Science.gov

Sample records for flux science

  1. AmeriFlux Measurement Network: Science Team Research

    SciTech Connect

    Law, B E

    2012-12-12

    Research involves analysis and field direction of AmeriFlux operations, and the PI provides scientific leadership of the AmeriFlux network. Activities include the coordination and quality assurance of measurements across AmeriFlux network sites, synthesis of results across the network, organizing and supporting the annual Science Team Meeting, and communicating AmeriFlux results to the scientific community and other users. Objectives of measurement research include (i) coordination of flux and biometric measurement protocols (ii) timely data delivery to the Carbon Dioxide Information and Analysis Center (CDIAC); and (iii) assurance of data quality of flux and ecosystem measurements contributed by AmeriFlux sites. Objectives of integration and synthesis activities include (i) integration of site data into network-wide synthesis products; and (ii) participation in the analysis, modeling and interpretation of network data products. Communications objectives include (i) organizing an annual meeting of AmeriFlux investigators for reporting annual flux measurements and exchanging scientific information on ecosystem carbon budgets; (ii) developing focused topics for analysis and publication; and (iii) developing data reporting protocols in support of AmeriFlux network goals.

  2. Panel session: Part 1, In flux -- Science Policy and the social structure of Big Laboratories, 1964--1979

    SciTech Connect

    Westfall, C. ||

    1993-09-01

    This report discusses the in flux of science policy and the social structure of big laboratories during the period of 1964 to 1979 and some sociological consequences of high energy physicists` development of the standard model during the same period.

  3. Science in Flux: NASA's Nuclear Program at Plum Brook Station 1955-2005

    NASA Technical Reports Server (NTRS)

    Bowles, Mark D.

    2006-01-01

    Science in Flux traces the history of one of the most powerful nuclear test reactors in the United States and the only nuclear facility ever built by NASA. In the late 1950's NASA constructed Plum Brook Station on a vast tract of undeveloped land near Sandusky, Ohio. Once fully operational in 1963, it supported basic research for NASA's nuclear rocket program (NERVA). Plum Brook represents a significant, if largely forgotten, story of nuclear research, political change, and the professional culture of the scientists and engineers who devoted their lives to construct and operate the facility. In 1973, after only a decade of research, the government shut Plum Brook down before many of its experiments could be completed. Even the valiant attempt to redefine the reactor as an environmental analysis tool failed, and the facility went silent. The reactors lay in costly, but quiet standby for nearly a quarter-century before the Nuclear Regulatory Commission decided to decommission the reactors and clean up the site. The history of Plum Brook reveals the perils and potentials of that nuclear technology. As NASA, Congress, and space enthusiasts all begin looking once again at the nuclear option for sending humans to Mars, the echoes of Plum Brook's past will resonate with current policy and space initiatives.

  4. DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

    DOE PAGES

    Capatina, D.; D’Amico, K.; Nudell, J.; ...

    2016-07-27

    The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures.more » Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm2. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm2. Finally, a new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.« less

  5. DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

    SciTech Connect

    Capatina, D.; D’Amico, K.; Nudell, J.; Collins, J.; Schmidt, O.

    2016-07-27

    The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures. Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm2. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm2. Finally, a new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.

  6. DCS - A High Flux Beamline for Time Resolved Dynamic Compression Science – Design Highlights

    SciTech Connect

    Capatina, D.; D'Amico, Kevin L.; Nudell, J.; Collins, J.; Schmidt, Oliver

    2016-07-27

    The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures. Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm2. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm2. A new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.

  7. DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

    SciTech Connect

    Capatina, D. D’Amico, K. Nudell, J. Collins, J. Schmidt, O.

    2016-07-27

    The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures. Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm{sup 2}. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm{sup 2}. A new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.

  8. DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

    SciTech Connect

    Capatina, D.; D’Amico, K.; Nudell, J.; Collins, J.; Schmidt, O.

    2016-07-27

    The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures. Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm2. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm2. Finally, a new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.

  9. JPRS Report, Science & Technology, Japan. Goto Quantum Magneto-Flux Logic Project.

    DTIC Science & Technology

    2007-11-02

    Overseas Publications ...................................................................................................... 17 (1) P atent L ist...When a quantum flux is used as a logic unit, the device keeps expanding, and supercomputers are now essential must always be operated in a...speed supercomputer device by .104CMOS developing appropriate evaluation techniques . This includes measuring the basic operational characteristics

  10. The flux and reflux of science: The study of the tides and the organization of early Victorian science

    NASA Astrophysics Data System (ADS)

    Reidy, Michael Sean

    2000-07-01

    For a fortnight in June, 1835, nine countries observed simultaneously the oceanic tides bordering their countries and their possessions. Over 650 tidal stations participated. This multi-national venture, which William Whewell affirmed to include the most ``multiplied and extensive observations yet encountered in science,'' was prototypical of what Susan Faye Cannon has termed ``Humboldtian science.'' This dissertation demonstrates how the beginnings of the politics of imperialism, the economics of a worldwide export trade, and the extensive diffusion of science to the middle and working classes laid the foundation for the increasing expansiveness Humboldtian research and the fruitful connection between science and government. The social matrix and internal mechanisms of this tidal research demonstrates that Humboldtian initiatives relied on a broad base of support and activity. This included significant contributions from Missionary Societies, the British Association, and especially the British Admiralty, from the Preventive Coast Guard to the Duke of Wellington, then Foreign Secretary. I also stress the essential contribution of the working-classes, a group previous historiography often described as mere data collectors. I uncover their roles in not only gathering data, but in initiating research topics, building self- registering instruments, reducing observational data, and advancing mathematical methods of analysis. Whewell's twenty-year research project helped him formulate what it was to do science and placed him at the forefront of the emerging profession of science in the early Victorian era. His approach to tidology was culled from a study of its history and philosophy and followed two major lines of research. The first entailed finding the phenomenological laws of the tides through long-term observations. His second approach entailed short-term but simultaneous observations along the entire coast of Great Britain, and eventually Europe and America

  11. Advances in Support of the CMAQ Bidirectional Science Option for the Estimation of Ammonia Flux from Agricultural cropland

    EPA Science Inventory

    Proposed Session: Emissions Inventories, Models and processes: Last year a new CMAQ bidirectional option for the estimation of ammonia flux (emission and deposition) was released. This option essentially replaces NEI crop ammonia emissions with emissions calculated dynamically...

  12. Advances in Support of the CMAQ Bidirectional Science Option for the Estimation of Ammonia Flux from Agricultural cropland

    EPA Science Inventory

    Proposed Session: Emissions Inventories, Models and processes: Last year a new CMAQ bidirectional option for the estimation of ammonia flux (emission and deposition) was released. This option essentially replaces NEI crop ammonia emissions with emissions calculated dynamically...

  13. The Solar Wind - Magnetosphere Energy Coupling Function and Open Magnetic Flux Estimation: Two Science Aspects of the SMILE Mission

    NASA Astrophysics Data System (ADS)

    Wang, C.; Dai, L.; Sun, T.; Han, J.

    2015-12-01

    The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a novel self-standing mission to observe solar wind - magnetosphere coupling via simultaneous in situ solar wind /magnetosheath plasma and magnetic field measurements, X-ray images of the magnetosphere, and UV images of global auroral distribution defining system - level consequences. The SMILE mission is jointly supported by ESA and CSA, and the launch date is expected to be in 2021. SMILE will address several key outstanding questions concerning how the solar wind interacts with the magnetospheres on a global level. Quantitatively estimating the energy input from the solar wind into the magnetosphere on a global scale is still an observational challenge. Using global MHD simulations, we derive a new solar wind - magnetosphere energy coupling function. The X-ray images of the magnetosphere from the SMILE mission will help estimate the energy transfer from the solar wind into the magnetosphere. A second aspect SMILE can address is the open magnetic flux, which is closely related to magnetic reconnections in the dayside magnetopause and magnetotail. In a similar way, we find that the open magnetic flux can be estimated through a combined parameter f, which is a function of the solar wind velocity, number density, the southern interplanetary magnetic field strength, and the ionospheric Pederson conductance. The UV auroral images from SMILE will be used to determine the open magnetic flux, which may serve as a key space weather forecast element in the future.

  14. Relative Fluxes of Primary Particles in B-C-N-O Group from the ATIC Experiment (Science Flight)

    NASA Technical Reports Server (NTRS)

    Panov, A. D.; Adams, J. H., Jr.; Ahn, H. S.; Bashindzhagyan, G. L.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Gunashingha, R. M.; Guzik, T. G.; hide

    2007-01-01

    The ATIC balloon-born experiment measures the energy spectra of elements from H to Fe in primary cosmic rays from about 100 GeV to 100 TeV. ATIC is comprised of a fully active bismuth germinate calorimeter, a carbon target with embedded scintillator hodoscopes, and a silicon matrix that is used as a main charge detector. The silicon matrix produces good charge resolution for the protons and helium but only a partial resolution for heavier nuclei. In the present paper a charge resolution of ATIC device was improved and backgrounds were reduced in the region from Be to Si by means of the upper layer of the scintillator hodoscope that was used as charge detector together with silicon matrix. Relative fluxes of nuclei B, C, N, O in the energy region from about 20 GeV/nucleon to 200 GeV/nucleon that were obtained from new high-resolution and high-quality charge spectra of nuclei are presented.

  15. Monte Carlo simulations for high-rate fast neutron flux measurements made at the RAON neutron science facility by using MICROMEGAS

    NASA Astrophysics Data System (ADS)

    Hwang, Dae Hee; Hong, Ser Gi; Kim, Jae Cheon; Kim, Gi Dong; Kim, Yong Kyun

    2015-10-01

    RAON is a Korean heavy-ion accelerator complex that is planned to be built by 2021. Deuterons (53 MeV) and protons (88 MeV) accelerated by using a low-energy driver linac (SCL1) are delivered to the neutron production target in the Neutron Science Facility (NSF) to produce high-energy neutrons in the interval from 1 to 88 MeV with high fluxes of the order of 1012 n/cm2-sec. The repetition rate of the neutron beam ranges from 1 kHz to 1 MHz, and the maximum beam current is ~12 μA at 1 MHz. The beam width is 1 ~ 2 ns. The high-energy and high-rate fast neutrons are used to estimate accurate neutron-induced cross sections for various nuclides at the NSF. A MICROMEGAS (MICRO Mesh Gaseous Structure), which is a gaseous detector initially developed for tracking in high-rate, high-energy physics experiments, is tentatively being considered as a neutron beam monitor. It can be used to measure both the energy distribution and the flux of the neutron beam. In this study, a MICROMEGAS detector for installation at the NSF was designed and investigated. 6Li, 10B, 235U and 238U targets are being considered as neutron/charged particle converters. For the low-energy region, 6Li(n,α)t and 10B(n,α)7Li are used in the energy range from thermal to 1 MeV. 235U(n,f) and 238U(n,f) reactions are used for high-energy region up to 90 MeV. All calculations are performed by using the GEANT4 toolkit.

  16. Multi-Scale Science Framework for Attributing and Tracking Greenhouse Gas Fluxes at LANL's Four Corners New Mexico Test Bed

    NASA Astrophysics Data System (ADS)

    Costigan, K. R.; Dubey, M. K.; Chylek, P.; Love, S. P.; Henderson, B. G.; Flowers, B. A.; Reisner, J. M.; Rahn, T.; Quick, C. R.

    2010-12-01

    Agreements to limit greenhouse gas emissions require scientifically valid methods for monitoring and validating anthropogenic emissions. However, the task of monitoring CO2 emissions is difficult because relatively small increases need to be detected against CO2’s variable and large background concentrations. To ensure fair compliance, remotely sensed measurements and an understanding of the atmospheric transport of CO2 from the sources are required. We hypothesize that CO2 from various natural and anthropogenic sources can be distinguished and tracked by monitoring co-emitted gases (e.g. NO2, SO2, and CO) and isotopomers (e.g.13CO2). The ratio of a co-emitted species to CO2 depends on fuel composition and combustion process and thus varies by energy sector. These ratios provide an independent method to quantify CO2 emissions. Their low backgrounds, their large perturbations from energy activities, and our ability to measure them precisely make them sensitive probes to attribute sources, especially when emission ratios of multiple species are used concurrently. This strategy of observing emission ratios of co-emitted species to derive regional and source-specific baselines and CO2 fluxes is being tested in the Four Corners region of northwestern New Mexico. The semi-arid ecology in the region has a weak natural carbon cycle, facilitating our goal of dissection of anthropogenic sector-specific sources. The net Four Corners and San Juan power plant emissions are the largest point source of CO2 and NOx in North America. The Four Corners plant produces much more NOx than the San Juan power plant, while their energy and CO2 outputs, and coal used, are similar. This difference offers us a unique opportunity to test discrimination methods. While their CO2 signals remain elusive for current satellites, their NO2 plumes have recently been resolved from space. The region also experiences dispersed CO2 urban emissions as well as emissions and leaks from thousands of oil

  17. Carbon Flux Explorers

    SciTech Connect

    Bishop, Jim

    2016-09-09

    Jim Bishop, senior scientist at Berkeley Lab and professor at UC Berkeley, is leading a project to deploy robotic floats that provide data on how microorganisms sequester carbon in the ocean. He recently led a research team on a 10-day voyage, funded by the National Science Foundation, to put the Carbon Flux Explorers to the test.

  18. Carbon Flux Explorers

    ScienceCinema

    Bishop, Jim

    2016-10-12

    Jim Bishop, senior scientist at Berkeley Lab and professor at UC Berkeley, is leading a project to deploy robotic floats that provide data on how microorganisms sequester carbon in the ocean. He recently led a research team on a 10-day voyage, funded by the National Science Foundation, to put the Carbon Flux Explorers to the test.

  19. Science.

    ERIC Educational Resources Information Center

    Roach, Linda E., Ed.

    This document contains the following papers on science instruction and technology: "A 3-D Journey in Space: A New Visual Cognitive Adventure" (Yoav Yair, Rachel Mintz, and Shai Litvak); "Using Collaborative Inquiry and Interactive Technologies in an Environmental Science Project for Middle School Teachers: A Description and…

  20. [The flux of historiography].

    PubMed

    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.

  1. GEWEX Radiative Flux Assessment Available Data

    Atmospheric Science Data Center

    2016-05-31

    ... GEWEX-SRBGLW_Ed021 GEWEX Surface Radiation Budget Global Longwave GEWEX-SRBGLW_Ed021.zip 48M ... GEWEX Radiative Flux Assessment data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. " In addition, ...

  2. Fast flux locked loop

    DOEpatents

    Ganther, Jr., Kenneth R.; Snapp, Lowell D.

    2002-09-10

    A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.

  3. Magnetic-flux pump

    NASA Technical Reports Server (NTRS)

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1966-01-01

    A magnetic flux pump is described for increasing the intensity of a magnetic field by transferring flux from one location to the magnetic field. The device includes a pair of communicating cavities formed in a block of superconducting material, and a piston for displacing the trapped magnetic flux into the secondary cavity producing a field having an intense flux density.

  4. Pulse flux measuring device

    DOEpatents

    Riggan, William C.

    1985-01-01

    A device for measuring particle flux comprises first and second photodiode detectors for receiving flux from a source and first and second outputs for producing first and second signals representing the flux incident to the detectors. The device is capable of reducing the first output signal by a portion of the second output signal, thereby enhancing the accuracy of the device. Devices in accordance with the invention may measure distinct components of flux from a single source or fluxes from several sources.

  5. Investigating the Dynamics of Canonical Flux Tubes

    NASA Astrophysics Data System (ADS)

    von der Linden, Jens; Sears, Jason; Intrator, Thomas; You, Setthivoine

    2016-10-01

    Canonical flux tubes are flux tubes of the circulation of a species' canonical momentum. They provide a convenient generalization of magnetic flux tubes to regimes beyond magnetohydrodynamics (MHD). We hypothesize that hierarchies of instabilities which couple disparate scales could transfer magnetic pitch into helical flows and vice versa while conserving the total canonical helicity. This work first explores the possibility of a sausage instability existing on top of a kink as mechanism for coupling scales, then presents the evolution of canonical helicity in a gyrating kinked flux rope. Analytical and numerical stability spaces derived for magnetic flux tubes with core and skin currents indicate that, as a flux tube lengthens and collimates, it may become kink unstable with a sausage instability developing on top of the kink. A new analysis of 3D magnetic field and ion flow data on gyrating kinked magnetic flux ropes from the Reconnection Scaling Experiment tracks the evolution of canonical flux tubes and their helicity. These results and methodology are being developed as part of the Mochi experiment specifically designed to observe the dynamics of canonical flux tubes. This work is supported by DOE Grant DE-SC0010340 and the DOE Office of Science Graduate Student Research Program and prepared in part by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-697161.

  6. Clustering of Emerging Flux

    NASA Technical Reports Server (NTRS)

    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.

  7. FLUXES FOR MECHANIZED ELECTRIC WELDING,

    DTIC Science & Technology

    WELDING FLUXES, WELDING ), (* WELDING , WELDING FLUXES), ARC WELDING , WELDS, STABILITY, POROSITY, WELDING RODS, STEEL, CERAMIC MATERIALS, FLUXES(FUSION), TITANIUM ALLOYS, ALUMINUM ALLOYS, COPPER ALLOYS, ELECTRODEPOSITION

  8. Aspects of flux compactification

    NASA Astrophysics Data System (ADS)

    Liu, Tao

    In this thesis, we study three main aspects of flux compactifications: (1) classify supergravity solutions from flux compactification; (2) construct flux-deformed geometry and 4D low-energy theory to describe these flux vacua; and (3) study 4D particle phenomenology and cosmology of flux vacua. In the first part, we review G-structure, the basic tool to study supersymmetric flux solutions, and some typical solutions obtained in heterotic, type IIA and type IIB string theories. Then we present a comprehensive classification of supersymmetric vacua of M-theory compactification on 7D manifolds with general four-form fluxes. We analyze the cases where the resulting four-dimensional vacua have N = 1, 2, 3, 4 supersymmetry and the internal space allows for SU(2)-, SU(3)- or G 2-structures. In particular, we find for N = 2 supersymmetry, that the external space-time is Minkowski and the base manifold of the internal space is conformally Kahler for SU(2) structures, while for SU(3) structures the internal space has to be Einstein-Sasaki and no internal fluxes are allowed. Moreover, we provide a new vacuum with N = 1 supersymmetry and SU(3) structure, where all fluxes are non-zero and the first order differential equations are solved. In the second part, we simply review the methods used to construct one subclass of fluxed-deformed geometry or the so-called "twisted manifold", and the associated 4D effective theory describing these flux vacua. Then by employing (generalized) Scherk-Schwarz reduction, we construct the geometric twisting for Calabi-Yau manifolds of Voisin-Borcea type (K 3 x T2)/ Z2 and study the superpotential in a type IIA orientifold based on this geometry. The twists modify the direct product by fibering the K 3 over T2 while preserving the Z2 involution. As an important application, the Voisin-Borcea class contains T6/( Z2 x Z2 ), the usual setting for intersecting D6 brane model building. Past work in this context considered only those twists inherited

  9. Video Meteor Fluxes

    NASA Technical Reports Server (NTRS)

    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

  10. Electron heat flux instability

    NASA Astrophysics Data System (ADS)

    Saeed, Sundas; Sarfraz, M.; Yoon, P. H.; Lazar, M.; Qureshi, M. N. S.

    2017-02-01

    The heat flux instability is an electromagnetic mode excited by a relative drift between the protons and two-component core-halo electrons. The most prominent application may be in association with the solar wind where drifting electron velocity distributions are observed. The heat flux instability is somewhat analogous to the electrostatic Buneman or ion-acoustic instability driven by the net drift between the protons and bulk electrons, except that the heat flux instability operates in magnetized plasmas and possesses transverse electromagnetic polarization. The heat flux instability is also distinct from the electrostatic counterpart in that it requires two electron species with relative drifts with each other. In the literature, the heat flux instability is often called the 'whistler' heat flux instability, but it is actually polarized in the opposite sense to the whistler wave. This paper elucidates all of these fundamental plasma physical properties associated with the heat flux instability starting from a simple model, and gradually building up more complexity towards a solar wind-like distribution functions. It is found that the essential properties of the instability are already present in the cold counter-streaming electron model, and that the instability is absent if the protons are ignored. These instability characteristics are highly reminiscent of the electron firehose instability driven by excessive parallel temperature anisotropy, propagating in parallel direction with respect to the ambient magnetic field, except that the free energy source for the heat flux instability resides in the effective parallel pressure provided by the counter-streaming electrons.

  11. Directed flux motor

    NASA Technical Reports Server (NTRS)

    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.

  12. Directed flux motor

    NASA Technical Reports Server (NTRS)

    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.

  13. Charged Particle Flux Sensor

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Stocks, C. D.

    1983-01-01

    Improved version of Faraday cup increases accuracy of measurements of flux density of charged particles incident along axis through collection aperture. Geometry of cone-and-sensing cup combination assures most particles are trapped.

  14. GEWEX Radiative Flux Assessment

    Atmospheric Science Data Center

    2016-05-20

    ... climate components (atmosphere, ocean, land, cryosphere, biosphere). The GEWEX Radiative Flux Assessment (RFA) project will provide a ... Spatial Coverage: (-20.45, -2.43)(-62.87, -47.90) Full Product Page ...

  15. Cryogenic flux-concentrator

    NASA Technical Reports Server (NTRS)

    Bailey, B. M.; Brechna, H.; Hill, D. A.

    1969-01-01

    Flux concentrator has high primary to secondary coupling efficiency enabling it to produce high magnetic fields. The device provides versatility in pulse duration, magnetic field strengths and power sources.

  16. Ultrahigh flux double donut research reactor design

    SciTech Connect

    Ryskamp, J.M.; Parsons, D.K.; Lake, J.A.

    1986-01-01

    A new steady-state thermal neutron source of unprecedented intensity is under development for materials science research, isotope production, and fundamental physics research. The challenge put forth by the research community is to produce a thermal neutron flux of 10/sup 16/ n/(cm/sup 2/s) in a large accessible volume with minimum fast neutron and gamma contamination. Ultrahigh flux reactor designs based on well-characterized plate-fuel technologies have been examined at the Idaho National Engineering Laboratory. A ''double donut'' core configuration extends the range of peak operating conditions, which are traditionally limited by fuel plate temperatures and thermal hydraulic conditions in the hot channel, to a point where these flux intensity goals can be attained.

  17. SAMOS Surface Fluxes

    NASA Astrophysics Data System (ADS)

    Smith, Shawn; Bourassa, Mark

    2014-05-01

    The development of a new surface flux dataset based on underway meteorological observations from research vessels will be presented. The research vessel data center at the Florida State University routinely acquires, quality controls, and distributes underway surface meteorological and oceanographic observations from over 30 oceanographic vessels. These activities are coordinated by the Shipboard Automated Meteorological and Oceanographic System (SAMOS) initiative in partnership with the Rolling Deck to Repository (R2R) project. Recently, the SAMOS data center has used these underway observations to produce bulk flux estimates for each vessel along individual cruise tracks. A description of this new flux product, along with the underlying data quality control procedures applied to SAMOS observations, will be provided. Research vessels provide underway observations at high-temporal frequency (1 min. sampling interval) that include navigational (position, course, heading, and speed), meteorological (air temperature, humidity, wind, surface pressure, radiation, rainfall), and oceanographic (surface sea temperature and salinity) samples. Vessels recruited to the SAMOS initiative collect a high concentration of data within the U.S. continental shelf and also frequently operate well outside routine shipping lanes, capturing observations in extreme ocean environments (Southern, Arctic, South Atlantic, and South Pacific oceans). These observations are atypical for their spatial and temporal sampling, making them very useful for many applications including validation of numerical models and satellite retrievals, as well as local assessments of natural variability. Individual SAMOS observations undergo routine automated quality control and select vessels receive detailed visual data quality inspection. The result is a quality-flagged data set that is ideal for calculating turbulent flux estimates. We will describe the bulk flux algorithms that have been applied to the

  18. Meromorphic flux compactification

    NASA Astrophysics Data System (ADS)

    Damian, Cesar; Loaiza-Brito, Oscar

    2017-04-01

    We present exact solutions of four-dimensional Einstein's equations related to Minkoswki vacuum constructed from Type IIB string theory with non-trivial fluxes. Following [1, 2] we study a non-trivial flux compactification on a fibered product by a four-dimensional torus and a two-dimensional sphere punctured by 5- and 7-branes. By considering only 3-form fluxes and the dilaton, as functions on the internal sphere coordinates, we show that these solutions correspond to a family of supersymmetric solutions constructed by the use of G-theory. Meromorphicity on functions constructed in terms of fluxes and warping factors guarantees that flux and 5-brane contributions to the scalar curvature vanish while fulfilling stringent constraints as tadpole cancelation and Bianchi identities. Different Einstein's solutions are shown to be related by U-dualities. We present three supersymmetric non-trivial Minkowski vacuum solutions and compute the corresponding soft terms. We also construct a non-supersymmetric solution and study its stability.

  19. Inflation from flux cascades

    NASA Astrophysics Data System (ADS)

    D'Amico, Guido; Gobbetti, Roberto; Kleban, Matthew; Schillo, Marjorie L.

    2013-10-01

    When electric-type flux threads compact extra dimensions, a quantum nucleation event can break a flux line and initiate a cascade that unwinds many units of flux. Here, we present a novel mechanism for inflation based on this phenomenon. From the 4D point of view, the cascade begins with the formation of a bubble containing an open Friedmann-Robertson-Walker cosmology, but the vacuum energy inside the bubble is initially only slightly reduced, and subsequently decreases gradually throughout the cascade. If the initial flux number Q0 ≳ O (100), during the cascade the universe can undergo N ≳ 60 efolds of inflationary expansion with gradually decreasing Hubble constant, producing a nearly scale-invariant spectrum of adiabatic density perturbations with amplitude and tilt consistent with observation, and a potentially observable level of non-Gaussianity and tensor modes. The power spectrum has a small oscillatory component that does not decay away during inflation, with a period set approximately by the light-crossing time of the compact dimension(s). Since the ingredients are fluxes threading compact dimensions, this mechanism fits naturally into the string landscape, but does not appear to suffer from the eta problem or require fine-tuning (beyond the usual anthropic requirement of small vacuum energy after reheating).

  20. Science and Science Fiction

    ERIC Educational Resources Information Center

    Oravetz, David

    2005-01-01

    This article is for teachers looking for new ways to motivate students, increase science comprehension, and understanding without using the old standard expository science textbook. This author suggests reading a science fiction novel in the science classroom as a way to engage students in learning. Using science fiction literature and language…

  1. Protected Flux Pairing Qubit

    NASA Astrophysics Data System (ADS)

    Bell, Matthew; Zhang, Wenyuan; Ioffe, Lev; Gershenson, Michael

    2014-03-01

    We have studied the coherent flux tunneling in a qubit containing two submicron Josephson junctions shunted by a superinductor (a dissipationless inductor with an impedance much greater than the resistance quantum). The two low energy quantum states of this device, 0 and 1, are represented by even and odd number of fluxes in the loop, respectively. This device is dual to the charge pairing Josephson rhombi qubit. The spectrum of the device, studied by microwave spectroscopy, reflects the interference between coherent quantum phase slips in the two junctions (the Aharonov-Casher effect). The time domain measurements demonstrate the suppression of the qubit's energy relaxation in the protected regime, which illustrates the potential of this flux pairing device as a protected quantum circuit. Templeton Foundation, NSF, and ARO.

  2. Flux flow microelectronics

    NASA Astrophysics Data System (ADS)

    Martens, J. S.; Hietala, V. M.; Plut, T. A.; Ginley, D. S.; Vawter, G. A.; Tigges, C. P.; Siegal, M. P.; Phillips, J. M.; Hou, S. Y.

    Flux-flow based devices such as the superconducting flux flow transistor and magnetically controlled long junctions have been made from thin films of TlCaBaCuO and YBaCuO. The devices are based on the magnetic control of flux flow in their respective structures: a long junction or an array of weak links. The equivalent circuits of the two devices are similar: a low impedance input control line, an output impedance of 3 - 20 ohm and an active current-controlled element. The long junctions have tended to be slower, have lower gain and be somewhat less noisy than their counterparts. The performance of circuits such as narrowband and distributed amplifiers (50 GHz bandwidths, noise figures less than 3 dB), phase shifters (continuous with less than 2 dB loss 4 - 40 GHz), logic gates (2 - 3 ps gate delays) and memories made using these devices will be compared and analyzed.

  3. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W.; Borella, Henry M.; Cates, Michael R.; Turley, W. Dale; MaCarthur, Charles D.; Cala, Gregory C.

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  4. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W.; Borella, Henry M.; Cates, Michael R.; Turley, W. Dale; MacArthur, Charles D.; Cala, Gregory C.

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  5. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W.; Borella, Henry M.; Cates, Michael R.; Turley, W. Dale; MacArthur, Charles D.; Cala, Gregory C.

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator wherein each thermographic layer comprises a plurality of respective thermographic phosphors. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  6. Optical heat flux gauge

    SciTech Connect

    Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.

    1991-06-25

    A heat flux gauge is described comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator wherein each thermographic layer comprises respective thermographic phosphors. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  7. Optical heat flux gauge

    SciTech Connect

    Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.

    1989-06-07

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figs.

  8. Optical heat flux gauge

    SciTech Connect

    Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MaCarthur, C.D.; Cala, G.C.

    1991-09-03

    A heat flux gauge is described comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figures.

  9. Generic flux coupling analysis.

    PubMed

    Reimers, Arne C; Goldstein, Yaron; Bockmayr, Alexander

    2015-04-01

    Flux coupling analysis (FCA) has become a useful tool for aiding metabolic reconstructions and guiding genetic manipulations. Originally, it was introduced for constraint-based models of metabolic networks that are based on the steady-state assumption. Recently, we have shown that the steady-state assumption can be replaced by a weaker lattice-theoretic property related to the supports of metabolic fluxes. In this paper, we further extend our approach and develop an efficient algorithm for generic flux coupling analysis that works with any kind of qualitative pathway model. We illustrate our method by thermodynamic flux coupling analysis (tFCA), which allows studying steady-state metabolic models with loop-law thermodynamic constraints. These models do not satisfy the lattice-theoretic properties required in our previous work. For a selection of genome-scale metabolic network reconstructions, we discuss both theoretically and practically, how thermodynamic constraints strengthen the coupling results that can be obtained with classical FCA. A prototype implementation of tFCA is available at http://hoverboard.io/L4FC. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. High flux heat exchanger

    NASA Astrophysics Data System (ADS)

    Flynn, Edward M.; Mackowski, Michael J.

    1993-01-01

    This interim report documents the results of the first two phases of a four-phase program to develop a high flux heat exchanger for cooling future high performance aircraft electronics. Phase 1 defines future needs for high flux heat removal in advanced military electronics systems. The results are sorted by broad application categories: (1) commercial digital systems, (2) military data processors, (3) power processors, and (4) radar and optical systems. For applications expected to be fielded in five to ten years, the outlook is for steady state flux levels of 30-50 W/sq cm for digital processors and several hundred W/sq cm for power control applications. In Phase 1, a trade study was conducted on emerging cooling technologies which could remove a steady state chip heat flux of 100 W/sq cm while holding chip junction temperature to 90 C. Constraints imposed on heat exchanger design, in order to reflect operation in a fighter aircraft environment, included a practical lower limit on coolant supply temperature, the preference for a nontoxic, nonflammable, and nonfreezing coolant, the need to minimize weight and volume, and operation in an accelerating environment. The trade study recommended the Compact High Intensity Cooler (CHIC) for design, fabrication, and test in the final two phases of this program.

  11. Muon and neutrino fluxes

    NASA Technical Reports Server (NTRS)

    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.

  12. Soluble organic nutrient fluxes

    Treesearch

    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,...

  13. Advanced Surface Flux Parameterization

    DTIC Science & Technology

    2001-09-30

    within PE 0602435N are BE-35-2-18, for the Mesoscale Modeling of the Atmos- phere and Aerosols, BE-35-2-19, and for the Exploratory Data Assimilation ... Methods . Related project at NPS is N0001401WR20242 for Evaluating Surface Flux and Boundary Layer Parameterizations in Mesoscale Models Using

  14. Flux Tube Model

    NASA Astrophysics Data System (ADS)

    Steiner, O.

    2011-05-01

    This Fortran code computes magnetohydrostatic flux tubes and sheets according to the method of Steiner, Pneuman, & Stenflo (1986) A&A 170, 126-137. The code has many parameters contained in one input file that are easily modified. Extensive documentation is provided in README files.

  15. Radiative Flux Analysis

    DOE Data Explorer

    Long, Chuck [NOAA

    2008-05-14

    The Radiative Flux Analysis is a technique for using surface broadband radiation measurements for detecting periods of clear (i.e. cloudless) skies, and using the detected clear-sky data to fit functions which are then used to produce continuous clear-sky estimates. The clear-sky estimates and measurements are then used in various ways to infer cloud macrophysical properties.

  16. Characterization of seismic hazard and structural response by energy flux

    USGS Publications Warehouse

    Afak, E.

    2000-01-01

    Seismic safety of structures depends on the structure's ability to absorb the seismic energy that is transmitted from ground to structure. One parameter that can be used to characterize seismic energy is the energy flux. Energy flux is defined as the amount of energy transmitted per unit time through a cross-section of a medium, and is equal to kinetic energy multiplied by the propagation velocity of seismic waves. The peak or the integral of energy flux can be used to characterize ground motions. By definition, energy flux automatically accounts for site amplification. Energy flux in a structure can be studied by formulating the problem as a wave propagation problem. For buildings founded on layered soil media and subjected to vertically incident plane shear waves, energy flux equations are derived by modeling the buildings as an extension of the layered soil medium, and considering each story as another layer. The propagation of energy flux in the layers is described in terms of the upgoing and downgoing energy flux in each layer, and the energy reflection and transmission coefficients at each interface. The formulation results in a pair of simple finite-difference equations for each layer, which can be solved recursively starting from the bedrock. The upgoing and downgoing energy flux in the layers allows calculation of the energy demand and energy dissipation in each layer. The methodology is applicable to linear, as well as nonlinear structures. ?? 2000 Published by Elsevier Science Ltd.

  17. Science and data science.

    PubMed

    Blei, David M; Smyth, Padhraic

    2017-08-07

    Data science has attracted a lot of attention, promising to turn vast amounts of data into useful predictions and insights. In this article, we ask why scientists should care about data science. To answer, we discuss data science from three perspectives: statistical, computational, and human. Although each of the three is a critical component of data science, we argue that the effective combination of all three components is the essence of what data science is about.

  18. A turnkey data logger program for field-scale energy flux density measurements using eddy covariance and surface renewal

    USDA-ARS?s Scientific Manuscript database

    Micrometeorological methods and ecosystem-scale energy and mass flux density measurements have become increasingly important in soil, agricultural, and environmental sciences. For many scientists without formal training in atmospheric science, these techniques are relatively inaccessible. Eddy cov...

  19. Flux compactifications grow lumps

    NASA Astrophysics Data System (ADS)

    Dahlen, Alex; Zukowski, Claire

    2014-12-01

    The simplest flux compactifications are highly symmetric—a q -form flux is wrapped uniformly around an extra-dimensional q -sphere. In this paper, we investigate solutions that break the internal SO (q +1 ) symmetry down to SO (q )×Z2 ; we find a large number of such lumpy solutions, and show that often at least one of them has lower vacuum energy, larger entropy, and is more stable than the symmetric solution. We construct the phase diagram of lumpy solutions, and provide an interpretation in terms of an effective potential. Finally, we provide evidence that the perturbatively stable vacua have a nonperturbative instability to spontaneously sprout lumps. We give an estimate of the decay rate and argue that generically it is exponentially faster than all other known decays.

  20. Optical heat flux gauge

    DOEpatents

    Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.

    1991-04-09

    A heat flux gauge is disclosed comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figures.

  1. Lobotomy of flux compactifications

    NASA Astrophysics Data System (ADS)

    Dibitetto, Giuseppe; Guarino, Adolfo; Roest, Diederik

    2014-05-01

    We provide the dictionary between four-dimensional gauged supergravity and type II compactifications on 6 with metric and gauge fluxes in the absence of supersymmetry breaking sources, such as branes and orientifold planes. Secondly, we prove that there is a unique isotropic compactification allowing for critical points. It corresponds to a type IIA background given by a product of two 3-tori with SO(3) twists and results in a unique theory (gauging) with a non-semisimple gauge algebra. Besides the known four AdS solutions surviving the orientifold projection to = 4 induced by O6-planes, this theory contains a novel AdS solution that requires non-trivial orientifold-odd fluxes, hence being a genuine critical point of the = 8 theory.

  2. NEUTRON FLUX INTENSITY DETECTION

    DOEpatents

    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)

  3. Reconnecting Flux Ropes

    NASA Astrophysics Data System (ADS)

    Gekelman, Walter; van Compernolle, Bart

    2012-10-01

    Magnetic flux ropes are due to helical currents and form a dense carpet of arches on the surface of the sun. Occasionally one tears loose as a coronal mass ejection and its rope structure is detected by satellites close to the earth. Current sheets can tear into filaments and these are nothing other than flux ropes. Ropes are not static, they exert mutual JxB forces causing them to twist about each other and merge. Kink instabilities cause them to violently smash into each other and reconnect at the point of contact. We report on experiments done in the large plasma device (LAPD) at UCLA (L=17m,dia=60cm,0.3<=B0z<=2.5kG,n˜2x10^12cm-3)on three dimensional flux ropes. Two, three or more magnetic flux ropes are generated from initially adjacent pulsed current channels in a background magnetized plasma. The currents and magnetic fields form exotic shapes with no ignorable direction and no magnetic nulls. Volumetric space-time data show multiple reconnection sites with time-dependent locations. The concept of a quasi-separatrix layer (QSL), a tool to understand 3D reconnection without null points. In our experiment the QSL is a narrow ribbon-like region(s) that twists between field lines. Within the QSL(s) field lines that start close to one another rapidly diverge as they pass through one or more reconnection regions. When the field lines are tracked they are observed to slip along the QSL when reconnection occurs. The Heating and other co-existing waves will be presented.

  4. Heat Flux Sensor Testing

    NASA Astrophysics Data System (ADS)

    Clark, D. W.

    2002-07-01

    This viewgraph presentation provides information on the following objectives: Developing secondary calibration capabilities for MSFC's (Marshall Space Flight Center) Hot Gas Facility (HGF), a Mach 4 Aerothermal Wind Tunnel; Evaluating ASTM (American Society for Testing and Materials) slug/ thinskin calorimeters against current HGF heat flux sensors; Providing verification of baselined AEDC (Arnold Engineering Development Center) / Medtherm gage calibrations; Addressing future calibration issues involving NIST (National Institute of Standards and Technology) certified radiant gages.

  5. Heat Flux Sensor Testing

    NASA Technical Reports Server (NTRS)

    Clark, D. W.

    2002-01-01

    This viewgraph presentation provides information on the following objectives: Developing secondary calibration capabilities for MSFC's (Marshall Space Flight Center) Hot Gas Facility (HGF), a Mach 4 Aerothermal Wind Tunnel; Evaluating ASTM (American Society for Testing and Materials) slug/ thinskin calorimeters against current HGF heat flux sensors; Providing verification of baselined AEDC (Arnold Engineering Development Center) / Medtherm gage calibrations; Addressing future calibration issues involving NIST (National Institute of Standards and Technology) certified radiant gages.

  6. Exact Vlasov Solutions of Kinetic Flux Ropes

    NASA Astrophysics Data System (ADS)

    Ng, C. S.

    2014-12-01

    Small-scale magnetic flux ropes have been observed to form within the diffusion region in three-dimensional (3D) kinetic simulations of magnetic reconnection. Such 3D structures and the 2D version of them (plasmoids, secondary islands) could have important dynamical effects on the reconnection physics itself. Small-scale flux ropes have also been observed within the interplanetary space. We have found exact time-steady solutions of kinetic flux ropes by generalizing exact solutions of 2D Bernstein-Greene-Kruskal (BGK) modes in a magnetized plasma with finite magnetic field strength [Ng, Bhattacharjee, and Skiff, Phys. Plasmas 13, 055903 (2006)] to cases with azimuthal magnetic fields so that these structures carry electric current as well as steady electric and magnetic fields. Such fully nonlinear solutions now satisfy exactly the Vlasov-Poisson-Ampere system of equations. Solutions like these could describe small-scale flux ropes observed in reconnection diffusion regions or in the interplanetary space. They are also exact nonlinear solutions that can be used to validate numerical schemes for kinetic simulations. This work is supported by a National Science Foundation grant PHY-1004357.

  7. Physics of magnetic flux ropes

    NASA Astrophysics Data System (ADS)

    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.

  8. Enhancing the precision and accuracy within and among AmeriFlux site measurements

    SciTech Connect

    Law, Bev

    2013-11-25

    This is the final report for AmeriFlux QA/QC at Oregon State University. The major objective of this project is to contribute to the AmeriFlux network by continuing to build consistency in AmeriFlux measurements by addressing objectives stated in the AmeriFlux strategic plan and self evaluation, the North American Carbon Program, and the US Carbon Cycle Science Program. The project directly contributes to NACP and CCSP goals to establish an integrated, near-real time network of observations to inform climate change science.

  9. Science in Science Fiction.

    ERIC Educational Resources Information Center

    Allday, Jonathan

    2003-01-01

    Offers some suggestions as to how science fiction, especially television science fiction programs such as "Star Trek" and "Star Wars", can be drawn into physics lessons to illuminate some interesting issues. (Author/KHR)

  10. Thermal flux transfer system

    NASA Technical Reports Server (NTRS)

    Freggens, R. A. (Inventor)

    1973-01-01

    A thermal flux transfer system for use in maintaining the thrust chamber of an operative reaction motor at given temperatures is described. The system is characterized by an hermetically sealed chamber surrounding a thrust chamber to be cooled, with a plurality of parallel, longitudinally spaced, disk-shaped wick members formed of a metallic mesh and employed in delivering a working fluid, in its liquid state, radially toward the thrust chamber and delivering the working fluid, in its vapor state, away from the nozzle for effecting a cooling of the nozzle, in accordance with known principles of an operating heat pipe.

  11. High flux reactor

    DOEpatents

    Lake, James A.; Heath, Russell L.; Liebenthal, John L.; DeBoisblanc, Deslonde R.; Leyse, Carl F.; Parsons, Kent; Ryskamp, John M.; Wadkins, Robert P.; Harker, Yale D.; Fillmore, Gary N.; Oh, Chang H.

    1988-01-01

    A high flux reactor is comprised of a core which is divided into two symetric segments housed in a pressure vessel. The core segments include at least one radial fuel plate. The spacing between the plates functions as a coolant flow channel. The core segments are spaced axially apart such that a coolant mixing plenum is formed between them. A channel is provided such that a portion of the coolant bypasses the first core section and goes directly into the mixing plenum. The outlet coolant from the first core segment is mixed with the bypass coolant resulting in a lower inlet temperature to the lower core segment.

  12. Genetic modification of flux for flux prediction of mutants.

    PubMed

    Zhao, Quanyu; Kurata, Hiroyuki

    2009-07-01

    Gene deletion and overexpression are critical technologies for designing or improving the metabolic flux distribution of microbes. Some algorithms including flux balance analysis (FBA) and minimization of metabolic adjustment (MOMA) predict a flux distribution from a stoichiometric matrix in the mutants in which some metabolic genes are deleted or non-functional, but there are few algorithms that predict how a broad range of genetic modifications, such as over- and underexpression of metabolic genes, alters the phenotypes of the mutants at the metabolic flux level. To overcome such existing limitations, we develop a novel algorithm that predicts the flux distribution of the mutants with a broad range of genetic modification, based on elementary mode analysis. It is denoted as genetic modification of flux (GMF), which couples two algorithms that we have developed: modified control effective flux (mCEF) and enzyme control flux (ECF). mCEF is proposed based on CEF to estimate the gene expression patterns in genetically modified mutants in terms of specific biological functions. GMF is demonstrated to predict the flux distribution of not only gene deletion mutants, but also the mutants with underexpressed and overexpressed genes in Escherichia coli and Corynebacterium glutamicum. This achieves breakthrough in the a priori flux prediction of a broad range of genetically modified mutants. Supplementary file and programs are available at Bioinformatics online or http://www.cadlive.jp.

  13. First Reconnected Flux Tubes

    NASA Astrophysics Data System (ADS)

    Andersson, L.; Lapenta, G.; Newman, D. L.; Markidis, S.; Spanswick, E. L.; Baker, J. B.; Clausen, L. B.; Larson, D. E.; Ergun, R. E.; Frey, H. U.; Singer, H. J.; Angelopoulos, V.; Bonnell, J. W.; McFadden, J. P.; Glassmeier, K.; Wolfgang, B.

    2011-12-01

    THEMIS observations from the magnetic equator (the equatorial plane) in the near-earth tail reveal a great amount of information regarding the plasma environment in the vicinity of the first reconnected flux tubes (a subgroup of dipolarization fronts). Two sequential observations of dipolarization fronts are analyzed in detail using three of the THEMIS spacecraft. Particle acceleration to high energies (>50 keV) is observed together with a void region interpreted as a region to which the full electron distribution has incomplete access. Whistler waves, which are observed, could be driven by one of the two electron populations located in the wake of the first reconnected flux tubes. The detailed observations are compared with 2D and 3D implicit kinetic simulation of reconnection events. This presentation focuses on the similarity between observation and simulation. One key aspect of this presentation is a demonstration of how different the signature is when observing at vs off the magnetic equator, since most observations in the literature (unlike the observations presented here) are from off the equator. For this event, additional spacecraft and ground observations have been analyzed, which demonstrate that a reconfiguration of the magnetosphere is taking place. However, the focus of this presentation is on the small scale (<~10 di), rather than the large scale (~20 Re).

  14. Computing the Flux Footprint

    NASA Astrophysics Data System (ADS)

    Wilson, J. D.

    2015-07-01

    We address the flux footprint for measurement heights in the atmospheric surface layer, comparing eddy diffusion solutions with those furnished by the first-order Lagrangian stochastic (or "generalized Langevin") paradigm. The footprint given by Langevin models differs distinctly from that given by the random displacement model (i.e. zeroth-order Lagrangian stochastic model) corresponding to its "diffusion limit," which implies that a well-founded theory of the flux footprint must incorporate the turbulent velocity autocovariance. But irrespective of the choice of the eddy diffusion or Langevin class of model as basis for the footprint, tuning relative to observations is ultimately necessary. Some earlier treatments assume Monin-Obukhov profiles for the mean wind and eddy diffusivity and that the effective Schmidt number (ratio of eddy viscosity to the tracer eddy diffusivity) in the neutral limit , while others calibrate the model to the Project Prairie Grass dispersion trials. Because there remains uncertainty as to the optimal specification of (or a related parameter in alternative theories, e.g. the Kolmogorov coefficient in Langevin models) it is recommended that footprint models should be explicit in this regard.

  15. Chaos in Magnetic Flux Ropes

    NASA Astrophysics Data System (ADS)

    Gekelman, W. N.; DeHaas, T.; Van Compernolle, B.

    2013-12-01

    Magnetic Flux Ropes Immersed in a uniform magnetoplasma are observed to twist about themselves, writhe about each other and rotate about a central axis. They are kink unstable and smash into one another as they move. Full three dimensional magnetic field and flows are measured at thousands of time steps. Each collision results in magnetic field line generation and the generation of a quasi-seperatrix layer and induced electric fields. Three dimensional magnetic field lines are computed by conditionally averaging the data using correlation techniques. The permutation entropy1 ,which is related to the Lyapunov exponent, can be calculated from the the time series of the magnetic field data (this is also done with flows) and used to calculate the positions of the data on a Jensen Shannon complexity map2. The location of data on this map indicates if the magnetic fields are stochastic, or fall into regions of minimal or maximal complexity. The complexity is a function of space and time. The complexity map, and analysis will be explained in the course of the talk. Other types of chaotic dynamical models such as the Lorentz, Gissinger and Henon process also fall on the map and can give a clue to the nature of the flux rope turbulence. The ropes fall in the region of the C-H plane where chaotic systems lie. The entropy and complexity change in space and time which reflects the change and possibly type of chaos associated with the ropes. The maps give insight as to the type of chaos (deterministic chaos, fractional diffusion , Levi flights..) and underlying dynamical process. The power spectra of much of the magnetic and flow data is exponential and Lorentzian structures in the time domain are embedded in them. Other quantities such as the Hurst exponent are evaluated for both magnetic fields and plasma flow. Work Supported by a UC-LANL Lab fund and the Basic Plasma Science Facility which is funded by DOE and NSF. 1) C. Bandt, B. Pompe, Phys. Rev. Lett., 88,174102 (2007) 2

  16. How Much Flux does a Flux Transfer Event Transfer?

    NASA Astrophysics Data System (ADS)

    Fear, R. C.; Trenchi, L.; Coxon, J.; Milan, S. E.

    2016-12-01

    Flux transfer events are bursts of reconnection at the dayside magnetopause, which give rise to characteristic signatures that are observed by a range of magnetospheric/ionospheric instrumentation. Spacecraft situated near the magnetopause observe a bipolar variation in the component of the magnetic field normal to the magnetopause (BN); auroral instrumentation (either ground- or space-based) observe poleward moving auroral forms which indicate the convection of newly-opened flux into the polar cap, and ionospheric radars similarly observe pulsed ionospheric flows or poleward moving radar auroral forms. One outstanding problem is the fact that there is a fundamental mismatch between the estimates of the flux that is opened by each flux transfer event - in other words, their overall significance in the Dungey cycle. Spacecraft-based estimates of the flux content of individual FTEs correspond to each event transferring flux equivalent to approximately 1% of the open flux in the magnetosphere, whereas studies based on global-scale radar and auroral observations suggest this figure could be more like 10%. In the former case, flux transfer events would be a minor detail in the Dungey cycle, but in the latter they could be its main driver. We present observations of a conjunction between flux transfer event signatures observed by the Cluster spacecraft, and pulsed ionospheric flows observed by the SuperDARN network on the 8th February 2002. Over the course of an hour, a similar number of FTE signatures were observed by Cluster (at 13 MLT) and the Prince George radar (at 7 MLT). We argue that the reason for the existing mismatch in flux estimates is that implicit assumptions about flux transfer event structure lead to a major underestimate of the flux content based on spacecraft observations. If these assumptions are removed, a much better match is found.

  17. Permanent magnet flux-biased magnetic actuator with flux feedback

    NASA Technical Reports Server (NTRS)

    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.

  18. Rotating reverse osmosis: a dynamic model for flux and rejection

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Reverse osmosis (RO) is a compact process for the removal of ionic and organic pollutants from contaminated water. However, flux decline and rejection deterioration due to concentration polarization and membrane fouling hinders the application of RO technology. In this study, a rotating cylindrical RO membrane is theoretically investigated as a novel method to reduce polarization and fouling. A dynamic model based on RO membrane transport incorporating concentration polarization is used to predict the performance of rotating RO system. Operating parameters such as rotational speed and transmembrane pressure play an important role in determining the flux and rejection in rotating RO. For a given geometry, a rotational speed sufficient to generate Taylor vortices in the annulus is essential to maintain high flux as well as high rejection. The flux and rejection were calculated for wide range of operating pressures and rotational speeds. c 2001 Elsevier Science B.V. All rights reserved.

  19. Rotating reverse osmosis: a dynamic model for flux and rejection

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Reverse osmosis (RO) is a compact process for the removal of ionic and organic pollutants from contaminated water. However, flux decline and rejection deterioration due to concentration polarization and membrane fouling hinders the application of RO technology. In this study, a rotating cylindrical RO membrane is theoretically investigated as a novel method to reduce polarization and fouling. A dynamic model based on RO membrane transport incorporating concentration polarization is used to predict the performance of rotating RO system. Operating parameters such as rotational speed and transmembrane pressure play an important role in determining the flux and rejection in rotating RO. For a given geometry, a rotational speed sufficient to generate Taylor vortices in the annulus is essential to maintain high flux as well as high rejection. The flux and rejection were calculated for wide range of operating pressures and rotational speeds. c 2001 Elsevier Science B.V. All rights reserved.

  20. Quantum transport in coupled resonators enclosed synthetic magnetic flux

    NASA Astrophysics Data System (ADS)

    Jin, L.

    2016-07-01

    Quantum transport properties are instrumental to understanding quantum coherent transport processes. Potential applications of quantum transport are widespread, in areas ranging from quantum information science to quantum engineering, and not restricted to quantum state transfer, control and manipulation. Here, we study light transport in a ring array of coupled resonators enclosed synthetic magnetic flux. The ring configuration, with an arbitrary number of resonators embedded, forms a two-arm Aharonov-Bohm interferometer. The influence of magnetic flux on light transport is investigated. Tuning the magnetic flux can lead to resonant transmission, while half-integer magnetic flux quantum leads to completely destructive interference and transmission zeros in an interferometer with two equal arms.

  1. Why different gas flux velocity parameterizations result in so similar flux results in the North Atlantic?

    NASA Astrophysics Data System (ADS)

    Piskozub, Jacek; Wróbel, Iwona

    2016-04-01

    The North Atlantic is a crucial region for both ocean circulation and the carbon cycle. Most of ocean deep waters are produced in the basin making it a large CO2 sink. The region, close to the major oceanographic centres has been well covered with cruises. This is why we have performed a study of net CO2 flux dependence upon the choice of gas transfer velocity k parameterization for this very region: the North Atlantic including European Arctic Seas. The study has been a part of a ESA funded OceanFlux GHG Evolution project and, at the same time, a PhD thesis (of I.W) funded by Centre of Polar Studies "POLAR-KNOW" (a project of the Polish Ministry of Science). Early results have been presented last year at EGU 2015 as a PICO presentation EGU2015-11206-1. We have used FluxEngine, a tool created within an earlier ESA funded project (OceanFlux Greenhouse Gases) to calculate the North Atlantic and global fluxes with different gas transfer velocity formulas. During the processing of the data, we have noticed that the North Atlantic results for different k formulas are more similar (in the sense of relative error) that global ones. This was true both for parameterizations using the same power of wind speed and when comparing wind squared and wind cubed parameterizations. This result was interesting because North Atlantic winds are stronger than the global average ones. Was the flux result similarity caused by the fact that the parameterizations were tuned to the North Atlantic area where many of the early cruises measuring CO2 fugacities were performed? A closer look at the parameterizations and their history showed that not all of them were based on North Atlantic data. Some of them were tuned to the South Ocean with even stronger winds while some were based on global budgets of 14C. However we have found two reasons, not reported before in the literature, for North Atlantic fluxes being more similar than global ones for different gas transfer velocity parametrizations

  2. California's Future Carbon Flux

    NASA Astrophysics Data System (ADS)

    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.

  3. Astronomical Flux Standards: Getting to 1%

    NASA Astrophysics Data System (ADS)

    Deustua, Susana; Cikota, Aleksandar; Hines, Dean C.; Bohlin, Ralph; Gordon, Karl

    2015-08-01

    The objective for pursuing sub-1% absolute photometric accuracies, and, establishing the Absolute Physical Flux of ever fainter standard stars, is motivated by the requirements of Dark Energy science with JWST and other facilities. Even with the best data available, the current determination of absolute physical flux is is plagued by the reliance on the Vega photometric system, which is known to be problematic primarily due to the fact that Vega is a pole-on rapid rotator with an infrared excess from its circumstellar disk! which makes it difficult to model. Vega is also far too bright for large aperture telescopes. In an effort to remedy these difficulties, teams from e.g. the National Institute of Standards (NIST), University of New Mexico, Johns Hopkins University and STScI have begun to develop a catalog of stars that have spectral energy distributions that are tied directly to SI (diode) standards with very precisely determined physical characteristics. A key element in this pursuit has been the efforts at STScI to measure the spectra of many of these objects with STIS. We discuss our program to extend this effort into the near-IR which is crucial to reliably extend the SEDs to longer wavelengths, including the mid IR. We describe results from our effort towards 1% absolute color calibration in the UV-VIS-NIR with Hubble Space Telescope's WFC3/IR observations of 15 carefully selected stars with the immediate objective of establishing their absolute flux.

  4. Neutron fluxes in test reactors

    SciTech Connect

    Youinou, Gilles Jean-Michel

    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.

  5. Science and Science Fiction

    ScienceCinema

    Scherrer, Robert [Vanderbilt University, Nashville, Tennessee, United States

    2016-07-12

    I will explore the similarities and differences between the process of writing science fiction and the process of 'producing' science, specifically theoretical physics. What are the ground rules for introducing unproven new ideas in science fiction, and how do they differ from the corresponding rules in physics? How predictive is science fiction? (For that matter, how predictive is theoretical physics?) I will also contrast the way in which information is presented in science fiction, as opposed to its presentation in scientific papers, and I will examine the relative importance of ideas (as opposed to the importance of the way in which these ideas are presented). Finally, I will discuss whether a background as a research scientist provides any advantage in writing science fiction.

  6. Science and Science Fiction

    SciTech Connect

    Scherrer, Robert

    2006-03-29

    I will explore the similarities and differences between the process of writing science fiction and the process of 'producing' science, specifically theoretical physics. What are the ground rules for introducing unproven new ideas in science fiction, and how do they differ from the corresponding rules in physics? How predictive is science fiction? (For that matter, how predictive is theoretical physics?) I will also contrast the way in which information is presented in science fiction, as opposed to its presentation in scientific papers, and I will examine the relative importance of ideas (as opposed to the importance of the way in which these ideas are presented). Finally, I will discuss whether a background as a research scientist provides any advantage in writing science fiction.

  7. Flux based active filter controller

    SciTech Connect

    Bhattacharya, S.; Divan, D.M.; Lorenz, R.D.; Veltman, A. |

    1995-12-31

    This paper presents a synchronous frame flux based control method for a parallel active filer application. The flux based controller directly implements the inverter switchings in the synchronous reference frame by a hysteresis rule based carrierless PWM strategy to achieve high current bandwidth. This paper addresses the issues and impact on parallel active filtering requirements for utility interface of commonly used harmonic front-ends. The synchronous frame flux based controller provides additional insights for harmonic current compensation requirements. Simulation results provide the validation of the flux based active filter controller to meet IEEE 519 recommended harmonic standards for large rated non-linear loads under balanced and unbalanced supply conditions.

  8. Neutron fluxes in radiotherapy rooms.

    PubMed

    Agosteo, S; Foglio Para, A; Maggioni, B

    1993-01-01

    The spatial distribution of the neutron flux, originated in an electron accelerator therapy room when energies above the threshold of (y,n) and (e,e'n) reactions are employed, is physically due to a direct flux, coming from the accelerator head, and to a flux diffused from the walls. In this work, the flux is described to a high degree of approximation by a set of functions whose spatial behavior is univocally determined by the angular distributions of the neutrons emitted from the shield of the accelerator head and diffused from the walls. The analytical results are verified with an extended series of Monte Carlo simulations obtained with the MCNP code.

  9. Carbon Dioxide Flux Measurement Systems (CO2Flux) Handbook

    SciTech Connect

    Fischer, M

    2005-01-01

    The Southern Great Plains (SGP) carbon dioxide flux (CO2 flux) measurement systems provide half-hour average fluxes of CO2, H2O (latent heat), and sensible heat. The fluxes are obtained by the eddy covariance technique, which computes the flux as the mean product of the vertical wind component with CO2 and H2O densities, or estimated virtual temperature. A three-dimensional sonic anemometer is used to obtain the orthogonal wind components and the virtual (sonic) temperature. An infrared gas analyzer is used to obtain the CO2 and H2O densities. A separate sub-system also collects half-hour average measures of meteorological and soil variables from separate 4-m towers.

  10. South Atlantic meridional fluxes

    NASA Astrophysics Data System (ADS)

    Garzoli, Silvia L.; Baringer, Molly O.; Dong, Shenfu; Perez, Renellys C.; Yao, Qi

    2013-01-01

    The properties of the meridional overturning circulation (MOC) and associated meridional heat transport (MHT) and salt fluxes are analyzed in the South Atlantic. The oceanographic data used for the study consist of Expendable bathythermograph (XBT) data collected along 27 sections at nominally 35°S for the period of time 2002-2011, and Argo profile data collected in the region. Previous estimates obtained with a shorter record are improved and extended, using new oceanographic sections and wind fields. Different wind products are analyzed to determine the uncertainty in the Ekman component of the MHT derived from their use. Results of the analysis provide a 9-year time series of MHT, and volume transport in the upper layer of the MOC. Salt fluxes at 35°S are estimated using a parameter introduced by numerical studies, the Mov that represents the salt flux and helps determine the basin scale salt feedback associated with the MOC. Volume and heat transport by the western and eastern boundary currents are estimated, and their covariablity is examined. Analysis of the data shows that the South Atlantic is responsible for a northward MHT with a mean value of 0.54±0.14 PW. The MHT exhibits no significant trend from 2002 to 2011. The MOC varies from 14.4 to 22.7 Sv with a mean value of 18.1±2.3 Sv and the maximum overturning transport is found at a mean depth of 1250 m. Statistical analysis suggests that an increase of 1 Sv in the MOC leads to an increase of the MHT of 0.04±0.02 PW. Estimates of the Mov from data collected from three different kinds of observations, contrary to those obtained from models, feature a positive salt advection feedback (Mov<0) suggesting that freshwater perturbations will be amplified and that the MOC is bistable. In other words, the MOC might collapse with a large enough freshwater perturbation. Observations indicate that the mean value of the Brazil Current is -8.6±4.1 Sv at 24°S and -19.4±4.3 Sv at 35°S, increasing towards the

  11. From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints

    PubMed Central

    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

  12. From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints.

    PubMed

    Klamt, Steffen; Regensburger, Georg; Gerstl, Matthias P; Jungreuthmayer, Christian; Schuster, Stefan; Mahadevan, Radhakrishnan; Zanghellini, Jürgen; Müller, Stefan

    2017-04-01

    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.

  13. Automated calculation of surface energy fluxes with high-frequency lake buoy data

    USGS Publications Warehouse

    Woolway, R Iestyn; Jones, Ian D; Hamilton, David P.; Maberly, Stephen C; Muroaka, Kohji; Read, Jordan S.; Smyth, Robyn L; Winslow, Luke A.

    2015-01-01

    Lake Heat Flux Analyzer is a program used for calculating the surface energy fluxes in lakes according to established literature methodologies. The program was developed in MATLAB for the rapid analysis of high-frequency data from instrumented lake buoys in support of the emerging field of aquatic sensor network science. To calculate the surface energy fluxes, the program requires a number of input variables, such as air and water temperature, relative humidity, wind speed, and short-wave radiation. Available outputs for Lake Heat Flux Analyzer include the surface fluxes of momentum, sensible heat and latent heat and their corresponding transfer coefficients, incoming and outgoing long-wave radiation. Lake Heat Flux Analyzer is open source and can be used to process data from multiple lakes rapidly. It provides a means of calculating the surface fluxes using a consistent method, thereby facilitating global comparisons of high-frequency data from lake buoys.

  14. Science in science fiction

    NASA Astrophysics Data System (ADS)

    Allday, Jonathan

    2003-01-01

    Science fiction, from Star Trek to Star Wars, is hugely popular and pupils will surely have encountered good and bad physics there, but do they really notice? Discussing the science implied in books and movies, such as in the use of transporters, can be a good way of getting students interested in physics.

  15. Hysteretic Flux Response and Nondegenerate Gain of Flux-Driven Josephson Parametric Amplifiers

    NASA Astrophysics Data System (ADS)

    Pogorzalek, Stefan; Fedorov, Kirill G.; Zhong, Ling; Goetz, Jan; Wulschner, Friedrich; Fischer, Michael; Eder, Peter; Xie, Edwar; Inomata, Kunihiro; Yamamoto, Tsuyoshi; Nakamura, Yasunobu; Marx, Achim; Deppe, Frank; Gross, Rudolf

    2017-08-01

    Josephson parametric amplifiers (JPAs) have become key devices in quantum science and technology with superconducting circuits. In particular, they can be utilized as quantum-limited amplifiers or as a source of squeezed microwave fields. Here, we report on the detailed measurements of five flux-driven JPAs exhibiting a hysteretic dependence of the resonant frequency on the applied magnetic flux. We model the measured characteristics by numerical simulations based on the two-dimensional potential landscape of the dc superconducting quantum interference devices, which provide the JPA nonlinearity for a nonzero screening parameter βL>0 and demonstrate excellent agreement between the numerical results and the experimental data. Furthermore, we study the nondegenerate response of different JPAs and accurately describe the experimental results with our theory.

  16. Flux Compression Magnetic Nozzle

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    In pulsed fusion propulsion schemes in which the fusion energy creates a radially expanding plasma, a magnetic nozzle is required to redirect the radially diverging flow of the expanding fusion plasma into a rearward axial flow, thereby producing a forward axial impulse to the vehicle. In a highly electrically conducting plasma, the presence of a magnetic field B in the plasma creates a pressure B(exp 2)/2(mu) in the plasma, the magnetic pressure. A gradient in the magnetic pressure can be used to decelerate the plasma traveling in the direction of increasing magnetic field, or to accelerate a plasma from rest in the direction of decreasing magnetic pressure. In principle, ignoring dissipative processes, it is possible to design magnetic configurations to produce an 'elastic' deflection of a plasma beam. In particular, it is conceivable that, by an appropriate arrangement of a set of coils, a good approximation to a parabolic 'magnetic mirror' may be formed, such that a beam of charged particles emanating from the focal point of the parabolic mirror would be reflected by the mirror to travel axially away from the mirror. The degree to which this may be accomplished depends on the degree of control one has over the flux surface of the magnetic field, which changes as a result of its interaction with a moving plasma.

  17. High flux reactor

    SciTech Connect

    Lake, J.A.; Heath, R.L.; Liebenthal, J.L.; DeBoisblanc, D.R.; Leyse, C.F.; Parsons, K.; Ryskamp, J.M.; Wadkins, R.P.; Harker, Y.D.; Fillmore, G.N.

    1988-08-16

    A high flux nuclear reactor is described comprising: (a) a pressure vessel including reactor coolant inlet means at the first end thereof and reactor coolant outlet means at the second end thereof; (b) a reactor coolant; (c) a first core segment housed within the pressure vessel, the first core segment including a plurality of concentric, circumferential fuel plates, the spacing between the concentric fuel plates forming coolant flow channels, each fuel plate being thin relative to the spacing between the fuel plates; (d) means for stationarily supporting the first core segment from the pressure vessel; (e) a second core segment housed within the pressure vessel and spaced axialy apart from the first core segment such that a coolant mixing plenum is formed therebetween, the second core segment including a plurality of concentric, circumferential fuel plates, the spacing between the concentric fuel plates forming coolant flow channels, each fuel plate being thin relative to the spacing between the fuel plates; (f) means for stationarily supporting the second core segment from the pressure vessel; and (g) first core coolant bypass means for channeling a volume of the coolant between the inlet means and the coolant mixing plenum such that the coolant volume bypasses the first core segment.

  18. Dynamics of Single Flux Rope in the Reconnection Scaling Experiment

    NASA Astrophysics Data System (ADS)

    Feng, Y.; Sears, J.; Intrator, T.; Weber, T.; Swan, H.; Dunn, J. P.; Gao, K.; Chapdelaine, L.

    2013-12-01

    A magnetic flux tube threaded by current is a flux rope with helically twisted field lines. In the Reconnection Scaling Experiment (RSX) we use a plasma gun to generate a single flux rope with a choice of axial boundary conditions. If this flux rope is driven hard enough, i.e., when J●B /B2 is larger than the kink instability threshold, we measure a helically distorted kinked structure. Rather than exploding in an Alfvén time, this kink appears to saturate to a steady amplitude, helical, gyrating flux rope, which persists as long as the plasma gun sources the current. To understand it, we have experimentally measured three-dimensional (3D) profiles of various quantities of this flux rope. These quantities include magnetic field B, plasma density n and potential φ, ion flow velocity vi, so that current density J, electron flow velocity ve and electron pressure Pe can also be derived. Consequently we can analyze the single flux rope dynamics systematically in 3D. Besides gyrating (writhe), we also find the flux rope has a spin (twist) center, around which the J×B - ▽Pe ≠ 0 suggesting that there should be other forces for the radial balance. We also find that there is a reverse current moving around with the flux rope at some locations, i.e. there are local induced currents that are not at all apparent from measurements outside the 3D volume. Work supported by LANL-DOE, DOE Fusion Energy Sciences DE-AC52-06NA25396, NASA Geospace NNHIOA044I Basic, CMSO, SULI, NUF.

  19. Designing with null flux coils

    SciTech Connect

    Davey, K.R.

    1997-09-01

    Null flux were suggested by Danby and Powell in the late 1960`s as a useful means for realizing induced lift with little drag. As an array of alternating magnets is translated past a set of null flux coils, the currents induced in these coils act to vertically center the magnets on those coils. At present, one Japanese MAGLEV system company and two American-based companies are employing either null flux or flux eliminating coils in their design for high speed magnetically levitated transportation. The principle question addressed in paper is: what is the proper choice of coil length to magnet length in a null flux system? A generic analysis in the time and frequency domain is laid out with the intent of showing the optimal design specification in terms of coil parameters.

  20. An integrated radon flux monitor

    NASA Astrophysics Data System (ADS)

    Abdelrazek, M. M.

    1984-07-01

    A radon flux monitor suitable for measuring radon flux emanating from cracks or small surface areas is described. The monitor consists of a charcoal canister, an air pump and a steel container. Radon gas exhaled from a crack or from a surface is collected inside a steel container (10 cm × 10 cm × 10 cm) and is simultaneously circulated through a charcoal canister using an air pump. Radon flux is estimated by measuring the gamma ray activity of the radon gas absorbed by the charcoal. Experimental investigations showed that an air flow of 8 1/min was found adequate for the purpose of the present work. A calibration coefficient representing the ratio of radon flux measured by the monitor to the actual flux was found to be 0.81∓0.03. Experimental results showed that this monitor gives fairly accurate and reliable results.

  1. Flux growth utilizing the reaction between flux and crucible

    DOE PAGES

    Yan, J. -Q.

    2015-01-22

    Flux growth involves dissolving the components of the target compound in an appropriate flux at high temperatures and then crystallizing under supersaturation controlled by cooling or evaporating the flux. A refractory crucible is generally used to contain the high temperature melt. Moreover, the reaction between the melt and crucible materials can modify the composition of the melt, which typically results in growth failure, or contaminates the crystals. Thus one principle in designing a flux growth is to select suitable flux and crucible materials thus to avoid any reaction between them. In this paper, we review two cases of flux growthmore » in which the reaction between flux and Al2O3 crucible tunes the oxygen content in the melt and helps the crystallization of desired compositions. For the case of La5Pb3O, the Al2O3 crucible oxidizes La to form a passivating La2O3 layer which not only prevents further oxidization of La in the melt but also provides [O] to the melt. Finally, in the case of La0.4Na0.6Fe2As2, it is believed that the Al2O3 crucible reacts with NaAsO2 and the reaction consumes oxygen in the melt thus maintaining an oxygen-free environment.« less

  2. PHLUX: Photographic Flux Tools for Solar Glare and Flux

    SciTech Connect

    2010-12-02

    A web-based tool to a) analytically and empirically quantify glare from reflected light and determine the potential impact (e.g., temporary flash blindness, retinal burn), and b) produce flux maps for central receivers. The tool accepts RAW digital photographs of the glare source (for hazard assessment) or the receiver (for flux mapping), as well as a photograph of the sun for intensity and size scaling. For glare hazard assessment, the tool determines the retinal irradiance (W/cm2) and subtended source angle for an observer and plots the glare source on a hazard spectrum (i.e., low-potential for flash blindness impact, potential for flash blindness impact, retinal burn). For flux mapping, the tool provides a colored map of the receiver scaled by incident solar flux (W/m2) and unwraps the physical dimensions of the receiver while accounting for the perspective of the photographer (e.g., for a flux map of a cylindrical receiver, the horizontal axis denotes receiver angle in degrees and the vertical axis denotes vertical position in meters; for a flat panel receiver, the horizontal axis denotes horizontal position in meters and the vertical axis denotes vertical position in meters). The flux mapping capability also allows the user to specify transects along which the program plots incident solar flux on the receiver.

  3. High-flux years

    SciTech Connect

    Not Available

    1992-01-01

    This article reviews the history of activities at the Clinton Laboratories from the end of World War II into roughly mid 1948. This was a period of great change for the laboratory. Monsanto Chemical Company who had served as the industrial operator of the laboratory was replaced by an academic team from the University of Chicago, which never really got started, and was replaced by a new industrial operator, Union Carbide Corporation. Clinton Laboratories became Clinton National Laboratory in 1947 and Oak Ridge National Laboratory in 1948. In the face of these management uncertainties and upheavals much productive work and cutting science was achieved. The Materials Testing Reactor was designed, and served as the model for light-water reactors. The Graphite Reactor began routine production of radioisotopes. New groups were formed to begin and strengthen work in biology, metallurgy, and health physics.

  4. Quantum transport in coupled resonators enclosed synthetic magnetic flux

    SciTech Connect

    Jin, L.

    2016-07-15

    Quantum transport properties are instrumental to understanding quantum coherent transport processes. Potential applications of quantum transport are widespread, in areas ranging from quantum information science to quantum engineering, and not restricted to quantum state transfer, control and manipulation. Here, we study light transport in a ring array of coupled resonators enclosed synthetic magnetic flux. The ring configuration, with an arbitrary number of resonators embedded, forms a two-arm Aharonov–Bohm interferometer. The influence of magnetic flux on light transport is investigated. Tuning the magnetic flux can lead to resonant transmission, while half-integer magnetic flux quantum leads to completely destructive interference and transmission zeros in an interferometer with two equal arms. -- Highlights: •The light transport is investigated through ring array of coupled resonators enclosed synthetic magnetic field. •Aharonov–Bohm ring interferometer of arbitrary configuration is investigated. •The half-integer magnetic flux quantum leads to destructive interference and transmission zeros for two-arm at equal length. •Complete transmission is available via tuning synthetic magnetic flux.

  5. Characteristic Dynamics of a Non-Linear Flux Rope

    NASA Astrophysics Data System (ADS)

    Dehaas, Timothy; Gekelman, Walter; van Compernolle, Bart

    2015-11-01

    A magnetic flux rope is a tube-like, current carrying plasma embedded in an external magnetic field. Commonly observed on the solar surface extending into the solar atmosphere, flux ropes are naturally occurring and have been observed by satellites in the near earth and often recreated in laboratory environments. In a series of experiments, a single flux rope of varying cross-section and length was formed in the cylindrical, magnetized plasma of the Large Plasma Device (LaPD, L = 2200 cm, r = 30 cm, no = 1012 cm-3, Te = 4 eV, He). The flux rope was generated via a DC discharge between a cathode and anode with a fixed-free boundary condition. Upon the initiation of the kink instability (IKink > πr2Bzc/2L), the displacement of the flux rope saturates, commencing complex motion. The flux ropes exhibit two types of motion, common to all cases of varying Alfven speeds, injection currents, lengths, and cross-sections. The first motion is characterized by a circular path in the transverse plane, whose displacement depends on the input power and whose frequency varies with injection current. The second motion is characterized by random Lorentzian pulses in the magnetic signals. The polarity of these pulses align with the transverse magnetic field and manifest with greater frequency with increases in magnetic field and injection current. This work is supported by LANL-UC research grant and done at the Basic Plasma Science Facility, which is funded by DOE and NSF.

  6. Magnetospheric-ionospheric Poynting flux

    NASA Technical Reports Server (NTRS)

    Thayer, Jeffrey P.

    1994-01-01

    Over the past three years of funding SRI, in collaboration with the University of Texas at Dallas, has been involved in determining the total electromagnetic energy flux into the upper atmosphere from DE-B electric and magnetic field measurements and modeling the electromagnetic energy flux at high latitudes, taking into account the coupled magnetosphere-ionosphere system. This effort has been very successful in establishing the DC Poynting flux as a fundamental quantity in describing the coupling of electromagnetic energy between the magnetosphere and ionosphere. The DE-B satellite electric and magnetic field measurements were carefully scrutinized to provide, for the first time, a large data set of DC, field-aligned, Poynting flux measurement. Investigations describing the field-aligned Poynting flux observations from DE-B orbits under specific geomagnetic conditions and from many orbits were conducted to provide a statistical average of the Poynting flux distribution over the polar cap. The theoretical modeling effort has provided insight into the observations by formulating the connection between Poynting's theorem and the electromagnetic energy conversion processes that occur in the ionosphere. Modeling and evaluation of these processes has helped interpret the satellite observations of the DC Poynting flux and improved our understanding of the coupling between the ionosphere and magnetosphere.

  7. Interpreting Flux from Broadband Photometry

    NASA Astrophysics Data System (ADS)

    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.

  8. Magnetospheric-ionospheric Poynting flux

    NASA Astrophysics Data System (ADS)

    Thayer, Jeffrey P.

    1994-08-01

    Over the past three years of funding SRI, in collaboration with the University of Texas at Dallas, has been involved in determining the total electromagnetic energy flux into the upper atmosphere from DE-B electric and magnetic field measurements and modeling the electromagnetic energy flux at high latitudes, taking into account the coupled magnetosphere-ionosphere system. This effort has been very successful in establishing the DC Poynting flux as a fundamental quantity in describing the coupling of electromagnetic energy between the magnetosphere and ionosphere. The DE-B satellite electric and magnetic field measurements were carefully scrutinized to provide, for the first time, a large data set of DC, field-aligned, Poynting flux measurement. Investigations describing the field-aligned Poynting flux observations from DE-B orbits under specific geomagnetic conditions and from many orbits were conducted to provide a statistical average of the Poynting flux distribution over the polar cap. The theoretical modeling effort has provided insight into the observations by formulating the connection between Poynting's theorem and the electromagnetic energy conversion processes that occur in the ionosphere. Modeling and evaluation of these processes has helped interpret the satellite observations of the DC Poynting flux and improved our understanding of the coupling between the ionosphere and magnetosphere.

  9. Correlation of SiO maser flux with stellar flux

    SciTech Connect

    Cahn, J.H.

    1981-12-01

    A survey of available SiO maser observations of the 43.122-GHz, v = 1, J = 1..-->..0 transition has been made in order to further investigate the question of a correlation of maser flux with bolometric flux. This correlation has been shown to exist both for data which have been phase shifted to mean maximum and for those which have not.

  10. On Potential Vorticity Flux Vectors.

    NASA Astrophysics Data System (ADS)

    Bannon, Peter R.; Schmidli, Jürg; Schär, Christoph

    2003-12-01

    Dynamical, rather than kinematical, considerations indicate that a generalized potential vorticity in terms of the gradient of an arbitrary scalar function requires that the potential vorticity flux vector contain a contribution due to gravity and the pressure gradient force. It is shown that such a potential vorticity flux vector has a simpler definition in terms of the gradient of the kinetic energy rather than that of a Bernoulli function. This result is valid for multicomponent fluids. Flux vectors for a salty ocean and a moist atmosphere with hydrometeors are presented.

  11. Coronal Heating and the Magnetic Flux Content of the Network

    NASA Astrophysics Data System (ADS)

    Moore, R. L.; Falconer, D. A.; Porter, J. G.; Hathaway, D. H.

    2003-05-01

    We investigate the heating of the quiet corona by measuring the increase of coronal luminosity with the amount of magnetic flux in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity is measured from Fe IX/X-Fe XII pairs of coronal images from SOHO/EIT. The network magnetic flux content is measured from SOHO/MDI magnetograms. We find that the luminosity of the corona in our quiet regions increases roughly in proportion to the square root of the magnetic flux content of the network and roughly in proportion to the length of the perimeter of the network magnetic flux clumps. From (1) this result, (2) other observations of many fine-scale explosive events at the edges of network flux clumps, and (3) a demonstration that it is energetically feasible for the heating of the corona in quiet regions to be driven by explosions of granule-sized sheared-core magnetic bipoles embedded in the edges of network flux clumps, we infer that in quiet regions that are not influenced by active regions the corona is mainly heated by such magnetic activity in the edges of the network flux clumps. Our observational results together with our feasibility analysis allow us to predict that (1) at the edges of the network flux clumps there are many transient sheared-core bipoles of the size and lifetime of granules and having transverse field strengths > 100 G, (2) 30 of these bipoles are present per supergranule, and (3) most spicules are produced by explosions of these bipoles. This work was supported by NASA's Office of Space Science through its Solar and Heliospheric Physics Supporting Research and Technology Program and its Sun-Earth Connection Guest Investigator Program.

  12. 2 π -flux loop semimetals

    NASA Astrophysics Data System (ADS)

    Li, Linhu; Chesi, Stefano; Yin, Chuanhao; Chen, Shu

    2017-08-01

    We introduce a model of 2 π -flux loop semimetals which holds nodal loops described by a winding number ν =2 . By adding some extra terms, this model can be transformed into a recently discovered Hopf-link semimetal, and the symmetries distinguishing these two types of semimetals are studied. We also propose a simpler physical implementation of 2 π -flux loops and of Hopf-link semimetals which only involves nearest-neighbor hoppings, although in the presence of spin-orbit interactions. Finally, we investigate the Floquet properties of the 2 π -flux loop, and find that such a loop may be driven into two separated π -flux loops or four Weyl points by light with circular polarization in certain directions.

  13. Solar flux and its variations

    NASA Technical Reports Server (NTRS)

    Smith, E. V. P.; Gottlieb, D. M.

    1975-01-01

    Data are presented on the solar irradiance as derived from a number of sources. An attempt was made to bring these data onto a uniform scale. Summation of fluxes at all wavelengths yields a figure of 1357.826 for the solar constant. Estimates are made of the solar flux variations due to flares, active regions (slowly varying component), 27-day period, and the 11-yr cycle. Solar activity does not produce a significant variation in the value of the solar constant. Variations in the X-ray and EUV portions of the solar flux may be several orders of magnitude during solar activity, especially at times of major flares. It is established that these short wavelength flux enhancements cause significant changes in the terrestrial ionosphere.

  14. Conical electromagnetic radiation flux concentrator

    NASA Technical Reports Server (NTRS)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  15. Flux networks in metabolic graphs

    NASA Astrophysics Data System (ADS)

    Warren, P. B.; Duarte Queiros, S. M.; Jones, J. L.

    2009-12-01

    A metabolic model can be represented as a bipartite graph comprising linked reaction and metabolite nodes. Here it is shown how a network of conserved fluxes can be assigned to the edges of such a graph by combining the reaction fluxes with a conserved metabolite property such as molecular weight. A similar flux network can be constructed by combining the primal and dual solutions to the linear programming problem that typically arises in constraint-based modelling. Such constructions may help with the visualization of flux distributions in complex metabolic networks. The analysis also explains the strong correlation observed between metabolite shadow prices (the dual linear programming variables) and conserved metabolite properties. The methods were applied to recent metabolic models for Escherichia coli, Saccharomyces cerevisiae and Methanosarcina barkeri. Detailed results are reported for E. coli; similar results were found for other organisms.

  16. Boundary fluxes for nonlocal diffusion

    NASA Astrophysics Data System (ADS)

    Cortazar, Carmen; Elgueta, Manuel; Rossi, Julio D.; Wolanski, Noemi

    We study a nonlocal diffusion operator in a bounded smooth domain prescribing the flux through the boundary. This problem may be seen as a generalization of the usual Neumann problem for the heat equation. First, we prove existence, uniqueness and a comparison principle. Next, we study the behavior of solutions for some prescribed boundary data including blowing up ones. Finally, we look at a nonlinear flux boundary condition.

  17. UVIS G280 Flux Calibration

    NASA Astrophysics Data System (ADS)

    Bushouse, Howard

    2009-07-01

    Flux calibration, image displacement, and spectral trace of the UVIS G280 grism will be established using observations of the HST flux standard start GD71. Accompanying direct exposures will provide the image displacement measurements and wavelength zeropoints for dispersed exposures. The calibrations will be obtained at the central position of each CCD chip and at the center of the UVIS field. No additional field-dependent variations will be derived.

  18. Methane flux from Minnesota peatlands

    SciTech Connect

    Crill, P.M.; Bartlett, K.B.; Harriss, R.C.; Gorham, E.; Verry, E.S. )

    1988-12-01

    Northern (> 40 deg N) wetlands have been suggested as the largest natural source of methane (CH{sub 4}) to the troposphere. To refine the authors estimates of source strengths from this region and to investigate climatic controls on the process, fluxes were measured from a variety of Minnesota peatlands during May, June, and August 1986. Late spring and summer fluxes ranged from 11 to 866 mg CH{sub 4}/sq/m/day, averaging 207 mg CH{sub 4} sq/m/day overall. At Marcell Forest, forested bogs and fen sites had lower fluxes than open bogs. In the Red Lake peatland, circumneutral fens, with standing water above the peat surface, produced more methane than acid bog sites in which the water table was beneath the moss surface. Peat temperature was an important control. Methane flux increased in response to increasing soil temperature. It is estimated that the methane flux from all peatlands north of 40 deg may be on the order of 70 to 90 Tg/yr though estimates of this sort are plagued by uncertainties in the areal extent of peatlands, length of the CH{sub 4} producing season, and the spatial and temporal variability of the flux. 60 refs., 7 figs., 5 tabs.

  19. Flux growth utilizing the reaction between flux and crucible

    SciTech Connect

    Yan, J. -Q.

    2015-01-22

    Flux growth involves dissolving the components of the target compound in an appropriate flux at high temperatures and then crystallizing under supersaturation controlled by cooling or evaporating the flux. A refractory crucible is generally used to contain the high temperature melt. Moreover, the reaction between the melt and crucible materials can modify the composition of the melt, which typically results in growth failure, or contaminates the crystals. Thus one principle in designing a flux growth is to select suitable flux and crucible materials thus to avoid any reaction between them. In this paper, we review two cases of flux growth in which the reaction between flux and Al2O3 crucible tunes the oxygen content in the melt and helps the crystallization of desired compositions. For the case of La5Pb3O, the Al2O3 crucible oxidizes La to form a passivating La2O3 layer which not only prevents further oxidization of La in the melt but also provides [O] to the melt. Finally, in the case of La0.4Na0.6Fe2As2, it is believed that the Al2O3 crucible reacts with NaAsO2 and the reaction consumes oxygen in the melt thus maintaining an oxygen-free environment.

  20. Ultra-high flux reactor design using plate fuel technology

    SciTech Connect

    Lake, J.A.; Parsons, D.K.; Ryskamp, J.M.; Liebenthal, J.L.; Fillmore, G.N.

    1986-01-01

    The need for a new steady-state thermal neutron source of unprecedented intensity for materials science, isotope production, and fundamental physics research has been the subject of numerous national meetings and discussions. The challenge put forth by the research community is to produce a thermal neutron flux of 10/sup 16/ n/cm/sup 2/ x s in a large accessible volume with minimum fast neutron and gamma contamination. Ultra-high-flux reactor designs based on well-characterized plate fuel technologies have been examined. A double donut core configuration extends the range of peak operating conditions, which are traditionally limited by fuel plate temperatures and thermal-hydraulic conditions in the hot channel, to a point where these flux intensity goals can be attained.

  1. TWINS Observations of Oxygen ENA Flux

    NASA Astrophysics Data System (ADS)

    Alquiza, J. C.; Goldstein, J.; Gruntman, M.; McComas, D. J.; Redfern, J.; Valek, P. W.

    2009-12-01

    As part of the science objectives of the TWINS (Two Wide-angle Imaging Neutral-atom Spectrometers) mission, we aim to enhance the knowledge of the workings of our magnetosphere by contributing compositional information of the observed energetic neutral atom (ENA) flux from the two TWINS instruments. We will present images of oxygen (O) ENA flux varying over time and space. Results from a few cases of TWINS flight data of geomagnetic significance will be presented with this analysis. One such example is a simultaneous and continuous observation of a minor geomagnetic storm (-60 nT) on 11 Oct 2008 as seen by both TWINS instruments. Initial TWINS images of this event show evidences of low-altitude emissions (LAEs) near the limb of the Earth and ring current signatures as well. Our compositional analysis is based on the secondary electron pulse height (PH) distributions measured by TWINS. Secondary electrons are generated as ENAs pass through an ultra-thin carbon foil in the TWINS instrument apertures. The secondary electron (PH) distribution varys as a function of the ENA’s energy and mass. The observed PH functions are then compared to the secondary electron PH distributions determined during instrument calibration. The flight data are simply treated as a linear combination of the two anticipated and most abundant species of magnetospheric ENAs, i.e., hydrogen (H) and oxygen (O).

  2. Scientific Visualization to Study Flux Transfer Events at the Community Coordinated Modeling Center

    NASA Technical Reports Server (NTRS)

    Rastatter, Lutz; Kuznetsova, Maria M.; Sibeck, David G.; Berrios, David H.

    2011-01-01

    In this paper we present results of modeling of reconnection at the dayside magnetopause with subsequent development of flux transfer event signatures. The tools used include new methods that have been added to the suite of visualization methods that are used at the Community Coordinated Modeling Center (CCMC). Flux transfer events result from localized reconnection that connect magnetosheath magnetic field and plasma with magnetospheric fields and plasma and results in flux rope structures that span the dayside magnetopause. The onset of flux rope formation and the three-dimensional structure of flux ropes are studied as they have been modeled by high-resolution magnetohydrodynamic simulations of the dayside magnetosphere of the Earth. We show that flux transfer events are complex three-dimensional structures that require modern visualization and analysis techniques. Two suites of visualization methods are presented and we demonstrate the usefulness of those methods through the CCMC web site to the general science user.

  3. Improved Prediction of Momentum and Scalar Fluxes Using MODIS Imagery

    NASA Technical Reports Server (NTRS)

    Crago, Richard D.; Jasinski, Michael F.

    2003-01-01

    There are remote sensing and science objectives. The remote sensing objectives are: To develop and test a theoretical method for estimating local momentum aerodynamic roughness length, z(sub 0m), using satellite multispectral imagery. To adapt the method to the MODIS imagery. To develop a high-resolution (approx. 1km) gridded dataset of local momentum roughness for the continental United States and southern Canada, using MODIS imagery and other MODIS derived products. The science objective is: To determine the sensitivity of improved satellite-derived (MODIS-) estimates of surface roughness on the momentum and scalar fluxes, within the context of 3-D atmospheric modeling.

  4. Science Processes.

    ERIC Educational Resources Information Center

    Finley, Fred N.

    1983-01-01

    Reports an investigation of the epistomologic foundations of Gagne's conception of science processes. Results indicate that a commitment to inductive empiricism pervades the presently held view of science processes. Implications for science education are considered. (Author/JN)

  5. A Thermally Actuated Flux Pump for Energizing YBCO Pucks

    DTIC Science & Technology

    2016-05-01

    magnetic circuit. The circuit was cooled using a cryocooler and heat pulses were applied to the dysprosium by turning the cold head on and off. These...on parts of the circuit. Currents through the coils generated flux in the magnetic circuit. The circuit was cooled using a cryocooler and heat pulses...Division Defence Science and Technology Group DST-Group-TN-1527 ABSTRACT This paper presents results for the magnetization of a disc of YBCO

  6. Science Anxiety and Science Learning.

    ERIC Educational Resources Information Center

    Mallow, Jeffrey V.; Greenburg, Sharon L.

    1983-01-01

    Discusses origins and nature of science anxiety and describes the Science Anxiety Clinic, outlining techniques used at the clinic. Techniques include science skills training and psychological interventions. Comments on the connection between science anxiety and cognitive processes in science learning. (Author/JN)

  7. Science Anxiety and Science Learning.

    ERIC Educational Resources Information Center

    Mallow, Jeffrey V.; Greenburg, Sharon L.

    1983-01-01

    Discusses origins and nature of science anxiety and describes the Science Anxiety Clinic, outlining techniques used at the clinic. Techniques include science skills training and psychological interventions. Comments on the connection between science anxiety and cognitive processes in science learning. (Author/JN)

  8. Slip Running Reconnection in Magnetic Flux Ropes

    NASA Astrophysics Data System (ADS)

    Gekelman, W. N.; Van Compernolle, B.; Vincena, S. T.; De Hass, T.

    2012-12-01

    Magnetic flux ropes are due to helical currents and form a dense carpet of arches on the surface of the sun. Occasionally one tears loose as a coronal mass ejection and its rope structure can be detected by satellites close to the earth. Current sheets can tear into filaments and these are nothing other than flux ropes. Ropes are not static, they exert mutual ěc{J}×ěc{B} forces causing them to twist about each other and eventually merge. Kink instabilities cause them to violently smash into each other and reconnect at the point of contact. We report on experiments on two adjacent ropes done in the large plasma device (LAPD) at UCLA ( ne ˜ 1012, Te ˜ 6 eV, B0z=330G, Brope}\\cong{10G,trep=1 Hz). The currents and magnetic fields form exotic shapes with no ignorable direction and no magnetic nulls. Volumetric space-time data (70,600 spatial locations) show multiple reconnection sites with time-dependent locations. The concept of a quasi-separatrix layer (QSL), a tool to understand and visualize 3D magnetic field lines reconnection without null points is introduced. Three-dimensional measurements of the QSL derived from magnetic field data are presented. Within the QSL field lines that start close to one another rapidly diverge as they pass through one or more reconnection regions. The motion of magnetic field lines are traced as reconnection proceeds and they are observed to slip through the regions of space where the QSL is largest. As the interaction proceeds we double the current in the ropes. This accompanied by intense heating as observed in uv light and plasma flows measured by Mach probes. The interaction of the ropes is clearly seen by vislaulizng magnetic field data , as well as in images from a fast framing camera. Work supported by the Dept. of Energy and The National Science Foundation, done at the Basic Plasma Science Facility at UCLA.Magnetic Field lines (measured) of three flux ropes and the plasma currents associated with them

  9. Flux flow and flux dynamics in high-Tc superconductors

    NASA Technical Reports Server (NTRS)

    Bennett, L. H.; Turchinskaya, M.; Swartzendruber, L. J.; Roitburd, A.; Lundy, D.; Ritter, J.; Kaiser, D. L.

    1991-01-01

    Because high temperature superconductors, including BYCO and BSSCO, are type 2 superconductors with relatively low H(sub c 1) values and high H(sub c 2) values, they will be in a critical state for many of their applications. In the critical state, with the applied field between H(sub c 1) and H(sub c 2), flux lines have penetrated the material and can form a flux lattice and can be pinned by structural defects, chemical inhomogeneities, and impurities. A detailed knowledge of how flux penetrates the material and its behavior under the influence of applied fields and current flow, and the effect of material processing on these properties, is required in order to apply, and to improve the properties of these superconductors. When the applied field is changed rapidly, the time dependence of flux change can be divided into three regions, an initial region which occurs very rapidly, a second region in which the magnetization has a 1n(t) behavior, and a saturation region at very long times. A critical field is defined for depinning, H(sub c,p) as that field at which the hysteresis loop changes from irreversible to reversible. As a function of temperature, it is found that H(sub c,p) is well described by a power law with an exponent between 1.5 and 2.5. The behavior of H(sub c,p) for various materials and its relationship to flux flow and flux dynamics are discussed.

  10. Soapy Science. Teaching Science.

    ERIC Educational Resources Information Center

    Leyden, Michael

    1997-01-01

    Describes a science and math activity that involves bubbles, shapes, colors, and solid geometry. Students build geometric shapes with soda straws and submerge the shapes in soapy water, allowing them to review basic geometry concepts, test hypotheses, and learn about other concepts such as diffraction, interference colors, and evaporation. (TJQ)

  11. Soapy Science. Teaching Science.

    ERIC Educational Resources Information Center

    Leyden, Michael

    1997-01-01

    Describes a science and math activity that involves bubbles, shapes, colors, and solid geometry. Students build geometric shapes with soda straws and submerge the shapes in soapy water, allowing them to review basic geometry concepts, test hypotheses, and learn about other concepts such as diffraction, interference colors, and evaporation. (TJQ)

  12. Real-time soil flux measurements and calculations with CRDS + Soil Flux Processor: comparison among flux algorithms and derivation of whole system error

    NASA Astrophysics Data System (ADS)

    Alstad, K. P.; Venterea, R. T.; Tan, S. M.; Saad, N.

    2015-12-01

    Understanding chamber-based soil flux model fitting and measurement error is key to scaling soils GHG emissions and resolving the primary uncertainties in climate and management feedbacks at regional scales. One key challenge is the selection of the correct empirical model applied to soil flux rate analysis in chamber-based experiments. Another challenge is the characterization of error in the chamber measurement. Traditionally, most chamber-based N2O and CH4 measurements and model derivations have used discrete sampling for GC analysis, and have been conducted using extended chamber deployment periods (DP) which are expected to result in substantial alteration of the pre-deployment flux. The development of high-precision, high-frequency CRDS analyzers has advanced the science of soil flux analysis by facilitating much shorter DP and, in theory, less chamber-induced suppression of the soil-atmosphere diffusion gradient. As well, a new software tool developed by Picarro (the "Soil Flux Processor" or "SFP") links the power of Cavity Ring-Down Spectroscopy (CRDS) technology with an easy-to-use interface that features flexible sample-ID and run-schemes, and provides real-time monitoring of chamber accumulations and environmental conditions. The SFP also includes a sophisticated flux analysis interface which offers a user-defined model selection, including three predominant fit algorithms as default, and an open-code interface for user-composed algorithms. The SFP is designed to couple with the Picarro G2508 system, an analyzer which simplifies soils flux studies by simultaneously measuring primary GHG species -- N2O, CH4, CO2 and H2O. In this study, Picarro partners with the ARS USDA Soil & Water Management Research Unit (R. Venterea, St. Paul), to examine the degree to which the high-precision, high-frequency Picarro analyzer allows for much shorter DPs periods in chamber-based flux analysis, and, in theory, less chamber-induced suppression of the soil

  13. Communicating Science

    NASA Astrophysics Data System (ADS)

    Russell, Nicholas

    2009-10-01

    Introduction: what this book is about and why you might want to read it; Prologue: three orphans share a common paternity: professional science communication, popular journalism, and literary fiction are not as separate as they seem; Part I. Professional Science Communication: 1. Spreading the word: the endless struggle to publish professional science; 2. Walk like an Egyptian: the alien feeling of professional science writing; 3. The future's bright? Professional science communication in the age of the internet; 4. Counting the horse's teeth: professional standards in science's barter economy; 5. Separating the wheat from the chaff: peer review on trial; Part II. Science for the Public: What Science Do People Need and How Might They Get It?: 6. The Public Understanding of Science (PUS) movement and its problems; 7. Public engagement with science and technology (PEST): fine principle, difficult practice; 8. Citizen scientists? Democratic input into science policy; 9. Teaching and learning science in schools: implications for popular science communication; Part III. Popular Science Communication: The Press and Broadcasting: 10. What every scientist should know about mass media; 11. What every scientist should know about journalists; 12. The influence of new media; 13. How the media represents science; 14. How should science journalists behave?; Part IV. The Origins of Science in Cultural Context: Five Historic Dramas: 15. A terrible storm in Wittenberg: natural knowledge through sorcery and evil; 16. A terrible storm in the Mediterranean: controlling nature with white magic and religion; 17. Thieving magpies: the subtle art of false projecting; 18. Foolish virtuosi: natural philosophy emerges as a distinct discipline but many cannot take it seriously; 19. Is scientific knowledge 'true' or should it just be 'truthfully' deployed?; Part V. Science in Literature: 20. Science and the Gothic: the three big nineteenth-century monster stories; 21. Science fiction: serious

  14. Two fluxes multistage induction coilgun

    NASA Astrophysics Data System (ADS)

    Gherman, L.; Pearsica, M.; Circiu, I.; Rotaru, C.

    2017-05-01

    This paper presents a brand new induction electromagnetic launcher, which uses two magnetic fluxes in order to accelerate a projectile. One magnetic flux induce a current in the armature and the second magnetic flux is creating a radial magnetic field. This aproach offer multiple advantages over single flux designs. First we are able to control the induced current in armature because we use the coil just to induce current inside the ring with a great efficiency. Second advantage is the angle of 900 between magnetic field density B and the ring. We used the induction to avoid contact between armature and accelerator. In order to create the magnetic field radial we used four coils perpendicular on armature. This approach alove us to control the phase difference between induced current in armature and current in magnetic field coils for a maximum force. The phase difference is obtained by changing the frequency of magnetic field coils power source. We used simulation software to analyze, and simulate a multistage induction coilgun design with two fluxes. The simulation results demonstrated the theoretical results.

  15. The flux qubit revisited to enhance coherence and reproducibility

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Gustavsson, Simon; Kamal, Archana; Birenbaum, Jeffrey; Sears, Adam P.; Hover, David; Gudmundsen, Ted J.; Rosenberg, Danna; Samach, Gabriel; Weber, S.; Yoder, Jonilyn L.; Orlando, Terry P.; Clarke, John; Kerman, Andrew J.; Oliver, William D.

    2016-11-01

    The scalable application of quantum information science will stand on reproducible and controllable high-coherence quantum bits (qubits). Here, we revisit the design and fabrication of the superconducting flux qubit, achieving a planar device with broad-frequency tunability, strong anharmonicity, high reproducibility and relaxation times in excess of 40 μs at its flux-insensitive point. Qubit relaxation times T1 across 22 qubits are consistently matched with a single model involving resonator loss, ohmic charge noise and 1/f-flux noise, a noise source previously considered primarily in the context of dephasing. We furthermore demonstrate that qubit dephasing at the flux-insensitive point is dominated by residual thermal-photons in the readout resonator. The resulting photon shot noise is mitigated using a dynamical decoupling protocol, resulting in T2~85 μs, approximately the 2T1 limit. In addition to realizing an improved flux qubit, our results uniquely identify photon shot noise as limiting T2 in contemporary qubits based on transverse qubit-resonator interaction.

  16. The flux qubit revisited to enhance coherence and reproducibility

    PubMed Central

    Yan, Fei; Gustavsson, Simon; Kamal, Archana; Birenbaum, Jeffrey; Sears, Adam P; Hover, David; Gudmundsen, Ted J.; Rosenberg, Danna; Samach, Gabriel; Weber, S; Yoder, Jonilyn L.; Orlando, Terry P.; Clarke, John; Kerman, Andrew J.; Oliver, William D.

    2016-01-01

    The scalable application of quantum information science will stand on reproducible and controllable high-coherence quantum bits (qubits). Here, we revisit the design and fabrication of the superconducting flux qubit, achieving a planar device with broad-frequency tunability, strong anharmonicity, high reproducibility and relaxation times in excess of 40 μs at its flux-insensitive point. Qubit relaxation times T1 across 22 qubits are consistently matched with a single model involving resonator loss, ohmic charge noise and 1/f-flux noise, a noise source previously considered primarily in the context of dephasing. We furthermore demonstrate that qubit dephasing at the flux-insensitive point is dominated by residual thermal-photons in the readout resonator. The resulting photon shot noise is mitigated using a dynamical decoupling protocol, resulting in T2≈85 μs, approximately the 2T1 limit. In addition to realizing an improved flux qubit, our results uniquely identify photon shot noise as limiting T2 in contemporary qubits based on transverse qubit–resonator interaction. PMID:27808092

  17. Overview of NASA's Carbon Monitoring System Flux-Pilot Project

    NASA Technical Reports Server (NTRS)

    Pawson, Steven; Gunson, Michael R.; Jucks, Kenneth

    2011-01-01

    NASA's space-based observations of physical, chemical and biological parameters in the Earth System along with state-of-the-art modeling capabilities provide unique capabilities for analyses of the carbon cycle. The Carbon Monitoring System is developing an exploratory framework for detecting carbon in the environment and its changes, with a view towards contributing to national and international monitoring activities. The Flux-Pilot Project aims to provide a unified view of land-atmosphere and ocean-atmosphere carbon exchange, using observation-constrained models. Central to the project is the application of NASA's satellite observations (especially MODIS), the ACOS retrievals of the JAXA-GOSAT observations, and the "MERRA" meteorological reanalysis produced with GEOS-S. With a primary objective of estimating uncertainty in computed fluxes, two land- and two ocean-systems are run for 2009-2010 and compared with existing flux estimates. An transport model is used to evaluate simulated CO2 concentrations with in-situ and space-based observations, in order to assess the realism of the fluxes and how uncertainties in fluxes propagate into atmospheric concentrations that can be more readily evaluated. Finally, the atmospheric partial CO2 columns observed from space are inverted to give new estimates of surface fluxes, which are evaluated using the bottom-up estimates and independent datasets. The focus of this presentation will be on the science goals and current achievements of the pilot project, with emphasis on how policy-relevant questions help focus the scientific direction. Examples include the issue of what spatio-temporal resolution of fluxes can be detected from polar-orbiting satellites and whether it is possible to use space-based observations to separate contributions to atmospheric concentrations of (say) fossil-fuel and biological activity

  18. Nitrogen flux and sources in the Mississippi River Basin

    USGS Publications Warehouse

    Goolsby, D.A.; Battaglin, W.A.; Aulenbach, Brent T.; Hooper, R.P.

    2000-01-01

    Nitrogen from the Mississippi River Basin is believed to be at least partly responsible for the large zone of oxygen-depleted water that develops in the Gulf of Mexico each summer. Historical data show that concentrations of nitrate in the Mississippi River and some of its tributaries have increased by factors of 2 to more than 5 since the early 1900s. We have used the historical streamflow and concentration data in regression models to estimate the annual flux of nitrogen (N) to the Gulf of Mexico and to determine where the nitrogen originates within the Mississippi Basin. Results show that for 1980-1996 the mean annual total N flux to the Gulf of Mexico was 1568000 t/year. The flux was approximately 61% nitrate as N, 37% organic N, and 2% ammonium as N. The flux of nitrate to the Gulf has approximately tripled in the last 30 years with most of the increase occurring between 1970 and 1983. The mean annual N flux has changed little since the early 1980s, but large year-to-year variations in N flux occur because of variations in precipitation. During wet years the N flux can increase by 50% or more due to flushing of nitrate that has accumulated in the soils and unsaturated zones in the basin. The principal source areas of N are basins in southern Minnesota, Iowa, Illinois, Indiana, and Ohio that drain agricultural land. Basins in this region yield 800 to more than 3100 kg total N/km2 per year to streams, several times the N yield of basins outside this region. Assuming conservative transport of N in the Mississippi River, streams draining Iowa and Illinois contribute on average approximately 35% of the total N discharged by the Mississippi River to the Gulf of Mexico. In years with high precipitation they can contribute a larger percentage. Copyright (C) 2000 Elsevier Science B.V.

  19. Eddy covariance for quantifying trace gas fluxes from soils

    NASA Astrophysics Data System (ADS)

    Eugster, W.; Merbold, L.

    2015-02-01

    Soils are highly complex physical and biological systems, and hence measuring soil gas exchange fluxes with high accuracy and adequate spatial representativity remains a challenge. A technique which has become increasingly popular is the eddy covariance (EC) method. This method takes advantage of the fact that surface fluxes are mixed into the near-surface atmosphere via turbulence. As a consequence, measurements with an EC system can be done at some distance above the surface, providing accurate and spatially integrated flux density estimates. In this paper we provide a basic overview targeting scientists who are not familiar with the EC method. This review gives examples of successful deployments from a wide variety of ecosystems. The primary focus is on the three major greenhouse gases: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Several limitations to the application of EC systems exist, requiring a careful experimental design, which we discuss in detail. Thereby we group these experiments into two main classes: (1) manipulative experiments, and (2) survey-type experiments. Recommendations and examples of successful studies using various approaches are given, including the combination of EC flux measurements with online measurements of stable isotopes. We conclude that EC should not be considered a substitute to traditional (e.g., chamber based) flux measurements but instead an addition to them. The greatest strength of EC measurements in soil science are (1) their uninterrupted continuous measurement of gas concentrations and fluxes that can also capture short-term bursts of fluxes that easily could be missed by other methods and (2) the spatial integration covering the ecosystem scale (several square meters to hectares), thereby integrating over small-scale heterogeneity in the soil.

  20. Anthropogenic heat flux estimation from space: first results

    NASA Astrophysics Data System (ADS)

    Chrysoulakis, Nektarios; Heldens, Wieke; Gastellu-Etchegorry, Jean-Philippe; Grimmond, Sue; Feigenwinter, Christian; Lindberg, Fredrik; Del Frate, Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Albitar, Ahmad; Gabey, Andrew; Parlow, Eberhard; Olofson, Frans

    2016-04-01

    While Earth Observation (EO) has made significant advances in the study of urban areas, there are several unanswered science and policy questions to which it could contribute. To this aim the recently launched Horizon 2020 project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of EO to retrieve anthropogenic heat flux, as a key component in the urban energy budget. The anthropogenic heat flux is the heat flux resulting from vehicular emissions, space heating and cooling of buildings, industrial processing and the metabolic heat release by people. Optical, thermal and SAR data from existing satellite sensors are used to improve the accuracy of the radiation balance spatial distribution calculation, using also in-situ reflectance measurements of urban materials are for calibration. EO-based methods are developed for estimating turbulent sensible and latent heat fluxes, as well as urban heat storage flux and anthropogenic heat flux spatial patterns at city scale and local scale by employing an energy budget closure approach. Independent methods and models are engaged to evaluate the derived products and statistical analyses provide uncertainty measures as well. Ultimate goal of the URBANFLUXES is to develop a highly automated method for estimating urban energy budget components to use with Copernicus Sentinel data, enabling its integration into applications and operational services. Thus, URBANFLUXES prepares the ground for further innovative exploitation of European space data in scientific activities (i.e. Earth system modelling and climate change studies in cities) and future and emerging applications (i.e. sustainable urban planning) by exploiting the improved data quality, coverage and revisit times of the Copernicus data. The URBANFLUXES products will therefore have the potential to support both sustainable planning strategies to improve the quality of life in cities, as well as Earth system models to

  1. Eddy covariance for quantifying trace gas fluxes from soils

    NASA Astrophysics Data System (ADS)

    Eugster, W.; Merbold, L.

    2014-10-01

    Soils are highly complex physical and biological systems, and hence measuring soil gas exchange fluxes with high accuracy and adequate spatial representativity remains a challenge. A technique which has become increasingly popular is the eddy covariance (EC) method. This method takes advantage of the fact that surface fluxes are mixed into the near-surface atmosphere via turbulence. As a consequence, measurement with an EC system can be done at some distance above the surface, providing accurate and spatially integrated flux density estimates. In this paper we provide a basic overview targeting at scientists who are not familiar with the EC method. This reviews gives examples of successful deployments from a wide variety of ecosystems. The primary focus is on the three major greenhouse gases carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Several limitations to the application of EC systems exist, requiring a careful experimental design, which we discuss in detail. Thereby we group these experiments into two main classes: (1) manipulative experiments, and (2) survey-type experiments. Recommendations and examples of successful studies using various approaches, including the combination of EC flux measurements with online measurements of stable isotopes are given. We conclude that EC should not be considered a substitution of traditional flux measurements, but an addition to the latter. The greatest strength of EC measurements in soil science are (1) their uninterrupted continuous measurement of gas concentrations and fluxes that also can capture short-term bursts of fluxes that easily could be missed by other methods; and (2) the spatial integration covering the ecosystem scale (several m2 to ha), thereby integrating over small-scale heterogeneity in the soil.

  2. Reconnecting flux-rope dynamo.

    PubMed

    Baggaley, Andrew W; Barenghi, Carlo F; Shukurov, Anvar; Subramanian, Kandaswamy

    2009-11-01

    We develop a model of the fluctuation dynamo in which the magnetic field is confined to thin flux ropes advected by a multiscale model of turbulence. Magnetic dissipation occurs only via reconnection of the flux ropes. This model can be viewed as an implementation of the asymptotic limit R_{m}-->infinity for a continuous magnetic field, where magnetic dissipation is strongly localized to small regions of strong-field gradients. We investigate the kinetic-energy release into heat mediated by the dynamo action, both in our model and by solving the induction equation with the same flow. We find that a flux-rope dynamo is an order of magnitude more efficient at converting mechanical energy into heat. The probability density of the magnetic energy release in reconnections has a power-law form with the slope -3 , consistent with the solar corona heating by nanoflares.

  3. Reconnecting flux-rope dynamo

    NASA Astrophysics Data System (ADS)

    Baggaley, Andrew W.; Barenghi, Carlo F.; Shukurov, Anvar; Subramanian, Kandaswamy

    2009-11-01

    We develop a model of the fluctuation dynamo in which the magnetic field is confined to thin flux ropes advected by a multiscale model of turbulence. Magnetic dissipation occurs only via reconnection of the flux ropes. This model can be viewed as an implementation of the asymptotic limit Rm→∞ for a continuous magnetic field, where magnetic dissipation is strongly localized to small regions of strong-field gradients. We investigate the kinetic-energy release into heat mediated by the dynamo action, both in our model and by solving the induction equation with the same flow. We find that a flux-rope dynamo is an order of magnitude more efficient at converting mechanical energy into heat. The probability density of the magnetic energy release in reconnections has a power-law form with the slope -3 , consistent with the solar corona heating by nanoflares.

  4. Chesapeake Bay Sediment Flux Model

    DTIC Science & Technology

    1993-06-01

    KL12J [N0 3(2)] = [N0 3 (l) 1 KNo3 .H KL2 (4) The equality s - K LoM, (eq.II-14), is used for the surface mass transfer coefficient where s - SOD/0 2 (O...L 2 = 0.01 (m/d), and KNo3 ., - 0.1 (m/d). Note that the normalized flux data exhibits an increased flux for intermediate s and an upward curvature...to compute the denitrification flux: [N2(g)]i, j= KN03. ,H,[NO3 (1)],.J KNO3 . 2 H 2 [N0 3 (2)],., 2 / (Tl. 1-20) - 0X•NO3𔃻"NO3$,. _ [N03(l)],. ’+VNO3

  5. Where is the Open Flux?

    NASA Astrophysics Data System (ADS)

    Linker, Jon A.; Downs, Cooper; Caplan, Ronald M.; Lionello, Roberto; Mikic, Zoran; Riley, Pete; Henney, Carl John; Arge, Charles; Owens, Matthew

    2017-08-01

    The Sun’s magnetic field has been observed in the photosphere from ground- and space-based observatories for many years. Global maps of the solar magnetic field based on full disk magnetograms (either built up over a solar rotation, or evolved using flux transport models) are commonly used as boundary conditions for coronal and solar wind models. Maps from different observatories typically agree qualitatively but often disagree quantitatively. Estimation of the coronal/solar wind physics can range from potential field source surface (PFSS) models with empirical prescriptions to magnetohydrodynamic (MHD) models with realistic energy transport and sub-grid scale descriptions of heating and acceleration. Two primary observational constraints on the models are (1) The open field regions in the model should approximately correspond to coronal holes observed in emission, and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. We have investigated the July 2010 time period, using PFSS and MHD models computed using several available magnetic maps, coronal hole boundaries detected from STEREO and SDO EUV observations, and estimates of the interplanetary magnetic flux from in situ ACE measurements. We show that for all the model/map combinations, models that agree for (1) underestimate the interplanetary magnetic flux, or, conversely, for models to match (2), the modeled open field regions are larger than observed coronal holes. Alternatively, we estimate the open magnetic flux entirely from solar observations by combining detected coronal hole boundaries with observatory synoptic magnetic maps, and show that this method also underestimates the interplanetary magnetic flux. We discuss possible resolutions.Research supported by NASA, AFOSR, and NSF.

  6. Phase versus flux coupling between resonator and superconducting flux qubit

    NASA Astrophysics Data System (ADS)

    Birenbaum, J. S.; O'Kelley, S. R.; Anton, S. M.; Nugroho, C. D.; Orlyanchik, V.; Dove, A. H.; Yoscovits, Z. R.; Olson, G. A.; van Harlingen, D. J.; Eckstein, J.; Braje, D. A.; Johnson, R. C.; Oliver, W. D.; Clarke, John

    2013-03-01

    The dispersive coupling of qubits to microwave resonators has become widely used for qubit readout. Recent advances in coupling qubits to 3D resonators have demonstrated the importance of the nature of the qubit-resonator coupling in determining the qubit relaxation and decoherence times, T1 and T2*. We study the effect of phase versus flux coupling on flux qubits coupled to planar resonators. Using an aluminum shadow evaporation technique we fabricate a low-loss planar resonator, consisting of a meandering inductor and interdigitated capacitor, and a flux qubit, all in a single processing step. Whereas the qubit and resonator are always flux coupled via a geometric mutual inductance, a phase coupling can be added by including a shared trace between the qubit and resonator. This technique allows us to control both the magnitude and nature of the qubit-resonator coupling without significantly affecting either the qubit or resonator design. We characterize the dependence of the qubit parameters T1, T2*, and spin echo time Techo on the resonator coupling parameters to gain insight into possible sources of decoherence and loss. This work was supported by ARO, IARPA, and the US Government

  7. High flux solar energy transformation

    DOEpatents

    Winston, Roland; Gleckman, Philip L.; O'Gallagher, Joseph J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.

  8. 13C metabolic flux analysis.

    PubMed

    Wiechert, W

    2001-07-01

    Metabolic flux analysis using 13C-labeled substrates has become an important tool in metabolic engineering. It allows the detailed quantification of all intracellular fluxes in the central metabolism of a microorganism. The method has strongly evolved in recent years by the introduction of new experimental procedures, measurement techniques, and mathematical data evaluation methods. Many of these improvements require advanced skills in the application of nuclear magnetic resonance and mass spectrometry techniques on the one hand and computational and statistical experience on the other hand. This minireview summarizes these recent developments and sketches the major practical problems. An outlook to possible future developments concludes the text.

  9. High flux solar energy transformation

    DOEpatents

    Winston, R.; Gleckman, P.L.; O'Gallagher, J.J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes. 7 figures.

  10. Beta ray flux measuring device

    DOEpatents

    Impink, Jr., Albert J.; Goldstein, Norman P.

    1990-01-01

    A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

  11. Modeling Coronal Jets with FLUX

    NASA Astrophysics Data System (ADS)

    Rachmeler, L. A.; Pariat, E.; Antiochos, S. K.; Deforest, C. E.

    2008-05-01

    We report on a comparative study of coronal jet formation with and without reconnection using two different simulation strategies. Coronal jets are features on the solar surface that appear to have some properties in common with coronal mass ejections, but are less energetic, massive, and broad. Magnetic free energy is built up over time and then suddenly released, which accelerates plasma outward in the form of a coronal jet. We compare results from the ARMS adaptive mesh and FLUX reconnection-less codes to study the role of reconnection in this system. This is the first direct comparison between FLUX and a numerical model with a 3D spatial grid.

  12. Charm production in flux tubes

    NASA Astrophysics Data System (ADS)

    Aguiar, C. E.; Kodama, T.; Nazareth, R. A. M. S.; Pech, G.

    1996-01-01

    We argue that the nonperturbative Schwinger mechanism may play an important role in the hadronic production of charm. We present a flux tube model which assumes that the colliding hadrons become color charged because of gluon exchange, and that a single nonelementary flux tube is built up as they recede. The strong chromoelectric field inside this tube creates quark pairs (including charmed ones) and the ensuing color screening breaks the tube into excited hadronic clusters. In their turn these clusters, or ``fireballs,'' decay statistically into the final hadrons. The model is able to account for the soft production of charmed, strange, and lighter hadrons within a unified framework.

  13. Science Sacks

    ERIC Educational Resources Information Center

    Freudenberg, Kimberlee

    2012-01-01

    With the emphasis placed on standardized testing, science education has been squeezed out. As a physics teacher, the author knows the importance of building children's interest in science early in their school career and of providing practice in basic science skills and inquiry. In order to make more time for science at her sons' elementary…

  14. Science Matters

    ERIC Educational Resources Information Center

    Odell, Bill

    2005-01-01

    The spaces and structures used for undergraduate science often work against new teaching methods and fail to provide environments that attract the brightest students to science. The undergraduate science building often offers little to inspire the imaginations of young minds. The typical undergraduate science building also tends to work against…

  15. Food Science.

    ERIC Educational Resources Information Center

    Barkman, Susan J.

    1996-01-01

    Presents food science experiments designed for high school science classes that aim at getting students excited about science and providing them with real-life applications. Enables students to see the application of chemistry, microbiology, engineering, and other basic and applied sciences to the production, processing, preservation, evaluation,…

  16. Science Matters

    ERIC Educational Resources Information Center

    Odell, Bill

    2005-01-01

    The spaces and structures used for undergraduate science often work against new teaching methods and fail to provide environments that attract the brightest students to science. The undergraduate science building often offers little to inspire the imaginations of young minds. The typical undergraduate science building also tends to work against…

  17. Science Sacks

    ERIC Educational Resources Information Center

    Freudenberg, Kimberlee

    2012-01-01

    With the emphasis placed on standardized testing, science education has been squeezed out. As a physics teacher, the author knows the importance of building children's interest in science early in their school career and of providing practice in basic science skills and inquiry. In order to make more time for science at her sons' elementary…

  18. Science: Secondary.

    ERIC Educational Resources Information Center

    Curriculum Review, 1980

    1980-01-01

    This article reviews and compares five recent secondary science texts: Addison-Wesley Life Science (Gr. 7-9); Prentice-Hall Life Science (Gr. 7-9); Scott Foresman Biology (Gr. 9-12); Biology: Living Systems (Gr. 10-12); and Biology: The Science of Life (Gr. 10-12). (SJL)

  19. Food Science.

    ERIC Educational Resources Information Center

    Barkman, Susan J.

    1996-01-01

    Presents food science experiments designed for high school science classes that aim at getting students excited about science and providing them with real-life applications. Enables students to see the application of chemistry, microbiology, engineering, and other basic and applied sciences to the production, processing, preservation, evaluation,…

  20. Orienting and Applying Flux to Solar Cells

    NASA Technical Reports Server (NTRS)

    Feder, H.; Frasch, W.

    1982-01-01

    Solar cells are oriented and fluxed automatically at first work station along solar-array assembly line. In under 2 seconds rotary drive rotates cell into proper position for applying solder flux to bus pad on collector side. When contact bus pad is in correct position, capstan drive is disengaged, and vacuum holddown beneath cell is turned on. Flux system lowers and applies preset amount of solder flux to bus pad. Two interconnect tabs are soldered to fluxed areas.

  1. Black branes in flux compactifications

    SciTech Connect

    Torroba, Gonzalo; Wang, Huajia

    2013-10-01

    We construct charged black branes in type IIA flux compactifications that are dual to (2 + 1)-dimensional field theories at finite density. The internal space is a general Calabi-Yau manifold with fluxes, with internal dimensions much smaller than the AdS radius. Gauge fields descend from the 3-form RR potential evaluated on harmonic forms of the Calabi-Yau, and Kaluza-Klein modes decouple. Black branes are described by a four-dimensional effective field theory that includes only a few light fields and is valid over a parametrically large range of scales. This effective theory determines the low energy dynamics, stability and thermodynamic properties. Tools from flux compactifications are also used to construct holographic CFTs with no relevant scalar operators, that can lead to symmetric phases of condensed matter systems stable to very low temperatures. The general formalism is illustrated with simple examples such as toroidal compactifications and manifolds with a single size modulus. We initiate the classification of holographic phases of matter described by flux compactifications, which include generalized Reissner-Nordstrom branes, nonsupersymmetric AdS2×R2 and hyperscaling violating solutions.

  2. High flux compact neutron generators

    SciTech Connect

    Reijonen, J.; Lou, T.-P.; Tolmachoff, B.; Leung, K.-N.; Verbeke, J.; Vujic, J.

    2001-06-15

    Compact high flux neutron generators are developed at the Lawrence Berkeley National Laboratory. The neutron production is based on D-D or D-T reaction. The deuterium or tritium ions are produced from plasma using either a 2 MHz or 13.56 MHz radio frequency (RF) discharge. RF-discharge yields high fraction of atomic species in the beam which enables higher neutron output. In the first tube design, the ion beam is formed using a multiple hole accelerator column. The beam is accelerated to energy of 80 keV by means of a three-electrode extraction system. The ion beam then impinges on a titanium target where either the 2.4 MeV D-D or 14 MeV D-T neutrons are generated. The MCNP computation code has predicted a neutron flux of {approximately}10{sup 11} n/s for the D-D reaction at beam intensity of 1.5 A at 150 kV. The neutron flux measurements of this tube design will be presented. Recently new compact high flux tubes are being developed which can be used for various applications. These tubes also utilize RF-discharge for plasma generation. The design of these tubes and the first measurements will be discussed in this presentation.

  3. Superconducting flux flow digital circuits

    DOEpatents

    Hietala, Vincent M.; Martens, Jon S.; Zipperian, Thomas E.

    1995-01-01

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

  4. Superconducting flux flow digital circuits

    DOEpatents

    Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

    1995-02-14

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

  5. Science Fiction and Science Education.

    ERIC Educational Resources Information Center

    Cavanaugh, Terence

    2002-01-01

    Uses science fiction films such as "Jurassic Park" or "Anaconda" to teach science concepts while fostering student interest. Advocates science fiction as a teaching tool to improve learning and motivation. Describes how to use science fiction in the classroom with the sample activity Twister. (YDS)

  6. Science Fiction and Science Education.

    ERIC Educational Resources Information Center

    Cavanaugh, Terence

    2002-01-01

    Uses science fiction films such as "Jurassic Park" or "Anaconda" to teach science concepts while fostering student interest. Advocates science fiction as a teaching tool to improve learning and motivation. Describes how to use science fiction in the classroom with the sample activity Twister. (YDS)

  7. Surface Fluxes and Wind-Wave Interactions in Weak Wind Conditions

    DTIC Science & Technology

    2016-06-07

    Surface Fluxes and Wind-Wave Interactions in Weak Wind Conditions Jielun Sun Microscale and Mesoscale Meteorology National Center for...science/abl/cblast LONG-TERM GOALS We will investigate air-sea transfer of momentum, heat, and moisture under weak wind conditions . We will...sea interactions. Improved understanding of wave effects on marine atmospheric turbulent fluxes under weak wind conditions will be used to modify

  8. Effects of high altitude clouds on the earth's infrared radiation flux

    NASA Technical Reports Server (NTRS)

    Wang, W.-C.; Kaplan, L. D.

    1983-01-01

    Attention is given to the results of a study of cirrus cloud properties which employed the Goddard Laboratory for Atmospheric Sciences' general circulation model and concentrated on the effects of the nonblackness of high clouds on the IR radiation flux. Although the thermal radiation flux is very sensitive to the treatment of cirrus optical properties in the IR, a more realistic assessment will depend on better parameterizations for cirrus cloud formation, persistence, and dissipation.

  9. Effects of high altitude clouds on the earth's infrared radiation flux

    NASA Technical Reports Server (NTRS)

    Wang, W.-C.; Kaplan, L. D.

    1983-01-01

    Attention is given to the results of a study of cirrus cloud properties which employed the Goddard Laboratory for Atmospheric Sciences' general circulation model and concentrated on the effects of the nonblackness of high clouds on the IR radiation flux. Although the thermal radiation flux is very sensitive to the treatment of cirrus optical properties in the IR, a more realistic assessment will depend on better parameterizations for cirrus cloud formation, persistence, and dissipation.

  10. Parameter trade-off studies for the ultra-high flux double donut reactor

    SciTech Connect

    Ryskamp, J.M.; Oh, C.H.; Ambrosek, R.G.; Lussie, W.G.; Lake, J.A.; Wadkins, R.P.

    1987-01-01

    The Idaho National Engineering Laboratory (INEL) is developing a reactor design in a double donut configuration for the advanced neutron source (ANS). The ANS, with a neutron flux ten times that of existing sources, is needed for materials science, isotope production, and fundamental physics research. The purpose of this study is to examine the reactor parameters for the INEL Ultrahigh Flux Reactor (UHFR) and recommend ways to optimize the reactor design.

  11. Parameter trade-off studies for the ultrahigh flux double donut reactor

    SciTech Connect

    Ryskamp, J.M.; Oh, C.H.; Ambrosek, R.G.; Lussie, W.G.; Lake, J.A.; Wadkins, R.P.

    1987-01-01

    The Idaho National Engineering Laboratory (INEL) is developing a reactor design in a double donut configuration for the advanced neutron source (ANS). The ANS, with a neutron flux ten times that of existing sources, is needed for materials science, isotope production, and fundamental physics research. The purpose of this study is to examine the reactor parameters for the INEL Ultrahigh Flux Reactor (UHFR) and recommend ways to optimize the reactor design.

  12. Towards understanding the role of turbulence on scaling of divertor heat flux profile widths on DIII-D

    NASA Astrophysics Data System (ADS)

    Tang, T. F.; Xu, X. Q.; Xia, T. Y.; Makowski, M.; Lasnier, C.; Leonard, T.; Osborne, T. H.; Sun, J. Z.; Wang, D. Z.

    2016-10-01

    Recent multi-machines scaling law of parallel heat flux width proportional to the inverse of plasma current. Theoretical models, such as Critical gradient models can match the experiment at certain points, however, the role of the neoclassical transport and the turbulence transport, on the heat flux remain uncertain. We have used BOUT + + 6-field 2-fluid module to analyze the nonlinear turbulent transport of three H-mode discharges from DIII-D. With the evolution of the plasma profiles, the heat flux amplitude is greater and the heat flux width is broader, comparing to the experimental results. The curvature drift and neoclassical transport contribution on the heat flux is estimated, which shows the heat flux is mainly carried by the turbulence transport. The simulation also shows the electron heat flux, saturated at the divertor target, is much larger than the ion heat flux. While the cases without evolution inside the separatrix gives a smaller heat flux amplitude and narrower width, comparable to the experimental results. To eliminate the uncertainty of the simulation, time averaged simulation results of the heat flux at different time windows are also given. CSC (No. 201406060053),National Magnetic Confinement Fusion Science Program of China Nos 2013GB107003, 2013GB109001, and National Natural Science Foundation of China No. 11575039.

  13. Large Area Lunar Dust Flux Measurement Instrument

    NASA Technical Reports Server (NTRS)

    Corsaro, R.; Giovane, F.; Liou, Jer-Chyi; Burchell, M.; Stansbery, Eugene; Lagakos, N.

    2009-01-01

    The instrument under development is designed to characterize the flux and size distribution of the lunar micrometeoroid and secondary ejecta environment. When deployed on the lunar surface, the data collected will benefit fundamental lunar science as well as enabling more reliable impact risk assessments for human lunar exploration activities. To perform this task, the instrument requirements are demanding. It must have as large a surface area as possible to sample the very sparse population of the larger potentially damage-inducing micrometeorites. It must also have very high sensitivity to enable it to measure the flux of small (<10 micron) micrometeorite and secondary ejecta dust particles. To be delivered to the lunar surface, it must also be very low mass, rugged and stow compactly. The instrument designed to meet these requirements is called FOMIS. It is a large-area thin film under tension (i.e. a drum) with multiple fiber optic displacement (FOD) sensors to monitor displacements of the film. This sensor was chosen since it can measure displacements over a wide dynamic range: 1 cm to sub-Angstrom. A prototype system was successfully demonstrated using the hypervelocity impact test facility at the University of Kent (Canterbury, UK). Based on these results, the prototype system can detect hypervelocity (approx.5 km/s) impacts by particles as small as 2 microns diameter. Additional tests using slow speeds find that it can detect secondary ejecta particles (which do not penetrate the film) with momentums as small as 15 pico-gram 100m/s, or nominally 5 microns diameter at 100 m/s.

  14. Large Area Lunar Dust Flux Measurement Instrument

    NASA Technical Reports Server (NTRS)

    Corsaro, R.; Giovane, F.; Liou, Jer-Chyi; Burchell, M.; Stansbery, Eugene; Lagakos, N.

    2009-01-01

    The instrument under development is designed to characterize the flux and size distribution of the lunar micrometeoroid and secondary ejecta environment. When deployed on the lunar surface, the data collected will benefit fundamental lunar science as well as enabling more reliable impact risk assessments for human lunar exploration activities. To perform this task, the instrument requirements are demanding. It must have as large a surface area as possible to sample the very sparse population of the larger potentially damage-inducing micrometeorites. It must also have very high sensitivity to enable it to measure the flux of small (<10 micron) micrometeorite and secondary ejecta dust particles. To be delivered to the lunar surface, it must also be very low mass, rugged and stow compactly. The instrument designed to meet these requirements is called FOMIS. It is a large-area thin film under tension (i.e. a drum) with multiple fiber optic displacement (FOD) sensors to monitor displacements of the film. This sensor was chosen since it can measure displacements over a wide dynamic range: 1 cm to sub-Angstrom. A prototype system was successfully demonstrated using the hypervelocity impact test facility at the University of Kent (Canterbury, UK). Based on these results, the prototype system can detect hypervelocity (approx.5 km/s) impacts by particles as small as 2 microns diameter. Additional tests using slow speeds find that it can detect secondary ejecta particles (which do not penetrate the film) with momentums as small as 15 pico-gram 100m/s, or nominally 5 microns diameter at 100 m/s.

  15. Topographic Science

    USGS Publications Warehouse

    Poppenga, Sandra; Evans, Gayla; Gesch, Dean; Stoker, Jason M.; Queija, Vivian R.; Worstell, Bruce; Tyler, Dean J.; Danielson, Jeff; Bliss, Norman; Greenlee, Susan

    2010-01-01

    The mission of U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center Topographic Science is to establish partnerships and conduct research and applications that facilitate the development and use of integrated national and global topographic datasets. Topographic Science includes a wide range of research and applications that result in improved seamless topographic datasets, advanced elevation technology, data integration and terrain visualization, new and improved elevation derivatives, and development of Web-based tools. In cooperation with our partners, Topographic Science is developing integrated-science applications for mapping, national natural resource initiatives, hazards, and global change science. http://topotools.cr.usgs.gov/.

  16. Contagious Coronal Heating from Recurring Emergence of Magnetic Flux

    NASA Astrophysics Data System (ADS)

    Moore, R. L.; Falconer, D. A.; Sterling, A. C.

    2002-01-01

    For each of six old bipolar active regions, we present and interpret Yohkoh/SXT and SOHO/MDI observations of the development, over several days, of enhanced coronal heating in and around the old bipole in response to new magnetic flux emergence within the old bipole. The observations show: 1. In each active region, new flux emerges in the equatorward side of the old bipole, around a lone remaining leading sunspot and/or on the equatorward end of the neutral line of the old bipole. 2. The emerging field is marked by intense internal coronal heating, and enhanced coronal heating occurs in extended loops stemming from the emergence site. 3. In five of the six cases, a "rooster tail" of coronal loops in the poleward extent of the old bipole also brightens in response to the flux emergence. 4. There are episodes of enhanced coronal heating in surrounding magnetic fields that are contiguous with the old bipole but are not directly connected to the emerging field. From these observations, we suggest that the accommodation of localized newly emerged flux within an old active region entails far reaching adjustments in the 3D magnetic field throughout the active region and in surrounding fields in which the active region is embedded, and that these adjustments produce the extensive enhanced coronal heating. We Also Note That The Reason For The recurrence of flux emergence in old active regions may be that active-region flux tends to emerge in giant-cell convection downflows. If so, the poleward "rooster tail" is a coronal flag of a long-lasting downflow in the convection zone. This work was funded by NASA's Office of Space Science through the Solar Physics Supporting Research and Technology Program and the Sun-Earth Connection Guest Investigator Program.

  17. Contagious Coronal Heating from Recurring Emergence of Magnetic Flux

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Falconer, David; Sterling, Alphonse; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    For each of six old bipolar active regions, we present and interpret Yohkoh/SXT and SOHO/MDI observations of the development, over several days, of enhanced coronal heating in and around the old bipole in response to new magnetic flux emerge= within the old bipole. The observations show: 1. In each active region, new flux emerges in the equatorward side of the old bipole, around a lone remaining leading sunspot and/or on the equatorward end of the neutral line of the old bipole. 2. The emerging field is marked by intense internal coronal heating, and enhanced coronal heating occurs in extended loops stemming from the emergence site. 3. In five of the six cases, a "rooster tail" of coronal loops in the poleward extent of the old bipole also brightens in response to the flux emergence. 4. There are episodes of enhanced coronal heating in surrounding magnetic fields that are contiguous with the old bipole but are not directly connected to the emerging field. From these observations, we suggest that the accommodation of localized newly emerged flux within an old active region entails far reaching adjustments in the 3D magnetic field throughout the active region and in surrounding fields in which the active region is embedded, and that these adjustments produce the extensive enhanced coronal heating. We also note that the reason for the recurrence of flux emergence in old active regions may be that active region flux tends to emerge in giant-cell convection downflows. If so, the poleward "rooster tail" is a coronal flag of a long-lasting downflow in the convection zone. This work was funded by NASA's Office of Space Science through the Solar Physics Supporting Research and Technology Program and the Sun-Earth Connection Guest Investigator Program.

  18. Contagious Coronal Heating from Recurring Emergence of Magnetic Flux

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Falconer, David; Sterling, Alphonse; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    For each of six old bipolar active regions, we present and interpret Yohkoh/SXT and SOHO/MDI observations of the development, over several days, of enhanced coronal heating in and around the old bipole in response to new magnetic flux emerge= within the old bipole. The observations show: 1. In each active region, new flux emerges in the equatorward side of the old bipole, around a lone remaining leading sunspot and/or on the equatorward end of the neutral line of the old bipole. 2. The emerging field is marked by intense internal coronal heating, and enhanced coronal heating occurs in extended loops stemming from the emergence site. 3. In five of the six cases, a "rooster tail" of coronal loops in the poleward extent of the old bipole also brightens in response to the flux emergence. 4. There are episodes of enhanced coronal heating in surrounding magnetic fields that are contiguous with the old bipole but are not directly connected to the emerging field. From these observations, we suggest that the accommodation of localized newly emerged flux within an old active region entails far reaching adjustments in the 3D magnetic field throughout the active region and in surrounding fields in which the active region is embedded, and that these adjustments produce the extensive enhanced coronal heating. We also note that the reason for the recurrence of flux emergence in old active regions may be that active region flux tends to emerge in giant-cell convection downflows. If so, the poleward "rooster tail" is a coronal flag of a long-lasting downflow in the convection zone. This work was funded by NASA's Office of Space Science through the Solar Physics Supporting Research and Technology Program and the Sun-Earth Connection Guest Investigator Program.

  19. Uncertainties in Atmospheric Muon-Neutrino Fluxes Arising from Cosmic-Ray Primaries

    NASA Astrophysics Data System (ADS)

    Porzio, Salvatore Davide; Evans, Justin; Soldner-Rembold, Stefan; Wren, Steven

    2017-01-01

    We present an updated calculation of the atmospheric muon-neutrino flux uncertainties arising from cosmic-ray primaries, including for the first time the information from recent measurements of the cosmic-ray primaries. We apply a statistical technique that allows the determination of correlations between the parameters of the GSHL primary-flux parametrisation, and the incorporation of these correlations into the uncertainty on the muon-neutrino flux. Given the unexpected hardening of the spectrum of primaries above 100 GeV observed in recent measurements, we propose an alternative parametrisation and discuss its impact on the neutrino flux uncertainties. We obtain an uncertainty on the primary cosmic-ray component of (5- 10) % , depending on energy, which is a about a factor of two smaller than for the previous fit. The hadron production uncertainty is added in quadrature to obtain the total uncertainty on the neutrino flux. Science and Technology Facilities Council (STFC) and the Royal Society.

  20. FluxSuite: a New Scientific Tool for Advanced Network Management and Cross-Sharing of Next-Generation Flux Stations

    NASA Astrophysics Data System (ADS)

    Burba, G. G.; Johnson, D.; Velgersdyk, M.; Beaty, K.; Forgione, A.; Begashaw, I.; Allyn, D.

    2015-12-01

    different actual networks This presentation provides detailed examples of FluxSuite currently utilized by two large flux networks in China (National Academy of Sciences & Agricultural Academy of Sciences), and smaller networks with stations in the USA, Germany, Ireland, Malaysia and other locations around the globe.

  1. Rosetta Radio Science Investigations

    NASA Technical Reports Server (NTRS)

    Patzold, M.; Neubauer, F. M.; Wennmacher, A.; Aksnes, K.; Anderson, J. D.; Asmar, S. W.; Tinto, M.; Tsurutani, B. T.; Yeomans, D. K.; Barriot, J. -P.; hide

    1996-01-01

    The Rosetta Radio Science Investigations (RSI) experiment was selected by the European Space Agency to be included in the International Rosetta Mission to comet P/Wirtanen (launch in 2003, arrival and operational phase at the comet 2011-2013). The RSI science objectives address fundamental aspects of cometary physics such as the mass and bulk density of the nucleus, the gravity field, non-gravitational forces, the size and shape, the internal structure, the composition and roughness of the nucleus surface, the abundance of large dust grains and the plasma content in the coma and the combined dust and gas mass flux on the orbiter. RSI will make use of the radio system of the Rosetta spacecraft.

  2. Fluxes across a thermohaline interface

    NASA Astrophysics Data System (ADS)

    Fleury, M.; Lueck, R. G.

    1991-07-01

    Measurements of velocity and temperature microstructure and hydrography were made with a towed vehicle moving in and around a single interface in a double-diffusive staircase. The interface was traversed 222 times in a saw-tooth pattern over a track 35 km long. The salinity and potential temperature and density in the mixed layers adjacent to the interface were spatially uniform except for one 8 km long anomaly. The rate of dissipation of kinetic energy was uniformly low in the interface and in the mixed layers, except for one section 600 m long where a Kelvin-Helmholtz instability generated turbulence. For the non-turbulent section of the interface, the mean rate of dissipation was 30.2 × 10 -10 W kg -1 in the mixed layers and 9.5 × 10 -10 W kg -1 in the interface. The non-dimensional dissipation rate, ɛ/vN 2, was almost always less than 16 in the interface and therfore, there was no turblent buoyancy flux according to ROHRet al. (1988, Journal of Fluid Mechanics, 195, 77-111). The average double-diffusive flux of buoyancy by heat was 3.6 × 10 -10 W kg -1. Under certain assumptions the ratio of the flux of buoyancy by heat and salt can be estimated to be 0.53 ± 0.10, in good agreement with laboratory and theoretical estimates for salt fingers. The average Cox number was about 8 in the interface, consistent with the theories of STERN (1975, Ocean circulation physics, Academic Press) and KUNZE (1987, Journal of Marine Research, 45 533-556), but displayed an inverse dependence on the vertical temperature gradient which was not predicted. As a result, the flux of buoyancy, as well as the individual contributions by heat and salt, were independent of the local mean vertical temperature gradient and the buoyancy frequency. The length of the turbulent section of the interface was only 1.7% of the total length observed. However, the turbulence was intense—the mean rate of dissipation was 2.5 × 10 -8 W kg -1—and may have sufficiently enhanced the flux of heat to

  3. Latest developments in advanced network management and cross-sharing of next-generation flux stations

    NASA Astrophysics Data System (ADS)

    Burba, George; Johnson, Dave; Velgersdyk, Michael; Begashaw, Israel; Allyn, Douglas

    2016-04-01

    be merged into a single quality-control file (v) Multiple flux stations can be linked into an automated time-synchronized network (vi) Flux network managers, or PI's, can see all stations in real-time, including fluxes, supporting data, automated reports, and email alerts (vii) PI's can assign rights, allow or restrict access to stations and data: selected stations can be shared via rights-managed access internally or with external institutions (viii) Researchers without stations could form "virtual networks" for specific projects by collaborating with PIs from different actual networks This presentation provides detailed examples of FluxSuite currently utilized to manage two large flux networks in China (National Academy of Sciences and Agricultural Academy of Sciences), and smaller networks with stations in the USA, Germany, Ireland, Malaysia and other locations around the globe. Very latest 2016 developments and expanded functionality are also discussed.

  4. Progress in Modeling Global Atmospheric CO2 Fluxes and Transport: Results from Simulations with Diurnal Fluxes

    NASA Technical Reports Server (NTRS)

    Collatz, G. James; Kawa, R.

    2007-01-01

    Progress in better determining CO2 sources and sinks will almost certainly rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. Use of advanced data requires improved modeling and analysis capability. Under NASA Carbon Cycle Science support we seek to develop and integrate improved formulations for 1) atmospheric transport, 2) terrestrial uptake and release, 3) biomass and 4) fossil fuel burning, and 5) observational data analysis including inverse calculations. The transport modeling is based on meteorological data assimilation analysis from the Goddard Modeling and Assimilation Office. Use of assimilated met data enables model comparison to CO2 and other observations across a wide range of scales of variability. In this presentation we focus on the short end of the temporal variability spectrum: hourly to synoptic to seasonal. Using CO2 fluxes at varying temporal resolution from the SIB 2 and CASA biosphere models, we examine the model's ability to simulate CO2 variability in comparison to observations at different times, locations, and altitudes. We find that the model can resolve much of the variability in the observations, although there are limits imposed by vertical resolution of boundary layer processes. The influence of key process representations is inferred. The high degree of fidelity in these simulations leads us to anticipate incorporation of realtime, highly resolved observations into a multiscale carbon cycle analysis system that will begin to bridge the gap between top-down and bottom-up flux estimation, which is a primary focus of NACP.

  5. Progress in Modeling Global Atmospheric CO2 Fluxes and Transport: Results from Simulations with Diurnal Fluxes

    NASA Technical Reports Server (NTRS)

    Collatz, G. James; Kawa, R.

    2007-01-01

    Progress in better determining CO2 sources and sinks will almost certainly rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. Use of advanced data requires improved modeling and analysis capability. Under NASA Carbon Cycle Science support we seek to develop and integrate improved formulations for 1) atmospheric transport, 2) terrestrial uptake and release, 3) biomass and 4) fossil fuel burning, and 5) observational data analysis including inverse calculations. The transport modeling is based on meteorological data assimilation analysis from the Goddard Modeling and Assimilation Office. Use of assimilated met data enables model comparison to CO2 and other observations across a wide range of scales of variability. In this presentation we focus on the short end of the temporal variability spectrum: hourly to synoptic to seasonal. Using CO2 fluxes at varying temporal resolution from the SIB 2 and CASA biosphere models, we examine the model's ability to simulate CO2 variability in comparison to observations at different times, locations, and altitudes. We find that the model can resolve much of the variability in the observations, although there are limits imposed by vertical resolution of boundary layer processes. The influence of key process representations is inferred. The high degree of fidelity in these simulations leads us to anticipate incorporation of realtime, highly resolved observations into a multiscale carbon cycle analysis system that will begin to bridge the gap between top-down and bottom-up flux estimation, which is a primary focus of NACP.

  6. Flavor mixings in flux compactifications

    NASA Astrophysics Data System (ADS)

    Buchmuller, Wilfried; Schweizer, Julian

    2017-04-01

    A multiplicity of quark-lepton families can naturally arise as zero modes in flux compactifications. The flavor structure of quark and lepton mass matrices is then determined by the wave function profiles of the zero modes. We consider a supersymmetric S O (10 )×U (1 ) model in six dimensions compactified on the orbifold T2/Z2 with Abelian magnetic flux. A bulk 16 -plet charged under the U (1 ) provides the quark-lepton generations whereas two uncharged 10 -plets yield two Higgs doublets. Bulk anomaly cancellation requires the presence of additional 16 - and 10 -plets. The corresponding zero modes form vectorlike split multiplets that are needed to obtain a successful flavor phenomenology. We analyze the pattern of flavor mixings for the two heaviest families of the Standard Model and discuss possible generalizations to three and more generations.

  7. Realism and quantum flux tunneling

    NASA Astrophysics Data System (ADS)

    Ballentine, L. E.

    1987-10-01

    The suggestion of Leggett and Garg (1985) that the phenomenon of quantum flux tunneling oscillations contradicts the predictions of quantum mechanics (QM) in the assumptions of both macroscopic realism and noninvasive measurability is reexamined. It is shown that the contradiction of QM is produced solely by the assumption of noninvasive measurability, and that no contradiction between QM and realism can be demonstrated in this case. These findings are illustrated by the calculation of the distribution function for successive flux measurements. It is noted that the previously suggested analogy between the Bell-type inequalities and the inequalities of Leggett and Garg is misleading because the physical principles of the Bell-type inequalities are not applicable to the presently considered SQUID.

  8. Forensic Science

    ERIC Educational Resources Information Center

    Berry, Keith O.; Nigh, W. G.

    1973-01-01

    A course is described, which was given during an interim, with an enrollment of 41 students. The course involved an in-depth study of forensic science, involving students with the methodology of science. (DF)

  9. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Presented are 27 science activities for secondary school science instruction. Topic areas include microbiology, botany, biochemistry, genetics, safety, earthquakes, problem solving, electricity, heat, solutions, mechanics, quantum mechanics, flame tests, and molecular structure. (CW)

  10. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Presented are 29 science activities for secondary school science instruction. Topic areas include botany, genetics, biochemistry, anatomy, entomology, molecular structure, spreadsheets, chemistry, mechanics, astronomy, relativity, aeronautics, instrumentation, electrostatics, quantum mechanics, and laboratory interfacing. (CW)

  11. Simple Science

    ERIC Educational Resources Information Center

    Cowens, John

    2006-01-01

    This brief article presents some quick and easy science experiments for those dreary winter days when classrooms need a pick-me-up. These seemingly easy science experiments will make a lasting impact on students.

  12. Science Sleuths.

    ERIC Educational Resources Information Center

    Lilly, Sherril L.

    1989-01-01

    Describes a two-day forensic science course that is offered to eighth grade students enrolled in Science, Mathematics, and Technology Magnet Schools. Provides sample student activity sheets for the course. (Author/RT)

  13. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Presented are 29 science activities for secondary school science instruction. Topic areas include botany, genetics, biochemistry, anatomy, entomology, molecular structure, spreadsheets, chemistry, mechanics, astronomy, relativity, aeronautics, instrumentation, electrostatics, quantum mechanics, and laboratory interfacing. (CW)

  14. Science Sleuths.

    ERIC Educational Resources Information Center

    Lilly, Sherril L.

    1989-01-01

    Describes a two-day forensic science course that is offered to eighth grade students enrolled in Science, Mathematics, and Technology Magnet Schools. Provides sample student activity sheets for the course. (Author/RT)

  15. Forensic Science

    ERIC Educational Resources Information Center

    Berry, Keith O.; Nigh, W. G.

    1973-01-01

    A course is described, which was given during an interim, with an enrollment of 41 students. The course involved an in-depth study of forensic science, involving students with the methodology of science. (DF)

  16. Improved Flux-Gate Magnetometer

    NASA Technical Reports Server (NTRS)

    Garner, H. Douglas

    1987-01-01

    Simplified circuit drives heading indicator and senses magnetic field of Earth. Simple flux-gate magnetometer supplies digital readout of magnetic heading of vehicle, developed to drive heading indicator, or supply heading information to autopilot or to other navigational instruments. Important feature is core driven into saturation in one direction only by alternating drive voltage, which swings from zero to one polarity and back. Made in part of commercially available integrated circuits.

  17. SQUID With Integral Flux Concentrator

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.; Sisk, Robert C.

    1989-01-01

    In improved superconducting quantum interference device (SQUID), change in size and shape of superconducting ring improves coupling to external signal coil and eases coil-positioning tolerances. More rugged and easier to manufacture than conventional SQUID's with comparable electrical characteristics. Thin-film superconducting flux concentrator utilizes Meissner effect to deflect magnetic field of signal coil into central hole of SQUID. Used in magnetometers, ammeters, analog-to-digital converters, and related electronic applications in which high signal-to-noise ratios required.

  18. Recent Solar-Proton Fluxes

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.

    2005-01-01

    The event-integrated fluences of energetic solar protons up to 2004 at the Earth have been determined and compared to previous data. The current solar cycle has been very active, and very large fluxes of solar protons have been observed that have had serious effects in the solar system and will have produced many radionuclides in the surfaces of meteorites. Such huge events are not expected again until about 2008 or 2009.

  19. SQUID With Integral Flux Concentrator

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.; Sisk, Robert C.

    1989-01-01

    In improved superconducting quantum interference device (SQUID), change in size and shape of superconducting ring improves coupling to external signal coil and eases coil-positioning tolerances. More rugged and easier to manufacture than conventional SQUID's with comparable electrical characteristics. Thin-film superconducting flux concentrator utilizes Meissner effect to deflect magnetic field of signal coil into central hole of SQUID. Used in magnetometers, ammeters, analog-to-digital converters, and related electronic applications in which high signal-to-noise ratios required.

  20. Structural Control of Metabolic Flux

    PubMed Central

    Sajitz-Hermstein, Max; Nikoloski, Zoran

    2013-01-01

    Organisms have to continuously adapt to changing environmental conditions or undergo developmental transitions. To meet the accompanying change in metabolic demands, the molecular mechanisms of adaptation involve concerted interactions which ultimately induce a modification of the metabolic state, which is characterized by reaction fluxes and metabolite concentrations. These state transitions are the effect of simultaneously manipulating fluxes through several reactions. While metabolic control analysis has provided a powerful framework for elucidating the principles governing this orchestrated action to understand metabolic control, its applications are restricted by the limited availability of kinetic information. Here, we introduce structural metabolic control as a framework to examine individual reactions' potential to control metabolic functions, such as biomass production, based on structural modeling. The capability to carry out a metabolic function is determined using flux balance analysis (FBA). We examine structural metabolic control on the example of the central carbon metabolism of Escherichia coli by the recently introduced framework of functional centrality (FC). This framework is based on the Shapley value from cooperative game theory and FBA, and we demonstrate its superior ability to assign “share of control” to individual reactions with respect to metabolic functions and environmental conditions. A comparative analysis of various scenarios illustrates the usefulness of FC and its relations to other structural approaches pertaining to metabolic control. We propose a Monte Carlo algorithm to estimate FCs for large networks, based on the enumeration of elementary flux modes. We further give detailed biological interpretation of FCs for production of lactate and ATP under various respiratory conditions. PMID:24367246

  1. Physical mechanisms of heat, momentum and turbulence fluxes

    NASA Technical Reports Server (NTRS)

    Theon, John S.

    1987-01-01

    In a qualitative way, the physical mechanisms which generate fluxes of heat, momentum, and turbulence in the atmosphere are discussed. This material is presented to acquaint people with the Earth science aspects of turbulence as important processes in the atmosphere. To attempt to describe turbulent fluxes of heat, momentum, and moisture in precise mathematical detail becomes an intractable problem. It is burdened by an eighth order set of equations involving more variables than equations. It is a closure problem which requires complicated assumptions that are not necessarily always satisfied, variable boundary conditions, and sparse observational data. Therefore, we must approach the problem in a simplified manner to obtain any kind of solution involving the variables of shear, stress, and heat, moisture, and momentum fluxes. There are other problems, of course, in which the inclusion of the planetary boundary layer is extremely important. Air pollution studies, air-sea exchanges, mesoscale models, and so on, must account for the planetary layer in very specific terms. Some of the physical mechanisms that are involved in generating fluxes are described.

  2. Wave nature of the deuterium flux permeating palladium thin film

    NASA Astrophysics Data System (ADS)

    Li, Xing Z.; Liu, Bin; Wei, Qing M.

    2009-03-01

    In the past 20 year research on Condensed matter Nuclear Science, the deuterium flux permeating palladium has been found correlated with the ``excess heat''ootnotetextJ. Phys. D: Appl. Phys.36 3095(2003). An experiment was conducted to reveal the wave nature of the deuterium flux permeating Pd thin film. at the temperature higher than the boiling point of the heavy water. The deuterium flux through Pd thin film was considered as a monotonic function of the thickness of the Pd film because the diffusion theory (Fick's Law) was applied. Indeed the deuteron could not be treated as a granular particle at low energy. It should be treated as a wave, because its de Broglie wave length is comparable with the lattice constant of the Pd crystal (3.84 Anstrons). When the titanium carbide (TiC) thin layer was sputtered on the surface of the Pd subtrate alternatively with Pd layers, we found that the flux might increase with the number of the layers first; then, it decreased after reaching a peak. which is the characteristics of a wave.

  3. Reconnection Between Twisted Flux Tubes - Implications for Coronal Heating

    NASA Astrophysics Data System (ADS)

    Knizhnik, K. J.; Antiochos, S. K.; DeVore, C. R.; Klimchuk, J. A.; Wyper, P. F.

    2015-12-01

    The nature of the heating of the Sun's corona has been a long-standing unanswered problem in solar physics. Beginning with the work of Parker (1972), many authors have argued that the corona is continuously heated through numerous small-scale reconnection events known as nanoflares. In these nanoflare models, stressing of magnetic flux tubes by photospheric motions causes the field to become misaligned, producing current sheets in the corona. These current sheets then reconnect, converting the free energy stored in the magnetic field into heat. In this work, we use the Adaptively Refined MHD Solver (ARMS) to perform 3D MHD simulations that dynamically resolve regions of strong current to study the reconnection between twisted flux tubes in a plane-parallel Parker configuration. We investigate the energetics of the process, and show that the flux tubes accumulate stress gradually before undergoing impulsive reconnection. We study the motion of the individual field lines during reconnection, and demonstrate that the connectivity of the configuration becomes extremely complex, with multiple current sheets being formed, which could lead to enhanced heating. In addition, we show that there is considerable interaction between the twisted flux tubes and the surrounding untwisted field, which contributes further to the formation of current sheets. The implications for observations will be discussed. This work was funded by a NASA Earth and Space Science Fellowship, and by the NASA TR&T Program.

  4. Science Fair

    NASA Image and Video Library

    2014-05-27

    NASA Administrator Charles Bolden (left) and Bill Nye, The Science Guy, speak with some students that participated in the White House Science Fair. The fourth White House Science Fair was held at the White House on May 27, 2014 and included 100 students from more than 30 different states who competed in science, technology, engineering, and math (STEM) competitions. (Photo Credit: NASA/Aubrey Gemignani)

  5. Sediment flux and the Anthropocene.

    PubMed

    Syvitski, James P M; Kettner, Albert

    2011-03-13

    Data and computer simulations are reviewed to help better define the timing and magnitude of human influence on sediment flux--the Anthropocene epoch. Impacts on the Earth surface processes are not spatially or temporally homogeneous. Human influences on this sediment flux have a secondary effect on floodplain and delta-plain functions and sediment dispersal into the coastal ocean. Human impact on sediment production began 3000 years ago but accelerated more widely 1000 years ago. By the sixteenth century, societies were already engineering their environment. Early twentieth century mechanization has led to global signals of increased sediment flux in most large rivers. By the 1950s, this sediment disturbance signal reversed for many rivers owing to the proliferation of dams, and sediment load reduction below pristine conditions is the dominant signal today. A delta subsidence signal began in the 1930s and is now a dominant signal in terms of sea level for many coastal environments, overwhelming even the global warming imprint on sea level. Humans have engineered how most water and sediment are discharged into the coastal ocean. Hyperpycnal flow events have become more common for some rivers, and less common for other rivers. Bottom trawling is now widespread, suggesting that even continental shelves have received a significant but as yet quantified Anthropocene impact. The Anthropocene attains the level of a geological climate event, such as that seen in the transition between the Pleistocene and the Holocene.

  6. Science First.

    ERIC Educational Resources Information Center

    Strycker, Jan Adkins

    1995-01-01

    Describes a teacher's efforts to put science first in the classroom. Discusses changing the place of science on the schedule and presents an activity to engage student interest. Concludes that a difference in teacher attitude towards science motivates students to learn. (NB)

  7. Science Facilities

    ERIC Educational Resources Information Center

    Butin, Dan W.; Biehle, James T.; Motz, LaMoine L.; West, Sandra S.

    2009-01-01

    The National Research Council's "National Science Education Standards" call for science education to be "developmentally appropriate, interesting, and relevant to students' lives, emphasize student understanding through inquiry, and be connected with other school subjects." This description captures the three major trends in science education…

  8. Sound Science

    ERIC Educational Resources Information Center

    Sickel, Aaron J.; Lee, Michele H.; Pareja, Enrique M.

    2010-01-01

    How can a teacher simultaneously teach science concepts through inquiry while helping students learn about the nature of science? After pondering this question in their own teaching, the authors developed a 5E learning cycle lesson (Bybee et al. 2006) that concurrently embeds opportunities for fourth-grade students to (a) learn a science concept,…

  9. Watershed Science.

    ERIC Educational Resources Information Center

    Green, Tom

    1996-01-01

    Presents activities from an interdisciplinary project studying local watersheds that incorporate a broad spectrum of disciplines including science, math, geography, English, computer science, and political science. Enables students to understand how precipitation changes chemically as it interacts with the soils and human-altered landscape as it…

  10. Science First.

    ERIC Educational Resources Information Center

    Strycker, Jan Adkins

    1995-01-01

    Describes a teacher's efforts to put science first in the classroom. Discusses changing the place of science on the schedule and presents an activity to engage student interest. Concludes that a difference in teacher attitude towards science motivates students to learn. (NB)

  11. Safer Science

    ERIC Educational Resources Information Center

    Roy, Ken

    2011-01-01

    This column provides best safety practices for the science classroom and laboratory. In this month's issue, pregnancy policy in the laboratory is discussed. One can't ignore the fact that student and faculty pregnancies--and the resulting potential hazards in the science laboratory--exist at the high school level. Science teachers need to be…

  12. Watershed Science.

    ERIC Educational Resources Information Center

    Green, Tom

    1996-01-01

    Presents activities from an interdisciplinary project studying local watersheds that incorporate a broad spectrum of disciplines including science, math, geography, English, computer science, and political science. Enables students to understand how precipitation changes chemically as it interacts with the soils and human-altered landscape as it…

  13. Sublime Science

    ERIC Educational Resources Information Center

    Girod, Mark

    2007-01-01

    One of the shortcomings in most efforts to integrate art and science is that many people have a shallow understanding of art, which inevitably leads to shallow connections between art and science. Coloring drawings of planets, building sculptures of volcanoes, and decorating scientific diagrams are fine activities, but they do not link science and…

  14. Sound Science

    ERIC Educational Resources Information Center

    Sickel, Aaron J.; Lee, Michele H.; Pareja, Enrique M.

    2010-01-01

    How can a teacher simultaneously teach science concepts through inquiry while helping students learn about the nature of science? After pondering this question in their own teaching, the authors developed a 5E learning cycle lesson (Bybee et al. 2006) that concurrently embeds opportunities for fourth-grade students to (a) learn a science concept,…

  15. Safer Science

    ERIC Educational Resources Information Center

    Roy, Ken

    2011-01-01

    This column provides best safety practices for the science classroom and laboratory. In this month's issue, pregnancy policy in the laboratory is discussed. One can't ignore the fact that student and faculty pregnancies--and the resulting potential hazards in the science laboratory--exist at the high school level. Science teachers need to be…

  16. Sublime Science

    ERIC Educational Resources Information Center

    Girod, Mark

    2007-01-01

    One of the shortcomings in most efforts to integrate art and science is that many people have a shallow understanding of art, which inevitably leads to shallow connections between art and science. Coloring drawings of planets, building sculptures of volcanoes, and decorating scientific diagrams are fine activities, but they do not link science and…

  17. Energetic particle characteristics of magnetotail flux ropes

    NASA Technical Reports Server (NTRS)

    Scholer, M.; Klecker, B.; Hovestadt, D.; Gloeckler, G.; Ipavich, F. M.; Galvin, A. B.

    1985-01-01

    During the recent ISEE-3 Geotail Mission three events have been identified from the magnetometer data which are consistent with a spacecraft crossing of a magnetotail flux rope. Energetic electron and proton observations obtained by the Max-Planck-Institut/University of Maryland sensor system during two of the possible flux rope events are presented. During one event remote sensing of the flux rope with energetic protons reveals that the flux rope is crossed by the spacecraft from south to north. This allows determination of the bandedness of the magnetic field twist and of the flux rope velocity relative to the spacecraft. A minimal flux rope radius of 3 earth radii is derived. Energetic proton intensity is highest just inside of the flux rope and decreases towards the core. Energetic electrons are streaming tailward near the outer boundary, indicating openness of the field lines, and are isotropic through the inner part of the flux rope.

  18. Turbulent crossed fluxes in incompressible flows

    PubMed

    Sancho

    2000-02-01

    We show in the framework of the stochastic calculus the existence of turbulent crossed fluxes in incompressible flows. Physically, these fluxes are related to the dependence of the phenomenological coefficients on the temperature and concentration variables.

  19. High-flux solar photon processes

    NASA Astrophysics Data System (ADS)

    Lorents, Donald C.; Narang, Subhash; Huestis, David C.; Mooney, Jack L.; Mill, Theodore; Song, Her-King; Ventura, Susanna

    1992-06-01

    This study was commissioned by the National Renewable Energy Laboratory (NREL) for the purpose of identifying high-flux photoprocesses that would lead to beneficial national and commercial applications. The specific focus on high-flux photoprocesses is based on the recent development by NREL of solar concentrator technology capable of delivering record flux levels. We examined photolytic and photocatalytic chemical processes as well as photothermal processes in the search for processes where concentrated solar flux would offer a unique advantage.

  20. Force sensor using changes in magnetic flux

    NASA Technical Reports Server (NTRS)

    Pickens, Herman L. (Inventor); Richard, James A. (Inventor)

    2012-01-01

    A force sensor includes a magnetostrictive material and a magnetic field generator positioned in proximity thereto. A magnetic field is induced in and surrounding the magnetostrictive material such that lines of magnetic flux pass through the magnetostrictive material. A sensor positioned in the vicinity of the magnetostrictive material measures changes in one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux.

  1. High-flux solar photon processes

    SciTech Connect

    Lorents, D.C.; Narang, S.; Huestis, D.C.; Mooney, J.L.; Mill, T.; Song, H.K.; Ventura, S.

    1992-06-01

    This study was commissioned by the National Renewable Energy Laboratory (NREL) for the purpose of identifying high-flux photoprocesses that would lead to beneficial national and commercial applications. The specific focus on high-flux photoprocesses is based on the recent development by NREL of solar concentrator technology capable of delivering record flux levels. We examined photolytic and photocatalytic chemical processes as well as photothermal processes in the search for processes where concentrated solar flux would offer a unique advantage. 37 refs.

  2. Flux balance analysis accounting for metabolite dilution.

    PubMed

    Benyamini, Tomer; Folger, Ori; Ruppin, Eytan; Shlomi, Tomer

    2010-01-01

    Flux balance analysis is a common method for predicting steady-state flux distributions within metabolic networks, accounting for the growth demand for the synthesis of a predefined set of essential biomass precursors. Ignoring the growth demand for the synthesis of intermediate metabolites required for balancing their dilution leads flux balance analysis to false predictions in some cases. Here, we present metabolite dilution flux balance analysis, which addresses this problem, resulting in improved metabolic phenotype predictions.

  3. High-flux solar photon processes

    SciTech Connect

    Lorents, D C; Narang, S; Huestis, D C; Mooney, J L; Mill, T; Song, H K; Ventura, S

    1992-06-01

    This study was commissioned by the National Renewable Energy Laboratory (NREL) for the purpose of identifying high-flux photoprocesses that would lead to beneficial national and commercial applications. The specific focus on high-flux photoprocesses is based on the recent development by NREL of solar concentrator technology capable of delivering record flux levels. We examined photolytic and photocatalytic chemical processes as well as photothermal processes in the search for processes where concentrated solar flux would offer a unique advantage. 37 refs.

  4. Magnetic flux assisted thermospin transport in a Rashba ring

    NASA Astrophysics Data System (ADS)

    Feng, Liang; Benling, Gao; Yu, Gu

    2016-10-01

    The electron transport through a Rashba ring with a magnetic flux and driven by a temperature difference is investigated. It is found that the spin interference effect induced by the Rashba spin-orbit interaction and by the magnetic flux can break the balance between the spin-up and spin-down component currents in the thermally driven charge current and thus result in a spin current. The analytical derivation and numerical calculations reveal that the magnitude, sign, peaks and spin-polarization of the generated spin current can be readily modulated by the system parameters. In particular, with some choices of the parameters, the spin polarization of the generated spin current can reach 100%, that is, a fully spin-polarized thermospin current can be produced. These results may help the use of the spin-dependent Seebeck effect to generate and manipulate a spin current. Project supported by the National Natural Science Foundation of China (No.11404142).

  5. Surface energy budget and turbulent fluxes at Arctic terrestrial sites

    NASA Astrophysics Data System (ADS)

    Grachev, Andrey; Persson, Ola; Uttal, Taneil; Konopleva-Akish, Elena; Crepinsek, Sara; Cox, Christopher; Fairall, Christopher; Makshtas, Alexander; Repina, Irina

    2017-04-01

    imbalance magnitude. All turbulent fluxes are highly correlated with net radiation because this balance between solar and longwave radiation is the principal energy source for daytime surface warming, evaporation, and photosynthesis. We find that turbulent fluxes of carbon dioxide and sensible heat are closely linked and, on average, change sign synchronously during the diurnal and annual cycles. The work is supported by the NOAA Climate Program Office, the U.S. National Science Foundation (NSF) with award ARC 11-07428, and by the U.S. Civilian Research & Development Foundation (CRDF) with award RUG1-2976-ST-10.

  6. Latent Heat in Soil Heat Flux Measurements

    USDA-ARS?s Scientific Manuscript database

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, the...

  7. Apparatus for measuring a flux of neutrons

    DOEpatents

    Stringer, James L.

    1977-01-01

    A flux of neutrons is measured by disposing a detector in the flux and applying electronic correlation techniques to discriminate between the electrical signals generated by the neutron detector and the unwanted interfering electrical signals generated by the incidence of a neutron flux upon the cables connecting the detector to the electronic measuring equipment at a remote location.

  8. What are Up, Down and Net Fluxes?

    Atmospheric Science Data Center

    2014-12-08

    ... is of particular interest. Hence the term "Up" and "Down" for characterizing the direction of flow of radiative fluxes at a ... level. Moreover, by counting in or out these "Up" and "Down" energy fluxes, one can define a "Net" flux that is ultimately ...

  9. Science Toys for Science Education.

    ERIC Educational Resources Information Center

    Raw, Isaias

    1982-01-01

    The absence of "hands-on" experiences with science equipment in schools stimulated the production of science kits for children. Thirty years later this enterprise has become a national institution in Brazil with a proud history of effecting change in the teaching of science throughout this country. (Author/JN)

  10. Science Squared: Teaching Science Visually.

    ERIC Educational Resources Information Center

    Paradis, Olga; Savage, Karen; Judice, Michelle

    This paper describes a collection of novel ideas for bulletin board displays that would be useful in supplementing science classroom instruction. Information on women and minorities in science; science concepts in everyday activities such as nutrition, baseball, and ice cream-making; and various holidays and celebratory events is included. Each…

  11. Science Squared: Teaching Science Visually.

    ERIC Educational Resources Information Center

    Paradis, Olga; Savage, Karen; Judice, Michelle

    This paper describes a collection of novel ideas for bulletin board displays that would be useful in supplementing science classroom instruction. Information on women and minorities in science; science concepts in everyday activities such as nutrition, baseball, and ice cream-making; and various holidays and celebratory events is included. Each…

  12. Science Teaching in Science Education

    ERIC Educational Resources Information Center

    Callahan, Brendan E.; Dopico, Eduardo

    2016-01-01

    Reading the interesting article "Discerning selective traditions in science education" by Per Sund, which is published in this issue of "CSSE," allows us to open the discussion on procedures for teaching science today. Clearly there is overlap between the teaching of science and other areas of knowledge. However, we must…

  13. Science Teaching in Science Education

    ERIC Educational Resources Information Center

    Callahan, Brendan E.; Dopico, Eduardo

    2016-01-01

    Reading the interesting article "Discerning selective traditions in science education" by Per Sund, which is published in this issue of "CSSE," allows us to open the discussion on procedures for teaching science today. Clearly there is overlap between the teaching of science and other areas of knowledge. However, we must…

  14. Comparison of surface fluxes and boundary-layer measurements at Arctic terrestrial sites

    NASA Astrophysics Data System (ADS)

    Grachev, Andrey; Uttal, Taneil; Persson, Ola; Stone, Robert; Crepinsek, Sara; Albee, Robert; Makshtas, Alexander; Kustov, Vasily; Repina, Irina; Artamonov, Arseniy

    2014-05-01

    dioxide was mostly negative (uptake by the surface) in summer indicating that the Arctic terrestrial sites are generally net sinks for atmospheric CO2 during the growing season when surface is extensively covered with vegetation. This study also shows that the sensible heat flux, water vapor, and carbon dioxide fluxes as well as air temperature exhibit clear diurnal cycles during the Arctic summer. During the Polar winter and cold seasons, the sensible heat flux, water vapor and carbon dioxide fluxes were small and mostly irregular when the ground is covered with snow and air temperatures are sufficiently below freezing. The work is supported by the U.S. National Science Foundation (NSF) with award ARC 11-07428 and by the U.S. Civilian Research & Development Foundation (CRDF) with award RUG1-2976-ST-10.

  15. Evaluation of various LandFlux evapotranspiration algorithms using the LandFlux-EVAL synthesis benchmark products and observational data

    NASA Astrophysics Data System (ADS)

    Michel, Dominik; Hirschi, Martin; Jimenez, Carlos; McCabe, Mathew; Miralles, Diego; Wood, Eric; Seneviratne, Sonia

    2014-05-01

    ., Wood, E. F., Zhang, Y., and Seneviratne, S. I. (2013). Benchmark products for land evapotranspiration: LandFlux-EVAL multi-data set synthesis. Hydrology and Earth System Sciences, 17(10): 3707-3720.

  16. Biomarker evidence for Archean oxygen fluxes (Invited)

    NASA Astrophysics Data System (ADS)

    Hallmann, C.; Waldbauer, J.; Sherman, L. S.; Summons, R. E.

    2010-12-01

    Knowledge of deep-time organismic diversity may be gained from the study of preserved sedimentary lipids with taxonomic specificity, i.e. biomarker hydrocarbons (e.g. Brocks and Summons, 2003; Waldbauer et al., 2009). As a consequence of long residence times and high thermal maturities however, biomarker concentrations are extremely low in most ancient (Precambrian) sediment samples, making them exceptionally prone to contamination during drilling, sampling and laboratory workup (e.g. Brocks et al., 2008). Outcrop samples most always carry a modern overprint and deep-time biogeochemistry thus relies on drilling operations to retrieve ‘clean’ sediment cores. One such effort was initiated by NASA’s Astrobiology Institute (NAI): the Archean biosphere drilling project (ABDP). We here report on the lipids retrieved from sediment samples in drill hole ABDP-9. Strong heterogeneities of extractable organic matter - both on a spatial scale and in free- vs. mineral-occluded bitumen - provide us with an opportunity to distinguish indigenous lipids from contaminants introduced during drilling. Stratigraphic trends in biomarker data for mineral-occluded bitumens are complementary to previously reported data (e.g. S- and N-isotopes, molybdenum enrichments) from ABDP-9 sediments (Anbar et al., 2007; Kaufman et al., 2007; Garvin et al., 2009) and suggest periodic fluxes of oxygen before the great oxidation event. Anbar et al. A whiff of oxygen before the great oxidation event. Science 317 (2007), 1903-1906. Brocks & Summons. Sedimentary hydrocarbons, biomarkers for early life. In: Schlesinger (Ed.) Treatise on Geochemistry, Vol. 8 (2003), 63-115. Brocks et al. Assessing biomarker syngeneity using branched alkanes with quaternary carbon (BAQCs) and other plastic contaminants. Geochimica et Cosmochimica Acta 72 (2008), 871-888. Garvin et al. Isotopic evidence for a aerobic nitrogen cycle in the latest Archean. Science 323 (2009), 1045-1048. Kaufman et al. Late Archean

  17. Diffuse neutrino flux from failed supernovae.

    PubMed

    Lunardini, Cecilia

    2009-06-12

    I study the diffuse flux of electron antineutrinos from stellar collapses with direct black hole formation (failed supernovae). This flux is more energetic than that from successful supernovae, and therefore it might contribute substantially to the total diffuse flux above realistic detection thresholds. The total flux might be considerably higher than previously thought, and approach the sensitivity of Super-Kamiokande. For more conservative values of the parameters, the flux from failed supernovae dominates for antineutrino energies above 30-45 MeV, with potential to give an observable spectral distortion at megaton detectors.

  18. Photometric analysis in the Kepler Science Operations Center pipeline

    NASA Astrophysics Data System (ADS)

    Twicken, Joseph D.; Clarke, Bruce D.; Bryson, Stephen T.; Tenenbaum, Peter; Wu, Hayley; Jenkins, Jon M.; Girouard, Forrest; Klaus, Todd C.

    2010-07-01

    We describe the Photometric Analysis (PA) software component and its context in the Kepler Science Operations Center (SOC) Science Processing Pipeline. The primary tasks of this module are to compute the photometric flux and photocenters (centroids) for over 160,000 long cadence (~thirty minute) and 512 short cadence (~one minute) stellar targets from the calibrated pixels in their respective apertures. We discuss science algorithms for long and short cadence PA: cosmic ray cleaning; background estimation and removal; aperture photometry; and flux-weighted centroiding. We discuss the end-to-end propagation of uncertainties for the science algorithms. Finally, we present examples of photometric apertures, raw flux light curves, and centroid time series from Kepler flight data. PA light curves, centroid time series, and barycentric timestamp corrections are exported to the Multi-mission Archive at Space Telescope [Science Institute] (MAST) and are made available to the general public in accordance with the NASA/Kepler data release policy.

  19. MINERvA's Flux Prediction

    NASA Astrophysics Data System (ADS)

    Golan, Tomasz; Aliaga, Leonidas; Kordosky, Mike

    The MINERvA (Main INjector ExpeRiment: νA) experiment is focused on the measurement of neutrino cross sections on various nuclear targets. For this kind of study it is crucial to know precisely neutrino flux. MINERvA uses the NuMI (Neutrinos at the Main Injector) beam produced at Fermilab. The recent study on the evaluation of the beam and its uncertainty is presented. The NuMI beam is also used by other neutrino experiment, like MINOS, ArgoNeuT, PEANUT, and NOvA, therefore, the results can be used by other collaborations.

  20. Instrumentation for Surface Flux Measurements

    DTIC Science & Technology

    2012-05-10

    National Park , she used the sonic and a Li-Cor C02-H20 analyzer at a height of 3 m to measure the vertical turbulent flux of C02 downwind of...SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U. S. Army Research Office P.O. Box 12211 Research Triangle Park , NC 27709-2211 3. REPORT TYPE...and subgrid-scale array measurements In summer 2000 we lent 7 of the CSAT3 sonics to the National Center for Atmo- spheric Research (NCAR) for use in

  1. Methane Fluxes from Subtropical Wetlands

    NASA Astrophysics Data System (ADS)

    DeLucia, N.; Gomez-Casanovas, N.; Bernacchi, C.

    2013-12-01

    It is well documented that green house gas concentrations have risen at unequivocal rates since the industrial revolution but the disparity between anthropogenic sources and natural sources is uncertain. Wetlands are one example of a natural ecosystem that can be a substantial source or sink for methane (CH4) depending on climate conditions. Due to strict anaerobic conditions required for CH4-generating microorganisms, natural wetlands are one of the main sources for biogenic CH4. Although wetlands occupy less than 5% of total land surface area, they contribute approximately 20% of total CH4 emissions to the atmosphere. The processes regulating CH4 emissions are sensitive to land use and management practices of areas surrounding wetlands. Variation in adjacent vegetation or grazing intensity by livestock can, for example, alter CH4 fluxes from wetland soils by altering nutrient balance, carbon inputs and hydrology. Therefore, understanding how these changes will affect wetland source strength is essential to understand the impact of wetland management practices on the global climate system. In this study we quantify wetland methane fluxes from subtropical wetlands on a working cattle ranch in central Florida near Okeechobee Lake (27o10'52.04'N, 81o21'8.56'W). To determine differences in CH4 fluxes associated with land use and management, a replicated (n = 4) full factorial experiment was designed for wetlands where the surrounding vegetation was (1) grazed or un-grazed and (2) composed of native vegetation or improved pasture. Net exchange of CH4 and CO2 between the land surface and the atmosphere were sampled with a LICOR Li-7700 open path CH4 analyzer and Li-7500A open path CO2/H20 analyzer mounted in a 1-m3 static gas-exchange chamber. Our results showed and verified that CH4 emissions from subtropical wetlands were larger when high soil moisture was coupled with high temperatures. The presence of cattle only amplified these results. These results help quantify

  2. Chromoelectric flux tubes in QCD

    SciTech Connect

    Cardaci, Mario Salvatore; Cea, Paolo; Cosmai, Leonardo; Falcone, Rossella; Papa, Alessandro

    2011-01-01

    We analyze the distribution of the chromoelectric field generated by a static quark-antiquark pair in the SU(3) vacuum and revisit previous results for SU(2). We find that the transverse profile of the flux tube resembles the dual version of the Abrikosov vortex field distribution. We give an estimate of the London penetration length of the chromoelectric field in the confined vacuum. We also speculate on the value of the ratio between the penetration lengths for SU(2) and SU(3) gauge theories.

  3. Using heat to characterize streambed water flux variability in four stream reaches

    USGS Publications Warehouse

    Essaid, H.I.; Zamora, C.M.; McCarthy, K.A.; Vogel, J.R.; Wilson, J.T.

    2008-01-01

    Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the streambed. Synoptic methods (seepage meter and differential discharge measurements) were compared with estimates obtained by using heat as a tracer. Water flux was estimated by modeling one-dimensional vertical flow of water and heat using the model VS2DH. Flux was influenced by physical heterogeneity of the stream channel and temporal variability in stream and ground-water levels. During most of the study period (April-December 2004), flux was upward through the streambeds. At the IN, NE, and CA sites, high-stage events resulted in rapid reversal of flow direction inducing short-term surface-water flow into the streambed. During late summer at the IN site, regional ground-water levels dropped, leading to surface-water loss to ground water that resulted in drying of the ditch. Synoptic measurements of flux generally supported the model flux estimates. Water flow through the streambed was roughly an order of magnitude larger in the humid basins (IN and NE) than in the arid basins (WA and CA). Downward flux, in response to sudden high streamflows, and seasonal variability in flux was most pronounced in the humid basins and in high conductivity zones in the streambed. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  4. Evaluating Surface Flux Results from CERES-FLASHFlux

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    The Clouds and Earth's Radiant Energy System (CERES) mission provides TOA (Top-of-Atmosphere) and surface radiative flux products for each CERES footprint (Single Scanner Footprint) and also time integrated and spatially averaged (TISA) to provide 1ox1o fluxes at various temporal averages. The CERES TISA products are available to the public within 3-6 months of observation. The CERES Fast Longwave and SHortwave radiative Flux (FLASHFlux) data products were developed to provide a rapid release version of the CERES data products. FLASHFlux data products are made available to the research and applications communities within one week of the satellite observations. Over the last several years, the CERES team has contributed to a section on the variability of radiation budget at the Top-of-Atmosphere in the annual "State of the Climate Report" published in BAMS using CERES TISA and FLASHFlux data products. Recently, the FLASHFlux data were used to investigate the radiative impacts of the intense 2015-2016 El Nino event. In addition FLASHFlux date are routinely used by applied science in energy related and agricultural sectors. The current version of FLASHFlux is being upgraded to FLASHFlux Version4A to improve consistency with the climate quality Edition 4 CERES data products. This presentation will describe the planned changes including the change to the latest meteorological product from Global Modeling and Assimilation Office (GMAO), GEOS FP-IT (5.12.4). GEOS 5.12.4 is an assimilation that is consistent with MERRA-2. We present comparisons of global and regional changes in the TOA and surface radiative fluxes as a result of the upgrade for both longwave (LW) and shortwave (SW) surface fluxes. We also compare the data products against ground measurements using data from the Baseline Surface Radiation Network (BSRN) - including NOAA SURFRAD, Atmospheric Radiation Measurement (ARM) and Ocean buoy measurements from Woods Hole Oceanographic Institute (WHOI).

  5. Sources of variability in mercury flux measurements

    NASA Astrophysics Data System (ADS)

    Edwards, G. C.; Rasmussen, P. E.; Schroeder, W. H.; Kemp, R. J.; Dias, G. M.; Fitzgerald-Hubble, C. R.; Wong, E. K.; Halfpenny-Mitchell, L.; Gustin, M. S.

    2001-03-01

    Chamber and micrometeorological mercury flux data collected during the Nevada STORMS intercomparison study were used to identify natural and methodological factors controlling data variability. Micrometeorological and chamber measurements revealed that flux variability at a site is closely related to the Hg concentrations in the substrate, which were found to vary with mineral composition, grain size, and sampling depth. Environmental factors also influenced flux variability. Following two rainfall events, fluxes measured by chamber and micrometeorological methods increased substantially. The micrometeorological flux was enhanced five fold following the rain event. Fluxes measured by both methods were also influenced by net radiation and temperature as evidenced by their tendency to follow the diel cycle in these variables. Daytime fluxes were 6 times greater than nighttime fluxes. Data analysis revealed that interactions between environmental and geochemical variables complicate relationships between the flux and these variables. Understanding the variability at a flux monitoring site is important to establish relationships for scaling up and for the development of consistent sampling protocols that allow comparisons from one study to another and adequately quantify mercury fluxes from natural sites to provide representative emission data that can be used for scaling up to regional and global scales.

  6. Flux Sampling Errors for Aircraft and Towers

    NASA Technical Reports Server (NTRS)

    Mahrt, Larry

    1998-01-01

    Various errors and influences leading to differences between tower- and aircraft-measured fluxes are surveyed. This survey is motivated by reports in the literature that aircraft fluxes are sometimes smaller than tower-measured fluxes. Both tower and aircraft flux errors are larger with surface heterogeneity due to several independent effects. Surface heterogeneity may cause tower flux errors to increase with decreasing wind speed. Techniques to assess flux sampling error are reviewed. Such error estimates suffer various degrees of inapplicability in real geophysical time series due to nonstationarity of tower time series (or inhomogeneity of aircraft data). A new measure for nonstationarity is developed that eliminates assumptions on the form of the nonstationarity inherent in previous methods. When this nonstationarity measure becomes large, the surface energy imbalance increases sharply. Finally, strategies for obtaining adequate flux sampling using repeated aircraft passes and grid patterns are outlined.

  7. Flux Sampling Errors for Aircraft and Towers

    NASA Technical Reports Server (NTRS)

    Mahrt, Larry

    1998-01-01

    Various errors and influences leading to differences between tower- and aircraft-measured fluxes are surveyed. This survey is motivated by reports in the literature that aircraft fluxes are sometimes smaller than tower-measured fluxes. Both tower and aircraft flux errors are larger with surface heterogeneity due to several independent effects. Surface heterogeneity may cause tower flux errors to increase with decreasing wind speed. Techniques to assess flux sampling error are reviewed. Such error estimates suffer various degrees of inapplicability in real geophysical time series due to nonstationarity of tower time series (or inhomogeneity of aircraft data). A new measure for nonstationarity is developed that eliminates assumptions on the form of the nonstationarity inherent in previous methods. When this nonstationarity measure becomes large, the surface energy imbalance increases sharply. Finally, strategies for obtaining adequate flux sampling using repeated aircraft passes and grid patterns are outlined.

  8. Flux of Millimetric Space Debris

    NASA Technical Reports Server (NTRS)

    Goldstein, R. M.; Goldstein, S. J., Jr.

    1995-01-01

    In 21.4 hr of zenith radar observations on 4 days at 8510 MHz, we found 831 particles with altitudes between 177 and 1662 km. From the duration of the echoes and the angular size (0.030 deg) of the antenna beam 157 particles were identified as passing through the side lobes and not through the main beam. Our analysis is based on the 674 particles that did not broaden the beam. On the assumptions that these particles went through the main beam, their radar cross sections vary between 0.02 and 260 sq mm , and their radial velocities vary between +/- 700 m/s. If they are conducting spheres, their diameters lie between 2 and 18 mm. If not, they must be larger. The flux of these particles, that is the number per sq km day, was determined in 100 km intervals. The maximum flux, 3.3 particles per sq km day, occurs at 950 km altitude. The small and large particles are not well mixed. The largest particles occur beyond 1000 km and middle-sized particles are missing below 300 km. If the earth's atmosphere caused the smallest particles to lose energy from initial orbits identical to those of the large particles, the orbits would have lower eccentricity at low altitudes. We find a larger eccentricity for the inner particles, and conclude that two or more populations are present.

  9. Cosmic Ray Neutron Flux Measurements

    NASA Astrophysics Data System (ADS)

    Dayananda, Mathes

    2009-11-01

    Cosmic rays are high-energetic particles originating from outer space that bombard the upper atmosphere of the Earth. Almost 90% of cosmic ray particles consist of protons, electrons and heavy ions. When these particles hit the Earth's atmosphere, cascade of secondary particles are formed. The most abundant particles reach to the surface of the Earth are muons, electrons and neutrons. In recent years many research groups are looking into potential applications of the effects of cosmic ray radiation at the surface of the Earth [1, 2]. At Georgia State University we are working on a long-term measurement of cosmic ray flux distribution. This study includes the simultaneous measurement of cosmic ray muons, neutrons and gamma particles at the Earth surface in downtown Atlanta. The initial effort is focusing on the correlation studies of the cosmic ray particle flux distribution and the atmospheric weather conditions. In this presentation, I will talk about the development of a cosmic ray detector using liquid scintillator and the preliminary results. [4pt] [1] K.Borozdin, G.Hogan, C.Morris, W.Priedhorsky, A.Saunders, L.Shultz, M.Teasdale, ``Radiographic imaging with cosmic-ray muons'', Nature, Vol.422, p.277, Mar.2003[0pt] [2] Svensmark Henrik, Physical Review 81, 3, (1998)

  10. Flux focusing eddy current probe

    NASA Technical Reports Server (NTRS)

    Simpson, John W. (Inventor); Clendenin, C. Gerald (Inventor); Fulton, James P. (Inventor); Wincheski, Russell A. (Inventor); Todhunter, Ronald G. (Inventor); Namkung, Min (Inventor); Nath, Shridhar C. (Inventor)

    1997-01-01

    A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks and material loss in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil. The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. The maximum sensor output is obtained when positioned symmetrically above the crack. Hence, by obtaining the position of the maximum sensor output, it is possible to track the fault and locate the area surrounding its tip. The accuracy of tip location is enhanced by two unique features of the sensor; a very high signal-to-noise ratio of the probe's output which results in an extremely smooth signal peak across the fault, and a rapidly decaying sensor output outside a small area surrounding the crack tip which enables the region for searching to be clearly defined. Under low frequency operation, material thinning due to corrosion damage causes an incomplete shielding of the pick-up coil. The low frequency output voltage of the probe is therefore a direct indicator of the thickness of the test sample.

  11. A solar EUV flux model

    SciTech Connect

    Tobiska, W.K.; Barth, C.A. )

    1990-06-01

    A model of the solar extreme ultraviolet (EUV) irradiance variability has been developed for aeronomical use and has been named SERF2 by the Solar Electromagnetic Radiation Flux Study. The model is valid between 1981 and 1989 and is based on the Atmosphere Explorer E (AE-E) satellite EUV data set which is correlated with independent solar emissions measured during and after the AE-E mission. Additionally, spectral modifications are made to the model based on 18 separate rocket flights for all levels of solar activity. Two daily measured solar emissions, the H Lyman {alpha} line at 121.6 nm observed by the Solar Mesosphere Explorer satellite and the Ottawa 10.7-cm radio flux observed at the ground, are used in the model as indices for full-disk solar EUV chromospheric irradiance variations and transition region-coronal irradiance variations, respectively. The model wavelength equation coefficients are presented in tabular form for 39 wavelength groups or discrete lines from 1.9 to 105.0 nm along with spectral weighting function coefficients which modify the irradiance magnitudes based upon model wavelength fits to rocket-observed spectra. The model satisfies the general constraint of duplicating rocket-observed EUV irradiance for a wise variety of solar activity conditions. The model development is discussed, an example calculation is given, and the comparisons with constraining rocket data sets are shown.

  12. Atmospheric discharges and particle fluxes

    NASA Astrophysics Data System (ADS)

    Chilingarian, A.; Chilingaryan, S.; Reymers, A.

    2015-07-01

    Fluxes of the electrons, gamma rays, and neutrons observed by particle detectors located on the Earth's surface during thunderstorms originate so-called Thunderstorm Ground Enhancements (TGEs). The relativistic runaway electron avalanches giving rise to TGEs originate in the thundercloud's lower dipole between the main negatively charged region in the middle of the thundercloud and transient lower positively charged region. Acceleration of electrons in the upper dipole between main negative and main positive charge regions leads to initiation of the terrestrial gamma flashes (TGFs) intensive researched during the last two decades by orbiting gamma ray observatories. TGFs are exceptionally intense, submillisecond bursts of electromagnetic radiation directed to the open space from the thunderstorm atmosphere. Unlike visible lightning, TGF beams do not create a hot plasma channel and optical flash; hence, in the literature they got name "dark lightning." We investigate the TGEs development in 1 min and 1 s time series of particle detector count rates. Synchronized time series of the near-surface electric field and lightning occurrences allows interconnecting two atmospheric phenomena. Registration of the Extensive Air Showers allows approaching problems of relation of the lightning occurrences and particle fluxes.

  13. SEP flux mapping with PHOEBUS

    NASA Astrophysics Data System (ADS)

    Grimani, C.; Bagni, G.; Fabi, M.; Vicerè, A.; Marconi, L.; Stanga, R.; Bosi, L.; Vocca, H.; Araújo, H.; Shaul, D.; Sumner, T.; Wass, P.; Boatella, C.; Lobo, A.; Chmeissani, M.; Martinez, I.

    2006-03-01

    We report about PHOEBUS (PHysics Of Events BUrsted by the Sun): a proposal for solar physics and space weather investigation with LISA (Laser Interferometer Space Antenna). Galactic and solar cosmic-ray particles with energies larger than 100 MeV(/n) penetrate and charge the LISA test masses. Spurious forces occur between the test masses and the surrounding electrodes mimicking gravitational wave signals. This process constitutes one of the major sources of acceleration noise for LISA. Silicon particle detectors will be placed on board the LISA-PF and LISA missions to monitor the overall energetic incident cosmic-ray fluxes. These telescopes can be also used to carry out a map of shock accelerated Solar Energetic Particle (SEPs) fluxes associated with evolving Coronal Mass Ejections (CMEs) at different steps in longitude. We discuss the role of protons, helium nuclei, galactic heavy nuclei and solar ions. We aim to contribute to the COST724 (European CO-operation in the field of Scientific and Technical Research) action inside WG1/WP13000 developing appropriate simulations of the dynamics of CMEs by using space-based data and theoretical models.

  14. The diffuse supernova neutrino flux

    NASA Astrophysics Data System (ADS)

    Lunardini, Cecilia

    2011-12-01

    I review the status and perspectives of the research on the diffuse flux of (core collapse) supernova neutrinos (DSNνF). Several upper bounds exist on this flux in different detection channels. The strongest is the limit from SuperKamiokande (SK) of 1.2 electron antineutrinos cm-2s-1 at 90% confidence level above 19.3 MeV of neutrino energy. The predictions of the DSNνF depend on the supernova rate and on the neutrino emission in a individual supernova. Above the SK threshold, they range between 0.05 electron antineutrinos cm-2s-1 up to touching the SK limit. The SK bound constrains part of the parameter space of the supernova rate - and indirectly of the star formation rate - only in models with relatively hard neutrino spectra. Experimentally, a feasible and very important goal for the future is the improvement of background discrimination and the resulting lowering of the detection threshold. Theory instead will benefit from reducing the uncertainties on the supernova neutrino emission (either with more precise numerical modeling or with data from a galactic supernova) and on the supernova rate. The latter will be provided precisely by next generation supernova surveys up to a normalization factor. Therefore, the detection of the DSNνF is likely to be precious chiefly to constrain such normalization and to study the physics of neutrino emission in supernovae.

  15. Constrained Allocation Flux Balance Analysis

    PubMed Central

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  16. Deconstructing science

    NASA Astrophysics Data System (ADS)

    Trifonas, Peter Pericles

    2012-12-01

    In this paper I expand on the premises of Jesse Bazzul's thesis in his paper, Neoliberal ideology, global capitalism, and science education: engaging the question of subjectivity, exploring the implications of the ideologies within the culturally emerging logic of science exposes the incommensurability of intents and purposes in its methods and epistemology. I argue that science needs to acknowledge the subjectivity at its core to make space for non-absolute agents and new fields of study.

  17. Reading Science

    ERIC Educational Resources Information Center

    Carlson, Kenneth

    2005-01-01

    Reading the average science textbook, one is struck with a question: Why would people devote their lives to the study of a subject as dry as the Sahara Desert? Students in science classes only need to be let in on the great secret of science. It is fun and full of the stuff in page-turner novels--intrigue, mystery, romance, and sometimes just dumb…

  18. Reading Science

    ERIC Educational Resources Information Center

    Carlson, Kenneth

    2005-01-01

    Reading the average science textbook, one is struck with a question: Why would people devote their lives to the study of a subject as dry as the Sahara Desert? Students in science classes only need to be let in on the great secret of science. It is fun and full of the stuff in page-turner novels--intrigue, mystery, romance, and sometimes just dumb…

  19. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1987

    1987-01-01

    Contains 31 activities and experiments from the biological and physical sciences. Addresses such areas as reproduction, biotechnology, ecology, proteins, nitrates, aerosols, metal crystallinity, circuit boards, and photoswitching. (ML)

  20. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1987

    1987-01-01

    Contains 31 activities and experiments from the biological and physical sciences. Addresses such areas as reproduction, biotechnology, ecology, proteins, nitrates, aerosols, metal crystallinity, circuit boards, and photoswitching. (ML)

  1. Regulation of the interplanetary magnetic flux

    SciTech Connect

    McComas, D.J.; Gosling, J.T.; Phillips, J.L.

    1991-01-01

    In this study we use a recently developed technique for measuring the 2-D magnetic flux in the ecliptic plane to examine (1) the long term variation of the magnetic flux in interplanetary space and (2) the apparent rate at which coronal mass ejections (CMEs) may be opening new flux from the Sun. Since there is a substantial variation ({approximately}50%) of the flux in the ecliptic plane over the solar cycle, we conclude that there must be some means whereby new flux can be opened from the Sun and previously open magnetic flux can be closed off. We briefly describe recently discovered coronal disconnections events which could serve to close off previously open magnetic flux. CMEs appear to retain at least partial magnetic connection to the Sun and hence open new flux, while disconnections appear to be likely signatures of the process that returns closed flux to the Sun; the combination of these processes could regulate the amount of open magnetic flux in interplanetary space. 6 refs., 3 figs.

  2. The Thermodynamic Meaning of Metabolic Exchange Fluxes

    PubMed Central

    Wiechert, Wolfgang

    2007-01-01

    Metabolic flux analysis (MFA) deals with the experimental determination of steady-state fluxes in metabolic networks. An important feature of the 13C MFA method is its capability to generate information on both directions of bidirectional reaction steps given by exchange fluxes. The biological interpretation of these exchange fluxes and their relation to thermodynamic properties of the respective reaction steps has never been systematically investigated. As a central result, it is shown here that for a general class of enzyme reaction mechanisms the quotients of net and exchange fluxes measured by 13C MFA are coupled to Gibbs energies of the reaction steps. To establish this relation the concept of apparent flux ratios of enzymatic isotope-labeling networks is introduced and some computing rules for these flux ratios are given. Application of these rules reveals a conceptional pitfall of 13C MFA, which is the inherent dependency of measured exchange fluxes on the chosen tracer atom. However, it is shown that this effect can be neglected for typical biochemical reaction steps under physiological conditions. In this situation, the central result can be formulated as a two-sided inequality relating fluxes, pool sizes, and standard Gibbs energies. This relation has far-reaching consequences for metabolic flux analysis, quantitative metabolomics, and network thermodynamics. PMID:17526563

  3. How the Saturnian Magnetosphere Conserves Magnetic Flux

    NASA Astrophysics Data System (ADS)

    Powell, R. L.; Wei, H.; Russell, C. T.; Arridge, C. S.; Dougherty, M. K.

    2012-12-01

    The magnetospheric dynamics at Saturn are driven by the centrifugal force of near co-rotating water group ions released at a rate of hundreds of kilograms per second by Saturn's moon Enceladus. The plasma is accelerated up to co-rotation speed by the magnetospheric magnetic field coupled to the Saturnian ionosphere. The plasma is lost ultimately through the process of magnetic reconnection in the tail. Conservation of magnetic flux requires that plasma-depleted, "empty" flux tubes return magnetic flux to the inner magnetosphere. After completion of the initial inrush of the reconnected and largely emptied flux tubes inward of the reconnection point, the flux tubes face the outflowing plasma and must move inward against the flow. Observations of such flux tubes have been identified in the eight years of Cassini magnetometer data. The occurrence of these tubes is observed at all local times indicating slow inward transport of the tubes relative to the co-rotation speed. Depleted flux tubes observed in the equatorial region appear as an enhancement in the magnitude of the magnetic field, whereas the same flux tubes observed at higher latitudes appear as decreased field strength. The difference in appearance of the low latitude and the high latitude tubes is due to the plasma environment just outside the tube. Warm low-density plasma fills the inside of the flux tube at all latitudes. This flux tube thus will expand in the less dense regions away from the magnetic equator and will be observed as a decrease in the magnitude of the magnetic field from the background. These flux tubes near the equator, where the plasma density outside of the flux tube is much greater, will be observed as an enhancement in the magnitude of the magnetic field. Cassini magnetometer and CAPS data are examined to understand the properties of these flux tubes and their radial and latitudinal evolution throughout the Saturnian magnetospheric environment.

  4. Science Fairs for Science Literacy

    NASA Astrophysics Data System (ADS)

    Mackey, K. R.

    2014-12-01

    Science literacy is imperative for well informed civic and personal decision making, yet only a quarter of American adults are proficient enough in science to understand science stories reported in the popular press. Hands-on research increases confidence in and understanding of science. When guiding students in designing and conducting science fair projects, mentors can foster science literacy by helping students focus on three goals: (1) articulating hypotheses or questions, (2) designing feasible projects, and (3) learning to make and interpret graphs. These objectives introduce students to the methodological nature of scientific research and give them the tools to interpret scientific facts and data in order to make informed decisions for themselves and society.

  5. The science in social science

    PubMed Central

    Bernard, H. Russell

    2012-01-01

    A recent poll showed that most people think of science as technology and engineering—life-saving drugs, computers, space exploration, and so on. This was, in fact, the promise of the founders of modern science in the 17th century. It is less commonly understood that social and behavioral sciences have also produced technologies and engineering that dominate our everyday lives. These include polling, marketing, management, insurance, and public health programs. PMID:23213222

  6. On The Solenoidal Heat Flux in Quasi-Ballistic Thermal Conduction

    NASA Astrophysics Data System (ADS)

    Ramu, Ashok; Bowers, John

    The Boltzmann transport equation for phonons is recast directly in terms of the heat-flux by means of iteration followed by truncation at the second order in the spherical harmonic expansion of the distribution function. This procedure displays the heat-flux in an explicitly coordinate-invariant form, and leads to a natural decomposition into two components, namely the solenoidal component in addition to the usual irrotational component. The solenoidal heat-flux is explicitly shown to arise in a right-circular cylinder when the transport is in the quasi-ballistic regime. These findings are important in the context of phonon resonators that utilize the strong quasi-ballistic thermal transport reported recently in silicon membranes at room temperature. Effects due to circulating heat fluxes are noted in the effective thermal conductivity of silicon discs. This work was funded by the National Science Foundation, USA under Project Number CMMI-1363207.

  7. Ship-based Surface Flux Observations Under Atmospheric Rivers During the CALWATER 2015 Field Campaign

    NASA Astrophysics Data System (ADS)

    Blomquist, B.; Fairall, C. W.; Intrieri, J. M.; Wolfe, D. E.; Pezoa, S.

    2015-12-01

    The NOAA Physical Sciences Division portable flux system was deployed on the R/V Ron Brown as part of the surface observational strategy for the CALWATER 2015 field investigation. Measurements included turbulent fluxes of temperature, water vapor and wind stress. A refined 'best' set of bulk meteorological measurements for the duration of the cruise was produced from combined NOAA, DOE ARM-AMF2 and shipboard sensors. Direct eddy correlation and bulk model estimates of sensible and latent heat are broadly consistent (RMSE < 10 W/m2). We present a comparison of in-situ fluxes with gridded forecast and reanalysis datasets and assess the potential magnitude of surface flux to the vapor transport budget.

  8. [Effects of straw mulching on CO2 flux in wintry fallow paddy field].

    PubMed

    Yin, Chun-mei; Xie, Xiao-li; Wang, Kai-rong

    2008-01-01

    This paper studied the effects of straw mulching on the CO2 flux in a wintry fallow paddy field at Taoyuan Agro-ecological Station, Chinese Academy of Sciences. The results showed that the effects of straw mulching mainly exerted in two ways. First, it positively affected soil temperature, making the CO2 flux increased obviously. Straw mulching gave a net emission of 2.68 g CO2 x m(-2) x d(-1), while no mulching gave a net fixation of 1.99 g CO2 x m(-2) x d(-1), the difference between them being very significant (P < 0.01). Second, straw mulching decreased the biomass of weeds and the photosynthetically active radiation they absorbed, which in turn resulted in an increase of CO2 flux. Under straw mulching, the water content in surface soil layer (0-15 cm) increased by 9% or more, but no significant change was observed in CO2 flux.

  9. The sciences of science communication

    PubMed Central

    Fischhoff, Baruch

    2013-01-01

    The May 2012 Sackler Colloquium on “The Science of Science Communication” brought together scientists with research to communicate and scientists whose research could facilitate that communication. The latter include decision scientists who can identify the scientific results that an audience needs to know, from among all of the scientific results that it would be nice to know; behavioral scientists who can design ways to convey those results and then evaluate the success of those attempts; and social scientists who can create the channels needed for trustworthy communications. This overview offers an introduction to these communication sciences and their roles in science-based communication programs. PMID:23942125

  10. The sciences of science communication.

    PubMed

    Fischhoff, Baruch

    2013-08-20

    The May 2012 Sackler Colloquium on "The Science of Science Communication" brought together scientists with research to communicate and scientists whose research could facilitate that communication. The latter include decision scientists who can identify the scientific results that an audience needs to know, from among all of the scientific results that it would be nice to know; behavioral scientists who can design ways to convey those results and then evaluate the success of those attempts; and social scientists who can create the channels needed for trustworthy communications. This overview offers an introduction to these communication sciences and their roles in science-based communication programs.

  11. Science Notes.

    ERIC Educational Resources Information Center

    Murray, A. J. S.; And Others

    1988-01-01

    Presents 31 science activities for use with high school or college science classes. Topics included are: chromatography, ecology, invertebrates, enzymes, genetics, botany, creep, crystals, diffusion, computer interfaces, acid rain, teaching techniques, chemical reactions, waves, electric fields, rainbows, electricity, magnetic fields, and a Pitot…

  12. Legendary Science.

    ERIC Educational Resources Information Center

    O'Keefe, William A.; Joe, Jimson

    1998-01-01

    Spiders and insects are studied in both Navajo Studies and science classes at a middle school in New Mexico. In Navajo Studies, students learn the names of ground-dwelling insects and the connection between those names and traditional Navajo stories. In science class, students study arthropods to illustrate taxonomy of life, trophic and biological…

  13. Shrinking Science.

    ERIC Educational Resources Information Center

    Goates, Wayne

    2002-01-01

    Describes an activity based on shrinkable thermoplastics in which students explore the percentage of shrinkage of a plastic ruler when it is heated. Includes science content knowledge behind the shrink, national science education standards related to this activity, and a complete guide. (KHR)

  14. Life sciences

    SciTech Connect

    Day, L.

    1991-04-01

    This document is the 1989--1990 Annual Report for the Life Sciences Divisions of the University of California/Lawrence Berkeley Laboratory. Specific progress reports are included for the Cell and Molecular Biology Division, the Research Medicine and Radiation Biophysics Division (including the Advanced Light Source Life Sciences Center), and the Chemical Biodynamics Division. 450 refs., 46 figs. (MHB)

  15. Personalizing Science

    ERIC Educational Resources Information Center

    Danielowich, Robert M.

    2014-01-01

    Science teachers are aware of many social issues that intersect with science. These socio-scientific issues (SSIs) are "open-ended problems without clear-cut solutions [that] can be informed by scientific principles, theories, and data, but…cannot be fully determined by [them]" (Sadler 2011, p. 4). This article describes the SSI lessons…

  16. Soundsational Science

    ERIC Educational Resources Information Center

    Carrier, Sarah J.; Scott, Catherine Marie; Hall, Debra T.

    2012-01-01

    The science of sound helps students learn that sound is energy traveling in waves as vibrations transfer the energy through various media: solids, liquids, and gases. In addition to learning about the physical science of sound, students can learn about the sounds of different animal species: how sounds contribute to animals' survival, and how…

  17. Deconstructing Science

    ERIC Educational Resources Information Center

    Trifonas, Peter Pericles

    2012-01-01

    In this paper I expand on the premises of Jesse Bazzul's thesis in his paper, "Neoliberal ideology, global capitalism, and science education: engaging the question of subjectivity," exploring the implications of the ideologies within the culturally emerging logic of science exposes the incommensurability of intents and purposes in its methods and…

  18. Dramatic Science

    ERIC Educational Resources Information Center

    McGregor, Debbie; Precious, Wendy

    2010-01-01

    The setting: the science classroom. The characters: you and your students. The scene: Your students acting out scientific discoveries, modeling a frog's life cycle, mimicking the transition from liquid to solid. This is "dramatic science", a teaching approach that uses acting techniques to explore and develop young children's ideas about…

  19. Dramatic Science

    ERIC Educational Resources Information Center

    McGregor, Debbie; Precious, Wendy

    2010-01-01

    The setting: the science classroom. The characters: you and your students. The scene: Your students acting out scientific discoveries, modeling a frog's life cycle, mimicking the transition from liquid to solid. This is "dramatic science", a teaching approach that uses acting techniques to explore and develop young children's ideas about…

  20. Science Notes.

    ERIC Educational Resources Information Center

    Murray, A. J. S.; And Others

    1988-01-01

    Presents 31 science activities for use with high school or college science classes. Topics included are: chromatography, ecology, invertebrates, enzymes, genetics, botany, creep, crystals, diffusion, computer interfaces, acid rain, teaching techniques, chemical reactions, waves, electric fields, rainbows, electricity, magnetic fields, and a Pitot…

  1. Deconstructing Science

    ERIC Educational Resources Information Center

    Trifonas, Peter Pericles

    2012-01-01

    In this paper I expand on the premises of Jesse Bazzul's thesis in his paper, "Neoliberal ideology, global capitalism, and science education: engaging the question of subjectivity," exploring the implications of the ideologies within the culturally emerging logic of science exposes the incommensurability of intents and purposes in its methods and…

  2. Shrinking Science.

    ERIC Educational Resources Information Center

    Goates, Wayne

    2002-01-01

    Describes an activity based on shrinkable thermoplastics in which students explore the percentage of shrinkage of a plastic ruler when it is heated. Includes science content knowledge behind the shrink, national science education standards related to this activity, and a complete guide. (KHR)

  3. Talking Science

    ERIC Educational Resources Information Center

    Shwartz, Yael; Weizman, Ayelet; Fortus, David; Sutherland, LeeAnn; Merrit, Joi; Krajcik, Joe

    2009-01-01

    Science is a social process--one that involves particular ways of talking, reasoning, observing, analyzing, and writing, which often have meaning only when shared within the scientific community. Discussions are one of the best ways to help students learn to "talk science" and construct understanding in a social context. Since inquiry is an…

  4. Science project

    NASA Image and Video Library

    2012-08-23

    DRIFTER sensor devices were designed by the Applied Science and Technology Project Office as inexpensive tools that can be used for science projects in local schools. The devices transmit information about water temperature and conductivity for use by Gulf Coast researchers. The DRIFTER project began as an effort to help Gulf Coast oyster fishermen dealing with the effects of fresh water intrusion.

  5. Advanced Science.

    ERIC Educational Resources Information Center

    Coles, Mike; Nelms, Rick

    1996-01-01

    Describes a study that explores the depth and breadth of scientific facts, principles, and procedures which are required in the Advanced General National Vocational Qualifications (GNVQ) science through comparison with GCE Advanced level. The final report takes account of the updated 1996 version of GNVQ science. (DDR)

  6. Integrated Science.

    ERIC Educational Resources Information Center

    Rainey, Larry; Miller, Roxanne Greitz

    1997-01-01

    Describes the Integrated Science program that integrates biology, earth/space science, chemistry, and physics over a three-year, spiraling sequence arranged around broad themes such as cycles, changes, patterns, and waves. Includes weekly telecasts via public television and satellite, teacher manuals, student handbooks, e-mail connections, staff…

  7. Soundsational Science

    ERIC Educational Resources Information Center

    Carrier, Sarah J.; Scott, Catherine Marie; Hall, Debra T.

    2012-01-01

    The science of sound helps students learn that sound is energy traveling in waves as vibrations transfer the energy through various media: solids, liquids, and gases. In addition to learning about the physical science of sound, students can learn about the sounds of different animal species: how sounds contribute to animals' survival, and how…

  8. Talking Science

    ERIC Educational Resources Information Center

    Shwartz, Yael; Weizman, Ayelet; Fortus, David; Sutherland, LeeAnn; Merrit, Joi; Krajcik, Joe

    2009-01-01

    Science is a social process--one that involves particular ways of talking, reasoning, observing, analyzing, and writing, which often have meaning only when shared within the scientific community. Discussions are one of the best ways to help students learn to "talk science" and construct understanding in a social context. Since inquiry is an…

  9. Personalizing Science

    ERIC Educational Resources Information Center

    Danielowich, Robert M.

    2014-01-01

    Science teachers are aware of many social issues that intersect with science. These socio-scientific issues (SSIs) are "open-ended problems without clear-cut solutions [that] can be informed by scientific principles, theories, and data, but…cannot be fully determined by [them]" (Sadler 2011, p. 4). This article describes the SSI lessons…

  10. Why Science?

    ERIC Educational Resources Information Center

    Primary Science Review, 2006

    2006-01-01

    This article presents people from many walks of life, including some well-known names, who share their views about science. Adam Hart-Davis, who studied chemistry at university and is now an author, photographer, historian and broadcaster, explains why science cannot start too soon. Lis Nairn, Manager, Stratigraphy, with Fugro Robertson Ltd (Oil…

  11. Why Science?

    ERIC Educational Resources Information Center

    Primary Science Review, 2006

    2006-01-01

    This article presents people from many walks of life, including some well-known names, who share their views about science. Adam Hart-Davis, who studied chemistry at university and is now an author, photographer, historian and broadcaster, explains why science cannot start too soon. Lis Nairn, Manager, Stratigraphy, with Fugro Robertson Ltd (Oil…

  12. Science Alive!

    ERIC Educational Resources Information Center

    Tally-Foos, Kay

    2005-01-01

    At the authors' school, as in many places, she struggles with making science a meaningful part of her students' lives. The teachers are working under state mandates to prepare students for reading and mathematics tests in third, fourth, and fifth grades. Often, this relegates science and social studies to a distant back burner. In an effort to…

  13. Quantifying trace element and isotope fluxes at the ocean–sediment boundary: a review

    PubMed Central

    Berelson, William M.; Severmann, Silke

    2016-01-01

    Quantifying fluxes of trace elements and their isotopes (TEIs) at the ocean's sediment–water boundary is a pre-eminent challenge to understand their role in the present, past and future ocean. There are multiple processes that drive the uptake and release of TEIs, and properties that determine their rates are unevenly distributed (e.g. sediment composition, redox conditions and (bio)physical dynamics). These factors complicate our efforts to find, measure and extrapolate TEI fluxes across ocean basins. GEOTRACES observations are unveiling the oceanic distributions of many TEIs for the first time. These data evidence the influence of the sediment–water boundary on many TEI cycles, and underline the fact that our knowledge of the source–sink fluxes that sustain oceanic distributions is largely missing. Present flux measurements provide low spatial coverage and only part of the empirical basis needed to predict TEI flux variations. Many of the advances and present challenges facing TEI flux measurements are linked to process studies that collect sediment cores, pore waters, sinking material or seawater in close contact with sediments. However, such sampling has not routinely been viable on GEOTRACES expeditions. In this article, we recommend approaches to address these issues: firstly, with an interrogation of emergent data using isotopic mass-balance and inverse modelling techniques; and secondly, by innovating pursuits of direct TEI flux measurements. We exemplify the value of GEOTRACES data with a new inverse model estimate of benthic Al flux in the North Atlantic Ocean. Furthermore, we review viable flux measurement techniques tailored to the sediment–water boundary. We propose that such activities are aimed at regions that intersect the GEOTRACES Science Plan on the basis of seven criteria that may influence TEI fluxes: sediment provenance, composition, organic carbon supply, redox conditions, sedimentation rate, bathymetry and the benthic nepheloid

  14. Quantifying trace element and isotope fluxes at the ocean-sediment boundary: a review

    NASA Astrophysics Data System (ADS)

    Homoky, William B.; Weber, Thomas; Berelson, William M.; Conway, Tim M.; Henderson, Gideon M.; van Hulten, Marco; Jeandel, Catherine; Severmann, Silke; Tagliabue, Alessandro

    2016-11-01

    Quantifying fluxes of trace elements and their isotopes (TEIs) at the ocean's sediment-water boundary is a pre-eminent challenge to understand their role in the present, past and future ocean. There are multiple processes that drive the uptake and release of TEIs, and properties that determine their rates are unevenly distributed (e.g. sediment composition, redox conditions and (bio)physical dynamics). These factors complicate our efforts to find, measure and extrapolate TEI fluxes across ocean basins. GEOTRACES observations are unveiling the oceanic distributions of many TEIs for the first time. These data evidence the influence of the sediment-water boundary on many TEI cycles, and underline the fact that our knowledge of the source-sink fluxes that sustain oceanic distributions is largely missing. Present flux measurements provide low spatial coverage and only part of the empirical basis needed to predict TEI flux variations. Many of the advances and present challenges facing TEI flux measurements are linked to process studies that collect sediment cores, pore waters, sinking material or seawater in close contact with sediments. However, such sampling has not routinely been viable on GEOTRACES expeditions. In this article, we recommend approaches to address these issues: firstly, with an interrogation of emergent data using isotopic mass-balance and inverse modelling techniques; and secondly, by innovating pursuits of direct TEI flux measurements. We exemplify the value of GEOTRACES data with a new inverse model estimate of benthic Al flux in the North Atlantic Ocean. Furthermore, we review viable flux measurement techniques tailored to the sediment-water boundary. We propose that such activities are aimed at regions that intersect the GEOTRACES Science Plan on the basis of seven criteria that may influence TEI fluxes: sediment provenance, composition, organic carbon supply, redox conditions, sedimentation rate, bathymetry and the benthic nepheloid inventory

  15. Estimation of the Magnetic Flux Emergence Rate in the Quiet Sun from Sunrise Data

    NASA Astrophysics Data System (ADS)

    Smitha, H. N.; Anusha, L. S.; Solanki, S. K.; Riethmüller, T. L.

    2017-03-01

    Small-scale internetwork (IN) features are thought to be the major source of fresh magnetic flux in the quiet Sun. During its first science flight in 2009, the balloon-borne observatory Sunrise captured images of the magnetic fields in the quiet Sun at a high spatial resolution. Using these data we measure the rate at which the IN features bring magnetic flux to the solar surface. In a previous paper it was found that the lowest magnetic flux in small-scale features detected using the Sunrise observations is 9 × 1014 Mx. This is nearly an order of magnitude smaller than the smallest fluxes of features detected in observations from the Hinode satellite. In this paper, we compute the flux emergence rate (FER) by accounting for such small fluxes, which was not possible before Sunrise. By tracking the features with fluxes in the range {10}15{--}{10}18 Mx, we measure an FER of 1100 {Mx} {{cm}}-2 {{day}}-1. The smaller features with fluxes ≤slant {10}16 Mx are found to be the dominant contributors to the solar magnetic flux. The FER found here is an order of magnitude higher than the rate from Hinode, obtained with a similar feature tracking technique. A wider comparison with the literature shows, however, that the exact technique of determining the rate of the appearance of new flux can lead to results that differ by up to two orders of magnitude, even when applied to similar data. The causes of this discrepancy are discussed and first qualitative explanations proposed.

  16. Flux quantization on quasicrystalline networks

    SciTech Connect

    Behrooz, A.; Burns, M.J.; Deckman, H.; Levine, D.; Whitehead, B.; Chaikin, P.M.

    1986-07-21

    We have measured the superconducting transition temperature T-italic/sub c-italic/(H) as a function of magnetic field for a network of thin aluminum wires arranged in two quasicrystalline arrays, a Fibonacci sequence and the eightfold-symmetric version of a Penrose tiling. The quasicrystals have two periods whose ratio sigma is irrational and are constructed of two tiles with irrationally related areas. We find a series of dips in deltaT-italic/sub c-italic/(H) corresponding to favorable arrangements of the flux lattice on the quasicrystalline substrate. The largest dips are found at sigma/sup n-italic/ and the dips approach the zero-field transition temperature as n-italic increases.

  17. Triode for Magnetic Flux Quanta

    SciTech Connect

    Vlasko-Vlasov, V. K.; Colauto, F.; Benseman, T.; Rosenmann, D.; Kwok, W. -K.

    2016-11-15

    In an electronic triode, the electron current emanating from the cathode is regulated by the electric potential on a grid between the cathode and the anode. Here we demonstrate a triode for single quantum magnetic field carriers, where the flow of individual magnetic vortices in a superconducting film is regulated by the magnetic potential of striae of soft magnetic strips deposited on the film surface. By rotating an applied in-plane field, the magnetic strip potential can be varied due to changes in the magnetic charges at the strip edges, allowing accelerated or retarded motion of magnetic vortices inside the superconductor. Scaling down our design and reducing the gap width between the magnetic stripes will enable controlled manipulation of individual vortices and creation of single flux quantum circuitry for novel high-speed low-power superconducting electronics.

  18. Triode for Magnetic Flux Quanta

    DOE PAGES

    Vlasko-Vlasov, V. K.; Colauto, F.; Benseman, T.; ...

    2016-11-15

    In an electronic triode, the electron current emanating from the cathode is regulated by the electric potential on a grid between the cathode and the anode. Here we demonstrate a triode for single quantum magnetic field carriers, where the flow of individual magnetic vortices in a superconducting film is regulated by the magnetic potential of striae of soft magnetic strips deposited on the film surface. By rotating an applied in-plane field, the magnetic strip potential can be varied due to changes in the magnetic charges at the strip edges, allowing accelerated or retarded motion of magnetic vortices inside the superconductor.more » Scaling down our design and reducing the gap width between the magnetic stripes will enable controlled manipulation of individual vortices and creation of single flux quantum circuitry for novel high-speed low-power superconducting electronics.« less

  19. Triode for Magnetic Flux Quanta

    NASA Astrophysics Data System (ADS)

    Vlasko-Vlasov, V. K.; Colauto, F.; Benseman, T.; Rosenmann, D.; Kwok, W.-K.

    2016-11-01

    In an electronic triode, the electron current emanating from the cathode is regulated by the electric potential on a grid between the cathode and the anode. Here we demonstrate a triode for single quantum magnetic field carriers, where the flow of individual magnetic vortices in a superconducting film is regulated by the magnetic potential of striae of soft magnetic strips deposited on the film surface. By rotating an applied in-plane field, the magnetic strip potential can be varied due to changes in the magnetic charges at the strip edges, allowing accelerated or retarded motion of magnetic vortices inside the superconductor. Scaling down our design and reducing the gap width between the magnetic stripes will enable controlled manipulation of individual vortices and creation of single flux quantum circuitry for novel high-speed low-power superconducting electronics.

  20. Triode for Magnetic Flux Quanta.

    PubMed

    Vlasko-Vlasov, V K; Colauto, F; Benseman, T; Rosenmann, D; Kwok, W-K

    2016-11-15

    In an electronic triode, the electron current emanating from the cathode is regulated by the electric potential on a grid between the cathode and the anode. Here we demonstrate a triode for single quantum magnetic field carriers, where the flow of individual magnetic vortices in a superconducting film is regulated by the magnetic potential of striae of soft magnetic strips deposited on the film surface. By rotating an applied in-plane field, the magnetic strip potential can be varied due to changes in the magnetic charges at the strip edges, allowing accelerated or retarded motion of magnetic vortices inside the superconductor. Scaling down our design and reducing the gap width between the magnetic stripes will enable controlled manipulation of individual vortices and creation of single flux quantum circuitry for novel high-speed low-power superconducting electronics.

  1. Triode for Magnetic Flux Quanta

    PubMed Central

    Vlasko-Vlasov, V. K.; Colauto, F.; Benseman, T.; Rosenmann, D.; Kwok, W.-K.

    2016-01-01

    In an electronic triode, the electron current emanating from the cathode is regulated by the electric potential on a grid between the cathode and the anode. Here we demonstrate a triode for single quantum magnetic field carriers, where the flow of individual magnetic vortices in a superconducting film is regulated by the magnetic potential of striae of soft magnetic strips deposited on the film surface. By rotating an applied in-plane field, the magnetic strip potential can be varied due to changes in the magnetic charges at the strip edges, allowing accelerated or retarded motion of magnetic vortices inside the superconductor. Scaling down our design and reducing the gap width between the magnetic stripes will enable controlled manipulation of individual vortices and creation of single flux quantum circuitry for novel high-speed low-power superconducting electronics. PMID:27845375

  2. A new flux splitting scheme

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Steffen, Christopher J., Jr.

    1991-01-01

    A new flux splitting scheme is proposed. The scheme is remarkably simple and yet its accuracy rivals and in some cases surpasses that of Roe's solver in the Euler and Navier-Stokes solutions performed in this study. The scheme is robust and converges as fast as the Roe splitting. An approximately defined cell-face advection Mach number is proposed using values from the two straddling cells via associated characteristic speeds. This interface Mach number is then used to determine the upwind extrapolation for the convective quantities. Accordingly, the name of the scheme is coined as Advection Upstream Splitting Method (AUSM). A new pressure splitting is introduced which is shown to behave successfully, yielding much smoother results than other existing pressure splittings. Of particular interest is the supersonic blunt body problem in which the Roe scheme gives anomalous solutions. The AUSM produces correct solutions without difficulty for a wide range of flow conditions as well as grids.

  3. Insects, infestations and nutrient fluxes

    NASA Astrophysics Data System (ADS)

    Michalzik, B.

    2012-04-01

    Forest ecosystems are characterized by a high temporal and spatial variability in the vertical transfer of energy and matter within the canopy and the soil compartment. The mechanisms and controlling factors behind canopy processes and system-internal transfer dynamics are imperfectly understood at the moment. Seasonal flux diversities and inhomogeneities in throughfall composition have been reported from coniferous and deciduous forests, and in most cases leaf leaching has been considered as principle driver for differences in the amount and quality of nutrients and organic compounds (Tukey and Morgan 1963). Since herbivorous insects and the processes they initiate received less attention in past times, ecologists now emphasize the need for linking biological processes occurring in different ecosystem strata to explain rates and variability of nutrient cycling (Bardgett et al. 1998, Wardle et al. 2004). Consequently, herbivore insects in the canopies of forests are increasingly identified to play an important role for the (re)cycling and availability of nutrients, or, more generally, for the functioning of ecosystems not only in outbreak situations but also at endemic (non-outbreak) density levels (Stadler et al. 2001, Hunter et al. 2003). Before, little attention was paid to insect herbivores when quantifying element and energy fluxes through ecosystems, although the numerous and different functions insects fulfill in ecosystems (e.g. as pollinators, herbivores or detritivores) were unanimously recognized (Schowalter 2000). Amongst the reasons for this restraint was the argument that the total biomass of insects tends to be relatively low compared to the biomass of trees or the pool of soil organic matter (Ohmart et al. 1983). A second argument which was put forward to justify the inferior role of insects in nutrient cycling were the supposed low defoliation losses between 5-10% of the annual leaf biomass, or net primary production, due to insect herbivory under

  4. Pyrolytic graphite gauge for measuring heat flux

    NASA Technical Reports Server (NTRS)

    Bunker, Robert C. (Inventor); Ewing, Mark E. (Inventor); Shipley, John L. (Inventor)

    2002-01-01

    A gauge for measuring heat flux, especially heat flux encountered in a high temperature environment, is provided. The gauge includes at least one thermocouple and an anisotropic pyrolytic graphite body that covers at least part of, and optionally encases the thermocouple. Heat flux is incident on the anisotropic pyrolytic graphite body by arranging the gauge so that the gauge surface on which convective and radiative fluxes are incident is perpendicular to the basal planes of the pyrolytic graphite. The conductivity of the pyrolytic graphite permits energy, transferred into the pyrolytic graphite body in the form of heat flux on the incident (or facing) surface, to be quickly distributed through the entire pyrolytic graphite body, resulting in small substantially instantaneous temperature gradients. Temperature changes to the body can thereby be measured by the thermocouple, and reduced to quantify the heat flux incident to the body.

  5. Minkowski vacuum transitions in (nongeometric) flux compactifications

    SciTech Connect

    Herrera-Suarez, Wilberth; Loaiza-Brito, Oscar

    2010-02-15

    In this work we study the generalization of twisted homology to geometric and nongeometric backgrounds. In the process, we describe the necessary conditions to wrap a network of D-branes on twisted cycles. If the cycle is localized in time, we show how by an instantonic brane mediation, some D-branes transform into fluxes on different backgrounds, including nongeometric fluxes. As a consequence, we show that in the case of a IIB six-dimensional torus compactification on a simple orientifold, the flux superpotential is not invariant by this brane-flux transition, allowing the connection among different Minkowski vacuum solutions. For the case in which nongeometric fluxes are turned on, we also discuss some topological restrictions for the transition to occur. In this context, we show that there are some vacuum solutions protected to change by a brane-flux transition.

  6. North Polar Radiative Flux Variability from 2002 Through 2014

    NASA Technical Reports Server (NTRS)

    Rutan, David; Rose, Fred; Doelling, David; Kato, Seiji; Smith, Bill, Jr.

    2017-01-01

    NASA's Clouds and the Earth's Radiant Energy System (CERES) project produces the SYN1Deg data product. SYN1deg provides global, 1deg gridded, hourly estimates of Top of Atmosphere (TOA) (CERES observations and calculations) and atmospheric and surface radiative flux (calculations). Examples of 12 year North Polar averages of some variables are shown to the right. Given recent interest in polar science we focus here on TOA and Surface validation of calculated irradiant fluxes. TOA upward longwave irradiance calculations match the CERES observations well both spatially and temporally with correlations remaining strong through PC 6. Compare SYN1Deg Calculations & Meteorological Teleconnections. TOA reflected shortwave irradiance calculations match the CERES observations well both spatially and temporally with correlations remaining string through PC 7. Comparing SYN1Deg calculations to teleconnection patterns requires expanding the area to 30N for EOF analyses. Correlating the Principal Components of various variables to teleconnection time series indicates which variable is most highly correlated with which teleconnection signal. The tables indicate the Pacific North American Oscillation is most correlated to the OLR EOF 1, and the North American Oscillation is correlated most closely to surface LW flux down EOF 1.

  7. Analysis of metabolic flux using dynamic labelling and metabolic modelling.

    PubMed

    Fernie, A R; Morgan, J A

    2013-09-01

    Metabolic fluxes and the capacity to modulate them are a crucial component of the ability of the plant cell to react to environmental perturbations. Our ability to quantify them and to attain information concerning the regulatory mechanisms that control them is therefore essential to understand and influence metabolic networks. For all but the simplest of flux measurements labelling methods have proven to be the most informative. Both steady-state and dynamic labelling approaches have been adopted in the study of plant metabolism. Here the conceptual basis of these complementary approaches, as well as their historical application in microbial, mammalian and plant sciences, is reviewed, and an update on technical developments in label distribution analyses is provided. This is supported by illustrative cases studies involving the kinetic modelling of secondary metabolism. One issue that is particularly complex in the analysis of plant fluxes is the extensive compartmentation of the plant cell. This problem is discussed from both theoretical and experimental perspectives, and the current approaches used to address it are assessed. Finally, current limitations and future perspectives of kinetic modelling of plant metabolism are discussed.

  8. Scaling Relationships for ELM Diverter Heat Flux on DIII D

    NASA Astrophysics Data System (ADS)

    Peters, E. A.; Makowski, M. A.; Leonard, A. W.

    2015-11-01

    Edge Localized Modes (ELMs) are periodic plasma instabilities that occur during H-mode operation in tokamaks. Left unmitigated, these instabilities result in concentrated particle and heat fluxes at the divertor and stand to cause serious damage to the plasma facing components of tokamaks. The purpose of this research is to find scaling relationships that predict divertor heat flux due to ELMs based on plasma parameters at the time of instability. This will be accomplished by correlating characteristic ELM parameters with corresponding plasma measurements and analyzing the data for trends. One early assessment is the effect of the heat transmission coefficient ? on the in/out asymmetry of the calculated ELM heat fluxes. Using IR camera data, further assessments in this study will continue to emphasize in/out asymmetry in ELMs, as this has important implications for ITER operation. Work supported in part by the US DOE, DE-AC52-07NA27344, DE-FC02-04ER54698, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships Program (SULI).

  9. Dependence of Global Poynting Flux on IMF By

    NASA Astrophysics Data System (ADS)

    Humberset, Beate K.; Gjerloev, Jesper W.

    2014-05-01

    In this study we present the dependence of the global Poynting flux on the IMF By orientation. The amount of energy that enters the near Earth system from the solar wind and IMF interacting with the geomagnetic field is a function of the solar wind speed and pressure and the IMF orientation. All the various published coupling models show that the polarity of the IMF By component does not change the energy input. In contrast the global convection patterns and thus the ionospheric Pedersen currents depends on the IMF By polarity. This apparent contrast between input (from the solar wind) and output (energy dissipating Pedersen currents) raises to the question: To what extend is the global Poynting flux dependent on the IMF By polarity. We have performed a large statistical study using abrupt transitions in the IMF By component (polarity changes) as measured by the ACE spacecraft. The effect of other solar wind parameters such as the solar wind pressure is minimized by selecting events where these are nearly constant. We use electric field distribution from SuperDARN and field-aligned current distributions from AMPERE to calculate the global distribution of the Poynting Flux. We show events as well statistical results to answer the science objective. The study emphasizes the global dynamic behavior of the ionosphere in its response to changes in the external driver (IMF).

  10. Observations of FRC Trapped Flux Lifetime Relative to Its Prolateness

    NASA Astrophysics Data System (ADS)

    Grabowski, Chris; Degnan, James; Domonkos, Matthew; Amdahl, David; Ruden, Edward; Wurden, Glen; Weber, Thomas

    2016-10-01

    The Field-Reversed Configuration Heating Experiment (FRCHX) explored scientific issues associated with HED laboratory plasmas (HEDLPs) and phenomena relevant to magneto-inertial fusion in a closed-field-line plasma. To create the HEDLP conditions, a field-reversed configuration (FRC) of moderate density was formed via reversed-field theta pinch, translated into a solid liner where it was trapped between two magnetic mirrors, and then adiabatically compressed by solid liner implosion. Shortly following formation, the FRCs typically had a separatrix radius of 3 3.5 cm, peak density of 1017 cm-3, and temperature of 200 eV. The lifetime of trapped flux within the plasma was initially 13-16 μs following formation, or 8-11 μs once the FRC settled within the capture region. This was too short to allow complete compression by the solid liner, even when starting implosion before FRC formation. By moving the mirror coils 10 cm further apart, the magnetic well width increased by 6 8 cm, which resulted in an increase in the trapped flux lifetime by 4 5 μs. This presentation describes characteristics of the FRC plasmas prior to and following the lengthening of the capture region. From the literature, conclusions are made linking FRC stability and prolateness to FRC trapped flux lifetime. This work was supported by DOE Office of Fusion Energy Sciences.

  11. STABILITY AND DYNAMICS OF A FLUX ROPE FORMED VIA FLUX EMERGENCE INTO THE SOLAR ATMOSPHERE

    SciTech Connect

    An, J. M.; Magara, T. E-mail: magara@khu.ac.kr

    2013-08-10

    We study the stability and dynamics of a flux rope formed through the emergence of a twisted magnetic flux tube into the solar atmosphere. A three-dimensional magnetohydrodynamic simulation has been performed to investigate several key factors affecting the dynamics of the flux rope. The stability of the flux rope is examined by deriving the decay index of the coronal magnetic field surrounding the flux rope. We investigate a transition between the quasi-static and dynamic states of the flux rope through an analysis of the curvature and scale height of emerging magnetic field. A practical application of this analysis for global eruptions is also considered.

  12. Science teaching in science education

    NASA Astrophysics Data System (ADS)

    Callahan, Brendan E.; Dopico, Eduardo

    2016-06-01

    Reading the interesting article Discerning selective traditions in science education by Per Sund , which is published in this issue of CSSE, allows us to open the discussion on procedures for teaching science today. Clearly there is overlap between the teaching of science and other areas of knowledge. However, we must constantly develop new methods to teach and differentiate between science education and teaching science in response to the changing needs of our students, and we must analyze what role teachers and teacher educators play in both. We must continually examine the methods and concepts involved in developing pedagogical content knowledge in science teachers. Otherwise, the possibility that these routines, based on subjective traditions, prevent emerging processes of educational innovation. Modern science is an enormous field of knowledge in its own right, which is made more expansive when examined within the context of its place in society. We propose the need to design educative interactions around situations that involve science and society. Science education must provide students with all four dimensions of the cognitive process: factual knowledge, conceptual knowledge, procedural knowledge, and metacognitive knowledge. We can observe in classrooms at all levels of education that students understand the concepts better when they have the opportunity to apply the scientific knowledge in a personally relevant way. When students find value in practical exercises and they are provided opportunities to reinterpret their experiences, greater learning gains are achieved. In this sense, a key aspect of educational innovation is the change in teaching methodology. We need new tools to respond to new problems. A shift in teacher education is needed to realize the rewards of situating science questions in a societal context and opening classroom doors to active methodologies in science education to promote meaningful learning through meaningful teaching.

  13. [Basic science and applied science].

    PubMed

    Pérez-Tamayo, R

    2001-01-01

    A lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico's National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at: http://www.insp.mx/salud/index.html

  14. Extra Mass Flux in Fluid Mechanics

    NASA Astrophysics Data System (ADS)

    Ván, Peter; Pavelka, Michal; Grmela, Miroslav

    2017-04-01

    The conditions of existence of extra mass flux in single-component dissipative nonrelativistic fluids are clarified. By considering Galilean invariance, we show that if total mass flux is equal to total momentum density, then mass, momentum, angular momentum and booster (center of mass) are conserved. However, these conservation laws may be fulfilled also by other means. We show an example of weakly nonlocal hydrodynamics where the conservation laws are satisfied as well although the total mass flux is different from momentum density.

  15. Novel thin-film heat flux sensors

    NASA Technical Reports Server (NTRS)

    Bhatt, Hemanshu; Zeller, Mary; Will, Herbert

    1992-01-01

    A new and simpler design for thin-film heat flux sensors for utilization in high heat flux environments is presented. The design of these sensors consists of a planar differential thermopile made up of a number of thermocouple pairs arranged in a circular array, two different thermal resistance layers deposited on the inside and outside junctions of the thermopile and a high emissivity coating. This design has shown good potential for measuring heat fluxes in severe environments of aerospace propulsion systems.

  16. The truth is out there: measured, calculated and modelled benthic fluxes.

    NASA Astrophysics Data System (ADS)

    Pakhomova, Svetlana; Protsenko, Elizaveta

    2016-04-01

    In a modern Earth science there is a great importance of understanding the processes, forming the benthic fluxes as one of element sources or sinks to or from the water body, which affects the elements balance in the water system. There are several ways to assess benthic fluxes and here we try to compare the results obtained by chamber experiments, calculated from porewater distributions and simulated with model. Benthic fluxes of dissolved elements (oxygen, nitrogen species, phosphate, silicate, alkalinity, iron and manganese species) were studied in the Baltic and Black Seas from 2000 to 2005. Fluxes were measured in situ using chamber incubations (Jch) and at the same time sediment cores were collected to assess the porewater distribution at different depths to calculate diffusive fluxes (Jpw). Model study was carried out with benthic-pelagic biogeochemical model BROM (O-N-P-Si-C-S-Mn-Fe redox model). It was applied to simulate biogeochemical structure of the water column and upper sediment and to assess the vertical fluxes (Jmd). By the behaviour at the water-sediment interface all studied elements can be divided into three groups: (1) elements which benthic fluxes are determined by the concentrations gradient only (Si, Mn), (2) elements which fluxes depend on redox conditions in the bottom water (Fe, PO4, NH4), and (3) elements which fluxes are strongly connected with organic matter fate (O2, Alk, NH4). For the first group it was found that measured fluxes are always higher than calculated diffusive fluxes (1.5flux. In this case bioturbation, bioirrigation and advection should be taken into account. For the second group measured fluxes can be both much lower (practically absent) and much higher than calculated diffusive fluxes (0.01

  17. Calibration of High Heat Flux Sensors at NIST

    PubMed Central

    Murthy, A. V.; Tsai, B. K.; Gibson, C. E.

    1997-01-01

    An ongoing program at the National Institute of Standards and Technology (NIST) is aimed at improving and standardizing heat-flux sensor calibration methods. The current calibration needs of U.S. science and industry exceed the current NIST capability of 40 kW/m2 irradiance. In achieving this goal, as well as meeting lower-level non-radiative heat flux calibration needs of science and industry, three different types of calibration facilities currently are under development at NIST: convection, conduction, and radiation. This paper describes the research activities associated with the NIST Radiation Calibration Facility. Two different techniques, transfer and absolute, are presented. The transfer calibration technique employs a transfer standard calibrated with reference to a radiometric standard for calibrating the sensors using a graphite tube blackbody. Plans for an absolute calibration facility include the use of a spherical blackbody and a cooled aperture and sensor-housing assembly to calibrate the sensors in a low convective environment. PMID:27805156

  18. Flux-Level Transit Injection Experiments with NASA Pleiades Supercomputer

    NASA Astrophysics Data System (ADS)

    Li, Jie; Burke, Christopher J.; Catanzarite, Joseph; Seader, Shawn; Haas, Michael R.; Batalha, Natalie; Henze, Christopher; Christiansen, Jessie; Kepler Project, NASA Advanced Supercomputing Division

    2016-06-01

    Flux-Level Transit Injection (FLTI) experiments are executed with NASA's Pleiades supercomputer for the Kepler Mission. The latest release (9.3, January 2016) of the Kepler Science Operations Center Pipeline is used in the FLTI experiments. Their purpose is to validate the Analytic Completeness Model (ACM), which can be computed for all Kepler target stars, thereby enabling exoplanet occurrence rate studies. Pleiades, a facility of NASA's Advanced Supercomputing Division, is one of the world's most powerful supercomputers and represents NASA's state-of-the-art technology. We discuss the details of implementing the FLTI experiments on the Pleiades supercomputer. For example, taking into account that ~16 injections are generated by one core of the Pleiades processors in an hour, the “shallow” FLTI experiment, in which ~2000 injections are required per target star, can be done for 16% of all Kepler target stars in about 200 hours. Stripping down the transit search to bare bones, i.e. only searching adjacent high/low periods at high/low pulse durations, makes the computationally intensive FLTI experiments affordable. The design of the FLTI experiments and the analysis of the resulting data are presented in “Validating an Analytic Completeness Model for Kepler Target Stars Based on Flux-level Transit Injection Experiments” by Catanzarite et al. (#2494058).Kepler was selected as the 10th mission of the Discovery Program. Funding for the Kepler Mission has been provided by the NASA Science Mission Directorate.

  19. Enhanced energy fluxes via phase precession in forced Burgers equation

    NASA Astrophysics Data System (ADS)

    Murray, Brendan; Bustamante, Miguel; Buzzicotti, Michele; Biferale, Luca

    2016-11-01

    We present a study of phase dynamics in the non-linear forced Burgers' equation. We uncover a connection between energy flux across scales and the evolution of triad phase combinations in Fourier space. As this energy is dissipated at small scales, real-space shock structures are associated with entangled correlations amongst the phase precession dynamics and the amplitude evolution of triads in Fourier space. We compute precession frequencies of the triad phases, which show a non-Gaussian distribution with multiple peaks and fat tails, with significant correlation between precession frequencies and amplitude growth. The observed fat tails and non-zero precession frequencies are two key criteria for enhancing energy fluxes via precession resonance. We search for this resonance by varying the forcing strength and frequency and, additionally, by modifying the dimension of the underlying system via fractal Fourier decimation. Supported by COST (European Cooperation in Science and Technology, Action MP1305) and SFI (Science Foundation Ireland, research Grant No. 12/IP/1491).

  20. Quantifying streambed advection and conduction heat fluxes

    NASA Astrophysics Data System (ADS)

    Caissie, Daniel; Luce, Charles H.

    2017-02-01

    Groundwater and accompanying heat fluxes are particularly relevant for aquatic habitats as they influence living conditions both within the river and streambed. This study focuses on the theory and the development of new equations to estimate conduction and advection heat fluxes into and out of the bed, correcting some earlier misunderstandings and adding parameterizations that extend our understanding of timing of heat fluxes. The new heat flux equations are illustrated using Catamaran Brook (New Brunswick, Canada) stream/streambed temperature data. We show important relationships between fluxes when the surface water temperature (1) follows a sinusoidal function superimposed on a steady state condition (constant deep streambed temperature) and (2) when sinusoidal variations in stream temperature at two frequencies (annual and diel) are superimposed. When the stream temperature is used as a prescribed boundary condition, the contribution of bed fluid fluxes to stream temperature occurs through the effects of conductive thermal gradients, not through direct contribution/mixing of cold/warm water. Boundary conditions can be modified, however, to account for direct contribution of cold/warm water (e.g., localized upwelling) and consequences for the conduction heat flux. Equations developed allow for prediction of conductive fluxes to the bed during summer driven by diel and annual temperature fluctuations of the stream water and good agreement was observed between analytic solutions and field data. Results from this study provide a better insight into groundwater and heat fluxes which will ultimately result in better stream temperature models and a better management of fisheries resources.

  1. Organic vapor fluxes through the vadose zone

    SciTech Connect

    Smith, J.A.; Tisdale, A.K.; Cho, H.J.

    1996-10-01

    Volatilization from shallow ground water followed by air-phase transport through the unsaturated zone is a poorly understood process that may be a significant natural remediation mechanism for volatile organic pollutants including chlorinated solvents and gasoline constituents (e.g., benzene, toluene, etc.). To improve understanding of this process, the upward flux of trichloroethene (TCE) vapor through the unsaturated zone above a contaminated, water-table aquifer at Picatinny Arsenal, New Jersey, has been studied under natural conditions over a 12-mo period. Vertical gas-phase diffusion fluxes were determined indirectly by measuring the TCE vapor concentration gradient in the unsaturated zone and using Fick`s Law to calculate the flux. The total gas-phase flux (e.g., the sum of diffusion and advection fluxes) was measured directly with a vertical flux chamber (VFC). In many cases, the upward TCE vapor flux was several orders of magnitude greater than the upward TCE diffusion flux, suggesting that the vertical transport of TCE vapors by gas advection is significant relative to vertical transport by diffusion. The measured total flux of TCE vapor from the subsurface to the atmosphere is approximately 50 kg/yr and is comparable in magnitude to the removal rate of TCE from the aquifer by an existing pump-and-treat system and by discharge into a nearby stream.

  2. Fluxing agent for metal cast joining

    DOEpatents

    Gunkel, Ronald W.; Podey, Larry L.; Meyer, Thomas N.

    2002-11-05

    A method of joining an aluminum cast member to an aluminum component. The method includes the steps of coating a surface of an aluminum component with flux comprising cesium fluoride, placing the flux coated component in a mold, filling the mold with molten aluminum alloy, and allowing the molten aluminum alloy to solidify thereby joining a cast member to the aluminum component. The flux preferably includes aluminum fluoride and alumina. A particularly preferred flux includes about 60 wt. % CsF, about 30 wt. % AlF.sub.3, and about 10 wt. % Al.sub.2 O.sub.3.

  3. Chloride flux out of Yellowstone National Park

    USGS Publications Warehouse

    Norton, D.R.; Friedman, I.

    1985-01-01

    Monitoring of the chloride concentration, electrical conductivity, and discharge was carried out for the four major rivers of Yellowstone National Park from September 1982 to January 1984. Chloride flux out of the Park was determined from the measured values of chloride concentration and discharge. The annual chloride flux from the Park was 5.86 ?? 1010 g. Of this amount 45% was from the Madison River drainage basin, 32% from the Yellowstone River basin, 12% from the Snake River basin, and 11% from the Falls River basin. Of the annual chloride flux from the Yellowstone River drainage basin 36% was attributed to the Yellowstone Lake drainage basin. The geothermal contribution to the chloride flux was determined by subtracting the chloride contribution from rock weathering and atmospheric precipitation and is 94% of the total chloride flux. Calculations of the geothermal chloride flux for each river are given and the implications of an additional chloride flux out of the western Park boundary discussed. An anomalous increase in chloride flux out of the Park was observed for several weeks prior to the Mt. Borah earthquake in Central Idaho on October 28, 1983, reaching a peak value shortly thereafter. It is suggested that the rise in flux was a precursor of the earthquake. The information in this paper provides baseline data against which future changes in the hydrothermal systems can be measured. It also provides measurements related to the thermal contributions from the different drainage basins of the Park. ?? 1985.

  4. Why should autophagic flux be assessed?

    PubMed Central

    Zhang, Xiao-jie; Chen, Sheng; Huang, Kai-xing; Le, Wei-dong

    2013-01-01

    As autophagy is involved in cell growth, survival, development and death, impaired autophagic flux has been linked to a variety of human pathophysiological processes, including neurodegeneration, cancer, myopathy, cardiovascular and immune-mediated disorders. There is a growing need to identify and quantify the status of autophagic flux in different pathological conditions. Given that autophagy is a highly dynamic and complex process that is regulated at multiple steps, it is often assessed accurately. This perspective review article will focus on the autophagic flux defects in different human disorders and update the current methods of monitoring autophagic flux. This knowledge is essential for developing autophagy-related therapeutics for treating the diseases. PMID:23474710

  5. Science Policy: Pangs of Science

    ERIC Educational Resources Information Center

    Handler, Philip

    1978-01-01

    Presented is the prepared text of a public lecture given by the president of the National Academy of Sciences. Dr. Handler attempts to articulate the state of science today. He deals with such issues as nuclear power and genetic engineering. (MDR)

  6. Cognitive Science and Science Education.

    ERIC Educational Resources Information Center

    Carey, Susan

    1986-01-01

    The premise behind the cognitive approach to teaching is that understanding results when new learning is integrated with existing knowledge. But the goal of science instruction is to replace existing ideas with new theories. Current research in science education seeks to resolve these conflicting instructional approaches. (Author/VM)

  7. Science Indicators and Science Priorities.

    ERIC Educational Resources Information Center

    Brooks, Harvey

    1982-01-01

    Discusses science/society interface and difficulties involved in developing realistic science indicators. Topics include: intrinsic vs. extrinsic indicators; four problems society faces as a result of technological activities (toxic chemicals, radioactive wastes, auto safety, cancer); research and development (R&D) priorities; international…

  8. Science Indicators and Science Priorities.

    ERIC Educational Resources Information Center

    Brooks, Harvey

    1982-01-01

    Discusses science/society interface and difficulties involved in developing realistic science indicators. Topics include: intrinsic vs. extrinsic indicators; four problems society faces as a result of technological activities (toxic chemicals, radioactive wastes, auto safety, cancer); research and development (R&D) priorities; international…

  9. Teaching Science. Ripping into Science.

    ERIC Educational Resources Information Center

    Leyden, Michael B.

    1995-01-01

    Describes how one activity can lead students to investigate and understand science concepts. Example provided involves ripping of a newspaper and the resultant discussions on saws, fabric, meat, and newsprint. Suggests that this activity can be a bridge to study in language arts, career education, graphic arts, mathematics, science, and…

  10. Science packages

    NASA Astrophysics Data System (ADS)

    1997-01-01

    Primary science teachers in Scotland have a new updating method at their disposal with the launch of a package of CDi (Compact Discs Interactive) materials developed by the BBC and the Scottish Office. These were a response to the claim that many primary teachers felt they had been inadequately trained in science and lacked the confidence to teach it properly. Consequently they felt the need for more in-service training to equip them with the personal understanding required. The pack contains five disks and a printed user's guide divided up as follows: disk 1 Investigations; disk 2 Developing understanding; disks 3,4,5 Primary Science staff development videos. It was produced by the Scottish Interactive Technology Centre (Moray House Institute) and is available from BBC Education at £149.99 including VAT. Free Internet distribution of science education materials has also begun as part of the Global Schoolhouse (GSH) scheme. The US National Science Teachers' Association (NSTA) and Microsoft Corporation are making available field-tested comprehensive curriculum material including 'Micro-units' on more than 80 topics in biology, chemistry, earth and space science and physics. The latter are the work of the Scope, Sequence and Coordination of High School Science project, which can be found at http://www.gsh.org/NSTA_SSandC/. More information on NSTA can be obtained from its Web site at http://www.nsta.org.

  11. Revolutionary Science

    PubMed Central

    Fang, Ferric C.

    2016-01-01

    ABSTRACT On rare occasions in the history of science, remarkable discoveries transform human society and forever alter mankind’s view of the world. Examples of such discoveries include the heliocentric theory, Newtonian physics, the germ theory of disease, quantum theory, plate tectonics and the discovery that DNA carries genetic information. The science philosopher Thomas Kuhn famously described science as long periods of normality punctuated by times of crisis, when anomalous observations culminate in revolutionary changes that replace one paradigm with another. This essay examines several transformative discoveries in the light of Kuhn’s formulation. We find that each scientific revolution is unique, with disparate origins that may include puzzle solving, serendipity, inspiration, or a convergence of disparate observations. The causes of revolutionary science are varied and lack an obvious common structure. Moreover, it can be difficult to draw a clear distinction between so-called normal and revolutionary science. Revolutionary discoveries often emerge from basic science and are critically dependent on nonrevolutionary research. Revolutionary discoveries may be conceptual or technological in nature, lead to the creation of new fields, and have a lasting impact on many fields in addition to the field from which they emerge. In contrast to political revolutions, scientific revolutions do not necessarily require the destruction of the previous order. For humanity to continue to benefit from revolutionary discoveries, a broad palette of scientific inquiry with a particular emphasis on basic science should be supported. PMID:26933052

  12. Revolutionary Science.

    PubMed

    Casadevall, Arturo; Fang, Ferric C

    2016-03-01

    On rare occasions in the history of science, remarkable discoveries transform human society and forever alter mankind's view of the world. Examples of such discoveries include the heliocentric theory, Newtonian physics, the germ theory of disease, quantum theory, plate tectonics and the discovery that DNA carries genetic information. The science philosopher Thomas Kuhn famously described science as long periods of normality punctuated by times of crisis, when anomalous observations culminate in revolutionary changes that replace one paradigm with another. This essay examines several transformative discoveries in the light of Kuhn's formulation. We find that each scientific revolution is unique, with disparate origins that may include puzzle solving, serendipity, inspiration, or a convergence of disparate observations. The causes of revolutionary science are varied and lack an obvious common structure. Moreover, it can be difficult to draw a clear distinction between so-called normal and revolutionary science. Revolutionary discoveries often emerge from basic science and are critically dependent on nonrevolutionary research. Revolutionary discoveries may be conceptual or technological in nature, lead to the creation of new fields, and have a lasting impact on many fields in addition to the field from which they emerge. In contrast to political revolutions, scientific revolutions do not necessarily require the destruction of the previous order. For humanity to continue to benefit from revolutionary discoveries, a broad palette of scientific inquiry with a particular emphasis on basic science should be supported.

  13. Closing the North American Carbon Budget: Continental Margin Fluxes Matter!

    NASA Astrophysics Data System (ADS)

    Najjar, R.; Benway, H. M.; Siedlecki, S. A.; Boyer, E. W.; Cai, W. J.; Coble, P. G.; Cross, J. N.; Friedrichs, M. A.; Goni, M. A.; Griffith, P. C.; Herrmann, M.; Lohrenz, S. E.; Mathis, J. T.; McKinley, G. A.; Pilskaln, C. H.; Smith, R. A.; Alin, S. R.

    2015-12-01

    Despite their relatively small surface area, continental margins are regions of intense carbon and nutrient processing, export and exchange, and thus have a significant impact on global biogeochemical cycles. In response to recommendations for regional synthesis and carbon budget estimation for North America put forth in the North American Continental Margins workshop report (Hales et al., 2008), the Ocean Carbon and Biogeochemistry (OCB) Program and North American Carbon Program (NACP) began coordinating a series of collaborative, interdisciplinary Coastal CARbon Synthesis (CCARS) research activities in five coastal regions of North America (Atlantic Coast, Pacific Coast, Gulf of Mexico, Arctic, Laurentian Great Lakes) to improve quantitative assessments of the North American carbon budget. CCARS workshops and collaborative research activities have resulted in the development of regional coastal carbon budgets based on recent literature- and model-based estimates of major carbon fluxes with estimated uncertainties. Numerous peer-reviewed papers and presentations by involved researchers have highlighted these findings and provided more in-depth analyses of processes underlying key carbon fluxes in continental margin systems. As a culminating outcome of these synthesis efforts, a comprehensive science plan highlights key knowledge gaps identified during this synthesis and provides explicit guidance on future research and observing priorities in continental margin systems to help inform future agency investments in continental margins research. This presentation will provide an overview of regional and flux-based (terrestrial inputs, biological transformations, sedimentary processes, atmospheric exchanges, lateral carbon transport) synthesis findings and key recommendations in the science plan, as well as a set of overarching priorities and recommendations on observations and modeling approaches for continental margin systems.

  14. Science Instructors' Views of Science and Nature of Science

    ERIC Educational Resources Information Center

    Karakas, Mehmet

    2011-01-01

    This qualitative study examined how college science faculty who teach introductory level undergraduate science courses including the fields of chemistry, biology, physics, and earth science, understand and define science and nature of science (NOS). Participants were seventeen science instructors from five different institutions in the…

  15. Earth Science

    NASA Image and Video Library

    1996-01-31

    The Near Earth Asteroid Rendezvous (NEAR) spacecraft embarks on a journey that will culminate in a close encounter with an asteroid. The launch of NEAR inaugurates NASA's irnovative Discovery program of small-scale planetary missions with rapid, lower-cost development cycles and focused science objectives. NEAR will rendezvous in 1999 with the asteroid 433 Eros to begin the first long-term, close-up look at an asteroid's surface composition and physical properties. NEAR's science payload includes an x-ray/gamma ray spectrometer, an near-infrared spectrograph, a laser rangefinder, a magnetometer, a radio science experiment and a multi-spectral imager.

  16. Self-organization in magnetic flux ropes

    NASA Astrophysics Data System (ADS)

    Lukin, Vyacheslav S.

    2014-06-01

    This cross-disciplinary special issue on 'Self-organization in magnetic flux ropes' follows in the footsteps of another collection of manuscripts dedicated to the subject of magnetic flux ropes, a volume on 'Physics of magnetic flux ropes' published in the American Geophysical Union's Geophysical Monograph Series in 1990 [1]. Twenty-four years later, this special issue, composed of invited original contributions highlighting ongoing research on the physics of magnetic flux ropes in astrophysical, space and laboratory plasmas, can be considered an update on our state of understanding of this fundamental constituent of any magnetized plasma. Furthermore, by inviting contributions from research groups focused on the study of the origins and properties of magnetic flux ropes in a variety of different environments, we have attempted to underline both the diversity of and the commonalities among magnetic flux ropes throughout the solar system and, indeed, the universe. So, what is a magnetic flux rope? The answer will undoubtedly depend on whom you ask. A flux rope can be as narrow as a few Larmor radii and as wide as the Sun (see, e.g., the contributions by Heli Hietala et al and by Angelous Vourlidas). As described below by Ward Manchester IV et al , they can stretch from the Sun to the Earth in the form of interplanetary coronal mass ejections. Or, as in the Swarthmore Spheromak Experiment described by David Schaffner et al , they can fit into a meter-long laboratory device tended by college students. They can be helical and line-tied (see, e.g., Walter Gekelman et al or J Sears et al ), or toroidal and periodic (see, e.g., John O'Bryan et al or Philippa Browning et al ). They can form in the low plasma beta environment of the solar corona (Tibor Török et al ), the order unity beta plasmas of the solar wind (Stefan Eriksson et al ) and the plasma pressure dominated stellar convection zones (Nicholas Nelson and Mark Miesch). In this special issue, Setthivoine You

  17. Sediment Diagenesis and Benthic Flux

    NASA Astrophysics Data System (ADS)

    Emerson, S.; Hedges, J.

    2003-12-01

    Chemical reactions in marine sediments and the resulting fluxes across the sediment-water interface influence the global carbon cycle and the pH of the sea and affect the abundance of CaCO3 and opal-forming plankton in the ocean. On very long timescales these diagenetic reactions control carbon burial in sedimentary rocks and the oxygen content of the atmosphere. Sedimentary deposits that remain after diagenesis are the geochemical artifacts used for interpreting past changes in ocean circulation, biogeochemical cycles, and climate. This chapter is about the processes of diagenesis and burial of the chemical elements that make up the bulk of the particulate matter that reaches the seafloor (organic matter, CaCO3, SiO2, Fe, Mn, and aluminosilicates).Understanding of sediment diagenesis and benthic fluxes has evolved with advances in both experimental methods and modeling. Measurements of chemical concentrations in sediments, their associated pore waters and fluxes at the sediment-water interface have been used to identify the most important reactions. Because transport in pore waters is usually by molecular diffusion, this medium is conducive to interpretation by models of heterogeneous chemical equilibrium and kinetics. Large chemical changes and manageable transport mechanisms have led to elegant models of sediment diagenesis and great advances in understanding of diagenetic processes.We shall see, though, that the environment does not yield totally to simple models of chemical equilibrium and chemical kinetics, and laboratory determined constants often cannot explain the field observations. For example, organic matter degradation rate constants determined from modeling are so variable that there are essentially no constraints on these values from laboratory experiments. In addition, reaction rates of CaCO3 and opal dissolution determined from modeling pore waters usually cannot be reproduced in laboratory experiments of these reactions. The inability to

  18. Photometric Analysis in the Kepler Science Operations Center Pipeline

    NASA Technical Reports Server (NTRS)

    Twicken, Joseph D.; Clarke, Bruce D.; Bryson, Stephen T.; Tenenbaum, Peter; Wu, Hayley; Jenkins, Jon M.; Girouard, Forrest; Klaus, Todd C.

    2010-01-01

    We describe the Photometric Analysis (PA) software component and its context in the Kepler Science Operations Center (SOC) pipeline. The primary tasks of this module are to compute the photometric flux and photocenters (centroids) for over 160,000 long cadence (thirty minute) and 512 short cadence (one minute) stellar targets from the calibrated pixels in their respective apertures. We discuss the science algorithms for long and short cadence PA: cosmic ray cleaning; background estimation and removal; aperture photometry; and flux-weighted centroiding. We discuss the end-to-end propagation of uncertainties for the science algorithms. Finally, we present examples of photometric apertures, raw flux light curves, and centroid time series from Kepler flight data. PA light curves, centroid time series, and barycentric timestamp corrections are exported to the Multi-mission Archive at Space Telescope [Science Institute] (MAST) and are made available to the general public in accordance with the NASA/Kepler data release policy.

  19. The Flux Calibration of Gaia

    NASA Astrophysics Data System (ADS)

    Pancino, E.

    2016-05-01

    The Gaia mission is described, along with its scientific potential and its updated science perfomances. Although it is often described as a self-calibrated mission, Gaia still needs to tie part of its measurements to external scales (or to convert them in physical units). A detailed decription of the Gaia spectro-photometric standard stars survey is provided, along with a short description of the Gaia calibration model. The model requires a grid of approximately 200 stars, calibrated to a few percent with respect to Vega, and covering different spectral types.

  20. Comparison of the high temperature heat flux sensor to traditional heat flux gages under high heat flux conditions.

    SciTech Connect

    Blanchat, Thomas K.; Hanks, Charles R.

    2013-04-01

    Four types of heat flux gages (Gardon, Schmidt-Boelter, Directional Flame Temperature, and High Temperature Heat Flux Sensor) were assessed and compared under flux conditions ranging between 100-1000 kW/m2, such as those seen in hydrocarbon fire or propellant fire conditions. Short duration step and pulse boundary conditions were imposed using a six-panel cylindrical array of high-temperature tungsten lamps. Overall, agreement between all gages was acceptable for the pulse tests and also for the step tests. However, repeated tests with the HTHFS with relatively long durations at temperatures approaching 1000ÀC showed a substantial decrease (10-25%) in heat flux subsequent to the initial test, likely due to the mounting technique. New HTHFS gages have been ordered to allow additional tests to determine the cause of the flux reduction.

  1. Aerosol properties derived from spectral actinic flux measurements

    NASA Astrophysics Data System (ADS)

    Stark, H.; Schmidt, K. S.; Pilewskie, P.; Cozic, J.; Wollny, A. G.; Brock, C. A.; Baynard, T.; Lack, D.; Parrish, D. D.; Fehsenfeld, F. C.

    2008-12-01

    Measurement of aerosol properties is very important for understanding climate change. Aerosol optical properties influence solar radiation throughout the troposphere. According to the Working Group I report of the intergovernmental panel for climate change [IPCC, 2007], aerosols have a direct radiative forcing of - 0.5±0.4 W/m2 with a medium to low level of scientific understanding. This relatively large uncertainty indicates the need for more frequent and precise measurements of aerosol properties. We will show how actinic flux measurements can be used to derive important optical aerosol parameters such as aerosol optical thickness and depth, surface albedo, angstrom exponent, radiative forcing by clouds and aerosols, aerosol extinction, and others. The instrument used for this study is a combination of two spectroradiometers measuring actinic flux in the ultraviolet and visible radiation range from 280 to 690 nm with a resolution of 1 nm. Actinic flux is measured as the radiation incident on a spherical surface with sensitivity independent of direction. In contrast, irradiance is measured as the radiation incident on a plane surface, which depends on the cosine of the incident angle. Our goal is to assess the capabilities of using spectral actinic flux measurements to derive various aerosol properties. Here we will compare 1) actinic flux measurements to irradiance measurements from the spectral solar flux radiometer (SSFR), 2) derived aerosol size distributions with measurements from a white light optical particle counter (WLOPC) and ultra high sensitivity aerosol size spectrometer (UHSAS), and 3) derived aerosol optical extinction with measurements from a cavity ringdown aerosol extinction spectrometer (CRD-AES). These comparisons will utilize data from three recent field campaigns over New England and the Atlantic Ocean (ICARTT 2004), Texas and the Gulf of Mexico during (TexAQS/GoMACCS 2006), and Alaska and the Arctic Ocean (ARCPAC 2008) when the instruments

  2. Magnetic Flux Compression in Plasmas

    NASA Astrophysics Data System (ADS)

    Velikovich, A. L.

    2012-10-01

    Magnetic flux compression (MFC) as a method for producing ultra-high pulsed magnetic fields had been originated in the 1950s by Sakharov et al. at Arzamas in the USSR (now VNIIEF, Russia) and by Fowler et al. at Los Alamos in the US. The highest magnetic field produced by explosively driven MFC generator, 28 MG, was reported by Boyko et al. of VNIIEF. The idea of using MFC to increase the magnetic field in a magnetically confined plasma to 3-10 MG, relaxing the strict requirements on the plasma density and Lawson time, gave rise to the research area known as MTF in the US and MAGO in Russia. To make a difference in ICF, a magnetic field of ˜100 MG should be generated via MFC by a plasma liner as a part of the capsule compression scenario on a laser or pulsed power facility. This approach was first suggested in mid-1980s by Liberman and Velikovich in the USSR and Felber in the US. It has not been obvious from the start that it could work at all, given that so many mechanisms exist for anomalously fast penetration of magnetic field through plasma. And yet, many experiments stimulated by this proposal since 1986, mostly using pulsed-power drivers, demonstrated reasonably good flux compression up to ˜42 MG, although diagnostics of magnetic fields of such magnitude in HED plasmas is still problematic. The new interest of MFC in plasmas emerged with the advancement of new drivers, diagnostic methods and simulation tools. Experiments on MFC in a deuterium plasma filling a cylindrical plastic liner imploded by OMEGA laser beam led by Knauer, Betti et al. at LLE produced peak fields of 36 MG. The novel MagLIF approach to low-cost, high-efficiency ICF pursued by Herrmann, Slutz, Vesey et al. at Sandia involves pulsed-power-driven MFC to a peak field of ˜130 MG in a DT plasma. A review of the progress, current status and future prospects of MFC in plasmas is presented.

  3. Dual Active Surface Heat Flux Gage Probe

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Kolodziej, Paul

    1995-01-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  4. Dual active surface heat flux gage probe

    NASA Astrophysics Data System (ADS)

    Liebert, Curt H.; Kolodziej, Paul

    1995-02-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  5. FiatFlux--a software for metabolic flux analysis from 13C-glucose experiments.

    PubMed

    Zamboni, Nicola; Fischer, Eliane; Sauer, Uwe

    2005-08-25

    Quantitative knowledge of intracellular fluxes is important for a comprehensive characterization of metabolic networks and their functional operation. In contrast to direct assessment of metabolite concentrations, in vivo metabolite fluxes must be inferred indirectly from measurable quantities in 13C experiments. The required experience, the complicated network models, large and heterogeneous data sets, and the time-consuming set-up of highly controlled experimental conditions largely restricted metabolic flux analysis to few expert groups. A conceptual simplification of flux analysis is the analytical determination of metabolic flux ratios exclusively from MS data, which can then be used in a second step to estimate absolute in vivo fluxes. Here we describe the user-friendly software package FiatFlux that supports flux analysis for non-expert users. In the first module, ratios of converging fluxes are automatically calculated from GC-MS-detected 13C-pattern in protein-bound amino acids. Predefined fragmentation patterns are automatically identified and appropriate statistical data treatment is based on the comparison of redundant information in the MS spectra. In the second module, absolute intracellular fluxes may be calculated by a 13C-constrained flux balancing procedure that combines experimentally determined fluxes in and out of the cell and the above flux ratios. The software is preconfigured to derive flux ratios and absolute in vivo fluxes from [1-13C] and [U-13C]glucose experiments and GC-MS analysis of amino acids for a variety of microorganisms. FiatFlux is an intuitive tool for quantitative investigations of intracellular metabolism by users that are not familiar with numerical methods or isotopic tracer experiments. The aim of this open source software is to enable non-specialists to adapt the software to their specific scientific interests, including other 13C-substrates, labeling mixtures, and organisms.

  6. Forensic Science.

    ERIC Educational Resources Information Center

    Brettell, T. A.; Saferstein, R.

    1989-01-01

    Presents a review of articles appealing to forensic practitioners. Topics include: drugs and poisons, forensic biochemistry, and trace evidence. Lists noteworthy books published on forensic science topics since 1986. (MVL)

  7. Forensic Science

    ERIC Educational Resources Information Center

    Cobb, P. G. W.

    1973-01-01

    Summarizes the type of work carried out by forensic chemists and the minimum qualification needed for appointment. Indicates that there are eight Home Office regional forensic science laboratories in addition to the Central Research Establishment at Aldermaston. (CC)

  8. Overnight Science.

    ERIC Educational Resources Information Center

    Smith, Nancy N.; Stahl, Robert J.

    1981-01-01

    Outlines objectives for an elementary science camping program and summarizes general operational procedures. Campsite activities related to such topics as microorganisms, eye and sight, nature trails, bees, carpentry, and astronomy are described. (DS)

  9. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1987

    1987-01-01

    Describes 20 teaching activities and experiments appropriate for use with various secondary school science classes. Instructional activities include the study of catalase, raising bees, a game about equilibrium, spectrometers, lead iodide, resonance, graphing, and electromagnetic waves. (TW)

  10. Science Notes.

    ERIC Educational Resources Information Center

    Thurman, Shirley; And Others

    1988-01-01

    Describes 36 science activities. Topics include: osmosis, fermentation, anhydrobiotic organisms, breathing monitors, trypsin, weeds, amyloplasts, electrolysis, polarimeters, ethene ripening of fruit, colorimetry, diffusion, redox reactions, equilibria, acid-base relationships, electricity, power, resonance, measurement, parallax, amplifiers,…

  11. Science Notes.

    ERIC Educational Resources Information Center

    Thurman, Shirley; And Others

    1988-01-01

    Describes 36 science activities. Topics include: osmosis, fermentation, anhydrobiotic organisms, breathing monitors, trypsin, weeds, amyloplasts, electrolysis, polarimeters, ethene ripening of fruit, colorimetry, diffusion, redox reactions, equilibria, acid-base relationships, electricity, power, resonance, measurement, parallax, amplifiers,…

  12. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1989

    1989-01-01

    Twenty-two activities are presented. Topics include: acid rain, microcomputers, fish farming, school-industry research projects, enzymes, equilibrium, assessment, science equipment, logic, Archimedes principle, electronics, optics, and statistics. (CW)

  13. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1987

    1987-01-01

    Describes 20 teaching activities and experiments appropriate for use with various secondary school science classes. Instructional activities include the study of catalase, raising bees, a game about equilibrium, spectrometers, lead iodide, resonance, graphing, and electromagnetic waves. (TW)

  14. Overnight Science.

    ERIC Educational Resources Information Center

    Smith, Nancy N.; Stahl, Robert J.

    1981-01-01

    Outlines objectives for an elementary science camping program and summarizes general operational procedures. Campsite activities related to such topics as microorganisms, eye and sight, nature trails, bees, carpentry, and astronomy are described. (DS)

  15. Scuba Science.

    ERIC Educational Resources Information Center

    Glickstein, Neil

    2000-01-01

    Introduces an integrated unit on scuba science. Studies oxygen in kinetic theory, Boyle's law, Charles's law, Dalton's law, human circulatory and respiratory systems, and diving dangers such as decompression sickness. (YDS)

  16. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1987

    1987-01-01

    This section of the journal includes several short notes on science activities and materials for secondary schools. Activities and materials are included that relate to biology, microbiology, microcomputers, chemistry, and physics. (RH)

  17. Communicating science

    USGS Publications Warehouse

    Farris, Gaye S.

    2005-01-01

    For science to have an impact, it must be communicated and easily accessible. The USGS National Wetlands Research Center communicates its research findings through several ways: publishing, the Web, the library, and education and outreach.

  18. Science Facilities.

    ERIC Educational Resources Information Center

    Biehle, James T.

    2002-01-01

    Describes how schools in Carroll County, Maryland; Toronto, Ontario; Durham, North Carolina; Englewood, Colorado; and Troy, New York, are renovating their vocational areas for inquiry-based, hands-on science learning. Includes sample floor plans and photographs. (EV)

  19. Scuba Science.

    ERIC Educational Resources Information Center

    Glickstein, Neil

    2000-01-01

    Introduces an integrated unit on scuba science. Studies oxygen in kinetic theory, Boyle's law, Charles's law, Dalton's law, human circulatory and respiratory systems, and diving dangers such as decompression sickness. (YDS)

  20. Science Weekly.

    ERIC Educational Resources Information Center

    Science and Children, 1986

    1986-01-01

    Reviews the space classroom that would have been conducted by Christa McAuliffe during the space shuttle flight. Includes lab activities, word puzzles, vocabulary lists, and graph reading exercises for elementary science students. (ML)

  1. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1985

    1985-01-01

    Presents 23 experiments, activities, field projects and computer programs in the biological and physical sciences. Instructional procedures, experimental designs, materials, and background information are suggested. Topics include fluid mechanics, electricity, crystals, arthropods, limpets, acid neutralization, and software evaluation. (ML)

  2. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1985

    1985-01-01

    Presents 23 experiments, activities, field projects and computer programs in the biological and physical sciences. Instructional procedures, experimental designs, materials, and background information are suggested. Topics include fluid mechanics, electricity, crystals, arthropods, limpets, acid neutralization, and software evaluation. (ML)

  3. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Included are 30 science activities that include computer monitoring, fieldwork, enzyme activity, pH, drugs, calorimeters, Raoult's Law, food content, solubility, electrochemistry, titration, physical properties of materials, gel filtration, energy, concepts in physics, and electricity. (KR)

  4. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1989

    1989-01-01

    Twenty-two activities are presented. Topics include: acid rain, microcomputers, fish farming, school-industry research projects, enzymes, equilibrium, assessment, science equipment, logic, Archimedes principle, electronics, optics, and statistics. (CW)

  5. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Included are 30 science activities that include computer monitoring, fieldwork, enzyme activity, pH, drugs, calorimeters, Raoult's Law, food content, solubility, electrochemistry, titration, physical properties of materials, gel filtration, energy, concepts in physics, and electricity. (KR)

  6. Forensic Science

    ERIC Educational Resources Information Center

    Cobb, P. G. W.

    1973-01-01

    Summarizes the type of work carried out by forensic chemists and the minimum qualification needed for appointment. Indicates that there are eight Home Office regional forensic science laboratories in addition to the Central Research Establishment at Aldermaston. (CC)

  7. Science Topics

    EPA Pesticide Factsheets

    EPA is one of the world’s leading environmental and human health research organizations. Science provides the foundation for Agency policies, actions, and decisions made on behalf of the American people.

  8. Science Weekly.

    ERIC Educational Resources Information Center

    Science and Children, 1986

    1986-01-01

    Reviews the space classroom that would have been conducted by Christa McAuliffe during the space shuttle flight. Includes lab activities, word puzzles, vocabulary lists, and graph reading exercises for elementary science students. (ML)

  9. Forensic Science.

    ERIC Educational Resources Information Center

    Brettell, T. A.; Saferstein, R.

    1989-01-01

    Presents a review of articles appealing to forensic practitioners. Topics include: drugs and poisons, forensic biochemistry, and trace evidence. Lists noteworthy books published on forensic science topics since 1986. (MVL)

  10. Citizen Science

    EPA Pesticide Factsheets

    Citizen Science is a fast-growing field in which scientific investigations are conducted by volunteers, which have been successful in expanding scientific knowledge, raising environmental awareness, and leveraging change.

  11. Dismal Science

    PubMed Central

    Evans, Robert G.

    2009-01-01

    “No prediction, no science.” By this standard, the past year has not been kind to the pretensions of “economic science,” Nobel prizes notwithstanding. The issue is more than semantic. As Neil Postman (1992) pointed out, sciences study natural processes that repeat themselves under constant conditions. The social disciplines study practices of human communities that are embedded in history. There are no constant conditions; it is impossible to step into the same river twice (Heraclitus). “Physics envy” has led mainstream economic theorists to attempt to understand their discipline through methods and models borrowed from the natural sciences. (By unfortunate coincidence, these have reinforced a certain class of ideological preconceptions and associated economic interests.) Today the results of this methodological mismatch speak for themselves. PMID:20436803

  12. Saturday Science

    ERIC Educational Resources Information Center

    Shugart, Cecil G.

    1976-01-01

    Describes the organization of demonstration oriented seminars in which the physics of toys, music, sports and other topics are investigated. Reports that this university based service has increased high school physics and science fair enrollments. (CP)

  13. Science Coalition

    NASA Astrophysics Data System (ADS)

    The National Coalition of Science and Technology (NCST) has elected S. Thomas Moser, of the international accounting firm Peat Marwick, to their board of advisors. Moser is the national director of Marwick's high-technology practice.NCST, based in Washington, D.C., is a broad-based science and technology advocacy organization that seeks to bridge the political interests of the scientific and academic research community with the business community.

  14. Science project

    NASA Image and Video Library

    2012-08-23

    Once tethered in place in Gulf Coast waters, a DRIFTER sensor device is able to transmit valuable information about water temperature and conductivity. The Applied Science and Technology Project Office at Stennis Space Center designed the DRIFTER as an inexpensive device that can be used for science projects in local schools. Two of the devices, deployed in coastal waters, survived Hurricane Isaac, continuing to transmit valuable data regarding the storm.

  15. Pharmacologic vitreodynamics and molecular flux.

    PubMed

    Goldenberg, David T; Trese, Michael T

    2009-01-01

    Several enzymatic agents, such as autologous plasmin enzyme and recombinant microplasmin, are able to cause vitreous liquefaction and a complete posterior vitreous detachment (PVD). Advancements in research have helped to explain the complex interactions that occur in the vitreous cavity after a PVD is created. The development of a PVD is a dynamic process that is thought to have a larger impact on the vitreous cavity milieu than just a separation of the posterior cortical vitreous from the retina. Pharmacologic vitreodynamics attempts to explain the mechanical and biochemical changes that occur at the vitreoretinal junction after a PVD is formed. The flow of molecules into and out of the vitreous cavity and across the vitreoretinal junction is thought to be influenced by the presence or absence of a PVD. A microplasmin-induced PVD has been shown to alter the vitreous levels of several molecules, and a PVD may have a protective role in multiple diseases. Significant progress has been made in the field of pharmacologic vitreodynamics. As we improve our understanding of the molecular flux in the vitreous cavity, pharmacologic vitreodynamics will likely become more important as it may allow for improved manipulation of intravitreal molecules.

  16. Pulmonary transvascular flux of transferrin

    SciTech Connect

    Cooper, J.A.; Malik, A.B. )

    1989-11-01

    We compared the pulmonary transvascular fluxes of transferrin and albumin in the intact sheep lung. Anesthetized sheep were prepared with lung lymph fistulas. The vascular blood pool was marked with {sup 99m}Tc-erythrocytes, autologous transferrin was labeled with {sup 113m}In, and albumin was labeled with {sup 125}I. Samples of blood, plasma, lymph, and lung were obtained up to 180 min after tracer infusion. Lymph tissue radioactivities were corrected for the intravascular component and expressed as extravascular-to-plasma concentration ratios. Clearance of transferrin and albumin from the plasma space followed a two-compartment model. The clearance rate constant was 2.1 {plus minus} 0.1 x 10(-3) min for albumin and 2.4 {plus minus} 0.1 x 10(-3) min for transferrin (P less than 0.05). Lymph-to-plasma ratios for albumin and transferrin were not different. However, the extravascular-to-plasma ratio for albumin was greater than transferrin (P less than 0.05). The lymph and lung data were deconvoluted for the plasma input function and fit to a two-compartment model. The results indicate that albumin and transferrin have similar permeabilities across the vascular barrier but have different pulmonary circulation to lymph kinetics because the extravascular volume of distribution of albumin is greater than transferrin.

  17. Extraterrestrial high energy neutrino fluxes

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1979-01-01

    Using the most recent cosmic ray spectra up to 2x10 to the 20th power eV, production spectra of high energy neutrinos from cosmic ray interactions with interstellar gas and extragalactic interactions of ultrahigh energy cosmic rays with 3K universal background photons are presented and discussed. Estimates of the fluxes from cosmic diffuse sources and the nearby quasar 3C273 are made using the generic relationship between secondary neutrinos and gammas and using recent gamma ray satellite data. These gamma ray data provide important upper limits on cosmological neutrinos. Quantitative estimates of the observability of high energy neutrinos from the inner galaxy and 3C273 above atmospheric background for a DUMAND type detector are discussed in the context of the Weinberg-Salam model with sq sin theta omega = 0.2 and including the atmospheric background from the decay of charmed mesons. Constraints on cosmological high energy neutrino production models are also discussed. It appears that important high energy neutrino astronomy may be possible with DUMAND, but very long observing times are required.

  18. Fast flux module detection using matroid theory.

    PubMed

    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.

  19. The minimum flux corona; theory or concept

    NASA Technical Reports Server (NTRS)

    Underwood, J. H.; Antiochos, S. K.

    1980-01-01

    The reply to the criticisms of the minimum flux theory is discussed. These criticisms are correct in substance, as well as in detail. Counter arguments that the minimum flux corona theory is untenable, because of errors in its formulation, are presented.

  20. AmeriFlux US-Brw Barrow

    DOE Data Explorer

    Oechel, Walt [San Diego State University; Zona, Donatella [San Diego State University

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Brw Barrow. Site Description - The local landscape surrounding the Barrow site has a history absent of any disturbances. The terrain was not heavily glaciated during the last period of glaciation. The vegetation is mature in an unmanaged and undisturbed Arctic tundra.

  1. AmeriFlux US-Dia Diablo

    SciTech Connect

    Wharton, Sonia

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Dia Diablo. Site Description - The site is on land owned by Lawrence Livermore National Laboratory (Site 300) and has no grazing or management history since the 1950's except for summer-time burning of selected acres for fire management (not included in the tower footprint).

  2. AmeriFlux US-Ivo Ivotuk

    DOE Data Explorer

    Oechel, Walter [San Diego State University; Zona, Donatella [San Diego State University

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ivo Ivotuk. Site Description - This site is 300 km south of Barrow and is located at the foothill of the Brooks Range and is classified as tussock sedge, dwarf-shrub, moss tundra.

  3. Surface Flux Modeling for Air Quality Applications

    EPA Science Inventory

    For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic c...

  4. Metabolic flux estimation in mammalian cell cultures.

    PubMed

    Goudar, Chetan T; Biener, Richard K; Piret, James M; Konstantinov, Konstantin B

    2014-01-01

    Metabolic flux analysis with its ability to quantify cellular metabolism is an attractive tool for accelerating cell line selection, medium optimization, and other bioprocess development activities. In the stoichiometric flux estimation approach, unknown fluxes are determined using intracellular metabolite mass balance expressions and measured extracellular rates. The simplicity of the stoichiometric approach extends its application to most cell culture systems, and the steps involved in metabolic flux estimation by the stoichiometric method are presented in detail in this chapter. Specifically, overdetermined systems are analyzed since the extra measurements can be used to check for gross measurement errors and system consistency. Cell-specific rates comprise the input data for flux estimation, and the logistic modeling approach is described for robust-specific rate estimation in batch and fed-batch systems. A simplified network of mammalian cell metabolism is used to illustrate the flux estimation procedure, and the steps leading up the consistency index determination are presented. If gross measurement errors are detected, a technique for determining the source of gross measurement error is also described. A computer program that performs most of the calculation described in this chapter is presented, and references to flux estimation software are provided. The procedure presented in this chapter should enable rapid metabolic flux estimation in any mammalian cell bioreaction network by the stoichiometric approach.

  5. Neutrino flux predictions for cross section measurements

    SciTech Connect

    Hartz, Mark

    2015-05-15

    Experiments that measure neutrino interaction cross sections using accelerator neutrino sources require a prediction of the neutrino flux to extract the interaction cross section from the measured neutrino interaction rate. This article summarizes methods of estimating the neutrino flux using in-situ and ex-situ measurements. The application of these methods by current and recent experiments is discussed.

  6. Surface Flux Modeling for Air Quality Applications

    EPA Science Inventory

    For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic c...

  7. Flux Noise in a Superconducting Transmission Line

    NASA Astrophysics Data System (ADS)

    Vasko, F. T.

    2017-08-01

    We study a superconducting transmission line (TL) formed by distributed L C oscillators and excited by external magnetic fluxes which are aroused from random magnetization (A ) placed in substrate or (B ) distributed at interfaces of a two-wire TL. The low-frequency dynamics of a random magnetic field is described based on the diffusion Langevin equation with a short-range source caused by (a ) a random amplitude or (b ) the gradient of magnetization. For a TL modeled as a two-port network with open and shorted ends, the effective magnetic flux at the open end has nonlocal dependency on noise distribution along the TL. The flux-flux correlation function is evaluated and analyzed for the regimes (A a ), (A b ), (B a ), and (B b ). Essential frequency dispersion takes place around the inverse diffusion time of random flux along the TL. Typically, noise effect increases with size faster than the area of the TL. The flux-flux correlator can be verified both via the population relaxation rate of the qubit, which is formed by the Josephson junction shunted by the TL with flux noises, and via random voltage at the open end of the TL.

  8. Investigating the Dynamics of Canonical Flux Tubes

    NASA Astrophysics Data System (ADS)

    von der Linden, Jens; Carroll, Evan; Kamikawa, Yu; Lavine, Eric; Vereen, Keon; You, Setthivoine

    2013-10-01

    Canonical flux tubes are defined by tracing areas of constant magnetic and fluid vorticity flux. This poster will present the theory for canonical flux tubes and current progress in the construction of an experiment designed to observe their evolution. In the zero flow limit, canonical flux tubes are magnetic flux tubes, but in full form, present the distinct advantage of reconciling two-fluid plasma dynamics with familiar concepts of helicity, twists and linkages. The experiment and the DCON code will be used to investigate a new MHD stability criterion for sausage and kink modes in screw pinches that has been generalized to magnetic flux tubes with skin and core currents. Camera images and a 3D array of ˙ B probes will measure tube aspect-ratio and ratio of current-to-magnetic flux, respectively, to trace these flux tube parameters in a stability space. The experiment's triple electrode planar gun is designed to generate azimuthal and axial flows. These diagnostics together with a 3D vector tomographic reconstruction of ion Doppler spectroscopy will be used to verify the theory of canonical helicity transport. This work was sponsored in part by the US DOE Grant DE-SC0010340.

  9. METHOD AND FLUX COMPOSITION FOR TREATING URANIUM

    DOEpatents

    Foote, F.

    1958-08-23

    ABS>A flux composition is described fer use with molten uranium or uranium alloys. The flux consists of about 46 weight per cent calcium fiuoride, 46 weight per cent magnesium fluoride and about 8 weight per cent of uranium tetrafiuoride.

  10. Heat flux viscosity in collisional magnetized plasmas

    SciTech Connect

    Liu, C.; Fox, W.; Bhattacharjee, A.

    2015-05-15

    Momentum transport in collisional magnetized plasmas due to gradients in the heat flux, a “heat flux viscosity,” is demonstrated. Even though no net particle flux is associated with a heat flux, in a plasma there can still be momentum transport owing to the velocity dependence of the Coulomb collision frequency, analogous to the thermal force. This heat-flux viscosity may play an important role in numerous plasma environments, in particular, in strongly driven high-energy-density plasma, where strong heat flux can dominate over ordinary plasma flows. The heat flux viscosity can influence the dynamics of the magnetic field in plasmas through the generalized Ohm's law and may therefore play an important role as a dissipation mechanism allowing magnetic field line reconnection. The heat flux viscosity is calculated directly using the finite-difference method of Epperlein and Haines [Phys. Fluids 29, 1029 (1986)], which is shown to be more accurate than Braginskii's method [S. I. Braginskii, Rev. Plasma Phys. 1, 205 (1965)], and confirmed with one-dimensional collisional particle-in-cell simulations. The resulting transport coefficients are tabulated for ease of application.

  11. Methane flux time series for tundra environments

    SciTech Connect

    Whalen, S.C.; Reeburgh, W.E. )

    1988-12-01

    Seasonal measurements of net methane flux were made at permanent sites representing important components of arctic tundra. The sites include Eriophorum tussocks, intertussock depressions, moss-covered areas, and Carex stands. Methane fluxes showed high diel, seasonal, intra site, and between site variability. Eriophorum tussocks and Carex dominated methane release to the atmosphere, with mean annual net methane fluxes of 8.05 + or{minus}2.50 g CH{sub 4}/sq m and 4.88 + or{minus}0.73 g CH{sub 4}/sq m, respectively. Methane fluxes form the moss sites and intertussock depressions were much lower. Over 90% of the mean annual methane flux from the Eriophorum, intertussock depressions, and Carex sites occurred between thaw and freeze-up. Some 40% of the mean annual methane flux from the moss sites occurred during winter. Composite methane fluxes for tussock tundra and Carex-dominated wet meadow tundra environments were produced by weighting measured component fluxes according to areal coverage. Tussock and wet meadow tundra account for an estimated global methane emission of 19-33 Tg/yr. 39 refs., 7 figs., 2 tabs.

  12. AmeriFlux US-Atq Atqasuk

    DOE Data Explorer

    Oechel, Walt [San Diego State University; Zona, Donatella [San Diego State University

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Atq Atqasuk. Site Description - This site is 100 km south of Barrow, Alaska, Variety of moist-wet coastal sedge tundra, and moist-tussock tundra surfaces in the more well-drained upland.

  13. Filament Interaction Modeled by Flux Rope Reconnection

    NASA Astrophysics Data System (ADS)

    Török, T.; Chandra, R.; Pariat, E.; Démoulin, P.; Schmieder, B.; Aulanier, G.; Linton, M. G.; Mandrini, C. H.

    2011-02-01

    Hα observations of solar active region NOAA 10501 on 2003 November 20 revealed a very uncommon dynamic process: during the development of a nearby flare, two adjacent elongated filaments approached each other, merged at their middle sections, and separated again, thereby forming stable configurations with new footpoint connections. The observed dynamic pattern is indicative of "slingshot" reconnection between two magnetic flux ropes. We test this scenario by means of a three-dimensional zero β magnetohydrodynamic simulation, using a modified version of the coronal flux rope model by Titov and Démoulin as the initial condition for the magnetic field. To this end, a configuration is constructed that contains two flux ropes which are oriented side-by-side and are embedded in an ambient potential field. The choice of the magnetic orientation of the flux ropes and of the topology of the potential field is guided by the observations. Quasi-static boundary flows are then imposed to bring the middle sections of the flux ropes into contact. After sufficient driving, the ropes reconnect and two new flux ropes are formed, which now connect the former adjacent flux rope footpoints of opposite polarity. The corresponding evolution of filament material is modeled by calculating the positions of field line dips at all times. The dips follow the morphological evolution of the flux ropes, in qualitative agreement with the observed filaments.

  14. Novel Sensor for the In Situ Measurement of Uranium Fluxes

    SciTech Connect

    Hatfield, Kirk

    2015-02-10

    controlled field conditions. In the third and fourth year a suite of larger field studies were conducted. For these studies, the uranium flux sensor was used with uranium speciation measurements and molecular-biological tools to characterize microbial community and active biomass at synonymous wells distributed in a large grid. These field efforts quantified spatial changes in uranium flux and field-scale rates of uranium attenuation (ambient and stimulated), uranium stability, and quantitatively assessed how fluxes and effective reaction rates were coupled to spatial variations in microbial community and active biomass. Analyses of data from these field experiments were used to generate estimates of Monod kinetic parameters that are ‘effective’ in nature and optimal for modeling uranium fate and transport at the field-scale. This project provided the opportunity to develop the first sensor that provides direct measures of both uranium (VI) and groundwater flux. A multidisciplinary team was assembled to include two geochemists, a microbiologist, and two quantitative contaminant hydrologists. Now that the project is complete, the sensor can be deployed at DOE sites to evaluate field-scale uranium attenuation, source behavior, the efficacy of remediation, and off-site risk. Because the sensor requires no power, it can be deployed at remote sites for periods of days to months. The fundamental science derived from this project can be used to advance the development of predictive models for various transport and attenuation processes in aquifers. Proper development of these models is critical for long-term stewardship of contaminated sites in the context of predicting uranium source behavior, remediation performance, and off-site risk.

  15. Spacecraft-produced neutron fluxes on Skylab

    NASA Technical Reports Server (NTRS)

    Quist, T. C.; Furst, M.; Burnett, D. S.; Baum, J. H.; Peacock, C. L., Jr.; Perry, D. G.

    1977-01-01

    Estimates of neutron fluxes in different energy ranges are reported for the Skylab spacecraft. Detectors composed of uranium, thorium, and bismuth foils with mica as a fission track recorder, as well as boron foils with cellulose acetate as an alpha-particle recorder, were deployed at different positions in the Orbital Workshop. It was found that the Skylab neutron flux was dominated by high energy (greater than 1 MeV) contributions and that there was no significant time variation in the fluxes. Firm upper limits of 7-15 neutrons/sq cm-sec, depending on the detector location in the spacecraft, were established for fluxes above 1 MeV. Below 1 MeV, the neutron fluxes were about an order of magnitude lower. The neutrons are interpreted as originating from the interactions of leakage protons from the radiation belt with the spacecraft.

  16. Presearch Data Conditioning in the Kepler Science Operations Center Pipeline

    NASA Technical Reports Server (NTRS)

    Twicken, Joseph D.; Chandrasekaran, Hema; Jenkins, Jon M.; Gunter, Jay P.; Girouard, Forrest; Klaus, Todd C.

    2010-01-01

    We describe the Presearch Data Conditioning (PDC) software component and its context in the Kepler Science Operations Center (SOC) pipeline. The primary tasks of this component are to correct systematic and other errors, remove excess flux due to aperture crowding, and condition the raw flux light curves for over 160,000 long cadence (thirty minute) and 512 short cadence (one minute) targets across the focal plane array. Long cadence corrected flux light curves are subjected to a transiting planet search in a subsequent pipeline module. We discuss the science algorithms for long and short cadence PDC: identification and correction of unexplained (i.e., unrelated to known anomalies) discontinuities; systematic error correction; and excess flux removal. We discuss the propagation of uncertainties from raw to corrected flux. Finally, we present examples of raw and corrected flux time series for flight data to illustrate PDC performance. Corrected flux light curves produced by PDC are exported to the Multi-mission Archive at Space Telescope [Science Institute] (MAST) and will be made available to the general public in accordance with the NASA/Kepler data release policy.

  17. Nitrogen Gas Fluxes in Northeastern Temperate Forests

    NASA Astrophysics Data System (ADS)

    Lafave, S.; Groffman, P. M.; Venterea, R. T.; Lovett, G. M.

    2002-12-01

    Nitrogen gas fluxes are a poorly quantified component of the nitrogen (N) cycle of forest ecosystems and are important to water quality, atmospheric chemistry and forest health. We measured fluxes of nitric oxide (NO), nitrous oxide (N2O) and dinitrogen (N2) in oak and maple stands in the Catskill mountains of New York State. Fluxes of NO and N2O were measured using in situ chambers and N2 flux was measured in intact cores incubated in a helium-oxygen atmosphere closed recirculation system in the laboratory. Fluxes of NO and N2O were higher in maple than in oak stands, which is consistent with previous work showing higher rates of N cycling under maple than oak. NO fluxes averaged 1.7 mg N m-2 d-1 in maple and 0.2 in oak. N2O fluxes averaged 0.10 mg N m-2 d-1 in maple and 0.004 in oak. However, N2 fluxes were higher in oak (2.3 mg N m-2 d-1) than maple (0.15), a surprising result that was supported by independent measurements of denitrification potential. There was marked variability in fluxes between replicate plots that was linked to the presence of understory vegetation and physical characteristics of the forest floor. Results suggest that N gas fluxes in northeastern temperate forests may be more important than previously thought and may be an important regulator of export of N to coastal waters, N-related atmospheric chemistry and forest N saturation.

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

    PubMed Central

    Quek, Lake-Ee; Wittmann, Christoph; Nielsen, Lars K; Krömer, Jens O

    2009-01-01

    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 (<20 sec). Conclusion We have developed a fast, accurate application to perform steady-state 13C metabolic flux analysis. OpenFLUX will strongly facilitate and enhance the design

  19. Science Education. Oryx Science Bibliographies, Volume 6.

    ERIC Educational Resources Information Center

    Schroeder, Eileen E., Comp.; Tyckoson, David A., Ed.

    This bibliography provides 337 annotated references covering: science teaching at the preschool, kindergarten, elementary, and high school levels; science education as it relates to various science disciplines; science education for special populations; sexual stereotyping in science education; teacher education for science teachers; and how…

  20. Preparation of Macroscopic Entangled Coherent States in Nitrogen-Vacancy Centers Ensembles Coupled to a Superconducting Flux Qubit

    NASA Astrophysics Data System (ADS)

    Wang, Liang-Wei; Long, Zhang-Cai

    2017-06-01

    We propose a potentially practical scheme for creating macroscopic entangled coherent state between two separate nitrogen-vacancy center spin ensembles placed near a superconducting flux qubit. Through the collective magnetic coupling and the in situ tunability of the flux qubit, the arbitrary entangled coherent states of spin ensembles can be achieved with high success possibilities under the influence from decoherence of the flux qubit and spin ensembles. The experimental feasibility and challenge are justified using currently available technology. Supported by the National Science Foundation of China under Grant No. 11374118

  1. Science Fairs for Science Literacy

    NASA Astrophysics Data System (ADS)

    Mackey, Katherine; Culbertson, Timothy

    2014-03-01

    Scientific discovery, technological revolutions, and complex global challenges are commonplace in the modern era. People are bombarded with news about climate change, pandemics, and genetically modified organisms, and scientific literacy has never been more important than in the present day. Yet only 29% of American adults have sufficient understanding to be able to read science stories reported in the popular press [Miller, 2010], and American students consistently rank below other nations in math and science [National Center for Education Statistics, 2012].

  2. SAMPEX science pointing with velocity avoidance

    NASA Astrophysics Data System (ADS)

    Frakes, Joseph P.; Henretty, Debra A.; Flatley, Thomas W.; Markley, F. L.; San, Josephine K.; Lightsey, E. G.

    The Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) science pointing mode is presented with the additional constraint of velocity avoidance. This constraint has been added in light of the orbital debris and micrometeoroid fluxes that have been revealed by the Long Duration Exposure Facility (LDEF) recovered in January 1990. These fluxes are 50-100 times higher than the flux tables that were used in the September 1988 proposal to NASA for the SAMPEX mission. The SAMPEX Heavey Ion Large Telescope (HILT) sensor includes a flow-through isobutane proportional counter that is susceptible to penetration by orbital debris and micrometeoroids. Thus, keeping the HILT sensor pointed away from the velocity vector, the direction of maximum flux, will compensate for the higher than expected fluxes. Using an orbital debris model and a micrometeoroid model developed at the Johnson Space Center (JSC), and a SAMPEX dynamic simulator developed by the Guidance and Control Branch at the Goddard Space Flight Center (GSFC), an 'optimal' minimum ram angle (the angle between the HILT boresight and the velocity vector) of 90 degrees has been determined. It is optimal in the sense of minimizing the science pointing performance degradation while providing approximately an 89 percent chance of survival for the HILT sensor over a three year period.

  3. Element flux in cleaved limestones

    SciTech Connect

    McNaught, M.A.; Erslev, E.A. . Dept. of Earth Resources)

    1992-01-01

    Spaced cleavage in limestone is commonly assumed to result from dissolution of carbonate minerals and passive concentration of other minerals in cleavage zones. More complicated processes are suggested by new element data acquired with the CSU XRF-macroprobe. Overlapping spot analyses were made along bed parallel traverses across cleavage zones in samples from the Twin Creek Formation (TCF) of southeast Idaho and the Poxono Island Formation (PIF) of eastern Pennsylvania. If calcite is the sole mobile phase, Ca should decrease as the other immobile elements increase proportionately. Though Ca is the only major element which consistently decreases in cleavage zones, changes in the relative proportions of the other elements indicate varying degrees of mobility. Al and Ti both increase in cleavage zones and maintain a constant ratio, suggesting immobile behavior. Because Al is more abundant than Ti, mobilities of other elements are determined relative to Al. Mg/Al and Fe/Al ratios are constant for PIF samples but show no systematic relationships in TCF samples, which have lower phyllosilicate contents. Si/Al ratios are relatively constant for most samples but in some PIF samples Si/Al ratios decrease in cleavage zones. This may be the result of dissolution of quartz or Si loss during phyllosilicate reactions. K/Al ratios are constant for limestones with average K/Al atomic ratios of 1/3 whereas samples lower K/Al ratios show increasing K/Al in cleavage zones. This suggests that the growth of new phyllosilicates in the K-poor cleavage zones causes preferential scavenging of potassium. In rocks with K/Al ratios of illite or muscovite, K appears to accumulate with Al by residual concentration. Thus, Al and Ti may be the only viable major element markers for calculating volume flux.

  4. Comparison of debris flux models

    NASA Astrophysics Data System (ADS)

    Sdunnus, H.; Beltrami, P.; Klinkrad, H.; Matney, M.; Nazarenko, A.; Wegener, P.

    The availability of models to estimate the impact risk from the man-made space debris and the natural meteoroid environment is essential for both, manned and unmanned satellite missions. Various independent tools based on different approaches have been developed in the past years. Due to an increased knowledge of the debris environment and its sources e.g. from improved measurement capabilities, these models could be updated regularly, providing more detailed and more reliable simulations. This paper addresses an in-depth, quantitative comparison of widely distributed debris flux models which were recently updated, namely ESA's MASTER 2001 model, NASA's ORDEM 2000 and the Russian SDPA 2000 model. The comparison was performed in the frame of the work of the 20t h Interagency Debris Coordination (IADC) meeting held in Surrey, UK. ORDEM 2000ORDEM 2000 uses careful empirical estimates of the orbit populations based onthree primary data sources - the US Space Command Catalog, the H ystackaRadar, and the Long Duration Exposure Facility spacecraft returned surfaces.Further data (e.g. HAX and Goldstone radars, impacts on Shuttle windows andradiators, and others) were used to adjust these populations for regions in time,size, and space not covered by the primary data sets. Some interpolation andextrapolation to regions with no data (such as projections into the future) wasprovided by the EVOLVE model. MASTER 2001The ESA MASTER model offers a full three dimensional description of theterrestrial debris distribution reaching from LEO up to the GEO region. Fluxresults relative to an orbiting target or to an inertial volume can be resolved intosource terms, impactor characteristics and orbit, as well as impact velocity anddirection. All relevant debris source terms are considered by the MASTERmodel. For each simulated source, a corresponding debris generation model interms of mass/diameter distribution, additional velocities, and directionalspreading has been developed. A

  5. AmeriFlux US-Ho2 Howland Forest (west tower)

    DOE Data Explorer

    Hollinger, David [USDA Forest Service; Hollinger, David [USDA Forest Service

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ho2 Howland Forest (west tower). Site Description - Closed conifer forest, minimal disturbance. References: Fernandez et al. (1993), Canadian Journal of Soil Science 73 317-328. Hollinger et al. (1999), Global Change Biology 5: 891-902. Savage KE, Davidson EA (2001), Global Biogeochemical Cycles 15 337-350. Scott et al. (2004), Environmental Management, Vol. 33, Supplement 1, pp. S9-S22. Hollinger et al. (2004), Global Change Biology 10: 1689-1706.

  6. AmeriFlux US-Ho1 Howland Forest (main tower)

    DOE Data Explorer

    Hollinger, David [USDA Forest Service; Hollinger, David [USDA Forest Service

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ho1 Howland Forest (main tower). Site Description - Closed conifer forest, minimal disturbance. References: Fernandez et al. (1993), Canadian Journal of Soil Science 73 317-328. Hollinger et al. (1999), Global Change Biology 5: 891-902. Savage KE, Davidson EA (2001), Global Biogeochemical Cycles 15 337-350. Scott et al. (2004), Environmental Management, Vol. 33, Supplement 1, pp. S9-S22. Hollinger et al. (2004), Global Change Biology 10: 1689-1706.

  7. AmeriFlux US-Ho3 Howland Forest (harvest site)

    DOE Data Explorer

    Hollinger, David [USDA Forest Service; Hollinger, David [USDA Forest Service

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ho3 Howland Forest (harvest site). Site Description - Closed conifer forest, minimal disturbance. References: Fernandez et al. (1993), Canadian Journal of Soil Science 73 317-328. Hollinger et al. (1999), Global Change Biology 5: 891-902. Savage KE, Davidson EA (2001), Global Biogeochemical Cycles 15 337-350. Scott et al. (2004), Environmental Management, Vol. 33, Supplement 1, pp. S9-S22. Hollinger et al. (2004), Global Change Biology 10: 1689-1706.

  8. Topology of magnetic flux ropes and formation of fossil flux transfer events and boundary layer plasmas

    NASA Technical Reports Server (NTRS)

    Lee, L. C.; Ma, Z. W.; Fu, Z. F.; Otto, A.

    1993-01-01

    A mechanism for the formation of fossil flux transfer events and the low-level boundary layer within the framework of multiple X-line reconnection is proposed. Attention is given to conditions for which the bulk of magnetic flux in a flux rope of finite extent has a simple magnetic topology, where the four possible connections of magnetic field lines are: IMF to MSP, MSP to IMF, IMF to IMF, and MSP to MSP. For a sufficient relative shift of the X lines, magnetic flux may enter a flux rope from the magnetosphere and exit into the magnetosphere. This process leads to the formation of magnetic flux ropes which contain a considerable amount of magnetosheath plasma on closed magnetospheric field lines. This process is discussed as a possible explanation for the formation of fossil flux transfer events in the magnetosphere and the formation of the low-latitude boundary layer.

  9. Topology of magnetic flux ropes and formation of fossil flux transfer events and boundary layer plasmas

    NASA Technical Reports Server (NTRS)

    Lee, L. C.; Ma, Z. W.; Fu, Z. F.; Otto, A.

    1993-01-01

    A mechanism for the formation of fossil flux transfer events and the low-level boundary layer within the framework of multiple X-line reconnection is proposed. Attention is given to conditions for which the bulk of magnetic flux in a flux rope of finite extent has a simple magnetic topology, where the four possible connections of magnetic field lines are: IMF to MSP, MSP to IMF, IMF to IMF, and MSP to MSP. For a sufficient relative shift of the X lines, magnetic flux may enter a flux rope from the magnetosphere and exit into the magnetosphere. This process leads to the formation of magnetic flux ropes which contain a considerable amount of magnetosheath plasma on closed magnetospheric field lines. This process is discussed as a possible explanation for the formation of fossil flux transfer events in the magnetosphere and the formation of the low-latitude boundary layer.

  10. Science Fiction on Film.

    ERIC Educational Resources Information Center

    Burmester, David

    1985-01-01

    Reviews science fiction films used in a science fiction class. Discusses feature films, short science fiction films, short story adaptations, original science fiction pieces and factual science films that enrich literature. (EL)

  11. Science Fiction on Film.

    ERIC Educational Resources Information Center

    Burmester, David

    1985-01-01

    Reviews science fiction films used in a science fiction class. Discusses feature films, short science fiction films, short story adaptations, original science fiction pieces and factual science films that enrich literature. (EL)

  12. Benthic fluxes in San Francisco Bay

    USGS Publications Warehouse

    Hammond, Douglas E.; Fuller, C.; Harmon, D.; Hartman, Blayne; Korosec, M.; Miller, L.G.; Rea, R.; Warren, S.; Berelson, W.; Hager, S.W.

    1985-01-01

    Measurements of benthic fluxes have been made on four occasions between February 1980 and February 1981 at a channel station and a shoal station in South San Francisco Bay, using in situ flux chambers. On each occasion replicate measurements of easily measured substances such as radon, oxygen, ammonia, and silica showed a variability (??1??) of 30% or more over distances of a few meters to tens of meters, presumably due to spatial heterogeneity in the benthic community. Fluxes of radon were greater at the shoal station than at the channel station because of greater macrofaunal irrigation at the former, but showed little seasonal variability at either station. At both stations fluxes of oxygen, carbon dioxide, ammonia, and silica were largest following the spring bloom. Fluxes measured during different seasons ranged over factors of 2-3, 3, 4-5, and 3-10 (respectively), due to variations in phytoplankton productivity and temperature. Fluxes of oxygen and carbon dioxide were greater at the shoal station than at the channel station because the net phytoplankton productivity is greater there and the organic matter produced must be rapidly incorporated in the sediment column. Fluxes of silica were greater at the shoal station, probably because of the greater irrigation rates there. N + N (nitrate + nitrite) fluxes were variable in magnitude and in sign. Phosphate fluxes were too small to measure accurately. Alkalinity fluxes were similar at the two stations and are attributed primarily to carbonate dissolution at the shoal station and to sulfate reduction at the channel station. The estimated average fluxes into South Bay, based on results from these two stations over the course of a year, are (in mmol m-2 d-1): O2 = -27 ?? 6; TCO2 = 23 ?? 6; Alkalinity = 9 ?? 2; N + N = -0.3 ?? 0.5; NH3 = 1.4 ?? 0.2; PO4 = 0.1 ?? 0.4; Si = 5.6 ?? 1.1. These fluxes are comparable in magnitude to those in other temperate estuaries with similar productivity, although the seasonal

  13. Macroscopic fluxes and local reciprocal relation in second-order stochastic processes far from equilibrium

    NASA Astrophysics Data System (ADS)

    Ge, Hao

    2015-01-01

    A stochastic process is an essential tool for the investigation of the physical and life sciences at nanoscale. In the first-order stochastic processes widely used in chemistry and biology, only the flux of mass rather than that of heat can be well defined. Here we investigate the two macroscopic fluxes in second-order stochastic processes driven by position-dependent forces and temperature gradient. We prove that the thermodynamic equilibrium defined through the vanishing of macroscopic fluxes is equivalent to that defined via time reversibility at mesoscopic scale. In the small noise limit, we find that the entropy production rate, which has previously been defined by the mesoscopic irreversible fluxes on the phase space, matches the classic macroscopic expression as the sum of the products of macroscopic fluxes and their associated thermodynamic forces. Further we show that the two pairs of forces and fluxes in such a limit follow a linear phenomenonical relation and the associated scalar coefficients always satisfy the reciprocal relation for both transient and steady states. The scalar coefficient is proportional to the square of local temperature divided by the local frictional coefficient and originated from the second moment of velocity distribution along each dimension. This result suggests the very close connection between the Soret effect (thermal diffusion) and Dufour effect at nanoscale even far from equilibrium.

  14. Plasma flux-dependent lipid A deactivation

    NASA Astrophysics Data System (ADS)

    Chang, Hung-Wen; Hsu, Cheng-Che; Ahmed, Musahid; Liu, Suet Yi; Fang, Yigang; Seog, Joonil; Oehrlein, Gottlieb S.; Graves, David B.

    2014-06-01

    This paper reports the influence of gas plasma flux on endotoxin lipid A film deactivation. To study the effect of the flux magnitude of reactive species, a modified low-pressure inductively coupled plasma (ICP) with O radical flux ˜1016 cm-2 s-1 was used. After ICP exposures, it was observed that while the Fourier transform infrared absorbance of fatty chains responsible for the toxicity drops by 80% through the film, no obvious film endotoxin deactivation is seen. This is in contrast to that previously observed under low flux exposure conducted in a vacuum beam system: near-surface only loss of fatty chains led to significant film deactivation. Secondary ion mass spectrometry characterization of changes at the film surface did not appear to correlate with the degree of deactivation. Lipid A films need to be nearly completely removed in order to detect significant deactivation under high flux conditions. Additional high reactive species flux experiments were conducted using an atmospheric pressure helium plasma jet and a UV/ozone device. Exposure of lipid A films to reactive species with these devices showed similar deactivation behaviour. The causes for the difference between low and high flux exposures may be due to the nature of near-surface structural modifications as a function of the rate of film removal.

  15. CO2 flux geothermometer for geothermal exploration

    NASA Astrophysics Data System (ADS)

    Harvey, M. C.; Rowland, J. V.; Chiodini, G.; Rissmann, C. F.; Bloomberg, S.; Fridriksson, T.; Oladottir, A. A.

    2017-09-01

    A new geothermometer (TCO2 Flux) is proposed based on soil diffuse CO2 flux and shallow temperature measurements made on areas of steam heated, thermally altered ground above active geothermal systems. This CO2 flux geothermometer is based on a previously reported CO2 geothermometer that was designed for use with fumarole analysis. The new geothermometer provides a valuable additional exploration tool for estimating subsurface temperatures in high-temperature geothermal systems. Mean TCO2 Flux estimates fall within the range of deep drill hole temperatures at Wairakei (New Zealand), Tauhara (New Zealand), Rotokawa (New Zealand), Ohaaki (New Zealand), Reykjanes (Iceland) and Copahue (Argentina). The spatial distribution of geothermometry estimates is consistent with the location of major upflow zones previously reported at the Wairakei and Rotokawa geothermal systems. TCO2 Flux was also evaluated at White Island (New Zealand) and Reporoa (New Zealand), where limited sub-surface data exists. Mode TCO2 Flux at White Island is high (320 °C), the highest of the systems considered in this study. However, the geothermometer relies on mineral-water equilibrium in neutral pH reservoir fluids, and would not be reliable in such an active and acidic environment. Mean TCO2 Flux at Reporoa (310 °C) is high, which indicates Reporoa has a separate upflow from the nearby Waiotapu geothermal system; an outflow from Waiotapu would not be expected to have such high temperature.

  16. Magnetic balltracking: Tracking the photospheric magnetic flux

    NASA Astrophysics Data System (ADS)

    Attie, R.; Innes, D. E.

    2015-02-01

    Context. One aspect of understanding the dynamics of the quiet Sun is to quantify the evolution of the flux within small-scale magnetic features. These features are routinely observed in the quiet photosphere and were given various names, such as pores, knots, magnetic patches. Aims: This work presents a new algorithm for tracking the evolution of the broad variety of small-scale magnetic features in the photosphere, with a precision equal to the instrumental resolution. Methods: We have developed a new technique to track the evolution of the individual magnetic features from magnetograms, called "magnetic balltracking". It quantifies the flux of the tracked features, and it can track the footpoints of magnetic field lines inferred from magnetic field extrapolation. The algorithm can detect and quantify flux emergence, as well as flux cancellation. Results: The capabilities of magnetic balltracking are demonstrated with the detection and the tracking of two cases of magnetic flux emergence that lead to the brightening of X-ray loops. The maximum emerged flux ranges from 1018 Mx to 1019 Mx (unsigned flux) when the X-ray loops are observed. Movies associated to Figs. 6 and 18 are available in electronic form at http://www.aanda.org

  17. Flux Calibration and Spectral Typing of the SPLASH Sample

    NASA Astrophysics Data System (ADS)

    Chang, Caroline; Vemuri, Nikita; Hamren, Katherine; Guhathakurta, Puragra

    2015-01-01

    We present the spectroscopic identification of M-stars in the disk of the Andromeda Galaxy (M31) and revised spectral types for the M-stars in the X-Shooter Library (XSL). Our dataset consists of optical spectra taken with the DEIMOS spectrograph on the Keck II 10-m telescope as part of the Spectroscopic Landscape of Andromeda's Stellar Halo (SPLASH) survey. We use stars from the MILES and X-Shooter Libraries to perform a first order flux calibration of these spectra, then use TiO-based indices from Fluks et al. 1994 to determine the probable M spectral subtype. While testing this procedure on the M-stars of the XSL, we find that the spectral subtypes derived from the spectra themselves are different from the spectral subtypes obtained from the literature and that XSL includes several spectra with subtypes seemingly later than M10. We suggest that this is due to stellar variability. We also identify ~2000 M-stars in the SPLASH sample. We present the distribution of subtypes here.This research was funded by grants from the National Science Foundation and the Space Telescope Science Institute. Some of the research presented here was conducted by high-school students under the auspices of the University of California Santa Cruz's Science Internship Program.

  18. Developing a High-Flux Isolated Attosecond Pulse Source

    NASA Astrophysics Data System (ADS)

    Kamalov, Andrei; Ware, Matthew; Bucksbaum, Philip; Cryan, James

    2016-05-01

    High harmonic based light sources have proven to be valuable experimental tools that facilitate studies of electron dynamics at their natural timescale, the attosecond regime. The nature of driving laser sources used in high harmonic generation make it difficult to attain attosecond pulses that are both isolated in time and of a high intensity. We present our progress in commissioning a beamline designed to produce high-flux isolated attosecond pulses. A multistep amplification process provides us with 30 mJ, 25 fs pulses centered around 800 nm with 100 Hz repetition rate. These pulses are spatially split and focused into a gas cell. A non-collinear optical gating scheme is used to produce a lighthouse source of high harmonic radiation wherein each beamlet is an isolated attosecond pulse. A variable-depth grazing-incidence stepped mirror is fabricated to extend the optical path length of the older beamlets and thus overlap the beamlets in time. The combined beam is tightly focused and ensuing mechanics will be studied with an electron spectrometer as well as a xuv photon spectrometer. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division.

  19. ON THE ERUPTION OF CORONAL FLUX ROPES

    SciTech Connect

    Fan, Y.

    2010-08-10

    We present three-dimensional MHD simulations of the evolution of the magnetic field in the corona where the emergence of a twisted magnetic flux tube is driven at the lower boundary into a pre-existing coronal potential arcade field. Through a sequence of simulations in which we vary the amount of twisted flux transported into the corona before the emergence is stopped, we investigate the conditions that lead to a dynamic eruption of the resulting coronal flux rope. It is found that the critical condition for the onset of eruption is for the center of the flux rope to reach a critical height at which the corresponding potential field declines with height at a sufficiently steep rate, consistent with the onset of the torus instability of the flux rope. In some cases, immediately after the emergence is stopped, the coronal flux rope first settles into a quasi-static rise with an underlying sigmoid-shaped current layer developing. Preferential heating of field lines going through this current layer may give rise to the observed quiescent X-ray sigmoid loops before eruption. Reconnections in the current layer during the initial quasi-static stage is found to add detached flux to the coronal flux rope, allowing it to rise quasi-statically to the critical height and dynamic eruption of the flux rope then ensues. By identifying field lines whose tops are in the most intense part of the current layer during the eruption, we deduce the evolution and morphology of the post-flare X-ray loops and the flare ribbons at their footpoints.

  20. Interplanetary magnetic flux: Measurement and balance

    SciTech Connect

    McComas, D.J.; Gosling, J.T.; Phillips, J.L. )

    1992-01-01

    The authors have developed a new method for determining the approximate magnetic flux content of the various solar wind structures in the ecliptic plane, using single-spacecraft measurements. The two-dimensional magnetic flux in a region of the solar wind is given by the integral of the radial magnetic field component over an arc perpendicular to the radial. Unfortunately, such measurements cannot be achieved with single (or even several) spacecraft in the solar wind. They will show that the desired two-dimensional, ecliptic plane magnetic flux integral, at least for regions with simple magnetic topologies, is equivalent to {phi} = {integral} B{sub y}{vert bar}v{vert bar}dt, where B{sub y} is the ecliptic plane field component perpendicular to the solar wind velocity vector v. Thus {phi} can be determined entirely from measured quantities. In this study they examine variations in the magnetic flux in the ecliptic plane over a 16-year interval. In addition, they address the question of the opening and closing of interplanetary magnetic flux by comparing the ecliptic plane flux content of both coronal mass ejections (CMEs) and heat flux droplets (HFDs). If CMEs remain at least partially attached to the Sun, they would serve to open new magnetic flux to the interplanetary medium. In contrast, flux could be closed off by reconnection across helmet streamers in the corona, leading to the release of U-shaped magnetic structures open to the outer heliosphere at both ends and to the return of closed arches to the Sun.

  1. Magnetic Flux Cancellation and Formation of Prominence

    NASA Astrophysics Data System (ADS)

    Miley, George; Kim, Mun Song; Chon Nam, Sok; Kim, Kyong Chol

    2015-08-01

    Magnetic flux cancellation appears to be closely related to various kinds of solar activities such as flares, microflares/surges/jets, X-ray bright points, erupting mini-filaments, transition region explosive events, filament formation, filament activation and eruption, and coronal mass ejections. It is commonly believed that magnetic reconnections in the low atmosphere are responsible for canceling magnetic features, and magnetic fragments are observed to originate as bipoles. According to the Sweet-Parker type reconnection model, the inflow speed closely corresponds to the converging speed of each pole in a canceling magnetic feature and the rate of flux cancellation must be explained by the observed converging speed. As distinct from the corona, the efficiency of photospheric magnetic reconnection may be due to the small Cowling conductivity, instead of the Spitzer, of weakly ionized and magnetized plasma in the low atmosphere of the sun. Using the VAL-C atmospheric model and Cowling conductivity, we have computed the parameters describing Sweet-Parker type reconnecting current sheets in the plasma of the solar photosphere and chromosphere, and particularly for the phenomena of magnetic flux cancellation and dark filament formation which occurred on July 2, 1994 we have estimated the rate of flux cancellation, the inflow speed(the converging speed) and the upward mass flux to compare with the observation. The results show that when taking account of the Cowling conductivity in the low atmosphere, large flux cancellation rates(>1019Mxhr-1) in solar active regions are better explained than by the Spitzer conductivity-considered reconnection model. Particularly for the flux cancellation event on July 2, 1994, the inflow speed(0.26kms-1)is almost similar to the converging speed(0.22kms-1)and the upward mass flux(3.3X1012gs-1) in the model is sufficient for the large dark filament formation in a time of several hours through magnetic flux cancellation process.

  2. Towards Improved Estimates of Ocean Heat Flux

    NASA Astrophysics Data System (ADS)

    Bentamy, Abderrahim; Hollman, Rainer; Kent, Elisabeth; Haines, Keith

    2014-05-01

    Recommendations and priorities for ocean heat flux research are for instance outlined in recent CLIVAR and WCRP reports, eg. Yu et al (2013). Among these is the need for improving the accuracy, the consistency, and the spatial and temporal resolution of air-sea fluxes over global as well as at region scales. To meet the main air-sea flux requirements, this study is aimed at obtaining and analyzing all the heat flux components (latent, sensible and radiative) at the ocean surface over global oceans using multiple satellite sensor observations in combination with in-situ measurements and numerical model analyses. The fluxes will be generated daily and monthly for the 20-year (1992-2011) period, between 80N and 80S and at 0.25deg resolution. Simultaneous estimates of all surface heat flux terms have not yet been calculated at such large scale and long time period. Such an effort requires a wide range of expertise and data sources that only recently are becoming available. Needed are methods for integrating many data sources to calculate energy fluxes (short-wave, long wave, sensible and latent heat) across the air-sea interface. We have access to all the relevant, recently available satellite data to perform such computations. Yu, L., K. Haines, M. Bourassa, M. Cronin, S. Gulev, S. Josey, S. Kato, A. Kumar, T. Lee, D. Roemmich: Towards achieving global closure of ocean heat and freshwater budgets: Recommendations for advancing research in air-sea fluxes through collaborative activities. INTERNATIONAL CLIVAR PROJECT OFFICE, 2013: International CLIVAR Publication Series No 189. http://www.clivar.org/sites/default/files/ICPO189_WHOI_fluxes_workshop.pdf

  3. On calculating the potential vorticity flux

    SciTech Connect

    Hsu, Pei-Chun; Diamond, P. H.

    2015-03-15

    We discuss and compare different approaches to calculating the dynamics of anisotropic flow structure formation in quasi two-dimensional turbulence based on potential vorticity (PV) transport in real space. The general structure of the PV flux in the relaxation processes is deduced non-perturbatively. The transport coefficients of the PV flux are then systematically calculated using perturbation theory. We develop two non-perturbative relaxation models: the first is a mean field theory for the dynamics of minimum enstrophy relaxation based on the requirement that the mean flux of PV dissipates total potential enstrophy but conserves total fluid kinetic energy. The results show that the structure of PV flux has the form of a sum of a positive definite hyper-viscous and a negative or positive viscous flux of PV. Turbulence spreading is shown to be related to PV mixing via the link of turbulence energy flux to PV flux. In the relaxed state, the ratio of the PV gradient to zonal flow velocity is homogenized. This homogenized quantity sets a constraint on the amplitudes of PV and zonal flow in the relaxed state. The second relaxation model is derived from symmetry principles alone. The form of PV flux contains a nonlinear convective term in addition to viscous and hyper-viscous terms. For both cases, the transport coefficients are calculated using perturbation theory. For a broad turbulence spectrum, a modulational calculation of the PV flux gives both a negative viscosity and a positive hyper-viscosity. For a narrow turbulence spectrum, the result of a parametric instability analysis shows that PV transport is also convective. In both relaxation and perturbative analyses, it is shown that turbulent PV transport is sensitive to flow structure, and the transport coefficients are nonlinear functions of flow shear.

  4. Islam and Science

    NASA Astrophysics Data System (ADS)

    Salam, Abdus

    The following sections are included: * The Holy Quran and Science * Modem Science, A Greco- Islamic Legacy * The Decline of Sciences in Islam * The Limitations of Science * Faith and Science * The Present Picture of Sciences in the Islamic Countries * Renaissance of Sciences in Islam * Steps Needed for Building up Sciences in the Islamic Countries * Science Education * Science Foundations in Islam * Technology in Our Countries * Concluding Remarks * REFERENCES

  5. Literacy, science, and science education

    NASA Astrophysics Data System (ADS)

    McVittie, Janet Elizabeth

    In examining the connections between literacy, science and science education, I laid out a number of questions. For example, what sorts of literate tools might facilitate writing to learn, and do children who are just becoming literate use these tools? I then examined the writing of children in science class in an attempt to determine if their writing can indeed facilitate their learning. The results of this research could help teachers make decisions about the use of writing in the learning of science. The kinds of literate tools I identified as being potentially helpful were transitionals---those words or grammatical devices which demonstrate how ideas are connected. Also, I suggested that data tables, sentences and paragraphs were also useful for students to learn. I found that grade 5/6 students used a wide range of literate tools, but that they were much more competent with those tools which were both oral and literate than those which could only be used for writing (punctuation, sentences, paragraphs, and data tables). When I attempted to determine if the children used their writing to learn, I found very little evidence that this was certainly so. However, there was some evidence that paragraphs had the potential to create a "dialogue" between student writing and thinking, so the students could make more explicit connections between science ideas. Lastly, I noticed certain gender difference in the classroom. Because of this, I contrasted the writing of the girls with the writing of the boys. I learned the girls were generally much more capable writers than the boys. More interesting, however, was that the girls generally attempted to explain their science concepts in different ways than did the boys. The girls were more likely to rely on their own reasoning, whereas the boys were more likely to persist in using culturally created science explanations. The research findings have important implications for analyzing students' learning and for finding ways to

  6. Magnetic refrigeration using flux compression in superconductors

    NASA Technical Reports Server (NTRS)

    Israelsson, U. E.; Strayer, D. M.; Jackson, H. W.; Petrac, D.

    1990-01-01

    The feasibility of using flux compression in high-temperature superconductors to produce the large time-varying magnetic fields required in a field cycled magnetic refrigerator operating between 20 K and 4 K is presently investigated. This paper describes the refrigerator concept and lists limitations and advantages in comparison with conventional refrigeration techniques. The maximum fields obtainable by flux compression in high-temperature supercoductor materials, as presently prepared, are too low to serve in such a refrigerator. However, reports exist of critical current values that are near usable levels for flux pumps in refrigerator applications.

  7. Eddy Correlation Flux Measurement System (ECOR) Handbook

    SciTech Connect

    Cook, DR

    2011-01-31

    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.

  8. FOLD LENS FLUX ANOMALIES: A GEOMETRIC APPROACH

    SciTech Connect

    Goldberg, David M.; Chessey, Mary K.; Harris, Wendy B.; Richards, Gordon T.

    2010-06-01

    We develop a new approach for studying flux anomalies in quadruply imaged fold lens systems. We show that in the absence of substructure, microlensing, or differential absorption, the expected flux ratios of a fold pair can be tightly constrained using only geometric arguments. We apply this technique to 11 known quadruple lens systems in the radio and infrared and compare our estimates to the Monte Carlo based results of Keeton et al. We show that a robust estimate for a flux ratio from a smoothly varying potential can be found, and at long wavelengths those lenses deviating from this ratio almost certainly contain significant substructure.

  9. Fold Lens Flux Anomalies: A Geometric Approach

    NASA Astrophysics Data System (ADS)

    Goldberg, David M.; Chessey, Mary K.; Harris, Wendy B.; Richards, Gordon T.

    2010-06-01

    We develop a new approach for studying flux anomalies in quadruply imaged fold lens systems. We show that in the absence of substructure, microlensing, or differential absorption, the expected flux ratios of a fold pair can be tightly constrained using only geometric arguments. We apply this technique to 11 known quadruple lens systems in the radio and infrared and compare our estimates to the Monte Carlo based results of Keeton et al. We show that a robust estimate for a flux ratio from a smoothly varying potential can be found, and at long wavelengths those lenses deviating from this ratio almost certainly contain significant substructure.

  10. Nitrous oxide flux following tropical land clearing

    NASA Technical Reports Server (NTRS)

    Luizao, Flavio; Luizao, Regina; Matson, Pamela; Livingston, Gerald; Vitousek, Peter

    1989-01-01

    The importance of seasonal cycles of N2O flux from tropical ecosystems and the possibility that tropical deforestation could contribute to the ongoing global increase in N2O concentrations were assessed by measuring N2O flux from forest, cleared land, and pasture over an annual cycle in the central Amazon. A pasture that had been converted from tropical forest had threefold greater annual N2O flux than a paired forest site; similar results were obtained in spot measurements in other pastures. If these results are general, such tropical pastures represent a globally significant source of increased N2O.

  11. Extending quantum coherence of superconducting flux

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Kamal, Archana; Orlando, Terry; Gustavsson, Simon; Oliver, William; Engineering Quantum Systems, MIT Team

    We present the design of a superconducting qubit with multiple Josephson junctions. The design starts with a capacitively shunted flux qubit, and it incorporates particular junction parameter choices for the purpose of simultaneously optimizing over transition frequency, anharmonicity, flux- and charge-noise sensitivity around flux degeneracy. By studying the scaling properties with design parameters, we identify directions to extend coherence substantially. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002.

  12. Magnetic flux amplification by Lenz lenses

    NASA Astrophysics Data System (ADS)

    Schoenmaker, J.; Pirota, K. R.; Teixeira, J. C.

    2013-08-01

    Tailoring magnetic flux distribution is highly desirable in a wide range of applications such as magnetic sensors and biomedicine. In this paper we study the manipulation of induced currents in passive devices in order to engineer the distribution of magnetic flux intensity in a given region. We propose two different approaches, one based on especially designed wire loops (Lenz law) and the other based on solid conductive pieces (eddy currents). The gain of such devices is mainly determined by geometry giving perspective of high amplification. We consistently modeled, simulated, and executed the proposed devices. Doubled magnetic flux intensity is demonstrated experimentally for a moderate aspect ratio.

  13. Diamagnetic flux measurement in Aditya tokamak

    SciTech Connect

    Kumar, Sameer; Jha, Ratneshwar; Lal, Praveen; Hansaliya, Chandresh; Gopalkrishna, M. V.; Kulkarni, Sanjay; Mishra, Kishore

    2010-12-15

    Measurements of diamagnetic flux in Aditya tokamak for different discharge conditions are reported for the first time. The measured diamagnetic flux in a typical discharge is less than 0.6 mWb and therefore it has required careful compensation for various kinds of pick-ups. The hardware and software compensations employed in this measurement are described. We introduce compensation of a pick-up due to plasma current of less than 20 kA in short duration discharges, in which plasma pressure gradient is supposed to be negligible. The flux measurement during radio frequency heating is also presented in order to validate compensation.

  14. Diamagnetic flux measurement in Aditya tokamak.

    PubMed

    Kumar, Sameer; Jha, Ratneshwar; Lal, Praveen; Hansaliya, Chandresh; Gopalkrishna, M V; Kulkarni, Sanjay; Mishra, Kishore

    2010-12-01

    Measurements of diamagnetic flux in Aditya tokamak for different discharge conditions are reported for the first time. The measured diamagnetic flux in a typical discharge is less than 0.6 mWb and therefore it has required careful compensation for various kinds of pick-ups. The hardware and software compensations employed in this measurement are described. We introduce compensation of a pick-up due to plasma current of less than 20 kA in short duration discharges, in which plasma pressure gradient is supposed to be negligible. The flux measurement during radio frequency heating is also presented in order to validate compensation.

  15. Minkowski Flux Vacua of Type II Supergravities

    NASA Astrophysics Data System (ADS)

    Andriot, David; Blâbäck, Johan; Van Riet, Thomas

    2017-01-01

    We study flux compactifications of 10D type II supergravities to 4D Minkowski space-time, supported by parallel orientifold Op planes with 3 ≤p ≤8 . With some geometric restrictions, the 4D Ricci scalar can be written as a negative sum of squares involving Bogomol'nyi-Prasad-Sommerfield-like conditions. Setting all squares to zero provides automatically a solution to 10D equations of motion. This way we characterize a broad class, if not the complete set, of Minkowski flux vacua with parallel orientifolds. We conjecture an extension with nongeometric fluxes. None of our results rely on supersymmetry.

  16. FLUX EMERGENCE IN A MAGNETIZED CONVECTION ZONE

    SciTech Connect

    Pinto, R. F.; Brun, A. S.

    2013-07-20

    We study the influence of a dynamo magnetic field on the buoyant rise and emergence of twisted magnetic flux ropes and their influence on the global external magnetic field. We ran three-dimensional MHD numerical simulations using the ASH code (anelastic spherical harmonics) and analyzed the dynamical evolution of such buoyant flux ropes from the bottom of the convection zone until the post-emergence phases. The global nature of this model can only very crudely and inaccurately represent the local dynamics of the buoyant rise of the implanted magnetic structure, but nonetheless allows us to study the influence of global effects, such as self-consistently generated differential rotation and meridional circulation, and of Coriolis forces. Although motivated by the solar context, this model cannot be thought of as a realistic model of the rise of magnetic structures and their emergence in the Sun, where the local dynamics are completely different. The properties of initial phases of the buoyant rise are determined essentially by the flux-rope's properties and the convective flows and consequently are in good agreement with previous studies. However, the effects of the interaction of the background dynamo field become increasingly strong as the flux ropes evolve. During the buoyant rise across the convection zone, the flux-rope's magnetic field strength scales as B{proportional_to}{rho}{sup {alpha}}, with {alpha} {approx}< 1. An increase of radial velocity, density, and current density is observed to precede flux emergence at all longitudes. The geometry, latitude, and relative orientation of the flux ropes with respect to the background magnetic field influences the resulting rise speeds, zonal flow amplitudes (which develop within the flux ropes), and the corresponding surface signatures. This influences the morphology, duration and amplitude of the surface shearing, and the Poynting flux associated with magnetic flux-rope emergence. The emerged magnetic flux

  17. Nitrous oxide flux following tropical land clearing

    NASA Technical Reports Server (NTRS)

    Luizao, Flavio; Luizao, Regina; Matson, Pamela; Livingston, Gerald; Vitousek, Peter

    1989-01-01

    The importance of seasonal cycles of N2O flux from tropical ecosystems and the possibility that tropical deforestation could contribute to the ongoing global increase in N2O concentrations were assessed by measuring N2O flux from forest, cleared land, and pasture over an annual cycle in the central Amazon. A pasture that had been converted from tropical forest had threefold greater annual N2O flux than a paired forest site; similar results were obtained in spot measurements in other pastures. If these results are general, such tropical pastures represent a globally significant source of increased N2O.

  18. A time-varying magnetic flux concentrator

    NASA Astrophysics Data System (ADS)

    Kibret, B.; Premaratne, M.; Lewis, P. M.; Thomson, R.; Fitzgerald, P. B.

    2016-08-01

    It is known that diverse technological applications require the use of focused magnetic fields. This has driven the quest for controlling the magnetic field. Recently, the principles in transformation optics and metamaterials have allowed the realization of practical static magnetic flux concentrators. Extending such progress, here, we propose a time-varying magnetic flux concentrator cylindrical shell that uses electric conductors and ferromagnetic materials to guide magnetic flux to its center. Its performance is discussed based on finite-element simulation results. Our proposed design has potential applications in magnetic sensors, medical devices, wireless power transfer, and near-field wireless communications.

  19. Warped Kähler potentials and fluxes

    NASA Astrophysics Data System (ADS)

    Martucci, Luca

    2017-01-01

    The four-dimensional effective theory for type IIB warped flux compactifications proposed in [1] is completed by taking into account the backreaction of the Kähler moduli on the three-form fluxes. The only required modification consists in a flux-dependent contribution to the chiral fields parametrising the Kähler moduli. The resulting supersymmetric effective theory satisfies the no-scale condition and consistently combines previous partial results present in the literature. Similar results hold for M-theory warped compactifications on Calabi-Yau fourfolds, whose effective field theory and Kähler potential are also discussed.

  20. Material Science

    NASA Image and Video Library

    2003-01-22

    Dr. Richard Grugel, a materials scientist at NASA's Marshall Space Flight in Huntsville, Ala., examines the furnace used to conduct his Pore Formation and Mobility Investigation -- one of the first two materials science experiments to be conducted on the International Space Station. This experiment studies materials processes similar to those used to make components used in jet engines. Grugel's furnace was installed in the Microgravity Science Glovebox through the circular port on the side. In space, crewmembers are able to change out samples using the gloves on the front of the facility's work area.

  1. A practical CO2 flux remote sensing technique

    NASA Astrophysics Data System (ADS)

    Queisser, Manuel; Burton, Mike

    2017-04-01

    An accurate quantification of CO2 flux from both natural and anthropogenic sources is of great interest in various areas of the Earth, environmental and atmospheric sciences. As emitted excess CO2 quickly dilutes into the 400 ppm ambient CO2 concentration and degassing often occurs diffusively, measuring CO2 fluxes is challenging. Therefore, fluxes are usually derived from grids of in-situ measurements, which are labour intensive measurements. Other than a safe measurement distance, remote sensing offers quick, spatially integrated and thus a more thorough measurement of gas fluxes. Active remote sensing combines these merits with operation independent of sunlight or clear sky conditions. Due to their weight and size, active remote sensing platforms for CO2, such as LIDAR, cannot easily be applied in the field or transported overseas. Moreover, their complexity requires a rather lengthy setup procedure to be undertaken by skilled personal. To meet the need for a rugged, practical CO2 remote sensing technique to scan volcanic plumes, we have developed the CO2 LIDAR. It measures 1-D column densities of CO2 with sufficient sensitivity to reveal the contribution of magmatic CO2. The CO2 LIDAR has been mounted inside a small aircraft and used to measure atmospheric column CO2 concentrations between the aircraft and the ground. It was further employed on the ground, measuring CO2 emissions from mud volcanism. During the measurement campaign the CO2 LIDAR demonstrated reliability, portability, quick set-up time (10 to 15 min) and platform independence. This new technique opens the possibility of rapid, comprehensive surveys of point source, open-vent CO2 emissions, as well as emissions from more diffuse sources such as lakes and fumarole fields. Currently, within the proof-of-concept ERC project CarbSens, a further reduction in size, weight and operational complexity is underway with the goal to commercialize the platform. Areas of potential applications include fugitive

  2. Solar Scientist Confirm Existence of Flux Ropes on the Sun

    NASA Image and Video Library

    2017-09-27

    Caption: This is an image of magnetic loops on the sun, captured by NASA's Solar Dynamics Observatory on July 18, 2012. It has been processed to highlight the edges of each loop to make the structure more clear. A series of loops such as this is known as a flux rope, and these lie at the heart of eruptions on the sun known as coronal mass ejections (CMEs.) This is the first time scientists were able to discern the timing of a flux rope's formation. Credit: NASA/Goddard Space Flight Center/SDO ---- On July 18, 2012, a fairly small explosion of light burst off the lower right limb of the sun. Such flares often come with an associated eruption of solar material, known as a coronal mass ejection or CME – but this one did not. Something interesting did happen, however. Magnetic field lines in this area of the sun's atmosphere, the corona, began to twist and kink, generating the hottest solar material – a charged gas called plasma – to trace out the newly-formed slinky shape. The plasma glowed brightly in extreme ultraviolet images from the Atmospheric Imaging Assembly (AIA) aboard NASA’s Solar Dynamics Observatory (SDO) and scientists were able to watch for the first time the very formation of something they had long theorized was at the heart of many eruptive events on the sun: a flux rope. Eight hours later, on July 19, the same region flared again. This time the flux rope's connection to the sun was severed, and the magnetic fields escaped into space, dragging billions of tons of solar material along for the ride -- a classic CME. "Seeing this structure was amazing," says Angelos Vourlidas, a solar scientist at the Naval Research Laboratory in Washington, D.C. "It looks exactly like the cartoon sketches theorists have been drawing of flux ropes since the 1970s. It was a series of figure eights lined up to look like a giant slinky on the sun." To read more about this new discovery go to: 1.usa.gov/14UHsTt NASA image use policy. NASA Goddard Space Flight Center

  3. Solar Scientist Confirm Existence of Flux Ropes on the Sun

    NASA Image and Video Library

    2017-09-27

    Caption: This is an image of magnetic loops on the sun, captured by NASA's Solar Dynamics Observatory (SDO). It has been processed to highlight the edges of each loop to make the structure more clear. A series of loops such as this is known as a flux rope, and these lie at the heart of eruptions on the sun known as coronal mass ejections (CMEs.) This is the first time scientists were able to discern the timing of a flux rope's formation. (Blended 131 Angstrom and 171 Angstrom images of July 19, 2012 flare and CME.) Credit: NASA/Goddard Space Flight Center/SDO ---- On July 18, 2012, a fairly small explosion of light burst off the lower right limb of the sun. Such flares often come with an associated eruption of solar material, known as a coronal mass ejection or CME – but this one did not. Something interesting did happen, however. Magnetic field lines in this area of the sun's atmosphere, the corona, began to twist and kink, generating the hottest solar material – a charged gas called plasma – to trace out the newly-formed slinky shape. The plasma glowed brightly in extreme ultraviolet images from the Atmospheric Imaging Assembly (AIA) aboard NASA’s Solar Dynamics Observatory (SDO) and scientists were able to watch for the first time the very formation of something they had long theorized was at the heart of many eruptive events on the sun: a flux rope. Eight hours later, on July 19, the same region flared again. This time the flux rope's connection to the sun was severed, and the magnetic fields escaped into space, dragging billions of tons of solar material along for the ride -- a classic CME. "Seeing this structure was amazing," says Angelos Vourlidas, a solar scientist at the Naval Research Laboratory in Washington, D.C. "It looks exactly like the cartoon sketches theorists have been drawing of flux ropes since the 1970s. It was a series of figure eights lined up to look like a giant slinky on the sun." To read more about this new discovery go to: 1.usa

  4. Regionalization of land surface heat fluxes and evapotranspiration over heterogeneous landscape of the Third Pole region

    NASA Astrophysics Data System (ADS)

    Ma, Y.

    2016-12-01

    The exchange of energy and evapotranspiration (ET) between land surface and atmosphere over the Third Pole region (Tibetan Plateau and the nearby surrounding regions) play an important role in the Asian climate system. Supported by the Chinese Academy of Sciences and some international organizations, a Third Pole Environment (TPE) Research Platform (TPEP) is now implementing over the Tibetan Plateau and surrounding region. The background of the establishment of the TPEP, the establishing and monitoring plan of long-term scale (5-10 years) of the TPEP will be shown firstly. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes partitioning, the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this study. The parameterization methods based on satellite data and Atmospheric Boundary Layer (ABL) observations have been proposed and tested for deriving regional distribution of surface reflectance, surface temperature, net radiation flux, soil heat flux, sensible heat flux, latent heat flux and ET over heterogeneous landscape. As cases study, the methods were applied to the whole Tibetan Plateau area and Nepal area. To validate the proposed methods, the ground-measured surface reflectance, surface temperature, net radiation flux, soil heat flux, sensible heat flux and latent heat flux in the TPEP are compared to the derived values. The results show that the derived surface variables, land surface heat fluxes and ET over the study area are in good accordance with the land surface status. These parameters show a wide range due to the strong contrast of surface features. And the estimated land surface variables and land surface heat fluxes are in good agreement with ground measurements, and all the absolute percent difference is less than 10% in the validation sites. It is therefore concluded that the

  5. Mapping carbon flux uncertainty and selecting optimal locations for future flux towers in the Great Plains

    USGS Publications Warehouse

    Gu, Y.; Howard, D.M.; Wylie, B.K.; Zhang, L.

    2012-01-01

    Flux tower networks (e. g., AmeriFlux, Agriflux) provide continuous observations of ecosystem exchanges of carbon (e. g., net ecosystem exchange), water vapor (e. g., evapotranspiration), and energy between terrestrial ecosystems and the atmosphere. The long-term time series of flux tower data are essential for studying and understanding terrestrial carbon cycles, ecosystem services, and climate changes. Currently, there are 13 flux towers located within the Great Plains (GP). The towers are sparsely distributed and do not adequately represent the varieties of vegetation cover types, climate conditions, and geophysical and biophysical conditions in the GP. This study assessed how well the available flux towers represent the environmental conditions or "ecological envelopes" across the GP and identified optimal locations for future flux towers in the GP. Regression-based remote sensing and weather-driven net ecosystem production (NEP) models derived from different extrapolation ranges (10 and 50%) were used to identify areas where ecological conditions were poorly represented by the flux tower sites and years previously used for mapping grassland fluxes. The optimal lands suitable for future flux towers within the GP were mapped. Results from this study provide information to optimize the usefulness of future flux towers in the GP and serve as a proxy for the uncertainty of the NEP map.

  6. Brown dwarf disks with Herschel: Linking far-infrared and (sub)-mm fluxes

    NASA Astrophysics Data System (ADS)

    Daemgen, Sebastian; Natta, Antonella; Scholz, Alexander; Testi, Leonardo; Jayawardhana, Ray; Greaves, Jane; Eastwood, Daniel

    2016-10-01

    Brown dwarf disks are excellent laboratories to test our understanding of disk physics in an extreme parameter regime. In this paper we investigate a sample of 29 well-characterized brown dwarfs and very low-mass stars, for which Herschel far-infrared fluxes and (sub)-mm fluxes are available. We measured new Herschel/PACS fluxes for 11 objects and complement these with (sub)-mm data and Herschel fluxes from the literature. We analyze their spectral energy distributions in comparison with results from radiative transfer modeling. Fluxes in the far-infrared are strongly affected by the shape and temperature of the disk (and hence stellar luminosity), whereas the (sub)-mm fluxes mostly depend on disk mass. Nevertheless, there is a clear correlation between far-infrared and (sub)-mm fluxes. We argue that the link results from the combination of the stellar mass-luminosity relation and a scaling between disk mass and stellar mass. We find strong evidence of dust settling to the disk midplane. The spectral slopes between near- and far-infrared are mostly between -0.5 and -1.2 in our sample, which is comparable to more massive T Tauri stars; this may imply that the disk shapes are similar as well, although highly flared disks are rare among brown dwarfs. We find that dust temperatures in the range of 7-15 K, calculated with T ≈ 25 (L/L⊙)0.25 K, are appropriate for deriving disk masses from (sub)-mm fluxes for these low luminosity objects. About half of our sample hosts disks with at least one Jupiter mass, confirming that many brown dwarfs harbor sufficient material for the formation of Earth-mass planets in their midst. Herschel is a ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  7. Brewing Science

    ERIC Educational Resources Information Center

    Pelter, Michael

    2006-01-01

    Following the brewing process from grain to glass, this course uses the biological and chemical principles of brewing to teach science to the nonscience major. Discussion of the scientific aspects of malting, mashing, fermentation, and the making of different beer styles is complemented by laboratory exercises that use scientific methods to…

  8. Kaleidoscope Science.

    ERIC Educational Resources Information Center

    Janes, Patricia

    2002-01-01

    Presents a collection of science activities that have elementary students investigate how color can trick the eye and the brain. The activities involve working with contrasting colors, creating a rainbow, and exploring the connection between colors and words. An instructor reproducible features two color activities. (SM)

  9. Skeptical Science.

    ERIC Educational Resources Information Center

    Scott, Alan J.; Barnhart, Carolyn M.; Parejko, Ken S.; Schultz, Forrest S.; Schultz, Steven E.

    2001-01-01

    Discusses the legitimacy of teaching about astrology, extrasensory perception, UFOs, touch therapy, cloning dinosaurs, or any other unusual claims in the classroom. Suggests that bringing unusual claims to the science classroom is an opportunity to motivate students in the principles of scientific thought. (SAH)

  10. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1986

    1986-01-01

    Describes 26 different activities, experiments, demonstrations, and computer simulations in various topics in science. Includes instructional activities dealing with mural ecology, surface area/volume ratios, energy transfer in ecosystems, electrochemical simulations, alternating and direct current, terminal velocity, measuring the size of the…

  11. Talking Science

    ERIC Educational Resources Information Center

    Eley, Alison

    2011-01-01

    The Talking Science project initially involved three secondary schools and eight of their feeder primary schools in the London Borough of Richmond Upon Thames. The project created, trialled and evaluated a set of key stage 2/3 transition materials for children moving from primary to secondary school, using argument as a teaching and learning…

  12. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Presented are 25 science activities on colorations of prey, evolution, blood, physiology, nutrition, enzyme kinetics, leaf pigments, analytical chemistry, milk, proteins, fermentation, surface effects of liquids, magnetism, drug synthesis, solvents, wintergreen synthesis, chemical reactions, multicore cables, diffraction, air resistance,…

  13. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1986

    1986-01-01

    Describes activities, games, experiments, demonstrations, and computer-oriented exercises in all science areas. Topics include energy flow through a marine ecosystem, using 2,4-dichlorophenoxyethanoic acid to demonstrate translocation in plants, use of the dichotomous key, use of leaf yeasts to monitor atmospheric pollution, and others. (JN)

  14. Science Journalism

    ERIC Educational Resources Information Center

    Polman, Joseph; Newman, Alan; Farrar, Cathy; Saul, E. Wendy

    2012-01-01

    Much of the National Science Education Standards (NRC 1996), aside from the inquiry and teaching sections, focus on content. The authors' call is instead to build standards that focus on what students need to be scientifically literate in 10 or 15 years. Although a basic understanding of important scientific concepts and an understanding of how…

  15. Nuclear Science.

    ERIC Educational Resources Information Center

    Pennsylvania State Dept. of Education, Harrisburg. Bureau of Curriculum Services.

    This document is a report on a course in nuclear science for the high school curriculum. The course is designed to provide a basic but comprehensive understanding of the atom in the light of modern knowledge, and to show how people attempt to harness the tremendous energy liberated through fission and fusion reactions. The course crosses what are…

  16. Cognitive Science.

    ERIC Educational Resources Information Center

    Soni, P. Sarita, Ed.; Carmichael, Ann G., Ed.

    1993-01-01

    This theme issue features five articles profiling Indiana University faculty whose work on various campuses continues to broaden and advance knowledge about cognitive science. The articles in the journal are: "A Matter of Time" (Karen Grooms) which discusses the work of Robert F. Port; "Perceiving as a Complex System" (Tom…

  17. Samara Science.

    ERIC Educational Resources Information Center

    Dyche, Steven E.

    1985-01-01

    Samara (winged seeds from maple and ash trees) can be used for open-ended inquiry or a series of directed science activities. Attributes, observations/inferences, drawing, motion, floating, seed structure, creative design, and measurement are some of the suggestions for classroom use of these seeds. (DH)

  18. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1985

    1985-01-01

    Activities, experiments, computer programs, equipment, procedures, demonstrations, and teaching techniques are provided for a wide variety of topics in the biological and physical sciences. They include an improved apparatus for measuring rate of photosynthesis, procedures for making rainbows and measuring stomatal openings, and others. (JN)

  19. Skeptical Science.

    ERIC Educational Resources Information Center

    Scott, Alan J.; Barnhart, Carolyn M.; Parejko, Ken S.; Schultz, Forrest S.; Schultz, Steven E.

    2001-01-01

    Discusses the legitimacy of teaching about astrology, extrasensory perception, UFOs, touch therapy, cloning dinosaurs, or any other unusual claims in the classroom. Suggests that bringing unusual claims to the science classroom is an opportunity to motivate students in the principles of scientific thought. (SAH)

  20. Organizational Science

    ERIC Educational Resources Information Center

    Beriwal, Madhu; Clegg, Stewart; Collopy, Fred; McDaniel, Reuben, Jr.; Morgan, Gareth; Sutcliffe, Kathleen; Kaufman, Roger; Marker, Anthony; Selwyn, Neil

    2013-01-01

    Scholars representing the field of organizational science, broadly defined as including many fields--organizational behavior and development, management, workplace performance, and so on--were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might…

  1. Literary Science.

    ERIC Educational Resources Information Center

    Garrison, Megan R.

    2000-01-01

    Explains the use of literacy in science education. Uses "Silent Spring", a book on environmental issues, to encourage students to think about the role of water in balancing the earth's system and possible actions against environmental concerns. Creates an environment for students to discuss their knowledge on the use of the pesticide…

  2. Space Science

    NASA Image and Video Library

    1992-03-24

    Space Shuttle Atlantis (STS-45) onboard photo of Mission Specialist Kathryn Sullivan working in the Atmospheric Laboratory for Applications and Science (Atlas-1) module. Atlas-1 flew in a series of Spacelab flights that measured long term variability in the total energy radiated by the Sun and determined the variability in the solar spectrum.

  3. Science Notes.

    ERIC Educational Resources Information Center

    Talbot, Chris; And Others

    1991-01-01

    Twenty science experiments are presented. Topics include recombinant DNA, physiology, nucleophiles, reactivity series, molar volume of gases, spreadsheets in chemistry, hydrogen bonding, composite materials, radioactive decay, magnetism, speed, charged particles, compression waves, heat transfer, Ursa Major, balloons, current, and expansion of…

  4. Science Notes.

    ERIC Educational Resources Information Center

    Talbot, Chris; And Others

    1991-01-01

    Twenty science experiments are presented. Topics include recombinant DNA, physiology, nucleophiles, reactivity series, molar volume of gases, spreadsheets in chemistry, hydrogen bonding, composite materials, radioactive decay, magnetism, speed, charged particles, compression waves, heat transfer, Ursa Major, balloons, current, and expansion of…

  5. Literary Science.

    ERIC Educational Resources Information Center

    Garrison, Megan R.

    2000-01-01

    Explains the use of literacy in science education. Uses "Silent Spring", a book on environmental issues, to encourage students to think about the role of water in balancing the earth's system and possible actions against environmental concerns. Creates an environment for students to discuss their knowledge on the use of the pesticide…

  6. Environmental Science

    ERIC Educational Resources Information Center

    Eads, Ewin A.

    1973-01-01

    Discusses implementation of an interdisciplinary bachelor of science degree program in Lamar University, Beaumont, with emphases upon the training of pollution and environmental quality control. Indicates that graduates' job opportunities are created by the enactment of recent laws for cleaner air and water. (CC)

  7. Earth Science

    NASA Image and Video Library

    1992-03-24

    Space Shuttle Atlantis (STS-45) onboard photo of Atmospheric Laboratory for Applications and Science (Atlas-1) module in open cargo bay. Atlas-1 pallets are back dropped against the Atlas Mountains. Taken over Mali in the western Sahara, shows dunes in the Iguidi Dune Sea.

  8. Actuarial Science.

    ERIC Educational Resources Information Center

    Warren, Bette

    1982-01-01

    Details are provided of a program on actuarial training developed at the State University of New York (SUNY) at Binghamton through the Department of Mathematical Sciences. An outline of its operation, including a few statistics on students in the program, is included. (MP)

  9. Cognitive Science.

    ERIC Educational Resources Information Center

    Cocking, Rodney R.; Mestre, Jose P.

    The focus of this paper is on cognitive science as a model for understanding the application of human skills toward effective problem-solving. Sections include: (1) "Introduction" (discussing information processing framework, expert-novice distinctions, schema theory, and learning process); (2) "Application: The Expert-Novice…

  10. Material Science

    NASA Image and Video Library

    2003-01-22

    One of the first materials science experiments on the International Space Station -- the Solidification Using a Baffle in Sealed Ampoules (SUBSA) -- will be conducted during Expedition Five inside the Microgravity Science Glovebox. The glovebox is the first dedicated facility delivered to the Station for microgravity physical science research, and this experiment will be the first one operated inside the glovebox. The glovebox's sealed work environment makes it an ideal place for the furnace that will be used to melt semiconductor crystals. Astronauts can change out samples and manipulate the experiment by inserting their hands into a pair of gloves that reach inside the sealed box. Dr. Aleksandar Ostrogorsky, a materials scientist from the Rensselaer Polytechnic Institute, Troy, N.Y., and the principal investigator for the SUBSA experiment, uses the gloves to examine an ampoule like the ones used for his experiment inside the glovebox's work area. The Microgravity Science Glovebox and the SUBSA experiment are managed by NASA's Marshall Space Flight Center in Huntsville, Ala.

  11. Animal Science.

    ERIC Educational Resources Information Center

    VanCleave, Janice

    2001-01-01

    Presents a set of hands-on, outdoor science experiments designed to teach elementary school students about animal adaptation. The experiments focus on: how color camouflage affects an insect population; how spiderlings find a home; and how chameleons camouflage themselves by changing color. (SM)

  12. Organizational Science

    ERIC Educational Resources Information Center

    Beriwal, Madhu; Clegg, Stewart; Collopy, Fred; McDaniel, Reuben, Jr.; Morgan, Gareth; Sutcliffe, Kathleen; Kaufman, Roger; Marker, Anthony; Selwyn, Neil

    2013-01-01

    Scholars representing the field of organizational science, broadly defined as including many fields--organizational behavior and development, management, workplace performance, and so on--were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might…

  13. Redirecting science

    SciTech Connect

    Aaserud, F.

    1990-01-01

    This book contains the following chapters. Science policy and fund-raising up to 1934; The Copenhagen spirit at work, late 1920's to mid-1930s; The refugee problem, 1933 to 1935; Experimental biology, late 1920s to 1935; and Consolidation of the transition, 1935 to 1940.

  14. Science Notes.

    ERIC Educational Resources Information Center

    Shaw, G. W.; And Others

    1989-01-01

    Provides a reading list for A- and S-level biology. Contains several experiments and demonstrations with topics on: the intestine, bullock corneal cells, valences, the science of tea, automated hydrolysis, electronics characteristics, bromine diffusion, enthalpy of vaporization determination, thermometers, pendulums, hovercraft, Bernoulli fluid…

  15. Environmental Science

    ERIC Educational Resources Information Center

    Eads, Ewin A.

    1973-01-01

    Discusses implementation of an interdisciplinary bachelor of science degree program in Lamar University, Beaumont, with emphases upon the training of pollution and environmental quality control. Indicates that graduates' job opportunities are created by the enactment of recent laws for cleaner air and water. (CC)

  16. Animal Science.

    ERIC Educational Resources Information Center

    VanCleave, Janice

    2001-01-01

    Presents a set of hands-on, outdoor science experiments designed to teach elementary school students about animal adaptation. The experiments focus on: how color camouflage affects an insect population; how spiderlings find a home; and how chameleons camouflage themselves by changing color. (SM)

  17. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1990

    1990-01-01

    Presented are 25 science activities on colorations of prey, evolution, blood, physiology, nutrition, enzyme kinetics, leaf pigments, analytical chemistry, milk, proteins, fermentation, surface effects of liquids, magnetism, drug synthesis, solvents, wintergreen synthesis, chemical reactions, multicore cables, diffraction, air resistance,…

  18. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1986

    1986-01-01

    Describes 26 different activities, experiments, demonstrations, and computer simulations in various topics in science. Includes instructional activities dealing with mural ecology, surface area/volume ratios, energy transfer in ecosystems, electrochemical simulations, alternating and direct current, terminal velocity, measuring the size of the…

  19. Subterranean science

    NASA Astrophysics Data System (ADS)

    Paling, Sean; Sadler, Stephen

    2015-05-01

    The deep underground laboratories of the world are no longer the scientific realm of astroparticle physics alone. From Mars rovers to muon tomography, and from radioactive dating to astrobiology, Sean Paling and Stephen Sadler describe the renaissance in the science taking place far beneath our feet.

  20. Science Notes.

    ERIC Educational Resources Information Center

    Shaw, G. W.; And Others

    1989-01-01

    Provides a reading list for A- and S-level biology. Contains several experiments and demonstrations with topics on: the intestine, bullock corneal cells, valences, the science of tea, automated hydrolysis, electronics characteristics, bromine diffusion, enthalpy of vaporization determination, thermometers, pendulums, hovercraft, Bernoulli fluid…

  1. Pathological Science

    NASA Astrophysics Data System (ADS)

    Stone, Sheldon

    2001-09-01

    I discuss examples of what Dr. Irving Langmuir, a Nobel prize winner in Chemistry, called "the science of things that aren't so." Some of his examples are reviewed and others from High Energy Physics are added. It is hoped that discussing these incidents will help us develop an understanding of some potential pitfalls.

  2. Kaleidoscope Science.

    ERIC Educational Resources Information Center

    Janes, Patricia

    2002-01-01

    Presents a collection of science activities that have elementary students investigate how color can trick the eye and the brain. The activities involve working with contrasting colors, creating a rainbow, and exploring the connection between colors and words. An instructor reproducible features two color activities. (SM)

  3. Tricky Science

    ERIC Educational Resources Information Center

    Stewart, Mike

    2004-01-01

    The author's favorite way to start the new school year is to perform a science demo for students. At the beginning of the period, he discusses the importance of making accurate observations. He tells them that he will perform a short demonstration that they are to carefully watch and then record their observations. They each have a sheet of paper…

  4. Science First

    ERIC Educational Resources Information Center

    Comstock, Diane

    2005-01-01

    At the elementary level, when children learn best through hands-on activities, when is the best time to use literacy and make that connection to enhance learning? For teachers involved in Colorado Springs, Colorado, Science Teacher Enhancement Program Unifying the Pikes Peak Region, STEP-uP professional development program for teachers, it is…

  5. Brewing Science

    ERIC Educational Resources Information Center

    Pelter, Michael

    2006-01-01

    Following the brewing process from grain to glass, this course uses the biological and chemical principles of brewing to teach science to the nonscience major. Discussion of the scientific aspects of malting, mashing, fermentation, and the making of different beer styles is complemented by laboratory exercises that use scientific methods to…

  6. Nuclear Science.

    ERIC Educational Resources Information Center

    Pennsylvania State Dept. of Education, Harrisburg. Bureau of Curriculum Services.

    This document is a report on a course in nuclear science for the high school curriculum. The course is designed to provide a basic but comprehensive understanding of the atom in the light of modern knowledge, and to show how people attempt to harness the tremendous energy liberated through fission and fusion reactions. The course crosses what are…

  7. Actuarial Science.

    ERIC Educational Resources Information Center

    Warren, Bette

    1982-01-01

    Details are provided of a program on actuarial training developed at the State University of New York (SUNY) at Binghamton through the Department of Mathematical Sciences. An outline of its operation, including a few statistics on students in the program, is included. (MP)

  8. Science Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1986

    1986-01-01

    Describes activities, games, experiments, demonstrations, and computer-oriented exercises in all science areas. Topics include energy flow through a marine ecosystem, using 2,4-dichlorophenoxyethanoic acid to demonstrate translocation in plants, use of the dichotomous key, use of leaf yeasts to monitor atmospheric pollution, and others. (JN)

  9. Science Journalism

    ERIC Educational Resources Information Center

    Polman, Joseph; Newman, Alan; Farrar, Cathy; Saul, E. Wendy

    2012-01-01

    Much of the National Science Education Standards (NRC 1996), aside from the inquiry and teaching sections, focus on content. The authors' call is instead to build standards that focus on what students need to be scientifically literate in 10 or 15 years. Although a basic understanding of important scientific concepts and an understanding of how…

  10. Systems Science

    ERIC Educational Resources Information Center

    Christakis, Alexander; Hammond, Debora; Jackson, Michael; Laszlo, Alexander; Mitroff, Ian; Snowden, Dave; Troncale, Len; Carr-Chellman, Alison; Spector, J. Michael; Wilson, Brent

    2013-01-01

    Scholars representing the field of systems science were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Alexander Christakis, Debora Hammond, Michael Jackson, Alexander Laszlo, Ian Mitroff, Dave…

  11. Systems Science

    ERIC Educational Resources Information Center

    Christakis, Alexander; Hammond, Debora; Jackson, Michael; Laszlo, Alexander; Mitroff, Ian; Snowden, Dave; Troncale, Len; Carr-Chellman, Alison; Spector, J. Michael; Wilson, Brent

    2013-01-01

    Scholars representing the field of systems science were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Alexander Christakis, Debora Hammond, Michael Jackson, Alexander Laszlo, Ian Mitroff, Dave…

  12. The Coupling of Solute Fluxes in Membranes

    PubMed Central

    Galey, William R.; Van Bruggen, J. T.

    1970-01-01

    Our previous description of solute drag on a synthetic membrane has been extended to include the solutes mannitol, sucrose, raffinose, inulin, and dextran. Labeled and nonlabeled forms of these solutes were used in pairs to quantitate solute flux interaction. Three membranes with pore sizes of 350, 80, and 20 A, respectively, have been utilized. It is shown that solute flux interaction occurs with all the solutes and that the extent of interaction is related directly to solute permeability, concentration, and molecular size. The magnitude of solute interaction is reciprocally related to the radii of the membrane pores, greater interaction occurring with small pored membranes. Solute drag is seen as an increased flux of tracer solute in the direction of the diffusion gradient of a second solute as well as a decreased tracer flux into the diffusion gradient. Values are given for self-diffusion and interaction coefficients as well as for a new coefficient, the "effectiveness coefficient." PMID:5413079

  13. Electron Flux of Radiation Belts Animation

    NASA Image and Video Library

    This animation shows meridional (from north-south) plane projections of the REPT-A and REPT-B electron flux values. The animation first shows the expected two-belt Van Allen zone structure; from Se...

  14. Flux-based active filter controller

    SciTech Connect

    Bhattacharya, S.; Divan, D.M.; Lorenz, R.D.; Veltman, A.

    1996-05-01

    This paper presents a synchronous frame flux-based control method for a parallel active filter application. The flux-based controller directly implements the inverter switchings in the synchronous reference frame by a hysteresis rule-based carrier-less pulse-width modulation (PWM) strategy to achieve high current bandwidth. This paper addresses the issues and impact on parallel active filtering requirements for utility interface of commonly used harmonic front-ends. The synchronous frame flux-based controller provides additional insights for harmonic current compensation requirements. Simulation results provide the validation of the flux-based active filter controller to meet IEEE Standard 519 recommended harmonic standards for large rated nonlinear loads under balanced and unbalanced supply conditions.

  15. Tetrakis-amido high flux membranes

    DOEpatents

    McCray, Scott B.

    1989-01-01

    Composite RO membranes of a microporous polymeric support and a polyamide reaction product of a tetrakis-aminomethyl compound and a polyacylhalide are disclosed, said membranes exhibiting high flux and good chlorine resistance.

  16. Tetrakis-amido high flux membranes

    DOEpatents

    McCray, S.B.

    1989-10-24

    Composite RO membranes of a microporous polymeric support and a polyamide reaction product of a tetrakis-aminomethyl compound and a polyacylhalide are disclosed, said membranes exhibiting high flux and good chlorine resistance.

  17. Cool and hot flux ropes, their helicity

    NASA Astrophysics Data System (ADS)

    Nindos, Alexander

    2016-07-01

    We will review recent indirect and direct evidence for the existence of magnetic flux ropes in the solar atmosphere. Magnetic flux ropes may appear as S-shaped or reverse S-shaped (sigmoidal) structures in regions that are likely to erupt, and may also show in nonlinear force-free field extrapolations that use data from photospheric vector magnetograms as boundary condition. The availability of high sensitivity data recorded with unprecedented spatial and temporal resolution in hot EUV wavelengths by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) has revealed the existence of coherent structures identified as hot flux ropes. In this presentation, we will review the properties of both cool and hot flux ropes with an emphasis on the frequency of their occurrence in large flares and on their magnetic helicity content.

  18. Hydrodynamic focusing of a particle flux

    SciTech Connect

    Makhviladze, G.M.; Melikhov, O.I.; Nikolova, I.P.

    1995-12-01

    Based on numerical integration of the equations of mechanics of multiphase media, an effect of focusing of a particle flux generated by a source located on the upper wall of a closed vessel has been revealed and investigated.

  19. Magnetic flux, Wilson line, and orbifold

    SciTech Connect

    Abe, Hiroyuki; Choi, Kang-Sin; Kobayashi, Tatsuo; Ohki, Hiroshi

    2009-12-15

    We study torus/orbifold models with magnetic flux and Wilson line backgrounds. The number of zero modes and their profiles depend on those backgrounds. That has interesting implications from the viewpoint of particle phenomenology.

  20. Experimental flux measurements on a network scale

    SciTech Connect

    Schwender, J.

    2011-10-11

    Metabolic flux is a fundamental property of living organisms. In recent years, methods for measuring metabolic flux in plants on a network scale have evolved further. One major challenge in studying flux in plants is the complexity of the plant's metabolism. In particular, in the presence of parallel pathways in multiple cellular compartments, the core of plant central metabolism constitutes a complex network. Hence, a common problem with the reliability of the contemporary results of {sup 13}C-Metabolic Flux Analysis in plants is the substantial reduction in complexity that must be included in the simulated networks; this omission partly is due to limitations in computational simulations. Here, I discuss recent emerging strategies that will better address these shortcomings.