scientists in the US and our various counterparts in the countries of interest.

  13. The Potential Uses of Commercial Satellite Imagery in the Middle East

    SciTech Connect (OSTI)

    Vannoni, M.G.

    1999-06-08

    It became clear during the workshop that the applicability of commercial satellite imagery to the verification of future regional arms control agreements is limited at this time. Non-traditional security topics such as environmental protection, natural resource management, and the development of infrastructure offer the more promising applications for commercial satellite imagery in the short-term. Many problems and opportunities in these topics are regional, or at least multilateral, in nature. A further advantage is that, unlike arms control and nonproliferation applications, cooperative use of imagery in these topics can be done independently of the formal Middle East Peace Process. The value of commercial satellite imagery to regional arms control and nonproliferation, however, will increase during the next three years as new, more capable satellite systems are launched. Aerial imagery, such as that used in the Open Skies Treaty, can also make significant contributions to both traditional and non-traditional security applications but has the disadvantage of requiring access to national airspace and potentially higher cost. There was general consensus that commercial satellite imagery is under-utilized in the Middle East and resources for remote sensing, both human and institutional, are limited. This relative scarcity, however, provides a natural motivation for collaboration in non-traditional security topics. Collaborations between scientists, businesses, universities, and non-governmental organizations can work at the grass-roots level and yield contributions to confidence building as well as scientific and economic results. Joint analysis projects would benefit the region as well as establish precedents for cooperation.

  14. Biomarker responses in cyprinids of the middle stretch of the River Po, Italy

    SciTech Connect (OSTI)

    Vigano, L.; Arillo, A.; Melodia, F.; Arlati, P.; Monti, C.

    1998-03-01

    Fish belonging to three species of cyprinids, that is, barbel (Barbus plebejus), chub (Leuciscus cephalus), and Italian nase (Chondrostoma soeetta), were collected from two sites of the River Po, located upstream and downstream from the confluence of one of its middle-reach polluted tributaries, the River Lambro. The two groups of individuals caught for each species were analyzed and compared for several microsomal and cytosolic biochemical markers. The enzymatic activities assayed in fish liver included ethoxyresorufin O-deethylase (EROD), aminopyrine-N-demethylase (APDM), uridine diphosphate glucuronyltransferase (UDPGT), glutathione S-transferase (GST), glutathione reductase, and glutathione peroxidase. In addition, the contents of reduced glutathione and nonprotein thiols were measured. Despite some differences among species, all microsomal activities (EROD, APDM, UDPGT) were found to be significantly induced in fish living downstream the River Lambro. With the exception of a higher GST enzyme activity of barbel from the downstream reach, no significant modification was evident in any of the tested cytosolic biomarkers. Results showed that barbel and nase better discriminated the two reaches of the River Po. In general, the alterations observed in feral fish are consistent with the results found in previous studies conducted with rainbow trout (Oncorhynchus mykiss) under both laboratory and field conditions in the same middle reach of the River Po. All of the data indicate that the downstream tract of the main river is exposed to the load of pollutants transported by the River Lambro, including known inducers such as polychlorinated biphenyls and polycyclic aromatic hydrocarbons (PAHs). The latter were analyzed in sediments sampled at the two sites of fish collection, and the downstream sediment showed the highest concentrations of PAHs, although their levels are comparable to those present in moderately polluted locations. Regardless of the site of exposure, barbel seem to be characterized by more efficient antioxidant defenses.

  15. Use of a dynamic simulation model to understand nitrogen cycling in the middle Rio Grande, NM.

    SciTech Connect (OSTI)

    Meixner, Tom; Tidwell, Vincent Carroll; Oelsner, Gretchen; Brooks, Paul; Roach, Jesse D.

    2008-08-01

    Water quality often limits the potential uses of scarce water resources in semiarid and arid regions. To best manage water quality one must understand the sources and sinks of both solutes and water to the river system. Nutrient concentration patterns can identify source and sink locations, but cannot always determine biotic processes that affect nutrient concentrations. Modeling tools can provide insight into these large-scale processes. To address questions about large-scale nitrogen removal in the Middle Rio Grande, NM, we created a system dynamics nitrate model using an existing integrated surface water--groundwater model of the region to evaluate our conceptual models of uptake and denitrification as potential nitrate removal mechanisms. We modeled denitrification in groundwater as a first-order process dependent only on concentration and used a 5% denitrification rate. Uptake was assumed to be proportional to transpiration and was modeled as a percentage of the evapotranspiration calculated within the model multiplied by the nitrate concentration in the water being transpired. We modeled riparian uptake as 90% and agricultural uptake as 50% of the respective evapotranspiration rates. Using these removal rates, our model results suggest that riparian uptake, agricultural uptake and denitrification in groundwater are all needed to produce the observed nitrate concentrations in the groundwater, conveyance channels, and river as well as the seasonal concentration patterns. The model results indicate that a total of 497 metric tons of nitrate-N are removed from the Middle Rio Grande annually. Where river nitrate concentrations are low and there are no large nitrate sources, nitrate behaves nearly conservatively and riparian and agricultural uptake are the most important removal mechanisms. Downstream of a large wastewater nitrate source, denitrification and agricultural uptake were responsible for approximately 90% of the nitrogen removal.

  16. Comparison of hydrocarbon production trends in Middle and Upper members of Minnelusa formation

    SciTech Connect (OSTI)

    Reel, C.L.; Horne, J.C.; Kelly, A.O.

    1985-05-01

    The main reservoir rocks in the upper and middle members of the Minnelusa Formation consist of wind blown dunal sands in the area surrounding the Lusk embayment. Changes in the local depositional setting, tectonic framework, and eustatic sea level controlled the distribution and reservior quality of these sandstones. The middle member exhibits two production trends. Age-equivalent Tensleep rocks deposited along the western margin of the embayment produce from sandstones accumulated in a sand sea paleoenvironment. Structure is atnececessary for trapping owing to permeability continuity. Along the eastern margin of the embayment, production comes from isolated accumulations of sandstone deposited as dunes on broad coastal sabkhas. Fields in these sandstones define a linear trend due to the coast-parallel alignment of these dunes. Production from the upper member defines four major trends. Upper member sandstones in the southern part of the basin, similar to Leo reservoirs, produce from sediments deposited as coast-parallel dunes in a northwest-southeast alignment. In the northern portion of the basin, production is from sandstones deposited in broad, flat eolian sand seas. Because of the permeability continuity of these sandstones, structural closure is necessary for trapping hydrocarbons. Upper member production has been influenced by the unconformity developed at the top of the Minnelusa. Movement along the Rosebud arch resulted in a southwest-northeast production trend apparent in each sandstone unit reflecting their northwestward erosional limits. The last, and most apparent, production trend, results from the Opeche Shale infilling of northwest-southeast-oriented stream valleys. Most production to date has been from sandstones following this alignment juxta-posed downdip of these impermeable shales.

  17. Synthesis of Cr-doped CaTiSiO{sub 5} ceramic pigments by spray drying

    SciTech Connect (OSTI)

    Lyubenova, T. Stoyanova Matteucci, F.; Costa, A.L.; Dondi, M.; Ocana, M.

    2009-04-02

    Cr-doped CaTiSiO{sub 5} was synthesized by spray drying and conventional ceramic method in order to assess its potential as ceramic pigment. The evolution of the phase composition with thermal treatment was investigated by X-ray powder diffraction (XRPD) and thermal analyses (DTA-TGA-EGA). Powder morphology and particle size distribution were analyzed by scanning electron microscopy (SEM) and laser diffraction, respectively. The color efficiency of pigments was evaluated by optical spectroscopy (UV-vis-NIR) and colorimetric analysis (CIE Lab). Results proved that spray drying is an efficient procedure to prepare highly reactive pigment precursors. The spray-dried powders consist of hollow spherical particles with aggregate size in the 1-10 {mu}m range, developing a brown coloration. Optical spectra reveal the occurrence of Cr(III) and Cr(IV), both responsible for the brown color of this pigment. The former occupies the octahedral site of titanite, in substitution of Ti(IV), while the latter is located at the tetrahedral site, where replaces Si(IV)

  18. Deformation Behavior of Laser Welds in High Temperature Oxidation Resistant Fe-Cr-Al Alloys for Fuel Cladding Applications

    SciTech Connect (OSTI)

    Field, Kevin G; Gussev, Maxim N; Yamamoto, Yukinori; Snead, Lance Lewis

    2014-11-01

    Ferritic-structured Fe-Cr-Al alloys are being developed and show promise as oxidation resistant accident tolerant light water reactor fuel cladding. This study focuses on investigating the weldability of three model alloys in a range of Fe-(13-17.5)Cr-(3-4.4)Al in weight percent with a minor addition of yttrium using laser-welding techniques. A detailed study on the mechanical performance of bead-on-plate welds has been carried out to determine the performance of welds as a function of alloy composition. Laser welding resulted in a defect free weld devoid of cracking or inclusions for all alloys studied. Results indicated a reduction in the yield strength within the fusion zone compared to the base metal. Yield strength reduction was found to be primarily constrained to the fusion zone due to grain coarsening with a less severe reduction in the heat affected zone. No significant correlation was found between the deformation behavior/mechanical performance of welds and the level of Cr or Al in the alloy ranges studied.

  19. Comparison of Crevice Corrosion of Fe-Based Amorphous Metal and Crystalline Ni-Cr-Mo Alloy

    SciTech Connect (OSTI)

    Shan, X; Ha, H; Payer, J H

    2008-07-24

    The crevice corrosion behaviors of an Fe-based bulk metallic glass alloy (SAM1651) and a Ni-Cr-Mo crystalline alloy (C-22) were studied in 4M NaCl at 100 C with cyclic potentiodynamic polarization and constant potential tests. The corrosion damage morphologies, corrosion products and the compositions of corroded surfaces of these two alloys were studied with optical 3D reconstruction, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Auger Electron Spectroscopy (AES). It was found that the Fe-based bulk metallic glass (amorphous alloy) SAM1651 had a more positive breakdown potential and repassivation potential than crystalline alloy C-22 in cyclic potentiodynamic polarization tests and required a more positive oxidizing potential to initiate crevice corrosion in constant potential test. Once crevice corrosion initiated, the corrosion propagation of C-22 was more localized near the crevice border compared to SAM1651, and SAM1651 repassivated more readily than C-22. The EDS results indicated that the corrosion products of both alloys contained high amount of O and were enriched in Mo and Cr. The AES results indicated that a Cr-rich oxide passive film was formed on the surfaces of both alloys, and both alloys were corroded congruently.

  20. Properties of molecular beam epitaxy grown Eu{sub x}(transition metal){sub y} films (transition metals: Mn, Cr)

    SciTech Connect (OSTI)

    Balin, K.; Nowak, A.; Gibaud, A.; Szade, J.; Celinski, Z.

    2011-04-01

    The electronic and crystallographic structures, as well as the magnetic properties, of Eu{sub x}(transition metal){sub y} (transition metals: Mn, Cr) thin films grown by molecular beam epitaxy were studied. Relative changes of the Eu/Mn and Eu/Cr ratios derived from the XPS lines, as well as x-ray reflectivity, indicate mixing of the Eu/Mn and Eu/Cr layers. Valency transitions from Eu{sup 2+} to Eu{sup 3+} were observed in both systems for most studied stoichiometries. A transition to a magnetically ordered phase was observed at 15 K, 40 K, and 62 K for selected films in the Eu-Mn system, and at 50 K for the film with a Eu/Cr ratio of 0.5.

  1. Laser welding and post weld treatment of modified 9Cr-1MoVNb steel.

    SciTech Connect (OSTI)

    Xu, Z.

    2012-04-03

    Laser welding and post weld laser treatment of modified 9Cr-1MoVNb steels (Grade P91) were performed in this preliminary study to investigate the feasibility of using laser welding process as a potential alternative to arc welding methods for solving the Type IV cracking problem in P91 steel welds. The mechanical and metallurgical testing of the pulsed Nd:YAG laser-welded samples shows the following conclusions: (1) both bead-on-plate and circumferential butt welds made by a pulsed Nd:YAG laser show good welds that are free of microcracks and porosity. The narrow heat affected zone has a homogeneous grain structure without conventional soft hardness zone where the Type IV cracking occurs in conventional arc welds. (2) The laser weld tests also show that the same laser welder has the potential to be used as a multi-function tool for weld surface remelting, glazing or post weld tempering to reduce the weld surface defects and to increase the cracking resistance and toughness of the welds. (3) The Vicker hardness of laser welds in the weld and heat affected zone was 420-500 HV with peak hardness in the HAZ compared to 240 HV of base metal. Post weld laser treatment was able to slightly reduce the peak hardness and smooth the hardness profile, but failed to bring the hardness down to below 300 HV due to insufficient time at temperature and too fast cooling rate after the time. Though optimal hardness of weld made by laser is to be determined for best weld strength, methods to achieve the post weld laser treatment temperature, time at the temperature and slow cooling rate need to be developed. (4) Mechanical testing of the laser weld and post weld laser treated samples need to be performed to evaluate the effects of laser post treatments such as surface remelting, glazing, re-hardening, or tempering on the strength of the welds.

  2. Collapse of the low temperature insulating state in Cr-doped V{sub 2}O{sub 3} thin films

    SciTech Connect (OSTI)

    Homm, P. Dillemans, L.; Menghini, M.; Van Bilzen, B.; Bakalov, P.; Su, C.-Y.; Lieten, R.; Houssa, M.; Locquet, J.-P.; Nasr Esfahani, D.; Covaci, L.; Peeters, F. M.; Seo, J. W.

    2015-09-14

    We have grown epitaxial Cr-doped V{sub 2}O{sub 3} thin films with Cr concentrations between 0% and 20% on (0001)-Al{sub 2}O{sub 3} by oxygen-assisted molecular beam epitaxy. For the highly doped samples (>3%), a regular and monotonous increase of the resistance with decreasing temperature is measured. Strikingly, in the low doping samples (between 1% and 3%), a collapse of the insulating state is observed with a reduction of the low temperature resistivity by up to 5 orders of magnitude. A vacuum annealing at high temperature of the films recovers the low temperature insulating state for doping levels below 3% and increases the room temperature resistivity towards the values of Cr-doped V{sub 2}O{sub 3} single crystals. It is well-know that oxygen excess stabilizes a metallic state in V{sub 2}O{sub 3} single crystals. Hence, we propose that Cr doping promotes oxygen excess in our films during deposition, leading to the collapse of the low temperature insulating state at low Cr concentrations. These results suggest that slightly Cr-doped V{sub 2}O{sub 3} films can be interesting candidates for field effect devices.

  3. AREVA NP Cr{sub 2}O{sub 3}-doped fuel development for BWRs

    SciTech Connect (OSTI)

    Delafoy, C.; Dewes, P.; Miles, T.

    2007-07-01

    The search for improvements in nuclear fuel cycle economics results in increasing demands for fuel discharged burnup and reliability, plant maneuverability and power up-rating. To achieve these objectives without any reduction of safety margins, fuel design and materials that enable enhanced performance capabilities have been developed or are under investigations. Research on fuel pellets focuses on the modification of the microstructure to increase fission product retention and pellet mechanical compliance. Currently, production of the desired large grain viscoplastic UO{sub 2} fuel microstructures has been extensively investigated by AREVA NP through the use of doping elements. This track is nowadays a worldwide working field. In this area, AREVA NP has launched the development of a new UO{sub 2} fuel pellet obtained by optimum chromium oxide doping. The purpose of this paper is first to present the current results with the AREVA NP optimized chromia doped fuel and to discuss the key advantages in terms of fuel performance for BWR applications. In particular, the development relies on ramp testing results, fuel temperature and fission gas release values acquired at high burnup and high power levels. Second, the paper focuses on the qualification process implemented by AREVA NP to assess the margins of the optimized Cr{sub 2}O{sub 3}-doped UO{sub 2} fuel towards safety criteria at high burnup and the risk of PCI failure, as well as to develop calculation tools to support design. The driving force in this qualification plan is to gain the accurate knowledge of the optimized doped fuel behavior under normal, transient and anticipated accident conditions. To support this effort, irradiation campaigns are under progress in PWR and BWR plants to cover a wide range of existing operating conditions and to anticipate future demands. Considering only the BWR part, the program has successfully run since 2005 and is designed to obtain data up to high burnup, at least 70 GWd/tU. The aim is to define the range of operational conditions for application of chromia-doped fuel in combination with LTP2 non-liner cladding as an alternative to the present standard Fe-enhanced Zr liner cladding. (authors)

  4. Negligible Magnetism in Excellent Structural Quality Cr[subscript x]Ti[subscript 1-x]O[subscript 2] Anatase: Contrast with High-T[subscript C] Ferromagnetism in Structurally Defective Cr[subscript x]Ti[subscript 1-x]O[subscript 2

    SciTech Connect (OSTI)

    Kaspar, T.C.; Heald, S.M.; Wang, C.M.; Bryan, J.D.; Droubay, T.; Shutthanandan, V.; Thevuthasan, S.; McCready, D.E.; Kellock, A.J.; Gamelin, D.R.; Chambers, S.A.

    2010-07-19

    We reexamine the mechanism of ferromagnetism in doped TiO{sub 2} anatase, using epitaxial Cr:TiO{sub 2} with excellent structural quality as a model system. In contrast to highly oriented but defective Cr:TiO{sub 2} ({approx}0.5{micro}{sub B}/Cr), these structurally superior single crystal films exhibit negligible ferromagnetism. Similar results were obtained for Co:TiO{sub 2}. We show for the first time that charge-compensating oxygen vacancies alone, as predicted by F-center mediated exchange, are not sufficient to activate ferromagnetism. Instead, the onset of ferromagnetism correlates with the presence of structural defects.

  5. Prediction and Monitoring Systems of Creep-Fracture Behavior of 9Cr-1Mo Steels for Teactor Pressure Vessels

    SciTech Connect (OSTI)

    Potirniche, Gabriel; Barlow, Fred D.; Charit, Indrajit; Rink, Karl

    2013-11-26

    A recent workshop on next-generation nuclear plant (NGNP) topics underscored the need for research studies on the creep fracture behavior of two materials under consideration for reactor pressure vessel (RPV) applications: 9Cr-1Mo and SA-5XX steels. This research project will provide a fundamental understanding of creep fracture behavior of modified 9Cr-1Mo steel welds for through modeling and experimentation and will recommend a design for an RPV structural health monitoring system. Following are the specific objectives of this research project: • Characterize metallurgical degradation in welded modified 9Cr-1Mo steel resulting from aging processes and creep service conditions. • Perform creep tests and characterize the mechanisms of creep fracture process. • Quantify how the microstructure degradation controls the creep strength of welded steel specimens. • Perform finite element (FE) simulations using polycrystal plasticity to understand how grain texture affects the creep fracture properties of welds. • Develop a microstructure-based creep fracture model to estimate RPVs service life . • Manufacture small, prototypic, cylindrical pressure vessels, subject them to degradation by aging, and measure their leak rates. • Simulate damage evolution in creep specimens by FE analyses. • Develop a model that correlates gas leak rates from welded pressure vessels with the amount of microstructural damage. • Perform large-scale FE simulations with a realistic microstructure to evaluate RPV performance at elevated temperatures and creep strength. • Develop a fracture model for the structural integrity of RPVs subjected to creep loads. • Develop a plan for a non-destructive structural health monitoring technique and damage detection device for RPVs.

  6. An example of mixing-zone dolomite, Middle Eocene Avon Park Formation, Floridan aquifer system

    SciTech Connect (OSTI)

    Cander, H.S. )

    1994-07-01

    A late-formed dolomite cement in a core of the Middle Eocene Avon Park Formation, peninsular Florida, provides an example of dolomite cement from a mixing zone and illustrates how dolomite textural alteration and stabilization can occur at earth-surface conditions. The Avon Park Formation is a pervasively dolomitized peritidal platform carbonate 400 m thick in the Florida aquifer system. Typical Avon Park dolomite is inclusion-rich, fine-grained (< 40 mm), noncathodoluminescent, highly porous (average, 20%), and formed during the Eocene by normal to hypersaline seawater ([delta][sup 18]O = + 3.7[per thousand] PDB; [delta][sup 13]C = + 2.0[per thousand]; [sup 87]Sr/[sup 86]Sr = 0.70778; Sr = 167 ppm). In a 20 m interval in a core from southwest Florida, inclusion-free, cathodoluminescent dolomite overgrows the early-formed noncathodoluminescent marine dolomite. The cathodoluminescent dolomite cement profoundly alters the texture of Avon Park dolomite from typical Cenozoic-like porous, poorly crystalline dolomite to hard, dense, low-porosity, highly crystalline Paleozoic-like dolomite. The dolomite cement is not a replacement of limestone but an overgrowth of early-formed marine dolomite and pore-occluding cement. This study demonstrates that: (1) dolomite precipitated from a 75% seawater mixing-zone fluid that was both calcite saturated and sulfate-rich, and (2) dramatic textural maturation and stabilization in dolomite can occur in the near surface environment, without elevated temperature and burial conditions.

  7. Simple bond-order-type interatomic potential for an intermixed Fe-Cr-C system of metallic and covalent bondings in heat-resistant ferritic steels

    SciTech Connect (OSTI)

    Kumagai, Tomohisa Nakamura, Kaoru; Yamada, Susumu; Ohnuma, Toshiharu

    2014-12-28

    It is known that M{sub 23}C{sub 6}(M?=?Cr/Fe) behavior in heat-resistant ferritic steels affects the strength of the material at high temperature. The ability to garner direct information regarding the atomic motion using classical molecular dynamics simulations is useful for investigating the M{sub 23}C{sub 6} behavior in heat-resistant ferritic steels. For such classical molecular dynamics calculations, a suitable interatomic potential is needed. To satisfy this requirement, an empirical bond-order-type interatomic potential for Fe-Cr-C systems was developed because the three main elements to simulate the M{sub 23}C{sub 6} behavior in heat-resistant ferritic steels are Fe, Cr, and C. The angular-dependent term, which applies only in non-metallic systems, was determined based on the similarity between a Finnis-Sinclair-type embedded-atom-method interatomic potential and a Tersoff-type bond-order potential. The potential parameters were determined such that the material properties of Fe-Cr-C systems were reproduced. These properties include the energy and lattice constants of 89 crystal structures; the elastic constants of four realistic precipitates; the bulk moduli of B1, B2, and B3 crystals; the surface energies of B1 and B2 crystals; and the defect-formation energies and atomic configurations of 66 Fe-Cr-C complexes. Most of these material properties were found to be reproduced by our proposed empirical bond-order potentials. The formation energies and lattice constants of randomly mixed Fe-Cr alloys calculated using the interatomic potentials were comparable to those obtained through experiments and first-principles calculations. Furthermore, the energies and structures of interfaces between Cr carbide and ?-Fe as predicted through first-principles calculations were well reproduced using these interatomic potentials.

  8. Electrical spin injection using GaCrN in a GaN based spin light emitting diode

    SciTech Connect (OSTI)

    Banerjee, D.; Ganguly, S.; Saha, D.; Adari, R.; Sankaranarayan, S.; Kumar, A.; Aldhaheri, R. W.; Hussain, M. A.; Balamesh, A. S.

    2013-12-09

    We have demonstrated electrical spin-injection from GaCrN dilute magnetic semiconductor (DMS) in a GaN-based spin light emitting diode (spin-LED). The remanent in-plane magnetization of the thin-film semiconducting ferromagnet has been used for introducing the spin polarized electrons into the non-magnetic InGaN quantum well. The output circular polarization obtained from the spin-LED closely follows the normalized in-plane magnetization curve of the DMS. A saturation circular polarization of ?2.5% is obtained at 200?K.

  9. Investigations of protons passing through the CR-39/PM-355 type of solid state nuclear track detectors

    SciTech Connect (OSTI)

    Malinowska, A.; Szyd?owski, A.; Jask?a, M.; Korman, A.; Kuk, M.; Sartowska, B.; Kuehn, T.

    2013-07-15

    Solid State Nuclear Track Detectors of the CR-39/PM-355 type were irradiated with protons with energies in the range from 0.2 to 8.5 MeV. Their intensities and energies were controlled by a Si surface barrier detector located in an accelerator scattering chamber. The ranges of protons with energies of 67 MeV were comparable to the thickness of the PM-355 track detectors. Latent tracks in the polymeric detectors were chemically etched under standard conditions to develop the tracks. Standard optical microscope and scanning electron microscopy techniques were used for surface morphology characterization.

  10. Application of USNRC NUREG/CR-6661 and draft DG-1108 to evolutionary and advanced reactor designs

    SciTech Connect (OSTI)

    Chang 'Apollo', Chen

    2006-07-01

    For the seismic design of evolutionary and advanced nuclear reactor power plants, there are definite financial advantages in the application of USNRC NUREG/CR-6661 and draft Regulatory Guide DG-1108. NUREG/CR-6661, 'Benchmark Program for the Evaluation of Methods to Analyze Non-Classically Damped Coupled Systems', was by Brookhaven National Laboratory (BNL) for the USNRC, and Draft Regulatory Guide DG-1108 is the proposed revision to the current Regulatory Guide (RG) 1.92, Revision 1, 'Combining Modal Responses and Spatial Components in Seismic Response Analysis'. The draft Regulatory Guide DG-1108 is available at http://members.cox.net/apolloconsulting, which also provides a link to the USNRC ADAMS site to search for NUREG/CR-6661 in text file or image file. The draft Regulatory Guide DG-1108 removes unnecessary conservatism in the modal combinations for closely spaced modes in seismic response spectrum analysis. Its application will be very helpful in coupled seismic analysis for structures and heavy equipment to reduce seismic responses and in piping system seismic design. In the NUREG/CR-6661 benchmark program, which investigated coupled seismic analysis of structures and equipment or piping systems with different damping values, three of the four participants applied the complex mode solution method to handle different damping values for structures, equipment, and piping systems. The fourth participant applied the classical normal mode method with equivalent weighted damping values to handle differences in structural, equipment, and piping system damping values. Coupled analysis will reduce the equipment responses when equipment, or piping system and structure are in or close to resonance. However, this reduction in responses occurs only if the realistic DG-1108 modal response combination method is applied, because closely spaced modes will be produced when structure and equipment or piping systems are in or close to resonance. Otherwise, the conservatism in the current Regulatory Guide 1.92, Revision 1, will overshadow the advantage of coupled analysis. All four participants applied the realistic modal combination method of DG-1108. Consequently, more realistic and reduced responses were obtained. (authors)

  11. Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter deposition

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

    An, Zhinan; Jia, Haoling; Wu, Yueying; Rack, Philip D.; Patchen, Allan D.; Liu, Yuzi; Ren, Yang; Li, Nan; Liaw, Peter K.

    2015-05-04

    The concept of high configurational entropy requires that the high-entropy alloys (HEAs) yield single-phase solid solutions. However, phase separations are quite common in bulk HEAs. A five-element alloy, CrCoCuFeNi, was deposited via radio frequency magnetron sputtering and confirmed to be a single-phase solid solution through the high-energy synchrotron X-ray diffraction, energy-dispersive spectroscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. The formation of the solid-solution phase is presumed to be due to the high cooling rate of the sputter-deposition process.

  12. Roles of Fe2+, Fe3+, and Cr3+ Surface Sites in the Oxidation of NO on the (Fe,Cr)3O4(1 1 1) Surface Termination of an ?-(Fe,Cr)2O3(0 0 0 1) Mixed Oxide

    SciTech Connect (OSTI)

    Henderson, Michael A.

    2014-10-01

    The oxidation and photooxidation reactions of nitric oxide were explored on a mixed Fe and Cr mixed oxide surface using temperature programmed desorption (TPD). The mixed oxide surface examined initially had a corundum (0001) structure with a nominal cation composition of 75% Fe and 25% Cr, but after sputter/anneal cleaning was transformed into a magnetite-like (111) surface structure enriched with Cr (~40%). TPD studies of nitric oxide on the (Fe,Cr)3O4(111) surface revealed two main desorption states at 220 and 370 K, along with a third minor desorption state at ~310 K. Similarly, O2 TPD occurred in two main TPD states (100 and 230 K) and a minor state (155 K). The more strongly and weakly bound NO and O2 molecules were assigned to adsorption at Fe2+ and Fe3+ sites, respectively, with the minor desorption states assigned to Cr3+ sites. No thermal decomposition or surface chemistry was detected in TPD for adsorbed NO (e.g., no N2 or N2O formation), whereas ~10% of the adsorbed O2 irreversibly dissociated at Fe2+ sites. These dissociated oxygen species did not react with coadsorbed NO, but instead blocked NO adsorption at the Fe2+ sites, but had no effect on NO adsorption at Fe3+ sites. In contrast, NO reacted with preadsorbed O2 molecules to generate an adsorbed nitrate/nitrite species that decomposed in TPD to liberate NO at 425 K, leaving an O atom on the surface. Coadsorption of 15N18O with 16O2 suggests the oxidized species was a nitrate based on the detected level of oxygen scrambling. Preadsorption of O2 was required for nitrate formation as preadsorbed NO blocked both O2 adsorption and the oxidation reaction. Irradiation of adsorbed NO with 460 nm light at 40 K resulted in rapid photodesorption of NO without generation of any new surface species. Irradiation of the coadsorbed NO+O2 system did not promote additional NO oxidation, but limited the extent of thermal NO oxidation (in subsequent TPD) by photodepleting the surface of adsorbed NO. Preheating the NO+O2 adlayer to 250 K prior to 460 nm light irradiation restored the level of thermal NO oxidation, revealing both that thermal activation is required for NO oxidation on the (Fe,Cr)3O4(111) surface and that the nitrate product was insensitive to 460 nm light. The author thanks Drs. Sara Chamberlin and Scott Chambers for supplying the film used in this work. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  13. Fluid diversion and sweep improvement with chemical gels in oil recovery processes. [Four types of gels: resorcinol-formaldehyde; colloidal silica; Cr sup 3+ (chloride)-xanthan; and Cr sup 3+ (acetate)-polyacrylamide

    SciTech Connect (OSTI)

    Seright, R.S.; Martin, F.D.

    1992-09-01

    The objectives of this project were to identify the mechanisms by which gel treatments divert fluids in reservoirs and to establish where and how gel treatments are best applied. Several different types of gelants were examined, including polymer-based gelants, a monomer-based gelant, and a colloidal-silica gelant. This research was directed at gel applications in water injection wells, in production wells, and in high-pressure gas floods. The work examined how the flow properties of gels and gelling agents are influenced by permeability, lithology, and wettability. Other goals included determining the proper placement of gelants, the stability of in-place gels, and the types of gels required for the various oil recovery processes and for different scales of reservoir heterogeneity. During this three-year project, a number of theoretical analyses were performed to determine where gel treatments are expected to work best and where they are not expected to be effective. The most important, predictions from these analyses are presented. Undoubtedly, some of these predictions will be controversial. However, they do provide a starting point in establishing guidelines for the selection of field candidates for gel treatments. A logical next step is to seek field data that either confirm or contradict these predictions. The experimental work focused on four types of gels: (1) resorcinol-formaldehyde, (2) colloidal silica, (3) Cr{sup 3+}(chloride)-xanthan, and (4) Cr{sup 3+}(acetate)-polyacrylamide. All experiments were performed at 41{degrees}C.

  14. Effect of Cr substitution on the magnetic and magnetic-transport properties of Fe{sub 2}Mn{sub 1-x}Cr{sub x}Si alloys

    SciTech Connect (OSTI)

    Pal, Lakhan; Gupta, Sachin; Suresh, K. G.; Nigam, A. K.

    2014-05-07

    Fe{sub 2}Mn{sub 1-x}Cr{sub x}Si (x?=?0, 0.1, and 0.2) alloys were investigated for their magnetic and transport properties in view of the expected half metallicity. It is found that Cr substitution suppresses the antiferromagnetic phase present in parent Fe{sub 2}MnSi, which completely disappears for x?=?0.2. Curie temperature of the alloys increases from 230?K to 299?K as x is increased from 0 to 0.2. The value of the Rhodes-Wohlfarth ratio indicates that the system shows iterant magnetism. Resistivity measurements also show absence of antiferromagnetic phase for x?=?0.2. Resistivity data have been fitted by considering the electron-phonon and electron-magnon scattering contributions, which indicates the presence of half metallicity in these compounds. Temperature dependence of resistivity data shows magnetoresistance of ?3% and ?2.5% at Curie temperature with applied field of 50 kOe for x?=?0.1 and 0.2, respectively.

  15. Study the effect of mechanical alloying parameters on synthesis of Cr{sub 2}NbAl{sub 2}O{sub 3} nanocomposite

    SciTech Connect (OSTI)

    Shayesteh, Payam Mirdamadi, Shamseddin; Razavi, Hossein

    2014-01-01

    Graphical abstract: - Highlights: Cr{sub 2}NbAl{sub 2}O{sub 3} nanocomposite synthesized through MA. Effect of BPR, rotating speed, milling time and PCA concentration investigated. After annealing at 1100 C crystalline phase were appeared. WilliamsonHall analysis was used in order to study the grain size of nano composite. - Abstract: In this study, Cr{sub 2}Nb20 vol.% Al{sub 2}O{sub 3} nanocomposite was prepared successfully by mechanochemical reaction between Al, Nb and Cr{sub 2}O{sub 3} powders. Amorphization of powder occurred during mechanical alloying because of high energy collisions between powders and steel balls in milling container which transfer high degree of energy to powders. Therefore, annealing was needed to form crystalline phases. The influence of different mechanical alloying parameters such as BPR, rotating speed, milling time and PCA concentration on synthesis of composite material were investigated. After mechanical alloying, the powder was encapsulated in quartz and then annealed at 1100 C for 3 h. After annealing, 3 different phases were appeared (Cr{sub 2}Nb (cubic), Cr{sub 2}Nb (hexagonal) and ?-Al{sub 2}O{sub 3}). The structural changes of powder particles during mechanical alloying were studied by X-ray diffractometry (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM)

  16. Ferromagnetism of magnetically doped topological insulators in Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films

    SciTech Connect (OSTI)

    Ni, Y.; Zhang, Z. Hadimani, R. L.; Tuttle, G.; Jiles, D. C.; Nlebedim, I. C.

    2015-05-07

    We investigated the effect of magnetic doping on magnetic and transport properties of Bi{sub 2}Te{sub 3} thin films. Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films with x = 0.03, 0.14, and 0.29 were grown epitaxially on mica substrate with low surface roughness (∼0.4 nm). It is found that Cr is an electron acceptor in Bi{sub 2}Te{sub 3} and increases the magnetization of Cr{sub x}Bi{sub 2−x}Te{sub 3}. When x = 0.14 and 0.29, ferromagnetism appears in Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films, where anomalous Hall effect and weak localization of magnetoconductance were observed. The Curie temperature, coercivity, and remnant Hall resistance of thin films increase with increasing Cr concentration. The Arrott-Noakes plot demonstrates that the critical mechanism of the ferromagnetism can be described better with 3D-Heisenberg model than with mean field model. Our work may benefit for the practical applications of magnetic topological insulators in spintronics and magnetoelectric devices.

  17. Influence of Cr and W alloying on the fiber-matrix interfacial shear strength in cast and directionally solidified sapphire NiAl composites

    SciTech Connect (OSTI)

    Asthana, R.; Tiwari, R.; Tewari, S.N.

    1995-08-01

    Sapphire-reinforced NiAl matrix composites with chromium or tungsten as alloying additions were synthesized using casting and zone directional solidification (DS) techniques and characterized by a fiber pushout test as well as by microhardness measurements. The sapphire-NiAl(Cr) specimens exhibited an interlayer of Cr rich eutectic at the fiber-matrix interface and a higher interfacial shear strength compared to unalloyed sapphire-NiAl specimens processed under identical conditions. In contrast, the sapphire-NiAl(W) specimens did not show interfacial excess of tungsten rich phases, although the interfacial shear strength was high and comparable to that of sapphire-NiAl(Cr). The postdebond sliding stress was higher in sapphire-NiAl(Cr) than in sapphire-NiAl(W) due to interface enrichment with chromium particles. The matrix microhardness progressively decreased with increasing distance from the interface in both DS NiAl and NiAl(Cr) specimens. The study highlights the potential of casting and DS techniques to improve the toughness and strength of NiAl by designing dual-phase microstructures in NiAl alloys reinforced with sapphire fibers.

  18. Magnetic Correlations in the Quasi-Two-Dimensional Semiconducting Ferromagnet CrSiTe3

    SciTech Connect (OSTI)

    Williams, Travis J.; Aczel, Adam A.; Lumsden, Mark D.; Nagler, Stephen E.; Stone, Matthew B.; Yan, Jiaqiang -Q.; Mandrus, D.

    2015-10-02

    Intrinsic, 2D ferromagnetic semiconductors are an important class of materials for overcoming dilute magnetic semiconductors’ limitations for spintronics. CrSiTe3 is a particularly interesting material of this class, since it can likely be exfoliated to single layers, for which Tc is predicted to increase dramatically. Establishing the nature of the bulk material’s magnetism is necessary for understanding the thin-film magnetic behavior and the material’s possible applications. In this work, we use elastic and inelastic neutron scattering to measure the magnetic properties of single crystalline CrSiTe3. We find a very small single ion anisotropy that favors magnetic ordering along the c-axis and that the measured spin waves fit well to a model in which the moments are only weakly coupled along that direction. Then, we find that both static and dynamic correlations persist within the ab-plane up to at least 300 K, which is strong evidence of the material's 2D characteristics that are relevant for future studies on thin film and monolayer samples.

  19. Nano-twin Mediated Plasticity in Carbon-containing FeNiCoCrMn High Entropy Alloys

    SciTech Connect (OSTI)

    Wu, Zhenggang; Bei, Hongbin; Parish, Chad M

    2015-06-14

    Equiatomic FeNiCoCrMn alloy has been reported to exhibit promising strength and ductility at cryogenic temperature and deformation mediated by nano-twining appeared to be one of the main reasons. We use the FeNiCoCrMn alloy as a base alloy to seek further improvement of its mechanical properties by alloying additional elements, i.e., interstitial carbon. Moreover, the effects of carbon on microstructures, mechanical properties and twinning activities were investigated in two different temperatures (77 and 293 K). With addition of 0.5 at% C, the high entropy alloy still remains entirely single phase face-centered cubic (FCC) crystal structure. We found that these materials can be cold rolled and recrystallized to produce a microstructure with equiaxed grains. Both strain hardening rate and strength are enhanced while high uniform elongations to fracture (~70% at 77 K and ~40% at 293 K) are still maintained. The increased strain hardening and strength could be caused by the promptness of deformation twinning in C-containing high entropy alloys.

  20. Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

    SciTech Connect (OSTI)

    Durmaz, M. Abakay, E.; Sen, U.; Sen, S.; Kilinc, B.

    2015-03-30

    In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1?m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575C for 8?h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000C for 2?h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr{sub 2}N. The depth of the layer was 8.15?m. The average hardness of the layer was 216015 HV{sub 0.025}. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

  1. Exceptional damage-tolerance of a medium-entropy alloy CrCoNi at cryogenic temperatures

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

    Gludovatz, Bernd; Hohenwarter, Anton; Thurston, Keli V. S.; Bei, Hongbin; Wu, Zhenggang; George, Easo P.; Ritchie, Robert O.

    2016-02-02

    The high-entropy alloys are an intriguing new class of metallic materials that derive their properties not from a single dominant constituent, such as iron in steels, nor from the presence of a second phase, such as in nickel-base superalloys, but rather comprise multi-element systems that crystallize as a single phase, despite containing high concentrations (~20 at.%) of five or more elements with different crystal structures. Indeed, we have recently reported on one such single-phase high-entropy alloy, NiCoCrFeMn, which displays exceptional strength and toughness at cryogenic temperatures. Here which displays unprecedented strength-toughness properties that exceed those of all high-entropy alloys andmore » most multi-phase alloys. With roomtemperature tensile strengths of almost 1 GPa and KJIc fracture-toughness values above 200 MPa.m 1/2 (with crack-growth toughnesses exceeding 300 MPa.m 1/2), the strength, ductility and toughness of the NiCoCr alloy actually improve at cryogenic temperatures to unprecedented levels of strengths above 1.3 GPa, failure strains up to 90% and KJIc values of 275 MPa.m 1/2 (with crackgrowth toughnesses above 400 MPa.m 1/2). These properties appear to result from continuous steady strain hardening, which acts to suppress plastic instability, resulting from pronounced dislocation activity and deformation-induced nano-twinning.« less

  2. Multiferroic CuCrO? under high pressure: In situ X-ray diffraction and Raman spectroscopic studies

    SciTech Connect (OSTI)

    Garg, Alka B. Mishra, A. K.; Pandey, K. K.; Sharma, Surinder M.

    2014-10-07

    The compression behavior of delafossite compound CuCrO? has been investigated by in situ x-ray diffraction (XRD) and Raman spectroscopic measurements up to 23.2 and 34 GPa, respectively. X-ray diffraction data show the stability of ambient rhombohedral structure up to ~23 GPa. Material shows large anisotropy in axial compression with c-axis compressibility, ?{sub c} = 1.26 10?(1) GPa? and a-axis compressibility, ?{sub a} = 8.90 10?(6) GPa?. Our XRD data show an irreversible broadening of diffraction peaks. Pressure volume data when fitted to 3rd order Birch-Murnaghan equation of state give the value of bulk modulus, B? = 156.7(2.8) GPa with its pressure derivative, B?{sup } as 5.3(0.5). All the observed vibrational modes in Raman measurements show hardening with pressure. Appearance of a new mode at ~24 GPa indicates the structural phase transition in the compound. Our XRD and Raman results indicate that CuCrO{sub 2} may be transforming to an ordered rocksalt type structure under compression.

  3. Exceptional damage-tolerance of a medium-entropy alloy NiCoCr at cryogenic temperatures

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

    Gludovatz, Bernd; Hohenwarter, Anton; Thurston, Keli; Bei, Hongbin; Wu, Zhenggang; George, Easo

    2016-01-01

    High-entropy alloys1 3 are an intriguing new class of metallic materials that derive their properties not from a single dominant constituent, such as iron in steels, nor from the presence of a second phase, such as in nickel-base superalloys, but rather comprise multi-element systems that crystallize as a single phase4 7, despite containing high concentrations (~20 at.%) of five or more elements with different crystal structures5 7. Indeed, we have recently reported on one such single-phase high-entropy alloy, NiCoCrFeMn, which displays exceptional strength and toughness at cryogenic temperatures8. Here which displays unprecedented strength-toughness properties that exceed those of all high-entropymore »alloys and most multi-phase alloys. With roomtemperature tensile strengths of almost 1 GPa and KJIc fracture-toughness values above 200 MPa.m1/2 (with crack-growth toughnesses exceeding 300 MPa.m1/2), the strength, ductility and toughness of the NiCoCr alloy actually improve at cryogenic temperatures to unprecedented levels of strengths above 1.3 GPa, failure strains up to 90% and KJIc values of 275 MPa.m1/2 (with crackgrowth toughnesses above 400 MPa.m1/2). Such properties appear to result from continuous steady strain hardening, which acts to suppress plastic instability, resulting from pronounced dislocation activity and deformation-induced nano-twinning.« less

  4. Nano-twin Mediated Plasticity in Carbon-containing FeNiCoCrMn High Entropy Alloys

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

    Wu, Zhenggang; Bei, Hongbin; Parish, Chad M

    2015-06-14

    Equiatomic FeNiCoCrMn alloy has been reported to exhibit promising strength and ductility at cryogenic temperature and deformation mediated by nano-twining appeared to be one of the main reasons. We use the FeNiCoCrMn alloy as a base alloy to seek further improvement of its mechanical properties by alloying additional elements, i.e., interstitial carbon. Moreover, the effects of carbon on microstructures, mechanical properties and twinning activities were investigated in two different temperatures (77 and 293 K). With addition of 0.5 at% C, the high entropy alloy still remains entirely single phase face-centered cubic (FCC) crystal structure. We found that these materials canmore » be cold rolled and recrystallized to produce a microstructure with equiaxed grains. Both strain hardening rate and strength are enhanced while high uniform elongations to fracture (~70% at 77 K and ~40% at 293 K) are still maintained. The increased strain hardening and strength could be caused by the promptness of deformation twinning in C-containing high entropy alloys.« less

  5. Crisis Prevention Centers as confidence building measures: Suggestions for the Middle East

    SciTech Connect (OSTI)

    Pregenzer, A.L.

    1995-05-01

    Relationships between countries generally exist somewhere in the grey area between war and peace. Crisis prevention activities are important in this area, and should have two goals: stabilizing tense situations that could push countries toward war, and supporting or reinforcing efforts to move countries toward peace. A Crisis Prevention Center (CPC) should facilitate efforts to achieve these goals. Its functions can be grouped into three broad, interrelated categories: establishing and facilitating communication among participating countries; supporting negotiations and consensus-building on regional security issues; and supporting implementation of agreed confidence and security building measures. Technology will play a critical role in a CPC. Technology is required for establishing communication systems to ensure the timely flow of information between countries and to provide the means for organizing and analyzing this information. Technically-based cooperative monitoring can provide an objective source of information on mutually agreed issues, thereby supporting the implementation of confidence building measures and treaties. Technology can be a neutral subject of interaction and collaboration between technical communities from different countries, thereby providing an important channel for improving relationships. Potential first steps for a CPC in the Middle Ease could include establishing communication channels and a dedicated communications center in each country, together with an agreement to use the system as a ``Hot Line` in bilateral and multilateral-lateral emergency situations. Bilateral cooperative monitoring centers could be established to assist with implementation of agreements. A centrally located CPC could serve as a regional communications hub, coordinating a number of functions aimed at stabilizing regional tensions and supporting confidence building activities. Specific recommendations for confidence building activities are discussed.

  6. HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel Citation Details In-Document Search Title: HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel Crystal and interfacial structures of oxide nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous

  7. Investigation of giant-dipole-resonance decay in the ({gamma}, n) reactions on {sup 52}Cr and {sup 51}V nuclei

    SciTech Connect (OSTI)

    Verbitsky, S. S.; Lapic, A.M. Ratner, B. S.; Rusakov, A. V.; Tikanov, M. A.; Tulupov, B. A.; Tzelebrovsky, A. N.

    2009-03-15

    The cross sections for the emission of fast neutrons ({epsilon}{sub n} > 3.7 MeV) in the reactions {sup 52}Cr({gamma}, n){sup 51}Cr and {sup 51}V({gamma}, n){sup 50}V at incident-photon energies in the range between 16.0 and 25.8 MeV were studied. The neutron energy spectra were measured at the bremsstrahlung-photon endpoint energies of 18.5, 21.0, and 23.0 MeV for the {sup 52}Cr and {sup 51}V nuclei and at the bremsstrahlung-photon energy of 25.5 MeV for the {sup 51}V nucleus. Special features of giant-dipole-resonance decay that are associated with the existence of a structure in photoneutron cross sections and spectra are discussed.

  8. Performance of LiAlloy/Ag(2)CrO(4) Couples in Molten CsBr-LiBr-KBr Eutectic

    SciTech Connect (OSTI)

    GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.

    1999-10-18

    The performance of Li-alloy/CsBr-LiBr-KBr/Ag{sub 2}CrO{sub 4} systems was studied over a temperature range of 250 C to 300 C, for possible use as a power source for geothermal borehole applications. Single cells were discharged at current densities of 15.8 and 32.6 mA/cm{sup 2} using Li-Si and Li-Al anodes. When tested in 5-cell batteries, the Li-Si/CsBr-LiBr-KBr/Ag{sub 2}CrO{sub 4} system exhibited thermal runaway. Thermal analytical tests showed that the Ag{sub 2}CrO{sub 4} cathode reacted exothermically with the electrolyte on activation. Consequently, this system would not be practical for the envisioned geothermal borehole applications.

  9. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

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

    Dong, Yujung; Brooks, John D.; Chen, Tsung-Liang; Mullins, David R.; Cox, David F.

    2015-06-10

    The reaction of iodomethane on the nearly stoichiometric α-Cr2O3(0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is first initiated by the dissociation of iodomethane into surface methyl fragments, -CH3, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, =CH2. The methylene intermediates formed from methyl dehydrogenation can then undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo β-H elimination to produce ethylene. Themore » liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr3+ cations.« less

  10. Band Alignment, Built-In Potential, and the Absence of Conductivity at the LaCrO3/SrTiO3(001) Heterojunction

    SciTech Connect (OSTI)

    Chambers, Scott A.; Qiao, Liang; Droubay, Timothy C.; Kaspar, Tiffany C.; Arey, Bruce W.; Sushko, P. V.

    2011-11-07

    MBE-grown LaCrO3/SrTiO3(001) exhibits a staggered band alignment with valence and conduction band offsets of 2.45(6) and 0.8(1) eV, respectively. Core-level XPS peak broadening is consistent with no band bending in the SrTiO3 and a gradient of ~200 meV per unit cell in the LaCrO3. This gradient is adequate to trigger an electronic reconstruction, and the attendant transfer of charge from film to substrate, to alleviate the polarity mismatch. However, the interface is insulating because charge redistribution within the CrO2 layers occurs rather than electronic reconstruction to screen the field.

  11. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric ?-Cr2O3(0001)

    SciTech Connect (OSTI)

    Dong, Yujung; Brooks, John D.; Chen, Tsung-Liang; Mullins, David R.; Cox, David F.

    2015-06-10

    The reaction of iodomethane on the nearly stoichiometric ?-Cr2O3(0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is first initiated by the dissociation of iodomethane into surface methyl fragments, -CH3, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, =CH2. The methylene intermediates formed from methyl dehydrogenation can then undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo ?-H elimination to produce ethylene. The liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr3+ cations.

  12. Structure and magnetic interactions in the solid solution Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8}

    SciTech Connect (OSTI)

    Grundmann, Henrik; Schilling, Andreas; Marjerrison, Casey A.; Dabkowska, Hanna A.; Gaulin, Bruce D.

    2013-09-01

    Highlights: We describe for the first time the preparation of single- and polycrystalline members of the solid solution Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8}. We report on the structural changes in the solid solution at room temperature depending on the stoichiometry. We describe the peculiar change of the magnetic behavior in the solid solution with the stoichiometry. - Abstract: Solid solutions of the magnetic insulators Ba{sub 3}Cr{sub 2}O{sub 8} and Sr{sub 3}Cr{sub 2}O{sub 8} (Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8}) have been prepared in polycrystalline form for the first time. Single crystalline material was obtained using a mirror image floating zone technique. X-ray diffraction data taken at room temperature indicate that the space group of Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8} remains unchanged for all values of x, while the cell parameters depend on the chemical composition, as expected. Magnetization data, measured from 300 K down to 2 K, suggest that the interaction constant J{sub d} within the Cr{sup 5+} dimers varies in a peculiar way as a function of x, starting at J{sub d} = 25 K for x = 0, then first slightly dropping to J{sub d} = 18 K for x ? 0.75, before reaching J{sub d} = 62 K for x = 3.

  13. Ga, Ca, and 3d transition element (Cr through Zn) partitioning among spinel-lherzolite phases from the Lanzo massif, Italy: Analytical results and crystal chemistry

    SciTech Connect (OSTI)

    Wogelius, R.A.; Fraser, D.G.

    1994-06-01

    Ultramafic rocks exposed in Lanzo massif, Italy is a record of mantle geochemistry, melting, sub-solidus re-equilibration. Plagioclase(+ spinel)-lherzolite samples were analyzed by Scanning Proton Microscopy, other techniques. Previous work postulated partial melting events and a two-stage sub-solidus cooling history; this paper notes Ga enrichment on spinel-clinopyroxene grain boundaries, high Ga and transition element content of spinel, and pyroxene zonation in Ca and Al. Trace element levels in olivine and orthopyroxene are also presented. Zoning trends are interpreted as due to diffusion during cooling. Olivine-clinopyroxene Cr and Ca exchange as well as clinopyroxene and spinel zonation trends indicate that the massif experienced at least two sub-solidus cooling episodes, one at 20 kbar to 1000 C and one at 8 kbar <750C. Ga levels in cores of Lanzo high-Cr spinels are high (82-66 ppM) relative to other mantle spinels (66-40 ppM), indicating enrichment. Ga content of ultramafic spinels apparently increases with Cr content; this may be due to: increased Ga solubility stemming from crystal chemical effects and/or higher Ga activities in associated silicate melts. Thus, during melting, high-Cr residual spinel may tend to buffer solid-phase Ga level. These spinels are not only rich in Ga and Cr (max 26.37 el. wt %), but also in Fe (max 21.07 el. wt %), Mn (max 3400 ppM), and Zn (max 2430 ppM). These enrichments are again due to melt extraction and partitioning into spinel structure. Low Ni (min 1050 ppM) levels are due to unsuccessful competition of Ni with Cr for octahedral structural sites caused by crystal field. Comparisons of change in partitioning vs Cr content among several 3d transition elements for spinels from Lanzo, other localities allow us to separate crystal field effects from bulk chemical effects and to show that in typical assemblages, inversion of olivine-spinel partition coefficient for Ni from <1 to >1 should occur at 11% el. wt. Cr in spinel.

  14. Microstructure and oxidation behavior of NiCoCrAl/YSZ microlaminates produced by EB-PVD

    SciTech Connect (OSTI)

    Shi Guodong, E-mail: gdshi@dlut.edu.cn [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China); Wang Zhi; Liu Mincong [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China); Liang Jun [Center for Composite Materials, Harbin Institute of Technology, Harbin, 150001 (China); Wu Zhanjun [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China)

    2011-11-15

    Two NiCoCrAl/ZrO{sub 2}-Y{sub 2}O{sub 3} microlaminates (A and B) were fabricated by electron beam physical vapor deposition, which were different in layer number and metal-layer thickness. The layer number was 20 and 26, respectively. And the metal-layer thickness was 35 and 14 {mu}m, respectively. The microstructure and isothermal oxidation behavior were investigated. During the exposure in air at 1000 deg. C for 100 h, the t to m phase transformation occurred in the ceramic layers, and oxide scales formed at the surfaces of not only the outer metal-layers but also the internal metal-layers for the microlaminates. The oxidation rate of microlaminate B was greater than that of microlaminate A. Their overall mass gains were significantly dependent on the number and thickness of the metal-layers. The oxidation products were also influenced by metal-layer thickness. Oxide scales of the 35 {mu}m thick metal-layer microlaminate (A) consisted mainly of {alpha}-Al{sub 2}O{sub 3} and {theta}-Al{sub 2}O{sub 3}, while the oxidation products of the 14 {mu}m thick metal-layer microlaminate (B) were the mixture of {alpha}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3} and Cr{sub 2}O{sub 3}. It was also found that the growth of the oxide scale adjacent to the top YSZ layer was controlled by the oxygen diffusion, and that the growth of the oxide scale adjacent to the internal YSZ layer was controlled by the metal ionic diffusion. - Highlights: {yields} Effect of laminate structure on oxidation behavior of microlaminates was studied. {yields} Oxygen diffusion through YSZ layers led to the oxidation of internal metal-layers. {yields} The thinner NiCoCrAl layer was more difficult to form the stable Al{sub 2}O{sub 3} scale. {yields} Control of oxide scale growth by the oxygen diffusion in the outer metal-layers. {yields} Control of oxide scale growth by the metal ionic diffusion in internal metal-layers.

  15. The Cr-substitution concentration dependence of the structural, electric and magnetic behaviors for Aurivillius Bi{sub 5}Ti{sub 3}FeO{sub 15} multiferroic ceramics

    SciTech Connect (OSTI)

    Liu, Jia; Bai, Wei E-mail: xdtang@sist.ecnu.edu.cn; Yang, Jing; Xu, Wenfei; Zhang, Yuanyuan; Tang, Xiaodong E-mail: xdtang@sist.ecnu.edu.cn; Lin, Tie; Meng, Xiangjian; Duan, Chun-Gang; Chu, Junhao

    2013-12-21

    Aurivillius Bi{sub 5}Ti{sub 3}FeO{sub 15} (BTFO) multiferroic ceramics with different Cr-doped concentrations have been synthesized by the conventional solid state reaction method. The influences of Cr-doping concentrations on the structural, magnetic, dielectric, and ferroelectric properties of BTFO ceramics are investigated in detail. All these sintered Cr-substituted BTFO ceramics are determined to be layered perovskite Aurivillius structure by X-ray diffraction, as well as the lattice parameters a, b, and c are in good accordance with Vegard's law along with the Cr-doping concentration. The lattice distortion a/b for Aurivillius family decreases with increasing Cr-doping concentration. Moreover, Cr-doping can promote greatly the grain growth of BTFO samples confirmed from field emission scanning electron microscopy characterization. However, no obvious signs of the improvement in ferroelectric properties are found in Cr-doped BTFO ceramics, and abnormal ferroelectric polarization versus electric field (P-E) loops are observed as Cr-doping content is beyond 0.1. Similar ? (tan?) versus frequency plots to those of the BTFO sample are exhibited when Cr-doping concentration is less than 0.1. Nevertheless, obvious dielectric dispersion phenomena are shown as the Cr-doping concentration is beyond 0.1, and this dispersion behavior becomes strong with further increasing Cr-doping concentration, which are clearly indicated by the appearance of dielectric loss relaxation peaks in the measurement frequency from 10{sup 2} Hz to 10{sup 6} Hz. In addition, the corresponding frequency to relaxation peak shifts towards high frequencies with the Cr-doping concentration. Finally, the same magnetic orderings for all these Cr-doped BTFO ceramics as those of the BTFO one, i.e., superparamagnetic state dominated with antiferromagnetic interaction, are unambiguously found, signifying that the predicted Fe{sup 3+}-O-Cr{sup 3+} 180 ferromagnetic superexchange interaction based on the Goodenough-Kanamori (G-K) rule might not be achieved in BTFO ceramics through Cr substitution by the conventional solid state reaction.

  16. The complete mitochondrial genome of a gecko and the phylogeneticposition of the Middle Eastern teratoscincus keyserlingii

    SciTech Connect (OSTI)

    Macey, J. Robert; Fong, Jonathan J.; Kuehl, Jennifer V.; Shafiei,Soheila; Ananjeva, Natalia B.; Papenfuss, Theodore J.; Boore, Jeffrey L.

    2005-04-22

    Sqamate reptiles are traditionally divided into six groups: Iguania, Anguimorpha, Scincomorpha, Gekkota (these four are lizards), Serpentes (snakes), and Amphisbaenia (the so-called worm lizards). Currently there are complete mitochondrial genomes from two representatives of the Iguania (Janke et al., 2001; Kumazawa, 2004), three from the Anguimorpha (Kumazawa, 2004; Kumazawa and Endo, 2004), two from the Scincomorpha (Kumazawa and Nishida, 1999; Kumazawa, 2004), two from Serpentes (Kumazawa et al., 1998; Kumazawa, 2004) and 12 from Amphisbaenia (Macey et al., 2004). The only traditional group of Squamata from which a complete mitochondrial genome has not been sequenced is the Gekkota. Here we report the complete mitochondrial genome of Teratoscincus keyserlingii, a Middle Eastern representative of the Gekkota. The gekkonid lizard genus Teratoscincus is distributed throughout the deserts of central and southwest Asia as shown in figure 1, with five species currently recognized (Macey et al. 1997a, 1999b). Included in this figure are the positions of mountain ranges discussed in the text; see also figure 1 in Macey et al. (1999b). Two species, T. bedriagai and T. microlepis, are restricted to Southwest Asia south of the Kopet Dagh and Hindu Kush in Iran, Afghanistan, and Pakistan (Anderson, 1999). Two species are found in the deserts of western China and Mongolia, with T. przewalskii occurring in the Taklimakan and lowland Gobi deserts, and T. roborowskii restricted to the Turpan Depression. The fifth species, T. scincus, is sometimes considered to be restricted to the Caspian Basin in Kazakhstan, Kyrgyzistan, Tadjikistan, Turkmenistan and Uzbekistan. Alternatively, Teratoscincus populations in Southwest Asia, primarily on the Iranian Plateau, situated directly north of the Arabian Plate, are sometimes considered to be a subspecies of T. scincus or, otherwise, to constitute a sixth species, T. keyserlingii. Macey et al. (1999b) assessed the phylogenetic relationships of four Teratoscincus species with mitochondrial DNA sequences from a {approx}1800 base-pair segment spanning from nad1 to cox1. Phylogenetic analysis places T. microlepis in a basal position to a clade containing T. scincus, T. przewalskii and T. roborowskii, with the later two as sister taxa. This phylogenetic arrangement suggests that tectonic plate movements in Southwest Asia and western China due to the Indian and Arabian collisions caused speciation among Teratoscincus species. No molecular phylogenetic study has included the putative species T. keyserlingii.

  17. Effect of composition changes on the structure and properties of W-Cr-Ni-C detonation gun coatings

    SciTech Connect (OSTI)

    Stavros, A.J.

    1995-12-31

    Changes in the microstructure and wear behavior of W-Cr-Ni-C coatings as a function of the composition of the starting powder were studied. The experimental powder compositions were chosen so that the results could be analyzed statistically as a mixture problem with the extreme vertices design. All coatings were deposited by identical detonation gun operating conditions. Although the variation of powder chemistry resulted in distinctively different powder morphologies, all coatings were found to be composed of the same 4 (possibly more) complex carbides. The amount and, to some degree, morphology of a particular carbide was found to change with composition. However, neither amount nor morphology could be correlated to microhardness or wear test results. Predictive equations based on powder composition were obtained which fit the wear test results very well.

  18. Steam Oxidation of FeCrAl and SiC in the Severe Accident Test Station (SATS)

    SciTech Connect (OSTI)

    Pint, Bruce A.; Unocic, Kinga A.; Terrani, Kurt A.

    2015-08-01

    Numerous research projects are directed towards developing accident tolerant fuel (ATF) concepts that will enhance safety margins in light water reactors (LWR) during severe accident scenarios. In the U.S. program, the high temperature steam oxidation performance of ATF solutions has been evaluated in the Severe Accident Test Station (SATS) at Oak Ridge National Laboratory (ORNL) since 2012 [1-3] and this facility continues to support those efforts in the ATF community. Compared to the current UO2/Zr-based alloy fuel system, alternative cladding materials can offer slower oxidation kinetics and a smaller enthalpy of oxidation that can significantly reduce the rate of heat and hydrogen generation in the core during a coolant-limited severe accident [4-5]. Thus, steam oxidation behavior is a key aspect of the evaluation of ATF concepts. This report summarizes recent work to measure steam oxidation kinetics of FeCrAl and SiC specimens in the SATS.

  19. Microstructure investigation of 13Cr-2Mo ODS steel components obtained by high voltage electric discharge compaction technique

    SciTech Connect (OSTI)

    Bogachev, Igor; Yudin, Artem; Grigoryev, Evgeniy; Chernov, Ivan; Staltsov, Maxim; Khasanov, Oleg; Olevsky, Eugene

    2015-11-02

    Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10–15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining the initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. As a result, the choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality.

  20. Experimental and Numerical Analysis on the Distortion of Parts Made of 20MnCr5 by Hot Metal Forming

    SciTech Connect (OSTI)

    Rentsch, Ruediger; Brinksmeier, Ekkard [Stiftung Institut fuer Werkstofftechnik, Badgasteiner Strasse 3, 28359 Bremen (Germany)

    2011-05-04

    For high performance applications, shafts and gears made of 20MnCr5 (AISI 5120) are manufactured in large numbers every year. Inhomogeneities in the material properties, process perturbations and asymmetries in shape and operation setups provide a potential for the distortion of parts, often released by heat treatment. In this contribution experimental results on the distortion of shafts and the dishing of disk-like gear wheel blanks are presented. The numerical analysis of the hot-rolling process allowed to trace a peculiar segregation distribution at the cross-section of the bars back to the casting process, and to identify an asymmetric strain distribution which may be the main cause for shaft distortion. For the dishing of the disks a correlation to the resulting distribution of the material flow was found and, a process perturbation parameter identified which is assumed to be responsible for the observed material flow variation.