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Sample records for boosted fast flux

  1. Boosted Fast Flux Loop Alternative Cooling Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Glen R. Longhurst; Donna Post Guillen; James R. Parry; Douglas L. Porter; Bruce W. Wallace

    2007-08-01

    The Gas Test Loop (GTL) Project was instituted to develop the means for conducting fast neutron irradiation tests in a domestic radiation facility. It made use of booster fuel to achieve the high neutron flux, a hafnium thermal neutron absorber to attain the high fast-to-thermal flux ratio, a mixed gas temperature control system for maintaining experiment temperatures, and a compressed gas cooling system to remove heat from the experiment capsules and the hafnium thermal neutron absorber. This GTL system was determined to provide a fast (E > 0.1 MeV) flux greater than 1.0E+15 n/cm2-s with a fast-to-thermal flux ratio in the vicinity of 40. However, the estimated system acquisition cost from earlier studies was deemed to be high. That cost was strongly influenced by the compressed gas cooling system for experiment heat removal. Designers were challenged to find a less expensive way to achieve the required cooling. This report documents the results of the investigation leading to an alternatively cooled configuration, referred to now as the Boosted Fast Flux Loop (BFFL). This configuration relies on a composite material comprised of hafnium aluminide (Al3Hf) in an aluminum matrix to transfer heat from the experiment to pressurized water cooling channels while at the same time providing absorption of thermal neutrons. Investigations into the performance this configuration might achieve showed that it should perform at least as well as its gas-cooled predecessor. Physics calculations indicated that the fast neutron flux averaged over the central 40 cm (16 inches) relative to ATR core mid-plane in irradiation spaces would be about 1.04E+15 n/cm2-s. The fast-to-thermal flux ratio would be in excess of 40. Further, the particular configuration of cooling channels was relatively unimportant compared with the total amount of water in the apparatus in determining performance. Thermal analyses conducted on a candidate configuration showed the design of the water coolant and

  2. Boosted Fast Flux Loop Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Boosted Fast Flux Loop Project Staff

    2009-09-01

    The Boosted Fast Flux Loop (BFFL) project was initiated to determine basic feasibility of designing, constructing, and installing in a host irradiation facility, an experimental vehicle that can replicate with reasonable fidelity the fast-flux test environment needed for fuels and materials irradiation testing for advanced reactor concepts. Originally called the Gas Test Loop (GTL) project, the activity included (1) determination of requirements that must be met for the GTL to be responsive to potential users, (2) a survey of nuclear facilities that may successfully host the GTL, (3) conceptualizing designs for hardware that can support the needed environments for neutron flux intensity and energy spectrum, atmosphere, flow, etc. needed by the experimenters, and (4) examining other aspects of such a system, such as waste generation and disposal, environmental concerns, needs for additional infrastructure, and requirements for interfacing with the host facility. A revised project plan included requesting an interim decision, termed CD-1A, that had objectives of' establishing the site for the project at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL), deferring the CD 1 application, and authorizing a research program that would resolve the most pressing technical questions regarding GTL feasibility, including issues relating to the use of booster fuel in the ATR. Major research tasks were (1) hydraulic testing to establish flow conditions through the booster fuel, (2) mini-plate irradiation tests and post-irradiation examination to alleviate concerns over corrosion at the high heat fluxes planned, (3) development and demonstration of booster fuel fabrication techniques, and (4) a review of the impact of the GTL on the ATR safety basis. A revised cooling concept for the apparatus was conceptualized, which resulted in renaming the project to the BFFL. Before the subsequent CD-1 approval request could be made, a decision was made in April

  3. Fast neutron boost for the treatment of grade IV astrocytomas

    International Nuclear Information System (INIS)

    Breteau, N.; Destembert, B.; Favre, A.; Pheline, C.; Schlienger, M.

    1989-01-01

    A previous study, on grade IV astrocytomas, compared a combination of photons and fast neutron boost to photons only, both treatments being delivered following a concentrated irradiation schedule. A slight improvement in survival was observed after neutron boost for non operated patients, but not for operated patients. Since death was always related to local recurrence and since no complication occurred after neutron boost, the neutron dose was increased from 6 to 7 Gy in January 1985. No improvement in survival was observed for patients treated with neutron boost after complete resection. After subtotal resection, the group that was treated with the higher neutron boost (7 Gy) showed a significant benefit in survival at twelve months. When patients had only a biopsy before irradiation, there was a benefit in survival after neutron boost, but no additional benefit was gained when the size of the neutron boost was increased from 6 to 7 Gy. (orig.) [de

  4. 400 Area/Fast Flux Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 400 Area at Hanford is home primarily to the Fast Flux Test Facility (FFTF), a DOE-owned, formerly operating, 400-megawatt (thermal) liquid-metal (sodium)-cooled...

  5. Pyroclastic Eruption Boosts Organic Carbon Fluxes Into Patagonian Fjords

    Science.gov (United States)

    Mohr, Christian H.; Korup, Oliver; Ulloa, Héctor; Iroumé, Andrés.

    2017-11-01

    Fjords and old-growth forests store large amounts of organic carbon. Yet the role of episodic disturbances, particularly volcanic eruptions, in mobilizing organic carbon in fjord landscapes covered by temperate rainforests remains poorly quantified. To this end, we estimated how much wood and soils were flushed to nearby fjords following the 2008 eruption of Chaitén volcano in south-central Chile, where pyroclastic sediments covered >12 km2 of pristine temperate rainforest. Field-based surveys of forest biomass, soil organic content, and dead wood transport reveal that the reworking of pyroclastic sediments delivered 66,500 + 14,600/-14,500 tC of large wood to two rivers entering the nearby Patagonian fjords in less than a decade. A similar volume of wood remains in dead tree stands and buried beneath pyroclastic deposits ( 79,900 + 21,100/-16,900 tC) or stored in active river channels (5,900-10,600 tC). We estimate that bank erosion mobilized 132,300+21,700/-30,600 tC of floodplain forest soil. Eroded and reworked forest soils have been accreting on coastal river deltas at >5 mm yr-1 since the eruption. While much of the large wood is transported out of the fjord by long-shore drift, the finer fraction from eroded forest soils is likely to be buried in the fjords. We conclude that the organic carbon fluxes boosted by rivers adjusting to high pyroclastic sediment loads may remain elevated for up to a decade and that Patagonian temperate rainforests disturbed by excessive loads of pyroclastic debris can be episodic short-lived carbon sources.

  6. FAST FLUX TEST FACILITY DRIVER FUEL MEETING

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1966-06-01

    The Pacific Northwest Laboratory has convened this meeting to enlist the best talents of our laboratories and industry in soliciting factual, technical information pertinent to the Pacific Northwest's Laboratory's evaluation of the potential fuel systems for the Fast Flux Test Facility. The particular factors emphasized for these fuel systems are those associated with safety, ability to meet testing objectives, and economics. The proceedings includes twenty-three presentations, along with a transcript of the discussion following each, as well as a summary discussion.

  7. Fast flux test facility noise data management

    International Nuclear Information System (INIS)

    Thie, J.A.

    1988-01-01

    An extensive collection of spectra from an automated data collection system at the Fast Flux Facility has features from neutron data extracted and managed by database software. Inquiry techniques, including screening, applied to database results show the influences of control rods on wideband noise and, more generally, abilities to detect diverse types of off-normal noise. Uncovering a temporary 0.1-Hz resonance shift gave additional diagnostic information on a 13-Hz mechanical motion characterized by the interference of two resonances. The latter phenomenon is discussed generically for possible application to other reactor types. (author)

  8. FFTF [Fast Flux Test Facility] management

    International Nuclear Information System (INIS)

    Bennett, C.L.

    1986-11-01

    Fuel Management at the Fast Flux Test Facility (FFTF) involves more than just the usual ex-core and in-core management of standard fuel and non-fuel components between storage locations and within the core since it is primarily an irradiation test facility. This mission involves testing an ever increasing variety of fueled and non-fueled experiments, each having unique requirements on the reactor core as well as having its own individual impact on the reload design. This paper describes the fuel management process used by the Westinghouse Hanford Company Core Engineering group that has led to the successful reload design of nine operating cycles and the irradiation of over 120 tests

  9. Fast flux module detection using matroid theory.

    Science.gov (United States)

    Reimers, Arne C; Bruggeman, Frank J; Olivier, Brett G; Stougie, Leen

    2015-05-01

    Flux balance analysis (FBA) is one of the most often applied methods on genome-scale metabolic networks. Although FBA uniquely determines the optimal yield, the pathway that achieves this is usually not unique. The analysis of the optimal-yield flux space has been an open challenge. Flux variability analysis is only capturing some properties of the flux space, while elementary mode analysis is intractable due to the enormous number of elementary modes. However, it has been found by Kelk et al. (2012) that the space of optimal-yield fluxes decomposes into flux modules. These decompositions allow a much easier but still comprehensive analysis of the optimal-yield flux space. Using the mathematical definition of module introduced by Müller and Bockmayr (2013b), we discovered useful connections to matroid theory, through which efficient algorithms enable us to compute the decomposition into modules in a few seconds for genome-scale networks. Using that every module can be represented by one reaction that represents its function, in this article, we also present a method that uses this decomposition to visualize the interplay of modules. We expect the new method to replace flux variability analysis in the pipelines for metabolic networks.

  10. Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree

    CERN Document Server

    Gligorov, V.V.

    2013-01-01

    High-level triggering is a vital component in many modern particle physics experiments. This paper describes a modification to the standard boosted decision tree (BDT) classifier, the so-called "bonsai" BDT, that has the following important properties: it is more efficient than traditional cut-based approaches; it is robust against detector instabilities, and it is very fast. Thus, it is fit-for-purpose for the online running conditions faced by any large-scale data acquisition system.

  11. Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree

    Science.gov (United States)

    Gligorov, V. V.; Williams, M.

    2013-02-01

    High-level triggering is a vital component of many modern particle physics experiments. This paper describes a modification to the standard boosted decision tree (BDT) classifier, the so-called bonsai BDT, that has the following important properties: it is more efficient than traditional cut-based approaches; it is robust against detector instabilities, and it is very fast. Thus, it is fit-for-purpose for the online running conditions faced by any large-scale data acquisition system.

  12. Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree

    International Nuclear Information System (INIS)

    Gligorov, V V; Williams, M

    2013-01-01

    High-level triggering is a vital component of many modern particle physics experiments. This paper describes a modification to the standard boosted decision tree (BDT) classifier, the so-called bonsai BDT, that has the following important properties: it is more efficient than traditional cut-based approaches; it is robust against detector instabilities, and it is very fast. Thus, it is fit-for-purpose for the online running conditions faced by any large-scale data acquisition system.

  13. Fast Flux Test Facility project plan. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Hulvey, R.K.

    1995-11-01

    The Fast Flux Test Facility (FFTF) Transition Project Plan, Revision 2, provides changes to the major elements and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition.

  14. Fast Flux Test Facility project plan. Revision 2

    International Nuclear Information System (INIS)

    Hulvey, R.K.

    1995-11-01

    The Fast Flux Test Facility (FFTF) Transition Project Plan, Revision 2, provides changes to the major elements and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition

  15. Automated reactivity anomaly surveillance in the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Knutson, B.J.; Harris, R.A.; Honeyman, D.J.; Shook, A.T.; Krohn, C.N.

    1985-01-01

    The automated technique for monitoring core reactivity during power operation used at the Fast Flux Test Facility (FFTF) is described. This technique relies on comparing predicted to measured rod positions to detect any anomalous (or unpredicted) core reactivity changes. It is implemented on the Plant Data System (PDS) computer and, thus, provides rapid indication of any abnormal core conditions. The prediction algorithms use thermal-hydraulic, control rod position and neutron flux sensor information to predict the core reactivity state

  16. Radiological operating experience at FFTF [Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Bunch, W.L.; Prevo, P.R.

    1986-11-01

    The Fast Flux Test Facility has been in operation for approximately five years, including about one thousand days of full power operation of the Fast Test Reactor. During that time the collective dose equivalents received by operating personnel have been about two orders of magnitude lower than those typically received at commercial light water reactors. No major contamination problems have been encountered in operating and maintaining the plant, and release of radioactive gas to the environment has been minimal and well below acceptable limits. All shields have performed satisfactorily. Experience to date indicates an apparent radiological superiority of liquid metal reactor systems over current light water plants

  17. A fast gauge for energy flux density measurement

    Science.gov (United States)

    Garcia, Jorge; Bana de Schor, Beatriz

    1990-01-01

    Herein, the design and characterization of a fast energy flux density gauge are described. The gauge is based on a thermoelectrical pair with the junction made of a thin layer of silver. High absorptivity is attained by an electrolytic deposit of platinum black on the silver coat. Dynamic calibration gives a response time below 100 microsec. Computer methods to obtain the energy flux density from temperature-time history were evaluated. The results of the tests performed with igniters of pelleted boron/potassium nitrate and black powder, used in solid propellant ignition, are shown. The gauge developed can be applied to fast processes which require small response time. The gauge does not need previous calibration, it is resistant to vibrations and accelerations, and, at the same time, it is small in size, economical, and easy to build.

  18. Energy and energy flux in axisymmetric slow and fast waves

    Science.gov (United States)

    Moreels, M. G.; Van Doorsselaere, T.; Grant, S. D. T.; Jess, D. B.; Goossens, M.

    2015-06-01

    Aims: We aim to calculate the kinetic, magnetic, thermal, and total energy densities and the flux of energy in axisymmetric sausage modes. The resulting equations should contain as few parameters as possible to facilitate applicability for different observations. Methods: The background equilibrium is a one-dimensional cylindrical flux tube model with a piecewise constant radial density profile. This enables us to use linearised magnetohydrodynamic equations to calculate the energy densities and the flux of energy for axisymmetric sausage modes. Results: The equations used to calculate the energy densities and the flux of energy in axisymmetric sausage modes depend on the radius of the flux tube, the equilibrium sound and Alfvén speeds, the density of the plasma, the period and phase speed of the wave, and the radial or longitudinal components of the Lagrangian displacement at the flux tube boundary. Approximate relations for limiting cases of propagating slow and fast sausage modes are also obtained. We also obtained the dispersive first-order correction term to the phase speed for both the fundamental slow body mode under coronal conditions and the slow surface mode under photospheric conditions. Appendix A is available in electronic form at http://www.aanda.org

  19. Determination of fast neutron flux distribution in irradiation sites of the Malaysian Nuclear Agency research reactor

    International Nuclear Information System (INIS)

    Yavar, A.R.; Sarmani, S.B.; Wood, A.K.; Fadzil, S.M.; Radir, M.H.; Khoo, K.S.

    2011-01-01

    Determination of thermal to fast neutron flux ratio (f fast ) and fast neutron fluxfast ) is required for fast neutron reactions, fast neutron activation analysis, and for correcting interference reactions. The f fast and subsequently φ fast were determined using the absolute method. The f fast ranged from 48 to 155, and the φ fast was found in the range 1.03x10 10 -4.89x10 10 n cm -2 s -1 . These values indicate an acceptable conformity and applicable for installation of the fast neutron facility at the MNA research reactor.

  20. Recovery strategies for fluxes affected by the Gill-Solent WindMaster-Pro "w-boost" firmware bug

    Science.gov (United States)

    Billesbach, D. P.; Chan, S. W.; Biraud, S.; David, C. R.

    2017-12-01

    In late 2015 and early 2016, work done by the AmeriFlux Tech Team helped to uncover a bug in the Gill WindMaster Pro sonic anemometers used by many researchers for eddy covariance flux measurements. Gill has addressed this issue and has since sent out a notice that the vertical wind speed component (a critical piece of all eddy covariance fluxes) was being erroneously computed and reported. The problem (known as the w-boost bug) resulted in positive (upward) wind speeds being under-reported by 16.6% and negative (downward) wind speeds being under-reported by 28.9%. This has the potential to cause similar underestimates in fluxes obtained from these instruments. While the manufacturer has offered a firmware upgrade to fix this bug, there exist many data sets that have already been affected by it. Researchers who use the affected units have contributed to numerous data archives (AmeriFlux, FluxNet, ICOS, etc.), and third-party scientists have, in turn used these data in many types of research projects. The volume of affected data over such a long period of time makes a complete reprocessing of the raw data sets impractical. To address this, the AmeriFlux Tech Team has endeavored to develop a method of correcting affected fluxes using only the downloadable data sets that are available from these archives. In a previous poster, we reported preliminary results from a pair of Arctic tundra flux towers, and showed that fluxes could be underestimated by 15% to 20%. In this poster, we present results that extend our study to include a forested site in Equatorial Africa. We also have evaluated methods to estimate flux errors without accessing the raw data sets.

  1. Performance measurements at the fast flux test facility

    International Nuclear Information System (INIS)

    In 1984, Fast Flux Test Facility (FFTF) management recognized the need to develop a measurement system that would quantify the operational performance of the FFTF and the human resources needed to operate it. Driven by declining budgets and the need to safely manage a manpower rampdown at FFTF, an early warning system was developed. Although the initiating event for the early warning system was the need to safely manage a manpower rampdown, many related uses have evolved. The initial desired objective for the FFTF performance measurements was to ensure safety and control of key performance trends. However, the early warning system has provided a more quantitative, supportable basis upon which to make decisions. From this initial narrow focus, efforts in the FFTF plant and supporting organizations are leading to measurement of and, subsequently, improvements in productivity. Pilot projects utilizing statistical process control have started with longer range productivity improvement

  2. Specifying and manufacturing piping for the fast flux test facility

    International Nuclear Information System (INIS)

    Moen, R.A.; O'Keefe, D.P.; Irvin, J.E.; Tobin, J.C.

    1974-01-01

    Specification of materials for liquid metal reactor coolant piping, at service temperatures up to 1200 0 F, involves a number of considerations unique to these systems. The mechanical property/design allowable stress considerations which led to the selection and specification of specific materials for the Fast Flux Test Facility piping are discussed. Additional considerations are described indicating allowances made for material changes anticipated in service. These measures primarily involved raising the minimum carbon content to a value that would insure the strength of the material always remains above that assumed in the initial design, although other considerations are discussed. The processes by which this piping was manufactured, its resulting characteristics and methods of subsequent handling/assembly are briefly discussed. (U.S.)

  3. Fast Flux Test Facility metal fuel pin fabrication

    International Nuclear Information System (INIS)

    Benecke, M.W.; Dittmer, J.O.; Feigenbutz, L.V.

    1989-05-01

    A new initiative to develop, irradiate, and qualify a binary uranium/zirconium metal fuel system in the Fast Flux Test Facility (FFTF) has been implemented by the Westinghouse Hanford Company for the US Department of Energy. Metal fuel test assemblies have been designed and fabricated and are now being irradiated in FFTF to provide the data needed to support the potential use of binary fuels in FFTF and other liquid metal reactors. These development efforts support licensing activities for metal fuel use in near-term advanced liquid metal reactors. New metal fuel pin design features, fabrication development, and fabrication processes for three metal fuel tests will be described and their irradiation status reported in this paper. 11 figs

  4. Fast Flux Test Facility Asbestos Location Tracking Program

    International Nuclear Information System (INIS)

    REYNOLDS, J.A.

    1999-01-01

    Procedure Number HNF-PRO-408, revision 0, paragraph 1.0, ''Purpose,'' and paragraph 2.0, ''Requirements for Facility Management of Asbestos,'' relate building inspection and requirements for documentation of existing asbestos-containing building material (ACBM) per each building assessment. This documentation shall be available to all personnel (including contractor personnel) entering the facility at their request. Corrective action was required by 400 Area Integrated Annual Appraisal/Audit for Fiscal Year 1992 (IAA-92-0007) to provide this notification documentation. No formal method had been developed to communicate the location and nature of ACBM to maintenance personnel in the Fast Flux Test Facility (FFTF) 400 Area. The scope of this Data Package Document is to locate and evaluate any ACBM found at FFTF which constitutes a baseline. This includes all buildings within the protected area. These findings are compiled from earlier reports, numerous work packages and engineering evaluations of employee findings

  5. Reactivity anomalies in the FFTF [Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Knutson, B.J.; Harris, R.A.

    1987-04-01

    Experience using an automated core reactivity monitoring technique at the Fast Flux Test Facility (FFTF) through eight operating cycles is described. This technique relies on comparing predicted to measured rod positions to detect any anomalous (or unpredicted) core reactivity changes. Reactivity worth predictions of core state changes (e.g., temperature and irradiation changes) and compensating control rod movements are required for the rod position comparison. A substantial data base now exists to evaluate changes in temperature reactivity feedback effects operational in the FFTF, rod worth changes due to core loading, temperature and irradiation effects and burnup effects associated with transmutation of fuel materials. This report summarizes preliminary work of correlating zero power and at-power rod worth measurement data, calculated burnup rates and rod worths using the latest ENDF/B-V cross section set for each cycle to evaluate the prediction models and attempt to resolve observed reactivity anomalies. 2 figs., 2 tabs

  6. Reactor cover gas monitoring at the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Bechtold, R.A.; Holt, F.E.; Meadows, G.E.; Schenter, R.E.

    1986-09-01

    The Fast Flux Test Facility (FFTF) is a 400-megawatt (thermal) sodium-cooled reactor designed for irradiation testing of fuels, materials and components for LMRs. It is operated by the Westinghouse Hanford Company for the US Department of Energy on the government-owned Hanford reservation near Richland, Washington. The first 100-day operating cycle began in April 1982 and the eighth operating cycle was completed in July 1986. Argon is used as the cover gas for all sodium systems at the plant. A program for cover gas monitoring has been in effect since the start of sodium fill in 1978. The argon is supplied to the FFTF by a liquid argon Dewar System and used without further purification

  7. Fuels and materials testing capabilities in Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Baker, R.B.; Chastain, S.A.; Culley, G.E.; Ethridge, J.L.; Lovell, A.J.; Newland, D.J.; Pember, L.A.; Puigh, R.J.; Waltar, A.E.

    1989-01-01

    The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop in-reactor assembly (CLIRA), and other special fuel assemblies. An interim examination and maintenance cell (FFTF/IEM cell) and other hot cells are used for nondestructive/destructive tests and physical/mechanical properties test of material after irradiation. (N.K.)

  8. Ten years operating experience at the Fast Flux Test Facility: A decade of excellence

    International Nuclear Information System (INIS)

    Swaim, D.J.; Waldo, J.B.; Farabee, O.A.

    1991-07-01

    The Fast Flux Test Facility is a 400 MW(t) fast reactor cooled by three sodium loops. The Fast Flux Test Facility is managed by the Westinghouse Hanford Company for the US Department of Energy. The Fast Flux Test Facility was designed and constructed to provide irradiation testing of fuels and materials for the US Department of Energy Liquid Metal Reactor research program. Facility activities have increased to include fusion power materials testing, passive safety testing, isotope production, and international collaboration. 5 figs

  9. Fast Flux Test Facility (FFTF) Briefing Book 1 Summary

    Energy Technology Data Exchange (ETDEWEB)

    WJ Apley

    1997-12-01

    This report documents the results of evaluations preformed during 1997 to determine what, if an, future role the Fast Flux Test Facility (FFTF) might have in support of the Department of Energy’s tritium productions strategy. An evaluation was also conducted to assess the potential for the FFTF to produce medical isotopes. No safety, environmental, or technical issues associated with producing 1.5 kilograms of tritium per year in the FFTF have been identified that would change the previous evaluations by the Department of Energy, the JASON panel, or Putnam, Hayes & Bartlett. The FFTF can be refitted and restated by July 2002 for a total expenditure of $371 million, with an additional $64 million of startup expense necessary to incorporate the production of medical isotopes. Therapeutic and diagnostic applications of reactor-generated medical isotopes will increase dramatically over the next decade. Essential medical isotopes can be produced in the FFTF simultaneously with tritium production, and while a stand-alone medical isotope mission for the facility cannot be economically justified given current marker conditions, conservative estimates based on a report by Frost &Sullivan indicate that 60% of the annual operational costs (reactor and fuel supply) could be offset by revenues from medical isotope production within 10 yeas of restart. The recommendation of the report is for the Department of Energy to continue to maintain the FFTF in standby and proceed with preparation of appropriate Nations Environmental Policy Act documentation in full consultation with the public to consider the FFTF as an interim tritium production option (1.5 kilograms/year) with a secondary mission of producing medical isotopes.

  10. Two-dimensional CsPbBr3/PCBM heterojunctions for sensitive, fast and flexible photodetectors boosted by charge transfer

    Science.gov (United States)

    Shen, Yalong; Yu, Dejian; Wang, Xiong; Huo, Chengxue; Wu, Ye; Zhu, Zhengfeng; Zeng, Haibo

    2018-02-01

    Inorganic halide perovskites exhibited promising potentials for high-performance wide-band photodetectors (PDs) due to their high light absorption coefficients, long carrier diffusion length and wide light absorption ranges. Here, we report two-dimensional (2D) CsPbBr3/PCBM heterojunctions for sensitive, fast and flexible PDs, whose performances can be greatly boosted by the charge transfer through the energy-aligned interface. The 2D CsPbBr3 nanosheets with high crystallinity were fabricated via a simple solution-process at room temperature, and then assembled into flexible heterojunctions films with polymerphenyl-C61-butyric acid methyl ester (PCBM). Significantly, the efficient and fast charge transfer at the heterojunctions interface was evidenced by the obvious photoluminescence quenching and variation of recombination dynamics. Subsequently, such heterojunctions PD exhibited an enhanced responsivity of 10.85 A W-1 and an ultrahigh detectivity of 3.06 × 1013 Jones. In addition, the PD shows a broad linear dynamic range of 73 dB, a fast response speed with rise time of 44 μs and decay time of 390 μs, respectively. Moreover, the PD lying on polyethylene terephthalate substrates exhibited an outstanding mechanical flexibility and a robust electrical stability. These results could provide a new avenue for integration of 2D perovskites and organic functional materials and for high-performance flexible PDs.

  11. Temperature-dependent attenuation of ex-vessel flux measurements at the Hanford Fast Flux Test Facility

    International Nuclear Information System (INIS)

    McLane, F.E.; Wood, M.R.; Rathbun, J.L.

    1982-01-01

    Indicated nuclear power, developed by measuring leakage neutrons, has been found to be temperature dependent at the Hanford Fast Flux Test Facility (FFTF). The magnitude, sense and speed of response of the effect suggest that hot sodium above th core and shield is a significant cause. Future designs which may minimize this effect are discussed

  12. Fast AdaBoost-Based Face Detection System on a Dynamically Coarse Grain Reconfigurable Architecture

    Science.gov (United States)

    Xiao, Jian; Zhang, Jinguo; Zhu, Min; Yang, Jun; Shi, Longxing

    An AdaBoost-based face detection system is proposed, on a Coarse Grain Reconfigurable Architecture (CGRA) named “REMUS-II”. Our work is quite distinguished from previous ones in three aspects. First, a new hardware-software partition method is proposed and the whole face detection system is divided into several parallel tasks implemented on two Reconfigurable Processing Units (RPU) and one micro Processors Unit (µPU) according to their relationships. These tasks communicate with each other by a mailbox mechanism. Second, a strong classifier is treated as a smallest phase of the detection system, and every phase needs to be executed by these tasks in order. A phase of Haar classifier is dynamically mapped onto a Reconfigurable Cell Array (RCA) only when needed, and it's quite different from traditional Field Programmable Gate Array (FPGA) methods in which all the classifiers are fabricated statically. Third, optimized data and configuration word pre-fetch mechanisms are employed to improve the whole system performance. Implementation results show that our approach under 200MHz clock rate can process up-to 17 frames per second on VGA size images, and the detection rate is over 95%. Our system consumes 194mW, and the die size of fabricated chip is 23mm2 using TSMC 65nm standard cell based technology. To the best of our knowledge, this work is the first implementation of the cascade Haar classifier algorithm on a dynamically CGRA platform presented in the literature.

  13. Measurement and evaluation of fast neutron flux of CT and OR5 irradiation hole in HANARO

    International Nuclear Information System (INIS)

    Yang, Seong Woo; Choo, Kee Nam; Lee, Seung-Kyu; Kim, Yong Kyun

    2012-01-01

    The irradiation test has been conducted to evaluate the irradiation performance of many materials by a material capsule at HANARO. Since the fast neutron fluence above 1 MeV is important for the irradiation test of material, it must be measured and evaluated exactly at each irradiation hole. Therefore, a fast neutron flux was measured and evaluated by a 09M-02K capsule irradiated in an OR5 irradiation hole and a 10M-01K capsule irradiated in a CT irradiation hole. Fe, Ni, and Ti wires as the fluence monitor were used for the detection of fast neutron flux. Before the irradiation test, the neutron flux and spectrum was calculated for each irradiation hole using an MCNP code. After the irradiation test, the activity of the fluence monitor was measured by an HPGe detector and the reaction rate was calculated. For the OR5 irradiation hole, the radial difference of the fast neutron flux was observed from a calculated data due to the OR5 irradiation hole being located outside the core. Furthermore, a control absorber rod was withdrawn from the core as the increase of the irradiation time at the same irradiation cycle, so the distribution of neutron flux was changed from the beginning to the end of the cycle. These effects were considered to evaluate the fast neutron flux. Neutron spectrums of the CT and OR5 irradiation hole were adjusted by the measured data. The fluxes of a fast neutron above 1 MeV were compared with calculated and measured value. Although the maximum difference was shown at 18.48%, most of the results showed good agreement. (author)

  14. Fasting boosts sensitivity of human skin melanoma to cisplatin-induced cell death.

    Science.gov (United States)

    Antunes, Fernanda; Corazzari, Marco; Pereira, Gustavo; Fimia, Gian Maria; Piacentini, Mauro; Smaili, Soraya

    2017-03-25

    Melanoma is one of leading cause of tumor death worldwide. Anti-cancer strategy includes combination of different chemo-therapeutic agents as well as radiation; however these treatments have limited efficacy and induce significant toxic effects on healthy cells. One of most promising novel therapeutic approach to cancer therapy is the combination of anti-cancer drugs with calorie restriction. Here we investigated the effect Cisplatin (CDDP), one of the most potent chemotherapeutic agent used to treat tumors, in association with fasting in wild type and mutated BRAF V600E melanoma cell lines. Here we show that nutrient deprivation can consistently enhance the sensitivity of tumor cells to cell death induction by CDDP, also of those malignancies particularly resistant to any treatment, such as oncogenic BRAF melanomas. Mechanistic studies revealed that the combined therapy induced cell death is characterized by ROS accumulation and ATF4 in the absence of ER-stress. In addition, we show that autophagy is not involved in the enhanced sensitivity of melanoma cells to combined CDDP/EBSS-induced apoptosis. While, the exposure to 2-DG further enhanced the apoptotic rate observed in SK Mel 28 cells upon treatment with both CDDP and EBSS. Copyright © 2016. Published by Elsevier Inc.

  15. Nonlinear fast sausage waves in homogeneous magnetic flux tubes

    Science.gov (United States)

    Mikhalyaev, Badma B.; Ruderman, Michael S.

    2015-12-01

    > We consider fast sausage waves in straight homogeneous magnetic tubes. The plasma motion is described by the ideal magnetohydrodynamic equations in the cold plasma approximation. We derive the nonlinear Schrödinger equation describing the nonlinear evolution of an envelope of a carrier wave. The coefficients of this equation are expressed in terms Bessel and modified Bessel functions. They are calculated numerically for various values of parameters. In particular, we show that the criterion for the onset of the modulational or Benjamin-Fair instability is satisfied. The implication of the obtained results for solar physics is discussed.

  16. Neutron flux shape effects in large fast reactor safety calculations

    International Nuclear Information System (INIS)

    Galati, A.; Loizzo, P.; Musco, A.

    1978-01-01

    Three classes of accidents in a large fast reactor were studied by the two-dimensional core dynamics code NADYP-2. A Modified version of the code, including a point kinetics module, allowed comparison between 2D and 0D power, reactivity and temperature histories. A strong shape effect was evidenced by these calculations in the boiling phase of LOF accidents as well as in the accident generated by control rod removal. Some future possibilities of by passing the consequences of this effect are indicated

  17. Boosting flood warning schemes with fast emulator of detailed hydrodynamic models

    Science.gov (United States)

    Bellos, V.; Carbajal, J. P.; Leitao, J. P.

    2017-12-01

    Floods are among the most destructive catastrophic events and their frequency has incremented over the last decades. To reduce flood impact and risks, flood warning schemes are installed in flood prone areas. Frequently, these schemes are based on numerical models which quickly provide predictions of water levels and other relevant observables. However, the high complexity of flood wave propagation in the real world and the need of accurate predictions in urban environments or in floodplains hinders the use of detailed simulators. This sets the difficulty, we need fast predictions that meet the accuracy requirements. Most physics based detailed simulators although accurate, will not fulfill the speed demand. Even if High Performance Computing techniques are used (the magnitude of required simulation time is minutes/hours). As a consequence, most flood warning schemes are based in coarse ad-hoc approximations that cannot take advantage a detailed hydrodynamic simulation. In this work, we present a methodology for developing a flood warning scheme using an Gaussian Processes based emulator of a detailed hydrodynamic model. The methodology consists of two main stages: 1) offline stage to build the emulator; 2) online stage using the emulator to predict and generate warnings. The offline stage consists of the following steps: a) definition of the critical sites of the area under study, and the specification of the observables to predict at those sites, e.g. water depth, flow velocity, etc.; b) generation of a detailed simulation dataset to train the emulator; c) calibration of the required parameters (if measurements are available). The online stage is carried on using the emulator to predict the relevant observables quickly, and the detailed simulator is used in parallel to verify key predictions of the emulator. The speed gain given by the emulator allows also to quantify uncertainty in predictions using ensemble methods. The above methodology is applied in real

  18. Fast flux measurements by means of threshold detectors on the reactor 'Melusine'

    International Nuclear Information System (INIS)

    Leger, P.; Sautiez, B.

    1959-01-01

    Using existing data on the (n,p) and (n,α) threshold reactions we have carried out fast flux measurements on the swimming pool type reactor 'Melusine'. Four common elements: P, S, Mg, Al were chosen because from the point of view of fast spectrum analysis they represent a fairly good energy range from 2.4 MeV to 8 MeV. The fission flux value found in the central element at a power of 1 MW is 1.4 x 10 13 n/cm 2 /s ± 0.14. (author) [fr

  19. Recovery of Information from the Fast Flux Test Facility for the Advanced Fuel Cycle Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Deborah L.; Makenas, Bruce J.; Wootan, David W.; Butner, R. Scott; Omberg, Ronald P.

    2009-09-30

    The Fast Flux Test Facility is the most recent Liquid Metal Reactor to operate in the United States. Information from the design, construction, and operation of this reactor was at risk as the facilities associated with the reactor are being shut down. The Advanced Fuel Cycle Initiative is a program managed by the Office of Nuclear Energy of the U.S. Department of Energy with a mission to develop new fuel cycle technologies to support both current and advanced reactors. Securing and preserving the knowledge gained from operation and testing in the Fast Flux Test Facility is an important part of the Knowledge Preservation activity in this program.

  20. Non-equilibrium reactive flux: A unified framework for slow and fast reaction kinetics.

    Science.gov (United States)

    Bose, Amartya; Makri, Nancy

    2017-10-21

    The flux formulation of reaction rate theory is recast in terms of the expectation value of the reactive flux with an initial condition that corresponds to a non-equilibrium, factorized reactant density. In the common case of slow reactive processes, the non-equilibrium expression reaches the plateau regime only slightly slower than the equilibrium flux form. When the reactants are described by a single quantum state, as in the case of electron transfer reactions, the factorized reactant density describes the true initial condition of the reactive process. In such cases, the time integral of the non-equilibrium flux expression yields the reactant population as a function of time, allowing characterization of the dynamics in cases where there is no clear separation of time scales and thus a plateau regime cannot be identified. The non-equilibrium flux offers a unified approach to the kinetics of slow and fast chemical reactions and is ideally suited to mixed quantum-classical methods.

  1. Fast Flux Test Facility: the first three years, 1982-1985

    International Nuclear Information System (INIS)

    1985-01-01

    General information is provided concerning the Fast Flux Test Facility. Topics discussed include: mission and major accomplishments; background information; major construction milestones; acceptance testing; plant performance; plant operation; fuel performance; interim examination and maintenance cell; environmental effects; and future plans for the FFTF

  2. Measurements of thermal and fast neutron fluxes at the TRIGA reactor

    International Nuclear Information System (INIS)

    Zerdin, F.; Grabovsek, Z.; Klinc, T.; Solinc, H.

    1966-01-01

    Gold foils were placed at different positions in the TRIGA reactor core and in the experimental devices. Absolute values of the thermal neutron flux at these positions were obtained by coincidence method. Preliminary fast neutron spectrum was measured by threshold detector and by 'Li 6 sandwich' detector. A short description of the applied method and obtained measurements results are included [sl

  3. Scoping assessment on medical isotope production at the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Scott, S.W.

    1997-01-01

    The Scoping Assessment addresses the need for medical isotope production and the capability of the Fast Flux Test Facility to provide such isotopes. Included in the discussion are types of isotopes used in radiopharmaceuticals, which types of cancers are targets, and in what way isotopes provide treatment and/or pain relief for patients

  4. Fast electron flux driven by lower hybrid wave in the scrape-off layer

    International Nuclear Information System (INIS)

    Li, Y. L.; Xu, G. S.; Wang, H. Q.; Wan, B. N.; Chen, R.; Wang, L.; Gan, K. F.; Yang, J. H.; Zhang, X. J.; Liu, S. C.; Li, M. H.; Ding, S.; Yan, N.; Zhang, W.; Hu, G. H.; Liu, Y. L.; Shao, L. M.; Li, J.; Chen, L.; Zhao, N.

    2015-01-01

    The fast electron flux driven by Lower Hybrid Wave (LHW) in the scrape-off layer (SOL) in EAST is analyzed both theoretically and experimentally. The five bright belts flowing along the magnetic field lines in the SOL and hot spots at LHW guard limiters observed by charge coupled device and infrared cameras are attributed to the fast electron flux, which is directly measured by retarding field analyzers (RFA). The current carried by the fast electron flux, ranging from 400 to 6000 A/m 2 and in the direction opposite to the plasma current, is scanned along the radial direction from the limiter surface to the position about 25 mm beyond the limiter. The measured fast electron flux is attributed to the high parallel wave refractive index n || components of LHW. According to the antenna structure and the LHW power absorbed by plasma, a broad parallel electric field spectrum of incident wave from the antennas is estimated. The radial distribution of LHW-driven current density is analyzed in SOL based on Landau damping of the LHW. The analytical results support the RFA measurements, showing a certain level of consistency. In addition, the deposition profile of the LHW power density in SOL is also calculated utilizing this simple model. This study provides some fundamental insight into the heating and current drive effects induced by LHW in SOL, and should also help to interpret the observations and related numerical analyses of the behaviors of bright belts and hot spots induced by LHW

  5. FAST FLUX TEST FACILITY MONTHLY INFORMAL TECHNICAL PROGRESS REPORT SEPTEMBER 1969

    Energy Technology Data Exchange (ETDEWEB)

    Astely, E. R.; Cabell, C. P.

    1969-10-07

    This report was prepared by Battelle-Northwest under Contract No. AT(45-1)-1830 for the Atomic Energy Commission, Division of Reactor Development and Technology, to summarize technical progress made in the Fast Flux Test Facility Program during September 1969.

  6. FAST FLUX TEST FACILITY MONTHLY INFORMAL TECHNICAL PROGRESS REPORT FEBRUARY 1969

    Energy Technology Data Exchange (ETDEWEB)

    Astley, E. R.

    1969-03-07

    This report was prepared by Battelle-Northwest under Contract No. AT (45-1)-1830 for the Atomic Energy Commission, Division of Reactor Development and Technology, to summarize technical progress made in the Fast Flux Test Facility Program during February 1969.

  7. FAST FLUX TEST FACILITY MONTHLY INFORMAL TECHNICAL PROGRESS REPORT MAY 1969

    Energy Technology Data Exchange (ETDEWEB)

    Astley, E. R.; Cabell, C. P.

    1969-06-06

    This report was prepared by Battelle-Northwest under Contract No. AT(45-1)-1830 for the Atomic Energy Commission, Division of Reactor Development and Technology, to summarize technical progress made in the Fast Flux Test Facility Program during May 1969 .

  8. On-line fast flux measurements in the BR2 reactor

    International Nuclear Information System (INIS)

    Vermeeren, L.

    2009-01-01

    Since 2001, CEA-Cadarache and the Belgian Nuclear Research Centre SCK-CEN are collaborating on the development and in-pile qualification of subminiature fission chambers (diameter of 1.5 mm). Initially, efforts concentrated on fission chambers for the in-pile measurement of thermal fluxes (with 235 U as fissile material). Meanwhile successful long-term tests of the prototypes have been performed in various environments: in low temperature (40-100 degress Celsius) BR2 pool water (up to a thermal neutron fluence of 3 1 0 21 n/cm 2 ) and in the CALLISTO PWR loop (300 degrees Celsius, 155 bars). The long-term qualification of derived industrial detectors (Photonis CFUZ53) in CALLISTO is still ongoing. However, for various types of irradiations in research reactors, the knowledge of the evolution of the fast neutron flux is even of more interest than the thermal flux data. Therefore the collaboration program was extended to the development and the in-pile qualification of subminiature or miniature fission chambers (with 3 mm diameter) for fast neutron detection, for which 242 Pu was selected as the optimal fissile material. In order to achieve the on-line in-pile measurement of fast neutron flux, the fission chambers will be operated in the Campbelling mode (based on the mean square fluctuation of the detector current). In this mode the gamma induced contribution to the signal can be efficiently suppressed. Moreover, a data processing software will take into account the evolution of the fissile deposit in order to assess on-line the fast flux sensitivity and to correct for the low energy neutron contributions. The final objective is to qualify a Fast Neutron Detector System (FNDS) able to provide on-line data for local fast neutron fluxes in Material Testing Reactors. The on-line measurement of the fast neutron flux would contribute significantly to the characterization of the irradiation conditions during test experiments with materials and innovative fuel elements

  9. CERES Fast Longwave And SHortwave Radiative Flux (FLASHFlux) Version4A.

    Science.gov (United States)

    Sawaengphokhai, P.; Stackhouse, P. W., Jr.; Kratz, D. P.; Gupta, S. K.

    2017-12-01

    The agricultural, renewable energy management, and science communities need global surface and top-of-atmosphere (TOA) radiative fluxes on a low latency basis. The Clouds and Earth's Radiant Energy System (CERES) FLASHFlux (Fast Longwave and SHortwave radiative Flux) data products address this need by enhancing the speed of CERES processing using simplified calibration and parameterized model of surface fluxes to provide a daily global radiative fluxes data set within one week of satellite observations. The CERES FLASHFlux provides two data products: 1) an overpass swath Level 2 Single Scanner Footprint (SSF) data products separately for both Aqua and Terra observations, and 2) a daily Level 3 Time Interpolated and Spatially Averaged (TISA) 1o x 1o gridded data that combines Aqua and Terra observations. The CERES FLASHFlux data product is being promoted to Version4A. Updates to FLASHFlux Version4A include a new cloud retrieval algorithm and an improved shortwave surface flux parameterization. We inter-compared FLASHFlux Version4A, FLASHFlux Version3C, CERES Edition 4 Syn1Deg and at the monthly scale CERES Edition4 EBAF (Energy Balanced and Filled) Top-of-Atmosphere and Edition 4 Surface EBAF fluxes to evaluate these improvements. We also analyze the impact of the new inputs and cloud algorithm to the surface shortwave and longwave radiative fluxes using ground sites measurement provided by CAVE (CERES/ARM Validation Experiment).

  10. Flux

    DEFF Research Database (Denmark)

    Ravn, Ib

    . FLUX betegner en flyden eller strømmen, dvs. dynamik. Forstår man livet som proces og udvikling i stedet for som ting og mekanik, får man et andet billede af det gode liv end det, som den velkendte vestlige mekanicisme lægger op til. Dynamisk forstået indebærer det gode liv den bedst mulige...... kanalisering af den flux eller energi, der strømmer igennem os og giver sig til kende i vore daglige aktiviteter. Skal vores tanker, handlinger, arbejde, samvær og politiske liv organiseres efter stramme og faste regelsæt, uden slinger i valsen? Eller skal de tværtimod forløbe ganske uhindret af regler og bånd...

  11. Fast neutron flux analyzer with real-time digital pulse shape discrimination

    Science.gov (United States)

    Ivanova, A. A.; Zubarev, P. V.; Ivanenko, S. V.; Khilchenko, A. D.; Kotelnikov, A. I.; Polosatkin, S. V.; Puryga, E. A.; Shvyrev, V. G.; Sulyaev, Yu. S.

    2016-08-01

    Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL-3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL-3 and GDT devices. This analyzer was tested and calibrated with the help of 137Cs and 252Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented.

  12. Closed Loop In-Reactor Assembly (CLIRA): a fast flux test facility test vehicle

    International Nuclear Information System (INIS)

    Oakley, D.J.

    1978-01-01

    The Closed Loop In-Reactor Assembly (CLIRA) is a test vehicle for in-core material and fuel experiments in the Fast Flux Test Facility (FFTF). The FFTF is a fast flux nuclear test reactor operated for the Department of Energy (DOE) by Westinghouse Hanford Company in Richland, Washington. The CLIRA is a removable/replaceable part of the Closed Loop System (CLS) which is a sodium coolant system providing flow and temperature control independent of the reactor coolant system. The primary purpose of the CLIRA is to provide a test vehicle which will permit testing of nuclear fuels and materials at conditions more severe than exist in the FTR core, and to isolate these materials from the reactor core

  13. FFTF [Fast Flux Test Facility] performance measurements for safety, productivity and control

    International Nuclear Information System (INIS)

    A useful set of performance measurements for Safety, Productivity and Control has evolved at the Fast Flux Test Facility (FFTF). In response to declining budgets and the resulting need to safely manage a manpower rampdown, an ''Early Warning System'' was developed in 1984. Its purpose was to monitor the effects of the staffing rampdown such that appropriate remedial action could be taken to correct adverse trends before a significant problem occurred. 1 tab

  14. Fast neutron flux analyzer with real-time digital pulse shape discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, A.A., E-mail: a.a.ivanova@inp.nsk.su [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Zubarev, P.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Ivanenko, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Khilchenko, A.D. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Kotelnikov, A.I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Polosatkin, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Puryga, E.A.; Shvyrev, V.G. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Sulyaev, Yu.S. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2016-08-11

    Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL–3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL–3 and GDT devices. This analyzer was tested and calibrated with the help of {sup 137}Cs and {sup 252}Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented. - Highlights: • Electronic equipment for measurement of fast neutron flux with stilbene scintillator is presented. • FPGA-implemented digital pulse-shape discrimination algorithm by charge comparison method is shown. • Calibration of analyzer was carried out with {sup 137}Cs and {sup 252}Cf. • Figures of Merit (FOM) values for energy cuts from 1/8 Cs to 2 Cs are from 1.264 to 2.34 respectively.

  15. Magnetic swirls and associated fast magnetoacoustic kink waves in a solar chromospheric flux tube

    Science.gov (United States)

    Murawski, K.; Kayshap, P.; Srivastava, A. K.; Pascoe, D. J.; Jelínek, P.; Kuźma, B.; Fedun, V.

    2018-02-01

    We perform numerical simulations of impulsively generated magnetic swirls in an isolated flux tube that is rooted in the solar photosphere. These swirls are triggered by an initial pulse in a horizontal component of the velocity. The initial pulse is launched either (a) centrally, within the localized magnetic flux tube or (b) off-central, in the ambient medium. The evolution and dynamics of the flux tube are described by three-dimensional, ideal magnetohydrodynamic equations. These equations are numerically solved to reveal that in case (a) dipole-like swirls associated with the fast magnetoacoustic kink and m = 1 Alfvén waves are generated. In case (b), the fast magnetoacoustic kink and m = 0 Alfvén modes are excited. In both these cases, the excited fast magnetoacoustic kink and Alfvén waves consist of a similar flow pattern and magnetic shells are also generated with clockwise and counter-clockwise rotating plasma within them, which can be the proxy of dipole-shaped chromospheric swirls. The complex dynamics of vortices and wave perturbations reveals the channelling of sufficient amount of energy to fulfil energy losses in the chromosphere (˜104 W m-1) and in the corona (˜102 W m-1). Some of these numerical findings are reminiscent of signatures in recent observational data.

  16. Fast Prediction of Differential Mode Noise Input Filter Requirements for FLyback and Boost Unity Power Factor Converters

    DEFF Research Database (Denmark)

    Andersen, Michael Andreas E.

    1997-01-01

    Two new and simple methods to make predictions of the differential mode (DM) input filter requirements are presented, one for flyback and one for boost unity power factor converters. They have been verified by measurements. They give the designer the ability to predict the DM input noise filter...

  17. Lactate flux and gluconeogenesis in fasting, weaned northern elephant seals (Mirounga angustirostris).

    Science.gov (United States)

    Tavoni, Stephen K; Champagne, Cory D; Houser, Dorian S; Crocker, Daniel E

    2013-05-01

    Elephant seals maintain rates of endogenous glucose production (EGP) typical of post-absorptive mammals despite enduring prolonged periods of food deprivation concurrent with low rates of glucose oxidation. These high rates of EGP suggest extensive glucose recycling during fasting. We investigated lactate metabolism in fasting elephant seals to assess its role in glucose recycling. Whole-animal glucose and lactate fluxes were measured as the rates of appearance of glucose and lactate (Ra gluc and Ra lac, respectively) using a primed constant infusion of [U-(14)C] lactate and [6-(3)H] glucose, and we calculated the minimum contribution of lactate to gluconeogenesis (GNG lac). Ra lac was high compared to resting values in other species (3.21 ± 0.71 mmol min(-1)* kg(-1)), did not change between 14 ± 1 and 31 ± 8 days of fasting and varied directly with Ra glu. The minimum GNG lac was 44.6 ± 6.0% of EGP, varied directly with plasma lactate levels, and did not change over the fast. Ra lac and Ra glu both varied directly with plasma insulin concentrations. These data suggest that lactate is the predominant gluconeogenic precursor in fasting elephant seals and that high rates of glucose recycling through Cori cycle activity contribute to the maintenance of EGP during fasting. High levels of Cori cycle activity and EGP may be important components of metabolic adaptations that maintain glucose production while avoiding ketosis during extended fasting or are related to sustained metabolic alterations associated with extended breath-holds in elephant seals.

  18. A fast, magnetics-free flux surface estimation and q-profile reconstruction algorithm for feedback control of plasma profiles

    NARCIS (Netherlands)

    Hommen, G.; de M. Baar,; Citrin, J.; de Blank, H. J.; Voorhoeve, R. J.; de Bock, M. F. M.; Steinbuch, M.

    2013-01-01

    The flux surfaces' layout and the magnetic winding number q are important quantities for the performance and stability of tokamak plasmas. Normally, these quantities are iteratively derived by solving the plasma equilibrium for the poloidal and toroidal flux. In this work, a fast, non-iterative

  19. Evaluation of the Initial Isothermal Physics Measurements at the Fast Flux Test Facility, a Prototypic Liquid Metal Fast Breeder Reactor

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess

    2010-03-01

    The Fast Flux Test Facility (FFTF) was a 400-MWt, sodium-cooled, low-pressure, high-temperature, fast-neutron flux, nuclear fission reactor plant designed for the irradiation testing of nuclear reactor fuels and materials for the development of liquid metal fast breeder reactors (LMFBRs). The FFTF was fueled with plutonium-uranium mixed oxide (MOX) and reflected by Inconel-600. Westinghouse Hanford Company operated the FFTF as part of the Hanford Engineering Development Laboratory (HEDL) for the U.S. Department of Energy on the Hanford Site near Richland, Washington. Although the FFTF was a testing facility not specifically designed to breed fuel or produce electricity, it did provide valuable information for LMFBR projects and base technology programs in the areas of plant system and component design, component fabrication, prototype testing, and site construction. The major objectives of the FFTF were to provide a strong, disciplined engineering base for the LMFBR program, provide fast flux testing for other U.S. programs, and contribute to the development of a viable self-sustaining competitive U.S. LMFBR industry. During its ten years of operation, the FFTF acted as a national research facility to test advanced nuclear fuels, materials, components, systems, nuclear power plant operating and maintenance procedures, and active and passive reactor safety technologies; it also produced a large number of isotopes for medical and industrial users, generated tritium for the U.S. fusion research program, and participated in cooperative, international research work. Prior to the implementation of the reactor characterization program, a series of isothermal physics measurements were performed; this acceptance testing program consisted of a series of control rod worths, critical rod positions, subcriticality measurements, maximum reactivity addition rates, shutdown margins, excess reactivity, and isothermal temperature coefficient reactivity. The results of these

  20. Fast flux test facility interim examination and maintenance cell fuel duct cutters: Remote operations design considerations

    International Nuclear Information System (INIS)

    Gibbons, P.W.

    1988-11-01

    Two remotely operated milltype slitting cutters, specifically designed for remote, hot-cell use have been in service in the Fast Flux Test Facility (FFTF) Interim Examination and Maintenance (IEM) Cell for 3 and 4 yr, respectively without the benefit of hands-on maintenance. These cutters are used to sever the outer duct of Driver Fuel Assemblies (DFA) being dismantled for further examination elsewhere. During this period, twelve DFAs requiring duct cutting were dismantled in the IEM Cell. A discussion of the remote design features of those cutters is presented that highlights features that were successful and addresses areas that needed improvement. 3 refs., 7 figs

  1. Enhanced operator-training simulator for the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Schrader, F.D.; Swanson, C.D.

    1983-01-01

    The FFTF Plant Operator Training Simulator Facility has proven to be a valuable asset throughtout the testing, startup and early operational phases of the Fast Flux Test facility. However, limitations inherent in the existing simulation facility, increased emphasis on the required quality of operator training, and an expanded scope of applications (e.g., MNI development) justify an enhanced facility. Direct use of plant operators in the development of improved reactor control room displays and other man/machine interface equipment and procedures increases the credibility of proposed techniques and reported results. The FFTF Plant Operator Training Simulator provides a key element in this development program

  2. FFTF [Fast Flux Test Facility]/IEM [Interim Examination and Maintenance] Cell Fuel Pin Weighing System

    International Nuclear Information System (INIS)

    Gibbons, P.W.

    1987-09-01

    A Fuel Pin Weighing Machine has been developed for use in the Fast Flux Test Facility (FFTF) Interim Examination and Maintenance (IEM) Cell to assist in identifying an individual breached fuel pin from its fuel assembly pin bundle. A weighing machine, originally purchased for use in the Fuels and Materials Examination Facility (FMEF) at Hanford, was used as the basis for the IEM Cell system. Design modifications to the original equipment were centered around: 1) adapting the FMEF machine for use in the IEM Cell and 2) correcting operational deficiencies discovered during functional testing in the IEM Cell Mockup

  3. High-sensitive spectrometer of fast neutrons and the results of fast neutron background flux measurements at the Gallium-Germanium Solar Neutrino Experiment

    CERN Document Server

    Abdurashitov, J N; Kalikhov, A V; Matushko, V L; Shikhin, A A; Yants, V E; Zaborskaia, O S

    2002-01-01

    The principle of operation, design, registration system and main characteristics of a fast neutron spectrometer are described. The spectrometer is intended for direct measurements of ultra low fluxes of fast neutrons. It is sensitive to neutron fluxes of 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 and lower. The detection efficiency of fast neutrons with simultaneous energy measurement was determined from Monte-Carlo simulation to be equal to 0.11+-0.01. The background counting rate in the detector corresponds to a neutron flux of (6.5+-2.1)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The natural neutron flux from the surrounding mine rock at the depth of 4600 m of water equivalent was measured to be (7.3+-2.4)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The flux of fast neutrons in the SAGE main room was measured to be <2.3x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in 1.0-11.0 MeV energy range.

  4. Rapid post-seismic landslide evacuation boosted by dynamic river width and implications for sediment fluxes during the seismic cycle

    Science.gov (United States)

    Steer, Philippe; Croissant, Thomas; Lague, Dimitri; Davy, Philippe

    2017-04-01

    along the fluvial network and of the exported sediment flux throughout several seismic cycles. These results highlight how landscapes and sediment fluxes respond on longer time scales to a succession of earthquakes able to trigger landslides.

  5. Calculation of gamma-rays and fast neutrons fluxes with the program Mercure-4

    International Nuclear Information System (INIS)

    Baur, A.; Dupont, C.; Totth, B.

    1978-01-01

    The program MERCURE-4 evaluates gamma ray or fast neutron attenuation, through laminated or bulky three-dimensionnal shields. The method used is that of line of sight point attenuation kernel, the scattered rays being taken into account by means of build-up factors for γ and removal cross sections for fast neutrons. The integration of the point kernel over the range of sources distributed in space and energy, is performed by the Monte-Carlo method, with an automatic adjustment of the importance functions. Since it is operationnal the program MERCURE-4 has been intensively used for many various problems, for example: - the calculation of gamma heating in reactor cores, control rods and shielding screens, as well as in experimental devices and irradiation loops; - the evaluation of fast neutron fluxes and corresponding damage in structural materials of reactors (vessel steels...); - the estimation of gamma dose rates on nuclear instrumentation in the reactors, around the reactor circuits and around spent fuel shipping casks

  6. Analytical solution and computer program (FAST) to estimate fluid fluxes from subsurface temperature profiles

    Science.gov (United States)

    Kurylyk, Barret L.; Irvine, Dylan J.

    2016-02-01

    This study details the derivation and application of a new analytical solution to the one-dimensional, transient conduction-advection equation that is applied to trace vertical subsurface fluid fluxes. The solution employs a flexible initial condition that allows for nonlinear temperature-depth profiles, providing a key improvement over most previous solutions. The boundary condition is composed of any number of superimposed step changes in surface temperature, and thus it accommodates intermittent warming and cooling periods due to long-term changes in climate or land cover. The solution is verified using an established numerical model of coupled groundwater flow and heat transport. A new computer program FAST (Flexible Analytical Solution using Temperature) is also presented to facilitate the inversion of this analytical solution to estimate vertical groundwater flow. The program requires surface temperature history (which can be estimated from historic climate data), subsurface thermal properties, a present-day temperature-depth profile, and reasonable initial conditions. FAST is written in the Python computing language and can be run using a free graphical user interface. Herein, we demonstrate the utility of the analytical solution and FAST using measured subsurface temperature and climate data from the Sendia Plain, Japan. Results from these illustrative examples highlight the influence of the chosen initial and boundary conditions on estimated vertical flow rates.

  7. A study on the optimum fast neutron flux for boron neutron capture therapy of deep-seated tumors.

    Science.gov (United States)

    Rasouli, Fatemeh S; Masoudi, S Farhad

    2015-02-01

    High-energy neutrons, named fast neutrons which have a number of undesirable biological effects on tissue, are a challenging problem in beam designing for Boron Neutron Capture Therapy, BNCT. In spite of this fact, there is not a widely accepted criterion to guide the beam designer to determine the appropriate contribution of fast neutrons in the spectrum. Although a number of researchers have proposed a target value for the ratio of fast neutron flux to epithermal neutron flux, it can be shown that this criterion may not provide the optimum treatment condition. This simulation study deals with the determination of the optimum contribution of fast neutron flux in the beam for BNCT of deep-seated tumors. Since the dose due to these high-energy neutrons damages shallow tissues, delivered dose to skin is considered as a measure for determining the acceptability of the designed beam. To serve this purpose, various beam shaping assemblies that result in different contribution of fast neutron flux are designed. The performances of the neutron beams corresponding to such configurations are assessed in a simulated head phantom. It is shown that the previously used criterion, which suggests a limit value for the contribution of fast neutrons in beam, does not necessarily provide the optimum condition. Accordingly, it is important to specify other complementary limits considering the energy of fast neutrons. By analyzing various neutron spectra, two limits on fast neutron flux are proposed and their validity is investigated. The results show that considering these limits together with the widely accepted IAEA criteria makes it possible to have a more realistic assessment of sufficiency of the designed beam. Satisfying these criteria not only leads to reduction of delivered dose to skin, but also increases the advantage depth in tissue and delivered dose to tumor during the treatment time. The Monte Carlo Code, MCNP-X, is used to perform these simulations. Copyright © 2014

  8. Inference of physical phenomena from FFTF [Fast Flux Test Facility] noise analysis

    International Nuclear Information System (INIS)

    Thie, J.A.; Damiano, B.; Campbell, L.R.

    1989-01-01

    The source of features observed in noise spectra collected by an automated data collection system operated by the Oak Ridge National Laboratory at the Fast Flux Test Facility (FFTF) can be identified using a methodology based on careful data observation and intuition. When a large collection of data is available, as in this case, automatic pattern recognition and parameter storage and retrieval using a data base can be used to extract useful information. However, results can be limited to empirical signature comparison monitoring unless an effort is made to determine the noise sources. This paper describes the identification of several FFTF noise data phenomena and suggests how this understanding may lead to new or enhanced monitoring. 13 refs., 4 figs

  9. Preliminary safety evaluation (PSE) for Sodium Storage Facility at the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Bowman, B.R.

    1994-01-01

    This evaluation was performed for the Sodium Storage Facility (SSF) which will be constructed at the Fast Flux Test Facility (FFTF) in the area adjacent to the South and West Dump Heat Exchanger (DHX) pits. The purpose of the facility is to allow unloading the sodium from the FFTF plant tanks and piping. The significant conclusion of this Preliminary Safety Evaluation (PSE) is that the only Safety Class 2 components are the four sodium storage tanks and their foundations. The building, because of its imminent risk to the tanks under an earthquake or high winds, will be Safety Class 3/2, which means the building has a Safety Class 3 function with the Safety Class 2 loads of seismic and wind factored into the design

  10. FFTF [fast flux tests facility] metal fuel pin sodium bond quality verification

    International Nuclear Information System (INIS)

    Pitner, A.L.

    1989-01-01

    The Fast Flux Tests Facility (FFTF) Series III driver fuel design consists of U-10 Zr fuel slugs contained in a ferritic alloy cladding. A liquid-metal, sodium bond between the fuel and cladding is required to prevent unacceptable temperatures during operation. Excessive voiding or porosity in the sodium thermal bond could result in localized fuel melting during irradiation. It is therefore imperative that bond quality be verified during fabrication of these metal fuel pins prior to irradiation. Cladding stripping of two spare metal fuel pins was successfully performed to inspect the quality of the sodium thermal bond and to compare observed defects in the bond with eddy current measurements. Bond quality was found to be generally good, thereby confirming the fabrication process used to bond the fuel and cladding with liquid-metal sodium to be acceptable. Observed porosity distribution in the sodium bond correlated well with eddy current indications

  11. Case Study of Lessons Learned from the Operation of the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Wootan, D.; Omberg, R.; Grandy, C.

    2016-01-01

    Full text: The lessons learned approach being followed at the Fast Flux Test Facility is to have domain experts in each subject area develop a short write-up or report on each lesson learned. Each lesson learned write-up is on the order of 4–6 pages. Longer reports can be developed as needed. Each lessons learned summary discusses the problem and the resolution method employed to address the problem, and also tries to capture the essential “tacit knowledge” associated with each topic in a focused manner. All lessons learned write-ups are supported by more detailed documents. For example, references of more detailed reports are generally included, where available. Topics are selected as those most likely to apply to future design or operating problems. This lessons learned approach has been successful in capturing essential tacit knowledge about key events in FFTF history and providing a context for interpreting the existing data and references. (author

  12. Thermal performance of fresh mixed-oxide fuel in a fast flux LMR [liquid metal reactor

    International Nuclear Information System (INIS)

    Ethridge, J.L.; Baker, R.B.

    1985-01-01

    A test was designed and irradiated to provide power-to-melt (heat generation rate necessary to initiate centerline fuel melting) data for fresh mixed-oxide UO 2 -PuO 2 fuel irradiated in a fast neutron flux under prototypic liquid metal reactor (LMR) conditions. The fuel pin parameters were selected to envelope allowable fabrication ranges and address mass production of LMR fuel using sintered-to-size techniques. The test included fuel pins with variations in fabrication technique, pellet density, fuel-to-cladding gap, Pu concentration, and fuel oxygen-to-metal ratios. The resulting data base has reestablished the expected power-to-melt in mixed-oxide fuels during initial reactor startup when the fuel temperatures are expected to be the highest. Calibration of heat transfer models of fuel pin performance codes with these data are providing more accurate capability for predicting steady-state thermal behavior of current and future mixed-oxide LMR fuels

  13. Fast Flux Test Facility interim examination and maintenance cell: Past, present, and future

    International Nuclear Information System (INIS)

    Vincent, J.R.

    1990-09-01

    The Fast Flux Test Facility Interim Examination and Maintenance Cell was designed to perform interim examination and/or disassembly of experimental core components for final analysis elsewhere, as well as maintenance of sodium-wetted or neutron-activated internal reactor parts and plant support hardware. The Interim Examination and Maintenance Cell equipment developed and used for the first ten years of operation has been primarily devoted to the disassembly and examination of core component test assemblies. While no major reactor equipment has required remote repair or maintenance, the Interim Examina Examination and Maintenance Cell has served as the remote repair facility for its own in-cell equipment, and several innovative remote repairs have been accomplished. The Interim Examination and Maintenance Cell's demonstrated versatility has shown its capability to support a challenging future. 12 refs., 9 figs

  14. Interim dry cask storage of irradiated Fast Flux Test Facility fuel

    International Nuclear Information System (INIS)

    Scott, P.L.

    1994-09-01

    The Fast Flux Test Facility (FFTF), located at the US Department of Energy's (DOE'S) Hanford Site, is the largest, most modern, liquid metal-cooled test reactor in the world. This paper will give an overview of the FFTF Spent Fuel Off load project. Major discussion areas will address the status of the fuel off load project, including an overview of the fuel off load system and detailed discussion on the individual components that make up the dry cask storage portion of this system. These components consist of the Interim Storage Cask (ISC) and Core Component Container (CCC). This paper will also discuss the challenges that have been addressed in the evolution of this project

  15. Verification of maximum impact force for interim storage cask for the Fast Flux Testing Facility

    International Nuclear Information System (INIS)

    Chen, W.W.; Chang, S.J.

    1996-01-01

    The objective of this paper is to perform an impact analysis of the Interim Storage Cask (ISC) of the Fast Flux Test Facility (FFTF) for a 4-ft end drop. The ISC is a concrete cask used to store spent nuclear fuels. The analysis is to justify the impact force calculated by General Atomics (General Atomics, 1994) using the ILMOD computer code. ILMOD determines the maximum force developed by the concrete crushing which occurs when the drop energy has been absorbed. The maximum force, multiplied by the dynamic load factor (DLF), was used to determine the maximum g-level on the cask during a 4-ft end drop accident onto the heavily reinforced FFTF Reactor Service Building's concrete surface. For the analysis, this surface was assumed to be unyielding and the cask absorbed all the drop energy. This conservative assumption simplified the modeling used to qualify the cask's structural integrity for this accident condition

  16. Feasibility study of Self Powered Neutron Detectors in Fast Reactors for detecting local change in neutron flux distribution

    International Nuclear Information System (INIS)

    Jammes, Christian; Filliatre, Philippe; Verma, Vasudha; Hellesen, Carl; Jacobsson Svard, Staffan

    2015-01-01

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor system. Diverse possibilities of detector systems installation have to be investigated with respect to practicality and feasibility according to the detection parameters. In this paper, we demonstrate the feasibility of using self powered neutron detectors as in-core detectors in fast reactors for detecting local change in neutron flux distribution. We show that the gamma contribution from fission products decay in the fuel and activation of structural materials is very small compared to the fission gammas. Thus, it is possible for the in-core SPND signal to follow changes in local neutron flux as they are proportional to each other. This implies that the signal from an in-core SPND can provide dynamic information on the neutron flux perturbations occurring inside the reactor core. (authors)

  17. Characterisation of CVD diamond detectors used for fast neutron flux monitoring

    CERN Document Server

    Foulon, F; Amosov, V N; Kaschuck, Y; Frunze, V; Tromson, D; Brambilla, A

    2002-01-01

    Natural diamond detectors (NDD) have been successfully used for fast neutron spectrometry on various fusion installations in plasma diagnostics. These detectors can work at high temperature, are radiation hard and exhibit a high energy resolution. However, the use of NDD is limited by the availability of IIa type diamonds exhibiting high electronic properties. With the recent advance in the growth of high quality chemically vapour deposited (CVD) diamond at LETI, CVD diamond appears to be a very promising material for plasma diagnostics. We present here for the first time results of the use of CVD diamond detectors for fast neutron flux monitoring on a neutron generator. The characteristics of CVD diamond detectors are compared with that of high quality NDD made by TRINITI. Pulse height spectra have been measured with CVD detectors and NDD under both 5.5 MeV alpha particles and 14.1 MeV neutrons. The quality of CVD diamond enables the recording of structured spectra allowing the distinction between the differ...

  18. CLOSURE OF THE FAST FLUX TEST FACILITY (FFTF) CURRENT STATUS & FUTURE PLANS

    Energy Technology Data Exchange (ETDEWEB)

    LESPERANCE, C.P.

    2007-05-23

    The Fast Flux Test Facility (FFTF) was a 400 MWt sodium-cooled fast reactor situated on the U.S. Department of Energy's (DOE) Hanford Site in the southeastern portion of Washington State. DOE issued the final order to shut down the facility in 2001, when it was concluded that there was no longer a need for FFTF. Deactivation activities are in progress to remove or stabilize major hazards and deactivate systems to achieve end points documented in the project baseline. The reactor has been defueled, and approximately 97% of the fuel has been removed from the facility. Approximately 97% of the sodium has been drained from the plant's systems and placed into an on-site Sodium Storage Facility. The residual sodium will be kept frozen under a blanket of inert gas until it is removed later as part of the facility's decontamination and decommissioning (D&D). Plant systems have been shut down and placed in a low-risk state to minimize requirements for surveillance and maintenance. D&D work cannot begin until an Environmental Impact Statement has been prepared to evaluate various end state options and to provide a basis for selecting one of the options. The Environmental Impact Statement is expected to be issued in 2009.

  19. CLOSURE OF THE FAST FLUX TEST FACILITY (FFTF) CURRENT STATUS and FUTURE PLANS

    International Nuclear Information System (INIS)

    LESPERANCE, C.P.

    2007-01-01

    The Fast Flux Test Facility (FFTF) was a 400 MWt sodium-cooled fast reactor situated on the U.S. Department of Energy's (DOE) Hanford Site in the southeastern portion of Washington State. DOE issued the final order to shut down the facility in 2001, when it was concluded that there was no longer a need for FFTF. Deactivation activities are in progress to remove or stabilize major hazards and deactivate systems to achieve end points documented in the project baseline. The reactor has been defueled, and approximately 97% of the fuel has been removed from the facility. Approximately 97% of the sodium has been drained from the plant's systems and placed into an on-site Sodium Storage Facility. The residual sodium will be kept frozen under a blanket of inert gas until it is removed later as part of the facility's decontamination and decommissioning (D and D). Plant systems have been shut down and placed in a low-risk state to minimize requirements for surveillance and maintenance. D and D work cannot begin until an Environmental Impact Statement has been prepared to evaluate various end state options and to provide a basis for selecting one of the options. The Environmental Impact Statement is expected to be issued in 2009

  20. Cost/schedule performance measurement system utilized on the Fast Flux Test Facility project

    International Nuclear Information System (INIS)

    Brown, R.K.; Frost, R.A.; Zimmerman, F.M.

    1976-01-01

    An Earned Value-Integrated Cost/Schedule Performance Measurement System has been applied to a major nonmilitary nuclear design and construction project. This system is similar to the Department of Defense Cost/Schedule Performance Measurement System. The project is the Fast Flux Test Facility (a Fuels and Materials test reactor for the Liquid Metal Fast Breeder Reactor Program) being built at the Hanford Engineering Development Laboratory, Richland, Washington, by Westinghouse Hanford Company for the U. S. Energy Research and Development Administration. Because the project was well into the construction phase when the Earned Value System was being considered, it was decided that the principles of DOD's Cost/Schedule Control System Criteria would be applied to the extent possible but no major changes in accounting practices or management systems were imposed. Implementation of this system enabled the following questions to be answered: For work performed, how do actual costs compare with the budget for that work. What is the impact of cost and schedule variances at an overall project level composed of different kinds of activities. Without the Earned Value system, these questions could be answered in a qualitative, subjective manner at best

  1. Fast flux fluid fuel reactor: A concept for the next generation of nuclear power production

    International Nuclear Information System (INIS)

    Palmiotti, G.; Feldman, E.E.

    1999-01-01

    Nuclear energy has not become the preferred method of electrical energy production largely because of economic, safety, and proliferation concerns and challenges posed by nuclear waste disposal. Economies is the most important factor. To reduce the capital costs, the authors propose a compact configuration with a very high power density and correspondingly reduced reactor component sizes. Enhanced efficiency made possible by higher operating temperatures will also improve the economics of the design, and design simplicity will keep capital, operational, and maintenance costs down. The most direct solution to the nuclear waste problem is to eliminate waste production or, at least, minimize its amount and long-term radiotoxicity. This can be achieved by very high burnups, ideally 100%, and by the eventual transmutation of the long-lived fission products in situ. Very high burnups also improve the economics by optimal exploitation of the fuel. Safety concerns can be addressed by an inherently safe reactor design. Because of the intrinsic nature of nuclear materials, there probably is no definitive answer to proliferation concerns for systems that generate neutrons; however, it is important to minimize proliferation risks. The thorium cycle is a promising option because (a) plutonium is produced only in very small quantities, (b) the presence of 232 U makes handling the fuel very difficult and therefore proliferation resistant, and (c) 233 U is a fissile isotope that is less suitable than 239 Pu for making weapons and can be diluted with other uranium isotopes. An additional benefit of the thorium cycle is that it increases nuclear fuel resources by one order of magnitude. A fast flux fluid fuel reactor is a concept that can satisfy all the foregoing requirements. The fluid fuel systems have a very simple structure. Because integrity of the fuel is not an issue, these systems can operate at very high temperatures, can have high power densities, and can achieve very

  2. WATSFAR: numerical simulation of soil WATer and Solute fluxes using a FAst and Robust method

    Science.gov (United States)

    Crevoisier, David; Voltz, Marc

    2013-04-01

    To simulate the evolution of hydro- and agro-systems, numerous spatialised models are based on a multi-local approach and improvement of simulation accuracy by data-assimilation techniques are now used in many application field. The latest acquisition techniques provide a large amount of experimental data, which increase the efficiency of parameters estimation and inverse modelling approaches. In turn simulations are often run on large temporal and spatial domains which requires a large number of model runs. Eventually, despite the regular increase in computing capacities, the development of fast and robust methods describing the evolution of saturated-unsaturated soil water and solute fluxes is still a challenge. Ross (2003, Agron J; 95:1352-1361) proposed a method, solving 1D Richards' and convection-diffusion equation, that fulfil these characteristics. The method is based on a non iterative approach which reduces the numerical divergence risks and allows the use of coarser spatial and temporal discretisations, while assuring a satisfying accuracy of the results. Crevoisier et al. (2009, Adv Wat Res; 32:936-947) proposed some technical improvements and validated this method on a wider range of agro- pedo- climatic situations. In this poster, we present the simulation code WATSFAR which generalises the Ross method to other mathematical representations of soil water retention curve (i.e. standard and modified van Genuchten model) and includes a dual permeability context (preferential fluxes) for both water and solute transfers. The situations tested are those known to be the less favourable when using standard numerical methods: fine textured and extremely dry soils, intense rainfall and solute fluxes, soils near saturation, ... The results of WATSFAR have been compared with the standard finite element model Hydrus. The analysis of these comparisons highlights two main advantages for WATSFAR, i) robustness: even on fine textured soil or high water and solute

  3. BENCHMARK EVALUATION OF THE INITIAL ISOTHERMAL PHYSICS MEASUREMENTS AT THE FAST FLUX TEST FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    John Darrell Bess

    2010-05-01

    The benchmark evaluation of the initial isothermal physics tests performed at the Fast Flux Test Facility, in support of Fuel Cycle Research and Development and Generation-IV activities at the Idaho National Laboratory, has been completed. The evaluation was performed using MCNP5 with ENDF/B-VII.0 nuclear data libraries and according to guidelines provided for inclusion in the International Reactor Physics Experiment Evaluation Project Handbook. Results provided include evaluation of the initial fully-loaded core critical, two neutron spectra measurements near the axial core center, 32 reactivity effects measurements (21 control rod worths, two control rod bank worths, six differential control rod worths, two shutdown margins, and one excess reactivity), isothermal temperature coefficient, and low-energy electron and gamma spectra measurements at the core center. All measurements were performed at 400 ºF. There was good agreement between the calculated and benchmark values for the fully-loaded core critical eigenvalue, reactivity effects measurements, and isothermal temperature coefficient. General agreement between benchmark experiment measurements and calculated spectra for neutrons and low-energy gammas at the core midplane exists, but calculations of the neutron spectra below the core and the low-energy gamma spectra at core midplane did not agree well. Homogenization of core components may have had a significant impact upon computational assessment of these effects. Future work includes development of a fully-heterogeneous model for comprehensive evaluation. The reactor physics measurement data can be used in nuclear data adjustment and validation of computational methods for advanced fuel cycle and nuclear reactor systems using Liquid Metal Fast Reactor technology.

  4. Integrated leak rate testing of the fast flux test facility reactor containment building

    International Nuclear Information System (INIS)

    James, E.B.; Farabee, O.A.; Bliss, R.J.

    1978-01-01

    The initial Integrated Leak Rate Test (ILRT) of the Fast Flux Test Facility containment building was performed from May 27 to June 2, 1978. The test was conducted in air with systems vented and with the containment recirculating coolers in operation. 10 psig and 5 psig tests were run using the absolute pressure test method. The measured leakage rates were .033% Vol/24 hr. and -.0015% Vol/24 hrs. respectively. Subsequent verification tests at both 10 psig and 5 psig proved that the test equipment was operating properly and it was sensitive enough to detect leaks at low pressures. This ILRT was performed at a lower pressure than any previous ILRT on a reactor containment structure in the United States. While the initial design requirements for ice condenser containments called for a part pressure test at 6 psig, the tests were waived due to the apparent statistical problems of data analysis and the repeatability of the data itself at such low pressure. In contrast to this belief, both the 5 and 10 psig ILRT's were performed in a successful manner at FFTF

  5. Fast measurements of the electron temperature and parallel heat flux in ELMy H-mode on the COMPASS tokamak

    Science.gov (United States)

    Adamek, J.; Seidl, J.; Komm, M.; Weinzettl, V.; Panek, R.; Stöckel, J.; Hron, M.; Hacek, P.; Imrisek, M.; Vondracek, P.; Horacek, J.; Devitre, A.; the COMPASS Team

    2017-02-01

    We report the latest results on fast measurements of the electron temperature and parallel heat flux in the COMPASS tokamak scrape-off layer (SOL) and divertor region during ELMy H-mode plasmas. The system of ball-pen and Langmuir probes installed on the divertor target, the horizontal reciprocating manipulator and the fast data-acquisition system with sampling frequency rate f  =  5 MSa s-1 allow us to measure the electron temperature and parallel heat flux during inter-ELM and ELM periods with high temporal resolution. The filamentary structure of the electron temperature and parallel heat flux was observed during ELMs in the SOL as well as in the divertor region. The position of the filaments within ELMs is not regular and therefore the resulting conditionally averaged ELM neglects the peak values of the electron temperature and parallel heat flux. We have found a substantial difference between the value of the radial power decay length in the inter-ELM period λ q,inter  =  2.5 mm and the decay length of the peak ELM heat flux λ q,ELM  =  13.1 mm. The decay length of the ELM energy density was found to be λ E,ELM  =  5.4 mm.

  6. Eddy Covariance Measurements of Methane Flux at Remote Sites with New Low-Power Lightweight Fast Gas Analyzer

    Science.gov (United States)

    Xu, Liukang; Burba, George; Schedlbauer, Jessica; Zona, Donatella; McDermitt, Dayle K.; Anderson, Tyler; Oberbauer, Steven; Oechel, Walter; Komissarov, Anatoly; Riensche, Brad

    2010-05-01

    Majority of natural methane production happens at remote unpopulated areas in ecosystems with little or no infrastructure or easily available grid power, such as arctic and boreal wetlands, tropical mangroves, etc. Present approaches for direct measurements of CH4 fluxes rely on fast closed-path analyzers, which have to work under significantly reduced pressures, and require powerful pumps and grid power. Power and labor demands may be reasons why CH4 flux is often measured at locations with good infrastructure and grid power, and not with high CH4 production. An instrument was developed to allow Eddy Covariance measurements of CH4 flux with power consumption 30-150 times below presently available technologies. This instrument, LI-7700, uses good frequency response and undisturbed in-situ sampling. It enables long-term deployment of permanent, portable or mobile CH4 flux stations at remote locations with high CH4 production, because it can be powered by a solar panels or a small generator. Authors appreciate help and support provided by the LI-COR Engineering Team, Barrow Arctic Science Consortium (BASC), and numerous colleagues involved in measurements, logistics, and maintenance of the experimental field sites. This project was supported by the Small Business Innovation Research (SBIR) and Small Business Technology Transfer Program (STTR) program of the Department of Energy (DOE), Grant Number DE-FG02-05ER84283.

  7. Evaluation of the current fast neutron flux monitoring instrumentation applied to LFR demonstrator ALFRED. Capabilities and limitations

    International Nuclear Information System (INIS)

    Lepore, Luigi; Remetti, Romolo; Cappelli, Mauro

    2015-01-01

    Among Gen IV projects for future nuclear power plants, Lead Fast Reactors (LFR) seem to be a very interesting solution due to their benefits in terms of fuel cycle, coolant-safety and waste management. The novelty of the matter causes some open issues about coolant chemical aspect, structural aspects, monitoring instrumentation, etc. Particularly hard neutron flux spectra would make traditional neutron instrumentation unfit to all reactor conditions, i.e. source, intermediate, and power range. Identification of new models of nuclear instrumentation specialized for LFR neutron flux monitoring asks for an accurate evaluation of the environment the sensor will work in. In this study, thermal-hydraulics and chemical conditions for LFR core environment will be assumed, as the neutron flux will be studied extensively by means of the Monte Carlo transport code MCNPX. The core coolant’s high temperature drastically reduces the candidate instrumentation, because only some kind of fission chambers and Self Powered Neutron Detectors can be operated in such an environment. This work aims to evaluate the capabilities of the available instrumentation (usually designed for Sodium Fast Reactors, SFRs) when exposed to the neutron spectrum derived from ALFRED, a pool-type small-power LFR project to demonstrate the feasibility of this technology into the European framework. This paper shows that such instruments do follow the power evolution, but they are not completely suitable to detect the whole range of reactor power. Some improvements are then possible in order to increase the signal-to-noise ratio, by optimizing each instrument in the range of reactor power, such to get the best solution. Some new detector designs are here proposed, and the possibilities for prototyping and testing by means of a fast reactor investigated. (author)

  8. Nitrogen determination in wheat by neutron activation analysis using fast neutron flux from a thermal nuclear reactor

    International Nuclear Information System (INIS)

    Ramirez G, T.

    1976-01-01

    This is a study of the technique for the determination of nitrogen and other elements in wheat flour through activation analysis with fast neutrons from a thermal nuclear reactor. The study begins with an introduction about the basis of the analytical methods, the equipment used in activation analysis and a brief description of the neutrons source. In the study are included the experiments carried out in order to determine the flux form in the site of irradiation, the N-13 half life and the interference due to the sample composition. (author)

  9. Determination of nitrogen in wheat flour through Activation analysis using Fast neutron flux of a Thermal nuclear reactor

    International Nuclear Information System (INIS)

    Ramirez G, T.

    1976-01-01

    In this work is done a technical study for determining Nitrogen (protein) and other elements in wheat flour Activation analysis, with Fast neutrons from a Thermal nuclear reactor. Initially it is given an introduction about the basic principles of the methods of analysis. Equipment used in Activation analysis and a brief description of the neutron source (Thermal nuclear reactor). The realized experiments for determining the flux form in the irradiation site, the half life of N-13 and the interferences due to the sample composition are included too. Finally, the obtained results by Activation and the Kjeldahl method are tabulated. (Author)

  10. Measurement system of gamma, X, thermal and/or fast neutron flux

    International Nuclear Information System (INIS)

    Siffert, P.; Regal, R.; Koebel, J.M.; Teissier, C.

    1987-01-01

    The system includes detection means of gamma or/and X radiation, detection means of gamma and/or X radiation from thermal neutrons, detection means of gamma and/or X radiation from thermal and/or fast neutrons. It includes also processing devices of the signals given by the detection means able to get a linear combination of the detected signals. These processing devices give a signal selectively representative of photon, thermal or fast neutron rate [fr

  11. Systematic assembly homogenization and local flux reconstruction for nodal method calculations of fast reactor power distributions

    International Nuclear Information System (INIS)

    Dorning, J.J.

    1991-01-01

    A simultaneous pin lattice cell and fuel bundle homogenization theory has been developed for use with nodal diffusion calculations of practical reactors. The theoretical development of the homogenization theory, which is based on multiple-scales asymptotic expansion methods carried out through fourth order in a small parameter, starts from the transport equation and systematically yields: a cell-homogenized bundled diffusion equation with self-consistent expressions for the cell-homogenized cross sections and diffusion tensor elements; and a bundle-homogenized global reactor diffusion equation with self-consistent expressions for the bundle-homogenized cross sections and diffusion tensor elements. The continuity of the angular flux at cell and bundle interfaces also systematically yields jump conditions for the scaler flux or so-called flux discontinuity factors on the cell and bundle interfaces in terms of the two adjacent cell or bundle eigenfunctions. The expressions required for the reconstruction of the angular flux or the 'de-homogenization' theory were obtained as an integral part of the development; hence the leading order transport theory angular flux is easily reconstructed throughout the reactor including the regions in the interior of the fuel bundles or computational nodes and in the interiors of the pin lattice cells. The theoretical development shows that the exact transport theory angular flux is obtained to first order from the whole-reactor nodal diffusion calculations, done using the homogenized nuclear data and discontinuity factors, is a product of three computed quantities: a ''cell shape function''; a ''bundle shape function''; and a ''global shape function''. 10 refs

  12. DFBAlab: a fast and reliable MATLAB code for dynamic flux balance analysis.

    Science.gov (United States)

    Gomez, Jose A; Höffner, Kai; Barton, Paul I

    2014-12-18

    Dynamic Flux Balance Analysis (DFBA) is a dynamic simulation framework for biochemical processes. DFBA can be performed using different approaches such as static optimization (SOA), dynamic optimization (DOA), and direct approaches (DA). Few existing simulators address the theoretical and practical challenges of nonunique exchange fluxes or infeasible linear programs (LPs). Both are common sources of failure and inefficiencies for these simulators. DFBAlab, a MATLAB-based simulator that uses the LP feasibility problem to obtain an extended system and lexicographic optimization to yield unique exchange fluxes, is presented. DFBAlab is able to simulate complex dynamic cultures with multiple species rapidly and reliably, including differential-algebraic equation (DAE) systems. In addition, DFBAlab's running time scales linearly with the number of species models. Three examples are presented where the performance of COBRA, DyMMM and DFBAlab are compared. Lexicographic optimization is used to determine unique exchange fluxes which are necessary for a well-defined dynamic system. DFBAlab does not fail during numerical integration due to infeasible LPs. The extended system obtained through the LP feasibility problem in DFBAlab provides a penalty function that can be used in optimization algorithms.

  13. A Fast, Portable, Fiber Optic Spectrofluorometer for Eddy Correlation Flux Measurement in the Aquatic Environment

    Science.gov (United States)

    Hu, I. H.; Senft-Grupp, S.; Hemond, H.

    2014-12-01

    The measurement of chemical fluxes between natural waters and their benthic sediments by most existing methods, such as benthic chambers and sediment core incubations, is slow, cumbersome, and often inaccurate. One promising new method for determining benthic fluxes is eddy correlation (EC), a minimally invasive, in situ technique based on high-speed velocity and concentration measurements. Widespread application of EC to a large range of chemicals of interest is currently limited, however, by the availability of rapid, high-resolution chemical sensors capable of precisely measuring concentrations at a point location and at sufficient speed (several Hz). A proof of concept spectrofluorometry instrument has been created that is capable of high-frequency concentration measurements of naturally fluorescent substances. Designed with the EC application in mind, the system utilizes optical fibers to transmit excitation and emission light, enabling in situ measurements at high spatial resolution. Emitted fluorescence light is passed through a tunable monochromator before reaching a photomultiplier tube; photons are quantified by a custom miniaturized, low-power photon counting circuit board. Preliminary results indicate that individual measurements made at 100 Hz of a 10 ppm humic acid solution were precise within 10%, thus yielding a precision of the order of +/- 1% in a second. Used in an EC system, this instrument will enable flux measurements of substances such as naturally occurring fluorescent dissolved organic material (FDOM). Measurement of fluxes of FDOM is significant in its own right, and also will allow the indirect measurement of the numerous other chemical fluxes that are associated with FDOM by using tracer techniques. The use of a tunable monochromator not only allows flexibility in detection wavelength, but also enables full wavelength scans of the emission spectrum, making the spectrofluorometer a dual-function device capable of both characterizing the

  14. Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions

    Science.gov (United States)

    Rannik, Ü.; Haapanala, S.; Shurpali, N. J.; Mammarella, I.; Lind, S.; Hyvönen, N.; Peltola, O.; Zahniser, M.; Martikainen, P. J.; Vesala, T.

    2015-01-01

    Four gas analysers capable of measuring nitrous oxide (N2O) concentration at a response time necessary for eddy covariance flux measurements were operated from spring until winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinacea, L.), a perennial bioenergy crop in eastern Finland. The instruments were TGA100A (Campbell Scientific Inc.), CW-TILDAS-CS (Aerodyne Research Inc.), N2O / CO-23d (Los Gatos Research Inc.) and QC-TILDAS-76-CS (Aerodyne Research Inc.). The period with high emissions, lasting for about 2 weeks after fertilization in late May, was characterized by an up to 2 orders of magnitude higher emission, whereas during the rest of the campaign the N2O fluxes were small, from 0.01 to 1 nmol m-2 s-1. Two instruments, CW-TILDAS-CS and N2O / CO-23d, determined the N2O exchange with minor systematic difference throughout the campaign, when operated simultaneously. TGA100A produced the cumulatively highest N2O estimates (with 29% higher values during the period when all instruments were operational). QC-TILDAS-76-CS obtained 36% lower fluxes than CW-TILDAS-CS during the first period, including the emission episode, whereas the correspondence with other instruments during the rest of the campaign was good. The reasons for systematic differences were not identified, suggesting further need for detailed evaluation of instrument performance under field conditions with emphasis on stability, calibration and any other factors that can systematically affect the accuracy of flux measurements. The instrument CW-TILDAS-CS was characterized by the lowest noise level (with a standard deviation of around 0.12 ppb at 10 Hz sampling rate) as compared to N2O / CO-23d and QC-TILDAS-76-CS (around 0.50 ppb) and TGA100A (around 2 ppb). We identified that for all instruments except CW-TILDAS-CS the random error due to instrumental noise was an important source of uncertainty at the 30 min averaging level and the total stochastic error was frequently

  15. BOOSTING LY α   AND He ii λ 1640 LINE FLUXES FROM POPULATION III GALAXIES: STOCHASTIC IMF SAMPLING AND DEPARTURES FROM CASE-B

    International Nuclear Information System (INIS)

    Mas-Ribas, Lluís; Dijkstra, Mark; Forero-Romero, Jaime E.

    2016-01-01

    We revisit calculations of nebular hydrogen Ly α and He ii λ 1640 line strengths for Population III (Pop III) galaxies, undergoing continuous, and bursts of, star formation. We focus on initial mass functions (IMFs) motivated by recent theoretical studies, which generally span a lower range of stellar masses than earlier works. We also account for case-B departures and the stochastic sampling of the IMF. In agreement with previous work, we find that departures from case-B can enhance the Ly α flux by a factor of a few, but we argue that this enhancement is driven mainly by collisional excitation and ionization, and not due to photoionization from the n  = 2 state of atomic hydrogen. The increased sensitivity of the Ly α flux to the high-energy end of the galaxy spectrum makes it more subject to stochastic sampling of the IMF. The latter introduces a dispersion in the predicted nebular line fluxes around the deterministic value by as much as a factor of ∼4. In contrast, the stochastic sampling of the IMF has less impact on the emerging Lyman Werner photon flux. When case-B departures and stochasticity effects are combined, nebular line emission from Pop III galaxies can be up to one order of magnitude brighter than predicted by “standard” calculations that do not include these effects. This enhances the prospects for detection with future facilities such as the James Webb Space Telescope and large, ground-based telescopes.

  16. Boosting Lyα and He II λ1640 Line Fluxes from Population III Galaxies: Stochastic IMF Sampling and Departures from Case-B

    Science.gov (United States)

    Mas-Ribas, Lluís; Dijkstra, Mark; Forero-Romero, Jaime E.

    2016-12-01

    We revisit calculations of nebular hydrogen Lyα and He II λ1640 line strengths for Population III (Pop III) galaxies, undergoing continuous, and bursts of, star formation. We focus on initial mass functions (IMFs) motivated by recent theoretical studies, which generally span a lower range of stellar masses than earlier works. We also account for case-B departures and the stochastic sampling of the IMF. In agreement with previous work, we find that departures from case-B can enhance the Lyα flux by a factor of a few, but we argue that this enhancement is driven mainly by collisional excitation and ionization, and not due to photoionization from the n = 2 state of atomic hydrogen. The increased sensitivity of the Lyα flux to the high-energy end of the galaxy spectrum makes it more subject to stochastic sampling of the IMF. The latter introduces a dispersion in the predicted nebular line fluxes around the deterministic value by as much as a factor of ˜4. In contrast, the stochastic sampling of the IMF has less impact on the emerging Lyman Werner photon flux. When case-B departures and stochasticity effects are combined, nebular line emission from Pop III galaxies can be up to one order of magnitude brighter than predicted by “standard” calculations that do not include these effects. This enhances the prospects for detection with future facilities such as the James Webb Space Telescope and large, ground-based telescopes.

  17. Digital Integrator for Fast Accurate Measurement of Magnetic Flux by Rotating Coils

    CERN Document Server

    Arpaia, P.; Spiezia, G.

    2007-01-01

    A fast digital integrator (FDI) with dynamic accuracy and a trigger frequency higher than those of a portable digital integrator (PDI), which is a state-of-the-art instrument for magnetic measurements based on rotating coils, was developed for analyzing superconducting magnets in particle accelerators. Results of static and dynamic metrological characterization show how the FDI prototype is already capable of overcoming the dynamic performance of PDI as well as covering operating regions that used to be inaccessible

  18. Explosive magnetic flux compression plate generators as fast high-energy power sources

    International Nuclear Information System (INIS)

    Caird, R.S.; Erickson, D.J.; Garn, W.B.; Fowler, C.M.

    1976-01-01

    A type of explosive driven generator, called a plate generator, is described. It is capable of delivering electrical energies in the MJ range at TW power levels. Plane wave detonated explosive systems accelerate two large-area metal plates to high opposing velocities. An initial magnetic field is compressed and the flux transferred to an external load. The characteristics of the plate generator are described and compared with those of other types of generators. Methods of load matching are discussed. The results of several high-power experiments are also given

  19. Feasibility study of fast swept divertor strike point suppressing transient heat fluxes in big tokamaks.

    Czech Academy of Sciences Publication Activity Database

    Horáček, Jan; Cunningham, G.; Entler, Slavomír; Dobias, P.; Duban, R.; Imríšek, Martin; Markovič, Tomáš; Havlíček, Josef; Enikeev, R.

    2017-01-01

    Roč. 123, November (2017), s. 646-649 ISSN 0920-3796. [SOFT 2016: Symposium on Fusion Technology /29./. Prague, 05.09.2016-09.09.2016] R&D Projects: GA ČR(CZ) GA16-14228S; GA MŠk(CZ) LM2015045; GA MŠk(CZ) 8D15001; GA MŠk LG14002 Institutional support: RVO:61389021 Keywords : DEMO * ELM * Divertor * Heat flux * Tokamak Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.319, year: 2016 http://www.sciencedirect.com/science/article/pii/S0920379617300376

  20. Storage for the Fast Flux Test Facility unirradiated fuel in the Plutonium Finishing Plant Complex, Hanford Site, Richland, Washington

    International Nuclear Information System (INIS)

    1992-01-01

    This Environmental Assessment evaluates the proposed action to relocate and store unirradiated Fast Flux Test Facility fuel in the Plutonium Finishing Plant Complex on the Hanford Site, Richland, Washington. The US Department of Energy has decided to cease fuel fabrication activities in the 308 Building in the 300 Area. This decision was based on a safety concern over the ability of the fuel fabrication portion of the 308 Building to withstand a seismic event. The proposed action to relocate and store the fuel is based on the savings that could be realized by consolidating security costs associated with storage of the fuel. While the 308 Building belowgrade fuel storage areas are not at jeopardy by a seismic event, the US Department of Energy is proposing to cease storage operations along with the related fabrication operations. The US Department of Energy proposes to remove the unirradiated fuel pins and fuel assemblies from the 308 Building and store them in Room 192A, within the 234-5Z Building, a part of the Plutonium Finishing Plant Complex, located in the 200 West Area. Minor modifications to Room 192A would be required to accommodate placement of the fuel. The US Department of Energy estimates that removing all of the fuel from the 308 Building would save $6.5 million annually in security expenditures for the Fast Flux Test Facility. Environmental impacts of construction, relocation, and operation of the proposed action and alternatives were evaluated. This evaluation concluded that the proposed action would have no significant impacts on the human environment

  1. Fast-charging compact seed source for magnetic flux compression generators.

    Science.gov (United States)

    Elsayed, M; Kristiansen, M; Neuber, A

    2008-12-01

    Flux compression generators (FCGs) are some of the most attractive sources of single-use compact pulsed power available today due to their high energy density output and mobility. Driving FCGs requires some seed energy, which is typically provided by applying a high seed current, usually in the kiloampere range for midsized helical FCGs. This initial current is supplied by a high-current seed source that is capable of driving an inductive load. High-current seed sources have typically been comprised of discharging large capacitors using spark gaps and overvoltage triggering mechanisms to provide the prime power for FCGs. This paper will discuss a recent design of a self-contained (battery powered with full charge time less than 40 s), single-use compact seed source (CSS) using solid-state components for the switching scheme. The CSS developed is a system (0.005 m(3) volume and weighing 3.9 kg) capable of delivering over 360 J ( approximately 12 kA) into a 5.20 muH load with a trigger energy of microjoules at the TTL triggering level. The newly designed solid-state switching scheme of the CSS incorporates off-the-shelf high-voltage semiconductor components that minimize system cost and size as necessary for a single-use application. A detailed evaluation of the CSS is presented primarily focusing on the switching mechanics and experimental characterization of the solid-state components used in the system.

  2. A fast and precise chemiluminescence ozone detector for eddy flux and airborne application

    Directory of Open Access Journals (Sweden)

    A. Zahn

    2012-02-01

    Full Text Available A commercially available dry chemiluminescence (CI instrument for fast and precise measurement of ozone (O3 is specified. The sensitivity is ~9000 counts s−1 per ppbv of ozone. Its precision is entirely determined by the number of photons reaching the detector (being a photomultiplier, i.e. is quantum-noise limited. The relative precision (ΔO3/O3 in % thus follows Poisson statistics and scales with the square root of the measurement frequency f and with the inverse O3 mixing ratio: ΔO3/O3f0.5 · O3−0.5. At typical O3 mixing ratios between 10 and 100 ppbv (and 1 bar, the precision is 0.3–1.0% at f = 10 Hz. The maximum measurement frequency is 50 Hz. The mechanical and electronic set-up as well as the instrument performance is described. Recommendations on the adequate inlet tube configuration (inlet tube length, sampling flow and on the way of calibration at stationary ground-based platforms and onboard aircraft are given.

  3. A study on physics parameters and flux behaviour for a fast critical facility using ''Baker'' model

    International Nuclear Information System (INIS)

    Abu-Leilah, M.M.; Hussein, A.Z.; Gaafar, M.A.; Hamouda, I.F.

    1983-01-01

    Comparative study was performed to emphasize the effects of using different nuclear data systems and methods on the various parameters of the fast reactor. Multigroup libraries as 11 (ANL-5800) and 26 (BNAB-64) energy group systems of nuclear data constants were used in the present work. The calculations were carried out for both infinite dilution (self-shielding factor F= 1) and self-shielded cross sections. Various computer codes were elaborated and derived to meet the conditional requirements for such calculations. The important output of these calculations are the neutron spectra, neutron balance, fission and capture rate distributions, critical mass, breeding ratio in each region and total breeding ratio of the reactor. Five different cases of study were considered employing two systems of constants, infinite dilution and self-shielded cross-sections and treating stainless steel of the reactor as to be substituted by iron. Moreover, calculations have been concerned for averaged one group nuclear data constants which were condensed from the 11 and 26 group systems. Comparisons of the multigroup results with those of the group were made. The condensation process for averaging to one group was done to estimate the effect of such physical simplification on the calculated parameters. The present work results have been compared with many published works. Fair agreements are obtained, which varified the consistance and completeness of the methods implemented and used

  4. Fast rise of broadly cross-reactive antibodies after boosting long-lived human memory B cells primed by an MF59 adjuvanted prepandemic vaccine

    Science.gov (United States)

    Galli, Grazia; Hancock, Kathy; Hoschler, Katja; DeVos, Joshua; Praus, Michaela; Bardelli, Monia; Malzone, Carmine; Castellino, Flora; Gentile, Chiara; McNally, Teresa; Del Giudice, Giuseppe; Banzhoff, Angelika; Brauer, Volker; Montomoli, Emanuele; Zambon, Maria; Katz, Jacqueline; Nicholson, Karl; Stephenson, Iain

    2009-01-01

    Proactive priming before the next pandemic could induce immune memory responses to novel influenza antigens. In an open-label study, we analyzed B cell memory and antibody responses of 54 adults who received 2 7.5-μg doses of MF59-adjuvanted A/Vietnam/1194/2004 clade 1 (H5N1) vaccine. Twenty-four subjects had been previously primed with MF59-adjuvanted or plain clade 0-like A/duck/Singapore/1997 (H5N3) vaccine during 1999–2001. The prevaccination frequency of circulating memory B cells reactive to A/Vietnam/1194/2004 was low in both primed and unprimed individuals. However, at day 21 after boosting, MF59-adjuvanted primed subjects displayed a higher frequency of H5N1-specific memory B cells than plain-primed or unprimed subjects. The immune memory was rapidly mobilized by a single vaccine administration and resulted in high titers of neutralizing antibodies to antigenically diverse clade 0, 1, and 2 H5N1 viruses already at day 7. In general, postvaccination antibody titers were significantly higher in primed subjects than in unprimed subjects. Subjects primed with MF59-adjuvanted vaccine responded significantly better than those primed with plain vaccine, most notably in early induction and duration of cross-reacting antibody responses. After 6 months, high titers of cross-reactive antibody remained detectable among MF59-primed subjects. We conclude that distant priming with clade 0-like H5N3 induces a pool of cross-reactive memory B cells that can be boosted rapidly years afterward by a mismatched MF59-adjuvanted vaccine to generate high titers of cross-reactive neutralizing antibodies rapidly. These results suggest that pre-pandemic vaccination strategies should be considered. PMID:19416838

  5. FAST

    DEFF Research Database (Denmark)

    Zuidmeer-Jongejan, Laurian; Fernandez-Rivas, Montserrat; Poulsen, Lars K.

    2012-01-01

    ABSTRACT: The FAST project (Food Allergy Specific Immunotherapy) aims at the development of safe and effective treatment of food allergies, targeting prevalent, persistent and severe allergy to fish and peach. Classical allergen-specific immunotherapy (SIT), using subcutaneous injections...... with aqueous food extracts may be effective but has proven to be accompanied by too many anaphylactic side-effects. FAST aims to develop a safe alternative by replacing food extracts with hypoallergenic recombinant major allergens as the active ingredients of SIT. Both severe fish and peach allergy are caused...... in depth serological and cellular immune analyses will be performed, allowing identification of novel biomarkers for monitoring treatment efficacy. FAST aims at improving the quality of life of food allergic patients by providing a safe and effective treatment that will significantly lower their threshold...

  6. Analysis and results of a hydrogen-moderated isotope production assembly in the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Wootan, D.W.; Rawlins, J.A.; Carter, L.L.; Brager, H.R.; Schenter, R.E.

    1989-01-01

    This paper reports on a cobalt test assembly containing yttrium hydride pins for neutron moderation irradiated in the Fast Flux Test Facility (FFTF) during cycle 9A for 137.7 equivalent full-power days at a power level of 291 MW. The 36 test pins consisted of a batch of 32 pins containing cobalt metal used to produce 60 Co and a set of four pins with europium oxide to produce 153 Gd, a radioisotope used in detection of the bone disease osteoporosis. Postirradiation examination of the cobalt pins determined the 60 Co production to be predictable to an accuracy of ∼ 5%. The measured 60 Co spatially distributed concentrations were within 20% of the calculated concentrations. The assembly average 60 Co measured activity was 4% less than the calculated value. The europium oxide pins were gamma scanned for the europium isotopes 152 Eu and 154 Eu to an absolute accuracy of ≅ 10%. The measured europium radioisotope and 153 Gd concentrations were within 20% of calculated values. The hydride assembly performed well and is an excellent vehicle for many FFTF isotope production applications. The results also demonstrate the accuracy of the calculational methods developed by the Westinghouse Hanford Company for predicting isotope production rates in this type of assembly

  7. Direct Evidence of an Eruptive, Filament-hosting Magnetic Flux Rope Leading to a Fast Solar Coronal Mass Ejection

    Science.gov (United States)

    Chen, Bin; Bastian, T. S.; Gary, D. E.

    2014-10-01

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  8. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bin; Gary, D. E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Bastian, T. S., E-mail: bin.chen@cfa.harvard.edu [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)

    2014-10-20

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  9. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    International Nuclear Information System (INIS)

    Chen, Bin; Gary, D. E.; Bastian, T. S.

    2014-01-01

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  10. FAST

    Science.gov (United States)

    Nathavitharana, R R; Daru, P; Barrera, A E; Mostofa Kamal, S M; Islam, S; Ul-Alam, M; Sultana, R; Rahman, M; Hossain, Md S; Lederer, P; Hurwitz, S; Chakraborty, K; Kak, N; Tierney, D B; Nardell, E

    2017-09-01

    National Institute of Diseases of the Chest and Hospital, Dhaka; Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders, Dhaka; and Chittagong Chest Disease Hospital, Chittagong, Bangladesh. To present operational data and discuss the challenges of implementing FAST (Find cases Actively, Separate safely and Treat effectively) as a tuberculosis (TB) transmission control strategy. FAST was implemented sequentially at three hospitals. Using Xpert® MTB/RIF, 733/6028 (12.2%, 95%CI 11.4-13.0) patients were diagnosed with unsuspected TB. Patients with a history of TB who were admitted with other lung diseases had more than twice the odds of being diagnosed with unsuspected TB as those with no history of TB (OR 2.6, 95%CI 2.2-3.0, P stakeholder engagement and laboratory capacity are important for sustainability and scalability.

  11. Boosting foundations and algorithms

    CERN Document Server

    Schapire, Robert E

    2012-01-01

    Boosting is an approach to machine learning based on the idea of creating a highly accurate predictor by combining many weak and inaccurate "rules of thumb." A remarkably rich theory has evolved around boosting, with connections to a range of topics, including statistics, game theory, convex optimization, and information geometry. Boosting algorithms have also enjoyed practical success in such fields as biology, vision, and speech processing. At various times in its history, boosting has been perceived as mysterious, controversial, even paradoxical.

  12. Measurement of the thermal and fast neutron flux in a research reactor with a Li and Th loaded optical fibre detector

    CERN Document Server

    Yamane, Y; Misawa, T; Karlsson, J K H; Pázsit, I

    1999-01-01

    The spatial dependence of thermal and fast neutron flux was measured axially in the core of a 1 MW research reactor. The measurements were made by a thin optical fibre detector with a neutron sensitive ZnS(Ag) scintillation tip. For thermal neutrons sup 6 Li was used, whereas for fast neutrons sup 2 sup 3 sup 2 Th was used as neutron converter. The spatial dependence was measured by moving the fibre axially with a uniform speed. The measurement takes a few minutes, compared to up to 10 h with the conventional wire activation method. Comparison with traditional measurements shows a good agreement. (author)

  13. A Quasi-periodic Fast-propagating Magnetosonic Wave Associated with the Eruption of a Magnetic Flux Rope

    Science.gov (United States)

    Shen, Yuandeng; Liu, Yu; Song, Tengfei; Tian, Zhanjun

    2018-01-01

    Using high temporal and high spatial resolution observations taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, we present a detailed observational analysis of a high-quality quasi-periodic fast-propagating (QFP) magnetosonic wave that was associated with the eruption of a magnetic flux rope and a GOES C5.0 flare. For the first time, we find that the QFP wave lasted for the entire flare lifetime rather than only during the rising phase of the accompanying flare, as reported in previous studies. In addition, the propagation of the different parts of the wave train showed different kinematics and morphologies. For the southern (northern) part, the speed, duration, and intensity variation are about 875 ± 29 (1485 ± 233) km s‑1, 45 (60) minutes, and 4% (2%), and their pronounced periods are 106 ± 12 and 160 ± 18 (75 ± 10 and 120 ± 16) s, respectively. It is interesting that the northern part of the wave train showed an obvious refraction effect when it passed through a region of strong magnetic field. The result of a periodicity analysis indicates that all of the periods of the QFP wave can be found in the period spectrum of the accompanying flare, suggesting their common physical origin. We propose that the quasi-periodic nonlinear magnetohydrodynamics process in the magnetic reconnection that produces the accompanying flare should be important in exciting a QFP wave, and the different magnetic distributions along different paths can account for the different speeds and morphology evolution of the wave fronts.

  14. Radiological transportation risk assessment of the shipment of sodium-bonded fuel from the Fast Flux Test Facility to the Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Green, J.R.

    1995-01-31

    This document was written in support of Environmental Assessment: Shutdown of the Fast Flux Test Facility (FFTF), Hanford Site, Richland, Washington. It analyzes the potential radiological risks associated with the transportation of sodium-bonded metal alloy and mixed carbide fuel from the FFTF on the Hanford Site in Washington State to the Idaho Engineering Laboratory in Idaho in the T-3 Cask. RADTRAN 4 is used for the analysis which addresses potential risk from normal transportation and hypothetical accident scenarios.

  15. Calculations of the thermal and fast neutron fluxes in the Syrian miniature neutron source reactor using the MCNP-4C code.

    Science.gov (United States)

    Khattab, K; Sulieman, I

    2009-04-01

    The MCNP-4C code, based on the probabilistic approach, was used to model the 3D configuration of the core of the Syrian miniature neutron source reactor (MNSR). The continuous energy neutron cross sections from the ENDF/B-VI library were used to calculate the thermal and fast neutron fluxes in the inner and outer irradiation sites of MNSR. The thermal fluxes in the MNSR inner irradiation sites were also measured experimentally by the multiple foil activation method ((197)Au (n, gamma) (198)Au and (59)Co (n, gamma) (60)Co). The foils were irradiated simultaneously in each of the five MNSR inner irradiation sites to measure the thermal neutron flux and the epithermal index in each site. The calculated and measured results agree well.

  16. Compton scattering for spectroscopic detection of ultra-fast, high flux, broad energy range X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Cipiccia, S.; Wiggins, S. M.; Brunetti, E.; Vieux, G.; Yang, X.; Welsh, G. H.; Anania, M.; Islam, M. R.; Ersfeld, B.; Jaroszynski, D. A. [Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Maneuski, D.; Montgomery, R.; Smith, G.; Hoek, M.; Hamilton, D. J.; Shea, V. O. [Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Issac, R. C. [Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Research Department of Physics, Mar Athanasius College, Kothamangalam 686666, Kerala (India); Lemos, N. R. C.; Dias, J. M. [GoLP/Instituto de Plasmas eFusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Symes, D. R. [Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, OX11 0QX Didcot (United Kingdom); and others

    2013-11-15

    Compton side-scattering has been used to simultaneously downshift the energy of keV to MeV energy range photons while attenuating their flux to enable single-shot, spectrally resolved, measurements of high flux X-ray sources to be undertaken. To demonstrate the technique a 1 mm thick pixelated cadmium telluride detector has been used to measure spectra of Compton side-scattered radiation from a Cobalt-60 laboratory source and a high flux, high peak brilliance X-ray source of betatron radiation from a laser-plasma wakefield accelerator.

  17. Learning Boost C++ libraries

    CERN Document Server

    Mukherjee, Arindam

    2015-01-01

    If you are a C++ programmer who has never used Boost libraries before, this book will get you up-to-speed with using them. Whether you are developing new C++ software or maintaining existing code written using Boost libraries, this hands-on introduction will help you decide on the right library and techniques to solve your practical programming problems.

  18. Deep Incremental Boosting

    OpenAIRE

    Mosca, Alan; Magoulas, George D

    2017-01-01

    This paper introduces Deep Incremental Boosting, a new technique derived from AdaBoost, specifically adapted to work with Deep Learning methods, that reduces the required training time and improves generalisation. We draw inspiration from Transfer of Learning approaches to reduce the start-up time to training each incremental Ensemble member. We show a set of experiments that outlines some preliminary results on some common Deep Learning datasets and discuss the potential improvements Deep In...

  19. ATLAS Boosted Objects tagging performance

    CERN Document Server

    Ferreira de Lima, D E; The ATLAS collaboration

    2014-01-01

    In the session on the performance of jet substructure reconstruction and boosted object tagging. This first contribution focuses on boosted object tagging performance. Material includes the shower deconstruction CONF note (missed BOOST2013, public), the Boosted boson tagging note (ATL-PHYS-PUB-2014-004, public since April). New papers on W/Z dsicrimination or top tagging are unlikely.

  20. Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams

    Directory of Open Access Journals (Sweden)

    Strugalska-Gola Elzbieta

    2017-01-01

    Full Text Available This work was performed within the international project “Energy plus Transmutation of Radioactive Wastes” (E&T - RAW for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89 samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this.

  1. Survey of the thermal and fast neutron flux distribution in the core of IPR-R1 reactor

    International Nuclear Information System (INIS)

    Guimaraes, R.R.R.

    1985-01-01

    A methodology to obtain the neutron flux distribution inside the core of a reactor is presented, aiming to analyze specifications for increasing reactor power. The activation measurement technique with irradiation of steel eletrodes of 700 mm of lenght, put in acrylic rods was used. In the detection process and in the counting of activation product, a Ge (Li) detector with high resolution and a scanning mechanical system, constructed and projected in CDTN (Nuclear Technology Development Center) were used. (E.G.) [pt

  2. New experimental space for irradiating samples by RA reactor fast neutron flux at temperatures up to 100 deg C

    International Nuclear Information System (INIS)

    Pavicevic, M.; Novakovic, M.; Zecevic, V.

    1961-01-01

    The objective of this paper is to present adaptation of the RA reactor which would enable samples irradiation by fast neutrons and describe new experimental possibilities. New experimental space was achieved using hollow fuel elements which have been reconstructed to enable placement of irradiation capsules inside the tube. This paper includes thermal analysis and describes problems related to operation, safety and radiation protection issues which arise from using reconstructed fuel elements

  3. Fast neutron induced flux pinning in Tl-based high-Tc single crystals and thin films, highly textured tapes and melt-textured bulk 123-superconductors

    International Nuclear Information System (INIS)

    Brandstaetter, G.; Samadi Hosseinalli, G.; Kern, C.; Sauerzopf, F.M.; Schulz, G.W.; Straif, W.; Yang, X.; Weber, H.W.; Hu, Q.Y.

    1999-01-01

    Various compounds (TI-2223, TI-1223, TI-2212) as well as material forms (single crystals, thin films, ceramics, tapes) of TI-based high temperature superconductors were investigated by magnetic and transport techniques. TI-2223 has a very 'low lying' irreversibility line (H parallel e) and negligible critical current densities J c at 77 K. However, the irreversibility line shifts to higher fields and temperatures and J c is strongly enhanced, even at 77 K, after fast neutron irradiation. In contrast, the related TI-1223 compound has a much steeper irreversibility line (H parallel c) similar to that of Y-123. J c is significant up to 77 K, even in the unirradiated state, and can be largely improved by neutron irradiation. Transport measurements made on TI-1223 tapes still show much lower critical current densities. TI-2212 and Tl-2223 thin films have J c 's at 77 K, which are comparable to those of TI-1223 single crystals. Transport measurements on highly textured Bi-2223 tapes as well as flux profile measurements on Nd-123 bulk superconductors confirm the beneficial effects of neutron induced defects (collision cascades) for flux pinning. (author)

  4. Procedure of calculation of the spatial distribution of temperatures and heat fluxes in the steam generator of a nuclear power installation with an RBEC fast-neutron reactor

    Science.gov (United States)

    Frolov, A. A.; Sedov, A. A.

    2016-08-01

    A method for combined 3D/1D-modeling of thermohydraulics of a once-through steam generator (SG) based on the joint analysis of three-dimensional thermo- and hydrodynamics of a single-phase heating coolant in the intertube space and one-dimensional thermohydraulics of steam-generating channels (tubes) with the use of well-known friction and heat-transfer correlations under various boiling conditions is discussed. This method allows one to determine the spatial distribution of temperatures and heat fluxes of heat-exchange surfaces of SGs with a single-phase heating coolant in the intertube space and with steam generation within tubes. The method was applied in the analytical investigation of typical operation of a once-through SG of a nuclear power installation with an RBEC fast-neutron heavy-metal reactor that is being designed by Kurchatov Institute in collaboration with OKB GIDROPRESS and Leipunsky Institute of Physics and Power Engineering. Flow pattern and temperature fields were obtained for the heavy-metal heating coolant in the intertube space. Nonuniformities of heating of the steam-water coolant in different heat-exchange tubes and nonuniformities in the distribution of heat fluxes at SG heat-exchange surfaces were revealed.

  5. NHE- and diffusion-dependent proton fluxes across the tubular system membranes of fast-twitch muscle fibers of the rat.

    Science.gov (United States)

    Launikonis, Bradley S; Cully, Tanya R; Csernoch, Laszlo; Stephenson, D George

    2018-01-02

    The complex membrane structure of the tubular system (t-system) in skeletal muscle fibers is open to the extracellular environment, which prevents measurements of H + movement across its interface with the cytoplasm by conventional methods. Consequently, little is known about the t-system's role in the regulation of cytoplasmic pH, which is different from extracellular pH. Here we describe a novel approach to measure H + -flux measurements across the t-system of fast-twitch fibers under different conditions. The approach involves loading the t-system of intact rat fast-twitch fibers with a strong pH buffer (20 mM HEPES) and pH-sensitive fluorescent probe (10 mM HPTS) before the t-system is sealed off. The pH changes in the t-system are then tracked by confocal microscopy after rapid changes in cytoplasmic ionic conditions. T-system sealing is achieved by removing the sarcolemma by microdissection (mechanical skinning), which causes the tubules to pinch off and seal tight. After this procedure, the t-system repolarizes to physiological levels and can be electrically stimulated when placed in K + -based solutions of cytosolic-like ionic composition. Using this approach, we show that the t-system of fast-twitch skeletal fibers displays amiloride-sensitive Na + /H + exchange (NHE), which decreases markedly at alkaline cytosolic pH and has properties similar to that in mammalian cardiac myocytes. We observed mean values for NHE density and proton permeability coefficient of 339 pmol/m 2 of t-system membrane and 158 µm/s, respectively. We conclude that the cytosolic pH in intact resting muscle can be quantitatively explained with respect to extracellular pH by assuming that these values apply to the t-system membrane and the sarcolemma. © 2018 Launikonis et al.

  6. Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging.

    Science.gov (United States)

    Abbene, Leonardo; Principato, Fabio; Gerardi, Gaetano; Bettelli, Manuele; Seller, Paul; Veale, Matthew C; Zambelli, Nicola; Benassi, Giacomo; Zappettini, Andrea

    2018-01-01

    Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2 mm-thick CZT pixel detector, with pixel pitches of 500 and 250 µm, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response of the system to photon energies below ( 109 Cd source) and above ( 241 Am source) the K-shell absorption energy of the CZT material was investigated, with particular attention to the mitigation of charge sharing and pile-up. The detector allows high bias voltage operation (>5000 V cm -1 ) and good energy resolution at moderate cooling (3.5% and 5% FWHM at 59.5 keV for the 500 and 250 µm arrays, respectively) by using fast pulse shaping with a low dead-time (300 ns). Charge-sharing investigations were performed using a fine time coincidence analysis (TCA), with very short coincidence time windows up to 10 ns. For the 500 µm pitch array (250 µm pitch array), sharing percentages of 36% (52%) and 60% (82%) at 22.1 and 59.5 keV, respectively, were measured. The potential of the pulse shape analysis technique for charge-sharing detection for corner/border pixels and at high rate conditions (250 kcps pixel -1 ), where the TCA fails, is also shown. Measurements demonstrated that significant amounts of charge are lost for interactions occurring in the volume of the inter-pixel gap. This charge loss must be accounted for in the correction of shared events. These activities are within the framework of an international collaboration on the development of energy

  7. In-Pile Experiment of a New Hafnium Aluminide Composite Material to Enable Fast Neutron Testing in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen; Douglas L. Porter; James R. Parry; Heng Ban

    2010-06-01

    A new hafnium aluminide composite material is being developed as a key component in a Boosted Fast Flux Loop (BFFL) system designed to provide fast neutron flux test capability in the Advanced Test Reactor. An absorber block comprised of hafnium aluminide (Al3Hf) particles (~23% by volume) dispersed in an aluminum matrix can absorb thermal neutrons and transfer heat from the experiment to pressurized water cooling channels. However, the thermophysical properties, such as thermal conductivity, of this material and the effect of irradiation are not known. This paper describes the design of an in-pile experiment to obtain such data to enable design and optimization of the BFFL neutron filter.

  8. Design of a single variable helium effects experiment for irradiation in FFTF [Fast Flux Test Facility] using alloys enriched in nickel 59

    International Nuclear Information System (INIS)

    Simons, R.L.; Brager, H.R.; Matsumoto, W.Y.

    1986-03-01

    Nickel enriched in nickel 59 was extracted from the fragments of a fracture toughness specimen of Inconel 600 irradiated in the Engineering Test Reactor (ETR). The nickel contained 2.0% nickel 59. Three heats of austenitic steel doped with nickel-59 were prepared and inserted in the Materials Open Test Assembly (MOTA) of the Fast Flux Test Facility (FFTF). The experiment was single variable in helium effects because chemically identical alloys without nickel-59 were being irradiated side by side with the doped material. The alloys doped with nickel 59 produced 10 to 100 times more helium than the control alloys. The materials included ternary and quaternary alloys in the form of transmission electron microscope (TEM) discs and miniature tensile specimens. The helium to dpa ratio was in the range 5 to 35 and was nearly constant throughout the irradiation. The exposures ranged from 0.25 to 50 displacements per atom (dpa) over the duration of the experiment. The irradiation temperatures covered the range of 360 to 600 0 C

  9. Distribution-Specific Agnostic Boosting

    OpenAIRE

    Feldman, Vitaly

    2009-01-01

    We consider the problem of boosting the accuracy of weak learning algorithms in the agnostic learning framework of Haussler (1992) and Kearns et al. (1992). Known algorithms for this problem (Ben-David et al., 2001; Gavinsky, 2002; Kalai et al., 2008) follow the same strategy as boosting algorithms in the PAC model: the weak learner is executed on the same target function but over different distributions on the domain. We demonstrate boosting algorithms for the agnostic learning framework tha...

  10. Boost C++ application development cookbook

    CERN Document Server

    Polukhin, Antony

    2013-01-01

    This book follows a cookbook approach, with detailed and practical recipes that use Boost libraries.This book is great for developers new to Boost, and who are looking to improve their knowledge of Boost and see some undocumented details or tricks. It's assumed that you will have some experience in C++ already, as well being familiar with the basics of STL. A few chapters will require some previous knowledge of multithreading and networking. You are expected to have at least one good C++ compiler and compiled version of Boost (1.53.0 or later is recommended), which will be used during the exer

  11. Gradient Boosting Machines, A Tutorial

    Directory of Open Access Journals (Sweden)

    Alexey eNatekin

    2013-12-01

    Full Text Available Gradient boosting machines are a family of powerful machine-learning techniques that have shown considerable success in a wide range of practical applications. They are highly customizable to the particular needs of the application, like being learned with respect to different loss functions. This article gives a tutorial introduction into the methodology of gradient boosting methods. A theoretical information is complemented with many descriptive examples and illustrations which cover all the stages of the gradient boosting model design. Considerations on handling the model complexity are discussed. A set of practical examples of gradient boosting applications are presented and comprehensively analyzed.

  12. Potential role of the Fast Flux Test Facility and the advanced test reactor in the U.S. tritium production system

    International Nuclear Information System (INIS)

    Dautel, W.A.

    1996-01-01

    The Department of Energy is currently engaged in a dual-track strategy to develop an accelerator and a commercial light water reactor (CLWR) as potential sources of tritium supply. New analysis of the production capabilities of the Fast Flux Test Facility (FFTF) at the Hanford Site argues for considering its inclusion in the tritium supply,system. The use of the FFTF (alone or together with the Advanced Test Reactor [ATR] at the Idaho National Engineering Laboratory) as an integral part of,a tritium production system would help (1) ensure supply by 2005, (2) provide additional time to resolve institutional and technical issues associated with the- dual-track strategy, and (3) reduce discounted total life-cycle'costs and near-tenn annual expenditures for accelerator-based systems. The FFRF would also provide a way to get an early start.on dispositioning surplus weapons-usable plutonium as well as provide a source of medical isotopes. Challenges Associated With the Dual-Track Strategy The Department's purchase of either a commercial reactor or reactor irradiation services faces challenging institutional issues associated with converting civilian reactors to defense uses. In addition, while the technical capabilities of the individual components of the accelerator have been proven, the entire system needs to be demonstrated and scaled upward to ensure that the components work together 1548 as a complete production system. These challenges create uncertainty over the ability of the du2a-track strategy to provide an assured tritium supply source by 2005. Because the earliest the accelerator could come on line is 2007, it would have to operate at maximum capacity for the first few years to regenerate the reserves lost through radioactive decay after 2005

  13. Boosted Higgs Shapes

    CERN Document Server

    Schlaffer, Matthias; Takeuchi, Michihisa; Weiler, Andreas; Wymant, Chris

    2014-01-01

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of $H\\to 2\\ell+\\mathbf{p}\\!\\!/_T$ via $H\\to \\tau\\tau$ and $H\\to WW^*$ could be performed and demonstrate that it offers a compelling alternative to the $t\\bar t H$ channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.

  14. Project BOOST implementation: lessons learned.

    Science.gov (United States)

    Williams, Mark V; Li, Jing; Hansen, Luke O; Forth, Victoria; Budnitz, Tina; Greenwald, Jeffrey L; Howell, Eric; Halasyamani, Lakshmi; Vidyarthi, Arpana; Coleman, Eric A

    2014-07-01

    Enhancing care coordination and reducing hospital readmissions have been a focus of multiple quality improvement (QI) initiatives. Project BOOST (Better Outcomes by Optimizing Safe Transitions) aims to enhance the discharge transition from hospital to home. Previous research indicates that QI initiatives originating externally often face difficulties gaining momentum or effecting lasting change in a hospital. We performed a qualitative evaluation of Project BOOST implementation by examining the successes and failures experienced by six pilot sites. We also evaluated the unique physician mentoring component of this program. Finally, we examined the impact of intensification of the physician mentoring model on adoption of BOOST interventions in two later Illinois cohorts (27 hospitals). Qualitative analysis of six pilot hospitals used a process of methodological triangulation and analysis of the BOOST enrollment applications, the listserv, and content from telephone interviews. Evaluation of BOOST implementation at Illinois hospitals occurred via mid-year and year-end surveys. The identified common barriers included inadequate understanding of the current discharge process, insufficient administrative support, lack of protected time or dedicated resources, and lack of frontline staff buy-in. Facilitators of implementation included the mentor, a small beginning, teamwork, and proactive engagement of the patient. Notably, hospitals viewed their mentors as essential facilitators of change. Sites consistently commented that the individualized mentoring was extremely helpful and provided significant accountability and stimulated creativity. In the Illinois cohorts, the improved mentoring model showed more complete implementation of BOOST interventions. The implementation of Project BOOST was well received by hospitals, although sites faced substantial barriers consistent with other QI research reports. The unique mentorship element of Project BOOST proved extremely

  15. AveBoost2: Boosting for Noisy Data

    Science.gov (United States)

    Oza, Nikunj C.

    2004-01-01

    AdaBoost is a well-known ensemble learning algorithm that constructs its constituent or base models in sequence. A key step in AdaBoost is constructing a distribution over the training examples to create each base model. This distribution, represented as a vector, is constructed to be orthogonal to the vector of mistakes made by the pre- vious base model in the sequence. The idea is to make the next base model's errors uncorrelated with those of the previous model. In previous work, we developed an algorithm, AveBoost, that constructed distributions orthogonal to the mistake vectors of all the previous models, and then averaged them to create the next base model s distribution. Our experiments demonstrated the superior accuracy of our approach. In this paper, we slightly revise our algorithm to allow us to obtain non-trivial theoretical results: bounds on the training error and generalization error (difference between training and test error). Our averaging process has a regularizing effect which, as expected, leads us to a worse training error bound for our algorithm than for AdaBoost but a superior generalization error bound. For this paper, we experimented with the data that we used in both as originally supplied and with added label noise-a small fraction of the data has its original label changed. Noisy data are notoriously difficult for AdaBoost to learn. Our algorithm's performance improvement over AdaBoost is even greater on the noisy data than the original data.

  16. Substructure boosts to dark matter annihilation from Sommerfeld enhancement

    International Nuclear Information System (INIS)

    Bovy, Jo

    2009-01-01

    The recently introduced Sommerfeld enhancement of the dark matter annihilation cross section has important implications for the detection of dark matter annihilation in subhalos in the Galactic halo. In addition to the boost to the dark matter annihilation cross section from the high densities of these subhalos with respect to the main halo, an additional boost caused by the Sommerfeld enhancement results from the fact that they are kinematically colder than the Galactic halo. If we further believe the generic prediction of the cold dark matter paradigm that in each subhalo there is an abundance of substructure which is approximately self-similar to that of the Galactic halo, then I show that additional boosts coming from the density enhancements of these small substructures and their small velocity dispersions enhance the dark matter annihilation cross section even further. I find that very large boost factors (10 5 to 10 9 ) are obtained in a large class of models. The implications of these boost factors for the detection of dark matter annihilation from dwarf spheroidal galaxies in the Galactic halo are such that, generically, they outshine the background gamma-ray flux and are detectable by the Fermi Gamma-ray Space Telescope.

  17. Boosting jet power in black hole spacetimes.

    Science.gov (United States)

    Neilsen, David; Lehner, Luis; Palenzuela, Carlos; Hirschmann, Eric W; Liebling, Steven L; Motl, Patrick M; Garrett, Travis

    2011-08-02

    The extraction of rotational energy from a spinning black hole via the Blandford-Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux.

  18. Neutron fluxes in test reactors

    Energy Technology Data Exchange (ETDEWEB)

    Youinou, Gilles Jean-Michel [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-01-01

    Communicate the fact that high-power water-cooled test reactors such as the Advanced Test Reactor (ATR), the High Flux Isotope Reactor (HFIR) or the Jules Horowitz Reactor (JHR) cannot provide fast flux levels as high as sodium-cooled fast test reactors. The memo first presents some basics physics considerations about neutron fluxes in test reactors and then uses ATR, HFIR and JHR as an illustration of the performance of modern high-power water-cooled test reactors.

  19. Determination of nitrogen in wheat flour through Activation analysis using Fast neutron flux of a Thermal nuclear reactor; Determinacion de nitrogeno en harina de trigo mediante analisis por activacion empleando el flujo de neutrones rapidos de un reactor nuclear termico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, T

    1976-07-01

    In this work is done a technical study for determining Nitrogen (protein) and other elements in wheat flour Activation analysis, with Fast neutrons from a Thermal nuclear reactor. Initially it is given an introduction about the basic principles of the methods of analysis. Equipment used in Activation analysis and a brief description of the neutron source (Thermal nuclear reactor). The realized experiments for determining the flux form in the irradiation site, the half life of N-13 and the interferences due to the sample composition are included too. Finally, the obtained results by Activation and the Kjeldahl method are tabulated. (Author)

  20. Boosted top: experimental tools overview

    CERN Document Server

    Usai, Emanuele

    2015-01-01

    An overview of tools and methods for the reconstruction of high-boost top quark decays at the LHC is given in this report. The focus is on hadronic decays, in particular an overview of the current status of top quark taggers in physics analyses is presented. The most widely used jet substructure techniques, normally used in combination with top quark taggers, are reviewed. Special techniques to treat pileup in large cone jets are described, along with a comparison of the performance of several boosted top quark reconstruction techniques.

  1. SemiBoost: boosting for semi-supervised learning.

    Science.gov (United States)

    Mallapragada, Pavan Kumar; Jin, Rong; Jain, Anil K; Liu, Yi

    2009-11-01

    Semi-supervised learning has attracted a significant amount of attention in pattern recognition and machine learning. Most previous studies have focused on designing special algorithms to effectively exploit the unlabeled data in conjunction with labeled data. Our goal is to improve the classification accuracy of any given supervised learning algorithm by using the available unlabeled examples. We call this as the Semi-supervised improvement problem, to distinguish the proposed approach from the existing approaches. We design a metasemi-supervised learning algorithm that wraps around the underlying supervised algorithm and improves its performance using unlabeled data. This problem is particularly important when we need to train a supervised learning algorithm with a limited number of labeled examples and a multitude of unlabeled examples. We present a boosting framework for semi-supervised learning, termed as SemiBoost. The key advantages of the proposed semi-supervised learning approach are: 1) performance improvement of any supervised learning algorithm with a multitude of unlabeled data, 2) efficient computation by the iterative boosting algorithm, and 3) exploiting both manifold and cluster assumption in training classification models. An empirical study on 16 different data sets and text categorization demonstrates that the proposed framework improves the performance of several commonly used supervised learning algorithms, given a large number of unlabeled examples. We also show that the performance of the proposed algorithm, SemiBoost, is comparable to the state-of-the-art semi-supervised learning algorithms.

  2. Boost.Asio C++ network programming

    CERN Document Server

    Torjo, John

    2013-01-01

    What you want is an easy level of abstraction, which is just what this book provides in conjunction with Boost.Asio. Switching to Boost.Asio is just a few extra #include directives away, with the help of this practical and engaging guide.This book is great for developers that need to do network programming, who don't want to delve into the complicated issues of a raw networking API. You should be familiar with core Boost concepts, such as smart pointers and shared_from_this, resource classes (noncopyable), functors and boost::bind, boost mutexes, and the boost date/time library. Readers should

  3. Q-Boosted Optomechanical Resonators

    Science.gov (United States)

    2015-11-18

    proposing team in 2004 [6], and apparently copied now by some in the optomechanical world, who seem to be calling it a spoke-supported toroid . Beyond merely...FA9550-10-1-0293 “Q-Boosted Optomechanical Resonators” CTN 9/18/15 24 [20] D. Armani, T. Kippenberg, S. Spillane and K. Vahala, "Ultra-high-Q toroid

  4. BIM-Boost in Nederland

    NARCIS (Netherlands)

    Berlo, L.A.H.M.

    2012-01-01

    Onlangs sloot TNO een samenwerkingsovereenkomst met brancheorganisaties in de bouwkolom waaromder Bouwend Nederland en BNA. Doel van de overeenkomst: een BIM-boost in Nederland bewerkstelligen. Een gesprek met Leon van Berlo van TNO over deze en andere BIM-actualiteiten

  5. ATLAS measurements of boosted object production

    CERN Document Server

    Arguin, Jean-Francois; The ATLAS collaboration

    2015-01-01

    This talk reviews ATLAS Standard Model measurements performed with boosted objects, i.e. boosted top quarks and W and Z bosons, which decay hadronically and are reconstructed as a single large radius jet.

  6. Milne boost from Galilean gauge theory

    Science.gov (United States)

    Banerjee, Rabin; Mukherjee, Pradip

    2018-03-01

    Physical origin of Milne boost invariance of the Newton Cartan spacetime is traced to the effect of local Galilean boosts in its metric structure, using Galilean gauge theory. Specifically, we do not require any gauge field to understand Milne boost invariance.

  7. Design and Implementation of a High-Flux Photoneutron Converter for Analysis of Fast Neutron Radiation Damage on Gallium Nitride Transistors

    Science.gov (United States)

    2017-06-01

    irradiation on dc electrical performances of 145 AlGaN/GaN transistors,” IEEE Transactions on Nuclear Science, vol. 59, no. 5, pp. 2556–2561, 2012. [32] C...relationship of the electrical and physical characteristics of the devices with respect to the fast neutron fluence. The damage was also analyzed using... ELECTRICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL June 2017 Approved by: Todd Weatherford Thesis Co-Advisor Frank Harmon, Idaho State

  8. ada: An R Package for Stochastic Boosting

    Directory of Open Access Journals (Sweden)

    Mark Culp

    2006-09-01

    Full Text Available Boosting is an iterative algorithm that combines simple classification rules with ‘mediocre’ performance in terms of misclassification error rate to produce a highly accurate classification rule. Stochastic gradient boosting provides an enhancement which incorporates a random mechanism at each boosting step showing an improvement in performance and speed in generating the ensemble. ada is an R package that implements three popular variants of boosting, together with a version of stochastic gradient boosting. In addition, useful plots for data analytic purposes are provided along with an extension to the multi-class case. The algorithms are illustrated with synthetic and real data sets.

  9. ada: An R Package for Stochastic Boosting

    Directory of Open Access Journals (Sweden)

    Mark Culp

    2006-09-01

    Full Text Available Boosting is an iterative algorithm that combines simple classification rules with "mediocre" performance in terms of misclassification error rate to produce a highly accurate classification rule. Stochastic gradient boosting provides an enhancement which incorporates a random mechanism at each boosting step showing an improvement in performance and speed in generating the ensemble. ada is an R package that implements three popular variants of boosting, together with a version of stochastic gradient boosting. In addition, useful plots for data analytic purposes are provided along with an extension to the multi-class case. The algorithms are illustrated with synthetic and real data sets.

  10. Boosting bonsai trees for handwritten/printed text discrimination

    Science.gov (United States)

    Ricquebourg, Yann; Raymond, Christian; Poirriez, Baptiste; Lemaitre, Aurélie; Coüasnon, Bertrand

    2013-12-01

    Boosting over decision-stumps proved its efficiency in Natural Language Processing essentially with symbolic features, and its good properties (fast, few and not critical parameters, not sensitive to over-fitting) could be of great interest in the numeric world of pixel images. In this article we investigated the use of boosting over small decision trees, in image classification processing, for the discrimination of handwritten/printed text. Then, we conducted experiments to compare it to usual SVM-based classification revealing convincing results with very close performance, but with faster predictions and behaving far less as a black-box. Those promising results tend to make use of this classifier in more complex recognition tasks like multiclass problems.

  11. Recursive bias estimation and L2 boosting

    Energy Technology Data Exchange (ETDEWEB)

    Hengartner, Nicolas W [Los Alamos National Laboratory; Cornillon, Pierre - Andre [INRA, FRANCE; Matzner - Lober, Eric [RENNE, FRANCE

    2009-01-01

    This paper presents a general iterative bias correction procedure for regression smoothers. This bias reduction schema is shown to correspond operationally to the L{sub 2} Boosting algorithm and provides a new statistical interpretation for L{sub 2} Boosting. We analyze the behavior of the Boosting algorithm applied to common smoothers S which we show depend on the spectrum of I - S. We present examples of common smoother for which Boosting generates a divergent sequence. The statistical interpretation suggest combining algorithm with an appropriate stopping rule for the iterative procedure. Finally we illustrate the practical finite sample performances of the iterative smoother via a simulation study.

  12. Characteristics of potential repository wastes: Volume 4, Appendix 4A, Nuclear reactors at educational institutions of the United States; Appendix 4B, Data sheets for nuclear reactors at educational institutions; Appendix 4C, Supplemental data for Fort St. Vrain spent fuel; Appendix 4D, Supplemental data for Peach Bottom 1 spent fuel; Appendix 4E, Supplemental data for Fast Flux Test Facility

    International Nuclear Information System (INIS)

    1992-07-01

    Volume 4 contains the following appendices: nuclear reactors at educational institutions in the United States; data sheets for nuclear reactors at educational institutions in the United States(operational reactors and shut-down reactors); supplemental data for Fort St. Vrain spent fuel; supplemental data for Peach Bottom 1 spent fuel; and supplemental data for Fast Flux Test Facility

  13. Advanced Airfoils Boost Helicopter Performance

    Science.gov (United States)

    2007-01-01

    Carson Helicopters Inc. licensed the Langley RC4 series of airfoils in 1993 to develop a replacement main rotor blade for their Sikorsky S-61 helicopters. The company's fleet of S-61 helicopters has been rebuilt to include Langley's patented airfoil design, and the helicopters are now able to carry heavier loads and fly faster and farther, and the main rotor blades have twice the previous service life. In aerial firefighting, the performance-boosting airfoils have helped the U.S. Department of Agriculture's Forest Service control the spread of wildfires. In 2003, Carson Helicopters signed a contract with Ducommun AeroStructures Inc., to manufacture the composite blades for Carson Helicopters to sell

  14. ATLAS boosted object tagging 2

    CERN Document Server

    Caudron, Julien; The ATLAS collaboration

    2015-01-01

    A detailed study into the optimal techniques for identifying boosted hadronically decaying W or Z bosons is presented. Various algorithms for reconstructing, grooming and tagging bosonic jets are compared for W bosons with a wide range of transverse momenta using 8 TeV data and 8 TeV and 13 TeV MC simulations. In addition, given that a hadronic jet has been identified as resulting from the hadronic decay of a W or Z, a technique is developed to discriminate between W and Z bosons. The modeling of the tagging variables used in this technique is studied using 8 TeV pp collision data and systematic uncertainties for the tagger efficiency and fake rates are evaluated.

  15. Orthodontics Align Crooked Teeth and Boost Self-Esteem

    Science.gov (United States)

    ... desktop! more... Orthodontics Align Crooked Teeth and Boost Self- esteem Article Chapters Orthodontics Align Crooked Teeth and Boost Self- esteem print full article print this chapter email this ...

  16. Practical Implementation of Embedded Controlled Boost Converter for Solar Installation System

    Directory of Open Access Journals (Sweden)

    A. Kalirasu

    2010-08-01

    Full Text Available The solar photovoltaic power has received great attention and experienced impressive progress in the countries all over the world in recent years because of more and more serious energy crisis and environmental pollution. This paper proposes a Embedded controlled boost converter for solar installation system. Boost converter system is simulated using Matlab and it is implemented using embedded controller. The simulation and experimental results of this system are presented and compared. This converter has advantages like improved power factor, fast response and reduced hardware.

  17. Modeling of asymmetrical boost converters

    Directory of Open Access Journals (Sweden)

    Eliana Isabel Arango Zuluaga

    2014-01-01

    Full Text Available The asymmetrical interleaved dual boost (AIDB is a fifth-order DC/DC converter designed to interface photovoltaic (PV panels. The AIDB produces small current harmonics to the PV panels, reducing the power losses caused by the converter operation. Moreover, the AIDB provides a large voltage conversion ratio, which is required to step-up the PV voltage to the large dc-link voltage used in grid-connected inverters. To reject irradiance and load disturbances, the AIDB must be operated in a closed-loop and a dynamic model is required. Given that the AIDB converter operates in Discontinuous Conduction Mode (DCM, classical modeling approaches based on Continuous Conduction Mode (CCM are not valid. Moreover, classical DCM modeling techniques are not suitable for the AIDB converter. Therefore, this paper develops a novel mathematical model for the AIDB converter, which is suitable for control-pur-poses. The proposed model is based on the calculation of a diode current that is typically disregarded. Moreover, because the traditional correction to the second duty cycle reported in literature is not effective, a new equation is designed. The model accuracy is contrasted with circuital simulations in time and frequency domains, obtaining satisfactory results. Finally, the usefulness of the model in control applications is illustrated with an application example.

  18. Fast Flux Test Facility (FFTF) standby plan

    Energy Technology Data Exchange (ETDEWEB)

    Hulvey, R.K.

    1997-03-06

    The FFTF Standby Plan, Revision 0, provides changes to the major elements and project baselines to maintain the FFTF plant in a standby condition and to continue washing sodium from irradiated reactor fuel. The Plan is consistent with the Memorandum of Decision approved by the Secretary of Energy on January 17, 1997, which directed that FFTF be maintained in a standby condition to permit the Department to make a decision on whether the facility should play a future role in the Department of Energy`s dual track tritium production strategy. This decision would be made in parallel with the intended December 1998 decision on the selection of the primary, long- term source of tritium. This also allows the Department to review the economic and technical feasibility of using the FFTF to produce isotopes for the medical community. Formal direction has been received from DOE-RL and Fluor 2020 Daniel Hanford to implement the FFTF standby decision. The objective of the Plan is maintain the condition of the FFTF systems, equipment and personnel to preserve the option for plant restart within three and one-half years of a decision to restart, while continuing deactivation work which is consistent with the standby mode.

  19. Fast flux test facility, transition project plan

    International Nuclear Information System (INIS)

    Guttenberg, S.

    1994-01-01

    The FFTF Transition Project Plan, Revision 1, provides changes and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition

  20. Fast flux test facility, transition project plan

    Energy Technology Data Exchange (ETDEWEB)

    Guttenberg, S.

    1994-11-15

    The FFTF Transition Project Plan, Revision 1, provides changes and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition.

  1. CANCER Escape from senescence boosts tumour growth

    NARCIS (Netherlands)

    Medema, Jan Paul

    2018-01-01

    Some chemotherapies block cancer growth by driving tumour cells into a state of cell-division arrest termed senescence. It emerges that such cells have a boosted capacity to drive tumour growth if they exit senescence

  2. Boosting Learning Algorithm for Stock Price Forecasting

    Science.gov (United States)

    Wang, Chengzhang; Bai, Xiaoming

    2018-03-01

    To tackle complexity and uncertainty of stock market behavior, more studies have introduced machine learning algorithms to forecast stock price. ANN (artificial neural network) is one of the most successful and promising applications. We propose a boosting-ANN model in this paper to predict the stock close price. On the basis of boosting theory, multiple weak predicting machines, i.e. ANNs, are assembled to build a stronger predictor, i.e. boosting-ANN model. New error criteria of the weak studying machine and rules of weights updating are adopted in this study. We select technical factors from financial markets as forecasting input variables. Final results demonstrate the boosting-ANN model works better than other ones for stock price forecasting.

  3. Avoiding Anemia: Boost Your Red Blood Cells

    Science.gov (United States)

    ... Issues Subscribe January 2014 Print this issue Avoiding Anemia Boost Your Red Blood Cells En español Send ... Disease When Blood Cells Bend Wise Choices Preventing Anemia To prevent or treat iron-deficiency anemia: Eat ...

  4. Top reconstruction and boosted top experimental overview

    CERN Document Server

    Skinnari, Louise

    2015-01-01

    An overview of techniques used to reconstruct resolved and boosted top quarks is presented. Techniques for resolved top quark reconstruction include kinematic likelihood fitters and pseudo- top reconstruction. Many tools and methods are available for the reconstruction of boosted top quarks, such as jet grooming techniques, jet substructure variables, and dedicated top taggers. Different techniques as used by ATLAS and CMS analyses are described and the performance of different variables and top taggers are shown.

  5. Generating energy dependent neutron flux maps for effective ...

    African Journals Online (AJOL)

    For activation analysis and irradiation scheme of miniature neutron source reactor, designers or engineers usually require information on thermal neutron flux levels and other energy group flux levels (such as fast, resonance and epithermal). A methodology for readily generating such flux maps and flux profiles for any ...

  6. A TEG Efficiency Booster with Buck-Boost Conversion

    Science.gov (United States)

    Wu, Hongfei; Sun, Kai; Zhang, Junjun; Xing, Yan

    2013-07-01

    A thermoelectric generator (TEG) efficiency booster with buck-boost conversion and power management is proposed as a TEG battery power conditioner suitable for a wide TEG output voltage range. An inverse-coupled inductor is employed in the buck-boost converter, which is used to achieve smooth current with low ripple on both the TEG and battery sides. Furthermore, benefiting from the magnetic flux counteraction of the two windings on the coupled inductor, the core size and power losses of the filter inductor are reduced, which can achieve both high efficiency and high power density. A power management strategy is proposed for this power conditioning system, which involves maximum power point tracking (MPPT), battery voltage control, and battery current control. A control method is employed to ensure smooth switching among different working modes. A modified MPPT control algorithm with improved dynamic and steady-state characteristics is presented and applied to the TEG battery power conditioning system to maximize energy harvesting. A 500-W prototype has been built, and experimental tests carried out on it. The power efficiency of the prototype at full load is higher than 96%, and peak efficiency of 99% is attained.

  7. FastJet user manual

    CERN Document Server

    Cacciari, Matteo; Soyez, Gregory

    2012-01-01

    FastJet is a C++ package that provides a broad range of jet finding and analysis tools. It includes efficient native implementations of all widely used 2-to-1 sequential recombination jet algorithms for pp and e+e- collisions, as well as access to 3rd party jet algorithms through a plugin mechanism, including all currently used cone algorithms. FastJet also provides means to facilitate the manipulation of jet substructure, including some common boosted heavy-object taggers, as well as tools for estimation of pileup and underlying-event noise levels, determination of jet areas and subtraction or suppression of noise in jets.

  8. Comprehensive review of high power factor ac-dc boost converters for PFC applications

    Science.gov (United States)

    De Castro Pereira, Dênis; Da Silva, Márcio Renato; Mateus Silva, Elder; Lessa Tofoli, Fernando

    2015-08-01

    High power factor rectifiers have been consolidated as an effective solution to improve power quality indices in terms of input power factor correction, reduction in the total harmonic distortion of the input current and also regulated dc voltages. Within this context, this subject has motivated the introduction of numerous converter topologies based on classic dc-dc structures associated with novel control techniques, thus leading to the manufacturing of dedicated integrated circuits that allow high input power factor by adding a front-end stage to switch-mode converters. In particular, boost converters in continuous current mode (CCM) are widely employed since they allow obtaining minimised electromagnetic interference levels. This work is concerned with a literature review involving relevant ac-dc single-phase boost-based topologies with high input power factor. The evolution of aspects regarding the conventional boost converter is shown in terms of improved characteristics inherent to other ac-dc boost converters. Additionally, the work intends to be a fast and concise reference to single-phase ac-dc boost converters operating in CCM for engineers, researchers and experts in the field of power electronics by properly analysing and comparing the aforementioned rectifiers.

  9. Global Dirac bispinor entanglement under Lorentz boosts

    Science.gov (United States)

    Bittencourt, Victor A. S. V.; Bernardini, Alex E.; Blasone, Massimo

    2018-03-01

    The effects of Lorentz boosts on the quantum entanglement encoded by a pair of massive spin-1/2 particles are described according to the Lorentz covariant structure described by Dirac bispinors. The quantum system considered incorporates four degrees of freedom: two of them related to the bispinor intrinsic parity and the other two related to the bispinor spin projection, i.e., the Dirac particle helicity. Because of the natural multipartite structure involved, the Meyer-Wallach global measure of entanglement is preliminarily used for computing global quantum correlations, while the entanglement separately encoded by spin degrees of freedom is measured through the negativity of the reduced two-particle spin-spin state. A general framework to compute the changes on quantum entanglement induced by a boost is developed and then specialized to describe three particular antisymmetric two-particle states. According to the results obtained, two-particle spin-spin entanglement cannot be created by the action of a Lorentz boost in a spin-spin separable antisymmetric state. On the other hand, the maximal spin-spin entanglement encoded by antisymmetric superpositions is degraded by Lorentz boosts driven by high-speed frame transformations. Finally, the effects of boosts on chiral states are shown to exhibit interesting invariance properties, which can only be obtained through such a Lorentz covariant formulation of the problem.

  10. Simulation of closed loop controlled boost converter for solar installation

    Directory of Open Access Journals (Sweden)

    Kalirasu Athimulam

    2010-01-01

    Full Text Available With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high stepup and high efficiency DC/DC converters is the major consideration in the renewable power applications due to the low voltage of PV arrays and fuel cells. In this paper digital simulation of closed loop controlled boost converter for solar installation is presented. Circuit models for open loop and closed loop controlled systems are developed using the blocks of simulink. The simulation results are compared with the theoretical results. This converter has advantages like improved power factor, fast response and reduced hardware. .

  11. Centrifugal compressor design for electrically assisted boost

    Science.gov (United States)

    Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.

    2013-12-01

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

  12. An Update on Statistical Boosting in Biomedicine

    Directory of Open Access Journals (Sweden)

    Andreas Mayr

    2017-01-01

    Full Text Available Statistical boosting algorithms have triggered a lot of research during the last decade. They combine a powerful machine learning approach with classical statistical modelling, offering various practical advantages like automated variable selection and implicit regularization of effect estimates. They are extremely flexible, as the underlying base-learners (regression functions defining the type of effect for the explanatory variables can be combined with any kind of loss function (target function to be optimized, defining the type of regression setting. In this review article, we highlight the most recent methodological developments on statistical boosting regarding variable selection, functional regression, and advanced time-to-event modelling. Additionally, we provide a short overview on relevant applications of statistical boosting in biomedicine.

  13. Improved Stereo Matching With Boosting Method

    Directory of Open Access Journals (Sweden)

    Shiny B

    2015-06-01

    Full Text Available Abstract This paper presents an approach based on classification for improving the accuracy of stereo matching methods. We propose this method for occlusion handling. This work employs classification of pixels for finding the erroneous disparity values. Due to the wide applications of disparity map in 3D television medical imaging etc the accuracy of disparity map has high significance. An initial disparity map is obtained using local or global stereo matching methods from the input stereo image pair. The various features for classification are computed from the input stereo image pair and the obtained disparity map. Then the computed feature vector is used for classification of pixels by using GentleBoost as the classification method. The erroneous disparity values in the disparity map found by classification are corrected through a completion stage or filling stage. A performance evaluation of stereo matching using AdaBoostM1 RUSBoost Neural networks and GentleBoost is performed.

  14. Transformer Isolated Buck-Boost Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2016-12-01

    Full Text Available Of the single-switch dc-to-dc converters, those with the buck-boost voltage transfer function offer most potential for transformer coupling, hence isolation, at the kilowatt level. This paper highlights the limitations of the traditional magnetic coupled, buck-boost topology. Then four split-capacitor transformer-coupled topologies (specifically the Cuk, sepic, zeta, and a new, converters with a common ac equivalent circuit are explored, that do not temporarily store core magnetic energy as does the traditional isolated buck-boost converter nor have a core dc magnetizing current bias, as with the sepic and zeta transformer coupled topologies. Core dc bias capacitive voltage compensation is a practical design constraint in three of the four topologies, while all four must cater for stray and leakage inductance effects. Simulations and experimental results for the new converter at 408W support the transformer-coupled, single-switch dc-to-dc converter concepts investigated.

  15. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats - A pharmacological study with the chlorogenic acid derivative S4048

    NARCIS (Netherlands)

    van Dijk, TH; van der Sluijs, FH; Wiegman, CH; Baller, JFW; Gustafson, LA; Burger, HJ; Herling, AW; Kuipers, F; Meijer, AJ; Reijngoud, DJ

    2001-01-01

    Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in

  16. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats. A pharmacological study with the chlorogenic acid derivative S4048

    NARCIS (Netherlands)

    van Dijk, T. H.; van der Sluijs, F. H.; Wiegman, C. H.; Baller, J. F.; Gustafson, L. A.; Burger, H. J.; Herling, A. W.; Kuipers, F.; Meijer, A. J.; Reijngoud, D. J.

    2001-01-01

    Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in

  17. Quadratic Boost A-Source Impedance Network

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede; Chub, Andrii

    2016-01-01

    A novel quadratic boost A-source impedance network is proposed to realize converters that demand very high voltage gain. To satisfy the requirement, the network uses an autotransformer where the obtained gain is quadratically dependent on the duty ratio and is unmatched by any existing impedance...... source networks and normal dc-dc converters with coupled magnetics at the same duty ratio and turns ratio. The term “Quadratic Boost A-Source” indicates its quadratic varying gain in the operating principle of the converter. The proposed converter draws a continuous current from the source and suits...

  18. Niacin to Boost Your HDL "Good" Cholesterol

    Science.gov (United States)

    Niacin can boost 'good' cholesterol Niacin is a B vitamin that may raise your HDL ("good") cholesterol. But side effects might outweigh benefits for most ... been used to increase high-density lipoprotein (HDL) cholesterol — the "good" cholesterol that helps remove low-density ...

  19. Detection of Illegitimate Emails using Boosting Algorithm

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    In this paper, we report on experiments to detect illegitimate emails using boosting algorithm. We call an email illegitimate if it is not useful for the receiver or for the society. We have divided the problem into two major areas of illegitimate email detection: suspicious email detection and s...

  20. Boosting China's research collaboration | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Boosting China's research collaboration. Rong Li presenting. Rong Li. Research Awards ... “China's cooperation to date has also largely ignored the role of research collaboration,” he says. Li focused on what China's foreign ... It was my first time formally working abroad,” he says. “It will definitely benefit my future career.”.

  1. Schools Enlisting Defense Industry to Boost STEM

    Science.gov (United States)

    Trotter, Andrew

    2008-01-01

    Defense contractors Northrop Grumman Corp. and Lockheed Martin Corp. are joining forces in an innovative partnership to develop high-tech simulations to boost STEM--or science, technology, engineering, and mathematics--education in the Baltimore County schools. The Baltimore County partnership includes the local operations of two major military…

  2. The Attentional Boost Effect with Verbal Materials

    Science.gov (United States)

    Mulligan, Neil W.; Spataro, Pietro; Picklesimer, Milton

    2014-01-01

    Study stimuli presented at the same time as unrelated targets in a detection task are better remembered than stimuli presented with distractors. This attentional boost effect (ABE) has been found with pictorial (Swallow & Jiang, 2010) and more recently verbal materials (Spataro, Mulligan, & Rossi-Arnaud, 2013). The present experiments…

  3. Boosting youth employment prospects in Tanzania | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2015-12-16

    Dec 16, 2015 ... Read the brief, Boosting youth employment prospects: Tanzania, (PDF, 999 KB); Read full report, Youth employment in Tanzania: Taking stock of the evidence and knowledge gaps, (1.14 MB); For a visual representation of the key findings see the infographic poster (PDF, 296 KB). Return to main page, ...

  4. The Attentional Boost Effect and Context Memory

    Science.gov (United States)

    Mulligan, Neil W.; Smith, S. Adam; Spataro, Pietro

    2016-01-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors--the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is…

  5. Extending statistical boosting. An overview of recent methodological developments.

    Science.gov (United States)

    Mayr, A; Binder, H; Gefeller, O; Schmid, M

    2014-01-01

    Boosting algorithms to simultaneously estimate and select predictor effects in statistical models have gained substantial interest during the last decade. This review highlights recent methodological developments regarding boosting algorithms for statistical modelling especially focusing on topics relevant for biomedical research. We suggest a unified framework for gradient boosting and likelihood-based boosting (statistical boosting) which have been addressed separately in the literature up to now. The methodological developments on statistical boosting during the last ten years can be grouped into three different lines of research: i) efforts to ensure variable selection leading to sparser models, ii) developments regarding different types of predictor effects and how to choose them, iii) approaches to extend the statistical boosting framework to new regression settings. Statistical boosting algorithms have been adapted to carry out unbiased variable selection and automated model choice during the fitting process and can nowadays be applied in almost any regression setting in combination with a large amount of different types of predictor effects.

  6. Primary Paralleled Isolated Boost Converter with Extended Operating Voltage Range

    DEFF Research Database (Denmark)

    Hernandez Botella, Juan Carlos; Sen, Gökhan; Mira Albert, Maria del Carmen

    2012-01-01

    Applications requiring wide input and output voltage range cannot often be satisfied by using buck or boost derived topologies. Primary paralleled isolated boost converter (PPIBC) [1]-[2] is a high efficiency boost derived topology. This paper proposes a new operation mode for extending the input...

  7. The boost transistor: a field plate controlled LDMOST

    NARCIS (Netherlands)

    Ferrara, A.; Schmitz, Jurriaan; Boksteen, B.K.; Hueting, Raymond Josephus Engelbart; Steeneken, P.G.; Heringa, A.; Claes, J.; van der Wel, A.P.

    2015-01-01

    In this work we present a new device: the boost transistor. The boost transistor is an LDMOS transistor that is controlled by a separate field plate boost electrode that reduces the specific on-resistance RonA. By applying a positive voltage Vboost, this electrode creates an accumulation layer in

  8. Critical flux determination by flux-stepping

    DEFF Research Database (Denmark)

    Beier, Søren; Jonsson, Gunnar Eigil

    2010-01-01

    In membrane filtration related scientific literature, often step-by-step determined critical fluxes are reported. Using a dynamic microfiltration device, it is shown that critical fluxes determined from two different flux-stepping methods are dependent upon operational parameters such as step......, such values are more or less useless in itself as critical flux predictors, and constant flux verification experiments have to be conducted to check if the determined critical fluxes call predict sustainable flux regimes. However, it is shown that using the step-by-step predicted critical fluxes as start...

  9. Glycogenolysis in the fasting dog.

    Science.gov (United States)

    de Bruijne, J J; de Koster, P

    1983-01-01

    Glycogen concentrations were determined in liver-biopsy specimens which were taken from four dogs during five consecutive days of fasting. It was found that maximal depletion of liver glycogen occurred between the second and the third day. Starvation-induced glycogenolysis was much slower in the dog than in men and rats. Fuel fluxes are discussed and it is tentatively concluded that in the fasting dog larger amounts of glycerol are available for gluconeogenesis than in other species.

  10. Substructure of Highly Boosted Massive Jets

    Energy Technology Data Exchange (ETDEWEB)

    Alon, Raz [Weizmann Inst. of Science, Rehovot (Israel)

    2012-10-01

    Modern particle accelerators enable researchers to study new high energy frontiers which have never been explored before. This realm opens possibilities to further examine known fields such as Quantum Chromodynamics. In addition, it allows searching for new physics and setting new limits on the existence of such. This study examined the substructure of highly boosted massive jets measured by the CDF II detector. Events from 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron Collider were collected out of a total integrated luminosity of 5.95 fb$^{-1}$. They were selected to have at least one jet with transverse momentum above 400 GeV/c. The jet mass, angularity, and planar flow were measured and compared with predictions of perturbative Quantum Chromodynamics, and were found to be consistent with the theory. A search for boosted top quarks was conducted and resulted in an upper limit on the production cross section of such top quarks.

  11. Boosting Nonlinear Additive Autoregressive Time Series

    OpenAIRE

    Shafik, Nivien; Tutz, Gerhard

    2007-01-01

    Within the last years several methods for the analysis of nonlinear autoregressive time series have been proposed. As in linear autoregressive models main problems are model identification, estimation and prediction. A boosting method is proposed that performs model identification and estimation simultaneously within the framework of nonlinear autoregressive time series. The method allows to select influential terms from a large numbers of potential lags and exogenous variables. The influence...

  12. Cash boost to Great British science unveiled

    CERN Multimedia

    2002-01-01

    "Trade and Industry Secretary, Patricia Hewitt today unveiled new plans for the DTI's record science budget over the next three years, to keep Britain at the forefront of world science. The plans include funding to develop life saving new health techniques, to seek alternative energy sources, to help our rural economy, to develop the computers of tomorrow and boost business with the next generation of leading edge technologies" (1 page).

  13. Boosted Random Ferns for Object Detection.

    Science.gov (United States)

    Vergel, Michael Villamizar; Andrade-Cetto, Juan; Sanfeliu, Alberto; Moreno-Noguer, Francesc

    2018-02-01

    In this paper we introduce the Boosted Random Ferns (BRFs) to rapidly build discriminative classifiers for learning and detecting object categories. At the core of our approach we use standard random ferns, but we introduce four main innovations that let us bring ferns from an instance to a category level, and still retain efficiency. First, we define binary features on the histogram of oriented gradients-domain (as opposed to intensity-), allowing for a better representation of intra-class variability. Second, both the positions where ferns are evaluated within the sliding window, and the location of the binary features for each fern are not chosen completely at random, but instead we use a boosting strategy to pick the most discriminative combination of them. This is further enhanced by our third contribution, that is to adapt the boosting strategy to enable sharing of binary features among different ferns, yielding high recognition rates at a low computational cost. And finally, we show that training can be performed online, for sequentially arriving images. Overall, the resulting classifier can be very efficiently trained, densely evaluated for all image locations in about 0.1 seconds, and provides detection rates similar to competing approaches that require expensive and significantly slower processing times. We demonstrate the effectiveness of our approach by thorough experimentation in publicly available datasets in which we compare against state-of-the-art, and for tasks of both 2D detection and 3D multi-view estimation.

  14. Multiclass AdaBoost ELM and Its Application in LBP Based Face Recognition

    Directory of Open Access Journals (Sweden)

    Yunliang Jiang

    2015-01-01

    Full Text Available Extreme learning machine (ELM is a competitive machine learning technique, which is simple in theory and fast in implementation; it can identify faults quickly and precisely as compared with traditional identification techniques such as support vector machines (SVM. As verified by the simulation results, ELM tends to have better scalability and can achieve much better generalization performance and much faster learning speed compared with traditional SVM. In this paper, we introduce a multiclass AdaBoost based ELM ensemble method. In our approach, the ELM algorithm is selected as the basic ensemble predictor due to its rapid speed and good performance. Compared with the existing boosting ELM algorithm, our algorithm can be directly used in multiclass classification problem. We also carried out comparable experiments with face recognition datasets. The experimental results show that the proposed algorithm can not only make the predicting result more stable, but also achieve better generalization performance.

  15. Study of intermittent bifurcations and chaos in boost PFC converters by nonlinear discrete models

    International Nuclear Information System (INIS)

    Zhang Hao; Ma Xikui; Xue Bianling; Liu Weizeng

    2005-01-01

    This paper mainly deals with nonlinear phenomena like intermittent bifurcations and chaos in boost PFC converters under peak-current control mode. Two nonlinear models in the form of discrete maps are derived to describe precisely the nonlinear dynamics of boost PFC converters from two points of view, i.e., low- and high-frequency regimes. Based on the presented discrete models, both the evolution of intermittent behavior and the periodicity of intermittency are investigated in detail from the fast and slow-scale aspects, respectively. Numerical results show that the occurrence of intermittent bifurcations and chaos with half one line period is one of the most distinguished dynamical characteristics. Finally, we make some instructive conclusions, which prove to be helpful in improving the performances of practical circuits

  16. Flux driven turbulence in tokamaks

    International Nuclear Information System (INIS)

    Garbet, X.; Ghendrih, P.; Ottaviani, M.; Sarazin, Y.; Beyer, P.; Benkadda, S.; Waltz, R.E.

    1999-01-01

    This work deals with tokamak plasma turbulence in the case where fluxes are fixed and profiles are allowed to fluctuate. These systems are intermittent. In particular, radially propagating fronts, are usually observed over a broad range of time and spatial scales. The existence of these fronts provide a way to understand the fast transport events sometimes observed in tokamaks. It is also shown that the confinement scaling law can still be of the gyroBohm type in spite of these large scale transport events. Some departure from the gyroBohm prediction is observed at low flux, i.e. when the gradients are close to the instability threshold. Finally, it is found that the diffusivity is not the same for a turbulence calculated at fixed flux than at fixed temperature gradient, with the same time averaged profile. (author)

  17. Measurements of neutron flux in the RA reactor

    International Nuclear Information System (INIS)

    Raisic, N.

    1961-12-01

    This report includes the following separate parts: Thermal neutron flux in the experimental channels od RA reactor; Epithermal neutron flux in the experimental channels od RA reactor; Fast neutron flux in the experimental channels od RA reactor; Thermal neutron flux in the thermal column and biological experimental channel; Neutronic measurements in the RA reactor cell; Temperature reactivity coefficient of the RA reactor; design of the device for measuring the activity of wire [sr

  18. Boosted cylindrical magnetized Kaluza-Klein wormhole

    Science.gov (United States)

    Hashemi, S. Sedigheh; Riazi, Nematollah

    2018-02-01

    In this work, we consider a vacuum solution of Kaluza-Klein theory with cylindrical symmetry. We investigate the physical properties of the solution as viewed in four dimensional spacetime, which turns out to be a stationary, cylindrical wormhole supported by a scalar field and a magnetic field oriented along the wormhole. We then apply a boost to the five dimensional solution along the extra dimension, and perform the Kaluza-Klein reduction. As a result, we show that the new solution is still a wormhole with a radial electric field and a magnetic field stretched along the wormhole throat.

  19. Flux at a point in MCNP

    International Nuclear Information System (INIS)

    Cashwell, E.D.; Schrandt, R.G.

    1980-01-01

    The current state of the art of calculating flux at a point with MCNP is discussed. Various techniques are touched upon, but the main emphasis is on the fast improved version of the once-more-collided flux estimator, which has been modified to treat neutrons thermalized by the free gas model. The method is tested on several problems on interest and the results are presented

  20. single-phase dc phase dc-ac boost converter ac boost converter

    African Journals Online (AJOL)

    User

    supply (UPS) AC motor drives and other power sup systems, need to step-up the DC input voltage. increase the output voltage level in order requirements, DC-DC boost converter is used provide DC bus voltage for PWM inverters. Hence, conventional design always cascades DC and a separate DC-AC converter.

  1. AdaBoost-based algorithm for network intrusion detection.

    Science.gov (United States)

    Hu, Weiming; Hu, Wei; Maybank, Steve

    2008-04-01

    Network intrusion detection aims at distinguishing the attacks on the Internet from normal use of the Internet. It is an indispensable part of the information security system. Due to the variety of network behaviors and the rapid development of attack fashions, it is necessary to develop fast machine-learning-based intrusion detection algorithms with high detection rates and low false-alarm rates. In this correspondence, we propose an intrusion detection algorithm based on the AdaBoost algorithm. In the algorithm, decision stumps are used as weak classifiers. The decision rules are provided for both categorical and continuous features. By combining the weak classifiers for continuous features and the weak classifiers for categorical features into a strong classifier, the relations between these two different types of features are handled naturally, without any forced conversions between continuous and categorical features. Adaptable initial weights and a simple strategy for avoiding overfitting are adopted to improve the performance of the algorithm. Experimental results show that our algorithm has low computational complexity and error rates, as compared with algorithms of higher computational complexity, as tested on the benchmark sample data.

  2. Aichelburg-Sexl boost of domain walls and cosmic strings

    International Nuclear Information System (INIS)

    Barrabes, C.; Hogan, P.A.; Israel, W.

    2002-01-01

    We consider the application of the Aichelburg-Sexl boost to plane and line distributions of matter. Our analysis shows that for a domain wall the space-time after the boost is flat except on a null hypersurface which is the history of a null shell. For a cosmic string we study the influence of the boost on the conical singularity and give the new value of the conical deficit

  3. Inelastic Boosted Dark Matter at direct detection experiments

    OpenAIRE

    Giudice, Gian F.; Kim, Doojin; Park, Jong-Chul; Shin, Seodong

    2018-01-01

    We explore a novel class of multi-particle dark sectors, called Inelastic Boosted Dark Matter (iBDM). These models are constructed by combining properties of particles that scatter off matter by making transitions to heavier states (Inelastic Dark Matter) with properties of particles that are produced with a large Lorentz boost in annihilation processes in the galactic halo (Boosted Dark Matter). This combination leads to new signals that can be observed at ordinary direct detection experimen...

  4. Generation and transport of fast electrons in the interaction of high intensity laser with matter; Generation et transport des electrons rapides dans l'interaction laser-matiere a haut flux

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, H

    2005-10-15

    The general context of this study is the Inertial Confinement for thermonuclear controlled fusion and, more precisely, the Fast Igniter (FI). In this context the knowledge of the generation and transport of fast electrons is crucial. This thesis is an experimental study of the generation and transport of fast electrons in the interaction of a high intensity laser ({>=} 10{sup 19} W/cm{sup 2}) with a solid target. The main diagnostic used here is the transition radiation. This radiation depends on the electrons which produce it and thus it gives important information on the electrons: energy, temperature, propagation geometry, etc. The spectral, temporal and spatial analysis permitted to put in evidence the acceleration of periodic electron bunches which, in this case, emit a Coherent Transition Radiation (CTR). During this thesis we have developed some theoretical models in order to explain the experimental results. We find this way two kinds of electron bunches, emitted either at the laser frequency ({omega}{sub 0}), either at the double of this frequency (2{omega}{sub 0}), involving several acceleration mechanisms: vacuum heating / resonance absorption and Lorentz force, respectively. These bunches are also observed in the PIC (particle-in-cell) simulations. The electron temperature is of about 2 MeV in our experimental conditions. The electrons are emitted starting from a point source (which is the laser focal spot) and then propagate in a ballistic way through the target. In some cases they can be re-injected in the target by the electrostatic field from the target edges. This diagnostic is only sensitive to the coherent relativistic electrons, which explains the weak total energy that they contain (about a few mJ). The CTR signal emitted by those fast electrons is largely dominating the signal emitted by the less energetic electrons, even if they contain the major part of the energy (about 1 J). (author)

  5. Boosted Higgs boson tagging using jet substructures

    CERN Document Server

    Shvydkin, Pavel

    2016-01-01

    Searching BSM particles via the Higgs boson final state has now become common. The mass of desired BSM particle is more than 1 TeV, thereby its decay products are highly Lorentz-boosted. Hence the jets from b quark-antiquark pair - which the Higgs boson mostly decays into - are very closed to each other, and merged into one jet, that is typically reconstructed using large jet sizes (∆R = 0.8). In this work regression technique is applied to AK8 jets (which defined by anti-kT algorithm, using ΔR = 0.8). The regression makes use of boosted jets with substructure information, coupled with the pecularities of a b quark decay, like the presence of a soft lepton (SL) inside the jet. It has allowed to improve the resolution of the mass reconstruction and transverse momentum of the Higgs boson. This application results in improvement of the mass reconstruction by 3-4 percent. These result may be improved firstly by making more careful pileup rejection. Then it is possible to combine base regression train for dif...

  6. Holocraneal irradiation with boost integrated simultaneous of oligo metastases using Exa frame and Exa skin with VMAI-IGRT; Irradiacion holocraneal con boost integrado simultaneo de oligometastasis usando Exaframe y Exaskin con VMAT-IGRT

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Miranda, S.; Montero Perea, E.; Ortiz Seidel, M.

    2013-07-01

    The described technique of prophylaxis back hippo-fractionated with simultaneous integrated boost presents advantages in terms of reduction of treatment time total, fast local effect on the oligo metastases and possible prevention of the emergence of new cranial metastasis. The possible impact on long-term survival remains to be determined. In any case, this technique is presented as a valid alternative in terms of clinical outcomes and toxicity to stereotaxic standard treatments. (Author)

  7. Load estimator-based hybrid controller design for two-interleaved boost converter dedicated to renewable energy and automotive applications.

    Science.gov (United States)

    Bougrine, Mohamed; Benmiloud, Mohammed; Benalia, Atallah; Delaleau, Emmanuel; Benbouzid, Mohamed

    2017-01-01

    This paper is devoted to the development of a hybrid controller for a two-interleaved boost converter dedicated to renewable energy and automotive applications. The control requirements, resumed in fast transient and low input current ripple, are formulated as a problem of fast stabilization of a predefined optimal limit cycle, and solved using hybrid automaton formalism. In addition, a real time estimation of the load is developed using an algebraic approach for online adjustment of the hybrid controller. Mathematical proofs are provided with simulations to illustrate the effectiveness and the robustness of the proposed controller despite different disturbances. Furthermore, a fuel cell system supplying a resistive load through a two-interleaved boost converter is also highlighted. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Holocraneal irradiation with boost integrated simultaneous of oligo metastases using Exa frame and Exa skin with VMAI-IGRT

    International Nuclear Information System (INIS)

    Velazquez Miranda, S.; Montero Perea, E.; Ortiz Seidel, M.

    2013-01-01

    The described technique of prophylaxis back hippo-fractionated with simultaneous integrated boost presents advantages in terms of reduction of treatment time total, fast local effect on the oligo metastases and possible prevention of the emergence of new cranial metastasis. The possible impact on long-term survival remains to be determined. In any case, this technique is presented as a valid alternative in terms of clinical outcomes and toxicity to stereotaxic standard treatments. (Author)

  9. OpenFLUX: efficient modelling software for 13C-based metabolic flux analysis

    Directory of Open Access Journals (Sweden)

    Nielsen Lars K

    2009-05-01

    Full Text Available Abstract Background The quantitative analysis of metabolic fluxes, i.e., in vivo activities of intracellular enzymes and pathways, provides key information on biological systems in systems biology and metabolic engineering. It is based on a comprehensive approach combining (i tracer cultivation on 13C substrates, (ii 13C labelling analysis by mass spectrometry and (iii mathematical modelling for experimental design, data processing, flux calculation and statistics. Whereas the cultivation and the analytical part is fairly advanced, a lack of appropriate modelling software solutions for all modelling aspects in flux studies is limiting the application of metabolic flux analysis. Results We have developed OpenFLUX as a user friendly, yet flexible software application for small and large scale 13C metabolic flux analysis. The application is based on the new Elementary Metabolite Unit (EMU framework, significantly enhancing computation speed for flux calculation. From simple notation of metabolic reaction networks defined in a spreadsheet, the OpenFLUX parser automatically generates MATLAB-readable metabolite and isotopomer balances, thus strongly facilitating model creation. The model can be used to perform experimental design, parameter estimation and sensitivity analysis either using the built-in gradient-based search or Monte Carlo algorithms or in user-defined algorithms. Exemplified for a microbial flux study with 71 reactions, 8 free flux parameters and mass isotopomer distribution of 10 metabolites, OpenFLUX allowed to automatically compile the EMU-based model from an Excel file containing metabolic reactions and carbon transfer mechanisms, showing it's user-friendliness. It reliably reproduced the published data and optimum flux distributions for the network under study were found quickly ( Conclusion We have developed a fast, accurate application to perform steady-state 13C metabolic flux analysis. OpenFLUX will strongly facilitate and

  10. Very boosted Higgs in gluon fusion

    CERN Document Server

    Grojean, Christophe; Schlaffer, Matthias; Weiler, Andreas

    2014-01-01

    The Higgs production and decay rates offer a new way to probe new physics beyond the Standard Model. While dynamics aiming at alleviating the hierarchy problem generically predict deviations in the Higgs rates, the current experimental analyses cannot resolve the long- and short-distance contributions to the gluon fusion process and thus cannot access directly the coupling between the Higgs and the top quark. We investigate the production of a boosted Higgs in association with a high-transverse momentum jet as an alternative to the $t\\bar{t}h$ channel to pin down this crucial coupling. Presented first in the context of an effective field theory, our analysis is then applied to models of partial compositeness at the TeV scale and of natural supersymmetry.

  11. Giving top quark effective operators a boost

    CERN Document Server

    Englert, Christoph

    2016-01-01

    We investigate the prospects to systematically improve generic effective field theory-based searches for new physics in the top sector during LHC run 2 as well as the high luminosity phase. In particular, we assess the benefits of high momentum transfer final states on top EFT-fit as a function of systematic uncertainties in comparison with sensitivity expected from fully-resolved analyses focusing on $t\\bar t$ production. We find that constraints are typically driven by fully-resolved selections, while boosted top quarks can serve to break degeneracies in the global fit. This demystifies and clarifies the importance of high momentum transfer final states for global fits to new interactions in the top sector from direct measurements.

  12. Very boosted Higgs in gluon fusion

    Energy Technology Data Exchange (ETDEWEB)

    Grojean, C. [Univ. Autonoma de Barcelona, Bellaterra (Spain). ICREA at IFAE; Salvioni, E. [California Univ., Davis, CA (United States). Dept. of Physics; European Organization for Nuclear Research (CERN), Geneva (Switzerland); Padova Univ. (Italy). Dipt. di Fisica e Astronomica; INFN, Sezione di Padova (Italy); Schlaffer, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Weiler, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-12-15

    The Higgs production and decay rates offer a new way to probe new physics beyond the Standard Model. While dynamics aiming at alleviating the hierarchy problem generically predict deviations in the Higgs rates, the current experimental analyses cannot resolve the long- and short-distance contributions to the gluon fusion process and thus cannot access directly the coupling between the Higgs and the top quark. We investigate the production of a boosted Higgs in association with a high-transverse momentum jet as an alternative to the t anti th channel to pin down this crucial coupling. Presented rst in the context of an effective field theory, our analysis is then applied to models of partial compositeness at the TeV scale and of natural supersymmetry.

  13. Boosted W/Z Tagging at ATLAS

    CERN Document Server

    Dattagupta, Aparajita; The ATLAS collaboration

    2016-01-01

    A detailed study of the techniques for identifying boosted hadronically decaying W or Z bosons is presented. The best performing algorithm for reconstructing, grooming and tagging bosonic jets as seen in studies using 8 TeV data and simulation is validated for W bosons with a wide range of transverse momenta using 13 TeV data and MC simulations. The same is studied for Z bosons in 13 TeV MC simulation. Improvement in tagger performance using detector tracking information is also studied. In addition, given that a hadronic jet has been identified as resulting from the hadronic decay of a W or Z, a technique is developed to discriminate between W and Z bosons using 8 TeV data. The alternative of using variable-R jets for capturing the hadronic decay products compared to standard techniques is also discussed.

  14. Radial Flux Distribution of Low-Energy Neutrons.

    Science.gov (United States)

    Higinbotham, J.

    1979-01-01

    Describes an experiment designed to illustrate the basic principle involved in the process of moderation of fast neutrons by water, and the monitoring of the low-energy neutron flux using indium as a probe. (GA)

  15. Boosted objects: a probe of beyond the standard model physics

    DEFF Research Database (Denmark)

    Abdesselam, A.; Belyaev, A.; Kuutmann, E. B.

    2011-01-01

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools...

  16. Higher-order Gaussian kernel in bootstrap boosting algorithm ...

    African Journals Online (AJOL)

    The bootstrap boosting algorithm is a bias reduction scheme. The adoption of higher-order Gaussian kernel in a bootstrap boosting algorithm in kernel density estimation was investigated. The algorithm used the higher-order. Gaussian kernel instead of the regular fixed kernels. A comparison of the scheme with existing ...

  17. Boosting aquaculture production systems in Osun state: Role of ...

    African Journals Online (AJOL)

    This scenario leaves a high percentage of the population who depend on fish and fish products food insecure, and thus, the need to boost aquaculture production to argument the supply from the wild. The study therefore looks into the possibility of boosting the production systems through the use of micro-credit and ...

  18. Diode-Assisted Buck-Boost Current Source Inverters

    DEFF Research Database (Denmark)

    Gao, F.; Cai, Liang; Loh, P.C.

    2007-01-01

    This paper presents a couple of novel current source inverters (CSIs) with the enhanced current buckboost capability. With the unique diode-inductor network added between current source inverter circuitry and current boost elements, the proposed buck-boost current source inverters demonstrate...

  19. The attentional boost effect and context memory.

    Science.gov (United States)

    Mulligan, Neil W; Smith, S Adam; Spataro, Pietro

    2016-04-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors-the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is unclear if context memory is likewise affected. Some accounts suggest enhanced perceptual encoding or associative binding, predicting an ABE on context memory, whereas other evidence suggests a more abstract, amodal basis of the effect. In Experiment 1, context memory was assessed in terms of an intramodal perceptual detail, the font and color of the study word. Experiment 2 examined context memory cross-modally, assessing memory for the modality (visual or auditory) of the study word. Experiments 3 and 4 assessed context memory with list discrimination, in which 2 study lists are presented and participants must later remember which list (if either) a test word came from. In all experiments, item (recognition) memory was also assessed and consistently displayed a robust ABE. In contrast, the attentional-boost manipulation did not enhance context memory, whether defined in terms of visual details, study modality, or list membership. There was some evidence that the mode of responding on the detection task (motoric response as opposed to covert counting of targets) may impact context memory but there was no evidence of an effect of target detection, per se. In sum, the ABE did not occur in context memory with verbal materials. (c) 2016 APA, all rights reserved).

  20. Glucose starvation boosts Entamoeba histolytica virulence.

    Directory of Open Access Journals (Sweden)

    Ayala Tovy

    2011-08-01

    Full Text Available The unicellular parasite, Entamoeba histolytica, is exposed to numerous adverse conditions, such as nutrient deprivation, during its life cycle stages in the human host. In the present study, we examined whether the parasite virulence could be influenced by glucose starvation (GS. The migratory behaviour of the parasite and its capability to kill mammalian cells and to lyse erythrocytes is strongly enhanced following GS. In order to gain insights into the mechanism underlying the GS boosting effects on virulence, we analyzed differences in protein expression levels in control and glucose-starved trophozoites, by quantitative proteomic analysis. We observed that upstream regulatory element 3-binding protein (URE3-BP, a transcription factor that modulates E.histolytica virulence, and the lysine-rich protein 1 (KRiP1 which is induced during liver abscess development, are upregulated by GS. We also analyzed E. histolytica membrane fractions and noticed that the Gal/GalNAc lectin light subunit LgL1 is up-regulated by GS. Surprisingly, amoebapore A (Ap-A and cysteine proteinase A5 (CP-A5, two important E. histolytica virulence factors, were strongly down-regulated by GS. While the boosting effect of GS on E. histolytica virulence was conserved in strains silenced for Ap-A and CP-A5, it was lost in LgL1 and in KRiP1 down-regulated strains. These data emphasize the unexpected role of GS in the modulation of E.histolytica virulence and the involvement of KRiP1 and Lgl1 in this phenomenon.

  1. Radon flux measurement methodologies

    International Nuclear Information System (INIS)

    Nielson, K.K.; Rogers, V.C.

    1984-01-01

    Five methods for measuring radon fluxes are evaluated: the accumulator can, a small charcoal sampler, a large-area charcoal sampler, the ''Big Louie'' charcoal sampler, and the charcoal tent sampler. An experimental comparison of the five flux measurement techniques was also conducted. Excellent agreement was obtained between the measured radon fluxes and fluxes predicted from radium and emanation measurements

  2. Boosted one dimensional fermionic superfluids on a lattice

    Science.gov (United States)

    Ray, Sayonee; Mukerjee, Subroto; Shenoy, Vijay B.

    2017-09-01

    We study the effect of a boost (Fermi sea displaced by a finite momentum) on one dimensional systems of lattice fermions with short-ranged interactions. In the absence of a boost such systems with attractive interactions possess algebraic superconducting order. Motivated by physics in higher dimensions, one might naively expect a boost to weaken and ultimately destroy superconductivity. However, we show that for one dimensional systems the effect of the boost can be to strengthen the algebraic superconducting order by making correlation functions fall off more slowly with distance. This phenomenon can manifest in interesting ways, for example, a boost can produce a Luther-Emery phase in a system with both charge and spin gaps by engendering the destruction of the former.

  3. Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop

    International Nuclear Information System (INIS)

    McCulloch, R.W.; MacPherson, R.E.

    1983-03-01

    The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm 2 , 1000 0 C cladding temperature, and (2) 40 h at 40 W/cm 2 , 1200 0 C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370 0 C

  4. Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, R.W.; MacPherson, R.E.

    1983-03-01

    The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

  5. Introducing state-trajectory control for the synchronous interleaved boost converter

    DEFF Research Database (Denmark)

    Peña-Alzola, Rafael; Ksiazek, Peter; Ordonez, Martin

    2015-01-01

    Synchronous interleaved boost converters (SIBCs) result in lower ripple currents and bidirectional power flow. The boost topology has a non-minimum phase characteristic, producing instability problems when a large bandwidth is required. Linear controllers inherently limit the boost controller...

  6. Novel Transverse Flux Machine for Vehicle Traction Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Z.; Ahmed, A.; Husain, I.; Muljadi, E.

    2015-04-02

    A novel transverse flux machine topology for electric vehicle traction applications using ferrite magnets is presented in this paper. The proposed transverse flux topology utilizes novel magnet arrangements in the rotor that are similar to the Halbach array to boost flux linkage; on the stator side, cores are alternately arranged around a pair of ring windings in each phase to make use of the entire rotor flux that eliminates end windings. Analytical design considerations and finite-element methods are used for an optimized design of a scooter in-wheel motor. Simulation results from finite element analysis (FEA) show that the motor achieved comparable torque density to conventional rare-earth permanent magnet (PM) machines. This machine is a viable candidate for direct-drive applications with low cost and high torque density.

  7. Nuclear transmutation by flux compression

    International Nuclear Information System (INIS)

    Seifritz, W.

    2001-01-01

    A new idea for the transmutation of minor actinides, long (and even short) lived fission products is presented. It is based an the property of neutron flux compression in nuclear (fast and/or thermal) reactors possessing spatially non-stationary critical masses. An advantage factor for the burn-up fluence of the elements to be transmuted in the order of magnitude of 100 and more is obtainable compared with the classical way of transmutation. Three typical examples of such transmuters (a subcritical ringreactor with a rotating reflector, a sub-critical ring reactor with a rotating spallation source, the socalled ''pulsed energy amplifier'', and a fast burn-wave reactor) are presented and analysed with regard to this purpose. (orig.) [de

  8. Fast breeder reactors an engineering introduction

    CERN Document Server

    Judd, A M

    1981-01-01

    Fast Breeder Reactors: An Engineering Introduction is an introductory text to fast breeder reactors and covers topics ranging from reactor physics and design to engineering and safety considerations. Reactor fuels, coolant circuits, steam plants, and control systems are also discussed. This book is comprised of five chapters and opens with a brief summary of the history of fast reactors, with emphasis on international and the prospect of making accessible enormous reserves of energy. The next chapter deals with the physics of fast reactors and considers calculation methods, flux distribution,

  9. FAST scan

    DEFF Research Database (Denmark)

    Müller, Anna

    FAST-skanning er en metode, der har til formål at hurtigt diagnosticere fri væske i bughulen hos traumapatienter og andre akutte patienter. Denne skanningsteknik blev først introduceret til hunde i 2004, og omfatter ultralydsskanning af specifikke punkter i bughulen, hvor der er stor chance....../sorte) områder. I dag bruges FAST-skanning meget hyppigt indenfor human og veterinær akutmedicin. Det kan ses som et værktøj for dyrlæger som ikke arbejder med ultralyd til daglig. FAST-skanning har mange fordele; proceduren er effektiv og kan tage under 3 minutter, men har alligevel høj diagnostisk værdi. Det...... nødvendigt. Det skal dog understreges, at de abdominale organer ikke undersøges specifikt. Det kan være svært at skelne mellem væske i peritonealhulen og i det retroperitoneale rum. Man kan heller ikke karakterisere væsken og derved skelne mellem f.eks. blod, pus eller urin. Siden FAST-skanning blev...

  10. Fast ejendom

    DEFF Research Database (Denmark)

    Pagh, Peter

    Bogen omfatter en gennemgang af lovgivning, praksis og teori vedrørende køb af fast ejendom og offentligretlig og privatretlig regulering. Bogen belyser bl.a. de privatretlige emner: købers misligholdelsesbeføjelser, servitutter, naboret, hævd og erstatningsansvar for miljøskader samt den...

  11. ResBoost: characterizing and predicting catalytic residues in enzymes

    Directory of Open Access Journals (Sweden)

    Freund Yoav

    2009-06-01

    Full Text Available Abstract Background Identifying the catalytic residues in enzymes can aid in understanding the molecular basis of an enzyme's function and has significant implications for designing new drugs, identifying genetic disorders, and engineering proteins with novel functions. Since experimentally determining catalytic sites is expensive, better computational methods for identifying catalytic residues are needed. Results We propose ResBoost, a new computational method to learn characteristics of catalytic residues. The method effectively selects and combines rules of thumb into a simple, easily interpretable logical expression that can be used for prediction. We formally define the rules of thumb that are often used to narrow the list of candidate residues, including residue evolutionary conservation, 3D clustering, solvent accessibility, and hydrophilicity. ResBoost builds on two methods from machine learning, the AdaBoost algorithm and Alternating Decision Trees, and provides precise control over the inherent trade-off between sensitivity and specificity. We evaluated ResBoost using cross-validation on a dataset of 100 enzymes from the hand-curated Catalytic Site Atlas (CSA. Conclusion ResBoost achieved 85% sensitivity for a 9.8% false positive rate and 73% sensitivity for a 5.7% false positive rate. ResBoost reduces the number of false positives by up to 56% compared to the use of evolutionary conservation scoring alone. We also illustrate the ability of ResBoost to identify recently validated catalytic residues not listed in the CSA.

  12. Component-Minimized Buck-Boost Voltage Source Inverters

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede

    2007-01-01

    . In order to form a distinct neutral potential in the corresponding voltage boost circuitry for correct B4 inverter operation, necessary modifications are derived step by step. The resulted dc networks with symmetrical placement of passive components allow complete charging and equal energy distribution...... semiconductors. Besides the advantage of reduced active components, buck-boost B4 inverters use a little more passive components when compared with buck-boost B6 inverters, which would allow a selectable tradeoff in practice. Moreover, analysis for discontinuous conduction mode of inductor current reveals...

  13. SMART STRATEGY TO BOOST STUDENTS’ READING COMPREHENSION

    Directory of Open Access Journals (Sweden)

    Muhammad Lukman Syafi’i

    2015-05-01

    Full Text Available Reading as one of language skills plays significant roles in the teaching English as a foreign language. Since the teacher still uses the conventional way to teach reading, students‘ ability in reading comprehension seems still unsatisfactory yet. So, teacher should explore and develop new strategies. One of strategies in reading comprehension that can trigger our students to attain that purpose is SMART (Self Monitoring Approach for Reading and Thinking strategy. This study is developing SMART strategy to boost the reading comprehension achievement of the ninth grade students. The research applies a collaborative classroom action research design in which the researcher and the collaborative teacher work together in preparing a suitable procedure of SMART strategy, designing the lesson plan, determining the criteria of success, implementing the action, observing, and doing reflection. The finding indicated that SMART strategy was successful to enhance students‘ motivation to be actively involved in the instructional process. The improvement on the students‘ participation was 75% in Cycle 1 and 87% in Cycle 2.

  14. Designing boosting ensemble of relational fuzzy systems.

    Science.gov (United States)

    Scherer, Rafał

    2010-10-01

    A method frequently used in classification systems for improving classification accuracy is to combine outputs of several classifiers. Among various types of classifiers, fuzzy ones are tempting because of using intelligible fuzzy if-then rules. In the paper we build an AdaBoost ensemble of relational neuro-fuzzy classifiers. Relational fuzzy systems bond input and output fuzzy linguistic values by a binary relation; thus, fuzzy rules have additional, comparing to traditional fuzzy systems, weights - elements of a fuzzy relation matrix. Thanks to this the system is better adjustable to data during learning. In the paper an ensemble of relational fuzzy systems is proposed. The problem is that such an ensemble contains separate rule bases which cannot be directly merged. As systems are separate, we cannot treat fuzzy rules coming from different systems as rules from the same (single) system. In the paper, the problem is addressed by a novel design of fuzzy systems constituting the ensemble, resulting in normalization of individual rule bases during learning. The method described in the paper is tested on several known benchmarks and compared with other machine learning solutions from the literature.

  15. Subcellular localization prediction through boosting association rules.

    Science.gov (United States)

    Yoon, Yongwook; Lee, Gary Geunbae

    2012-01-01

    Computational methods for predicting protein subcellular localization have used various types of features, including N-terminal sorting signals, amino acid compositions, and text annotations from protein databases. Our approach does not use biological knowledge such as the sorting signals or homologues, but use just protein sequence information. The method divides a protein sequence into short $k$-mer sequence fragments which can be mapped to word features in document classification. A large number of class association rules are mined from the protein sequence examples that range from the N-terminus to the C-terminus. Then, a boosting algorithm is applied to those rules to build up a final classifier. Experimental results using benchmark datasets show our method is excellent in terms of both the classification performance and the test coverage. The result also implies that the $k$-mer sequence features which determine subcellular locations do not necessarily exist in specific positions of a protein sequence. Online prediction service implementing our method is available at http://isoft.postech.ac.kr/research/BCAR/subcell.

  16. RAMOBoost: Ranked Minority Oversampling in Boosting.

    Science.gov (United States)

    Chen, Sheng; He, Haibo; Garcia, Edwardo A

    2010-10-01

    In recent years, learning from imbalanced data has attracted growing attention from both academia and industry due to the explosive growth of applications that use and produce imbalanced data. However, because of the complex characteristics of imbalanced data, many real-world solutions struggle to provide robust efficiency in learning-based applications. In an effort to address this problem, this paper presents Ranked Minority Oversampling in Boosting (RAMOBoost), which is a RAMO technique based on the idea of adaptive synthetic data generation in an ensemble learning system. Briefly, RAMOBoost adaptively ranks minority class instances at each learning iteration according to a sampling probability distribution that is based on the underlying data distribution, and can adaptively shift the decision boundary toward difficult-to-learn minority and majority class instances by using a hypothesis assessment procedure. Simulation analysis on 19 real-world datasets assessed over various metrics-including overall accuracy, precision, recall, F-measure, G-mean, and receiver operation characteristic analysis-is used to illustrate the effectiveness of this method.

  17. Distinctiveness and the Attentional Boost Effect.

    Science.gov (United States)

    Smith, S Adam; Mulligan, Neil W

    2018-02-01

    The typical pattern of results in divided attention experiments is that subjects in a full attention (FA) condition perform markedly better on tests of memory than subjects in a divided attention (DA) condition which forces subjects to split their attention between studying to-be-remembered stimuli and completing some peripheral task. Nevertheless, recent research has revealed an exception wherein stimuli presented concurrently with targets in a detection task are better remembered than stimuli which co-occur with distractors. Research on this phenomenon-the Attentional Boost Effect (ABE)-has demonstrated that the ABE is reduced or eliminated for words made distinct by their word frequency or orthographic properties-forms of secondary distinctiveness. However, it is unclear how primary distinctiveness effects may interact with the ABE. The current study observed how perceptual and semantic manipulations of primary distinctiveness via the isolation paradigm interact with the ABE, and revealed these interactions to be fundamentally different than those of secondary distinctiveness. Specifically, whereas the effects of secondary distinctiveness in earlier studies were found to be redundant with the ABE, the current study demonstrated that items characterized by primary distinctiveness enhanced memory performance independently of the ABE. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. A boost for the ISOLDE beams

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    The first HIE-ISOLDE cryomodule was commissioned at the end of October. The radioactive ion beams can now be accelerated to 4.3 MeV per nucleon.   The ISOLDE beamline that supplies the Miniball array. The first HIE-ISOLDE cryomodule can be seen in the background, in its light-grey cryostat. ISOLDE is getting an energy boost. The first cryomodule of the new superconducting linear accelerator HIE-ISOLDE (High Intensity and Energy ISOLDE), located downstream of the REX-ISOLDE accelerator, increases the energy of the radioactive ion beams from 3 to 4.3 MeV per nucleon. It supplies the Miniball array, where an experiment using radioactive zinc ions (see box) began at the end of October. This is the first stage in the commissioning of HIE-ISOLDE. The facility will ultimately be equipped with four cryomodules that will accelerate the beams to 10 MeV per nucleon. Each cryomodule has five accelerating cavities and a solenoid, which focuses the beam. All of these components are superconducting. This first ...

  19. Evolution of magnetic flux ropes associated with flux transfer events and interplanetary magnetic clouds

    International Nuclear Information System (INIS)

    Wei, C.Q.; Lee, L.C.; Wang, S.; Akasofu, S.I.

    1991-01-01

    Spacecraft observations suggest that flux transfer events and interplanetary magnetic clouds may be associated with magnetic flux ropes which are magnetic flux tubes containing helical magnetic field lines. In the magnetic flux ropes, the azimuthal magnetic field (B θ ) is superposed on the axial field (B z ). In this paper the time evolution of a localized magnetic flux rope is studied. A two-dimensional compressible magnetohydrodynamic simulation code with a cylindrical symmetry is developed to study the wave modes associated with the evolution of flux ropes. It is found that in the initial phase both the fast magnetosonic wave and the Alfven wave are developed in the flux rope. After this initial phase, the Alfven wave becomes the dominant wave mode for the evolution of the magnetic flux rope and the radial expansion velocity of the flux rope is found to be negligible. Numerical results further show that even for a large initial azimuthal component of the magnetic field (B θ ≅ 1-4 B z ) the propagation velocity along the axial direction of the flux rope remains to be the Alfven velocity. Diagnoses show that after the initial phase the transverse kinetic energy equals the transverse magnetic energy, which is characteristic of the Alfven mode. It is also found that the localized magnetic flux rope tends to evolve into two separate magnetic ropes propagating in opposite directions. The simulation results are used to study the evolution of magnetic flux ropes associated with flux transfer events observed at the Earth's dayside magnetopause and magnetic clouds in the interplanetary space

  20. Clustering of Emerging Flux

    Science.gov (United States)

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  1. Boosting the Kerr geometry in an arbitrary direction

    Science.gov (United States)

    Balasin, Herbert; Nachbagauer, Herbert

    1996-04-01

    We construct ultrarelativistic Kerr geometries from their distributional energy - momentum tensors. The latter are obtained by boosting Kerr's distributional energy - momentum tensor in arbitrary directions, thereby generalizing previous work by the authors.

  2. Superconducting Electric Boost Pump for Nuclear Thermal Propulsion, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Design, fabrication, assembly and test of the Florida Turbine Technologies, Inc. (FTT) concept for a submersible, superconducting electric boost pump during Phase II...

  3. TOPOLOGICAL REVIEW AND ANALYSIS OF DC-DC BOOST CONVERTERS

    Directory of Open Access Journals (Sweden)

    V. INDRA GANDHI

    2017-06-01

    Full Text Available DC voltage boost up is essential in numerous applications; especially considering Photovoltaic (PV based renewable power generation system. The conventional DC-DC boost converter is the most admired configuration for this scheme, even if the converter efficiency is restricted at duty cycle near to maximum value. In order to find solution to the problem and improve its conversion capability, many converter configurations have been implemented so far. With this circumstance, this research work proposes to give overview of a few most imperative research works related to DC-DC boost converters. Some configurations are covered and classified basically based on the application. The major benefits and disadvantages related to the available techniques are also briefly conveyed. At last, a proper evaluation is recognized among the important types of DC-DC boost converters in terms of efficiency, number of components, and stability.

  4. Superconducting Electric Boost Pump for Nuclear Thermal Propulsion, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A submersible, superconducting electric boost pump sized to meet the needs of future Nuclear Thermal Propulsion systems in the 25,000 lbf thrust range is proposed....

  5. The Synergy Between PAV and AdaBoost.

    Science.gov (United States)

    Wilbur, W John; Yeganova, Lana; Kim, Won

    2005-11-01

    Schapire and Singer's improved version of AdaBoost for handling weak hypotheses with confidence rated predictions represents an important advance in the theory and practice of boosting. Its success results from a more efficient use of information in weak hypotheses during updating. Instead of simple binary voting a weak hypothesis is allowed to vote for or against a classification with a variable strength or confidence. The Pool Adjacent Violators (PAV) algorithm is a method for converting a score into a probability. We show how PAV may be applied to a weak hypothesis to yield a new weak hypothesis which is in a sense an ideal confidence rated prediction and that this leads to an optimal updating for AdaBoost. The result is a new algorithm which we term PAV-AdaBoost. We give several examples illustrating problems for which this new algorithm provides advantages in performance.

  6. Surface fluxes in heterogeneous landscape

    Energy Technology Data Exchange (ETDEWEB)

    Bay Hasager, C.

    1997-01-01

    The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and soil moisture information. (au) 10 tabs., 49 ills., 223 refs.

  7. 2001 BUDGET: Research Gets Hefty Boost in 2001 Defense Budget.

    Science.gov (United States)

    Malakoff, D

    2000-09-08

    Next year's $289 billion defense budget, which President Bill Clinton signed last month, includes big boosts for a host of science programs, from endangered species research to developing laser weapons. And with the two major presidential candidates pledging further boosts, the Pentagon's portfolio is attracting increasing attention from the life sciences community as well. But some analysts worry that Congress and the Pentagon may be shortchanging long-term, high-risk research in favor of projects with a more certain payoff.

  8. Searches with Boosted Objects at ATLAS and CMS

    CERN Document Server

    Behr, K; The ATLAS collaboration

    2014-01-01

    This talk presents an overview of searches for new physics in boosted final states conducted by the ATLAS and CMS experiments during Run-I of the LHC. An emphasis is put on techniques for the reconstruction and identification of both hadronic and leptonic decays of objects with large transverse momenta: Various substructure and grooming techniques as well as modified lepton isolation criteria are reviewed and their use in the most common algorithms for boosted top and boson tagging is discussed.

  9. Buck-Boost Current-Source Inverters With Diode-Inductor Network

    DEFF Research Database (Denmark)

    Gao, Feng; Liang, Chao; Loh, Poh Chiang

    2009-01-01

    This paper presents a number of novel currentsource inverters (CSIs) with enhanced current buck-boost capability. By adding a unique diode-inductor network between the inverter circuitry and current-boost elements, the proposed buck-boost CSIs demonstrate a doubling of current-boost capability...

  10. Are Quasar Jets Dominated by Poynting Flux?

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, M

    2005-02-02

    The formation of relativistic astrophysical jets is presumably mediated by magnetic fields threading accretion disks and central, rapidly rotating objects. As it is accelerated by magnetic stresses, the jet's kinetic energy flux grows at the expense of its Poynting flux. However, it is unclear how efficient is the conversion from magnetic to kinetic energy and whether there are any observational signatures of this process. We address this issue in the context of jets in quasars. Using data from all spatial scales, we demonstrate that in these objects the conversion from Poynting-flux-dominated to matter-dominated jets is very likely to take place closer to the black hole than the region where most of the Doppler boosted radiation observed in blazars is produced. We briefly discuss the possibility that blazar activity can be induced by global MHD instabilities, e.g., via the production of localized velocity gradients that lead to dissipative events such as shocks or magnetic reconnection, where acceleration of relativistic particles and production of non-thermal flares is taking place.

  11. Chemistry of fast electrons.

    Science.gov (United States)

    Maximoff, Sergey N; Head-Gordon, Martin P

    2009-07-14

    A chemicurrent is a flux of fast (kinetic energy approximately > 0.5-1.3 eV) metal electrons caused by moderately exothermic (1-3 eV) chemical reactions over high work function (4-6 eV) metal surfaces. In this report, the relation between chemicurrent and surface chemistry is elucidated with a combination of top-down phenomenology and bottom-up atomic-scale modeling. Examination of catalytic CO oxidation, an example which exhibits a chemicurrent, reveals 3 constituents of this relation: The localization of some conduction electrons to the surface via a reduction reaction, 0.5 O(2) + deltae(-) --> O(delta(-)) (Red); the delocalization of some surface electrons into a conduction band in an oxidation reaction, O(delta(-)) + CO --> CO(2)(delta-) --> CO(2) + deltae(-) (Ox); and relaxation without charge transfer (Rel). Juxtaposition of Red, Ox, and Rel produces a daunting variety of metal electronic excitations, but only those that originate from CO(2) reactive desorption are long-range and fast enough to dominate the chemicurrent. The chemicurrent yield depends on the universality class of the desorption process and the distribution of the desorption thresholds. This analysis implies a power-law relation with exponent 2.66 between the chemicurrent and the heat of adsorption, which is consistent with experimental findings for a range of systems. This picture also applies to other oxidation-reduction reactions over high work function metal surfaces.

  12. Fast calcium wave propagation mediated by electrically conducted excitation and boosted by CICR.

    NARCIS (Netherlands)

    Kusters, J.M.A.M.; Meerwijk, W.P. van; Ypey, D.L.; Theuvenet, A.P.R.; Gielen, C.C.A.M.

    2008-01-01

    We have investigated synchronization and propagation of calcium oscillations, mediated by gap junctional excitation transmission. For that purpose we used an experimentally based model of normal rat kidney (NRK) cells, electrically coupled in a one-dimensional configuration (linear strand).

  13. Prediction of heart disease using apache spark analysing decision trees and gradient boosting algorithm

    Science.gov (United States)

    Chugh, Saryu; Arivu Selvan, K.; Nadesh, RK

    2017-11-01

    Numerous destructive things influence the working arrangement of human body as hypertension, smoking, obesity, inappropriate medication taking which causes many contrasting diseases as diabetes, thyroid, strokes and coronary diseases. The impermanence and horribleness of the environment situation is also the reason for the coronary disease. The structure of Apache start relies on the evolution which requires gathering of the data. To break down the significance of use programming focused on data structure the Apache stop ought to be utilized and it gives various central focuses as it is fast in light as it uses memory worked in preparing. Apache Spark continues running on dispersed environment and chops down the data in bunches giving a high profitability rate. Utilizing mining procedure as a part of the determination of coronary disease has been exhaustively examined indicating worthy levels of precision. Decision trees, Neural Network, Gradient Boosting Algorithm are the various apache spark proficiencies which help in collecting the information.

  14. Compact neutron flux monitor

    International Nuclear Information System (INIS)

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  15. Measurement of fast neutron background in SAGE

    CERN Document Server

    Abdurashitov, J N; Kalikhov, A V; Matushko, V L; Shikhin, A A; Yants, V E; Zaborskaia, O S

    2002-01-01

    The spectrometer intended for direct measurements of ultra low fluxes of fast neutrons is described. It is sensitive to neutron fluxes of 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 and lower. The detection efficiency of fast neutrons with simultaneous energy measurement was determined from Monte-Carlo simulation to be equal to 0.11 +- 0.01. The background counting rate in the detector corresponds to a neutron flux of (6.5 +- 2.1) x 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The natural neutron flux from the surrounding mine rock at the depth of 4700 meters of water equivalent was measured to be (7.3 +- 2.4) x 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The flux of fast neutrons in the SAGE main room was measured to be < 2.3 x 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in 1.0-11.0 MeV energy range.

  16. Estimation of reliability of a interleaving PFC boost converter

    Directory of Open Access Journals (Sweden)

    Gulam Amer Sandepudi

    2010-01-01

    Full Text Available Reliability plays an important role in power supplies. For other electronic equipment, a certain failure mode, at least for a part of the total system, can often be employed without serious (critical effects. However, for power supply no such condition can be accepted, since very high demands on its reliability must be achieved. At higher power levels, the continuous conduction mode (CCM boost converter is preferred topology for implementation a front end with PFC. As a result, significant efforts have been made to improve the performance of high boost converter. This paper is one of the efforts for improving the performance of the converter from the reliability point of view. In this paper, interleaving boost power factor correction converter is simulated with single switch in continuous conduction mode (CCM, discontinuous conduction mode (DCM and critical conduction mode (CRM under different output power ratings. Results of the converter are explored from reliability point of view.

  17. Radiotherapy Boost Following Conservative Surgery for Locally Advanced Breast Cancer

    International Nuclear Information System (INIS)

    Cendales, Ricardo; Ospino, Rosalba; Torres, Felipe; Cotes, Martha

    2009-01-01

    Nearly half of breast cancer patients in developing countries present with a locally advanced cancer. Treatment is centered on a multimodal approach based on chemotherapy, surgery and radiotherapy. The growing use of neoadjuvant chemotherapy has led to a more conservative surgical approach; nonetheless, it is not yet considered as a standard. There are no clear recommendations on the use of a radiotherapy boost in such situation. A Medline search was developed. Most articles are retrospective series. Survival free of locoregional relapse in patients treated with neoadjuvant chemotherapy, breast conserving surgery and radiotherapy is good. All articles described a boost administered to nearly all patients without regard to their prognostic factors, given that a locally advanced tumor is already considered as a poor prognostic factor. Even tough the poor level of evidence, a recommendation can be made: radiotherapy boost should be administered to all patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and breast conserving surgery.

  18. Boosted black holes on Kaluza-Klein bubbles

    International Nuclear Information System (INIS)

    Iguchi, Hideo; Mishima, Takashi; Tomizawa, Shinya

    2007-01-01

    We construct an exact stationary solution of black-hole-bubble sequence in the five-dimensional Kaluza-Klein theory by using solitonic solution-generating techniques. The solution describes two stationary black holes with topology S 3 on a Kaluza-Klein bubble and has a linear momentum component in the compactified direction. We call the solution boosted black holes on Kaluza-Klein bubble because it has the linear momentum. The Arnowitt-Deser-Misner mass and the linear momentum depend on the two boosted velocity parameters of black holes. In the effective four-dimensional theory, the solution has an electric charge which is proportional to the linear momentum. The solution includes the static solution found by Elvang and Horowitz. The small and the big black holes limits are investigated. The relation between the solution and the single boosted black string are considered

  19. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-05-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  20. Performance of Boosted W Boson Identification with the ATLAS Detector

    CERN Document Server

    The ATLAS collaboration

    2014-01-01

    This note presents the performance of a variety of techniques used to identify highly- boosted hadronically-decaying $W$ bosons. The studies presented here are divided into two parts: the first is based on Monte Carlo simulation, and the second compares the simulations to 20.3$\\pm$0.6 fb$^{-1}$ of proton-–proton collisions data collected by the ATLAS detector in 2012 at $\\sqrt{s} = 8$ TeV. Various tagging approaches and different grooming algorithms are compared in simulation, using a signal of large-$R$ jets containing a highly boosted $W$ boson and a background of large-$R$ jets originating from high-momentum light quarks or gluons. These techniques could also be utilised to identify hadronic decays of boosted $Z$ and Higgs bosons. A sample enriched in $t\\bar{t}\\to (W^+b)(W^-\\bar{b}) \\to (q\\bar{q}b)(\\mu \\bar{\

  1. Video Meteor Fluxes

    Science.gov (United States)

    Campbell-Brown, M. D.; Braid, D.

    2011-01-01

    The flux of meteoroids, or number of meteoroids per unit area per unit time, is critical for calibrating models of meteoroid stream formation and for estimating the hazard to spacecraft from shower and sporadic meteors. Although observations of meteors in the millimetre to centimetre size range are common, flux measurements (particularly for sporadic meteors, which make up the majority of meteoroid flux) are less so. It is necessary to know the collecting area and collection time for a given set of observations, and to correct for observing biases and the sensitivity of the system. Previous measurements of sporadic fluxes are summarized in Figure 1; the values are given as a total number of meteoroids striking the earth in one year to a given limiting mass. The Gr n et al. (1985) flux model is included in the figure for reference. Fluxes for sporadic meteoroids impacting the Earth have been calculated for objects in the centimeter size range using Super-Schmidt observations (Hawkins & Upton, 1958); this study used about 300 meteors, and used only the physical area of overlap of the cameras at 90 km to calculate the flux, corrected for angular speed of meteors, since a large angular speed reduces the maximum brightness of the meteor on the film, and radiant elevation, which takes into account the geometric reduction in flux when the meteors are not perpendicular to the horizontal. They bring up corrections for both partial trails (which tends to increase the collecting area) and incomplete overlap at heights other than 90 km (which tends to decrease it) as effects that will affect the flux, but estimated that the two effects cancelled one another. Halliday et al. (1984) calculated the flux of meteorite-dropping fireballs with fragment masses greater than 50 g, over the physical area of sky accessible to the MORP fireball cameras, counting only observations in clear weather. In the micron size range, LDEF measurements of small craters on spacecraft have been used to

  2. Self-boosting vaccines and their implications for herd immunity.

    Science.gov (United States)

    Arinaminpathy, Nimalan; Lavine, Jennie S; Grenfell, Bryan T

    2012-12-04

    Advances in vaccine technology over the past two centuries have facilitated far-reaching impact in the control of many infections, and today's emerging vaccines could likewise open new opportunities in the control of several diseases. Here we consider the potential, population-level effects of a particular class of emerging vaccines that use specific viral vectors to establish long-term, intermittent antigen presentation within a vaccinated host: in essence, "self-boosting" vaccines. In particular, we use mathematical models to explore the potential role of such vaccines in situations where current immunization raises only relatively short-lived protection. Vaccination programs in such cases are generally limited in their ability to raise lasting herd immunity. Moreover, in certain cases mass vaccination can have the counterproductive effect of allowing an increase in severe disease, through reducing opportunities for immunity to be boosted through natural exposure to infection. Such dynamics have been proposed, for example, in relation to pertussis and varicella-zoster virus. In this context we show how self-boosting vaccines could open qualitatively new opportunities, for example by broadening the effective duration of herd immunity that can be achieved with currently used immunogens. At intermediate rates of self-boosting, these vaccines also alleviate the potential counterproductive effects of mass vaccination, through compensating for losses in natural boosting. Importantly, however, we also show how sufficiently high boosting rates may introduce a new regime of unintended consequences, wherein the unvaccinated bear an increased disease burden. Finally, we discuss important caveats and data needs arising from this work.

  3. The Lateral Decubitus Breast Boost: Description, Rationale, and Efficacy

    International Nuclear Information System (INIS)

    Ludwig, Michelle S.; McNeese, Marsha D.; Buchholz, Thomas A.; Perkins, George H.; Strom, Eric A.

    2010-01-01

    Purpose: To describe and evaluate the modified lateral decubitus boost, a breast irradiation technique. Patients are repositioned and resimulated for electron boost to minimize the necessary depth for the electron beam and optimize target volume coverage. Methods and Materials: A total of 2,606 patients were treated with post-lumpectomy radiation at our institution between January 1, 2000, and February 1, 2008. Of these, 231 patients underwent resimulation in the lateral decubitus position with electron boost. Distance from skin to the maximal depth of target volume was measured in both the original and boost plans. Age, body mass index (BMI), boost electron energy, and skin reaction were evaluated. Results: Resimulation in the lateral decubitus position reduced the distance from skin to maximal target volume depth in all patients. Average depth reduction by repositioning was 2.12 cm, allowing for an average electron energy reduction of approximately 7 MeV. Mean skin entrance dose was reduced from about 90% to about 85% (p < 0.001). Only 14 patients (6%) experienced moist desquamation in the boost field at the end of treatment. Average BMI of these patients was 30.4 (range, 17.8-50.7). BMI greater than 30 was associated with more depth reduction by repositioning and increased risk of moist desquamation. Conclusions: The lateral decubitus position allows for a decrease in the distance from the skin to the target volume depth, improving electron coverage of the tumor bed while reducing skin entrance dose. This is a well-tolerated regimen for a patient population with a high BMI or deep tumor location.

  4. Boosted Objects: A Probe of Beyond the Standard Model Physics

    Energy Technology Data Exchange (ETDEWEB)

    Abdesselam, A.; /Oxford U.; Kuutmann, E.Bergeaas; /DESY; Bitenc, U.; /Freiburg U.; Brooijmans, G.; /Columbia U.; Butterworth, J.; /University Coll. London; Bruckman de Renstrom, P.; /Cracow, INP; Buarque Franzosi, D.; /Turin U.; Buckingham, R.; /Oxford U.; Chapleau, B.; /McGill U.; Dasgupta, M.; /Manchester U.; Davison, A.; /University Coll. London; Dolen, J.; /UC, Davis; Ellis, S.; /Washington U., Seattle; Fassi, F.; /Lyon, IPN; Ferrando, J.; /Oxford U.; Frandsen, M.T.; /Oxford U.; Frost, J.; /Cambridge U.; Gadfort, T.; /Brookhaven; Glover, N.; /Durham U.; Haas, A.; /SLAC; Halkiadakis, E.; /Rutgers U., Piscataway /INFN, Milan Bicocca /Oxford U. /Ohio State U. /Rutherford /Oxford U. /Oxford U. /Maryland U. /Bristol U. /Princeton U. /Oxford U. /Oxford U. /Arizona U. /Johns Hopkins U. /Oxford U. /Fermilab /Rutherford /Bristol U. /Karlsruhe U., EKP /Weizmann Inst. /Washington U., Seattle /Johns Hopkins U. /Oslo U. /Durham U. /Princeton U. /Paris, LPTHE /CERN /Southern Denmark U., CP3-Origins /Granada U. /SLAC /Rutherford /Toronto U. /Stockholm U., OKC /Stockholm U. /Yale U.; /more authors..

    2012-06-12

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.

  5. A Two-Stage Wind Grid Inverter with Boost Converter

    OpenAIRE

    Che, Yanbo; Zhang, Wen; Ge, Leijiao; Zhang, Jijie

    2014-01-01

    At present, the conversion efficiency of commercial small wind grid inverter is low, and, in case of low wind speed, the wind energy cannot be used efficiently. In order to resolve this problem, it is necessary to improve the topological structure and control strategy, and design a new small wind grid inverter. In this paper, we apply a two-voltage stage topology with boost converter. The boost circuit is to achieve the maximum power output of the wind energy by the segmented regulation, whil...

  6. Boosted objects: a probe of beyond the Standard Model physics

    CERN Document Server

    Abdesselam, A; Bitenc, U; Brooijmans, G; Butterworth, J; Bruckman de Renstrom, P; Buarque Franzosi, D; Buckingham, R; Chapleau, B; Dasgupta, M; Davison, A; Dolen, J; Ellis, S; Fassi, F; Ferrando, J; Frandsen, M T; Frost, J; Gadfort, T; Glover, N; Haas, A; Halkiadakis, E; Hamilton, K; Hays, C; Hill, C; Jackson, J; Issever, C; Karagoz, M; Katz, A; Kreczko, L; Krohn, D; Lewis, A; Livermore, S; Loch, P; Maksimovic, P; March-Russell, J; Martin, A; McCubbin, N; Newbold, D; Ott, J; Perez, G; Policchio, A; Rappoccio, S; Raklev, A R; Richardson, P; Salam, G P; Sannino, F; Santiago, J; Schwartzman, A; Shepherd-Themistocleous, C; Sinervo, P; Sjoelin, J; Son, M; Spannowsky, M; Strauss, E; Takeuchi, M; Tseng, J; Tweedie, B; Vermillion, C; Voigt, J; Vos, M; Wacker, J; Wagner-Kuhr, J; Wilson, M G

    2011-01-01

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.

  7. Solar Magnetic Flux Ropes

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fill the whole volume of a dark coronal cavity. The flux ropes can be in stable equilibrium in the coronal magnetic field for weeks and even months, but suddenly they lose their stability and erupt with ...

  8. Turbulent fluxes by "Conditional Eddy Sampling"

    Science.gov (United States)

    Siebicke, Lukas

    2015-04-01

    Turbulent flux measurements are key to understanding ecosystem scale energy and matter exchange, including atmospheric trace gases. While the eddy covariance approach has evolved as an invaluable tool to quantify fluxes of e.g. CO2 and H2O continuously, it is limited to very few atmospheric constituents for which sufficiently fast analyzers exist. High instrument cost, lack of field-readiness or high power consumption (e.g. many recent laser-based systems requiring strong vacuum) further impair application to other tracers. Alternative micrometeorological approaches such as conditional sampling might overcome major limitations. Although the idea of eddy accumulation has already been proposed by Desjardin in 1972 (Desjardin, 1977), at the time it could not be realized for trace gases. Major simplifications by Businger and Oncley (1990) lead to it's widespread application as 'Relaxed Eddy Accumulation' (REA). However, those simplifications (flux gradient similarity with constant flow rate sampling irrespective of vertical wind velocity and introduction of a deadband around zero vertical wind velocity) have degraded eddy accumulation to an indirect method, introducing issues of scalar similarity and often lack of suitable scalar flux proxies. Here we present a real implementation of a true eddy accumulation system according to the original concept. Key to our approach, which we call 'Conditional Eddy Sampling' (CES), is the mathematical formulation of conditional sampling in it's true form of a direct eddy flux measurement paired with a performant real implementation. Dedicated hardware controlled by near-real-time software allows full signal recovery at 10 or 20 Hz, very fast valve switching, instant vertical wind velocity proportional flow rate control, virtually no deadband and adaptive power management. Demonstrated system performance often exceeds requirements for flux measurements by orders of magnitude. The system's exceptionally low power consumption is ideal

  9. Facility effluent monitoring plan for the fast flux test facility

    International Nuclear Information System (INIS)

    Nickels, J.M.; Dahl, N.R.

    1992-11-01

    A facility effluent monitoring plan is required by the US Department of Energy in US Department of Energy Order 5400.1 for any operations that involve hazardous materials and radioactive substances that could affect employee or public safety or the environment. A Facility Effluent Monitoring Plan determination was performed during calendar year 1991 and the evaluation requires the need for a facility effluent monitoring plan. This facility effluent monitoring plan assesses effluent monitoring systems and evaluates whether they are adequate to ensure the public health and safety as specified in applicable federal, state, and local requirements

  10. Fast Flux Test Facility (FFTF) feedback reactivity components

    International Nuclear Information System (INIS)

    Nguyen, D.H.

    1988-04-01

    The static tests conducted during Cycle 8A (1986) of the FFTF have allowed, for the first time, the experimental determination of each of the feedback reactivities caused by the following mechanisms: fuel axial expansion, control rod repositioning, core radial expansion, and subassembly bowing. A semiempirical equation was obtained to describe each of these feedback components that depended only on the relevant reactor temperature (bowing was presented in a tabular form). The Doppler and sodium density reactivities were calculated using existing mechanistic methods. Although they could also be fitted with closed-form equations depending only on temperatures, these equations are not needed in transient analyses using whole core safety computer codes, which use mechanistic methods. The static feedback reactivity model was extended to obtain a dynamic model via the concept of ''time constants.'' Besides being used for transient analyses in the FFTF, these feedback equations constitute a database for the validation and/or calibration of mechanistic feedback reactivity models. 2 refs., 6 tabs

  11. Safety evaluation report. Fast Flux Test Facility. Project No. 448

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    Information on the safety of the FFTF Reactor is presented under the following chapter headings: site characteristics; design of structures, components, equipment, and systems; reactor; reactor coolant system and connected systems; engineered safety features; electric power; auxiliary systems; radioactive waste management systems; radiation protection; conduct of operations; initial test programs; accident analysis; and quality assurance.

  12. Safety evaluation report. Fast Flux Test Facility. Project No. 448

    International Nuclear Information System (INIS)

    1978-01-01

    Information on the safety of the FFTF Reactor is presented under the following chapter headings: site characteristics; design of structures, components, equipment, and systems; reactor; reactor coolant system and connected systems; engineered safety features; electric power; auxiliary systems; radioactive waste management systems; radiation protection; conduct of operations; initial test programs; accident analysis; and quality assurance

  13. Fast flux test facility performance monitoring management information, July 1988

    Energy Technology Data Exchange (ETDEWEB)

    Newland, D J

    1988-08-01

    The purpose of this report is to provide management with performance data on key performance indicators selected from the FFTF Early Warning System performance indicators. This report contains the results for key performance indicators divided into two categories of ``overall`` and ``other.`` The ``overall`` performance indicators, when considered in the aggregate, provide one means of monitoring overall plant performance. The data should be used in conjunction with the results of other management assessment activities to focus improvement efforts. Use of these key performance indicators as a group is stressed, since focusing on a single indicator or a narrow set of indicators can be counterproductive both to safety and to long-term performance improvement.

  14. Fast flux test facility performance monitoring management information, May 1988

    Energy Technology Data Exchange (ETDEWEB)

    Newland, D J

    1988-06-01

    The plant operated at full power until May 6 when it was shut down for a planned outage for refueling and maintenance. The success of outage activity placed it slightly ahead of the 37-day outage schedule at month`s end. Operational efficiency in May was again 100%. The plant has operated over 110 effective full power days this year through Cycle 10A. As a result, the plant remains on target for meeting the 96% Operational Efficiency Factor and 70% Capacity Factor goals for 1988. Focus on outage activity resulted in little progress on further reduction of maintenance backlogs. An unfavorable trend was experienced in spare parts availability and a slight increase in overdue commitments. Otherwise, there were no significant trends apparent in May.

  15. Fast flux test facility final safety analysis report amendment 79

    International Nuclear Information System (INIS)

    Dautel, W.A.

    1999-01-01

    This document is provided to replace, remove, or add applicable pages to the chapters on: Heat Transport System; Containment and Structures; Auxiliary Systems; Reactor Refueling System; Conduct of Operations; Safety Analysis; Quality Assurance; FFTF Criticality Specifications; and Appendix H's TRIGA Fuel Storage System

  16. Experience in startup and operation of fast flux facility

    International Nuclear Information System (INIS)

    Moffitt, W.C.

    1980-01-01

    The testing program was structured to perform all testing under formal testing procedures with a test engineer as the test director and the plant operators operating the systems and equipment. This provided excellent training and experience for the operators in preparation for eventual reactor operation. Operations preparations for the testing and operation activities has consisted of academic training, formal on-the-job training including systems operation and examinations by persons with an expert knowledge on that portion of the plant, training at EBR-II and the High Temperature Sodium Facility for selected senior operators, operating procedure preparation, training on an FFTF Control Room operator training simulator, and formal written, oral and operating examinations

  17. Simulation of the space-time evolution of color-flux tubes (guidelines to the TERMITE program)

    International Nuclear Information System (INIS)

    Dyrek, A.

    1990-08-01

    We give the description of the computer program which simulates boost-invariant evolution of color-flux tubes in high-energy processes. The program provides a graphic demonstration of space-time trajectories of created particles and can also be used as Monte-Carlo generator of events. (author)

  18. Standardized Automated CO2/H2O Flux Systems for Individual Research Groups and Flux Networks

    Science.gov (United States)

    Burba, George; Begashaw, Israel; Fratini, Gerardo; Griessbaum, Frank; Kathilankal, James; Xu, Liukang; Franz, Daniela; Joseph, Everette; Larmanou, Eric; Miller, Scott; Papale, Dario; Sabbatini, Simone; Sachs, Torsten; Sakai, Ricardo; McDermitt, Dayle

    2017-04-01

    models, and the improvements focused on increased stability in the presence of contamination, refining temperature control and compensation, and providing more accurate fast gas concentration measurements. In terms of the flux calculations, improvements focused on automating the on-site flux calculations using EddyPro® software run by a weatherized fully digital microcomputer, SmartFlux2. In terms of site management and data sharing, the development focused on web-based software, FluxSuite, which allows real-time station monitoring and data access by multiple users. The presentation will describe details for the key developments and will include results from field tests of the RS gas analyzer models in comparison with older models and control reference instruments.

  19. Fast Convolution Module (Fast Convolution Module)

    National Research Council Canada - National Science Library

    Bierens, L

    1997-01-01

    This report describes the design and realisation of a real-time range azimuth compression module, the so-called 'Fast Convolution Module', based on the fast convolution algorithm developed at TNO-FEL...

  20. Boosted jet identification using particle candidates and deep neural networks

    CERN Document Server

    CMS Collaboration

    2017-01-01

    This note presents developments for the identification of hadronically decaying top quarks using deep neural networks in CMS. A new method that utilizes one dimensional convolutional neural networks based on jet constituent particles is proposed. Alternative methods using boosted decision trees based on jet observables are compared. The new method shows significant improvement in performance.

  1. Integrated Current Balancing Transformer for Primary Parallel Isolated Boost Converter

    DEFF Research Database (Denmark)

    Sen, Gökhan; Ouyang, Ziwei; Thomsen, Ole Cornelius

    2011-01-01

    A simple, PCB compatible integrated solution is proposed for the current balancing requirement of the primary parallel isolated boost converter (PPIBC). Input inductor and the current balancing transformer are merged into the same core, which reduces the number of components allowing a cheaper an...

  2. Biochar boosts tropical but not temperate crop yields

    NARCIS (Netherlands)

    Jeffery, Simon; Abalos Rodriguez, Diego; Prodana, Marija; Bastos, Ana Catarina; Groenigen, van Jan Willem; Hungate, Bruce A.; Verheijen, Frank

    2017-01-01

    Applying biochar to soil is thought to have multiple benefits, from helping mitigate climate change [1, 2], to managing waste [3] to conserving soil [4]. Biochar is also widely assumed to boost crop yield [5, 6], but there is controversy regarding the extent and cause of any yield benefit [7].

  3. Solar-Based Boost Differential Single Phase Inverter | Eya | Nigerian ...

    African Journals Online (AJOL)

    ... current concurrently and finally, it is portable. This research also shows the disparity between the simulated results of open loop and closed loop of boost differential inverter systems. The dc power source is photovoltaic cell. The maximum power point tracker is in-cooperated in capturing the maximum power from the sun.

  4. Boosting food security in sub-Saharan Africa through cassava ...

    African Journals Online (AJOL)

    Boosting food security in sub-Saharan Africa through cassava production: a case study of Nigeria. ... Nigerian Journal of Economic History ... The paper argues that cassava which is widely grown in Sub-Saharan Africa with a lot of variety of food derivatives from it can reduce to the barest minimum the present state of food ...

  5. HIV-prevention studies: Educate smarter, boost women's earning ...

    African Journals Online (AJOL)

    the 'very hard-to-reach' youth of informal settlements countrywide. 'Although it was done in a small community, we need to think of feasible ways in which we can ... strewn about below the condocans, perhaps indicating the community's. HIV-prevention studies: Educate smarter, boost women's earning power. Professor ...

  6. Adaptive Kernel in Meshsize Boosting Algorithm in KDE ...

    African Journals Online (AJOL)

    This paper proposes the use of adaptive kernel in a meshsize boosting algorithm in kernel density estimation. The algorithm is a bias reduction scheme like other existing schemes but uses adaptive kernel instead of the regular fixed kernels. An empirical study for this scheme is conducted and the findings are comparatively ...

  7. Adaptive Kernel In The Bootstrap Boosting Algorithm In KDE ...

    African Journals Online (AJOL)

    This paper proposes the use of adaptive kernel in a bootstrap boosting algorithm in kernel density estimation. The algorithm is a bias reduction scheme like other existing schemes but uses adaptive kernel instead of the regular fixed kernels. An empirical study for this scheme is conducted and the findings are comparatively ...

  8. Characteristics of thermalization of boost-invariant plasma from holography

    NARCIS (Netherlands)

    Heller, M.P.; Janik, R.A.; Witaszczyk, P.

    2012-01-01

    We report on the approach toward the hydrodynamic regime of boost-invariant N=4 super Yang-Mills plasma at strong coupling starting from various far-from-equilibrium states at τ=0. The results are obtained through a numerical solution of Einstein’s equations for the dual geometries, as described in

  9. Congress OKs $2 Billion Boost for the NIH.

    Science.gov (United States)

    2017-07-01

    President Donald Trump last week signed a $1.1 trillion spending bill for fiscal year 2017, including a welcome $2 billion boost for the NIH that will support former Vice President Joe Biden's Cancer Moonshot initiative, among other priorities. However, researchers who rely heavily on NIH grant funding remain concerned about proposed cuts for 2018. ©2017 American Association for Cancer Research.

  10. Higher-Order Hybrid Gaussian Kernel in Meshsize Boosting Algorithm

    African Journals Online (AJOL)

    In this paper, we shall use higher-order hybrid Gaussian kernel in a meshsize boosting algorithm in kernel density estimation. Bias reduction is guaranteed in this scheme like other existing schemes but uses the higher-order hybrid Gaussian kernel instead of the regular fixed kernels. A numerical verification of this scheme ...

  11. A THREE-PHASE BOOST DC-AC CONVERTER

    African Journals Online (AJOL)

    - strate the feasibility of the proposed three-phase inverter. The inverter is intended to be used in three-phase electric drives and uninterruptible power supply (UPS) systems. Keywords: Boost converter, three-phase dc-ac converter, sliding ...

  12. Multistage switched inductor boost converter for renewable energy application

    DEFF Research Database (Denmark)

    Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Bhaskar, Mahajan Sagar

    2017-01-01

    In this paper Multistage Switched Inductor Boost Converter (Multistage SIBC) is uttered for renewable energy applications. The projected converter is derived from an amalgamation of the conventional step-up converter and inductor stack. The number of inductor and duty ratio decides the overall...

  13. Primary Parallel Isolated Boost Converter with Bidirectional Operation

    DEFF Research Database (Denmark)

    Hernandez Botella, Juan Carlos; Mira Albert, Maria del Carmen; Sen, Gökhan

    2012-01-01

    This paper presents a bidirectional dc/dc converter operated with batteries both in the input and output. Primary parallel isolated boost converter (PPIBC) with transformer series connection on the high voltage side is preferred due to its ability to handle high currents in the low voltage side...

  14. Boost IORT in Breast Cancer: Body of Evidence

    Directory of Open Access Journals (Sweden)

    Felix Sedlmayer

    2014-01-01

    Full Text Available The term IORT (intraoperative radiotherapy is currently used for various techniques that show decisive differences in dose delivery. The largest evidence for boost IORT preceding whole breast irradiation (WBI originates from intraoperative electron treatments with single doses around 10 Gy, providing outstandingly low local recurrence rates in any risk constellation also at long term analyses. Compared to other boost methods, an intraoperative treatment has evident advantages as follows. Precision. Direct visualisation of the tumour bed during surgery guarantees an accurate dose delivery. This fact has additionally gained importance in times of primary reconstruction techniques after lumpectomy to optimise cosmetic outcome. IORT is performed before breast tissue is mobilised for plastic purposes. Cosmesis. As a consequence of direct tissue exposure without distension by hematoma/seroma, IORT allows for small treatment volumes and complete skin sparing, both having a positive effect on late tissue tolerance and, hence, cosmetic appearance. Patient Comfort. Boost IORT marginally prolongs the surgical procedure, while significantly shortening postoperative radiotherapy. Its combination with a 3-week hypofractionated external beam radiotherapy to the whole breast (WBI is presently tested in the HIOB trial (hypofractionated WBI preceded by IORT electron boost, a prospective multicenter trial of the International Society of Intraoperative Radiotherapy (ISIORT.

  15. Tricky treats: how and when temptations boost self-control

    NARCIS (Netherlands)

    Kroese, F.M.|info:eu-repo/dai/nl/313869871

    2012-01-01

    The overall aim of this dissertation was to explore how and when temptations boost self-control. More specifically, we aimed to a) replicate and extend previous findings showing that temptations yield enhanced self-control on cognitive as well as behavioral measures; b) examine the role of

  16. 438 Adaptive Kernel in Meshsize Boosting Algorithm in KDE (Pp ...

    African Journals Online (AJOL)

    FIRST LADY

    2011-01-18

    Jan 18, 2011 ... Birke, Melanie (2009). “Shape constrained KDE.” Journal of Statistical. Planning & Inference, vol 139, issue 8 , August 2009, pg 2851 –. 2862. Duffy, N. and Hemlbold, D. (2000). “Potential bosters? Advances in Neural info.” Proc. Sys. 12, 258 – 264. Freund, Y. (1995). “Boosting a Weak Learning Algorithm ...

  17. Search for new resonances with boosted signatures at CMS

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    The LHC and its experiments are ideally suited to search for these new resonances in order to validate or constrain the corresponding theories. At resonance masses well above 1 TeV, these searches face specific challenges. The decay products have large Lorentz boosts, resulting in very collimated final state topologies. Jet substructure methods and the use of non-isolate...

  18. Modeling and Control of Primary Parallel Isolated Boost Converter

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Hernandez Botella, Juan Carlos; Sen, Gökhan

    2012-01-01

    In this paper state space modeling and closed loop controlled operation have been presented for primary parallel isolated boost converter (PPIBC) topology as a battery charging unit. Parasitic resistances have been included to have an accurate dynamic model. The accuracy of the model has been...

  19. A new disjunct eddy-covariance system for BVOC flux measurements - validation on CO2 and H2O fluxes

    Science.gov (United States)

    Baghi, R.; Durand, P.; Jambert, C.; Jarnot, C.; Delon, C.; Serça, D.; Striebig, N.; Ferlicoq, M.; Keravec, P.

    2012-12-01

    The disjunct eddy covariance (DEC) method is an interesting alternative to the conventional eddy covariance (EC) method because it allows the estimation of turbulent fluxes of species for which fast sensors are not available. We have developed and validated a new disjunct sampling system (called MEDEE). This system is built with chemically inert materials. Air samples are taken quickly and alternately in two cylindrical reservoirs, the internal pressures of which are regulated by a moving piston. The MEDEE system was designed to be operated either on the ground or aboard an aircraft. It is also compatible with most analysers since it transfers the air samples at a regulated pressure. To validate the system, DEC and EC measurements of CO2 and latent heat fluxes were performed concurrently during a field campaign. EC fluxes were first compared to simulated DEC (SDEC) fluxes and then to actual DEC fluxes. Both the simulated and actual DEC fluxes showed a good agreement with EC fluxes in terms of correlation. The determination coefficients (R2) were 0.93 and 0.91 for DEC and SDEC latent heat fluxes, respectively. For DEC and SDEC CO2 fluxes R2 was 0.69 in both cases. The conditions of low fluxes experienced during the campaign impaired the comparison of the different techniques especially for CO2 flux measurements. Linear regression analysis showed an 14% underestimation of DEC fluxes for both CO2 and latent heat compared to EC fluxes. A first field campaign, focusing on biogenic volatile organic compound (BVOC) emissions, was carried out to measure isoprene fluxes above a downy oak (Quercus Pubescens) forest in the south-east of France. The measured standard emission rate was in the lower range of reported values in earlier studies. Further analysis will be conducted through ground-based and airborne campaigns in the coming years.

  20. Directed flux motor

    Science.gov (United States)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  1. Production flux of sea spray aerosol

    Energy Technology Data Exchange (ETDEWEB)

    de Leeuw, G.; Lewis, E.; Andreas, E. L.; Anguelova, M. D.; Fairall, C. W.; O’Dowd, C.; Schulz, M.; Schwartz, S. E.

    2011-05-07

    Knowledge of the size- and composition-dependent production flux of primary sea spray aerosol (SSA) particles and its dependence on environmental variables is required for modeling cloud microphysical properties and aerosol radiative influences, interpreting measurements of particulate matter in coastal areas and its relation to air quality, and evaluating rates of uptake and reactions of gases in sea spray drops. This review examines recent research pertinent to SSA production flux, which deals mainly with production of particles with r{sub 80} (equilibrium radius at 80% relative humidity) less than 1 {micro}m and as small as 0.01 {micro}m. Production of sea spray particles and its dependence on controlling factors has been investigated in laboratory studies that have examined the dependences on water temperature, salinity, and the presence of organics and in field measurements with micrometeorological techniques that use newly developed fast optical particle sizers. Extensive measurements show that water-insoluble organic matter contributes substantially to the composition of SSA particles with r{sub 80} < 0.25 {micro}m and, in locations with high biological activity, can be the dominant constituent. Order-of-magnitude variation remains in estimates of the size-dependent production flux per white area, the quantity central to formulations of the production flux based on the whitecap method. This variation indicates that the production flux may depend on quantities such as the volume flux of air bubbles to the surface that are not accounted for in current models. Variation in estimates of the whitecap fraction as a function of wind speed contributes additional, comparable uncertainty to production flux estimates.

  2. EXPERIMENTAL VALIDATION OF A DUAL LOOP CONTROL OF TWO PHASES INTERLEAVED BOOST CONVERTER FOR FUEL CELL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    O. Kraa

    2016-05-01

    Full Text Available In this paper, a modelling, an implementation and a control of a dc-dc converter structure called “two phases Interleaved Boost Converter (IBC” will be presented. This topology is widely used in order to reduce the input current ripples and the size of passive component with high efficiency. The control of the IBC converter is designed by dual loop control that contains a voltage loop with a linear PI controller and a fast current loop with a non-linear sliding controller to ensure a good tracking in steady state and fast performance in transient state. The proposed control loop has been validated, first by the simulation results under Matlab-Simulink and after by the experimental results using a small-scale test bench with the dSPACE-1104 card.

  3. Wide Temperature Range DC-DC Boost Converters for Command/Control/Drive Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We shall develop wide temperature range DC-DC boost converters that can be fabricated using commercial CMOS foundries. The boost converters will increase the low...

  4. Aeronet Solar Flux

    Data.gov (United States)

    National Aeronautics and Space Administration — SolRad-Net (Solar Radiation Network) is an established network of ground-based sensors providing high-frequency solar flux measurements in quasi-realtime to the...

  5. Flux in Tallinn

    Index Scriptorium Estoniae

    2004-01-01

    Rahvusvahelise elektroonilise kunsti sümpoosioni ISEA2004 klubiõhtu "Flux in Tallinn" klubis Bon Bon. Eestit esindasid Ropotator, Ars Intel Inc., Urmas Puhkan, Joel Tammik, Taavi Tulev (pseud. Wochtzchee). Klubiõhtu koordinaator Andres Lõo

  6. Advanced Safeguards Approaches for New Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Durst, Philip C.; Therios, Ike; Bean, Robert; Dougan, A.; Boyer, Brian; Wallace, Rick L.; Ehinger, Michael H.; Kovacic, Don N.; Tolk, K.

    2007-12-15

    This third report in the series reviews possible safeguards approaches for new fast reactors in general, and the ABR in particular. Fast-neutron spectrum reactors have been used since the early 1960s on an experimental and developmental level, generally with fertile blanket fuels to “breed” nuclear fuel such as plutonium. Whether the reactor is designed to breed plutonium, or transmute and “burn” actinides depends mainly on the design of the reactor neutron reflector and the whether the blanket fuel is “fertile” or suitable for transmutation. However, the safeguards issues are very similar, since they pertain mainly to the receipt, shipment and storage of fresh and spent plutonium and actinide-bearing “TRU”-fuel. For these reasons, the design of existing fast reactors and details concerning how they have been safeguarded were studied in developing advanced safeguards approaches for the new fast reactors. In this regard, the design of the Experimental Breeder Reactor-II “EBR-II” at the Idaho National Laboratory (INL) was of interest, because it was designed as a collocated fast reactor with a pyrometallurgical reprocessing and fuel fabrication line – a design option being considered for the ABR. Similarly, the design of the Fast Flux Facility (FFTF) on the Hanford Site was studied, because it was a successful prototype fast reactor that ran for two decades to evaluate fuels and the design for commercial-scale fast reactors.

  7. Determining Reactor Neutrino Flux

    OpenAIRE

    Cao, Jun

    2011-01-01

    Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understa...

  8. Theoretical magnetic flux emergence

    OpenAIRE

    MacTaggart, David

    2011-01-01

    Magnetic flux emergence is the subject of how magnetic fields from the solar interior can rise and expand into the atmosphere to produce active regions. It is the link that joins dynamics in the convection zone with dynamics in the atmosphere. In this thesis, we study many aspects of magnetic flux emergence through mathematical modelling and computer simulations. Our primary aim is to understand the key physical processes that lie behind emergence. The first chapter intro...

  9. Flux Emergence (Theory)

    Science.gov (United States)

    Cheung, Mark C. M.; Isobe, Hiroaki

    2014-07-01

    Magnetic flux emergence from the solar convection zone into the overlying atmosphere is the driver of a diverse range of phenomena associated with solar activity. In this article, we introduce theoretical concepts central to the study of flux emergence and discuss how the inclusion of different physical effects (e.g., magnetic buoyancy, magnetoconvection, reconnection, magnetic twist, interaction with ambient field) in models impact the evolution of the emerging field and plasma.

  10. Neutron flux monitoring device

    International Nuclear Information System (INIS)

    Shimazu, Yoichiro.

    1995-01-01

    In a neutron flux monitoring device, there are disposed a neutron flux measuring means for outputting signals in accordance with the intensity of neutron fluxes, a calculation means for calculating a self power density spectrum at a frequency band suitable to an object to be measured based on the output of the neutron flux measuring means, an alarm set value generation means for outputting an alarm set value as a comparative reference, and an alarm judging means for comparing the alarm set value with the outputted value of the calculation means to judge requirement of generating an alarm and generate an alarm in accordance with the result of the judgement. Namely, the time-series of neutron flux signals is put to fourier transformation for a predetermined period of time by the calculation means, and from each of square sums for real number component and imaginary number component for each of the frequencies, a self power density spectrum in the frequency band suitable to the object to be measured is calculated. Then, when the set reference value is exceeded, an alarm is generated. This can reliably prevent generation of erroneous alarm due to neutron flux noises and can accurately generate an alarm at an appropriate time. (N.H.)

  11. Neutron flux monitor

    International Nuclear Information System (INIS)

    Oda, Naotaka.

    1993-01-01

    The device of the present invention greatly saves an analog processing section such as an analog filter and an analog processing circuit. That is, the device of the present invention comprises (1) a neutron flux detection means for detecting neutron fluxed in the reactor, (2) a digital filter means for dividing signals corresponding to the detected neutron fluxes into predetermined frequency band regions, (3) a calculation processing means for applying a calculation processing corresponding to the frequency band regions to the neutron flux detection signals divided by the digital filter means. With such a constitution, since the neutron detection signals are processed by the digital filter means, the accuracy is improved and the change for the property of the filter is facilitated. Further, when a neutron flux level is obtained, a calculation processing corresponding to the frequency band region can be conducted without the analog processing circuit. Accordingly, maintenance and accuracy are improved by greatly decreasing the number of parts. Further, since problems inherent to the analog circuit are solved, neutron fluxes are monitored at high reliability. (I.S.)

  12. Metabolic fuels: regulating fluxes to select mix.

    Science.gov (United States)

    Weber, Jean-Michel

    2011-01-15

    Animals must regulate the fluxes of multiple fuels to support changing metabolic rates that result from variation in physiological circumstances. The aim of fuel selection strategies is to exploit the advantages of individual substrates while minimizing the impact of disadvantages. All exercising mammals share a general pattern of fuel selection: at the same %V(O(2,max)) they oxidize the same ratio of lipids to carbohydrates. However, highly aerobic species rely more on intramuscular fuels because energy supply from the circulation is constrained by trans-sarcolemmal transfer. Fuel selection is performed by recruiting different muscles, different fibers within the same muscles or different pathways within the same fibers. Electromyographic analyses show that shivering humans can modulate carbohydrate oxidation either through the selective recruitment of type II fibers within the same muscles or by regulating pathway recruitment within type I fibers. The selection patterns of shivering and exercise are different: at the same %V(O(2,max)), a muscle producing only heat (shivering) or significant movement (exercise) strikes a different balance between lipid and carbohydrate oxidation. Long-distance migrants provide an excellent model to characterize how to increase maximal substrate fluxes. High lipid fluxes are achieved through the coordinated upregulation of mobilization, transport and oxidation by activating enzymes, lipid-solubilizing proteins and membrane transporters. These endurance athletes support record lipolytic rates in adipocytes, use lipoprotein shuttles to accelerate transport and show increased capacity for lipid oxidation in muscle mitochondria. Some migrant birds use dietary omega-3 fatty acids as performance-enhancing agents to boost their ability to process lipids. These dietary fatty acids become incorporated in membrane phospholipids and bind to peroxisome proliferator-activated receptors to activate membrane proteins and modify gene expression.

  13. A Survey on Voltage Boosting Techniques for Step-Up DC-DC Converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam Prasad; Gorji, Saman Asghari

    2016-01-01

    Step-up dc-dc converters are used to boost the voltage level of the input to a higher output level. Despite of its features such as simplicity of implementation, the fundamental boost dc-dc converter has shortcomings such as low boost ability and low power density. With these limitations, researc...

  14. 14 CFR 27.695 - Power boost and power-operated control system.

    Science.gov (United States)

    2010-01-01

    ... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

  15. 14 CFR 29.695 - Power boost and power-operated control system.

    Science.gov (United States)

    2010-01-01

    ... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

  16. Concomitant boost radiotherapy for squamous carcinoma of the tonsillar fossa

    International Nuclear Information System (INIS)

    Gwozdz, John T.; Morrison, William H.; Garden, Adam S.; Weber, Randal S.; Peters, Lester J.; Ang, K. Kian

    1997-01-01

    Purpose: To assess the efficacy of a concomitant boost fractionation schedule of radiotherapy for treating patients with squamous carcinoma of the tonsillar fossa. Patients and Methods: Between December 1983 and November 1992, 83 patients with squamous carcinoma of the tonsil were treated with concomitant boost fractionation. The distribution of American Joint Committee on Cancer T stages was TX-4, T1-5, T2-29, T3-41, T4-4; N stages were NX-1, N0-26, N1-13, N2-31, N3-12. Patients were treated with standard large fields to 54 Gy in 6 weeks. The boost treatment consisted of a second daily 1.5 Gy fraction for 10-12 fractions, usually delivered during the final phase of treatment. The tumor dose was 69-72 Gy, given over 6 weeks. Twenty-one patients, who all had N2 or N3 regional disease, underwent neck dissections, either before (13 patients) or 6 weeks after radiotherapy (8 patients); the other patients were treated with radiotherapy alone. Results: The 5-year actuarial disease-specific survival and overall survival rates were 71 and 60%, respectively. Patients with T2 and T3 primary tumors had 5-year actuarial local control rates of 96 and 78%, respectively. Patients with T3 disease who received the final-phase boost had a 5-year actuarial local control rate of 82%. Actuarial 5-year regional disease control rates were N0, 92%; N1, 76%; N2, 89%; and N3, 89%. The 21 patients who had neck dissections all had their disease regionally controlled. Patients presenting with nodal disease or after a node excision who were treated with radiation alone had a 5-year actuarial regional disease control rate of 79%. All but five patients had confluent Grade 4 mucositis during treatment. Severe late complications attributable to radiation included mandibular necrosis, in-field osteosarcoma, and chronic dysphagia for solid foods. Conclusions: High rates of local and regional disease control were achieved with the concomitant boost fractionation schedule, with few cases of severe late

  17. The Open Flux Problem

    International Nuclear Information System (INIS)

    Linker, J. A.; Caplan, R. M.; Downs, C.; Riley, P.; Mikic, Z.; Lionello, R.; Henney, C. J.; Arge, C. N.; Liu, Y.; Derosa, M. L.; Yeates, A.; Owens, M. J.

    2017-01-01

    The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun’s photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. In this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun’s magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission.

  18. Nitric oxide fluxes from an agricultural soil using a flux-gradient method

    Science.gov (United States)

    Taylor, N. M.; Wagner-Riddle, C.; Thurtell, G. W.; Beauchamp, E. G.

    1999-05-01

    Soil emission of nitric oxide may be a significant source of NOx in rural areas. Agricultural practices may enhance these emissions by addition of nitrogen fertilizers. A system that enables continuous measurement of NO fluxes from agricultural surfaces using the flux-gradient method was developed. Hourly differences in NO concentrations in air sampled at two intake heights (0.6 and 1 m) were determined using a chemiluminescence analyzer. Eddy diffusivities were determined using wind profiles (cup anemometers), and stability corrections calculated using a 5 cm path sonic anemometer. Fast switching of sampling between air intake heights (every 30 s) and determination of concentration values at a frequency of 2 Hz minimized the errors due to fluctuations in background concentration. Low travel times for air samples in the tubing (˜8 s) were estimated to result in small errors in flux values (chemical reactions. The overall resolution of the system was estimated as ˜1 ng N m-2s-1. NO fluxes from a bare soil were measured quasi-continuously from January to June 1995 at Elora, Canada, comprising a total of 1833 hourly values. Daily NO fluxes before nitrogen fertilization were small, increasing after nitrogen fertilizer was added (>10 ng N m-2 s-1). Monthly NO fluxes estimated were similar to those observed in previous studies. The designed system could be easily modified to measure NOx and NO fluxes by using an additional chemiluminescence analyzer. The system also could be adapted to measure fluxes sequentially from various plots, enabling testing of agricultural practices on NO emissions.

  19. Eddy Correlation Flux Measurement System Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration. The instruments used are: • a fast-response, three-dimensional (3D) wind sensor (sonic anemometer) to obtain the orthogonal wind components and the speed of sound (SOS) (used to derive the air temperature) • an open-path infrared gas analyzer (IRGA) to obtain the water vapor density and the CO2 concentration, and • an open-path infrared gas analyzer (IRGA) to obtain methane density and methane flux at one SGP EF and at the NSA CF. The ECOR systems are deployed at the locations where other methods for surface flux measurements (e.g., energy balance Bowen ratio [EBBR] systems) are difficult to employ, primarily at the north edge of a field of crops. A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system in SGP, NSA, Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes. The SEBS at one SGP and one NSA site also support upwelling and downwelling PAR measurements to qualify those two locations as Ameriflux sites.

  20. Boosted H­->bb Tagger In Run II

    CERN Document Server

    Sahinsoy, Merve; The ATLAS collaboration

    2016-01-01

    Several searches for Higgs bosons decaying to b­quark pairs benefit from the increased Run II centre­of­mass energy by exploiting the large transvers­momentum (boosted) Higgs boson regime, where the two b­jets are merged into one large­radius jet. ATLAS uses a boosted H­>bb tagger algorithm to separate the Higgs signal from the background processes (QCD, W and Z bosons, top quarks). The tagger takes as input a large­R=1.0 jet calibrating the pseudorapidity, energy and mass scale. The tagger employs b­tagging, Higgs candidate mass, and substructure information. The performance of several operating points in Higgs boson signal and QCD and ttbar all­hadronic backgrounds are presented. Systematic uncertainties are evaluated so that this tagger can be used in analyses.

  1. High Efficient Universal Buck Boost Solar Array Regulator SAR Module

    Science.gov (United States)

    Kimmelmann, Stefan; Knorr, Wolfgang

    2014-08-01

    The high efficient universal Buck Boost Solar Array Regulator (SAR) module concept is applicable for a wide range of input and output voltages. The single point failure tolerant SAR module contains 3 power converters for the transfer of the SAR power to the battery dominated power bus. The converters are operating parallel in a 2 out of 3 redundancy and are driven by two different controllers. The output power of one module can be adjusted up to 1KW depending on the requirements. The maximum power point tracker (MPPT) is placed on a separate small printed circuit board and can be used if no external tracker signal is delivered. Depending on the mode and load conditions an efficiency of more than 97% is achievable. The stable control performance is achieved by implementing the magnetic current sense detection. The sensed power coil current is used in Buck and Boost control mode.

  2. Investigating light NMSSM pseudoscalar states with boosted ditau tagging

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Eric [Groupe de Recherche de Physique des Hautes Énergies (GRPHE),Université de Haute-Alsace, IUT Colmar,34 rue du Grillenbreit BP 50568, 68008 Colmar Cedex (France); Fuks, Benjamin [Sorbonne Universités, UPMC University Paris 06,UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589, LPTHE, F-75005, Paris (France); Guo, Jun [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190 (China); Institut Pluridisciplinaire Hubert Curien/Département Recherches Subatomiques,Université de Strasbourg/CNRS-IN2P3,23 rue du Loess, F-67037 Strasbourg (France); Li, Jinmian; Williams, Anthony G. [ARC Centre of Excellence for Particle Physics at the Terascale and CSSM,Department of Physics, University of Adelaide,Adelaide, SA 5005 (Australia)

    2016-05-17

    We study a class of realizations of the Next-to-Minimal Supersymmetric Standard Model that is motivated by dark matter and Higgs data, and in which the lightest pseudoscalar Higgs boson mass is smaller than twice the bottom quark mass and greater than twice the tau lepton mass. In such scenarios, the lightest pseudoscalar Higgs boson can be copiously produced at the LHC from the decay of heavier superpartners and will dominantly further decay into a pair of tau leptons that is generally boosted. We make use of a boosted object tagging technique designed to tag such a ditau jet, and estimate the sensitivity of the LHC to the considered supersymmetric scenarios with 20 to 50 fb{sup −1} of proton-proton collisions at a center-of-mass energy of 13 TeV.

  3. Diode-Assisted Buck-Boost Voltage-Source Inverters

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Teodorescu, Remus

    2009-01-01

    , a number of diode-assisted inverter variants can be designed with each having its own operational principle and voltage gain expression. For controlling them, a generic modulation scheme that can be used for controlling all diode-assisted variants with minimized harmonic distortion and component stress......This paper proposes a number of diode-assisted buck-boost voltage-source inverters with a unique X-shaped diode-capacitor network inserted between the inverter circuitry and dc source for producing a voltage gain that is comparatively higher than those of other buck-boost conversion techniques....... Using the diode-assisted network, the proposed inverters can naturally configure themselves to perform capacitive charging in parallel and discharging in series to give a higher voltage multiplication factor without compromising waveform quality. In addition, by adopting different front-end circuitries...

  4. High Temperature Boost (HTB) Power Processing Unit (PPU) Formulation Study

    Science.gov (United States)

    Chen, Yuan; Bradley, Arthur T.; Iannello, Christopher J.; Carr, Gregory A.; Mohammad, Mojarradi M.; Hunter, Don J.; DelCastillo, Linda; Stell, Christopher B.

    2013-01-01

    This technical memorandum is to summarize the Formulation Study conducted during fiscal year 2012 on the High Temperature Boost (HTB) Power Processing Unit (PPU). The effort is authorized and supported by the Game Changing Technology Division, NASA Office of the Chief Technologist. NASA center participation during the formulation includes LaRC, KSC and JPL. The Formulation Study continues into fiscal year 2013. The formulation study has focused on the power processing unit. The team has proposed a modular, power scalable, and new technology enabled High Temperature Boost (HTB) PPU, which has 5-10X improvement in PPU specific power/mass and over 30% in-space solar electric system mass saving.

  5. Implementation of Carrier-Based Simple Boost Pulse Width Modulation (PWM) for Z-Source Inverter (ZSI) using Field Programming Gate Array (FPGA)

    Science.gov (United States)

    Muhammad, M.; Rasin, Z.; Jidin, A.

    2017-08-01

    In recent years, the research on the Z-source inverter (ZSI) has received a wide acceptance due to its attractive solution for example in the renewable energy interface that requires voltage boost capability. The conventional inverter circuit based on the SPWM technique for example does not able to fully utilize its DC input voltage to produce a greater output voltage. The ZSI shoot-through implementation in high switching frequency requires a processor with fast sampling and high precision. In simulation, this can be easily carried out with the available advanced engineering software. In the hardware implementation however, the processor used is not only handle the switching, but also needs to read the data obtained by the sensor, voltage and current control, information display etc. This limits the capacity that can be used to implement the switching fast sampling with high precision. The aims of this work are to implement high precision of carrier-based simple boost PWM for ZSI using FPGA and to verify its real time hardware implementation. The high precision of PWM control algorithm based on the FPGA platform is verified by comparing the simulation results with the experimental results for different modulation index and boost factor, and a good agreement is concluded. It is observed that the application of FPGA reduces complexity, increases speed and the design of the switching technique can be altered without having to modify the hardware implementation.

  6. Consistent Holographic Description of Boost-Invariant Plasma

    Science.gov (United States)

    Heller, Michal P.; Surówka, Piotr; Loganayagam, R.; Spaliński, Michał; Vázquez, Samuel E.

    2009-01-01

    Prior attempts to construct the gravity dual of boost-invariant flow of N=4 supersymmetric Yang-Mills gauge theory plasma suffered from apparent curvature singularities in the late-time expansion. This Letter shows how these problems can be resolved by a different choice of expansion parameter. The calculations presented correctly reproduce the plasma energy-momentum tensor within the framework of second-order viscous hydrodynamics.

  7. Boosted PWM open loop control of hydraulic proportional valves

    International Nuclear Information System (INIS)

    Amirante, R.; Innone, A.; Catalano, L.A.

    2008-01-01

    This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots

  8. Corrector del factor de potencia mediante convertidor boost multifase

    OpenAIRE

    Barriocanal Escobar, Jordi

    2009-01-01

    Las fuentes de alimentación tradicionales provocan una clara disminución del factor de potencia. Es necesario encontrar un circuito que pase la corr iente alterna a corriente continua, con un elevado factor de potencia. Para ello se puede utilizar un convertidor de poten cia Boost posterior a un rectificador. Se aumenta el factor de potencia pero en la tensión de salida aparece un rizado de baja frecuenci...

  9. Motivating quantum field theory: the boosted particle in a box

    International Nuclear Information System (INIS)

    Vutha, Amar C

    2013-01-01

    It is a maxim often stated, yet rarely illustrated, that the combination of special relativity and quantum mechanics necessarily leads to quantum field theory. An elementary illustration is provided using the familiar particle in a box, boosted to relativistic speeds. It is shown that quantum fluctuations of momentum lead to energy fluctuations, which are inexplicable without a framework that endows the vacuum with dynamical degrees of freedom and allows particle creation/annihilation. (letters and comments)

  10. The Voltage Boost Enabled by Luminescence Extraction in Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Ganapati, Vidya; Steiner, Myles A.; Yablonovitch, Eli

    2016-11-21

    A new physical principle has emerged to produce record voltages and efficiencies in photovoltaic cells, 'luminescence extraction.' This is exemplified by the mantra 'a good solar cell should also be a good LED.' Luminescence extraction is the escape of internal photons out of the front surface of a solar cell. Basic thermodynamics says that the voltage boost should be related to concentration ratio, C, of a resource by ..delta..V=(kT/q)ln{C}. In light trapping, (i.e. when the solar cell is textured and has a perfect back mirror) the concentration ratio of photons C={4n2}, so one would expect a voltage boost of ..delta..V=kT ln{4n2} over a solar cell with no texture and zero back reflectivity, where n is the refractive index. Nevertheless, there has been ambiguity over the voltage benefit to be expected from perfect luminescence extraction. Do we gain an open circuit voltage boost of ..delta..V=(kT/q)ln{n2}, ..delta..V=(kT/q)ln{2n2}, or ..delta..V=(kT/q)ln{4n2}? What is responsible for this voltage ambiguity ..delta..V=(kT/q)ln{4}=36mVolts? We show that different results come about, depending on whether the photovoltaic cell is optically thin or thick to its internal luminescence. In realistic intermediate cases of optical thickness the voltage boost falls in between; ln{n2}q..delta..V/kT)<;ln{4n2}.

  11. Concurrent Boost with Adjuvant Breast Hypofractionated Radiotherapy and Toxicity Assessment

    Directory of Open Access Journals (Sweden)

    Mona M. Sayed

    2015-01-01

    Full Text Available Background: The use of shorter radiotherapy schedules has an economic and logistic advantage for radiotherapy departments, as well as a high degree of patient convenience. The aim of this study is to assess the acute and short-term late toxicities of a hypofractionated radiotherapy schedule with a concomitant boost. Methods: We enrolled 57 eligible patients as group A. These patients received 42.5 Gy in 16 fractions of 2.66 Gy each to the whole breast over 3.2 weeks. A concomitant electron boost of 12 Gy in 16 fractions was also administered which gave an additional 0.75 Gy daily to the lumpectomy area for a total radiation dose of 54.5 Gy. Toxicity was recorded at three weeks and at three months for this group as well as for a control group (group B. The control group comprised 76 eligible patients treated conventionally with 50 Gy to the whole breast over five weeks followed by a sequential electron boost of 12 Gy in 2 Gy per fraction. Results: There were no statistically significant differences observed in the incidence of acute skin toxicity, breast pain, and edema recorded at three weeks or pigmentation and fibrosis recorded at three months between the two groups (P0.05. Conclusion: The results of this study suggest there are no increased acute and shortterm late toxicities affiliated with the hypofractionated schedule plus a concomitant boost as prescribed compared to the conventional fractionation of adjuvant breast radiotherapy. Large randomized trials and long-term follow-up are needed to confirm these favorable findings.

  12. Consistent holographic description of boost-invariant plasma.

    Science.gov (United States)

    Heller, Michal P; Surówka, Piotr; Loganayagam, R; Spaliński, Michał; Vázquez, Samuel E

    2009-01-30

    Prior attempts to construct the gravity dual of boost-invariant flow of N=4 supersymmetric Yang-Mills gauge theory plasma suffered from apparent curvature singularities in the late-time expansion. This Letter shows how these problems can be resolved by a different choice of expansion parameter. The calculations presented correctly reproduce the plasma energy-momentum tensor within the framework of second-order viscous hydrodynamics.

  13. Asia-Pacific Region Water Boosted Rocket Events

    Science.gov (United States)

    Oyama, K.-I.; Hidayat, A.; Sofyan, E.; Sinha, H. S. S.; Herudi, K.; Kubota, T.; Sukkarieh, S.; Arban, J. L.; Chung, D. M.; Medagangoda, I.; Mohd, Z. B.; Pitan, S.; Chin, C.; Sarkar, F. R.

    2010-05-01

    Space Education and Awareness Working Group, which is one of four working groups of Asia-Pacific Regional Space Agency Forum, had organized water boosted rocket competition in Japan in 2005, in Indonesia in 2006, and in 2007 in India. One junior high school student (12-15 years old) and one leader from 9 and 13 Asian/Pacific countries attended the 1st, 2nd, and 3rd water rocket events, respectively. The 4th event is planned in Vietnam, in December 2008. The manuscript introduces the structure and activities of Space Education and Awareness Working Group, which is working under Asia-Pacific Regional Space Agency Forum sponsored by Ministry of Education, Culture, Sports, and Technology of Japan; and application of water-boosted rocket to other field is described. Details of the water boosted rocket events, such as the purpose, competition rules, and the schedules are provided. Finally we discuss the issues to be taken into account for the future event.

  14. Stereotactic Body Radiation Therapy Boost in Locally Advanced Pancreatic Cancer

    International Nuclear Information System (INIS)

    Seo, Young Seok; Kim, Mi-Sook; Yoo, Sung Yul; Cho, Chul Koo; Yang, Kwang Mo; Yoo, Hyung Jun; Choi, Chul Won; Lee, Dong Han; Kim, Jin; Kim, Min Suk; Kang, Hye Jin; Kim, YoungHan

    2009-01-01

    Purpose: To investigate the clinical application of a stereotactic body radiation therapy (SBRT) boost in locally advanced pancreatic cancer patients with a focus on local efficacy and toxicity. Methods and Materials: We retrospectively reviewed 30 patients with locally advanced and nonmetastatic pancreatic cancer who had been treated between 2004 and 2006. Follow-up duration ranged from 4 to 41 months (median, 14.5 months). A total dose of 40 Gy was delivered in 20 fractions using a conventional three-field technique, and then a single fraction of 14, 15, 16, or 17 Gy SBRT was administered as a boost without a break. Twenty-one patients received chemotherapy. Overall and local progression-free survival were calculated and prognostic factors were evaluated. Results: One-year overall survival and local progression-free survival rates were 60.0% and 70.2%, respectively. One patient (3%) developed Grade 4 toxicity. Carbohydrate antigen 19-9 response was found to be an independent prognostic factor for survival. Conclusions: Our findings indicate that a SBRT boost provides a safe means of increasing radiation dose. Based on the results of this study, we recommend that a well controlled Phase II study be conducted on locally advanced pancreatic cancer.

  15. Boosted dark matter signals uplifted with self-interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Kyoungchul, E-mail: kckong@ku.edu [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Mohlabeng, Gopolang, E-mail: mohlabeng319@gmail.com [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Park, Jong-Chul, E-mail: log1079@gmail.com [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-04-09

    We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in the assisted freeze-out mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier) dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.

  16. Chagas Parasite Detection in Blood Images Using AdaBoost

    Directory of Open Access Journals (Sweden)

    Víctor Uc-Cetina

    2015-01-01

    Full Text Available The Chagas disease is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi. Visual detection of such parasite through microscopic inspection is a tedious and time-consuming task. In this paper, we provide an AdaBoost learning solution to the task of Chagas parasite detection in blood images. We give details of the algorithm and our experimental setup. With this method, we get 100% and 93.25% of sensitivity and specificity, respectively. A ROC comparison with the method most commonly used for the detection of malaria parasites based on support vector machines (SVM is also provided. Our experimental work shows mainly two things: (1 Chagas parasites can be detected automatically using machine learning methods with high accuracy and (2 AdaBoost + SVM provides better overall detection performance than AdaBoost or SVMs alone. Such results are the best ones known so far for the problem of automatic detection of Chagas parasites through the use of machine learning, computer vision, and image processing methods.

  17. Boosted dark matter signals uplifted with self-interaction

    Directory of Open Access Journals (Sweden)

    Kyoungchul Kong

    2015-04-01

    Full Text Available We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in the assisted freeze-out mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.

  18. Boosting target tracking using particle filter with flow control

    Science.gov (United States)

    Moshtagh, Nima; Chan, Moses W.

    2013-05-01

    Target detection and tracking with passive infrared (IR) sensors can be challenging due to significant degradation and corruption of target signature by atmospheric transmission and clutter effects. This paper summarizes our efforts in phenomenology modeling of boosting targets with IR sensors, and developing algorithms for tracking targets in the presence of background clutter. On the phenomenology modeling side, the clutter images are generated using a high fidelity end-to-end simulation testbed. It models atmospheric transmission, structured clutter and solar reflections to create realistic background images. The dynamics and intensity of a boosting target are modeled and injected onto the background scene. Pixel level images are then generated with respect to the sensor characteristics. On the tracking analysis side, a particle filter for tracking targets in a sequence of clutter images is developed. The particle filter is augmented with a mechanism to control particle flow. Specifically, velocity feedback is used to constrain and control the particles. The performance of the developed "adaptive" particle filter is verified with tracking of a boosting target in the presence of clutter and occlusion.

  19. Inertial-Dissipation flux measurements over south Bay of Bengal ...

    Indian Academy of Sciences (India)

    The data were collected on ORV Sagar Kanya during BOBMEX-Pilot cruise during the period 23rd October 1998 to 12th November 1998 over south Bay of Bengal. The fluxes are estimated using the data collected through fast response sensors namely Gill anemometer, Sonic anemometer and IR Hygrometer. In this paper ...

  20. Neutron flux measurement at the Baksan Underground Scintillation Telescope

    Science.gov (United States)

    Kochkarov, M. M.; Boliev, M. M.; Dzaparova, I. M.; Novoseltseva, R. V.; Novoseltsev, Yu. F.; Petkov, V. B.; Volchenko, V. I.; Volchenko, G. V.; Yanin, A. F.

    2018-01-01

    The characteristics of fast neutrons produced by cosmic-ray muons at the Baksan Underground Scintillation Telescope (BUST) are investigated. A novel approach to the problem consists in estimating the neutron flux by the production rate of the unstable radioactive nuclide 12 B in the ( n, p) reaction on carbon nuclei of the BUST organic scintillator. The processing of the data collected in 2002-2015 yielded {N_{{{12}_B}}} = 337 ± 2.5 events consistent with those of the reaction 12 C( n, p)12 B. For the BUST internal planes, the background of fast neutrons with E > 28.6 MeV is experimentally estimated as Φ ∝ 10-11cm-2 s-1. This is lower than the theoretically predicted total neutron flux by nearly two orders of magnitude. The disagreement with predictions is attributed to the suppression of neutron flux in the external scintillator planes of the detector.

  1. Strong Coupling of a Quantum Oscillator to a Flux Qubit at Its Symmetry Point

    NARCIS (Netherlands)

    Fedorov, A.; Feofanov, A.K.; Macha, P.; Forn-Díaz, P.; Harmans, C.J.P.M.; Mooij, J.E.

    2010-01-01

    A flux qubit biased at its symmetry point shows a minimum in the energy splitting (the gap), providing protection against flux noise. We have fabricated a qubit of which the gap can be tuned fast and have coupled this qubit strongly to an LC oscillator. We show full spectroscopy of the

  2. A conceptual high flux reactor design with scope for use in ADS ...

    Indian Academy of Sciences (India)

    The physics design considers high enriched metallic alloy fuel in the form of annular plates placed in a D2O moderator tank in a hexagonal lattice arrangement. By choosing a tight lattice pitch in the central region and double the lattice pitch in the outer region, it is possible to have both high fast flux and thermal flux trap ...

  3. Soluble organic nutrient fluxes

    Science.gov (United States)

    Robert G. Qualls; Bruce L. Haines; Wayne Swank

    2014-01-01

    Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

  4. Radiation flux measuring device

    International Nuclear Information System (INIS)

    Corte, E.; Maitra, P.

    1977-01-01

    A radiation flux measuring device is described which employs a differential pair of transistors, the output of which is maintained constant, connected to a radiation detector. Means connected to the differential pair produce a signal representing the log of the a-c component of the radiation detector, thereby providing a signal representing the true root mean square logarithmic output. 3 claims, 2 figures

  5. Muon and neutrino fluxes

    Science.gov (United States)

    Edwards, P. G.; Protheroe, R. J.

    1985-01-01

    The result of a new calculation of the atmospheric muon and neutrino fluxes and the energy spectrum of muon-neutrinos produced in individual extensive air showers (EAS) initiated by proton and gamma-ray primaries is reported. Also explained is the possibility of detecting atmospheric nu sub mu's due to gamma-rays from these sources.

  6. Flux scaling: Ultimate regime

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

  7. An Original Transformer and Switched-Capacitor (T & SC-Based Extension for DC-DC Boost Converter for High-Voltage/Low-Current Renewable Energy Applications: Hardware Implementation of a New T & SC Boost Converter

    Directory of Open Access Journals (Sweden)

    Sanjeevikumar Padmanaban

    2018-03-01

    Full Text Available In this article a new Transformer and Switched Capacitor-based Boost Converter (T & SC-BC is proposed for high-voltage/low-current renewable energy applications. The proposed T & SC-BC is an original extension for DC-DC boost converter which is designed by utilizing a transformer and switched capacitor (T & SC. Photovoltaic (PV energy is a fast emergent segment among the renewable energy systems. The proposed T & SC-BC combines the features of the conventional boost converter and T & SC to achieve a high voltage conversion ratio. A Maximum Power Point Tracking (MPPT controller is compulsory and necessary in a PV system to extract maximum power. Thus, a photovoltaic MPPT control mechanism also articulated for the proposed T & SC-BC. The voltage conversion ratio (Vo/Vin of proposed converter is (1 + k/(1 − D where, k is the turns ratio of the transformer and D is the duty cycle (thus, the converter provides 9.26, 13.88, 50/3 voltage conversion ratios at 78.4 duty cycle with k = 1, 2, 2.6, respectively. The conspicuous features of proposed T & SC-BC are: (i a high voltage conversion ratio (Vo/Vin; (ii continuous input current (Iin; (iii single switch topology; (iv single input source; (v low drain to source voltage (VDS rating of control switch; (vi a single inductor and a single untapped transformer are used. Moreover, the proposed T & SC-BC topology was compared with recently addressed DC-DC converters in terms of number of components, cost, voltage conversion ratio, ripples, efficiency and power range. Simulation and experimental results are provided which validate the functionality, design and concept of the proposed approach.

  8. A conceptual high flux reactor design with scope for use in ADS ...

    Indian Academy of Sciences (India)

    enriched metallic alloy fuel in the form of annular plates placed in a D2O moderator tank in a hexagonal lattice arrangement. By choosing a tight lattice pitch in the central region and double the lattice pitch in the outer region, it is possible to have both high fast flux and thermal flux trap zones. By design the flux level in the ...

  9. RP-2 Thermal Stability and Heat Transfer Investigation for Hydrocarbon Boost Engines

    Science.gov (United States)

    VanNoord, J. L.; Stiegemeier, B. R.

    2010-01-01

    A series of electrically heated tube tests were performed at the NASA Glenn Research Center s Heated Tube Facility to investigate the use of RP-2 as a fuel for next generation regeneratively cooled hydrocarbon boost engines. The effect that test duration, operating condition and test piece material have on the overall thermal stability and materials compatibility characteristics of RP-2 were evaluated using copper and 304 stainless steel test sections. The copper tests were run at 1000 psia, heat flux up to 6.0 Btu/in.2-sec, and wall temperatures up to 1180 F. Preliminary results, using measured wall temperature as an indirect indicator of the carbon deposition process, show that in copper test pieces above approximately 850 F, RP-2 begins to undergo thermal decomposition resulting in local carbon deposits. Wall temperature traces show significant local temperature increases followed by near instantaneous drops which have been attributed to the carbon deposition/shedding process in previous investigations. Data reduction is currently underway for the stainless steel test sections and carbon deposition measurements will be performed in the future for all test sections used in this investigation. In conjunction with the existing thermal stability database, these findings give insight into the feasibility of cooling a long life, high performance, high-pressure liquid rocket combustor and nozzle with RP-2.

  10. Acid-fast stain

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003766.htm Acid-fast stain To use the sharing features on this page, please enable JavaScript. The acid-fast stain is a laboratory test that determines ...

  11. Fast food (image)

    Science.gov (United States)

    Fast foods are quick, reasonably priced, and readily available alternatives to home cooking. While convenient and economical for a busy lifestyle, fast foods are typically high in calories, fat, saturated fat, ...

  12. Fast food tips (image)

    Science.gov (United States)

    ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ...

  13. Sequentially delivered boost plans are superior to simultaneously delivered plans in head and neck cancer when the boost volume is located further away from the parotid glands

    International Nuclear Information System (INIS)

    Lamers-Kuijper, Emmy; Heemsbergen, Wilma; Mourik, Anke van; Rasch, Coen

    2011-01-01

    Purpose: To find parameters that predict which head and neck patients benefit from a sequentially delivered boost treatment plan compared to a simultaneously delivered plan, with the aim to spare the salivary glands. Methods and materials: We evaluated 50 recently treated head and neck cancer patients. Apart from the clinical plan with a sequentially (SEQ) given boost using an Intensity Modulated Radiotherapy Technique (IMRT), a simultaneous integrated boost (SIB) technique plan was constructed with the same beam set-up. The mean dose to the parotid glands was calculated and compared. The elective nodal areas were bilateral in all cases, with a boost on either one side or both sides of the neck. Results: When the parotid gland volume and the Planning Target Volume (PTV) for the boost overlap there is on average a lower dose to the parotid gland with a SIB technique (-1.2 Gy), which is, however, not significant (p = 0.08). For all parotid glands with no boost PTV overlap, there is a benefit from a SEQ technique compared to a SIB technique for the gland evaluated (on average a 2.5 Gy lower dose to the parotid gland, p < 0.001). When the distance between gland and PTV is 0-1 cm, this difference is on average 0.8 Gy, for 1-2 cm distance 2.9 Gy and for glands with a distance greater than 2 cm, 3.3 Gy. When the lymph nodes on the evaluated side are also included in the boost PTV, however, this relationship between the distance and the gain of a SEQ seems less clear. Conclusions: A sequentially delivered boost technique results in a better treatment plan for most cases, compared to a simultaneous integrated boost IMRT technique, if the boost PTV is more than 1 cm away from at least one parotid gland.

  14. How Giant Magnetospheres Maintain Their Magnetic Flux.

    Science.gov (United States)

    Rymer, A. M.

    2017-12-01

    Magnetic flux lost from a planet must be returned [Maxwell's first law, there are no magnetic monopoles (div(B) = 0)], and the dominant mechanism by which this is achieved is still to be determined. Here we compare a mechanism for magnetic flux return via small-scale plasma circulation. The existence of bi-modal superposed electron distributions at Jupiter and Saturn was a surprise to Voyager researchers [e.g. Sittler et al., 1983] that remains something of a mystery to this day. Electrons are virtually massless and are expected to rapidly thermalize to a single distribution. Observations by the Cassini spacecraft at Saturn have elucidated on the source of the hot electron component - small scale isolated flux tubes (commonly referred to as `injection events') that bubble planetward, returning magnetic flux that had been convected outward by centrifugal forces or stripped away during magnetospheric reconfigurations, such as substorms [Rymer et al., 2008]. Saturn is an ideal place to study injection events; relatively quiescent, aligned magnetic and geographic spins axes and a nice fast rotation rate in comparison to plasma drift speeds. The other magnetospheric laboratories in our solar system (Jupiter, Uranus and Neptune) will be more challenging. In this presentation we describe predictions for how plasma injection will be manifest as a function of magnetic field strength, topology and planetary spin rate and its importance in conservation of magnetic flux globally. Sittler, E. C., Jr., K. W. Ogilvie, and J. D. Scudder, 1983. Survey of low-energy plasma electrons in Saturn's magnetosphere: Voyager 1 and 2, J. Geophys. Res., 88, 8847- 8870. Rymer, A. M., Mauk, B. H. , Hill, T. W., Paranicas, C., Mitchell, D. G., Coates, A. J., Young, D. T. , 2008. Electron circulation in Saturn's magnetosphere. J. Geophys. Res.113, A01201.

  15. ULY JUP COSPIN HIGH FLUX TELESCOPE HIGH RES. ION FLUX

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains ion flux data recorded by the COSPIN High Flux Telescope (HFT) during the Ulysses Jupiter encounter 1992-Jan-25 to 1992-Feb-18.

  16. Physiology of Ramadan fasting

    OpenAIRE

    Shokoufeh Bonakdaran

    2016-01-01

    Considering the emphasis of Islam on the importance of fasting, Muslims attempt to fast from dawn until sunset during the holy month of Ramadan. Fasting is associated with several benefits for normal and healthy individuals. However, it could pose high risks to the health of diabetic patients due to certain physiological changes. This study aimed to compare the physiological changes associated with fasting in healthy individuals and diabetic patients during Ramadan. Furthermore, we reviewed t...

  17. Ramadan, fasting and pregnancy

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery...

  18. Fast determination of plasma parameters

    International Nuclear Information System (INIS)

    Wijnands, T.J.; Parlange, F.; Joffrin, E.

    1995-01-01

    Fast analysis of diagnostic signals of a tokamak discharge is demonstrated by using 4 fundamentally different techniques. A comparison between Function Parametrization (FP), Canonical Correlation Analysis (CCA) and a particular Neural Network (NN) configuration known as the Multi Layer Perceptron (MLP) is carried out, thereby taking a unique linear model based on a Singular Value Decomposition (SVD) as a reference. The various techniques provide all functional representations of characteristic plasma parameters in terms of the values of the measurements and are based on an analysis of a large, experimentally achieved database. A brief mathematical description of the various techniques is given, followed by two particular applications to Tore Supra diagnostic data. The first problem is concerned with the identification of the plasma boundary parameters using the poloidal field and differential poloidal flux measurements. A second application involves the interpretation of line integrated data from the multichannel interfero-polarimeter to obtain the central value of the safety factor. (author) 4 refs.; 3 figs

  19. How citation boosts promote scientific paradigm shifts and nobel prizes.

    Directory of Open Access Journals (Sweden)

    Amin Mazloumian

    Full Text Available Nobel Prizes are commonly seen to be among the most prestigious achievements of our times. Based on mining several million citations, we quantitatively analyze the processes driving paradigm shifts in science. We find that groundbreaking discoveries of Nobel Prize Laureates and other famous scientists are not only acknowledged by many citations of their landmark papers. Surprisingly, they also boost the citation rates of their previous publications. Given that innovations must outcompete the rich-gets-richer effect for scientific citations, it turns out that they can make their way only through citation cascades. A quantitative analysis reveals how and why they happen. Science appears to behave like a self-organized critical system, in which citation cascades of all sizes occur, from continuous scientific progress all the way up to scientific revolutions, which change the way we see our world. Measuring the "boosting effect" of landmark papers, our analysis reveals how new ideas and new players can make their way and finally triumph in a world dominated by established paradigms. The underlying "boost factor" is also useful to discover scientific breakthroughs and talents much earlier than through classical citation analysis, which by now has become a widespread method to measure scientific excellence, influencing scientific careers and the distribution of research funds. Our findings reveal patterns of collective social behavior, which are also interesting from an attention economics perspective. Understanding the origin of scientific authority may therefore ultimately help to explain how social influence comes about and why the value of goods depends so strongly on the attention they attract.

  20. Heterologous Prime-Boost Immunisation Regimens Against Infectious Diseases

    Science.gov (United States)

    2006-08-01

    virulence challenge. Vet Res 2003, 34(1), 119-125. 95 Degano, P., Schneider, J., Hannan, C.M., Gilbert, S.C. & Hill, A.V. Gene gun intradermal DNA...phosphate guanosine oligodeoxynucleotide (CpG) as an adjuvant with protein as a prime followed by adenovirus boost [62]; a rabies virus (RV) vaccine...intratracheal virulent M. Bovis challenge even though the elicited T-cell responses were higher than those seen in the DNA alone vaccinated group of animals

  1. Single-Phase Direct Boost AC-AC Converter

    Directory of Open Access Journals (Sweden)

    URSARU, O.

    2017-11-01

    Full Text Available This paper introduces and studies a boost AC-AC converter circuit that can be used to supply power to the 220V receivers in the 110V grids or to increase and adjust voltage at the end of long lines. High frequency AC-AC converters have better specifications than alternative voltage phase control drives with thyristors or TRIACs. When frequency exceeds 20kHz, noise is eliminated, filters are smaller and efficiency is higher. The current waveform is much better, the output voltage can be higher than the input voltage and voltage control is more accurate.

  2. Closed-loop waveform control of boost inverter

    DEFF Research Database (Denmark)

    Zhu, Guo Rong; Xiao, Cheng Yuan; Wang, Haoran

    2016-01-01

    The input current of single-phase inverter typically has an AC ripple component at twice the output frequency, which causes a reduction in both the operating lifetime of its DC source and the efficiency of the system. In this paper, the closed-loop performance of a proposed waveform control method...... to eliminate such a ripple current in boost inverter is investigated. The small-signal stability and the dynamic characteristic of the inverter system for input voltage or wide range load variations under the closed-loop waveform control method are studied. It is validated that with the closedloop waveform...

  3. Quasi-Y-Source Boost DC–DC Converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    In this letter, a new topology called “quasi-Y-source dc-dc converter” is presented. It inherits all the advantages of the original Y-source converter. In addition, the new topology draws a continuous current from the source, which is definitely more appropriate for most renewable sources. It als...... has dc-current-blocking capacitors, which will definitely help to prevent the coupled inductor core from saturation. Experimental testing has proven the validity of the proposed network and its application as a high boost dc-dc converter....

  4. ATLAS searches for New Physics with Boosted Objects

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    With the increase of energy and luminosity at the LHC, searches for new physics are focusing on the multi-TeV mass range. Decays of heavy resonances associated with new physics in this mass range often result in highly boosted very massive objects such as W/Z bosons or Top quarks. New reconstruction techniques, based on jet sub-structure algorithms, are needed to efficiently reconstruct such decay signatures. We will review recent ATLAS developments of jet sub-structure reconstruction tools, and their application to searches for physics beyond the Standard Model.

  5. Dimensional Representation and Gradient Boosting for Seismic Event Classification

    Science.gov (United States)

    Semmelmayer, F. C.; Kappedal, R. D.; Magana-Zook, S. A.

    2017-12-01

    In this research, we conducted experiments of representational structures on 5009 seismic signals with the intent of finding a method to classify signals as either an explosion or an earthquake in an automated fashion. We also applied a gradient boosted classifier. While perfect classification was not attained (approximately 88% was our best model), some cases demonstrate that many events can be filtered out as very high probability being explosions or earthquakes, diminishing subject-matter experts'(SME) workload for first stage analysis. It is our hope that these methods can be refined, further increasing the classification probability.

  6. Distributed Generation using Indirect Matrix Converter in Boost Operating Mode

    DEFF Research Database (Denmark)

    Liu, Xiong; Loh, Poh Chiang; Wang, Peng

    2011-01-01

    , reverse power flow operation of IMC can be implemented to meet voltage boost requirement, where the input ac source is connected to the converter's voltage source side and the output utility grid or load is connected to the current source side. This paper proposes control schemes of IMC under reverse...... power flow operation for both grid-connected and isolated modes with distributed generation suggested as a potential application. In grid-connected mode, the commanded power must be extracted from the input ac source to the grid, in addition to guarantee sinusoidal input/output waveforms, unity input...

  7. High Efficiency Boost Converter with Three State Switching Cell

    DEFF Research Database (Denmark)

    Klimczak, Pawel; Munk-Nielsen, Stig

    2009-01-01

    is on performance improvement of this type of the converter. Use of foil windings helps to reduce conduction losses in magnetic components and to reduce size of these components. Also it has been demonstrated that the regulation range of this type of converter can be increased by operation with duty cycle lower......The boost converter with the three-state switching cell seems to be a good candidate for a dc-dc stage for non-isolated generators based on alternative energy sources. It provides a high voltage gain, a reduced voltage stress on transistors and limited input current ripples. In this paper the focus...

  8. Atmospheric lepton fluxes

    Directory of Open Access Journals (Sweden)

    Gaisser Thomas K.

    2015-01-01

    Full Text Available This review of atmospheric muons and neutrinos emphasizes the high energy range relevant for backgrounds to high-energy neutrinos of astrophysical origin. After a brief historical introduction, the main distinguishing features of atmospheric νμ and νe are discussed, along with the implications of the muon charge ratio for the νµ / ν̅µ ratio. Methods to account for effects of the knee in the primary cosmic-ray spectrum and the energy-dependence of hadronic interactions on the neutrino fluxes are discussed and illustrated in the context of recent results from IceCube. A simple numerical/analytic method is proposed for systematic investigation of uncertainties in neutrino fluxes arising from uncertainties in the primary cosmic-ray spectrum/composition and hadronic interactions.

  9. NEUTRON FLUX INTENSITY DETECTION

    Science.gov (United States)

    Russell, J.T.

    1964-04-21

    A method of measuring the instantaneous intensity of neutron flux in the core of a nuclear reactor is described. A target gas capable of being transmuted by neutron bombardment to a product having a resonance absorption line nt a particular microwave frequency is passed through the core of the reactor. Frequency-modulated microwave energy is passed through the target gas and the attenuation of the energy due to the formation of the transmuted product is measured. (AEC)

  10. Physics of magnetic flux ropes

    Science.gov (United States)

    Russell, C. T.; Priest, E. R.; Lee, L. C.

    The present work encompasses papers on the structure, waves, and instabilities of magnetic flux ropes (MFRs), photospheric flux tubes (PFTs), the structure and heating of coronal loops, solar prominences, coronal mass ejections and magnetic clouds, flux ropes in planetary ionospheres, the magnetopause, magnetospheric field-aligned currents and flux tubes, and the magnetotail. Attention is given to the equilibrium of MFRs, resistive instability, magnetic reconnection and turbulence in current sheets, dynamical effects and energy transport in intense flux tubes, waves in solar PFTs, twisted flux ropes in the solar corona, an electrodynamical model of solar flares, filament cooling and condensation in a sheared magnetic field, the magnetopause, the generation of twisted MFRs during magnetic reconnection, ionospheric flux ropes above the South Pole, substorms and MFR structures, evidence for flux ropes in the earth magnetotail, and MFRs in 3D MHD simulations.

  11. Topological Design and Modulation Strategy for Buck-Boost Three-Level Inverters

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Teodorescu, Remus

    2009-01-01

    To date, designed topologies for dc-ac inversion with both voltage buck and boost capabilities are mainly focused on two-level circuitries with extensions to three-level possibilities left nearly unexplored. Contributing to this area of research, this paper presents the design of a number of viable...... can perform distinct five-level line voltage and three-level phase voltage switching by simply controlling the active switches located in the designed voltage boost section of the circuits. As a cost saving option, one active switch can further be removed from the voltage boost section of the circuits...... buck-boost threelevel inverters that can also support bidirectional power conversion. The proposed front-end circuitry is developed from the C´ ukderived buck-boost two-level inverter, and by using the "alternative phase opposition disposition" modulation scheme, the buck-boost three-level inverters...

  12. Application of a synchronous generator with a boost converter in wind turbines: an experimental overview

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Rasmussen, Tonny Wederberg; Jensen, Bogi Bech

    2012-01-01

    An electrical structure of a variable-speed wind turbine based on an externally excited synchronous generator; a passive diode rectifier; and a boost converter is discussed in this study. The clear advantage of such a system is its lower-semi-conductor devices count. A brief theoretical explanation...... of such a system is included. A boost converter normally utilies an inductor (energy storage) to boost the voltage level from its input to a higher output value. This study analyses the possibility of using the generator inductance as a boost inductor. It is discussed and verified in the study that for the given...... switching frequency of the boost converter (fs=1= kHz), the generator sub-transient inductance (not the synchronous inductance) appears as an equivalent inductance seen by the boost converter. The parasitic capacitors present in the generator terminals are often neglected from design issues. It is presented...

  13. Measuring performance in health care: case-mix adjustment by boosted decision trees.

    Science.gov (United States)

    Neumann, Anke; Holstein, Josiane; Le Gall, Jean-Roger; Lepage, Eric

    2004-10-01

    The purpose of this paper is to investigate the suitability of boosted decision trees for the case-mix adjustment involved in comparing the performance of various health care entities. First, we present logistic regression, decision trees, and boosted decision trees in a unified framework. Second, we study in detail their application for two common performance indicators, the mortality rate in intensive care and the rate of potentially avoidable hospital readmissions. For both examples the technique of boosting decision trees outperformed standard prognostic models, in particular linear logistic regression models, with regard to predictive power. On the other hand, boosting decision trees was computationally demanding and the resulting models were rather complex and needed additional tools for interpretation. Boosting decision trees represents a powerful tool for case-mix adjustment in health care performance measurement. Depending on the specific priorities set in each context, the gain in predictive power might compensate for the inconvenience in the use of boosted decision trees.

  14. Ramadan, faste og graviditet

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery......, but there are reports of decreased foetal movements. Furthermore, the fasting may have long-term health consequences for the offspring, especially when they reach their middle age. According to Islam and the interpretation, pregnant and breast-feeding women are allowed to postpone the fasting of the month of Ramadan...

  15. Fast ion collective Thomson scattering diagnostic for ITER: Design elements

    DEFF Research Database (Denmark)

    Tsakadze, Erekle; Bindslev, Henrik; Korsholm, Søren Bang

    2008-01-01

    The proposed fast ion collective Thomson scattering (CTS) diagnostic system for ITER provides the unique capability of measuring the temporally and spatially resolved velocity distribution of the confined fast ions and fusion alpha particles in a burning ITER plasma. The present paper describes t...... in the studies, and new HFS receiver mock-up measurements are presented as well as neutron flux calculations of the influence of the increased slot height....

  16. Simulation Opportunity Index, A Simple and Effective Method to Boost the Hydrocarbon Recovery

    KAUST Repository

    Saputra, Wardana

    2016-09-08

    During periods of low oil prices, profitability of field developments drops drastically. To help with this difficulty, a cost-effective method has been proposed to boost the hydrocarbon recovery by optimizing well locations through the Simulated Opportunity Index (SOI). SOI is an intelligent method to identify zones with high potential for production which is empirically calculated from basic rock and fluid properties, and from reservoir pressure as its energy capacity. In order to obtain the best results, the original SOI formula (Molina et al., 2009) was extended to both oil and gas fields. Based on this modified SOI formula, a software program has been developed to locate the best well locations considering multilayer, existing wells, and fault existences. This paper describes how the SOI software helps as a simple, fast, and accurate way to obtain the higher hydrocarbon production than that of trial-error method and previous studies in two different fields located in offshore Indonesia. On one hand, the proposed method could save money by minimizing the required number of wells. On the other hand, it could maximize profit by maximizing recovery.

  17. Using boosted decision trees for tau identification in the ATLAS experiment

    CERN Document Server

    Godfrey, Jennifer

    The ATLAS detector will begin taking data from p - p collisions in 2009. This experiment will allo w for man y dif ferent physics measurements and searches. The production of tau leptons at the LHC is a key signature of the decay of both the standard model Higgs (via H ! t t ) and SUSY particles. Taus have a short lifetime ( c t = 87 m m) and decay hadroni- cally 65% of the time. Man y QCD interactions produce similar hadronic sho wers and have cross-sections about 1 billion times lar ger than tau production. Multi variate techniques are therefore often used to distinguish taus from this background. Boosted Decision Trees (BDTs) are a machine-learning technique for developing cut-based discriminants which can signicantly aid in extracting small signal samples from overwhelming backgrounds. In this study , BDTs are used for tau identication for the ATLAS experiment. The y are a fast, exible alternati ve to existing discriminants with comparable or better performance.

  18. Boosting the FM-Index on the GPU: Effective Techniques to Mitigate Random Memory Access.

    Science.gov (United States)

    Chacón, Alejandro; Marco-Sola, Santiago; Espinosa, Antonio; Ribeca, Paolo; Moure, Juan Carlos

    2015-01-01

    The recent advent of high-throughput sequencing machines producing big amounts of short reads has boosted the interest in efficient string searching techniques. As of today, many mainstream sequence alignment software tools rely on a special data structure, called the FM-index, which allows for fast exact searches in large genomic references. However, such searches translate into a pseudo-random memory access pattern, thus making memory access the limiting factor of all computation-efficient implementations, both on CPUs and GPUs. Here, we show that several strategies can be put in place to remove the memory bottleneck on the GPU: more compact indexes can be implemented by having more threads work cooperatively on larger memory blocks, and a k-step FM-index can be used to further reduce the number of memory accesses. The combination of those and other optimisations yields an implementation that is able to process about two Gbases of queries per second on our test platform, being about 8 × faster than a comparable multi-core CPU version, and about 3 × to 5 × faster than the FM-index implementation on the GPU provided by the recently announced Nvidia NVBIO bioinformatics library.

  19. Actin Waves Do Not Boost Neurite Outgrowth in the Early Stages of Neuron Maturation

    Directory of Open Access Journals (Sweden)

    Simone Mortal

    2017-12-01

    Full Text Available During neurite development, Actin Waves (AWs emerge at the neurite base and move up to its tip, causing a transient retraction of the Growth Cone (GC. Many studies have shown that AWs are linked to outbursts of neurite growth and, therefore, contribute to the fast elongation of the nascent axon. Using long term live cell-imaging, we show that AWs do not boost neurite outgrowth and that neurites without AWs can elongate for several hundred microns. Inhibition of Myosin II abolishes the transient GC retraction and strongly modifies the AWs morphology. Super-resolution nanoscopy shows that Myosin IIB shapes the growth cone-like AWs structure and is differently distributed in AWs and GCs. Interestingly, depletion of membrane cholesterol and inhibition of Rho GTPases decrease AWs frequency and velocity. Our results indicate that Myosin IIB, membrane tension, and small Rho GTPases are important players in the regulation of the AW dynamics. Finally, we suggest a role for AWs in maintaining the GCs active during environmental exploration.

  20. Identifying Chemical-Disease Relationship in Biomedical Text Using a Multiple Kernel Learning-Boosting Method.

    Science.gov (United States)

    Sun, Yueping; Zhang, Yu; Li, Jiao

    2017-01-01

    Chemical-induced disease relations (CID) are crucial in various biomedical tasks. In the CID task of Biocreative V, no classifiers with multiple kernels have been developed. In this study, a multiple kernel learning-boosting (MKLB) method is proposed. Different kernel functions according to different types of features were constucted and boosted, each of which were learned with multiple kernels. Our multiple kernel learning-boosting (MKLB) method achieved a F1 score of 0.5068 without incorporating knowledge bases.

  1. Greenhouse gas flux dynamics in wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Silvola, J.; Alm, J.; Saarnio, S. [Joensuu Univ. (Finland). Dept. of Biology; Martikainen, P.J. [National Public Health Inst., Kuopio (Finland). Dept. of Environmental Microbiology

    1996-12-31

    Two important greenhouse gases, CO{sub 2} and CH{sub 4}, are closely connected to the carbon cycling of wetlands. Although virgin wetlands are mostly carbon accumulating ecosystems, major proportion of the CO{sub 2} bound annually in photosynthesis is released back to the atmosphere. Main portion of the carbon cycling in wetlands is quite fast while a small proportion of carbon diffusing from soil is released from organic matter, which may be ten thousand years old. Methane is formed in the anaerobic layers of wetlands, from where it is released gradually to the atmosphere. The decomposition in anaerobic conditions is very slow, which means that usually only a few percent of the annual carbon cycling takes place as methane. Research on CO{sub 2} fluxes of different virgin and managed peatlands was the main topic of this project during the first phase of SILMU. The measurements were made during two seasons in varying conditions in c. 30 study sites. In the second phase of SILMU the research topics were the spatial and temporal variation of CO{sub 2} and CH{sub 4} fluxes, the relationships between vegetation and gas fluxes as well as carbon balance studies in wetlands at some intensive sites

  2. AlignerBoost: A Generalized Software Toolkit for Boosting Next-Gen Sequencing Mapping Accuracy Using a Bayesian-Based Mapping Quality Framework.

    Directory of Open Access Journals (Sweden)

    Qi Zheng

    2016-10-01

    Full Text Available Accurate mapping of next-generation sequencing (NGS reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost's algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost.

  3. AlignerBoost: A Generalized Software Toolkit for Boosting Next-Gen Sequencing Mapping Accuracy Using a Bayesian-Based Mapping Quality Framework.

    Science.gov (United States)

    Zheng, Qi; Grice, Elizabeth A

    2016-10-01

    Accurate mapping of next-generation sequencing (NGS) reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely) mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost's algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost.

  4. Sliding Mode Control of a Bidirectional Buck/Boost DC-DC Converter with Constant Switching Frequency

    Directory of Open Access Journals (Sweden)

    A. Safari

    2018-03-01

    Full Text Available In this paper, sliding mode control (SMC for a bidirectional buck/boost DC-DC converter (BDC with constant frequency in continuous conduction mode (CCM is discussed. Since the converter is a high-order converter, the reduced-order sliding manifold is exploited. Because of right-half-plan zero (RHPZ in the converter’s duty ratio to output voltage transfer function, sliding mode current controller is used. This controller benefits from various advantages such as fast dynamic response, robustness, stable and small variation of the settling time over a wide range of operation conditions. Because the converter operates in both step-down and step-up modes, two sliding manifold is derived for each mode. The existence and stability conditions are analyzed for both SMC in step-down and step-up modes. Finally, Simulation results are also provided to justify the feasibility of the controller using MATLAB/Simulink.

  5. Playing tag with ANN: boosted top identification with pattern recognition

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Leandro G. [Institut de Biologie de l’École Normale Supérieure (IBENS), Inserm 1024- CNRS 8197,46 rue d’Ulm, 75005 Paris (France); Backović, Mihailo [Center for Cosmology, Particle Physics and Phenomenology - CP3,Universite Catholique de Louvain,Louvain-la-neuve (Belgium); Cliche, Mathieu [Laboratory for Elementary Particle Physics, Cornell University,Ithaca, NY 14853 (United States); Lee, Seung J. [Department of Physics, Korea Advanced Institute of Science and Technology,335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); School of Physics, Korea Institute for Advanced Study,Seoul 130-722 (Korea, Republic of); Perelstein, Maxim [Laboratory for Elementary Particle Physics, Cornell University,Ithaca, NY 14853 (United States)

    2015-07-17

    Many searches for physics beyond the Standard Model at the Large Hadron Collider (LHC) rely on top tagging algorithms, which discriminate between boosted hadronic top quarks and the much more common jets initiated by light quarks and gluons. We note that the hadronic calorimeter (HCAL) effectively takes a “digital image' of each jet, with pixel intensities given by energy deposits in individual HCAL cells. Viewed in this way, top tagging becomes a canonical pattern recognition problem. With this motivation, we present a novel top tagging algorithm based on an Artificial Neural Network (ANN), one of the most popular approaches to pattern recognition. The ANN is trained on a large sample of boosted tops and light quark/gluon jets, and is then applied to independent test samples. The ANN tagger demonstrated excellent performance in a Monte Carlo study: for example, for jets with p{sub T} in the 1100–1200 GeV range, 60% top-tag efficiency can be achieved with a 4% mis-tag rate. We discuss the physical features of the jets identified by the ANN tagger as the most important for classification, as well as correlations between the ANN tagger and some of the familiar top-tagging observables and algorithms.

  6. Comparison of posterior fossa and tumor bed boost in medulloblastoma.

    Science.gov (United States)

    Paulino, A C; Saw, C B; Wen, B C

    2000-10-01

    To quantify the difference between the area of brain irradiated using the posterior fossa boost (PFB) and tumor bed boost (TBB) in medulloblastoma, we studied 15 simulation radiographs of patients treated in our institution from 1990 and 1999. The PFB was compared with the TBB, which was defined as the tumor bed plus 2-cm margin as demonstrated by postoperative magnetic resonance imaging. The PFB field treated a mean area of 9.43 cm2 more brain than the TBB. In 3 patients (20%), the area of the brain in the TBB was larger than the PFB. In 11 patients (73.3%), the PFB field had more than 10% more brain than the TBB. The cochlea was in the PFB and TBB field in all patients. In more than two thirds of patients, the area of brain irradiated with the PFB was at least 10% greater than the TBB. Future studies are needed to determine whether the TBB can replace the PFB in patients with medulloblastoma.

  7. Boosting color feature selection for color face recognition.

    Science.gov (United States)

    Choi, Jae Young; Ro, Yong Man; Plataniotis, Konstantinos N

    2011-05-01

    This paper introduces the new color face recognition (FR) method that makes effective use of boosting learning as color-component feature selection framework. The proposed boosting color-component feature selection framework is designed for finding the best set of color-component features from various color spaces (or models), aiming to achieve the best FR performance for a given FR task. In addition, to facilitate the complementary effect of the selected color-component features for the purpose of color FR, they are combined using the proposed weighted feature fusion scheme. The effectiveness of our color FR method has been successfully evaluated on the following five public face databases (DBs): CMU-PIE, Color FERET, XM2VTSDB, SCface, and FRGC 2.0. Experimental results show that the results of the proposed method are impressively better than the results of other state-of-the-art color FR methods over different FR challenges including highly uncontrolled illumination, moderate pose variation, and small resolution face images.

  8. Playing tag with ANN: boosted top identification with pattern recognition

    International Nuclear Information System (INIS)

    Almeida, Leandro G.; Backović, Mihailo; Cliche, Mathieu; Lee, Seung J.; Perelstein, Maxim

    2015-01-01

    Many searches for physics beyond the Standard Model at the Large Hadron Collider (LHC) rely on top tagging algorithms, which discriminate between boosted hadronic top quarks and the much more common jets initiated by light quarks and gluons. We note that the hadronic calorimeter (HCAL) effectively takes a “digital image" of each jet, with pixel intensities given by energy deposits in individual HCAL cells. Viewed in this way, top tagging becomes a canonical pattern recognition problem. With this motivation, we present a novel top tagging algorithm based on an Artificial Neural Network (ANN), one of the most popular approaches to pattern recognition. The ANN is trained on a large sample of boosted tops and light quark/gluon jets, and is then applied to independent test samples. The ANN tagger demonstrated excellent performance in a Monte Carlo study: for example, for jets with p T in the 1100–1200 GeV range, 60% top-tag efficiency can be achieved with a 4% mis-tag rate. We discuss the physical features of the jets identified by the ANN tagger as the most important for classification, as well as correlations between the ANN tagger and some of the familiar top-tagging observables and algorithms.

  9. Iatrogenic Cushing's syndrome after triamcinolone plus ritonavir-boosted atazanavir.

    Science.gov (United States)

    Jakeman, Bernadette; Conklin, Jessica; Bouchonville, Matthew; Thornton, Karla

    2015-01-01

    To describe a case of iatrogenic Cushing's syndrome (ICS) following a triamcinolone injection for subscapular bursitis in an HIV-positive patient receiving an antiretroviral regimen that included ritonavir boosted-atazanavir. University outpatient HIV clinic. A 60-year-old HIV-positive man on a ritonavir-boosted, atazanavir-containing antiretroviral regimen was diagnosed with subscapular bursitis. The patient received two intrabursal injections with 1% lidocaine plus triamcinolone 20 mg. Four weeks after the injections, the patient experienced symptoms of Cushing's syndrome with a pronounced drop in his CD4+ T-cell count, requiring treatment of oral candidiasis and prophylaxis for opportunistic infections. The interaction between ritonavir and oral corticosteroids, resulting in ICS, has been established. This case adds to the literature as one of the few cases illustrating that interaction can also occur between ritonavir and intrabursal administration of corticosteroids. This case further supports concerns regarding use of corticosteroids in HIV-infected patients who are treated with ritonavir-containing antiretroviral regimens.

  10. Data to support "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations & Biological Condition"

    Data.gov (United States)

    U.S. Environmental Protection Agency — Spreadsheets are included here to support the manuscript "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition". This...

  11. Electron and high-dose-rate brachytherapy boost in the conservative treatment of stage I-II breast cancer. First results of the randomized Budapest boost trial

    International Nuclear Information System (INIS)

    Polgar, C.; Fodor, J.; Orosz, Z.

    2002-01-01

    Background and Aims: To evaluate the effect of electron and high-dose-rate brachytherapy (HDR BT) boost on local tumor control (LTC), side effects and cosmesis after breast-conserving surgery (BCS) in a prospective randomized study. Patients and Methods: 207 women with stage I-II breast cancer who underwent BCS were treated by 50 Gy irradiation to the whole breast and then randomly assigned to receive either a boost to the tumor bed (n=104) or no further radiotherapy (n=103). Boost treatments consisted of either 16 Gy electron irradiation (n=52) or 12-14.25 Gy HDR BT (n=52). Breast cancer-related events, side effects, and cosmetic results were assessed. Results: At a median follow-up of 5.3 years, the crude rate of local recurrence was 6.7% (7/104) with and 15.5% (16/103) without boost. The 5-year probability of LTC, relapse-free survival (RFS), and cancer-specific survival (CSS) was 92.7% vs 84.9% (p=0.049), 76.6% vs 66.2% (p=0.044), and 90.4% vs. 82.1% (p=0.053), respectively. There was no significant difference in LTC between patients treated with electron or HDR BT boost (94.2% vs 91.4%; p=0.74). On multivariate analysis, patient age <40 years (RR: 4.53), positive margin status (RR: 4.17), and high mitotic activity index (RR: 3.60) were found to be significant risk factors for local recurrence. The incidence of grade 2-3 side effects was higher in the boost arm (17.3% vs 7.8%; p=0.03). However, the rate of excellent/good cosmetic results was similar for the two arms (85.6% vs 91.3%; p=0.14). Cosmesis was rated as excellent/good in 88.5% of patients treated with HDR BT and 82.7% of patients with electron boost (p=0.29). Conclusions: Boost dose significantly improves LTC and RFS in patients treated with BCS and radiotherapy. In spite of the higher incidence of late side effects in the boost arm, boost dose is strongly recommended for patients at high risk for local recurrence. Positive or close margin status, high mitotic activity index, and young patient age

  12. Transient critical heat flux under flow coast-down in vertical annulus with non-uniform heat flux distribution

    International Nuclear Information System (INIS)

    Moon, S.K.; Chun, S.Y.; Choi, K.Y.; Yang, S.K.

    2001-01-01

    An experimental study on transient critical heat flux (CHF) under flow coast-down has been performed for water flow in a non-uniformly heated vertical annulus under low flow and a wide range of pressure conditions. The objectives of this study are to systematically investigate the effect of the flow transient on the CHF and to compare the transient CHF with steady state CHF. The transient CHF experiments have been performed for three kinds of flow transient modes based on the coast-down data of the Kori 3/4 nuclear power plant reactor coolant pump. Most of the CHFs occurred in the annular-mist flow regime. Thus, it means that the possible CHF mechanism might be the liquid film dryout in the annular-mist flow regime. For flow transient mode with the smallest flow reduction rate, the time-to-CHF is the largest. At the same inlet subcooling, system pressure and heat flux, the effect of the initial mass flux on the critical mass flux can be negligible. However, the effect of the initial mass flux on the time-to-CHF becomes large as the heat flux decreases. Usually, the critical mass flux is large for slow flow reduction. There is a pressure effect on the ratio of the transient CHF data to steady state CHF data. Some conventional correlations show relatively better CHF prediction results for high system pressure, high quality and slow transient modes than for low system pressure, low quality and fast transient modes. (author)

  13. Reactor flux calculations

    Energy Technology Data Exchange (ETDEWEB)

    Lhuillier, D. [Commissariat à l' Énergie Atomique et aux Énergies Alternatives, Centre de Saclay, IRFU/SPhN, 91191 Gif-sur-Yvette (France)

    2013-02-15

    The status of the prediction of reactor anti-neutrino spectra is presented. The most accurate method is still the conversion of total β spectra of fissionning isotopes as measured at research reactors. Recent re-evaluations of the conversion process led to an increased predicted flux by few percent and were at the origin of the so-called reactor anomaly. The up to date predictions are presented with their main sources of error. Perspectives are given on the complementary ab-initio predictions and upcoming experimental cross-checks of the predicted spectrum shape.

  14. Australian methane fluxes

    International Nuclear Information System (INIS)

    Williams, D.J.

    1990-01-01

    Estimates are provided for the amount of methane emitted annually into the atmosphere in Australia for a variety of sources. The sources considered are coal mining, landfill, motor vehicles, natural gas suply system, rice paddies, bushfires, termites, wetland and animals. This assessment indicates that the major sources of methane are natural or agricultural in nature and therefore offer little scope for reduction. Nevertheless the remainder are not trival and reduction of these fluxes could play a significant part in any Australian action on the greenhouse problem. 19 refs., 7 tabs., 1 fig

  15. [The flux of historiography].

    Science.gov (United States)

    Mazzolini, R G

    2001-01-01

    The author places Grmek's editorial within the flux of the historiographical debate which, since the middle of the 1970s, has concentrated on two major crises due to the end of social science-oriented 'scientific history' and to the 'linguistic turn'. He also argues that Grmek's historiographical work of the 1980s and 1990s was to some extent an alternative to certain observed changes in historical fashion and has achieved greater intelligibility because of its commitment to a rational vision of science and historiography.

  16. High-Dose-Rate Brachytherapy Boost Effect on Local Tumor Control in Young Women With Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Guinot, Jose-Luis, E-mail: jguinot@fivo.org [Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain); Baixauli-Perez, Cristobal [Health Services Research Unit, Center for Public Health Research, Valencia (Spain); Soler, Pablo; Tortajada, Maria Isabel; Moreno, Araceli; Santos, Miguel Angel; Mut, Alejandro [Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain); Gozalbo, Francisco [Department of Pathology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain); Arribas, Leoncio [Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain)

    2015-01-01

    Purpose: To evaluate the local control rate and complications of a single fraction of high-dose-rate brachytherapy (HDR BT) boost in women aged 45 yeas and younger after breast-conserving therapy. Methods and Materials: Between 1999 and 2007, 167 patients between the ages of 26 and 45 years old (72 were 40 years old or younger), with stages T1 to T2 invasive breast cancer with disease-free margin status of at least 5 mm after breast-conserving surgery received 46 to 50 Gy whole-breast irradiation plus a 7-Gy HDR-BT boost (“fast boost”). An axillary dissection was performed in 72.5% of the patients and sentinel lymph node biopsy in 27.5%. A supraclavicular area was irradiated in 19% of the patients. Chemotherapy was used in 86% of the patients and hormone treatment in 77%. Clinical nodes were present in 18% and pathological nodes in 29%. The pathological stage was pT0: 5%, pTis: 3%, pT1: 69% and pT2: 23%. Intraductal component was present in 40% and 28% were G3. Results: At a median follow-up of 92 months, 9 patients relapsed on the margin of the implant, and 1 patient in another quadrant, resulting in a 10-year local relapse rate of 4.3% and a breast relapse rate of 4.9%, with breast preservation in 93.4%; no case of mastectomy due to poor cosmesis arose. Actuarial 5- and 10-year disease-free, cause-specific, and overall survival rates were 87.9% and 85.8%, and 92.1% and 88.4%, and 92.1% and 87.3%, respectively. In a univariate analysis, triple-negative cases and negative hormone receptors did worse, but in a multivariate analysis, only the last factor was significant for local and breast control. Asymptomatic fibrosis G2 was recorded in 3 cases, and there were no other late complications. Cosmetic results were good to excellent in 97% of cases. Conclusions: A single dose of 7 Gy using the fast-boost technique is well tolerated, with a low rate of late complications and improved local tumor control in women aged 45 and younger, compared to published data

  17. The fast breeder reactor

    International Nuclear Information System (INIS)

    Collier, J.

    1990-01-01

    The arguments for and against the fast breeder reactor are debated. The case for the fast reactor is that the world energy demand will increase due to increasing population over the next forty years and that the damage to the global environment from burning fossil fuels which contribute to the greenhouse effect. Nuclear fission is the only large scale energy source which can achieve a cut in the use of carbon based fuels although energy conservation and renewable sources will also be important. Fast reactors produce more energy from uranium than other types of (thermal) reactors such as AGRs and PWRs. Fast reactors would be important from about 2020 onwards especially as by then many thermal reactors will need to be replaced. Fast reactors are also safer than normal reactors. The arguments against fast reactors are largely economic. The cost, especially the capital cost is very high. The viability of the technology is also questioned. (UK)

  18. Fast breeder reactors

    International Nuclear Information System (INIS)

    Heinzel, V.

    1975-01-01

    The author gives a survey of 'fast breeder reactors'. In detail the process of breeding, the reasons for the development of fast breeders, the possible breeder reactors, the design criteria, fuels, cladding, coolant, and safety aspects are reported on. Design data of some experimental reactors already in operation are summarized in stabular form. 300 MWe Prototype-Reactors SNR-300 and PFR are explained in detail and data of KWU helium-cooled fast breeder reactors are given. (HR) [de

  19. Upscaling surface energy fluxes over the North Slope of Alaska using airborne eddy-covariance measurements and environmental response functions

    Science.gov (United States)

    Serafimovich, Andrei; Metzger, Stefan; Hartmann, Jörg; Kohnert, Katrin; Zona, Donatella; Sachs, Torsten

    2018-03-01

    The objective of this study was to upscale airborne flux measurements of sensible heat and latent heat and to develop high resolution flux maps. In order to support the evaluation of coupled atmospheric/land-surface models we investigated spatial patterns of energy fluxes in relation to land-surface properties. We used airborne eddy-covariance measurements acquired by the POLAR 5 research aircraft in June-July 2012 to analyze surface fluxes. Footprint-weighted surface properties were then related to 21 529 sensible heat flux observations and 25 608 latent heat flux observations using both remote sensing and modelled data. A boosted regression tree technique was used to estimate environmental response functions between spatially and temporally resolved flux observations and corresponding biophysical and meteorological drivers. In order to improve the spatial coverage and spatial representativeness of energy fluxes we used relationships extracted across heterogeneous Arctic landscapes to infer high-resolution surface energy flux maps, thus directly upscaling the observational data. These maps of projected sensible heat and latent heat fluxes were used to assess energy partitioning in northern ecosystems and to determine the dominant energy exchange processes in permafrost areas. This allowed us to estimate energy fluxes for specific types of land cover, taking into account meteorological conditions. Airborne and modelled fluxes were then compared with measurements from an eddy-covariance tower near Atqasuk. Our results are an important contribution for the advanced, scale-dependent quantification of surface energy fluxes and provide new insights into the processes affecting these fluxes for the main vegetation types in high-latitude permafrost areas.

  20. Islamic fasting and health.

    Science.gov (United States)

    Azizi, Fereidoun

    2010-01-01

    Muslims fast from sunrise to sunset during the month of Ramadan, the 9th lunar month. The duration of fasting varies from 13 to 18 h/day. Fasting includes avoidance of drinking liquids and eating foods. The aim of this article is to review health-related aspects of Ramadan fasting. Related abstracts from 1960 to 2009 were obtained from Medline and local journals in Islamic countries. One hundred and thirteen articles meeting the criteria for paper selection were reviewed in depth to identify details of related materials. During the fasting days of Ramadan glucose homeostasis is maintained by meals taken before dawn and by liver glycogen stores. Changes in serum lipids are variable and depend on the quality and quantity of food consumption and changes in weight. Compliant, well-controlled type 2 diabetics may observe Ramadan fasting, but fasting is not recommended for type 1, noncompliant, poorly controlled and pregnant diabetics. There are no adverse effects of Ramadan fasting on the heart, lung, liver, kidney, eyes, hematologic profile, endocrine and neuropsychiatric functions. Although Ramadan fasting is safe for all healthy individuals, those with various diseases should consult their physicians and follow scientific recommendations.

  1. Cell swelling and glycogen metabolism in hepatocytes from fasted rats

    NARCIS (Netherlands)

    Gustafson, L. A.; Jumelle-Laclau, M. N.; van Woerkom, G. M.; van Kuilenburg, A. B.; Meijer, A. J.

    1997-01-01

    Cell swelling is known to increase net glycogen production from glucose in hepatocytes from fasted rats by activating glycogen synthase. Since both active glycogen synthase and phosphorylase are present in hepatocytes, suppression of flux through phosphorylase may also contribute to the net increase

  2. Confinement forces in fast backward nucleon production off nuclei

    International Nuclear Information System (INIS)

    Kopeliovich, B.Z.; Niedermayer, F.

    1982-01-01

    Multiple colour exchange mechanism is proposed to describe fast backward nucleon production off nuclei at high energies. Cross section of hd → psub(B)X reaction is calculated in the colour flux tube model. This contribution is found to dominate in the hard part of momentum spectra

  3. Defined three-dimensional microenvironments boost induction of pluripotency

    Science.gov (United States)

    Caiazzo, Massimiliano; Okawa, Yuya; Ranga, Adrian; Piersigilli, Alessandra; Tabata, Yoji; Lutolf, Matthias P.

    2016-03-01

    Since the discovery of induced pluripotent stem cells (iPSCs), numerous approaches have been explored to improve the original protocol, which is based on a two-dimensional (2D) cell-culture system. Surprisingly, nothing is known about the effect of a more biologically faithful 3D environment on somatic-cell reprogramming. Here, we report a systematic analysis of how reprogramming of somatic cells occurs within engineered 3D extracellular matrices. By modulating microenvironmental stiffness, degradability and biochemical composition, we have identified a previously unknown role for biophysical effectors in the promotion of iPSC generation. We find that the physical cell confinement imposed by the 3D microenvironment boosts reprogramming through an accelerated mesenchymal-to-epithelial transition and increased epigenetic remodelling. We conclude that 3D microenvironmental signals act synergistically with reprogramming transcription factors to increase somatic plasticity.

  4. Usefulness of effective field theory for boosted Higgs production

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Lewis, I. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Zeng, Mao [Stony Brook Univ., Stony Brook, NY (United States)

    2015-04-07

    The Higgs + jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high pT. We examine the production process using an effective field theory (EFT) language and discussing the possibility of determining the nature of the underlying high-scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension-5 and dimension-7 are included in the EFT. As a byproduct of our study, we examine the region of validity of the EFT. Dimension-7 contributions in realistic new physics models give effects in the high pT tail of the Higgs signal which are so tiny that they are likely to be unobservable.

  5. Searches for New Physics in boosted topologies at ATLAS

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The large increase in collision energy that the LHC reached in Run 2  provides an unprecedented opportunity to search for new physics beyond the Standard Model (SM). Various extensions of the SM predict heavy resonances at the TeV scale, which couple predominantly to the Higgs and electroweak gauge bosons and to top and bottom quarks. At resonance masses well above 1 TeV, these searches face specific challenges and  employ new identification techniques to disentangle the decay products of the boson in highly boosted configurations. This talk will review recent ATLAS Run-2 searches in various possible final states as well as  the dedicated techniques related to the specificity of such event topologies.

  6. Distributed control system for parallel-connected DC boost converters

    Science.gov (United States)

    Goldsmith, Steven

    2017-08-15

    The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.

  7. Passive vs Active Knowledge Transfer: boosting grant proposal impact

    DEFF Research Database (Denmark)

    Grigorov, Ivo; Bayliss-Brown, Georgia; Murphy, David

    2017-01-01

    Research funders are increasingly concerned with measurable socio-economic impact of investment in research, and on increasingly shorter timescales. Innovation, and “open innovation” are the policy priorities of the moment and optimising the flow of ideas along the lab-2-market spectrum is essent......Research funders are increasingly concerned with measurable socio-economic impact of investment in research, and on increasingly shorter timescales. Innovation, and “open innovation” are the policy priorities of the moment and optimising the flow of ideas along the lab-2-market spectrum...... is essential for re-use of results, fuelling open innovation, and boosting socio-economic impact or public funded research....

  8. Metabolic engineering of resveratrol and other longevity boosting compounds.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y; Chen, H; Yu, O

    2010-09-16

    Resveratrol, a compound commonly found in red wine, has attracted many attentions recently. It is a diphenolic natural product accumulated in grapes and a few other species under stress conditions. It possesses a special ability to increase the life span of eukaryotic organisms, ranging from yeast, to fruit fly, to obese mouse. The demand for resveratrol as a food and nutrition supplement has increased significantly in recent years. Extensive work has been carried out to increase the production of resveratrol in plants and microbes. In this review, we will discuss the biosynthetic pathway of resveratrol and engineering methods to heterologously express the pathway in various organisms. We will outline the shortcuts and limitations of common engineering efforts. We will also discuss briefly the features and engineering challenges of other longevity boosting compounds.

  9. Experimental results with boosted top quarks in the final state

    CERN Document Server

    Erdmann, Johannes

    2014-01-01

    An overview of analyses using data at sqrt(s) = 7 TeV and 8 TeV of proton-proton collisions at the LHC is presented. These analyses use boosted techniques to search for new phenomena involving top quarks and to measure the production of top quarks at high transverse momenta. Such techniques involve top-quark tagging algorithms, boson-tagging algorithms, and strategies for b-tagging and lepton identification in the environment where the top quark decay products are close to each other. The strategies are optimized for the different final states and for different ranges of the transverse momenta of the particles involved, improving on traditional resolved analysis strategies.

  10. Boosting association rule mining in large datasets via Gibbs sampling

    Science.gov (United States)

    Qian, Guoqi; Rao, Calyampudi Radhakrishna; Sun, Xiaoying; Wu, Yuehua

    2016-01-01

    Current algorithms for association rule mining from transaction data are mostly deterministic and enumerative. They can be computationally intractable even for mining a dataset containing just a few hundred transaction items, if no action is taken to constrain the search space. In this paper, we develop a Gibbs-sampling–induced stochastic search procedure to randomly sample association rules from the itemset space, and perform rule mining from the reduced transaction dataset generated by the sample. Also a general rule importance measure is proposed to direct the stochastic search so that, as a result of the randomly generated association rules constituting an ergodic Markov chain, the overall most important rules in the itemset space can be uncovered from the reduced dataset with probability 1 in the limit. In the simulation study and a real genomic data example, we show how to boost association rule mining by an integrated use of the stochastic search and the Apriori algorithm. PMID:27091963

  11. A mechatronic power boosting design for piezoelectric generators

    International Nuclear Information System (INIS)

    Liu, Haili; Liang, Junrui; Ge, Cong

    2015-01-01

    It was shown that the piezoelectric power generation can be boosted by using the synchronized switch power conditioning circuits. This letter reports a self-powered and self-sensing mechatronic design in substitute of the auxiliary electronics towards a compact and universal synchronized switch solution. The design criteria are derived based on the conceptual waveforms and a two-degree-of-freedom analytical model. Experimental result shows that, compared to the standard bridge rectifier interface, the mechatronic design leads to an extra 111% increase of generated power from the prototyped piezoelectric generator under the same deflection magnitude excitation. The proposed design has introduced a valuable physical insight of electromechanical synergy towards the improvement of piezoelectric power generation

  12. An update on Shankhpushpi, a cognition-boosting Ayurvedic medicine.

    Science.gov (United States)

    Sethiya, Neeraj Kumar; Nahata, Alok; Mishra, Sri Hari; Dixit, Vinod Kumar

    2009-11-01

    Shankhpushpi is an Ayurvedic drug used for its action on the central nervous system, especially for boosting memory and improving intellect. Quantum of information gained from Ayurvedic and other Sanskrit literature revealed the existence of four different plant species under the name of Shankhpushpi, which is used in various Ayurvedic prescriptions described in ancient texts, singly or in combination with other herbs. The sources comprise of entire herbs with following botanicals viz., Convulvulus pluricaulis Choisy. (Convulvulaceae), Evolvulus alsinoides Linn. (Convulvulaceae), Clitoria ternatea Linn. (Papilionaceae) and Canscora decussata Schult. (Gentianaceae). A review on the available scientific information in terms of pharmacognostical characteristics, chemical constituents, pharmacological activities, preclinical and clinical applications of controversial sources of Shankhpushpi is prepared with a view to review scientific work undertaken on Shankhpushpi. It may provide parameters of differentiation and permit appreciation of variability of drug action by use of different botanical sources.

  13. Dark Matter "Collider" from Inelastic Boosted Dark Matter.

    Science.gov (United States)

    Kim, Doojin; Park, Jong-Chul; Shin, Seodong

    2017-10-20

    We propose a novel dark matter (DM) detection strategy for models with a nonminimal dark sector. The main ingredients in the underlying DM scenario are a boosted DM particle and a heavier dark sector state. The relativistic DM impinged on target material scatters off inelastically to the heavier state, which subsequently decays into DM along with lighter states including visible (standard model) particles. The expected signal event, therefore, accompanies a visible signature by the secondary cascade process associated with a recoiling of the target particle, differing from the typical neutrino signal not involving the secondary signature. We then discuss various kinematic features followed by DM detection prospects at large-volume neutrino detectors with a model framework where a dark gauge boson is the mediator between the standard model particles and DM.

  14. Boosting Discriminant Learners for Gait Recognition Using MPCA Features

    Directory of Open Access Journals (Sweden)

    Haiping Lu

    2009-01-01

    Full Text Available This paper proposes a boosted linear discriminant analysis (LDA solution on features extracted by the multilinear principal component analysis (MPCA to enhance gait recognition performance. Three-dimensional gait objects are projected in the MPCA space first to obtain low-dimensional tensorial features. Then, lower-dimensional vectorial features are obtained through discriminative feature selection. These feature vectors are then fed into an LDA-style booster, where several regularized and weakened LDA learners work together to produce a strong learner through a novel feature weighting and sampling process. The LDA learner employs a simple nearest-neighbor classifier with a weighted angle distance measure for classification. The experimental results on the NIST/USF “Gait Challenge” data-sets show that the proposed solution has successfully improved the gait recognition performance and outperformed several state-of-the-art gait recognition algorithms.

  15. A mechatronic power boosting design for piezoelectric generators

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Haili; Liang, Junrui, E-mail: liangjr@shanghaitech.edu.cn; Ge, Cong [School of Information Science and Technology, ShanghaiTech University, No. 8 Building, 319 Yueyang Road, Shanghai 200031 (China)

    2015-10-05

    It was shown that the piezoelectric power generation can be boosted by using the synchronized switch power conditioning circuits. This letter reports a self-powered and self-sensing mechatronic design in substitute of the auxiliary electronics towards a compact and universal synchronized switch solution. The design criteria are derived based on the conceptual waveforms and a two-degree-of-freedom analytical model. Experimental result shows that, compared to the standard bridge rectifier interface, the mechatronic design leads to an extra 111% increase of generated power from the prototyped piezoelectric generator under the same deflection magnitude excitation. The proposed design has introduced a valuable physical insight of electromechanical synergy towards the improvement of piezoelectric power generation.

  16. Pinning down top dipole moments with ultra-boosted tops

    CERN Document Server

    Aguilar-Saavedra, Juan A.; Mangano, Michelangelo L.

    2015-01-01

    We investigate existing and future hadron-collider constraints on the top dipole chromomagnetic and chromoelectric moments, two quantities that are expected to be modified in the presence of new physics. We focus first on recent measurements of the inclusive top pair production cross section at the Tevatron and at the Large Hadron Collider. We then analyse the role of top-antitop events produced at very large invariant masses, in the context of the forthcoming 13-14 TeV runs of the LHC, and at a future 100 TeV proton-proton collider. In this latter case, the selection of semileptonic decays to hard muons allows to tag top quarks boosted to the multi-TeV regime, strongly reducing the QCD backgrounds and leading to a significant improvement in the sensitivity to anomalous top couplings.

  17. Link prediction boosted psychiatry disorder classification for functional connectivity network

    Science.gov (United States)

    Li, Weiwei; Mei, Xue; Wang, Hao; Zhou, Yu; Huang, Jiashuang

    2017-02-01

    Functional connectivity network (FCN) is an effective tool in psychiatry disorders classification, and represents cross-correlation of the regional blood oxygenation level dependent signal. However, FCN is often incomplete for suffering from missing and spurious edges. To accurate classify psychiatry disorders and health control with the incomplete FCN, we first `repair' the FCN with link prediction, and then exact the clustering coefficients as features to build a weak classifier for every FCN. Finally, we apply a boosting algorithm to combine these weak classifiers for improving classification accuracy. Our method tested by three datasets of psychiatry disorder, including Alzheimer's Disease, Schizophrenia and Attention Deficit Hyperactivity Disorder. The experimental results show our method not only significantly improves the classification accuracy, but also efficiently reconstructs the incomplete FCN.

  18. Pilot of the BOOST-A™: An online transition planning program for adolescents with autism.

    Science.gov (United States)

    Hatfield, Megan; Murray, Nina; Ciccarelli, Marina; Falkmer, Torbjörn; Falkmer, Marita

    2017-12-01

    Many adolescents with autism face difficulties with the transition from high school into post-school activities. The Better OutcOmes & Successful Transitions for Autism (BOOST-A™) is an online transition planning program which supports adolescents on the autism spectrum to prepare for leaving school. This study describes the development of the BOOST-A™ and aimed to determine the feasibility and viability of the program. Two pilot studies were conducted. In Pilot A, the BOOST-A™ was trialled by six adolescents on the autism spectrum, their parents, and the professionals who worked with them, to determine its feasibility. In Pilot B, 88 allied health professionals (occupational therapists, speech pathologists, and psychologists) reviewed the BOOST-A™ to determine its viability. Participants rated the BOOST-A™ as a feasible tool for transition planning. The majority of allied health professionals agreed that it was a viable program. Based on participant feedback, the BOOST-A™ was modified to improve usability and feasibility. The BOOST-A™ is a viable and feasible program that has the potential to assist adolescents with autism in preparing for transitioning out of high school. Future research will determine the effectiveness of the BOOST-A™ with adolescents across Australia. © 2017 Occupational Therapy Australia.

  19. A Novel Single Switch Transformerless Quadratic DC/DC Buck-Boost Converter

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2017-01-01

    A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...

  20. Cross Voltage Control with Inner Hysteresis Current Control for Multi-output Boost Converter

    DEFF Research Database (Denmark)

    Nami, Alireza; Zare, Firuz; Blaabjerg, Frede

    2009-01-01

    Multi-output boost (MOB) converter is a novel DC-DC converter unlike the regular boost converter, has the ability to share its total output voltage and to have different series output voltage from a given duty cycle for low and high power applications. In this paper, discrete voltage control...

  1. Multiclass Boosting with Adaptive Group-Based kNN and Its Application in Text Categorization

    Directory of Open Access Journals (Sweden)

    Lei La

    2012-01-01

    Full Text Available AdaBoost is an excellent committee-based tool for classification. However, its effectiveness and efficiency in multiclass categorization face the challenges from methods based on support vector machine (SVM, neural networks (NN, naïve Bayes, and k-nearest neighbor (kNN. This paper uses a novel multi-class AdaBoost algorithm to avoid reducing the multi-class classification problem to multiple two-class classification problems. This novel method is more effective. In addition, it keeps the accuracy advantage of existing AdaBoost. An adaptive group-based kNN method is proposed in this paper to build more accurate weak classifiers and in this way control the number of basis classifiers in an acceptable range. To further enhance the performance, weak classifiers are combined into a strong classifier through a double iterative weighted way and construct an adaptive group-based kNN boosting algorithm (AGkNN-AdaBoost. We implement AGkNN-AdaBoost in a Chinese text categorization system. Experimental results showed that the classification algorithm proposed in this paper has better performance both in precision and recall than many other text categorization methods including traditional AdaBoost. In addition, the processing speed is significantly enhanced than original AdaBoost and many other classic categorization algorithms.

  2. Hedonic price models and indices based on boosting applied to the Dutch housing market

    NARCIS (Netherlands)

    M. Kagie (Martijn); M.C. van Wezel (Michiel)

    2006-01-01

    textabstractWe create a hedonic price model for house prices for six geographical submarkets in the Netherlands. Our model is based on a recent data mining technique called boosting. Boosting is an ensemble technique that combines multiple models, in our case decision trees, into a combined

  3. Modeling and Simulation of PMSG Wind Turbine with Boost Converter Working under Discontinuous Conduction Mode

    DEFF Research Database (Denmark)

    Qin, Nan; Xu, Zhao

    2008-01-01

    in the discontinuous conducting mode (DCM). The new wind turbine model with the variable speed control of the PMSG based on duty cycle control of the boost converter has been developed in Matlab Simulink. Simulation studies show that DCM working mode of the boost converter provides more flexibility in controlling...

  4. Y-Source Boost DC/DC Converter for Distributed Generation

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    This paper introduces a versatile Y-source boost dc/dc converter intended for distributed power generation, where high gain is often demanded. The proposed converter uses a Y-source impedance network realized with a tightly coupled three-winding inductor for high voltage boosting that is presently...

  5. Prime-boost vaccine strategy against viral infections: Mechanisms and benefits.

    Science.gov (United States)

    Kardani, Kimia; Bolhassani, Azam; Shahbazi, Sepideh

    2016-01-20

    The essential goal of vaccination is to generate potent and long-term protection against diseases. Among different vaccine modalities, prime-boost vaccine strategies could enhance cellular and also humoral immunity in several animal models. These strategies have been applied for the development of vaccines against important infectious diseases such as HIV, SIV, HCV, HSV, and HBV indicating promising results even in clinical trials. Several factors including selection of antigen, type of vector, delivery route, dose, adjuvant, boosting regimen, the order of vector injection, and the intervals between different vaccinations influence the outcome of prime-boost immunization approaches. The reported data suggest that the prime-boost strategy as a combination of vaccines (i.e., heterologous prime-boost) may be better than a single vaccine for protection against infectious diseases. Indeed, in many cases, heterologous prime-boost can be more immunogenic than homologous prime-boost strategy. This review discusses the recent advances in prime-boost immunization strategies as well as their benefits and mechanisms of action. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Single-Phase DC-AC Boost Converter | Odeh | Nigerian Journal of ...

    African Journals Online (AJOL)

    The proposed boost inverter configuration performs single stage power conversion, which minimizes switching losses and attains higher efficiency as compared to the conventional boost inverter. The steady-state operating principle of the power circuit configuration and control strategy are described. A multi-loop structure ...

  7. Pulse width modulated buck-boost five-level current source inverters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Gao, F.; Loh, P.C.

    2008-01-01

    -level buck-boost CSIs. Next by observing the hidden current charging path during inductive charging interval under APOD modulation, it is noted that the buck-boost five-level CSI can then be further modified with lesser active component without degrading output performance. To verify the theoretical findings...

  8. Boosting feature selection for Neural Network based regression.

    Science.gov (United States)

    Bailly, Kevin; Milgram, Maurice

    2009-01-01

    The head pose estimation problem is well known to be a challenging task in computer vision and is a useful tool for several applications involving human-computer interaction. This problem can be stated as a regression one where the input is an image and the output is pan and tilt angles. Finding the optimal regression is a hard problem because of the high dimensionality of the input (number of image pixels) and the large variety of morphologies and illumination. We propose a new method combining a boosting strategy for feature selection and a neural network for the regression. Potential features are a very large set of Haar-like wavelets which are well known to be adapted to face image processing. To achieve the feature selection, a new Fuzzy Functional Criterion (FFC) is introduced which is able to evaluate the link between a feature and the output without any estimation of the joint probability density function as in the Mutual Information. The boosting strategy uses this criterion at each step: features are evaluated by the FFC using weights on examples computed from the error produced by the neural network trained at the previous step. Tests are carried out on the commonly used Pointing 04 database and compared with three state-of-the-art methods. We also evaluate the accuracy of the estimation on FacePix, a database with a high angular resolution. Our method is compared positively to a Convolutional Neural Network, which is well known to incorporate feature extraction in its first layers.

  9. Permanent magnet flux-biased magnetic actuator with flux feedback

    Science.gov (United States)

    Groom, Nelson J. (Inventor)

    1991-01-01

    The invention is a permanent magnet flux-biased magnetic actuator with flux feedback for adjustably suspending an element on a single axis. The magnetic actuator includes a pair of opposing electromagnets and provides bi-directional forces along the single axis to the suspended element. Permanent magnets in flux feedback loops from the opposing electromagnets establish a reference permanent magnet flux-bias to linearize the force characteristics of the electromagnets to extend the linear range of the actuator without the need for continuous bias currents in the electromagnets.

  10. Flux effect analysis in WWER-440 reactor pressure vessel steels

    Science.gov (United States)

    Kryukov, A.; Blagoeva, D.; Debarberis, L.

    2013-11-01

    The results of long term research programme concerning the determination of irradiation embrittlement dependence on fast neutron flux for WWER-440 reactor pressure vessel steels before and after annealing are presented in this paper. The study of flux effect was carried out on commercial WWER-440 steels which differ significantly in phosphorous (0.013-0.036 wt%) and copper (0.08-0.20 wt%) contents. All specimens were irradiated in surveillance channel positions under similar conditions at high ˜4 × 1012 сm-2 s-1 and low ˜6 × 1011 сm-2 s-1 fluxes (E > 0.5 MeV) at a temperature of 270 °С. The radiation embrittlement was evaluated by transition temperature shift on the basis of Charpy specimens test results. In case of low flux, the measured Tk shifts could be 25-50 °C bigger than the Tk shifts obtained from high flux data. A significant flux effect is observed in WWER-440 reactor pressure vessel steels with higher copper content (>0.13 wt%).

  11. Coherent oscillations in a superconducting flux qubit without microwave pulses

    Energy Technology Data Exchange (ETDEWEB)

    Poletto, Stefano; Lisenfeld, Juergen; Lukashenko, Alexander; Ustinov, Alexey V. [Physikalisches Institut III, Universitaet Erlangen-Nuernberg (Germany); Castellano, Maria Gabriella; Chiarello, Fabio [Istituto di Fotonica e Nanotecnologie del CNR, Roma (Italy); Cosmelli, Carlo [Dipartimento di Fisica and INFN, Universita' di Roma La Sapienza (Italy); Carelli, Pasquale [Universita' degli Studi dell' Acquila (Italy)

    2008-07-01

    We report on observation of coherent oscillations in a superconducting flux qubit by using no microwave excitation but only nanosecond-long dc flux pulses. The investigated circuit is a double-SQUID consisting of a superconducting loop interrupted by a small dc-SQUID, which we control via two bias fluxes {phi}{sub c} and {phi}{sub x}. The potential energy profile of the qubit has the shape of a double well, where the flux {phi}{sub c} controls the height of the barrier between the two minima and the flux {phi}{sub x} changes the potential symmetry. The two computational states of the qubit are identified with the two energy minima and physically correspond to clockwise or anticlockwise circulating currents in the double-SQUID main loop. We observed coherent oscillations, in the frequency range between 8 and 20 GHz, induced by fast pulses of the control flux {phi}{sub c} modulating the barrier between the two potential wells. The quantum dynamics that leads to this kind of oscillations is composed of a non-adiabatic and adiabatic evolution of the two lowest energy states.

  12. Reactor neutron flux measuring device

    International Nuclear Information System (INIS)

    Okutani, Yasushi; Hayakawa, Toshifumi.

    1994-01-01

    The present invention concerns a device for displaying an approximate neutron flux distribution to recognize the neutron flux distribution of the whole reactor in a short period of time. The device of the present invention displays, the results of measurement for neutron fluxes collected by a data collecting section on every results of the measurements at measuring points situating at horizontally identical positions of the reactor core. In addition, every results of the measurements at the measuring points situating at the identical height in the reactor core are accumulated, and the results of the integration are graphically displayed. With such procedures, the neutron flux distribution in the entire reactor is approximately displayed. Existent devices could not recognize the neutron flux distribution of the entire reactor at a glance and it took much time for the recognition. The device of the present invention can recognize the neutron flux distribution of the entire reactor in a short period of time. (I.S.)

  13. Flux compactifications and generalized geometries

    International Nuclear Information System (INIS)

    Grana, Mariana

    2006-01-01

    Following the lectures given at CERN Winter School 2006, we present a pedagogical overview of flux compactifications and generalized geometries, concentrating on closed string fluxes in type II theories. We start by reviewing the supersymmetric flux configurations with maximally symmetric four-dimensional spaces. We then discuss the no-go theorems (and their evasion) for compactifications with fluxes. We analyse the resulting four-dimensional effective theories for Calabi-Yau and Calabi-Yau orientifold compactifications, concentrating on the flux-induced superpotentials. We discuss the generic mechanism of moduli stabilization and illustrate with two examples: the conifold in IIB and a T 6 /(Z 3 x Z 3 ) torus in IIA. We finish by studying the effective action and flux vacua for generalized geometries in the context of generalized complex geometry

  14. California's Future Carbon Flux

    Science.gov (United States)

    Xu, L.; Pyles, R. D.; Paw U, K.; Gertz, M.

    2008-12-01

    The diversity of the climate and vegetation systems in the state of California provides a unique opportunity to study carton dioxide exchange between the terrestrial biosphere and the atmosphere. In order to accurately calculate the carbon flux, this study couples the sophisticated analytical surface layer model ACASA (Advance Canopy-Atmosphere-Soil Algorithm, developed in the University of California, Davis) with the newest version of mesoscale model WRF (the Weather Research & Forecasting Model, developed by NCAR and several other agencies). As a multilayer, steady state model, ACASA incorporates higher-order representations of vertical temperature variations, CO2 concentration, radiation, wind speed, turbulent statistics, and plant physiology. The WRF-ACASA coupling is designed to identify how multiple environmental factors, in particularly climate variability, population density, and vegetation distribution, impact on future carbon cycle prediction across a wide geographical range such as in California.

  15. Islamic Fasting and Diabetes

    Directory of Open Access Journals (Sweden)

    Fereidoun Azizi

    2013-07-01

    Full Text Available The aim of this article is to review health-related aspects of Ramadan fasting in normal individuals and diabetics. During fasting days of Ramadan, glucose homeostasis is maintained by meal taken bepore dawn and by liver glycogen stores. Changes in serum lipids are variable and defend on the quality and quantity of food consumption and changes in weight. Compliant, well controlled type 2 diabetics may observe Ramadan fasting; but fasting is not recommended for type 1, non complaint, poorly controlled and pregnant diabetics. Although Ramadan fasting is safe for all healthy individuals and well controlled diabetics, those with uncontrolled diabetics and diabetics with complications should consult physicians and follow scientific recommendations.

  16. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  17. Fast ejendom III

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    Bogen er det tredje bind af tre planlagte bind om fast ejendom: I Overdragelsen, II Bolighandlen og III Ejerbeføjelsen. Fremstillingens giver et grundigt overblik over centrale områder af en omfattende regulering af fast ejendom, med angivelse af litteratur, hvor læseren kan søge yderligere...... oplysning. En ejer af fast ejendom er på særdeles mange områder begrænset i sin råden sammenlignet med ejeren af et formuegode i almindelighed. Fremstillingen tager udgangspunkt i ejerens perspektiv (fremfor samfundets eller myndighedernes). Både den privatretlige og offentligretlige regulering behandles......, eksempelvis ejendomsdannelsen, servitutter, naboretten, hævd, zoneinddelingen, den fysiske planlægning, beskyttelse af natur, beskyttelse af kultur, forurening fra fast ejendom, erstatning for forurening, jordforurening, ekspropriation, byggeri og adgang til fast ejendom....

  18. Fast neutron activation analysis by means of low voltage neutron generator

    Directory of Open Access Journals (Sweden)

    M.E. Medhat

    Full Text Available A description of D-T neutron generator (NG is presented. This machine can be used for fast neutron activation analysis applied to determine some selected elements, especially light elements, in different materials. Procedure of neutron flux determination and efficiency calculation is described. Examples of testing some Egyptian natural cosmetics are given. Keywords: Neutron generator, Fast neutron activation analysis, Elemental analysis

  19. Data Acquisition and Flux Calculations

    DEFF Research Database (Denmark)

    Rebmann, C.; Kolle, O; Heinesch, B

    2012-01-01

    In this chapter, the basic theory and the procedures used to obtain turbulent fluxes of energy, mass, and momentum with the eddy covariance technique will be detailed. This includes a description of data acquisition, pretreatment of high-frequency data and flux calculation.......In this chapter, the basic theory and the procedures used to obtain turbulent fluxes of energy, mass, and momentum with the eddy covariance technique will be detailed. This includes a description of data acquisition, pretreatment of high-frequency data and flux calculation....

  20. Heat Flux Instrumentation Laboratory (HFIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Heat Flux Instrumentation Laboratory is used to develop advanced, flexible, thin film gauge instrumentation for the Air Force Research Laboratory....

  1. Use of CITATION code for flux calculation in neutron activation analysis with voluminous sample using an Am-Be source

    International Nuclear Information System (INIS)

    Khelifi, R.; Idiri, Z.; Bode, P.

    2002-01-01

    The CITATION code based on neutron diffusion theory was used for flux calculations inside voluminous samples in prompt gamma activation analysis with an isotopic neutron source (Am-Be). The code uses specific parameters related to the energy spectrum source and irradiation system materials (shielding, reflector). The flux distribution (thermal and fast) was calculated in the three-dimensional geometry for the system: air, polyethylene and water cuboidal sample (50x50x50 cm). Thermal flux was calculated in a series of points inside the sample. The results agreed reasonably well with observed values. The maximum thermal flux was observed at a distance of 3.2 cm while CITATION gave 3.7 cm. Beyond a depth of 7.2 cm, the thermal flux to fast flux ratio increases up to twice and allows us to optimise the detection system position in the scope of in-situ PGAA

  2. KoFlux: Korean Regional Flux Network in AsiaFlux

    Science.gov (United States)

    Kim, J.

    2002-12-01

    AsiaFlux, the Asian arm of FLUXNET, held the Second International Workshop on Advanced Flux Network and Flux Evaluation in Jeju Island, Korea on 9-11 January 2002. In order to facilitate comprehensive Asia-wide studies of ecosystem fluxes, the meeting launched KoFlux, a new Korean regional network of long-term micrometeorological flux sites. For a successful assessment of carbon exchange between terrestrial ecosystems and the atmosphere, an accurate measurement of surface fluxes of energy and water is one of the prerequisites. During the 7th Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) held in Nagoya, Japan on 1-2 October 2001, the Implementation Committee of the Coordinated Enhanced Observing Period (CEOP) was established. One of the immediate tasks of CEOP was and is to identify the reference sites to monitor energy and water fluxes over the Asian continent. Subsequently, to advance the regional and global network of these reference sites in the context of both FLUXNET and CEOP, the Korean flux community has re-organized the available resources to establish a new regional network, KoFlux. We have built up domestic network sites (equipped with wind profiler and radiosonde measurements) over deciduous and coniferous forests, urban and rural rice paddies and coastal farmland. As an outreach through collaborations with research groups in Japan, China and Thailand, we also proposed international flux sites at ecologically and climatologically important locations such as a prairie on the Tibetan plateau, tropical forest with mixed and rapid land use change in northern Thailand. Several sites in KoFlux already begun to accumulate interesting data and some highlights are presented at the meeting. The sciences generated by flux networks in other continents have proven the worthiness of a global array of micrometeorological flux towers. It is our intent that the launch of KoFlux would encourage other scientists to initiate and

  3. Improved prediction of critical heat flux in liquid metal pool boiling

    International Nuclear Information System (INIS)

    Bankoff, S.G.; Fauske, H.K.

    1974-01-01

    The Kutateladze criterion for the pool boiling critical heat flux, which works well for nonmetallic liquids at or above atmospheric pressure, fails for the alkali liquid metals in the pressure range of interest for Liquid Metal Fast Breeder Reactor applications. In this pressure range bubble growth of the alkali liquid metals is largely inertia-controlled, in view of the large thermal conductivities, which implies a significant condensing heat flux within the bubbles themselves. The bubble growth is assumed to be described by the Mikic, Rohsenow, and Griffith equation. In this way a mean bubble age is determined, and hence a mean bubble thermal boundary layer thickness. The time-average critical heat flux is then obtained as the sum of the Kutateladze flux and the flux due to condensation on the bubble surfaces. No empirical parameters are employed. The present analysis predicts critical heat fluxes lying generally within the data band. (U.S.)

  4. CyberKnife boost for patients with cervical cancer unable to undergo brachytherapy

    Directory of Open Access Journals (Sweden)

    Jonathan Andrew Haas

    2012-03-01

    Full Text Available Standard radiation therapy for patients undergoing primary chemosensitized radiation for carcinomas of the cervix usually consists of external beam radiation followed by an intracavitary brachytherapy boost. On occasion, the brachytherapy boost cannot be performed due to unusual anatomy or because of coexisting medical conditions. We examined the safety and efficacy of using CyberKnife SBRT as a boost to the cervix after external beam radiation in those patients unable to have brachytherapy to give a more effective dose to the cervix than with conventional external beam radiation alone. Six consecutive patients with anatomic or medical conditions precluding a tandem and ovoid boost were treated with combined external beam radiation and CyberKnife boost to the cervix. Five patients received 45 Gy to the pelvis with serial IMRT boost to the uterus and cervix to a dose of 61.2 Gy. These 4 patients received an SBRT boost to the cervix to a dose of 20 Gy in 5 fractions of 4 Gy each. One patient was treated to the pelvis to a dose of 45 Gy with an external beam boost to the uterus and cervix to a dose of 50.4 Gy. This patient received an SBRT boost to the cervix to a dose of 19.5 Gy in 3 fractions of 6.5 Gy. Five percent volumes of the bladder and rectum were kept to < 75 Gy in all patients (i.e. V75Gy < 5%. All of the patients remain locally controlled with no evidence of disease following treatment. Grade 1 diarrhea occurred in 4/6 patients during the conventional external beam radiation. There has been no grade 3 or 4 rectal or bladder toxicity. There were no toxicities observed following SBRT boost. At a median follow-up of 14 months, CyberKnife radiosurgical boost is well tolerated and efficacious in providing a boost to patients with cervix cancer who are unable to undergo brachytherapy boost. Further follow-up is required to see if these results remain durable.

  5. CyberKnife Boost for Patients with Cervical Cancer Unable to Undergo Brachytherapy

    International Nuclear Information System (INIS)

    Haas, Jonathan Andrew; Witten, Matthew R.; Clancey, Owen; Episcopia, Karen; Accordino, Diane; Chalas, Eva

    2012-01-01

    Standard radiation therapy for patients undergoing primary chemosensitized radiation for carcinomas of the cervix usually consists of external beam radiation followed by an intracavitary brachytherapy boost. On occasion, the brachytherapy boost cannot be performed due to unfavorable anatomy or because of coexisting medical conditions. We examined the safety and efficacy of using CyberKnife stereotactic body radiotherapy (SBRT) as a boost to the cervix after external beam radiation in those patients unable to have brachytherapy to give a more effective dose to the cervix than with conventional external beam radiation alone. Six consecutive patients with anatomic or medical conditions precluding a tandem and ovoid boost were treated with combined external beam radiation and CyberKnife boost to the cervix. Five patients received 45 Gy to the pelvis with serial intensity-modulated radiation therapy boost to the uterus and cervix to a dose of 61.2 Gy. These five patients received an SBRT boost to the cervix to a dose of 20 Gy in five fractions of 4 Gy each. One patient was treated to the pelvis to a dose of 45 Gy with an external beam boost to the uterus and cervix to a dose of 50.4 Gy. This patient received an SBRT boost to the cervix to a dose of 19.5 Gy in three fractions of 6.5 Gy. Five percent volumes of the bladder and rectum were kept to ≤75 Gy in all patients (i.e., V75 Gy ≤ 5%). All of the patients remain locally controlled with no evidence of disease following treatment. Grade 1 diarrhea occurred in 4/6 patients during the conventional external beam radiation. There has been no grade 3 or 4 rectal or bladder toxicity. There were no toxicities observed following SBRT boost. At a median follow-up of 14 months, CyberKnife radiosurgical boost is well tolerated and efficacious in providing a boost to patients with cervix cancer who are unable to undergo brachytherapy boost. Further follow-up is required to see if these results remain durable.

  6. The JET fast transfer diagnostic system

    International Nuclear Information System (INIS)

    Burgin, D.R.; Charles, R.A.; Hyam, R.E.L.

    1984-01-01

    The Fast Transfer Diagnostic is a system which will carry four probes from the JET Diagnostic hall to the Torus vessel and expose them to the plasma discharge. These probes will measure the thermal flux, impurities and electromagnetic properties of the plasma boundary layer and will be transported on a 3.7 metre long train inside a 26 metre long by 150 mm diameter ultra high vacuum stainless steel tube. The whole process will be operated under the remote control of the JET Control and Data Acquisition System. (author)

  7. Fast IR diodes thermometer for tokamak

    International Nuclear Information System (INIS)

    Chen Xiangbo

    2001-01-01

    A 30 channel fast IR pyrometry array has been constructed for tokamak, which has 0.5 μs time response, 10 mm diameter spatial resolution and 5 degree C temperature resolution. The temperature measuring range is from 250 degree C to 1200 degree C. The two dimensional temperature profiles of the first wall during both major and minor disruptions can be measured with an accuracy of about 1% measuring temperature, which is adequate for tokamak experiments. This gives a very useful tool for the disruption study, especially for the divertor physics and edge heat flux research on tokamak and other magnetic confinement devices

  8. From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints

    Science.gov (United States)

    Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan

    2017-01-01

    Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903

  9. A simulated Antarctic fast ice ecosystem

    Science.gov (United States)

    Arrigo, Kevin R.; Kremer, James N.; Sullivan, Cornelius W.

    1993-01-01

    A 2D numerical ecosystem model of Antarctic land fast ice is developed to elucidate the primary production with the Antarctic sea ice zone. The physical component employs atmospheric data to simulate congelation ice growth, initial brine entrapment, desalination, and nutrient flux. The biological component is based on the concept of a maximum temperature-dependent algal growth rate which is reduced by limitations imposed from insufficient light or nutrients, as well as suboptimal salinity. Preliminary simulations indicate that, during a bloom, microalgae are able to maintain their vertical position relative to the lower congelation ice margin and are not incorporated into the crystal matrix as the ice sheet thickens. It is inferred that land fast sea ice contains numerous microhabitats that are functionally distinct based upon the unique set of processes that control microalgal growth and accumulation within each.

  10. Development of fast neutron profiling method

    CERN Document Server

    Miura, T; Sanami, T; Yamazaki, T; Ibaraki, M; Hirasawa, Y; Hiroishi, T; Aoki, T; Yamadera, A; Nakamura, T

    2002-01-01

    We discuss the effects of neutron scattering and gamma-ray background in fast neutron imaging and the method to reduce them. As a profiling device, a combination of an imaging plate (IP) and a polypropylene film (CH sub 2) has been employed in this study. Good profiles were obtained by employing appropriate neutron energy, a CH sub 2 thickness and geometry for accelerator-based fast neutrons (5-14 MeV). The neutron flux was approx 3.5x10 sup 4 cm sup - sup 2 s sup - sup 1 in the CH sub 2 -IP position. Furthermore, we are designing the device using a position-sensitive photomultiplier in order to improve the signal-to-noise ratio by obtaining the information of pulse height for particle selection together with position.

  11. FastJet user manual (for version 3.0.2)

    International Nuclear Information System (INIS)

    Cacciari, Matteo; Salam, Gavin P.; Soyez, Gregory

    2012-01-01

    FastJet is a C++ package that provides a broad range of jet finding and analysis tools. It includes efficient native implementations of all widely used 2→1 sequential recombination jet algorithms for pp and e + e - collisions, as well as access to 3rd party jet algorithms through a plugin mechanism, including all currently used cone algorithms. FastJet also provides means to facilitate the manipulation of jet substructure, including some common boosted heavy-object taggers, as well as tools for estimation of pileup and underlying-event noise levels, determination of jet areas and subtraction or suppression of noise in jets. (orig.)

  12. Balanced G-band Gm-boosted frequency doublers in transferred substrate InP HBT technology

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Thualfiqar, Al-Sawaf; Weimann, Nils

    2016-01-01

    In this paper, balanced G-band Gm-boosted frequency doublers in transferred substrate (TS) InP HBT technology are reported for the first time. The Gm-boosted frequency doublers consist of a phase compensated Marchand balun, Gm-boosted doubler stage, and an optional cascode gain stage at the outpu...

  13. Fast track-hoftealloplastik

    DEFF Research Database (Denmark)

    Hansen, Torben Bæk; Gromov, Kirill; Kristensen, Billy B

    2017-01-01

    Fast-track surgery implies a coordinated perioperative approach aimed at reducing surgical stress and facilitating post-operative recovery. The fast-track programme has reduced post-operative length of stay and has led to shorter convalescence with more rapid functional recovery and decreased...... morbidity and mortality in total hip arthroplasty. It should now be a standard total hip arthroplasty patient pathway, but fine tuning of the multiple factors in the fast-track pathway is still needed in patients with special needs or high comorbidity burden....

  14. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  15. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  16. Squeezing Flux Out of Fat

    DEFF Research Database (Denmark)

    Gonzalez-Franquesa, Alba; Patti, Mary-Elizabeth

    2018-01-01

    Merging transcriptomics or metabolomics data remains insufficient for metabolic flux estimation. Ramirez et al. integrate a genome-scale metabolic model with extracellular flux data to predict and validate metabolic differences between white and brown adipose tissue. This method allows both metab...

  17. Radiographer-led breast boost localisation – A service evaluation study

    International Nuclear Information System (INIS)

    Smith, S.; Comins, C.

    2015-01-01

    A radiation boost to the tumour bed as part of breast conserving therapy reduces the rate of local recurrence. Radiographer-led planning for tangential field radiotherapy has been the practice at our centre since 2007. The transition from conventional simulation to computed tomography (CT) and virtual simulation enhanced the radiographer's role in the breast planning process. Electron boost mark ups continued to be marked up freehand by doctors using available imaging to determine tumour bed. The paper reports on a service evaluation undertaken to establish a change in practice for electron breast boosts to be simulated using the virtual simulator by suitably trained radiographers. The retrospective simulation of ten patients confirmed the consistency of radiographer tumour bed localisation, followed by the prospective simulation of ten patients' boost fields. The introduction of a radiographer-led planning breast boost service has given greater autonomy and job satisfaction to individuals as well as resulting in a cost effective use of available resources. - Highlights: • A service evaluation study was undertaken to train a radiographer to perform breast boost planning. • Retrospective breast boost planning established proposed technique was workable. • Prospective planning by radiographer proved their competence. • Introduction of new technique provided job satisfaction and service improvement

  18. Impact of the Radiation Boost on Outcomes After Breast-Conserving Surgery and Radiation

    International Nuclear Information System (INIS)

    Murphy, Colin; Anderson, Penny R.; Li Tianyu; Bleicher, Richard J.; Sigurdson, Elin R.; Goldstein, Lori J.; Swaby, Ramona; Denlinger, Crystal; Dushkin, Holly; Nicolaou, Nicos; Freedman, Gary M.

    2011-01-01

    Purpose: We examined the impact of radiation tumor bed boost parameters in early-stage breast cancer on local control and cosmetic outcomes. Methods and Materials: A total of 3,186 women underwent postlumpectomy whole-breast radiation with a tumor bed boost for Tis to T2 breast cancer from 1970 to 2008. Boost parameters analyzed included size, energy, dose, and technique. Endpoints were local control, cosmesis, and fibrosis. The Kaplan-Meier method was used to estimate actuarial incidence, and a Cox proportional hazard model was used to determine independent predictors of outcomes on multivariate analysis (MVA). The median follow-up was 78 months (range, 1-305 months). Results: The crude cosmetic results were excellent in 54%, good in 41%, and fair/poor in 5% of patients. The 10-year estimate of an excellent cosmesis was 66%. On MVA, independent predictors for excellent cosmesis were use of electron boost, lower electron energy, adjuvant systemic therapy, and whole-breast IMRT. Fibrosis was reported in 8.4% of patients. The actuarial incidence of fibrosis was 11% at 5 years and 17% at 10 years. On MVA, independent predictors of fibrosis were larger cup size and higher boost energy. The 10-year actuarial local failure was 6.3%. There was no significant difference in local control by boost method, cut-out size, dose, or energy. Conclusions: Likelihood of excellent cosmesis or fibrosis are associated with boost technique, electron energy, and cup size. However, because of high local control and rare incidence of fair/poor cosmesis with a boost, the anatomy of the patient and tumor cavity should ultimately determine the necessary boost parameters.

  19. Magnetic Fields Boosted by Gluon Vortices in Color Superconductivity

    International Nuclear Information System (INIS)

    Ferrer, Efrain J.; Incera, Vivian de la

    2006-01-01

    We investigate the effects of an external magnetic field in the gluon dynamics of a color superconductor with three massless quark flavors. In the framework of gluon mean-field theory at asymptotic densities, we show that the long-range component H(tilde sign) of the external magnetic field that penetrates the color-flavor locked phase produces an instability when its strength becomes larger than the Meissner mass of the charged gluons. As a consequence, the magnetic field causes the formation of a vortex state characterized by the condensation of charged gluons and the creation of magnetic flux tubes. Inside the flux tubes, the magnetic field is stronger than the applied one. This antiscreening effect is connected to the anomalous magnetic moment of the gluon field. We suggest how this same mechanism could serve to remove the chromomagnetic instabilities existing in gapless color superconductivity

  20. Principal Metabolic Flux Mode Analysis.

    Science.gov (United States)

    Bhadra, Sahely; Blomberg, Peter; Castillo, Sandra; Rousu, Juho; Wren, Jonathan

    2018-02-06

    In the analysis of metabolism, two distinct and complementary approaches are frequently used: Principal component analysis (PCA) and stoichiometric flux analysis. PCA is able to capture the main modes of variability in a set of experiments and does not make many prior assumptions about the data, but does not inherently take into account the flux mode structure of metabolism. Stoichiometric flux analysis methods, such as Flux Balance Analysis (FBA) and Elementary Mode Analysis, on the other hand, are able to capture the metabolic flux modes, however, they are primarily designed for the analysis of single samples at a time, and not best suited for exploratory analysis on a large sets of samples. We propose a new methodology for the analysis of metabolism, called Principal Metabolic Flux Mode Analysis (PMFA), which marries the PCA and stoichiometric flux analysis approaches in an elegant regularized optimization framework. In short, the method incorporates a variance maximization objective form PCA coupled with a stoichiometric regularizer, which penalizes projections that are far from any flux modes of the network. For interpretability, we also introduce a sparse variant of PMFA that favours flux modes that contain a small number of reactions. Our experiments demonstrate the versatility and capabilities of our methodology. The proposed method can be applied to genome-scale metabolic network in efficient way as PMFA does not enumerate elementary modes. In addition, the method is more robust on out-of-steady steady-state experimental data than competing flux mode analysis approaches. Matlab software for PMFA and SPMFA and data set used for experiments are available in https://github.com/aalto-ics-kepaco/PMFA. sahely@iitpkd.ac.in, juho.rousu@aalto.fi, Peter.Blomberg@vtt.fi, Sandra.Castillo@vtt.fi. Detailed results are in Supplementary files. Supplementary data are available at https://github.com/aalto-ics-kepaco/PMFA/blob/master/Results.zip.

  1. Fast and pure

    Science.gov (United States)

    De Franceschi, Silvano

    2018-02-01

    Removing nuclear spins by means of isotopically purified silicon, and introducing magnetic field gradients by means of microfabricated ferromagnets yields electron spin qubits with enhanced fidelity and fast electrical control.

  2. Fast neutrons dosimetry

    International Nuclear Information System (INIS)

    Rzyski, B.M.

    1977-01-01

    A proton recoil technique has been developed for inducing thermoluminescence with incident fast neutrons. CaF 2 was used as the TL phosphor, and cane sugar and polyethylene were used as proton radiators. The phosphor and the hydrogeneous material powders were well mixed, encapsulated in glass tubes and exposed to Am-Be sources, resulting in recoils from incident fast neutrons of energy between 0,25 and 11,25 MeV. The intrinsic response of pure CaF 2 to fast neutrons without a hydrogeneous radiator was checked by using LiF (TLD-700). Glow curves were recorded from room temperature up to 350 0 C after different doses of neutrons and gamma rays of 60 Co. First collision dose due to fast neutrons in tissue like materials such as cane sugar and polyethylene was also calculated [pt

  3. Fast Optimal Motion Planning

    Data.gov (United States)

    National Aeronautics and Space Administration — Computationally-efficient, fast and real-time, and provably-optimal motion planner for systems with highly nonlinear dynamics that can be extended for cooperative...

  4. CMS Fast Facts

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS has developed a new quick reference statistical summary on annual CMS program and financial data. CMS Fast Facts includes summary information on total program...

  5. First absolute measurements of fast-ion losses in the ASDEX Upgrade tokamak

    Science.gov (United States)

    Rodriguez-Ramos, M.; Garcia-Munoz, M.; Jimenez-Ramos, M. C.; Garcia Lopez, J.; Galdon-Quiroga, J.; Sanchis-Sanchez, L.; Ayllon-Guerola, J.; Faitsch, M.; Gonzalez-Martin, J.; Hermann, A.; de Marne, P.; Rivero-Rodriguez, J. F.; Sieglin, B.; Snicker, A.; the ASDEX Upgrade Team

    2017-10-01

    A new diagnostic technique that allows to obtain absolute fluxes of fast-ion losses measured with absolutely calibrated scintillator based fast-ion loss detectors (FILD) is presented here. First absolute fluxes of fast-ion losses have been obtained in the ASDEX Upgrade tokamak. An instrument function that includes the scintillator efficiency, collimator geometry, optical transmission and camera efficiency has been constructed. The scintillator response to deuterium ions in the relevant energy range of fast-ions has been characterized using a tandem accelerator. Absolute flux of neutral beam injection (NBI) prompt losses has been obtained in magnetohydrodynamic quiescent plasmas. The temporal evolution of the heat load measured with FILD follows that measured at the FILD entrance obtained with an Infra-Red camera looking at the FILD detector head. ASCOT simulations are in good agreement with the absolute heat load of NBI prompt losses measured with FILD.

  6. Brug af faste vendinger

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Bjærge, Esben

    Ordbogen indelholder tekstproduktionsangivelser til ca. 17.000 idiomer, ordsprog, bevingede ord og andre faste vendinger. Det drejer sig bl.a. om angivelser til betydningen, grammatik, kollokationer, eksempler, synonymer og antonymer.......Ordbogen indelholder tekstproduktionsangivelser til ca. 17.000 idiomer, ordsprog, bevingede ord og andre faste vendinger. Det drejer sig bl.a. om angivelser til betydningen, grammatik, kollokationer, eksempler, synonymer og antonymer....

  7. Fast focus field calculations

    OpenAIRE

    Leutenegger, M.; Rao, R.; Leitgeb, R. A.; Lasser, T.

    2006-01-01

    We present a fast calculation of the electromagnetic field near the focus of an objective with a high numerical aperture (NA). Instead of direct integration, the vectorial Debye diffraction integral is evaluated with the fast Fourier transform for calculating the electromagnetic field in the entire focal region. We generalize this concept with the chirp z transform for obtaining a flexible sampling grid and an additional gain in computation speed. Under ...

  8. Design and Testing of Boost Type DC/DC Converter for DC Motor Control Applications

    OpenAIRE

    Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.

    2017-01-01

    in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...

  9. The performance of the DC motor by the PID controlling PWM DC-DC boost converter

    OpenAIRE

    Can, Erol; Sayan, Hasan Hüseyin

    2017-01-01

    This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...

  10. Digitally-controlled PC-interfaced Boost Converter for Educational Purposes

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael A. E.

    2004-01-01

    This paper describes implementation of a simple digital PID control algorithm for a boost converter using a cheap fixed-point 8-bit microcontroller. Serial communication to a PC server program is established for easier downloading of compensator parameters and current and voltage waveform...... acquisition. At the end, client program is presented which uses TCP/IP connection for operating the digitally controlled boost converter over Internet. The aim of this cheap and flexible PC-interfaced boost converter bench is predominantly educational, to allow students to synthesize different digital...... controllers and compare their performance....

  11. A new DC/AC boost transformerless converter in application of photovoltaic power generation

    DEFF Research Database (Denmark)

    Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede

    2011-01-01

    This paper presents a new DC/AC boost transformerless converter in the applications of photovoltaic (PV) power generation. A new circuit topology of single phase full bridge power inverter with additional DC/DC boost stage is proposed. The proposed topology overcomes two commonly existing...... shortcomings of transformerless PV system: namely one, the voltage generated sometimes low and insufficient to fulfill the load requirement; and two, there always leakage current flowing through parasitic capacitance between PV panel and ground. This configuration helps to boost the voltage at the PV side...

  12. Single Phase Transformer-less Buck-Boost Inverter with Zero Leakage Current for PV Systems

    DEFF Research Database (Denmark)

    Mostaan, Ali; Abdelhakim, Ahmed; N. Soltani, Mohsen

    2017-01-01

    In this paper, a novel single-stage single-phase transformer-less buck-boost inverter is proposed, in which a reduced number of passive components is used. The proposed inverter combines the conventional buck, boost, and buck-boost converters in one converter in order to obtain a sinusoidal output...... voltage. In the proposed inverter, the input DC source and the load or grid have the same ground. Therefore, the leakage current problem in photovoltaic (PV) systems is eliminated. Furthermore, the proposed inverter supports the bi-directional power flow capability and it can inject reactive power...

  13. Extracting Baseline Electricity Usage Using Gradient Tree Boosting

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taehoon [Ulsan Nat. Inst. of Sci. & Tech., Ulsan (South Korea); Lee, Dongeun [Ulsan Nat. Inst. of Sci. & Tech., Ulsan (South Korea); Choi, Jaesik [Ulsan Nat. Inst. of Sci. & Tech., Ulsan (South Korea); Spurlock, Anna [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sim, Alex [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Todd, Annika [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Kesheng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-05-05

    To understand how specific interventions affect a process observed over time, we need to control for the other factors that influence outcomes. Such a model that captures all factors other than the one of interest is generally known as a baseline. In our study of how different pricing schemes affect residential electricity consumption, the baseline would need to capture the impact of outdoor temperature along with many other factors. In this work, we examine a number of different data mining techniques and demonstrate Gradient Tree Boosting (GTB) to be an effective method to build the baseline. We train GTB on data prior to the introduction of new pricing schemes, and apply the known temperature following the introduction of new pricing schemes to predict electricity usage with the expected temperature correction. Our experiments and analyses show that the baseline models generated by GTB capture the core characteristics over the two years with the new pricing schemes. In contrast to the majority of regression based techniques which fail to capture the lag between the peak of daily temperature and the peak of electricity usage, the GTB generated baselines are able to correctly capture the delay between the temperature peak and the electricity peak. Furthermore, subtracting this temperature-adjusted baseline from the observed electricity usage, we find that the resulting values are more amenable to interpretation, which demonstrates that the temperature-adjusted baseline is indeed effective.

  14. Controlled Vocabularies Boost International Participation and Normalization of Searches

    Science.gov (United States)

    Olsen, Lola M.

    2006-01-01

    The Global Change Master Directory's (GCMD) science staff set out to document Earth science data and provide a mechanism for it's discovery in fulfillment of a commitment to NASA's Earth Science progam and to the Committee on Earth Observation Satellites' (CEOS) International Directory Network (IDN.) At the time, whether to offer a controlled vocabulary search or a free-text search was resolved with a decision to support both. The feedback from the user community indicated that being asked to independently determine the appropriate 'English" words through a free-text search would be very difficult. The preference was to be 'prompted' for relevant keywords through the use of a hierarchy of well-designed science keywords. The controlled keywords serve to 'normalize' the search through knowledgeable input by metadata providers. Earth science keyword taxonomies were developed, rules for additions, deletions, and modifications were created. Secondary sets of controlled vocabularies for related descriptors such as projects, data centers, instruments, platforms, related data set link types, and locations, along with free-text searches assist users in further refining their search results. Through this robust 'search and refine' capability in the GCMD users are directed to the data and services they seek. The next step in guiding users more directly to the resources they desire is to build a 'reasoning' capability for search through the use of ontologies. Incorporating twelve sets of Earth science keyword taxonomies has boosted the GCMD S ability to help users define and more directly retrieve data of choice.

  15. Coherent-light-boosted, sub-shot noise, quantum interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Plick, William N; Dowling, Jonathan P [Hearne Institute for Theoretical Physics, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Agarwal, Girish S, E-mail: bplick@yahoo.co [Department of Physics, Oklahoma State University, Stillwater, OK 74078 (United States)

    2010-08-15

    We present in this paper a new scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach far below the shot-noise limit in phase sensitivity. This new proposal avoids the pitfalls of other setups, such as difficulty in creating the required resource. Furthermore, our scheme requires no complicated detection protocol, relying instead only on simple intensity measurement. Also, bright, coherent sources 'boost' squeezed light, creating a very sensitive device. This hybrid scheme relies on no unknown components and can be constructed with current technology. In this paper, we present our analysis of this relatively straightforward device, using the operator propagation method. We derive the phase sensitivity and provide a simple numerical example of the power of our new proposal. Sensitivity to unknown phase shifts scales as a shot-noise-limited Mach-Zehnder interferometer, multiplied by a sub-Heisenberg contribution from the squeezed light.

  16. Coherent-light-boosted, sub-shot noise, quantum interferometry

    International Nuclear Information System (INIS)

    Plick, William N; Dowling, Jonathan P; Agarwal, Girish S

    2010-01-01

    We present in this paper a new scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach far below the shot-noise limit in phase sensitivity. This new proposal avoids the pitfalls of other setups, such as difficulty in creating the required resource. Furthermore, our scheme requires no complicated detection protocol, relying instead only on simple intensity measurement. Also, bright, coherent sources 'boost' squeezed light, creating a very sensitive device. This hybrid scheme relies on no unknown components and can be constructed with current technology. In this paper, we present our analysis of this relatively straightforward device, using the operator propagation method. We derive the phase sensitivity and provide a simple numerical example of the power of our new proposal. Sensitivity to unknown phase shifts scales as a shot-noise-limited Mach-Zehnder interferometer, multiplied by a sub-Heisenberg contribution from the squeezed light.

  17. No Money Down. Boost State Nuclear Forensics Capabilities with Less

    International Nuclear Information System (INIS)

    Henriques, Sasha

    2013-01-01

    Any mention of boosting nuclear forensics capabilities can have governments clutching their wallets reflexively. That's because it sounds very high tech, and therefore very expensive. In a time of austerity measures, countries can find it difficult to take on additional financial responsibilities, even when those responsibilities have to do with nuclear security. But according to the IAEA's Office of Nuclear Security, becoming proficient in nuclear forensics isn't as expensive as it initially appears. Nuclear forensics is the science of uncovering the origin and history of nuclear materials, especially those found at a crime scene. ''And every country can engage in a nuclear forensics examination, using existing technical capabilities that are readily adapted as part of a nuclear security infrastructure,'' says David Smith, IAEA Nuclear Security Coordinator. ''They already have the right analytical equipment - spectrometry and inorganic chemistry equipment, for example - in universities, regulatory bodies and mining companies, just to name a few places. And they have much of the expertise - trained technicians and law enforcement officials - but are unaware that putting these things together along with workable plans and strategies - that the IAEA can provide - can create an effective means for the practice of nuclear forensics''

  18. Biochar boosts tropical but not temperate crop yields

    Science.gov (United States)

    Jeffery, Simon; Abalos, Diego; Prodana, Marija; Catarina Bastos, Ana; van Groenigen, Jan Willem; Hungate, Bruce A.; Verheijen, Frank

    2017-05-01

    Applying biochar to soil is thought to have multiple benefits, from helping mitigate climate change [1, 2], to managing waste [3] to conserving soil [4]. Biochar is also widely assumed to boost crop yield [5, 6], but there is controversy regarding the extent and cause of any yield benefit [7]. Here we use a global-scale meta-analysis to show that biochar has, on average, no effect on crop yield in temperate latitudes, yet elicits a 25% average increase in yield in the tropics. In the tropics, biochar increased yield through liming and fertilization, consistent with the low soil pH, low fertility, and low fertilizer inputs typical of arable tropical soils. We also found that, in tropical soils, high-nutrient biochar inputs stimulated yield substantially more than low-nutrient biochar, further supporting the role of nutrient fertilization in the observed yield stimulation. In contrast, arable soils in temperate regions are moderate in pH, higher in fertility, and generally receive higher fertilizer inputs, leaving little room for additional benefits from biochar. Our findings demonstrate that the yield-stimulating effects of biochar are not universal, but may especially benefit agriculture in low-nutrient, acidic soils in the tropics. Biochar management in temperate zones should focus on potential non-yield benefits such as lime and fertilizer cost savings, greenhouse gas emissions control, and other ecosystem services.

  19. Negative emotion boosts quality of visual working memory representation.

    Science.gov (United States)

    Xie, Weizhen; Zhang, Weiwei

    2016-08-01

    Negative emotion impacts a variety of cognitive processes, including working memory (WM). The present study investigated whether negative emotion modulated WM capacity (quantity) or resolution (quality), 2 independent limits on WM storage. In Experiment 1, observers tried to remember several colors over 1-s delay and then recalled the color of a randomly picked memory item by clicking a best-matching color on a continuous color wheel. On each trial, before the visual WM task, 1 of 3 emotion conditions (negative, neutral, or positive) was induced by having observers to rate the valence of an International Affective Picture System image. Visual WM under negative emotion showed enhanced resolution compared with neutral and positive conditions, whereas the number of retained representations was comparable across the 3 emotion conditions. These effects were generalized to closed-contour shapes in Experiment 2. To isolate the locus of these effects, Experiment 3 adopted an iconic memory version of the color recall task by eliminating the 1-s retention interval. No significant change in the quantity or quality of iconic memory was observed, suggesting that the resolution effects in the first 2 experiments were critically dependent on the need to retain memory representations over a short period of time. Taken together, these results suggest that negative emotion selectively boosts visual WM quality, supporting the dissociable nature quantitative and qualitative aspects of visual WM representation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. Characteristics of Thermalization of Boost-Invariant Plasma from Holography

    Science.gov (United States)

    Heller, Michal P.; Janik, Romuald A.; Witaszczyk, Przemysław

    2012-05-01

    We report on the approach toward the hydrodynamic regime of boost-invariant N=4 super Yang-Mills plasma at strong coupling starting from various far-from-equilibrium states at τ=0. The results are obtained through a numerical solution of Einstein’s equations for the dual geometries, as described in detail in the companion article [M. P. Heller, R. A. Janik, and P. Witaszczyk, arXiv:1203.0755]. Despite the very rich far-from-equilibrium evolution, we find surprising regularities in the form of clear correlations between initial entropy and total produced entropy, as well as between initial entropy and the temperature at thermalization, understood as the transition to a hydrodynamic description. For 29 different initial conditions that we consider, hydrodynamics turns out to be definitely applicable for proper times larger than 0.7 in units of inverse temperature at thermalization. We observe a sizable anisotropy in the energy-momentum tensor at thermalization, which is nevertheless entirely due to hydrodynamic effects. This suggests that effective thermalization in heavy-ion collisions may occur significantly earlier than true thermalization.

  1. Characteristics of thermalization of boost-invariant plasma from holography.

    Science.gov (United States)

    Heller, Michal P; Janik, Romuald A; Witaszczyk, Przemysław

    2012-05-18

    We report on the approach toward the hydrodynamic regime of boost-invariant N=4 super Yang-Mills plasma at strong coupling starting from various far-from-equilibrium states at τ=0. The results are obtained through a numerical solution of Einstein's equations for the dual geometries, as described in detail in the companion article [M. P. Heller, R. A. Janik, and P. Witaszczyk, arXiv:1203.0755]. Despite the very rich far-from-equilibrium evolution, we find surprising regularities in the form of clear correlations between initial entropy and total produced entropy, as well as between initial entropy and the temperature at thermalization, understood as the transition to a hydrodynamic description. For 29 different initial conditions that we consider, hydrodynamics turns out to be definitely applicable for proper times larger than 0.7 in units of inverse temperature at thermalization. We observe a sizable anisotropy in the energy-momentum tensor at thermalization, which is nevertheless entirely due to hydrodynamic effects. This suggests that effective thermalization in heavy-ion collisions may occur significantly earlier than true thermalization.

  2. Electrochemical, H2O2-Boosted Catalytic Oxidation System

    Science.gov (United States)

    Akse, James R.; Thompson, John O.; Schussel, Leonard J.

    2004-01-01

    An improved water-sterilizing aqueous-phase catalytic oxidation system (APCOS) is based partly on the electrochemical generation of hydrogen peroxide (H2O2). This H2O2-boosted system offers significant improvements over prior dissolved-oxygen water-sterilizing systems in the way in which it increases oxidation capabilities, supplies H2O2 when needed, reduces the total organic carbon (TOC) content of treated water to a low level, consumes less energy than prior systems do, reduces the risk of contamination, and costs less to operate. This system was developed as a variant of part of an improved waste-management subsystem of the life-support system of a spacecraft. Going beyond its original intended purpose, it offers the advantage of being able to produce H2O2 on demand for surface sterilization and/or decontamination: this is a major advantage inasmuch as the benign byproducts of this H2O2 system, unlike those of systems that utilize other chemical sterilants, place no additional burden of containment control on other spacecraft air- or water-reclamation systems.

  3. Industry poised to boost production on Angola/Cabinda acreage

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that development spending off Angola will peak at $750 million/year in 1993 and 1994 as operators start to implement plans to boost oil to 680,000 b/d in 1996 from 505,000 b/d last year. And during the next 9 years, upstream spending will jump to $4.7 billion at 1992 prices, compared with $3.3 billion spent in the past 9 years, says County NatWest WoodMac. Angolan exploration and appraisal drilling this year will slip from the 1991 record level of 36 wells to about 33 wells. The decline will be eased by first wells drilled on newly awarded Blocks 4, 6, and 7 operated by units of Ranger Oil Ltd., Conoco Inc., and Ste. Nationale Elf Aquitaine. As exploration drops in more mature areas, activity will shift to frontier regions. As a result, drilling activity in the mid-1990s will be at least as high as the record levels of 1991, WoodMac predicts

  4. Administration of RANKL boosts thymic regeneration upon bone marrow transplantation.

    Science.gov (United States)

    Lopes, Noella; Vachon, Hortense; Marie, Julien; Irla, Magali

    2017-06-01

    Cytoablative treatments lead to severe damages on thymic epithelial cells (TECs), which result in delayed de novo thymopoiesis and a prolonged period of T-cell immunodeficiency. Understanding the mechanisms that govern thymic regeneration is of paramount interest for the recovery of a functional immune system notably after bone marrow transplantation (BMT). Here, we show that RANK ligand (RANKL) is upregulated in CD4 + thymocytes and lymphoid tissue inducer (LTi) cells during the early phase of thymic regeneration. Importantly, whereas RANKL neutralization alters TEC recovery after irradiation, ex vivo RANKL administration during BMT boosts the regeneration of TEC subsets including thymic epithelial progenitor-enriched cells, thymus homing of lymphoid progenitors, and de novo thymopoiesis. RANKL increases specifically in LTi cells, lymphotoxin α, which is critical for thymic regeneration. RANKL treatment, dependent on lymphotoxin α, is beneficial upon BMT in young and aged individuals. This study thus indicates that RANKL may be clinically useful to improve T-cell function recovery after BMT by controlling multiple facets of thymic regeneration. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  5. Fasting and Urinary Stones

    Directory of Open Access Journals (Sweden)

    Ali Shamsa

    2013-11-01

    Full Text Available Introduction: Fasting is considered as one of the most important practices of Islam, and according to Prophet Mohammad, fasting is obligatory upon Muslims. The aim of this study is to evaluate the effects of fasting on urinary stones. Materials and Methods: Very few studies have been carried out on urinary stones and the effect of Ramadan fasting. The sources of the present study are Medline and articles presented by local and Muslim researchers. Meanwhile, since we are acquainted with three well-known researchers in the field of urology, we contacted them via email and asked for their professional opinions. Results: The results of studies about the relationship of urinary stones and their incidence in Ramadan are not alike, and are even sometimes contradictory. Some believe that increased incidence of urinary stones in Ramadan is related not to fasting, but to the rise of weather temperature in hot months, and an increase in humidity. Conclusion: Numerous biological and behavioral changes occur in people who fast in Ramadan and some researchers believe that urinary stone increases during this month.

  6. Clinical experience in patients with Pancoast's tumor treated by fast neutron therapy

    International Nuclear Information System (INIS)

    Sawada, Kinya; Fukuma, Seigo; Seki, Yasuo

    1983-01-01

    We reveiw our results with fast neutron therapy in Pancoast's tumor, and compare them with results obtained by photon beam therapy. 13 patients with Pancoast's tumor were divided into two groups; Group I (8 patients) received fast neutron therapy. Group II (5 patients) were treated by voltage X-ray therapy. 1. Group I was comprised of 3 patients receiving mixed beam therapy (TDF 80-100) and 5 patients subjected to boost therapy. All group II patients received 3100 to 8000 rads. 2. Fast neutron therapy was effective in 7 patients. In group II, high voltage X-ray therapy was effective in only 3 patients. 3. Two group I patients are still alive without signs of recurrence. The others died with a mean survival of 11 months. All group II patients died; their mean survival was 4.2 months. Our results suggest that fast neutron therapy is suitable and effective in patients with Pancoast's tumor. (author)

  7. Thermal-Electromagnetic Analysis for Driving Cycles of Embedded Flux-Switching Permanent Magnet Motors

    OpenAIRE

    Li , Guangjin; Ojeda , Javier; Hoang , Emmanuel; Gabsi , Mohamed; Lécrivain , Michel

    2012-01-01

    International audience; This paper presents a fast and precise electromagnetic-thermal model of a redundant dual star Flux-Switching Permanent Magnet (FSPM) motor for the embedded applications with driving cycles, e.g. Hybrid Electrical Vehicle (HEV), aerospace, etc. This model is based on a prior steady characterization by Finite Element Method (FEM) 2D of the FSPM motor via calculating the instantaneous torque, the normal and tangential components of magnetic flux density (Br and ) of each ...

  8. HIGH-ENERGY PARTICLES FLUX ORIGIN IN THE CLOUDS, DARK LIGHTNING

    Directory of Open Access Journals (Sweden)

    Kuznetsov, V.V.

    2016-11-01

    Full Text Available Problem of high-energy particles flux origin in clouds is discussed. Conditions in which dark lightning preceding the ordinary one and creating additional ionization, fluxes of fast electrons with MeV energy prior to the earthquake detected among lightning initiating ball-lightning, glow, sprites are considered. All above phenomena appear to be of general nature founded on quantum entanglement of hydrogen bonds protons in water clasters inside clouds.

  9. Mars: The Terra Arabia Low Epithermal Neutron Flux Anomaly

    Science.gov (United States)

    Basilevsky, A. T.; Rodin, A. V.; Kozyrev, A. S.; Mitrofanov, I. G.; Neukum, G.; Werner, S. C.; Head, J. W.; Boynton, W.; Saunders, R. S.

    2004-01-01

    The High Energy Neutron Spectrometer (HEND) and Neutron Specrometer, part of the Mars Odyssey Gamma Ray Spectrometer suite of instruments, measured anomalously low epithermal neutron flux in two low-latitude areas, Terra Arabia and SW of Olympus Mons (SWOM). The low epithermal neutron flux, an indirect measure of Hydrogen abundance, is indicative of relatively high water content (in this case up to 8 mass percent) in the upper 1-2 m of the surface layer. The epithermal flux within the 60 degree latitude zone does not correlate with bedrock geology or topography but partially correlates (for Arabia) with thermal inertia. According to theoretical estimates for the current geologic epoch, ground ice should not be stable at this depth at these low latitudes so it was concluded that the anomalies are due to the presence of chemically bound water (e.g. clays, hydroxides or hydrosalts). Fast neutron flux, which is indicative of the presence of water at 20-30 cm depth, does not correlate in this latitude zone with the epithermal neutron flux. As a further step of the analysis a geotraverse including study of 152 high resolution MOC images within the Arabia anomaly was done by to find out if the area inside the anomaly differs from the neighboring areas by the presence of fluvial channels and layered deposits (possible links to chemically bound water) or in thickness and apparent texture of the surface layer. No differences were found.

  10. Interpreting Flux from Broadband Photometry

    Science.gov (United States)

    Brown, Peter J.; Breeveld, Alice; Roming, Peter W. A.; Siegel, Michael

    2016-10-01

    We discuss the transformation of observed photometry into flux for the creation of spectral energy distributions (SED) and the computation of bolometric luminosities. We do this in the context of supernova studies, particularly as observed with the Swift spacecraft, but the concepts and techniques should be applicable to many other types of sources and wavelength regimes. Traditional methods of converting observed magnitudes to flux densities are not very accurate when applied to UV photometry. Common methods for extinction and the integration of pseudo-bolometric fluxes can also lead to inaccurate results. The sources of inaccuracy, though, also apply to other wavelengths. Because of the complicated nature of translating broadband photometry into monochromatic flux densities, comparison between observed photometry and a spectroscopic model is best done by forward modeling the spectrum into the count rates or magnitudes of the observations. We recommend that integrated flux measurements be made using a spectrum or SED which is consistent with the multi-band photometry rather than converting individual photometric measurements to flux densities, linearly interpolating between the points, and integrating. We also highlight some specific areas where the UV flux can be mischaracterized.

  11. Boosted objects and jet substructure at the LHC. Report of BOOST2012, held at IFIC Valencia, 23rd-27th of July 2012

    Energy Technology Data Exchange (ETDEWEB)

    Altheimer, A.; Thompson, E.N. [Columbia University, Nevis Laboratory, Irvington, NY (United States); Arce, A.; Bjergaard, D. [Duke University, Durham, NC (United States); Asquith, L. [Argonne National Laboratory, Lemont, IL (United States); Backus Mayes, J.; Hook, A.; Izaguirre, E.; Jankowiak, M.; Larkoski, A.; Nef, P.; Schwartzman, A.; Swiatlowski, M.; Wacker, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Kuutmann, E.B. [Deutsches Elektronen-Synchrotron, DESY, Zeuthen (Germany); Humboldt University, Berlin (Germany); Berger, J. [Cornell University, Ithaca, NY (United States); Bryngemark, L. [Lund University, Lund (Sweden); Buckley, A.; Debenedetti, C. [University of Edinburgh, Edinburgh (United Kingdom); Butterworth, J.; Campanelli, M.; Davison, A. [University College London, London (United Kingdom); Cacciari, M. [CERN, Geneva 23 (Switzerland); Carli, T.; Roeck, A. de [LPTHE, UPMC Univ. Paris 6 et CNRS UMR, Paris (France); Chala, M. [CAFPE and Univ. of Granada, Granada (Spain); Chapleau, B. [McGill University, Montreal, QC (Canada); Chen, C. [Iowa State University, Ames, IA (United States); Chou, J.P. [Rutgers University, Piscataway, NJ (United States); Cornelissen, T.; Fleischmann, S. [Bergische Universitaet Wuppertal, Wuppertal (Germany); Curtin, D. [YITP, Stony Brook University, Stony Brook, NY (United States); Dasgupta, M. [University of Manchester, Manchester (United Kingdom); Almeida Dias, F. de [UNESP-Universidade Estadual Paulista, Sao Paulo (Brazil); De Cosa, A. [INFN, Naples (Italy); University of Naples, Naples (Italy); Doglioni, C.; Guescini, F. [University of Geneva, Geneva 4 (Switzerland); Ellis, S.D.; Hornig, A.; Scholtz, J. [University of Washington, Seattle, WA (United States); Fassi, F.; Hoz, S.G. de la; Kaci, M.; Oliver Garcia, E.; Rodrigo, G.; Salt, J.; Sanchez Martinez, V.; Villaplana, M.; Vos, M. [Instituto de Fisica Corpuscular, IFIC/CSIC-UVEG, Valencia (Spain); Ferrando, J.; Kar, D.; Nordstrom, K. [University of Glasgow, Glasgow (United Kingdom); Freytsis, M. [University of California, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); University of California, Berkeley, CA (United States); Gonzalez Silva, M.L. [Universidad de Buenos Aires, Buenos Aires (Argentina); Han, Z.; Lopez Mateos, D.; Schwartz, M.D. [Harvard University, Cambridge, MA (United States); Juknevich, J. [Weizmann Institute, Rehovot (Israel); Kasieczka, G.; Plehn, T.; Schaetzel, S.; Takeuchi, M. [Universitaet Heidelberg, Heidelberg (Germany); Kogler, R. [Universitaet Hamburg, Hamburg (Germany); Loch, P. [University of Arizona, Tucson, AZ (United States); Marzani, S.; Spannowsky, M. [IPPP, University of Durham, Durham (United Kingdom); Masetti, L. [Universitaet Mainz, Mainz (Germany); Mateu, V.; Stewart, I.; Thaler, J. [MIT, Cambridge, MA (United States); Miller, D.W. [University of Chicago, Chicago, IL (United States); Mishra, K.; Tran, N.V. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Penwell, J. [Indiana University, Bloomington, IN (United States); Pilot, J. [University of California, Davis, CA (United States); Rappoccio, S. [Johns Hopkins University, Baltimore, MD (United States); University at Buffalo, State University of New York, Buffalo, NY (United States); Rizzi, A. [INFN, Pisa (Italy); University of Pisa, Pisa (Italy); Safonov, A. [Texas A and M University, College Station, TX (United States); Salam, G.P. [CERN, Geneva 23 (Switzerland); LPTHE, UPMC Univ. Paris 6 et CNRS UMR, Paris (France); Schioppa, M. [INFN, Rende (IT); University of Calabria, Rende (IT); Schmidt, A. [Universitaet Hamburg, Hamburg (DE); Universitaet Heidelberg, Heidelberg (DE); Segala, M. [Brown University, Richmond, RI (US); Son, M. [Yale University, New Haven, CT (US); Soyez, G. [CEA Saclay, Gif-sur-Yvette (FR); Strom, D. [University of Illinois, Chicago, IL (US); Vermilion, C. [University of California, Lawrence Berkeley National Laboratory, Berkeley, CA (US); Walsh, J. [University of California, Berkeley, CA (US)

    2014-03-15

    This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments' ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. A final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks. (orig.)

  12. Boosted objects and jet substructure at the LHC. Report of BOOST2012, held at IFIC Valencia, 23rd-27th of July 2012

    International Nuclear Information System (INIS)

    Altheimer, A.; Thompson, E.N.; Arce, A.; Bjergaard, D.; Asquith, L.; Backus Mayes, J.; Hook, A.; Izaguirre, E.; Jankowiak, M.; Larkoski, A.; Nef, P.; Schwartzman, A.; Swiatlowski, M.; Wacker, J.; Kuutmann, E.B.; Berger, J.; Bryngemark, L.; Buckley, A.; Debenedetti, C.; Butterworth, J.; Campanelli, M.; Davison, A.; Cacciari, M.; Carli, T.; Roeck, A. de; Chala, M.; Chapleau, B.; Chen, C.; Chou, J.P.; Cornelissen, T.; Fleischmann, S.; Curtin, D.; Dasgupta, M.; Almeida Dias, F. de; De Cosa, A.; Doglioni, C.; Guescini, F.; Ellis, S.D.; Hornig, A.; Scholtz, J.; Fassi, F.; Hoz, S.G. de la; Kaci, M.; Oliver Garcia, E.; Rodrigo, G.; Salt, J.; Sanchez Martinez, V.; Villaplana, M.; Vos, M.; Ferrando, J.; Kar, D.; Nordstrom, K.; Freytsis, M.; Gonzalez Silva, M.L.; Han, Z.; Lopez Mateos, D.; Schwartz, M.D.; Juknevich, J.; Kasieczka, G.; Plehn, T.; Schaetzel, S.; Takeuchi, M.; Kogler, R.; Loch, P.; Marzani, S.; Spannowsky, M.; Masetti, L.; Mateu, V.; Stewart, I.; Thaler, J.; Miller, D.W.; Mishra, K.; Tran, N.V.; Penwell, J.; Pilot, J.; Rappoccio, S.; Rizzi, A.; Safonov, A.; Salam, G.P.; Schioppa, M.; Schmidt, A.; Segala, M.; Son, M.; Soyez, G.; Strom, D.; Vermilion, C.; Walsh, J.

    2014-01-01

    This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments' ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. A final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks. (orig.)

  13. State space analysis of boost DC/DC converter with voltage mode control

    Science.gov (United States)

    Shenoy, K. Latha; Nayak, C. Gurudas; Mandi, Rajashekar P.

    2017-07-01

    The boost converter belongs to the family of indirect energy transfer converters. The inductor stores energy during switch on and the output capacitor deliver power to the load. During switch off condition, the stored inductive energy appears in series with the input source and supply the output. The paper deals with the small signal analysis of dc-dc boost converter. It is used in modeling the closed loop converter parameters. The boost converter produces an undesirable Right-Half Plane Zero (RHPZ) in the small signal analysis due to which the implementation of voltage mode control needs attention. This requires compensating the regulator such that the crossover frequency occurs well below the frequency of the RHP zero. The paper describes modeling of voltage mode control boost converter operating in continuous conduction mode.

  14. Experimental Treatment for Duchenne Muscular Dystrophy Gets Boost from Existing Medication

    Science.gov (United States)

    ... on Research Spotlight on Research Experimental Treatment for Duchenne Muscular Dystrophy Gets Boost from Existing Medication By Colleen Labbe, ... the effects of a promising experimental treatment for Duchenne muscular dystrophy (DMD), according to research partially funded by the ...

  15. Genome-scale metabolic flux analysis of Streptomyces lividans growing on a complex medium.

    Science.gov (United States)

    D'Huys, Pieter-Jan; Lule, Ivan; Vercammen, Dominique; Anné, Jozef; Van Impe, Jan F; Bernaerts, Kristel

    2012-09-15

    Constraint-based metabolic modeling comprises various excellent tools to assess experimentally observed phenotypic behavior of micro-organisms in terms of intracellular metabolic fluxes. In combination with genome-scale metabolic networks, micro-organisms can be investigated in much more detail and under more complex environmental conditions. Although complex media are ubiquitously applied in industrial fermentations and are often a prerequisite for high protein secretion yields, such multi-component conditions are seldom investigated using genome-scale flux analysis. In this paper, a systematic and integrative approach is presented to determine metabolic fluxes in Streptomyces lividans TK24 grown on a nutritious and complex medium. Genome-scale flux balance analysis and randomized sampling of the solution space are combined to extract maximum information from exometabolome profiles. It is shown that biomass maximization cannot predict the observed metabolite production pattern as such. Although this cellular objective commonly applies to batch fermentation data, both input and output constraints are required to reproduce the measured biomass production rate. Rich media hence not necessarily lead to maximum biomass growth. To eventually identify a unique intracellular flux vector, a hierarchical optimization of cellular objectives is adopted. Out of various tested secondary objectives, maximization of the ATP yield per flux unit returns the closest agreement with the maximum frequency in flux histograms. This unique flux estimation is hence considered as a reasonable approximation for the biological fluxes. Flux maps for different growth phases show no active oxidative part of the pentose phosphate pathway, but NADPH generation in the TCA cycle and NADPH transdehydrogenase activity are most important in fulfilling the NADPH balance. Amino acids contribute to biomass growth by augmenting the pool of available amino acids and by boosting the TCA cycle, particularly

  16. Coherence properties in superconducting flux qubits

    Energy Technology Data Exchange (ETDEWEB)

    Spilla, Samuele

    2015-02-16

    The research work discussed in this thesis deals with the study of superconducting Josephson qubits. Superconducting qubits are solid-state artificial atoms which are based on lithographically defined Josephson tunnel junctions properties. When sufficiently cooled, these superconducting devices exhibit quantized states of charge, flux or junction phase depending on their design parameters. This allows to observe coherent evolutions of their states. The results presented can be divided into two parts. In a first part we investigate operations of superconducting qubits based on the quantum coherence in superconducting quantum interference devices (SQUID). We explain experimental data which has been observed in a SQUID subjected to fast, large-amplitude modifications of its effective potential shape. The motivations for this work come from the fact that in the past few years there have been attempts to interpret the supposed quantum behavior of physical systems, such as Josephson devices, within a classical framework. Moreover, we analyze the possibility of generating GHZ states, namely maximally entangled states, in a quantum system made out of three Josephson qubits. In particular, we investigate the possible limitations of the GHZ state generation due to coupling to bosonic baths. In the second part of the thesis we address a particular cause of decoherence of flux qubits which has been disregarded until now: thermal gradients, which can arise due to accidental non equilibrium quasiparticle distributions. The reason for these detrimental effects is that heat currents flowing through Josephson tunnel junctions in response to a temperature gradient are periodic functions of the phase difference between the electrodes. The phase dependence of the heat current comes from Andreev reflection, namely an interplay between the quasiparticles which carry heat and the superconducting condensate which is sensitive to the superconducting phase difference. Generally speaking

  17. Spatially explicit regionalization of airborne flux measurements using environmental response functions

    Directory of Open Access Journals (Sweden)

    S. Metzger

    2013-04-01

    Full Text Available The goal of this study is to characterize the sensible (H and latent (LE heat exchange for different land covers in the heterogeneous steppe landscape of the Xilin River catchment, Inner Mongolia, China. Eddy-covariance flux measurements at 50–100 m above ground were conducted in July 2009 using a weight-shift microlight aircraft. Wavelet decomposition of the turbulence data enables a spatial discretization of 90 m of the flux measurements. For a total of 8446 flux observations during 12 flights, MODIS land surface temperature (LST and enhanced vegetation index (EVI in each flux footprint are determined. Boosted regression trees are then used to infer an environmental response function (ERF between all flux observations (H, LE and biophysical (LST, EVI and meteorological drivers. Numerical tests show that ERF predictions covering the entire Xilin River catchment (≈3670 km2 are accurate to ≤18% (1 σ. The predictions are then summarized for each land cover type, providing individual estimates of source strength (36 W m−2 H −2, 46 W m−2 −2 and spatial variability (11 W m−2 H −2, 14 W m−2 LE −2 to a precision of ≤5%. Lastly, ERF predictions of land cover specific Bowen ratios are compared between subsequent flights at different locations in the Xilin River catchment. Agreement of the land cover specific Bowen ratios to within 12 ± 9% emphasizes the robustness of the presented approach. This study indicates the potential of ERFs for (i extending airborne flux measurements to the catchment scale, (ii assessing the spatial representativeness of long-term tower flux measurements, and (iii designing, constraining and evaluating flux algorithms for remote sensing and numerical modelling applications.

  18. Fast breeder reactors

    International Nuclear Information System (INIS)

    Waltar, A.E.; Reynolds, A.B.

    1981-01-01

    This book describes the major design features of fast breeder reactors and the methods used for their design and analysis. The foremost objective of this book is to fulfill the need for a textbook on Fast Breeder Reactor (FBR) technology at the graduate level or the advanced undergraduate level. It is assumed that the reader has an introductory understanding of reactor theory, heat transfer, and fluid mechanics. The book is expected to be used most widely for a one-semester general course on fast breeder reactors, with the extent of material covered to vary according to the interest of the instructor. The book could also be used effectively for a two-quarter or a two-semester course. In addition, the book could serve as a text for a course on fast reactor safety since many topics other than those appearing in the safety chapters relate to FBR safety. Methodology in fast reactor design and analysis, together with physical descriptions of systems, is emphasized in this text more than numerical results. Analytical and design results continue to change with the ongoing evolution of FBR design whereas many design methods have remained fundamentally unchanged for a considerable time

  19. Fast reactor programme

    International Nuclear Information System (INIS)

    Plakman, J.C.

    1982-01-01

    This progress report summarizes the fast reactor research carried out by ECN during the period covering the year 1980. This research is mainly concerned with the cores of sodium-cooled breeders, in particular the SNR-300, and its related safety aspects. It comprises six items: A programme to determine relevant nuclear data of fission- and corrosion-products; A fuel performance programme comprising in-pile cladding failure experiments and a study of the consequences of loss-of-cooling and overpower; Basic research on fuel; Investigation of the changes in the mechanical properties of austenitic stainless steel DIN 1.4948 due to fast neutron doses, this material has been used in the manufacture of the reactor vessel and its internal components; Study of aerosols which could be formed at the time of a fast reactor accident and their progressive behaviour on leaking through cracks in the concrete containment; Studies on heat transfer in a sodium-cooled fast reactor core. As fast breeders operate at high power densities, an accurate knowledge of the heat transfer phenomena under single-phase and two-phase conditions is sought. (Auth.)

  20. 7th International Workshop on Boosted Object Phenomenology, Reconstruction and Searches in HEP

    CERN Document Server

    2015-01-01

    BOOST2015 is the seventh of a series of successful joint theory/experiment workshops which bring together the world leading experts from theory and the Tevatron and LHC experiments to discuss the latest progress and develop new approaches on the reconstruction and use of boosted decay topologies as search tools for new physics. This year, the workshop is hosted by the University of Chicago.