National Library of Energy BETA

Sample records for flare capture project

  1. Oilfield Flare Gas Electricity Systems (OFFGASES Project)

    SciTech Connect (OSTI)

    Rachel Henderson; Robert Fickes

    2007-12-31

    The Oilfield Flare Gas Electricity Systems (OFFGASES) project was developed in response to a cooperative agreement offering by the U.S. Department of Energy (DOE) and the National Energy Technology Laboratory (NETL) under Preferred Upstream Management Projects (PUMP III). Project partners included the Interstate Oil and Gas Compact Commission (IOGCC) as lead agency working with the California Energy Commission (CEC) and the California Oil Producers Electric Cooperative (COPE). The project was designed to demonstrate that the entire range of oilfield 'stranded gases' (gas production that can not be delivered to a commercial market because it is poor quality, or the quantity is too small to be economically sold, or there are no pipeline facilities to transport it to market) can be cost-effectively harnessed to make electricity. The utilization of existing, proven distribution generation (DG) technologies to generate electricity was field-tested successfully at four marginal well sites, selected to cover a variety of potential scenarios: high Btu, medium Btu, ultra-low Btu gas, as well as a 'harsh', or high contaminant, gas. Two of the four sites for the OFFGASES project were idle wells that were shut in because of a lack of viable solutions for the stranded noncommercial gas that they produced. Converting stranded gas to useable electrical energy eliminates a waste stream that has potential negative environmental impacts to the oil production operation. The electricity produced will offset that which normally would be purchased from an electric utility, potentially lowering operating costs and extending the economic life of the oil wells. Of the piloted sites, the most promising technologies to handle the range were microturbines that have very low emissions. One recently developed product, the Flex-Microturbine, has the potential to handle the entire range of oilfield gases. It is deployed at an oilfield near Santa Barbara to run on waste gas that is only 4% the strength of natural gas. The cost of producing oil is to a large extent the cost of electric power used to extract and deliver the oil. Researchers have identified stranded and flared gas in California that could generate 400 megawatts of power, and believe that there is at least an additional 2,000 megawatts that have not been identified. Since California accounts for about 14.5% of the total domestic oil production, it is reasonable to assume that about 16,500 megawatts could be generated throughout the United States. This power could restore the cost-effectiveness of thousands of oil wells, increasing oil production by millions of barrels a year, while reducing emissions and greenhouse gas emissions by burning the gas in clean distributed generators rather than flaring or venting the stranded gases. Most turbines and engines are designed for standardized, high-quality gas. However, emerging technologies such as microturbines have increased the options for a broader range of fuels. By demonstrating practical means to consume the four gas streams, the project showed that any gases whose properties are between the extreme conditions also could be utilized. The economics of doing so depends on factors such as the value of additional oil recovered, the price of electricity produced, and the alternate costs to dispose of stranded gas.

  2. Sauget Plant Flare Gas Reduction Project 

    E-Print Network [OSTI]

    Ratkowski, D. P.

    2007-01-01

    Empirical analysis of stack gas heating value allowed the Afton Chemical Corporation Sauget Plant to reduce natural gas flow to its process flares by about 50% while maintaining the EPA-required minimum heating value of the gas streams....

  3. Recovery Act: ArcelorMittal USA Blast Furnace Gas Flare Capture

    SciTech Connect (OSTI)

    Seaman, John

    2013-01-14

    The U.S. Department of Energy (DOE) awarded a financial assistance grant under the American Recovery and Reinvestment Act of 2009 (Recovery Act) to ArcelorMittal USA, Inc. (ArcelorMittal) for a project to construct and operate a blast furnace gas recovery boiler and supporting infrastructure at ArcelorMittal’s Indiana Harbor Steel Mill in East Chicago, Indiana. Blast furnace gas (BFG) is a by-product of blast furnaces that is generated when iron ore is reduced with coke to create metallic iron. BFG has a very low heating value, about 1/10th the heating value of natural gas. BFG is commonly used as a boiler fuel; however, before installation of the gas recovery boiler, ArcelorMittal flared 22 percent of the blast furnace gas produced at the No. 7 Blast Furnace at Indiana Harbor. The project uses the previously flared BFG to power a new high efficiency boiler which produces 350,000 pounds of steam per hour. The steam produced is used to drive existing turbines to generate electricity and for other requirements at the facility. The goals of the project included job creation and preservation, reduced energy consumption, reduced energy costs, environmental improvement, and sustainability.

  4. Energy Department Project Captures and Stores more than One Million...

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

    facility in Port Arthur, Texas. Using an innovative technology called vacuum swing adsorption, the project captures more than 90 percent of the CO2 from the...

  5. Ownership of Carbon Dioxide Captured by Clean Coal Project (Texas)

    Broader source: Energy.gov [DOE]

    This legislation stipulates that the Railroad Commission of Texas automatically acquires the title to any carbon dioxide captured by a clean coal project in the state. The Bureau of Economic...

  6. Lake Charles Carbon Capture and Sequestration Project U. S. Department...

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

    plant will not receive co-funding from DOE. The Lake Charles CCS Project will capture carbon dioxide (CO 2 ) from the LCCE Gasification plant and transport the CO 2 via a new...

  7. Mountaineer Commerical Scale Carbon Capture and Storage (CCS) Project

    SciTech Connect (OSTI)

    Deanna Gilliland; Matthew Usher

    2011-12-31

    The Final Technical documents all work performed during the award period on the Mountaineer Commercial Scale Carbon Capture & Storage project. This report presents the findings and conclusions produced as a consequence of this work. As identified in the Cooperative Agreement DE-FE0002673, AEP's objective of the Mountaineer Commercial Scale Carbon Capture and Storage (MT CCS II) project is to design, build and operate a commercial scale carbon capture and storage (CCS) system capable of treating a nominal 235 MWe slip stream of flue gas from the outlet duct of the Flue Gas Desulfurization (FGD) system at AEP's Mountaineer Power Plant (Mountaineer Plant), a 1300 MWe coal-fired generating station in New Haven, WV. The CCS system is designed to capture 90% of the CO{sub 2} from the incoming flue gas using the Alstom Chilled Ammonia Process (CAP) and compress, transport, inject and store 1.5 million tonnes per year of the captured CO{sub 2} in deep saline reservoirs. Specific Project Objectives include: (1) Achieve a minimum of 90% carbon capture efficiency during steady-state operations; (2) Demonstrate progress toward capture and storage at less than a 35% increase in cost of electricity (COE); (3) Store CO{sub 2} at a rate of 1.5 million tonnes per year in deep saline reservoirs; and (4) Demonstrate commercial technology readiness of the integrated CO{sub 2} capture and storage system.

  8. Is FLARE for Solar flare?

    E-Print Network [OSTI]

    D. Fargion

    2005-12-07

    The Fermi Lab Liquid ARgon experiment, FLARE, a huge neutrino argon-liquid project detector of 50 kt mass, might in a near future enlarge the neutrino telescope accuracy revealing in detail solar, supernova, atmospheric as well as largest solar flares neutrino. Indeed the solar energetic (E_p > 100 MeVs) flare particles (protons, alpha) while scattering among themselves or hitting the solar atmosphere must produce on sun prompt charged pions, whose decay (as well as their sequent muon decays) into secondaries is source of a copious solar neutrino "flare" (at tens or hundreds MeV energy). These brief (minutes) neutrino "burst" at largest flare peak may overcome by three to five order of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their emergence and detection above the thresholds. The largest prompt "burst" solar neutrino flare may be detected in future FLARE neutrino detectors both in electron and positron and possibly in its muon pair neutrino component. Our estimate for the recent and exceptional October - November 2003 solar flares and last January 20th 2005 exceptional flare might lead to a few events for future FLARE or near unity for present Super-KamiokandeII. The neutrino spectra may reflect the neutrino flavor oscillations and mixing in flight. In neutrino detectors a surprising (correlated) muon appearance may occur while a rarer tau appearance may even marginally take place. A comparison of the solar neutrino flare signal with other neutrino foreground is estimated: it offer the first opportunity for an independent road map to disentangle the neutrino flavor puzzles, as well a prompt alarm system for dangerous solar flare eruptions.

  9. CO2 CAPTURE PROJECT - AN INTEGRATED, COLLABORATIVE TECHNOLOGY DEVELOPMENT PROJECT FOR NEXT GENERATION CO2 SEPARATION, CAPTURE AND GEOLOGIC SEQUESTRATION

    SciTech Connect (OSTI)

    Dr. Helen Kerr

    2003-08-01

    The CO{sub 2} Capture Project (CCP) is a joint industry project, funded by eight energy companies (BP, ChevronTexaco, EnCana, Eni, Norsk Hydro, Shell, Statoil, and Suncor) and three government agencies (1) European Union (DG Res & DG Tren), (2) Norway (Klimatek) and (3) the U.S.A. (Department of Energy). The project objective is to develop new technologies, which could reduce the cost of CO{sub 2} capture and geologic storage by 50% for retrofit to existing plants and 75% for new-build plants. Technologies are to be developed to ''proof of concept'' stage by the end of 2003. The project budget is approximately $24 million over 3 years and the work program is divided into eight major activity areas: (1) Baseline Design and Cost Estimation--defined the uncontrolled emissions from each facility and estimate the cost of abatement in $/tonne CO{sub 2}. (2) Capture Technology, Post Combustion: technologies, which can remove CO{sub 2} from exhaust gases after combustion. (3) Capture Technology, Oxyfuel: where oxygen is separated from the air and then burned with hydrocarbons to produce an exhaust with high CO{sub 2} for storage. (4) Capture Technology, Pre -Combustion: in which, natural gas and petroleum coke are converted to hydrogen and CO{sub 2} in a reformer/gasifier. (5) Common Economic Model/Technology Screening: analysis and evaluation of each technology applied to the scenarios to provide meaningful and consistent comparison. (6) New Technology Cost Estimation: on a consistent basis with the baseline above, to demonstrate cost reductions. (7) Geologic Storage, Monitoring and Verification (SMV): providing assurance that CO{sub 2} can be safely stored in geologic formations over the long term. (8) Non-Technical: project management, communication of results and a review of current policies and incentives governing CO{sub 2} capture and storage. Technology development work dominated the past six months of the project. Numerous studies are making substantial progress towards their goals. Some technologies are emerging as preferred over others. Pre-combustion Decarbonization (hydrogen fuel) technologies are showing good progress and may be able to meet the CCP's aggressive cost reduction targets for new-build plants. Chemical looping to produce oxygen for oxyfuel combustion shows real promise. As expected, post-combustion technologies are emerging as higher cost options that may have niche roles. Storage, measurement, and verification studies are moving rapidly forward. Hyper-spectral geo-botanical measurements may be an inexpensive and non-intrusive method for long-term monitoring. Modeling studies suggest that primary leakage routes from CO{sub 2} storage sites may be along wellbores in areas disturbed by earlier oil and gas operations. This is good news because old wells are usually mapped and can be repaired during the site preparation process. Many studies are nearing completion or have been completed. Their preliminary results are summarized in the attached report and presented in detail in the attached appendices.

  10. A scaled gradient projection method for the X-ray imaging of solar flares

    E-Print Network [OSTI]

    Bonettini, S

    2013-01-01

    In this paper we present a new optimization algorithm for the reconstruction of X-ray images of solar flares by means of the data collected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The imaging concept of the satellite is based of rotating modulation collimator instruments, which allow the use of both Fourier imaging approaches and reconstruction techniques based on the straightforward inversion of the modulated count profiles. Although in the last decade a greater attention has been devoted to the former strategies due to their very limited computational cost, here we consider the latter model and investigate the effectiveness of a scaled gradient projection method for the solution of the corresponding constrained minimization problem. Moreover, regularization is introduced through either an early stopping of the iterative procedure, or a Tikhonov term added to the discrepancy function, by means of a discrepancy principle accounting for the Poisson nature of the noise affecting th...

  11. U.S. China Carbon Capture and Storage Development Project at...

    Office of Scientific and Technical Information (OSTI)

    Capture and Storage Development Project at West Virginia University Fletcher, Jerald 01 COAL, LIGNITE, AND PEAT COAL - ENVIRONMENTAL PROCESSES COAL - ENVIRONMENTAL PROCESSES The...

  12. Energy Department Project Captures and Stores One Million Metric...

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

    the widespread deployment of carbon capture technologies in real-world settings," said Energy Secretary Ernest Moniz. "The successful testing of these technologies and the lessons...

  13. Energy Department Project Captures and Stores more than One Million...

    Office of Environmental Management (EM)

    successfully capturing more than one million metric tons of carbon dioxide (CO2) at the hydrogen-production facility in Port Arthur, Texas. Using an innovative technology called...

  14. World's Largest Post-Combustion Carbon Capture Project Begins...

    Office of Environmental Management (EM)

    plant in Texas. The captured CO2 will then be used to extract additional, hard-to-access oil from a previously depleted field 80 miles away, safely storing the carbon underground...

  15. DOE Awards Cooperative Agreement for Post-Combustion Carbon Capture Project

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy has awarded a cooperative agreement to American Electric Power Service Corporation for the Mountaineer Commercial Scale Carbon Capture and Storage Project to design, construct, and operate a system that will capture and store approximately 1.5 million tons per year of carbon dioxide.

  16. Carbon Dioxide (CO2) Capture Project Phase 2 (CCP2) - Storage...

    Open Energy Info (EERE)

    Carbon Dioxide (CO2) Capture Project Phase 2 (CCP2) - Storage Program: Closing Long-Term CO2 Geological Storage Gaps Relevant to Regulatory and Policy Development Jump to:...

  17. DOE Seeks Proposals to Increase Investment in Industrial Carbon Capture and Sequestration Projects

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy has issued a Funding Opportunity Announcement soliciting projects to capture and sequester carbon dioxide from industrial sources and to put CO2 to beneficial use.

  18. Secretary Chu Announces Six Projects to Convert Captured CO2...

    Energy Savers [EERE]

    that Americans can use. "These innovative projects convert carbon pollution from a climate threat to an economic resource," said Secretary Chu. "This is part of our broad...

  19. DOE Selects 16 Transformational Carbon Capture Technologies Projects...

    Energy Savers [EERE]

    meet DOE's mission to lower the cost associated with reducing CO2 emissions from existing coal-fired power plants. The project will last 30 months. Cost: DOE: 2,705,013; Non DOE:...

  20. EIS-0464: Lake Charles Carbon Capture and Storage (CCS) Project in Calcasieu Parish, Louisiana

    Broader source: Energy.gov [DOE]

    This EIS evaluates the potential environmental impacts of providing financial assistance for the construction and operation of a project proposed by Leucadia Energy, LLC. DOE selected this project for an award of financial assistance through a competitive process under the Industrial Carbon Capture and Sequestration Program.

  1. CO2 CAPTURE PROJECT-AN INTEGRATED, COLLABORATIVE TECHNOLOGY DEVELOPMENT PROJECT FOR NEXT GENERATION CO2 SEPARATION, CAPTURE AND GEOLOGIC SEQUESTRATION

    SciTech Connect (OSTI)

    Helen Kerr

    2004-04-01

    The CO{sub 2} Capture Project (CCP) is a joint industry project, funded by eight energy companies (BP, ChevronTexaco, EnCana, Eni, Norsk Hydro, Shell, Statoil, and Suncor) and three government agencies (European Union (DG Res & DG Tren), Norway (Klimatek) and the U.S.A. (Department of Energy)). The project objective is to develop new technologies, which could reduce the cost of CO{sub 2} capture and geologic storage by 50% for retrofit to existing plants and 75% for new-build plants. Technologies are to be developed to ''proof of concept'' stage by the end of 2003. The project budget is approximately $24 million over 3 years and the work program is divided into eight major activity areas: (1) Baseline Design and Cost Estimation--defined the uncontrolled emissions from each facility and estimate the cost of abatement in $/tonne CO{sub 2}. (2) Capture Technology, Post Combustion--technologies, which can remove CO{sub 2} from exhaust gases after combustion. (3) Capture Technology, Oxyfuel--where oxygen is separated from the air and then burned with hydrocarbons to produce an exhaust with wet high concentrations of CO{sub 2} for storage. (4) Capture Technology, Pre-Combustion--in which, natural gas and petroleum coke are converted to hydrogen and CO{sub 2} in a reformer/gasifier. (5) Common Economic Model/Technology Screening--analysis and evaluation of each technology applied to the scenarios to provide meaningful and consistent comparison. (6) New Technology Cost Estimation: on a consistent basis with the baseline above, to demonstrate cost reductions. (7) Geologic Storage, Monitoring and Verification (SMV)--providing assurance that CO{sub 2} can be safely stored in geologic formations over the long term. (8) Non-Technical: project management, communication of results and a review of current policies and incentives governing CO{sub 2} capture and storage. Technology development work dominated the past six months of the project. Numerous studies have completed their 2003 stagegate review and are reported here. Some will proceed to the next stagegate review in 2004. Some technologies are emerging as preferred over others. Pre-combustion De-carbonization (hydrogen fuel) technologies are showing excellent results and may be able to meet the CCP's aggressive cost reduction targets for new-build plants. The workscopes planned for the next key stagegates are under review before work begins based on the current economic assessment of their performance. Chemical looping to produce oxygen for oxyfuel combustion shows real promise. As expected, post-combustion technologies are emerging as higher cost options but even so some significant potential reductions in cost have been identified and will continue to be explored. Storage, measurement, and verification studies are moving rapidly forward and suggest that geologic sequestration can be a safe form of long-term CO{sub 2} storage. Hyper-spectral geo-botanical measurements may be an inexpensive and non-intrusive method for long-term monitoring. Modeling studies suggest that primary leakage routes from CO{sub 2} storage sites may be along old wellbores in areas disturbed by earlier oil and gas operations. This is good news because old wells are usually mapped and can be repaired during the site preparation process. Wells are also easy to monitor and intervention is possible if needed. The project will continue to evaluate and bring in novel studies and ideas within the project scope as requested by the DOE. The results to date are summarized in the attached report and presented in detail in the attached appendices.

  2. Expansion of Michigan EOR Operations Using Advanced Amine Technology at a 600 MW Project Wolverine Carbon Capture and Storage Project

    SciTech Connect (OSTI)

    H Hoffman; Y kishinevsky; S. Wu; R. Pardini; E. Tripp; D. Barnes

    2010-06-16

    Wolverine Power Supply Cooperative Inc, a member owned cooperative utility based in Cadillac Michigan, proposes to demonstrate the capture, beneficial utilization and storage of CO{sub 2} in the expansion of existing Enhanced Oil Recovery operations. This project is being proposed in response to the US Department of Energy Solicitation DE-FOA-0000015 Section III D, 'Large Scale Industrial CCS projects from Industrial Sources' Technology Area 1. The project will remove 1,000 metric tons per day of CO{sub 2} from the Wolverine Clean Energy Venture 600 MW CFB power plant owned and operated by WPC. CO{sub 2} from the flue gas will be captured using Hitachi's CO{sub 2} capture system and advanced amine technology. The capture system with the advanced amine-based solvent supplied by Hitachi is expected to significantly reduce the cost and energy requirements of CO{sub 2} capture compared to current technologies. The captured CO{sub 2} will be compressed and transported for Enhanced Oil Recovery and CO{sub 2} storage purposes. Enhanced Oil Recovery is a proven concept, widely used to recover otherwise inaccessible petroleum reserves. While post-combustion CO{sub 2} capture technologies have been tested at the pilot scale on coal power plant flue gas, they have not yet been demonstrated at a commercial scale and integrated with EOR and storage operations. Amine-based CO{sub 2} capture is the leading technology expected to be available commercially within this decade to enable CCS for utility and industrial facilities firing coal and waste fuels such as petroleum coke. However, traditional CO{sub 2} capture process utilizing commercial amine solvents is very energy intensive for regeneration and is also susceptible to solvent degradation by oxygen as well as SOx and NO{sub 2} in the flue gas, resulting in large operating costs. The large volume of combustion flue gas with its low CO{sub 2} concentration requires large equipment sizes, which together with the highly corrosive nature of the typical amine-based separation process leads to high plant capital investment. According to recent DOE-NETL studies, MEA-based CCS will increase the cost of electricity of a new pulverized coal plant by 80-85% and reduce the net plant efficiency by about 30%. Non-power industrial facilities will incur similar production output and efficiency penalties when implementing conventional carbon capture systems. The proposed large scale demonstration project combining advanced amine CO{sub 2} capture integrated with commercial EOR operations significantly advances post-combustion technology development toward the DOE objectives of reducing the cost of energy production and improving the efficiency of CO{sub 2} Capture technologies. WPC has assembled a strong multidisciplinary team to meet the objectives of this project. WPC will provide the host site and Hitachi will provide the carbon capture technology and advanced solvent. Burns and Roe bring expertise in overall engineering integration and plant design to the team. Core Energy, an active EOR producer/operator in the State of Michigan, is committed to support the detailed design, construction and operation of the CO{sub 2} pipeline and storage component of the project. This team has developed a Front End Engineering Design and Cost Estimate as part of Phase 1 of DOE Award DE-FE0002477.

  3. CO2 Capture Project-An Integrated, Collaborative Technology Development Project for Next Generation CO2 Separation, Capture and Geologic Sequestration

    SciTech Connect (OSTI)

    Helen Kerr; Linda M. Curran

    2005-04-15

    The CO{sub 2} Capture Project (CCP) was a joint industry project, funded by eight energy companies (BP, ChevronTexaco, EnCana, ENI, Norsk Hydro, Shell, Statoil, and Suncor) and three government agencies (European Union [DG RES & DG TREN], the Norwegian Research Council [Klimatek Program] and the U.S. Department of Energy [NETL]). The project objective was to develop new technologies that could reduce the cost of CO{sub 2} capture and geologic storage by 50% for retrofit to existing plants and 75% for new-build plants. Technologies were to be developed to ''proof of concept'' stage by the end of 2003. Certain promising technology areas were increased in scope and the studies extended through 2004. The project budget was approximately $26.4 million over 4 years and the work program is divided into eight major activity areas: Baseline Design and Cost Estimation--defined the uncontrolled emissions from each facility and estimate the cost of abatement in $/tonne CO{sub 2}. Capture Technology, Post Combustion: technologies, which can remove CO{sub 2} from exhaust gases after combustion. Capture Technology, Oxyfuel: where oxygen is separated from the air and then burned with hydrocarbons to produce an exhaust with high CO{sub 2} for storage. Capture Technology, Pre-Combustion: in which, natural gas and petroleum cokes are converted to hydrogen and CO{sub 2} in a reformer/gasifier. Common Economic Model/Technology Screening: analysis and evaluation of each technology applied to the scenarios to provide meaningful and consistent comparison. New Technology Cost Estimation: on a consistent basis with the baseline above, to demonstrate cost reductions. Geologic Storage, Monitoring and Verification (SMV): providing assurance that CO{sub 2} can be safely stored in geologic formations over the long term. Non-Technical: project management, communication of results and a review of current policies and incentives governing CO{sub 2} capture and storage. Pre-combustion De-carbonization (hydrogen fuel) technologies showed excellent results and may be able to meet the CCP's aggressive cost reduction targets for new-build plants. Chemical looping to produce oxygen for oxyfuel combustion shows real promise. Post-combustion technologies emerged as higher cost options that may only have niche roles. Storage, measurement, and verification studies suggest that geologic sequestration will be a safe form of long-term CO{sub 2} storage. Economic modeling shows that options to reduce costs by 50% exist. A rigorous methodology for technology evaluation was developed. Public acceptance and awareness were enhanced through extensive communication of results to the stakeholder community (scientific, NGO, policy, and general public). Two volumes of results have been published and are available to all. Well over 150 technical papers were produced. All funded studies for this phase of the CCP are complete. The results are summarized in this report and all final reports are presented in the attached appendices.

  4. Mountaineer Commercial Scale Carbon Capture and Storage Project Topical Report: Preliminary Public Design Report

    SciTech Connect (OSTI)

    Guy Cerimele

    2011-09-30

    This Preliminary Public Design Report consolidates for public use nonproprietary design information on the Mountaineer Commercial Scale Carbon Capture & Storage project. The report is based on the preliminary design information developed during the Phase I - Project Definition Phase, spanning the time period of February 1, 2010 through September 30, 2011. The report includes descriptions and/or discussions for: (1) DOE's Clean Coal Power Initiative, overall project & Phase I objectives, and the historical evolution of DOE and American Electric Power (AEP) sponsored projects leading to the current project; (2) Alstom's Chilled Ammonia Process (CAP) carbon capture retrofit technology and the carbon storage and monitoring system; (3) AEP's retrofit approach in terms of plant operational and integration philosophy; (4) The process island equipment and balance of plant systems for the CAP technology; (5) The carbon storage system, addressing injection wells, monitoring wells, system monitoring and controls logic philosophy; (6) Overall project estimate that includes the overnight cost estimate, cost escalation for future year expenditures, and major project risks that factored into the development of the risk based contingency; and (7) AEP's decision to suspend further work on the project at the end of Phase I, notwithstanding its assessment that the Alstom CAP technology is ready for commercial demonstration at the intended scale.

  5. Integrated Mid-Continent Carbon Capture, Sequestration & Enhanced Oil Recovery Project

    SciTech Connect (OSTI)

    Brian McPherson

    2010-08-31

    A consortium of research partners led by the Southwest Regional Partnership on Carbon Sequestration and industry partners, including CAP CO2 LLC, Blue Source LLC, Coffeyville Resources, Nitrogen Fertilizers LLC, Ash Grove Cement Company, Kansas Ethanol LLC, Headwaters Clean Carbon Services, Black & Veatch, and Schlumberger Carbon Services, conducted a feasibility study of a large-scale CCS commercialization project that included large-scale CO{sub 2} sources. The overall objective of this project, entitled the 'Integrated Mid-Continent Carbon Capture, Sequestration and Enhanced Oil Recovery Project' was to design an integrated system of US mid-continent industrial CO{sub 2} sources with CO{sub 2} capture, and geologic sequestration in deep saline formations and in oil field reservoirs with concomitant EOR. Findings of this project suggest that deep saline sequestration in the mid-continent region is not feasible without major financial incentives, such as tax credits or otherwise, that do not exist at this time. However, results of the analysis suggest that enhanced oil recovery with carbon sequestration is indeed feasible and practical for specific types of geologic settings in the Midwestern U.S.

  6. Macroalgae for CO{sub 2} Capture and Renewable Energy - A Pilot Project

    SciTech Connect (OSTI)

    Kristine Wiley

    2010-10-31

    The objective of this project was to demonstrate, at a pilot scale, the beneficial use of carbon dioxide (CO{sub 2}) through a technology designed to capture CO2 from fossil-fuel fired power plant stack gas, generating macroalgae and converting the macroalgae at high efficiency to renewable methane that can be utilized in the power plant or introduced into a natural gas pipeline. The proposed pilot plant would demonstrate the cost-effectiveness and CO{sub 2}/ NO{sub x} flue-gas removal efficiency of an innovative â??algal scrubberâ?ť technology where seaweeds are grown out of water on specially-designed supporting structures contained within greenhouses where the plants are constantly bathed by recycled nutrient sprays enriched by flue gas constituents. The work described in this document addresses Phase 1 of the project only. The scope of work for Phase 1 includes the completion of a preliminary design package; the collection of additional experimental data to support the preliminary and detailed design for a pilot scale utilization of CO{sub 2} to cultivate macroalage and to process that algae to produce methane; and a technological and economic analysis to evaluate the potential of the system. Selection criteria for macroalgae that could survive the elevated temperatures and potential periodic desiccation of near desert project sites were identified. Samples of the selected macroalgae species were obtained and then subjected to anaerobic digestion to determine conversions and potential methane yields. A Process Design Package (PDP) was assembled that included process design, process flow diagram, material balance, instrumentation, and equipment list, sizes, and cost for the Phase 2 pilot plant. Preliminary economic assessments were performed under the various assumptions made, which are purposely conservative. Based on the results, additional development work should be conducted to delineate the areas for improving efficiency, reducing contingencies, and reducing overall costs.

  7. Solar Flare Element Abundances from the Solar Assembly for X-rays (SAX) on MESSENGER

    E-Print Network [OSTI]

    Nittler, Larry R.

    Solar Flare Element Abundances from the Solar Assembly for X-rays (SAX) on MESSENGER Brian RV have been analyzed for 526 large flares detected with the Solar Assembly for X-rays (SAX on 2004 August 3 and capture into orbit around Mercury in 2011, SAX has observed hundreds of solar flares

  8. EIS-0473: W.A. Parish Post-Combustion CO2 Capture and Sequestration Project (PCCS), Fort Bend County, TX

    Broader source: Energy.gov [DOE]

    This EIS evaluates the environmental impacts of a proposal to provide financial assistance for a project proposed by NRG Energy, Inc (NRG). DOE selected NRG’s proposed W.A. Parish Post-Combustion CO2 Capture and Sequestration Project for a financial assistance award through a competitive process under the Clean Coal Power Initiative Program. NRG would design, construct and operate a commercial-scale carbon dioxide (CO2) capture facility at its existing W.A. Parish Generating Station in Fort Bend County, Texas; deliver the CO2 via a new pipeline to the existing West Ranch oil field in Jackson County, Texas, for use in enhanced oil recovery operations; and demonstrate monitoring techniques to verify the permanence of geologic CO2 storage.

  9. Construction Begins on DOE-Sponsored Carbon-Capture Project at...

    Energy Savers [EERE]

    modules to process more flue gas, while so-called "waste heat" from the carbon-capture system will be recovered in the cooling tower. This robust system integration will improve...

  10. A Demonstration Project for Capturing Geothermal Energy from Mine Waters beneath Butte, MT

    Broader source: Energy.gov [DOE]

    Project objectives. Demonstrate performance of heat pumps in a large HVAC system in a heating-dominated climate.

  11. Carbon Capture and Storage FutureGen 2.0 Project Moves Forward...

    Energy Savers [EERE]

    of the first phase, the Energy Department today announced the beginning of Phase II of project development with a new cooperative agreement between the FutureGen Industrial...

  12. Lake Charles Carbon Capture and Sequestration Project U. S. Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogo and mastheadLake Charles Carbon Capture and

  13. Department of Energy Awards $71 Million to Accelerate Innovative Carbon Capture Project

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy today announced that Arizona Public Service (APS), Phoenix, Ariz., has been awarded $70.5 million from the American Recovery and Reinvestment Act (ARRA) to expand an existing industrial and innovative reuse carbon mitigation project.

  14. Collective Acceleration in Solar Flares

    E-Print Network [OSTI]

    Barletta, W.

    2008-01-01

    Collective Acceleration in Solar Flares w. Barletta, S.S.COLLECTIVE ACCELERATION IN SOLAR FLARES* W. Barletta (1), S.Park, MD 20742 Abstract Solar flare data are examined with

  15. Flare System Optimization 

    E-Print Network [OSTI]

    Aegerter, R.

    2003-01-01

    , steam, nitrogen, and natural gas. By properly operating and maintaining the flare system and with minor improvements, significant savings can be achieved....

  16. Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Financing Tool FitsProjectData DashboardSolar »ConferencePartnership of theInnovator"

  17. Nucleosynthesis in stellar flares

    E-Print Network [OSTI]

    V. Tatischeff; J. -P. Thibaud; I. Ribas

    2008-01-11

    Nuclear interactions of ions accelerated at the surface of flaring stars can produce fresh isotopes in stellar atmospheres. Although this nucleosynthesis is not significant for the chemical evolution of the Galaxy, it can be important for a number of measurements of "anomalously" high 6-Li and 7-Li abundances. We discuss the possible role of stellar flares to explain the recent report of high 6-Li abundances in metal-poor halo stars and the well-established correlation between Li abundance and stellar activity in young open clusters. We then study the possibility of observing directly Li production during flares of nearby and active dwarfs of spectral type M.

  18. IMPACCT: Carbon Capture Technology

    SciTech Connect (OSTI)

    2012-01-01

    IMPACCT Project: IMPACCT’s 15 projects seek to develop technologies for existing coal-fired power plants that will lower the cost of carbon capture. Short for “Innovative Materials and Processes for Advanced Carbon Capture Technologies,” the IMPACCT Project is geared toward minimizing the cost of removing carbon dioxide (CO2) from coal-fired power plant exhaust by developing materials and processes that have never before been considered for this application. Retrofitting coal-fired power plants to capture the CO2 they produce would enable greenhouse gas reductions without forcing these plants to close, shifting away from the inexpensive and abundant U.S. coal supply.

  19. Cryogenic Carbon Capture

    SciTech Connect (OSTI)

    2010-07-15

    IMPACCT Project: SES is developing a process to capture CO2 from the exhaust gas of coal-fired power plants by desublimation - the conversion of a gas to a solid. Capturing CO2 as a solid and delivering it as a liquid avoids the large energy cost of CO2 gas compression. SES’ capture technology facilitates the prudent use of available energy resources. Coal is our most abundant energy resource and is an excellent fuel for baseline power production. SES capture technology can capture 99% of the CO2 emissions in addition to a wide range of other pollutants more efficiently and at lower costs than existing capture technologies. SES’ capture technology can be readily added to our existing energy infrastructure.

  20. Parameterization of solar flare dose 

    E-Print Network [OSTI]

    Lamarche, Anne Helene

    1995-01-01

    A critical aspect of missions to the Moon or Mars is the safety and health of the crew. Radiation in space is a hazard for astronauts, especially high-energy radiation following certain types of solar flares. A solar flare ...

  1. Gamma-ray burst flares: X-ray flaring. II

    SciTech Connect (OSTI)

    Swenson, C. A.; Roming, P. W. A., E-mail: cswenson@astro.psu.edu [Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2014-06-10

    We present a catalog of 498 flaring periods found in gamma-ray burst (GRB) light curves taken from the online Swift X-Ray Telescope GRB Catalogue. We analyzed 680 individual light curves using a flare detection method developed and used on our UV/optical GRB Flare Catalog. This method makes use of the Bayesian Information Criterion to analyze the residuals of fitted GRB light curves and statistically determines the optimal fit to the light curve residuals in an attempt to identify any additional features. These features, which we classify as flares, are identified by iteratively adding additional 'breaks' to the light curve. We find evidence of flaring in 326 of the analyzed light curves. For those light curves with flares, we find an average number of ?1.5 flares per GRB. As with the UV/optical, flaring in our sample is generally confined to the first 1000 s of the afterglow, but can be detected to beyond 10{sup 5} s. Only ?50% of the detected flares follow the 'classical' definition of ?t/t ? 0.5, with many of the largest flares exceeding this value.

  2. Solar Flares and particle acceleration

    E-Print Network [OSTI]

    energy ~2 1032 ergs #12;"Standard" model of a solar flare/CME Solar corona T ~ 106 K => 0.1 keV per MeV Proton energies >100 MeV Large solar flare releases about 1032 ergs (about half energy-free emission) #12;X-ray spectrum of solar flares Thermal X-rays Non-thermal X-rays Gamma-ray lines Ramaty High

  3. On flare predictability based on sunspot group evolution

    E-Print Network [OSTI]

    Korsos, Marianna; Erdelyi, Robert; Baranyi, Tunde

    2015-01-01

    The forecast method introduced by Kors\\'os et al.(2014) is generalised from the horizontal magnetic gradient (GM), defined between two opposite polarity spots, to all spots within an appropriately defined region close to the magnetic neutral line of an active region. This novel approach is not limited to searching for the largest GM of two single spots as in previous methods. Instead, the pre-flare conditions of the evolution of spot groups is captured by the introduction of the weighted horizontal magnetic gradient, or W_GM. This new proxy enables the potential of forecasting flares stronger than M5. The improved capability includes (i) the prediction of flare onset time and (ii) an assessment whether a flare is followed by another event within about 18 hours. The prediction of onset time is found to be more accurate here. A linear relationship is established between the duration of converging motion and the time elapsed from the moment of closest position to that of the flare onset of opposite polarity spot...

  4. Reduction of Hydrocarbon Losses to Flare Systems 

    E-Print Network [OSTI]

    Page, J.

    1979-01-01

    action to minimize hydrocarbon releases, 2) install flare gas recovery systems, and 3) recover or reduce process streams which have to be continuous1y vented to the flare system. This report discusses alternate designs for flare gas monitoring and flare...

  5. NETL emphasizes CO{sub 2} capture from existing plants

    SciTech Connect (OSTI)

    NONE

    2008-04-01

    This paper gives brief description of several carbon dioxide capture projects that were directed toward a broader range of capture technologies.

  6. A Bayesian Approach to Solar Flare Prediction

    E-Print Network [OSTI]

    M. S. Wheatland

    2004-03-26

    A number of methods of flare prediction rely on classification of physical characteristics of an active region, in particular optical classification of sunspots, and historical rates of flaring for a given classification. However these methods largely ignore the number of flares the active region has already produced, in particular the number of small events. The past history of occurrence of flares (of all sizes) is an important indicator to future flare production. We present a Bayesian approach to flare prediction, which uses the flaring record of an active region together with phenomenological rules of flare statistics to refine an initial prediction for the occurrence of a big flare during a subsequent period of time. The initial prediction is assumed to come from one of the extant methods of flare prediction. The theory of the method is outlined, and simulations are presented to show how the refinement step of the method works in practice.

  7. Stored CO2 and Methane Leakage Risk Assessment and Monitoring Tool Development: CO2 Capture Project Phase 2 (CCP2)

    SciTech Connect (OSTI)

    Dan Kieki

    2008-09-30

    The primary project goal is to develop and test tools for optimization of ECBM recovery and geologic storage of CO{sub 2} in coalbeds, in addition to tools for monitoring CO{sub 2} sequestration in coalbeds to support risk assessment. Three critical topics identified are (1) the integrity of coal bed methane geologic and engineered systems, (2) the optimization of the coal bed storage process, and (3) reliable monitoring and verification systems appropriate to the special conditions of CO{sub 2} storage and flow in coals.

  8. RHESSI observation of flare elements

    E-Print Network [OSTI]

    Paolo C. Grigis; Arnold O. Benz

    2006-02-14

    RHESSI observations of elementary flare bursts are presented. These solar flare elements are distinct emission peaks of a duration of some tens of seconds present in the hard X-ray light curves. They are characterized by consistent soft-hard-soft spectral behavior, which can be described in a quantitative way and compared which predictions from acceleration models. A detailed analysis of hard X-ray images for an M5 class flare shows that elementary flare bursts do not occur at distinct locations, but as twin X-ray sources move smoothly along an arcade of magnetic loops. This observation apparently contradicts the predictions of standard translation invariant 2.5-dimensional reconnection models.

  9. North Dakota: EERE-Funded Project Recycles Energy, Generates...

    Office of Environmental Management (EM)

    of its Flare Gas Micro-turbine. The microturbine pilot project places generators at oil production well sites to transform wellhead flare gas into high-quality, three-phase...

  10. Earth Planets Space, , , Flares and the Chromosphere

    E-Print Network [OSTI]

    Hudson, Hugh

    produces in the photospheric magnetic field. Key words: Solar flares, Solar chromosphere, Solar corona understand about solar flares. The reason for this was the recognition, in the 19th and early 20th cen The radiative energy of a solar flare appears mainly in the optical and UV continuum, which form in the lower

  11. OVERVIEW OF SOLAR FLARES The Yohkoh Perspective

    E-Print Network [OSTI]

    California at Berkeley, University of

    Chapter 8 OVERVIEW OF SOLAR FLARES The Yohkoh Perspective Hugh Hudson Space Sciences Laboratory, UC This chapter reviews the physics of solar flares, with special emphasis on the past decade. During this decade, corona 1 #12;2 1. Introduction The physics of solar flares seems too broad a subject to review adequately

  12. Solar Flares STFC Advanced Summer School

    E-Print Network [OSTI]

    California at Berkeley, University of

    Solar Flares STFC Advanced Summer School in Solar Physics H. S. Hudson Space Sciences Laboratory · A solar flare is, strictly speaking, the electromagnetic radiation from a coronal magnetic energy release and CME require a magnetic storage to supply the energy: #12;Glasgow Summerschool 2011 Why is flare

  13. Lithium-6 from Solar Flares

    E-Print Network [OSTI]

    R. Ramaty; V. Tatischeff; J. P. Thibaud; B. Kozlovsky; N. Mandzhavidze

    2000-03-23

    By introducing a hitherto ignored Li-6 producing process, due to accelerated He-3 reactions with He-4, we show that accelerated particle interactions in solar flares produce much more Li-6 than Li-7. By normalizing our calculations to gamma-ray data we demonstrate that the Li-6 produced in solar flares, combined with photospheric Li-7, can account for the recently determined solar wind lithium isotopic ratio, obtained from measurements in lunar soil, provided that the bulk of the flare produced lithium is evacuated by the solar wind. Further research in this area could provide unique information on a variety of problems, including solar atmospheric transport and mixing, solar convection and the lithium depletion issue, and solar wind and solar particle acceleration.

  14. Scaling laws of solar and stellar flares

    E-Print Network [OSTI]

    Markus J. Aschwanden; Robert A. Stern; Manuel Güdel

    2007-10-12

    In this study we compile for the first time comprehensive data sets of solar and stellar flare parameters, including flare peak temperatures T_p, flare peak volume emission measures EM_p, and flare durations t_f from both solar and stellar data, as well as flare length scales L from solar data. Key results are that both the solar and stellar data are consistent with a common scaling law of EM_p ~ T_p^4.7, but the stellar flares exhibit ~250 times higher emission measures (at the same flare peak temperature). For solar flares we observe also systematic trends for the flare length scale L(T_p) ~ T_p^0.9 and the flare duration t_F(T_p) ~ T_p^0.9 as a function of the flare peak temperature. Using the theoretical RTV scaling law and the fractal volume scaling observed for solar flares, i.e., V(L) ~ L^2.4, we predict a scaling law of EM_p ~ T_p^4.3, which is consistent with observations, and a scaling law for electron densities in flare loops, n_p ~ T_p^2/L ~ T_p^1.1. The RTV-predicted electron densities were also found to be consistent with densities inferred from total emission measures, n_p=(EM_p/q_V*V)^1/2, using volume filling factors of q_V=0.03-0.08 constrained by fractal dimensions measured in solar flares. Our results affect also the determination of radiative and conductive cooling times, thermal energies, and frequency distributions of solar and stellar flare energies.

  15. Global Energetics of Solar Flares: II. Thermal Energies

    E-Print Network [OSTI]

    Aschwanden, M J; Ryan, D; Caspi, A; McTiernan, J M; Warren, H P

    2015-01-01

    We present the second part of a project on the global energetics of solar flares and CMEs that includes about 400 M- and X-class flares observed with AIA/SDO during the first 3.5 years of its mission. In this Paper II we compute the differential emission measure (DEM) distribution functions and associated multi-thermal energies, using a spatially-synthesized Gaussian DEM forward-fitting method. The multi-thermal DEM function yields a significantly higher (by an average factor of $\\approx 14$), but more comprehensive (multi-)thermal energy than an isothermal energy estimate from the same AIA data. We find a statistical energy ratio of $E_{th}/E_{diss} \\approx 2\\%-40\\%$ between the multi-thermal energy $E_{th}$ and the magnetically dissipated energy $E_{diss}$, which is an order of magnitude higher than the estimates of Emslie et al.~2012. For the analyzed set of M and X-class flares we find the following physical parameter ranges: $L=10^{8.2}-10^{9.7}$ cm for the length scale of the flare areas, $T_p=10^{5.7}-...

  16. Detecting Solar Neutrino Flares and Flavors

    E-Print Network [OSTI]

    D. Fargion

    2004-04-16

    Intense solar flares originated in sun spots produce high energy particles (protons, $\\alpha$) well observable by satellites and ground-based detectors. The flare onset produces signals in different energy bands (radio, X, gamma and neutrons). The most powerful solar flares as the ones occurred on 23 February 1956, 29 September 1989 and the more recent on October 28th, and the 2nd, 4th, 13th of November 2003 released in sharp times the largest flare energies (${E}_{FL} \\simeq {10}^{31}\\div {10}^{32} erg). The high energy solar flare protons scatter within the solar corona and they must be source of a prompt neutrino burst through the production of charged pions. Later on, solar flare particles hitting the atmosphere may marginally increase the atmospheric neutrino flux. The prompt solar neutrino flare may be detected in the largest underground $\

  17. Robust automated knowledge capture.

    SciTech Connect (OSTI)

    Stevens-Adams, Susan Marie; Abbott, Robert G.; Forsythe, James Chris; Trumbo, Michael Christopher Stefan; Haass, Michael Joseph; Hendrickson, Stacey M. Langfitt

    2011-10-01

    This report summarizes research conducted through the Sandia National Laboratories Robust Automated Knowledge Capture Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding of the influence of individual cognitive attributes on decision making. The project has developed a quantitative model known as RumRunner that has proven effective in predicting the propensity of an individual to shift strategies on the basis of task and experience related parameters. Three separate studies are described which have validated the basic RumRunner model. This work provides a basis for better understanding human decision making in high consequent national security applications, and in particular, the individual characteristics that underlie adaptive thinking.

  18. Magnetic reconnection configurations and particle acceleration in solar flares

    E-Print Network [OSTI]

    Chen, P. F.

    types of solar flares. Upper panel: two-ribbon flares; Lower panel: compact flares. The color showsMagnetic reconnection configurations and particle acceleration in solar flares P. F. Chen, W. J space under different magnetic configurations. Key words: solar flares, magnetic reconnection, particle

  19. Recent Flare Studies at NJIT Outline of Studies

    E-Print Network [OSTI]

    continuum brightening (white-light flares) Black-light solar flares (BLFs; Henoux et al. 1990): electron flares. - Solar limb in D3, showing a narrow, bright band above the photosphere between 1000 and 2500 km3/28/2014 1 Recent Flare Studies at NJIT Lecture 10 Outline of Studies Black Light Flares Moreton

  20. The Ulysses Catalog of Solar Hard X-Ray Flares

    E-Print Network [OSTI]

    Tranquille, C.; Hurley, K.; Hudson, H. S.

    2009-01-01

    Sturrock, P.A. (ed. ) Solar Flares: A Monograph from SkylabSmith E.V.P. : 1963, Solar Flares, Macmillan, New York.Catalog of Solar Hard X-Ray Flares Table 1 (Continued. )

  1. Flare Gas Recovery in Shell Canada Refineries 

    E-Print Network [OSTI]

    Allen, G. D.; Wey, R. E.; Chan, H. H.

    1983-01-01

    six years total operating experience with modern flare gas recovery units. The compression facilities in each utilize a two-stage reciprocating machine, one liquid seal drum per flare stack, and an automated load control strategy. The purpose... these issues. SYSTEM CONFIGURATION A schematic of a typical refinery flare gas recovery facility is shown in Figure I. The facilities include the following pieces of equipment: - compressor suction drum - compressor set - inter-stage knock-out drum...

  2. Solar flares: Preflare Phase SOLAR FLARES are believed to be the result of a sud

    E-Print Network [OSTI]

    Martens, Petrus C.

    build­up and the trigger mechanism is at the heart of understanding the physics of solar flaresSolar flares: Preflare Phase SOLAR FLARES are believed to be the result of a sud­ den conversion of a large amount of FREE MAGNETIC ENERGY, previously stored in the solar CORONA. The release takes place

  3. Feasibility of air capture

    E-Print Network [OSTI]

    Ranjan, Manya

    2010-01-01

    Capturing CO2 from air, referred to as Air Capture, is being proposed as a viable climate change mitigation technology. The two major benefits of air capture, reported in literature, are that it allows us to reduce the ...

  4. North Dakota: EERE-Funded Project Recycles Energy, Generates...

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

    Development grant, funded by EERE, to demonstrate the commercial viability of its Flare Gas Micro-turbine. The microturbine pilot project places generators at oil production well...

  5. Prediction of Solar Flare Size and Time-to-Flare Using Support Vector Machine Regression

    E-Print Network [OSTI]

    Boucheron, Laura E; McAteer, R T James

    2015-01-01

    We study the prediction of solar flare size and time-to-flare using 38 features describing magnetic complexity of the photospheric magnetic field. This work uses support vector regression to formulate a mapping from the 38-dimensional feature space to a continuous-valued label vector representing flare size or time-to-flare. When we consider flaring regions only, we find an average error in estimating flare size of approximately half a \\emph{geostationary operational environmental satellite} (\\emph{GOES}) class. When we additionally consider non-flaring regions, we find an increased average error of approximately 3/4 a \\emph{GOES} class. We also consider thresholding the regressed flare size for the experiment containing both flaring and non-flaring regions and find a true positive rate of 0.69 and a true negative rate of 0.86 for flare prediction. The results for both of these size regression experiments are consistent across a wide range of predictive time windows, indicating that the magnetic complexity fe...

  6. The local Poisson hypothesis for solar flares

    E-Print Network [OSTI]

    M. S. Wheatland

    2001-07-09

    The question of whether flares occur as a Poisson process has important consequences for flare physics. Recently Lepreti et al. presented evidence for local departure from Poisson statistics in the Geostationary Operational Environmental Satellite (GOES) X-ray flare catalog. Here it is argued that this effect arises from a selection effect inherent in the soft X-ray observations; namely that the slow decay of enhanced flux following a large flare makes detection of subsequent flares less likely. It is also shown that the power-law tail of the GOES waiting-time distribution varies with the solar cycle. This counts against any intrinsic significance to the appearance of a power law, or to the value of its index.

  7. SOLAR FLARE CYCLES , M. D. POPESCU1, 2

    E-Print Network [OSTI]

    SOLAR FLARE CYCLES G. MARI1 , M. D. POPESCU1, 2 1 Astronomical Institute of the Romanian Academy solar flare periodicity intervals. Our analysis includes a statistical investigation of flare occurrence and the strength of solar cycles. For that purpose, we studied not only the number of flares occurring monthly

  8. Dynamic Precursors of Flares in Active Region NOAA 10486

    E-Print Network [OSTI]

    Korsos, M B; Baranyi, T; Ludmany, A

    2015-01-01

    Four different methods are applied here to study the precursors of flare activity in the Active Region NOAA 10486. Two approaches track the temporal behaviour of suitably chosen features (one, the weighted horizontal gradient WGM, is generalised form the horizontal gradient of the magnetic field, GM; another is the sum of the horizontal gradient of the magnetic field, GS, for all sunspot pairs). WGM is a photospheric indicator that is a proxy measure of magnetic non-potentiality of a specific area of the active region, i.e. it captures the temporal variation of the weighted horizontal gradient of magnetic flux summed up for the region where opposite magnetic polarities are highly mixed. The third one, referred to as the separateness parameter, S(lf), considers the overall morphology. Further, GS and S(lf) are photospheric newly defined quick-look indicators of the polarity mix of the entire active region. The fourth method is tracking the temporal variation of small x-ray flares, their times of succession and...

  9. Location of Narrowband Spikes in Solar Flares

    E-Print Network [OSTI]

    Arnold O. Benz; Pascal Saint-Hilaire; Nicole Vilmer

    2001-12-19

    Narrowband spikes of the decimeter type have been identified in dynamic spectrograms of Phoenix-2 of ETH Zurich and located in position with the Nancay Radioheliograph at the same frequency. The spike positions have been compared with the location of hard X-ray emission and the thermal flare plasma in soft X-rays and EUV lines. The decimetric spikes are found to be single sources located some 20" to 400" away from the flare site in hard or soft X-rays. In most cases there is no bright footpoint nearby. In at least two cases the spikes are near loop tops. These observations do not confirm the widely held view that the spike emission is produced by some loss-cone instability masering near the footpoints of flare loops. On the other hand, the large distance to the flare sites and the fact that these spikes are all observed in the flare decay phase make the analyzed spike sources questionable sites for the main flare electron acceleration. They possibly indicate coronal post-flare acceleration sites.

  10. Giant AGN Flares and Cosmic Ray Bursts

    E-Print Network [OSTI]

    Glennys R. Farrar; Andrei Gruzinov

    2008-09-15

    We predict a new class of very intense, short-duration AGN flares capable of accelerating the highest energy cosmic rays, resulting from the tidal disruption of a star or from a disk instability. The rate and power of these flares readily explains the observed flux and density statistics of UHECRs. The photon bursts produced by the predicted AGN flares are discussed; they may soon be detectable. Observations are shown to exclude that continuous jets of powerful Active Galactic Nuclei are the sole source of ultrahigh energy cosmic rays; the stringent requirements for Gamma Ray Bursts to be the source are delineated.

  11. The Energetics of a Flaring Solar Active Region, and Observed Flare Statistics

    E-Print Network [OSTI]

    M. S. Wheatland

    2008-02-26

    A stochastic model for the energy of a flaring solar active region is presented, generalising and extending the approach of Wheatland & Glukhov (1998). The probability distribution for the free energy of an active region is described by the solution to a master equation involving deterministic energy input and random jump transitions downwards in energy (solar flares). It is shown how two observable distributions, the flare frequency-energy distribution and the flare waiting-time distribution, may be derived from the steady-state solution to the master equation, for given choices for the energy input and for the rates of flare transitions. An efficient method of numerical solution of the steady-state master equation is presented. Solutions appropriate for flaring, involving a constant rate of energy input and power-law distributed jump transition rates, are numerically investigated. The flare-like solutions exhibit power-law flare frequency-energy distributions below a high energy rollover, set by the largest energy the active region is likely to have. The solutions also exhibit approximately exponential (i.e. Poisson) waiting-time distributions, despite the rate of flaring depending on the free energy of the system.

  12. Global energetics of solar flares. I. Magnetic energies

    SciTech Connect (OSTI)

    Aschwanden, Markus J.; Xu, Yan; Jing, Ju E-mail: yan.xu@njit.edu

    2014-12-10

    We present the first part of a project on the global energetics of solar flares and coronal mass ejections that includes about 400 M- and X-class flares observed with Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). We calculate the potential (E{sub p} ), the nonpotential (E {sub np}) or free energies (E {sub free} = E {sub np} – E{sub p} ), and the flare-dissipated magnetic energies (E {sub diss}). We calculate these magnetic parameters using two different NLFFF codes: the COR-NLFFF code uses the line-of-sight magnetic field component B{sub z} from HMI to define the potential field, and the two-dimensional (2D) coordinates of automatically detected coronal loops in six coronal wavelengths from AIA to measure the helical twist of coronal loops caused by vertical currents, while the PHOT-NLFFF code extrapolates the photospheric three-dimensional (3D) vector fields. We find agreement between the two codes in the measurement of free energies and dissipated energies within a factor of ? 3. The size distributions of magnetic parameters exhibit powerlaw slopes that are approximately consistent with the fractal-diffusive self-organized criticality model. The magnetic parameters exhibit scaling laws for the nonpotential energy, E{sub np}?E{sub p}{sup 1.02}, for the free energy, E{sub free}?E{sub p}{sup 1.7} and E{sub free}?B{sub ?}{sup 1.0}L{sup 1.5}, for the dissipated energy, E{sub diss}?E{sub p}{sup 1.6} and E{sub diss}?E{sub free}{sup 0.9}, and the energy dissipation volume, V?E{sub diss}{sup 1.2}. The potential energies vary in the range of E{sub p} = 1 × 10{sup 31}-4 × 10{sup 33} erg, while the free energy has a ratio of E {sub free}/E{sub p} ? 1%-25%. The Poynting flux amounts to F {sub flare} ? 5 × 10{sup 8}-10{sup 10} erg cm{sup –2} s{sup –1} during flares, which averages to F {sub AR} ? 6 × 10{sup 6} erg cm{sup –2} s{sup –1} during the entire observation period and is comparable with the coronal heating rate requirement in active regions.

  13. Reducing Safety Flaring through Advanced Control 

    E-Print Network [OSTI]

    Hokanson, D.; Lehman, K.; Matsumoto, S.; Takai, N.; Takase, F.

    2010-01-01

    An advanced process control application, using DMCplus® (Aspen Technology, Inc.), was developed to substantially reduce fuel gas losses to the flare at a large integrated refining / petrochemical complex. Fluctuations in internal fuel gas system...

  14. Secretary Chu Announces $2.4 billion in Funding for Carbon Capture...

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

    .4 billion in Funding for Carbon Capture and Storage Projects Secretary Chu Announces 2.4 billion in Funding for Carbon Capture and Storage Projects May 15, 2009 - 12:00am Addthis...

  15. The Shape of M Dwarf Flares in Kepler Light Curves

    E-Print Network [OSTI]

    Davenport, James R A

    2015-01-01

    Ultra-precise light curves from Kepler provide the best opportunity to determine rates and statistical properties of stellar flares. From 11 months of data on the active M4 dwarf, GJ 1243, we have built the largest catalog of flares for a single star: over 6100 events. Combining 885 of our most pristine flares, we generated an empirical white-light flare template. This high-fidelity template shows a rapid initial rise, and two distinct exponential cooling phases. This template is useful in constraining flare energies and for improved flare detection in many surveys. Complex, multi-peaked events are more common for higher energy flares in this sample. Using our flare template we characterize the structure of complex events. In this contributed talk, I presented results from our boutique study of GJ 1243, and described an expanded investigation of the structure of complex flares and their connection to solar events.

  16. ON THE DURATION OF BLAZAR SYNCHROTRON FLARES

    SciTech Connect (OSTI)

    Eichmann, B.; Schlickeiser, R.; Rhode, W.

    2012-01-10

    A semi-analytical model is presented that describes the temporal development of a blazar synchrotron flare for the case of a broadband synchrotron power spectrum. We examine three different injection scenarios and present its influence on the synchrotron flare. An accurate approximation of the half-life of a synchrotron flare is analytically computed and we give some illustrative examples of the time evolution of the emergent synchrotron intensity by using a numerical integration method. The synchrotron flare starts at all photon energies right after the injection of ultrarelativistic electrons into the spherical emission volume of radius R and its duration exceeds the light travel time 2R/c in the low energy regime. Furthermore, the flare duration extends by the period of injection of relativistic electrons into the emission knot. However, the energetic and spatial distribution of these injected electrons has no significant influence on the flare duration. We obtain a temporal behavior that agrees most favorably with the observations of PKS 2155-304 on 2006 July 29-30 and it differs considerably from the results that were recently achieved by using a monochromatic approximation of the synchrotron power.

  17. EIT and TRACE responses to flare plasma

    E-Print Network [OSTI]

    D. Tripathi; G. Del Zanna; H. E. Mason; C. Chifor

    2008-02-26

    Aims: To understand the contribution of active region and flare plasmas to the $\\lambda$195 channels of SOHO/EIT (Extreme-ultraviolet Imaging Telescope) and TRACE (Transition Region and Coronal Explorer). Methods: We have analysed an M8 flare simultaneously observed by the Coronal Diagnostic Spectrometer (CDS), EIT, TRACE and RHESSI. We obtained synthetic spectra for the flaring region and an outer region using the differential emission measures (DEM) of emitting plasma based on CDS and RHESSI observations and the CHIANTI atomic database. We then predicted the EIT and TRACE count rates. Results: For the flaring region, both EIT and TRACE images taken through the $\\lambda$195 filter are dominated by Fe ${\\rm XXIV}$ (formed at about 20 MK). However, in the outer region, the emission was primarily due to the Fe${\\rm XII}$, with substantial contributions from other lines. The average count rate for the outer region was within 25% the observed value for EIT, while for TRACE it was a factor of two higher. For the flare region, the predicted count rate was a factor of two (in case of EIT) and a factor of three (in case of TRACE) higher than the actual count rate. Conclusions: During a solar flare, both TRACE and EIT $\\lambda$195 channels are found to be dominated by Fe ${\\rm XXIV}$ emission. Reasonable agreement between predictions and observations is found, however some discrepancies need to be further investigated.

  18. Are there Radio-quiet Solar Flares?

    E-Print Network [OSTI]

    Arnold O. Benz; Roman Brajsa; Jasmina Magdalenic

    2007-01-19

    Some 15% of solar flares having a soft X-ray flux above GOES class C5 are reported to lack coherent radio emission in the 100 - 4000 MHz range (type I - V and decimetric emissions). A detailed study of 29 such events reveals that 22 (76%) of them occurred at a radial distance of more than 800'' from the disk center, indicating that radio waves from the limb may be completely absorbed in some flares. The remaining seven events have statistically significant trends to be weak in GOES class and to have a softer non-thermal X-ray spectrum. All of the non-limb flares that were radio-quiet > 100 MHz were accompanied by metric type III emission below 100 MHz. Out of 201 hard X-ray flares, there was no flare except near the limb (R>800'') without coherent radio emission in the entire meter and decimeter range. We suggest that flares above GOES class C5 generally emit coherent radio waves when observed radially above the source.

  19. Petra Nova Project Breaks Ground on World's Largest Post-Combustion...

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

    Petra Nova Project Breaks Ground on World's Largest Post-Combustion Carbon Capture Project Petra Nova Project Breaks Ground on World's Largest Post-Combustion Carbon Capture...

  20. Metazen – metadata capture for metagenomes

    SciTech Connect (OSTI)

    Bischof, Jared; Harrison, Travis; Paczian, Tobias; Glass, Elizabeth; Wilke, Andreas; Meyer, Folker

    2014-12-08

    Background: As the impact and prevalence of large-scale metagenomic surveys grow, so does the acute need for more complete and standards compliant metadata. Metadata (data describing data) provides an essential complement to experimental data, helping to answer questions about its source, mode of collection, and reliability. Metadata collection and interpretation have become vital to the genomics and metagenomics communities, but considerable challenges remain, including exchange, curation, and distribution. Currently, tools are available for capturing basic field metadata during sampling, and for storing, updating and viewing it. These tools are not specifically designed for metagenomic surveys; in particular, they lack the appropriate metadata collection templates, a centralized storage repository, and a unique ID linking system that can be used to easily port complete and compatible metagenomic metadata into widely used assembly and sequence analysis tools. Results: Metazen was developed as a comprehensive framework designed to enable metadata capture for metagenomic sequencing projects. Specifically, Metazen provides a rapid, easy-to-use portal to encourage early deposition of project and sample metadata. Conclusion: Metazen is an interactive tool that aids users in recording their metadata in a complete and valid format. A defined set of mandatory fields captures vital information, while the option to add fields provides flexibility.

  1. Metazen – metadata capture for metagenomes

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

    Bischof, Jared; Harrison, Travis; Paczian, Tobias; Glass, Elizabeth; Wilke, Andreas; Meyer, Folker

    2014-12-08

    Background: As the impact and prevalence of large-scale metagenomic surveys grow, so does the acute need for more complete and standards compliant metadata. Metadata (data describing data) provides an essential complement to experimental data, helping to answer questions about its source, mode of collection, and reliability. Metadata collection and interpretation have become vital to the genomics and metagenomics communities, but considerable challenges remain, including exchange, curation, and distribution. Currently, tools are available for capturing basic field metadata during sampling, and for storing, updating and viewing it. These tools are not specifically designed for metagenomic surveys; in particular, they lack themore »appropriate metadata collection templates, a centralized storage repository, and a unique ID linking system that can be used to easily port complete and compatible metagenomic metadata into widely used assembly and sequence analysis tools. Results: Metazen was developed as a comprehensive framework designed to enable metadata capture for metagenomic sequencing projects. Specifically, Metazen provides a rapid, easy-to-use portal to encourage early deposition of project and sample metadata. Conclusion: Metazen is an interactive tool that aids users in recording their metadata in a complete and valid format. A defined set of mandatory fields captures vital information, while the option to add fields provides flexibility.« less

  2. The Origin of the Solar Flare Waiting-Time Distribution

    E-Print Network [OSTI]

    M. S. Wheatland

    2000-05-08

    It was recently pointed out that the distribution of times between solar flares (the flare waiting-time distribution) follows a power law, for long waiting times. Based on 25 years of soft X-ray flares observed by Geostationary Operational Environmental Satellite (GOES) instruments it is shown that 1. the waiting-time distribution of flares is consistent with a time-dependent Poisson process, and 2. the fraction of time the Sun spends with different flaring rates approximately follows an exponential distribution. The second result is a new phenomenological law for flares. It is shown analytically how the observed power-law behavior of the waiting times originates in the exponential distribution of flaring rates. These results are argued to be consistent with a non-stationary avalanche model for flares.

  3. Reversible Acid Gas Capture

    ScienceCinema (OSTI)

    Dave Heldebrant

    2012-12-31

    Pacific Northwest National Laboratory scientist David Heldebrant demonstrates how a new process called reversible acid gas capture works to pull carbon dioxide out of power plant emissions.

  4. Spatial Relationship between Solar Flares and Coronal Mass Ejections

    E-Print Network [OSTI]

    S. Yashiro; G. Michalek; S. Akiyama; N. Gopalswamy; R. A. Howard

    2007-10-16

    We report on the spatial relationship between solar flares and coronal mass ejections (CMEs) observed during 1996-2005 inclusive. We identified 496 flare-CME pairs considering limb flares (distance from central meridian > 45 deg) with soft X-ray flare size > C3 level. The CMEs were detected by the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO). We investigated the flare positions with respect to the CME span for the events with X-class, M-class, and C-class flares separately. It is found that the most frequent flare site is at the center of the CME span for all the three classes, but that frequency is different for the different classes. Many X-class flares often lie at the center of the associated CME, while C-class flares widely spread to the outside of the CME span. The former is different from previous studies, which concluded that no preferred flare site exists. We compared our result with the previous studies and conclude that the long-term LASCO observation enabled us to obtain the detailed spatial relation between flares and CMEs. Our finding calls for a closer flare-CME relationship and supports eruption models typified by the CSHKP magnetic reconnection model.

  5. Rapid Transition of Uncombed Penumbrae to Faculae during Large Flares

    E-Print Network [OSTI]

    field evolution in solar photosphere plays important roles in building energy and triggering eruption structure associated with major flares. Taking advantage of two near-limb events, we found that in sections: flares -- Sun: magnetic topology -- sunspots #12;­ 2 ­ 1. INTRODUCTION Solar flares have been understood

  6. Version on March 21, 2002 STATISTICAL EVIDENCE FOR SYMPATHETIC FLARES

    E-Print Network [OSTI]

    . Subject headings: Sun: flare - Sun: X-ray - Sun: corona 1 Big Bear Solar Observatory, NJIT, 40386 North as solar flares in different active regions that apparently occur as the common result of activation, which are defined as unrelated solar flares that occur at nearly the same time. However

  7. Probabilistic forecasting of solar flares from vector magnetogram data

    E-Print Network [OSTI]

    Barnes, Graham

    Probabilistic forecasting of solar flares from vector magnetogram data G. Barnes,1 K. D. Leka,1 E to solar flare forecasting, adapted to provide the probability that a measurement belongs to either group, the groups in this case being solar active regions which produced a flare within 24 hours and those

  8. Driving Major Solar Flares and Eruptions: Carolus J. Schrijver

    E-Print Network [OSTI]

    Schrijver, Karel

    Driving Major Solar Flares and Eruptions: A Review Carolus J. Schrijver Lockheed Martin Adv. Techn: emerging flux 1 Introduction We have known of the phenomenon called 'solar flare' ever since the first,000 refereed publications with the words 'flare' and 'Sun' or 'solar' in the abstract. Even the limited focus

  9. THE 22-YEAR SOLAR MAGNETIC CYCLE. II. FLARE ACTIVITY

    E-Print Network [OSTI]

    THE 22-YEAR SOLAR MAGNETIC CYCLE. II. FLARE ACTIVITY G. MARI, M. D. POPESCU, A. C. DONEA, M. MIERLA cycle, a cycle that had an unexpected behaviour. Here we analyze the occurrence of the solar flares predicted of the current 11-year solar cycle. We conclude that it could be determined by a pulse of flare

  10. Blazar Flaring Rates Measured with GLAST

    E-Print Network [OSTI]

    C. D. Dermer; B. L. Dingus

    2003-12-22

    We derive the minimum observing time scales to detect a blazar at a given flux level with the LAT on GLAST in the scanning and pointing modes. Based upon Phase 1 observations with EGRET, we predict the GLAST detection rate of blazar flares at different flux levels. With some uncertainty given the poor statistics of bright blazars, we predict that a blazar flare with integral flux >~ 200e-8 ph(> 100 MeV) cm^{-2} s^{-1}, which are the best candidates for Target of Opportunity pointings and extensive temporal and spectral studies, should occur every few days.

  11. Blazar Flaring Rates Measured with GLAST

    E-Print Network [OSTI]

    Dermer, C D

    2004-01-01

    We derive the minimum observing time scales to detect a blazar at a given flux level with the LAT on GLAST in the scanning and pointing modes. Based upon Phase 1 observations with EGRET, we predict the GLAST detection rate of blazar flares at different flux levels. With some uncertainty given the poor statistics of bright blazars, we predict that a blazar flare with integral flux >~ 200e-8 ph(> 100 MeV) cm^{-2} s^{-1}, which are the best candidates for Target of Opportunity pointings and extensive temporal and spectral studies, should occur every few days.

  12. The Relation between Solar Eruption Topologies and Observed Flare Features I: Flare Ribbons

    E-Print Network [OSTI]

    Savcheva, A; McKillop, S; McCauley, P; Hanson, E; Su, Y; Werner, E; DeLuca, E E

    2015-01-01

    In this paper we present a topological magnetic field investigation of seven two-ribbon flares in sigmoidal active regions observed with Hinode, STEREO, and SDO. We first derive the 3D coronal magnetic field structure of all regions using marginally unstable 3D coronal magnetic field models created with the flux rope insertion method. The unstable models have been shown to be a good model of the flaring magnetic field configurations. Regions are selected based on their pre-flare configurations along with the appearance and observational coverage of flare ribbons, and the model is constrained using pre-flare features observed in extreme ultraviolet and X-ray passbands. We perform a topology analysis of the models by computing the squashing factor, Q, in order to determine the locations of prominent quasi-separatrix layers (QSLs). QSLs from these maps are compared to flare ribbons at their full extents. We show that in all cases the straight segments of the two J-shaped ribbons are matched very well by the flux...

  13. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    SciTech Connect (OSTI)

    Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  14. Properties of Flares-Generated Seismic Waves on the Sun

    E-Print Network [OSTI]

    A. G. Kosovichev

    2005-12-31

    The solar seismic waves excited by solar flares (``sunquakes'') are observed as circular expanding waves on the Sun's surface. The first sunquake was observed for a flare of July 9, 1996, from the Solar and Heliospheric Observatory (SOHO) space mission. However, when the new solar cycle started in 1997, the observations of solar flares from SOHO did not show the seismic waves, similar to the 1996 event, even for large X-class flares during the solar maximum in 2000-2002. The first evidence of the seismic flare signal in this solar cycle was obtained for the 2003 ``Halloween'' events, through acoustic ``egression power'' by Donea and Lindsey. After these several other strong sunquakes have been observed. Here, I present a detailed analysis of the basic properties of the helioseismic waves generated by three solar flares in 2003-2005. For two of these flares, X17 flare of October 28, 2003, and X1.2 flare of January 15, 2005, the helioseismology observations are compared with simultaneous observations of flare X-ray fluxes measured from the RHESSI satellite. These observations show a close association between the flare seismic waves and the hard X-ray source, indicating that high-energy electrons accelerated during the flare impulsive phase produced strong compression waves in the photosphere, causing the sunquake. The results also reveal new physical properties such as strong anisotropy of the seismic waves, the amplitude of which varies significantly with the direction of propagation. The waves travel through surrounding sunspot regions to large distances, up to 120 Mm, without significant decay. These observations open new perspectives for helioseismic diagnostics of flaring active regions on the Sun and for understanding the mechanisms of the energy release and transport in solar flares.

  15. ATK - Supersonic Carbon Capture

    ScienceCinema (OSTI)

    Castrogiovanni, Anthony (ACEnT Laboratories, President and CEO); Calayag, Bon (ATK, Program Manager)

    2014-04-11

    ATK and ACEnt Laboratories, with the help of ARPA-E funding, have taken an aerospace problem, supersonic condensation, and turned it into a viable clean energy solution for carbon capture.

  16. ATK - Supersonic Carbon Capture

    SciTech Connect (OSTI)

    Castrogiovanni, Anthony; Calayag, Bon

    2014-03-05

    ATK and ACEnt Laboratories, with the help of ARPA-E funding, have taken an aerospace problem, supersonic condensation, and turned it into a viable clean energy solution for carbon capture.

  17. Carbon Capture and Storage

    SciTech Connect (OSTI)

    Friedmann, S

    2007-10-03

    Carbon capture and sequestration (CCS) is the long-term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. This includes a range of approaches including soil carbon sequestration (e.g., through no-till farming), terrestrial biomass sequestration (e.g., through planting forests), direct ocean injection of CO{sub 2} either onto the deep seafloor or into the intermediate depths, injection into deep geological formations, or even direct conversion of CO{sub 2} to carbonate minerals. Some of these approaches are considered geoengineering (see the appropriate chapter herein). All are considered in the 2005 special report by the Intergovernmental Panel on Climate Change (IPCC 2005). Of the range of options available, geological carbon sequestration (GCS) appears to be the most actionable and economic option for major greenhouse gas reduction in the next 10-30 years. The basis for this interest includes several factors: (1) The potential capacities are large based on initial estimates. Formal estimates for global storage potential vary substantially, but are likely to be between 800 and 3300 Gt of C (3000 and 10,000 Gt of CO{sub 2}), with significant capacity located reasonably near large point sources of the CO{sub 2}. (2) GCS can begin operations with demonstrated technology. Carbon dioxide has been separated from large point sources for nearly 100 years, and has been injected underground for over 30 years (below). (3) Testing of GCS at intermediate scale is feasible. In the US, Canada, and many industrial countries, large CO{sub 2} sources like power plants and refineries lie near prospective storage sites. These plants could be retrofit today and injection begun (while bearing in mind scientific uncertainties and unknowns). Indeed, some have, and three projects described here provide a great deal of information on the operational needs and field implementation of CCS. Part of this interest comes from several key documents written in the last three years that provide information on the status, economics, technology, and impact of CCS. These are cited throughout this text and identified as key references at the end of this manuscript. When coupled with improvements in energy efficiency, renewable energy supplies, and nuclear power, CCS help dramatically reduce current and future emissions (US CCTP 2005, MIT 2007). If CCS is not available as a carbon management option, it will be much more difficult and much more expensive to stabilize atmospheric CO{sub 2} emissions. Recent estimates put the cost of carbon abatement without CCS to be 30-80% higher that if CCS were to be available (Edmonds et al. 2004).

  18. Smokeless Control of Flare Steam Flow Rate 

    E-Print Network [OSTI]

    Agar, J.; Balls, B. W.

    1979-01-01

    inside the glass. The instrument has a vibrating spool accu rately machined from a material resistant to wet H2S, The patented flow path through the transducer (Figure 8) inhibits moisture and dirt from contaminating the spool and enables installation..., also the inclusion of average values for ZG and ZA' REFERENCES 1. API Publication 931, Chapter 15, "Flares", Manual on Disposal of Refinery Wastes, Volume on Atmospheric Emissions, 1977 American Petroleum Institute, Refinery Department, 2120 L...

  19. Proton capture resonance studies

    SciTech Connect (OSTI)

    Mitchell, G.E. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Bilpuch, E.G. [Duke University, Durham, North Carolina (United States) 27708]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Bybee, C.R. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Cox, J.M.; Fittje, L.M. [Tennessee Technological University, Cookeville, Tennessee (United States) 38505]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Labonte, M.A.; Moore, E.F.; Shriner, J.D. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Shriner, J.F. Jr. [Tennessee Technological University, Cookeville, Tennessee (United States) 38505]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Vavrina, G.A. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Wallace, P.M. [Duke University, Durham, North Carolina (United States) 27708]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708

    1997-02-01

    The fluctuation properties of quantum systems now are used as a signature of quantum chaos. The analyses require data of extremely high quality. The {sup 29}Si(p,{gamma}) reaction is being used to establish a complete level scheme of {sup 30}P to study chaos and isospin breaking in this nuclide. Determination of the angular momentum J, the parity {pi}, and the isospin T from resonance capture data is considered. Special emphasis is placed on the capture angular distributions and on a geometric description of these angular distributions. {copyright} {ital 1997 American Institute of Physics.}

  20. Super-hot (T > 30 MK) Thermal Plasma in Solar Flares

    E-Print Network [OSTI]

    Caspi, Amir

    2010-01-01

    R. , et al. 1980, in Solar Flares: A Monograph from SKYLABR. , et al. 1980, in Solar Flares: A Monograph from SKYLAB1988, The Physics of Solar Flares (Cambridge, UK: Cambridge

  1. Faint Coronal Hard X-rays From Accelerated Electrons in Solar Flares

    E-Print Network [OSTI]

    Glesener, Lindsay Erin

    2012-01-01

    also be applicable to solar flares. Figure is from Lin (High-Energy Aspects of Solar Flares, (Space Science Reviews2002 July 23 class X4.8 solar flare, showing thermal (red)

  2. Initial Observations of Sunspot Oscillations Excited by Solar Flare

    E-Print Network [OSTI]

    A. G. Kosovichev; T. Sekii

    2007-10-09

    Observations of a large solar flare of December 13, 2006, using Solar Optical Telescope (SOT) on Hinode spacecraft revealed high-frequency oscillations excited by the flare in the sunspot chromosphere. These oscillations are observed in the region of strong magnetic field of the sunspot umbra, and may provide a new diagnostic tool for probing the structure of sunspots and understanding physical processes in solar flares.

  3. First-of-its-Kind Carbon Capture and Conversion Demonstration...

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

    News Media Contact 202-586-4940 First-of-its-Kind Carbon Capture and Conversion Demonstration Technology Opening in Texas Department of Energy Supported Project to Find Innovative...

  4. Modelling repeatedly flaring delta-sunspots

    E-Print Network [OSTI]

    Chatterjee, Piyali; Carlsson, Mats

    2016-01-01

    Active regions (AR) appearing on the surface of the Sun are classified into $\\alpha$, $\\beta$, $\\gamma$, and $\\delta$ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the $\\delta$-sunspots are known to be super-active and produce the most X-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin sub-photospheric magnetic sheet breaks into multiple flux-tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic $\\delta$-sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections.

  5. Massively Parallel Simulations of Solar Flares and Plasma Turbulence

    E-Print Network [OSTI]

    Grauer, Rainer

    in space- and astrophysical plasmasystems include solar flares and hydro- or magnetohydrodynamic turbulence a pure MPI parallelization, which, however requires a careful optimization of the multi

  6. Carbon Smackdown: Carbon Capture

    SciTech Connect (OSTI)

    Jeffrey Long

    2010-07-12

    In this July 9, 2010 Berkeley Lab summer lecture, Lab scientists Jeff Long of the Materials Sciences and Nancy Brown of the Environmental Energy Technologies Division discuss their efforts to fight climate change by capturing carbon from the flue gas of power plants, as well as directly from the air

  7. Carbon Smackdown: Carbon Capture

    ScienceCinema (OSTI)

    Jeffrey Long

    2010-09-01

    In this July 9, 2010 Berkeley Lab summer lecture, Lab scientists Jeff Long of the Materials Sciences and Nancy Brown of the Environmental Energy Technologies Division discuss their efforts to fight climate change by capturing carbon from the flue gas of power plants, as well as directly from the air

  8. Neutron capture therapies

    DOE Patents [OSTI]

    Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

    1999-01-01

    In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  9. Realistic costs of carbon capture

    SciTech Connect (OSTI)

    Al Juaied, Mohammed . Belfer Center for Science and International Affiaris); Whitmore, Adam )

    2009-07-01

    There is a growing interest in carbon capture and storage (CCS) as a means of reducing carbon dioxide (CO2) emissions. However there are substantial uncertainties about the costs of CCS. Costs for pre-combustion capture with compression (i.e. excluding costs of transport and storage and any revenue from EOR associated with storage) are examined in this discussion paper for First-of-a-Kind (FOAK) plant and for more mature technologies, or Nth-of-a-Kind plant (NOAK). For FOAK plant using solid fuels the levelised cost of electricity on a 2008 basis is approximately 10 cents/kWh higher with capture than for conventional plants (with a range of 8-12 cents/kWh). Costs of abatement are found typically to be approximately US$150/tCO2 avoided (with a range of US$120-180/tCO2 avoided). For NOAK plants the additional cost of electricity with capture is approximately 2-5 cents/kWh, with costs of the range of US$35-70/tCO2 avoided. Costs of abatement with carbon capture for other fuels and technologies are also estimated for NOAK plants. The costs of abatement are calculated with reference to conventional SCPC plant for both emissions and costs of electricity. Estimates for both FOAK and NOAK are mainly based on cost data from 2008, which was at the end of a period of sustained escalation in the costs of power generation plant and other large capital projects. There are now indications of costs falling from these levels. This may reduce the costs of abatement and costs presented here may be 'peak of the market' estimates. If general cost levels return, for example, to those prevailing in 2005 to 2006 (by which time significant cost escalation had already occurred from previous levels), then costs of capture and compression for FOAK plants are expected to be US$110/tCO2 avoided (with a range of US$90-135/tCO2 avoided). For NOAK plants costs are expected to be US$25-50/tCO2. Based on these considerations a likely representative range of costs of abatement from CCS excluding transport and storage costs appears to be US$100-150/tCO2 for first-of-a-kind plants and perhaps US$30-50/tCO2 for nth-of-a-kind plants.The estimates for FOAK and NOAK costs appear to be broadly consistent in the light of estimates of the potential for cost reductions with increased experience. Cost reductions are expected from increasing scale, learning on individual components, and technological innovation including improved plant integration. Innovation and integration can both lower costs and increase net output with a given cost base. These factors are expected to reduce abatement costs by approximately 65% by 2030. The range of estimated costs for NOAK plants is within the range of plausible future carbon prices, implying that mature technology would be competitive with conventional fossil fuel plants at prevailing carbon prices.

  10. W.A. Parish Post-Combustion CO{sub 2} Capture and Sequestration...

    Office of Scientific and Technical Information (OSTI)

    COsub 2 Capture and Sequestration Project Phase 1 Definition Armpriester, Anthony; Smith, Roger; Scheriffius, Jeff; Smyth, Rebecca; Istre, Michael 20 FOSSIL-FUELED POWER...

  11. U.S.-Norway Conference Focuses on Advancing Carbon Capture and...

    Energy Savers [EERE]

    There are carbon capture and storage (CCS) projects all over the world. The multinational Carbon Sequestration Leadership Forum (CSLF) recognizes more than 40 active and completed...

  12. Manifestations of energetic electrons with anisotropic distributions in solar flares

    E-Print Network [OSTI]

    observations of hard X-ray (HXR) and microwave (MW) emissions in foot- points of solar flares are often closelyManifestations of energetic electrons with anisotropic distributions in solar flares II. Gyrosynchrotron microwave emission Alexey A. Kuznetsov1,2 & Valentina V. Zharkova3 ABSTRACT We investigate

  13. Blazar Alerts with the HAWC Online Flare Monitor

    E-Print Network [OSTI]

    Weisgarber, Thomas

    2015-01-01

    The High Altitude Water Cherenkov (HAWC) Observatory monitors the gamma-ray sky in the 100 GeV to 100 TeV energy range with > 95% uptime and unprecedented sensitivity for a survey instrument. The HAWC Collaboration has implemented an online flare monitor that detects episodes of rapid flaring activity from extragalactic very high energy (VHE) sources in the declination band from -26 to 64 degrees. This allows timely alerts to be sent to multiwavelength instruments without human intervention. The preliminary configuration of the online flare monitor achieves sensitivity to flares of at least 1 hour duration that attain an average flux of 10 times that of the Crab Nebula. While flares of this magnitude are not common, several flares reaching the level of 10 Crab have been observed in the VHE band within the past decade. With its survey capabilities and high duty cycle, HAWC will expand the observational data set on these particularly extreme flares. We characterize the sensitivity of the online flare monitor an...

  14. Size dependence of solar X-ray flare properties

    E-Print Network [OSTI]

    Marina Battaglia; Paolo C. Grigis; Arnold O. Benz

    2005-05-09

    Non-thermal and thermal parameters of 85 solar flares of GOES class B1 to M6 (background subtracted classes A1 to M6) have been compared to each other. The hard X-ray flux has been measured by RHESSI and a spectral fitting provided flux and spectral index of the non-thermal emission, as well as temperature and emission measure of the thermal emission. The soft X-ray flux was taken from GOES measurements. We find a linear correlation in a double logarithmic plot between the non-thermal flux and the spectral index. The higher the acceleration rate of a flare, the harder the non-thermal electron distribution. The relation is similar to the one found by a comparison of the same parameters from several sub-peaks of a single flare. Thus small flares behave like small subpeaks of large flares. Thermal flare properties such as temperature, emission measure and the soft X-ray flux also correlate with peak non-thermal flux. A large non-thermal peak flux entails an enhancement in both thermal parameters. The relation between spectral index and the non-thermal flux is an intrinsic feature of the particle acceleration process, depending on flare size. This property affects the reported frequency distribution of flare energies.

  15. Initial test of a Bayesian approach to solar flare prediction

    E-Print Network [OSTI]

    M. S. Wheatland

    2004-11-14

    A test of a new Bayesian approach to solar flare prediction (Wheatland 2004a) is presented. The approach uses the past history of flaring together with phenomenological rules of flare statistics to make a prediction for the probability of occurrence of a large flare within an interval of time, or to refine an initial prediction (which may incorporate other information). The test of the method is based on data from the Geostationary Observational Environmental Satellites (GOES), and involves whole-Sun prediction of soft X-ray flares for 1976-2003. The results show that the method somewhat over-predicts the probability of all events above a moderate size, but performs well in predicting large events.

  16. Design Enhancements To Improve Flare Efficiency 

    E-Print Network [OSTI]

    Dooley, K. A.; McLeod, G. M.; Lorenz, M. D.

    1997-01-01

    and purge gases. It was configured as a two-stage system with each stage consisting of multiple burners. The original burners were of a fin plate design. The flare system was designed to operate at low pressure due to venting constraints imposed... was reconfigured to accommodate the lower heat content via the addition of an alternate first stage. The new stage was comprised of three new burners designed for lower flowrates and for gases with lower heating values than the original fin-plate burners...

  17. Summarizing FLARE assay images in colon carcinogenesis 

    E-Print Network [OSTI]

    Leyk Williams, Malgorzata

    2006-04-12

    times the distance between the moments of the head and tail DNA distributions. Symmetry of the head was assumed, and hence the tail area could be identi ed. Another measure used in comet analysis is the relative tail moment (RTM) (Riso et al. 1999... of damage was then computed by the program for each comet. The standard output from FLARE analysis is the relative tail moment (RTM) (Hellman et al. 1995, Morris et al. 1999, Riso et al. 1999), de ned as RTM = 100*(tail moment)/(tail moment + head moment...

  18. An Experiment to Locate the Site of TeV Flaring in M87

    SciTech Connect (OSTI)

    Harris, D.E.; /Harvard-Smithsonian Ctr. Astrophys.; Massaro, F.; /Harvard-Smithsonian Ctr. Astrophys. /KIPAC, Menlo Park /SLAC; Cheung, C.C.; /Natl. Acad. Sci. /Naval Research Lab, Wash., D.C.; Horns, D.; Raue, M.; /Hamburg U.; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.; Wagner, S.; /Heidelberg Observ.; Colin, P.; /Munich, Max Planck Inst.; Mazin, D.; /Barcelona, IFAE; Wagner, R.; /Munich, Max Planck Inst.; Beilicke, M.; /McDonnell Ctr. Space Sci.; LeBohec, S.; Hui, M.; /Utah U.; Mukherjee, R.; /Barnard Coll.

    2012-05-18

    We describe a Chandra X-ray target-of-opportunity project designed to isolate the site of TeV flaring in the radio galaxy M87. To date, we have triggered the Chandra observations only once (2010 April) and by the time of the first of our nine observations, the TeV flare had ended. However, we found that the X-ray intensity of the unresolved nucleus was at an elevated level for our first observation. Of the more than 60 Chandra observations we have made of the M87 jet covering nine years, the nucleus was measured at a comparably high level only three times. Two of these occasions can be associated with TeV flaring, and at the time of the third event, there were no TeV monitoring activities. From the rapidity of the intensity drop of the nucleus, we infer that the size of the emitting region is of order a few light days x the unknown beaming factor; comparable to the same sort of estimate for the TeV emitting region. We also find evidence of spectral evolution in the X-ray band which seems consistent with radiative losses affecting the non-thermal population of the emitting electrons within the unresolved nucleus.

  19. The Flare-ona of EK Draconis

    E-Print Network [OSTI]

    Ayres, Thomas R

    2015-01-01

    EK Draconis (HD 129333: G1.5 V) is a well-known young (50 Myr) solar analog. In 2012, Hubble Space Telescope returned to EK Dra to follow up a far-ultraviolet (FUV) SNAPshot visit by Cosmic Origins Spectrograph (COS) two years earlier. The brief SNAP pointing had found surprisingly redshifted, impulsively variable subcoronal "hot-line" emission of Si IV 140 nm (T~ 80,000 K). Serendipitously, the 2012 follow-on program witnessed one of the largest FUV flares ever recorded on a sunlike star, which again displayed strong redshifts (downflows) of 30-40 km/s, even after compensating for small systematics in the COS velocity scales, uncovered through a cross-calibration by Space Telescope Imaging Spectrograph (STIS). The (now reduced, but still substantial) ~10 km/s hot-line redshifts outside the flaring interval did not vary with rotational phase, so cannot be caused by "Doppler Imaging" (bright surface patches near a receding limb). Density diagnostic O IV] 140 nm multiplet line ratios of EK Dra suggest log(Ne)~ ...

  20. The study of solar flares with the extended cellular automaton (XCA) model

    E-Print Network [OSTI]

    Anastasiadis, Anastasios

    ) at a temporal snap­shot during a flare. explain the power­law frequency distributions of the solar flareThe study of solar flares with the extended cellular automaton (X­CA) model H. Isliker 1 , A of cellular automaton (CA) model, the extended CA (X­CA), for the study of solar flares. The X­CA model

  1. SMALL AND LARGE-SCALE MAGNETIC FIELDS INVOLVED WITH SOLAR FLARES

    E-Print Network [OSTI]

    ABSTRACT SMALL AND LARGE-SCALE MAGNETIC FIELDS INVOLVED WITH SOLAR FLARES by Chang Liu Solar flares of an EUV sigmoid. #12;SMALL AND LARGE-SCALE MAGNETIC FIELDS INVOLVED WITH SOLAR FLARES by Chang Liu RESERVED #12;APPROVAL PAGE SMALL AND LARGE-SCALE MAGNETIC FIELDS INVOLVED WITH SOLAR FLARES Chang Liu Dr

  2. Solar Flares and the Chromosphere A white paper for the Decadal Survey*

    E-Print Network [OSTI]

    California at Berkeley, University of

    Solar Flares and the Chromosphere A white paper for the Decadal Survey* L. Fletcher, R. Turkmani, H acceleration (De Pontieu et al. 2007). The need for chromospheric observations of flares: The solar flare of radiation in a solar flare (Canfield et al 1986, Neidig 1989, Woods et al. 2004). In other words, solar

  3. Earth Planets Space, 00, 000--000, 2000 Solar Flare Mechanism Based on Magnetic Arcade

    E-Print Network [OSTI]

    Earth Planets Space, 00, 000--000, 2000 Solar Flare Mechanism Based on Magnetic Arcade Reconnection of solar flares based on re­ sistive reconnection of magnetic field subject to continuous increase flares. 1. INTRODUCTION Solar flares are intense, abrupt release of energy occurring usually

  4. Submitted to Ap.J. A Model of Solar Flares and Their Homologous Behavior

    E-Print Network [OSTI]

    Submitted to Ap.J. A Model of Solar Flares and Their Homologous Behavior G. S. Choe and C. Z. Cheng@pppl.gov ABSTRACT A model describing physical processes of solar flares and their homologous behavior is presented. #12; -- 2 -- Subject headings: Sun: flares, MHD, methods: numerical 1. INTRODUCTION Solar flares

  5. X-ray and EUV Observations of GOES C8 Solar Flare

    E-Print Network [OSTI]

    Wolfe, Patrick J.

    X-ray and EUV Observations of GOES C8 Solar Flare Events Kathy Reeves1, Trevor Bowen1,2, Paola;Solar Flares Tuesday, February 19, 2013 #12;Solar Flares Tuesday, February 19, 2013 #12;Solar Dynamics Veronig et al, A&A, 2002 Tuesday, February 19, 2013 #12;Flare Timing GOESflux(Wm-2) Rise Decay Tuesday

  6. GAMMA-RAY POLARIMETRY OF TWO X-CLASS SOLAR FLARES Steven E. Boggs,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    GAMMA-RAY POLARIMETRY OF TWO X-CLASS SOLAR FLARES Steven E. Boggs,1 W. Coburn, and E. Kalemci Space 2005 May 29; accepted 2005 October 18 ABSTRACT We have performed the first polarimetry of solar flare Energy Solar Spectroscopic Imager (RHESSI) for two large flares: the GOES X4.8-class solar flare of 2002

  7. The Effects of Solar Flares on Planetary Ionospheres PAUL WITHERS1

    E-Print Network [OSTI]

    Withers, Paul

    The Effects of Solar Flares on Planetary Ionospheres PAUL WITHERS1 and MICHAEL MENDILLO1 1 Center 353 1531) During solar flares, the Sun's X-ray irradiance increases dramatically, often within a few during solar flares. Similar increases in plasma densities during solar flares have been observed

  8. Submitted to Ap.J. A Model of Solar Flares and Their Homologous Behavior

    E-Print Network [OSTI]

    Submitted to Ap.J. A Model of Solar Flares and Their Homologous Behavior G. S. Choe and C. Z. Cheng@pppl.gov ABSTRACT A model describing physical processes of solar flares and their homologous behavior is presented. #12;­ 2 ­ Subject headings: Sun: flares, MHD, methods: numerical 1. INTRODUCTION Solar flares

  9. Carbon Capture FAQs

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B LReports from thecarbon capture faqs faq-header-big.jpg CARBON

  10. Statistics of X-ray flares of Sgr A*: evidence for solar-like self-organized criticality phenomenon

    E-Print Network [OSTI]

    Li, Ya-Ping; Yuan, Qiang; Wang, Q Daniel; Chen, P F; Neilsen, Joseph; Fang, Taotao; Zhang, Shuo; Dexter, Jason

    2015-01-01

    X-ray flares have routinely been observed from the supermassive black hole, Sgr A*, at our Galactic center. The nature of these flares remains largely unclear, despite of many theoretical models,. In this paper, we study the statistical properties of the Sgr A* X-ray flares, by fitting the count rate (CR) distribution and the structure function (SF) of the light curve with a Markov Chain Monte Carlo (MCMC) method. With the 3 million second \\textit{Chandra} observations accumulated in the Sgr A* X-ray Visionary Project, we construct the theoretical light curves through Monte Carlo simulations. We find that the $2-8$ keV X-ray light curve can be decomposed into a quiescent component with a constant count rate of $ 6\\times10^{-3} $count s$^{-1}$ and a flare component with a power-law fluence distribution $dN/dE\\propto E^{-\\alpha_{\\rm E}}$ with $\\alpha_{\\rm E}=1.65\\pm0.17$. The duration-fluence correlation can also be modelled as a power-law $T\\propto E^{\\alpha_{\\rm ET}}$ with $\\alpha_{\\rm ET} < 0.55$ ($95\\%$ ...

  11. Solar-type Magnetic Reconnection Model for Magnetar Giant Flare

    E-Print Network [OSTI]

    Youhei Masada; Shigehiro Nagataki; Kazunari Shibata; Toshio Terasawa

    2010-05-24

    We present a theoretical model describing magnetar giant flares on the basis of solar flare/coronal mass ejection theory. In our model, a preflare activity plays a crucial role in driving evaporating flows and supplying baryonic matters into the magnetosphere. The loaded baryonic matter, that is called "prominence", is then gradually uplifted via crustal cracking with maintaining a quasi-force-free equilibrium of the magnetosphere. Finally the prominence is erupted by the magnetic pressure force due to the loss of equilibrium triggered by the explosive magnetic reconnection. The giant flare should be induced as a final outcome of the prominence eruption accompanied by large-scale field reconfigurations. An essential difference between solar and magnetar flares is the control process of their evolutionary dynamics. The flaring activity on magnetars is mainly controlled by the radiative process unlike the solar flare governed by the electron conduction. It is highly suggestive that our model is accountable for the physical properties of the extraordinary giant flare observed on 2004 December 27 from SGR1806-20, including the source of baryonic matters loaded in the expanding ejecta observed after the giant burst.

  12. Distinguishing Solar Flare Types by Differences in Reconnection Regions

    E-Print Network [OSTI]

    Eric G. Blackman

    1997-04-24

    Observations show that magnetic reconnection and its slow shocks occur in solar flares. The basic magnetic structures are similar for long duration event (LDE) flares and faster compact impulsive (CI) flares, but the former require less non-thermal electrons than the latter. Slow shocks can produce the required non-thermal electron spectrum for CI flares by Fermi acceleration if electrons are injected with large enough energies to resonate with scattering waves. The dissipation region may provide the injection electrons, so the overall number of non-thermal electrons reaching the footpoints would depend on the size of the dissipation region and its distance from the chromosphere. In this picture, the LDE flares have converging inflows toward a dissipation region that spans a smaller overall length fraction than for CI flares. Bright loop-top X-ray spots in some CI flares can be attributed to particle trapping at fast shocks in the downstream flow, the presence of which is determined by the angle of the inflow field and velocity to the slow shocks.

  13. OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT

    SciTech Connect (OSTI)

    Warren, Harry P.; Doschek, George A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mariska, John T. [School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

    2013-06-20

    One of the defining characteristics of a solar flare is the impulsive formation of very high temperature plasma. The properties of the thermal emission are not well understood, however, and the analysis of solar flare observations is often predicated on the assumption that the flare plasma is isothermal. The EUV Variability Experiment (EVE) on the Solar Dynamics Observatory provides spectrally resolved observations of emission lines that span a wide range of temperatures (e.g., Fe XV-Fe XXIV) and allow for thermal flare plasma to be studied in detail. In this paper we describe a method for computing the differential emission measure distribution in a flare using EVE observations and apply it to several representative events. We find that in all phases of the flare the differential emission measure distribution is broad. Comparisons of EVE spectra with calculations based on parameters derived from the Geostationary Operational Environmental Satellites soft X-ray fluxes indicate that the isothermal approximation is generally a poor representation of the thermal structure of a flare.

  14. CONSTRAINING SOLAR FLARE DIFFERENTIAL EMISSION MEASURES WITH EVE AND RHESSI

    SciTech Connect (OSTI)

    Caspi, Amir [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); McTiernan, James M. [Space Sciences Laboratory University of California, Berkeley, CA 94720 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-06-20

    Deriving a well-constrained differential emission measure (DEM) distribution for solar flares has historically been difficult, primarily because no single instrument is sensitive to the full range of coronal temperatures observed in flares, from ?2 to ?50 MK. We present a new technique, combining extreme ultraviolet (EUV) spectra from the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory with X-ray spectra from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), to derive, for the first time, a self-consistent, well-constrained DEM for jointly observed solar flares. EVE is sensitive to ?2-25 MK thermal plasma emission, and RHESSI to ?10 MK; together, the two instruments cover the full range of flare coronal plasma temperatures. We have validated the new technique on artificial test data, and apply it to two X-class flares from solar cycle 24 to determine the flare DEM and its temporal evolution; the constraints on the thermal emission derived from the EVE data also constrain the low energy cutoff of the non-thermal electrons, a crucial parameter for flare energetics. The DEM analysis can also be used to predict the soft X-ray flux in the poorly observed ?0.4-5 nm range, with important applications for geospace science.

  15. Distinguishing Solar Flare Types by Differences in Reconnection Regions

    E-Print Network [OSTI]

    Blackman, E G

    1997-01-01

    Observations show that magnetic reconnection and its slow shocks occur in solar flares. The basic magnetic structures are similar for long duration event (LDE) flares and faster compact impulsive (CI) flares, but the former require less non-thermal electrons than the latter. Slow shocks can produce the required non-thermal electron spectrum for CI flares by Fermi acceleration if electrons are injected with large enough energies to resonate with scattering waves. The dissipation region may provide the injection electrons, so the overall number of non-thermal electrons reaching the footpoints would depend on the size of the dissipation region and its distance from the chromosphere. In this picture, the LDE flares have converging inflows toward a dissipation region that spans a smaller overall length fraction than for CI flares. Bright loop-top X-ray spots in some CI flares can be attributed to particle trapping at fast shocks in the downstream flow, the presence of which is determined by the angle of the inflow...

  16. Discovering Tau and Muon Solar Neutrino Flares above backgrounds

    E-Print Network [OSTI]

    D. Fargion; F. Moscato

    2004-07-11

    Solar neutrino flares astronomy is at the edge of its discover. High energy flare particles (protons, alpha) whose self scattering within the solar corona is source of a rich prompt charged pions are also source of sharp solar neutrino "burst" (at tens-hundred MeV) produced by their pion-muon primary decay in flight. This brief (minute) solar neutrino "burst" at largest peak overcome by four-five order of magnitude the steady atmospheric neutrino noise at the Earth. Later on, solar flare particles hitting the terrestrial atmosphere may marginally increase the atmospheric neutrino flux without relevant consequences. Largest prompt "burst" solar neutrino flare may be detected in present or better in future largest neutrino underground neutrino detectors. Our estimate for the recent and exceptional October - November 2003 solar flares gives a number of events above or just near unity for Super-Kamiokande. The neutrino spectra may reflect in a subtle way the neutrino flavour mixing in flight. A surprising tau appearance may even occur for a hard ({E}_{nu}_{mu}--> {E}_{nu}_{tau} > 4 GeV) flare spectra. A comparison of the solar neutrino flare (at their birth place on Sun and after oscillation on the arrival on the Earth) with other neutrino foreground is here described and it offer an independent road map to disentangle the neutrino flavour puzzles and its secret flavour mixing angles .

  17. Solar Flare Measurements with STIX and MiSolFA

    E-Print Network [OSTI]

    Casadei, Diego

    2014-01-01

    Solar flares are the most powerful events in the solar system and the brightest sources of X-rays, often associated with emission of particles reaching the Earth and causing geomagnetic storms, giving problems to communication, airplanes and even black-outs. X-rays emitted by accelerated electrons are the most direct probe of solar flare phenomena. The Micro Solar-Flare Apparatus (MiSolFA) is a proposed compact X-ray detector which will address the two biggest issues in solar flare modeling. Dynamic range limitations prevent simultaneous spectroscopy with a single instrument of all X-ray emitting regions of a flare. In addition, most X-ray observations so far are inconsistent with the high anisotropy predicted by the models usually adopted for solar flares. Operated at the same time as the STIX instrument of the ESA Solar Orbiter mission, at the next solar maximum (2020), they will have the unique opportunity to look at the same flare from two different directions: Solar Orbiter gets very close to the Sun wit...

  18. Modelling of Reflective Propagating Slow-mode Wave in a Flaring Loop

    E-Print Network [OSTI]

    Fang, X; Van Doorsselaere, T; Keppens, R; Xia, C

    2015-01-01

    Quasi-periodic propagating intensity disturbances have been observed in large coronal loops in EUV images over a decade, and are widely accepted to be slow magnetosonic waves. However, spectroscopic observations from Hinode/EIS revealed their association with persistent coronal upflows, making this interpretation debatable. We perform a 2.5D magnetohydrodynamic simulation to imitate the chromospheric evaporation and the following reflected patterns in a flare loop. Our model encompasses the corona, transition region, and chromosphere. We demonstrate that the quasi periodic propagating intensity variations captured by the synthesized \\textit{Solar Dynamics Observatory}/Atmospheric Imaging Assembly (AIA) 131, 94~\\AA~emission images match the previous observations well. With particle tracers in the simulation, we confirm that these quasi periodic propagating intensity variations consist of reflected slow mode waves and mass flows with an average speed of 310 km/s in an 80 Mm length loop with an average temperatu...

  19. The first observed stellar X-ray flare oscillation: Constraints on the flare loop length and the magnetic field

    E-Print Network [OSTI]

    U. Mitra-Kraev; L. K. Harra; D. R. Williams; E. Kraev

    2005-03-17

    We present the first X-ray observation of an oscillation during a stellar flare. The flare occurred on the active M-type dwarf AT Mic and was observed with XMM-Newton. The soft X-ray light curve (0.2-12 keV) is investigated with wavelet analysis. The flare's extended, flat peak shows clear evidence for a damped oscillation with a period of around 750 s, an exponential damping time of around 2000 s, and an initial, relative peak-to-peak amplitude of around 15%. We suggest that the oscillation is a standing magneto-acoustic wave tied to the flare loop, and find that the most likely interpretation is a longitudinal, slow-mode wave, with a resulting loop length of (2.5 +- 0.2) e10 cm. The local magnetic field strength is found to be (105 +- 50) G. These values are consistent with (oscillation-independent) flare cooling time models and pressure balance scaling laws. Such a flare oscillation provides an excellent opportunity to obtain coronal properties like the size of a flare loop or the local magnetic field strength for the otherwise spatially-unresolved star.

  20. Fragment capture device

    DOE Patents [OSTI]

    Payne, Lloyd R.; Cole, David L.

    2010-03-30

    A fragment capture device for use in explosive containment. The device comprises an assembly of at least two rows of bars positioned to eliminate line-of-sight trajectories between the generation point of fragments and a surrounding containment vessel or asset. The device comprises an array of at least two rows of bars, wherein each row is staggered with respect to the adjacent row, and wherein a lateral dimension of each bar and a relative position of each bar in combination provides blockage of a straight-line passage of a solid fragment through the adjacent rows of bars, wherein a generation point of the solid fragment is located within a cavity at least partially enclosed by the array of bars.

  1. Evidence that solar flares drive global oscillations in the Sun

    E-Print Network [OSTI]

    C. Karoff; H. Kjeldsen

    2008-03-21

    Solar flares are large explosions on the Sun's surface caused by a sudden release of magnetic energy. They are known to cause local short-lived oscillations travelling away from the explosion like water rings. Here we show that the energy in the solar acoustic spectrum is correlated with flares. This means that the flares drive global oscillations in the Sun in the same way that the entire Earth is set ringing for several weeks after a major earthquake like the December 2004 Sumatra-Andaman Earthquake. The correlation between flares and energy in the acoustic spectrum of disk-integrated sunlight is stronger for high-frequency waves than for ordinary p-modes which are excited by the turbulence in the near surface convection zone immediately beneath the photosphere.

  2. Detecting Solar Neutrino Flare in Megaton and km^3 detectors

    E-Print Network [OSTI]

    Daniele Fargion; Paola Di Giacomo

    2009-01-21

    To foresee a solar flare neutrino signal we infer its upper and lower bound. The upper bound was derived since a few years by general energy equipartition arguments on observed solar particle flare. The lower bound, the most compelling one for any guarantee neutrino signal, is derived by most recent records of hard Gamma bump due to solar flare on January 2005 (by neutral pion decay).The observed gamma flux reflects into a corresponding one for the neutrinos, almost one to one. Therefore we obtain minimal bounds already at the edge of present but quite within near future Megaton neutrino detectors. Such detectors are considered mostly to reveal cosmic supernova background or rare Local Group (few Mpc) Supernovas events. However Megaton or even inner ten Megaton Ice Cube detector at ten GeV threshold may also reveal traces of solar neutrino in hardest energy of solar flares. Icecube, marginally, too. Solar neutrino flavors may shine light on neutrino mixing angles.

  3. Interferometric at-wavelength flare characterization of EUV optical systems

    DOE Patents [OSTI]

    Naulleau, Patrick P. (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA)

    2001-01-01

    The extreme ultraviolet (EUV) phase-shifting point diffraction interferometer (PS/PDI) provides the high-accuracy wavefront characterization critical to the development of EUV lithography systems. Enhancing the implementation of the PS/PDI can significantly extend its spatial-frequency measurement bandwidth. The enhanced PS/PDI is capable of simultaneously characterizing both wavefront and flare. The enhanced technique employs a hybrid spatial/temporal-domain point diffraction interferometer (referred to as the dual-domain PS/PDI) that is capable of suppressing the scattered-reference-light noise that hinders the conventional PS/PDI. Using the dual-domain technique in combination with a flare-measurement-optimized mask and an iterative calculation process for removing flare contribution caused by higher order grating diffraction terms, the enhanced PS/PDI can be used to simultaneously measure both figure and flare in optical systems.

  4. Obscuration of Flare Emission by an Eruptive Prominence

    E-Print Network [OSTI]

    Gopalswamy, Nat

    2013-01-01

    We report on the eclipsing of microwave flare emission by an eruptive prominence from a neighboring region as observed by the Nobeyama Radioheliograph at 17 GHz. The obscuration of the flare emission appears as a dimming feature in the microwave flare light curve. We use the dimming feature to derive the temperature of the prominence and the distribution of heating along the length of the filament. We find that the prominence is heated to a temperature above the quiet Sun temperature at 17 GHz. The duration of the dimming is the time taken by the eruptive prominence in passing over the flaring region. We also find evidence for the obscuration in EUV images obtained by the Solar and Heliospheric Observatory (SOHO) mission.

  5. Leukemia cutis resembling a flare-up of psoriasis

    E-Print Network [OSTI]

    Ferreira, Márcia; Caetano, Mónica; Amorim, Isabel; Selores, Manuela

    2006-01-01

    resembling a flare-up of psoriasis Márcia Ferreira, Mónicaof a 64-year-old man with psoriasis who presented with a 4-colored to erythematous, psoriasis-like papules and plaques

  6. Associated Shale Gas- From Flares to Rig Power 

    E-Print Network [OSTI]

    Wallace, Elizabeth Michelle

    2014-10-16

    From September 2011 to July 2013 the percentage of flared associated gas produced in the Bakken shale formation decreased from 36% to 29%. Although the percentage decreased, the volume of associated gas produced has almost tripled to 900 MMcf...

  7. Electron Firehose instability and acceleration of electrons in solar flares

    E-Print Network [OSTI]

    Gunnar Paesold; Arnold O. Benz

    2000-01-14

    An electron distribution with a temperature anisotropy T_par/T_perp > 1 can lead to the Electron Firehose instability (Here par and perp denote directions relative to the background magnetic field B_0). Since possible particle acceleration mechanisms in solar flares exhibit a preference of energizing particles in parallel direction, such an anisotropy is expected during the impulsive phase of a flare. The properties of the excited waves and the thresholds for instability are investigated by using linearized kinetic theory. These thresholds were connected to the pre-flare plasma parameters by assuming an acceleration model acting exclusively in parallel direction. For usually assumed pre-flare plasma conditions the electrons become unstable during the acceleration process and lefthand circularly polarized waves with frequencies of about the proton gyrofrequency are excited at parallel propagation. Indications have been found, that the largest growth rates occur at oblique propagation and the according frequencies lie well above the proton gyrofrequency.

  8. Resource capture by single leaves

    SciTech Connect (OSTI)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  9. Statistical Models for Solar Flare Interval Distribution in Individual Active Regions

    E-Print Network [OSTI]

    Yuki Kubo

    2008-02-01

    This article discusses statistical models for solar flare interval distribution in individual active regions. We analyzed solar flare data in 55 active regions that are listed in the GOES soft X-ray flare catalog. We discuss some problems with a conventional procedure to derive probability density functions from any data set and propose a new procedure, which uses the maximum likelihood method and Akaike Information Criterion (AIC) to objectively compare some competing probability density functions. We found that lognormal and inverse Gaussian models are more likely models than the exponential model for solar flare interval distribution in individual active regions. The results suggest that solar flares do not occur randomly in time; rather, solar flare intervals appear to be regulated by solar flare mechanisms. We briefly mention a probabilistic solar flare forecasting method as an application of a solar flare interval distribution analysis.

  10. Multi-Thread Hydrodynamic Modeling of a Solar Flare

    E-Print Network [OSTI]

    Harry P. Warren

    2005-07-13

    Past hydrodynamic simulations have been able to reproduce the high temperatures and densities characteristic of solar flares. These simulations, however, have not been able to account for the slow decay of the observed flare emission or the absence of blueshifts in high spectral resolution line profiles. Recent work has suggested that modeling a flare as an sequence of independently heated threads instead of as a single loop may resolve the discrepancies between the simulations and observations. In this paper we present a method for computing multi-thread, time-dependent hydrodynamic simulations of solar flares and apply it to observations of the Masuda flare of 1992 January 13. We show that it is possible to reproduce the temporal evolution of high temperature thermal flare plasma observed with the instruments on the \\textit{GOES} and \\textit{Yohkoh} satellites. The results from these simulations suggest that the heating time-scale for a individual thread is on the order of 200 s. Significantly shorter heating time scales (20 s) lead to very high temperatures and are inconsistent with the emission observed by \\textit{Yohkoh}.

  11. Observational evidence for return currents in solar flare loops

    E-Print Network [OSTI]

    Marina Battaglia; Arnold O. Benz

    2008-06-11

    Context: The common flare scenario comprises an acceleration site in the corona and particle transport to the chromosphere. Using satellites available to date it has become possible to distinguish between the two processes of acceleration and transport, and study the particle propagation in flare loops in detail, as well as complete comparisons with theoretical predictions. Aims: We complete a quantitative comparison between flare hard X-ray spectra observed by RHESSI and theoretical predictions. This enables acceleration to be distinguished from transport and the nature of transport effects to be explored. Methods: Data acquired by the RHESSI satellite were analyzed using full sun spectroscopy as well as imaging spectroscopy methods. Coronal source and footpoint spectra of well observed limb events were analyzed and quantitatively compared to theoretical predictions. New concepts are introduced to existing models to resolve discrepancies between observations and predictions. Results: The standard thin-thick target solar flare model cannot explain the observations of all events. In the events presented here, propagation effects in the form of non-collisional energy loss are of importance to explain the observations. We demonstrate that those energy losses can be interpreted in terms of an electric field in the flare loop. One event seems consistent with particle propagation or acceleration in lower than average density in the coronal source. Conclusions: We find observational evidence for an electric field in flare loops caused by return currents.

  12. CO? Capture Membrane Process for Power Plant Flue Gas

    SciTech Connect (OSTI)

    Toy, Lora; Kataria, Atish; Gupta, Raghubir

    2011-09-30

    Because the fleet of coal-fired power plants is of such importance to the nation's energy production while also being the single largest emitter of CO?, the development of retrofit, post-combustion CO? capture technologies for existing and new, upcoming coal power plants will allow coal to remain a major component of the U.S. energy mix while mitigating global warming. Post-combustion carbon capture technologies are an attractive option for coal-fired power plants as they do not require modification of major power-plant infrastructures, such as fuel processing, boiler, and steam-turbine subsystems. In this project, the overall objective was to develop an advanced, hollow-fiber, polymeric membrane process that could be cost-effectively retrofitted into current pulverized coal-fired power plants to capture at least 90% of the CO? from plant flue gas with 95% captured CO? purity. The approach for this project tackled the technology development on three different fronts in parallel: membrane materials R&D, hollow-fiber membrane module development, and process development and engineering. The project team consisted of RTI (prime) and two industrial partners, Arkema, Inc. and Generon IGS, Inc. Two CO?-selective membrane polymer platforms were targeted for development in this project. For the near term, a next-generation, high-flux polycarbonate membrane platform was spun into hollow-fiber membranes that were fabricated into both lab-scale and larger prototype (~2,200 ft˛) membrane modules. For the long term, a new fluoropolymer membrane platform based on poly(vinylidene fluoride) [PVDF] chemistry was developed using a copolymer approach as improved capture membrane materials with superior chemical resistance to flue-gas contaminants (moisture, SO?, NOx, etc.). Specific objectives were: - Development of new, highly chemically resistant, fluorinated polymers as membrane materials with minimum selectivity of 30 for CO? over N? and CO? permeance greater than 300 gas permeation units (GPU) targeted; - Development of next-generation polycarbonate hollow-fiber membranes and membrane modules with higher CO? permeance than current commercial polycarbonate membranes; - Development and fabrication of membrane hollow fibers and modules from candidate polymers; - Development of a CO? capture membrane process design and integration strategy suitable for end-of-pipe, retrofit installation; and - Techno-economic evaluation of the "best" integrated CO? capture membrane process design package In this report, the results of the project research and development efforts are discussed and include the post-combustion capture properties of the two membrane material platforms and the hollow-fiber membrane modules developed from them and the multi-stage process design and analysis developed for 90% CO? capture with 95% captured CO? purity.

  13. Gamma-Ray Polarimetry of Two X-Class Solar Flares

    E-Print Network [OSTI]

    Steven E. Boggs; W. Coburn; E. Kalemci

    2005-10-19

    We have performed the first polarimetry of solar flare emission at gamma-ray energies (0.2-1 MeV). These observations were performed with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) for two large flares: the GOES X4.8-class solar flare of 2002 July 23, and the X17-class flare of 2003 October 28. We have marginal polarization detections in both flares, at levels of 21% +/- 9% and -11% +/- 5% respectively. These measurements significantly constrain the levels and directions of solar flare gamma-ray polarization, and begin to probe the underlying electron distributions.

  14. Anti-Neutrino Imprint in Solar Neutrino Flare

    E-Print Network [OSTI]

    D. Fargion

    2006-06-09

    Future neutrino detector at Megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares neutrino. Indeed the solar energetic flare particles while scattering among themselves on Solar corona atmosphere must produce prompt charged pions, whose chain decays are source of solar (electron-muon) neutrino "flare" (at tens or hundreds MeV energy). These brief (minutes) neutrino "burst" at largest flare peak may overcome by three to five order of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their detection above detection. Moreover the birth of anti-neutrinos at a few tens MeVs is well loudly flaring above a null thermal "hep" anti-neutrino solar background and also above a tiny supernova relic and atmospheric noise. The largest prompt solar anti-neutrino "burst" may be well detected in future SuperKamikande (Gadolinium implemented) by anti-neutrino signatures mostly in inverse Beta decay. Our estimate for the recent and exceptional October - November 2003 solar flares and January 20th 2005 exceptional eruption might lead to a few events above or near unity for existing Super-Kamiokande and above unity for Megaton detectors. The neutrino spectra may reflect in a subtle way the neutrino flavor oscillations and mixing in flight. A comparison of the solar neutrino flare (at their birth place on Sun and after oscillation on the arrival on the Earth) with other neutrino foreground is estimated: it offers an independent track to disentangle the neutrino flavor puzzles and its most secret mixing angles. The sharpest noise-free anti-neutrino imprint maybe its first clean voice.

  15. PUBLISHED ONLINE: 2 JULY 2013 | DOI: 10.1038/NPHYS2670 Self-organized criticality in X-ray flares of

    E-Print Network [OSTI]

    Loss, Daniel

    statistical results of X-ray flares of GRBs with known redshifts, and show that X-ray flares and solar flares-organized criticality (SOC) system. The statistical properties of X-ray flares of GRBs are similar to solar flares for the first time. On the other hand, it is well known that solar flares with a timescale of hours

  16. Product transfer service chosen over LPG flaring

    SciTech Connect (OSTI)

    Horn, J.; Powers, M.

    1994-07-01

    Seadrift Pipeline Corp. recently decommissioned its Ella Pipeline, an 108-mile, 8-in. line between the King Ranch and a Union Carbide plant at Seadrift, Texas. The pipeline company opted for the product transfer services of pipeline Dehydrators Inc. to evacuate the ethane-rich LPG mixture from the pipeline instead of flaring the LPG or displacing it with nitrogen at operating pressures into another pipeline. The product transfer system of Pipeline Dehydrators incorporates the use of highly specialized portable compressors, heat exchangers and interconnected piping. The product transfer process of evacuating a pipeline is an economically viable method that safely recovers a very high percentage of the product while maintaining product purity. Using positive-displacement compressors, PLD transferred the LPG from the idled 8-in. Ella line into an adjacent 12-in. ethane pipeline that remained in service at approximately 800 psig. Approximately 4.3 million lb of LPG (97% ethane, 2.7% methane and 0.3% propane) were transferred into the ethane pipeline, lowering the pressure on the Ella Pipeline from 800 psig to 65 psig.

  17. Spectral Hardening of Large Solar Flares

    E-Print Network [OSTI]

    Paolo C. Grigis; Arnold O. Benz

    2008-05-01

    RHESSI observations are used to quantitatively study the hard X-ray evolution in 5 large solar flares selected for spectral hardening in the course of the event. The X-ray bremsstrahlung emission from non-thermal electrons is characterized by two spectroscopically distinct phases: impulsive and gradual. The impulsive phase usually consists of several emission spikes following a soft-hard-soft spectral pattern, whereas the gradual stage manifests itself as spectral hardening while the flux slowly decreases. Both the soft-hard-soft (impulsive) phase and the hardening (gradual) phase are well described by piecewise linear dependence of the photon spectral index on the logarithm of the hard X-ray flux. The different linear parts of this relation correspond to different rise and decay phases of emission spikes. The temporal evolution of the spectra is compared with the configuration and motion of the hard X-ray sources in RHESSI images. These observations reveal that the two stages of electron acceleration causing these two different behaviors are closely related in space and time. The transition between the impulsive and gradual phase is found to be smooth and progressive rather than abrupt. This suggests that they arise because of a slow change in a common accelerator rather than being caused by two independent and distinct acceleration processes. We propose that the hardening during the decay phase is caused by continuing particle acceleration with longer trapping in the accelerator before escape.

  18. OPTICAL DISCOVERY OF PROBABLE STELLAR TIDAL DISRUPTION FLARES

    SciTech Connect (OSTI)

    Van Velzen, Sjoert; Farrar, Glennys R. [Center for Cosmology and Particle Physics, New York University, NY 10003 (United States); Gezari, Suvi [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Morrell, Nidia [Carnegie Observatories, Las Campanas Observatory, Casillas 601, La Serena (Chile); Zaritsky, Dennis [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Oestman, Linda [Institut de Fisica d'Altes Energies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Smith, Mathew [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch, 7701 (South Africa); Gelfand, Joseph [New York University-Abu Dhabi, Abu Dhabi (United Arab Emirates); Drake, Andrew J., E-mail: s.vanvelzen@astro.ru.nl [Center for Advance Computing Research, California Institute of Technology, Pasadena, CA 91225 (United States)

    2011-11-10

    Using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by supermassive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified. The TDE flares have optical blackbody temperatures of 2 Multiplication-Sign 10{sup 4} K and observed peak luminosities of M{sub g} = -18.3 and -20.4 ({nu}L{sub {nu}} = 5 Multiplication-Sign 10{sup 42}, 4 Multiplication-Sign 10{sup 43} erg s{sup -1}, in the rest frame); their cooling rates are very low, qualitatively consistent with expectations for tidal disruption flares. The properties of the TDE candidates are examined using (1) SDSS imaging to compare them to other flares observed in the search, (2) UV emission measured by GALEX, and (3) spectra of the hosts and of one of the flares. Our pipeline excludes optically identifiable AGN hosts, and our variability monitoring over nine years provides strong evidence that these are not flares in hidden AGNs. The spectra and color evolution of the flares are unlike any SN observed to date, their strong late-time UV emission is particularly distinctive, and they are nuclear at high resolution arguing against these being first cases of a previously unobserved class of SNe or more extreme examples of known SN types. Taken together, the observed properties are difficult to reconcile with an SN or an AGN-flare explanation, although an entirely new process specific to the inner few hundred parsecs of non-active galaxies cannot be excluded. Based on our observed rate, we infer that hundreds or thousands of TDEs will be present in current and next-generation optical synoptic surveys. Using the approach outlined here, a TDE candidate sample with O(1) purity can be selected using geometric resolution and host and flare color alone, demonstrating that a campaign to create a large sample of TDEs, with immediate and detailed multi-wavelength follow-up, is feasible. A by-product of this work is quantification of the power spectrum of extreme flares in AGNs.

  19. Super-hot (T > 30 MK) Thermal Plasma in Solar Flares

    E-Print Network [OSTI]

    Caspi, Amir

    2010-01-01

    MNRAS, 148, 17 Kane, S. R. , et al. 1980, in Solar Flares: AMonograph from SKYLAB Solar Workshop II, ed. P. A.Moore, R. , et al. 1980, in Solar Flares: A Monograph from

  20. ELECTROMAGNETIC AND CORPUSCULAR EMISSION FROM THE SOLAR FLARE OF 1991 JUNE 15: CONTINUOUS ACCELERATON OF

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    detected previously in only a few ground level events (GLE) detected by the neutron monitor network (e-flare loop system were also recorded. In Figure 1 we show the post-flare loops observed at Big Bear

  1. Connecting Flares and Transient Mass Loss Events in Magnetically Active Stars

    E-Print Network [OSTI]

    Osten, Rachel A

    2015-01-01

    We explore the ramification of associating the energetics of extreme mag- netic reconnection events with transient mass loss in a stellar analogy with solar eruptive events. We establish energy partitions relative to the total bolometric radiated flare energy for different observed components of stellar flares, and show that there is rough agreement for these values with solar flares. We apply an equipartition between the bolometric radiated flare energy and kinetic energy in an accompanying mass ejection, seen in solar eruptive events and expected from reconnection. This allows an integrated flare rate in a particular waveband to be used to estimate the amount of associated transient mass loss. This approach is supported by a good correspondence between observational flare signatures on high flaring rate stars and the Sun, which suggests a common physical origin. If the frequent and extreme flares that young solar-like stars and low-mass stars experience are accompanied by transient mass loss in the form of ...

  2. Space weather effects on the Mars ionosphere due to solar flares and meteors

    E-Print Network [OSTI]

    Withers, Paul

    Space weather effects on the Mars ionosphere due to solar flares and meteors P. Withers (1), M observed two aspects of space weather at Mars. Following solar flares of both moderate to strong magnitude

  3. Thermal and non-thermal energies in solar flares

    E-Print Network [OSTI]

    Pascal Saint-Hilaire; Arnold O. Benz

    2005-03-03

    The energy of the thermal flare plasma and the kinetic energy of the non-thermal electrons in 14 hard X-ray peaks from 9 medium-sized solar flares have been determined from RHESSI observations. The emissions have been carefully separated in the spectrum. The turnover or cutoff in the low-energy distribution of electrons has been studied by simulation and fitting, yielding a reliable lower limit to the non-thermal energy. It remains the largest contribution to the error budget. Other effects, such as albedo, non-uniform target ionization, hot target, and cross-sections on the spectrum have been studied. The errors of the thermal energy are about equally as large. They are due to the estimate of the flare volume, the assumption of the filling factor, and energy losses. Within a flare, the non-thermal/thermal ratio increases with accumulation time, as expected from loss of thermal energy due to radiative cooling or heat conduction. Our analysis suggests that the thermal and non-thermal energies are of the same magnitude. This surprising result may be interpreted by an efficient conversion of non-thermal energy to hot flare plasma.

  4. Impulsive Heating of Solar Flare Ribbons Above 10 MK

    E-Print Network [OSTI]

    Simőes, Paulo J A; Fletcher, Lyndsay

    2015-01-01

    The chromospheric response to the input of flare energy is marked by extended extreme ultraviolet (EUV) ribbons and hard X-ray (HXR) footpoints. These are usually explained as the result of heating and bremsstrahlung emission from accelerated electrons colliding in the dense chromospheric plasma. We present evidence of impulsive heating of flare ribbons above 10 MK in a two-ribbon flare. We analyse the impulsive phase of SOL2013-11-09T06:38, a C2.6 class event using data from Atmospheric Imaging Assembly (AIA) on board of Solar Dynamics Observatory (SDO) and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) to derive the temperature, emission measure and differential emission measure of the flaring regions and investigate the evolution of the plasma in the flaring ribbons. The ribbons were visible at all SDO/AIA EUV/UV wavelengths, in particular, at 94 and 131 \\AA\\ filters, sensitive to temperatures of 8 MK and 12 MK. Time evolution of the emission measure of the plasma above 10 MK at the ribb...

  5. Repeated X-ray Flaring Activity in Sagittarius A*

    E-Print Network [OSTI]

    Guillaume Belanger; Andrea Goldwurm; Fulvio Melia; Farah Yusef-Zadeh; Philippe Ferrando; Delphine Porquet; Nicolas Grosso; Robert Warwick

    2005-08-19

    Investigating the spectral and temporal characteristics of the X-rays coming from Sagittarius A* (Sgr A*) is essential to our development of a more complete understanding of the emission mechanisms in this supermassive black hole located at the center of our Galaxy. Several X-ray flares with varying durations and spectral features have already been observed from this object. Here we present the results of two long XMM-Newton observations of the Galactic nucleus carried out in 2004, for a total exposure time of nearly 500 ks. During these observations we detected two flares from Sgr A* with peak 2-10 keV luminosities about 40 times (L ~ 9x10^34 erg s?1) above the quiescent luminosity: one on 2004 March 31 and another on 2004 August 31. The first flare lasted about 2.5 ks and the second about 5 ks. The combined fit on the Epic spectra yield photon indeces of about 1.5 and 1.9 for the first and second flare respectively. This hard photon index strongly suggests the presence of an important population of non-thermal electrons during the event and supports the view that the majority of flaring events tend to be hard and not very luminous.

  6. Muon and Tau Neutrinos Spectra from Solar Flares

    E-Print Network [OSTI]

    D. Fargion; F. Moscato

    2004-05-03

    Solar neutrino flares and mixing are considered. Most power-full solar flare as the ones occurred on 23th February 1956, September 29th 1989, 28th October and on 2nd-4th November 2003 are sources of cosmic rays, X, gamma and neutrino bursts. These flares took place both on front or in the edge and in the hidden solar disk. The observed and estimated total flare energy should be a source of a prompt secondary neutrino burst originated, by proton-proton-pion production on the sun itself; a more delayed and spread neutrino flux signal arise by the solar charged flare particles reaching the terrestrial atmosphere. Our first estimates of neutrino signals in largest underground detectors hint for few events in correlation with, gamma,radio onser. Our approximated spectra for muons and taus from these rare solar eruption are shown over the most common background. The muon and tau signature is very peculiar and characteristic over electron and anti-electron neutrino fluxes. The rise of muon neutrinos will be detectable above the minimal muon threshold of 113 MeV. The rarest tau appearence will be possible only for hardest solar neutrino energies above 3.471 GeV

  7. A Unified Computational Model for Solar and Stellar Flares

    E-Print Network [OSTI]

    Allred, Joel C; Carlsson, Mats

    2015-01-01

    We present a unified computational framework which can be used to describe impulsive flares on the Sun and on dMe stars. The models assume that the flare impulsive phase is caused by a beam of charged particles that is accelerated in the corona and propagates downward depositing energy and momentum along the way. This rapidly heats the lower stellar atmosphere causing it to explosively expand and dramatically brighten. Our models consist of flux tubes that extend from the sub-photosphere into the corona. We simulate how flare-accelerated charged particles propagate down one-dimensional flux tubes and heat the stellar atmosphere using the Fokker-Planck kinetic theory. Detailed radiative transfer is included so that model predictions can be directly compared with observations. The flux of flare-accelerated particles drives return currents which additionally heat the stellar atmosphere. These effects are also included in our models. We examine the impact of the flare-accelerated particle beams on model solar and...

  8. Neutron Capture Experiments on Unstable Nuclei

    SciTech Connect (OSTI)

    Schwantes, Jon M.; Sudowe, Ralf; Folden, Charles M., III; Nitsche, Heino; Hoffman, Darleane C.

    2005-01-15

    The overall objective of this project is the measurement of neutron capture cross sections of importance to stewardship science and astrophysical modeling of nucleosynthesis, while at the same time helping to train the next generation of scientists with expertise relevant to U.S. national nuclear security missions and to stewardship science. A primary objective of this project is to study neutron capture cross sections for various stable and unstable isotopes that will contribute to the Science Based Stockpile Stewardship (SBSS) program by providing improved data for modeling and interpretation of nuclear device performance. Much of the information obtained will also be important in astrophysical modeling of nucleosynthesis. Measurements of these neutron capture cross sections are being conducted in collaboration with researchers at the Los Alamos Neutron Science Center (LANSCE) facility using the unique Detector for Advanced Neutron Capture Experiments (DANCE). In our early discussions with the DANCE group, decisions were made on the first cross sections to be measured and how our expertise in target preparation, radiochemical separations chemistry, and data analysis could best be applied. The initial emphasis of the project was on preparing suitable targets of both natural and separated stable europium isotopes in preparation for the ultimate goal of preparing a sufficiently large target of radioactive 155Eu (t1/2 = 4.7 years) and other radioactive and stable species for neutron cross-section measurements at DANCE. Our Annual Report, ''Neutron Capture Experiments on Unstable Nuclei'' by J. M. Schwantes, R. Sudowe, C. M. Folden III, H. Nitsche, and D. C. Hoffman, submitted to NNSA in December 2003, gives details about the initial considerations and scope of the project. During the current reporting period, electroplated targets of natural Eu together with valuable, stable, and isotopically pure 151Eu and 153Eu, and isotopically separated 154Sm were measured for the first time at the DANCE facility in early 2004. The Eu targets, suitable blanks, Be backing foils, and standards had been sent to the DANCE group in early fall 2003. Some preliminary data analysis was performed and more sophisticated analysis has begun. We developed plans for a suitable computer system for data analysis within our group at Berkeley and had meetings with counterparts at Lawrence Livermore National Laboratory (LLNL) and LANL concerning analysis of these data. Our major emphasis in 2004 has been to develop the separations and processes ultimately required to prepare radioactive targets of 4.7-year 155Eu. Efforts continued to devise an optimum multiprocess procedure suitable for use in separating radioactive 155Eu already produced by irradiation of stable 154Sm in a high neutron flux reactor at the Institut Laue-Langevin in France and shipped to LANL (the 22-min 155Sm neutron-capture product decays to 155Eu). This separation is extremely demanding because the highly radioactive 155Eu must be isolated from about 20 times as much mass of samarium before a target can be prepared for DANCE measurements. After all the procedures have been fully tested the radioactive 155Eu will be separated. The same electroplating methods already used successfully to prepare stable Eu isotope targets will be used to prepare the 155Eu target for DANCE. Discussions were held with LANL radiochemists in the Chemistry (C) Division about appropriate facilities at LANL for conducting the full-scale separation and purification of the radioactive targets. Three more multiprocess separations were developed that generated less chemical and radioactive waste, but they must still be adapted for processing hundred-milligram quantities. Until these separations can be successfully implemented at this scale, standard HPLC procedures will be used for separating and preparing radioactive 155Eu, 2.6-year 147Pm, and 1.9-year 171Tm target materials. Future directions beyond the preparation of radioactive lanthanide targets include closer collaboration with both LLNL and LANL to prepare ac

  9. Knowledge Capture and Transfer Program

    Broader source: Energy.gov [DOE]

    The Office of Learning and Workforce Development is working with Heads of Departmental Elements, DOE senior leaders and subject-matter-experts to capture and transfer the knowledge and experiences...

  10. Experience with capture cavity II

    SciTech Connect (OSTI)

    Koeth, T.; /Fermilab /Rutgers U., Piscataway; Branlard, J.; Edwards, H.; Fliller, R.; Harms, E.; Hocker, A.; McGee, M.; Pischalnikov, Y.; Prieto, P.; Reid, J.; /Fermilab

    2007-06-01

    Valuable experience in operating and maintaining superconducting RF cavities in a horizontal test module has been gained with Capture Cavity II. We report on all facets of our experience to date.

  11. Capturing CO2 via reactions in nanopores.

    SciTech Connect (OSTI)

    Leung, Kevin; Nenoff, Tina Maria; Criscenti, Louise Jacqueline; Tang, Z; Dong, J. H.

    2008-10-01

    This one-year exploratory LDRD aims to provide fundamental understanding of the mechanism of CO2 scrubbing platforms that will reduce green house gas emission and mitigate the effect of climate change. The project builds on the team member's expertise developed in previous LDRD projects to study the capture or preferential retention of CO2 in nanoporous membranes and on metal oxide surfaces. We apply Density Functional Theory and ab initio molecular dynamics techniques to model the binding of CO2 on MgO and CaO (100) surfaces and inside water-filled, amine group functionalized silica nanopores. The results elucidate the mechanisms of CO2 trapping and clarify some confusion in the literature. Our work identifies key future calculations that will have the greatest impact on CO2 capture technologies, and provides guidance to science-based design of platforms that can separate the green house gas CO2 from power plant exhaust or even from the atmosphere. Experimentally, we modify commercial MFI zeolite membranes and find that they preferentially transmit H2 over CO2 by a factor of 34. Since zeolite has potential catalytic capability to crack hydrocarbons into CO2 and H2, this finding paves the way for zeolite membranes that can convert biofuel into H2 and separate the products all in one step.

  12. Well-observed dynamics of flaring and peripheral coronal magnetic loops during an M-class limb flare

    SciTech Connect (OSTI)

    Shen, Jinhua; Zhou, Tuanhui; Ji, Haisheng; Feng, Li; Wiegelmann, Thomas; Inhester, Bernd

    2014-08-20

    In this paper, we present a variety of well-observed dynamic behaviors for the flaring and peripheral magnetic loops of the M6.6 class extreme limb flare that occurred on 2011 February 24 (SOL2011-02-24T07:20) from EUV observations by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory and X-ray observations by RHESSI. The flaring loop motion confirms the earlier contraction-expansion picture. We find that the U-shaped trajectory delineated by the X-ray corona source of the flare roughly follows the direction of a filament eruption associated with the flare. Different temperature structures of the coronal source during the contraction and expansion phases strongly suggest different kinds of magnetic reconnection processes. For some peripheral loops, we discover that their dynamics are closely correlated with the filament eruption. During the slow rising to abrupt, fast rising of the filament, overlying peripheral magnetic loops display different responses. Two magnetic loops on the elbow of the active region had a slow descending motion followed by an abrupt successive fast contraction, while magnetic loops on the top of the filament were pushed outward, slowly being inflated for a while and then erupting as a moving front. We show that the filament activation and eruption play a dominant role in determining the dynamics of the overlying peripheral coronal magnetic loops.

  13. Early Abnormal Temperature Structure of X-ray Looptop Source of Solar Flares

    E-Print Network [OSTI]

    Jinhua Shen; Tuanhui Zhou; Haisheng Ji; Na Wang; Wenda Cao; Haimin Wang

    2008-08-29

    This Letter is to investigate the physics of a newly discovered phenomenon -- contracting flare loops in the early phase of solar flares. In classical flare models, which were constructed based on the phenomenon of expansion of flare loops, an energy releasing site is put above flare loops. These models can predict that there is a vertical temperature gradient in the top of flare loops due to heat conduction and cooling effects. Therefore, the centroid of an X-ray looptop source at higher energy bands will be higher in altitude, for which we can define as normal temperature distribution. With observations made by {\\it RHESSI}, we analyzed 10 M- or X-class flares (9 limb flares). For all these flares, the movement of looptop sources shows an obvious U-shaped trajectory, which we take as the signature of contraction-to-expansion of flare loops. We find that, for all these flares, normal temperature distribution does exist, but only along the path of expansion. The temperature distribution along the path of contraction is abnormal, showing no spatial order at all. The result suggests that magnetic reconnection processes in the contraction and expansion phases of these solar flares are different.

  14. Automatic Solar Flare Detection Using MLP, RBF and SVM , Frank Y. Shih1

    E-Print Network [OSTI]

    in light curves. In the mean time, solar flares also emit high velocity charged particles that take one1 Automatic Solar Flare Detection Using MLP, RBF and SVM Ming Qu1 , Frank Y. Shih1 , Ju Jing2. The focus of the automatic solar flare detection is on the development of efficient feature

  15. Solar Flare Intermittency and the Earth's Temperature Anomalies Nicola Scafetta1,2

    E-Print Network [OSTI]

    Scafetta, Nicola

    Solar Flare Intermittency and the Earth's Temperature Anomalies Nicola Scafetta1,2 and Bruce J; published 17 June 2003) We argue that Earth's short-term temperature anomalies and the solar flare data sets that corresponds to the one that would be induced by the solar flare intermittency. The mean

  16. LETTER Earth Planets Space, 61, 577580, 2009 Flares and the chromosphere

    E-Print Network [OSTI]

    California at Berkeley, University of

    magnetic field. Key words: Solar flares, solar chromosphere, solar corona, Alfv´en waves. 1. Introduction The chromosphere historically has been the origin of much of what we understand about solar flares. The rea- son of a solar flare appears mainly in the optical and UV continuum, which form in the lower solar atmosphere

  17. Statistical Assessment of Photospheric Magnetic Features in Imminent Solar Flares Predictions

    E-Print Network [OSTI]

    Statistical Assessment of Photospheric Magnetic Features in Imminent Solar Flares Predictions Hui in solar physics to predict solar flares. 1. Introduction Over the past decades, mankind has become more of the primary objectives in space weather research is to predict the occurrence of solar flares and Coronal Mass

  18. Relationship between magnetic power spectrum and flare productivity in solar active regions

    E-Print Network [OSTI]

    Relationship between magnetic power spectrum and flare productivity in solar active regions V day, being equal to 1 when the specific flare productivity is one C1.0 flare per day. The power index.I. Abramenko Big Bear Solar Observatory, 40386 N. Shore Lane, Big Bear City, CA 92314, USA ABSTRACT Power

  19. Modeling atmospheric effects of the September 1859 solar flare B. C. Thomas,1

    E-Print Network [OSTI]

    Jackman, Charles H.

    Modeling atmospheric effects of the September 1859 solar flare B. C. Thomas,1 C. H. Jackman,2 and A. Melott(2007),ModelingatmosphericeffectsoftheSeptember1859 solar flare, Geophys. Res. Lett., 34, L06810 of the work in this area. [3] The solar flare of 1 September 1859 was one of the most intense white

  20. Splinter Proposal for Cool Stars 16 Title: Solar and Stellar Flares

    E-Print Network [OSTI]

    Hudson, Hugh

    Splinter Proposal for Cool Stars 16 Title: Solar and Stellar Flares 1. Names of the session for CS16. Solar and stellar flares have striking similarities, so important parts of the underlying to initiate discussions to bridge this gap, via a splinter session on solar and stellar flares at Cool Stars

  1. A Novel Forecasting System for Solar Particle Events and Flares (FORSPEF)

    E-Print Network [OSTI]

    Anastasiadis, Anastasios

    A Novel Forecasting System for Solar Particle Events and Flares (FORSPEF) A Papaioannou1 Energetic Particles (SEPs) result from intense solar eruptive events such as solar flares and coronal mass. In this work, we present FORSPEF (Forecasting Solar Particle Events and Flares), a novel dual system, designed

  2. GEOMAGNETIC CONSEQUENCES OF THE SOLAR FLARES DURING THE LAST HALE SOLAR CYCLE (II)

    E-Print Network [OSTI]

    GEOMAGNETIC CONSEQUENCES OF THE SOLAR FLARES DURING THE LAST HALE SOLAR CYCLE (II) Georgeta Maris phenomena. We analyze the cyclic variability of solar flares (registered in H and X-ray) and compare)) for the last Hale cycle. The solar cycles 22 and 23 are different in the level of flare activity

  3. Anisotropic Bremsstrahlung Emission and the form of Regularized Electron Flux Spectra in Solar Flares

    E-Print Network [OSTI]

    Piana, Michele

    ,3 , & John C. Brown4 ABSTRACT The cross-section for bremsstrahlung photon emission in solar flares is in gen is related to the position of the flare on the solar disk and the direction(s) of the pre-collision electrons relative to the local solar vertical. We compare mean electron flux spectra for the flare of August 21

  4. PROPERTIES OF THE ACCELERATION REGIONS IN SEVERAL LOOP-STRUCTURED SOLAR FLARES

    E-Print Network [OSTI]

    Piana, Michele

    PROPERTIES OF THE ACCELERATION REGIONS IN SEVERAL LOOP-STRUCTURED SOLAR FLARES Jingnan Guo1 , A-energy electrons accelerated in solar flares is the hard X-ray bremsstrahlung that they produce as they propagate et al. (2008) analyzed a set of extended coronal flare loops located near the solar limb, and were

  5. Early Abnormal Temperature Structure of X-ray Looptop Source of Solar Flares

    E-Print Network [OSTI]

    Early Abnormal Temperature Structure of X-ray Looptop Source of Solar Flares Jinhua Shen1 processes in the contraction and expansion phases of these solar flares are different. Subject headings: Sun: activity -- Sun: magnetic reconnection -- Sun: flares 1. Introduction It is widely accepted that solar

  6. Automatic Solar Flare Tracking Using Image Processing Qu Ming and Shih Frank (shih@njit.edu)

    E-Print Network [OSTI]

    Automatic Solar Flare Tracking Using Image Processing Techniques Qu Ming and Shih Frank (shih Abstract. Measurement of the evolution properties of solar flares through their complete cyclic development the properties of solar flares. We also present our solution for automatically tracking the apparent separation

  7. PPPL-3450 PPPL-3450 Solar Flare Mechanism Based on Magnetic Arcade

    E-Print Network [OSTI]

    PPPL-3450 PPPL-3450 UC-70 Solar Flare Mechanism Based on Magnetic Arcade Reconnection and Island, 00, 000­000, 2000 Solar Flare Mechanism Based on Magnetic Arcade Reconnection and Island Merging C. Z-0451 (Received ; Revised ; Accepted ) We propose a model describing physical processes of solar flares based

  8. A topological analysis of the magnetic breakout model for an eruptive solar flare

    E-Print Network [OSTI]

    Priest, Eric

    A topological analysis of the magnetic breakout model for an eruptive solar flare BY RHONA MACLEAN model gives an elegant explanation for the onset of an eruptive solar flare, involving magnetic types of bifurcation. Keywords: solar flare; magnetic breakout; magnetic topology; solar corona 1

  9. Regularized reconstruction of the differential emission measure from solar flare hard X-ray spectra

    E-Print Network [OSTI]

    Piana, Michele

    Regularized reconstruction of the differential emission measure from solar flare hard X-ray spectra for solar flare hard X-rays, it is currently unclear whether the electron distribution responsible simulated data and real photon spectra recorded by RHESSI. Subject headings: Sun: flares 1. Introduction

  10. Toward magnetic field dissipation during the 23 July 2002 solar flare measured with Solar

    E-Print Network [OSTI]

    Zharkova, Valentina V.

    Toward magnetic field dissipation during the 23 July 2002 solar flare measured with Solar. Benkhalil (2005), Toward magnetic field dissipation during the 23 July 2002 solar flare measured with Solar] It is widely accepted that the source of primary energy release in solar flares is associated with magnetic

  11. Determination of Electron Flux Spectra in a Solar Flare with Ran Augmented Regularization Method: Application

    E-Print Network [OSTI]

    Piana, Michele

    Determination of Electron Flux Spectra in a Solar Flare with Ran Augmented Regularization Method. (2004) have shown how to recover mean source electron spectra F(E) in solar flares through a physical a solar flare observed by RHESSI on 26 February, 2002. Results using different orders of regularization

  12. Solar Flare Tracking Using Image Processing Techniques , Frank Y. Shih1

    E-Print Network [OSTI]

    Solar Flare Tracking Using Image Processing Techniques Ming Qu1 , Frank Y. Shih1 , Ju Jing2 grants IIS-0324816, ATM 0233931 and ATM 0313591. Abstract. Automatic property measurement of solar flares through their complete cyclic development is valuable in the studies of solar flares. From the analysis

  13. DOI 10.1007/s11207-015-0710-3 SOLAR AND STELLAR FLARES

    E-Print Network [OSTI]

    Aulanier, Guillaume

    Solar Phys DOI 10.1007/s11207-015-0710-3 SOLAR AND STELLAR FLARES From Coronal Observations to MHD Simulations, the Building Blocks for 3D Models of Solar Flares (Invited Review) M. Janvier1 · G. Aulanier2 · P Abstract Solar flares are energetic events taking place in the Sun's atmosphere, and their effects can

  14. Radio emission from acceleration sites of solar flares , Gregory D. Fleishman1,2

    E-Print Network [OSTI]

    microwave and decimeter continuum bursts may be a signature of the stochastic acceleration in solar flaresRadio emission from acceleration sites of solar flares Yixuan Li1 , Gregory D. Fleishman1 acceleration site of a solar flare. Specifically, we calculate incoherent radio emission produced within two

  15. Dynamic Magnetography of Solar Flaring Loops Gregory D. Fleishman1,2

    E-Print Network [OSTI]

    ) demonstrated that the mean magnetic field in a solar flare derived from the microwave spectrum yields resultsDynamic Magnetography of Solar Flaring Loops Gregory D. Fleishman1,2 , Gelu M. Nita1 , Dale E. Gary with shaking, which allows the derivation of the magnetic field and other parameters along a solar flaring loop

  16. A Reconnecting Current Sheet Imaged in A Solar Flare

    E-Print Network [OSTI]

    Liu, Rui; Wang, Tongjiang; Stenborg, Guillermo; Liu, Chang; Wang, Haimin

    2010-01-01

    Magnetic reconnection changes the magnetic field topology and powers explosive events in astrophysical, space and laboratory plasmas. For flares and coronal mass ejections (CMEs) in the solar atmosphere, the standard model predicts the presence of a reconnecting current sheet, which has been the subject of considerable theoretical and numerical modeling over the last fifty years, yet direct, unambiguous observational verification has been absent. In this Letter we show a bright sheet structure of global length (>0.25 Rsun) and macroscopic width ((5 - 10)x10^3 km) distinctly above the cusp-shaped flaring loop, imaged during the flare rising phase in EUV. The sheet formed due to the stretch of a transequatorial loop system, and was accompanied by various reconnection signatures that have been dispersed in the literature. This unique event provides a comprehensive view of the reconnection geometry and dynamics in the solar corona.

  17. Complex Flare Dynamics Initiated by a Filament-Filament Interaction

    E-Print Network [OSTI]

    Zhu, Chunming; Alexander, David; Sun, Xudong; McAteer, James

    2015-01-01

    We report on an eruption involving a relatively rare filament-filament interaction on 2013 June 21, observed by SDO and STEREO-B. The two filaments were separated in height within AR 11777. The onset of the eruption of the lower filament was accompanied simultaneously by the apparent descent of the upper filament resulting in a convergence and direct interaction of the two filaments. The interaction was accompanied by the heating of plasmas surrounding the upper filament and the subsequent coalescence of the filaments into a magnetically complex structure, whose eruption was associated with an M2.9 class solar flare. Magnetic loop shrinkage and descending dark voids were observed at different locations as part of the large flare energy release giving us a unique insight into these dynamic flare phenomena.

  18. Observations of Electrons from the Decay of Solar Flare Neutrons

    E-Print Network [OSTI]

    W. Dröge; D. Ruffolo; B. Klecker

    1996-04-03

    We have found evidence for fluxes of energetic electrons in interplanetary space on board the ISEE-3 spacecraft which we interpret as the decay products of neutrons generated in a solar flare on 1980 June 21. The decay electrons arrived at the s/c shortly before the electrons from the flare and can be distinguished from the latter by their distinctive energy spectrum. The time profile of the decay electrons is in good agreement with the results from a simulation based on a scattering mean free path derived from a fit to the flare electron data. The comparison with simultaneously observed decay protons and a published direct measurement of high-energy neutrons places important constraints on the parent neutron spectrum.

  19. Energy Partitions and Evolution in a Purely Thermal Solar Flare

    E-Print Network [OSTI]

    Fleishman, Gregory D; Gary, Dale E

    2015-01-01

    This paper presents a solely thermal flare, which we detected in the microwave range from the thermal gyro- and free-free emission it produced. An advantage of analyzing thermal gyro emission is its unique ability to precisely yield the magnetic field in the radiating volume. When combined with observationally-deduced plasma density and temperature, these magnetic field measurements offer a straightforward way of tracking evolution of the magnetic and thermal energies in the flare. For the event described here, the magnetic energy density in the radio-emitting volume declines over the flare rise phase, then stays roughly constant during the extended peak phase, but recovers to the original level over the decay phase. At the stage where the magnetic energy density decreases, the thermal energy density increases; however, this increase is insufficient, by roughly an order of magnitude, to compensate for the magnetic energy decrease. When the magnetic energy release is over, the source parameters come back to ne...

  20. High-Performance Sorbents for Carbon Dioxide Capture from Air

    SciTech Connect (OSTI)

    Sholl, David; Jones, Christopher

    2013-03-13

    This project has focused on capture of CO{sub 2} from ambient air (“air capture”). If this process is technically and economically feasible, it could potentially contribute to net reduction of CO{sub 2} emissions in ways that are complementary to better developed techniques for CO{sub 2} from concentrated point sources. We focused on cyclic adsorption processes for CO{sub 2} capture from air in which the entire cycle is performed at moderate temperatures. The project involved both experimental studies of sorbent materials and process level modeling of cyclic air capture processes. In our experimental work, a series of amine-functionalized silica adsorbents were prepared and characterized to determine the impact of molecular architecture on CO{sub 2} capture. Some key findings were: • Amine functionalized silicas can be prepared with high enough CO{sub 2} capacities under ambient conditions to merit consideration for use in air capture processes. • Primary amines are better candidates for CO{sub 2} capture than secondary or tertiary amines, both in terms of amine efficiency for CO{sub 2} adsorption and enhanced water affinity. • Mechanistic understanding of degradation of these materials can enable control of molecular architecture to significantly improve material stability. Our process modeling work provided the first publically available cost and energy estimates for cyclic adsorption processes for air capture of CO{sub 2}. Some key findings were: • Cycles based on diurnal ambient heating and cooling cannot yield useful purities or amounts of captured CO{sub 2}. • Cycles based on steam desorption at 110 oC can yield CO{sub 2} purities of ~88%. • The energy requirements for cycles using steam desorption are dominated by needs for thermal input, which results in lower costs than energy input in the form of electricity. Cyclic processes with operational costs of less than $100 tCO{sub 2}-net were described, and these results point to process and material improvements that could substantially reduce these costs. The most critical conclusions from our work are that (i) CO{sub 2} capture from ambient air using moderate temperature cyclic adsorption processes is technically feasible and (ii) the operational costs of realistic versions of these processes are moderate enough to encourage future development of this technology. Because of the very modest net investment that has been made in R&D associated with this approach from all sources worldwide (relative to the massive public and private investment that has been made in technologies for CO{sub 2} from concentrated point sources), our results strongly suggest that continued development of air capture is justified.

  1. Speeding Up Zeolite Evaluation for Carbon Capture

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

    Speeding Up Zeolite Evaluation for Carbon Capture Speeding Up Zeolite Evaluation for Carbon Capture Zeolite.png Schematic of an important class of porous materials known as...

  2. Supercomputers Capture Turbulence in the Solar Wind

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

    Capture Turbulence in the Solar Wind Supercomputers Capture Turbulence in the Solar Wind Berkeley Lab visualizations could help scientists forecast destructive space weather...

  3. Better Enzymes for Carbon Capture: Low-Cost Biological Catalyst to Enable Efficient Carbon Dioxide Capture

    SciTech Connect (OSTI)

    2010-07-01

    IMPACCT Project: Codexis is developing new and efficient forms of enzymes known as carbonic anhydrases to absorb CO2 more rapidly and under challenging conditions found in the gas exhaust of coal-fired power plants. Carbonic anhydrases are common and are among the fastest enzymes, but they are not robust enough to withstand the harsh environment found in the power plant exhaust steams. In this project, Codexis will be using proprietary technology to improve the enzymes’ ability to withstand high temperatures and large swings in chemical composition. The project aims to develop a carbon-capture process that uses less energy and less equipment than existing approaches. This would reduce the cost of retrofitting today’s coal-fired power plants.

  4. Multi-wavelength analysis of high energy electrons in solar flares: a case study of August 20, 2002 flare

    E-Print Network [OSTI]

    J. Kasparova; M. Karlicky; E. P. Kontar; R. A. Schwartz; B. R. Dennis

    2005-08-30

    A multi-wavelength spatial and temporal analysis of solar high energy electrons is conducted using the August 20, 2002 flare of an unusually flat (gamma=1.8) hard X-ray spectrum. The flare is studied using RHESSI, Halpha, radio, TRACE, and MDI observations with advanced methods and techniques never previously applied in the solar flare context. A new method to account for X-ray Compton backscattering in the photosphere (photospheric albedo) has been used to deduce the primary X-ray flare spectra. The mean electron flux distribution has been analysed using both forward fitting and model independent inversion methods of spectral analysis. We show that the contribution of the photospheric albedo to the photon spectrum modifies the calculated mean electron flux distribution, mainly at energies below 100 keV. The positions of the Halpha emission and hard X-ray sources with respect to the current-free extrapolation of the MDI photospheric magnetic field and the characteristics of the radio emission provide evidence of the closed geometry of the magnetic field structure and the flare process in low altitude magnetic loops. In agreement with the predictions of some solar flare models, the hard X-ray sources are located on the external edges of the Halpha emission and show chromospheric plasma heated by the non-thermal electrons. The fast changes of Halpha intensities are located not only inside the hard X-ray sources, as expected if they are the signatures of the chromospheric response to the electron bombardment, but also away from them.

  5. Sudden Disappearance of a Small Sunspot Associated with the February 20, 2002 M2.4 Flare

    E-Print Network [OSTI]

    with, solar flares (Severny 1964; Zvereva & Severny 1970; Moore et al. 1984; Kosovichev & Zharkova 1999 the solar surface. Spirock et al. (2002) studied the X20 flare on April 2, 2001, the largest solar flare solar flares. It now becomes clear that with the high cadence (1 minute) and high resolution (1 to 2

  6. FLARE ACTIVITY AND THE STRENGTH OF SOLAR CYCLES Miruna Daniela Popescu, Georgeta Mari, Adrian Oncica, Marilena Mierla

    E-Print Network [OSTI]

    FLARE ACTIVITY AND THE STRENGTH OF SOLAR CYCLES Miruna Daniela Popescu, Georgeta Mari, Adrian The paper evaluates the solar flare activity during the last three 11-year cycles (the period 1976 - 2001). The flare occurrence follows the solar cycle (SC) with some particularities for each class of flares

  7. A STATISTICAL STUDY OF SHEAR MOTION OF THE FOOTPOINTS IN TWO-RIBBON FLARES Yingna Su,1,2

    E-Print Network [OSTI]

    Su, Yingna

    : corona -- Sun: flares -- Sun: magnetic fields -- Sun: UV radiation 1. INTRODUCTION Solar flares can been reported in almost 20 solar flares, which suggests that this motion may be a common feature in solar flares. In this paper we have made a detailed statistical study of the shear motion

  8. Membrane-based systems for carbon capture and hydrogen purification

    SciTech Connect (OSTI)

    Berchtold, Kathryn A

    2010-11-24

    This presentation describes the activities being conducted at Los Alamos National Laboratory to develop carbon capture technologies for power systems. This work is aimed at continued development and demonstration of a membrane based pre- and post-combustion carbon capture technology and separation schemes. Our primary work entails the development and demonstration of an innovative membrane technology for pre-combustion capture of carbon dioxide that operates over a broad range of conditions relevant to the power industry while meeting the US DOE's Carbon Sequestration Program goals of 90% CO{sub 2} capture at less than a 10% increase in the cost of energy services. Separating and capturing carbon dioxide from mixed gas streams is a first and critical step in carbon sequestration. To be technically and economically viable, a successful separation method must be applicable to industrially relevant gas streams at realistic temperatures and pressures as well as be compatible with large gas volumes. Our project team is developing polymer membranes based on polybenzimidazole (PBI) chemistries that can purify hydrogen and capture CO{sub 2} at industrially relevant temperatures. Our primary objectives are to develop and demonstrate polymer-based membrane chemistries, structures, deployment platforms, and sealing technologies that achieve the critical combination of high selectivity, high permeability, chemical stability, and mechanical stability all at elevated temperatures (> 150 C) and packaged in a scalable, economically viable, high area density system amenable to incorporation into an advanced Integrated Gasification Combined-Cycle (IGCC) plant for pre-combustion CO{sub 2} capture. Stability requirements are focused on tolerance to the primary synthesis gas components and impurities at various locations in the IGCC process. Since the process stream compositions and conditions (temperature and pressure) vary throughout the IGCC process, the project is focused on the optimization of a technology that could be positioned upstream or downstream of one or more of the water-gas-shift reactors (WGSRs) or integrated with a WGSR.

  9. TIDAL DISRUPTION FLARES: THE ACCRETION DISK PHASE

    SciTech Connect (OSTI)

    Montesinos Armijo, Matias; De Freitas Pacheco, Jose A. [Observatoire de la Cote d'Azur, Laboratoire Cassiopee, Universite de Nice Sophia-Antipolis Bd de l'Observatoire, BP 4229, 06304 Nice Cedex 4 (France)

    2011-08-01

    The evolution of an accretion disk, formed as a consequence of the disruption of a star by a black hole, is followed by solving numerically hydrodynamic equations. The present investigation aims to study the dependence of resulting light curves on dynamical and physical properties of such a transient disk during its existence. One of the main results derived from our simulations is that blackbody fits of X-ray data tend to overestimate the true mean disk temperature. In fact, the temperature derived from blackbody fits should be identified with the color X-ray temperature rather than the average value derived from the true temperature distribution along the disk. The time interval between the beginning of the circularization of the bound debris and the beginning of the accretion process by the black hole is determined by the viscous (or accretion) timescale, which also fixes the rising part of the resulting light curve. The luminosity peak coincides with the beginning of matter accretion by the black hole and the late evolution of the light curve depends on the evolution of the debris fallback rate. Peak bolometric luminosities are in the range 10{sup 45}-10{sup 46} erg s{sup -1}, whereas peak luminosities in soft X-rays (0.2-2.0 keV) are typically one order of magnitude lower. The typical timescale derived from our preferred models for the flare luminosity to decay by two orders of magnitude is about 3-4 yr. Predicted soft X-ray light curves reproduce quite well data on galaxies in which a variable X-ray emission possibly related to a tidal event was detected. In the cases of NGC 3599 and IC 3599, data are reproduced well by models defined by a black hole with mass {approx}10{sup 7} M{sub sun} and a disrupted star of about 1 solar mass. The X-ray variation observed in XMMSL1 is consistent with a model defined by a black hole with mass {approx}3 x 10{sup 6} M{sub sun} and a disrupted star of 1 solar mass, while that observed in the galaxy situated in the cluster A1689 is consistent with a model including a black hole of {approx}10{sup 7} M{sub sun} and a disrupted star of {approx}0.5 M{sub sun}.

  10. EUV Non-thermal Line Broadening and High-energy particles during Solar Flares

    E-Print Network [OSTI]

    Kawate, Tomoko

    2013-01-01

    We have studied the relationship between the location of EUV nonthermal broadening and high-energy particles during the large flares by using EUV imaging spectrometer onboard {\\it Hinode}, Nobeyama Radio Polarimeter, Nobeyama Radioheliograph, and Atmospheric Imaging Assembly onboard {\\it Solar Dynamic Observatory}. We have analyzed the five large flare events which contain thermal rich, intermediate, and thermal poor flares classified by the definition discussed in the paper. We found that, in the case of thermal rich flares, the nonthermal broadening of \\ion{Fe}{24} occurred at the top of the flaring loop at the beginning of the flares. The source of the 17 GHz microwave is located at the footpoint of the flare loop. On the other hand, in the case of intermediate/thermal poor flares, the nonthermal broadening of \\ion{Fe}{24} occurred at the footpoint of the flare loop at the beginning of the flares. The source of the 17 GHz microwave is located at the top of the flaring loop. We discussed the difference betw...

  11. GRB 060714: No Clear Dividing Line Between Prompt Emission and X-ray Flares

    E-Print Network [OSTI]

    H. A. Krimm; J. Granot; F. Marshal; M. Perri; S. D. Barthelmy; D. N. Burrows; N. Gehrels; P. Mészáros; D. Morris

    2007-04-16

    The long gamma-ray burst GRB 060714 was observed to exhibit a series of five X-ray flares beginning ~70 s after the burst trigger T0 and continuing until T0 + ~200 s. The first two flares were detected by the Burst Alert Telescope (BAT) on the Swift satellite, before Swift had slewed to the burst location, while the last three flares were strongly detected by the X-Ray Telescope (XRT) but only weakly detected by the BAT. This burst provides an unusual opportunity to track a complete sequence of flares over a wide energy range. The flares were very similar in their light curve morphology, showing power-law rise and fall components, and in most cases significant sub-structure. The flares also showed strong evolution with time, both spectrally and temporally. The small time scale and large amplitude variability observed are incompatible with an external shock origin for the flares, and support instead late time sporadic activity either of the central source or of localized dissipation events within the outflow. We show that the flares in GRB 060714 cannot be the result of internal shocks in which the contrast in the Lorentz factor of the colliding shells is very small, and that this mechanism faces serious difficulties in most Swift GRBs. The morphological similarity of the flares and the prompt emission and the gradual and continual evolution of the flares with time makes it difficult and arbitrary to draw a dividing line between the prompt emission and the flares.

  12. Temporal aspects and frequency distributions of solar soft X-ray flares

    E-Print Network [OSTI]

    A. Veronig; M. Temmer; A. Hanslmeier; W. Otruba; M. Messerotti

    2002-07-11

    A statistical analysis of almost 50000 soft X-ray (SXR) flares observed by GOES during the period 1976-2000 is presented. On the basis of this extensive data set, statistics on temporal properties of soft X-ray flares, such as duration, rise and decay times with regard to the SXR flare classes is presented. Correlations among distinct flare parameters, i.e. SXR peak flux, fluence and characteristic times, and frequency distributions of flare occurrence as function of the peak flux, the fluence and the duration are derived. We discuss the results of the analysis with respect to statistical flare models, the idea of coronal heating by nanoflares, and elaborate on implications of the obtained results on the Neupert effect in solar flares.

  13. Prediction of Solar Flares from a Statistical Analysis of Events during Solar Cycle 23

    E-Print Network [OSTI]

    Z. Q. Qu

    2008-11-14

    Ways to give medium- and short-term predictions of solar flares are proposed according to the statistical analysis of events during solar cycle 23. On one hand, the time distribution of both C and M class flares shows two main periods of 13.2 and 26.4 months in this cycle by wavelet analysis. On the other hand, active regions of specific magnetic configurations and their evolutions give high productivity of C class flares but relatively low productivity of energetic (M and X class) flares. Furthermore, by considering the measurable kinetic features of active regions, i.e., the rotation of the sunspots, some active regions of specified types are observed to have high energetic flare productivity, above 66%. The periodicity of the activity revealed can be used for medium-term C and M class flare forecasting and the high productivity of active regions forms the basis for short-term prediction of individual energetic flares.

  14. Adaptive capture of expert behavior

    SciTech Connect (OSTI)

    Jones, R.D.; Barrett, C.L.; Hand, U.; Gordon, R.C.

    1994-08-01

    The authors smoothed and captured a set of expert rules with adaptive networks. The motivation for doing this is discussed. (1) Smoothing leads to stabler control actions. (2) For some sets of rules, the evaluation of the rules can be sped up. This is important in large-scale simulations where many intelligent elements are present. (3) Variability of the intelligent elements can be achieved by adjusting the weights in an adaptive network. (4) After capture has occurred, the weights can be adjusted based on performance criteria. The authors thus have the capability of learning a new set of rules that lead to better performance. The set of rules the authors chose to capture were based on a set of threat determining rules for tank commanders. The approach in this paper: (1) They smoothed the rules. The rule set was converted into a simple set of arithmetic statements. Continuous, non-binary inputs, are now permitted. (2) An operational measure of capturability was developed. (3) They chose four candidate networks for the rule set capture: (a) multi-linear network, (b) adaptive partial least squares, (c) connectionist normalized local spline (CNLS) network, and (d) CNLS net with a PLS preprocessor. These networks were able to capture the rule set to within a few percent. For the simple tank rule set, the multi-linear network performed the best. When the rules were modified to include more nonlinear behavior, CNLS net performed better than the other three nets which made linear assumptions. (4) The networks were tested for robustness to input noise. Noise levels of plus or minus 10% had no real effect on the network performance. Noise levels in the plus or minus 30% range degraded performance by a factor of two. Some performance enhancement occurred when the networks were trained with noisy data. (5) The scaling of the evaluation time was calculated. (6) Human variation can be mimicked in all the networks by perturbing the weights.

  15. Plasma Turbulence and Stochastic Acceleration in Solar Flares

    E-Print Network [OSTI]

    Vahe Petrosian

    1999-11-18

    Observational aspects of solar flares relevant to the acceleration process of electrons and protons are reviewed and it is shown that most of these observations can be explained by the interaction with flare plasma of a power law energy distribution of electrons (and protons) that are injected at the top of a flaring loop, in the so-called thick target model. Some new observations that do not agree with this model are described and it is shown that these can be explained most naturally if most of the energy released by the reconnection process goes first into the generation of plasma turbulence, which accelerates, scatters and traps the ambient electrons near the top of the loop stochastically. The resultant bremsstrahlung photon spectral and spatial distributions agree with the new observations. This model is also justified by some theoretical arguments. Results from numerical evaluation of the spectra of the accelerated electrons and their bremsstrahlung emission are compared with observations and shown how one can constrain the model parameters describing the flare plasma and the spectrum and the energy density of the turbulence.

  16. Relative timing of solar flares observed at different wavelengths

    E-Print Network [OSTI]

    A. Veronig; B. Vrsnak; M. Temmer; A. Hanslmeier

    2002-08-05

    The timing of 503 solar flares observed simultaneously in hard X-rays, soft X-rays and H-alpha is analyzed. We investigated the start and the peak time differences in different wavelengths, as well as the differences between the end of the hard X-ray emission and the maximum of the soft X-ray and H-alpha emission. In more than 90% of the analyzed events, a thermal preheating seen in soft X-rays is present prior to the impulsive flare phase. On average, the soft X-ray emission starts 3 min before the hard X-ray and the H-alpha emission. No correlation between the duration of the preheating phase and the importance of the subsequent flare is found. Furthermore, the duration of the preheating phase does not differ for impulsive and gradual flares. For at least half of the events, the end of the nonthermal emission coincides well with the maximum of the thermal emission, consistent with the beam-driven evaporation model. On the other hand, for about 25% of the events there is strong evidence for prolonged evaporation beyond the end of the hard X-rays. For these events, the presence of an additional energy transport mechanism, most probably thermal conduction, seems to play an important role.

  17. Solar flare impulsive phase emission observed with SDO/EVE

    SciTech Connect (OSTI)

    Kennedy, Michael B.; Milligan, Ryan O.; Mathioudakis, Mihalis; Keenan, Francis P., E-mail: mkennedy29@qub.ac.uk [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN (United Kingdom)

    2013-12-10

    Differential emission measures (DEMs) during the impulsive phase of solar flares were constructed using observations from the EUV Variability Experiment (EVE) and the Markov-Chain Monte Carlo method. Emission lines from ions formed over the temperature range log T{sub e} = 5.8-7.2 allow the evolution of the DEM to be studied over a wide temperature range at 10 s cadence. The technique was applied to several M- and X-class flares, where impulsive phase EUV emission is observable in the disk-integrated EVE spectra from emission lines formed up to 3-4 MK and we use spatially unresolved EVE observations to infer the thermal structure of the emitting region. For the nine events studied, the DEMs exhibited a two-component distribution during the impulsive phase, a low-temperature component with peak temperature of 1-2 MK, and a broad high-temperature component from 7 to 30 MK. A bimodal high-temperature component is also found for several events, with peaks at 8 and 25 MK during the impulsive phase. The origin of the emission was verified using Atmospheric Imaging Assembly images to be the flare ribbons and footpoints, indicating that the constructed DEMs represent the spatially average thermal structure of the chromospheric flare emission during the impulsive phase.

  18. Coronal Trapping of Energetic Flare Particles: Yohkoh/HXT Observations

    E-Print Network [OSTI]

    Metcalf, Thomas R.

    the energization of the solar corona. The most common interpretation for the production of the observed HXR fluxes Alexander Lockheed Martin Solar and Astrophysics Laboratory, Department H1­12, Bldg. 252, 3251 Hanover St in a search for spectral evidence of the coronal trapping of energetic particles during solar flares. Two

  19. Simulations of the Mars ionosphere during a solar flare

    E-Print Network [OSTI]

    Withers, Paul

    .05.23 08:00-10:00 Spring AGU Meeting 2006, Acapulco, Mexico #12;Increased fluxes of X-rays during solarSimulations of the Mars ionosphere during a solar flare Paul Withers, Joei Wroten, Michael Mendillo simulations of the Mars ionosphere driven by temporally-varying solar fluxes, concentrating on 15 and 26 April

  20. Soft X-ray emission in flaring coronal loops

    E-Print Network [OSTI]

    Pinto, R F; Brun, A S

    2014-01-01

    Solar flares are associated with intense soft X-ray emission generated by the hot flaring plasma in coronal magnetic loops. Kink unstable twisted flux-ropes provide a source of magnetic energy which can be released impulsively and account for the heating of the plasma in flares. We investigate the temporal, spectral and spatial evolution of the properties of the thermal X-ray emission produced in such kink-unstable magnetic flux-ropes using a series of MHD simulations. We deduce emission diagnostics and their temporal evolution and discuss the results of the simulations with respect to observations. The numerical setup used consists of a highly twisted loop embedded in a region of uniform and untwisted background coronal magnetic field. We let the kink instability develop, compute the evolution of the plasma properties in the loop (density, temperature) and deduce the X-ray emission properties of the plasma during the whole flaring episode. During the initial phase of the instability plasma heating is mostly ...

  1. Solar flare electron acceleration: comparing theories and observations

    E-Print Network [OSTI]

    Arnold O. Benz; Pascal Saint-Hilaire

    2003-08-19

    A popular scenario for electron acceleration in solar flares is transit-time damping of low-frequency MHD waves excited by reconnection and its outflows. The scenario requires several processes in sequence to yield energetic electrons of the observed large number. Until now there was very little evidence for this scenario, as it is even not clear where the flare energy is released. RHESSI measurements of bremsstrahlung by non-thermal flare electrons yield energy estimates as well as the position where the energy is deposited. Thus quantitative measurements can be put into the frame of the global magnetic field configuration as seen in coronal EUV line observations. We present RHESSI observations combined with TRACE data that suggest primary energy inputs mostly into electron acceleration and to a minor fraction into coronal heating and primary motion. The more sensitive and lower energy X-ray observations by RHESSI have found also small events (C class) at the time of the acceleration of electron beams exciting meter wave Type III bursts. However, not all RHESSI flares involve Type III radio emissions. The association of other decimeter radio emissions, such as narrowband spikes and pulsations, with X-rays is summarized in view of electron acceleration

  2. Carbon Capture Research and Development

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B LReports from thecarbon capture faqs faq-header-big.jpgCapture

  3. MemTable: An integrated system for capture and recall of shared histories in group workspaces

    E-Print Network [OSTI]

    Hunter, Seth Edward

    This paper presents the design, implementation, and evaluation of an interactive tabletop system that supports co-located meeting capture and asynchronous search and review of past meetings. The goal of the project is to ...

  4. The Flare-energy Distributions Generated by Kink-unstable Ensembles of Zero-net-current Coronal Loops

    E-Print Network [OSTI]

    Bareford, M R; Van der Linden, R A M

    2011-01-01

    It has been proposed that the million degree temperature of the corona is due to the combined effect of barely-detectable energy releases, so called nanoflares, that occur throughout the solar atmosphere. Alas, the nanoflare density and brightness implied by this hypothesis means that conclusive verification is beyond present observational abilities. Nevertheless, we investigate the plausibility of the nanoflare hypothesis by constructing a magnetohydrodynamic (MHD) model that can derive the energy of a nanoflare from the nature of an ideal kink instability. The set of energy-releasing instabilities is captured by an instability threshold for linear kink modes. Each point on the threshold is associated with a unique energy release and so we can predict a distribution of nanoflare energies. When the linear instability threshold is crossed, the instability enters a nonlinear phase as it is driven by current sheet reconnection. As the ensuing flare erupts and declines, the field transitions to a lower energy sta...

  5. Geological Sequestration Training and Research Program in Capture and Transport: Development of the Most Economical Separation Method for CO2 Capture

    SciTech Connect (OSTI)

    Vahdat, Nader

    2013-09-30

    The project provided hands-on training and networking opportunities to undergraduate students in the area of carbon dioxide (CO2) capture and transport, through fundamental research study focused on advanced separation methods that can be applied to the capture of CO2 resulting from the combustion of fossil-fuels for power generation . The project team’s approach to achieve its objectives was to leverage existing Carbon Capture and Storage (CCS) course materials and teaching methods to create and implement an annual CCS short course for the Tuskegee University community; conduct a survey of CO2 separation and capture methods; utilize data to verify and develop computer models for CO2 capture and build CCS networks and hands-on training experiences. The objectives accomplished as a result of this project were: (1) A comprehensive survey of CO2 capture methods was conducted and mathematical models were developed to compare the potential economics of the different methods based on the total cost per year per unit of CO2 avoidance; and (2) Training was provided to introduce the latest CO2 capture technologies and deployment issues to the university community.

  6. The Mississippi CCS Project

    SciTech Connect (OSTI)

    Doug Cathro

    2010-09-30

    The Mississippi CCS Project is a proposed large-scale industrial carbon capture and sequestration (CCS) project which would have demonstrated advanced technologies to capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically, the Mississippi CCS Project was to accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petcoke to Substitute Natural Gas (SNG) plant that is selected for a Federal Loan Guarantee and would be the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Mississippi CCS Project was to promote the expansion of enhanced oil recovery (EOR) in the Mississippi, Alabama and Louisiana region which would supply greater energy security through increased domestic energy production. The capture, compression, pipeline, injection, and monitoring infrastructure would have continued to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project were expected to be fulfilled through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 included the studies that establish the engineering design basis for the capture, compression and transportation of CO{sub 2} from the MG SNG Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Soso oil field in Mississippi. The overall objective of Phase 2, was to execute design, construction and operations of three capital projects: the CO{sub 2} capture and compression equipment, the Mississippi CO{sub 2} Pipeline to Denbury's Free State Pipeline, and an MVA system at the Soso oil field.

  7. Air Capture Introduction and Overview

    E-Print Network [OSTI]

    largely eliminated centralized sources of CO2 emissions, especially at coal and natural gas power plants buildings and vehicles, which prove expensive to reduce by other means. It can be useful in niche CO2 first." It is much cheaper to capture CO2 from the flue gas of a coal power plant than from ambient air

  8. University of Leeds Lecture Capture

    E-Print Network [OSTI]

    Rzepa, Henry S.

    University of Leeds Lecture Capture As part of your study lectures will be recorded Recording for Educational Purposes (see http://www.leeds.ac.uk/secretariat/documents/0Audio (see http://www.leeds.ac.uk/secretariat/documents/ipr_policy.pdf) in general where staff or students

  9. 1 Introduction Synthetic motion capture

    E-Print Network [OSTI]

    Terzopoulos, Demetri

    animation of animals in virtual worlds, but at significant computational cost. Syn- thetic motion capture). Lifelike virtual animals naturally beckon active in- volvement, and one feels compelled to interact also form the basis of Miller's snakes and worms (Miller 1988), the virtual humans of Hodgins et al

  10. EA-1745: Final Environmental Assessment | Department of Energy

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

    Gas Flare Capture Project At The Arcelormittal USA, Inc. Indiana Harbor Steel Mill, East Chicago, Indiana, DOEEA-1745 (August 2010) More Documents & Publications EA-1745:...

  11. The optical flare and afterglow light curve of GRB 050904 at redshift z=6.29

    E-Print Network [OSTI]

    D. M. Wei; T. Yan; Y. Z. Fan

    2005-12-07

    GRB050904 is very interesting since it is by far the most distant GRB event known to date($z=6.29$). It was reported that during the prompt high energy emission phase, a very bright optical flare was detected, and it was temporal coincident with an X-ray flare. Here we use two models to explain the optical flare, One is the "late internal shock model", in which the optical flare is produced by the synchrotron radiation of the electrons accelerated by the late internal shock, and the X-ray flare is produced by the synchrotron-self-Compton mechanism. The other is the external forward-reverse shock model, in which the optical flare is from the reverse shock emission and the X-ray flare is attributed to the central engine activity. We show that with proper parameters, a bright optical flare can appear in both models. We think the "late internal shock model" is more favored since in this model the optical flash and the X-ray flare have the same origin, which provides a natural explanation of the temporal coincidence of them. In the forward-reverse shock scenario, fits to the optical flare and the late afterglow suggests that the physical parameters of the reverse shock are much different from that of forward shock, as found in modeling the optical flash of GRB 990123 previously.

  12. Lake Charles CCS Project

    SciTech Connect (OSTI)

    Leib, Thomas; Cole, Dan

    2015-06-30

    In late September 2014 development of the Lake Charles Clean Energy (LCCE) Plant was abandoned resulting in termination of Lake Charles Carbon Capture and Sequestration (CCS) Project which was a subset the LCCE Plant. As a result, the project was only funded through Phase 2A (Design) and did not enter Phase 2B (Construction) or Phase 2C (Operations). This report was prepared relying on information prepared and provided by engineering companies which were engaged by Leucadia Energy, LLC to prepare or review Front End Engineering and Design (FEED) for the Lake Charles Clean Energy Project, which includes the Carbon Capture and Sequestration (CCS) Project in Lake Charles, Louisiana. The Lake Charles Carbon Capture and Sequestration (CCS) Project was to be a large-scale industrial CCS project intended to demonstrate advanced technologies that capture and sequester carbon dioxide (CO2) emissions from industrial sources into underground formations. The Scope of work was divided into two discrete sections; 1) Capture and Compression prepared by the Recipient Leucadia Energy, LLC, and 2) Transport and Sequestration prepared by sub-Recipient Denbury Onshore, LLC. Capture and Compression-The Lake Charles CCS Project Final Technical Report describes the systems and equipment that would be necessary to capture CO2 generated in a large industrial gasification process and sequester the CO2 into underground formations. The purpose of each system is defined along with a description of its equipment and operation. Criteria for selection of major equipment are provided and ancillary utilities necessary for safe and reliable operation in compliance with environmental regulations are described. Construction considerations are described including a general arrangement of the CCS process units within the overall gasification project. A cost estimate is provided, delineated by system area with cost breakdown showing equipment, piping and materials, construction labor, engineering, and other costs. The CCS Project Final Technical Report is based on a Front End Engineering and Design (FEED) study prepared by SK E&C, completed in [June] 2014. Subsequently, Fluor Enterprises completed a FEED validation study in mid-September 2014. The design analyses indicated that the FEED package was sufficient and as expected. However, Fluor considered the construction risk based on a stick-build approach to be unacceptable, but construction risk would be substantially mitigated through utilization of modular construction where site labor and schedule uncertainty is minimized. Fluor’s estimate of the overall EPC project cost utilizing the revised construction plan was comparable to SKE&C’s value after reflecting Fluor’s assessment of project scope and risk characteristic. Development was halted upon conclusion of Phase 2A FEED and the project was not constructed.Transport and Sequestration – The overall objective of the pipeline project was to construct a pipeline to transport captured CO2 from the Lake Charles Clean Energy project to the existing Denbury Green Line and then to the Hastings Field in Southeast Texas to demonstrate effective geologic sequestration of captured CO2 through commercial EOR operations. The overall objective of the MVA portion of the project was to demonstrate effective geologic sequestration of captured CO2 through commercial Enhanced Oil Recovery (EOR) operations in order to evaluate costs, operational processes and technical performance. The DOE target for the project was to capture and implement a research MVA program to demonstrate the sequestration through EOR of approximately one million tons of CO2 per year as an integral component of commercial operations.

  13. High-Energy Gamma-Ray Emission From Solar Flares: Summary of Fermi LAT Detections and Analysis of Two M-Class Flares

    E-Print Network [OSTI]

    ,

    2013-01-01

    We present the detections of 19 solar flares detected in high-energy gamma rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first four years of operation. Interestingly, all flares are associated with fairly fast Coronal Mass Ejections (CMEs) and are not all powerful X-ray flares. We then describe the detailed temporal, spatial and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying gamma-ray emission over 13 hours, and the 2011 June 7 M2.5 flare, which was followed by gamma-ray emission lasting for 2 hours. We compare the Fermi-LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that a hadronic origin of the gamma rays is more likely than a leptonic origin and find that the energy spectrum of the proton distribution softens after the 2011 March 7 flare, favoring a scenario with continuous acceleration at the flare site. This work suggests that proton acceleratio...

  14. Fermi Solar Flare Observations We propose to continue and expand our work over the last three years to make Fermi solar flare

    E-Print Network [OSTI]

    Nishikawa, Ken-Ichi

    1 Fermi Solar Flare Observations 1. Summary We propose to continue and expand our work over the last three years to make Fermi solar flare data readily available for analysis by the international solar physics community. The two-year time frame of the proposed effort is extremely important for solar

  15. Composite Membranes for CO2 Capture: High Performance Metal Organic Frameworks/Polymer Composite Membranes for Carbon Dioxide Capture

    SciTech Connect (OSTI)

    2010-07-01

    IMPACCT Project: A team of six faculty members at Georgia Tech are developing an enhanced membrane by fitting metal organic frameworks, compounds that show great promise for improved carbon capture, into hollow fiber membranes. This new material would be highly efficient at removing CO2 from the flue gas produced at coal-fired power plants. The team is analyzing thousands of metal organic frameworks to identify those that are most suitable for carbon capture based both on their ability to allow coal exhaust to pass easily through them and their ability to select CO2 from that exhaust for capture and storage. The most suitable frameworks would be inserted into the walls of the hollow fiber membranes, making the technology readily scalable due to their high surface area. This composite membrane would be highly stable, withstanding the harsh gas environment found in coal exhaust.

  16. CO2 Capture with Liquid-to-Solid Absorbents: CO2 Capture Process Using Phase-Changing Absorbents

    SciTech Connect (OSTI)

    2010-10-01

    IMPACCT Project: GE and the University of Pittsburgh are developing a unique CO2 capture process in which a liquid absorbent, upon contact with CO2, changes into a solid phase. Once in solid form, the material can be separated and the CO2 can be released for storage by heating. Upon heating, the absorbent returns to its liquid form, where it can be reused to capture more CO2. The approach is more efficient than other solventbased processes because it avoids the heating of extraneous solvents such as water. This ultimately leads to a lower cost of CO2 capture and will lower the additional cost to produce electricity for coal-fired power plants that retrofit their facilities to include this technology.

  17. Capture Gamma-Ray Libraries for Nuclear Applications

    SciTech Connect (OSTI)

    Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

    2010-05-01

    The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90percent of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

  18. Natural materials for carbon capture.

    SciTech Connect (OSTI)

    Myshakin, Evgeniy M.; Romanov, Vyacheslav N.; Cygan, Randall Timothy

    2010-11-01

    Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

  19. The consequences of failure should be considered in siting geologic carbon sequestration projects

    E-Print Network [OSTI]

    Price, P.N.

    2009-01-01

    2007. Geologic Carbon Sequestration Strategies forfor carbon capture and sequestration. Environmental Sciencein Siting Geologic Carbon Sequestration Projects Phillip N.

  20. Discovery of 6.035GHz Hydroxyl Maser Flares in IRAS18566+0408

    E-Print Network [OSTI]

    Al-Marzouk, A A; Hofner, P; Kurtz, S; Linz, H; Olmi, L

    2012-01-01

    We report the discovery of 6.035GHz hydroxyl (OH) maser flares toward the massive star forming region IRAS18566+0408 (G37.55+0.20), which is the only region known to show periodic formaldehyde (4.8 GHz H2CO) and methanol (6.7 GHz CH3OH) maser flares. The observations were conducted between October 2008 and January 2010 with the 305m Arecibo Telescope in Puerto Rico. We detected two flare events, one in March 2009, and one in September to November 2009. The OH maser flares are not simultaneous with the H2CO flares, but may be correlated with CH3OH flares from a component at corresponding velocities. A possible correlated variability of OH and CH3OH masers in IRAS18566+0408 is consistent with a common excitation mechanism (IR pumping) as predicted by theory.

  1. DISCOVERY OF 6.035 GHz HYDROXYL MASER FLARES IN IRAS 18566+0408

    SciTech Connect (OSTI)

    Al-Marzouk, A. A.; Araya, E. D.; Hofner, P.; Kurtz, S.; Linz, H.; Olmi, L.

    2012-05-10

    We report the discovery of 6.035 GHz hydroxyl (OH) maser flares toward the massive star-forming region IRAS 18566+0408 (G37.55+0.20), which is the only region known to show periodic formaldehyde (4.8 GHz H{sub 2}CO) and methanol (6.7 GHz CH{sub 3}OH) maser flares. The observations were conducted between 2008 October and 2010 January with the 305 m Arecibo Telescope in Puerto Rico. We detected two flare events, one in 2009 March and one in 2009 September to November. The OH maser flares are not simultaneous with the H{sub 2}CO flares, but may be correlated with CH{sub 3}OH flares from a component at corresponding velocities. A possible correlated variability of OH and CH{sub 3}OH masers in IRAS 18566+0408 is consistent with a common excitation mechanism (IR pumping) as predicted by theory.

  2. Return currents and energy transport in the solar flaring atmosphere

    E-Print Network [OSTI]

    Codispoti, Anna; Piana, Michele; Pinamonti, Nicola

    2013-01-01

    According to a standard ohmic perspective, the injection of accelerated electrons into the flaring region violates local charge equilibrium and therefore, in response, return currents are driven by an electric field to equilibrate such charge violation. In this framework, the energy loss rate associated to these local currents has an ohmic nature and significantly shortens the acceleration electron path. In the present paper we adopt a different viewpoint and, specifically, we study the impact of the background drift velocity on the energy loss rate of accelerated electrons in solar flares. We first utilize the Rutherford cross-section to derive the formula of the energy loss rate when the collisional target has a finite temperature and the background instantaneously and coherently moves up to equilibrate the electron injection. We then use the continuity equation for electrons and imaging spectroscopy data provided by RHESSI to validate this model. Specifically, we show that this new formula for the energy l...

  3. The Acceleration of Ions in Solar Flares During Magnetic Reconnection

    E-Print Network [OSTI]

    Knizhnik, Kalman; Drake, James F

    2011-01-01

    The acceleration of solar flare ions during magnetic reconnection is explored via particle-in-cell simulations that self-consistently follow the motions of both protons and $\\alpha$ particles. We demonstrate that the dominant ion heating during reconnection with a guide field (a magnetic component perpendicular to the reconnection plane) results from pickup behavior during the entry into reconnection exhausts. In contrast with anti-parallel reconnection, the temperature increment is dominantly transverse, rather than parallel, to the local magnetic field. The comparison of protons and alphas reveals a mass-to-charge ($M/Q$) threshold in pickup behavior that favors heating of high $M/Q$ ions over protons, which is consistent with impulsive flare observations.

  4. Slow Magnetoacoustic Oscillations in the Microwave Emission of Solar Flares

    E-Print Network [OSTI]

    Kim, Sujin; Shibasaki, K

    2013-01-01

    Analysis of the microwave data, obtained in the 17 GHz channel of the Nobeyama Radioheliograph during the M1.6 flare on 4th Nov 2010, revealed the presence of 11.8-min oscillations of the emitting plasma density. The oscilla- tions decayed with the characteristic time of about 25-min. These oscillations are also well-seen in the variation of EUV emission intensity measured in the 335 A channel of SDO/AIA. The observed properties of the oscillations are consistent with the properties of so-called SUMER oscillations, observed in the EUV and soft X-ray bands usually as a periodic Doppler shift. The accepted interpretation of SUMER oscillations is a standing slow magnetoacoustic wave. Our analysis presents the first direct observation of the slow magnetoacoustic oscillations in the microwave emission of a solar flare.

  5. Max '91: flare research at the next solar maximum

    SciTech Connect (OSTI)

    Dennis, B.; Canfield, R.; Bruner, M.; Emslie, G.; Hildner, E.; Hudson, H.; Hurford, G.; Lin, R.; Novick, R.; Tarbell, T.

    1988-01-01

    To address the central scientific questions surrounding solar flares, coordinated observations of electromagnetic radiation and energetic particles must be made from spacecraft, balloons, rockets, and ground-based observatories. A program to enhance capabilities in these areas in preparation for the next solar maximum in 1991 is recommended. The major scientific issues are described, and required observations and coordination of observations and analyses are detailed. A program plan and conceptual budgets are provided.

  6. Recovering Flare Gas Energy - A Different Approach 

    E-Print Network [OSTI]

    Brenner, W.

    1987-01-01

    pressure drop burner for the boiler. We were able to settle on an operating range of 1 to 1.5 psig. This is a safe range and required a minimum. of safety valve re-ratings. A manufacturer was found who produces a low pressure drop burner capable... of firing at the rates we required. The burner can also be fired with natural gas. A preliminary P & I drawing was then prepared so that a Ha.zard and Operability Study (HAZOP) could be made on the entire project. We were then able to develop a final...

  7. Notes of frequency of occurence and energetics of the solar-type stellar flares

    E-Print Network [OSTI]

    Gershberg, R E

    2015-01-01

    On the basis of the 30-year ago ground-based photometry and the recent Kepler space experiment there have been considered frequencies of occurrence and energetics of the solar-type stellar flares. It was concluded that frequencies of occurrence of such flares are proportional to sizes of stellar surfaces, and estimates of maximum flare radiation from the results of the ground-based photometry and space observations practically coincide.

  8. HARD X-RAY AND MICROWAVE FLUX SPECTRA OF THE 2 NOVEMBER 1991 SOLAR FLARE

    E-Print Network [OSTI]

    HARD X-RAY AND MICROWAVE FLUX SPECTRA OF THE 2 NOVEMBER 1991 SOLAR FLARE CHIK-YIN LEE1,2 and HAIMIN analysed the hard X-ray and microwave flux spectra of the solar flare (BATSE No. 1791) on 2 November 1991 for this study. This paper studies the hard X-ray and microwave spectra of the solar flare on 2 November 1991

  9. Seismic Emissions from a Highly Impulsive M6.7 Solar Flare

    E-Print Network [OSTI]

    J. C. Martinez-Oliveros; H. Moradi; A-C. Donea

    2008-01-09

    On 10 March 2001 the active region NOAA 9368 produced an unusually impulsive solar flare in close proximity to the solar limb. This flare has previously been studied in great detail, with observations classifying it as a type 1 white-light flare with a very hard spectrum in hard X-rays. The flare was also associated with a type II radio burst and coronal mass ejection. The flare emission characteristics appeared to closely correspond with previous instances of seismic emission from acoustically active flares. Using standard local helioseismic methods, we identified the seismic signatures produced by the flare that, to date, is the least energetic (in soft X-rays) of the flares known to have generated a detectable acoustic transient. Holographic analysis of the flare shows a compact acoustic source strongly correlated with the impulsive hard X-ray, visible continuum, and radio emission. Time-distance diagrams of the seismic waves emanating from the flare region also show faint signatures, mainly in the eastern sector of the active region. The strong spatial coincidence between the seismic source and the impulsive visible continuum emission reinforces the theory that a substantial component of the seismic emission seen is a result of sudden heating of the low photosphere associated with the observed visible continuum emission. Furthermore, the low-altitude magnetic loop structure inferred from potential--field extrapolations in the flaring region suggests that there is a significant inverse correlation between the seismicity of a flare and the height of the magnetic loops that conduct the particle beams from the corona.

  10. Extremely Large EUV Late Phase of Solar Flares

    E-Print Network [OSTI]

    Liu, Kai; Zhang, Jie; Cheng, Xin; Liu, Rui; Shen, Chenglong

    2015-01-01

    The second peak in the Fe XVI 33.5 nm line irradiance observed during solar flares by Extreme ultraviolet Variability Experiment (EVE) is known as Extreme UltraViolet (EUV) late phase. Our previous paper (Liu et al. 2013) found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different from the post flare loops (PFLs), and we also proposed that a long cooling process without additional heating could explain the late phase. In this paper, we define the extremely large late phase because it not only has a bigger peak in the warm 33.5 irradiance profile, but also releases more EUV radiative energy than the main phase. Through detailedly inspecting the EUV images from three point-of-view, it is found that, besides the later phase loop arcades, the more contribution of the extremely large late phase is from a hot structure that fails to erupt. This hot structure is identified as a flux rope, which is quickly energized by the flare reconnection...

  11. Interacting CMEs and their associated flare and SEP activities

    E-Print Network [OSTI]

    Shanmugaraju, A

    2015-01-01

    We have analyzed a set of 25 interacting events which are associated with the DH type II bursts. These events are selected from the Coronal Mass Ejections observed during the period 1997-2010 in SOHO/LASCO and DH type IIs in Wind/WAVES. Their pre and primary CMEs from nearby active regions are identified using LASCO and EIT images and their height-time diagrams. Their interacting time and height are obtained, and their associated activities, such as, flares and solar energetic particles (>10pfu) are also investigated. Results from the analysis are: primary CMEs are much faster than the pre-CMEs, their X-ray flares are also stronger (X and M class) compared to the flares (C and M class) of pre-CMEs. Most of the events occurred during the period 2000-2006. From the observed width and speed of pre and primary CMEs, the pre-CMEs are found to be less energetic than the primary CMEs. While the primary CMEs are tracked up to the end of LASCO field of view, most of the pre-CMEs are tracked up to < 26Rs. The SEP in...

  12. Magnetic Energy Dissipation during the 2014 March 29 Solar Flares

    E-Print Network [OSTI]

    Aschwanden, Markus J

    2015-01-01

    We calculated the time evolution of the free magnetic energy during the 2014-Mar-29 flare (SOL2014-03-29T17:48), the first X-class flare detected by IRIS. The free energy was calculated from the difference between the nonpotential field, constrained by the geometry of observed loop structures, and the potential field. We use AIA/SDO and IRIS images to delineate the geometry of coronal loops in EUV wavelengths, as well as to trace magnetic field directions in UV wavelengths in the chromosphere and transition region. We find an identical evolution of the free energy for both the coronal and chromospheric tracers, as well as agreement between AIA and IRIS results, with a peak free energy of $E_{free}(t_{peak}) \\approx (45 \\pm 2) \\times 10^{30}$ erg, which decreases by an amount of $\\Delta E_{free} \\approx (29 \\pm 3) \\times 10^{30}$ erg during the flare decay phase. The consistency of free energies measured from different EUV and UV wavelengths for the first time here, demonstrates that vertical electric currents...

  13. The spectral evolution of impulsive solar X-ray flares

    E-Print Network [OSTI]

    Paolo C. Grigis; Arnold O. Benz

    2004-07-20

    The time evolution of the spectral index and the non-thermal flux in 24 impulsive solar hard X-ray flares of GOES class M was studied in RHESSI observations. The high spectral resolution allows for a clean separation of thermal and non-thermal components in the 10-30 keV range, where most of the non-thermal photons are emitted. Spectral index and flux can thus be determined with much better accuracy than before. The spectral soft-hard-soft behavior in rise-peak-decay phases is discovered not only in the general flare development, but even more pronounced in subpeaks. An empirically found power-law dependence between the spectral index and the normalization of the non-thermal flux holds during the rise and decay phases of the emission peaks. It is still present in the combined set of all flares. We find an asymmetry in this dependence between rise and decay phases of the non-thermal emission. There is no delay between flux peak and spectral index minimum. The soft-hard-soft behavior appears to be an intrinsic signature of the elementary electron acceleration process.

  14. Looptop Hard X-Ray Emission in Solar Flares: Images and Statistics

    E-Print Network [OSTI]

    Vahe' Petrosian; Timothy Q. Donaghy; James M. McTiernan

    2001-12-14

    The discovery of hard X-ray sources near the top of a flaring loop by the HXT instrument on board the YOHKOH satellite represents a significant progress towards the understanding of the basic processes driving solar flares. In this paper we extend the previous study of limb flares by Masuda (1994) by including all YOHKOH observations up through August 1998. We report that from October 1991 to August 1998, YOHKOH observed 20 X-ray bright limb flares (where we use the same selection criteria as Masuda), of which we have sufficient data to analyze 18 events, including 8 previously unanalyzed flares. Of these 18 events, 15 show detectable impulsive looptop emission. Considering that the finite dynamic range (about a decade) of the detection introduces a strong bias against observing comparatively weak looptop sources, we conclude that looptop emission is a common feature of all flares. We summarize the observations of the footpoint to looptop flux ratio and the spectral indices. We present light curves and images of all the important newly analyzed limb flares. Whenever possible we present results for individual pulses in multipeak flares and for different loops for multiloop flares. We then discuss the statistics of the fluxes and spectral indices of the looptop and footpoint sources taking into account observational selection biases. The importance of these observations (and those expected from the scheduled HESSI satellite with its superior angular spectral and temporal resolution) in constraining acceleration models and parameters is discussed briefly.

  15. Observation of solar flares through the ART-P telescope side shield

    E-Print Network [OSTI]

    A. Lutovinov; M. Pavlinsky; S. Grebenev

    2001-06-13

    Some preliminary results of observations of six solar flares though the ART-P telescop side shield in 1990-1992 are presented.

  16. Space weather effects on the Mars ionosphere due to solar flares and

    E-Print Network [OSTI]

    Withers, Paul

    Space weather effects on the Mars ionosphere due to solar flares and meteors Paul Withers1, Michael in the ionospheric response to these aspects of space weather. #12;

  17. Bench-Scale Process for Low-Cost Carbon Dioxide (CO2) Capture Using a Phase-Changing Absorbent

    SciTech Connect (OSTI)

    Westendorf, Tiffany; Caraher, Joel; Chen, Wei; Farnum, Rachael; Perry, Robert; Spiry, Irina; Wilson, Paul; Wood, Benjamin

    2015-03-31

    The objective of this project is to design and build a bench-scale process for a novel phase-changing aminosilicone-based CO2-capture solvent. The project will establish scalability and technical and economic feasibility of using a phase-changing CO2-capture absorbent for post-combustion capture of CO2 from coal-fired power plants with 90% capture efficiency and 95% CO2 purity at a cost of $40/tonne of CO2 captured by 2025 and a cost of <$10/tonne of CO2 captured by 2035. In the first budget period of this project, the bench-scale phase-changing CO2 capture process was designed using data and operating experience generated under a previous project (ARPA-e project DE-AR0000084). Sizing and specification of all major unit operations was completed, including detailed process and instrumentation diagrams. The system was designed to operate over a wide range of operating conditions to allow for exploration of the effect of process variables on CO2 capture performance.

  18. Carbon Capture and Storage, 2008

    SciTech Connect (OSTI)

    2009-03-19

    The U.S. Department of Energy is researching the safe implementation of a technology called carbon sequestration, also known as carbon capture and storage, or CCS. Based on an oilfield practice, this approach stores carbon dioxide, or CO2 generated from human activities for millennia as a means to mitigate global climate change. In 2003, the Department of Energys National Energy Technology Laboratory formed seven Regional Carbon Sequestration Partnerships to assess geologic formations suitable for storage and to determine the best approaches to implement carbon sequestration in each region. This video describes the work of these partnerships.

  19. Carbon Capture and Storage, 2008

    ScienceCinema (OSTI)

    None

    2010-01-08

    The U.S. Department of Energy is researching the safe implementation of a technology called carbon sequestration, also known as carbon capture and storage, or CCS. Based on an oilfield practice, this approach stores carbon dioxide, or CO2 generated from human activities for millennia as a means to mitigate global climate change. In 2003, the Department of Energys National Energy Technology Laboratory formed seven Regional Carbon Sequestration Partnerships to assess geologic formations suitable for storage and to determine the best approaches to implement carbon sequestration in each region. This video describes the work of these partnerships.

  20. Hydropower Projects

    SciTech Connect (OSTI)

    2015-04-02

    The Water Power Program helps industry harness this renewable, emissions-free resource to generate environmentally sustainable and cost-effective electricity. Through support for public, private, and nonprofit efforts, the Water Power Program promotes the development, demonstration, and deployment of advanced hydropower devices and pumped storage hydropower applications. These technologies help capture energy stored by diversionary structures, increase the efficiency of hydroelectric generation, and use excess grid energy to replenish storage reserves for use during periods of peak electricity demand. In addition, the Water Power Program works to assess the potential extractable energy from domestic water resources to assist industry and government in planning for our nation’s energy future. From FY 2008 to FY 2014, DOE’s Water Power Program announced awards totaling approximately $62.5 million to 33 projects focused on hydropower. Table 1 provides a brief description of these projects.

  1. Robust Aerial Object Tracking in Images with Lens Flare Andreas Nussberger1, Helmut Grabner1 and Luc Van Gool1

    E-Print Network [OSTI]

    Grabner, Helmut

    often result in a high number of false detections. Depending on the solar radiation lens flares are very the date, time, position and attitude of the observer we predict the lens flare direction within the image

  2. Breakthrough Large-Scale Industrial Project Begins Carbon Capture...

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

    one of the company's steam methane reformers using a gas-separation technology called "vacuum swing adsorption." After compression and drying, the CO2 purity is greater than 97...

  3. CO2 Capture and Storage Project, Education and Training Center...

    Energy Savers [EERE]

    Addthis The new National Sequestration Education Center (NSEC) is a 15,000 square-foot sustainably designed center that will contain classrooms and training and laboratory...

  4. DOE Selects 16 Transformational Carbon Capture Technologies Projects...

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

    Corporation (Woburn, MA), and Trimeric Corporation (Buda, TX) - will combine a graphene oxide (GO) membrane unit with the polyether ether ketone (PEEK) hollow fiber membrane...

  5. Second Phase of Innovative Technology Project to Capture CO2...

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

    help reduce greenhouse gas emissions and provide a source of liquid biofuels and biogas, reducing U.S. dependence on foreign energy sources. Touchstone Research Laboratory in...

  6. Grangemouth Advanced CO2 Capture Project GRACE | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainableGlynn County, Georgia: EnergyGorlitzLedge,Ohio: Energy Resources

  7. DOE Selects 16 Transformational Carbon Capture Technologies Projects for

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i pStateDOE FederalThe DepartmentEnergyends inTechnicalFunding |

  8. Breakthrough Large-Scale Industrial Project Begins Carbon Capture and

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De pEnergy Industrialof Energy 7:30PM PDT

  9. DOE Signs Cooperative Agreement for Carbon Capture Project | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based| Department8, 2015 GATEWAY Takes onand CoalDepartment ofDepartment

  10. Energy Department Sponsored Project Captures One Millionth Metric Ton of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12, 2015 Infographic courtesy ofDepartmentPortland PublicCyclingCO2 | Department

  11. Industrial Carbon Capture Project Selections | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergy HeadquartersFuelBConservation StandardsEnergy In2008DepartmentIndustrial Carbon

  12. World's Largest Post-Combustion Carbon Capture Project Begins

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann JacksonDepartment| Department of EnergyDataWindof Energy Scott Minos Office

  13. Tribal Ownership & Capturing the Government Tax Base - 3 Projects

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996HowFOAShowing YouNeed forUnruhDepartment ofM I C H A E L C O N N O L L Y

  14. Worldwide Carbon Capture and Storage Projects on the Increase | Department

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996HowFOAShowingFuelWeatherize »EvePlant |MetLifeWorkshop Report :Airportof

  15. Energy Department Investments in Innovative Carbon Capture Projects |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansasCommunities Energy Efficiency Competition |Natural GasMeet

  16. DOE-Supported Project Advances Clean Coal, Carbon Capture Technology |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann JacksonDepartment ofOffice ofof Energy Brad Bugger 208-526-083315January

  17. Breakthrough Industrial Carbon Capture, Utilization and Storage Project

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann JacksonDepartment|Marketing, LLC |Energycurrently providesDepartment ofAwards |Begins

  18. The Impulsive Phase in Solar Flares: Recent Multi-wavelength Results and their Implications for Microwave Modeling and Observations

    E-Print Network [OSTI]

    Fletcher, Lyndsay

    2013-01-01

    This short paper reviews several recent key observations of the processes occurring in the lower atmosphere (chromosphere and photosphere) during flares. These are: evidence for compact and fragmentary structure in the flare chromosphere, the conditions in optical flare footpoints, step-like variations in the magnetic field during the flare impulsive phase, and hot, dense 'chromospheric' footpoints. The implications of these observations for microwaves are also discussed.

  19. The Lake Charles CCS Project

    SciTech Connect (OSTI)

    Doug Cathro

    2010-06-30

    The Lake Charles CCS Project is a large-scale industrial carbon capture and sequestration (CCS) project which will demonstrate advanced technologies that capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically the Lake Charles CCS Project will accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petroleum coke to chemicals plant (the LCC Gasification Project) and the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Lake Charles CCS Project will promote the expansion of EOR in Texas and Louisiana and supply greater energy security by expanding domestic energy supplies. The capture, compression, pipeline, injection, and monitoring infrastructure will continue to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project are expected to be fulfilled by working through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 includes the studies attached hereto that will establish: the engineering design basis for the capture, compression and transportation of CO{sub 2} from the LCC Gasification Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Hastings oil field in Texas. The overall objective of Phase 2, provided a successful competitive down-selection, is to execute design, construction and operations of three capital projects: (1) the CO{sub 2} capture and compression equipment, (2) a Connector Pipeline from the LLC Gasification Project to the Green Pipeline owned by Denbury and an affiliate of Denbury, and (3) a comprehensive MVA system at the Hastings oil field.

  20. Temporal Evolution of Free Magnetic Energy Associated with Four X-class Flares

    E-Print Network [OSTI]

    energy for much of the solar activity such as flares and coronal mass ejections (CMEs)(see, for review magnetic configuration for conversion into kinetic and/or thermal energy) and its temporal variationTemporal Evolution of Free Magnetic Energy Associated with Four X-class Flares Ju Jing1 , P. F

  1. A SOLAR FLARE MODEL IN BETWEEN MHD AND CELLULAR AUTOMATON* Heinz Isliker1

    E-Print Network [OSTI]

    Anastasiadis, Anastasios

    ) and the reproduction of the observed solar flare statistics. On the other hand the energy release process has been to explain the solar flare statistics derived from observations. These models simulate the storage of this approach is the treatment of a large number of elementary energy release events (avalanches

  2. ACCELERATION AND ENRICHMENT OF 3 IMPULSIVE SOLAR FLARES BY ELECTRON FIREHOSE

    E-Print Network [OSTI]

    ACCELERATION AND ENRICHMENT OF 3 He IN IMPULSIVE SOLAR FLARES BY ELECTRON FIREHOSE WAVES G. Paesold A new mechanism for acceleration and enrichment of 3 He during impulsive solar flares is presented. Low of the free energy stored in a temperature anisotropy (Te > Te ) of the bulk energized electron population

  3. TRACE and YOHKOH Observations of a White Light Flare Thomas R. Metcalf1

    E-Print Network [OSTI]

    Metcalf, Thomas R.

    . Hudson 2 , and Dana W. Longcope3 ABSTRACT We present observations of a large solar white light flare at 400 km s-1 . This is evidence in favor of particle acceleration models which energize the electrons), are typically the most energetic of solar flares. "White light" refers to continuum emission in excess

  4. HARD X-RAY EMISSIONS FROM PARTIALLY OCCULTED SOLAR FLARES Sam Krucker1

    E-Print Network [OSTI]

    California at Berkeley, University of

    HARD X-RAY EMISSIONS FROM PARTIALLY OCCULTED SOLAR FLARES Sa¨m Krucker1 and R. P. Lin1,2 krucker occulted by the solar limb provide diagnostics of coronal hard X-ray (HXR) emissions in the absence of generally much brighter emissions from footpoints of flare loops. In this paper, a statis- tical survey

  5. Extended decimeter radio emission after large solar flares A.O. Benz a,*, H. Perret a

    E-Print Network [OSTI]

    California at Berkeley, University of

    by extremely intense radio emissions at decimeter wave- lengths. The radio emission continued long afterExtended decimeter radio emission after large solar flares A.O. Benz a,*, H. Perret a , P. Saint; accepted 19 September 2005 Abstract The large solar flares of October and November 2003 were accompanied

  6. Electron-Electron Bremsstrahlung Emission and the Inference of Electron Flux Spectra in Solar Flares

    E-Print Network [OSTI]

    Piana, Michele

    to the hard X-ray emission from solar flares, the latter is normally ignored. Such an omission in the study of hard X-ray spectra from solar flares. With the high-resolution hard X- ray spectra madeElectron-Electron Bremsstrahlung Emission and the Inference of Electron Flux Spectra in Solar

  7. Longrange magnetic couplings between solar flares and coronal mass ejections observed by SDO

    E-Print Network [OSTI]

    Schrijver, Karel

    Longrange magnetic couplings between solar flares and coronal mass ejections observed by SDO between solar flares and coronal mass ejections observed by SDO and STEREO, J. Geophys. Res., 116, A04108 to view much of the solar surface and atmosphere simultaneously and continuously. These nearglobal

  8. Thermodynamic Spectrum of Solar Flares Based on SDO/EVE Observations: Techniques and First Results

    E-Print Network [OSTI]

    Wang, Yuming; Zhang, Jie; Liu, Kai; Liu, Rui; Shen, Chenglong; Chamberlin, Phillip C

    2015-01-01

    SDO/EVE provide rich information of the thermodynamic processes of solar activities, particularly of solar flares. Here, we develop a method to construct thermodynamic spectrum (TDS) charts based on the EVE spectral lines. Reading from the charts, we are able to easily recognize if there is a late phase following a main phase of a flare, and able to learn the begin, peak and end times of the flare as well as the drift of the temperature, i.e., the cooling rate, of the heated plasma during the flare. Through four M-class flares of different types, we illustrate which thermodynamic information can be revealed from the TDS charts. Further, we investigate the TDS charts of all the flares greater than M5.0, and some interesting results are achieved. First, there are two distinct drift patterns, called Type I and Type II. For Type I flares, the enhanced emission drifts from high to low temperture, whereas for Type II flares, the drift is somewhat reversed, suggesting a more violent and durable heating during Type I...

  9. NEUTRON AND ELECTROMAGNETIC EMISSIONS DURING THE 1990 MAY 24 SOLAR FLARE

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    NEUTRON AND ELECTROMAGNETIC EMISSIONS DURING THE 1990 MAY 24 SOLAR FLARE L. G. KOCHAROV,* JEONGWOO revised form 15 July, 1994) Abstract. In this paper, we are primarilyconcerned with the solar neutron emission during the 1990 May 24 flare, utilizing the counting rate of the Climax neutron monitor

  10. Calibrated Estimates of the Energy in Major Flares of GRS 1915+105

    E-Print Network [OSTI]

    Punsly, Brian

    2013-01-01

    We analyze the energetics of the major radio flare of October 8 2005 in GRS 1915+105. The flare is of particular interest because it is one of the most luminous and energetic radio flares from a Galactic black hole that has ever been observed. The motivation is two-fold. One, to learn more about the energetics of this most extreme phenomenon and its relationship to the accretion state. The second is to verify if the calibrated estimates of the energy of major radio flares (based on the peak low frequency optically thin flux) derived from flares in the period 1996-2001 in Punsly & Rodriguez (2013), PR13 hereafter, can be used to estimate plasmoid energy beyond this time period. We find evidence that the calibrated curves are still accurate for this strong flare. Furthermore, the physically important findings of PR13 are supported by the inclusion of this flare: the flare energy is correlated with both the intrinsic bolometric X-ray luminosity, $L_{\\mathrm{bol}}$, $\\sim 1$ hour before ejection and $L_{\\math...

  11. Return currents and energy transport in the solar flaring Anna Codispoti1

    E-Print Network [OSTI]

    Piana, Michele

    Return currents and energy transport in the solar flaring atmosphere Anna Codispoti1 ,Gabriele electrons in solar flares. We first utilize the Rutherford cross-section to derive the formula of the energy for the energy loss rate provides a better fit of the experimental data with respect to the model based

  12. MICROWAVE AND HARD XRAY OBSERVATIONS OF FOOTPOINT EMISSION FROM SOLAR FLARES

    E-Print Network [OSTI]

    White, Stephen

    MICROWAVE AND HARD X­RAY OBSERVATIONS OF FOOTPOINT EMISSION FROM SOLAR FLARES M. R. KUNDU Dept radio and X­ray imaging data for two solar flares in order to test the idea that asymmetric microwaves and hard x­rays (HXR) has been known to exist for a long time. This connection is manifested

  13. Free Magnetic Energy and Flare Productivity of Active Regions , Changyi Tan2,3

    E-Print Network [OSTI]

    Free Magnetic Energy and Flare Productivity of Active Regions Ju Jing1 , Changyi Tan2,3 , Yuan Yuan with which we are able to estimate the free magnetic energy stored in the active regions. The magnitude scaling correlation between the free magnetic energy and the soft X-ray flare index of active regions

  14. Seismic Emissions from a Highly Impulsive M6.7 Solar Flare

    E-Print Network [OSTI]

    California at Berkeley, University of

    Seismic Emissions from a Highly Impulsive M6.7 Solar Flare J.C. Mart´inez-Oliveros, H. Moradi, A characteristics appeared to closely correspond with previous instances of seismic emission from acoustically active flares. Using standard local helioseismic methods, we identified the seismic sig- natures produced

  15. Large Solar Flares and their Ionospheric D-region Enhancements Neil R. Thomson and Craig J. Rodger

    E-Print Network [OSTI]

    Otago, University of

    1 Large Solar Flares and their Ionospheric D-region Enhancements Neil R. Thomson and Craig J Division, British Antarctic Survey, Cambridge, UK On 4 November 2003, the largest solar flare ever recorded solar flares the X-ray flux received at the Earth increases dramatically, often within a few minutes

  16. ELECTRON FLUX SPECTRAL IMAGING OF SOLAR FLARES THROUGH REGULARIZED ANALYSIS OF HARD X-RAY SOURCE VISIBILITIES

    E-Print Network [OSTI]

    Piana, Michele

    ELECTRON FLUX SPECTRAL IMAGING OF SOLAR FLARES THROUGH REGULARIZED ANALYSIS OF HARD X-RAY SOURCE a new method for imaging spectroscopy analysis of hard X-ray emission during solar flares. The method the method to a solar flare observed on 2002 February 20 by the RHESSI instrument. The event is characterized

  17. STEREOSCOPIC OBSERVATIONS OF THE HARD X-RAY SOURCE IN THE GIANT SOLAR FLARE ON 2003 NOVEMBER 4

    E-Print Network [OSTI]

    McTiernan, James M.

    STEREOSCOPIC OBSERVATIONS OF THE HARD X-RAY SOURCE IN THE GIANT SOLAR FLARE ON 2003 NOVEMBER 4 S. R Received 2004 June xx; accepted 2004 xxxx xx ABSTRACT The hard X-ray source in the "giant" solar flare on 4 indicated that, in each of the eleven solar flares, the 20 keV non-thermal electrons at the Sun dissipated

  18. Global analysis of active longitudes of solar X-ray flares L. Zhang a,b,c

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    Global analysis of active longitudes of solar X-ray flares L. Zhang a,b,c , K. Mursula a,Ă, I: Solar X-rays Flares Active longitudes a b s t r a c t There is increasing evidence that various called active longitudes. We have earlier analyzed the longitudinal occurrence of solar X-ray flares

  19. Solar Physics with Radio Observations, Proceedings of Nobeyama Symposium 1998, NRO Report Millimeter Interferometer Observations of Flares

    E-Print Network [OSTI]

    White, Stephen

    the current state of millimeter interferometry of solar flares and the issues which can be addressedV--energy electrons in the impulsive phase of solar flares as well as from hot dense plasma in the thermal decay phase. BIMA now consists of 10 antennas and is capable of snapshot imaging of solar flares with excellent

  20. SOLAR FLARE ELEMENT ABUNDANCES FROM THE SOLAR ASSEMBLY FOR X-RAYS (SAX) ON Brian R. Dennis1

    E-Print Network [OSTI]

    Nittler, Larry R.

    SOLAR FLARE ELEMENT ABUNDANCES FROM THE SOLAR ASSEMBLY FOR X-RAYS (SAX) ON MESSENGER Brian R been analyzed for 526 large flares detected with the Solar Assembly for X-rays (SAX) on the Mercury ­ Sun: flares ­ Sun: X-rays, gamma-rays 1. INTRODUCTION The Solar Assembly for X-rays (SAX) is part

  1. Using the Maximum X-ray Flux Ratio and X-ray Background to Predict Solar Flare Class

    E-Print Network [OSTI]

    Winter, Lisa M

    2015-01-01

    We present the discovery of a relationship between the maximum ratio of the flare flux (namely, 0.5-4 Ang to the 1-8 Ang flux) and non-flare background (namely, the 1-8 Ang background flux), which clearly separates flares into classes by peak flux level. We established this relationship based on an analysis of the Geostationary Operational Environmental Satellites (GOES) X-ray observations of ~ 50,000 X, M, C, and B flares derived from the NOAA/SWPC flares catalog. Employing a combination of machine learning techniques (K-nearest neighbors and nearest-centroid algorithms) we show a separation of the observed parameters for the different peak flaring energies. This analysis is validated by successfully predicting the flare classes for 100% of the X-class flares, 76% of the M-class flares, 80% of the C-class flares and 81% of the B-class flares for solar cycle 24, based on the training of the parametric extracts for solar flares in cycles 22-23.

  2. ON THE MECHANICAL ENERGY AVAILABLE TO DRIVE SOLAR FLARES A. N. McClymont and G. H. Fisher

    E-Print Network [OSTI]

    California at Berkeley, University of

    ON THE MECHANICAL ENERGY AVAILABLE TO DRIVE SOLAR FLARES A. N. McClymont and G. H. Fisher Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 Abstract. Where does solar flare energy come from? More, generated in the solar interior, can carry sufficient free energy to power even the largest flares ever

  3. Subsurface capture of carbon dioxide

    DOE Patents [OSTI]

    Blount, Gerald; Siddal, Alvin A.; Falta, Ronald W.

    2014-07-22

    A process and apparatus of separating CO.sub.2 gas from industrial off-gas source in which the CO.sub.2 containing off-gas is introduced deep within an injection well. The CO.sub.2 gases are dissolved in the, liquid within the injection well while non-CO.sub.2 gases, typically being insoluble in water or brine, are returned to the surface. Once the CO.sub.2 saturated liquid is present within the injection well, the injection well may be used for long-term geologic storage of CO.sub.2 or the CO.sub.2 saturated liquid can be returned to the surface for capturing a purified CO.sub.2 gas.

  4. Bad data packet capture device

    DOE Patents [OSTI]

    Chen, Dong; Gara, Alan; Heidelberger, Philip; Vranas, Pavlos

    2010-04-20

    An apparatus and method for capturing data packets for analysis on a network computing system includes a sending node and a receiving node connected by a bi-directional communication link. The sending node sends a data transmission to the receiving node on the bi-directional communication link, and the receiving node receives the data transmission and verifies the data transmission to determine valid data and invalid data and verify retransmissions of invalid data as corresponding valid data. A memory device communicates with the receiving node for storing the invalid data and the corresponding valid data. A computing node communicates with the memory device and receives and performs an analysis of the invalid data and the corresponding valid data received from the memory device.

  5. Workshop on neutron capture therapy

    SciTech Connect (OSTI)

    Fairchild, R.G.; Bond, V.P.

    1986-01-01

    Potentially optimal conditions for Neutron Capture Therapy (NCT) may soon be in hand due to the anticipated development of band-pass filtered beams relatively free of fast neutron contaminations, and of broadly applicable biomolecules for boron transport such as porphyrins and monoclonal antibodies. Consequently, a number of groups in the US are now devoting their efforts to exploring NCT for clinical application. The purpose of this Workshop was to bring these groups together to exchange views on significant problems of mutual interest, and to assure a unified and effective approach to the solutions. Several areas of preclinical investigation were deemed to be necessary before it would be possible to initiate clinical studies. As neither the monomer nor the dimer of sulfhydryl boron hydride is unequivocally preferable at this time, studies on both compounds should be continued until one is proven superior.

  6. Abatement of Air Pollution: Greenhouse Gas Emissions Offset Projects...

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

    Projects that either capture and destroy landfill methane, avoid sulfur hexafluoride emissions, sequester carbon through afforestation, provide end-use energy efficiency, or avoid...

  7. Abatement of Air Pollution: Greenhouse Gas Emissions Offset Projects (Connecticut)

    Broader source: Energy.gov [DOE]

    Projects that either capture and destroy landfill methane, avoid sulfur hexafluoride emissions, sequester carbon through afforestation, provide end-use energy efficiency, or avoid methane emissions...

  8. From coronal observations to MHD simulations, the building blocks for 3D models of solar flares

    E-Print Network [OSTI]

    Janvier, Miho; Demoulin, Pascal

    2015-01-01

    Solar flares are energetic events taking place in the Sun's atmosphere, and their effects can greatly impact the environment of the surrounding planets. In particular, eruptive flares, as opposed to confined flares, launch coronal mass ejections into the interplanetary medium, and as such, are one of the main drivers of space weather. After briefly reviewing the main characteristics of solar flares, we summarize the processes that can account for the build up and release of energy during their evolution. In particular, we focus on the development of recent 3D numerical simulations that explain many of the observed flare features. These simulations can also provide predictions of the dynamical evolution of coronal and photospheric magnetic field. Here we present a few observational examples that, together with numerical modelling, point to the underlying physical mechanisms of the eruptions.

  9. Looptop and Footpoint Impulsive Hard X-Rays and Stochastic Electron Acceleration in Solar Flares

    E-Print Network [OSTI]

    Vahé Petrosian

    2002-07-22

    The discovery of hard X-rays from tops of flaring loops by the HXT of YOHKOH represents a significant progress in the understanding of solar flares. This report describes the properties of 20 limb flares observed by YOHKOH from October 1991 to August 1998, 15 of which show detectable impulsive looptop emission. Considering the finite dynamic range (about a decade) of the detection it can be concluded that looptop emission is a common feature of all flares. The light curves and images of a representative flare are presented and the statistical properties of the footpoint and looptop fluxes and spectral indexes are summarized. The importance of these observations, and those expected from RHESSI with its superior angular, spectral and temporal resolution, in constraining the acceleration models and parameters is discussed. briefly.

  10. Illinois Natural Gas Vented and Flared (Million Cubic Feet)

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet)DecadeYear Jan Feb Mar Apr MayYearYear Jan Feb MarMay-15Vented and Flared

  11. Solar Flare Activity Closely Monitored | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLE DIRECTIVES PursuantEnergySolar Flare Activity Closely Monitored

  12. Ohio Natural Gas Vented and Flared (Million Cubic Feet)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home PageMonthly","10/2015"4,"Ames5 Tables July 1996 Energy Information Administration Office of Coal, Nuclear,DecadeYear JanNew FieldDecade Year-0 Year-1Vented and Flared

  13. CO2 Capture Project: An Integrated, Collaborative Technology Development Project For CO2 Separation, Capture And Geologic Sequestration

    SciTech Connect (OSTI)

    Helen Kerr

    2002-01-10

    This report (which forms part of the requirements of the Statement of Work Task 0, subtask 0.4) records progress towards defining a detailed Work Plan for the CCP 30 days after contract initiation. It describes the studies planned, workscope development and technology provider bid evaluation status at that time. Business sensitive information is provided separately in Appendix 1. Contract negotiations are on hold pending award of patent waiver status to the CCP.

  14. Solar X-ray Flare Hazards on the Surface of Mars

    E-Print Network [OSTI]

    David S. Smith; John M. Scalo

    2006-10-03

    Putative organisms on the Martian surface would be exposed to potentially high doses of ionizing radiation during strong solar X-ray flares. We extrapolate the observed flare frequency-energy release scaling relation to releases much larger than seen so far for the sun, an assumption supported by observations of flares on other solar- and subsolar-mass main sequence stars. We calculate the surficial reprocessed X-ray spectra using a Monte Carlo code we have developed. Biological doses from indirect genome damage are calculated for each parameterized flare spectrum by integration over the X-ray opacity of water. We estimate the mean waiting time for solar flares producing a given biological dose of ionizing radiation on Mars and compare with lethal dose data for a wide range of terrestrial organisms. These timescales range from decades for significant human health risk to 0.5 Myr for D. radiodurans lethality. Such doses require total flare energies of 10^33--10^38 erg, the lower range of which has been observed for other stars. Flares are intermittent bursts, so acute lethality will only occur on the sunward hemisphere during a sufficiently energetic flare, unlike low-dose-rate, extended damage by cosmic rays. We estimate the soil and CO_2 ice columns required to provide 1/e shielding as 4--9 g cm^-2, depending on flare mean energy and atmospheric column density. Topographic altitude variations give a factor of two variation in dose for a given flare. Life in ice layers that may exist ~ 100 g cm^-2 below the surface would be well protected.

  15. Brightest Fermi-LAT flares of PKS 1222+216: implications on emission and acceleration processes

    SciTech Connect (OSTI)

    Kushwaha, Pankaj; Singh, K. P.; Sahayanathan, Sunder

    2014-11-20

    We present a high time resolution study of the two brightest ?-ray outbursts from a blazar PKS 1222+216 observed by the Fermi Large Area Telescope (LAT) in 2010. The ?-ray light curves obtained in four different energy bands, 0.1-3, 0.1-0.3, 0.3-1, and 1-3 GeV, with time bins of six hours, show asymmetric profiles with similar rise times in all the bands but a rapid decline during the April flare and a gradual one during the June flare. The light curves during the April flare show an ?2 day long plateau in 0.1-0.3 GeV emission, erratic variations in 0.3-1 GeV emission, and a daily recurring feature in 1-3 GeV emission until the rapid rise and decline within a day. The June flare shows a monotonic rise until the peak, followed by a gradual decline powered mainly by the multi-peak 0.1-0.3 GeV emission. The peak fluxes during both the flares are similar except in the 1-3 GeV band in April, which is twice the corresponding flux during the June flare. Hardness ratios during the April flare indicate spectral hardening in the rising phase followed by softening during the decay. We attribute this behavior to the development of a shock associated with an increase in acceleration efficiency followed by its decay leading to spectral softening. The June flare suggests hardening during the rise followed by a complicated energy dependent behavior during the decay. Observed features during the June flare favor multiple emission regions while the overall flaring episode can be related to jet dynamics.

  16. In silico screening of carbon-capture materials

    SciTech Connect (OSTI)

    Lin, LC; Berger, AH; Martin, RL; Kim, J; Swisher, JA; Jariwala, K; Rycroft, CH; Bhown, AS; Deem, MW; Haranczyk, M; Smit, B

    2012-05-27

    One of the main bottlenecks to deploying large-scale carbon dioxide capture and storage (CCS) in power plants is the energy required to separate the CO2 from flue gas. For example, near-term CCS technology applied to coal-fired power plants is projected to reduce the net output of the plant by some 30% and to increase the cost of electricity by 60-80%. Developing capture materials and processes that reduce the parasitic energy imposed by CCS is therefore an important area of research. We have developed a computational approach to rank adsorbents for their performance in CCS. Using this analysis, we have screened hundreds of thousands of zeolite and zeolitic imidazolate framework structures and identified many different structures that have the potential to reduce the parasitic energy of CCS by 30-40% compared with near-term technologies.

  17. New waste-heat refrigeration unit cuts flaring, reduces pollution

    SciTech Connect (OSTI)

    Brant, B.; Brueske, S.; Erickson, D.; Papar, R.

    1998-05-18

    Planetec Utility Services Co. Inc. and Energy Concepts Co. (ECC), with the help of the US Department of Energy (DOE), developed and commissioned a unique waste-heat powered LPG recovery plant in August 1997 at the 30,000 b/d Denver refinery, operated by Ultramar Diamond Shamrock (UDS). This new environmentally friendly technology reduces flare emissions and the loss of salable liquid-petroleum products to the fuel-gas system. The waste heat ammonia absorption refrigeration plant (Whaarp) is the first technology of its kind to use low-temperature waste heat (295 F) to achieve sub-zero refrigeration temperatures ({minus}40 F) with the capability of dual temperature loads in a refinery setting. The ammonia absorption refrigeration is applied to the refinery`s fuel-gas makeup streams to condense over 180 b/d of salable liquid hydrocarbon products. The recovered liquid, about 64,000 bbl/year of LPG and gasoline, increases annual refinery profits by nearly $1 million, while substantially reducing air pollution emissions from the refinery`s flare.

  18. RETURN CURRENTS AND ENERGY TRANSPORT IN THE SOLAR FLARING ATMOSPHERE

    SciTech Connect (OSTI)

    Codispoti, Anna; Torre, Gabriele; Piana, Michele; Pinamonti, Nicola [Dipartimento di Matematica, Universita di Genova, via Dodecaneso 35, I-16146 Genova (Italy)

    2013-08-20

    According to the standard Ohmic perspective, the injection of accelerated electrons into the flaring region violates local charge equilibrium and therefore, in response, return currents are driven by an electric field to equilibrate such charge violation. In this framework, the energy loss rate associated with these local currents has an Ohmic nature and significantly shortens the accelerated electron path. In the present paper, we adopt a different viewpoint and, specifically, we study the impact of the background drift velocity on the energy loss rate of accelerated electrons in solar flares. We first utilize the Rutherford cross-section to derive the formula of the energy loss rate when the collisional target has a finite temperature and the background instantaneously and coherently moves up to equilibrate the electron injection. We then use the continuity equation for electrons and imaging spectroscopy data provided by RHESSI to validate this model. We show that this new formula for the energy loss rate provides a better fit of the experimental data with respect to the model based on the effects of standard Ohmic return currents.

  19. Maximum gravitational-wave energy emissible in magnetar flares

    E-Print Network [OSTI]

    Alessandra Corsi; Benjamin J. Owen

    2011-02-16

    Recent searches of gravitational-wave (GW) data raise the question of what maximum GW energies could be emitted during gamma-ray flares of highly magnetized neutron stars (magnetars). The highest energies (\\sim 10^{49} erg) predicted so far come from a model [K. Ioka, Mon. Not. Roy. Astron. Soc. 327, 639 (2001)] in which the internal magnetic field of a magnetar experiences a global reconfiguration, changing the hydromagnetic equilibrium structure of the star and tapping the gravitational potential energy without changing the magnetic potential energy. The largest energies in this model assume very special conditions, including a large change in moment of inertia (which was observed in at most one flare), a very high internal magnetic field, and a very soft equation of state. Here we show that energies of 10^{48}-10^{49} erg are possible under more generic conditions by tapping the magnetic energy, and we note that similar energies may also be available through cracking of exotic solid cores. Current observational limits on gravitational waves from magnetar fundamental modes are just reaching these energies and will beat them in the era of advanced interferometers.

  20. Financing Capture Ready Coal-Fired Power Plants in China by Issuing Capture Options

    E-Print Network [OSTI]

    Liang, Xi; Reiner, David; Gibbons, Jon; Li, Jia

    investors diversify risk, and offer global warming investors an alternative investment opportunity. As a detailed case study, we assess the value of a Capture Option and Capture Ready plant for a 600 MW supercritical pulverized coal power plant in China...

  1. Measurements and modeling of total solar irradiance in X-class solar flares

    SciTech Connect (OSTI)

    Moore, Christopher Samuel; Chamberlin, Phillip Clyde; Hock, Rachel

    2014-05-20

    The Total Irradiance Monitor (TIM) from NASA's SOlar Radiation and Climate Experiment can detect changes in the total solar irradiance (TSI) to a precision of 2 ppm, allowing observations of variations due to the largest X-class solar flares for the first time. Presented here is a robust algorithm for determining the radiative output in the TIM TSI measurements, in both the impulsive and gradual phases, for the four solar flares presented in Woods et al., as well as an additional flare measured on 2006 December 6. The radiative outputs for both phases of these five flares are then compared to the vacuum ultraviolet (VUV) irradiance output from the Flare Irradiance Spectral Model (FISM) in order to derive an empirical relationship between the FISM VUV model and the TIM TSI data output to estimate the TSI radiative output for eight other X-class flares. This model provides the basis for the bolometric energy estimates for the solar flares analyzed in the Emslie et al. study.

  2. GRB 060714: No Clear Dividing Line Between Prompt Emission and X-ray Flares

    E-Print Network [OSTI]

    Krimm, H A; Marshal, F; Perri, M; Barthelmy, S D; Burrows, D N; Gehrels, N; Mészáros, P; Morris, D

    2007-01-01

    The long gamma-ray burst GRB 060714 was observed to exhibit a series of five X-ray flares beginning ~70 s after the burst trigger T0 and continuing until T0 + ~200 s. The first two flares were detected by the Burst Alert Telescope (BAT) on the Swift satellite, before Swift had slewed to the burst location, while the last three flares were strongly detected by the X-Ray Telescope (XRT) but only weakly detected by the BAT. This burst provides an unusual opportunity to track a complete sequence of flares over a wide energy range. The flares were very similar in their light curve morphology, showing power-law rise and fall components, and in most cases significant sub-structure. The flares also showed strong evolution with time, both spectrally and temporally. The small time scale and large amplitude variability observed are incompatible with an external shock origin for the flares, and support instead late time sporadic activity either of the central source or of localized dissipation events within the outflow. ...

  3. Confined Flares in Solar Active Region 12192 from 2014 October 18 to 29

    E-Print Network [OSTI]

    Chen, Huadong; Ma, Suli; Yang, Shuhong; Li, Leping; Huang, Xin; Xiao, Junmin

    2015-01-01

    Using the observations from the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO), we investigate six X-class and twenty-nine M-class flares occurring in solar active region (AR) 12192 from October 18 to 29. Among them, thirty (including six X- and twenty-four M-class) flares originated from the AR core and the other five M-flares appeared at the AR periphery. Four of the X-flares exhibited similar flaring structures, indicating they were homologous flares with analogous triggering mechanism. The possible scenario is: photospheric motions of emerged magnetic fluxes lead to shearing of the associated coronal magnetic field, which then yields a tether-cutting favorable configuration. Among the five periphery M-flares, four were associated with jet activities. The HMI vertical magnetic field data show that the photospheric fluxes of opposite magnetic polarities emerged, converged and canceled with each other at the footpoints of the jets bef...

  4. UNIVERSAL BEHAVIOR OF X-RAY FLARES FROM BLACK HOLE SYSTEMS

    SciTech Connect (OSTI)

    Wang, F. Y.; Dai, Z. G.; Yi, S. X.; Xi, S. Q. E-mail: dzg@nju.edu.cn

    2015-01-01

    X-ray flares have been discovered in black hole systems such as gamma-ray bursts, the tidal disruption event Swift J1644+57, the supermassive black hole Sagittarius A* at the center of our Galaxy, and some active galactic nuclei. Occurrences of X-ray flares are always accompanied by relativistic jets. However, it is still unknown whether or not there is a physical analogy among such X-ray flares produced in black hole systems spanning nine orders of magnitude in mass. Here, we report observed data of X-ray flares and show that they have three statistical properties similar to solar flares, including power-law distributions of their energies, durations, and waiting times, which can be explained by a fractal-diffusive, self-organized criticality model. These statistical similarities, together with the fact that solar flares are triggered by a magnetic reconnection process, suggest that all of the X-ray flares are consistent with magnetic reconnection events, implying that their concomitant relativistic jets may be magnetically dominated.

  5. Survey on solar X-ray flares and associated coherent radio emissions

    E-Print Network [OSTI]

    Arnold O. Benz; Paolo Grigis; Andre Csillagy; Pascal Saint-Hilaire

    2004-10-19

    The radio emission during 201 X-ray selected solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zurich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June 30, 2003. Detailed association rates of radio emission during X-ray flares are reported. In the decimeter wavelength range, type III bursts and the genuinely decimetric emissions (pulsations, continua, and narrowband spikes) were found equally frequently. Both occur predominantly in the peak phase of hard X-ray (HXR) emission, but are less in tune with HXRs than the high-frequency continuum exceeding 4 GHz, attributed to gyrosynchrotron radiation. In 10% of the HXR flares, an intense radiation of the above genuine decimetric types followed in the decay phase or later. Classic meter-wave type III bursts are associated in 33% of all HXR flares, but only in 4% they are the exclusive radio emission. Noise storms were the only radio emission in 5% of the HXR flares, some of them with extended duration. Despite the spatial association (same active region), the noise storm variations are found to be only loosely correlated in time with the X-ray flux. In a surprising 17% of the HXR flares, no coherent radio emission was found in the extremely broad band surveyed. The association but loose correlation between HXR and coherent radio emission is interpreted by multiple reconnection sites connected by common field lines.

  6. Feasibility of Air Capture Manya Ranjan

    E-Print Network [OSTI]

    the biological process of CO2 capture by biomass. The cost of direct air capture reported in literatureC ($420-$630/tCO2) or greater. To this, one must add the capital costs, which will be significant its avoided cost in the range of $150/tCO2 to $300/CO2. However, the land requirement of this process

  7. Microfluidic Platforms for Capturing Circulating Tumor Cells

    E-Print Network [OSTI]

    Tang, William C

    Microfluidic Platforms for Capturing Circulating Tumor Cells Sweta Gupta, Allison C. Baker-cost microfluidic device that can be used to isolate and capture circulating tumor cells (CTCs) from whole blood. The device was made from polydimethylsiloxane (PDMS) consisting of a microfluidic channel with microposts

  8. Pion capture and transport system for PRISM

    E-Print Network [OSTI]

    McDonald, Kirk

    solenoid cold mass Transport pions+muons in long 2T solenoid channelPion capture and transport system for PRISM M. Yoshida Osaka Univ. 2005/8/28 NuFACT06 at UCI #12 and transport system proton beam Phase rotator PRIME detector #12;Concepts of pion capture/transport system

  9. Financing Capture Ready Coal-Fired Power Plants in China by Issuing Capture Options

    E-Print Network [OSTI]

    Aickelin, Uwe

    Financing Capture Ready Coal-Fired Power Plants in China by Issuing Capture Options Xi Liang, Jia Li, Jon Gibbons and David Reiner December 2007 EPRG 0728 & CWPE 0761 #12;FINANCING CAPTURE READY COAL supercritical pulverized coal power plant in China, using a cash flow model with Monte-Carlo simulations

  10. CO2 Capture Using Electric Fields: Low-Cost Electrochromic Film on Plastic for Net-Zero Energy Building

    SciTech Connect (OSTI)

    None

    2010-01-01

    Broad Funding Opportunity Announcement Project: Two faculty members at Lehigh University created a new technique called supercapacitive swing adsorption (SSA) that uses electrical charges to encourage materials to capture and release CO2. Current CO2 capture methods include expensive processes that involve changes in temperature or pressure. Lehigh University’s approach uses electric fields to improve the ability of inexpensive carbon sorbents to trap CO2. Because this process uses electric fields and not electric current, the overall energy consumption is projected to be much lower than conventional methods. Lehigh University is now optimizing the materials to maximize CO2 capture and minimize the energy needed for the process.

  11. LOW-PRESSURE MEMBRANE CONTACTORS FOR CARBON DIOXIDE CAPTURE

    SciTech Connect (OSTI)

    Baker, Richard; Kniep, Jay; Hao, Pingjiao; Chan, Chi Cheng; Nguyen, Vincent; Huang, Ivy; Amo, Karl; Freeman, Brice; Fulton, Don; Ly, Jennifer; Lipscomb, Glenn; Lou, Yuecun; Gogar, Ravikumar

    2014-09-30

    This final technical progress report describes work conducted by Membrane Technology and Research, Inc. (MTR) for the Department of Energy (DOE NETL) on development of low-pressure membrane contactors for carbon dioxide (CO2) capture from power plant flue gas (award number DE-FE0007553). The work was conducted from October 1, 2011 through September 30, 2014. The overall goal of this three-year project was to build and operate a prototype 500 m2 low-pressure sweep membrane module specifically designed to separate CO2 from coal-fired power plant flue gas. MTR was assisted in this project by a research group at the University of Toledo, which contributed to the computational fluid dynamics (CFD) analysis of module design and process simulation. This report details the work conducted to develop a new type of membrane contactor specifically designed for the high-gas-flow, low-pressure, countercurrent sweep operation required for affordable membrane-based CO2 capture at coal power plants. Work for this project included module development and testing, design and assembly of a large membrane module test unit at MTR, CFD comparative analysis of cross-flow, countercurrent, and novel partial-countercurrent sweep membrane module designs, CFD analysis of membrane spacers, design and fabrication of a 500 m2 membrane module skid for field tests, a detailed performance and cost analysis of the MTR CO2 capture process with low-pressure sweep modules, and a process design analysis of a membrane-hybrid separation process for CO2 removal from coal-fired flue gas. Key results for each major task are discussed in the report.

  12. Urinary Symptom Flare in 712 {sup 125}I Prostate Brachytherapy Patients: Long-Term Follow-Up

    SciTech Connect (OSTI)

    Keyes, Mira; Miller, Stacy; Moravan, Veronika; Pickles, Tom; Liu, Mitchell; Spadinger, Ingrid; Lapointe, Vincent; Morris, W. James

    2009-11-01

    Purpose: To describe the late transient worsening of urinary symptoms ('urinary symptom flare') in 712 consecutive prostate brachytherapy patients, associated predictive factors, association with rectal and urinary toxicity, and the development of erectile dysfunction. Methods and Materials: Patients underwent implantation between 1998 and 2003 (median follow-up, 57 months). International Prostate Symptom Score (IPSS), Radiation Therapy Oncology Group (RTOG) toxicity, and erectile function data were prospectively collected. Flare was defined as an increase in IPSS of >=5 and of >=8 points greater than the post-treatment nadir. The relationships between the occurrence of flare and the patient, tumor, and treatment characteristics were examined. The Cox proportional hazards method was used to test individual variables and the multivariate models. Results: The incidence of flare was 52% and 30% using the flare definition of an IPSS of >=5 and >=8 points greater than the postimplant nadir, respectively. Of the patients with symptoms, 65% had resolution of their symptoms within 6 months and 91% within 1 year. Flares most commonly occurred 16-24 months after implantation. On multivariate analysis, a greater baseline IPSS and greater maximal postimplant IPSS were the predictors of flare, regardless of the flare definition used. Androgen suppression was a predictor for fewer flares (IPSS >=5). Diabetes and prostate edema predicted for more frequent flares (IPSS >=8). Patients with flare had a greater incidence of RTOG Grade 3 urinary toxicity and RTOG Grade 2 or greater rectal toxicity. No association was found between erectile dysfunction and the occurrence of flare. Conclusion: Urinary symptom flare is a common, transient phenomenon after prostate brachytherapy. A greater baseline IPSS and maximal postimplant IPSS were the strongest predictive factors. Flare was associated with a greater incidence of late RTOG Grade 3 urinary toxicity and greater rate of late RTOG Grade 2 or greater rectal toxicity.

  13. An X-ray, IR, and Submillimeter Flare of Sagittarius A*

    E-Print Network [OSTI]

    D. P. Marrone; F. K. Baganoff; M. R. Morris; J. M. Moran; A. M. Ghez; S. D. Hornstein; C. D. Dowell; D. J. Munoz; M. W. Bautz; G. R. Ricker; W. N. Brandt; G. P. Garmire; J. R. Lu; K. Matthews; J. -H. Zhao; R. Rao; G. C. Bower

    2008-07-14

    Energetic flares are observed in the Galactic supermassive black hole Sagittarius A* from radio to X-ray wavelengths. On a few occasions, simultaneous flares have been detected in IR and X-ray observations, but clear counterparts at longer wavelengths have not been seen. We present a flare observed over several hours on 2006 July 17 with the Chandra X-Ray Observatory, the Keck II telescope, the Caltech Submillimeter Observatory, and the Submillimeter Array. All telescopes observed strong flare events, but the submillimeter peak is found to occur nearly 100 minutes after the X-ray peak. Submillimeter polarization data show linear polarization in the excess flare emission, increasing from 9% to 17% as the flare passes through its peak, consistent with a transition from optically thick to thin synchrotron emission. The temporal and spectral behavior of the flare require that the energetic electrons responsible for the emission cool faster than expected from their radiative output. This is consistent with adiabatic cooling in an expanding emission region, with X-rays produced through self-Compton scattering, although not consistent with the simplest model of such expansion. We also present a submillimeter flare that followed a bright IR flare on 2005 July 31. Compared to 2006, this event had a larger peak IR flux and similar submillimeter flux, but it lacked measurable X-ray emission. It also showed a shorter delay between the IR and submillimeter peaks. Based on these events we propose a synchrotron and self-Compton model to relate the submillimeter lag and the variable IR/X-ray luminosity ratio.

  14. On the variation of solar flare coronal X-ray source sizes with energy

    SciTech Connect (OSTI)

    Jeffrey, Natasha L. S.; Kontar, Eduard P.; Bian, Nicolas H. [School of Physics and Astronomy, University of Glasgow, G12 8QQ Glasgow (United Kingdom); Emslie, A. Gordon, E-mail: n.jeffrey@physics.gla.ac.uk [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States)

    2014-05-20

    Observations with RHESSI have enabled the detailed study of the structure of dense hard X-ray coronal sources in solar flares. The variation of source extent with electron energy has been discussed in the context of streaming of non-thermal particles in a one-dimensional cold target model and the results used to constrain both the physical extent of, and density within, the electron acceleration region. Here, we extend this investigation to a more physically realistic model of electron transport that takes into account the finite temperature of the ambient plasma, the initial pitch angle distribution of the accelerated electrons, and the effects of collisional pitch angle scattering. The finite temperature results in the thermal diffusion of electrons, which leads to the observationally inferred value of the acceleration region volume being an overestimate of its true value. The different directions of the electron trajectories, a consequence of both the non-zero injection pitch angle and scattering within the target, cause the projected propagation distance parallel to the guiding magnetic field to be reduced, so that a one-dimensional interpretation can overestimate the actual density by a factor of up to ?6. The implications of these results for the determination of acceleration region properties (specific acceleration rate, filling factor, etc.) are discussed.

  15. Optical polarization map of the Polaris Flare with RoboPol

    E-Print Network [OSTI]

    Panopoulou, G V; Blinov, D; Pavlidou, V; King, O G; Paleologou, E; Ramaprakash, A; Angelakis, E; Balokovic, M; Das, H K; Feiler, R; Hovatta, T; Khodade, P; Kiehlmann, S; Kus, A; Kylafis, N; Liodakis, I; Modi, D; Myserlis, I; Papadakis, I; Papamastorakis, I; Pazderska, B; Pazderski, E; Pearson, T J; Rajarshi, C; Readhead, A C S; Reig, P; Zensus, J A

    2015-01-01

    The stages before the formation of stars in molecular clouds are poorly understood. Insights can be gained by studying the properties of quiescent clouds, such as their magnetic field structure. The plane-of-the-sky orientation of the field can be traced by polarized starlight. We present the first extended, wide-field ($\\sim$10 $\\rm deg^2$) map of the Polaris Flare cloud in dust-absorption induced optical polarization of background stars, using the RoboPol polarimeter at the Skinakas Observatory. This is the first application of the wide-field imaging capabilities of RoboPol. The data were taken in the R-band and analysed with the automated reduction pipeline of the instrument. We present in detail optimizations in the reduction pipeline specific to wide-field observations. Our analysis resulted in reliable measurements of 648 stars with median fractional linear polarization 1.3%. The projected magnetic field shows a large scale ordered pattern. At high longitudes it appears to align with faint striations se...

  16. A NEW CORRELATION BETWEEN GRB X-RAY FLARES AND THE PROMPT EMISSION

    SciTech Connect (OSTI)

    Sonbas, E. [Department of Physics, University of Adiyaman, 02040 Adiyaman (Turkey); MacLachlan, G. A.; Shenoy, A.; Dhuga, K. S.; Parke, W. C., E-mail: edasonbas@yahoo.com [Department of Physics, George Washington University, Washington, DC 20052 (United States)

    2013-04-20

    From a sample of gamma-ray bursts (GRBs) detected by the Fermi and Swift missions, we have extracted the minimum variability timescales for temporal structures in the light curves associated with the prompt emission and X-ray flares. A comparison of this variability timescale with pulse parameters such as rise times, determined via pulse-fitting procedures, and spectral lags, extracted via the cross-correlation function, indicates a tight correlation between these temporal features for both the X-ray flares and the prompt emission. These correlations suggest a common origin for the production of X-ray flares and the prompt emission in GRBs.

  17. Simbol-X capability of detecting the non-thermal emission of stellar flares

    E-Print Network [OSTI]

    C. Argiroffi; G. Micela; A. Maggio

    2008-01-16

    We investigate the capability of detecting, with Simbol-X, non-thermal emission during stellar flares, and distinguishing it from hot thermal emission. We find that flare non-thermal emission is detectable when at least ~20 cts are detected with the CZT detector in the 20-80 keV band. Therefore Simbol-X will detect the non-thermal emission from some of the X-ray brightest nearby stars, whether the thermal vs. non-thermal relation, derived for solar flares, holds.

  18. Neutrino Solar Flare detection for a saving alert system of satellites and astronauts

    E-Print Network [OSTI]

    Daniele Fargion

    2011-06-19

    Largest Solar Neutrino Flare may be soon detectable by Deep Core neutrino detector immediately and comunicate to satellites or astronauts. Its detection is the fastest manifestation of a later (tens minutes,hours) dangerous cosmic shower. The precursor trigger maybe saving satellites and even long flight astronauts lives. We shall suggest how. Moreover their detection may probe the inner solar flare acceleration place as well as the neutrino flavor mixing in a new different parameter windows. We show the updated expected rate and signature of neutrinos and antineutrinos in largest solar flare for present tens Megaton Deep Core telescope at tens Gev range. Speculation for additional Icecube gigaton array signals are also considered.

  19. Regularized energy-dependent solar flare hard x-ray spectral index

    E-Print Network [OSTI]

    Eduard P. Kontar; Alexander L. MacKinnon

    2005-06-05

    The deduction from solar flare X-ray photon spectroscopic data of the energy dependent model-independent spectral index is considered as an inverse problem. Using the well developed regularization approach we analyze the energy dependency of spectral index for a high resolution energy spectrum provided by Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The regularization technique produces much smoother derivatives while avoiding additional errors typical of finite differences. It is shown that observations imply a spectral index varying significantly with energy, in a way that also varies with time as the flare progresses. The implications of these findings are discussed in the solar flare context.

  20. Observations and modelling of Helium lines in solar flares

    E-Print Network [OSTI]

    Simőes, Paulo J A; Labrosse, Nicolas; Kerr, Graham S

    2015-01-01

    We explore the response of the He II 304 {\\AA} and He I 584 {\\AA} line intensities to electron beam heating in solar flares using radiative hydrodynamic simulations. Comparing different electron beams parameters, we found that the intensities of both He lines are very sensitive to the energy flux deposited in the chromosphere, or more specifically to the heating rate, with He II 304 {\\AA} being more sensitive to the heating than He I 584 {\\AA}. Therefore, the He line ratio increases for larger heating rates in the chromosphere. A similar trend is found in observations, using SDO/EVE He irradiance ratios and estimates of the electron beam energy rate obtained from hard X-ray data. From the simulations, we also found that spectral index of the electrons can affect the He ratio but a similar effect was not found in the observations.

  1. Optimal Electron Energies for Driving Chromospheric Evaporation in Solar Flares

    E-Print Network [OSTI]

    Reep, Jeffrey; Alexander, David

    2015-01-01

    In the standard model of solar flares, energy deposition by a beam of electrons drives strong chromospheric evaporation leading to a significantly denser corona and much brighter emission across the spectrum. Chromospheric evaporation was examined in great detail by Fisher, Canfield, & McClymont (1985a,b,c), who described a distinction between two different regimes, termed explosive and gentle evaporation. In this work, we examine the importance of electron energy and stopping depths on the two regimes and on the atmospheric response. We find that with explosive evaporation, the atmospheric response does not depend strongly on electron energy. In the case of gentle evaporation, lower energy electrons are significantly more efficient at heating the atmosphere and driving up-flows sooner than higher energy electrons. We also find that the threshold between explosive and gentle evaporation is not fixed at a given beam energy flux, but also depends strongly on the electron energy and duration of heating. Furt...

  2. Microwave Signature of Relativistic Positrons in Solar Flares

    E-Print Network [OSTI]

    Fleishman, Gregory; Meshalkina, Nataliia

    2013-01-01

    Relativistic antiparticles can be created in high-energy nuclear interactions; thus, detection of antiparticles in an astrophysical source can tell us something remarkable about the underlying high-energy processes and nuclear interactions. However, once created, the antiparticles remain a minor fraction of their conjugant normal particles, so the detection of the antiparticles represents a big science challenge. To address this challenge we employ imaging and polarimetry of microwave radiation produced as the positrons gyrate in the ambient magnetic field. The key property of the radiation used in this method is that the oppositely charged particles, electrons and positrons, produce radiation with opposite helicity, easily distinguishable by currently operating radio facilities. Analysis of available spatially resolved microwave data augmented by independent magnetic field measurements allows us to remotely detect the relativistic positron component in several solar flares.

  3. Triggering of Remote Flares by Magnetic Flux Emergence

    E-Print Network [OSTI]

    Fu, Yixing

    2015-01-01

    We study the effect of new emerging solar active regions on the large-scale magnetic environment of existing regions. We first present a theoretical approach to quantify the "interaction energy" between new and pre-existing regions as the difference between (i) the summed magnetic energies of their individual potential fields and (ii) the energy of their superposed potential fields. We expect that this interaction energy can, depending upon the relative arrangements of newly emerged and pre-existing magnetic flux, indicate the existence of "topological" free magnetic energy in the global coronal field that is independent of any "internal" free magnetic energy due to coronal electric currents flowing within the newly emerged and pre-existing flux systems. We then examine the interaction energy in two well-studied cases of flux emergence, but find that the predicted energetic perturbation is relatively small compared to energies released in large solar flares. Next, we present an observational study on the infl...

  4. Neutrino Capture and r-Process Nucleosynthesis

    E-Print Network [OSTI]

    Bradley S. Meyer; Gail C. McLaughlin; George M. Fuller

    1998-09-18

    We explore neutrino capture during r-process nucleosynthesis in neutrino-driven ejecta from nascent neutron stars. We focus on the interplay between charged-current weak interactions and element synthesis, and we delineate the important role of equilibrium nuclear dynamics. During the period of coexistence of free nucleons and light and/or heavy nuclei, electron neutrino capture inhibits the r-process. At all stages, capture on free neutrons has a larger impact than capture on nuclei. However, neutrino capture on heavey nuclei by itself, if it is very strong, is also detrimental to the r-process until large nuclear equilibrium clusters break down and the classical neutron-capture phase of the r-process begins. The sensitivity of the r-process to neutrino irradiation means that neutrino-capture effects can strongly constrain the r-process site, neutrino physics, or both. These results apply also to r-process scenarios other than neutrino-heated winds.

  5. Project Year Project Team

    E-Print Network [OSTI]

    Gray, Jeffrey J.

    Project Year 2001 Project Team Faculty: Grace Brush, Geography & Environmental Engineering, Whiting School of Engineering Fellow: Dan Bain, Geography & Environmental Engineering, Whiting School. Through this project, the team proposes to develop a variety of resources: a set of general, web

  6. Binary Capture Rates for Massive Protostars

    E-Print Network [OSTI]

    Nickolas Moeckel; John Bally

    2007-04-09

    The high multiplicity of massive stars in dense, young clusters is established early in their evolution. The mechanism behind this remains unresolved. Recent results suggest that massive protostars may capture companions through disk interactions with much higher efficiency than their solar mass counterparts. However, this conclusion is based on analytic determinations of capture rates and estimates of the robustness of the resulting binaries. We present the results of coupled n-body and SPH simulations of star-disk encounters to further test the idea that disk-captured binaries contribute to the observed multiplicity of massive stars.

  7. Modeling sulfur dioxide capture in a pulverized coal combustor

    SciTech Connect (OSTI)

    Nair, R.B.; Yavuzkurt, S. [Pennsylvania State Univ., University Park, PA (United States)

    1997-04-01

    The formation and capture of sulfur dioxide in a pulverized coal combustor is investigated. A two-dimensional, steady, axisymmetric code, PCGC-2 (Pulverized Coal Gasification and Combustion-two Dimensional), originally developed at Brigham Young University, has been used to simulate combustion of the pulverized coal. This paper represents part of a project to investigate simultaneously enhancing sulfur capture and particulate agglomeration in combustor effluents. Results from the code have been compared to experimental data obtained from MTCI`s (Manufacturing Technology and Conversion International) test pulse combustor, which generates sound pressure levels of {approximately}180 dB. The overall goal behind the pulse combustor program at MTCI is to develop combustors for stationary gas turbines that use relatively inexpensive coal-based fuels. This study attempts to model the capture of sulfur dioxide when injected into a pulse combustor firing micronized coal. While this work does not presume to model the complex gas flow-field generated by the pulsating flow, the effects of the acoustic field are expressed by increased heat and mass transfer to the particles (coal/sorbent) in question. A comprehensive calcination-sintering-sulfation model for single particles was used to model the capture of sulfur dioxide by limestone sorbent. Processes controlling sulfation are external heat and mass transfer, pore diffusion, diffusion through the product layer of CaSO{sub 4}, sintering, and calcination. The model was incorporated into the PCGC-2 program. Comparisons of exit concentrations of SO{sub 2} showed a fairly good agreement (within {approximately}10 percent) with the experimental results from MTCI.

  8. Particle Acceleration in Solar Flares and Enrichment of 3He and Heavy Ions

    E-Print Network [OSTI]

    Vahe' Petrosian

    2008-08-13

    We discuss possible mechanisms of acceleration of particles in solar flares and show that turbulence plays an important role in all the mechanism. It is also argued that stochastic particle acceleration by turbulent plasma waves is the most likely mechanism for production of the high energy electrons and ions responsible for observed radiative signatures of solar flares and for solar energetic particle or SEPs, and that the predictions of this model agrees well with many past and recent high spectral and temporal observations of solar flares. It is shown that, in addition, the model explains many features of SEPs that accompany flares. In particular we show that it can successfully explain the observed extreme enhancement, relative to photospheric values, of $^3$He ions and the relative spectra of $^3$He and $^4$He. It has also the potential of explaining the relative abundances of most ions including the increasing enhancements of heavy ions with ion mass or mass-to-charge ratio.

  9. Plasma motions and non-thermal line broadening in flaring twisted coronal loops

    E-Print Network [OSTI]

    Gordovskyy, Mykola; Browning, Philippa

    2015-01-01

    Observation of coronal EUV spectral lines offers an opportunity to evaluate the thermal structure and flows in flaring atmospheres. This, in turn, can be used to estimate the partitioning between the thermal and kinetic energies released in flares. Our aim is to forward-model large-scale (50-10000 km) velocity distributions in order to interpret non-thermal broadening of different spectral EUV lines observed in flares. The developed models allow us to understand the origin of the observed spectral line shifts and broadening, and link these features to particular physical phenomena in flaring atmospheres. We use ideal MHD to derive unstable twisted magnetic fluxtube configurations in a gravitationally-stratified atmosphere. The evolution of these twisted fluxtubes is followed using resistive MHD, with anomalous resistivity depending on the local density and temperature. The model also takes into account the thermal conduction and radiative losses. The model allows us to evaluate average velocities and velocity...

  10. The Search for >35 MeV Neutrons from the June 3, 2012 Impulsive Flare

    E-Print Network [OSTI]

    Koga, K; Matsumoto, H; Muraki, Y; Okudaira, T Obara O; Shibata, S; Yamamoto, T; Goka, T

    2015-01-01

    We analyzed a highly impulsive solar flare observed on June 3, 2012. In association with this flare, emissions of hard X-rays, high-energy gamma rays, and neutrons were detected by the detectors onboard the FERMI, RHESSI satellites and the International Space Station. We compared those results with the pictures taken by the UV telescope onboard the Solar Dynamics Observatory satellite and found the crossing structure of two magnetic ropes at two positions on the solar surface almost at the same time. High-energy gamma rays were detected by the Fermi Large Area Telescope satellite, implying that the impulsive flare was one of a major source of proton acceleration processes on the solar surface. At the beginning of research, impulsive solar flares were considered to be the main source of particle acceleration processes; our current observations have confirmed this hypothesis.

  11. X-ray flares from dense shells formed in gamma-ray burst explosions

    E-Print Network [OSTI]

    Hascoet, R; Daigne, F; Mochkovitch, R

    2015-01-01

    Bright X-ray flares are routinely detected by the Swift satellite during the early afterglow of gamma-ray bursts, when the explosion ejecta drives a blast wave into the external medium. We suggest that the flares are produced as the reverse shock propagates into the tail of the ejecta. The ejecta is expected to contain a few dense shells formed at an earlier stage of the explosion. We show an example of how such dense shells form and describe how the reverse shock interacts with them. A new reflected shock is generated in this interaction, which produces a short-lived X-ray flare. The model provides a natural explanation for the main observed features of the X-ray flares --- the fast rise, the steep power-law decline, and the characteristic peak duration \\Delta t /t= (0.1-0.3).

  12. RELATIVE ASTROMETRY OF COMPACT FLARING STRUCTURES IN Sgr A* WITH POLARIMETRIC VERY LONG BASELINE INTERFEROMETRY

    E-Print Network [OSTI]

    Johnson, Michael D.

    We demonstrate that polarimetric interferometry can be used to extract precise spatial information about compact polarized flares of Sgr A*. We show that, for a faint dynamical component, a single interferometric baseline ...

  13. Evidence of Bulk Acceleration of the GRB X-ray Flare Emission Region

    E-Print Network [OSTI]

    Uhm, Z Lucas

    2015-01-01

    Gamma-ray bursts (GRBs), the most luminous explosions in the universe, invoke relativistic jets beaming towards Earth with the highest velocities for bulk motion in the universe. Some of them are followed by softer, less energetic, X-ray flares, which also move with relativistic velocities towards Earth. Observations and theoretical modeling suggest that X-ray flares share a similar physical mechanism as GRB prompt emission itself. Here we show a clear observational evidence that the X-ray flare emission region is undergoing rapid acceleration as the photons are emitted. The observed X-ray flare light curves and photon index evolution can be interpreted within a simple toy model invoking synchrotron radiation in an accelerating emission region far from the GRB central engine. Such an acceleration process demands an additional energy dissipation source other than kinetic energy, which points towards a significant Poynting-flux in the emission region.

  14. Statistical study of free magnetic energy and flare productivity of solar active regions

    SciTech Connect (OSTI)

    Su, J. T.; Jing, J.; Wang, S.; Wang, H. M. [Space Weather Research Laboratory, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States); Wiegelmann, T., E-mail: sjt@bao.ac.cn [Max-Planck-Institut fur Sonnensystemforschung, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau (Germany)

    2014-06-20

    Photospheric vector magnetograms from the Helioseismic and Magnetic Imager on board the Solar Dynamic Observatory are utilized as the boundary conditions to extrapolate both nonlinear force-free and potential magnetic fields in solar corona. Based on the extrapolations, we are able to determine the free magnetic energy (FME) stored in active regions (ARs). Over 3000 vector magnetograms in 61 ARs were analyzed. We compare FME with the ARs' flare index (FI) and find that there is a weak correlation (<60%) between FME and FI. FME shows slightly improved flare predictability relative to the total unsigned magnetic flux of ARs in the following two aspects: (1) the flare productivity predicted by FME is higher than that predicted by magnetic flux and (2) the correlation between FI and FME is higher than that between FI and magnetic flux. However, this improvement is not significant enough to make a substantial difference in time-accumulated FI, rather than individual flare, predictions.

  15. Correction of SOHO CELIAS/SEM EUV Measurements saturated by extreme solar flare events

    E-Print Network [OSTI]

    L. V. Didkovsky; D. L. Judge; A. R. Jones; S. Wieman; B. T. Tsurutani; D. McMullin

    2006-10-04

    The solar irradiance in the Extreme Ultraviolet (EUV) spectral bands has been observed with a 15 sec cadence by the SOHO Solar EUV Monitor (SEM) since 1995. During remarkably intense solar flares the SEM EUV measurements are saturated in the central (zero) order channel (0.1 -- 50.0 nm) by the flare soft X-ray and EUV flux. The first order EUV channel (26 -- 34 nm) is not saturated by the flare flux because of its limited bandwidth, but it is sensitive to the arrival of Solar Energetic Particles (SEP). While both channels detect nearly equal SEP fluxes, their contributions to the count rate is sensibly negligible in the zero order channel but must be accounted for and removed from the first channel count rate. SEP contribution to the measured SEM signals usually follows the EUV peak for the gradual solar flare events. Correcting the extreme solar flare SEM EUV measurements may reveal currently unclear relations between the flare magnitude, dynamics observed in different EUV spectral bands, and the measured Earth atmosphere response. A simple and effective correction technique based on analysis of SEM count-rate profiles, GOES X-ray, and GOES proton data has been developed and used for correcting EUV measurements for the five extreme solar flare events of July 14, 2000, October 28, November 2, November 4, 2003, and January 20, 2005. Although none of the 2000 and 2003 flare peaks were contaminated by the presence of SEPs, the January 20, 2005 SEPs were unusually prompt and contaminated the peak. The estimated accuracy of the correction is about 7.5% for large X-class events.

  16. High-temperature phase transition in a plasma and the mechanism of powerful solar flares

    E-Print Network [OSTI]

    Fedor V. Prigara

    2006-05-04

    It is shown that the high- temperature phase transition in a plasma gives the mechanism of transition from the highly conductive state to the highly resistive state of a plasma in the `electric circuit' model of solar flares which was first introduced by H.Alfven and P.Carlqvist in 1967. With this addendum, the modern version of the electric circuit model can explain both the fast dissipation of energy and the acceleration of particles in a solar flare.

  17. Underground muons from the direction of Cygnus X-3 during the January 1991 radio flare

    SciTech Connect (OSTI)

    The Soudan 2 Collaboration

    1991-08-01

    Muons recorded in the Soudan 2 underground nucleon decay detector from January 1989 to February 1991 have been examined for any correlation with the radio flares of Cyguns X-3 observed during this period. On two nearby days during the radio flare of January 1991 a total of 32 muons within 2.0{degrees} of the Cyguns X-3 direction were observed when 11.4 were expected.

  18. Bioenergy with Carbon Capture and Sequestration Workshop

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy’s (DOE’s) Office of Fossil Energy (FE) and Bioenergy Technologies Office (BETO) co-hosted the Bioenergy with Carbon Capture and Sequestration (BECCS) Workshop on...

  19. Determination of thermal neutron capture gamma yields

    E-Print Network [OSTI]

    Harper, Thomas Lawrence

    1969-01-01

    A method of analysing Ge(Li) thermal neutron capture gamma spectra to obtain total gamma yields has been developed. Tie method determines both the yields from the well resolved gamma peaks in a spectrum as well as the gamma ...

  20. Determination of thermal neutron capture gamma yields.

    E-Print Network [OSTI]

    Harper, Thomas Lawrence

    1969-01-01

    A method of analysing Ge(Li) thermal neutron capture gamma spectra to obtain total gamma yields has been developed. Tie method determines both the yields from the well resolved gamma peaks in a spectrum as well as the gamma ...

  1. Electrochemically mediated separation for carbon capture

    E-Print Network [OSTI]

    Simeon, Fritz

    Carbon capture technology has been proposed as an effective approach for the mitigation of anthropogenic CO[subscript 2] emissions. Thermal-swing separation technologies based on wet chemical scrubbing show potential for ...

  2. Economic assessment of CO? capture and disposal

    E-Print Network [OSTI]

    Eckaus, Richard S.; Jacoby, Henry D.; Ellerman, A. Denny.; Leung, Wing-Chi.; Yang, Zili.

    A multi-sector multi-region general equilibrium model of economic growth and emissions is used to explore the conditions that will determine the market penetration of CO2 capture and disposal technology.

  3. Capturing Waste Gas: Saves Energy, Lower Costs

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

    Capturing Waste Gas: Saves Energy, Lowers Costs ArcelorMittal's Indiana Harbor plant in East Chicago, Indiana, is the largest steel mill in the Western Hemisphere. It operates five...

  4. Regulating carbon dioxide capture and storage

    E-Print Network [OSTI]

    De Figueiredo, Mark A.

    2007-01-01

    This essay examines several legal, regulatory and organizational issues that need to be addressed to create an effective regulatory regime for carbon dioxide capture and storage ("CCS"). Legal, regulatory, and organizational ...

  5. Carbon Capture and Storage | Department of Energy

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

    Through Office of Fossil Energy R&D the United States has become a world leader in carbon capture and storage science and technology. Fossil Energy Research Benefits - Carbon...

  6. Effects of Compton scattering on the Gamma Ray Spectra of Solar flares

    E-Print Network [OSTI]

    Jun'ichi Kotoku; Kazuo Makishima; Yukari Matsumoto; Mitsuhiro Kohama; Yukikatsu Terada; Toru Tamagawa

    2007-08-01

    Using fully relativistic GEANT4 simulation tool kit, the transport of energetic electrons generated in solar flares was Monte-Carlo simulated, and resultant bremsstrahlung gamma-ray spectra were calculated. The solar atmosphere was approximated by 10 vertically-stacked zones. The simulation took into account two important physical processes,that the bremsstrahlung photons emitted by precipitating relativistic electrons are strongly forward beamed toward the photosphere, and that the majority of these gamma-rays must be Compton back-scattered by the solar atmosphere in order to reach the observer. Then, the Compton degradation was found to make the observable gamma-ray spectra much softer than is predicted by simple analytic calculations. The gamma-ray signals were found to be enhanced by several conditions, including a broad pitch-angle distribution of the electrons, a near-limb flare longitude, and a significant tilt in the magnetic field lines if the flare longitude is rather small. These results successfully explain several important flare properties observed in the hard X-ray to gamma-ray range, including in particular those obtained with Yohkoh. A comparison of the Yohkoh spectrum from a GOES X3.7 class limb flare on 1998 November 22, with a simulation assuming a broad electron pitch-angle distribution, suggests that gamma-rays from this particular solar flare were a mixture of direct bremsstrahlung photons and their Comptonization.

  7. Transition Region Emission and Energy Input to Thermal Plasma During the Impulsive Phase of Solar Flares

    E-Print Network [OSTI]

    J. C. Raymond; G. Holman; A. Ciaravella; A. Panasyuk; Y. -K. Ko; J. Kohl

    2007-01-12

    The energy released in a solar flare is partitioned between thermal and non-thermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the energy radiated at transition region temperatures during the impulsive phases of flares. We use UVCS measurements of O VI photons produced by 5 flares and subsequently scattered by O VI ions in the corona to determine the 5.0 thermal energy and the conductive losses deduced from RHESSI and GOES X-ray data using areas from RHESSI images to estimate the loop volumes, cross-sectional areas and scale lengths. The transition region luminosities during the impulsive phase exceed the X-ray luminosities for the first few minutes, but they are smaller than the rates of increase of thermal energy unless the filling factor of the X-ray emitting gas is ~ 0.01. The estimated conductive losses from the hot gas are too large to be balanced by radiative losses or heating of evaporated plasma, and we conclude that the area of the flare magnetic flux tubes is much smaller than the effective area measured by RHESSI during this phase of the flares. For the 2002 July 23 flare, the energy deposited by non-thermal particles exceeds the X-ray and UV energy losses and the rate of increase of the thermal energy.

  8. Radiative hydrodynamic modelling and observations of the X-class solar flare on 2011 March 9

    E-Print Network [OSTI]

    Kennedy, Michael B; Allred, Joel C; Mathioudakis, Mihalis; Keenan, Francis P

    2015-01-01

    We investigated the response of the solar atmosphere to non-thermal electron beam heating using the radiative transfer and hydrodynamics modelling code RADYN. The temporal evolution of the parameters that describe the non-thermal electron energy distribution were derived from hard X-ray observations of a particular flare, and we compared the modelled and observed parameters. The evolution of the non-thermal electron beam parameters during the X1.5 solar flare on 2011 March 9 were obtained from analysis of RHESSI X-ray spectra. The RADYN flare model was allowed to evolve for 110 seconds, after which the electron beam heating was ended, and was then allowed to continue evolving for a further 300s. The modelled flare parameters were compared to the observed parameters determined from extreme-ultraviolet spectroscopy. The model produced a hotter and denser flare loop than that observed and also cooled more rapidly, suggesting that additional energy input in the decay phase of the flare is required. In the explosi...

  9. Hinode Observations of Vector Magnetic Field Change Associated with a Flare on 2006 December 13

    E-Print Network [OSTI]

    Masahito Kubo; Takaaki Yokoyama; Yukio Katsukawa; Bruce W Lites; Saku Tsuneta; Yoshinori Suematsu; Kiyoshi Ichimoto; Toshifumi Shimizu; Shin'ichi Nagata; Theodore D Tarbell; Richard A Shine; Alan M Title; David Elmore

    2007-09-17

    Continuous observations of a flare productive active region 10930 were successfully carried out with the Solar Optical Telescope onboard the Hinode spacecraft during 2007 December 6 to 19. We focus on the evolution of photospheric magnetic fields in this active region, and magnetic field properties at the site of the X3.4 class flare, using a time series of vector field maps with high spatial resolution. The X3.4 class flare occurred on 2006 December 13 at the apparent collision site between the large, opposite polarity umbrae. Elongated magnetic structures with alternatingly positive and negative polarities resulting from flux emergence appeared one day before the flare in the collision site penumbra. Subsequently, the polarity inversion line at the collision site became very complicated. The number of bright loops in Ca II H increased during the formation of these elongated magnetic structures. The flare ribbons and bright loops evolved along the polarity inversion line and one footpoint of the bright loop was located in a region having a large departure of field azimuth angle with respect to its surroundings. The SOT observations with high spatial resolution and high polarization precision reveal temporal change in fine structure of magnetic fields at the flare site: some parts of the complicated polarity inversion line then disappeared, and in those regions the azimuth angle of photospheric magnetic field changed by about 90 degrees, becoming more spatially uniform within the collision site.

  10. A STATISTICAL STUDY OF SPECTRAL HARDENING IN SOLAR FLARES AND RELATED SOLAR ENERGETIC PARTICLE EVENTS

    SciTech Connect (OSTI)

    Grayson, James A.; Krucker, Saem [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Lin, R. P., E-mail: jgrayson@berkeley.ed, E-mail: krucker@ssl.berkeley.ed, E-mail: rlin@ssl.berkeley.ed [Also at Department of Physics, University of California, Berkeley, CA 94720-7300 (United States)

    2009-12-20

    Using hard X-ray observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), we investigate the reliability of spectral hardening during solar flares as an indicator of related solar energetic particle (SEP) events at Earth. All RHESSI data are analyzed, from 2002 February through the end of Solar Cycle 23, thereby expanding upon recent work on a smaller sample of flares. Previous investigations have found very high success when associating soft-hard-harder (SHH) spectral behavior with energetic proton events, and confirmation of this link would suggest a correlation between electron acceleration in solar flares and SEPs seen in interplanetary space. In agreement with these past findings, we find that of 37 magnetically well-connected flares (W30-W90), 12 of 18 flares with SHH behavior produced SEP events and none of 19 flares without SHH behavior produced SEPs. This demonstrates a statistically significant dependence of SHH and SEP observations, a link that is unexplained in the standard scenario of SEP acceleration at the shock front of coronal mass ejections and encourages further investigation of the mechanisms which could be responsible.

  11. TIME EVOLUTION OF FLARES IN GRB 130925A: JET PRECESSION IN A BLACK HOLE ACCRETION SYSTEM

    SciTech Connect (OSTI)

    Hou, Shu-Jin; Liu, Tong; Gu, Wei-Min; Sun, Mou-Yuan; Lu, Ju-Fu [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Lin, Da-Bin [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning, Guangxi 530004 (China); Wu, Xue-Feng, E-mail: tongliu@xmu.edu.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-01-20

    GRB 130925A, composed of three gamma-ray emission episodes and a series of orderly flares, has been detected by Swift, Fermi, Konus-Wind, and INTEGRAL. If the third weakest gamma-ray episode can be considered a giant flare, we find that after the second gamma-ray episode observed by INTEGRAL located at about 2000 s, a positive relation exists between the time intervals of the adjacent flares and the time since the episode. We suggest that the second gamma-ray episode and its flares originate from the resumption of the accretion process due to the fragments from the collapsar falling back; such a relation may be related to a hyperaccretion disk around a precessed black hole (BH). We propose that the origin and time evolution of the flares, and the approximately symmetrical temporal structure and spectral evolution of the single flare can be explained well by a jet precession model. In addition, the mass and spin of the BH can be constrained, which indicates a stellar-mass, fast-rotating BH located in the center of GRB 130925A.

  12. Pion-capture probabilities in organic molecules

    SciTech Connect (OSTI)

    Jackson, D.F.; Lewis, C.A.; O'Leary, K.

    1982-06-01

    Experimental results are presented for atomic-capture probabilities of negative pions in organic molecules. The data are analyzed in terms of atomic and molecular models. This analysis shows that the Fermi-Teller law (Z law) and its modifications do not give an adequate description of the data, but that a mesomolecular model together with hydrogen transfer contains the features essential to fit the data. Clear evidence is given for chemical effects in the pion-capture process.

  13. Feasibility of CO2 Capture from Mobile Sources | Department of...

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

    CO2 Capture from Mobile Sources Feasibility of CO2 Capture from Mobile Sources Presents integrated system for post-combustion CO2 capture from mobile sources p-16davis.pdf More...

  14. INTEGRATING MEA REGENERATION WITH CO2 COMPRESSION AND PEAKING TO REDUCE CO2 CAPTURE COSTS

    E-Print Network [OSTI]

    Rochelle, Gary T.

    by combining use of the heat integration configurations evaluated in this study and for the support and guidance of the DOE/NETL project manager, Jose D. Figueroa. Platte River Power Authority's insight on integrating a CO2 capture system into a full-scale power plant was also of great value

  15. Talking to the Enemy: Germany's Capture of British Voices in the Great War

    E-Print Network [OSTI]

    Talking to the Enemy: Germany's Capture of British Voices in the Great War Catherine Robson Between 1915 and 1918, members of a Royal Prussian Phonogramm Commission visited 70 prisoner-of- war camps of this remarkable episode in the Great War; it explores the project's informing contexts and operational details

  16. Detecting non-relativistic cosmic neutrinos by capture on tritium: phenomenology and physics potential

    E-Print Network [OSTI]

    Andrew J. Long; Cecilia Lunardini; Eray Sabancilar

    2014-11-12

    We study the physics potential of the detection of the Cosmic Neutrino Background via neutrino capture on tritium, taking the proposed PTOLEMY experiment as a case study. With the projected energy resolution of $\\Delta \\sim$ 0.15 eV, the experiment will be sensitive to neutrino masses with degenerate spectrum, $m_1 \\simeq m_2 \\simeq m_3 = m_\

  17. How gas-dynamic flare models powered by Petschek reconnection differ from those with ad hoc energy sources

    E-Print Network [OSTI]

    Longcope, Dana

    2015-01-01

    Aspects of solar flare dynamics, such as chromospheric evaporation and flare light-curves, have long been studied using one-dimensional models of plasma dynamics inside a static flare loop, subjected to some energy input. While extremely successful at explaining the observed characteristics of flares, all such models so far have specified energy input ad hoc, rather than deriving it self-consistently. There is broad consensus that flares are powered by magnetic energy released through reconnection. Recent work has generalized Petschek's basic reconnection scenario, topological change followed by field line retraction and shock heating, to permit its inclusion into a one-dimensional flare loop model. Here we compare the gas dynamics driven by retraction and shocking to those from more conventional static loop models energized by ad hoc source terms. We find significant differences during the first minute, when retraction leads to larger kinetic energies and produces higher densities at the loop top, while ad h...

  18. Fermi Large Area Telescope observations of high-energy gamma-ray emission from behind-the-limb solar flares

    E-Print Network [OSTI]

    Pesce-Rollins, Melissa; Petrosian, Vahe'; Liu, Wei; da Costa, Fatima Rubio; Allafort, Alice

    2015-01-01

    Fermi-LAT >30 MeV observations have increased the number of detected solar flares by almost a factor of 10 with respect to previous space observations. These sample both the impulsive and long duration phases of GOES M and X class flares. Of particular interest is the recent detections of three solar flares whose position behind the limb was confirmed by the STEREO-B spacecraft. While gamma-ray emission up to tens of MeV resulting from proton interactions has been detected before from occulted solar flares, the significance of these particular events lies in the fact that these are the first detections of >100 MeV gamma-ray emission from footpoint-occulted flares. We will present the Fermi-LAT, RHESSI and STEREO observations of these flares and discuss the various emission scenarios for these sources and implications for the particle acceleration mechanisms.

  19. New Funding from DOE Boosts Carbon Capture and Storage Research...

    Energy Savers [EERE]

    New Funding from DOE Boosts Carbon Capture and Storage Research and Development New Funding from DOE Boosts Carbon Capture and Storage Research and Development September 16, 2009 -...

  20. Secretary Chu Announces $3 Billion Investment for Carbon Capture...

    Office of Environmental Management (EM)

    Billion Investment for Carbon Capture and Sequestration Secretary Chu Announces 3 Billion Investment for Carbon Capture and Sequestration December 4, 2009 - 12:00am Addthis...

  1. First-of-its-Kind Carbon Capture and Conversion Demonstration...

    Office of Environmental Management (EM)

    First-of-its-Kind Carbon Capture and Conversion Demonstration Technology Opening in Texas First-of-its-Kind Carbon Capture and Conversion Demonstration Technology Opening in Texas...

  2. Pore Models Track Reactions in Underground Carbon Capture

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

    Pore Models Track Reactions in Underground Carbon Capture Pore Models Track Reactions in Underground Carbon Capture September 25, 2014 | Tags: Advanced Scientific Computing...

  3. The Water-Energy Nexus: Capturing the Benefits of Integrated...

    Energy Savers [EERE]

    The Water-Energy Nexus: Capturing the Benefits of Integrated Resource Management for Water & Electricity Utilities and their Partners The Water-Energy Nexus: Capturing the Benefits...

  4. Carbon Capture, Transport and Storage Regulatory Test Exercise...

    Open Energy Info (EERE)

    Carbon Capture, Transport and Storage Regulatory Test Exercise: Output Report Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Carbon Capture, Transport and Storage...

  5. DOE Approves Field Test for Promising Carbon Capture Technology...

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

    DOE Approves Field Test for Promising Carbon Capture Technology DOE Approves Field Test for Promising Carbon Capture Technology November 20, 2012 - 12:00pm Addthis Washington, DC -...

  6. Readout of Secretary Chu Meetings on Carbon Capture and Sequestration...

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

    Readout of Secretary Chu Meetings on Carbon Capture and Sequestration and State Grid Readout of Secretary Chu Meetings on Carbon Capture and Sequestration and State Grid July 16,...

  7. Polyacrylonitrile-Chalcogel Hybrid Sorbents for Radioiodine Capture...

    Office of Scientific and Technical Information (OSTI)

    Polyacrylonitrile-Chalcogel Hybrid Sorbents for Radioiodine Capture Citation Details In-Document Search Title: Polyacrylonitrile-Chalcogel Hybrid Sorbents for Radioiodine Capture...

  8. GE Awarded DOE Funding to Pilot Carbon Capture Technology | GE...

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

    Capture Technology to be piloted at world's largest carbon test center in Mongstad, Norway OKLAHOMA CITY, OK - September 16, 2015 - Calling it CO2 "Capture Technology in a...

  9. Advanced Post-Combustion CO2 Capture Prepared for the

    E-Print Network [OSTI]

    Advanced Post-Combustion CO2 Capture Prepared for the Clean Air Task Force under a grant from...................................................................................... 3 2. Current Status of Post-Combustion Capture

  10. EFRC Carbon Capture and Sequestration Activities at NERSC

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

    EFRC Carbon Capture and Sequestration Activities at NERSC EFRC Carbon Capture and Sequestration Activities at NERSC Why it Matters: Carbon dioxide (CO2) gas is considered to be...

  11. Fact #869: April 20, 2015 Gasoline Direct Injection Captures...

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

    9: April 20, 2015 Gasoline Direct Injection Captures 38% Market Share in Just Seven Years from First Significant Use Fact 869: April 20, 2015 Gasoline Direct Injection Captures...

  12. Theoretical Synthesis of Mixed Materials for CO2 Capture Applications...

    Office of Scientific and Technical Information (OSTI)

    Theoretical Synthesis of Mixed Materials for CO2 Capture Applications Citation Details In-Document Search Title: Theoretical Synthesis of Mixed Materials for CO2 Capture...

  13. Capturing Energy Upgrades in the Real Estate Transaction | Department...

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

    Capturing Energy Upgrades in the Real Estate Transaction Capturing Energy Upgrades in the Real Estate Transaction Because green building techniques and products may impact the...

  14. Water Challenges for Geologic Carbon Capture and Sequestration

    E-Print Network [OSTI]

    Newmark, Robin L.; Friedmann, Samuel J.; Carroll, Susan A.

    2010-01-01

    and HB 90:Carbon capture and sequestration, http://legisweb.conference on carbon capture and sequestration, Pittsburgh,The DOE’s Regional Carbon Sequestration Partnerships are

  15. Strategies for demonstration and early deployment of carbon capture and storage : a technical and economic assessment of capture percentage

    E-Print Network [OSTI]

    Hildebrand, Ashleigh Nicole

    2009-01-01

    Carbon capture and storage (CCS) is a critical technology for reducing greenhouse gas emissions from electricity production by coal-fired power plants. However, full capture (capture of nominally 90% of emissions) has ...

  16. 2 Solar flare signatures of the ionospheric GPS total electron content 3 J. Y. Liu,1,2

    E-Print Network [OSTI]

    Chen, Yuh-Ing

    2 Solar flare signatures of the ionospheric GPS total electron content 3 J. Y. Liu,1,2 C. H. Lin,1, ionospheric solar flare effects on the total electron content (TEC) and 7 associated time rate of change (r. The occurrence times and 9 locations of 11 solar flares are isolated from the 1­8 A° X-ray radiations of the 10

  17. Measurement of the rate of stellar tidal disruption flares

    SciTech Connect (OSTI)

    Van Velzen, Sjoert

    2014-09-01

    We report an observational estimate of the rate of stellar tidal disruption flares (TDFs) in inactive galaxies based on a successful search for these events among transients in galaxies using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82). This search yielded 186 nuclear flares in galaxies, 2 of which are excellent TDF candidates. Because of the systematic nature of the search, the very large number of galaxies, the long time of observation, and the fact that non-TDFs were excluded without resorting to assumptions about TDF characteristics, this study provides an unparalleled opportunity to measure the TDF rate. To compute the rate of optical stellar tidal disruption events, we simulate our entire pipeline to obtain the efficiency of detection. The rate depends on the light curves of TDFs, which are presently still poorly constrained. Using only the observed part of the SDSS light curves gives a model-independent upper limit to the optical TDF rate, N-dot <2×10{sup ?4} yr{sup ?1} galaxy{sup ?1} (90% CL), under the assumption that the SDSS TDFs are representative examples. We develop three empirical models of the light curves based on the two SDSS light curves and two more recent and better-sampled Pan-STARRS TDF light curves, leading to our best estimate of the rate: N-dot {sub TDF}=(1.5--2.0){sub ?1.3}{sup +2.7}×10{sup ?5} yr{sup ?1} galaxy{sup ?1}. We explore the modeling uncertainties by considering two theoretically motivated light curve models, as well as two different relationships between black hole mass and galaxy luminosity, and two different treatments of the cutoff in the visibility of TDFs at large M {sub BH}. From this we conclude that these sources of uncertainty are not significantly larger than the statistical ones. Our results are applicable for galaxies hosting black holes with mass in the range of a few 10{sup 6}-10{sup 8} M {sub ?}, and translates to a volumetric TDF rate of (4-8) × 10{sup –8±0.4} yr{sup –1} Mpc{sup –3}, with the statistical uncertainty in the exponent.

  18. Impulsive phase flare energy transport by large-scale Alfven waves and the electron acceleration problem

    E-Print Network [OSTI]

    L. Fletcher; H. S. Hudson

    2007-12-20

    The impulsive phase of a solar flare marks the epoch of rapid conversion of energy stored in the pre-flare coronal magnetic field. Hard X-ray observations imply that a substantial fraction of flare energy released during the impulsive phase is converted to the kinetic energy of mildly relativistic electrons (10-100 keV). The liberation of the magnetic free energy can occur as the coronal magnetic field reconfigures and relaxes following reconnection. We investigate a scenario in which products of the reconfiguration - large-scale Alfven wave pulses - transport the energy and magnetic-field changes rapidly through the corona to the lower atmosphere. This offers two possibilities for electron acceleration. Firstly, in a coronal plasma with beta waves propagate as inertial Alfven waves. In the presence of strong spatial gradients, these generate field-aligned electric fields that can accelerate electrons to energies on the order of 10 keV and above, including by repeated interactions between electrons and wavefronts. Secondly, when they reflect and mode-convert in the chromosphere, a cascade to high wavenumbers may develop. This will also accelerate electrons by turbulence, in a medium with a locally high electron number density. This concept, which bridges MHD-based and particle-based views of a flare, provides an interpretation of the recently-observed rapid variations of the line-of-sight component of the photospheric magnetic field across the flare impulsive phase, and offers solutions to some perplexing flare problems, such as the flare "number problem" of finding and resupplying sufficient electrons to explain the impulsive-phase hard X-ray emission.

  19. RADIOACTIVE POSITRON EMITTER PRODUCTION BY ENERGETIC ALPHA PARTICLES IN SOLAR FLARES

    SciTech Connect (OSTI)

    Murphy, R. J. [Code 7650, Naval Research Laboratory, Washington, DC 20375 (United States); Kozlovsky, B. [Tel Aviv University, Tel Aviv (Israel); Share, G. H., E-mail: murphy@ssd5.nrl.navy.mil, E-mail: benz@wise.tau.ac.il, E-mail: share@astro.umd.edu [University of Maryland, College Park, MD 20742 (United States)

    2015-01-01

    Measurements of the 0.511 MeV positron-annihilation line from solar flares are used to explore the flare process in general and ion acceleration in particular. In flares, positrons are produced primarily by the decay of radioactive positron-emitting isotopes resulting from nuclear interactions of flare-accelerated ions with ambient solar material. Kozlovsky et al. provided ion-energy-dependent production cross sections for 67 positron emitters evaluated from their threshold energies (some <1 MeV nucleon{sup –1}) to a GeV nucleon{sup –1}, incorporating them into a computer code for calculating positron-emitter production. Adequate cross-section measurements were available for proton reactions, but not for ?-particle reactions where only crude estimates were possible. Here we re-evaluate the ?-particle cross sections using new measurements and nuclear reaction codes. In typical large gamma-ray line flares, proton reactions dominate positron production, but ?-particle reactions will dominate for steeper accelerated-ion spectra because of their relatively low threshold energies. With the accelerated-{sup 3}He reactions added previously, the code is now reliable for calculating positron production from any distribution of accelerated-ion energies, not just those of typical flares. We have made the code available in the online version of the Journal. We investigate which reactions, projectiles, and ion energies contribute to positron production. We calculate ratios of the annihilation-line fluence to fluences of other gamma-ray lines. Such ratios can be used in interpreting flare data and in determining which nuclear radiation is most sensitive for revealing acceleration of low-energy ions at the Sun.

  20. Neutron star blackbody contraction during flaring in X1624-490

    E-Print Network [OSTI]

    M. Balucinska-Church; R. Barnard; M. J. Church; A. P. Smale

    2001-10-01

    We present results of an investigation of the physical changes taking place in the emission regions of the LMXB X1624-490 during strong flaring in RXTE observations. Based on the detailed light curve, we propose that the flaring consists of a superposition of X-ray bursts. It is shown that major changes take place in the blackbody emission component, the temperature kT_BB increasing to ~2.2 keV in flaring. Remarkably, the blackbody area decreases by a factor of ~5 in flaring. During flare evolution, the blackbody luminosity remains approximately constant, constituting a previously unknown Eddington limiting effect which we propose is due to radiation pressure of the blackbody as kT_BB increases affecting the inner disk or accretion flow resulting in a decreased emitting area on the star. We argue that the large decrease in area cannot be explained in terms of modification of the blackbody spectrum by electron scattering in the atmosphere of the neutron star. The height of the emitting region on the non-flaring neutron star is shown to agree with the height of the inner radiatively-supported disk as found for sources in the ASCA survey of LMXB of Church & Balucinska-Church (2001). The decrease in height during flaring is discussed in terms of possible models, including radial accretion flow onto the stellar surface and the theory of accretion flow spreading on the neutron star surface of Inogamov & Sunyaev (1999). We demonstrate that the intensity of the broad iron line at 6.4 keV is strongly correlated with the luminosity of the blackbody emission from the neutron star, and discuss the probable origin of this line in the ADC. Finally, possible reasons for non-detection of a reflection component in this source, and LMXB in general, are discussed.

  1. CONTINUUM CONTRIBUTIONS TO THE SDO/AIA PASSBANDS DURING SOLAR FLARES

    SciTech Connect (OSTI)

    Milligan, Ryan O.; McElroy, Sarah A.

    2013-11-01

    Data from the Multiple EUV Grating Spectrograph component of the Extreme-ultraviolet Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) were used to quantify the contribution of continuum emission to each of the extreme ultraviolet (EUV) channels of the Atmospheric Imaging Assembly (AIA), also on SDO, during an X-class solar flare that occurred on 2011 February 15. Both the pre-flare-subtracted EVE spectra and fits to the associated free-free continuum were convolved with the AIA response functions of the seven EUV passbands at 10 s cadence throughout the course of the flare. It was found that 10%-25% of the total emission in the 94 Ĺ, 131 Ĺ, 193 Ĺ, and 335 Ĺ passbands throughout the main phase of the flare was due to free-free emission. Reliable measurements could not be made for the 171 Ĺ channel, while the continuum contribution to the 304 Ĺ channel was negligible due to the presence of the strong He II emission line. Up to 50% of the emission in the 211 Ĺ channel was found to be due to free-free emission around the peak of the flare, while an additional 20% was due to the recombination continuum of He II. The analysis was extended to a number of M- and X-class flares and it was found that the level of free-free emission contributing to both the 171 Ĺ and 211 Ĺ passbands increased with increasing GOES class. These results suggest that the amount of continuum emission that contributes to AIA observations during flares is more significant than stated in previous studies which used synthetic, rather than observed, spectra. These findings highlight the importance of spectroscopic observations carried out in conjunction with those from imaging instruments so that the data are interpreted correctly.

  2. Onset of electron acceleration in a flare loop

    SciTech Connect (OSTI)

    Sharykin, Ivan; Liu, Siming [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210008 (China); Fletcher, Lyndsay, E-mail: liusm@pmo.ac.cn [School of Physics and Astronomy, SUPA, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

    2014-09-20

    We carried out a detailed analysis of X-ray and radio observations of a simple flare loop that occurred on 2002 August 12, with the impulsive hard X-ray (HXR) light curves dominated by a single pulse. The emission spectra of the early impulsive phase are consistent with an isothermal model in the coronal loop with a temperature reaching several keV. A power-law high-energy spectral tail is evident near the HXR peak time, in accordance with the appearance of footpoints at high energies, and is well correlated with the radio emission. The energy content of the thermal component keeps increasing gradually after the disappearance of this nonthermal component. These results suggest that electron acceleration only covers the central period of a longer and more gradual energy dissipation process and that the electron transport within the loop plays a crucial role in the formation of the inferred power-law electron distribution. The spectral index of power-law photons shows a very gradual evolution, indicating that the electron accelerator is in a quasi-steady state, which is confirmed by radio observations. These results are consistent with the theory of stochastic electron acceleration from a thermal background. Advanced modeling with coupled electron acceleration and spatial transport processes is needed to explain these observations more quantitatively, which may reveal the dependence of the electron acceleration on the spatial structure of the acceleration region.

  3. High-sensitivity observations of solar flare decimeter radiation

    E-Print Network [OSTI]

    Arnold O. Benz; Peter Messmer; Christian Monstein

    2000-12-05

    A new acousto-optic radio spectrometer has observed the 1 - 2 GHz radio emission of solar flares with unprecedented sensitivity. The number of detected decimeter type III bursts is greatly enhanced compared to observations by conventional spectrometers observing only one frequency at the time. The observations indicate a large number of electron beams propagating in dense plasmas. For the first time, we report weak, reversed drifting type III bursts at frequencies above simultaneous narrowband decimeter spikes. The type III bursts are reliable signatures of electron beams propagating downward in the corona, apparently away from the source of the spikes. The observations contradict the most popular spike model that places the spike sources at the footpoints of loops. Conspicuous also was an apparent bidirectional type U burst forming a fish-like pattern. It occurs simultaneously with an intense U-burst at 600-370 MHz observed in Tremsdorf. We suggest that it intermodulated with strong terrestrial interference (cellular phones) causing a spurious symmetric pattern in the spectrogram at 1.4 GHz. Symmetric features in the 1 - 2 GHz range, some already reported in the literature, therefore must be considered with utmost caution.

  4. Electron Acceleration in Solar Flares: Theory of Spectral Evolution

    E-Print Network [OSTI]

    Paolo C. Grigis; Arnold O. Benz

    2006-08-14

    Context: Stochastic acceleration is thought to be a key mechanism in the energization of solar flare electrons. Aims: We study whether stochastic acceleration can reproduce the observed soft-hard-soft evolution of the spectral features of the hard X-ray emitted by suprathermal electron. We pay special attention to the effects of particle trapping and escape. Methods: The Fokker-Planck equation for the electron distribution is integrated numerically using the coefficients derived by Miller et al. for transit-time damping acceleration. The electron spectra are then converted to photon spectra for comparison with RHESSI observation of looptop sources. Results: The presence of particle escape softens the model spectra computed in the stochastic acceleration framework. The ratio between the efficiency of trapping and acceleration controls the spectral evolution which follows a soft-hard-soft pattern. Furthermore, a pivot point (that is, a common crossing point of the accelerated particle spectra at different times) is found at around 10 keV. It can be brought into agreement with the observed value of 20 keV by enhanced trapping through an electric potential. Conclusions: The model proposed here accounts for the key features observed in the spectral evolution of hard X-ray emission from looptop sources.

  5. Development of a Dry Sorbent-based Post-Combustion CO2 Capture Technology for Retrofit in Existing Power Plants

    SciTech Connect (OSTI)

    Nelson, Thomas; Coleman, Luke; Anderson, Matthew; Gupta, Raghubir; Herr, Joshua; Kalluri, Ranjeeth; Pavani, Maruthi

    2009-12-31

    The objective of this research and development (R&D) project was to further the development of a solid sorbent-based CO2 capture process based on sodium carbonate (i.e. the Dry Carbonate Process) that is capable of capturing>90% of the CO2 as a nearly pure stream from coal-fired power plant flue gas with <35% increase in the cost of electrictiy (ICOE).

  6. Quantifying protein diffusion and capture on filaments

    E-Print Network [OSTI]

    Emanuel Reithmann; Louis Reese; Erwin Frey

    2015-03-03

    The functional relevance of regulating proteins is often limited to specific binding sites such as the ends of microtubules or actin-filaments. A localization of proteins on these functional sites is of great importance. We present a quantitative theory for a diffusion and capture process, where proteins diffuse on a filament and stop diffusing when reaching the filament's end. It is found that end-association after one-dimensional diffusion is the main source for tip-localization of such proteins. As a consequence, diffusion and capture is highly efficient in enhancing the reaction velocity of enzymatic reactions, where proteins and filament ends are to each other as enzyme and substrate. We show that the reaction velocity can effectively be described within a Michaelis-Menten framework. Together one-dimensional diffusion and capture beats the (three-dimensional) Smoluchowski diffusion limit for the rate of protein association to filament ends.

  7. Quantifying protein diffusion and capture on filaments

    E-Print Network [OSTI]

    Reithmann, Emanuel; Frey, Erwin

    2015-01-01

    The functional relevance of regulating proteins is often limited to specific binding sites such as the ends of microtubules or actin-filaments. A localization of proteins on these functional sites is of great importance. We present a quantitative theory for a diffusion and capture process, where proteins diffuse on a filament and stop diffusing when reaching the filament's end. It is found that end-association after one-dimensional diffusion is the main source for tip-localization of such proteins. As a consequence, diffusion and capture is highly efficient in enhancing the reaction velocity of enzymatic reactions, where proteins and filament ends are to each other as enzyme and substrate. We show that the reaction velocity can effectively be described within a Michaelis-Menten framework. Together one-dimensional diffusion and capture beats the (three-dimensional) Smoluchowski diffusion limit for the rate of protein association to filament ends.

  8. Thermal Neutron Capture y's (CapGam)

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

    The National Nuclear Data Center (NNDC) presents two tables showing energy and photon intensity with uncertainties of gamma rays as seen in thermal-neutron capture.  One table is organized in ascending order of gamma energy, and the second is organized by Z, A of the target. In the energy-ordered table the three strongest transitions are indicated in each case. The nuclide given is the target nucleus in the capture reaction. The gamma energies given are in keV. The gamma intensities given are relative to 100 for the strongest transition. %I? (per 100 n-captures) for the strongest transition is given, where known. All data are taken from the Evaluated Nuclear Structure Data File (ENSDF), a computer file of evaluated nuclear structure data and from the eXperimental Unevaluated Nuclear Data List (XUNDL). (Specialized Interface)

  9. Annual Report: Carbon Capture Simulation Initiative (CCSI) (30 September 2012)

    SciTech Connect (OSTI)

    Miller, David C.; Syamlal, Madhava; Cottrell, Roger; Kress, Joel D.; Sun, Xin; Sundaresan, S.; Sahinidis, Nikolaos V.; Zitney, Stephen E.; Bhattacharyya, D.; Agarwal, Deb; Tong, Charles; Lin, Guang; Dale, Crystal; Engel, Dave; Calafiura, Paolo; Beattie, Keith; Shinn, John

    2012-09-30

    The Carbon Capture Simulation Initiative (CCSI) is a partnership among national laboratories, industry and academic institutions that is developing and deploying state-of-the-art computational modeling and simulation tools to accelerate the commercialization of carbon capture technologies from discovery to development, demonstration, and ultimately the widespread deployment to hundreds of power plants. The CCSI Toolset will provide end users in industry with a comprehensive, integrated suite of scientifically validated models, with uncertainty quantification (UQ), optimization, risk analysis and decision making capabilities. The CCSI Toolset incorporates commercial and open-source software currently in use by industry and is also developing new software tools as necessary to fill technology gaps identified during execution of the project. Ultimately, the CCSI Toolset will (1) enable promising concepts to be more quickly identified through rapid computational screening of devices and processes; (2) reduce the time to design and troubleshoot new devices and processes; (3) quantify the technical risk in taking technology from laboratory-scale to commercial-scale; and (4) stabilize deployment costs more quickly by replacing some of the physical operational tests with virtual power plant simulations. CCSI is organized into 8 technical elements that fall under two focus areas. The first focus area (Physicochemical Models and Data) addresses the steps necessary to model and simulate the various technologies and processes needed to bring a new Carbon Capture and Storage (CCS) technology into production. The second focus area (Analysis & Software) is developing the software infrastructure to integrate the various components and implement the tools that are needed to make quantifiable decisions regarding the viability of new CCS technologies. CCSI also has an Industry Advisory Board (IAB). By working closely with industry from the inception of the project to identify industrial challenge problems, CCSI ensures that the simulation tools are developed for the carbon capture technologies of most relevance to industry. CCSI is led by the National Energy Technology Laboratory (NETL) and leverages the Department of Energy (DOE) national laboratories' core strengths in modeling and simulation, bringing together the best capabilities at NETL, Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Lawrence Livermore National Laboratory (LLNL), and Pacific Northwest National Laboratory (PNNL). The CCSI's industrial partners provide representation from the power generation industry, equipment manufacturers, technology providers and engineering and construction firms. The CCSI's academic participants (Carnegie Mellon University, Princeton University, West Virginia University, and Boston University) bring unparalleled expertise in multiphase flow reactors, combustion, process synthesis and optimization, planning and scheduling, and process control techniques for energy processes. During Fiscal Year (FY) 12, CCSI released its first set of computational tools and models. This pre-release, a year ahead of the originally planned first release, is the result of intense industry interest in getting early access to the tools and the phenomenal progress of the CCSI technical team. These initial components of the CCSI Toolset provide new models and computational capabilities that will accelerate the commercial development of carbon capture technologies as well as related technologies, such as those found in the power, refining, chemicals, and gas production industries. The release consists of new tools for process synthesis and optimization to help identify promising concepts more quickly, new physics-based models of potential capture equipment and processes that will reduce the time to design and troubleshoot new systems, a framework to quantify the uncertainty of model predictions, and various enabling tools that provide new capabilities such as creating reduced order models (ROMs) from reacting multiphase flow simul

  10. Bench-Scale Development of a Hybrid Membrane-Absorption CO{sub 2} Capture Process: Preliminary Cost Assessment

    SciTech Connect (OSTI)

    Freeman, Brice; Kniep, Jay; Pingjiao, Hao; Baker, Richard; Rochelle, Gary; Chen, Eric; Frailie, Peter; Ding, Junyuan; Zhang, Yue

    2014-03-31

    This report describes a study of capture costs for a hybrid membrane-absorption capture system based on Membrane Technology and Research, Inc. (MTR)’s low-pressure membrane contactors and the University of Texas at Austin’s 5 m piperazine (PZ) Advanced Flash Stripper (AFS; 5 m PZ AFS) based CO2 capture system. The report is submitted for NETL review, and may be superseded by a final topical report on this topic that will be submitted to satisfy the Task 2 report requirement of the current project (DE-FE0013118).

  11. Carbon Capture and Storage Database (CCS) from DOE's National Energy Technology Laboratory (NETL)

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

    NETL's Carbon Capture and Storage (CCS) Database includes active, proposed, canceled, and terminated CCS projects worldwide. Information in the database regarding technologies being developed for capture, evaluation of sites for carbon dioxide (CO2) storage, estimation of project costs, and anticipated dates of completion is sourced from publically available information. The CCS Database provides the public with information regarding efforts by various industries, public groups, and governments towards development and eventual deployment of CCS technology. The database contains more than 260 CCS projects worldwide in more than 30 countries across 6 continents. Access to the database requires use of Google Earth, as the NETL CCS database is a layer in Google Earth. Or, users can download a copy of the database in MS-Excel directly from the NETL website.

  12. OFF-SITE RADIOLOGICAL SAFETY PROGRAM FOR PROJECT RULISON FLARING, PHASE I11

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReport for the Weldon Spring,7=cr5rnP 7694 i+lJNew

  13. A HR-like Diagram for Solar/Stellar Flares and Corona -- Emission Measure vs Temperature Diagram

    E-Print Network [OSTI]

    Kazunari Shibata; Takaaki Yokoyama

    2002-06-03

    In our previous paper, we have presented a theory to explain the observed universal correlation between the emission measure ($EM=n^2 V$) and temperature (T) for solar/stellar flares on the basis of the magnetic reconnection model with heat conduction and chromospheric evaporation. Here n is the electron density and V is the volume. By extending our theory to general situations, we examined the EM-T diagram in detail, and found the following properties: 1) The universal correlation sequence (``main sequence flares'') with $EM \\propto T^{17/2}$ corresponds to the case of constant heating flux or equivalently the case of constant magnetic field strength in the reconnection model. 2) The EM-T diagram has a forbidden region, where gas pressure of flares exceeds magnetic pressure. 3) There is a coronal branch with $EM \\propto T^{15/2}$ for $T 10^7$ K. This branch is situated left side of the main sequence flares in the EM-T diagram. 4) There is another forbidden region determined by the length of flare loop; a lower limit of flare loop is $10^7$ cm. Small flares near this limit correspond to nanoflares observed by SOHO/EIT. 5) We can plot flare evolution track on the EM-T diagram. A flare evolves from the coronal branch to main sequence flares, then returns to the coronal branch eventually. These properties of the EM-T diagram are similar to those of the HR diagram for stars, and thus we propose that the EM-T diagram is quite useful to estimate the physical quantities (loop length, heating flux, magnetic field strength, total energy and so on) of flares and corona when there is no spatially resolved imaging observations.

  14. EVALUATION OF CARBON DIOXIDE CAPTURE FROM EXISTING COAL FIRED PLANTS BY HYBRID SORPTION USING SOLID SORBENTS

    SciTech Connect (OSTI)

    Benson, Steven; Browers, Bruce; Srinivasachar, Srivats; Laudal, Daniel

    2014-12-31

    Under contract DE-FE0007603, the University of North Dakota conducted the project Evaluation of Carbon Dioxide Capture from Existing Coal Fired Plants by Hybrid Sorption Using Solid Sorbents. As an important element of this effort, a Technical and Economic Feasibility Study was conducted by Barr Engineering Co. (Barr) in association with the University of North Dakota. The assessment developed a process flow diagram, major equipment list, heat balances for the SCPC power plant, capital cost estimate, operating cost estimate, levelized cost of electricity, cost of CO2 capture ($/ton) and three sensitivity cases for the CACHYS™ process.

  15. Carbon Dioxide Capture DOI: 10.1002/anie.200902836

    E-Print Network [OSTI]

    Paik Suh, Myunghyun

    Carbon Dioxide Capture DOI: 10.1002/anie.200902836 Highly Selective CO2 Capture in Flexible 3D Coordination Polymer Networks** Hye-Sun Choi and Myunghyun Paik Suh* Carbon dioxide capture has been capture, storage, and sensing. Compounds 1 and 2 are the first 3D pillared networks assembled from Ni

  16. Project Reports for Chaninik Wind Group- 2010 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The goals of this project are to reduce the consumption of fossil fuel by 40% in four Lower Kuskokwim Alaska villages and use wind energy to displace 200,000 gallons of diesel fuel, 70,000 of which is now being used to generate power, and 130,000 of which will be captured and stored for use as heat.

  17. Solar Neutrinos from CNO Electron Capture

    E-Print Network [OSTI]

    L. C. Stonehill; J. A. Formaggio; R. G. H. Robertson

    2003-11-18

    The neutrino flux from the sun is predicted to have a CNO-cycle contribution as well as the known pp-chain component. Previously, only the fluxes from beta+ decays of 13N, 15O, and 17F have been calculated in detail. Another neutrino component that has not been widely considered is electron capture on these nuclei. We calculate the number of interactions in several solar neutrino detectors due to neutrinos from electron capture on 13N, 15O, and 17F, within the context of the Standard Solar Model. We also discuss possible non-standard models where the CNO flux is increased.

  18. Amine Functionalized Nanoporous Materials for Carbon Dioxide Capture

    SciTech Connect (OSTI)

    Zheng, Feng; Addleman, Raymond S.; Aardahl, Chris L.; Fryxell, Glen E.; Brown, Daryl R.; Zemanian, Thomas S.

    2007-04-04

    Increasing CO2 concentration level in the earth atmosphere and rising global average temperature have raised serious concerns about the effects of anthropogenic CO2 on global climate change. Meanwhile, most analyses project that fossil fuels will continue to be the dominant energy source world wide until at least the middle of the twenty first century. Significant reduction from the current level of CO2 emission due to the consumption of fossil fuels is necessary to stabilize atmospheric concentration of CO2. The focus of this chapter will be on the CO2 capture technologies related to energy production from fossil fuels, as over one third of the world’s CO2 emissions from fossil-fuel use are attributed to fossil-fuel electric power-generation plants. Solid amine sorbents have promise to overcome some of the shortcomings of liquid amines for CO2 capture in energy production. The dispersion, immobilization, and confinement of the amine functional groups into a porous solid support can result in a more stable, more mass transfer efficient, less toxic, and less corrosive material than the corresponding liquid amines. Solid amine sorbents allow a dry scrubbing process where the energy penalty associated with the evaporation of a large amount of water is avoided. Further, the amine functional groups can be tailored for lower regeneration energy requirement. The supports can be tailored independently for high stability and low mass transfer resistance. This book chapter deals with the topics of solid amine sorbents (both supported and tethered amines) as the functional materials for CO2 separation. The design rational and the performance of such materials are discussed in detail. The state of the art in the synthesis and the CO2 capture performance of solid amine sorbent is reviewed.

  19. Soot and SO[subscript 2] contribution to the supersites in the MILAGRO campaign from elevated flares in the Tula Refinery

    E-Print Network [OSTI]

    Molina, Luisa Tan

    This work presents a simulation of the plume trajectory emitted by flaring activities of the Miguel Hidalgo Refinery in Mexico. The flame of a representative sour gas flare is modeled with a CFD combustion code in order ...

  20. EA-1846: Demonstration of Carbon Dioxide Capture and Sequestration of Steam Methane Reforming Process Gas Used for Large-Scale Hydrogen Production, Port Arthur, Texas

    Broader source: Energy.gov [DOE]

    DOE completed a final environmental assessment (EA) for a project under Area I of the Industrial Carbon Capture and Sequestration from Industrial Sources and Innovative Concepts for Beneficial CO2...

  1. MAGNETIC NONPOTENTIALITY IN PHOTOSPHERIC ACTIVE REGIONS AS A PREDICTOR OF SOLAR FLARES

    SciTech Connect (OSTI)

    Yang Xiao; Lin Ganghua; Zhang Hongqi; Mao Xinjie

    2013-09-10

    Based on several magnetic nonpotentiality parameters obtained from the vector photospheric active region magnetograms obtained with the Solar Magnetic Field Telescope at the Huairou Solar Observing Station over two solar cycles, a machine learning model has been constructed to predict the occurrence of flares in the corresponding active region within a certain time window. The Support Vector Classifier, a widely used general classifier, is applied to build and test the prediction models. Several classical verification measures are adopted to assess the quality of the predictions. We investigate different flare levels within various time windows, and thus it is possible to estimate the rough classes and erupting times of flares for particular active regions. Several combinations of predictors have been tested in the experiments. The True Skill Statistics are higher than 0.36 in 97% of cases and the Heidke Skill Scores range from 0.23 to 0.48. The predictors derived from longitudinal magnetic fields do perform well, however, they are less sensitive in predicting large flares. Employing the nonpotentiality predictors from vector fields improves the performance of predicting large flares of magnitude {>=}M5.0 and {>=}X1.0.

  2. OBSERVATION OF HEATING BY FLARE-ACCELERATED ELECTRONS IN A SOLAR CORONAL MASS EJECTION

    SciTech Connect (OSTI)

    Glesener, Lindsay; Bain, Hazel M.; Krucker, Säm; Lin, Robert P.

    2013-12-20

    We report a Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observation of flare-accelerated electrons in the core of a coronal mass ejection (CME) and examine their role in heating the CME. Previous CME observations have revealed remarkably high thermal energies that can far surpass the CME's kinetic energy. A joint observation by RHESSI and the Atmospheric Imaging Assembly of a partly occulted flare on 2010 November 3 allows us to test the hypothesis that this excess energy is collisionally deposited by flare-accelerated electrons. Extreme ultraviolet (EUV) images show an ejection forming the CME core and sheath, with isothermal multifilter analysis revealing temperatures of ?11 MK in the core. RHESSI images reveal a large (?100 × 50 arcsec{sup 2}) hard X-ray (HXR) source matching the location, shape, and evolution of the EUV plasma, indicating that the emerging CME is filled with flare-accelerated electrons. The time derivative of the EUV emission matches the HXR light curve (similar to the Neupert effect observed in soft and HXR time profiles), directly linking the CME temperature increase with the nonthermal electron energy loss, while HXR spectroscopy demonstrates that the nonthermal electrons contain enough energy to heat the CME. This is the most direct observation to date of flare-accelerated electrons heating a CME, emphasizing the close relationship of the two in solar eruptive events.

  3. Solar Neutron Event in Association with a Large Solar Flare on November 24, 2000

    E-Print Network [OSTI]

    K. Watanabe; Y. Muraki; Y. Matsubara; K. Murakami; T. Sako; H. Tsuchiya; S. Masuda; M. Yoshimori; N. Ohmori; P. Miranda; N. Martinic; R. Ticona; A. Velarde; F. Kakimoto; S. Ogio; Y. Tsunesada; H. Tokuno; Y. Shirasaki

    2003-04-03

    Solar neutrons have been detected using the neutron monitor located at Mt. Chacaltaya, Bolivia, in association with a large solar flare on November 24, 2000. This is the first detection of solar neutrons by the neutron monitor that have been reported so far in solar cycle 23. The statistical significance of the detection is 5.5 sigma. In this flare, the intense emission of hard X-rays and gamma-rays has been observed by the Yohkoh Hard X-ray Telescope (HXT) and Gamma Ray Spectrometer (GRS), respectively. The production time of solar neutrons is better correlated with those of hard X-rays and gamma-rays than with the production time of soft X-rays. The observations of the solar neutrons on the ground have been limited to solar flares with soft X-ray class greater than X8 in former solar cycles. In this cycle, however, neutrons were detected associated with an X2.3 solar flare on November 24, 2000. This is the first report of the detection of solar neutrons on the ground associated with a solar flare with its X-ray class smaller than X8.

  4. First Simultaneous NIR/X-ray Detection of a Flare from SgrA*

    E-Print Network [OSTI]

    A. Eckart; F. K. Baganoff; M. Morris; M. W. Bautz; W. N. Brandt; G. P. Garmire; R. Genzel; T. Ott; G. R. Ricker; C. Straubmeier; T. Viehmann; R. Schödel

    2004-06-17

    We report on the first simultaneous near-infrared/X-ray detection of the Sgr A* counterpart which is associated with the massive black hole at the center of the Milky Way. The observations have been carried out using the NACO adaptive optics (AO) instrument at the European Southern Observatory's Very Large Telescope and the ACIS-I instrument aboard the Chandra X-ray Observatory. We also report on quasi-simultaneous observations at a wavelength of 3.4 mm using the Berkeley-Illinois-Maryland Association (BIMA) array. A flare was detected in the X-domain with an excess 2-8 keV luminosity of about 6$\\times10^{33}$ erg/s. A fading flare of Sgr A* with $>$2 times the interim-quiescent flux was also detected at the beginning of the NIR observations, that overlapped with the fading part of the X-ray flare. Compared to 8-9 hours before the NIR/X-ray flare we detected a marginally significant increase in the millimeter flux density of Sgr A* during measurements about 7-9 hours afterwards. We find that the flaring state can be conveniently explained with a synchrotron self-Compton model involving up-scattered sub-millimeter photons from a compact source component, possibly with modest bulk relativistic motion. The size of that component is assumed to be of the order of a few times the Schwarzschild radius. The overall spectral indices $\\alpha_{NIR/X-ray}$ ($S_{\

  5. An explanation for long flares from extragalactic globular cluster X-ray sources

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2005-09-21

    Repeatedly flaring X-ray binaries have recently been discovered in NGC 4697 by Sivakoff and collaborators. We show that these flares can be explained as the result of eccentric binaries in globular clusters which accrete more rapidly at periastron than during the rest of the binary orbit. We show that theoretical timescales for producing eccentricities and circularising the binaries are consistent with what is needed to produce the observed population of flaring sources, although the circularisation timescales are highly uncertain on both observational and theoretical grounds. This model makes two clear theoretical predictions (1) the flares should be seen to be strictly periodic if adequate sampling is provided, and that periodicity should be of approximately 15 hours (2) this class of flaring behaviour should be seen only in globular cluster sources, and predominantly in the densest globular clusters. We also test the model for producing eccentricities through fly-by's of a third star near the binary in a globular cluster against a much larger database of millisecond pulsar observations than has been used in past work, and find that the theoretical cross sections for producing eccentricity in binaries are in reasonable agreement with most of the data, provided that the pulsar ages are about $4\\times10^9$ years.

  6. HARD X-RAY AND MICROWAVE EMISSIONS FROM SOLAR FLARES WITH HARD SPECTRAL INDICES

    SciTech Connect (OSTI)

    Kawate, T. [Kwasan and Hida Observatory, Kitashirakawa-oiwakecho, Sakyo, Kyoto 606-8502 (Japan); Nishizuka, N. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 229-8510 (Japan); Oi, A. [College of Science, Ibaraki University, Mito, Ibaraki 310-8512 (Japan); Ohyama, M. [Faculty of Education, Shiga University, 2-5-1 Hiratsu, Otsu, Shiga 1-1, Baba Hikone city, Siga 522-8522 (Japan); Nakajima, H., E-mail: kawate@kusastro.kyoto-u.ac.jp [Nobeyama Solar Radio Observatory, NAOJ, Nobeyama, Minamisaku, Nagano 384-1305 (Japan)

    2012-03-10

    We analyze 10 flare events that radiate intense hard X-ray (HXR) emission with significant photons over 300 keV to verify that the electrons that have a common origin of acceleration mechanism and energy power-law distribution with solar flares emit HXRs and microwaves. Most of these events have the following characteristics. HXRs emanate from the footpoints of flare loops, while microwaves emanate from the tops of flare loops. The time profiles of the microwave emission show delays of peak with respect to those of the corresponding HXR emission. The spectral indices of microwave emissions show gradual hardening in all events, while the spectral indices of the corresponding HXR emissions are roughly constant in most of the events, though rather rapid hardening is simultaneously observed in some for both indices during the onset time and the peak time. These characteristics suggest that the microwave emission emanates from the trapped electrons. Then, taking into account the role of the trapping of electrons for the microwave emission, we compare the observed microwave spectra with the model spectra calculated by a gyrosynchrotron code. As a result, we successfully reproduce the eight microwave spectra. From this result, we conclude that the electrons that have a common acceleration and a common energy distribution with solar flares emit both HXR and microwave emissions in the eight events, though microwave emission is contributed to by electrons with much higher energy than HXR emission.

  7. Predicting Solar Flares by Data Assimilation in Avalanche Models. I. Model Design and Validation

    E-Print Network [OSTI]

    Eric Bélanger; Alain Vincent; Paul Charbonneau

    2007-08-14

    Data assimilation techniques, developed in the last two decades mainly for weather prediction, produce better forecasts by taking advantage of both theoretical/numerical models and real-time observations. In this paper, we explore the possibility of applying the data-assimilation techniques known as 4D-VAR to the prediction of solar flares. We do so in the context of a continuous version of the classical cellular-automaton-based self-organized critical avalanche models of solar flares introduced by Lu and Hamilton (Astrophys. J., 380, L89, 1991). Such models, although a priori far removed from the physics of magnetic reconnection and magneto-hydrodynamical evolution of coronal structures, nonetheless reproduce quite well the observed statistical distribution of flare characteristics. We report here on a large set of data assimilation runs on synthetic energy release time series. Our results indicate that, despite the unpredictable (and unobservable) stochastic nature of the driving/triggering mechanism within the avalanche model, 4D-VAR succeeds in producing optimal initial conditions that reproduce adequately the time series of energy released by avalanches/flares. This is an essential first step towards forecasting real flares.

  8. Constraints on the Bulk Lorentz Factors of GRB X-Ray Flares

    E-Print Network [OSTI]

    Yi, Shuang-Xi; Wang, Fa-Yin; Dai, Zi-Gao

    2015-01-01

    X-ray flares were discovered in the afterglow phase of gamma-ray bursts (GRBs) by the {\\em Swift} satellite a decade ago and known as a canonical component in GRB X-ray afterglows. In this paper, we constrain the Lorentz factors of GRB X-ray flares using two different methods. For the first method, we estimate the lower limit on the bulk Lorentz factor with the flare duration and jet break time. In the second method, the upper limit on the Lorentz factor is derived by assuming that the X-ray flare jet has undergone saturated acceleration. We also re-estimate the initial Lorentz factor with GRB afterglow onsets, and find the coefficient of the theoretical Lorentz factor is 1.67 rather than the commonly used 2 for interstellar medium (ISM) and 1.44 for the wind case. We find that the correlation between the limited Lorentz factor and the isotropic radiation energy of X-ray flares in the ISM case is more consistent with that of prompt emission than the wind case in a statistical sense. For a comparison, the lowe...

  9. IRIS Observations of the Mg II h & k Lines During a Solar Flare

    E-Print Network [OSTI]

    Kerr, Graham S; Qiu, Jiong; Fletcher, Lyndsay

    2015-01-01

    The bulk of the radiative output of a solar flare is emitted from the chromosphere, which produces enhancements in the optical and UV continuum, and in many lines, both optically thick and thin. We have, until very recently, lacked observations of two of the strongest of these lines: the Mg II h & k resonance lines. We present a detailed study of the response of these lines to a solar flare. The spatial and temporal behaviour of the integrated intensities, k/h line ratios, line of sight velocities, line widths and line asymmetries were investigated during an M class flare (SOL2014-02-13T01:40). Very intense, spatially localised energy input at the outer edge of the ribbon is observed, resulting in redshifts equivalent to velocities of ~15-26km/s, line broadenings, and a blue asymmetry in the most intense sources. The characteristic central reversal feature that is ubiquitous in quiet Sun observations is absent in flaring profiles, indicating that the source function increases with height during the flare....

  10. Observational Evidences of Electron-driven Evaporation in two Solar Flares

    E-Print Network [OSTI]

    Li, Dong; Zhang, Qingmin

    2015-01-01

    We have explored the relationship between hard X-ray (HXR) emissions and Doppler velocities caused by the chromospheric evaporation in two X1.6 class solar flares on 2014 September 10 and October 22, respectively. Both events display double ribbons and Interface Region Imaging Spectrograph (IRIS) slit is fixed on one of their ribbons from the flare onset. The explosive evaporations are detected in these two flares. The coronal line of Fe XXI 1354.09 A shows blue shifts, but chromospheric line of C I 1354.29 A shows red shifts during the impulsive phase. The chromospheric evaporation tends to appear at the front of flare ribbon. Both Fe XXI and C I display their Doppler velocities with a `increase-peak-decrease' pattern which is well related to the `rising-maximum- decay' phase of HXR emissions. Such anti-correlation between HXR emissions and Fe XXI Doppler shifts, and correlation with C I Doppler shifts indicate the electron-driven evaporation in these two flares.

  11. X-ray flares, neutrino cooled disks, and the dynamics of late accretion in GRB engines

    E-Print Network [OSTI]

    Davide Lazzati; Rosalba Perna; Mitchell C. Begelman

    2008-05-01

    We compute the average luminosity of X-ray flares as a function of time, for a sample of 10 long-duration gamma-ray burst afterglows. The mean luminosity, averaged over a timescale longer than the duration of the individual flares, declines as a power-law in time with index ~-1.5. We elaborate on the properties of the central engine that can produce such a decline. Assuming that the engine is an accreting compact object, and for a standard conversion factor between accretion rate and jet luminosity, the switch between a neutrino-cooled thin disk and a non-cooled thick disk takes place at the transition from the prompt to the flaring phase. We discuss the implications of this coincidence under different scenarios for the powering of the GRB outflow. We also show that the interaction of the outflow with the envelope of the progenitor star cannot produce flares out of a continuous relativistic flow, and conclude that it is the dynamics of the disk or the jet-launching mechanism that generates an intrinsically unsteady outflow on timescales much longer than the dynamical timescale of the system. This is consistent with the fact that X-ray flares are observed in short-duration GRBs as well as in long-duration ones.

  12. Are Heating Events in the Quiet Solar Corona Small Flares? - Multiwavelength Observations of Individual Events

    E-Print Network [OSTI]

    Sam Krucker; Arnold O. Benz

    1999-12-23

    Temporary enhancements of the coronal emission measure in a quiet region have been shown to constitute a significant energy input. Here some relatively large events are studied for simultaneous brightenings in transition region lines and in radio emission. Associated emissions are discussed and tested for characteristics known from full-sized impulsive flares in active regions. Heating events and flares are found to have many properties in common, including (i) associated polarized radio emission, which usually precedes the emission measure peak (Neupert effect) and sometimes has a non-thermal spectrum, and (ii) associated and often preceding peaks in O V and He I emission. On the other hand, heating events also differ from impulsive flares: (i) In half of the cases, their radio emission at centimeter waves shows a spectrum consistent with thermal radiation,(ii) the ratio of the gyro-synchrotron emission to the estimated thermal soft X-ray emission is smaller than in flares, and (iii) the associated emission in the O V transition region line shows red shifts and blue shifts, indicating upflows in the rise phase and downflows in the decay phase, respectively. Nevertheless, the differences seem to be mainly quantitative, and the analyzed heating events with thermal energies around 10^26 erg may in principle be considered as microflares or large nanoflares, thus small versions of regular flares.

  13. Correlation of hard X-ray and white light emission in solar flares

    E-Print Network [OSTI]

    Kuhar, Matej; Oliveros, Juan Carlos Martínez; Battaglia, Marina; Kleint, Lucia; Casadei, Diego; Hudson, Hugh S

    2015-01-01

    A statistical study of the correlation between hard X-ray and white light emission in solar flares is performed in order to search for a link between flare-accelerated electrons and white light formation. We analyze 43 flares spanning GOES classes M and X using observations from RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) and HMI (Helioseismic and Magnetic Imager). We calculate X-ray fluxes at 30 keV and white light fluxes at 6173 \\r{A} summed over the hard X-ray flare ribbons with an integration time of 45 seconds around the peak hard-X ray time. We find a good correlation between hard X-ray fluxes and excess white light fluxes, with a highest correlation coefficient of 0.68 for photons with energy of 30 keV. Assuming the thick target model, a similar correlation is found between the deposited power by flare-accelerated electrons and the white light fluxes. The correlation coefficient is found to be largest for energy deposition by electrons above ~50 keV. At higher electron energies the co...

  14. Evaluation of expected solar flare neutrino events in the IceCube observatory

    E-Print Network [OSTI]

    de Wasseige, G; Hanson, K; van Eijndhoven, N; Klein, K -L

    2015-01-01

    Since the end of the eighties and in response to a reported increase in the total neutrino flux in the Homestake experiment in coincidence with a solar flare, solar neutrino detectors have searched for solar flare signals. Neutrinos from the decay of mesons, which are themselves produced in collisions of accelerated protons with the solar atmosphere, would provide a novel window on the underlying physics of the acceleration process. For our studies we focus on the IceCube Neutrino Observatory, a cubic kilometer neutrino detector located at the geographical South Pole. Due to its Supernova data acquisition system and its DeepCore component, dedicated to low energy neutrinos, IceCube may be sensitive to solar flare neutrinos and thus permit either a measurement of the signal or the establishment of more stringent upper limits on the solar flare neutrino flux. We present an approach for a time profile analysis based on a stacking method and an evaluation of a possible solar flare signal in IceCube using the Gean...

  15. Carbon Capture and Sequestration from a Hydrogen Production Facility in an Oil Refinery

    SciTech Connect (OSTI)

    Engels, Cheryl; Williams, Bryan, Valluri, Kiranmal; Watwe, Ramchandra; Kumar, Ravi; Mehlman, Stewart

    2010-06-21

    The project proposed a commercial demonstration of advanced technologies that would capture and sequester CO2 emissions from an existing hydrogen production facility in an oil refinery into underground formations in combination with Enhanced Oil Recovery (EOR). The project is led by Praxair, Inc., with other project participants: BP Products North America Inc., Denbury Onshore, LLC (Denbury), and Gulf Coast Carbon Center (GCCC) at the Bureau of Economic Geology of The University of Texas at Austin. The project is located at the BP Refinery at Texas City, Texas. Praxair owns and operates a large hydrogen production facility within the refinery. As part of the project, Praxair would construct a CO2 capture and compression facility. The project aimed at demonstrating a novel vacuum pressure swing adsorption (VPSA) based technology to remove CO2 from the Steam Methane Reformers (SMR) process gas. The captured CO2 would be purified using refrigerated partial condensation separation (i.e., cold box). Denbury would purchase the CO2 from the project and inject the CO2 as part of its independent commercial EOR projects. The Gulf Coast Carbon Center at the Bureau of Economic Geology, a unit of University of Texas at Austin, would manage the research monitoring, verification and accounting (MVA) project for the sequestered CO2, in conjunction with Denbury. The sequestration and associated MVA activities would be carried out in the Hastings field at Brazoria County, TX. The project would exceed DOE?s target of capturing one million tons of CO2 per year (MTPY) by 2015. Phase 1 of the project (Project Definition) is being completed. The key objective of Phase 1 is to define the project in sufficient detail to enable an economic decision with regard to proceeding with Phase 2. This topical report summarizes the administrative, programmatic and technical accomplishments completed in Phase 1 of the project. It describes the work relative to project technical and design activities (associated with CO2 capture technologies and geologic sequestration MVA), and Environmental Information Volume. Specific accomplishments of this Phase include: 1. Finalization of the Project Management Plan 2. Development of engineering designs in sufficient detail for defining project performance and costs 3. Preparation of Environmental Information Volume 4. Completion of Hazard Identification Studies 5. Completion of control cost estimates and preparation of business plan During the Phase 1 detailed cost estimate, project costs increased substantially from the previous estimate. Furthermore, the detailed risk assessment identified integration risks associated with potentially impacting the steam methane reformer operation. While the Phase 1 work identified ways to mitigate these integration risks satisfactorily from an operational perspective, the associated costs and potential schedule impacts contributed to the decision not to proceed to Phase 2. We have concluded that the project costs and integration risks at Texas City are not commensurate with the potential benefits of the project at this time.

  16. Chaninik Wind Group- 2010 Project

    Broader source: Energy.gov [DOE]

    The goals of this project are to reduce the consumption of fossil fuel by 40% in four Lower Kuskokwim Alaska villages and use wind energy to displace 200,000 gallons of diesel fuel, 70,000 of which is now being used to generate power, and 130,000 of which will be captured and stored for use as heat.

  17. Chemical Looping Gasification for Hydrogen Enhanced Syngas Production with In-Situ CO2 Capture

    SciTech Connect (OSTI)

    Kathe, Mandar; Xu, Dikai; Hsieh, Tien-Lin; Simpson, James; Statnick, Robert; Tong, Andrew; Fan, Liang-Shih

    2014-12-31

    This document is the final report for the project titled “Chemical Looping Gasification for Hydrogen Enhanced Syngas Production with In-Situ CO2 Capture” under award number FE0012136 for the performance period 10/01/2013 to 12/31/2014.This project investigates the novel Ohio State chemical looping gasification technology for high efficiency, cost efficiency coal gasification for IGCC and methanol production application. The project developed an optimized oxygen carrier composition, demonstrated the feasibility of the concept and completed cold-flow model studies. WorleyParsons completed a techno-economic analysis which showed that for a coal only feed with carbon capture, the OSU CLG technology reduced the methanol required selling price by 21%, lowered the capital costs by 28%, increased coal consumption efficiency by 14%. Further, using the Ohio State Chemical Looping Gasification technology resulted in a methanol required selling price which was lower than the reference non-capture case.

  18. Bioenergy with Carbon Capture and Sequestration Workshop

    Broader source: Energy.gov [DOE]

    The Office of Fossil Energy (FE) and the Bioenergy Technologies Office (BETO) in the Office of Energy Efficiency and Renewable Energy (EERE) at the U.S. Department of Energy (DOE) is hosting a Bioenergy with Carbon Capture and Sequestration (BECCS) Workshop on Monday, May 18, 2015 in Washington, DC.

  19. Synthesis of optimal adsorptive carbon capture processes.

    SciTech Connect (OSTI)

    chang, Y.; Cozad, A.; Kim, H.; Lee, A.; Vouzis, P.; Konda, M.; Simon, A.; Sahinidis, N.; Miller, D.

    2011-01-01

    Solid sorbent carbon capture systems have the potential to require significantly lower regeneration energy compared to aqueous monoethanol amine (MEA) systems. To date, the majority of work on solid sorbents has focused on developing the sorbent materials themselves. In order to advance these technologies, it is necessary to design systems that can exploit the full potential and unique characteristics of these materials. The Department of Energy (DOE) recently initiated the Carbon Capture Simulation Initiative (CCSI) to develop computational tools to accelerate the commercialization of carbon capture technology. Solid sorbents is the first Industry Challenge Problem considered under this initiative. An early goal of the initiative is to demonstrate a superstructure-based framework to synthesize an optimal solid sorbent carbon capture process. For a given solid sorbent, there are a number of potential reactors and reactor configurations consisting of various fluidized bed reactors, moving bed reactors, and fixed bed reactors. Detailed process models for these reactors have been modeled using Aspen Custom Modeler; however, such models are computationally intractable for large optimization-based process synthesis. Thus, in order to facilitate the use of these models for process synthesis, we have developed an approach for generating simple algebraic surrogate models that can be used in an optimization formulation. This presentation will describe the superstructure formulation which uses these surrogate models to choose among various process alternatives and will describe the resulting optimal process configuration.

  20. An Architecture for Motion Capture Animation

    E-Print Network [OSTI]

    de Figueiredo, Luiz Henrique

    An Architecture for Motion Capture Animation Fernando Wagner da Silva Luiz Velho Jonas Gomes Paulo System's Architecture q Conclusions q Future work / Work in progress General Outline #12;q Motion systems Our Motivation #12;q MoCap as main animation tool q Modular architecture (Input, Processing

  1. Carbon Dioxide Capture from Coal-Fired

    E-Print Network [OSTI]

    Carbon Dioxide Capture from Coal-Fired Power Plants: A Real Options Analysis May 2005 MIT LFEE 2005. LFEE 2005-002 Report #12;#12;i ABSTRACT Investments in three coal-fired power generation technologies environment. The technologies evaluated are pulverized coal (PC), integrated coal gasification combined cycle

  2. The Outlook for CO2 Capture Costs

    E-Print Network [OSTI]

    Common Measures of CCS Cost · Capital cost · Increased cost of electricity · Cost of CO2 avoided · Cost of CO2 captured E.S. Rubin, Carnegie Mellon Elements of Capital Cost Note: · Nomenclature and cost items construction Total Capital Requirement (TCR) E.S. Rubin, Carnegie Mellon Cost of Electricity (COE) COE ($/MWh

  3. March 2005 Number 238 CARBON CAPTURE AND

    E-Print Network [OSTI]

    Mather, Tamsin A.

    stationary sources such as power stations and industrial plants, where CO2 can be separated from the flue's existing power stations as well as included in new build. All capture technologies consume energy and reduce the efficiency of the power station. Further research and development will lead to cost reductions

  4. Porphyrins for boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, Michiko (Center Moriches, NY); Gabel, Detlef (Bremen, DE)

    1990-01-01

    Novel compounds for treatment of brain tumors in Boron Neutron Capture Therapy are disclosed. A method for preparing the compounds as well as pharmaceutical compositions containing said compounds are also disclosed. The compounds are water soluble, non-toxic and non-labile boronated porphyrins which show significant uptake and retention in tumors.

  5. Capture and Utilisation of Landfill Gas

    E-Print Network [OSTI]

    Columbia University

    about 955 landfills that recovered biogas. The largest number of such landfills were in the USA landfills in Denmark that in total captured 5,800Nm3 of biogas per hour, equivalent to 276.4MW of contained #12;Biomass US DATA ON GENERATION OF BIOGAS AT LANDFILLS Eileen Berenyi, a Research Associate of EEC

  6. A MULTIMEDIA APPROACH TO REQUIREMENTS CAPTURE

    E-Print Network [OSTI]

    Stevens, Scott M.

    OF ELECTRICAL AND ELECTRONICS ENGINEERS, INC. I EEE COMPUTER SOCIETY #12;A Multimedia Approach to Requirements. Stevens Reprinted from the PROCEEDINGS OF THE FIRST INTERNATIONAL CONFERENCE ON REQUIREMENTS ENGINEERING Capture and Modeling David P. Wood Michael G. Christel Scott M. Stevens Software Engineering Institute

  7. Neutron Capture Nucleosynthesis in Early Galactic Environments #

    E-Print Network [OSTI]

    Cowan, John

    Neutron Capture Nucleosynthesis in Early Galactic Environments # James W. Truran 1 , John J. Cowan we can extract useful clues to and constraints upon the star formation and nucleosynthesis history that provide the site for s­process nucleosynthesis during the AGB phase of their evolution. We review recent

  8. Empirical Determination of the Energy Loss Rate of Accelerated Electrons in a Well-Observed Solar Flare

    E-Print Network [OSTI]

    Piana, Michele

    & Michele Piana1,3 ABSTRACT We present electron images of an extended solar flare source, deduced from the impulsive phase of a solar flare typically appears in the form of accelerated electrons. In the generallyEmpirical Determination of the Energy Loss Rate of Accelerated Electrons in a Well-Observed Solar

  9. NEUTRON MONITOR DATA ON THE 15 JUNE 1991 FLARE: NEUTRONS AS A TEST FOR PROTON ACCELERATION SCENARIO

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    NEUTRON MONITOR DATA ON THE 15 JUNE 1991 FLARE: NEUTRONS AS A TEST FOR PROTON ACCELERATION SCENARIO.J.TANSKANEN University of Oulu, SF-90570, Oulu, Finland ABSTRACT. Response of A1ma-Ata neuuon monitor for solar neutrons of proton acceleration during the flare. The analysis of neutron monitor is an evidence in favour

  10. PROPERTIES OF FAST SUBMILLIMETER TIME STRUCTURES DURING A LARGE SOLAR FLARE Jean-Pierre Raulin, Pierre Kaufmann,1

    E-Print Network [OSTI]

    Giménez de Castro, Guillermo Carlos

    et al. 1994). It has long been recognized that microwave solar bursts are composed of variationsPROPERTIES OF FAST SUBMILLIMETER TIME STRUCTURES DURING A LARGE SOLAR FLARE Jean-Pierre Raulin of the strongest solar radio flares of solar cycle 23. Emission was obtained by the Solar Submillimeter

  11. MAGNETIC RECONNECTION: FROM 'OPEN' EXTREME-ULTRAVIOLET LOOPS TO CLOSED POST-FLARE ONES OBSERVED BY SDO

    SciTech Connect (OSTI)

    Zhang, Jun; Yang, Shuhong; Li, Ting; Zhang, Yuzong; Li, Leping [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Jiang, Chaowei, E-mail: zjun@nao.cas.cn, E-mail: shuhongyang@nao.cas.cn, E-mail: liting@nao.cas.cn, E-mail: yuzong@nao.cas.cn, E-mail: lepingli@nao.cas.cn, E-mail: cwjiang@spaceweather.ac.cn [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-10-10

    We employ Solar Dynamics Observatory observations and select three well-observed events including two flares and one extreme-ultraviolet (EUV) brightening. During the three events, the EUV loops clearly changed. One event was related to a major solar flare that took place on 2012 July 12 in active region NOAA AR 11520. 'Open' EUV loops rooted in a facula of the AR deflected to the post-flare loops and then merged with them while the flare ribbon approached the facula. Meanwhile, 'open' EUV loops rooted in a pore disappeared from top to bottom as the flare ribbon swept over the pore. The loop evolution was similar in the low-temperature channels (e.g., 171 Ĺ) and the high-temperature channels (e.g., 94 Ĺ). The coronal magnetic fields extrapolated from the photospheric vector magnetograms also show that the fields apparently 'open' prior to the flare become closed after it. The other two events were associated with a B1.1 flare on 2010 May 24 and an EUV brightening on 2013 January 03, respectively. During both of these two events, some 'open' loops either disappeared or darkened before the formation of new closed loops. We suggest that the observations reproduce the picture predicted by the standard magnetic reconnection model: 'open' magnetic fields become closed due to reconnection, manifesting as a transformation from 'open' EUV loops to closed post-flare ones.

  12. Annual Report: Carbon Capture (30 September 2012)

    SciTech Connect (OSTI)

    Luebke, David; Morreale, Bryan; Richards, George; Syamlal, Madhava

    2014-04-16

    Capture of carbon dioxide (CO{sub 2}) is a critical component in reducing greenhouse gas emissions from fossil fuel-based processes. The Carbon Capture research to be performed is aimed at accelerating the development of efficient, cost-effective technologies which meet the post-combustion programmatic goal of capture of 90% of the CO{sub 2} produced from an existing coal-fired power plant with less than a 35% increase in the cost of electricity (COE), and the pre-combustion goal of 90% CO{sub 2} capture with less than a 10% increase in COE. The specific objective of this work is to develop innovative materials and approaches for the economic and efficient capture of CO{sub 2} from coal-based processes, and ultimately assess the performance of promising technologies at conditions representative of field application (i.e., slip stream evaluation). The Carbon Capture research includes seven core technical research areas: post-combustion solvents, sorbents, and membranes; pre-combustion solvents, sorbents, and membranes; and oxygen (O{sub 2}) production. The goal of each of these tasks is to develop advanced materials and processes that are able to reduce the energy penalty and cost of CO{sub 2} (or O{sub 2}) separation over conventional technologies. In the first year of development, materials will be examined by molecular modeling, and then synthesized and experimentally characterized at lab scale. In the second year, they will be tested further under ideal conditions. In the third year, they will be tested under realistic conditions. The most promising materials will be tested at the National Carbon Capture Center (NCCC) using actual flue or fuel gas. Systems analyses will be used to determine whether or not materials developed are likely to meet the Department of Energy (DOE) COE targets. Materials which perform well and appear likely to improve in performance will be licensed for further development outside of the National Energy Technology Laboratory (NETL), Office of Research and Development (ORD).

  13. Evidence for Extended Acceleration of Solar-Flare Ions from 18-MeV Solar Neutrons Detected with the MESSENGER Neutron Spectrometer

    E-Print Network [OSTI]

    Nittler, Larry R.

    Evidence for Extended Acceleration of Solar-Flare Ions from 1­8-MeV Solar Neutrons Detected. These observations are the first detection of solar neutrons inside 1 AU. This flare contained multiple acceleration in solar flares. These ions are difficult to detect remotely if they do not have access to Page 2 of 33 #12

  14. Effect of the 14 July 2000 solar flare on Earth's FUV Thomas J. Immel, Stephen B. Mende, Harald U. Frey, and N. stgaard

    E-Print Network [OSTI]

    Mende, Stephen B.

    Effect of the 14 July 2000 solar flare on Earth's FUV emissions Thomas J. Immel, Stephen B. Mende; revised 18 September 2002; accepted 4 February 2003; published 15 April 2003. [1] An X-class solar flare) confirm the close correlation between solar EUV and terrestrial FUV emissions. A comparison of the flare

  15. Filament Eruption after the Onset of the X1.5 Flare on 2005 September 13 Haimin Wang, Chang Liu, Ju Jing, and Vasyl Yurchyshyn

    E-Print Network [OSTI]

    Filament Eruption after the Onset of the X1.5 Flare on 2005 September 13 Haimin Wang, Chang Liu, Ju Erupting filaments usually play the role as the initial driver of flaring process pre- ceding September 13, a filament at the boundary of the NOAA AR 0808 erupted 13 minutes after the flare onset at 19

  16. Particle dynamics in a non-flaring solar active region model

    E-Print Network [OSTI]

    Threlfall, J; Neukirch, T; Parnell, C E

    2015-01-01

    The aim of this work is to investigate and characterise particle behaviour in a (observationally-driven) 3D MHD model of the solar atmosphere above a slowly evolving, non-flaring active region. We use a relativistic guiding-centre particle code to investigate particle acceleration in a single snapshot of the 3D MHD simulation. Despite the lack of flare-like behaviour in the active region, direct acceleration of electrons and protons to non-thermal energies ($\\lesssim420$MeV) was found, yielding spectra with high-energy tails which conform to a power law. Examples of particle dynamics, including particle trapping caused by local electric rather than magnetic field effects, are observed and discussed, together with implications for future experiments which simulate non-flaring active region heating and reconnection.

  17. Clusters of small eruptive flares produced by magnetic reconnection in the sun

    E-Print Network [OSTI]

    Archontis, V

    2015-01-01

    We report on the formation of small solar flares produced by patchy magnetic reconnection between interacting magnetic loops. A three-dimensional (3D) magnetohydrodynamic (MHD) numerical experiment was performed, where a uniform magnetic flux sheet was injected into a fully developed convective layer. The gradual emergence of the field into the solar atmosphere results in a network of magnetic loops, which interact dynamically forming current layers at their interfaces. The formation and ejection of plasmoids out of the current layers leads to patchy reconnection and the spontaneous formation of several small (size ? 1-2Mm) flares. We find that these flares are short-lived (30 s - 3 min) bursts of energy in the range O(10^25 - 10^27) ergs, which is basically the nanoflare-microflare range. Their persistent formation and co-operative action and evolution leads to recurrent emission of fast EUV/X-ray jets and considerable plasma heating in the active corona.

  18. Observation and numerical modeling of chromospheric evaporation during the impulsive phase of a solar flare

    E-Print Network [OSTI]

    Imada, Shinsuke; Watanabe, Tetsuya

    2015-01-01

    We have studied the chromospheric evaporation flow during the impulsive phase of the flare by using the Hinode/EIS observation and 1D hydrodynamic numerical simulation coupled to the time-dependent ionization. The observation clearly shows that the strong redshift can be observed at the base of the flaring loop only during the impulsive phase. We performed two different numerical simulations to reproduce the strong downflows in FeXII and FeXV during the impulsive phase. By changing the thermal conduction coefficient, we carried out the numerical calculation of chromospheric evaporation in the thermal conduction dominant regime (conductivity coefficient kappa0 = classical value) and the enthalpy flux dominant regime (kappa0 = 0.1 x classical value). The chromospheric evaporation calculation in the enthalpy flux dominant regime could reproduce the strong redshift at the base of the flare during the impulsive phase. This result might indicate that the thermal conduction can be strongly suppressed in some cases o...

  19. CLUSTERS OF SMALL ERUPTIVE FLARES PRODUCED BY MAGNETIC RECONNECTION IN THE SUN

    SciTech Connect (OSTI)

    Archontis, V.; Hansteen, V.

    2014-06-10

    We report on the formation of small solar flares produced by patchy magnetic reconnection between interacting magnetic loops. A three-dimensional (3D) magnetohydrodynamic (MHD) numerical experiment was performed, where a uniform magnetic flux sheet was injected into a fully developed convective layer. The gradual emergence of the field into the solar atmosphere results in a network of magnetic loops, which interact dynamically forming current layers at their interfaces. The formation and ejection of plasmoids out of the current layers leads to patchy reconnection and the spontaneous formation of several small (size ?1-2 Mm) flares. We find that these flares are short-lived (30 s–3 minutes) bursts of energy in the range O(10{sup 25}-10{sup 27}) erg, which is basically the nanoflare-microflare range. Their persistent formation and co-operative action and evolution leads to recurrent emission of fast EUV/X-ray jets and considerable plasma heating in the active corona.

  20. Gamma-ray flares in the Crab Nebula: A case of relativistic reconnection?

    SciTech Connect (OSTI)

    Cerutti, B.; Werner, G. R. Uzdensky, D. A.; Begelman, M. C.

    2014-05-15

    The Crab Nebula was formed after the collapse of a massive star about a thousand years ago, leaving behind a pulsar that inflates a bubble of ultra-relativistic electron-positron pairs permeated with magnetic field. The observation of brief but bright flares of energetic gamma rays suggests that pairs are accelerated to PeV energies within a few days; such rapid acceleration cannot be driven by shocks. Here, it is argued that the flares may be the smoking gun of magnetic dissipation in the Nebula. Using 2D and 3D particle-in-cell simulations, it is shown that the observations are consistent with relativistic magnetic reconnection, where pairs are subject to strong radiative cooling. The Crab flares may highlight the importance of relativistic magnetic reconnection in astrophysical sources.

  1. Assessing out-of-band flare effects at the wafer level for EUV lithography

    SciTech Connect (OSTI)

    George, Simi; Naulleau, Patrick; Kemp, Charles; Denham, Paul; Rekawa, Senajith

    2010-01-25

    To accurately estimate the flare contribution from the out-of-band (OOB), the integration of a DUV source into the SEMATECH Berkeley 0.3-NA Micro-field Exposure tool is proposed, enabling precisely controlled exposures along with the EUV patterning of resists in vacuum. First measurements evaluating the impact of bandwidth selected exposures with a table-top set-up and subsequent EUV patterning show significant impact on line-edge roughness and process performance. We outline a simulation-based method for computing the effective flare from resist sensitive wavelengths as a function of mask pattern types and sizes. This simulation method is benchmarked against measured OOB flare measurements and the results obtained are in agreement.

  2. Evolution of the Loop-Top Source of Solar Flares--Heating and Cooling Processes

    E-Print Network [OSTI]

    Yan Wei Jiang; Siming Liu; Wei Liu; Vahe Petrosian

    2005-08-24

    We present a study of the spatial and spectral evolution of the loop-top (LT) sources in a sample of 6 flares near the solar limb observed by {\\it RHESSI}. A distinct coronal source, which we identify as the LT source, was seen in each of these flares from the early ``pre-heating'' phase through the late decay phase. Spectral analyses reveal an evident steep power-law component in the pre-heating and impulsive phases, suggesting that the particle acceleration starts upon the onset of the flares. In the late decay phase the LT source has a thermal spectrum and appears to be confined within a small region near the top of the flare loop, and does not spread throughout the loop, as is observed at lower energies. The total energy of this source decreases usually faster than expected from the radiative cooling but much slower than that due to the classical Spitzer conductive cooling along the flare loop. These results indicate the presence of a distinct LT region, where the thermal conductivity is suppressed significantly and/or there is a continuous energy input. We suggest that plasma wave turbulence could play important roles in both heating the plasma and suppressing the conduction during the decay phase of solar flares. With a simple quasi-steady loop model we show that the energy input in the gradual phase can be comparable to that in the impulsive phase and demonstrate how the observed cooling and confinement of the LT source can be used to constrain the wave-particle interaction.

  3. MAGNETIC ENERGY PARTITION BETWEEN THE CORONAL MASS EJECTION AND FLARE FROM AR 11283

    SciTech Connect (OSTI)

    Feng, L.; Li, Y. P.; Gan, W. Q.; Wiegelmann, T.; Inhester, B.; Su, Y.; Sun, X. D.

    2013-03-01

    On 2011 September 6, an X-class flare and a halo coronal mass ejection (CME) were observed from Earth erupting from the same active region AR 11283. The magnetic energy partition between them has been investigated. SDO/HMI vector magnetograms were used to obtain the coronal magnetic field using the nonlinear force-free field (NLFFF) extrapolation method. The free magnetic energies before and after the flare were calculated to estimate the released energy available to power the flare and the CME. For the flare energetics, thermal and nonthermal energies were derived using the RHESSI and GOES data. To obtain the radiative output, SDO/EVE data in the 0.1-37 nm waveband were utilized. We have reconstructed the three-dimensional (3D) periphery of the CME from the coronagraph images observed by STEREO-A, B, and SOHO. The mass calculations were then based on a more precise Thomson-scattering geometry. The subsequent estimate of the kinetic and potential energies of the CME took advantage of the more accurate mass, and the height and speed in a 3D frame. The released free magnetic energy resulting from the NLFFF model is about 6.4 Multiplication-Sign 10{sup 31} erg, which has a possible upper limit of 1.8 Multiplication-Sign 10{sup 32} erg. The thermal and nonthermal energies are lower than the radiative output of 2.2 Multiplication-Sign 10{sup 31} erg from SDO/EVE for this event. The total radiation covering the whole solar spectrum is probably a few times larger. The sum of the kinetic and potential energy of the CME could go up to 6.5 Multiplication-Sign 10{sup 31} erg. Therefore, the free energy is able to power the flare and the CME in AR 11283. Within the uncertainty, the flare and the CME may consume a similar amount of free energy.

  4. RHESSI AND TRACE OBSERVATIONS OF MULTIPLE FLARE ACTIVITY IN AR 10656 AND ASSOCIATED FILAMENT ERUPTION

    SciTech Connect (OSTI)

    Joshi, Bhuwan; Kushwaha, Upendra; Cho, K.-S.; Veronig, Astrid M.

    2013-07-01

    We present Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and Transition Region and Coronal Explorer (TRACE) observations of multiple flare activity that occurred in the NOAA active region 10656 over a period of 2 hr on 2004 August 18. Out of four successive flares, three were class C events, and the final event was a major X1.8 solar eruptive flare. The activities during the pre-eruption phase, i.e., before the X1.8 flare, are characterized by three localized episodes of energy release occurring in the vicinity of a filament that produces intense heating along with non-thermal emission. A few minutes before the eruption, the filament undergoes an activation phase during which it slowly rises with a speed of {approx}12 km s{sup -1}. The filament eruption is accompanied by an X1.8 flare, during which multiple hard X-ray (HXR) bursts are observed up to 100-300 keV energies. We observe a bright and elongated coronal structure simultaneously in E(UV) and 50-100 keV HXR images underneath the expanding filament during the period of HXR bursts, which provides strong evidence for ongoing magnetic reconnection. This phase is accompanied by very high plasma temperatures of {approx}31 MK, followed by the detachment of the prominence from the solar source region. From the location, timing, strength, and spectrum of HXR emission, we conclude that the prominence eruption is driven by the distinct events of magnetic reconnection occurring in the current sheet below the erupting prominence. These multi-wavelength observations also suggest that the localized magnetic reconnections associated with different evolutionary stages of the filament in the pre-eruption phase play an important role in destabilizing the active-region filament through the tether-cutting process, leading to large-scale eruption and X-class flare.

  5. Commerical-Scale CO2 Capture and Sequestration for the Cement Industry

    SciTech Connect (OSTI)

    Adolfo Garza

    2010-07-28

    On June 8, 2009, DOE issued Funding Opportunity Announcement (FOA) Number DE-FOA-000015 seeking proposals to capture and sequester carbon dioxide from industrial sources. This FOA called for what was essentially a two-tier selection process. A number of projects would receive awards to conduct front-end engineering and design (FEED) studies as Phase I. Those project sponsors selected would be required to apply for Phase II, which would be the full design, construction, and operation of their proposed technology. Over forty proposals were received, and ten were awarded Phase I Cooperative Agreements. One of those proposers was CEMEX. CEMEX proposed to capture and sequester carbon dioxide (CO2) from one of their existing cement plants and either sequester the CO2 in a geologic formation or use it for enhanced oil recovery. The project consisted of evaluating their plants to identify the plant best suited for the demonstration, identify the best available capture technology, and prepare a design basis. The project also included evaluation of the storage or sequestration options in the vicinity of the selected plant.

  6. Search for correlations between solar flares and decay rate of radioactive nuclei

    E-Print Network [OSTI]

    E. Bellotti; C. Broggini; G. Di Carlo; M. Laubenstein; R. Menegazzo

    2013-02-05

    The deacay rate of three different radioactive sources 40K, 137Cs and natTh has been measured with NaI and Ge detectors. Data have been analyzed to search for possible variations in coincidence with the two strongest solar flares of the years 2011 and 2012. No significant deviations from standard expectation have been observed, with a few 10-4 sensitivity. As a consequence, we could not find any effect like that recently reported by Jenkins and Fischbach: a few per mil decrease in the decay rate of 54Mn during solar flares in December 2006.

  7. Plastic damping of Alfv\\'en waves in magnetar flares and delayed afterglow emission

    E-Print Network [OSTI]

    Li, Xinyu

    2015-01-01

    Magnetar flares generate Alfv\\'en waves bouncing in the closed magnetosphere with energy up to $\\sim 10^{46}$ erg. We show that on a 10-ms timescale the waves are transmitted into the star and form a compressed packet of high energy density. This packet strongly shears the stellar crust and initiates a plastic flow, heating the crust and melting it hundreds of meters below the surface. A fraction of the deposited plastic heat is eventually conducted to the stellar surface, contributing to the surface afterglow months to years after the flare. A large fraction of heat is lost to neutrino emission or conducted into the core of the neutron star.

  8. Lag-luminosity relation in gamma-ray burst X-ray flares

    SciTech Connect (OSTI)

    Margutti, R.

    2010-10-15

    In strict analogy to prompt pulses, X-ray flares observed by Swift-XRT in long Gamma-Ray Bursts define a lag-luminosity relation: L{sub p,iso}{sup 0.3-10} k{sup eV} {infinity}t{sub lag}{sup -0.95{+-}0.23}. The lag-luminosity is proven to be a fundamental law extending {approx}5 decades in time and {approx}5 in energy. This is direct evidence that GRB X-ray flares and prompt gamma-ray pulses are produced by the same mechanism.

  9. 1 Hz FLARING IN SAX J1808.4-3658: FLOW INSTABILITIES NEAR THE PROPELLER STAGE

    SciTech Connect (OSTI)

    Patruno, Alessandro; Watts, Anna; Klein Wolt, Marc; Wijnands, Rudy; Van der Klis, Michiel

    2009-12-20

    We present a simultaneous periodic and aperiodic timing study of the accreting millisecond X-ray pulsar SAX J1808.4-3658. We analyze five outbursts of the source and for the first time provide a full and systematic investigation of the enigmatic phenomenon of the 1 Hz flares observed during the final stages of some of the outbursts. We show that links between pulsations and 1 Hz flares might exist, and suggest that they are related with hydrodynamic disk instabilities that are triggered close to the disk-magnetosphere boundary layer when the system is entering the propeller regime.

  10. EIS-0445: American Electric Power Service Corporation's Mountaineer Commercial Scale Carbon Capture and Storage Demonstration, New Haven, Mason County, West Virginia

    Broader source: Energy.gov [DOE]

    DOE evaluates the potential environmental impacts of providing financial assistance for the construction and operation of a project proposed by American Electric Power Service Corporation (AEP). DOE selected tbis project for an award of financial assistance through a competitive process under the Clean Coal Power Initiative (CCPI) Program. AEP's Mountaineer Commercial Scale Carbon Capture and Storage Project (Mountaineer CCS II Project) would construct a commercial scale carbon dioxide (C02l capture and storage (CCS) system at AEP's existing Mountaineer Power Plant and other AEP owned properties located near New Haven, West Virginia.

  11. PRELIMINARY CARBON DIOXIDE CAPTURE TECHNICAL AND ECONOMIC FEASIBILITY STUDY EVALUATION OF CARBON DIOXIDE CAPTURE FROM EXISTING COAL FIRED PLANTS BY HYBRID SORPTION USING SOLID SORBENTS

    SciTech Connect (OSTI)

    Benson, Steven; Envergex, Srivats; Browers, Bruce; Thumbi, Charles

    2013-01-01

    Barr Engineering Co. was retained by the Institute for Energy Studies (IES) at University of North Dakota (UND) to conduct a technical and economic feasibility analysis of an innovative hybrid sorbent technology (CACHYS™) for carbon dioxide (CO2) capture and separation from coal combustion–derived flue gas. The project team for this effort consists of the University of North Dakota, Envergex LLC, Barr Engineering Co., and Solex Thermal Science, along with industrial support from Allete, BNI Coal, SaskPower, and the North Dakota Lignite Energy Council. An initial economic and feasibility study of the CACHYS™ concept, including definition of the process, development of process flow diagrams (PFDs), material and energy balances, equipment selection, sizing and costing, and estimation of overall capital and operating costs, is performed by Barr with information provided by UND and Envergex. The technology—Capture from Existing Coal-Fired Plants by Hybrid Sorption Using Solid Sorbents Capture (CACHYS™)—is a novel solid sorbent technology based on the following ideas: reduction of energy for sorbent regeneration, utilization of novel process chemistry, contactor conditions that minimize sorbent-CO2 heat of reaction and promote fast CO2 capture, and a low-cost method of heat management. The technology’s other key component is the use of a low-cost sorbent.

  12. High-cadence and high-resolution H? imaging spectroscopy of a circular flare's remote ribbon with IBIS

    SciTech Connect (OSTI)

    Deng, Na; Jing, Ju; Chen, Xin; Liu, Chang; Xu, Yan; Wang, Haimin [Space Weather Research Laboratory, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States); Tritschler, Alexandra; Reardon, Kevin [National Solar Observatory, Sacramento Peak, Sunspot, NM 88349-0062 (United States); Denker, Carsten, E-mail: na.deng@njit.edu [Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)

    2013-06-01

    We present an unprecedented high-resolution H? imaging spectroscopic observation of a C4.1 flare taken with the Interferometric Bidimensional Spectrometer (IBIS) in conjunction with the adaptive optics system at the 76 cm Dunn Solar Telescope on 2011 October 22 in the active region NOAA 11324. Such a two-dimensional spectroscopic observation covering the entire evolution of a flare ribbon with high spatial (0.''1 pixel{sup –1} image scale), cadence (4.8 s), and spectral (0.1 Ĺ step size) resolution is rarely reported. The flare consists of a main circular ribbon that occurred in a parasitic magnetic configuration and a remote ribbon that was observed by the IBIS. Such a circular-ribbon flare with a remote brightening is predicted in three-dimensional fan-spine reconnection but so far has been rarely studied. During the flare impulsive phase, we define 'core' and 'halo' structures in the observed ribbon based on IBIS narrowband images in the H? line wing and line center. Examining the H? emission spectra averaged in the flare core and halo areas, we find that only those from the flare cores show typical nonthermal electron beam heating characteristics that have been revealed by previous theoretical simulations and observations of flaring H? line profiles. These characteristics include broad and centrally reversed emission spectra, excess emission in the red wing with regard to the blue wing (i.e., red asymmetry), and redshifted bisectors of the emission spectra. We also observe rather quick timescales for the heating (?30 s) and cooling (?14-33 s) in the flare core locations. Therefore, we suggest that the flare cores revealed by IBIS track the sites of electron beam precipitation with exceptional spatial and temporal resolution. The flare cores show two-stage motion (a parallel motion along the ribbon followed by an expansion motion perpendicular to the ribbon) during the two impulsive phases of the flare. Some cores jump quickly (30 km s{sup –1}) between discrete magnetic elements implying reconnection involving different flux tubes. We observe a very high temporal correlation (? 0.9) between the integrated H? and hard X-rays (HXR) emission during the flare impulsive phase. A short time delay (4.6 s) is also found in the H? emission spikes relative to HXR bursts. The ionization timescale of the cool chromosphere and the extra time taken for the electrons to travel to the remote ribbon site may contribute to this delay.

  13. Layered solid sorbents for carbon dioxide capture

    DOE Patents [OSTI]

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  14. Thermal neutron capture gamma-rays

    SciTech Connect (OSTI)

    Tuli, J.K.

    1983-01-01

    The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.

  15. Electron capture cross sections for stellar nucleosynthesis

    E-Print Network [OSTI]

    P. G. Giannaka; T. S. Kosmas

    2015-02-25

    In the first stage of this work, we perform detailed calculations for the cross sections of the electron capture on nuclei under laboratory conditions. Towards this aim we exploit the advantages of a refined version of the proton-neutron quasi-particle random-phase approximation (pn-QRPA) and carry out state-by-state evaluations of the rates of exclusive processes that lead to any of the accessible transitions within the chosen model space. In the second stage of our present study, we translate the above mentioned $e^-$-capture cross sections to the stellar environment ones by inserting the temperature dependence through a Maxwell-Boltzmann distribution describing the stellar electron gas. As a concrete nuclear target we use the $^{66}Zn$ isotope, which belongs to the iron group nuclei and plays prominent role in stellar nucleosynthesis at core collapse supernovae environment.

  16. Reduced Nitrogen and Natural Gas Consumption at Deepwell Flare 

    E-Print Network [OSTI]

    Williams, C.

    2004-01-01

    Facing both an economic downturn and the liklihood of steep natural gas price increases, company plants were challenged to identify and quickly implement energy saving projects that would reduce natural gas usage. Unit operating personnel...

  17. Data Capture Technique for High Speed Signaling

    DOE Patents [OSTI]

    Barrett, Wayne Melvin (Rochester, MN); Chen, Dong (Croton On Hudson, NY); Coteus, Paul William (Yorktwon Heights, NY); Gara, Alan Gene (Mount Kisco, NY); Jackson, Rory (Eastchester, NY); Kopcsay, Gerard Vincent (Yorktown Hieghts, NY); Nathanson, Ben Jesse (Teaneck, NY); Vranas, Paylos Michael (Bedford Hills, NY); Takken, Todd E. (Brewster, NY)

    2008-08-26

    A data capture technique for high speed signaling to allow for optimal sampling of an asynchronous data stream. This technique allows for extremely high data rates and does not require that a clock be sent with the data as is done in source synchronous systems. The present invention also provides a hardware mechanism for automatically adjusting transmission delays for optimal two-bit simultaneous bi-directional (SiBiDi) signaling.

  18. The shock reprocessing model of electron acceleration in impulsive solar flares

    E-Print Network [OSTI]

    Robert Selkowitz; Eric G. Blackman

    2005-09-14

    We propose a new two-stage model for acceleration of electrons in solar flares. In the first stage, electrons are accelerated stochastically in a post-reconnection turbulent downflow. The second stage is the reprocessing of a subset of these electrons as they pass through a weakly compressive fast shock above the apex of the closed flare loop on their way to the chromosphere. We call this the "shock reprocessing" model. The model reproduces the energy dependent arrival time delays observed for both the pulsed and smooth components of impulsive solar flare x-rays with physically reasonable parameters for the downflow region. The model also predicts an emission site above the loop-top, as seen in the Masuda flare. The loop-top source distinguishes the shock reprocessing model from previous models. The model makes testable predictions for the energy dependence of footpoint pulse strengths and the location and spectrum of the loop-top emission, and can account for the observed soft-hard-soft trend in the spectral evolution of footpoint emission. Our model highlights the concept that reconnection is an acceleration environment rather than a single process. Which combination of processes operate may depend on the initial conditions that determine, for example, whether the reconnection downflow is turbulent. The shock reprocessing model comprises one such combination.

  19. The shock reprocessing model of electron acceleration in impulsive solar flares

    E-Print Network [OSTI]

    Selkowitz, R; Selkowitz, Robert; Blackman, Eric G.

    2005-01-01

    We propose a new two-stage model for acceleration of electrons in solar flares. In the first stage, electrons are accelerated stochastically in a post-reconnection turbulent downflow. The second stage is the reprocessing of a subset of these electrons as they pass through a weakly compressive fast shock above the apex of the closed flare loop on their way to the chromosphere. We call this the "shock reprocessing" model. The model reproduces the energy dependent arrival time delays observed for both the pulsed and smooth components of impulsive solar flare x-rays with physically reasonable parameters for the downflow region. The model also predicts an emission site above the loop-top, as seen in the Masuda flare. The loop-top source distinguishes the shock reprocessing model from previous models. The model makes testable predictions for the energy dependence of footpoint pulse strengths and the location and spectrum of the loop-top emission, and can account for the observed soft-hard-soft trend in the spectral...

  20. An investigation of Fe XV emission lines in solar flare spectra

    E-Print Network [OSTI]

    F P Keenan; K M Aggarwal; D S Bloomfield; A Z Msezane; K G Widing

    2005-12-22

    Previously, large discrepancies have been found between theory and observation for Fe XV emission line ratios in solar flare spectra covering the 224-327 A wavelength range, obtained by the Naval Research Laboratory's S082A instrument on board Skylab. These discrepancies have been attributed to either errors in the adopted atomic data or the presence of additional atomic processes not included in the modelling, such as fluorescence. However our analysis of these plus other S082A flare observations (the latter containing Fe XV transitions between 321-482 A), performed using the most recent Fe XV atomic physics calculations in conjunction with a CHIANTI synthetic flare spectrum, indicate that blending of the lines is primarily responsible for the discrepancies. As a result, most Fe XV lines cannot be employed as electron density diagnostics for solar flares, at least at the spectral resolution of S082A and similar instruments (i.e. ~ 0.1 A). An exception is the intensity ratio I(321.8 A)/I(327.0 A), which appears to provide good estimates of the electron density at this spectral resolution.

  1. Observations of Solar Flare Doppler Shift Oscillations with the Bragg Crystal Spectrometer on Yohkoh

    E-Print Network [OSTI]

    John T. Mariska

    2005-01-06

    Oscillations in solar coronal loops appear to be a common phenomenon. Transverse and longitudinal oscillations have been observed with both the Transition Region and Coronal Explorer and Extreme Ultraviolet Imaging Telescope imaging experiments. Damped Doppler shift oscillations have been observed in emission lines from ions formed at flare temperatures with the Solar Ultraviolet Measurements of Emitted Radiation Spectrometer. These observations provide valuable diagnostic information on coronal conditions and may help refine our understanding of coronal heating mechanisms. I have initiated a study of the time dependence of Doppler shifts measured during flares with the Bragg Crystal Spectrometer (BCS) on Yohkoh. This Letter reports the detection of oscillatory behavior in Doppler shifts measured as a function of time in the emission lines of S XV and Ca XIX. For some flares, both lines exhibit damped Doppler shift oscillations with amplitudes of a few km/s and periods and decay times of a few minutes. The observations appear to be consistent with transverse oscillations. Because the BCS observed continuously for almost an entire solar cycle, it provides numerous flare data sets, which should permit an excellent characterization of the average properties of the oscillations.

  2. The Sun as an X-ray Star: III. Flares F. Reale, G. Peres

    E-Print Network [OSTI]

    distribution vs. temperature and its evolution during some selected solar ares, representative of the wideThe Sun as an X-ray Star: III. Flares F. Reale, G. Peres Dip. di Scienze Fisiche & Astronomiche class C5.8) to very intense ones (X9) are selected as representative of the aring Sun. The emission

  3. CHARACTERISTIC SIZE OF FLARE KERNELS IN THE VISIBLE AND NEAR-INFRARED CONTINUA

    SciTech Connect (OSTI)

    Xu, Yan; Jing, Ju; Wang, Haimin [Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States); Cao, Wenda, E-mail: yx2@njit.edu [Big Bear Solar Observatory, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States)

    2012-05-01

    In this Letter, we present a new approach to estimate the formation height of visible and near-infrared emission of an X10 flare. The sizes of flare emission cores in three wavelengths are accurately measured during the peak of the flare. The source size is the largest in the G band at 4308 A and shrinks toward longer wavelengths, namely the green continuum at 5200 A and NIR at 15600 A, where the emission is believed to originate from the deeper atmosphere. This size-wavelength variation is likely explained by the direct heating model as electrons need to move along converging field lines from the corona to the photosphere. Therefore, one can observe the smallest source, which in our case is 0.''65 {+-} 0.''02 in the bottom layer (represented by NIR), and observe relatively larger kernels in upper layers of 1.''03 {+-} 0.''14 and 1.''96 {+-} 0.''27, using the green continuum and G band, respectively. We then compare the source sizes with a simple magnetic geometry to derive the formation height of the white-light sources and magnetic pressure in different layers inside the flare loop.

  4. The Temporal Behaviour of Lyman-alpha Emission During Solar Flares From SDO/EVE

    E-Print Network [OSTI]

    Milligan, Ryan O

    2015-01-01

    Despite being the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyman-alpha (Ly$\\alpha$) emission during solar flares in recent years. The few examples that do exist, however, have shown Ly$\\alpha$ emission to be a substantial radiator of the total energy budget of solar flares (on the order of 10%). It is also a known driver of fluctuations in earth's ionosphere. The EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory now provides broadband, photometric Ly$\\alpha$ data at 10 s cadence, and has observed scores of solar flares in the 5 years since it was launched. However, the time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H$\\alpha$, Ly$\\beta$, LyC, C III, etc.). Furthermore, the Ly$\\alpha$ emission peaks around the time of the peak of thermal soft X-ray e...

  5. THE 5 GHz ARECIBO SEARCH FOR RADIO FLARES FROM ULTRACOOL DWARFS

    SciTech Connect (OSTI)

    Route, Matthew; Wolszczan, Alexander E-mail: alex@astro.psu.edu

    2013-08-10

    We present the results of a 4.75 GHz survey of 33 brown dwarfs and one young exoplanetary system for flaring radio emission, conducted with the 305 m Arecibo radio telescope. The goal of this program was to detect and characterize the magnetic fields of objects cooler than spectral type L3.5, the coolest brown dwarf detected prior to our survey. We have also attempted to detect flaring radio emission from the HR 8799 planetary system, guided by theoretical work indicating that hot, massive exoplanets may have strong magnetic fields capable of generating radio emission at GHz frequencies. We have detected and confirmed radio flares from the T6.5 dwarf 2MASS J10475385+2124234. This detection dramatically extends the temperature range over which brown dwarfs appear to be at least sporadic radio-emitters, from 1900 K (L3.5) down to 900 K (T6.5). It also demonstrates that the utility of radio detection as a unique tool to study the magnetic fields of substellar objects extends to the coolest dwarfs, and, plausibly to hot, massive exoplanets. We have also identified a single, 3.6{sigma} flare from the L1 dwarf, 2MASS J1439284+192915. This detection is tentative and requires confirmation by additional monitoring observations.

  6. NO FLARES FROM GAMMA-RAY BURST AFTERGLOW BLAST WAVES ENCOUNTERING SUDDEN CIRCUMBURST DENSITY CHANGE

    SciTech Connect (OSTI)

    Gat, Ilana; Van Eerten, Hendrik; MacFadyen, Andrew [Center for Cosmology and Particle Physics, Physics Department, New York University, New York, NY 10003 (United States)

    2013-08-10

    Afterglows of gamma-ray bursts are observed to produce light curves with the flux following power-law evolution in time. However, recent observations reveal bright flares at times on the order of minutes to days. One proposed explanation for these flares is the interaction of a relativistic blast wave with a circumburst density transition. In this paper, we model this type of interaction computationally in one and two dimensions, using a relativistic hydrodynamics code with adaptive mesh refinement called RAM, and analytically in one dimension. We simulate a blast wave traveling in a stellar wind environment that encounters a sudden change in density, followed by a homogeneous medium, and compute the observed radiation using a synchrotron model. We show that flares are not observable for an encounter with a sudden density increase, such as a wind termination shock, nor for an encounter with a sudden density decrease. Furthermore, by extending our analysis to two dimensions, we are able to resolve the spreading, collimation, and edge effects of the blast wave as it encounters the change in circumburst medium. In all cases considered in this paper, we find that a flare will not be observed for any of the density changes studied.

  7. Effect of radioactivity decrease. Is there a link with solar flares?

    E-Print Network [OSTI]

    A. G. Parkhomov

    2010-05-15

    Results obtained with multichannel installation created for long-term studies of various processes, are collated with the data published by J.H. Jenkins and E.Fischbach, who found a decrease of 54Mn radioactivity near the time of series of solar flares between 5 and 17 December 2006. Analysis of the data from our installation in December 2006 has not revealed any deviations from the usual behaviour of the count rates for 90Sr-90Y, 60Co and 239Pu sources. The same can be said of the data collected during the period of highly powerful solar flares between 19 October and 4 November 2003. Apparent drops in the count rate were detected between 10 and 12 May 2002 while registering the activity of 60Co and on 19 and 20 June 2004 for 90Sr-90Y source. Around the time of these events, no observations of large solar flares were reported. Thus, proposed link between the drop in the rates of radioactive decay and appearance of solar flares could not be confirmed. From obtained outcomes follows, that the radioactivity drop effect, if it really exists, is rather rare, and that the reason calling this effect unequally influences various radioactive sources.

  8. Temporal evolution of multiple evaporating ribbon sources in a solar flare

    E-Print Network [OSTI]

    Graham, D R

    2015-01-01

    We present new results from the Interface Region Imaging Spectrograph showing the dynamic evolution of chromospheric evaporation and condensation in a flare ribbon, with the highest temporal and spatial resolution to date. IRIS observed the entire impulsive phase of the X-class flare SOL2014-09-10T17:45 using a 9.4 second cadence `sit-and-stare' mode. As the ribbon brightened successively at new positions along the slit, a unique impulsive phase evolution was observed for many tens of individual pixels in both coronal and chromospheric lines. Each activation of a new footpoint displays the same initial coronal up-flows of up to ~300 km/s, and chromospheric downflows up to 40 km/s. Although the coronal flows can be delayed by over 1 minute with respect to those in the chromosphere, the temporal evolution of flows is strikingly similar between all pixels, and consistent with predictions from hydrodynamic flare models. Given the large sample of independent footpoints, we conclude that each flaring pixel can be c...

  9. A unified view of coronal loop contraction and oscillation in flares

    E-Print Network [OSTI]

    Russell, Alexander J B; Fletcher, Lyndsay

    2015-01-01

    Context: Transverse loop oscillations and loop contractions are commonly associated with solar flares, but the two types of motion have traditionally been regarded as separate phenomena. Aims: We present an observation of coronal loops contracting and oscillating following onset of a flare. We aim to explain why both behaviours are seen together and why only some of the loops oscillate. Methods: A time sequence of SDO/AIA 171 \\r{A} images is analysed to identify positions of coronal loops following the onset of M6.4 flare SOL2012-03-09T03:53. We focus on five loops in particular, all of which contract during the flare, with three of them oscillating as well. A simple model is then developed for contraction and oscillation of a coronal loop. Results: We propose that coronal loop contractions and oscillations can occur in a single response to removal of magnetic energy from the corona. Our model reproduces the various types of loop motion observed and explains why the highest loops oscillate during their contra...

  10. Hard X-ray Emission During Flares and Photospheric Field Changes

    E-Print Network [OSTI]

    Burtseva, O; Petrie, G J D; Pevtsov, A A

    2015-01-01

    We study the correlation between abrupt permanent changes of magnetic field during X-class flares observed by the GONG and HMI instruments, and the hard X-ray (HXR) emission observed by RHESSI, to relate the photospheric field changes to the coronal restructuring and investigate the origin of the field changes. We find that spatially the early RHESSI emission corresponds well to locations of the strong field changes. The field changes occur predominantly in the regions of strong magnetic field near the polarity inversion line (PIL). The later RHESSI emission does not correspond to significant field changes as the flare footpoints are moving away from the PIL. Most of the field changes start before or around the start time of the detectable HXR signal, and they end at about the same time or later than the detectable HXR flare emission. Some of the field changes propagate with speed close to that of the HXR footpoint at a later phase of the flare. The propagation of the field changes often takes place after the...

  11. Hard X-ray and ultraviolet emission during the 2011 June 7 solar flare

    E-Print Network [OSTI]

    Inglis, Andrew R

    2013-01-01

    The relationship between X-ray and UV emission during flares, particularly in the context of quasi-periodic pulsations, remains unclear. To address this, we study the X-ray and UV emission during the eruptive flare of 2011 June 7 utilising X-ray imaging from RHESSI and UV 1700A imaging from SDO/AIA. This event is associated with synchronous quasi-periodic pulsations in both the X-ray and UV emission, as well as substantial motion of the hard X-ray footpoints. The motion of the footpoint associated with the left-hand flare ribbon is shown to reverse direction along the flare ribbons on at least two occasions. Over the same time interval, the footpoints also gradually move apart at v ~ 12 km/s. This is consistent with the measured plane-of-sky thermal X-ray source outward velocity of ~ 14 km/s, and matches the gradual outward expansion of the UV ribbons. However, there is no associated short-timescale motion of the UV bright regions. We find that the locations of the brightest X-ray and UV regions are different...

  12. On the Relation between Filament Eruptions, Flares, and Coronal Mass Ejections

    E-Print Network [OSTI]

    On the Relation between Filament Eruptions, Flares, and Coronal Mass Ejections Ju Jing, Vasyl B a statistical study of 106 filament eruptions, which were automat- ically detected by a pattern recognition and Large Angle and Spectrometric Corona- graph (LASCO) data to determine the relationship between filament

  13. A Circular-ribbon Solar Flare Following an Asymmetric Filament Eruption

    E-Print Network [OSTI]

    Liu, Chang; Liu, Rui; Lee, Jeongwoo; Pariat, Etienne; Wiegelmann, Thomas; Liu, Yang; Kleint, Lucia; Wang, Haimin

    2015-01-01

    The dynamic properties of flare ribbons and the often associated filament eruptions can provide crucial information on the flaring coronal magnetic field. This Letter analyzes the GOES-class X1.0 flare on 2014 March 29 (SOL2014-03-29T17:48), in which we found an asymmetric eruption of a sigmoidal filament and an ensuing circular flare ribbon. Initially both EUV images and a preflare nonlinear force-free field model show that the filament is embedded in magnetic fields with a fan-spine-like structure. In the first phase, which is defined by a weak but still increasing X-ray emission, the western portion of the sigmoidal filament arches upward and then remains quasi-static for about five minutes. The western fan-like and the outer spine-like fields display an ascending motion, and several associated ribbons begin to brighten. Also found is a bright EUV flow that streams down along the eastern fan-like field. In the second phase that includes the main peak of hard X-ray (HXR) emission, the filament erupts, leavi...

  14. CELLULAR AUTOMATA MODELS AND MHD APPROACH IN THE CONTEXT OF SOLAR FLARES 1

    E-Print Network [OSTI]

    Anastasiadis, Anastasios

    CELLULAR AUTOMATA MODELS AND MHD APPROACH IN THE CONTEXT OF SOLAR FLARES 1 Anastasios Anastasiadis anastasi@space.noa.gr Abstract: We address in detail the cellular automaton approach, developed be used. These types of mathematical tools are the Automata and the Cellular Automata (CA). The advantage

  15. PRODUCTIVITY OF SOLAR FLARES AND MAGNETIC HELICITY INJECTION IN ACTIVE REGIONS

    E-Print Network [OSTI]

    effect on cell phones and the global positioning system and heat up the terrestrial atmosphere within). Solar flares produce high energy particles, radiation, and erupting magnetic structures that are related to geomagnetic storms. Their strong electro- magnetic radiations from radio waves to gamma-rays have direct

  16. GRB 051103 and GRB 070201 as Giant Flares from SGRs in Nearby Galaxies

    E-Print Network [OSTI]

    California at Berkeley, University of

    -7450, USA ^Max-Plank-Institutfiir extraterrestrische Physik, D-85741 Garching, Germany Abstract. The Konus-Wind, 12]. The energy of the initial pulse of the giant flare from SGR 1806-20 was found of '-^ 2 x 10 of commonly accepted observational GF criteria (i.e. short duration, single pulse event with hard energy

  17. The use of electron maps to constrain some physical properties of solar flares

    E-Print Network [OSTI]

    Piana, Michele

    astrophysical phenomenon into observable data. In the case of the NASA Reuven Ramaty High Energy Solar Energy Solar Spectroscopic Imager (RHESSI) is a set of Fourier components of the X-ray radiation samThe use of electron maps to constrain some physical properties of solar flares A. M. Massone1 and M

  18. Systematic Microwave Source Motions along Flare-arcade Observed by Nobeyama Radioheliograph and AIA/SDO

    E-Print Network [OSTI]

    Kim, Sujin; Masuda, Satoshi

    2013-01-01

    We found systematic microwave source motions along a flare-arcade using Nobeyama Radioheliograph (NoRH) 17 GHz images. The motions were associated with a X-class disk flare which occurred on 15th February 2011. For this study, we also used EUV images from Atmospheric Imaging Assembly (AIA) and magnetograms from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory, and multi-channel microwave data from Nobeyama Radiopolarimeters (NoRP) and Korean Solar Radio Burst Locator (KSRBL). We traced centroids of the microwave source observed by NoRH 17 GHz during the flare and found two episodes of the motion with several facts: 1) The microwave source moved systematically along the flare-arcade, which was observed by the AIA 94 A in a direction parallel to the neutral line. 2) The period of each episode was 5 min and 14 min, respectively. 3) Estimated parallel speed was 34 km/s for the first episode and 22 km/s for the second episode. The spectral slope of microwave flux above 10 GHz obtained by N...

  19. A Multiwavelength Study of Three Solar Flares M. R. Kundu, A. Nindos 1 , S. M. White

    E-Print Network [OSTI]

    White, Stephen

    of the are phenomenon. Microwave emission from solar ares can provide important diagnostics of acceleration pro- cesses 1998) that the basic emission mechanism of solar microwave bursts is gyrosynchrotron from mildlyA Multiwavelength Study of Three Solar Flares M. R. Kundu, A. Nindos 1 , S. M. White Astronomy

  20. Relations between concurrent hard X-ray sources in solar flares

    E-Print Network [OSTI]

    Marina Battaglia; Arnold O. Benz

    2006-06-14

    Context: Solar flares release a large fraction of their energy into non-thermal electrons, but it is not clear where and how. Bremsstrahlung X-rays are observed from the corona and chromosphere. Aims: We aim to characterize the acceleration process by the coronal source and its leakage toward the footpoints in the chromosphere. The relations between the sources reflect the geometry and constrict the configuration of the flare. Methods: We studied solar flares of GOES class larger than M1 with three or more hard X-ray sources observed simultaneously in the course of the flare. The events were observed with the X-ray satellite RHESSI from February 2002 until July 2005. We used imaging spectroscopy methods to determine the spectral evolution of each source in each event. The images of all of the five events show two sources visible only at high energies (footpoints) and one source only visible at low energies (coronal or looptop source, in two cases situated over the limb). Results: We find soft-hard-soft behavior in both, coronal source and footpoints. The coronal source is nearly always softer than the footpoints. The footpoint spectra differ significantly only in one event out of five. Conclusions: The observations are consistent with acceleration in the coronal source and an intricate connection between the corona and chromosphere.