Science.gov

Sample records for billion electron volts

  1. Feasibility study for mega-electron-volt electron beam tomography

    SciTech Connect

    Hampel, U.; Baertling, Y.; Hoppe, D.; Kuksanov, N.; Fadeev, S.; Salimov, R.

    2012-09-15

    Electron beam tomography is a promising imaging modality for the study of fast technical processes. But for many technical objects of interest x rays of several hundreds of keV energy are required to achieve sufficient material penetration. In this article we report on a feasibility study for fast electron beam computed tomography with a 1 MeV electron beam. The experimental setup comprises an electrostatic accelerator with beam optics, transmission target, and a single x-ray detector. We employed an inverse fan-beam tomography approach with radiographic projections being generated from the linearly moving x-ray source. Angular projections were obtained by rotating the object.

  2. Feasibility study for mega-electron-volt electron beam tomography.

    PubMed

    Hampel, U; Bärtling, Y; Hoppe, D; Kuksanov, N; Fadeev, S; Salimov, R

    2012-09-01

    Electron beam tomography is a promising imaging modality for the study of fast technical processes. But for many technical objects of interest x rays of several hundreds of keV energy are required to achieve sufficient material penetration. In this article we report on a feasibility study for fast electron beam computed tomography with a 1 MeV electron beam. The experimental setup comprises an electrostatic accelerator with beam optics, transmission target, and a single x-ray detector. We employed an inverse fan-beam tomography approach with radiographic projections being generated from the linearly moving x-ray source. Angular projections were obtained by rotating the object.

  3. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

    SciTech Connect

    Weathersby, S. P.; Brown, G.; Centurion, M.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K.; Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D.; Nguyen, M. N.; Reid, A. H.; Shen, X.; Sokolowski-Tinten, K.; Vecchione, T.; Vetter, S. L.; Wu, J.; Yang, J.; Dürr, H. A.; Wang, X. J.

    2015-07-01

    Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

  4. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

    SciTech Connect

    Weathersby, S. P.; Brown, G.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K. Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D.; and others

    2015-07-15

    Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

  5. Ultralow Energy Electron Attachment at Sub-Millielectron Volt Resolution

    NASA Technical Reports Server (NTRS)

    Chutjian, A.; Kortyna, A.; Darrach, M. R.; Howe, P. -T.

    1999-01-01

    The technique of rare-gas photoionization has been extended by use of direct laser ionization to electron energies epsilon in the range 0-100 meV, with a resolution Delta(epsilon) of 0.4-0.5 meV (FWHM). Tunable UV light at (Lambda)276 nm is produced using a pulsed Nd:YAG laser and nonlinear mixing techniques. The beam is frequency tripled in a pulsed jet of xenon. The VUV radiation, tunable at (Lambda)92 nm, is then used to photoionize Xe at its 2P(sub 1/2) threshold (single-photon ionization). The photoelectrons produced interact with admixed target gas to generate negative ions through the s-wave capture process. Recent results in electron attachment to SF(sub 6) will be reported which show resonance structure at the opening of the ground-state vibrational channels. This structure corresponds to the process of vibrational excitation + attachment, which is superimposed on the underlying s-wave (direct) capture process. It should be a general phenomenon, present in a wide variety of zero-energy electron attaching molecules.

  6. Direct observation of radiation-belt electron acceleration from electron-volt energies to megavolts by nonlinear whistlers.

    PubMed

    Mozer, F S; Agapitov, O; Krasnoselskikh, V; Lejosne, S; Reeves, G D; Roth, I

    2014-07-18

    The mechanisms for accelerating electrons from thermal to relativistic energies in the terrestrial magnetosphere, on the sun, and in many astrophysical environments have never been verified. We present the first direct observation of two processes that, in a chain, cause this acceleration in Earth's outer radiation belt. The two processes are parallel acceleration from electron-volt to kilovolt energies by parallel electric fields in time-domain structures (TDS), after which the parallel electron velocity becomes sufficiently large for Doppler-shifted upper band whistler frequencies to be in resonance with the electron gyration frequency, even though the electron energies are kilovolts and not hundreds of kilovolts. The electrons are then accelerated by the whistler perpendicular electric field to relativistic energies in several resonant interactions. TDS are packets of electric field spikes, each spike having duration of a few hundred microseconds and containing a local parallel electric field. The TDS of interest resulted from nonlinearity of the parallel electric field component in oblique whistlers and consisted of ∼ 0.1 msec pulses superposed on the whistler waveform with each such spike containing a net parallel potential the order of 50 V. Local magnetic field compression from remote activity provided the free energy to drive the two processes. The expected temporal correlations between the compressed magnetic field, the nonlinear whistlers with their parallel electric field spikes, the electron flux and the electron pitch angle distributions were all observed. PMID:25083648

  7. FOREWORD: VI Workshop in Electron Volt Neutron Spectroscopy: Frontiers and Horizons

    NASA Astrophysics Data System (ADS)

    Seel, A. G.; Senesi, R.; Fernandez-Alonso, F.

    2014-12-01

    January 2014 saw the congregation in Abingdon (UK) of scientists from across the world, to discuss the current state and future of spectroscopy using epithermal neutrons. This meeting was the sixth in a series of workshops held in collaboration between the Science and Technology Facilities Council (UK) and the Consiglio Nazionale delle Ricerche (Italy), aimed at bringing together researchers with an interest in the use of electron-volt neutrons in spectroscopic studies [1]. This technique is termed Deep Inelastic Neutron Scattering (DINS), and also Neutron Compton Scattering (NCS) in reference to the analogy with Compton scattering of X-rays from electrons. In particular, this meeting centred jointly around experimentalists and theoreticians, formulating animated discussions as to the current overview of DINS and future horizons facing the field. The use of electron Volt neutrons for spectroscopic measurements dates back to the advent of proton-driven spallation neutron sources in the 1970s and 1980s. Following an initial scientific meeting in Los Alamos (USA) [2], the first two meetings in this series were held in Abingdon (UK) in 1995 and 1998, with subsequent meetings held in Santa Fe (USA) in 2005 [3], Oak Ridge National Laboratory (USA) in 2006 [4], and Rome, Italy; in 2010 [5]. The flagship instrument serving a continual user-programme for DINS measurements, and the main focus of this meeting, has been the VESUVIO spectrometer at ISIS [6, 7]. Subsequent instruments like SEQUOIA in the USA [8, 9] and a newer spectrometer in the Bariloche LINAC in Argentina [10, 11] have also been commissioned and began serving a growing user community. The availability of DINS measurements has extended the range of possible spectroscopic techniques that utilise neutrons into the kinematic region of high energy and momentum transfers, shown schematically in Figure 1. Spectroscopic instrument suites such as that of ISIS are thus able to probe processes on timescales across nine

  8. Image plate characterization and absolute calibration to low kilo-electron-volt electrons

    SciTech Connect

    Busold, S.; Philipp, K.; Otten, A.; Roth, M.

    2014-11-15

    We report on the characterization of an image plate and its absolute calibration to electrons in the low keV energy range (1–30 keV). In our case, an Agfa MD4.0 without protection layer was used in combination with a Fuji FLA7000 scanner. The calibration data are compared to other published data and a consistent picture of the sensitivity of image plates to electrons is obtained, which suggests a validity of the obtained calibration up to 100 keV.

  9. FOREWORD: VI Workshop in Electron Volt Neutron Spectroscopy: Frontiers and Horizons

    NASA Astrophysics Data System (ADS)

    Seel, A. G.; Senesi, R.; Fernandez-Alonso, F.

    2014-12-01

    January 2014 saw the congregation in Abingdon (UK) of scientists from across the world, to discuss the current state and future of spectroscopy using epithermal neutrons. This meeting was the sixth in a series of workshops held in collaboration between the Science and Technology Facilities Council (UK) and the Consiglio Nazionale delle Ricerche (Italy), aimed at bringing together researchers with an interest in the use of electron-volt neutrons in spectroscopic studies [1]. This technique is termed Deep Inelastic Neutron Scattering (DINS), and also Neutron Compton Scattering (NCS) in reference to the analogy with Compton scattering of X-rays from electrons. In particular, this meeting centred jointly around experimentalists and theoreticians, formulating animated discussions as to the current overview of DINS and future horizons facing the field. The use of electron Volt neutrons for spectroscopic measurements dates back to the advent of proton-driven spallation neutron sources in the 1970s and 1980s. Following an initial scientific meeting in Los Alamos (USA) [2], the first two meetings in this series were held in Abingdon (UK) in 1995 and 1998, with subsequent meetings held in Santa Fe (USA) in 2005 [3], Oak Ridge National Laboratory (USA) in 2006 [4], and Rome, Italy; in 2010 [5]. The flagship instrument serving a continual user-programme for DINS measurements, and the main focus of this meeting, has been the VESUVIO spectrometer at ISIS [6, 7]. Subsequent instruments like SEQUOIA in the USA [8, 9] and a newer spectrometer in the Bariloche LINAC in Argentina [10, 11] have also been commissioned and began serving a growing user community. The availability of DINS measurements has extended the range of possible spectroscopic techniques that utilise neutrons into the kinematic region of high energy and momentum transfers, shown schematically in Figure 1. Spectroscopic instrument suites such as that of ISIS are thus able to probe processes on timescales across nine

  10. Coherent kilo-electron-volt backscattering from plasma-wave boosted relativistic electron mirrors

    SciTech Connect

    Li, F. Y.; Chen, M. Liu, Y.; Zhang, J.; Sheng, Z. M. E-mail: zmsheng@sjtu.edu.cn; Wu, H. C.; Meyer-ter-Vehn, J.; Mori, W. B.

    2014-10-20

    A different parameter regime of laser wakefield acceleration driven by sub-petawatt femtosecond lasers is proposed, which enables the generation of relativistic electron mirrors further accelerated by the plasma wave. Integrated particle-in-cell simulation, including both the mirror formation and Thomson scattering, demonstrates that efficient coherent backscattering up to keV photon energy can be obtained with moderate driving laser intensities and high density gas targets.

  11. Absolute differential cross sections for electron capture and loss by kilo-electron-volt hydrogen atoms

    NASA Technical Reports Server (NTRS)

    Smith, G. J.; Johnson, L. K.; Gao, R. S.; Smith, K. A.; Stebbings, R. F.

    1991-01-01

    This paper reports measurements of absolute differential cross sections for electron capture and loss for fast hydrogen atoms incident on H2, N2, O2, Ar, and He. Cross sections have been determined in the 2.0- to 5.0-keV energy range over the laboratory angular range 0.02-2 deg, with an angular, resolution of 0.02 deg. The high angular resolution allows observation of the structure at small angles in some of the cross sections. Comparison of the present results with those of other authors generally shows very good agreement.

  12. Generation of high-quality mega-electron volt proton beams with intense-laser-driven nanotube accelerator

    NASA Astrophysics Data System (ADS)

    Murakami, M.; Tanaka, M.

    2013-04-01

    An ion acceleration scheme using carbon nanotubes (CNTs) is proposed, in which embedded fragments of low-Z materials are irradiated by an ultrashort intense laser to eject substantial numbers of electrons. Due to the resultant characteristic electrostatic field, the nanotube and embedded materials play the roles of the barrel and bullets of a gun, respectively, to produce highly collimated and quasimonoenergetic ion beams. Three-dimensional particle simulations, that take all the two-body Coulomb interactions into account, demonstrate generation of quasimonoenergetic MeV-order proton beams using nanometer-size CNT under a super-intense electrostatic field ˜1014 V m-1.

  13. Electron microscopy reveals unique microfossil preservation in 1 billion-year-old lakes

    NASA Astrophysics Data System (ADS)

    Saunders, M.; Kong, C.; Menon, S.; Wacey, D.

    2014-06-01

    Electron microscopy was applied to the study of 1 billion-year-old microfossils from northwest Scotland in order to investigate their 3D morphology and mode of fossilization. 3D-FIB-SEM revealed high quality preservation of organic cell walls with only minor amounts of post-mortem decomposition, followed by variable degrees of morphological alteration (folding and compression of cell walls) during sediment compaction. EFTEM mapping plus SAED revealed a diverse fossilizing mineral assemblage including K-rich clay, Fe-Mg-rich clay and calcium phosphate, with each mineral occupying specific microenvironments in proximity to carbonaceous microfossil cell walls.

  14. The ExaVolt Antenna

    NASA Astrophysics Data System (ADS)

    Dailey, Brian

    2014-03-01

    There are strong motivations for a flux of ultra-high energy (UHE) neutrinos that is observable on earth, yet they remain undetected. The proposed ExaVolt Antenna (EVA) uses a novel approach to increase the expected rate of neutrinos in a balloon-borne experiment such as ANITA by 100-fold by turning a 100m-diameter, long-duration, super pressure NASA balloon into an antenna reflector with receivers deployed in the interior of the balloon. EVA would be the world's largest airborne telescope with ~ 1000 m2 of collection area. I will present preliminary results from a 1:20 scale EVA prototype test conducted in early 2014 in a hangar at NASA's Wallops Flight Facility. I will conclude with the expected sensitivity of the full EVA experiment to UHE neutrino fluxes.

  15. Development of the VOLT-A Shuttle experiment. [Volt Operating Limit Tests

    NASA Technical Reports Server (NTRS)

    Bifano, William J.; Bozek, John M.; Ferguson, Dale C.

    1985-01-01

    The NASA Lewis Research Center (LeRC) is investigating potential problems associated with the operation of high voltage solar cell arrays in the space plasma environment. At high voltages, interactions between the solar array and the space plasma could result in unacceptable levels of electrical discharge (arcing) and/or parasitic losses (current drains from the array to the plasma). The objective of the Voltage Operating Limit Tests (VOLT-A) Shuttle bay experiment is to characterize space plasma/solar cell panel interactions in low earth orbit. VOLT-A consists of an experiment plate subassembly which contains four solar panels, an electronics subassembly and a Langmuir probe subassembly mounted on an MPESS carrier. During a given 8.25 hour data taking period (5-1/2 continuous orbits), the solar panels, which represent state-of-the-art solar cell technologies, will be sequentially subjected to bias voltages in steps ranging from minus 626 V to plus 313 V. Appropriate measurements will be made at each voltage to characterize arcing and parasitic losses. Corresponding measurements of the plasma environment (plasma density, electron temperature and neutral density) will also be made. Data will be recorded on an on-board tape recorder for subsequent data reduction and analysis.

  16. Constraint on a varying proton-electron mass ratio 1.5 billion years after the big bang.

    PubMed

    Bagdonaite, J; Ubachs, W; Murphy, M T; Whitmore, J B

    2015-02-20

    A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10% of the age of the Universe today, is analyzed to put a constraint on a varying proton-electron mass ratio, μ. A high resolution spectrum of the J1443+2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to μ, yielding a limit on the relative deviation from the current laboratory value of Δμ/μ=(-9.5 ± 5.4(stat)± 5.3(syst))×10(-6).

  17. Constraint on a varying proton-electron mass ratio 1.5 billion years after the big bang.

    PubMed

    Bagdonaite, J; Ubachs, W; Murphy, M T; Whitmore, J B

    2015-02-20

    A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10% of the age of the Universe today, is analyzed to put a constraint on a varying proton-electron mass ratio, μ. A high resolution spectrum of the J1443+2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to μ, yielding a limit on the relative deviation from the current laboratory value of Δμ/μ=(-9.5 ± 5.4(stat)± 5.3(syst))×10(-6). PMID:25763949

  18. Steady State Load Characterization Fact Sheet: 2012 Chevy Volt

    SciTech Connect

    Don Scoffield

    2015-01-01

    This fact sheet characterizes the steady state charging behavior of a 2012 Chevy Volt. Both level 1 charging (120 volt) and level 2 charging (208 volts) is investigated. This fact sheet contains plots of efficiency, power factor, and current harmonics as vehicle charging is curtailed. Prominent current harmonics are also displayed in a histogram for various charge rates.

  19. Development of the VOLT-A shuttle experiment

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Bozek, J. M.; Ferguson, D. C.

    1985-01-01

    The NASA Lewis Research Center (LeRC) is investigating potential problems associated with the operation of high voltage solar cell arrays in the space plasma environment. At high voltages, interactions between the solar array and the space plasma could result in unacceptable levels of electrical discharge (arcing) and/or parasitic losses (current drains from the array to the plasma). The objective of the Voltage Operating Limit Tests (VOLT-A) Shuttle bay experiment is to characterize space plasma/solar cell panel interactions in low earth orbit. VOLT-A consists of an experiment plate subassembly which contains four solar panels, an electronics subassembly and a Langmuir probe subassembly mounted on an MPESS carrier. During a given 8.25 hour data taking period (5-1/2 continuous orbits), the solar panels, which represent state-of-the-art solar cell technologies, will be sequentially subjected to bias voltages in steps ranging from minus 626 V to plus 313 V. Appropriate measurements will be made at each voltage to characterize arcing and parasitic losses. Corresponding measurements of the plasma environment (plasma density, electron temperature and neutral density) will also be made. Data will be recorded on an on-board tape recorder for subsequent data reduction and analysis.

  20. Application considerations for variable volts per turn power transformers

    SciTech Connect

    Ebert, J.A. )

    1994-01-01

    Power transformer tap changing, either under load or when the transformer is de-energized, can be achieved by tapping the winding other than that which is experiencing the voltage change to be compensated. Thus the transformer has a variable volts per turn or variable excitation. The design technique is well known to transformer manufacturers but the author's experience is that it is not widely understood, nor are its advantages appreciated by transformer users. A search for papers revealed a surprising lack of material on this subject. The intent of this tutorial paper is to familiarize transformer users with the principles of designing variable volts per turn transformers and with performance differences from the usual constant volts per turn design, and with the economic advantages of reduced losses and reduced initial cost that is often possible with a variable volts per turn transformer design.

  1. Will a New Milli-Volt Switch Replace the Transistor for Digital Applications?

    NASA Astrophysics Data System (ADS)

    Yablonovitch, Eli

    2008-03-01

    In contemplating the headlong rush toward miniaturization represented by Moore’s Law, it is tempting to think only of the progression toward molecular sized components. There is a second aspect of Moore’s Law, that is sometimes overlooked. Because of miniaturization, the energy efficiency of information processing steadily improves. We anticipate that the energy required to process a single bit of information will eventually become as tiny as 1 electron Volt per function, truly indeed a molecular sized energy. Inevitably most logic functions including storage, readout, and other logical manipulations will eventually be that efficient. However there is one information-processing-function that bucks this trend. That is communication, especially over short distances. Our best projections of improvements in the short distance communication function show that it will still require hundreds of thousand of electron Volts, just to move one bit of information the tiny distance of only 10 micro meters. Why this energy per bit discrepancy for communications? It is caused by the difference in voltage scale between the wires and the transistor switches. Transistors are thermally activated, leading to a characteristic voltage >>kT/q. Wires are long and they have a low impedance, allowing them to operate efficiently even at 1milli-Volt. The challenge then is to replace transistors with a new low-voltage switch , that is better matched to the wires. I will present some of the technical options for such a new switch.

  2. A Method for Evaluating Volt-VAR Optimization Field Demonstrations

    SciTech Connect

    Schneider, Kevin P.; Weaver, T. F.

    2014-08-31

    In a regulated business environment a utility must be able to validate that deployed technologies provide quantifiable benefits to the end-use customers. For traditional technologies there are well established procedures for determining what benefits will be derived from the deployment. But for many emerging technologies procedures for determining benefits are less clear and completely absent in some cases. Volt-VAR Optimization is a technology that is being deployed across the nation, but there are still numerous discussions about potential benefits and how they are achieved. This paper will present a method for the evaluation, and quantification of benefits, for field deployments of Volt-VAR Optimization technologies. In addition to the basic methodology, the paper will present a summary of results, and observations, from two separate Volt-VAR Optimization field evaluations using the proposed method.

  3. 59. View of high voltage (4160 volts alternating current) electric ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. View of high voltage (4160 volts alternating current) electric load center and motor control center at mezzanine level in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  4. Plant Generator driven by a small Delco 32 volt DC ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plant Generator driven by a small Delco 32 volt DC steam engine with a maximum output of 17.6 kilowatts - East Broad Top Railroad & Coal Company, Machine Shop, State Route 994, West of U.S. Route 522, Rockhill Furnace, Huntingdon County, PA

  5. Zero Volt Paper Spray Ionization and Its Mechanism.

    PubMed

    Wleklinski, Michael; Li, Yafeng; Bag, Soumabha; Sarkar, Depanjan; Narayanan, Rahul; Pradeep, T; Cooks, R Graham

    2015-07-01

    The analytical performance and a suggested mechanism for zero volt paper spray using chromatography paper are presented. A spray is generated by the action of the pneumatic force of the mass spectrometer (MS) vacuum at the inlet. Positive and negative ion signals are observed, and comparisons are made with standard kV paper spray (PS) ionization and nanoelectrospray ionization (nESI). While the range of analytes to which zero volt PS is applicable is very similar to kV PS and nESI, differences in the mass spectra of mixtures are interpreted in terms of the more significant effects of analyte surface activity in the gentler zero volt experiment than in the other methods due to the significantly lower charge. The signal intensity of zero volt PS is also lower than in the other methods. A Monte Carlo simulation based on statistical fluctuation of positive and negative ions in solution has been implemented to explain the production of ions from initially uncharged droplets. Uncharged droplets first break up due to aerodynamics forces until they are in the 2-4 μm size range and then undergo Coulombic fission. A model involving statistical charge fluctuations in both phases predicts detection limits similar to those observed experimentally and explains the effects of binary mixture components on relative ionization efficiencies. The proposed mechanism may also play a role in ionization by other voltage-free methods. PMID:26024306

  6. 75 FR 21353 - Intel Corporation, Fab 20 Division, Including On-Site Leased Workers From Volt Technical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-23

    ... From Volt Technical Resources, Staff Finders Technical, Kelly Services, Retronix International... Division, including on-site leased workers of Volt Technical Resources, Staff Finders Technical and Kelly... workers from Volt Technical Resources, Staff Finders Technical, Kelly Services, Retronix...

  7. Particle physicist's dreams about PetaelectronVolt laser plasma accelerators

    SciTech Connect

    Vesztergombi, G.

    2012-07-09

    Present day accelerators are working well in the multi TeV energy scale and one is expecting exciting results in the coming years. Conventional technologies, however, can offer only incremental (factor 2 or 3) increase in beam energies which does not follow the usual speed of progress in the frontiers of high energy physics. Laser plasma accelerators theoretically provide unique possibilities to achieve orders of magnitude increases entering the PetaelectronVolt (PeV) energy range. It will be discussed what kind of new perspectives could be opened for the physics at this new energy scale. What type of accelerators would be required?.

  8. Matter-antimatter gigaelectron volt gamma ray laser rocket propulsion

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2012-12-01

    It is shown that the idea of a photon rocket through the complete annihilation of matter with antimatter, first proposed by Sänger, is not a utopian scheme as it is widely believed. Its feasibility appears to be possible by the radiative collapse of a relativistic high current pinch discharge in a hydrogen-antihydrogen ambiplasma down to a radius determined by Heisenberg's uncertainty principle. Through this collapse to ultrahigh densities the proton-antiproton pairs in the center of the pinch can become the upper gigaelectron volt laser level for the transition into a coherent gamma ray beam by proton-antiproton annihilation, with the magnetic field of the collapsed pinch discharge absorbing the recoil momentum of the beam and transmitting it by the Moessbauer effect to the spacecraft. The gamma ray laser beam is launched as a photon avalanche from one end of the pinch discharge channel. Because of the enormous technical problems to produce and store large amounts of anti-matter, such a propulsion concept may find its first realization in small unmanned space probes to explore nearby solar systems. The laboratory demonstration of a gigaelectron volt gamma ray laser by comparison requiring small amounts of anti-matter may be much closer.

  9. What kind of charging infrastructure do Chevrolet Volts Drivers in The EV Project use?

    SciTech Connect

    John Smart

    2013-09-01

    This report summarizes key conclusions from analysis of data collected from Chevrolet Volts participating in The EV Project. Topics include how much Volt drivers charge at level 1 vs. level 2 rates and how much they charge at home vs. away from home.

  10. Field emission electron source

    DOEpatents

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  11. Sub-parts-per-billion determination of nitro-substituted polynuclear aromatic hydrocarbons in airborne particulate matter and soil by electron capture-Tandem mass spectrometry.

    PubMed

    Vincenti, M; Minero, C; Pelizzetti, E; Fontana, M; De Maria, R

    1996-12-01

    A procedure for the determination of nitro-substiruted polynuclear aromatic hydrocarbons (nitro-PAH) on crude air-particulate and soil extracts is introduced. Elimination of purification and fractionation procedures was made possible by the use of both a selective ionization method, such as electron-capture chemical ionization, and a specific fragmentation process, in an experiment of tandem mass spectrometry (gas chromatography-electron capture tandem mass spectrometry). Different mass spectrometric procedures were compared. The best performance was observed when the nitro-PAH molecular ions [M](-) were mass-selected by the first analyzer under multiple reaction monitoring conditions and then fragmented to NO 2 (-) (m/z 46). Detection limits were on the order of hundreds of femtograms, as determined in extracts of real environmental samples. This corresponds approximately to 5-15 pg of nitro-PAH per cubic meter of air sampled. Calibration curves were linear over 3 orders of magnitude. Applications to contamination from motor vehicle combustion and the iron industry are briefly discussed.

  12. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators

    NASA Astrophysics Data System (ADS)

    O'Shea, B. D.; Andonian, G.; Barber, S. K.; Fitzmorris, K. L.; Hakimi, S.; Harrison, J.; Hoang, P. D.; Hogan, M. J.; Naranjo, B.; Williams, O. B.; Yakimenko, V.; Rosenzweig, J. B.

    2016-09-01

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m-1) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347+/-0.020 GeV m-1 using a dielectric wakefield accelerator of 15 cm length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320+/-17 MeV m-1. Both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons.

  13. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators.

    PubMed

    O'Shea, B D; Andonian, G; Barber, S K; Fitzmorris, K L; Hakimi, S; Harrison, J; Hoang, P D; Hogan, M J; Naranjo, B; Williams, O B; Yakimenko, V; Rosenzweig, J B

    2016-01-01

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m(-1)) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m(-1) using a dielectric wakefield accelerator of 15 cm length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m(-1). Both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons. PMID:27624348

  14. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators

    PubMed Central

    O'Shea, B. D.; Andonian, G.; Barber, S. K.; Fitzmorris, K. L.; Hakimi, S.; Harrison, J.; Hoang, P. D.; Hogan, M. J.; Naranjo, B.; Williams, O. B.; Yakimenko, V.; Rosenzweig, J. B.

    2016-01-01

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m−1) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m−1 using a dielectric wakefield accelerator of 15 cm length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m−1. Both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons. PMID:27624348

  15. Volt-Ampere characteristics and the anatomy of gas discharges

    NASA Astrophysics Data System (ADS)

    Petrović, Zoran; Marić, Dragana; Malović, Gordana; Škoro, Nikola; Radmilović-Radjenović, Marija

    2008-11-01

    We are presenting time resolved recordings of the spatial profile (radial and axial) of cylindrically symmetric discharges recorded by ICCD camera. These pictures are closely associated with temporal development of voltage and current. Volta-Ampere characteristics are recorded in order to test the pd, jd^2 and E/N scaling in such discharges and we have performed measurements both and standard, cm size discharges and for micro discharges. Most importantly we have recorded carefully the area of the discharge in order to make proper normalization of the total measured current into current density j. The proper breakdown voltage versus current density normalized by the square of the gap length characteristics is obtained where entire glow discharge is a single point as expected by the basic phenomenology. This has never been directly proven by measurements. We have also found that the Paschen curves and Volt- Ampere characteristics hold well, if properly normalized down to 200 micro meters. We have also found several modes, presumably associated with spatial profiles in hollow cathode and even in parallel plate discharges when radial dimension exceeds the mean free path by a large amount. We have also found evidence that flat Paschen curves recorded to the left of the minimum are in some cases due to the long path breakdown. This work was funded by project 155 of the Serbian Academy of Sciences and arts.

  16. Technology Development for the ExaVolt Antenna (EVA) Suborbital Ultra-High Energy Particle Observatory

    NASA Astrophysics Data System (ADS)

    Baginski, Frank; Brakke, Kenneth; Gorham, Peter; Furer, Joshua; Miki, Christian

    We describe technology development for the ExaVolt Antenna (EVA), the next generation balloon-borne ultra-high energy (UHE) particle observatory under development for NASA's suborbital super-pressure balloon program in Antarctica. The design is based on a novel application of toroidal reflector optics, utilizing the super-pressure balloon surface to mount an RF reflector and an internal feed-array suspended inside of the balloon, to create an ultra-large radio antenna system with a synoptic view of the Antarctic ice sheet below it. A 1/20 scale model test with an actual inflated balloon is planned for late Spring 2014 at the NASA Wallops Flight Facility. A 5.8~meter diameter super-pressure balloon will be pulsed at 3~GHz to test electronics and data acquisition systems. The 1/20 scale model will also be used to investigate deployment of the EVA system. Feed deployment is a semi-autonomous process that proceeds gradually as the volume of the ascending balloon increases. A mathematical model was developed to analyze deployment of the EVA system. Numerical solutions based on the model will be compared with measurements of ascent-like shapes assumed by the physical model during inflation.

  17. Automation of Coordinated Planning Between Observatories: The Visual Observation Layout Tool (VOLT)

    NASA Technical Reports Server (NTRS)

    Maks, Lori; Koratkar, Anuradha; Kerbel, Uri; Pell, Vince

    2002-01-01

    Fulfilling the promise of the era of great observatories, NASA now has more than three space-based astronomical telescopes operating in different wavebands. This situation provides astronomers with the unique opportunity of simultaneously observing a target in multiple wavebands with these observatories. Currently scheduling multiple observatories simultaneously, for coordinated observations, is highly inefficient. Coordinated observations require painstaking manual collaboration among the observatory staff at each observatory. Because they are time-consuming and expensive to schedule, observatories often limit the number of coordinated observations that can be conducted. In order to exploit new paradigms for observatory operation, the Advanced Architectures and Automation Branch of NASA's Goddard Space Flight Center has developed a tool called the Visual Observation Layout Tool (VOLT). The main objective of VOLT is to provide a visual tool to automate the planning of coordinated observations by multiple astronomical observatories. Four of NASA's space-based astronomical observatories - the Hubble Space Telescope (HST), Far Ultraviolet Spectroscopic Explorer (FUSE), Rossi X-ray Timing Explorer (RXTE) and Chandra - are enthusiastically pursuing the use of VOLT. This paper will focus on the purpose for developing VOLT, as well as the lessons learned during the infusion of VOLT into the planning and scheduling operations of these observatories.

  18. World population beyond six billion.

    PubMed

    Gelbard, A; Haub, C; Kent, M M

    1999-03-01

    This world report reviews population growth pre-1900, population change during 1900-50 and 1950-2000, causes and effects of population change and projections to 2050. World population grew from 2 billion in 1900 to almost 6 billion in 2000. Population showed more rapid growth in the 17th and 18th centuries. Better hygiene and public sanitation in the 19th century led to expanded life expectancies and quicker growth, primarily in developed countries. Demographic transition in the 19th and 20th centuries was the result of shifts from high to low mortality and fertility. The pace of change varies with culture, level of economic development, and other factors. Not all countries follow the same path of change. The reproductive revolution in the mid-20th century and modern contraception led to greater individual control of fertility and the potential for rapid fertility decline. Political and cultural barriers that limit access affect the pace of decline. Population change is also affected by migration. Migration has the largest effect on the distribution of population. Bongaarts explains differences in fertility by the proportion in unions, contraceptive prevalence, infertility, and abortion. Educational status has a strong impact on adoption of family planning. Poverty is associated with multiple risks. In 2050, population could reach 10.7 billion or remain low at 7.3 billion.

  19. Volt-VAR Optimization on American Electric Power Feeders in Northeast Columbus

    SciTech Connect

    Schneider, Kevin P.; Weaver, T. F.

    2012-05-10

    In 2007 American Electric Power launched the gridSMART® initiative with the goals of increasing efficiency of the electricity delivery system and improving service to the end-use customers. As part of the initiative, a coordinated Volt-VAR system was deployed on eleven distribution feeders at five substations in the Northeast Columbus Ohio Area. The goal of the coordinated Volt-VAR system was to decrease the amount of energy necessary to provide end-use customers with the same quality of service. The evaluation of the Volt-VAR system performance was conducted in two stages. The first stage was composed of simulation, analysis, and estimation, while the second stage was composed of analyzing collected field data. This panel paper will examine the analysis conducted in both stages and present the estimated improvements in system efficiency.

  20. Actual Versus Estimated Utility Factor of a Large Set of Privately Owned Chevrolet Volts

    SciTech Connect

    John Smart; Thomas Bradley; Stephen Schey

    2014-04-01

    In order to determine the overall fuel economy of a plug-in hybrid electric vehicle (PHEV), the amount of operation in charge depleting (CD) versus charge sustaining modes must be determined. Mode of operation is predominantly dependent on customer usage of the vehicle and is therefore highly variable. The utility factor (UF) concept was developed to quantify the distance a group of vehicles has traveled or may travel in CD mode. SAE J2841 presents a UF calculation method based on data collected from travel surveys of conventional vehicles. UF estimates have been used in a variety of areas, including the calculation of window sticker fuel economy, policy decisions, and vehicle design determination. The EV Project, a plug-in electric vehicle charging infrastructure demonstration being conducted across the United States, provides the opportunity to determine the real-world UF of a large group of privately owned Chevrolet Volt extended range electric vehicles. Using data collected from Volts enrolled in The EV Project, this paper compares the real-world UF of two groups of Chevrolet Volts to estimated UF's based on J2841. The actual observed fleet utility factors (FUF) for the MY2011/2012 and MY2013 Volt groups studied were observed to be 72% and 74%, respectively. Using the EPA CD ranges, the method prescribed by J2841 estimates a FUF of 65% and 68% for the MY2011/2012 and MY2013 Volt groups, respectively. Volt drivers achieved higher percentages of distance traveled in EV mode for two reasons. First, they had fewer long-distance travel days than drivers in the national travel survey referenced by J2841. Second, they charged more frequently than the J2841 assumption of once per day - drivers of Volts in this study averaged over 1.4 charging events per day. Although actual CD range varied widely as driving conditions varied, the average CD ranges for the two Volt groups studied matched the EPA CD range estimates, so CD range variation did not affect FUF results.

  1. Experimental evaluation of a volts-per-hertz reference circuit for the isotope Brayton system

    NASA Technical Reports Server (NTRS)

    Wimmer, H. L.

    1972-01-01

    In Brayton-cycle power systems, the speed decreases rapidly with overload. If the voltage decreases linearly with speed (frequency), the power decreases as the square of the voltage. This makes the system more tolerant of overloads. A volts-per-hertz reference circuit, consisting of a volts-per-hertz sensor and a voltage limiter, was designed and fabricated. This reference circuit was incorporated in an existing voltage regulator to control a turbine-driven alternator. Test results show that the control does function to reduce voltage at speeds below the rated speed and that it performed successfully during transients.

  2. Battery Test Manual For 12 Volt Start/Stop Hybrid Electric Vehicles

    SciTech Connect

    Belt, Jeffrey R.

    2015-05-01

    This manual was prepared by and for the United Stated Advanced Battery Consortium (USABC) Electrochemical Energy Storage Team. It is based on the targets established for 12 Volt Start/Stop energy storage development and is similar (with some important changes) to an earlier manual for the former FreedomCAR program. The specific procedures were developed primarily to characterize the performance of energy storage devices relative to the USABC requirements. However, it is anticipated that these procedures will have some utility for characterizing 12 Volt Start/Stop hybrid energy storage device behavior in general.

  3. 33 CFR 183.435 - Conductors in circuits of 50 volts or more.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems Manufacturer... nominal voltage of 50 volts or more must be: (1) A conductor that has insulation listed and classified moisture resistant and flame retardant in Article 310, NFPA No. 70, National Electric Code; (2) A...

  4. 29. INDUCTION MOTOR (6600 VOLTS, 5750 H.P.) DRIVES THE 21INCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. INDUCTION MOTOR (6600 VOLTS, 5750 H.P.) DRIVES THE 21-INCH AND 18-INCH BILLET MILLS. MOTOR WAS MANUFACTURED BY THE GENERAL ELECTRIC COMPANY, SCHENECTADY, NEW YORK. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

  5. How much are Chevrolet Volts in The EV Project driven in EV Mode?

    SciTech Connect

    John Smart

    2013-08-01

    This report summarizes key conclusions from analysis of data collected from Chevrolet Volts participating in The EV Project. Topics include how many miles are driven in EV mode, how far vehicles are driven between charging events, and how much energy is charged from the electric grid per charging event.

  6. How many electric miles do Nissan Leafs and Chevrolet Volts in The EV Project travel?

    SciTech Connect

    John Smart

    2014-05-01

    This paper presents travel statistics and metrics describing the driving behavior of Nissan Leaf and Chevrolet Volt drivers in the EV Project. It specifically quantifies the distance each group of vehicles drives each month. This paper will be published to INL's external website and will be accessible by the general public.

  7. 39. NORTH WALL OF MST AT STATION 124. 480VOLT MASTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. NORTH WALL OF MST AT STATION 124. 480-VOLT MASTER POWER SHUTOFF AND CIRCUIT BREAKERS FOR CRANE NORTH DOORS/CRANE SOUTH DOORS ON LEFT; FOR BRIDGE CRANE AND DUCT HEATER 122 ON RIGHT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  8. Advanced Vehicle Testing Activity Cold Weather On-road Testing of the Chevrolet Volt

    SciTech Connect

    Smart, John

    2015-03-01

    This report details cold weather on-road testing of a Chevrolet Volt. It quantifies changes in efficiency and electric range as ambient temperature changes. It will be published to INL's AVTA website as an INL technical report and will be accessible to the general public.

  9. 75 FR 11920 - Agilent Technologies, Eesof Division, Including On-Site Leased Workers From Volt and Managed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... Technologies, EEsof Division, including on-site leased workers from Volt and Managed Business Solutions (MBS... Employment and Training Administration Agilent Technologies, Eesof Division, Including On-Site Leased Workers From Volt and Managed Business Solutions (MBS), Westlake Village, CA, Santa Rosa, CA, Santa Clara,...

  10. An optimization approach for online identification of harmonic resonance due to pending Volt/VAr operation

    NASA Astrophysics Data System (ADS)

    McBee, Kerry D.

    The emphasis on creating a more efficient distribution system has led many utility companies to employ dynamic voltage and VAr compensation (Volt/VAr) applications that reduce energy demand, generation, and losses associated with the transmission and distribution of energy. To achieve these benefits, Volt/VAr applications rely upon algorithms to control voltage support equipment, such as transformer load tap changers, voltage regulators, and capacitor banks. The majority of these algorithms utilize metaheuristic programming methods to determine the Volt/VAr scheme that produces the most energy efficient operating conditions. It has been well documented that the interaction between capacitor bank reactance and the inductive reactance of a distribution system can produce parallel harmonic resonance that can damage utility and customer equipment. The Volt/VAr controlling algorithms that account for harmonics do so in an indirect manner that can mask harmonic resonance conditions. Unlike previous research endeavors, the primary focus of the method described within this dissertation is to identify Volt/VAr schemes that prevent harmonic resonance due to capacitor bank operation. Instead of a metaheuristic approach, the harmonic resonance identification algorithm relies upon constrained mixed integer nonlinear programming (MINLP), which is more suited for analyzing impedance characteristics created by the energized states of a system of capacitor banks. Utilizing a numerical approach improves the accuracy of identifying harmonic resonance conditions, while also reducing the complexity of the process by exclusively relying upon the system's admittance characteristics. The novel harmonic resonance identification method is applicable to distribution systems that are dynamically reconfigured, which can result in a number of unknown harmonic resonance producing conditions, a feature unavailable with existing controlling algorithms. The ability to identify all harmonic

  11. Life: the first two billion years.

    PubMed

    Knoll, Andrew H; Bergmann, Kristin D; Strauss, Justin V

    2016-11-01

    Microfossils, stromatolites, preserved lipids and biologically informative isotopic ratios provide a substantial record of bacterial diversity and biogeochemical cycles in Proterozoic (2500-541 Ma) oceans that can be interpreted, at least broadly, in terms of present-day organisms and metabolic processes. Archean (more than 2500 Ma) sedimentary rocks add at least a billion years to the recorded history of life, with sedimentological and biogeochemical evidence for life at 3500 Ma, and possibly earlier; phylogenetic and functional details, however, are limited. Geochemistry provides a major constraint on early evolution, indicating that the first bacteria were shaped by anoxic environments, with distinct patterns of major and micronutrient availability. Archean rocks appear to record the Earth's first iron age, with reduced Fe as the principal electron donor for photosynthesis, oxidized Fe the most abundant terminal electron acceptor for respiration, and Fe a key cofactor in proteins. With the permanent oxygenation of the atmosphere and surface ocean ca 2400 Ma, photic zone O2 limited the access of photosynthetic bacteria to electron donors other than water, while expanding the inventory of oxidants available for respiration and chemoautotrophy. Thus, halfway through Earth history, the microbial underpinnings of modern marine ecosystems began to take shape.This article is part of the themed issue 'The new bacteriology'.

  12. Life: the first two billion years.

    PubMed

    Knoll, Andrew H; Bergmann, Kristin D; Strauss, Justin V

    2016-11-01

    Microfossils, stromatolites, preserved lipids and biologically informative isotopic ratios provide a substantial record of bacterial diversity and biogeochemical cycles in Proterozoic (2500-541 Ma) oceans that can be interpreted, at least broadly, in terms of present-day organisms and metabolic processes. Archean (more than 2500 Ma) sedimentary rocks add at least a billion years to the recorded history of life, with sedimentological and biogeochemical evidence for life at 3500 Ma, and possibly earlier; phylogenetic and functional details, however, are limited. Geochemistry provides a major constraint on early evolution, indicating that the first bacteria were shaped by anoxic environments, with distinct patterns of major and micronutrient availability. Archean rocks appear to record the Earth's first iron age, with reduced Fe as the principal electron donor for photosynthesis, oxidized Fe the most abundant terminal electron acceptor for respiration, and Fe a key cofactor in proteins. With the permanent oxygenation of the atmosphere and surface ocean ca 2400 Ma, photic zone O2 limited the access of photosynthetic bacteria to electron donors other than water, while expanding the inventory of oxidants available for respiration and chemoautotrophy. Thus, halfway through Earth history, the microbial underpinnings of modern marine ecosystems began to take shape.This article is part of the themed issue 'The new bacteriology'. PMID:27672146

  13. Evaluation of Multiple Inverter Volt-VAR Control Interactions with Realistic Grid Impedances

    SciTech Connect

    Chakraborty, Sudipta; Hoke, Anderson; Lundstrom, Blake

    2015-07-03

    Integration of large numbers of distributed photovoltaic (PV) systems in electric distribution circuits often requires advanced functions (e.g. volt-VAR, frequency-Watt etc.). However, significant concerns have been raised about potential for PV inverters with such controls to interact with one another in a way that could cause grid instability. The lack of standardized inverter models makes it hard to simulate such transient interactions in software. Similarly it is very hard to test these dynamic inverter interactions in the laboratory. In this paper, unique Power Hardware-in-the-Loop (PHIL) techniques are presented to experimentally test for interactions of multiple PV inverters connected to multiple points-of-common-coupling (PCCs) with grid impedances between them. Sample test results are provided from simulation-only scenarios and PHIL testing. Though simulation results indicated possible harmful interactions between inverters' volt-VAR controllers; no such interactions were found in the limited hardware testing.

  14. 134. View of former high tension (55,000 volt) bus room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    134. View of former high tension (55,000 volt) bus room on the third floor, looking north. This room now contains shelves and boxes for storing company records (to the left along the wall). Insulators through which the live line ran remains in place. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  15. Charge Transfer Between Ground-State Si(3+) and He at Electron-Volt Energies

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.

    1997-01-01

    The charge-transfer rate coefficient for the reaction Si(3+)(3s(sup 2)S) + He yields products is measured by means of a combined technique of laser ablation and ion storage. A cylindrical radio-frequency ion trap was used to store Si(3+) ions produced by laser ablation of solid silicon targets. The rate coefficient of the reaction was derived from the decay rate of the ion signal. The measured rate coefficient is 6.27(exp +0.68)(sub -0.52) x 10(exp -10)cu cm/s at T(sub equiv) = 3.9 x 10(exp 3)K. This value is about 30% higher than the Landau-Zener calculation of Butler and Dalgarno and is larger by about a factor of 3 than the recent full quantal calculation of Honvault et al.

  16. X-ray laser resonator for the kilo-electron-volt range

    SciTech Connect

    Chen, Jie; Tomov, Ivan V.; Er, Ali O.; Rentzepis, Peter M.

    2013-04-29

    We have designed, constructed, and tested an x-ray laser resonator operating in the hard x-ray, keV energy region. This ring x-ray laser cavity is formed by four highly oriented pyrolytic graphite crystals. The crystals are set at the Bragg angles that allow for the complete 360 Degree-Sign round trip of the 2.37 A, 5.23 keV L{sub {alpha}} line of neodymium. In addition, we also present experimental data of a similar ring laser resonator that utilizes the Cr K{sub {alpha}}, 5.41 keV, x-ray line to propagate through the four mirrors of the cavity. The specific properties of these x-ray laser resonator mirrors, including reflection losses and cavity arrangement, are presented.

  17. Assessing the ability of mechanistic volatilization models to simulate soil surface conditions: a study with the Volt'Air model.

    PubMed

    Garcia, L; Bedos, C; Génermont, S; Braud, I; Cellier, P

    2011-09-01

    Ammonia and pesticide volatilization in the field is a surface phenomenon involving physical and chemical processes that depend on the soil surface temperature and water content. The water transfer, heat transfer and energy budget sub models of volatilization models are adapted from the most commonly accepted formalisms and parameterizations. They are less detailed than the dedicated models describing water and heat transfers and surface status. The aim of this work was to assess the ability of one of the available mechanistic volatilization models, Volt'Air, to accurately describe the pedo-climatic conditions of a soil surface at the required time and space resolution. The assessment involves: (i) a sensitivity analysis, (ii) an evaluation of Volt'Air outputs in the light of outputs from a reference Soil-Vegetation-Atmosphere Transfer model (SiSPAT) and three experimental datasets, and (iii) the study of three tests based on modifications of SiSPAT to establish the potential impact of the simplifying assumptions used in Volt'Air. The analysis confirmed that a 5 mm surface layer was well suited, and that Volt'Air surface temperature correlated well with the experimental measurements as well as with SiSPAT outputs. In terms of liquid water transfers, Volt'Air was overall consistent with SiSPAT, with discrepancies only during major rainfall events and dry weather conditions. The tests enabled us to identify the main source of the discrepancies between Volt'Air and SiSPAT: the lack of gaseous water transfer description in Volt'Air. They also helped to explain why neither Volt'Air nor SiSPAT was able to represent lower values of surface water content: current classical water retention and hydraulic conductivity models are not yet adapted to cases of very dry conditions. Given the outcomes of this study, we discuss to what extent the volatilization models can be improved and the questions they pose for current research in water transfer modeling and parameterization.

  18. Spend Billions and They Will Come

    ERIC Educational Resources Information Center

    Fox, Bette-Lee

    2004-01-01

    People look at one billion dollars in one of two ways: if it is the result of the long, hard effort of years of fundraising, they rejoice; if it signifies an astronomical budget deficit, they cringe. How, then, should people respond as a community to reaching the $1 billion mark ($1,242,436,438, to be exact) in this year's spending for public…

  19. Countdown to Six Billion Teaching Kit.

    ERIC Educational Resources Information Center

    Zero Population Growth, Inc., Washington, DC.

    This teaching kit features six activities focused on helping students understand the significance of the world population reaching six billion for our society and our environment. Featured activities include: (1) History of the World: Part Six Billion; (2) A Woman's Place; (3) Baby-O-Matic; (4) Earth: The Apple of Our Eye; (5) Needs vs. Wants; and…

  20. Life with Four Billion Atoms

    SciTech Connect

    Knight, Thomas

    2013-04-10

    Today it is commonplace to design and construct single silicon chips with billions of transistors. These are complex systems, difficult (but possible) to design, test, and fabricate. Remarkably, simple living systems can be assembled from a similar number of atoms, most of them in water molecules. In this talk I will present the current status of our attempts at full understanding and complexity reduction of one of the simplest living systems, the free-living bacterial species Mesoplasma florum. This 400 nm diameter cell thrives and replicates every 40 minutes with a genome of only 800 kilobases. Our recent experiments using transposon gene knockouts identified 354 of 683 annotated genes as inessential in laboratory culture when inactivated individually. While a functional redesigned genome will certainly not remove all of those genes, this suggests that roughly half the genome can be removed in an intentional redesign. I will discuss our recent knockout results and methodology, and our future plans for Genome re-engineering using targeted knock-in/knock-out double recombination; whole cell metabolic models; comprehensive whole cell metabolite measurement techniques; creation of plug-and-play metabolic modules for the simplified organism; inherent and engineered biosafety control mechanisms. This redesign is part of a comprehensive plan to lay the foundations for a new discipline of engineering biology. Engineering biological systems requires a fundamentally different viewpoint from that taken by the science of biology. Key engineering principles of modularity, simplicity, separation of concerns, abstraction, flexibility, hierarchical design, isolation, and standardization are of critical importance. The essence of engineering is the ability to imagine, design, model, build, and characterize novel systems to achieve specific goals. Current tools and components for these tasks are primitive. Our approach is to create and distribute standard biological parts

  1. Connectivity-Enhanced Route Selection and Adaptive Control for the Chevrolet Volt: Preprint

    SciTech Connect

    Gonder, J.; Wood, E.; Rajagopalan, S.

    2014-09-01

    The National Renewable Energy Laboratory and General Motors evaluated connectivity-enabled efficiency enhancements for the Chevrolet Volt. A high-level model was developed to predict vehicle fuel and electricity consumption based on driving characteristics and vehicle state inputs. These techniques were leveraged to optimize energy efficiency via green routing and intelligent control mode scheduling, which were evaluated using prospective driving routes between tens of thousands of real-world origin/destination pairs. The overall energy savings potential of green routing and intelligent mode scheduling was estimated at 5% and 3% respectively. These represent substantial opportunities considering that they only require software adjustments to implement.

  2. Connectivity-enhanced route selection and adaptive control for the Chevrolet Volt

    DOE PAGES

    Gonder, Jeffrey; Wood, Eric; Rajagopalan, Sai

    2016-01-01

    The National Renewable Energy Laboratory and General Motors evaluated connectivity-enabled efficiency enhancements for the Chevrolet Volt. A high-level model was developed to predict vehicle fuel and electricity consumption based on driving characteristics and vehicle state inputs. These techniques were leveraged to optimize energy efficiency via green routing and intelligent control mode scheduling, which were evaluated using prospective driving routes between tens of thousands of real-world origin/destination pairs. The overall energy savings potential of green routing and intelligent mode scheduling was estimated at 5% and 3%, respectively. Furthermore, these represent substantial opportunities considering that they only require software adjustments to implement.

  3. Electron-atom /molecule/ collision processes

    NASA Technical Reports Server (NTRS)

    Trajmar, S.

    1980-01-01

    Electron-atom (molecule) collision processes at low and intermediate energies, from near threshold to a few hundred electron volts, are discussed. Attention is given to experimental techniques and procedures, electron impact cross sections, impact excitation and electron-atom scattering in laser fields. Specific examples are presented that illustrate various experimental techniques and interpretations of observations.

  4. Performance criteria guideline for three explosion protection methods of electrical equipment rated up to 15,000 volts AC

    NASA Astrophysics Data System (ADS)

    Linley, L. J.; Luper, A. B.; Dunn, J. H.

    1982-12-01

    The Bureau of Mines, U.S. Department of the Interior, is reviewing explosion protection methods for use in gassy coal mines. This performance criteria guideline is an evaluation of three explosion protection methods of machines electrically powered with voltages up to 15,000 volts ac. A sufficient amount of basic research has been accomplished to verify that the explosion proof and pressurized enclosure methods can provide adequate explosion protection with the present state of the art up to 15,000 volts ac. This routine application of the potted enclosure as a stand alone protection method requires further investigation or development in order to clarify performance criteria and verification certification requirements. An extensive literature search, a series of high voltage tests, and a design evaluation of the three explosion protection methods indicate that the explosion proof, pressurized, and potted enclosures can all be used to enclose up to 15,000 volts ac.

  5. Performance criteria guideline for three explosion protection methods of electrical equipment rated up to 15,000 volts AC

    NASA Technical Reports Server (NTRS)

    Linley, L. J.; Luper, A. B.; Dunn, J. H.

    1982-01-01

    The Bureau of Mines, U.S. Department of the Interior, is reviewing explosion protection methods for use in gassy coal mines. This performance criteria guideline is an evaluation of three explosion protection methods of machines electrically powered with voltages up to 15,000 volts ac. A sufficient amount of basic research has been accomplished to verify that the explosion proof and pressurized enclosure methods can provide adequate explosion protection with the present state of the art up to 15,000 volts ac. This routine application of the potted enclosure as a stand alone protection method requires further investigation or development in order to clarify performance criteria and verification certification requirements. An extensive literature search, a series of high voltage tests, and a design evaluation of the three explosion protection methods indicate that the explosion proof, pressurized, and potted enclosures can all be used to enclose up to 15,000 volts ac.

  6. Assessing the ability of mechanistic volatilization models to simulate soil surface conditions: a study with the Volt'Air model.

    PubMed

    Garcia, L; Bedos, C; Génermont, S; Braud, I; Cellier, P

    2011-09-01

    Ammonia and pesticide volatilization in the field is a surface phenomenon involving physical and chemical processes that depend on the soil surface temperature and water content. The water transfer, heat transfer and energy budget sub models of volatilization models are adapted from the most commonly accepted formalisms and parameterizations. They are less detailed than the dedicated models describing water and heat transfers and surface status. The aim of this work was to assess the ability of one of the available mechanistic volatilization models, Volt'Air, to accurately describe the pedo-climatic conditions of a soil surface at the required time and space resolution. The assessment involves: (i) a sensitivity analysis, (ii) an evaluation of Volt'Air outputs in the light of outputs from a reference Soil-Vegetation-Atmosphere Transfer model (SiSPAT) and three experimental datasets, and (iii) the study of three tests based on modifications of SiSPAT to establish the potential impact of the simplifying assumptions used in Volt'Air. The analysis confirmed that a 5 mm surface layer was well suited, and that Volt'Air surface temperature correlated well with the experimental measurements as well as with SiSPAT outputs. In terms of liquid water transfers, Volt'Air was overall consistent with SiSPAT, with discrepancies only during major rainfall events and dry weather conditions. The tests enabled us to identify the main source of the discrepancies between Volt'Air and SiSPAT: the lack of gaseous water transfer description in Volt'Air. They also helped to explain why neither Volt'Air nor SiSPAT was able to represent lower values of surface water content: current classical water retention and hydraulic conductivity models are not yet adapted to cases of very dry conditions. Given the outcomes of this study, we discuss to what extent the volatilization models can be improved and the questions they pose for current research in water transfer modeling and parameterization

  7. 2011 Chevrolet Volt VIN 0815 Plug-In Hybrid Electric Vehicle Battery Test Results

    SciTech Connect

    Tyler Gray; Matthew Shirk; Jeffrey Wishart

    2013-07-01

    The U.S. Department of Energy (DOE) Advanced Vehicle Testing Activity (AVTA) program consists of vehicle, battery, and infrastructure testing on advanced technology related to transportation. The activity includes tests on plug-in hybrid electric vehicles (PHEVs), including testing the PHEV batteries when both the vehicles and batteries are new and at the conclusion of 12,000 miles of on-road fleet testing. This report documents battery testing performed for the 2011 Chevrolet Volt PHEV (VIN 1G1RD6E48BU100815). The battery testing was performed by the Electric Transportation Engineering Corporation (eTec) dba ECOtality North America. The Idaho National Laboratory and ECOtality North America collaborate on the AVTA for the Vehicle Technologies Program of the DOE.

  8. Electric shock and the human body - or 'Is it amps or volts that kill you, sir?'

    NASA Astrophysics Data System (ADS)

    Brown, Colin

    1986-11-01

    One of the experiences that children seem to find most exciting in the school science laboratory is the hair raising one of being charged up using a van de Graaf generator and receiving small electric shocks. Children are quite rightly concerned about when electricity might hurt them and what its effects are. They are motivated by science directly concerned with the human body, with obvious impact on their lives. This is particularly important for girls, who often seem to find other aspects of electricity amongst the least interesting topics in science. Here is an opportunity for the teacher to build on immediate and genuine curiosity. Pupils are already well aware that mains electricity at 240 V can be lethal, yet the teacher seems strangely happy to expose them here to what he claims is tens of thousands of volts! They ask questions such as 'Is it amps of volts that kill you?' with a genuine desire to try and resolve the paradox. When young pupils see an oscilloscope for the first time, they often immediately associate it with the heart monitor seen on a TV hospital drama. ('He's dead sir!' they say, as you show them the timebase operating in the absence of an input signal). They use a microphone to try and detect an ECG signal without success. The real heart monitor works in a totally different way, and that it is in fact quite closely related to the action of electric shocks. The article is a summary of the reading the author undertook to try and cure his ignorance of the interaction between electricity and the human body, so that he could make something of this spontaneous interest on the part of the pupils. It also provides background material for A-level potential medical students, who often study physics without seeing its direct relevance to medicine.

  9. The study of volt-ampere characteristics of ionic channels formed by gramicidin A.

    PubMed

    Passechnik, V I; Flerov, M N; Hianik, T

    1985-02-01

    A method of measurement of the non-linearity coefficient of volt-ampere characteristics of the type i(U) approximately = U(1 + beta U2) has been developed for ionic channels formed by gramicidin A, using the third harmonic of the membrane current. The shape of the volt-ampere characteristics (VA) of ionic channels formed by gramicidin A did not depend on the antibiotic concentration in the membrane. The coefficient beta of non-linearity of VA of membranes modified by gramicidin A depended on electrolyte concentration "c" and it increased proportionally with the lg c from -17 V-2 at 0.03 mol/l KC1 to 8 V-2 at 3.4 mol/l KCl, and it was zero at co = 0.3 - 1 mol/l KCl. Egg lecithin and glycerol monooleate (GMO) membranes differ in their co values. The substitution of K+ for Li+ of the membrane solvent (n-heptane for n-hexadecane) did not influence the value of beta; the same applied for GMO membranes without any solvent. In a number of membranes, spontaneous change of the non-linearity coefficient with time observed after the membrane formation, as well as jumps of the non-linearity coefficient at a practically unchanged membrane conductivity. An analysis of some theoretical models of the ion transport through the channel has shown that, at voltages above 200 mV, these models provide rather small values of beta, or extremely high VA non-linearity.

  10. Atmospheric oxygenation three billion years ago.

    PubMed

    Crowe, Sean A; Døssing, Lasse N; Beukes, Nicolas J; Bau, Michael; Kruger, Stephanus J; Frei, Robert; Canfield, Donald E

    2013-09-26

    It is widely assumed that atmospheric oxygen concentrations remained persistently low (less than 10(-5) times present levels) for about the first 2 billion years of Earth's history. The first long-term oxygenation of the atmosphere is thought to have taken place around 2.3 billion years ago, during the Great Oxidation Event. Geochemical indications of transient atmospheric oxygenation, however, date back to 2.6-2.7 billion years ago. Here we examine the distribution of chromium isotopes and redox-sensitive metals in the approximately 3-billion-year-old Nsuze palaeosol and in the near-contemporaneous Ijzermyn iron formation from the Pongola Supergroup, South Africa. We find extensive mobilization of redox-sensitive elements through oxidative weathering. Furthermore, using our data we compute a best minimum estimate for atmospheric oxygen concentrations at that time of 3 × 10(-4) times present levels. Overall, our findings suggest that there were appreciable levels of atmospheric oxygen about 3 billion years ago, more than 600 million years before the Great Oxidation Event and some 300-400 million years earlier than previous indications for Earth surface oxygenation.

  11. Atmospheric oxygenation three billion years ago.

    PubMed

    Crowe, Sean A; Døssing, Lasse N; Beukes, Nicolas J; Bau, Michael; Kruger, Stephanus J; Frei, Robert; Canfield, Donald E

    2013-09-26

    It is widely assumed that atmospheric oxygen concentrations remained persistently low (less than 10(-5) times present levels) for about the first 2 billion years of Earth's history. The first long-term oxygenation of the atmosphere is thought to have taken place around 2.3 billion years ago, during the Great Oxidation Event. Geochemical indications of transient atmospheric oxygenation, however, date back to 2.6-2.7 billion years ago. Here we examine the distribution of chromium isotopes and redox-sensitive metals in the approximately 3-billion-year-old Nsuze palaeosol and in the near-contemporaneous Ijzermyn iron formation from the Pongola Supergroup, South Africa. We find extensive mobilization of redox-sensitive elements through oxidative weathering. Furthermore, using our data we compute a best minimum estimate for atmospheric oxygen concentrations at that time of 3 × 10(-4) times present levels. Overall, our findings suggest that there were appreciable levels of atmospheric oxygen about 3 billion years ago, more than 600 million years before the Great Oxidation Event and some 300-400 million years earlier than previous indications for Earth surface oxygenation. PMID:24067713

  12. Billion shot flashlamp for spaceborne lasers

    NASA Technical Reports Server (NTRS)

    Richter, Linda; Schuda, Felix; Degnan, John

    1990-01-01

    A billion-shot flashlamp developed under a NASA contract for spaceborne laser missions is presented. Lifetime-limiting mechanisms are identified and addressed. Two energy loadings of 15 and 44 Joules were selected for the initial accelerated life testing. A fluorescence-efficiency test station was used for measuring the useful-light output degradation of the lamps. The design characteristics meeting NASA specifications are outlined. Attention is focused on the physical properties of tungsten-matrix cathodes, the chemistry of dispenser cathodes, and anode degradation. It is reported that out of the total 83 lamps tested in the program, 4 lamps reached a billion shots and one lamp is beyond 1.7 billion shots, while at 44 Joules, 4 lamps went beyond 100 million shots and one lamp reached 500 million shots.

  13. Billion particle linac simulations for future light sources

    SciTech Connect

    Ryne, R. D.; Venturini, M.; Zholents, A. A.; Qiang, J.

    2008-09-25

    In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.

  14. What Kind of Charging Infrastructure Do Chevrolet Volt Drivers in The EV Project Use and When Do They Use It?

    SciTech Connect

    Shawn Salisbury

    2014-09-01

    This document will present information describing the charging behavior of Chevrolet Volts that were enrolled in the EV Project. It will included aggregated data from more than 1,800 vehicles regarding locations, power levels, and time-of-day of charging events performed by those vehicles. This document will be published to the INL AVTA website.

  15. Where Have All the Billions Gone?

    ERIC Educational Resources Information Center

    Leask, Linda; And Others

    1987-01-01

    Providing a basis to help Alaskans determine future spending levels and priorities, this report traces how the state spent more than $26 billion in general funds from fiscal years 1981 through 1986 before oil prices crashed and brought state revenues tumbling down with them. Figures indicate that cumulative general fund expenditures over the…

  16. Thirteen Billion Years in Half AN Hour

    NASA Astrophysics Data System (ADS)

    Bassett, Bruce A.

    2005-10-01

    We take a high-speed tour of the approximately thirteen billion-year history of our universe focusing on unsolved mysteries and the key events that have sculpted and shaped it - from inflation in the first split second to the dark energy which is currently causing the expansion of the cosmos to accelerate.

  17. ZnO Nanowire-Based Corona Discharge Devices Operated Under Hundreds of Volts.

    PubMed

    Yang, Wenming; Zhu, Rong; Zong, Xianli

    2016-12-01

    Minimizing the voltage of corona discharges, especially when using nanomaterials, has been of great interest in the past decade or so. In this paper, we report a new corona discharge device by using ZnO nanowires operated in atmospheric air to realize continuous corona discharge excited by hundreds of volts. ZnO nanowires were synthesized on microelectrodes using electric-field-assisted wet chemical method, and a thin tungsten film was deposited on the microchip to enhance discharging performance. The testing results showed that the corona inception voltages were minimized greatly by using nanowires compared to conventional dischargers as a result of the local field enhancement of nanowires. The corona could be continuously generated and self-sustaining. It was proved that the law of corona inception voltage obeyed the conventional Peek's breakdown criterion. An optimal thickness of tungsten film coated over ZnO nanowires was figured out to obtain the lowest corona inception voltage. The ion concentration of the nanowire-based discharger attained 10(17)/m(3) orders of magnitude, which is practicable for most discharging applications.

  18. ZnO Nanowire-Based Corona Discharge Devices Operated Under Hundreds of Volts.

    PubMed

    Yang, Wenming; Zhu, Rong; Zong, Xianli

    2016-12-01

    Minimizing the voltage of corona discharges, especially when using nanomaterials, has been of great interest in the past decade or so. In this paper, we report a new corona discharge device by using ZnO nanowires operated in atmospheric air to realize continuous corona discharge excited by hundreds of volts. ZnO nanowires were synthesized on microelectrodes using electric-field-assisted wet chemical method, and a thin tungsten film was deposited on the microchip to enhance discharging performance. The testing results showed that the corona inception voltages were minimized greatly by using nanowires compared to conventional dischargers as a result of the local field enhancement of nanowires. The corona could be continuously generated and self-sustaining. It was proved that the law of corona inception voltage obeyed the conventional Peek's breakdown criterion. An optimal thickness of tungsten film coated over ZnO nanowires was figured out to obtain the lowest corona inception voltage. The ion concentration of the nanowire-based discharger attained 10(17)/m(3) orders of magnitude, which is practicable for most discharging applications. PMID:26880727

  19. ZnO Nanowire-Based Corona Discharge Devices Operated Under Hundreds of Volts

    NASA Astrophysics Data System (ADS)

    Yang, Wenming; Zhu, Rong; Zong, Xianli

    2016-02-01

    Minimizing the voltage of corona discharges, especially when using nanomaterials, has been of great interest in the past decade or so. In this paper, we report a new corona discharge device by using ZnO nanowires operated in atmospheric air to realize continuous corona discharge excited by hundreds of volts. ZnO nanowires were synthesized on microelectrodes using electric-field-assisted wet chemical method, and a thin tungsten film was deposited on the microchip to enhance discharging performance. The testing results showed that the corona inception voltages were minimized greatly by using nanowires compared to conventional dischargers as a result of the local field enhancement of nanowires. The corona could be continuously generated and self-sustaining. It was proved that the law of corona inception voltage obeyed the conventional Peek's breakdown criterion. An optimal thickness of tungsten film coated over ZnO nanowires was figured out to obtain the lowest corona inception voltage. The ion concentration of the nanowire-based discharger attained 1017/m3 orders of magnitude, which is practicable for most discharging applications.

  20. Electron

    NASA Astrophysics Data System (ADS)

    Springford, Michael

    1997-03-01

    1. J. J. Thomson and the discovery of the electron A. B. P. Pippard; 2. The isolated electron W. N. Cottingham; 3. The relativistic electron D. I. Olive; 4. The electron glue B. L. Gyorffy; 5. The electron fluid P. Coleman; 6. The magnetic electron G. G. Lonzarich; 7. The paired electron A. J. Leggett; 8. The heavy electron M. Springford; 9. The coherent electron Y. Imry and M. Peskin; 10. The composite electron R. Nicholas; 11. The electron in the cosmos M. S. Longair.

  1. Electron

    NASA Astrophysics Data System (ADS)

    Springford, Michael

    2008-12-01

    1. J. J. Thomson and the discovery of the electron A. B. P. Pippard; 2. The isolated electron W. N. Cottingham; 3. The relativistic electron D. I. Olive; 4. The electron glue B. L. Gyorffy; 5. The electron fluid P. Coleman; 6. The magnetic electron G. G. Lonzarich; 7. The paired electron A. J. Leggett; 8. The heavy electron M. Springford; 9. The coherent electron Y. Imry and M. Peskin; 10. The composite electron R. Nicholas; 11. The electron in the cosmos M. S. Longair.

  2. Four billion people facing severe water scarcity

    PubMed Central

    Mekonnen, Mesfin M.; Hoekstra, Arjen Y.

    2016-01-01

    Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolution on a monthly basis. We find that two-thirds of the global population (4.0 billion people) live under conditions of severe water scarcity at least 1 month of the year. Nearly half of those people live in India and China. Half a billion people in the world face severe water scarcity all year round. Putting caps to water consumption by river basin, increasing water-use efficiencies, and better sharing of the limited freshwater resources will be key in reducing the threat posed by water scarcity on biodiversity and human welfare. PMID:26933676

  3. Four billion people facing severe water scarcity.

    PubMed

    Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2016-02-01

    Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolution on a monthly basis. We find that two-thirds of the global population (4.0 billion people) live under conditions of severe water scarcity at least 1 month of the year. Nearly half of those people live in India and China. Half a billion people in the world face severe water scarcity all year round. Putting caps to water consumption by river basin, increasing water-use efficiencies, and better sharing of the limited freshwater resources will be key in reducing the threat posed by water scarcity on biodiversity and human welfare.

  4. Four billion people facing severe water scarcity.

    PubMed

    Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2016-02-01

    Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolution on a monthly basis. We find that two-thirds of the global population (4.0 billion people) live under conditions of severe water scarcity at least 1 month of the year. Nearly half of those people live in India and China. Half a billion people in the world face severe water scarcity all year round. Putting caps to water consumption by river basin, increasing water-use efficiencies, and better sharing of the limited freshwater resources will be key in reducing the threat posed by water scarcity on biodiversity and human welfare. PMID:26933676

  5. Design of a Versatile and Low Cost μVolt Level A to D Conversion System for Use in Medical Instrumentation Applications

    NASA Astrophysics Data System (ADS)

    Williams, Kerry; Robinson, Neil

    2008-12-01

    Modern medical facilities place considerable reliance on electronic instrumentation for purposes of calibration and monitoring of therapeutic processes, many of which employ electrical and electronic apparatus that itself generates considerable levels of interference in the form of background electromagnetic radiation (EMR). Additionally diverse ambient conditions in the clinical environment such as uncontrolled temperature, humidity, noise, and vibration place added stress on sensitive instrumentation. In order to obtain accurate, repeatable, and reliable data in such environments, instrumentation used must be largely immune to these factors. Analogue instrumentation is particularly susceptible to unstable environmental conditions. Sensors typically output an analogue current or voltage and it can be demonstrated that considerable overall benefit to the measuring process would result if sensor outputs could be converted to a robust digital format at the earliest possible stage. A practical and low cost system for A to D conversion at μVolt signal levels is described in this work. It has been successfully employed in portable radiation dosimetry instrumentation and used under diverse clinical conditions and it affords an improvement in signal resolution in excess of an order of magnitude over commonly used analogue techniques.

  6. Optimization of Solar Cell Design for Use with GreenVolts CPV System: Cooperative Research and Development Final Report, CRADA Number CRD-08-00281

    SciTech Connect

    Ward, S.

    2011-05-01

    GreenVolts, a Bay area start-up, was developing a CPV system that was based on a unique reflective optical design. They were interested in adapting the inverted GaInP/GaAs/GaInAs cell structure designed at NREL for use in their system. The purpose of this project was to optimize the inverted GaInP/GaAs/GaInAs cell for operation in the GreenVolts optical system.

  7. The updated billion-ton resource assessment

    SciTech Connect

    Turhollow, Anthony; Perlack, Robert; Eaton, Laurence; Langholtz, Matthew; Brandt, Craig; Downing, Mark; Wright, Lynn; Skog, Kenneth; Hellwinckel, Chad; Stokes, Bryce; Lebow, Patricia

    2014-10-03

    This paper summarizes the results of an update to a resource assessment, published in 2005, commonly referred to as the billion-ton study (BTS). The updated results are consistent with the 2005 BTS in terms of overall magnitude. However, in looking at the major categories of feedstocks the forest residue biomass potential was determined to be less owing to tighter restrictions on forest residue supply including restrictions due to limited projected increase in traditional harvest for pulpwood and sawlogs. The crop residue potential was also determined to be less because of the consideration of soil carbon and not allowing residue removal from conventionally tilled corn acres. The energy crop potential was estimated to be much greater largely because of land availability and modeling of competition among various competing uses of the land. Generally, the scenario assumptions in the updated assessment are much more plausible to show a billion-ton resource, which would be sufficient to displace 30% or more of the country s present petroleum consumption.

  8. The updated billion-ton resource assessment

    DOE PAGES

    Turhollow, Anthony; Perlack, Robert; Eaton, Laurence; Langholtz, Matthew; Brandt, Craig; Downing, Mark; Wright, Lynn; Skog, Kenneth; Hellwinckel, Chad; Stokes, Bryce; et al

    2014-10-03

    This paper summarizes the results of an update to a resource assessment, published in 2005, commonly referred to as the billion-ton study (BTS). The updated results are consistent with the 2005 BTS in terms of overall magnitude. However, in looking at the major categories of feedstocks the forest residue biomass potential was determined to be less owing to tighter restrictions on forest residue supply including restrictions due to limited projected increase in traditional harvest for pulpwood and sawlogs. The crop residue potential was also determined to be less because of the consideration of soil carbon and not allowing residue removalmore » from conventionally tilled corn acres. The energy crop potential was estimated to be much greater largely because of land availability and modeling of competition among various competing uses of the land. Generally, the scenario assumptions in the updated assessment are much more plausible to show a billion-ton resource, which would be sufficient to displace 30% or more of the country s present petroleum consumption.« less

  9. Endemic Cardiovascular Diseases of the Poorest Billion.

    PubMed

    Kwan, Gene F; Mayosi, Bongani M; Mocumbi, Ana O; Miranda, J Jaime; Ezzati, Majid; Jain, Yogesh; Robles, Gisela; Benjamin, Emelia J; Subramanian, S V; Bukhman, Gene

    2016-06-14

    The poorest billion people are distributed throughout the world, though most are concentrated in rural sub-Saharan Africa and South Asia. Cardiovascular disease (CVD) data can be sparse in low- and middle-income countries beyond urban centers. Despite this urban bias, CVD registries from the poorest countries have long revealed a predominance of nonatherosclerotic stroke, hypertensive heart disease, nonischemic and Chagas cardiomyopathies, rheumatic heart disease, and congenital heart anomalies, among others. Ischemic heart disease has been relatively uncommon. Here, we summarize what is known about the epidemiology of CVDs among the world's poorest people and evaluate the relevance of global targets for CVD control in this population. We assessed both primary data sources, and the 2013 Global Burden of Disease Study modeled estimates in the world's 16 poorest countries where 62% of the population are among the poorest billion. We found that ischemic heart disease accounted for only 12% of the combined CVD and congenital heart anomaly disability-adjusted life years (DALYs) in the poorest countries, compared with 51% of DALYs in high-income countries. We found that as little as 53% of the combined CVD and congenital heart anomaly burden (1629/3049 DALYs per 100 000) was attributed to behavioral or metabolic risk factors in the poorest countries (eg, in Niger, 82% of the population among the poorest billion) compared with 85% of the combined CVD and congenital heart anomaly burden (4439/5199 DALYs) in high-income countries. Further, of the combined CVD and congenital heart anomaly burden, 34% was accrued in people under age 30 years in the poorest countries, while only 3% is accrued under age 30 years in high-income countries. We conclude although the current global targets for noncommunicable disease and CVD control will help diminish premature CVD death in the poorest populations, they are not sufficient. Specifically, the current framework (1) excludes deaths of

  10. Simulating Billion-Task Parallel Programs

    SciTech Connect

    Perumalla, Kalyan S; Park, Alfred J

    2014-01-01

    In simulating large parallel systems, bottom-up approaches exercise detailed hardware models with effects from simplified software models or traces, whereas top-down approaches evaluate the timing and functionality of detailed software models over coarse hardware models. Here, we focus on the top-down approach and significantly advance the scale of the simulated parallel programs. Via the direct execution technique combined with parallel discrete event simulation, we stretch the limits of the top-down approach by simulating message passing interface (MPI) programs with millions of tasks. Using a timing-validated benchmark application, a proof-of-concept scaling level is achieved to over 0.22 billion virtual MPI processes on 216,000 cores of a Cray XT5 supercomputer, representing one of the largest direct execution simulations to date, combined with a multiplexing ratio of 1024 simulated tasks per real task.

  11. Causal Analysis of the Inadvertent Contact with an Uncontrolled Electrical Hazardous Energy Source (120 Volts AC)

    SciTech Connect

    David E. James; Dennis E. Raunig; Sean S. Cunningham

    2014-10-01

    On September 25, 2013, a Health Physics Technician (HPT) was performing preparations to support a pneumatic transfer from the HFEF Decon Cell to the Room 130 Glovebox in HFEF, per HFEF OI 3165 section 3.5, Field Preparations. This activity involves an HPT setting up and climbing a portable ladder to remove the 14-C meter probe from above ball valve HBV-7. The HPT source checks the meter and probe and then replaces the probe above HBV-7, which is located above Hood ID# 130 HP. At approximately 13:20, while reaching past the HBV-7 valve position indicator switches in an attempt to place the 14-C meter probe in the desired location, the HPT’s left forearm came in contact with one of the three sets of exposed terminals on the valve position indication switches for HBV 7. This resulted in the HPT receiving an electrical shock from a 120 Volt AC source. Upon moving the arm, following the electrical shock, the HPT noticed two exposed electrical connections on a switch. The HPT then notified the HFEF HPT Supervisor, who in turn notified the MFC Radiological Controls Manager and HFEF Operations Manager of the situation. Work was stopped in the area and the hazard was roped off and posted to prevent access to the hazard. The HPT was escorted by the HPT Supervisor to the MFC Dispensary and then preceded to CFA medical for further evaluation. The individual was evaluated and released without any medical restrictions. Causal Factor (Root Cause) A3B3C01/A5B2C08: - Knowledge based error/Attention was given to wrong issues - Written Communication content LTA, Incomplete/situation not covered The Causal Factor (root cause) was attention being given to the wrong issues during the creation, reviews, verifications, and actual performance of HFEF OI-3165, which covers the need to perform the weekly source check and ensure placement of the probe prior to performing a “rabbit” transfer. This resulted in the hazard not being identified and mitigated in the procedure. Work activities

  12. Electronic timer for sounding rocket payload use

    NASA Astrophysics Data System (ADS)

    Williams, C. P.

    1986-10-01

    An electronic timer has been developed for sounding rocket use. The timer uses CMOS technology for low power consumption and has a battery back-up to keep the timing circuit active in case of a dropout on the payload power bus. Time-event decoding is done by programming EPROM's which enable a +28 volt dc sourcing output. There are 32 discrete outputs which can provide +28 volt dc into a minimum load impedance of 150 ohms. Inputs are designed to operate on standard CMOS voltage levels, but they can withstand +28 volts dc without damage. The timer can be started by either 'G' or lift-off switch closure or umbilical release at lift-off.

  13. Electronic timer for sounding rocket payload use

    NASA Technical Reports Server (NTRS)

    Williams, C. P.

    1986-01-01

    An electronic timer has been developed for sounding rocket use. The timer uses CMOS technology for low power consumption and has a battery back-up to keep the timing circuit active in case of a dropout on the payload power bus. Time-event decoding is done by programming EPROM's which enable a +28 volt dc sourcing output. There are 32 discrete outputs which can provide +28 volt dc into a minimum load impedance of 150 ohms. Inputs are designed to operate on standard CMOS voltage levels, but they can withstand +28 volts dc without damage. The timer can be started by either 'G' or lift-off switch closure or umbilical release at lift-off.

  14. 33 CFR 183.430 - Conductors in circuits of less than 50 volts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standard 1128. (b) This section does not apply to communication systems; electronic navigation equipment... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems...

  15. 33 CFR 183.430 - Conductors in circuits of less than 50 volts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Standard 1128. (b) This section does not apply to communication systems; electronic navigation equipment... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems...

  16. 33 CFR 183.430 - Conductors in circuits of less than 50 volts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Standard 1128. (b) This section does not apply to communication systems; electronic navigation equipment... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems...

  17. 33 CFR 183.430 - Conductors in circuits of less than 50 volts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Standard 1128. (b) This section does not apply to communication systems; electronic navigation equipment... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems...

  18. 33 CFR 183.430 - Conductors in circuits of less than 50 volts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Standard 1128. (b) This section does not apply to communication systems; electronic navigation equipment... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems...

  19. Measurement of Charge Transfer Rate Coefficient Between Ground-State N(2+) Ion and He at Electron-Volt Energies

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.

    1997-01-01

    The charge transfer rate coefficient for the reaction N(2+)(2p(sup 2)P(sup 0)) + He yields products is measured by recording the time dependence of the N(2+) ions stored in an ion trap. A cylindrical radio-frequency ion trap was used to store N(2+) ions produced by laser ablation of a solid titanium nitride target. The decay of the ion signals was analyzed by single exponential least-squares fits to the data. The measured rate coefficient is 8.67(0.76) x 10(exp -11)sq cm/s. The N(2+) ions were at a mean energy of 2.7 eV while He gas was at room temperature, corresponding to an equivalent temperature of 3.9 x 10(exp 3) K. The measured value is in good agreement with a recent calculation.

  20. Figures of merit for focusing mega-electron-volt ion beams in biomedical imaging and proton beam writing

    SciTech Connect

    Ren Minqin; Whitlow, Harry J.; Ananda Sagari, A. R.; Kan, Jeroen A. van; Osipowicz, Thomas; Watt, Frank

    2008-01-01

    A figure of merit (FOM) has been developed for focusing quadrupole multiplet lenses for ion micro- and nanobeam systems. The method which is based on measurement of the central peak of the two-dimensional autocorrelation function of an image provides separate FOM for the horizontal and vertical directions. The approach has been tested by comparison with the edge widths obtained by nonlinear fitting the edge widths of a Ni grid and found to be reliable. The FOM has the important advantage for ion beam imaging of biomedical samples that the fluence needed is considerably lower than for edge fitting.

  1. Investigating fusion plasma instabilities in the Mega Amp Spherical Tokamak using mega electron volt proton emissions (invited)

    SciTech Connect

    Perez, R. V. Boeglin, W. U.; Angulo, A.; Avila, P.; Leon, O.; Lopez, C.; Darrow, D. S.; Cecconello, M.; Klimek, I.; Allan, S. Y.; Akers, R. J.; Keeling, D. L.; McClements, K. G.; Scannell, R.; Conway, N. J.; Turnyanskiy, M.; Jones, O. M.; Michael, C. A.

    2014-11-15

    The proton detector (PD) measures 3 MeV proton yield distributions from deuterium-deuterium fusion reactions within the Mega Amp Spherical Tokamak (MAST). The PD’s compact four-channel system of collimated and individually oriented silicon detectors probes different regions of the plasma, detecting protons (with gyro radii large enough to be unconfined) leaving the plasma on curved trajectories during neutral beam injection. From first PD data obtained during plasma operation in 2013, proton production rates (up to several hundred kHz and 1 ms time resolution) during sawtooth events were compared to the corresponding MAST neutron camera data. Fitted proton emission profiles in the poloidal plane demonstrate the capabilities of this new system.

  2. Investigating fusion plasma instabilities in the Mega Amp Spherical Tokamak using mega electron volt proton emissions (invited).

    PubMed

    Perez, R V; Boeglin, W U; Darrow, D S; Cecconello, M; Klimek, I; Allan, S Y; Akers, R J; Keeling, D L; McClements, K G; Scannell, R; Turnyanskiy, M; Angulo, A; Avila, P; Leon, O; Lopez, C; Jones, O M; Conway, N J; Michael, C A

    2014-11-01

    The proton detector (PD) measures 3 MeV proton yield distributions from deuterium-deuterium fusion reactions within the Mega Amp Spherical Tokamak (MAST). The PD's compact four-channel system of collimated and individually oriented silicon detectors probes different regions of the plasma, detecting protons (with gyro radii large enough to be unconfined) leaving the plasma on curved trajectories during neutral beam injection. From first PD data obtained during plasma operation in 2013, proton production rates (up to several hundred kHz and 1 ms time resolution) during sawtooth events were compared to the corresponding MAST neutron camera data. Fitted proton emission profiles in the poloidal plane demonstrate the capabilities of this new system.

  3. Eight billion asteroids in the Oort cloud

    NASA Astrophysics Data System (ADS)

    Shannon, Andrew; Jackson, Alan P.; Veras, Dimitri; Wyatt, Mark

    2015-01-01

    The Oort cloud is usually thought of as a collection of icy comets inhabiting the outer reaches of the Solar system, but this picture is incomplete. We use simulations of the formation of the Oort cloud to show that ˜4 per cent of the small bodies in the Oort cloud should have formed within 2.5 au of the Sun, and hence be ice-free rock-iron bodies. If we assume that these Oort cloud asteroids have the same size distribution as their cometary counterparts, the Large Synoptic Survey Telescope should find roughly a dozen Oort cloud asteroids during 10 years of operations. Measurement of the asteroid fraction within the Oort cloud can serve as an excellent test of the Solar system's formation and dynamical history. Oort cloud asteroids could be of particular concern as impact hazards as their high mass density, high impact velocity, and low visibility make them both hard to detect and hard to divert or destroy. However, they should be a rare class of object, and we estimate globally catastrophic collisions should only occur about once per billion years.

  4. Uranium in Canada: A billion dollar industry

    SciTech Connect

    Ruzicka, V. )

    1989-12-01

    In 1988, Canada maintained its position as the world's leading producer of uranium with an output of more than 12,400 MT of uranium in concentrates, worth $1.1 billion Canadian. As domestic requirements represent only 15% of current Canadian production, most of the output was exported. With current implementation of the Canada/US Free Trade Agreement, the US has become Canada's major uranium export customer. With a large share of the world's known uranium resources, Canada remains the focus of international uranium exploration activity. In 1988, the uranium exploration expenditures in Canada exceeded $58 million Canadian. The principal exploration targets were deposits associated with Proterozoic unconformities in Saskatchewan and Northwest Territories, particularly those in the Athabasca and Thelon basin regions of the Canadian Shield. Major attention was also paid to polymetallic deposits in which uranium is associated with precious metals, such as gold and platinum group elements. Conceptual genetic models for these deposit types represent useful tools to guide exploration.

  5. Amorphous-diamond electron emitter

    DOEpatents

    Falabella, Steven

    2001-01-01

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  6. Colleges Angle for Billions to Build Obama's Broadband Network

    ERIC Educational Resources Information Center

    Parry, Marc

    2009-01-01

    As the federal government prepares to pour billions of stimulus dollars into increased broadband Internet access, colleges are trying to claim much of the money and shape the emerging national networking policy. Their focus is $4.7-billion that will be doled out under a new grant program administered by a small Commerce Department agency called…

  7. FAO aims for audience of two billion.

    PubMed

    Along with large programs to produce more food, the United Nations Food and Agriculture Organization (FAO) is 1 of the largest communicators and teachers of social development information to the developing world's agricultural and rural citizenry. The U.N. has given the FAO responsibility to raise rural levels of living. FAO does not try to reach directly its audience of 2 billion people who earn their living from agriculture; it works with communicators and educators located within national institutions in each country. FAO's communication program begins at the top-most level of national government in attempts to gain the attention and priority that the agricultural sector of the economy merits in total national development. The main activities of the FAO's population education program fall under several headings: 1) assistance to countries in collecting data and preparing projections on agricultural population and labor force; 2) dissemination of information to countries about implications of population trends on food supply and demand, agricultural employment, and assistance in research activities related to these implications; 3) training of national agricultural planners in demographic aspects of agricultural development; 4) assistance to countries that want to include population concepts in the curricula of agricultural training institutions and training programs for rural development staff; 5) preparation of training and communications materials related to the introduction of population concepts into agricultural training institutions and programs; 6) orienting special types of agricultural institutions toward population motivation; and 7) assistance to countries to strengthen population programs in the context of rural development needs. FAO is emphatic that its population education programs do not include family planning communication, for it does not want to introduce information about contraceptive methods or where to get contraceptive services.

  8. Monochromatic electron photoemission from diamondoid monolayers

    SciTech Connect

    Yang, Wanli; Yang, Wanli L.; Fabbri, J.D.; Willey, T.M.; Lee, J.R.I.; Dahl, J.E.; Carlson, R.M.K.; Schreiner, P.R.; Fokin, A.A.; Tkachenko, B.A.; Fokina, N.A.; Meevasana, W.; Mannella, N.; Tanaka, K.; Zhou, X.J.; van Buuren, T.; Kelly, M.A.; Hussain, Z.; Melosh, N.A.; Shen, Z.-X.

    2007-02-27

    We found monochromatic electron photoemission from large-area self-assembled monolayers of a functionalized diamondoid, [121]tetramantane-6-thiol. Photoelectron spectra of the diamondoid monolayers exhibited a peak at the low-kinetic energy threshold; up to 68percent of all emitted electrons were emitted within this single energy peak. The intensity of the emission peak is indicative of diamondoids being negative electron affinity materials. With an energy distribution width of less than 0.5 electron volts, this source of monochromatic electrons may find application in technologies such as electron microscopy, electron beam lithography, and field-emission flatpanel displays.

  9. Volt-ampere characteristics and nonlinear properties of indium phosphide Gunn diodes in intense microwave fields

    NASA Astrophysics Data System (ADS)

    Borisov, V. I.; Galanin, A. L.; Liubchenko, V. E.; Rogashkov, A. S.; Telegin, A. A.

    1988-10-01

    Experimental results are presented on InP Gunn diodes in intense microwave fields. Two important features of such devices which distinguish them from GaAs devices were found: (1) microwave oscillation at an active-layer electron density of about 10 to the 17th/cu cm and (2) the substantial heating of the near-cathode region of the active layer, leading to characteristic changes in the I-V characteristics.

  10. Atomic images by electron-wave holography.

    PubMed

    Bartell, L S; Ritz, C L

    1974-09-27

    Direct views of electron clouds in atoms h-ave been observed visually and photographed by means of a two-stage holographic miscroscope based on Gabor's principle of image reconstruction. Holograms are produced with 40-kilo-volt electron radiation and decoded with an optical laser. The obviation of an objective lens makes feasible a numerical aperture of 0.37 and a resolving power exceeding 0.1 angstrom.

  11. Academic Pork Barrel Tops $2-Billion for the First Time.

    ERIC Educational Resources Information Center

    Brainard, Jeffrey; Borrego, Anne Marie

    2003-01-01

    Describes how, despite the growing budget deficit, Congress directed a record $2 billion to college projects in 2003, many of them dealing with security and bioterrorism. Includes data tables on the earmarks. (EV)

  12. Harnessing Energy from the Sun for Six Billion People

    SciTech Connect

    Daniel Nocera

    2011-09-12

    Daniel Nocera, a Massachusetts Institute of Technology professor whose recent research focuses on solar-powered fuels, presents a Brookhaven Science Associates Distinguished Lecture, titled "Harnessing Energy from the Sun for Six Billion People -- One at a Time."

  13. NASA Now Minute: Earth and Space Science: 100 Billion Planets

    NASA Video Gallery

    Stephen Kane, co-author of the article, “Study Shows Our Galaxy has 100Billion Planets” reveals details about this incredible study explainsjust how common planets are in our Milky Way galaxy...

  14. Harnessing Energy from the Sun for Six Billion People

    ScienceCinema

    Daniel Nocera

    2016-07-12

    Daniel Nocera, a Massachusetts Institute of Technology professor whose recent research focuses on solar-powered fuels, presents a Brookhaven Science Associates Distinguished Lecture, titled "Harnessing Energy from the Sun for Six Billion People -- One at a Time."

  15. Change in operating parameters of the Continuous Electron Beam Accelerator Facility and Free Electron Laser, Thomas Jefferson National Accelerator Facility, Newport News, Virginia

    SciTech Connect

    1997-10-01

    In this environmental assessment (EA), the US Department of Energy (DOE) reports the results of an analysis of the potential environmental impacts from a proposed change in operating parameters of the Continuous Electron Beam Accelerator Facility (CEBAF), and operation of the Free Electron Laser (FEL) facility beyond the initial demonstration period. With this proposal, DOE intends to increase CEBAF operating range from its current operating maximum beam energy of 4.0 GeV [giga-(billion) electron volts] to 8.0 GeV at a beam power of no greater than 1,000 kW [1 megawatt (MW)], its maximum attainable level, based on current technology and knowledge, without significant, costly equipment modifications. DOE has prepared an EA for this action to determine the potential for adverse impacts from operation of CEBAF and the FEL at the proposed levels. Changing the operating parameters of CEBAF would require no new major construction and minor modifications to the accelerator, its support systems, the FEL, and onsite utility systems. Modifications and performance improvements would be made to (1) the accelerator housed in the underground tunnels, (2) its support systems located in the above ground service buildings, and (3) the water and equipment cooling systems both in the tunnel and at the ground surface. All work would be performed on previously disturbed land and in, on, or adjacent to existing buildings, structures, and equipment. With the proposed action, the recently constructed FEL facility at the Jefferson Lab would operate in concert with CEBAF beyond its demonstration period and up to its maximum effective electron beam power level of 210 kW. In this EA, DOE evaluates the impacts of the no-action alternative and the proposed action alternative. Alternatives considered, but dismissed from further evaluation, were the use of another accelerator facility and the use of another technology.

  16. Early Archean (3.3-billion to 3.5-billion-year-old) microfossils from Warrawoona Group, Australia.

    PubMed

    Schopf, J W; Packer, B M

    1987-07-01

    Cellularly preserved filamentous and colonial fossil microorganisms have been discovered in bedded carbonaceous cherts from the Early Archean Apex Basalt and Towers Formation of northwestern Western Australia. The cell types detected suggest that cyanobacteria, and therefore oxygen-producing photosynthesis, may have been extant as early as 3.3 billion to 3.5 billion years ago. These fossils are among the oldest now known from the geologic record; their discovery substantiates previous reports of Early Archean microfossils in Warrawoona Group strata.

  17. Inventory Control. Easily Made Electronic Device for Conductivity Experiments.

    ERIC Educational Resources Information Center

    Gadek, Frank J.

    1987-01-01

    Describes how to construct an electronic device to be used in conductivity experiments using a 35 millimeter film canister, nine volt battery replacement snaps, a 200-300 ohm resistor, and a light-emitting diode. Provides a diagram and photographs of the device. (TW)

  18. Impacts of Varying Penetration of Distributed Resources with & without Volt/Var Control: Case Study of Varying Load Types

    SciTech Connect

    Rizy, D Tom; Li, Huijuan; Li, Fangxing; Xu, Yan; Adhikari, Sarina; Irminger, Philip

    2011-01-01

    This paper provides a follow-up to an earlier one on impacts of distributed energy resources (DR) on distribution feeders. As DR penetration level on the feeder increases, there can be impacts to distribution system/feeder capacity, line losses, and voltage regulation. These can vary as the penetration level reaches the capacity of the distribution feeder/system or loading. The question is how high of a DR level can be accommodated without any major changes to system operation, system design and protection. Our objective for this work was to address the question of how the DR impacts vary in regards to both DR voltage regulation capability and load mix. A dynamic analysis was used to focus on the impacts of DR with and without volt/var control with different load composition on the distribution feeder. The study considered an example 10MVA distribution feeder in which two inverter-based DRs were used to provide voltage regulation. The results due to DR without voltage regulation capability are compared with DR capable of providing local (at its bus) voltage regulation. The analysis was repeated for four different feeder load compositions consisting of (1) constant power, (2) constant impedance, (3) constant current and (4) ZIP (equal combination of previous three).

  19. Winglets Save Billions of Dollars in Fuel Costs

    NASA Technical Reports Server (NTRS)

    2010-01-01

    The upturned ends now featured on many airplane wings are saving airlines billions of dollars in fuel costs. Called winglets, the drag-reducing technology was advanced through the research of Langley Research Center engineer Richard Whitcomb and through flight tests conducted at Dryden Flight Research Center. Seattle-based Aviation Partners Boeing -- a partnership between Aviation Partners Inc., of Seattle, and The Boeing Company, of Chicago -- manufactures Blended Winglets, a unique design featured on Boeing aircraft around the world. These winglets have saved more than 2 billion gallons of jet fuel to date, representing a cost savings of more than $4 billion and a reduction of almost 21.5 million tons in carbon dioxide emissions.

  20. Negative-ion formation in the explosives RDX, PETN, and TNT using the Reversal Electron Attachment Detection (READ) technique

    NASA Technical Reports Server (NTRS)

    Chutijian, Ara; Boumsellek, S.; Alajajian, S. H.

    1992-01-01

    In the search for high sensitivity and direct atmospheric sampling of trace species, techniques have been developed such as atmospheric-sampling, glow-discharge ionization (ASGDI), corona discharge, atmospheric pressure ionization (API), electron-capture detection (ECD), and negative-ion chemical ionization (NICI) that are capable of detecting parts-per-billion to parts-per-trillion concentrations of trace species. These techniques are based on positive- or negative-ion formation via charge-transfer to the target, or electron capture under multiple-collision conditions in a Maxwellian distribution of electron energies at the source temperature. One drawback of the high-pressure, corona- or glow-discharge devices is that they are susceptible to interferences either through indistinguishable product masses, or through undesired ion-molecule reactions. The ASGDI technique is relatively immune from such interferences, since at target concentrations of less than 1 ppm the majority of negative ions arises via electron capture rather than through ion-molecule chemistry. A drawback of the conventional ECD, and possibly of the ASGDI, is that they exhibit vanishingly small densities of electrons with energies in the range 0-10 millielectron volts (meV), as can be seen from a typical Maxwellian electron energy distribution function at T = 300 K. Slowing the electrons to these subthermal (less than 10 meV) energies is crucial, since the cross section for attachment of several large classes of molecules is known to increase to values larger than 10(exp -12) sq cm at near-zero electron energies. In the limit of zero energy these cross sections are predicted to diverge as epsilon(exp -1/2), where epsilon is the electron energy. In order to provide a better 'match' between the electron energy distribution function and attachment cross section, a new concept of attachment in an electrostatic mirror was developed. In this scheme, electrons are brought to a momentary halt by

  1. Colleges' Billion-Dollar Campaigns Feel the Economy's Sting

    ERIC Educational Resources Information Center

    Masterson, Kathryn

    2009-01-01

    The economy's collapse has caught up with the billion-dollar campaign. In the past 12 months, the amount of money raised by a dozen of the colleges engaged in higher education's biggest fund-raising campaigns fell 32 percent from the year before. The decline, which started before the worst of the recession, has forced colleges to postpone…

  2. Congress Gives Colleges a Billion-Dollar Bonanza.

    ERIC Educational Resources Information Center

    Brainard, Jeffrey; Southwick, Ron

    2000-01-01

    Reports that Congress has earmarked a record amount of money (more than $1 billion) for projects involving specific colleges in the 2000 fiscal year. Notes that such "pork-barrel" spending has tripled since 1996. Charts show trends in earmarks since 1989, year 2000 earmarks by agency, the top 20 recipients of earmarked grants, and ranking of…

  3. 78 FR 34565 - Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ..., and Handling of Animal Feed and Pet Food; Electron Beam and X-Ray Sources for Irradiation of Poultry... generated from machine sources at energy levels not to exceed 10 million electron volts (MeV); (3) X-rays... this chapter; or (4) X-rays generated from machine sources using tantalum or gold as the...

  4. Conservation of protein structure over four billion years

    PubMed Central

    Ingles-Prieto, Alvaro; Ibarra-Molero, Beatriz; Delgado-Delgado, Asuncion; Perez-Jimenez, Raul; Fernandez, Julio M.; Gaucher, Eric A.; Sanchez-Ruiz, Jose M.; Gavira, Jose A.

    2013-01-01

    SUMMARY Little is known with certainty about the evolution of protein structures in general and the degree of protein structure conservation over planetary time scales in particular. Here we report the X-ray crystal structures of seven laboratory resurrections of Precambrian thioredoxins dating back up to ~4 billion years before present. Despite considerable sequence differences compared with extant enzymes, the ancestral proteins display the canonical thioredoxin fold while only small structural changes have occurred over 4 billion years. This remarkable degree of structure conservation since a time near the last common ancestor of life supports a punctuated-equilibrium model of structure evolution in which the generation of new folds occurs over comparatively short periods of time and is followed by long periods of structural stasis. PMID:23932589

  5. Conservation of protein structure over four billion years.

    PubMed

    Ingles-Prieto, Alvaro; Ibarra-Molero, Beatriz; Delgado-Delgado, Asuncion; Perez-Jimenez, Raul; Fernandez, Julio M; Gaucher, Eric A; Sanchez-Ruiz, Jose M; Gavira, Jose A

    2013-09-01

    Little is known about the evolution of protein structures and the degree of protein structure conservation over planetary time scales. Here, we report the X-ray crystal structures of seven laboratory resurrections of Precambrian thioredoxins dating up to approximately four billion years ago. Despite considerable sequence differences compared with extant enzymes, the ancestral proteins display the canonical thioredoxin fold, whereas only small structural changes have occurred over four billion years. This remarkable degree of structure conservation since a time near the last common ancestor of life supports a punctuated-equilibrium model of structure evolution in which the generation of new folds occurs over comparatively short periods and is followed by long periods of structural stasis. PMID:23932589

  6. Ubiquitous Supercritical Wing Design Cuts Billions in Fuel Costs

    NASA Technical Reports Server (NTRS)

    2015-01-01

    A Langley Research Center engineer’s work in the 1960s and ’70s to develop a wing with better performance near the speed of sound resulted in a significant increase in subsonic efficiency. The design was shared with industry. Today, Renton, Washington-based Boeing Commercial Airplanes, as well as most other plane manufacturers, apply it to all their aircraft, saving the airline industry billions of dollars in fuel every year.

  7. Braking formula for electrons of relativistic speed

    NASA Astrophysics Data System (ADS)

    Bethe, H.; Bartschat, Klaus

    2014-12-01

    The current translation is by Klaus Bartschat, Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA. An attempt has been made to preserve Bethe's writing style as much as possible, including his use of "Volt" instead of "electron volt". Even though the term "stopping power" is quite common in present scientific English, we generally use "braking [capability]" rather than "stopping [power]", in order to emphasize the act [and ability] of slowing down the particle rather than the ultimate result of bringing it to a complete halt. Also, a few typographical errors were kept in the English translation to ensure the translation replicates the original paper. Please, see Section 3 of the annotation to Bethe's article [Fontes, C.J., Bostock, C.J. and Bartschat, K. 2014. Eur. Phys. J. H, 39: 517-536] for a list. The references were converted to EPJH style, and the footnotes are numbered consecutively.

  8. Opioid Epidemic Costs U.S. $78.5 Billion Annually: CDC

    MedlinePlus

    ... Epidemic Costs U.S. $78.5 Billion Annually: CDC Economic burden includes health care, lost productivity and treatment ... powerful prescription painkillers called opioids costs the U.S. economy $78.5 billion a year, according to a ...

  9. Dynamics of chemical bonding mapped by energy-resolved 4D electron microscopy.

    PubMed

    Carbone, Fabrizio; Kwon, Oh-Hoon; Zewail, Ahmed H

    2009-07-10

    Chemical bonding dynamics are fundamental to the understanding of properties and behavior of materials and molecules. Here, we demonstrate the potential of time-resolved, femtosecond electron energy loss spectroscopy (EELS) for mapping electronic structural changes in the course of nuclear motions. For graphite, it is found that changes of milli-electron volts in the energy range of up to 50 electron volts reveal the compression and expansion of layers on the subpicometer scale (for surface and bulk atoms). These nonequilibrium structural features are correlated with the direction of change from sp2 [two-dimensional (2D) graphene] to sp3 (3D-diamond) electronic hybridization, and the results are compared with theoretical charge-density calculations. The reported femtosecond time resolution of four-dimensional (4D) electron microscopy represents an advance of 10 orders of magnitude over that of conventional EELS methods. PMID:19589997

  10. Scalable in-memory RDFS closure on billions of triples.

    SciTech Connect

    Goodman, Eric L.; Mizell, David

    2010-06-01

    We present an RDFS closure algorithm, specifically designed and implemented on the Cray XMT supercomputer, that obtains inference rates of 13 million inferences per second on the largest system configuration we used. The Cray XMT, with its large global memory (4TB for our experiments), permits the construction of a conceptually straightforward algorithm, fundamentally a series of operations on a shared hash table. Each thread is given a partition of triple data to process, a dedicated copy of the ontology to apply to the data, and a reference to the hash table into which it inserts inferred triples. The global nature of the hash table allows the algorithm to avoid a common obstacle for distributed memory machines: the creation of duplicate triples. On LUBM data sets ranging between 1.3 billion and 5.3 billion triples, we obtain nearly linear speedup except for two portions: file I/O, which can be ameliorated with the additional service nodes, and data structure initialization, which requires nearly constant time for runs involving 32 processors or more.

  11. $75 Billion in Formula Grants Failed to Drive Reform. Can $5 Billion in Competitive Grants Do the Job? Education Stimulus Watch. Special Report 2

    ERIC Educational Resources Information Center

    Smarick, Andy

    2009-01-01

    In early 2009, Congress passed and President Barack Obama signed into law the American Recovery and Reinvestment Act (ARRA), the federal government's nearly $800 billion stimulus legislation. According to key members of Congress and the Obama administration, the education portions of the law, totaling about $100 billion, were designed both to…

  12. Electron deposition in water vapor, with atmospheric applications.

    NASA Technical Reports Server (NTRS)

    Olivero, J. J.; Stagat, R. W.; Green, A. E. S.

    1972-01-01

    Examination of the consequences of electron impact on water vapor in terms of the microscopic details of excitation, dissociation, ionization, and combinations of these processes. Basic electron-impact cross-section data are assembled in many forms and are incorporated into semianalytic functions suitable for analysis with digital computers. Energy deposition in water vapor is discussed, and the energy loss function is presented, along with the 'electron volts per ion pair' and the efficiencies of energy loss in various processes. Several applications of electron and water-vapor interactions in the atmospheric sciences are considered, in particular, H2O comets, aurora and airglow, and lightning.

  13. Submicron mass spectrometry imaging of single cells by combined use of mega electron volt time-of-flight secondary ion mass spectrometry and scanning transmission ion microscopy

    SciTech Connect

    Siketić, Zdravko; Bogdanović Radović, Ivančica; Jakšić, Milko; Popović Hadžija, Marijana; Hadžija, Mirko

    2015-08-31

    In order to better understand biochemical processes inside an individual cell, it is important to measure the molecular composition at the submicron level. One of the promising mass spectrometry imaging techniques that may be used to accomplish this is Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), using MeV energy heavy ions for excitation. MeV ions have the ability to desorb large intact molecules with a yield that is several orders of magnitude higher than conventional SIMS using keV ions. In order to increase the spatial resolution of the MeV TOF-SIMS system, we propose an independent TOF trigger using a STIM (scanning transmission ion microscopy) detector that is placed just behind the thin transmission target. This arrangement is suitable for biological samples in which the STIM detector simultaneously measures the mass distribution in scanned samples. The capability of the MeV TOF-SIMS setup was demonstrated by imaging the chemical composition of CaCo-2 cells.

  14. Direct determination of impact-parameter-dependent stopping powers for million-electron-volt He ions penetrating Er-doped GaAs

    SciTech Connect

    Yamamoto, Y.; Kaczanowski, J.; Kido, Y.; Nakata, J.; Yamaguchi, H.; Takahei, K.

    1996-03-01

    We have directly determined the impact-parameter-dependent stopping powers for 2.0- and 2.5-MeV He ions passing through GaAs single crystals. The points reside in the preparation of the single-crystal sample with a dopant of a heavy element located in some definite interstitial site at definite depth and in synthesis of a Monte Carlo program to simulate accurately the ion trajectories. Er-doped homoepitaxial GaAs layers grown by molecular-beam epitaxy and by metal-organic chemical-vapor deposition were used for this purpose. As previously reported, fine single-crystal clusters of ErAs are formed in the GaAs host and Er takes the position exactly equivalent to the tetrahedral interstitial site. The present Monte Carlo simulation has revealed the fact that some definite impact-parameter region dominates the backscattering Er peak position and this region shifts continuously by tilting the incident beam axis slightly from a major crystal axis. The results obtained are compared with the Oen-Robinson [Nucl. Instrum. Methods {bold 132}, 647 (1976)] model and other theoretical predictions and clearly show that inner-shell excitations and ionizations contribute significantly to the stopping power even for large impact parameters. {copyright} {ital 1996 The American Physical Society.}

  15. European cogeneration market estimated at $12 billion by 1995

    SciTech Connect

    Not Available

    1987-09-01

    A new study by an international market research firm projects that European companies will install some $12 billion worth of cogeneration equipment by 1995. Products for waste heat recovery, steam and turbine generators made up a $993 million cogeneration market in 1986 in Europe. West Germany is expected to account for nearly a quarter of all volume throughout the 1986-95 period. In 1986, industry there spent some $218 million on cogeneration equipment. France and the U.K. are expected to account for another 17% and 16% of sales, respectively. The report discusses the various industrial end users, and on average finds that commercial/institutional establishments; food, beverage and tobacco producers; fuels processors; and the pulp and paper industry each represent between 10% and 15% of cogeneration purchases.

  16. Bigger, Better Catalog Unveils Half a Billion Celestial Objects

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These frames are samples from the photographic sky surveys, which have been digitized by a technical team at the Space Telescope Science Institute to support the Hubble Space Telescope operations. The team processed these images to create a new astronomical catalog, called the Guide Star Catalog II. This project was undertaken by the Space Telescope Science Institute as an upgrade to an earlier sky survey and catalog (DSS-I and GSC-I), initially done to provide guide stars for pointing the Hubble Space Telescope. By virtue of its sheer size, the DSS-II and GSC-II have many research applications for both professional and amateur astronomers. [Top] An example from the DSS-II shows the Rosette Nebula, (originally photographed by the Palomar Observatory) as digitized in the DSS-I (left) and DSS-II (right). The DSS-II includes views of the sky at both red and blue wavelengths, providing invaluable color information on about one billion deep-sky objects. [Bottom] This blow-up of the inset box in the raw DSS-I scan shows examples of the GSC-I and the improved GSC-II catalogs. Astronomers extracted the stars from the scanned plate of the Rosette and listed them in the catalogs. The new GSC-II catalog provides the colors, positions, and luminosities of nearly half a billion stars -- over 20 times as many as the original GSC-I. The GSC-II contains information on stars as dim as the 19th magnitude. Credit: NASA, the DSS-II and GSC-II Consortia (with images from the Palomar Observatory-STScI Digital Sky Survey of the northern sky, based on scans of the Second Palomar Sky Survey are copyright c 1993-1999 by the California Institute of Technology)

  17. Searching for Organics Preserved in 4.5 Billion Year Old Salt

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Fries, M.; Steele, A.; Bodnar, R.

    2012-01-01

    Our understanding of early solar system fluids took a dramatic turn a decade ago with the discovery of fluid inclusion-bearing halite (NaCl) crystals in the matrix of two freshly fallen brecciated H chondrite falls, Monahans and Zag. Both meteorites are regolith breccias, and contain xenolithic halite (and minor admixed sylvite -- KCl, crystals in their regolith lithologies. The halites are purple to dark blue, due to the presence of color centers (electrons in anion vacancies) which slowly accumulated as 40K (in sylvite) decayed over billions of years. The halites were dated by K-Ar, Rb-Sr and I-Xe systematics to be 4.5 billion years old. The "blue" halites were a fantastic discovery for the following reasons: (1) Halite+sylvite can be dated (K is in sylvite and will substitute for Na in halite, Rb substitutes in halite for Na, and I substitutes for Cl). (2) The blue color is lost if the halite dissolves on Earth and reprecipitates (because the newly-formed halite has no color centers), so the color serves as a "freshness" or pristinity indicator. (3) Halite frequently contains aqueous fluid inclusions. (4) Halite contains no structural oxygen, carbon or hydrogen, making them ideal materials to measure these isotopic systems in any fluid inclusions. (5) It is possible to directly measure fluid inclusion formation temperatures, and thus directly measure the temperature of the mineralizing aqueous fluid. In addition to these two ordinary chondrites halite grains have been reliably reported in several ureilites, an additional ordinary chondrite (Jilin), and in the carbonaceous chondrite (Murchison), although these reports were unfortunately not taken seriously. We have lately found additional fluid inclusions in carbonates in several additional carbonaceous chondrites. Meteoritic aqueous fluid inclusions are apparently relatively widespread in meteorites, though very small and thus difficult to analyze.

  18. Electron energy loss and diffraction of backscattered electrons from silicon

    NASA Astrophysics Data System (ADS)

    Winkelmann, Aimo; Aizel, Koceila; Vos, Maarten

    2010-05-01

    Electrons backscattered from crystals can show Kikuchi patterns: variations in intensity for different outgoing directions due to diffraction by the lattice. Here, we measure these effects as a function of their energy loss for 30 keV electrons backscattered from silicon. The change in diffraction contrast with energy loss depends strongly on the scattering geometry. At steep incidence on the sample, diffraction contrast in the observed Kikuchi bands decreases rapidly with energy loss. For an energy loss larger than about 150 eV the contrast is more than 5 times less than the contrast due to electrons near zero energy loss. However, for grazing incidence angles, maximum Kikuchi band contrast is observed for electrons with an energy loss near 60 eV, where the contrast is more than 2.5× larger than near zero energy loss. In addition, in this grazing incidence geometry, the Kikuchi diffraction effects stay significant even for electrons that have lost hundreds of electron volts. For the maximum measured energy loss of 440 eV, the electrons still show a contrast that is 1.5 × larger than that of the electrons near zero energy loss. These geometry-dependent observations of Kikuchi band diffraction contrast are interpreted based on the elastic and inelastic scattering properties of electrons and dynamical diffraction simulations.

  19. Suprathermal electrons produced by beam-plasma-discharge

    NASA Technical Reports Server (NTRS)

    Sharp, W. E.

    1982-01-01

    Experiments conducted with a low energy plasma lens, HARP, in the electron beam of the large vacuum chamber at Johnson Space Center indicate that an enhanced population of 50 to 300 volt electrons appear when the beam goes into the Beam-Plasma Discharge (BPD) mode. Below the BPD instability the electron distribution appears to be characterized as non-energized single particle scattering and energy loss. At 100 cm from the beam core in the BPD mode the fluxes parallel to the beam are reduced by a factor of 20 with respect to the fluxes at 25 cm. Some evidence for isotropy near the beam core is presented.

  20. Energetic electrons in the magnetosphere of jupiter.

    PubMed

    Van Allen, J A; Baker, D N; Randall, B A; Thomsen, M F; Sentman, D D; Flindt, H R

    1974-01-25

    Observations of energetic electrons ( greater, similar 0.07 million electron volts) show that the outer magnetosphere of Jupiter consists of a thin disklike, quasitrapping region extending from about 20 to 100 planetary radii (R(J)). This magnetodisk is confined to the vicinity of the magnetic equatorial plane and appears to be an approximate figure of revolution about the magnetic axis of the planet. Hard trapping is observed within a radial distance of about 20 R(J). The omnidirectional intensity J(0) of electrons with energy greater, similar 21 million electron volts within the region 3 r 20 R(J) is given by the following provisional expression in terms of radial distance r and magnetic latitude theta: J(0) = 2.1 x 10(8) exp[-(r/a) - (theta/b)(2)]. In this expression J(0) is particles per square centimeter per second; a = 1.52 R(J) for 3

  1. Space processing of electronic materials

    NASA Technical Reports Server (NTRS)

    Holland, L. R.

    1982-01-01

    The bulk growth of solid solution alloys of mercury telluride and cadmium telluride is discussed. These alloys are usually described by the formula Hg1-xCdxTe, and are useful for the construction of infrared detectors. The electronic energy band gap can be controlled between zero and 1.6 electron volts by adjusting the composition x. The most useful materials are at x approximately 20%, suitable for detection wavelengths of about 10 micrometers. The problems of growing large crystals are rooted in the wide phase diagram of the HgTe-CdTe pseudobinary system which leads to exaggerate segregation in freezing, constitutional supercooling, and other difficulties, and in the high vapor pressure of mercury at the growth temperatures, which leads to loss of stoichiometry and to the necessity of working in strong, pressure resistant sealed containers.

  2. Orbital forcing of climate 1.4 billion years ago

    PubMed Central

    Zhang, Shuichang; Wang, Xiaomei; Hammarlund, Emma U.; Wang, Huajian; Costa, M. Mafalda; Bjerrum, Christian J.; Connelly, James N.; Zhang, Baomin; Bian, Lizeng; Canfield, Donald E.

    2015-01-01

    Fluctuating climate is a hallmark of Earth. As one transcends deep into Earth time, however, both the evidence for and the causes of climate change become difficult to establish. We report geochemical and sedimentological evidence for repeated, short-term climate fluctuations from the exceptionally well-preserved ∼1.4-billion-year-old Xiamaling Formation of the North China Craton. We observe two patterns of climate fluctuations: On long time scales, over what amounts to tens of millions of years, sediments of the Xiamaling Formation record changes in geochemistry consistent with long-term changes in the location of the Xiamaling relative to the position of the Intertropical Convergence Zone. On shorter time scales, and within a precisely calibrated stratigraphic framework, cyclicity in sediment geochemical dynamics is consistent with orbital control. In particular, sediment geochemical fluctuations reflect what appear to be orbitally forced changes in wind patterns and ocean circulation as they influenced rates of organic carbon flux, trace metal accumulation, and the source of detrital particles to the sediment. PMID:25775605

  3. Nine Billion Years: Past and Future of the Solar System

    NASA Astrophysics Data System (ADS)

    Leubner, I. H.

    2013-05-01

    As the Sun is losing mass and thus gravity by radiation and solar wind, solar-planetary energy balances diminish. Since the planets are only weakly bound to the Sun, the planets have been moving away from the Sun, causing increases of orbits and orbital periods. This is modeled for selected planets from Mercury to Sedna and from the formation of the Solar system at -4.5 to +4.5 billion years (Byr/Ma). Planets were initially significantly closer to the Sun, suggesting that modeling of the formation of the solar system needs to be revisited. By +4.5Byr planets beyond Saturn will have separated from the Solar System. The presently outermost solar object, Sedna, is in the process of separation. Climate changes of Mars and Earth are modeled as a function of time. The prediction of the transition of Mars from water to ice at -3.6 Byr is in agreement with observations (-2.9 to -3.7 Byr). This provides for the first time answers to the why and when of water to ice transition on Mars. Earth temperatures are predicted to decrease by of 38, 24, and 20C between -4.5 Byr to +4.5 Byr for present temperatures of +50, 0, and -50 C, respectively. Mars: Water - Ice Transition

  4. Thermal Evolution of the Earth During the First Billion Years

    NASA Astrophysics Data System (ADS)

    Sotin, Christophe

    There is good evidence that life occurred on Earth during the first billion years of its history. Modelling the dynamics of the Earth at this period of time is critical to understand the conditions of the emergence of life. These conditions are the result of the coupling between the inner and outer envelopes of the Earth. Several processes such as volcanism, magnetic field and plate tectonics originate in the Earth's deep layers. They control the physical and chemical conditions of the outer layers (atmosphere, hydrosphere, and crust) where life appeared and developed. The goal of this chapter is to describe these internal processes and to present models for Earth's evolution. After a descriptive summary of our current knowledge of the Earth's deep interior, this chapter explains the mechanisms of heat transfer to the surface by subsolidus thermal convection, a process that drives the Earth's surface dynamics (volcanism and plate tectonics). The last part of this chapter addresses the Earth's magnetic field and how it prevents atmospheric escape and preserves the present atmosphere. Throughout this chapter, references to conditions existing on Earth-like planets are given to illustrate how the knowledge of these planets contributes to a better understanding of the history of our own planet.

  5. The nuclear interaction at Oklo 2 billion years ago

    NASA Astrophysics Data System (ADS)

    Fujii, Yasunori; Iwamoto, Akira; Fukahori, Tokio; Ohnuki, Toshihiko; Nakagawa, Masayuki; Hidaka, Hiroshi; Oura, Yasuji; Möller, Peter

    2000-05-01

    We re-examine the effort to constrain the time variability of the coupling constants of the fundamental interactions by studying the anomalous isotopic abundance of Sm observed at the remnants of the natural reactors which were in operation at Oklo about 2 billion years ago, in terms of a possible deviation of the resonance energy from the value observed today. We rely on new samples that were carefully collected to minimize natural contamination and also on a careful temperature estimate of the reactors. We obtain the upper bound (-0.2±0.8)×10 -17 y -1 on the fractional rate of change of the electromagnetic as well as the strong interaction coupling constants. Our result basically agrees with and even suggests some improvement of the result due recently to Damour and Dyson. Strictly speaking, however, we find another choice of the resonance energy shift indicating a non-zero time variation of the constants. However, we find a rather strong but still tentative indication that this non-null range can be ruled out by including Gd data, for which it is essential to take the effect of contamination into account.

  6. Deep space communication - A one billion mile noisy channel

    NASA Technical Reports Server (NTRS)

    Smith, J. G.

    1982-01-01

    Deep space exploration is concerned with the study of natural phenomena in the solar system with the aid of measurements made at spacecraft on deep space missions. Deep space communication refers to communication between earth and spacecraft in deep space. The Deep Space Network is an earth-based facility employed for deep space communication. It includes a network of large tracking antennas located at various positions around the earth. The goals and achievements of deep space exploration over the past 20 years are discussed along with the broad functional requirements of deep space missions. Attention is given to the differences in space loss between communication satellites and deep space vehicles, effects of the long round-trip light time on spacecraft autonomy, requirements for the use of massive nuclear power plants on spacecraft at large distances from the sun, and the kinds of scientific return provided by a deep space mission. Problems concerning a deep space link of one billion miles are also explored.

  7. Fuel efficient stoves for the poorest two billion

    NASA Astrophysics Data System (ADS)

    Gadgil, Ashok

    2012-03-01

    About 2 billion people cook their daily meals on generally inefficient, polluting, biomass cookstoves. The fuels include twigs and leaves, agricultural waste, animal dung, firewood, and charcoal. Exposure to resulting smoke leads to acute respiratory illness, and cancers, particularly among women cooks, and their infant children near them. Resulting annual mortality estimate is almost 2 million deaths, higher than that from malaria or tuberculosis. There is a large diversity of cooking methods (baking, boiling, long simmers, brazing and roasting), and a diversity of pot shapes and sizes in which the cooking is undertaken. Fuel-efficiency and emissions depend on the tending of the fire (and thermal power), type of fuel, stove characteristics, and fit of the pot to the stove. Thus, no one perfect fuel-efficient low-emitting stove can suit all users. Affordability imposes a further severe constraint on the stove design. For various economic strata within the users, a variety of stove designs may be appropriate and affordable. In some regions, biomass is harvested non-renewably for cooking fuel. There is also increasing evidence that black carbon emitted from stoves is a significant contributor to atmospheric forcing. Thus improved biomass stoves can also help mitigate global climate change. The speaker will describe specific work undertaken to design, develop, test, and disseminate affordable fuel-efficient stoves for internally displaced persons (IDPs) of Darfur, Sudan, where the IDPs face hardship, humiliation, hunger, and risk of sexual assault owing to their dependence on local biomass for cooking their meals.

  8. Program Calculates Power Demands Of Electronic Designs

    NASA Technical Reports Server (NTRS)

    Cox, Brian

    1995-01-01

    CURRENT computer program calculates power requirements of electronic designs. For given design, CURRENT reads in applicable parts-list file and file containing current required for each part. Program also calculates power required for circuit at supply potentials of 5.5, 5.0, and 4.5 volts. Written by use of AWK utility for Sun4-series computers running SunOS 4.x and IBM PC-series and compatible computers running MS-DOS. Sun version of program (NPO-19590). PC version of program (NPO-19111).

  9. Survey of electron cyclotron waves in the magnetosphere and the diffuse auroral electron precipitation

    SciTech Connect

    Roeder, J.L.; Koons, H.C.

    1990-03-09

    Narrowband electrostatic wave emissions at frequencies above the local electron cyclotron frequency are known variously as electron cyclotron harmonic (ECH) waves or n+1/2 waves since they tend to occur at odd half-multiples of the electron cyclotron frequency. Natural ECH emissions in the outer magnetosphere are often cited as the electron scattering mechanism which results in the diffuse auroral precipitation. A survey is presented of the characteristics of these waves using data from both the SCATHA and AMPTE-IRM plasma wave instruments. The emissions were observed most often in the 0300-0600 LT sector at L = approx. 4-8 and magnetic latitudes in the range + or - 10 deg. In this region, emissions exceeding 35 microVolt/m were detected only 25% of the time and those exceeding 12 microVolt/m were detected 60% of the time. In agreement with Belmont et al., we consider these amounts grossly insufficient to account for the diffuse auroral electron precipitation by quasilinear pitch angle diffusion.

  10. Early-type Galaxy Evolution: The Last 8 Billion Years

    NASA Astrophysics Data System (ADS)

    Kaviraj, Sugata; Yi, S. K.; Ellis, R.; Schawinski, K.; Gawiser, E.; Silk, J.; van Dokkum, P.; Urry, M.

    2010-01-01

    I review our current understanding of the star formation histories of early-type galaxies, in the context of recent observational studies of their rest-frame ultraviolet (UV) properties. By combining GALEX and SDSS photometry at low reshift, and exploiting (deep) optical surveys (MUSYC/COMBO-17/GEMS/COSMOS) at intermediate redshift, we are able to put unprecedented constraints on the formation and evolution of these galaxies over the last 8 billion years. In agreement with previous (optical) studies, the results indicate that the bulk of the stellar mass in early-types forms at high redshift (z > 1), possibly over short timescales (< 1 Gyr). Nevertheless, early-types of all luminosities form stars over the lifetime of the Universe, with most luminous (-23 < M(V) -21) systems forming up to 10-15% of their stellar mass after z = 1 (with a scatter to higher values), while their less massive counterparts form up to 30-60% of their mass in the same redshift range. The intensity of recent star formation and the UV colour distribution is quantitatively consistent with what might be expected from minor mergers (mass ratios < 1:3) in an LCDM cosmology. This is supported by visual inspection of HST images of early-types around z 0.5 which show a remarkable correspondence between the presence of morphological disturbances and UV excess. We use our results to speculate on the potentially significant role of minor merging on the evolution of the massive galaxy population at late epochs and the possible characteristics that future surveys will have to possess to study the minor merger process. This research was supported by a Fellowship from the Royal Commission for the Exhibition of 1851 and a Senior Research Fellowship from Worcester College, Oxford (SK).

  11. 3.5 billion years of reshaped Moho, southern Africa

    NASA Astrophysics Data System (ADS)

    Stankiewicz, Jacek; de Wit, Maarten

    2013-12-01

    According to some previous studies, Archean continental crust is, on global average, apparently thinner than Proterozoic crust. Subsequently, the validity of this statement has been questioned. To provide an additional perspective on this issue, we present analyses of Moho signatures derived from recent seismic data along swaths 2000 km in length across southern Africa and its flanking ocean. The imaged crust has a near continuous age range between ca. 0.1 and 3.7 billion years, and the seismic data allow direct comparison of Moho depths between adjacent Archean, Proterozoic and Phanerozoic crust. We find no simple secular change in depth to Moho over this time period. In contrast, there is significant variation in depth to Moho beneath both Archean and Proterozoic crust; Archean crust of southern Africa displays as much crustal diversity in thickness as the adjacent Proterozoic crust. The Moho beneath all crustal provinces that we have analysed has been severely altered by tectono-metamorphic and igneous processes, in many cases more than once, and cannot provide unequivocal data for geodynamic models dealing with secular changes in continental crust formation. These results and conclusions are similar to those documented along ca. 2000 km swaths across the Canadian Shield recorded by Lithoprobe. Tying the age and character of the Precambrian crust of southern Africa to their depth diversities is clearly related to manifold processes of tectono-thermal ‘surgery’ subsequent to their origin, the details of which are still to be resolved, as they are in most Precambrian terranes. Reconstructing pristine Moho of the early Earth therefore remains a formidable challenge. In South Africa, better knowledge of ‘fossilised’ Archean crustal sections ‘turned-on-edge’, such as at the Vredefort impact crater (for the continental crust), and from the Barberton greenstone belt (for oceanic crust) is needed to characterize potential pristine Archean Moho transitions.

  12. Limiting Superluminal Electron and Neutrino Velocities Using the 2010 Crab Nebula Flare and the IceCube PeV Neutrino Events

    NASA Technical Reports Server (NTRS)

    Stecker, Floyd W.

    2014-01-01

    The observation of two PetaelectronVolt (PeV)-scale neutrino events reported by Ice Cube allows one to place constraints on Lorentz invariance violation (LIV) in the neutrino sector. After first arguing that at least one of the PetaelectronVolt IceCube events was of extragalactic origin, I derive an upper limit for the difference between putative superluminal neutrino and electron velocities of less than or equal to approximately 5.6 x 10(exp -19) in units where c = 1, confirming that the observed PetaelectronVolt neutrinos could have reached Earth from extragalactic sources. I further derive a new constraint on the superluminal electron velocity, obtained from the observation of synchrotron radiation from the Crab Nebula flare of September, 2010. The inference that the greater than 1 GigaelectronVolt gamma-rays from synchrotron emission in the flare were produced by electrons of energy up to approx. 5.1 PetaelectronVolt indicates the nonoccurrence of vacuum Cerenkov radiation by these electrons. This implies a new, strong constraint on superluminal electron velocities delta(sub e) less than or equal to approximately 5 x 10(exp -21). It immediately follows that one then obtains an upper limit on the superluminal neutrino velocity alone of delta(sub v) less than or equal to approximately 5.6 x 10(exp -19), many orders of magnitude better than the time-of-flight constraint from the SN1987A neutrino burst. However, if the electrons are subluminal the constraint on the absolute value of delta(sub e) less than or equal to approximately 8 x 10(exp -17), obtained from the Crab Nebula gamma-ray spectrum, places a weaker constraint on superluminal neutrino velocity of delta(sub v) less than or equal to approximately 8 x 10(exp -17).

  13. Slow electron cooling in colloidal quantum dots.

    PubMed

    Pandey, Anshu; Guyot-Sionnest, Philippe

    2008-11-01

    Hot electrons in semiconductors lose their energy very quickly (within picoseconds) to lattice vibrations. Slowing this energy loss could prove useful for more efficient photovoltaic or infrared devices. With their well-separated electronic states, quantum dots should display slow relaxation, but other mechanisms have made it difficult to observe. We report slow intraband relaxation (>1 nanosecond) in colloidal quantum dots. The small cadmium selenide (CdSe) dots, with an intraband energy separation of approximately 0.25 electron volts, are capped by an epitaxial zinc selenide (ZnSe) shell. The shell is terminated by a CdSe passivating layer to remove electron traps and is covered by ligands of low infrared absorbance (alkane thiols) at the intraband energy. We found that relaxation is markedly slowed with increasing ZnSe shell thickness.

  14. A large neutral fraction of cosmic hydrogen a billion years after the Big Bang.

    PubMed

    Wyithe, J Stuart B; Loeb, Abraham

    2004-02-26

    The fraction of ionized hydrogen left over from the Big Bang provides evidence for the time of formation of the first stars and quasar black holes in the early Universe; such objects provide the high-energy photons necessary to ionize hydrogen. Spectra of the two most distant known quasars show nearly complete absorption of photons with wavelengths shorter than the Lyman alpha transition of neutral hydrogen, indicating that hydrogen in the intergalactic medium (IGM) had not been completely ionized at a redshift of z approximately 6.3, about one billion years after the Big Bang. Here we show that the IGM surrounding these quasars had a neutral hydrogen fraction of tens of per cent before the quasar activity started, much higher than the previous lower limits of approximately 0.1 per cent. Our results, when combined with the recent inference of a large cumulative optical depth to electron scattering after cosmological recombination therefore suggest the presence of a second peak in the mean ionization history of the Universe.

  15. Constraining the geodynamo and magnetopause during Earth's first billion years

    NASA Astrophysics Data System (ADS)

    Cottrell, R. D.; Tarduno, J. A.; Davis, W. J.; Mamajek, E.

    2013-12-01

    A key parameter in determining solar-terrestrial interactions for the early Earth is the magnetopause standoff distance, determined by the balance between the geomagnetic field and solar wind pressure. The oldest constraints are for 3.45 Ga, during which the magnetopause standoff was less than half the distance of present-day, suggesting an environment where enhanced volatile loss (including water) from the atmosphere seems unavoidable (Tarduno et al., Science, 2010). As we look further back in time there are two vastly different, but currently viable models for the geodynamo. In one the dynamo started shortly after core formation, whereas in the other the dynamo was delayed by as much as 1 billion years by slow lower mantle cooling. A further uncertainty in standoff calculations is solar mass loss for the first 700 million years of the young Sun. Here we address both the uncertainties in solar winds and Earth's dipole moment. We constrain solar mass loss using a new model for the evolution of solar magnetic topology with time, allowing us to extend our prior calculations to the earliest Sun. Extant rocks suitable for paleomagnetic analysis are not available older than ca. 3.47 Ga, however, silicate minerals containing magnetic inclusions composing sedimentary rocks could preserve an ancient record of the geodynamo. Among these, the Jack Hills metaconglomerate (Yilgarn craton, Western Australia) is a promising unit because cobbles pass a conglomerate test (Tarduno and Cottrell, EPSL, 2013). Following our work on zircons and other single silicate crystals hosting magnetic inclusions in the Rochester laboratory since 1997, we discuss the first successful Thellier-Thellier paleointensity results on zircons measured in situ in quartz and as isolated crystals. We employ a CO2 laser demagnetization system and a small bore (6.3 mm) 3-component DC SQUID magnetometer; the latter offers the highest currently available moment resolution. We will discuss our related

  16. Secondary Electron Emission and the Exploration of Space

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.

    2006-01-01

    The emission of secondary electrons from surfaces exposed to the space plasma and radiation environment is a process of great importance to space system engineering design and operations. A spacecraft will collect charge until it reaches an equilibrium potential gov,erned by the balance of incoming electron and ion currents from the space environment with outgoing secondary, backscattered, and photoelectron currents. Laboratory measurements of secondary electron yields are an important parameter for use in spacecraft charging analyses because the magnitude and sign of the equilibrium potential depends on both the energy spectrum of electrons and ions in the space environment and the electrical properties of the surface materials (including the energy dependent secondary electron yields). Typical benign equilibrium potentials range &om a few tens of volts positive in interplanetary space to a few volts negative in low Earth orbit. However, spacecraft are known to charge to negative potentials exceeding one to ten kilovolts in some environments and anomalies or system failures due to electrostatic discharges originating from highly charged surfaces becomes a serious concern. This presentation will provide a review of the spacecraft charging process with special emphasis on the role of secondary electrons in controlling the current balance process. Charging examples will include spacecraft in Earth orbit and interplanetary space as well as dust charging on the lunar surface, a phenomenon of importance to future lunar surface operations.

  17. A SWIRE Picture is Worth Billions of Years

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: SWIRE View of Distant Galaxies [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 2Figure 3 Figure 4

    These spectacular images, taken by the Spitzer Wide-area Infrared Extragalactic (SWIRE) Legacy project, encapsulate one of the primary objectives of the Spitzer mission: to connect the evolution of galaxies from the distant, or early, universe to the nearby, or present day, universe.

    The Tadpole galaxy (main image) is the result of a recent galactic interaction in the local universe. Although these galactic mergers are rare in the universe's recent history, astronomers believe that they were much more common in the early universe. Thus, SWIRE team members will use this detailed image of the Tadpole galaxy to help understand the nature of the 'faint red-orange specks' of the early universe.

    The larger picture (figure 2) depicts one-sixteenth of the SWIRE survey field called ELAIS-N1. In this image, the bright blue sources are hot stars in our own Milky Way, which range anywhere from 3 to 60 times the mass of our Sun. The fainter green spots are cooler stars and galaxies beyond the Milky Way whose light is dominated by older stellar populations. The red dots are dusty galaxies that are undergoing intense star formation. The faintest specks of red-orange are galaxies billions of light-years away in the distant universe.

    Figure 3 features an unusual ring-like galaxy called CGCG 275-022. The red spiral arms indicate that this galaxy is very dusty and perhaps undergoing intense star formation. The star-forming activity could have been initiated by a near head-on collision with another galaxy.

    The most distant galaxies that SWIRE is able to detect are revealed in a zoom of deep space (figure 4). The colors in this feature represent the same objects as those in the larger field image of ELAIS

  18. Low-energy electron intensities at large distances over the earth's polar cap

    NASA Technical Reports Server (NTRS)

    Yeager, D. M.; Frank, L. A.

    1975-01-01

    The results of the character and temporal fluctuations study of electron intensities in the energy range of hundreds of electron volts, are reported which were measured at high latitudes and altitudes on geomagnetic field lines corresponding to those of the polar cap and magnetotail lobes. It is concluded that such electron intensities are diminutive relative to those found in other regions of the magnetosphere. Severe variations of intensities were found and the magnitudes of electron intensities appear to be strongly coupled to the directions of the interplanetary magnetic fields.

  19. Monte Carlo approach to the spatial deposition of energy by electrons in molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Heaps, M. G.; Green, A. E. S.

    1974-01-01

    The Monte Carlo (MC) and continuous slowdown approximation (CSDA) approaches to the spatial deposition of energy by electrons are compared using the same detailed atomic cross section (DACS). It is found that the CSDA method overestimates the amount of energy that is deposited near the end of the path for electrons above a few hundred electron volts. The MC results are in approximate agreement with experimental data in such a way as to be relatively independent of the actual gas used. Our MC results are extended to obtain the three-dimensional deposition of energy by sub-keV electrons in molecular hydrogen.

  20. Titan's Spectacular Volte-Face

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin A.

    2013-10-01

    Like Earth, Titan sports lakes, storms and rainfall. These features derive from a methane cycle, reminiscent of Earth's hydrological cycle; methane exists as an ice, liquid and gas and transfers between the surface and atmosphere, according to the seasonal weather. Titan's seasons contrast Earth’s. Imagine a summer trip to 70 latitude, where hurricane-sized storms burst forth out of a clear sky every few months for about 15 years. Then they vanish for another 15 years. Envision a trip to the winter polar region. Here the sky is perhaps clear except that the high haze, which filters sunlight like a translucent globe, is somewhat thicker than it is in the summer. Imperceptibly, you are blocking the diffuse organic matter, which is slowly settling out of the hazy orb, and accumulating on the polar surface. These effects are a few of the many that derive from Titan’s circulation and its seasonal changes during the satellite's 29.5 Earth year orbit about the Sun. In particular, and as indicated in recent observations, Titan's circulation flip-flopped. Before equinox in 2009, on average, air rose in the southern polar region and downwelled in the northern polar region. Now the reverse appears to be happening. Here we discuss the observations ranging from the surface to ~500 km altitude that reveal the symphony of responses of Titan's surface and atmosphere to this dramatic shift. In addition we discuss the syntheses of these effects, from theoretical efforts involving microphysical models, local cloud models and general circulation models, with the question of why Titan's seasonal changes are so much more spectacular compared to those of Earth.

  1. Rubidium-strontium date of possibly 3 billion years for a granitic rock from antarctica.

    PubMed

    Halpern, M

    1970-09-01

    A single total rock sample of biotite granite from Jule Peaks, Antarctica, has been dated by the rubidium-strontium method at about 3 billion years. The juxtaposition of this sector of Antarctica with Africa in the Dietz and Sproll continental drift reconstruction results in a possible geochronologic fit of the Princess Martha Coast of Antarctica with a covered possible notheastern extension of the African Swaziland Shield, which contains granitic rocks that are also 3 billion years old.

  2. Indian farmers need help to feed over 1.5 billion people in 2030.

    PubMed

    Jagadish, Mittur N

    2012-01-01

    In view of the enormous challenge and pressure on farmers to feed 9 billion plus people and billions of animals who are going to be living in our planet in 2050, new technologies must be invented, assessed and adapted. Farmer welfare and provision of resources required for their work is of paramount importance. India has benefited from Bt cotton technology and will certainly benefit from other biotech crops that have been carefully developed and assessed for consumption and environmental safety.

  3. Rules Set for $4 Billion Race to Top Contest: Final Rules Give States Detailed Map in Quest for $4 Billion in Education Stimulus Aid

    ERIC Educational Resources Information Center

    McNeil, Michele

    2009-01-01

    For a good shot at $4 billion in grants from the federal Race to the Top Fund, states will need to make a persuasive case for their education reform agendas, demonstrate significant buy-in from local school districts, and devise plans to evaluate teachers and principals based on student performance, according to final regulations released last…

  4. Expert fears doom if world population hits 12-15 billion.

    PubMed

    1994-02-22

    Earth's land, water and cropland are disappearing so rapidly that the world population must be slashed to 2 billion or less by 2100 to provide prosperity for all in that year, says a study released yesterday. The alternative, if current trends continue, is a population of 12 billion to 15 billion people and an apocalyptic worldwide scene of "absolute misery, poverty, disease and starvation," said the study's author, David Pimentel, an ecologist at Cornell University. In the US, the population would climb to 500 million and the standard of living would decline to slightly better than in present-day China. Mr. Pimentel said at the annual meeting of the American Association for the Advancement of Science. Even now, the world population of 6 billion is at least 3 times what the Earth's battered natural resources and depleted energy reserves would be able to comfortably support in 2100, Mr. Pimentel said. Mr. Pimentel defines "comfortably support" as providing something close to the current American standard of living, but with wiser use of energy and natural resources. Although a decline to 1 billion or 2 billion people over the next century sounds nearly impossible, it could be done by limiting families around the world to an average of 1.5 children, Mr. Pimentel said. Currently, US women have an average of 2.1 children, while the average in Rwanda is 8.5.

  5. Studying Atomic Structures by Aberration-Corrected Transmission Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Urban, Knut W.

    2008-07-01

    Seventy-five years after its invention, transmission electron microscopy has taken a great step forward with the introduction of aberration-corrected electron optics. An entirely new generation of instruments enables studies in condensed-matter physics and materials science to be performed at atomic-scale resolution. These new possibilities are meeting the growing demand of nanosciences and nanotechnology for the atomic-scale characterization of materials, nanosynthesized products and devices, and the validation of expected functions. Equipped with electron-energy filters and electron-energy loss spectrometers, the new instruments allow studies not only of structure but also of elemental composition and chemical bonding. The energy resolution is about 100 milli electron volts, and the accuracy of spatial measurements has reached a few picometers. However, understanding the results is generally not straightforward and only possible with extensive quantum-mechanical computer calculations.

  6. Studying atomic structures by aberration-corrected transmission electron microscopy.

    PubMed

    Urban, Knut W

    2008-07-25

    Seventy-five years after its invention, transmission electron microscopy has taken a great step forward with the introduction of aberration-corrected electron optics. An entirely new generation of instruments enables studies in condensed-matter physics and materials science to be performed at atomic-scale resolution. These new possibilities are meeting the growing demand of nanosciences and nanotechnology for the atomic-scale characterization of materials, nanosynthesized products and devices, and the validation of expected functions. Equipped with electron-energy filters and electron-energy-loss spectrometers, the new instruments allow studies not only of structure but also of elemental composition and chemical bonding. The energy resolution is about 100 milli-electron volts, and the accuracy of spatial measurements has reached a few picometers. However, understanding the results is generally not straightforward and only possible with extensive quantum-mechanical computer calculations. PMID:18653874

  7. Evidence for global electron transportation into the jovian inner magnetosphere.

    PubMed

    Yoshioka, K; Murakami, G; Yamazaki, A; Tsuchiya, F; Kimura, T; Kagitani, M; Sakanoi, T; Uemizu, K; Kasaba, Y; Yoshikawa, I; Fujimoto, M

    2014-09-26

    Jupiter's magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.

  8. Evidence for global electron transportation into the jovian inner magnetosphere.

    PubMed

    Yoshioka, K; Murakami, G; Yamazaki, A; Tsuchiya, F; Kimura, T; Kagitani, M; Sakanoi, T; Uemizu, K; Kasaba, Y; Yoshikawa, I; Fujimoto, M

    2014-09-26

    Jupiter's magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves. PMID:25258073

  9. Evidence for global electron transportation into the jovian inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Yoshioka, K.; Murakami, G.; Yamazaki, A.; Tsuchiya, F.; Kimura, T.; Kagitani, M.; Sakanoi, T.; Uemizu, K.; Kasaba, Y.; Yoshikawa, I.; Fujimoto, M.

    2014-09-01

    Jupiter’s magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.

  10. Electron transfer, ionization, and excitation in atomic collisions. Progress report, June 15, 1992--June 14, 1995

    SciTech Connect

    Winter, T.G.; Alston, S.G.

    1995-08-01

    The research program of Winter and Alston addresses the fundamental processes of electron transfer, ionization, and excitation in ion-atom, ion-ion, and ion-molecule collisions. Attention is focussed on one- and two-electron systems and, more recently, quasi-one-electron systems whose electron-target-core interaction can be accurately modeled by one-electron potentials. The basic computational approaches can then be taken with few, if any, approximations, and the underlying collisional mechanisms can be more clearly revealed. Winter has focussed on intermediate collision energies (e.g., proton energies for p-He{sup +} collisions on the order of 100 kilo-electron volts), in which many electron states are strongly coupled during the collision and a coupled-state approach, such as a coupled-Sturmian-pseudostate approach, is appropriate. Alston has concentrated on higher collision energies (million electron-volt energies), or asymmetric collision systems, for which the coupling of the projectile is weaker with, however, many more target states being coupled together so that high-order perturbation theory is essential. Several calculations by Winter and Alston are described, as set forth in the original proposal.

  11. 3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence.

    PubMed

    Ohmoto, H; Kakegawa, T; Lowe, D R

    1993-10-22

    Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>10(-13) of the present atmospheric level) of free oxygen. PMID:11539502

  12. 3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence

    NASA Technical Reports Server (NTRS)

    Ohmoto, H.; Kakegawa, T.; Lowe, D. R.

    1993-01-01

    Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>>10(-13) of the present atmospheric level) of free oxygen.

  13. NOAA Budget Increases to $4.1 Billion, But Some Key Items Are Reduced

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2008-02-01

    The Bush administration has proposed a US$4.1 billion budget for fiscal year (FY) 2009 for the U.S. National Oceanic and Atmospheric Administration (NOAA). The proposed budget, which would be the agency's largest ever, is $202.6 million, or 5.2%, above the FY 2008 enacted budget. By topping $4 billion and the amount Congress passed for FY 2008, the budget proposal crosses into ``a new threshold,'' according Navy Vice Admiral Conrad Lautenbacher, undersecretary of commerce for oceans and atmosphere and NOAA administrator.

  14. 3.4-Billion-Year-Old Biogenic Pyrites from Barberton, South Africa: Sulfur Isotope Evidence

    NASA Astrophysics Data System (ADS)

    Ohmoto, Hiroshi; Kakegawa, Takeshi; Lowe, Donald R.

    1993-10-01

    Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (> > 10-13 of the present atmospheric level) of free oxygen.

  15. 3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence.

    PubMed

    Ohmoto, H; Kakegawa, T; Lowe, D R

    1993-10-22

    Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>10(-13) of the present atmospheric level) of free oxygen.

  16. Billions for biodefense: federal agency biodefense funding, FY2001-FY2005.

    PubMed

    Schuler, Ari

    2004-01-01

    Over the past several years, the United States government has spent substantial resources on preparing the nation against a bioterrorist attack. This article analyzes the civilian biodefense funding by the federal government from fiscal years 2001 through 2005, specifically analyzing the budgets and allocations for biodefense at the Department of Health and Human Services, the Department of Homeland Security, the Department of Defense, the Department of Agriculture, the Environmental Protection Agency, the National Science Foundation, and the Department of State. In total, approximately $14.5 billion has been funded for civilian biodefense through FY2004, with an additional $7.6 billion in the President's budget request for FY2005. PMID:15225402

  17. How Measuring the Planck Constant gets to an Electronic Kilogram Standard

    SciTech Connect

    Steiner, Richard

    2007-08-01

    The best measurement of the Planck constant is now derived from the watt balance method. This method measures mechanical power, in reference units of the kilogram (artifact mass standard), second (atomic clocks), and meter (lasers), in ratio to electrical power, in reference units of the volt (Josephson effect) and ohm (quantum Hall effect). Of these reference standards, only the kilogram is still an artifact standard. Thus a high precision measurement of the Planck constant is equivalent to monitoring the SI kilogram artifact, and may be used to redefine the kilogram. This talk will summarize the complexity of making a Planck constant measurement, where there are interesting aspects of basic physics that appear when the ultimate precision of the standards laboratory is applied to obtain an uncertainty of 20 parts in a billion.

  18. 405th Brookhaven Lecture

    ScienceCinema

    Vadim Ptitsyn

    2016-07-12

    "E-RHIC - Future Electron-Ion Collider at BNL. While RHIC scientists continue their quest to look deep into nuclear phenomena resulting from collisions of ion beams and beams of polarized protons, new design work is under way for a possible extension of RHIC to include e-RHIC, a 10-billion electron volt, high-intensity polarized proton beam.

  19. Cancer costs projected to reach at least $158 billion in 2020

    Cancer.gov

    Based on growth and aging of the U.S. population, medical expenditures for cancer in the year 2020 are projected to reach at least $158 billion (in 2010 dollars) – an increase of 27 percent over 2010. If newly developed tools for cancer diagnosis, treatme

  20. Two Billion Cars: What it Means for Climate and Energy Policy

    ScienceCinema

    Daniel Sperling

    2016-07-12

    April 13, 2009: Daniel Sperling, director of the Institute of Transportation Studies at UC Davis, presents the next installment of Berkeley Lab's Environmental Energy Technologies Divisions Distinguished Lecture series. He discusses Two Billion Cars and What it Means for Climate and Energy Policy.

  1. Nitrogen, phosphorus, and potassium requirements to support a multi-billion gallon biofuel industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To accomplish the goals for biofuel and bioenergy production, 1 billion tons of biomass will need to be produced annually by the year 2030. Crop production data from a joint study by the U.S. Department of Energy (US DOE) and the U.S. Department of Agriculture (USDA) demonstrated how this goal could...

  2. Two Billion Cars: What it Means for Climate and Energy Policy

    SciTech Connect

    Daniel Sperling

    2009-04-15

    April 13, 2009: Daniel Sperling, director of the Institute of Transportation Studies at UC Davis, presents the next installment of Berkeley Lab's Environmental Energy Technologies Divisions Distinguished Lecture series. He discusses Two Billion Cars and What it Means for Climate and Energy Policy.

  3. Universities Report $1.8-Billion in Earnings on Inventions in 2011

    ERIC Educational Resources Information Center

    Blumenstyk, Goldie

    2012-01-01

    Universities and their inventors earned more than $1.8-billion from commercializing their academic research in the 2011 fiscal year, collecting royalties from new breeds of wheat, from a new drug for the treatment of HIV, and from longstanding arrangements over enduring products like Gatorade. Northwestern University earned the most of any…

  4. Multi-Billion Shot, High-Fluence Exposure of Cr(4+): YAG Passive Q-Switch

    NASA Technical Reports Server (NTRS)

    Stephen, Mark A.; Dallas, Joseph L.; Afzal, Robert S.

    1997-01-01

    NASA's Goddard Space Flight Center is developing the Geoscience Laser Altimeter System (GLAS) employing a diode pumped, Q-Switched, ND:YAG laser operating at 40 Hz repetition rate. To meet the five-year mission lifetime goal, a single transmitter would accumulate over 6.3 billion shots. Cr(4+):YAG is a promising candidate material for passively Q-switching the laser. Historically, the performance of saturable absorbers has degraded over long-duration usage. To measure the multi-billion shot performance of Cr(4+):YAG, a passively Q-switched GLAS-like oscillator was tested at an accelerated repetition rate of 500 Hz. The intracavity fluence was calculated to be approximately 2.5 J/cm(exp 2). The laser was monitored autonomously for 165 days. There was no evidence of change in the material optical properties during the 7.2 billion shot test.. All observed changes in laser operation could be attributed to pump laser diode aging. This is the first demonstration of multi-billion shot exposure testing of Cr(4+):YAG in this pulse energy regime

  5. Conservation in a World of Six Billion: A Grassroots Action Guide.

    ERIC Educational Resources Information Center

    Hren, Benedict J.

    This grassroots action guide features a conservation initiative working to bring the impacts of human population growth, economic development, and natural resource consumption into balance with the limits of nature for the benefit of current and future generations. Contents include information sheets entitled "Six Billion People and Growing,""The…

  6. US Physician Practices Spend More Than $15.4 Billion Annually To Report Quality Measures.

    PubMed

    Casalino, Lawrence P; Gans, David; Weber, Rachel; Cea, Meagan; Tuchovsky, Amber; Bishop, Tara F; Miranda, Yesenia; Frankel, Brittany A; Ziehler, Kristina B; Wong, Meghan M; Evenson, Todd B

    2016-03-01

    Each year US physician practices in four common specialties spend, on average, 785 hours per physician and more than $15.4 billion dealing with the reporting of quality measures. While much is to be gained from quality measurement, the current system is unnecessarily costly, and greater effort is needed to standardize measures and make them easier to report. PMID:26953292

  7. High-Stakes Hustle: Public Schools and the New Billion Dollar Accountability

    ERIC Educational Resources Information Center

    Baines, Lawrence A.; Stanley, Gregory Kent

    2004-01-01

    High-stakes testing costs up to $50 billion per annum, has no impact on student achievement, and has changed the focus of American public schools. This article analyzes the benefits and costs of the accountability movement, as well as discusses its roots in the eugenics movements of the early 20th century.

  8. Search by mariner 10 for electrons and protons accelerated in association with venus.

    PubMed

    Simpson, J A; Eraker, J H; Lamport, J E; Walpole, P H

    1974-03-29

    The University of Chicago instrumnents on board the Mariner 10 spacecraft bound for Mercury have measured energy spectra and fluxes of electrons from 0.18 to 30 million electron volts and protons from 0.5 to 68 million electron volts along the plasma wake and in the bow shock regions associated with Venus. Unusually quiet solar conditions and improved instrumentation made it possible to search for much lower fluxes of protons and electrons in similar energy regions as compared to earlier Mariner missions to Venus-that is, lower by a factor of 10(2) for protons and 10(3) for electrons. We found no evidence for electrons or protons either in the form of increases of intensity or energy spectral changes in the vicinity of the planet, nor any evidence of bursts of radiation in or near the observed bow shock where bursts of electrons might have been expected in analogy with the bow shock at the earth. The importance of these null results for determining the necessary and sufficient conditions for particle acceleration is discussed with respect to magnetometer evidence that Venus does not have a magnetosphere. PMID:17791375

  9. Preliminary tests of vulnerability of typical aircraft electronics to lightning-induced voltages

    NASA Technical Reports Server (NTRS)

    Plumer, J. A.; Walko, L. C.

    1974-01-01

    Tests made on two pieces of typical aircraft electronics equipment to ascertain their vulnerability to simulated lightning-induced transient voltages representative of those which might occur in flight when the aircraft is struck by lightning were conducted. The test results demonstrated that such equipment can be interfered with or damaged by transient voltages as low as 21 volts peak. Greater voltages can cause failure of semiconductor components within the equipment. The results emphasize a need for establishment of coordinated system susceptibility and component vulnerability criteria to achieve lightning protection of aerospace electrical and electronic systems.

  10. Propulsion using the electron spiral toroid

    SciTech Connect

    Seward, Clint

    1998-01-15

    A new propulsion method is proposed which could potentially reduce propellant needed for space travel by three orders of magnitude. It uses the newly patented electron spiral toroid (EST), which stores energy as magnetic field energy. The EST is a hollow toroid of electrons, all spiraling in parallel paths in a thin outer shell. The electrons satisfy the coupling condition, forming an electron matrix. Stability is assured as long as the coupling condition is satisfied. The EST is held in place with a small external electric field; without an external magnetic field. The EST system is contained in a vacuum chamber. The EST can be thought of as an energetic entity, with electrons at 10,000 electron volts. Propulsion would not use combustion, but would heat propellant through elastic collisions with the EST surface and eject them for thrust. Chemical rocket combustion heats propellant to 4000 deg. C; an EST will potentially heat the propellant 29,000 times as much, reducing propellant needs accordingly. The thrust can be turned ON and OFF. The EST can be recharged as needed.

  11. LLNL's Big Science Capabilities Help Spur Over $796 Billion in U.S. Economic Activity Sequencing the Human Genome

    SciTech Connect

    Stewart, Jeffrey S.

    2015-07-28

    LLNL’s successful history of taking on big science projects spans beyond national security and has helped create billions of dollars per year in new economic activity. One example is LLNL’s role in helping sequence the human genome. Over $796 billion in new economic activity in over half a dozen fields has been documented since LLNL successfully completed this Grand Challenge.

  12. Resonant diffusion of energetic electrons by narrowband Z mode waves in Saturn's inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Gu, Xudong; Thorne, Richard M.; Ni, Binbin; Ye, Sheng-Yi

    2013-01-01

    Abstract<p label="1">Banded emissions near 5 and 20 kHz are observed by the Cassini Radio and Plasma Wave Science (RPWS) instrument and are identified as Z mode waves in the regions where the plasma frequency is below the <span class="hlt">electron</span> gyrofrequency. Using wave parameters derived from Gaussian fits to the measured power spectral density for narrow-band Z mode waves and the ambient density and magnetic field information at L = ~4, we compute the bounce-averaged diffusion coefficients for the Saturnian radiation belt <span class="hlt">electrons</span>. Our results indicate that 5 kHz Z mode emissions can cause resonant scattering of <span class="hlt">electrons</span> from ~2 MeV to tens of megaelectron <span class="hlt">volts</span>, while 20 kHz waves can interact with <span class="hlt">electrons</span> from hundreds of kiloelectron <span class="hlt">volts</span> to ~2 MeV. In principle, the rate of momentum diffusion can be an order of magnitude larger than that of pitch angle diffusion and cross diffusion for <span class="hlt">electrons</span> at equatorial pitch angles > ~10°, suggesting that Z mode waves on Saturn are responsible for local acceleration of radiation belt energetic <span class="hlt">electrons</span> at intermediate pitch angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17833552','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17833552"><span id="translatedtitle">Observations of Energetic Ions and <span class="hlt">Electrons</span> in Saturn's Magnetosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Trainor, J H; McDonald, F B; Schardt, A W</p> <p>1980-01-25</p> <p>The passage of Pioneer 11 by Saturn provided a detailed view of a planetary magnetosphere that is intermediate between those of Jupiter and Earth in both scale and the complexity of its dynamic processes. It appears to have at least three distinct regions: (i) an outer magnetosphere, extending from 17 to 7.5 Saturn radii, that resembles that of Earth in many important aspects; (ii) a slot region, between 7.5 and 4 Saturn radii, where a marked decrease in all protons and low-energy <span class="hlt">electrons</span> is observed; and (iii) an inner region, extending from 4 Saturn radii to the ring edge, that features a sharp increase in the proton flux extending to energies greater than 20 million <span class="hlt">electron</span> <span class="hlt">volts</span>. A cutoff of both proton and <span class="hlt">electron</span> fluxes occurred just beyond the nominal edge of the A ring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5119717','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5119717"><span id="translatedtitle">Site geotechnical considerations for expansion of the Strategic Petroleum Reserve (SPR) to one <span class="hlt">billion</span> barrels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Neal, J.T. ); Whittington, D.W. ); Magorian, T.R. , Amherst, NY )</p> <p>1991-01-01</p> <p>Eight Gulf Coast salt domes have emerged as candidate sites for possible expansion of the Strategic Petroleum Reserve (SPR) to one <span class="hlt">billion</span> barrels. Two existing SPR sites, Big Hill, TX, and Weeks Island, LA, are among the eight that are being considered. To achieve the <span class="hlt">billion</span> barrel capacity, some 25 new leached caverns would be constructed, and would probably be established in two separate sites in Louisiana and Texas because of distribution requirements. Geotechnical factors involved in siting studies have centered first and foremost on cavern integrity and environmental acceptability, once logistical suitability is realized. Other factors have involved subsidence and flooding potential, loss of coastal marshlands, seismicity, brine injection well utility, and co-use by multiple operators. 5 refs., 11 figs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1020957','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1020957"><span id="translatedtitle">CESR Conversion Damping Ring Studies of <span class="hlt">Electron</span> Cloud Instabilities (CESR-TA)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rubin, David L.; Palmer, Mark A.</p> <p>2011-08-02</p> <p>In the International Linear Collider, two linear accelerators will accelerate bunches of positrons and <span class="hlt">electrons</span> to over a hundred <span class="hlt">billion</span> <span class="hlt">electron</span> <span class="hlt">volts</span> and collide them in a central detector. In order to obtain useful collision rates, the bunches, each containing twenty <span class="hlt">billion</span> particles, must be compressed to a cross section of a few nanometers by a few hundred nanometers. In order to prepare these ultra high density bunches, damping rings (DRs) are employed before the linear accelerators. The DRs take the high emittance bunches that are provided by the <span class="hlt">electron</span> and positron sources and, through the process of radiation damping, squeeze them into ultra low emittance beams that are ready for the main linear accelerators. In the damping rings, a number of effects can prevent the successful preparation of the beams. In the <span class="hlt">electron</span> ring, an effect known as the fast ion instability can lead to beam growth and, in the positron ring, the build-up of an <span class="hlt">electron</span> cloud (EC), which interacts with the circulating bunches, can produce the same effect. EC build-up and the subsequent interaction of the cloud with the positron beam in the DR have been identified as major risks for the successful construction of a linear collider. The CESRTA research program at the Cornell <span class="hlt">Electron</span> Storage Ring (CESR) was developed in order to study the build-up of the EC, the details of its impact on ultra low emittance beams, as well as methods to mitigate the impact of the cloud. In the DR, the EC forms when synchrotron photons radiated from the circulating beam strike the walls of the vacuum chamber, resulting in the emission of photoelectrons. These low energy <span class="hlt">electrons</span> can be accelerated across the vacuum chamber by the electric field of the beam, and strike the walls, causing the emission of secondary <span class="hlt">electrons</span>. The secondary <span class="hlt">electrons</span> are subsequently accelerated into the walls yet again via the same mechanism. The result is that the EC can rapidly begin to fill the vacuum chamber. In</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/1007509','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/1007509"><span id="translatedtitle">How to Bring Solar Energy to Seven <span class="hlt">Billion</span> People (LBNL Science at the Theater)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a></p> <p>Wadia, Cyrus</p> <p>2016-07-12</p> <p>By exploiting the powers of nanotechnology and taking advantage of non-toxic, Earth-abundant materials, Berkeley Lab's Cyrus Wadia has fabricated new solar cell devices that have the potential to be several orders of magnitude less expensive than conventional solar cells. And by mastering the chemistry of these materials-and the economics of solar energy-he envisions bringing electricity to the 1.2 <span class="hlt">billion</span> people now living without it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1007509','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1007509"><span id="translatedtitle">How to Bring Solar Energy to Seven <span class="hlt">Billion</span> People (LBNL Science at the Theater)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wadia, Cyrus</p> <p>2009-04-06</p> <p>By exploiting the powers of nanotechnology and taking advantage of non-toxic, Earth-abundant materials, Berkeley Lab's Cyrus Wadia has fabricated new solar cell devices that have the potential to be several orders of magnitude less expensive than conventional solar cells. And by mastering the chemistry of these materials-and the economics of solar energy-he envisions bringing electricity to the 1.2 <span class="hlt">billion</span> people now living without it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22901282','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22901282"><span id="translatedtitle">Mobile hydrocarbon microspheres from >2-<span class="hlt">billion</span>-year-old carbon-bearing seams in the South African deep subsurface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wanger, G; Moser, D; Hay, M; Myneni, S; Onstott, T C; Southam, G</p> <p>2012-11-01</p> <p>By ~2.9 Ga, the time of the deposition of the Witwatersrand Supergroup, life is believed to have been well established on Earth. Carbon remnants of the microbial biosphere from this time period are evident in sediments from around the world. In the Witwatersrand Supergroup, the carbonaceous material is often concentrated in seams, closely associated with the gold deposits and may have been a mobile phase 2 <span class="hlt">billion</span> years ago. Whereas today the carbon in the Witwatersrand Supergroup is presumed to be immobile, hollow hydrocarbon spheres ranging in size from <1 μm to >50 μm were discovered emanating from a borehole drilled through the carbon-bearing seams suggesting that a portion of the carbon may still be mobile in the deep subsurface. ToF-SIMS and STXM analyses revealed that these spheres contain a suite of alkane, alkenes, and aromatic compounds consistent with the described organic-rich carbon seams within the Witwatersrand Supergroup's auriferous reef horizons. Analysis by <span class="hlt">electron</span> microscopy and ToF-SIMS, however, revealed that these spheres, although most likely composed of biogenic carbon and resembling biological organisms, do not retain any true structural, that is, fossil, information and were formed by an abiogenic process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22158244','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22158244"><span id="translatedtitle">Two ten-<span class="hlt">billion</span>-solar-mass black holes at the centres of giant elliptical galaxies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McConnell, Nicholas J; Ma, Chung-Pei; Gebhardt, Karl; Wright, Shelley A; Murphy, Jeremy D; Lauer, Tod R; Graham, James R; Richstone, Douglas O</p> <p>2011-12-01</p> <p>Observational work conducted over the past few decades indicates that all massive galaxies have supermassive black holes at their centres. Although the luminosities and brightness fluctuations of quasars in the early Universe suggest that some were powered by black holes with masses greater than 10 <span class="hlt">billion</span> solar masses, the remnants of these objects have not been found in the nearby Universe. The giant elliptical galaxy Messier 87 hosts the hitherto most massive known black hole, which has a mass of 6.3 <span class="hlt">billion</span> solar masses. Here we report that NGC 3842, the brightest galaxy in a cluster at a distance from Earth of 98 megaparsecs, has a central black hole with a mass of 9.7 <span class="hlt">billion</span> solar masses, and that a black hole of comparable or greater mass is present in NGC 4889, the brightest galaxy in the Coma cluster (at a distance of 103 megaparsecs). These two black holes are significantly more massive than predicted by linearly extrapolating the widely used correlations between black-hole mass and the stellar velocity dispersion or bulge luminosity of the host galaxy. Although these correlations remain useful for predicting black-hole masses in less massive elliptical galaxies, our measurements suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27049949','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27049949"><span id="translatedtitle">A 17-<span class="hlt">billion</span>-solar-mass black hole in a group galaxy with a diffuse core.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J; Greene, Jenny E; Blakeslee, John P; Janish, Ryan</p> <p>2016-04-21</p> <p>Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten <span class="hlt">billion</span> solar masses already existed 13 <span class="hlt">billion</span> years ago. Two possible present-day 'dormant' descendants of this population of 'active' black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall--the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600--a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 <span class="hlt">billion</span> solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes. PMID:27049949</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27049949','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27049949"><span id="translatedtitle">A 17-<span class="hlt">billion</span>-solar-mass black hole in a group galaxy with a diffuse core.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J; Greene, Jenny E; Blakeslee, John P; Janish, Ryan</p> <p>2016-04-21</p> <p>Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten <span class="hlt">billion</span> solar masses already existed 13 <span class="hlt">billion</span> years ago. Two possible present-day 'dormant' descendants of this population of 'active' black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall--the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600--a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 <span class="hlt">billion</span> solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860015492','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860015492"><span id="translatedtitle">Set-up and demonstration of a Low Energy <span class="hlt">Electron</span> Magnetometer (LEEM)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rayborn, G. H.</p> <p>1986-01-01</p> <p>Described are the design, construction and test results of a Low Energy <span class="hlt">Electron</span> Magnetometer (LEEM). The <span class="hlt">electron</span> source is a commercial <span class="hlt">electron</span> gun capable of providing several microamperes of <span class="hlt">electron</span> beam. These <span class="hlt">electrons</span>, after acceleration through a selected potential difference of 100-300 <span class="hlt">volts</span>, are sent through two 30 degree second-order focussing parallel plate electrostatic analyzers. The first analyzer acts as a monochromator located in the field-free space. It is capable of providing energy resolution of better than 10 to the -3 power. The second analyzer, located in the test field region, acts as the detector for <span class="hlt">electrons</span> deflected by the test field. The entire magnetometer system is expected to have a resolution of 1 part in 1000 or better.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615589P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615589P"><span id="translatedtitle">Evidence for Oxygenic Photosynthesis Half a <span class="hlt">Billion</span> Years Before the Great Oxidation Event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Planavsky, Noah; Reinhard, Chris; Asael, Dan; Lyons, Tim; Hofmann, Axel; Rouxel, Olivier</p> <p>2014-05-01</p> <p>Despite detailed investigations over the past 50 years, there is still intense debate about when oxygenic photosynthesis evolved. Current estimates span over a <span class="hlt">billion</span> years of Earth history, ranging from prior to 3.7 Ga, the age of the oldest sedimentary rocks, to 2.4-2.3 Ga, coincident with the rise of atmospheric oxygen ("The Great Oxidation Event" or GOE). As such, a new, independent perspective is needed. We will provide such a perspective herein by using molybdenum (Mo) isotopes in a novel way to track the onset of manganese(II)oxidation and thus biological oxygen production. The oxidation of Mn(II) in modern marine setting requires free dissolved oxygen. Mn is relatively unique in its environmental specificity for oxygen as an <span class="hlt">electron</span> acceptor among the redox-sensitive transition metals, many of which, like Fe, can be oxidized under anoxic conditions either through a microbial pathway and/or with alternative oxidants such as nitrate. There are large Mo isotope fractionations associated with the sorption of Mo (as a polymolybdate complex) onto Mn-oxyhydroxides, with an approximately -2.7‰ fractionation in d98Mo associated with Mo sorption onto Mn-oxyhydroxides (e.g., birnessite, vernadite). In contrast, sorption of Mo onto the Fe-oxyhydroxide (e.g., ferrihydrite) results in a fractionation of only -1.1‰ or less. Because of this difference in Mo isotope fractionation, Mo isotope values should become lighter with increasing Mn content, if Mn oxidation occurred during deposition and is an important vector of Mo transfer to the sediment. We find a strong positive correlation between d98Mo values and Fe/Mn ratios in iron formations deposited before and after the Great Oxidation Event. Most strikingly, Mo isotope data and Fe/Mn ratios correlate over a 2.5‰ range in d98Mo values in the Mn-rich (0.1 - 6%) iron formation of the 2.95 Ga Sinqeni Formation, South Africa. The large isotopic shifts occur over a relatively thin (3 meter thick) horizon, reflecting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10103023','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10103023"><span id="translatedtitle">The use of <span class="hlt">electron</span> beams for pasteurization of meats</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Prestwich, K.R.; Kaye, R.J.; Turman, B.N.; Neau, E.L.</p> <p>1994-12-01</p> <p><span class="hlt">Electron</span> beam accelerators can be used for <span class="hlt">electronic</span> pasteurization of meat products by: (1) using the <span class="hlt">electrons</span> directly impacting the products, or (2) optimizing the conversion of <span class="hlt">electron</span> energy to x-rays and treating the product with these x-rays. The choice of process depends on the configuration of the product when it is treated. For <span class="hlt">electron</span> treatment, ten million <span class="hlt">electron</span> <span class="hlt">volt</span> (MeV) kinetic energy is the maximum allowed by international agreement. The depth of penetration of <span class="hlt">electrons</span> with that energy into a product with density of meat is about five centimeters (cm). Two-sided treatment can be done on products up to 10 cm thick with a two-to-one ratio between minimum and maximum dose. Ground beef patties are about 1.25 cm (0.5 inch thick). Beams with 2.5 MeV <span class="hlt">electron</span> energy could be used to treat these products. Our calculations show that maximum to minimum dose ratios less than 1.2 can be achieved with this energy if the transverse beam energy is small. If the product thickness is greater than 10 cm, x-rays can provide the needed dose uniformity. Uniform doses can be supplied for pallets with dimensions greater than 1.2 m on each side using x-rays from a 5 MeV <span class="hlt">electron</span> beam. The efficiency of converting the <span class="hlt">electron</span> beam to x-rays and configurations to achieve dose uniformity are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=cosmic+AND+rays&pg=3&id=EJ046436','ERIC'); return false;" href="http://eric.ed.gov/?q=cosmic+AND+rays&pg=3&id=EJ046436"><span id="translatedtitle">Research Frontier</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Physics Teacher, 1971</p> <p>1971-01-01</p> <p>New research topics have been brought about by the acceleration of nitrogen nuclei to the energy of 36 <span class="hlt">billion</span> <span class="hlt">electron</span> <span class="hlt">volts</span>. Describes experiments on tumor cells, cosmic rays, and nuclear fission performed with the Bevatron at the Lawrence Berkeley Laboratory. (TS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=PCT&pg=6&id=EJ326904','ERIC'); return false;" href="http://eric.ed.gov/?q=PCT&pg=6&id=EJ326904"><span id="translatedtitle">States' Spending on Colleges Rises 19 Pct. in 2 Years, Nears $31-<span class="hlt">Billion</span> for'85-86.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Evangelauf, Jean</p> <p>1985-01-01</p> <p>The U.S. states' expenditures to nearly $31 <span class="hlt">billion</span> in tax money mark a continuing recovery in support for higher education. Shaping this year's appropriations levels were concerns about tuition and efforts to promote economic development. (MLW)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12343749','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12343749"><span id="translatedtitle">[The year 2000: one <span class="hlt">billion</span> couples of child-bearing age].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lintong, L J</p> <p>1988-04-01</p> <p>Out of 1 <span class="hlt">billion</span> couples there are only 124 million who use modern and effective contraceptives. World abortions number 33 million/year. 250 million sexually active women of child-bearing age in developing countries outside China do not use modern and effective contraceptives. Fertility control costs on the average US$2.5 <span class="hlt">billion</span> a year in each developing country, 20% of which is assistance from developed countries. Expanding the family planning service to the 250 million sexually active child-bearing aged women costs an additional U.S. $5 <span class="hlt">billion</span> yearly. A family planning accessibility survey was conducted by the Population Crisis Committee. PCC divided the countries into 2 categories: Developed and developing countries. The 110 countries (15 developed and 95 developing) covered 96% of the world population. The survey placed the countries in 5 classes according to accessibility levels: Excellent, good, fair, poor, very poor. The developed countries were analyzed according to effective contraceptive methods, service to the poor and minorities, sex education in the schools, and family planning information and advertisement. The developing countries were analyzed according to effective contraceptive methods, performance of service and distribution, public information and education, private sector participation, government finance and policies. Of the 15 developed countries, 43% were excellent, 22% good, 24% fair, and 2% poor. Of the 95 developing countries, 5 were excellent, 10 good, 16 fair, and 64 either poor or very poor countries in respect to family planning accessibility. In the face of a population explosion in the year 2000, many countries lack of government support for family planning programs. After 30 years of world effort in population control, half of the world population still has no effective family planning services.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Natur.532..340T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Natur.532..340T"><span id="translatedtitle">A 17-<span class="hlt">billion</span>-solar-mass black hole in a group galaxy with a diffuse core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J.; Greene, Jenny E.; Blakeslee, John P.; Janish, Ryan</p> <p>2016-04-01</p> <p>Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten <span class="hlt">billion</span> solar masses already existed 13 <span class="hlt">billion</span> years ago. Two possible present-day ‘dormant’ descendants of this population of ‘active’ black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall—the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600—a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 <span class="hlt">billion</span> solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Sci...352..205C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Sci...352..205C&link_type=ABSTRACT"><span id="translatedtitle">Exploiting the colloidal nanocrystal library to construct <span class="hlt">electronic</span> devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Ji-Hyuk; Wang, Han; Oh, Soong Ju; Paik, Taejong; Sung, Pil; Sung, Jinwoo; Ye, Xingchen; Zhao, Tianshuo; Diroll, Benjamin T.; Murray, Christopher B.; Kagan, Cherie R.</p> <p>2016-04-01</p> <p>Synthetic methods produce libraries of colloidal nanocrystals with tunable physical properties by tailoring the nanocrystal size, shape, and composition. Here, we exploit colloidal nanocrystal diversity and design the materials, interfaces, and processes to construct all-nanocrystal <span class="hlt">electronic</span> devices using solution-based processes. Metallic silver and semiconducting cadmium selenide nanocrystals are deposited to form high-conductivity and high-mobility thin-film electrodes and channel layers of field-effect transistors. Insulating aluminum oxide nanocrystals are assembled layer by layer with polyelectrolytes to form high–dielectric constant gate insulator layers for low-voltage device operation. Metallic indium nanocrystals are codispersed with silver nanocrystals to integrate an indium supply in the deposited electrodes that serves to passivate and dope the cadmium selenide nanocrystal channel layer. We fabricate all-nanocrystal field-effect transistors on flexible plastics with <span class="hlt">electron</span> mobilities of 21.7 square centimeters per <span class="hlt">volt</span>-second.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Sci...352..205C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Sci...352..205C"><span id="translatedtitle">Exploiting the colloidal nanocrystal library to construct <span class="hlt">electronic</span> devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Ji-Hyuk; Wang, Han; Oh, Soong Ju; Paik, Taejong; Sung, Pil; Sung, Jinwoo; Ye, Xingchen; Zhao, Tianshuo; Diroll, Benjamin T.; Murray, Christopher B.; Kagan, Cherie R.</p> <p>2016-04-01</p> <p>Synthetic methods produce libraries of colloidal nanocrystals with tunable physical properties by tailoring the nanocrystal size, shape, and composition. Here, we exploit colloidal nanocrystal diversity and design the materials, interfaces, and processes to construct all-nanocrystal <span class="hlt">electronic</span> devices using solution-based processes. Metallic silver and semiconducting cadmium selenide nanocrystals are deposited to form high-conductivity and high-mobility thin-film electrodes and channel layers of field-effect transistors. Insulating aluminum oxide nanocrystals are assembled layer by layer with polyelectrolytes to form high-dielectric constant gate insulator layers for low-voltage device operation. Metallic indium nanocrystals are codispersed with silver nanocrystals to integrate an indium supply in the deposited electrodes that serves to passivate and dope the cadmium selenide nanocrystal channel layer. We fabricate all-nanocrystal field-effect transistors on flexible plastics with <span class="hlt">electron</span> mobilities of 21.7 square centimeters per <span class="hlt">volt</span>-second.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27124455','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27124455"><span id="translatedtitle">Exploiting the colloidal nanocrystal library to construct <span class="hlt">electronic</span> devices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Choi, Ji-Hyuk; Wang, Han; Oh, Soong Ju; Paik, Taejong; Sung, Pil; Sung, Jinwoo; Ye, Xingchen; Zhao, Tianshuo; Diroll, Benjamin T; Murray, Christopher B; Kagan, Cherie R</p> <p>2016-04-01</p> <p>Synthetic methods produce libraries of colloidal nanocrystals with tunable physical properties by tailoring the nanocrystal size, shape, and composition. Here, we exploit colloidal nanocrystal diversity and design the materials, interfaces, and processes to construct all-nanocrystal <span class="hlt">electronic</span> devices using solution-based processes. Metallic silver and semiconducting cadmium selenide nanocrystals are deposited to form high-conductivity and high-mobility thin-film electrodes and channel layers of field-effect transistors. Insulating aluminum oxide nanocrystals are assembled layer by layer with polyelectrolytes to form high-dielectric constant gate insulator layers for low-voltage device operation. Metallic indium nanocrystals are codispersed with silver nanocrystals to integrate an indium supply in the deposited electrodes that serves to passivate and dope the cadmium selenide nanocrystal channel layer. We fabricate all-nanocrystal field-effect transistors on flexible plastics with <span class="hlt">electron</span> mobilities of 21.7 square centimeters per <span class="hlt">volt</span>-second. PMID:27124455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26494753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26494753"><span id="translatedtitle"><span class="hlt">Electron</span> paramagnetic resonance of individual atoms on a surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baumann, Susanne; Paul, William; Choi, Taeyoung; Lutz, Christopher P; Ardavan, Arzhang; Heinrich, Andreas J</p> <p>2015-10-23</p> <p>We combined the high-energy resolution of conventional spin resonance (here ~10 nano-<span class="hlt">electron</span> <span class="hlt">volts</span>) with scanning tunneling microscopy to measure <span class="hlt">electron</span> paramagnetic resonance of individual iron (Fe) atoms placed on a magnesium oxide film. We drove the spin resonance with an oscillating electric field (20 to 30 gigahertz) between tip and sample. The readout of the Fe atom's quantum state was performed by spin-polarized detection of the atomic-scale tunneling magnetoresistance. We determine an energy relaxation time of T1 ≈ 100 microseconds and a phase-coherence time of T2 ≈ 210 nanoseconds. The spin resonance signals of different Fe atoms differ by much more than their resonance linewidth; in a traditional ensemble measurement, this difference would appear as inhomogeneous broadening.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23984993','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23984993"><span id="translatedtitle">Interface control of semiconducting metal oxide layers for efficient and stable inverted polymer solar cells with open-circuit voltages over 1.0 <span class="hlt">volt</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yin, Zhigang; Zheng, Qingdong; Chen, Shan-Ci; Cai, Dongdong</p> <p>2013-09-25</p> <p>Inverted polymer solar cells (PSCs) with high open-circuit voltages of 1.00-1.06 V are fabricated by using an indenofluorene-containing copolymer (PIFTBT8) as an <span class="hlt">electron</span> donor material and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an <span class="hlt">electron</span> acceptor material. To improve the photovoltaic performance, interface control of various low-temperature processed ZnO films as cathode buffer layers is systematically investigated for effective <span class="hlt">electron</span> transportation, while transition metal oxides including MoO3, WO3, NiO, and Cu2O are employed as anode buffer layers for hole-extraction. Incorporation of optimized semiconducting metal oxide interlayers can minimize interfacial power losses, which thus affords large open-circuit voltages (Voc), increased short-circuit current densities (Jsc), and fill factors (FF), eventually contributing to higher power conversion efficiencies (PCEs) as well as better device stability. Due to the improved interfacial contacts and fine-matching energy levels, inverted PSCs with a device configuration of ITO/ZnO/PIFTBT8:PC71BM/MoO3/Ag exhibit a high PCE of 5.05% with a large Voc of 1.04 V, a Jsc of 9.74 mA cm(-2), and an FF of 50.1%. For the single junction inverted PSCs with efficiencies over 5.0%, 1.04 V is the largest Voc ever achieved. By controlling the processing conditions of the active layer, the Voc can further be improved to 1.05 and 1.06 V, with PCEs of 4.70% and 4.18%, respectively. More importantly, the inverted PSCs are ascertained to maintain a PCE of 4.55% (>90% of its initial efficiency) and a Voc of 1.05 V over 180 days, demonstrating good long-term stability, which is much better than that of the conventional devices. The results suggest that the interface engineering of metal oxide interlayers is an important strategy to develop PSCs with good performance. PMID:23984993</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000SerAJ.162...35T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000SerAJ.162...35T"><span id="translatedtitle">Mathematical Model for the 0.5 <span class="hlt">Billion</span> Years Aged Sun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tatomir, E.</p> <p></p> <p>An algorithm is given for constructing evolutionary tracks for a star with the mass equal to one solar mass. The presented model can be applied to the stars belonging to the inferior main sequence, which have the proton-proton reaction as energy source and present a radiative core and a convective shell. This paper presents an original way of solving the system of equations corresponding to the radiative nucleus by using Taylor's series in close vicinity to the center of the Sun. It also presents the numerical integration and the results for a 0.5 <span class="hlt">billion</span> years aged solar model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2257631I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2257631I"><span id="translatedtitle">The First <span class="hlt">Billion</span> Years: The Growth of Galaxies in the Reionization Epoch</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Illingworth, Garth</p> <p>2015-08-01</p> <p>Detection and measurement of the earliest galaxies in the first <span class="hlt">billion</span> years only became possible after the Hubble Space Telescope was updated in 2009 with the infrared WFC3/IR camera during Shuttle servicing mission SM4. The first <span class="hlt">billion</span> years is a fascinating epoch, not just because of the earliest galaxies known from about 450 Myr after the Big Bang, but also because it encompasses the reionization epoch that peaked around z~9, as Planck has recently shown, and ended around redshift z~6 at 900 Myr. Before 2009 just a handful of galaxies were known in the reionization epoch at z>6. But within the last 5 years, with the first HUDF09 survey, the HUDF12, CANDELS and numerous other surveys on the GOODS and CANDELS fields, as well as detections from the cluster lensing programs like CLASH and the Frontier Fields, the number of galaxies at redshifts 7-10 has exploded, with some 700 galaxies being found and characterized. The first <span class="hlt">billion</span> years was a period of extraordinary growth in the galaxy population with rapid growth in the star formation rate density and global mass density in galaxies. Spitzer observations in the infrared of these Hubble fields are establishing masses as well as giving insights into the nature and timescales of star formation from the very powerful emission lines being revealed by the Spitzer IRAC data. I will discuss what we understand about the growth of galaxies in this epoch from the insights gained from remarkable deep fields like the XDF, as well as the wide-area GOODS/CANDELS fields, the detection of unexpectedly luminous galaxies at redshifts 8-10, the impact of early galaxies on reionization, confirmation of a number of galaxies at z~7-8 from ground-based spectroscopic measurements, and the indications of a change in the growth of the star formation rate around 500 Myr. The first <span class="hlt">billion</span> years was a time of dramatic growth and change in the early galaxy population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22391089','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22391089"><span id="translatedtitle">Mathematical model and software complex for computer simulation of field emission <span class="hlt">electron</span> sources</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nikiforov, Konstantin</p> <p>2015-03-10</p> <p>The software complex developed in MATLAB allows modelling of function of diode and triode structures based on field emission <span class="hlt">electron</span> sources with complex sub-micron geometry, their <span class="hlt">volt</span>-ampere characteristics, calculating distribution of electric field for educational and research needs. The goal of this paper is describing the physical-mathematical model, calculation methods and algorithms the software complex is based on, demonstrating the principles of its function and showing results of its work. For getting to know the complex, a demo version with graphical user interface is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1029150','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1029150"><span id="translatedtitle">Parametrization and Classification of 20 <span class="hlt">Billion</span> LSST Objects: Lessons from SDSS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ivezic, Z.; Axelrod, T.; Becker, A.C.; Becla, J.; Borne, K.; Burke, David L.; Claver, C.F.; Cook, K.H.; Connolly, A.; Gilmore, D.K.; Jones, R.L.; Juric, M.; Kahn, Steven M.; Lim, K-T.; Lupton, R.H.; Monet, D.G.; Pinto, P.A.; Sesar, B.; Stubbs, Christopher W.; Tyson, J.Anthony; /UC, Davis</p> <p>2011-11-10</p> <p>The Large Synoptic Survey Telescope (LSST) will be a large, wide-field ground-based system designed to obtain, starting in 2015, multiple images of the sky that is visible from Cerro Pachon in Northern Chile. About 90% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg{sup 2} region about 1000 times during the anticipated 10 years of operations (distributed over six bands, ugrizy). Each 30-second long visit will deliver 5{sigma} depth for point sources of r {approx} 24.5 on average. The co-added map will be about 3 magnitudes deeper, and will include 10 <span class="hlt">billion</span> galaxies and a similar number of stars. We discuss various measurements that will be automatically performed for these 20 <span class="hlt">billion</span> sources, and how they can be used for classification and determination of source physical and other properties. We provide a few classification examples based on SDSS data, such as color classification of stars, color-spatial proximity search for wide-angle binary stars, orbital-color classification of asteroid families, and the recognition of main Galaxy components based on the distribution of stars in the position-metallicity-kinematics space. Guided by these examples, we anticipate that two grand classification challenges for LSST will be (1) rapid and robust classification of sources detected in difference images, and (2) simultaneous treatment of diverse astrometric and photometric time series measurements for an unprecedentedly large number of objects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC13A1124D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC13A1124D"><span id="translatedtitle">Greenhouse gas implications of a 32 <span class="hlt">billion</span> gallon bioenergy landscape in the US</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeLucia, E. H.; Hudiburg, T. W.; Wang, W.; Khanna, M.; Long, S.; Dwivedi, P.; Parton, W. J.; Hartman, M. D.</p> <p>2015-12-01</p> <p>Sustainable bioenergy for transportation fuel and greenhouse gas (GHGs) reductions may require considerable changes in land use. Perennial grasses have been proposed because of their potential to yield substantial biomass on marginal lands without displacing food and reduce GHG emissions by storing soil carbon. Here, we implemented an integrated approach to planning bioenergy landscapes by combining spatially-explicit ecosystem and economic models to predict a least-cost land allocation for a 32 <span class="hlt">billion</span> gallon (121 <span class="hlt">billion</span> liter) renewable fuel mandate in the US. We find that 2022 GHG transportation emissions are decreased by 7% when 3.9 million hectares of eastern US land are converted to perennial grasses supplemented with corn residue to meet cellulosic ethanol requirements, largely because of gasoline displacement and soil carbon storage. If renewable fuel production is accompanied by a cellulosic biofuel tax credit, CO2 equivalent emissions could be reduced by 12%, because it induces more cellulosic biofuel and land under perennial grasses (10 million hectares) than under the mandate alone. While GHG reducing bioenergy landscapes that meet RFS requirements and do not displace food are possible, the reductions in GHG emissions are 50% less compared to previous estimates that did not account for economically feasible land allocation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.460.2862B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.460.2862B"><span id="translatedtitle">The evolution in the stellar mass of brightest cluster galaxies over the past 10 <span class="hlt">billion</span> years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bellstedt, Sabine; Lidman, Chris; Muzzin, Adam; Franx, Marijn; Guatelli, Susanna; Hill, Allison R.; Hoekstra, Henk; Kurinsky, Noah; Labbe, Ivo; Marchesini, Danilo; Marsan, Z. Cemile; Safavi-Naeini, Mitra; Sifón, Cristóbal; Stefanon, Mauro; van de Sande, Jesse; van Dokkum, Pieter; Weigel, Catherine</p> <p>2016-08-01</p> <p>Using a sample of 98 galaxy clusters recently imaged in the near-infrared with the European Southern Observatory (ESO) New Technology Telescope, WIYN telescope and William Herschel Telescope, supplemented with 33 clusters from the ESO archive, we measure how the stellar mass of the most massive galaxies in the universe, namely brightest cluster galaxies (BCGs), increases with time. Most of the BCGs in this new sample lie in the redshift range 0.2 < z < 0.6, which has been noted in recent works to mark an epoch over which the growth in the stellar mass of BCGs stalls. From this sample of 132 clusters, we create a subsample of 102 systems that includes only those clusters that have estimates of the cluster mass. We combine the BCGs in this subsample with BCGs from the literature, and find that the growth in stellar mass of BCGs from 10 <span class="hlt">billion</span> years ago to the present epoch is broadly consistent with recent semi-analytic and semi-empirical models. As in other recent studies, tentative evidence indicates that the stellar mass growth rate of BCGs may be slowing in the past 3.5 <span class="hlt">billion</span> years. Further work in collecting larger samples, and in better comparing observations with theory using mock images, is required if a more detailed comparison between the models and the data is to be made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25162527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25162527"><span id="translatedtitle">A massive galaxy in its core formation phase three <span class="hlt">billion</span> years after the Big Bang.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nelson, Erica; van Dokkum, Pieter; Franx, Marijn; Brammer, Gabriel; Momcheva, Ivelina; Schreiber, Natascha Förster; da Cunha, Elisabete; Tacconi, Linda; Bezanson, Rachel; Kirkpatrick, Allison; Leja, Joel; Rix, Hans-Walter; Skelton, Rosalind; van der Wel, Arjen; Whitaker, Katherine; Wuyts, Stijn</p> <p>2014-09-18</p> <p>Most massive galaxies are thought to have formed their dense stellar cores in early cosmic epochs. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes, but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we report a candidate core in the process of formation 11 <span class="hlt">billion</span> years ago, at redshift z = 2.3. This galaxy, GOODS-N-774, has a stellar mass of 100 <span class="hlt">billion</span> solar masses, a half-light radius of 1.0 kiloparsecs and a star formation rate of solar masses per year. The star-forming gas has a velocity dispersion of 317 ± 30 kilometres per second. This is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, which are compact quiescent galaxies at z ≈ 2 (refs 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 seem to be rare; however, from the star formation rate and size of this galaxy we infer that many star-forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25162527','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25162527"><span id="translatedtitle">A massive galaxy in its core formation phase three <span class="hlt">billion</span> years after the Big Bang.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nelson, Erica; van Dokkum, Pieter; Franx, Marijn; Brammer, Gabriel; Momcheva, Ivelina; Schreiber, Natascha Förster; da Cunha, Elisabete; Tacconi, Linda; Bezanson, Rachel; Kirkpatrick, Allison; Leja, Joel; Rix, Hans-Walter; Skelton, Rosalind; van der Wel, Arjen; Whitaker, Katherine; Wuyts, Stijn</p> <p>2014-09-18</p> <p>Most massive galaxies are thought to have formed their dense stellar cores in early cosmic epochs. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes, but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we report a candidate core in the process of formation 11 <span class="hlt">billion</span> years ago, at redshift z = 2.3. This galaxy, GOODS-N-774, has a stellar mass of 100 <span class="hlt">billion</span> solar masses, a half-light radius of 1.0 kiloparsecs and a star formation rate of solar masses per year. The star-forming gas has a velocity dispersion of 317 ± 30 kilometres per second. This is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, which are compact quiescent galaxies at z ≈ 2 (refs 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 seem to be rare; however, from the star formation rate and size of this galaxy we infer that many star-forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys. PMID:25162527</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatGe...7..811S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatGe...7..811S"><span id="translatedtitle">Evidence for arsenic metabolism and cycling by microorganisms 2.7 <span class="hlt">billion</span> years ago</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sforna, Marie Catherine; Philippot, Pascal; Somogyi, Andrea; van Zuilen, Mark A.; Medjoubi, Kadda; Schoepp-Cothenet, Barbara; Nitschke, Wolfgang; Visscher, Pieter T.</p> <p>2014-11-01</p> <p>The ability of microbes to metabolize arsenic may have emerged more than 3.4 <span class="hlt">billion</span> years ago. Some of the modern environments in which prominent arsenic metabolism occurs are anoxic, as were the Precambrian oceans. Early oceans may also have had a relatively high abundance of arsenic. However, it is unclear whether arsenic cycling occurred in ancient environments. Here we assess the chemistry and nature of cell-like globules identified in salt-encrusted portions of 2.72-<span class="hlt">billion</span>-year-old fossil stromatolites from Western Australia. We use Raman spectroscopy and X-ray fluorescence to show that the globules are composed of organic carbon and arsenic (As). We argue that our data are best explained by the occurrence of a complete arsenic cycle at this site, with As(III) oxidation and As(V) reduction by microbes living in permanently anoxic conditions. We therefore suggest that arsenic cycling could have occurred more widely in marine environments in the several hundred million years before the Earth’s atmosphere and shallow oceans were oxygenated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26085486','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26085486"><span id="translatedtitle">The Value Of The Nonprofit Hospital Tax Exemption Was $24.6 <span class="hlt">Billion</span> In 2011.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosenbaum, Sara; Kindig, David A; Bao, Jie; Byrnes, Maureen K; O'Laughlin, Colin</p> <p>2015-07-01</p> <p>The federal government encourages public support for charitable activities by allowing people to deduct donations to tax-exempt organizations on their income tax returns. Tax-exempt hospitals are major beneficiaries of this policy because it encourages donations to the hospitals while shielding them from federal and state tax liability. In exchange, these hospitals must engage in community benefit activities, such as providing care to indigent patients and participating in Medicaid. The congressional Joint Committee on Taxation estimated the value of the nonprofit hospital tax exemption at $12.6 <span class="hlt">billion</span> in 2002--a number that included forgone taxes, public contributions, and the value of tax-exempt bond financing. In this article we estimate that the size of the exemption reached $24.6 <span class="hlt">billion</span> in 2011. The Affordable Care Act (ACA) brings a new focus on community benefit activities by requiring tax-exempt hospitals to engage in communitywide planning efforts to improve community health. The magnitude of the tax exemption, coupled with ACA reforms, underscores the public's interest not only in community benefit spending generally but also in the extent to which nonprofit hospitals allocate funds for community benefit expenditures that improve the overall health of their communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19907491','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19907491"><span id="translatedtitle">Oxygen and hydrogen isotope evidence for a temperate climate 3.42 <span class="hlt">billion</span> years ago.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hren, M T; Tice, M M; Chamberlain, C P</p> <p>2009-11-12</p> <p>Stable oxygen isotope ratios (delta(18)O) of Precambrian cherts have been used to establish much of our understanding of the early climate history of Earth and suggest that ocean temperatures during the Archaean era ( approximately 3.5 <span class="hlt">billion</span> years ago) were between 55 degrees C and 85 degrees C (ref. 2). But, because of uncertainty in the delta(18)O of the primitive ocean, there is considerable debate regarding this conclusion. Examination of modern and ancient cherts indicates that another approach, using a combined analysis of delta(18)O and hydrogen isotopes (deltaD) rather than delta(18)O alone, can provide a firmer constraint on formational temperatures without independent knowledge of the isotopic composition of ambient waters. Here we show that delta(18)O and deltaD sampled from 3.42-<span class="hlt">billion</span>-year-old Buck Reef Chert rocks in South Africa are consistent with formation from waters at varied low temperatures. The most (18)O-enriched Buck Reef Chert rocks record the lowest diagenetic temperatures and were formed in equilibrium with waters below approximately 40 degrees C. Geochemical and sedimentary evidence suggests that the Buck Reef Chert was formed in shallow to deep marine conditions, so our results indicate that the Palaeoarchaean ocean was isotopically depleted relative to the modern ocean and far cooler (<or=40 degrees C) than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19907491','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19907491"><span id="translatedtitle">Oxygen and hydrogen isotope evidence for a temperate climate 3.42 <span class="hlt">billion</span> years ago.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hren, M T; Tice, M M; Chamberlain, C P</p> <p>2009-11-12</p> <p>Stable oxygen isotope ratios (delta(18)O) of Precambrian cherts have been used to establish much of our understanding of the early climate history of Earth and suggest that ocean temperatures during the Archaean era ( approximately 3.5 <span class="hlt">billion</span> years ago) were between 55 degrees C and 85 degrees C (ref. 2). But, because of uncertainty in the delta(18)O of the primitive ocean, there is considerable debate regarding this conclusion. Examination of modern and ancient cherts indicates that another approach, using a combined analysis of delta(18)O and hydrogen isotopes (deltaD) rather than delta(18)O alone, can provide a firmer constraint on formational temperatures without independent knowledge of the isotopic composition of ambient waters. Here we show that delta(18)O and deltaD sampled from 3.42-<span class="hlt">billion</span>-year-old Buck Reef Chert rocks in South Africa are consistent with formation from waters at varied low temperatures. The most (18)O-enriched Buck Reef Chert rocks record the lowest diagenetic temperatures and were formed in equilibrium with waters below approximately 40 degrees C. Geochemical and sedimentary evidence suggests that the Buck Reef Chert was formed in shallow to deep marine conditions, so our results indicate that the Palaeoarchaean ocean was isotopically depleted relative to the modern ocean and far cooler (<or=40 degrees C) than previously thought. PMID:19907491</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26085486','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26085486"><span id="translatedtitle">The Value Of The Nonprofit Hospital Tax Exemption Was $24.6 <span class="hlt">Billion</span> In 2011.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosenbaum, Sara; Kindig, David A; Bao, Jie; Byrnes, Maureen K; O'Laughlin, Colin</p> <p>2015-07-01</p> <p>The federal government encourages public support for charitable activities by allowing people to deduct donations to tax-exempt organizations on their income tax returns. Tax-exempt hospitals are major beneficiaries of this policy because it encourages donations to the hospitals while shielding them from federal and state tax liability. In exchange, these hospitals must engage in community benefit activities, such as providing care to indigent patients and participating in Medicaid. The congressional Joint Committee on Taxation estimated the value of the nonprofit hospital tax exemption at $12.6 <span class="hlt">billion</span> in 2002--a number that included forgone taxes, public contributions, and the value of tax-exempt bond financing. In this article we estimate that the size of the exemption reached $24.6 <span class="hlt">billion</span> in 2011. The Affordable Care Act (ACA) brings a new focus on community benefit activities by requiring tax-exempt hospitals to engage in communitywide planning efforts to improve community health. The magnitude of the tax exemption, coupled with ACA reforms, underscores the public's interest not only in community benefit spending generally but also in the extent to which nonprofit hospitals allocate funds for community benefit expenditures that improve the overall health of their communities. PMID:26085486</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatCo...5E5038Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatCo...5E5038Y"><span id="translatedtitle">Gigahertz single-trap <span class="hlt">electron</span> pumps in silicon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamahata, Gento; Nishiguchi, Katsuhiko; Fujiwara, Akira</p> <p>2014-10-01</p> <p>Manipulation of single <span class="hlt">electrons</span> is the key to developing ultimate <span class="hlt">electronics</span> such as single-<span class="hlt">electron</span>-based information processors and electrical standards in metrology. Especially, high-frequency and high-accuracy single-<span class="hlt">electron</span> pumps are essential to realize practical current standards. While electrically defined quantum dots are widely used to build single-<span class="hlt">electron</span> pumps, a localized state in semiconductors is also a potential candidate for accurate pumps because it can have a large activation energy for the captured <span class="hlt">electron</span>. However, the transfer mechanism of such localized-state-mediated single-<span class="hlt">electron</span> pumps for high-accuracy operation at a high frequency has not been well examined. Here we demonstrate a single-<span class="hlt">electron</span> pump using a single-trap level with an activation energy of a few ten millielectron <span class="hlt">volts</span> in Si nanotransistors. By means of gate control of capture and emission rates, the pump operates at a frequency of 3 GHz with an accuracy of better than 10-3 at 17 K, indicating that an electric field at the trap level lowers the capture and emission time to less than 25 ps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22299715','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22299715"><span id="translatedtitle">Measurements of the <span class="hlt">volt</span>-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Klas, M.; Matejčik, Š.; Radjenović, B.; Radmilović-Radjenović, M.</p> <p>2014-10-15</p> <p>The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1 μm and 100 μm. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100 μm interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted <span class="hlt">electrons</span>, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhPl...21j3503K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21j3503K"><span id="translatedtitle">Measurements of the <span class="hlt">volt</span>-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klas, M.; Matejčik, Š.; Radjenović, B.; Radmilović-Radjenović, M.</p> <p>2014-10-01</p> <p>The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1 μm and 100 μm. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100 μm interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted <span class="hlt">electrons</span>, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.138j4315M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.138j4315M"><span id="translatedtitle">Radiative charge transfer in He+ + H2 collisions in the milli- to nano-<span class="hlt">electron-volt</span> range: A theoretical study within state-to-state and optical potential approaches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mrugała, Felicja; Kraemer, Wolfgang P.</p> <p>2013-03-01</p> <p>The paper presents a theoretical study of the low-energy dynamics of the radiative charge transfer (RCT) reaction He+(^{2}S) + H2(X ^{1}Σ +g) rArr He(^{1}S) + H2+(X 2Σ +g)+hν extending our previous studies on radiative association of HeH2+ [F. Mrugała, V. Špirko, and W. P. Kraemer, J. Chem. Phys. 118, 10547 (2003), 10.1063/1.1573184; F. Mrugała and W. P. Kraemer, J. Chem. Phys. 122, 224321 (2005), 10.1063/1.1924453]. The calculations account for the vibrational and rotational motions of the H2/H_2^+ diatomics and for the atom-diatom complex formation in the reactant and the product channels of the RCT reaction. Continuum states of He+ + H2(v = 0, j = 0) in the collision energy range ˜10-7-18.6 meV and all quasi-bound states of the He+ - H2(para; v = 0) complex formed in this range are taken into account. Close-coupling calculations are performed to determine rates of radiative transitions from these states to the continuum and quasi-bound states of the He + H+2 system in the energy range extending up to ˜0.16 eV above the opening of the HeH+ + H arrangement channel. From the detailed state-to-state calculated characteristics global functions of the RCT reaction, such as cross-section σ(E), emission intensity I(ν, T), and rate constant k(T) are derived, and are presented together with their counterparts for the radiative association (RA) reaction He+(2S) + H_2(X ^{1}Σ +g) rArr HeH2+(X ^{2}A^' })+ hν. The rate constant kRCT is approximately 20 times larger than kRA at the considered temperatures, 0.1 μK-50 K. Formation of rotational Feshbach resonances in the reactant channel plays an important role in both reactions. Transitions mediated by these resonances contribute more than 70% to the respective rates. An extension of the one-dimensional optical potential model is developed to allow inclusion of all three vibrational modes in the atom-diatom system. This three-dimensional optical potential model is used to check to which extent the state-to-state RCT rate constant is influenced by the possibility to access ground state continuum levels well above the opening of the HeH++ H arrangement channel. The results indicate that these transitions contribute about 30% to the "true" rate constant kRCT whereas their impact on the populations of the vibration-rotational states of the product H2+ ion is only minor. Present theoretical rate constant functions kRCT(T) obtained at different approximation levels are compared to experimental data: 1-1.1 × 10-14 s-1 cm3 at T = 15-35 K and ˜7.5 × 10-15 s-1 cm3 at 40 K [M. M. Schauer, S. R. Jefferts, S. E. Barlow, and G. H. Dunn, J. Chem. Phys. 91, 4593 (1989), 10.1063/1.456748]. The most reliable theoretical values of kRCT, obtained by combining results from the state-to-state and the optical potential calculations, are between 2.5 and 3.5 times larger than these experimental numbers. Possible sources for discrepancies are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22105426','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22105426"><span id="translatedtitle">Radiative charge transfer in He{sup +}+ H{sub 2} collisions in the milli- to nano-<span class="hlt">electron-volt</span> range: A theoretical study within state-to-state and optical potential approaches</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mrugala, Felicja; Kraemer, Wolfgang P.</p> <p>2013-03-14</p> <p>The paper presents a theoretical study of the low-energy dynamics of the radiative charge transfer (RCT) reaction He{sup +}({sup 2}S)+H{sub 2}(X{sup 1}{Sigma}{sub g}{sup +}){yields}He({sup 1}S)+H{sub 2}{sup +}(X{sup 2}{Sigma}{sub g}{sup +})+h{nu} extending our previous studies on radiative association of HeH{sub 2}{sup +} [F. Mrugala, V. Spirko, and W. P. Kraemer, J. Chem. Phys. 118, 10547 (2003); F. Mrugala and W. P. Kraemer, ibid. 122, 224321 (2005)]. The calculations account for the vibrational and rotational motions of the H{sub 2}/H{sub 2}{sup +} diatomics and for the atom-diatom complex formation in the reactant and the product channels of the RCT reaction. Continuum states of He{sup +}+ H{sub 2}(v= 0, j= 0) in the collision energy range {approx}10{sup -7}-18.6 meV and all quasi-bound states of the He{sup +}- H{sub 2}(para;v= 0) complex formed in this range are taken into account. Close-coupling calculations are performed to determine rates of radiative transitions from these states to the continuum and quasi-bound states of the He +H{sub 2}{sup +} system in the energy range extending up to {approx}0.16 eV above the opening of the HeH{sup +}+ H arrangement channel. From the detailed state-to-state calculated characteristics global functions of the RCT reaction, such as cross-section {sigma}(E), emission intensity I({nu}, T), and rate constant k(T) are derived, and are presented together with their counterparts for the radiative association (RA) reaction He{sup +}({sup 2}S) +H{sub 2}(X{sup 1}{Sigma}{sub g}{sup +}){yields} HeH{sub 2}{sup +}(X{sup 2}A{sup Prime })+h{nu}. The rate constant k{sup RCT} is approximately 20 times larger than k{sup RA} at the considered temperatures, 0.1 {mu}K-50 K. Formation of rotational Feshbach resonances in the reactant channel plays an important role in both reactions. Transitions mediated by these resonances contribute more than 70% to the respective rates. An extension of the one-dimensional optical potential model is developed to allow inclusion of all three vibrational modes in the atom-diatom system. This three-dimensional optical potential model is used to check to which extent the state-to-state RCT rate constant is influenced by the possibility to access ground state continuum levels well above the opening of the HeH{sup +}+ H arrangement channel. The results indicate that these transitions contribute about 30% to the 'true' rate constant k{sup RCT} whereas their impact on the populations of the vibration-rotational states of the product H{sub 2}{sup +} ion is only minor. Present theoretical rate constant functions k{sup RCT}(T) obtained at different approximation levels are compared to experimental data: 1-1.1 Multiplication-Sign 10{sup -14} s{sup -1} cm{sup 3} at T= 15-35 K and {approx}7.5 Multiplication-Sign 10{sup -15} s{sup -1} cm{sup 3} at 40 K [M. M. Schauer, S. R. Jefferts, S. E. Barlow, and G. H. Dunn, J. Chem. Phys. 91, 4593 (1989)]. The most reliable theoretical values of k{sup RCT}, obtained by combining results from the state-to-state and the optical potential calculations, are between 2.5 and 3.5 times larger than these experimental numbers. Possible sources for discrepancies are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920029430&hterms=Harp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHarp','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920029430&hterms=Harp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHarp"><span id="translatedtitle">On the possible source of the ionization in the nighttime Martian ionosphere. I - Phobos 2 HARP <span class="hlt">electron</span> spectrometer measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Verigin, M. I.; Gringauz, K. I.; Shutte, N. M.; Haider, S. A.; Szego, K.; Kiraly, P.; Nagy, A. F.; Gombosi, T. I.</p> <p>1991-01-01</p> <p>The measurements of <span class="hlt">electron</span> spectra in the Martian magnetosphere by the HARP instrument on board the Phobos 2 orbiter are presented. The energy of the <span class="hlt">electrons</span> (a few tens of <span class="hlt">electron</span> <span class="hlt">volts</span>) is sufficient for the impact ionization of the planetary neutral gas, and the characteristic flux of <span class="hlt">electrons</span> (about 10 exp 8/sq cm per sec) could produce the nightside ionospheric layer with a peak density of a few thousands of <span class="hlt">electrons</span> per cubic centimeter, which corresponds to densities observed earlier during radio occultations of the Mars 4 and 5 and Viking 1 and 2 spacecraft. The possibility of magnetospheric <span class="hlt">electron</span> precipitation into the nightside atmosphere of Mars is in agreement with the mainly induced nature of the magnetic field in the planetary magnetotail (as at Venus), while the variability of the Martian nightside ionosphere may be explained by the partial screening of the atmosphere by a weak intrinsic magnetic field of the planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17747452','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17747452"><span id="translatedtitle">Search for Trapped <span class="hlt">Electrons</span> and a Magnetic Moment at Mars by Mariner IV.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>O'gallagher, J J; Simpson, J A</p> <p>1965-09-10</p> <p>The Mariner IV spacecraft on 14-15 July 1965 passed within 9850 kilometers of Mars, carrying a solid-state charged-particle telescope which could detect <span class="hlt">electrons</span> greater than 40 kiloelectron <span class="hlt">volts</span> and protons greater than 1 million <span class="hlt">electron</span> <span class="hlt">volts</span>. The trajectory could have passed through a bow shock, a transition region, and a magnetospheric boundary where particles could be stably trapped for a wide range of Martian magnetic moments. No evidence of charged-particle radiation was found in any of these regions. In view of these results, an upper limit is established for the Martian magnetic moment provided it is assumed that the same physical processes leading to acceleration and trapping of <span class="hlt">electrons</span> in Earth's magnetic field would be found in a Martian magnetic field. On this basis, the upper limit for the Martian magnetic moment is 0.1 percent that of Earth for a wide range of postulated orientations with respect to the rotational axis of Mars. The implications of these results for the physical and biological environment of Mars are briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740022165','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740022165"><span id="translatedtitle">Observations of low-energy <span class="hlt">electrons</span> upstream of the earth's bow shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reasoner, D. L.</p> <p>1974-01-01</p> <p>Observations of <span class="hlt">electron</span> fluxes with a lunar-based <span class="hlt">electron</span> spectrometer when the moon was upstream of the earth have shown that a subset of observed fluxes are strongly controlled by the interplanetary magnetic field direction. The fluxes occur only when the IMF lines connect back to the earth's bow shock. Observed densities and temperatures were in the ranges 2-4 x 0,001/cu cm and 1.7-2.8 x 1,000,000 K. It is shown that these <span class="hlt">electrons</span> can account for increases in effective solar wind <span class="hlt">electron</span> temperatures on bow-shock connected field lines which have been observed previously by other investigators. It is further shown that if a model of the bow shock with an electrostatic potential barrier is assumed, the potential can be estimated to be 500 <span class="hlt">volts</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21960629','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21960629"><span id="translatedtitle">MESSENGER observations of transient bursts of energetic <span class="hlt">electrons</span> in Mercury's magnetosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ho, George C; Krimigis, Stamatios M; Gold, Robert E; Baker, Daniel N; Slavin, James A; Anderson, Brian J; Korth, Haje; Starr, Richard D; Lawrence, David J; McNutt, Ralph L; Solomon, Sean C</p> <p>2011-09-30</p> <p>The MESSENGER spacecraft began detecting energetic <span class="hlt">electrons</span> with energies greater than 30 kilo-<span class="hlt">electron</span> <span class="hlt">volts</span> (keV) shortly after its insertion into orbit about Mercury. In contrast, no energetic protons were observed. The energetic <span class="hlt">electrons</span> arrive as bursts lasting from seconds to hours and are most intense close to the planet, distributed in latitude from the equator to the north pole, and present at most local times. Energies can exceed 200 keV but often exhibit cutoffs near 100 keV. Angular distributions of the <span class="hlt">electrons</span> about the magnetic field suggest that they do not execute complete drift paths around the planet. This set of characteristics demonstrates that Mercury's weak magnetic field does not support Van Allen-type radiation belts, unlike all other planets in the solar system with internal magnetic fields. PMID:21960629</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21960629','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21960629"><span id="translatedtitle">MESSENGER observations of transient bursts of energetic <span class="hlt">electrons</span> in Mercury's magnetosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ho, George C; Krimigis, Stamatios M; Gold, Robert E; Baker, Daniel N; Slavin, James A; Anderson, Brian J; Korth, Haje; Starr, Richard D; Lawrence, David J; McNutt, Ralph L; Solomon, Sean C</p> <p>2011-09-30</p> <p>The MESSENGER spacecraft began detecting energetic <span class="hlt">electrons</span> with energies greater than 30 kilo-<span class="hlt">electron</span> <span class="hlt">volts</span> (keV) shortly after its insertion into orbit about Mercury. In contrast, no energetic protons were observed. The energetic <span class="hlt">electrons</span> arrive as bursts lasting from seconds to hours and are most intense close to the planet, distributed in latitude from the equator to the north pole, and present at most local times. Energies can exceed 200 keV but often exhibit cutoffs near 100 keV. Angular distributions of the <span class="hlt">electrons</span> about the magnetic field suggest that they do not execute complete drift paths around the planet. This set of characteristics demonstrates that Mercury's weak magnetic field does not support Van Allen-type radiation belts, unlike all other planets in the solar system with internal magnetic fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24611581','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24611581"><span id="translatedtitle">Few-<span class="hlt">electron</span> edge-state quantum dots in a silicon nanowire field-effect transistor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Voisin, Benoit; Nguyen, Viet-Hung; Renard, Julien; Jehl, Xavier; Barraud, Sylvain; Triozon, François; Vinet, Maud; Duchemin, Ivan; Niquet, Yann-Michel; de Franceschi, Silvano; Sanquer, Marc</p> <p>2014-01-01</p> <p>We investigate the gate-induced onset of few-<span class="hlt">electron</span> regime through the undoped channel of a silicon nanowire field-effect transistor. By combining low-temperature transport measurements and self-consistent calculations, we reveal the formation of one-dimensional conduction modes localized at the two upper edges of the channel. Charge traps in the gate dielectric cause <span class="hlt">electron</span> localization along these edge modes, creating elongated quantum dots with characteristic lengths of ∼10 nm. We observe single-<span class="hlt">electron</span> tunneling across two such dots in parallel, specifically one in each channel edge. We identify the filling of these quantum dots with the first few <span class="hlt">electrons</span>, measuring addition energies of a few tens of millielectron <span class="hlt">volts</span> and level spacings of the order of 1 meV, which we ascribe to the valley orbit splitting. The total removal of valley degeneracy leaves only a 2-fold spin degeneracy, making edge quantum dots potentially promising candidates for silicon spin qubits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MNRAS.428.2001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MNRAS.428.2001M"><span id="translatedtitle">Constraining the last 7 <span class="hlt">billion</span> years of galaxy evolution in semi-analytic models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mutch, Simon J.; Poole, Gregory B.; Croton, Darren J.</p> <p>2013-01-01</p> <p>We investigate the ability of the Croton et al. semi-analytic model to reproduce the evolution of observed galaxies across the final 7 <span class="hlt">billion</span> years of cosmic history. Using Monte Carlo Markov Chain techniques we explore the available parameter space to produce a model which attempts to achieve a statistically accurate fit to the observed stellar mass function at z = 0 and z ≈ 0.8, as well as the local black hole-bulge relation. We find that in order to be successful we are required to push supernova feedback efficiencies to extreme limits which are, in some cases, unjustified by current observations. This leads us to the conclusion that the current model may be incomplete. Using the posterior probability distributions provided by our fitting, as well as the qualitative details of our produced stellar mass functions, we suggest that any future model improvements must act to preferentially bolster star formation efficiency in the most massive haloes at high redshift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22422979','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22422979"><span id="translatedtitle">A change in the geodynamics of continental growth 3 <span class="hlt">billion</span> years ago.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dhuime, Bruno; Hawkesworth, Chris J; Cawood, Peter A; Storey, Craig D</p> <p>2012-03-16</p> <p>Models for the growth of continental crust rely on knowing the balance between the generation of new crust and the reworking of old crust throughout Earth's history. The oxygen isotopic composition of zircons, for which uranium-lead and hafnium isotopic data provide age constraints, is a key archive of crustal reworking. We identified systematic variations in hafnium and oxygen isotopes in zircons of different ages that reveal the relative proportions of reworked crust and of new crust through time. Growth of continental crust appears to have been a continuous process, albeit at variable rates. A marked decrease in the rate of crustal growth at ~3 <span class="hlt">billion</span> years ago may be linked to the onset of subduction-driven plate tectonics. PMID:22422979</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22232760','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22232760"><span id="translatedtitle">Atmospheric carbon dioxide: a driver of photosynthetic eukaryote evolution for over a <span class="hlt">billion</span> years?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beerling, David J</p> <p>2012-02-19</p> <p>Exciting evidence from diverse fields, including physiology, evolutionary biology, palaeontology, geosciences and molecular genetics, is providing an increasingly secure basis for robustly formulating and evaluating hypotheses concerning the role of atmospheric carbon dioxide (CO(2)) in the evolution of photosynthetic eukaryotes. Such studies span over a <span class="hlt">billion</span> years of evolutionary change, from the origins of eukaryotic algae through to the evolution of our present-day terrestrial floras, and have relevance for plant and ecosystem responses to future global CO(2) increases. The papers in this issue reflect the breadth and depth of approaches being adopted to address this issue. They reveal new discoveries pointing to deep evidence for the role of CO(2) in shaping evolutionary changes in plants and ecosystems, and establish an exciting cross-disciplinary research agenda for uncovering new insights into feedbacks between biology and the Earth system.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21499769','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21499769"><span id="translatedtitle"><span class="hlt">Billion</span>-atom synchronous parallel kinetic Monte Carlo simulations of critical 3D Ising systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martinez, E.; Monasterio, P.R.; Marian, J.</p> <p>2011-02-20</p> <p>An extension of the synchronous parallel kinetic Monte Carlo (spkMC) algorithm developed by Martinez et al. [J. Comp. Phys. 227 (2008) 3804] to discrete lattices is presented. The method solves the master equation synchronously by recourse to null events that keep all processors' time clocks current in a global sense. Boundary conflicts are resolved by adopting a chessboard decomposition into non-interacting sublattices. We find that the bias introduced by the spatial correlations attendant to the sublattice decomposition is within the standard deviation of serial calculations, which confirms the statistical validity of our algorithm. We have analyzed the parallel efficiency of spkMC and find that it scales consistently with problem size and sublattice partition. We apply the method to the calculation of scale-dependent critical exponents in <span class="hlt">billion</span>-atom 3D Ising systems, with very good agreement with state-of-the-art multispin simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/944304','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/944304"><span id="translatedtitle">Investigation of Radar Propagation in Buildings: A 10 <span class="hlt">Billion</span> Element Cartesian-Mesh FETD Simulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stowell, M L; Fasenfest, B J; White, D A</p> <p>2008-01-14</p> <p>In this paper large scale full-wave simulations are performed to investigate radar wave propagation inside buildings. In principle, a radar system combined with sophisticated numerical methods for inverse problems can be used to determine the internal structure of a building. The composition of the walls (cinder block, re-bar) may effect the propagation of the radar waves in a complicated manner. In order to provide a benchmark solution of radar propagation in buildings, including the effects of typical cinder block and re-bar, we performed large scale full wave simulations using a Finite Element Time Domain (FETD) method. This particular FETD implementation is tuned for the special case of an orthogonal Cartesian mesh and hence resembles FDTD in accuracy and efficiency. The method was implemented on a general-purpose massively parallel computer. In this paper we briefly describe the radar propagation problem, the FETD implementation, and we present results of simulations that used over 10 <span class="hlt">billion</span> elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AAS...21933301T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AAS...21933301T"><span id="translatedtitle">Star Formation in Galaxy Clusters Over the Past 10 <span class="hlt">Billion</span> Years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tran, Kim-Vy</p> <p>2012-01-01</p> <p>Galaxy clusters are the largest gravitationally bound systems in the universe and include the most massive galaxies in the universe; this makes galaxy clusters ideal laboratories for disentangling the nature versus nurture aspect of how galaxies evolve. Understanding how galaxies form and evolve in clusters continues to be a fundamental question in astronomy. The ages and assembly histories of galaxies in rich clusters test both stellar population models and hierarchical formation scenarios. Is star formation in cluster galaxies simply accelerated relative to their counterparts in the lower density field, or do cluster galaxies assemble their stars in a fundamentally different manner? To answer this question, I review multi-wavelength results on star formation in galaxy clusters from Coma to the most distant clusters yet discovered at look-back times of 10 <span class="hlt">billion</span> years (z 2).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25361142','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25361142"><span id="translatedtitle">Barium fluoride whispering-gallery-mode disk-resonator with one <span class="hlt">billion</span> quality-factor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Guoping; Diallo, Souleymane; Henriet, Rémi; Jacquot, Maxime; Chembo, Yanne K</p> <p>2014-10-15</p> <p>We demonstrate a monolithic optical whispering-gallery-mode resonator fabricated with barium fluoride (BaF₂) with an ultra-high quality (Q) factor above 10⁹ at 1550 nm, and measured with both the linewidth and cavity-ring-down methods. Vertical scanning optical profilometry shows that the root mean square surface roughness of 2 nm is achieved for our mm-size disk. To the best of our knowledge, we show for the first time that one <span class="hlt">billion</span> Q-factor is achievable by precision polishing in relatively soft crystals with mohs hardness of 3. We show that complex thermo-optical dynamics can take place in these resonators. Beside usual applications in nonlinear optics and microwave photonics, high-energy particle scintillation detection utilizing monolithic BaF₂ resonators potentially becomes feasible. PMID:25361142</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22223803','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22223803"><span id="translatedtitle">An exhumation history of continents over <span class="hlt">billion</span>-year time scales.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blackburn, Terrence J; Bowring, Samuel A; Perron, J Taylor; Mahan, Kevin H; Dudas, Francis O; Barnhart, Katherine R</p> <p>2012-01-01</p> <p>The continental lithosphere contains the oldest and most stable structures on Earth, where fragments of ancient material have eluded destruction by tectonic and surface processes operating over <span class="hlt">billions</span> of years. Although present-day erosion of these remnants is slow, a record of how they have uplifted, eroded, and cooled over Earth's history can provide insight into the physical properties of the continents and the forces operating to exhume them over geologic time. We constructed a continuous record of ancient lithosphere cooling with the use of uranium-lead (U-Pb) thermochronology on volcanically exhumed lower crustal fragments. Combining these measurements with thermal and Pb-diffusion models constrains the range of possible erosion histories. Measured U-Pb data are consistent with extremely low erosion rates persisting over time scales approaching the age of the continents themselves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035961','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035961"><span id="translatedtitle">Extraterrestrial demise of banded iron formations 1.85 <span class="hlt">billion</span> years ago</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Slack, J.F.; Cannon, W.F.</p> <p>2009-01-01</p> <p>In the Lake Superior region of North America, deposition of most banded iron formations (BIFs) ended abruptly 1.85 Ga ago, coincident with the oceanic impact of the giant Sudbury extraterrestrial bolide. We propose a new model in which this impact produced global mixing of shallow oxic and deep anoxic waters of the Paleoproterozoic ocean, creating a suboxic redox state for deep seawater. This suboxic state, characterized by only small concentrations of dissolved O2 (???1 ??M), prevented transport of hydrothermally derived Fe(II) from the deep ocean to continental-margin settings, ending an ???1.1 <span class="hlt">billion</span>-year-long period of episodic BIF mineralization. The model is supported by the nature of Precambrian deep-water exhalative chemical sediments, which changed from predominantly sulfide facies prior to ca. 1.85 Ga to mainly oxide facies thereafter. ?? 2009 Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeCoA.120...65L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeCoA.120...65L"><span id="translatedtitle">An anoxic, Fe(II)-rich, U-poor ocean 3.46 <span class="hlt">billion</span> years ago</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Weiqiang; Czaja, Andrew D.; Van Kranendonk, Martin J.; Beard, Brian L.; Roden, Eric E.; Johnson, Clark M.</p> <p>2013-11-01</p> <p>The oxidation state of the atmosphere and oceans on the early Earth remains controversial. Although it is accepted by many workers that the Archean atmosphere and ocean were anoxic, hematite in the 3.46 <span class="hlt">billion</span>-year-old (Ga) Marble Bar Chert (MBC) from Pilbara Craton, NW Australia has figured prominently in arguments that the Paleoarchean atmosphere and ocean was fully oxygenated. In this study, we report the Fe isotope compositions and U concentrations of the MBC, and show that the samples have extreme heavy Fe isotope enrichment, where δ56Fe values range between +1.5‰ and +2.6‰, the highest δ56Fe values for bulk samples yet reported. The high δ56Fe values of the MBC require very low levels of oxidation and, in addition, point to a Paleoarchean ocean that had high aqueous Fe(II) contents. A dispersion/reaction model indicates that O2 contents in the photic zone of the ocean were less than 10-3 μM, which suggests that the ocean was essentially anoxic. An independent test of anoxic conditions is provided by U-Th-Pb isotope systematics, which show that U contents in the Paleoarchean ocean were likely below 0.02 ppb, two orders-of-magnitude lower than the modern ocean. Collectively, the Fe and U data indicate a reduced, Fe(II)-rich, U-poor environment in the Archean oceans at 3.46 <span class="hlt">billion</span> years ago. Given the evidence for photosynthetic communities provided by broadly coeval stromatolites, these results suggests that an important photosynthetic pathway in the Paleoarchean oceans may have been anoxygenic photosynthetic Fe(II) oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22004282','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22004282"><span id="translatedtitle">IRON AND {alpha}-ELEMENT PRODUCTION IN THE FIRST ONE <span class="hlt">BILLION</span> YEARS AFTER THE BIG BANG</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Becker, George D.; Carswell, Robert F.; Sargent, Wallace L. W.; Rauch, Michael E-mail: acalver@ast.cam.ac.uk E-mail: mr@obs.carnegiescience.edu</p> <p>2012-01-10</p> <p>We present measurements of carbon, oxygen, silicon, and iron in quasar absorption systems existing when the universe was roughly one <span class="hlt">billion</span> years old. We measure column densities in nine low-ionization systems at 4.7 < z < 6.3 using Keck, Magellan, and Very Large Telescope optical and near-infrared spectra with moderate to high resolution. The column density ratios among C II, O I, Si II, and Fe II are nearly identical to sub-damped Ly{alpha} systems (sub-DLAs) and metal-poor ([M/H] {<=} -1) DLAs at lower redshifts, with no significant evolution over 2 {approx}< z {approx}< 6. The estimated intrinsic scatter in the ratio of any two elements is also small, with a typical rms deviation of {approx}< 0.1 dex. These facts suggest that dust depletion and ionization effects are minimal in our z > 4.7 systems, as in the lower-redshift DLAs, and that the column density ratios are close to the intrinsic relative element abundances. The abundances in our z > 4.7 systems are therefore likely to represent the typical integrated yields from stellar populations within the first gigayear of cosmic history. Due to the time limit imposed by the age of the universe at these redshifts, our measurements thus place direct constraints on the metal production of massive stars, including iron yields of prompt supernovae. The lack of redshift evolution further suggests that the metal inventories of most metal-poor absorption systems at z {approx}> 2 are also dominated by massive stars, with minimal contributions from delayed Type Ia supernovae or winds from asymptotic giant branch stars. The relative abundances in our systems broadly agree with those in very metal-poor, non-carbon-enhanced Galactic halo stars. This is consistent with the picture in which present-day metal-poor stars were potentially formed as early as one <span class="hlt">billion</span> years after the big bang.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12266393','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12266393"><span id="translatedtitle">China. Country profile. [China's <span class="hlt">billion</span> consumers are a rapidly changing market].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hardee, K</p> <p>1984-10-01</p> <p>This article provides a summary of demographic, social, and economic characteristics of the People's Republic of China. Chinese leaders project that achievement of the 4 modernizations (agriculture, industry, science, and technology) will double the per capita income level to $800/year by 2000. Although industrial and agricultural growth have outpaced population growth, stringent population control is considered necessary for continued economic development. China's 1982 population was 1.008 <span class="hlt">billion</span>, with a birth rate of 20.91, a death rate of 6.36, and a 14.55 rate of natural increase. The growth rate declined from 1.3% in 1982 to 1.15% in 1983. To achieve its goal of preventing the population from exceeding 1.2 <span class="hlt">billion</span> by the year 2000, the government urges couples to have only 1 child. This policy has been successful in the cities but faces opposition in the rural areas. The sex ratio is 106 males to every 100 females, and there is concern about female infanticide. In 1982 the average household size ranged from a high of 5.2 persons in Qinghai and Yunnan to a low of 3.6 persons in Shanghai. 39% of the population lives in nuclear families without relatives. The literacy rate stood at 77% of those over 12 years of age in 1982, but males outnumber females at higher levels of education. China's campaign to improve health has focused on preventive measures, and there are an estimated 3-5 million health care workers. The 1982 labor force participation rate for those 15-64 years of age was 87.7%, with 44% of workers employed in agricculture. 76.6% of women work, primarily in labor-intensive, low-wage occupations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175359','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175359"><span id="translatedtitle"><span class="hlt">Electron</span> radiography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Merrill, Frank E.; Morris, Christopher</p> <p>2005-05-17</p> <p>A system capable of performing radiography using a beam of <span class="hlt">electrons</span>. Diffuser means receive a beam of <span class="hlt">electrons</span> and diffuse the <span class="hlt">electrons</span> before they enter first matching quadrupoles where the diffused <span class="hlt">electrons</span> are focused prior to the diffused <span class="hlt">electrons</span> entering an object. First imaging quadrupoles receive the focused diffused <span class="hlt">electrons</span> after the focused diffused <span class="hlt">electrons</span> have been scattered by the object for focusing the scattered <span class="hlt">electrons</span>. Collimator means receive the scattered <span class="hlt">electrons</span> and remove scattered <span class="hlt">electrons</span> that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered <span class="hlt">electrons</span> and refocus the collimated scattered <span class="hlt">electrons</span> and map the focused collimated scattered <span class="hlt">electrons</span> to transverse locations on an image plane representative of the <span class="hlt">electrons</span>' positions in the object.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25883353','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25883353"><span id="translatedtitle">Galaxy evolution. Evidence for mature bulges and an inside-out quenching phase 3 <span class="hlt">billion</span> years after the Big Bang.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tacchella, S; Carollo, C M; Renzini, A; Förster Schreiber, N M; Lang, P; Wuyts, S; Cresci, G; Dekel, A; Genzel, R; Lilly, S J; Mancini, C; Newman, S; Onodera, M; Shapley, A; Tacconi, L; Woo, J; Zamorani, G</p> <p>2015-04-17</p> <p>Most present-day galaxies with stellar masses ≥10(11) solar masses show no ongoing star formation and are dense spheroids. Ten <span class="hlt">billion</span> years ago, similarly massive galaxies were typically forming stars at rates of hundreds solar masses per year. It is debated how star formation ceased, on which time scales, and how this "quenching" relates to the emergence of dense spheroids. We measured stellar mass and star-formation rate surface density distributions in star-forming galaxies at redshift 2.2 with ~1-kiloparsec resolution. We find that, in the most massive galaxies, star formation is quenched from the inside out, on time scales less than 1 <span class="hlt">billion</span> years in the inner regions, up to a few <span class="hlt">billion</span> years in the outer disks. These galaxies sustain high star-formation activity at large radii, while hosting fully grown and already quenched bulges in their cores. PMID:25883353</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4137040','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4137040"><span id="translatedtitle">Switching To Less-Expensive Blindness Drug Could Save Medicare Part B $18 <span class="hlt">Billion</span> Over A Ten-Year Period</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hutton, DW; Newman-Casey, PA; Tavag, M; Zacks, DN; Stein, JD</p> <p>2014-01-01</p> <p>The biologic drugs bevacizumab and ranibizumab have revolutionized treatment of diabetic macular edema and macular degeneration, leading causes of blindness. Ophthalmologic use of these drugs has increased, now accounting for roughly one-sixth of the Medicare Part B drug budget. Ranibizumab and bevacizumab have similar efficacy and potentially minor differences in adverse event rates, but at $2,023 per dose, ranibizumab costs forty times more than bevacizumab. Using modeling methods, we predict ten-year (2010–2020) population-level costs and health benefits of using bevacizumab and ranibizumab. Our results show that if all patients were treated with the less-expensive bevacizumab instead of current usage patterns, Medicare Part B, patients, and the health care system would save $18 <span class="hlt">billion</span>, $4.6 <span class="hlt">billion</span>, and $29 <span class="hlt">billion</span>, respectively. Altering patterns of use with these therapies by encouraging bevacizumab use and hastening approval of biosimilar therapies would dramatically reduce spending without substantially affecting patient outcomes. PMID:24889941</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25883353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25883353"><span id="translatedtitle">Galaxy evolution. Evidence for mature bulges and an inside-out quenching phase 3 <span class="hlt">billion</span> years after the Big Bang.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tacchella, S; Carollo, C M; Renzini, A; Förster Schreiber, N M; Lang, P; Wuyts, S; Cresci, G; Dekel, A; Genzel, R; Lilly, S J; Mancini, C; Newman, S; Onodera, M; Shapley, A; Tacconi, L; Woo, J; Zamorani, G</p> <p>2015-04-17</p> <p>Most present-day galaxies with stellar masses ≥10(11) solar masses show no ongoing star formation and are dense spheroids. Ten <span class="hlt">billion</span> years ago, similarly massive galaxies were typically forming stars at rates of hundreds solar masses per year. It is debated how star formation ceased, on which time scales, and how this "quenching" relates to the emergence of dense spheroids. We measured stellar mass and star-formation rate surface density distributions in star-forming galaxies at redshift 2.2 with ~1-kiloparsec resolution. We find that, in the most massive galaxies, star formation is quenched from the inside out, on time scales less than 1 <span class="hlt">billion</span> years in the inner regions, up to a few <span class="hlt">billion</span> years in the outer disks. These galaxies sustain high star-formation activity at large radii, while hosting fully grown and already quenched bulges in their cores.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21537650','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21537650"><span id="translatedtitle">Target-heating effects on the K{sub {alpha}{sub 1{sub ,{sub 2}}}}-emission spectrum from solid targets heated by laser-generated hot <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nilson, P. M.; Theobald, W.; Mileham, C.; Stoeckl, C.; Myatt, J. F.; Delettrez, J. A.; Begishev, I. A.; Zuegel, J. D.; Sangster, T. C.; MacFarlane, J.; Betti, R.; Meyerhofer, D. D.</p> <p>2011-04-15</p> <p>Target-heating effects on the K{sub {alpha}{sub 1{sub ,{sub 2}}}}-emission spectrum from small-mass Cu targets irradiated with 1-ps pulses focused to intensities >10{sup 18} W/cm{sup 2} have been observed. A collisional-radiative atomic physics model is unable to reproduce the time-integrated K{sub {alpha}{sub 1{sub ,{sub 2}}}}-emission spectrum from the smallest-mass targets when calculated with a single, time-independent thermal-<span class="hlt">electron</span> temperature. When time-dependent heating to several hundred <span class="hlt">electron</span> <span class="hlt">volts</span> is included in the model, the synthetic spectra better reproduce the main observed spectral features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1544136','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1544136"><span id="translatedtitle">Sub-parts-per-<span class="hlt">billion</span> level detection of NO2 using room-temperature quantum cascade lasers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pushkarsky, Michael; Tsekoun, Alexei; Dunayevskiy, Ilya G.; Go, Rowel; Patel, C. Kumar N.</p> <p>2006-01-01</p> <p>We report the sub-parts-per-<span class="hlt">billion</span>-level detection of NO2 using tunable laser-based photoacoustic spectroscopy where the laser radiation is obtained from a room-temperature continuous-wave high-power quantum cascade laser operating in an external grating cavity configuration. The continuously tunable external grating cavity quantum cascade laser produces maximum single-frequency output of ≈300 mW tunable over ≈350 nm centered at 6.25 μm. We demonstrate minimum detection level of ≈0.5 parts per <span class="hlt">billion</span> of NO2 in the presence of humidified air. PMID:16829569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17816892','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17816892"><span id="translatedtitle">The 18O/16O Ratio of 2-<span class="hlt">Billion</span>-Year-Old Seawater Inferred from Ancient Oceanic Crust.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Holmden, C; Muehlenbachs, K</p> <p>1993-03-19</p> <p>An oxygen isotope profile of the 2-<span class="hlt">billion</span>-year-old Purtuniq ophiolite overlaps with similar profiles of younger ophiolites and the modern oceanic crust. This overlap implies (i) that there was a similar style of seawater-ocean crust interaction during the past 2 <span class="hlt">billion</span> years; (ii) that the oxygen isotope composition of early Proterozoic seawater was similar to the modern value; (iii) that early Proterozoic sea-floor spreading rates were similar to, or greater than, average modern rates; and (iv) that early Proterozoic carbonate rocks and cherts with low (18)O/(16)O ratios do not reflect global-scale (18)O depletion of early Proterozoic oceans. PMID:17816892</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1023318','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1023318"><span id="translatedtitle">U.S. <span class="hlt">Billion</span>-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Downing, Mark; Eaton, Laurence M; Graham, Robin Lambert; Langholtz, Matthew H; Perlack, Robert D; Turhollow Jr, Anthony F; Stokes, Bryce; Brandt, Craig C</p> <p>2011-08-01</p> <p>The report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a <span class="hlt">Billion</span>-Ton Annual Supply (generally referred to as the <span class="hlt">Billion</span>-Ton Study or 2005 BTS), was an estimate of 'potential' biomass based on numerous assumptions about current and future inventory, production capacity, availability, and technology. The analysis was made to determine if conterminous U.S. agriculture and forestry resources had the capability to produce at least one <span class="hlt">billion</span> dry tons of sustainable biomass annually to displace 30% or more of the nation's present petroleum consumption. An effort was made to use conservative estimates to assure confidence in having sufficient supply to reach the goal. The potential biomass was projected to be reasonably available around mid-century when large-scale biorefineries are likely to exist. The study emphasized primary sources of forest- and agriculture-derived biomass, such as logging residues, fuel treatment thinnings, crop residues, and perennially grown grasses and trees. These primary sources have the greatest potential to supply large, reliable, and sustainable quantities of biomass. While the primary sources were emphasized, estimates of secondary residue and tertiary waste resources of biomass were also provided. The original <span class="hlt">Billion</span>-Ton Resource Assessment, published in 2005, was divided into two parts-forest-derived resources and agriculture-derived resources. The forest resources included residues produced during the harvesting of merchantable timber, forest residues, and small-diameter trees that could become available through initiatives to reduce fire hazards and improve forest health; forest residues from land conversion; fuelwood extracted from forests; residues generated at primary forest product processing mills; and urban wood wastes, municipal solid wastes (MSW), and construction and demolition (C&D) debris. For these forest resources, only residues, wastes, and small-diameter trees were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1009078','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1009078"><span id="translatedtitle">Accelerating Into the Future: From 0 to GeV in a Few Centimeters (LBNL Summer Lecture Series)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Leemans, Wim</p> <p>2008-07-08</p> <p>Summer Lecture Series 2008: By exciting electric fields in plasma-based waveguides, lasers accelerate <span class="hlt">electrons</span> in a fraction of the distance conventional accelerators require. The Accelerator and Fusion Research Division's LOASIS program, headed by Wim Leemans, has used 40-trillion-watt laser pulses to deliver <span class="hlt">billion-electron-volt</span> (1 GeV) <span class="hlt">electron</span> beams within centimeters. Leemans looks ahead to BELLA, 10-GeV accelerating modules that could power a future linear collider.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/987103','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/987103"><span id="translatedtitle">Accelerating Into the Future: From 0 to GeV in a Few Centimeters (LBNL Summer Lecture Series)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a></p> <p>Leemans, Wim [LOASIS Program, AFRD</p> <p>2016-07-12</p> <p>July 8, 2008 Berkeley Lab lecture: By exciting electric fields in plasma-based waveguides, lasers accelerate <span class="hlt">electrons</span> in a fraction of the distance conventional accelerators require. The Accelerator and Fusion Research Division's LOASIS program, headed by Wim Leemans, has used 40-trillion-watt laser pulses to deliver <span class="hlt">billion-electron-volt</span> (1 GeV) <span class="hlt">electron</span> beams within centimeters. Leemans looks ahead to BELLA, 10-GeV accelerating modules that could power a future linear collider.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/1009078','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/1009078"><span id="translatedtitle">Accelerating Into the Future: From 0 to GeV in a Few Centimeters (LBNL Summer Lecture Series)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a></p> <p>Leemans, Wim [LOASIS Program, AFRD</p> <p>2016-07-12</p> <p>Summer Lecture Series 2008: By exciting electric fields in plasma-based waveguides, lasers accelerate <span class="hlt">electrons</span> in a fraction of the distance conventional accelerators require. The Accelerator and Fusion Research Division's LOASIS program, headed by Wim Leemans, has used 40-trillion-watt laser pulses to deliver <span class="hlt">billion-electron-volt</span> (1 GeV) <span class="hlt">electron</span> beams within centimeters. Leemans looks ahead to BELLA, 10-GeV accelerating modules that could power a future linear collider.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JChPh.131x4501S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JChPh.131x4501S"><span id="translatedtitle">The dynamics of highly excited <span class="hlt">electronic</span> systems: Applications of the <span class="hlt">electron</span> force field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Julius T.; Goddard, William A.</p> <p>2009-12-01</p> <p>Highly excited heterogeneous complex materials are essential elements of important processes, ranging from inertial confinement fusion to semiconductor device fabrication. Understanding the dynamics of these systems has been challenging because of the difficulty in extracting mechanistic information from either experiment or theory. We describe here the <span class="hlt">electron</span> force field (eFF) approximation to quantum mechanics which provides a practical approach to simulating the dynamics of such systems. eFF includes all the normal electrostatic interactions between <span class="hlt">electrons</span> and nuclei and the normal quantum mechanical description of kinetic energy for the <span class="hlt">electrons</span>, but contains two severe approximations: first, the individual <span class="hlt">electrons</span> are represented as floating Gaussian wave packets whose position and size respond instantaneously to various forces during the dynamics; and second, these wave packets are combined into a many-body wave function as a Hartree product without explicit antisymmetrization. The Pauli principle is accounted for by adding an extra spin-dependent term to the Hamiltonian. These approximations are a logical extension of existing approaches to simulate the dynamics of fermions, which we review. In this paper, we discuss the details of the equations of motion and potentials that form eFF, and evaluate the ability of eFF to describe ground-state systems containing covalent, ionic, multicenter, and/or metallic bonds. We also summarize two eFF calculations previously reported on <span class="hlt">electronically</span> excited systems: (1) the thermodynamics of hydrogen compressed up to ten times liquid density and heated up to 200 000 K; and (2) the dynamics of Auger fragmentation in a diamond nanoparticle, where hundreds of <span class="hlt">electron</span> <span class="hlt">volts</span> of excitation energy are dissipated over tens of femtoseconds. These cases represent the first steps toward using eFF to model highly excited <span class="hlt">electronic</span> processes in complex materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25636403','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25636403"><span id="translatedtitle">An empirical method for deriving RBE values associated with <span class="hlt">electrons</span>, photons and radionuclides.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bellamy, M; Puskin, J; Hertel, N; Eckerman, K</p> <p>2015-12-01</p> <p>There is substantial evidence to justify using relative biological effectiveness (RBE) values of >1 for low-energy <span class="hlt">electrons</span> and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer has been assigned a radiation weighting factor wR of 1. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for <span class="hlt">electrons</span> based upon the fractional deposition of absorbed dose of energies less than a few kiloelectron <span class="hlt">volts</span>. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and <span class="hlt">electrons</span> are the primary emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.430...43S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.430...43S"><span id="translatedtitle">A redox-stratified ocean 3.2 <span class="hlt">billion</span> years ago</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Satkoski, Aaron M.; Beukes, Nicolas J.; Li, Weiqiang; Beard, Brian L.; Johnson, Clark M.</p> <p>2015-11-01</p> <p>Before the Great Oxidation Event (GOE) 2.4-2.2 <span class="hlt">billion</span> years ago it has been traditionally thought that oceanic water columns were uniformly anoxic due to a lack of oxygen-producing microorganisms. Recently, however, it has been proposed that transient oxygenation of shallow seawater occurred between 2.8 and 3.0 <span class="hlt">billion</span> years ago. Here, we present a novel combination of stable Fe and radiogenic U-Th-Pb isotope data that demonstrate significant oxygen contents in the shallow oceans at 3.2 Ga, based on analysis of the Manzimnyama Banded Iron Formation (BIF), Fig Tree Group, South Africa. This unit is exceptional in that proximal, shallow-water and distal, deep-water facies are preserved. When compared to the distal, deep-water facies, the proximal samples show elevated U concentrations and moderately positive δ56Fe values, indicating vertical stratification in dissolved oxygen contents. Confirmation of oxidizing conditions using U abundances is robustly constrained using samples that have been closed to U and Pb mobility using U-Th-Pb geochronology. Although redox-sensitive elements have been commonly used in ancient rocks to infer redox conditions, post-depositional element mobility has been rarely tested, and U-Th-Pb geochronology can constrain open- or closed-system behavior. The U abundances and δ56Fe values of the Manzimnyama BIF suggest the proximal, shallow-water samples record precipitation under stronger oxidizing conditions compared to the distal deeper-water facies, which in turn indicates the existence of a discrete redox boundary between deep and shallow ocean waters at this time; this work, therefore, documents the oldest known preserved marine redox gradient in the rock record. The relative enrichment of O2 in the upper water column is likely due to the existence of oxygen-producing microorganisms such as cyanobacteria. These results provide a new approach for identifying free oxygen in Earth's ancient oceans, including confirming the age of redox</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.443..985D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.443..985D"><span id="translatedtitle">The First <span class="hlt">Billion</span> Years project: dark matter haloes going from contraction to expansion and back again</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, Andrew J.; Khochfar, Sadegh; Dalla Vecchia, Claudio</p> <p>2014-09-01</p> <p>We study the effect of baryons on the inner dark matter profile of the first galaxies using the First <span class="hlt">Billion</span> Years simulation between z = 16 and 6 before secular evolution sets in. Using a large statistical sample from two simulations of the same volume and cosmological initial conditions, one with and one without baryons, we are able to directly compare haloes with their baryon-free counterparts, allowing a detailed study of the modifications to the dark matter density profile due to the presence of baryons during the first <span class="hlt">billion</span> years of galaxy formation. For each of the ≈5000 haloes in our sample (3 × 107 M⊙ ≤ Mtot ≤ 5 × 109 M⊙), we quantify the impact of the baryons using η, defined as the ratio of dark matter mass enclosed in 100 pc in the baryonic run to its counterpart without baryons. During this epoch of rapid growth of galaxies, we find that many haloes of these first galaxies show an enhancement of dark matter in the halo centre compared to the baryon-free simulation, while many others show a deficit. We find that the mean value of η is close to unity, but there is a large dispersion, with a standard deviation of 0.677. The enhancement is cyclical in time and tracks the star formation cycle of the galaxy; as gas falls to the centre and forms stars, the dark matter moves in as well. Supernova (SN) feedback then removes the gas, and the dark matter again responds to the changing potential. We study three physical models relating the motion of baryons to that of the dark matter: adiabatic contraction, dynamical friction, and rapid outflows. We find that dynamical friction plays only a very minor role, while adiabatic contraction and the rapid outflows due to feedback describe well the enhancement (or decrement) of dark matter. For haloes which show significant decrements of dark matter in the core, we find that to remove the dark matter requires an energy input between 1051 and 1053 erg. For our SN feedback proscription, this requires as a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10186346','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10186346"><span id="translatedtitle"><span class="hlt">Electron</span> cooling of <span class="hlt">electron</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Larson, D.J.</p> <p>1993-09-01</p> <p><span class="hlt">Electron</span> cooling of <span class="hlt">electron</span> (and positron) sources may be important for future linear collider applications. In order to cool <span class="hlt">electrons</span> with <span class="hlt">electrons</span>, an intermediary positron beam must be employed, since it is impossible to merge two beams of identical particles into the cooling straight. By adjusting the beta functions of the <span class="hlt">electron</span> and positron lattices appropriately, the final emittance of the stored <span class="hlt">electron</span> beam can be made less than the emittance of the cooling <span class="hlt">electron</span> beam. This paper will discuss accelerator physics issues relating to an <span class="hlt">electron</span>-cooled <span class="hlt">electron</span> beam source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/accomplishments/documents/fullText/ACC0398.pdf','DOE-RDACC'); return false;" href="http://www.osti.gov/accomplishments/documents/fullText/ACC0398.pdf"><span id="translatedtitle">The Breakthrough Behind the Chevy <span class="hlt">Volt</span> Battery</span></a></p> <p><a target="_blank" href="http://www.osti.gov/accomplishments/fieldedsearch.html">DOE R&D Accomplishments Database</a></p> <p>Lerner, Louise</p> <p>2011-03-28</p> <p>A revolutionary breakthrough cathode for lithium-ion batteries—the kind in your cell phone, laptop and new hybrid cars—makes them last longer, run more safely and perform better than batteries currently on the market.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=recent+AND+work+AND+mechanical+AND+properties+AND+materials&id=EJ325533','ERIC'); return false;" href="http://eric.ed.gov/?q=recent+AND+work+AND+mechanical+AND+properties+AND+materials&id=EJ325533"><span id="translatedtitle"><span class="hlt">Electrons</span>, <span class="hlt">Electronic</span> Publishing, and <span class="hlt">Electronic</span> Display.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brownrigg, Edwin B.; Lynch, Clifford A.</p> <p>1985-01-01</p> <p>Provides a perspective on <span class="hlt">electronic</span> publishing by distinguishing between "Newtonian" publishing and "quantum-mechanical" publishing. Highlights include media and publishing, works delivered through <span class="hlt">electronic</span> media, <span class="hlt">electronic</span> publishing and the printed word, management of intellectual property, and recent copyright-law issues and their…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004NIMPA.532...19M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004NIMPA.532...19M"><span id="translatedtitle"><span class="hlt">Electron</span> cooling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meshkov, I.; Sidorin, A.</p> <p>2004-10-01</p> <p>The brief review of the most significant and interesting achievements in <span class="hlt">electron</span> cooling method, which took place during last two years, is presented. The description of the <span class="hlt">electron</span> cooling facilities-storage rings and traps being in operation or under development-is given. The applications of the <span class="hlt">electron</span> cooling method are considered. The following modern fields of the method development are discussed: crystalline beam formation, expansion into middle and high energy <span class="hlt">electron</span> cooling (the Fermilab Recycler <span class="hlt">Electron</span> Cooler, the BNL cooler-recuperator, cooling with circulating <span class="hlt">electron</span> beam, the GSI project), <span class="hlt">electron</span> cooling in traps, antihydrogen generation, <span class="hlt">electron</span> cooling of positrons (the LEPTA project).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED123060.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED123060.pdf"><span id="translatedtitle">Industrial R&D Expenditures Rise to $22 <span class="hlt">Billion</span> in 1974. Science Resources Studies Highlights, January 14, 1976.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>National Science Foundation, Washington, DC. Div. of Science Resources Studies.</p> <p></p> <p>Reported in this newsletter in narrative, graphical, and tabular form are data related to industrial research and development expenditures in 1974, showing a seven percent increase over 1973. It is noted that more than 80 percent of a total of $22.3 <span class="hlt">billion</span> was spent by five industries; these included electrical equipment and communication,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2012-05-17/pdf/2012-11989.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-05-17/pdf/2012-11989.pdf"><span id="translatedtitle">77 FR 29458 - Supervisory Guidance on Stress Testing for Banking Organizations With More Than $10 <span class="hlt">Billion</span> in...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-05-17</p> <p>... Prudential Standards and Early Remediation Requirements for Covered Companies, 77 FR 594 (Jan. 5, 2012... organizations with consolidated assets of $10 <span class="hlt">billion</span> or less. \\1\\ See 76 FR 35072 (June 15, 2011). All banking... (Pillar 2) Related to the Implementation of the Basel II Advanced Capital Framework, 73 FR 44620 (July...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27193027','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27193027"><span id="translatedtitle">Mental Disorders Top The List Of The Most Costly Conditions In The United States: $201 <span class="hlt">Billion</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roehrig, Charles</p> <p>2016-06-01</p> <p>Estimates of annual health spending for a comprehensive set of medical conditions are presented for the entire US population and with totals benchmarked to the National Health Expenditure Accounts. In 2013 mental disorders topped the list of most costly conditions, with spending at $201 <span class="hlt">billion</span>. PMID:27193027</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=pump&pg=7&id=ED509613','ERIC'); return false;" href="http://eric.ed.gov/?q=pump&pg=7&id=ED509613"><span id="translatedtitle">$100 <span class="hlt">Billion</span>: For Reform...or to Subsidize the Status Quo? Education Stimulus Watch. Special Report 1</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Smarick, Andy</p> <p>2009-01-01</p> <p>This is the first in a quarterly series of special reports on the K-12 education implications of the federal government's economic stimulus package, the American Recovery and Reinvestment Act (ARRA). That the ARRA, which was signed into law in February, will pump nearly $100 <span class="hlt">billion</span>--an unprecedented sum of federal money--into K-12 education is…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19416859','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19416859"><span id="translatedtitle">The controversial "Cambrian" fossils of the Vindhyan are real but more than a <span class="hlt">billion</span> years older.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bengtson, Stefan; Belivanova, Veneta; Rasmussen, Birger; Whitehouse, Martin</p> <p>2009-05-12</p> <p>The age of the Vindhyan sedimentary basin in central India is controversial, because geochronology indicating early Proterozoic ages clashes with reports of Cambrian fossils. We present here an integrated paleontologic-geochronologic investigation to resolve this conundrum. New sampling of Lower Vindhyan phosphoritic stromatolitic dolomites from the northern flank of the Vindhyans confirms the presence of fossils most closely resembling those found elsewhere in Cambrian deposits: annulated tubes, embryo-like globules with polygonal surface pattern, and filamentous and coccoidal microbial fabrics similar to Girvanella and Renalcis. None of the fossils, however, can be ascribed to uniquely Cambrian or Ediacaran taxa. Indeed, the embryo-like globules are not interpreted as fossils at all but as former gas bubbles trapped in mucus-rich cyanobacterial mats. Direct dating of the same fossiliferous phosphorite yielded a Pb-Pb isochron of 1,650 +/- 89 (2sigma) million years ago, confirming the Paleoproterozoic age of the fossils. New U-Pb geochronology of zircons from tuffaceous mudrocks in the Lower Vindhyan Porcellanite Formation on the southern flank of the Vindhyans give comparable ages. The Vindhyan phosphorites provide a window of 3-dimensionally preserved Paleoproterozoic fossils resembling filamentous and coccoidal cyanobacteria and filamentous eukaryotic algae, as well as problematic forms. Like Neoproterozoic phosphorites a <span class="hlt">billion</span> years later, the Vindhyan deposits offer important new insights into the nature and diversity of life, and in particular, the early evolution of multicellular eukaryotes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AIPC..845.1462G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AIPC..845.1462G"><span id="translatedtitle">Ballography: A <span class="hlt">Billion</span> Nanosecond History of the Bee Bluff Impact Crater of South Texas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graham, R. A.</p> <p>2006-07-01</p> <p>The Bee Bluff Structure of South Texas in Zavala County near Uvalde has been found to exhibit unusual features permitting study of impactites and meteorite impact processes from the standpoint of grain-level, nanosecond shock-compression science. The site is characterized by a thin cap of Carrizo Sandstone covering a thin hard Indio fm calcareous siltstone. A soft calcareous silt lies below the hard cap. Calculations based on the Earth Impact Effects web-based program indicate that the site is best described by a 60 m diameter iron meteorite striking the ground at 11 km/sec. Such an impact into sandstone is expected to produce a shock pressure of 250 GPa. A large release wave originates from the bottom of the hard target with upward moving melt-vaporization waves of solid, liquid and vapor products that become trapped at the impact interface. Numerous distinctive types of impactites result from this `bottom-up' release behavior. Evidence for hydrodynamic instabilities and resulting density gradients are abundant at the impact interface. An unusually valuable breccia sample called `The Uvalde Crater Rosetta Stone' contains at least seven types of impactites in a well defined arrangement that can be used to read the <span class="hlt">billion</span> nanosecond history of the impact and identify scattered impactites relative to their place in that history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1313070','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1313070"><span id="translatedtitle">Potentially biogenic carbon preserved in a 4.1 <span class="hlt">billion</span>-year-old zircon</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bell, Elizabeth A.; Boehnke, Patrick; Harrison, T. Mark; Mao, Wendy L.</p> <p>2015-10-19</p> <p>Here, evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ~3.5 <span class="hlt">billion</span> years (Ga), the chemofossil record arguably to ~3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ<sup>13</sup>C<sub>PDB</sub> of –24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ~300 My earlier than has been previously proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11541449','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11541449"><span id="translatedtitle">A <span class="hlt">billion</span> years of environmental stability and the emergence of eukaryotes: new data from northern Australia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brasier, M D; Lindsay, J F</p> <p>1998-06-01</p> <p>Carbon isotopes through 6km of fully cored drill holes in 1.7 to 1.5 Ga carbonates of the Mount Isa and McArthur basins, Australia (which host the earliest known eukaryote biomarkers) provide the most comprehensive and best-dated delta 13C stratigraphy yet obtained from such ancient rocks. Both basins reveal remarkably stable temporal delta 13C trends (mean of -0.6% +/- 2% PDB [Peedee belemnite]) and confirm the impression of delta 13C stasis between 2.0 and 1.0 Ga, which, together with other evidence, suggest a prolonged period of stability in crustal dynamics, redox state of surface environments, and planetary climate. This delta 13C stasis is consistent with great stability in the carbon cycle controlled, we suggest, by P limitation of primary productivity. Recent evidence shows that P depletion is a major factor in obligate associations between photosymbionts and host cells. We argue that a <span class="hlt">billion</span> years of stability in the carbon and nutrient cycles may have been the driving force that propelled prokaryotes toward photosymbiosis and the emergence of the autotrophic eukaryote cell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27386544','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27386544"><span id="translatedtitle">Rapid oxygenation of Earth's atmosphere 2.33 <span class="hlt">billion</span> years ago.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luo, Genming; Ono, Shuhei; Beukes, Nicolas J; Wang, David T; Xie, Shucheng; Summons, Roger E</p> <p>2016-05-01</p> <p>Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth's biogeochemical cycles. Although "whiffs" of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. We report the transition (that is, from being mass-independent to becoming mass-dependent) in multiple sulfur isotope signals of diagenetic pyrite in a continuous sedimentary sequence in three coeval drill cores in the Transvaal Supergroup, South Africa. These data precisely constrain the GOE to 2.33 <span class="hlt">billion</span> years ago. The new data suggest that the oxygenation occurred rapidly-within 1 to 10 million years-and was followed by a slower rise in the ocean sulfate inventory. Our data indicate that a climate perturbation predated the GOE, whereas the relationships among GOE, "Snowball Earth" glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4928975','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4928975"><span id="translatedtitle">Rapid oxygenation of Earth’s atmosphere 2.33 <span class="hlt">billion</span> years ago</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Luo, Genming; Ono, Shuhei; Beukes, Nicolas J.; Wang, David T.; Xie, Shucheng; Summons, Roger E.</p> <p>2016-01-01</p> <p>Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth’s biogeochemical cycles. Although “whiffs” of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. We report the transition (that is, from being mass-independent to becoming mass-dependent) in multiple sulfur isotope signals of diagenetic pyrite in a continuous sedimentary sequence in three coeval drill cores in the Transvaal Supergroup, South Africa. These data precisely constrain the GOE to 2.33 <span class="hlt">billion</span> years ago. The new data suggest that the oxygenation occurred rapidly—within 1 to 10 million years—and was followed by a slower rise in the ocean sulfate inventory. Our data indicate that a climate perturbation predated the GOE, whereas the relationships among GOE, “Snowball Earth” glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions. PMID:27386544</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21471478','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21471478"><span id="translatedtitle">The $17.1 <span class="hlt">billion</span> problem: the annual cost of measurable medical errors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Den Bos, Jill; Rustagi, Karan; Gray, Travis; Halford, Michael; Ziemkiewicz, Eva; Shreve, Jonathan</p> <p>2011-04-01</p> <p>At a minimum, high-quality health care is care that does not harm patients, particularly through medical errors. The first step in reducing the large number of harmful medical errors that occur today is to analyze them. We used an actuarial approach to measure the frequency and costs of measurable US medical errors, identified through medical claims data. This method focuses on the analysis of comparative rates of illness, using mathematical models to assess the risk of occurrence and to project costs to the total population. We estimate that the annual cost of measurable medical errors that harm patients was $17.1 <span class="hlt">billion</span> in 2008. Pressure ulcers were the most common measurable medical error, followed by postoperative infections and by postlaminectomy syndrome, a condition characterized by persistent pain following back surgery. A total of ten types of errors account for more than two-thirds of the total cost of errors, and these errors should be the first targets of prevention efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9071T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9071T"><span id="translatedtitle">Constraints on the first <span class="hlt">billion</span> years of the geodynamo from paleointensity studies of zircons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tarduno, John; Cottrell, Rory; Davis, William</p> <p>2014-05-01</p> <p>Several lines of reasoning, including new ideas on core thermal conductivity, suggest that onset of a strong geomagnetic field might have been delayed by one <span class="hlt">billion</span> years (or more) after the lunar forming event. Here we extend the Proterozoic/Archean to Paleoarchean record of the geomagnetic field constrained by single crystal paleointensity (SCP) analyses (Tarduno et al., Science, 2010) to older times using zircons containing minute magnetic inclusions. Specifically, we focus on samples from the Jack Hills (Yilgarn Craton, Western Australia). We employ a CO2 laser demagnetization system and a small bore (6.3 mm) 3-component DC SQUID magnetometer; the latter offers the highest currently available moment resolution. Sample age is analyzed using SHRIMP U-Pb geochronology. Preliminary data support the presence of a relatively strong Paleoarchean field produced by a core dynamo, extending the known record by at least 100 million years, to approximately 3.55 Ga. These data only serve to exacerbate the apparent problem posed by the presence of a Paleoarchean dynamo. Alternative dynamo driving mechanisms, or efficient core/lowermost mantle heat loss processes unique to the Paleoarchean (and older times) might have been at work. We will discuss these processes, and our efforts to study even older Eoarchean-Hadean zircons.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/815500','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/815500"><span id="translatedtitle">Providing safe drinking water to 1.2 <span class="hlt">billion</span> unserved people</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gadgil, Ashok J.; Derby, Elisabeth A.</p> <p>2003-06-01</p> <p>Despite substantial advances in the past 100 years in public health, technology and medicine, 20% of the world population, mostly comprised of the poor population segments in developing countries (DCs), still does not have access to safe drinking water. To reach the United Nations (UN) Millennium Goal of halving the number of people without access to safe water by 2015, the global community will need to provide an additional one <span class="hlt">billion</span> urban residents and 600 million rural residents with safe water within the next twelve years. This paper examines current water treatment measures and implementation methods for delivery of safe drinking water, and offers suggestions for making progress towards the goal of providing a timely and equitable solution for safe water provision. For water treatment, based on the serious limitations of boiling water and chlorination, we suggest an approach based on filtration coupled with ultraviolet (UV) disinfection, combined with public education. Additionally, owing to the capacity limitations for non-governmental organizations (NGOs) to take on this task primarily on their own, we suggest a strategy based on financially sustainable models that include the private sector as well as NGOs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017418','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017418"><span id="translatedtitle">A Massive Galaxy in Its Core Formation Phase Three <span class="hlt">Billion</span> Years After the Big Bang</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelson, Erica; van Dokkum, Pieter; Franx, Marijn; Brammer, Gabriel; Momcheva, Ivelina; Schreiber, Natascha M. Forster; da Cunha, Elisabete; Tacconi, Linda; Bezanson, Rachel; Kirkpatrick, Allison; Leja, Joel; Rix, Hans-Walter; Skelton, Rosalind; van der Wel, Arjen; Whitaker, Katherine; Wuyts, Stijn</p> <p>2014-01-01</p> <p>Most massive galaxies are thought to have formed their dense stellar cores at early cosmic epochs. However, cores in their formation phase have not yet been observed. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we present a candidate core in formation 11 <span class="hlt">billion</span> years ago, at z = 2.3. GOODS-N-774 has a stellar mass of 1.0 × 10 (exp 11) solar mass, a half-light radius of 1.0 kpc, and a star formation rate of 90 (sup +45 / sub -20) solar mass/yr. The star forming gas has a velocity dispersion 317 plus or minus 30 km/s, amongst the highest ever measured. It is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, compact quiescent galaxies at z is approximately equal to 2 (exp 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 appear to be rare; however, from the star formation rate and size of the galaxy we infer that many star forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998Geo....26..555B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998Geo....26..555B"><span id="translatedtitle">A <span class="hlt">billion</span> years of environmental stability and the emergence of eukaryotes: New data from northern Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brasier, M. D.; Lindsay, J. F.</p> <p>1998-06-01</p> <p>Carbon isotopes through 6 km of fully cored drill holes in 1.7 to 1.5 Ga carbonates of the Mount Isa and McArthur basins, Australia (which host the earliest known eukaryote biomarkers) provide the most comprehensive and best-dated δ13C stratigraphy yet obtained from such ancient rocks. Both basins reveal remarkably stable temporal δ13C trends (mean of -0.6‰ ± 2‰ PDB [Peedee belemnite]) and confirm the impression of δ13C stasis between 2.0 and 1.0 Ga, which, together with other evidence, suggest a prolonged period of stability in crustal dynamics, redox state of surface environments, and planetary climate. This δ13C stasis is consistent with great stability in the carbon cycle controlled, we suggest, by P limitation of primary productivity. Recent evidence shows that P depletion is a major factor in obligate associations between photosymbionts and host cells. We argue that a <span class="hlt">billion</span> years of stability in the carbon and nutrient cycles may have been the driving force that propelled prokaryotes toward photosymbiosis and the emergence of the autotrophic eukaryote cell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25068404','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25068404"><span id="translatedtitle">Enhanced cellular preservation by clay minerals in 1 <span class="hlt">billion</span>-year-old lakes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wacey, David; Saunders, Martin; Roberts, Malcolm; Menon, Sarath; Green, Leonard; Kong, Charlie; Culwick, Timothy; Strother, Paul; Brasier, Martin D</p> <p>2014-07-28</p> <p>Organic-walled microfossils provide the best insights into the composition and evolution of the biosphere through the first 80 percent of Earth history. The mechanism of microfossil preservation affects the quality of biological information retained and informs understanding of early Earth palaeo-environments. We here show that 1 <span class="hlt">billion</span>-year-old microfossils from the non-marine Torridon Group are remarkably preserved by a combination of clay minerals and phosphate, with clay minerals providing the highest fidelity of preservation. Fe-rich clay mostly occurs in narrow zones in contact with cellular material and is interpreted as an early microbially-mediated phase enclosing and replacing the most labile biological material. K-rich clay occurs within and exterior to cell envelopes, forming where the supply of Fe had been exhausted. Clay minerals inter-finger with calcium phosphate that co-precipitated with the clays in the sub-oxic zone of the lake sediments. This type of preservation was favoured in sulfate-poor environments where Fe-silicate precipitation could outcompete Fe-sulfide formation. This work shows that clay minerals can provide an exceptionally high fidelity of microfossil preservation and extends the known geological range of this fossilization style by almost 500 Ma. It also suggests that the best-preserved microfossils of this time may be found in low-sulfate environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatGe...7..283P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatGe...7..283P"><span id="translatedtitle">Evidence for oxygenic photosynthesis half a <span class="hlt">billion</span> years before the Great Oxidation Event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Planavsky, Noah J.; Asael, Dan; Hofmann, Axel; Reinhard, Christopher T.; Lalonde, Stefan V.; Knudsen, Andrew; Wang, Xiangli; Ossa Ossa, Frantz; Pecoits, Ernesto; Smith, Albertus J. B.; Beukes, Nicolas J.; Bekker, Andrey; Johnson, Thomas M.; Konhauser, Kurt O.; Lyons, Timothy W.; Rouxel, Olivier J.</p> <p>2014-04-01</p> <p>The early Earth was characterized by the absence of oxygen in the ocean-atmosphere system, in contrast to the well-oxygenated conditions that prevail today. Atmospheric concentrations first rose to appreciable levels during the Great Oxidation Event, roughly 2.5-2.3 Gyr ago. The evolution of oxygenic photosynthesis is generally accepted to have been the ultimate cause of this rise, but it has proved difficult to constrain the timing of this evolutionary innovation. The oxidation of manganese in the water column requires substantial free oxygen concentrations, and thus any indication that Mn oxides were present in ancient environments would imply that oxygenic photosynthesis was ongoing. Mn oxides are not commonly preserved in ancient rocks, but there is a large fractionation of molybdenum isotopes associated with the sorption of Mo onto the Mn oxides that would be retained. Here we report Mo isotopes from rocks of the Sinqeni Formation, Pongola Supergroup, South Africa. These rocks formed no less than 2.95 Gyr ago in a nearshore setting. The Mo isotopic signature is consistent with interaction with Mn oxides. We therefore infer that oxygen produced through oxygenic photosynthesis began to accumulate in shallow marine settings at least half a <span class="hlt">billion</span> years before the accumulation of significant levels of atmospheric oxygen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010JAESc..39..483M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010JAESc..39..483M&link_type=ABSTRACT"><span id="translatedtitle">Precambrian crustal evolution of Peninsular India: A 3.0 <span class="hlt">billion</span> year odyssey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meert, Joseph G.; Pandit, Manoj K.; Pradhan, Vimal R.; Banks, Jonathan; Sirianni, Robert; Stroud, Misty; Newstead, Brittany; Gifford, Jennifer</p> <p>2010-11-01</p> <p>The Precambrian geologic history of Peninsular India covers nearly 3.0 <span class="hlt">billion</span> years of time. India is presently attached to the Eurasian continent although it remains (for now) a separate plate. It comprises several cratonic nuclei namely, Aravalli-Bundelkhand, Eastern Dharwar, Western Dharwar, Bastar and Singhbhum Cratons along with the Southern Granulite Province. Cratonization of India was polyphase, but a stable configuration between the major elements was largely complete by 2.5 Ga. Each of the major cratons was intruded by various age granitoids, mafic dykes and ultramafic bodies throughout the Proterozoic. The Vindhyan, Chhattisgarh, Cuddapah, Pranhita-Godavari, Indravati, Bhima-Kaladgi, Kurnool and Marwar basins are the major Meso to Neoproterozoic sedimentary repositories. In this paper we review the major tectonic and igneous events that led to the formation of Peninsular India and provide an up to date geochronologic summary of the Precambrian. India is thought to have played a role in a number of supercontinental cycles including (from oldest to youngest) Ur, Columbia, Rodinia, Gondwana and Pangea. This paper gives an overview of the deep history of Peninsular India as an introduction to this special TOIS volume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12342936','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12342936"><span id="translatedtitle">Broadcasts for a <span class="hlt">billion</span>: the growth of commercial television in China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmuck, C</p> <p>1987-01-01</p> <p>At present, Chinese television reaches 35% of the population (80-90% in urban areas) and is used by the government as a source of education and information. In recognition of the potential market represented by 1.1 <span class="hlt">billions</span> consumers, Western advertisers have commissioned elaborate market research studies. Drama, sports, news, and movies are consistently identified as the favorite type of programming among Chinese television viewers. About 75% of Beijing adults watch television daily, making the medium both an important target for advertising campaigns and a way for Westerners to influence Chinese business and government leaders. Western advertisers have tended to concentrate their investments in the more urban, affluent regions where products have the greatest likelihood of being sold. There has been a recent trend, however, toward industrial commercials, with British and French companies buying television time to promote their image as partners in China's modernization. Key to the future of commercial advertising on Chinese Television. In many provinces, local television stations have developed a unique character and portray different sociocultural values than the national channel. Outside advertisers have sometimes experienced problems with local networks that substitute local advertising without informing the network. To correct this situation, the government is enacting pro-sponsor regulations that forbid the preemption of the national channel and its advertisements. At the same time, efforts are being made to improve relationships with local television stations by either paying them a fee or airing local commercials on the national network. PMID:12342936</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26483481','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26483481"><span id="translatedtitle">Potentially biogenic carbon preserved in a 4.1 <span class="hlt">billion</span>-year-old zircon.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bell, Elizabeth A; Boehnke, Patrick; Harrison, T Mark; Mao, Wendy L</p> <p>2015-11-24</p> <p>Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼ 3.5 <span class="hlt">billion</span> years (Ga), the chemofossil record arguably to ∼ 3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ(13)CPDB of -24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼ 300 My earlier than has been previously proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19581586','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19581586"><span id="translatedtitle">Sharing global CO2 emission reductions among one <span class="hlt">billion</span> high emitters.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chakravarty, Shoibal; Chikkatur, Ananth; de Coninck, Heleen; Pacala, Stephen; Socolow, Robert; Tavoni, Massimo</p> <p>2009-07-21</p> <p>We present a framework for allocating a global carbon reduction target among nations, in which the concept of "common but differentiated responsibilities" refers to the emissions of individuals instead of nations. We use the income distribution of a country to estimate how its fossil fuel CO(2) emissions are distributed among its citizens, from which we build up a global CO(2) distribution. We then propose a simple rule to derive a universal cap on global individual emissions and find corresponding limits on national aggregate emissions from this cap. All of the world's high CO(2)-emitting individuals are treated the same, regardless of where they live. Any future global emission goal (target and time frame) can be converted into national reduction targets, which are determined by "Business as Usual" projections of national carbon emissions and in-country income distributions. For example, reducing projected global emissions in 2030 by 13 GtCO(2) would require the engagement of 1.13 <span class="hlt">billion</span> high emitters, roughly equally distributed in 4 regions: the U.S., the OECD minus the U.S., China, and the non-OECD minus China. We also modify our methodology to place a floor on emissions of the world's lowest CO(2) emitters and demonstrate that climate mitigation and alleviation of extreme poverty are largely decoupled.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9118E..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9118E..02D"><span id="translatedtitle">Large data analysis: automatic visual personal identification in a demography of 1.2 <span class="hlt">billion</span> persons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Daugman, John</p> <p>2014-05-01</p> <p>The largest biometric deployment in history is now underway in India, where the Government is enrolling the iris patterns (among other data) of all 1.2 <span class="hlt">billion</span> citizens. The purpose of the Unique Identification Authority of India (UIDAI) is to ensure fair access to welfare benefits and entitlements, to reduce fraud, and enhance social inclusion. Only a minority of Indian citizens have bank accounts; only 4 percent possess passports; and less than half of all aid money reaches its intended recipients. A person who lacks any means of establishing their identity is excluded from entitlements and does not officially exist; thus the slogan of UIDAI is: To give the poor an identity." This ambitious program enrolls a million people every day, across 36,000 stations run by 83 agencies, with a 3-year completion target for the entire national population. The halfway point was recently passed with more than 600 million persons now enrolled. In order to detect and prevent duplicate identities, every iris pattern that is enrolled is first compared against all others enrolled so far; thus the daily workflow now requires 600 trillion (or 600 million-million) iris cross-comparisons. Avoiding identity collisions (False Matches) requires high biometric entropy, and achieving the tremendous match speed requires phase bit coding. Both of these requirements are being delivered operationally by wavelet methods developed by the author for encoding and comparing iris patterns, which will be the focus of this Large Data Award" presentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26483481','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26483481"><span id="translatedtitle">Potentially biogenic carbon preserved in a 4.1 <span class="hlt">billion</span>-year-old zircon.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bell, Elizabeth A; Boehnke, Patrick; Harrison, T Mark; Mao, Wendy L</p> <p>2015-11-24</p> <p>Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼ 3.5 <span class="hlt">billion</span> years (Ga), the chemofossil record arguably to ∼ 3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ(13)CPDB of -24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼ 300 My earlier than has been previously proposed. PMID:26483481</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NatSR...4E5841W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NatSR...4E5841W&link_type=ABSTRACT"><span id="translatedtitle">Enhanced cellular preservation by clay minerals in 1 <span class="hlt">billion</span>-year-old lakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wacey, David; Saunders, Martin; Roberts, Malcolm; Menon, Sarath; Green, Leonard; Kong, Charlie; Culwick, Timothy; Strother, Paul; Brasier, Martin D.</p> <p>2014-07-01</p> <p>Organic-walled microfossils provide the best insights into the composition and evolution of the biosphere through the first 80 percent of Earth history. The mechanism of microfossil preservation affects the quality of biological information retained and informs understanding of early Earth palaeo-environments. We here show that 1 <span class="hlt">billion</span>-year-old microfossils from the non-marine Torridon Group are remarkably preserved by a combination of clay minerals and phosphate, with clay minerals providing the highest fidelity of preservation. Fe-rich clay mostly occurs in narrow zones in contact with cellular material and is interpreted as an early microbially-mediated phase enclosing and replacing the most labile biological material. K-rich clay occurs within and exterior to cell envelopes, forming where the supply of Fe had been exhausted. Clay minerals inter-finger with calcium phosphate that co-precipitated with the clays in the sub-oxic zone of the lake sediments. This type of preservation was favoured in sulfate-poor environments where Fe-silicate precipitation could outcompete Fe-sulfide formation. This work shows that clay minerals can provide an exceptionally high fidelity of microfossil preservation and extends the known geological range of this fossilization style by almost 500 Ma. It also suggests that the best-preserved microfossils of this time may be found in low-sulfate environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4664351','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4664351"><span id="translatedtitle">Potentially biogenic carbon preserved in a 4.1 <span class="hlt">billion</span>-year-old zircon</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bell, Elizabeth A.; Harrison, T. Mark; Mao, Wendy L.</p> <p>2015-01-01</p> <p>Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼3.5 <span class="hlt">billion</span> years (Ga), the chemofossil record arguably to ∼3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ13CPDB of −24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼300 My earlier than has been previously proposed. PMID:26483481</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RaPC..116...43T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RaPC..116...43T"><span id="translatedtitle">Analysis of precious metals at parts-per-<span class="hlt">billion</span> levels in industrial applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tickner, James; O'Dwyer, Joel; Roach, Greg; Smith, Michael; Van Haarlem, Yves</p> <p>2015-11-01</p> <p>Precious metals, including gold and the platinum group metals (notable Pt, Pd and Rh), are mined commercially at concentrations of a few parts-per-million and below. Mining and processing operations demand sensitive and rapid analysis at concentrations down to about 100 parts-per-<span class="hlt">billion</span> (ppb). In this paper, we discuss two technologies being developed to meet this challenge: X-ray fluorescence (XRF) and gamma-activation analysis (GAA). We have designed on-stream XRF analysers capable of measuring targeted elements in slurries with precisions in the 35-70 ppb range. For the past two years, two on-stream analysers have been in continuous operation at a precious metals concentrator plant. The simultaneous measurement of feed and waste stream grades provides real-time information on metal recovery, allowing changes in operating conditions and plant upsets to be detected and corrected more rapidly. Separately, we have been developing GAA for the measurement of gold as a replacement for the traditional laboratory fire-assay process. High-energy Bremsstrahlung X-rays are used to excite gold via the 197Au(γ,γ‧)197Au-M reaction, and the gamma-rays released in the decay of the meta-state are then counted. We report on work to significantly improve accuracy and detection limits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Natur.506..355L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Natur.506..355L"><span id="translatedtitle">Prodigious degassing of a <span class="hlt">billion</span> years of accumulated radiogenic helium at Yellowstone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lowenstern, J. B.; Evans, W. C.; Bergfeld, D.; Hunt, A. G.</p> <p>2014-02-01</p> <p>Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 <span class="hlt">billion</span> years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24553240','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24553240"><span id="translatedtitle">Prodigious degassing of a <span class="hlt">billion</span> years of accumulated radiogenic helium at Yellowstone.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lowenstern, J B; Evans, W C; Bergfeld, D; Hunt, A G</p> <p>2014-02-20</p> <p>Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 <span class="hlt">billion</span> years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27386544','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27386544"><span id="translatedtitle">Rapid oxygenation of Earth's atmosphere 2.33 <span class="hlt">billion</span> years ago.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luo, Genming; Ono, Shuhei; Beukes, Nicolas J; Wang, David T; Xie, Shucheng; Summons, Roger E</p> <p>2016-05-01</p> <p>Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth's biogeochemical cycles. Although "whiffs" of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. We report the transition (that is, from being mass-independent to becoming mass-dependent) in multiple sulfur isotope signals of diagenetic pyrite in a continuous sedimentary sequence in three coeval drill cores in the Transvaal Supergroup, South Africa. These data precisely constrain the GOE to 2.33 <span class="hlt">billion</span> years ago. The new data suggest that the oxygenation occurred rapidly-within 1 to 10 million years-and was followed by a slower rise in the ocean sulfate inventory. Our data indicate that a climate perturbation predated the GOE, whereas the relationships among GOE, "Snowball Earth" glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions. PMID:27386544</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25068404','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25068404"><span id="translatedtitle">Enhanced cellular preservation by clay minerals in 1 <span class="hlt">billion</span>-year-old lakes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wacey, David; Saunders, Martin; Roberts, Malcolm; Menon, Sarath; Green, Leonard; Kong, Charlie; Culwick, Timothy; Strother, Paul; Brasier, Martin D</p> <p>2014-01-01</p> <p>Organic-walled microfossils provide the best insights into the composition and evolution of the biosphere through the first 80 percent of Earth history. The mechanism of microfossil preservation affects the quality of biological information retained and informs understanding of early Earth palaeo-environments. We here show that 1 <span class="hlt">billion</span>-year-old microfossils from the non-marine Torridon Group are remarkably preserved by a combination of clay minerals and phosphate, with clay minerals providing the highest fidelity of preservation. Fe-rich clay mostly occurs in narrow zones in contact with cellular material and is interpreted as an early microbially-mediated phase enclosing and replacing the most labile biological material. K-rich clay occurs within and exterior to cell envelopes, forming where the supply of Fe had been exhausted. Clay minerals inter-finger with calcium phosphate that co-precipitated with the clays in the sub-oxic zone of the lake sediments. This type of preservation was favoured in sulfate-poor environments where Fe-silicate precipitation could outcompete Fe-sulfide formation. This work shows that clay minerals can provide an exceptionally high fidelity of microfossil preservation and extends the known geological range of this fossilization style by almost 500 Ma. It also suggests that the best-preserved microfossils of this time may be found in low-sulfate environments. PMID:25068404</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20334437','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20334437"><span id="translatedtitle">Rapid analysis of perchlorate in drinking water at parts per <span class="hlt">billion</span> levels using microchip electrophoresis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gertsch, Jana C; Noblitt, Scott D; Cropek, Donald M; Henry, Charles S</p> <p>2010-05-01</p> <p>A microchip capillary electrophoresis (MCE) system has been developed for the determination of perchlorate in drinking water. The United States Environmental Protection Agency (USEPA) recently proposed a health advisory limit for perchlorate in drinking water of 15 parts per <span class="hlt">billion</span> (ppb), a level requiring large, sophisticated instrumentation, such as ion chromatography coupled with mass spectrometry (IC-MS), for detection. An inexpensive, portable system is desired for routine online monitoring applications of perchlorate in drinking water. Here, we present an MCE method using contact conductivity detection for perchlorate determination. The method has several advantages, including reduced analysis times relative to IC, inherent portability, high selectivity, and minimal sample pretreatment. Resolution of perchlorate from more abundant ions was achieved using zwitterionic, sulfobetaine surfactants, N-hexadecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (HDAPS) and N-tetradecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (TDAPS). The system performance and the optimization of the separation chemistry, including the use of these surfactants to resolve perchlorate from other anions, are discussed in this work. The system is capable of detection limits of 3.4 +/- 1.8 ppb (n = 6) in standards and 5.6 +/- 1.7 ppb (n = 6) in drinking water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24553240','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24553240"><span id="translatedtitle">Prodigious degassing of a <span class="hlt">billion</span> years of accumulated radiogenic helium at Yellowstone.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lowenstern, J B; Evans, W C; Bergfeld, D; Hunt, A G</p> <p>2014-02-20</p> <p>Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 <span class="hlt">billion</span> years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions. PMID:24553240</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1313070-potentially-biogenic-carbon-preserved-billion-year-old-zircon','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1313070-potentially-biogenic-carbon-preserved-billion-year-old-zircon"><span id="translatedtitle">Potentially biogenic carbon preserved in a 4.1 <span class="hlt">billion</span>-year-old zircon</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bell, Elizabeth A.; Boehnke, Patrick; Harrison, T. Mark; Mao, Wendy L.</p> <p>2015-10-19</p> <p>Here, evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ~3.5 <span class="hlt">billion</span> years (Ga), the chemofossil record arguably to ~3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in amore » crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ13CPDB of –24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ~300 My earlier than has been previously proposed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70058458','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70058458"><span id="translatedtitle">Prodigious degassing of a <span class="hlt">billion</span> years of accumulated radiogenic helium at Yellowstone</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lowenstern, Jacob B.; Evans, William C.; Bergfeld, D.; Hunt, Andrew G.</p> <p>2014-01-01</p> <p>Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents1. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot2. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 <span class="hlt">billion</span> years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..GECCT1025M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..GECCT1025M"><span id="translatedtitle">Glow Discharge with Confinement of <span class="hlt">Electrons</span> in an Electrostatic Trap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Metel, Alexander</p> <p>2013-09-01</p> <p>Theory based on the concept of the gas ionization cost W is found to be in a good agreement with experimental study of the glow discharge with electrostatic trap in the gas pressure range 0.001-10 Pa. When the mean ionization length λ of emitted by the cathode <span class="hlt">electrons</span> exceeds the trap width a = 4 V/ S, where Vis the trap volume and S is area of the trap boundary, and their energy relaxation length Λ = (eUc/ W) λ , where Uc is cathode fall of potential, is lower than the trap length L = 4 V/So, where So is output aperture of the trap, Uc is independent of the pressure p. In this middle pressure range due to multiplication of fast <span class="hlt">electrons</span> in the cathode sheath Uc diminishes about 2 times from its maximum W/e γ, where γ is coefficient of ion-induced <span class="hlt">electron</span> emission, with the discharge current reduction. At Λ > L the cathode fall Uc rises from hundreds to thousands of <span class="hlt">volts</span> and p tends to the discharge extinction pressure pex, at which the ionization length λ of <span class="hlt">electrons</span> with energy equal to the energy of <span class="hlt">electrons</span> emitted by the cathode in the middle pressure range is equal to L.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ApPhL..96l1501H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..96l1501H"><span id="translatedtitle"><span class="hlt">Electron</span> energy boosting in laser-wake-field acceleration with external magnetic field B˜1 T and laser prepulses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hosokai, Tomonao; Zhidkov, Alexei; Yamazaki, Atsushi; Mizuta, Yoshio; Uesaka, Mitsuru; Kodama, Ryosuke</p> <p>2010-03-01</p> <p>Hundred-mega-<span class="hlt">electron-volt</span> <span class="hlt">electron</span> beams with quasi-monoenergetic distribution, and a transverse geometrical emittance as small as ˜0.02 π mm mrad are generated by low power (7 TW, 45 fs) laser pulses tightly focused in helium gas jets in an external static magnetic field, B˜1 T. Generation of monoenergetic beams strongly correlates with appearance of a straight, at least 2 mm length plasma channel in a short time before the main laser pulse and with the energy of copropagating picosecond pedestal pulses (PPP). For a moderate energy PPP, the multiple or staged <span class="hlt">electron</span> self-injection in the channel gives several narrow peaks in the <span class="hlt">electron</span> energy distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......434B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......434B"><span id="translatedtitle">Ten <span class="hlt">Billion</span> Years of Growth: Massive Galaxy Evolution from Structures and Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bezanson, Rachel</p> <p></p> <p>Once thought to be relies of a much earlier epoch, the most massive local galaxies are red and dead ellipticals, with little ongoing star formation or organized rotation. In the last decade, observations of their assumed progenitors have demonstrated that <span class="hlt">billions</span> of years ago, massive galaxies were more compact and morphologically different, possibly with more disklike structures. The details of this observed evolution can place constraints on the physical processes that have driven massive galaxy evolution through cosmic time. The work presented in this thesis provides observational constraints on the dynamical and structural evolution of massive galaxies since z ~ 1.5 - 2 using a variety of photometric and spectroscopic surveys, including OBEY, SDSS, NMBS, and UDS. First, we find that although overall densities of these galaxies have decreased with time, the central densities of massive galaxies at high and low redshifts, are quite similar. This suggests that massive galaxies grow "inside-out": compact cores form early and then gradually build a more diffuse envelope of stars in their outskirts. Balancing the need for efficient size growth and consistent number densities of progenitor and descendent galaxies, we conclude that minor-merging is the best physical explanation for the observed size evolution. The remainder of this dissertation focuses on the inferred and measured dynamical evolution of massive galaxies since z ~ 2. Using velocity dispersions inferred by galaxy stellar masses and morphologies, we find that the number density of galaxies at a given velocity dispersion, or velocity dispersion function , is quite stable with redshift since z ~ 1.5, with a weak evolution at the low dispersion end due to a growing population of quenched galaxies. The constancy provides evidence in favor of inside-out growth of galaxies and is consistent with theoretical predictions that the central potentials of massive galaxies are set early. We suggest a toy model that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Natur.525..496N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Natur.525..496N"><span id="translatedtitle">The formation of submillimetre-bright galaxies from gas infall over a <span class="hlt">billion</span> years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Narayanan, Desika; Turk, Matthew; Feldmann, Robert; Robitaille, Thomas; Hopkins, Philip; Thompson, Robert; Hayward, Christopher; Ball, David; Faucher-Giguère, Claude-André; Kereš, Dušan</p> <p>2015-09-01</p> <p>Submillimetre-bright galaxies at high redshift are the most luminous, heavily star-forming galaxies in the Universe and are characterized by prodigious emission in the far-infrared, with a flux of at least five millijanskys at a wavelength of 850 micrometres. They reside in haloes with masses about 1013 times that of the Sun, have low gas fractions compared to main-sequence disks at a comparable redshift, trace complex environments and are not easily observable at optical wavelengths. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy that simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter haloes have increasing rates of star formation that peak at collective rates of about 500-1,000 solar masses per year at redshifts of two to three, by which time the interstellar medium is sufficiently enriched with metals that the region may be observed as a submillimetre-selected system. The intense star formation rates are fuelled in part by the infall of a reservoir gas supply enabled by stellar feedback at earlier times, not through major mergers. With a lifetime of nearly a <span class="hlt">billion</span> years, our simulations show that the submillimetre-bright phase of high-redshift galaxies is prolonged and associated with significant mass buildup in early-Universe proto-clusters, and that many submillimetre-bright galaxies are composed of numerous unresolved components (for which there is some observational evidence).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014hitr.confE..58V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014hitr.confE..58V"><span id="translatedtitle">No Photon Left Behind: How <span class="hlt">Billions</span> of Spectral Lines are Transforming Planetary Sciences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villanueva, Geronimo L.</p> <p>2014-06-01</p> <p>With the advent of realistic potential energy surface (PES) and dipole moment surface (DMS) descriptions, theoretically computed linelists can now synthesize accurate spectral parameters for <span class="hlt">billions</span> of spectral lines sampling the untamed high-energy molecular domain. Being the initial driver for these databases the characterization of stellar spectra, these theoretical databases, in combination with decades of precise experimental studies (nicely compiled in community databases such as HITRAN and GEISA), are leading to unprecedented precisions in the characterization of planetary atmospheres. Cometary sciences are among the most affected by this spectroscopic revolution. Even though comets are relatively cold bodies (T˜100 K), their infrared molecular emission is mainly defined by non-LTE solar fluorescence induced by a high-energy source (Sun, T˜5600 K). In order to interpret high-resolution spectra of comets acquired with extremely powerful telescopes (e.g., Keck, VLT, NASA-IRTF), we have developed advanced non-LTE fluorescence models that integrate the high-energy dynamic range of ab-initio databases (e.g., BT2, VTT, HPT2, BYTe, TROVE) and the precision of laboratory and semi-empirical compilations (e.g., HITRAN, GEISA, CDMS, WKMC, SELP, IUPAC). These new models allow us to calculate realistic non-LTE pumps, cascades, branching-ratios, and emission rates for a broad range of excitation regimes for H2O, HDO, HCN, HNC and NH3. We have implemented elements of these compilations to the study of Mars spectra, and we are now exploring its application to modeling non-LTE emission in exoplanets. In this presentation, we present application of these advanced models to interpret highresolution spectra of comets, Mars and exoplanets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012E%26PSL.355..144M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012E%26PSL.355..144M"><span id="translatedtitle">A sawtooth-like timeline for the first <span class="hlt">billion</span> years of lunar bombardment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morbidelli, A.; Marchi, S.; Bottke, W. F.; Kring, D. A.</p> <p>2012-11-01</p> <p>We revisit the early evolution of the Moon's bombardment. Our work combines modeling (based on plausible projectile sources and their dynamical decay rates) with constraints from the lunar crater record, radiometric ages of the youngest lunar basins, and the abundance of highly siderophile elements in the lunar crust and mantle. We deduce that the evolution of the impact flux did not decline exponentially over the first <span class="hlt">billion</span> years of lunar history, but also there was no prominent and narrow impact spike ˜3.9Gy ago, unlike that typically envisioned in the lunar cataclysm scenario. Instead, we show the timeline of the lunar bombardment has a sawtooth-like profile, with an uptick in the impact flux near ˜4.1Gy ago. The impact flux at the beginning of this weaker cataclysm was 5-10 times higher than the immediately preceding period. The Nectaris basin should have been one of the first basins formed at the sawtooth. We predict the bombardment rate since ˜4.1Gy ago declined slowly and adhered relatively close to classic crater chronology models (Neukum and Ivanov, 1994). Overall we expect that the sawtooth event accounted for about one-fourth of the total bombardment suffered by the Moon since its formation. Consequently, considering that ˜12-14 basins formed during the sawtooth event, we expect that the net number of basins formed on the Moon was ˜45-50. From our expected bombardment timeline, we derived a new and improved lunar chronology suitable for use on pre-Nectarian surface units. According to this chronology, a significant portion of the oldest lunar cratered terrains has an age of 4.38-4.42 Gyr. Moreover, the largest lunar basin, South Pole Aitken, is older than 4.3 Gy, and therefore was not produced during the lunar cataclysm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AstBu..71...24A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AstBu..71...24A"><span id="translatedtitle">Searching for the birthplaces of open clusters with ages of several <span class="hlt">billion</span> years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Acharova, I. A.; Shevtsova, E. S.</p> <p>2016-01-01</p> <p>We discuss the possibility of finding the birthplaces of open clusters (OC) with ages of several <span class="hlt">billion</span> years. The proposed method is based on the comparison of the results of the chemical evolution modeling of the Galactic disk with the parameters of the cluster. Five OCs older than 7 Gyr are known: NGC6791, BH176, Collinder 261, Berkeley 17, and Berkeley 39. The oxygen and iron abundances in NGC6791 and the oxygen abundance in BH176 are twice the solar level, the heavy-element abundances in other clusters are close to the corresponding solar values. According to chemical evolution models, at the time of the formation of the objects considered the regions where the oxygen and iron abundances reached the corresponding levels extended out to 5 kpc from the Galactic center.At present time theOCs considered are located several kpc from the Galactic center. Some of these clusters are located extremely high, about 1 kpc above the disk midplane, i.e., they have been subject to some mechanism that has carried them into orbits uncharacteristic of this type of objects. It follows from a comparison with the results of chemical evolution that younger clusters with ages of 4-5 Gyr, e.g., NGC1193,M67, and others, may have formed in a broad range of Galactocentric distances. Their large heights above the disk midplane is sufficient to suggest that these clusters have moved away from their likely birthplaces. Clusters are carried far away from the Galactic disk until the present time: about 40 clusters with ages from 0 to 2 Gyr are observed at heights ranging from 300 to 750 pc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24950200','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24950200"><span id="translatedtitle">A highly functional synthetic phage display library containing over 40 <span class="hlt">billion</span> human antibody clones.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weber, Marcel; Bujak, Emil; Putelli, Alessia; Villa, Alessandra; Matasci, Mattia; Gualandi, Laura; Hemmerle, Teresa; Wulhfard, Sarah; Neri, Dario</p> <p>2014-01-01</p> <p>Several synthetic antibody phage display libraries have been created and used for the isolation of human monoclonal antibodies. The performance of antibody libraries, which is usually measured in terms of their ability to yield high-affinity binding specificities against target proteins of interest, depends both on technical aspects (such as library size and quality of cloning) and on design features (which influence the percentage of functional clones in the library and their ability to be used for practical applications). Here, we describe the design, construction and characterization of a combinatorial phage display library, comprising over 40 <span class="hlt">billion</span> human antibody clones in single-chain fragment variable (scFv) format. The library was designed with the aim to obtain highly stable antibody clones, which can be affinity-purified on protein A supports, even when used in scFv format. The library was found to be highly functional, as >90% of randomly selected clones expressed the corresponding antibody. When selected against more than 15 antigens from various sources, the library always yielded specific and potent binders, at a higher frequency compared to previous antibody libraries. To demonstrate library performance in practical biomedical research projects, we isolated the human antibody G5, which reacts both against human and murine forms of the alternatively spliced BCD segment of tenascin-C, an extracellular matrix component frequently over-expressed in cancer and in chronic inflammation. The new library represents a useful source of binding specificities, both for academic research and for the development of antibody-based therapeutics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26399829','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26399829"><span id="translatedtitle">The formation of submillimetre-bright galaxies from gas infall over a <span class="hlt">billion</span> years.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Narayanan, Desika; Turk, Matthew; Feldmann, Robert; Robitaille, Thomas; Hopkins, Philip; Thompson, Robert; Hayward, Christopher; Ball, David; Faucher-Giguère, Claude-André; Kereš, Dušan</p> <p>2015-09-24</p> <p>Submillimetre-bright galaxies at high redshift are the most luminous, heavily star-forming galaxies in the Universe and are characterized by prodigious emission in the far-infrared, with a flux of at least five millijanskys at a wavelength of 850 micrometres. They reside in haloes with masses about 10(13) times that of the Sun, have low gas fractions compared to main-sequence disks at a comparable redshift, trace complex environments and are not easily observable at optical wavelengths. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy that simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter haloes have increasing rates of star formation that peak at collective rates of about 500-1,000 solar masses per year at redshifts of two to three, by which time the interstellar medium is sufficiently enriched with metals that the region may be observed as a submillimetre-selected system. The intense star formation rates are fuelled in part by the infall of a reservoir gas supply enabled by stellar feedback at earlier times, not through major mergers. With a lifetime of nearly a <span class="hlt">billion</span> years, our simulations show that the submillimetre-bright phase of high-redshift galaxies is prolonged and associated with significant mass buildup in early-Universe proto-clusters, and that many submillimetre-bright galaxies are composed of numerous unresolved components (for which there is some observational evidence).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8701E..0MM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8701E..0MM"><span id="translatedtitle">Layout finishing of a 28nm, 3 <span class="hlt">billions</span> transistors, multi-core processor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morey-Chaisemartin, Philippe; Beisser, Eric</p> <p>2013-06-01</p> <p>Designing a fully new 256 cores processor is a great challenge for a fabless startup. In addition to all architecture, functionalities and timing issues, the layout by itself is a bottleneck due to all the process constraints of a 28nm technology. As developers of advanced layout finishing solutions, we were involved in the design flow of this huge chip with its 3 <span class="hlt">billions</span> transistors. We had to face the issue of dummy patterns instantiation with respect to design constraints. All the design rules to generate the "dummies" are clearly defined in the Design Rule Manual, and some automatic procedures are provided by the foundry itself, but these routines don't take care of the designer requests. Such a chip, embeds both digital parts and analog modules for clock and power management. These two different type of designs have each their own set of constraints. In both cases, the insertion of dummies should not introduce unexpected variations leading to malfunctions. For example, on digital parts were signal race conditions are critical on long wires or bus, introduction of uncontrolled parasitic along these nets are highly critical. For analog devices such as high frequency and high sensitivity comparators, the exact symmetry of the two parts of a current mirror generator should be guaranteed. Thanks to the easily customizable features of our dummies insertion tool, we were able to configure it in order to meet all the designer requirements as well as the process constraints. This paper will present all these advanced key features as well as the layout tricks used to fulfill all requirements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26399829','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26399829"><span id="translatedtitle">The formation of submillimetre-bright galaxies from gas infall over a <span class="hlt">billion</span> years.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Narayanan, Desika; Turk, Matthew; Feldmann, Robert; Robitaille, Thomas; Hopkins, Philip; Thompson, Robert; Hayward, Christopher; Ball, David; Faucher-Giguère, Claude-André; Kereš, Dušan</p> <p>2015-09-24</p> <p>Submillimetre-bright galaxies at high redshift are the most luminous, heavily star-forming galaxies in the Universe and are characterized by prodigious emission in the far-infrared, with a flux of at least five millijanskys at a wavelength of 850 micrometres. They reside in haloes with masses about 10(13) times that of the Sun, have low gas fractions compared to main-sequence disks at a comparable redshift, trace complex environments and are not easily observable at optical wavelengths. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy that simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter haloes have increasing rates of star formation that peak at collective rates of about 500-1,000 solar masses per year at redshifts of two to three, by which time the interstellar medium is sufficiently enriched with metals that the region may be observed as a submillimetre-selected system. The intense star formation rates are fuelled in part by the infall of a reservoir gas supply enabled by stellar feedback at earlier times, not through major mergers. With a lifetime of nearly a <span class="hlt">billion</span> years, our simulations show that the submillimetre-bright phase of high-redshift galaxies is prolonged and associated with significant mass buildup in early-Universe proto-clusters, and that many submillimetre-bright galaxies are composed of numerous unresolved components (for which there is some observational evidence). PMID:26399829</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcAau.127..394M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcAau.127..394M"><span id="translatedtitle">ESA's <span class="hlt">billion</span> star surveyor - Flight operations experience from Gaia's first 1.5 Years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milligan, D.; Rudolph, A.; Whitehead, G.; Loureiro, T.; Serpell, E.; di Marco, F.; Marie, J.; Ecale, E.</p> <p>2016-10-01</p> <p>This paper details the initial in-flight mission operations experience from ESA's ultra-precise Gaia spacecraft. Tasked with mapping the positions and movements of 1 <span class="hlt">billion</span> stars to unprecedented precision (to the 10 s of micro-arc-second level, comparable to the width of a coin on the Moon as viewed from Earth). ESA's Science cornerstone mission is expected to also discover and chart 100,000's of new objects including near Earth Asteroids, exoplanets, brown dwarfs and Quasars. After a flawless launch 19 Dec 2013, Gaia was brought the circa 1.5 million kms into L2 via a sequence of technically demanding orbit transfer manoeuvres using onboard thrusters in thrust vectoring mode. Starting in parallel to this, and lasting 6 months, the full spacecraft was commissioned and brought gradually up to the highest operational mode. A number of problems were detected and tackled during commissioning and early routine phase operations. An apparent dimming of the on-board laser and imaged stars, was tracked down to water ice building up inside the telescope enclosure. Also apparent was more straylight than expected. Elsewhere, a micro-propulsion thruster developed unexpected performance levels and a back-up chemical thruster suffered a failed latch valve. These issues, like several others, were dealt with and solved in a series of review meetings, in-orbit special operations and newly developed procedures and on-board software changes. After commissioning Gaia was working so well that it was producing approximately 45% more science data than originally foreseen, primarily since it was able to see stars fainter than required. The mission operations concept was quickly adapted to partially automate ground operations and increase ground station time to allow the full scientific potential of Gaia to be realised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GeCoA..72..844G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GeCoA..72..844G"><span id="translatedtitle">Preservation of hydrocarbons and biomarkers in oil trapped inside fluid inclusions for >2 <span class="hlt">billion</span> years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>George, Simon C.; Volk, Herbert; Dutkiewicz, Adriana; Ridley, John; Buick, Roger</p> <p>2008-02-01</p> <p>Oil-bearing fluid inclusions occur in a ca. 2.45 Ga fluvial metaconglomerate of the Matinenda Formation at Elliot Lake, Canada. The oil, most likely derived from the conformably overlying deltaic McKim Formation, was trapped in quartz and feldspar during diagenesis and early metamorphism of the host rock, probably before ca. 2.2 Ga. Molecular geochemical analyses of the oil reveal a wide range of compounds, including CH 4, CO 2, n-alkanes, isoprenoids, monomethylalkanes, aromatic hydrocarbons, low molecular weight cyclic hydrocarbons, and trace amounts of complex multi-ring biomarkers. Maturity ratios show that the oil was generated in the oil window, with no evidence of extensive thermal cracking. This is remarkable, given that the oils were exposed to upper prehnite-pumpellyite facies metamorphism (280-350 °C) either during migration or after entrapment. The fluid inclusions are closed systems, with high fluid pressures, and contain no clays or other minerals or metals that might catalyse oil-to-gas cracking. These three attributes may all contribute to the thermal stability of the included oil and enable survival of biomarkers and molecular ratios over <span class="hlt">billions</span> of years. The biomarker geochemistry of the oil in the Matinenda Formation fluid inclusions enables inferences about the organisms that contributed to the organic matter deposited in the Palaeoproterozoic source rocks from which the analysed oil was generated and expelled. The presence of biomarkers produced by cyanobacteria and eukaryotes that are derived from and trapped in rocks deposited before ca. 2.2 Ga is consistent with an earlier evolution of oxygenic photosynthesis and suggests that some aquatic settings had become sufficiently oxygenated for sterol biosynthesis by this time. The extraction of biomarker molecules from Palaeoproterozoic oil-bearing fluid inclusions thus establishes a new method, using low detection limits and system blank levels, to trace evolution through Earth's early history</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4065035','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4065035"><span id="translatedtitle">A Highly Functional Synthetic Phage Display Library Containing over 40 <span class="hlt">Billion</span> Human Antibody Clones</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Weber, Marcel; Bujak, Emil; Putelli, Alessia; Villa, Alessandra; Matasci, Mattia; Gualandi, Laura; Hemmerle, Teresa; Wulhfard, Sarah; Neri, Dario</p> <p>2014-01-01</p> <p>Several synthetic antibody phage display libraries have been created and used for the isolation of human monoclonal antibodies. The performance of antibody libraries, which is usually measured in terms of their ability to yield high-affinity binding specificities against target proteins of interest, depends both on technical aspects (such as library size and quality of cloning) and on design features (which influence the percentage of functional clones in the library and their ability to be used for practical applications). Here, we describe the design, construction and characterization of a combinatorial phage display library, comprising over 40 <span class="hlt">billion</span> human antibody clones in single-chain fragment variable (scFv) format. The library was designed with the aim to obtain highly stable antibody clones, which can be affinity-purified on protein A supports, even when used in scFv format. The library was found to be highly functional, as >90% of randomly selected clones expressed the corresponding antibody. When selected against more than 15 antigens from various sources, the library always yielded specific and potent binders, at a higher frequency compared to previous antibody libraries. To demonstrate library performance in practical biomedical research projects, we isolated the human antibody G5, which reacts both against human and murine forms of the alternatively spliced BCD segment of tenascin-C, an extracellular matrix component frequently over-expressed in cancer and in chronic inflammation. The new library represents a useful source of binding specificities, both for academic research and for the development of antibody-based therapeutics. PMID:24950200</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=infarction&pg=2&id=ED534156','ERIC'); return false;" href="http://eric.ed.gov/?q=infarction&pg=2&id=ED534156"><span id="translatedtitle">Exploring the Relationships between the <span class="hlt">Electronic</span> Health Record System Components and Patient Outcomes in an Acute Hospital Setting</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wiggley, Shirley L.</p> <p>2011-01-01</p> <p>Purpose: The purpose of this study was to examine the relationship between the <span class="hlt">electronic</span> health record system components and patient outcomes in an acute hospital setting, given that the current presidential administration has earmarked nearly $50 <span class="hlt">billion</span> to the implementation of the <span class="hlt">electronic</span> health record. The relationship between the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=microscopes+AND+microscopy&pg=5&id=EJ226260','ERIC'); return false;" href="http://eric.ed.gov/?q=microscopes+AND+microscopy&pg=5&id=EJ226260"><span id="translatedtitle"><span class="hlt">Electron</span> Microscopy.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Beer, Michael</p> <p>1980-01-01</p> <p>Reviews technical aspects of structure determination in biological <span class="hlt">electron</span> microscopy (EM). Discusses low dose EM, low temperature microscopy, <span class="hlt">electron</span> energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ASPC..399...63B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ASPC..399...63B"><span id="translatedtitle">Galaxies in the First <span class="hlt">Billion</span> Years: Implications for Reionization and the Star Formation History at z>6</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bunker, A. J.; Stanway, E. R.; Ellis, R. S.; Lacy, M.; Stark, D. P.; Chie, K.; McMahon, R. G.; Eyles, L. P.</p> <p>2008-10-01</p> <p>Redshift 6, one <span class="hlt">billion</span> years after the Big Bang, marks the end of the reionization epoch. A crucial question is whether the UV flux from young starbursts at this redshift is sufficient to achieve this reionization. We have used the Lyman break technique to identify candidate star-forming galaxies at this redshift in deep HST/ACS images (Stanway et al. 2003; Bunker et al. 2004).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12290527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12290527"><span id="translatedtitle">$17 <span class="hlt">billion</span> needed for population programme to year 2000: Dr. Nafis Sadik launches State of World Population Report.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p></p> <p>1995-01-01</p> <p>Dr. Nafis Sadik, Executive Director of the United Nations Population Fund (UNFPA), in her address on July 11 to the Foreign Press Association in London on the occasion of the release of the "1995 State of the World Population Report," stated that governments needed to invest in people, and that the estimated amount needed to reduce population numbers in developing countries was $17 <span class="hlt">billion</span> for the year 2000. Two-thirds of the cost would be supplied by the developing countries. She said that coordinating population policies globally through such documents as the Programme of Action from the Cairo Conference would aid in slowing population growth. World population, currently 5.7 <span class="hlt">billion</span>, is projected to reach 7.1-7.83 <span class="hlt">billion</span> in 2015 and 7.9-11.9 <span class="hlt">billion</span> in 2050. She also noted that certain conditions faced by women bear upon unsustainable population growth. The cycle of poverty continues in developing countries because very young mothers, who face higher risks in pregnancy and childbirth than those who delay childbearing until after the age of 20, are less likely to continue their education, more likely to have lower-paying jobs, and have a higher rate of separation and divorce. The isolation of women from widespread political participation and the marginalization of women's concerns from mainstream topics has resulted in ineffective family planning programs, including prevention of illness or impairment related to pregnancy or childbirth. Women, in most societies, cannot fully participate in economic and public life, have limited access to positions of influence and power, have narrower occupational choices and lower earnings than men, and must struggle to reconcile activities outside the home with their traditional roles. Sustainable development can only be achieved when social development expands opportunities for individuals (men and women), and their families, empowering them in the attainment of their social, economic, political, and cultural aspirations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED248880.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED248880.pdf"><span id="translatedtitle"><span class="hlt">Electronic</span> Mail.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Pollard, Jim; Holznagel, Don</p> <p>1984-01-01</p> <p>Decision makers must address the issues of (1) just what are <span class="hlt">electronic</span> communications? (2) how will they help me teach, administer, or survive? and (3) what will it cost in time and money? <span class="hlt">Electronic</span> mail allows the sending of letters, memos, and messages to anyone who uses the same <span class="hlt">electronic</span> mail system, and provides most of the options that…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=pneumatic&pg=4&id=ED282026','ERIC'); return false;" href="http://eric.ed.gov/?q=pneumatic&pg=4&id=ED282026"><span id="translatedtitle"><span class="hlt">Electronics</span> Curriculum.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Prickett, Charlotte</p> <p></p> <p>This document presents results of research conducted by industry representatives regarding tasks performed by <span class="hlt">electronic</span> technicians and line manufacturing electro-mechanical technicians in Arizona <span class="hlt">electronics</span> industries. Based on this research, a competency-based curriculum was developed for training entry-level <span class="hlt">electronics</span> technicians. Twelve…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B31H..04F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B31H..04F"><span id="translatedtitle">The Other Inconvenient Truth: Feeding 9 <span class="hlt">Billion</span> While Sustaining the Earth System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foley, J. A.</p> <p>2010-12-01</p> <p>As the international community focuses on climate change as the great challenge of our era, we have been largely ignoring another looming problem — the global crisis in agriculture, food security and the environment. Our use of land, particularly for agriculture, is absolutely essential to the success of the human race: we depend on agriculture to supply us with food, feed, fiber, and, increasingly, biofuels. Without a highly efficient, productive, and resilient agricultural system, our society would collapse almost overnight. But we are demanding more and more from our global agricultural systems, pushing them to their very limits. Continued population growth (adding more than 70 million people to the world every year), changing dietary preferences (including more meat and dairy consumption), rising energy prices, and increasing needs for bioenergy sources are putting tremendous pressure on the world’s resources. And, if we want any hope of keeping up with these demands, we’ll need to double the agricultural production of the planet in the next 30 to 40 years. Meeting these huge new agricultural demands will be one of the greatest challenges of the 21st century. At present, it is completely unclear how (and if) we can do it. If this wasn’t enough, we must also address the massive environmental impacts of our current agricultural practices, which new evidence indicates rival the impacts of climate change. Simply put, providing for the basic needs of 9 <span class="hlt">billion</span>-plus people, without ruining the biosphere in the process, will be one of the greatest challenges our species has ever faced. In this presentation, I will present a new framework for evaluating and assessing global patterns of agriculture, food / fiber / fuel production, and their relationship to the earth system, particularly in terms of changing stocks and flows of water, nutrients and carbon in our planetary environment. This framework aims to help us manage the challenges of increasing global food</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25177538','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25177538"><span id="translatedtitle">Subsampled open-reference clustering creates consistent, comprehensive OTU definitions and scales to <span class="hlt">billions</span> of sequences.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rideout, Jai Ram; He, Yan; Navas-Molina, Jose A; Walters, William A; Ursell, Luke K; Gibbons, Sean M; Chase, John; McDonald, Daniel; Gonzalez, Antonio; Robbins-Pianka, Adam; Clemente, Jose C; Gilbert, Jack A; Huse, Susan M; Zhou, Hong-Wei; Knight, Rob; Caporaso, J Gregory</p> <p>2014-01-01</p> <p>We present a performance-optimized algorithm, subsampled open-reference OTU picking, for assigning marker gene (e.g., 16S rRNA) sequences generated on next-generation sequencing platforms to operational taxonomic units (OTUs) for microbial community analysis. This algorithm provides benefits over de novo OTU picking (clustering can be performed largely in parallel, reducing runtime) and closed-reference OTU picking (all reads are clustered, not only those that match a reference database sequence with high similarity). Because more of our algorithm can be run in parallel relative to "classic" open-reference OTU picking, it makes open-reference OTU picking tractable on massive amplicon sequence data sets (though on smaller data sets, "classic" open-reference OTU clustering is often faster). We illustrate that here by applying it to the first 15,000 samples sequenced for the Earth Microbiome Project (1.3 <span class="hlt">billion</span> V4 16S rRNA amplicons). To the best of our knowledge, this is the largest OTU picking run ever performed, and we estimate that our new algorithm runs in less than 1/5 the time than would be required of "classic" open reference OTU picking. We show that subsampled open-reference OTU picking yields results that are highly correlated with those generated by "classic" open-reference OTU picking through comparisons on three well-studied datasets. An implementation of this algorithm is provided in the popular QIIME software package, which uses uclust for read clustering. All analyses were performed using QIIME's uclust wrappers, though we provide details (aided by the open-source code in our GitHub repository) that will allow implementation of subsampled open-reference OTU picking independently of QIIME (e.g., in a compiled programming language, where runtimes should be further reduced). Our analyses should generalize to other implementations of these OTU picking algorithms. Finally, we present a comparison of parameter settings in QIIME's OTU picking workflows and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145071','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145071"><span id="translatedtitle">Subsampled open-reference clustering creates consistent, comprehensive OTU definitions and scales to <span class="hlt">billions</span> of sequences</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rideout, Jai Ram; He, Yan; Navas-Molina, Jose A.; Walters, William A.; Ursell, Luke K.; Gibbons, Sean M.; Chase, John; McDonald, Daniel; Gonzalez, Antonio; Robbins-Pianka, Adam; Clemente, Jose C.; Gilbert, Jack A.; Huse, Susan M.; Zhou, Hong-Wei; Knight, Rob</p> <p>2014-01-01</p> <p>We present a performance-optimized algorithm, subsampled open-reference OTU picking, for assigning marker gene (e.g., 16S rRNA) sequences generated on next-generation sequencing platforms to operational taxonomic units (OTUs) for microbial community analysis. This algorithm provides benefits over de novo OTU picking (clustering can be performed largely in parallel, reducing runtime) and closed-reference OTU picking (all reads are clustered, not only those that match a reference database sequence with high similarity). Because more of our algorithm can be run in parallel relative to “classic” open-reference OTU picking, it makes open-reference OTU picking tractable on massive amplicon sequence data sets (though on smaller data sets, “classic” open-reference OTU clustering is often faster). We illustrate that here by applying it to the first 15,000 samples sequenced for the Earth Microbiome Project (1.3 <span class="hlt">billion</span> V4 16S rRNA amplicons). To the best of our knowledge, this is the largest OTU picking run ever performed, and we estimate that our new algorithm runs in less than 1/5 the time than would be required of “classic” open reference OTU picking. We show that subsampled open-reference OTU picking yields results that are highly correlated with those generated by “classic” open-reference OTU picking through comparisons on three well-studied datasets. An implementation of this algorithm is provided in the popular QIIME software package, which uses uclust for read clustering. All analyses were performed using QIIME’s uclust wrappers, though we provide details (aided by the open-source code in our GitHub repository) that will allow implementation of subsampled open-reference OTU picking independently of QIIME (e.g., in a compiled programming language, where runtimes should be further reduced). Our analyses should generalize to other implementations of these OTU picking algorithms. Finally, we present a comparison of parameter settings in QIIME’s OTU</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130011297','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130011297"><span id="translatedtitle">A Portable <span class="hlt">Electronic</span> Nose For Hydrazine and Monomethyl Hydrazine Detection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Young, Rebecca C.; Linnell, Bruce R.; Peterson, Barbara V.; Brooks, Kathy B.; Griffin, Tim P.</p> <p>2004-01-01</p> <p>The Space Program and military use large quantities Hydrazine (Hz) and monomethyl hydrazine (MMI-I) as rocket propellant. These substances are very toxic and are suspected human carcinogens. The American Conference of Governmental Industrial Hygienist set the threshold limit value to be 10 parts per <span class="hlt">billion</span> (ppb). Current off-the-shelf portable instruments require 10 to 20 minutes of exposure to detect 10 ppb concentration. This shortcofriing is not acceptable for many operations. A new prototype instrument using a gas sensor array and pattern recognition software technology (i.e., an <span class="hlt">electronic</span> nose) has demonstrated the ability to identify either Hz or MM}{ and quantify their concentrations at 10 parts per <span class="hlt">billion</span> in 90 seconds. This paper describes the design of the portable <span class="hlt">electronic</span> nose (e-nose) instrument, test equipment setup, test protocol, pattern recognition algorithm, concentration estimation method, and laboratory test results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.B54B..03P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.B54B..03P"><span id="translatedtitle">Evidence for Oxygenic Photosynthesis Half a <span class="hlt">Billion</span> Years Before the Great Oxidation Event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Planavsky, N.; Asael, D.; Reinhard, C.; Hofmann, A.; Lyons, T. W.; Rouxel, O.</p> <p>2012-12-01</p> <p>Despite detailed investigations over the past 50 years, there is still intense debate about when oxygenic photosynthesis evolved. Current estimates span over a <span class="hlt">billion</span> years of Earth history, ranging from prior to 3.8 Ga, the age of the oldest sedimentary rocks, to 2.5-2.3 Ga, coincident with the rise of atmospheric oxygen ("The Great Oxidation Event" or GOE). Hitherto, geochemical and biomarker evidence for the development of oxygenic photosynthesis prior to the GOE has been inconclusive and so a new, independent perspective is needed to constrain when oxygenesis evolved. Through the use of molybdenum (Mo) isotopes, we can track the onset of manganese(II) (Mn2+) oxidation, which requires free oxygen. It is only through photosynthesis that free oxygen is produced in significant quantities, allowing local oxygen build up in aqueous environments. Therefore, if we find a clear signal for appreciable Mn oxidation in the sedimentary rock record, oxygenic photosynthesis must have evolved by that time. There are large Mo isotope fractionations associated with the sorption of Mo onto Fe and Mn oxyhydroxides, with an approximately -2.7‰ δ98Mo fractionation associated with Mo sorption onto Mn oxyhydroxides. In contrast, sorption of Mo onto the common Fe oxyhydroxide ferrihydrite results in a fractionation of only ca. -1.1‰. Because of these differences in Mo isotope fractionations, Mo isotope values should become lighter with increasing Mn content if Mn oxidation occurs during deposition and is an important vector of Mo transfer to the sediment. In other words, a negative correlation between Fe/Mn ratios and Mo isotope values in chemical sediments is an unambiguous signal for Mn oxidation. Importantly, this Mo isotope approach holds up regardless of the original isotopic composition of seawater. We found a strong negative correlation between δ98Mo values and Fe/Mn ratios in iron formations deposited before and after the Great Oxidation Event. Most strikingly, Mo</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16148927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16148927"><span id="translatedtitle">Wave acceleration of <span class="hlt">electrons</span> in the Van Allen radiation belts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Horne, Richard B; Thorne, Richard M; Shprits, Yuri Y; Meredith, Nigel P; Glauert, Sarah A; Smith, Andy J; Kanekal, Shrikanth G; Baker, Daniel N; Engebretson, Mark J; Posch, Jennifer L; Spasojevic, Maria; Inan, Umran S; Pickett, Jolene S; Decreau, Pierrette M E</p> <p>2005-09-01</p> <p>The Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million <span class="hlt">electron</span> <span class="hlt">volts</span>. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth, that the long established theory of acceleration by radial diffusion is inadequate; the <span class="hlt">electrons</span> are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the <span class="hlt">electron</span> flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........24X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........24X"><span id="translatedtitle">Superthermal <span class="hlt">electrons</span> at Mars: Photoelectrons, solar wind <span class="hlt">electrons</span>, and dust storm influences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Shaosui</p> <p></p> <p>Mars is unique in the solar system in terms of its interaction with solar wind because it lacks of a significant intrinsic global magnetic field but possesses localized strong crustal fields. This interaction results in a very complex magnetic topology at Mars so that superthermal <span class="hlt">electrons</span>, mainly including photoelectrons and solar wind <span class="hlt">electrons</span>, can be distinctively important for such a complicated planetary space environment. These energetic <span class="hlt">electrons</span> (1-1000 <span class="hlt">electron</span> <span class="hlt">volts</span>) can carry and rapidly redistribute energy along the magnetic field lines. They are also a reliable tool to deduce the Martian magnetic topology, which is critical to understand the electromagnetic dynamics of the Martian space environment. The investigation methodology involves both data analysis and modeling. This dissertation mainly investigates three topics of superthermal <span class="hlt">electrons</span> at Mars. (1) This dissertation confirms that the long-lived influence of Martian low-altitude dust storms on high-altitude photoelectron fluxes is common for a wide range of energy and pitch angles and determines that this effect originates from the thermosphere-ionosphere source region of the photoelectrons, rather than at exospheric altitudes at or above MGS. Through simulations, the results suggest that the global dust storm altered the photoelectron fluxes by causing CO2 to be the dominant species at a much larger altitude range than usual. (2) Because the integral of the production rate above the superthermal <span class="hlt">electron</span> exobase is about the same for all solar zenith angles, quite counterintuitively, it is found, observationally and numerically/theoretically, that the high-altitude photoelectron fluxes are quite independent of solar zenith angle. (3) Based on the energy spectral (flux against energy) difference between photoelectrons and solar wind <span class="hlt">electrons</span>, a statistical approach is taken to distinguish the two populations and also allows us to quantify the occurrence rate of solar wind <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970003103','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970003103"><span id="translatedtitle"><span class="hlt">Electronic</span> Photography</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Payne, Meredith Lindsay</p> <p>1995-01-01</p> <p>The main objective was to assist in the production of <span class="hlt">electronic</span> images in the <span class="hlt">Electronic</span> Photography Lab (EPL). The EPL is a new facility serving the <span class="hlt">electronic</span> photographic needs of the Langley community. The purpose of the <span class="hlt">Electronic</span> Photography lab is to provide Langley with access to digital imaging technology. Although the EPL has been in operation for less than one year, almost 1,000 images have been produced. The decision to establish the lab was made after careful determination of the centers needs for <span class="hlt">electronic</span> photography. The LaRC community requires <span class="hlt">electronic</span> photography for the production of <span class="hlt">electronic</span> printing, Web sites, desktop publications, and its increased enhancement capabilities. In addition to general use, other considerations went into the planning of the EPL. For example, <span class="hlt">electronic</span> photography is much less of a burden on the environment compared to conventional photography. Also, the possibilities of an on-line database and retrieval system could make locating past work more efficient. Finally, information in an <span class="hlt">electronic</span> image is quantified, making measurements and calculations easier for the researcher.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21433116','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21433116"><span id="translatedtitle">Paper <span class="hlt">electronics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tobjörk, Daniel; Österbacka, Ronald</p> <p>2011-05-01</p> <p>Paper is ubiquitous in everyday life and a truly low-cost substrate. The use of paper substrates could be extended even further, if <span class="hlt">electronic</span> applications would be applied next to or below the printed graphics. However, applying <span class="hlt">electronics</span> on paper is challenging. The paper surface is not only very rough compared to plastics, but is also porous. While this is detrimental for most <span class="hlt">electronic</span> devices manufactured directly onto paper substrates, there are also approaches that are compatible with the rough and absorptive paper surface. In this review, recent advances and possibilities of these approaches are evaluated and the limitations of paper <span class="hlt">electronics</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22711057','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22711057"><span id="translatedtitle">Microfluidic <span class="hlt">electronics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Shi; Wu, Zhigang</p> <p>2012-08-21</p> <p>Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as <span class="hlt">electronics</span>, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based <span class="hlt">electronics</span> have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky <span class="hlt">electronics</span> are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic <span class="hlt">electronics</span> contribute to both the microfluidics and <span class="hlt">electronics</span> fields, but it may also shape the future of our daily life. Nevertheless, microfluidic <span class="hlt">electronics</span> are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic <span class="hlt">electronics</span>, and address current technical challenges and issues. The outlook of future development in microfluidic <span class="hlt">electronic</span> devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and <span class="hlt">electronics</span> communities to further exploit this newly-established field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27016613','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27016613"><span id="translatedtitle"><span class="hlt">Electron</span> bifurcation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peters, John W; Miller, Anne-Frances; Jones, Anne K; King, Paul W; Adams, Michael Ww</p> <p>2016-04-01</p> <p><span class="hlt">Electron</span> bifurcation is the recently recognized third mechanism of biological energy conservation. It simultaneously couples exergonic and endergonic oxidation-reduction reactions to circumvent thermodynamic barriers and minimize free energy loss. Little is known about the details of how <span class="hlt">electron</span> bifurcating enzymes function, but specifics are beginning to emerge for several bifurcating enzymes. To date, those characterized contain a collection of redox cofactors including flavins and iron-sulfur clusters. Here we discuss the current understanding of bifurcating enzymes and the mechanistic features required to reversibly partition multiple <span class="hlt">electrons</span> from a single redox site into exergonic and endergonic <span class="hlt">electron</span> transfer paths. PMID:27016613</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26658165','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26658165"><span id="translatedtitle">1.8 <span class="hlt">Billion</span> Years of Detrital Zircon Recycling Calibrates a Refractory Part of Earth's Sedimentary Cycle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hadlari, Thomas; Swindles, Graeme T; Galloway, Jennifer M; Bell, Kimberley M; Sulphur, Kyle C; Heaman, Larry M; Beranek, Luke P; Fallas, Karen M</p> <p>2015-01-01</p> <p>Detrital zircon studies are providing new insights on the evolution of sedimentary basins but the role of sedimentary recycling remains largely undefined. In a broad region of northwestern North America, this contribution traces the pathway of detrital zircon sand grains from Proterozoic sandstones through Phanerozoic strata and argues for multi-stage sedimentary recycling over more than a <span class="hlt">billion</span> years. As a test of our hypothesis, integrated palynology and detrital zircon provenance provides clear evidence for erosion of Carboniferous strata in the northern Cordillera as a sediment source for Upper Cretaceous strata. Our results help to calibrate Earth's sedimentary cycle by showing that recycling dominates sedimentary provenance for the refractory mineral zircon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/992807','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/992807"><span id="translatedtitle">NREL Helps Clean Cities Displace <span class="hlt">Billions</span> of Gallons of Petroleum, One Vehicle at a Time (Fact Sheet)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>2010-10-01</p> <p>With more than 15 years and nearly 3 <span class="hlt">billion</span> gallons of displaced petroleum under its belt, the Clean Cities program relies on the support and expertise of the National Renewable Energy Laboratory (NREL). An initiative of the U.S. Department of Energy (DOE), Clean Cities creates public-private partnerships with a common mission: to reduce petroleum consumption in the transportation sector. Since the inception of Clean Cities in 1993, NREL has played a central role in supporting the program, an effort that stems from the laboratory's strategy to put scientific innovation into action in the marketplace.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=general+AND+video+AND+communication+AND+system&pg=2&id=ED319913','ERIC'); return false;" href="http://eric.ed.gov/?q=general+AND+video+AND+communication+AND+system&pg=2&id=ED319913"><span id="translatedtitle">Communications <span class="hlt">Electronics</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Vorderstrasse, Ron; Siebert, Leo</p> <p></p> <p>This module is the third in a series of <span class="hlt">electronics</span> publications and serves as a supplement to "General <span class="hlt">Electronics</span> Technician." It is designed to provide students with an overview of the broad field of communications. Included are those tasks above the basic skills level that allow students to progress to a higher level of competency in the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=cereal&pg=6&id=EJ533171','ERIC'); return false;" href="http://eric.ed.gov/?q=cereal&pg=6&id=EJ533171"><span id="translatedtitle"><span class="hlt">Electronic</span> Cereal.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Frentrup, Julie R.; Phillips, Donald B.</p> <p>1996-01-01</p> <p>Describes activities that use Froot Loops breakfast cereal to help students master the concepts of valence <span class="hlt">electrons</span> and chemical bonding and the implications of the duet and octet rules. Involves students working in groups to create <span class="hlt">electron</span> dot structures for various compounds. (JRH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016382','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016382"><span id="translatedtitle">Printed <span class="hlt">electronics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel A. (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-hua (Inventor); Prud'Homme, Robert K. (Inventor)</p> <p>2012-01-01</p> <p>Printed <span class="hlt">electronic</span> device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed <span class="hlt">electronic</span> devices is further disclosed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150003266','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150003266"><span id="translatedtitle">Printed <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel A. (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)</p> <p>2014-01-01</p> <p>Printed <span class="hlt">electronic</span> device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed <span class="hlt">electronic</span> devices is further disclosed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150016929','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150016929"><span id="translatedtitle">Printed <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)</p> <p>2015-01-01</p> <p>Printed <span class="hlt">electronic</span> device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed <span class="hlt">electronic</span> devices is further disclosed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyW...29i..33G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyW...29i..33G"><span id="translatedtitle">A <span class="hlt">billion</span> pixels, a <span class="hlt">billion</span> stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilmore, Gerry; van Leeuwen, Floor</p> <p>2016-09-01</p> <p>The Gaia spacecraft is conducting the most ambitious and thorough census of our galaxy ever attempted, gathering data on 100,000 stars every hour. With the mission's first major data release due this month, Gerry Gilmore and Floor van Leeuwen explain how the spacecraft works and assess its likely impact on the field of astrophysics</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25471883','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25471883"><span id="translatedtitle">Single-shot compressed ultrafast photography at one hundred <span class="hlt">billion</span> frames per second.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gao, Liang; Liang, Jinyang; Li, Chiye; Wang, Lihong V</p> <p>2014-12-01</p> <p>The capture of transient scenes at high imaging speed has been long sought by photographers, with early examples being the well known recording in 1878 of a horse in motion and the 1887 photograph of a supersonic bullet. However, not until the late twentieth century were breakthroughs achieved in demonstrating ultrahigh-speed imaging (more than 10(5) frames per second). In particular, the introduction of <span class="hlt">electronic</span> imaging sensors based on the charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) technology revolutionized high-speed photography, enabling acquisition rates of up to 10(7) frames per second. Despite these sensors' widespread impact, further increasing frame rates using CCD or CMOS technology is fundamentally limited by their on-chip storage and <span class="hlt">electronic</span> readout speed. Here we demonstrate a two-dimensional dynamic imaging technique, compressed ultrafast photography (CUP), which can capture non-repetitive time-evolving events at up to 10(11) frames per second. Compared with existing ultrafast imaging techniques, CUP has the prominent advantage of measuring an x-y-t (x, y, spatial coordinates; t, time) scene with a single camera snapshot, thereby allowing observation of transient events with temporal resolution as tens of picoseconds. Furthermore, akin to traditional photography, CUP is receive-only, and so does not need the specialized active illumination required by other single-shot ultrafast imagers. As a result, CUP can image a variety of luminescent--such as fluorescent or bioluminescent--objects. Using CUP, we visualize four fundamental physical phenomena with single laser shots only: laser pulse reflection and refraction, photon racing in two media, and faster-than-light propagation of non-information (that is, motion that appears faster than the speed of light but cannot convey information). Given CUP's capability, we expect it to find widespread applications in both fundamental and applied sciences, including</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Natur.516...74G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Natur.516...74G"><span id="translatedtitle">Single-shot compressed ultrafast photography at one hundred <span class="hlt">billion</span> frames per second</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Liang; Liang, Jinyang; Li, Chiye; Wang, Lihong V.</p> <p>2014-12-01</p> <p>The capture of transient scenes at high imaging speed has been long sought by photographers, with early examples being the well known recording in 1878 of a horse in motion and the 1887 photograph of a supersonic bullet. However, not until the late twentieth century were breakthroughs achieved in demonstrating ultrahigh-speed imaging (more than 105 frames per second). In particular, the introduction of <span class="hlt">electronic</span> imaging sensors based on the charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) technology revolutionized high-speed photography, enabling acquisition rates of up to 107 frames per second. Despite these sensors' widespread impact, further increasing frame rates using CCD or CMOS technology is fundamentally limited by their on-chip storage and <span class="hlt">electronic</span> readout speed. Here we demonstrate a two-dimensional dynamic imaging technique, compressed ultrafast photography (CUP), which can capture non-repetitive time-evolving events at up to 1011 frames per second. Compared with existing ultrafast imaging techniques, CUP has the prominent advantage of measuring an x-y-t (x, y, spatial coordinates; t, time) scene with a single camera snapshot, thereby allowing observation of transient events with temporal resolution as tens of picoseconds. Furthermore, akin to traditional photography, CUP is receive-only, and so does not need the specialized active illumination required by other single-shot ultrafast imagers. As a result, CUP can image a variety of luminescent--such as fluorescent or bioluminescent--objects. Using CUP, we visualize four fundamental physical phenomena with single laser shots only: laser pulse reflection and refraction, photon racing in two media, and faster-than-light propagation of non-information (that is, motion that appears faster than the speed of light but cannot convey information). Given CUP's capability, we expect it to find widespread applications in both fundamental and applied sciences, including biomedical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910014732','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910014732"><span id="translatedtitle"><span class="hlt">Electronic</span> neuroprocessors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thakoor, Anil</p> <p>1991-01-01</p> <p>The JPL Center for Space Microelectronics Technology (CSMT) is actively pursuing research in the neural network theory, algorithms, and <span class="hlt">electronics</span> as well as optoelectronic neural net hardware implementations, to explore the strengths and application potential for a variety of NASA, DoD, as well as commercial application problems, where conventional computing techniques are extremely time-consuming, cumbersome, or simply non-existent. An overview of the JPL <span class="hlt">electronic</span> neural network hardware development activities and some of the striking applications of the JPL <span class="hlt">electronic</span> neuroprocessors are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890017129','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890017129"><span id="translatedtitle"><span class="hlt">Electronic</span> prototyping</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hopcroft, J.</p> <p>1987-01-01</p> <p>The potential benefits of automation in space are significant. The science base needed to support this automation not only will help control costs and reduce lead-time in the earth-based design and construction of space stations, but also will advance the nation's capability for computer design, simulation, testing, and debugging of sophisticated objects <span class="hlt">electronically</span>. Progress in automation will require the ability to <span class="hlt">electronically</span> represent, reason about, and manipulate objects. Discussed here is the development of representations, languages, editors, and model-driven simulation systems to support <span class="hlt">electronic</span> prototyping. In particular, it identifies areas where basic research is needed before further progress can be made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23903747','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23903747"><span id="translatedtitle">An age difference of two <span class="hlt">billion</span> years between a metal-rich and a metal-poor globular cluster.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hansen, B M S; Kalirai, J S; Anderson, J; Dotter, A; Richer, H B; Rich, R M; Shara, M M; Fahlman, G G; Hurley, J R; King, I R; Reitzel, D; Stetson, P B</p> <p>2013-08-01</p> <p>Globular clusters trace the formation history of the spheroidal components of our Galaxy and other galaxies, which represent the bulk of star formation over the history of the Universe. The clusters exhibit a range of metallicities (abundances of elements heavier than helium), with metal-poor clusters dominating the stellar halo of the Galaxy, and higher-metallicity clusters found within the inner Galaxy, associated with the stellar bulge, or the thick disk. Age differences between these clusters can indicate the sequence in which the components of the Galaxy formed, and in particular which clusters were formed outside the Galaxy and were later engulfed along with their original host galaxies, and which were formed within it. Here we report an absolute age of 9.9 ± 0.7 <span class="hlt">billion</span> years (at 95 per cent confidence) for the metal-rich globular cluster 47 Tucanae, determined by modelling the properties of the cluster's white-dwarf cooling sequence. This is about two <span class="hlt">billion</span> years younger than has been inferred for the metal-poor cluster NGC 6397 from the same models, and provides quantitative evidence that metal-rich clusters like 47 Tucanae formed later than metal-poor halo clusters like NGC 6397.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070037443','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070037443"><span id="translatedtitle">White Light Demonstration of One Hundred Parts per <span class="hlt">Billion</span> Irradiance Suppression in Air by New Starshade Occulters</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Levinton, Douglas B.; Cash, Webster C.; Gleason, Brian; Kaiser, Michael J.; Levine, Sara A.; Lo, Amy S.; Schindhelm, Eric; Shipley, Ann F.</p> <p>2007-01-01</p> <p>A new mission concept for the direct imaging of exo-solar planets called the New Worlds Observer (NWO) has been proposed. The concept involves flying a meter-class space telescope in formation with a newly-conceived, specially-shaped, deployable star-occulting shade several meters across at a separation of some tens of thousands of kilometers. The telescope would make its observations from behind the starshade in a volume of high suppression of incident irradiance from the star around which planets orbit. The required level of irradiance suppression created by the starshade for an efficacious mission is of order 0.1 to 10 parts per <span class="hlt">billion</span> in broadband light. This paper discusses the experimental setup developed to accurately measure the suppression ratio of irradiance produced at the null position behind candidate starshade forms to these levels. It also presents results of broadband measurements which demonstrated suppression levels of just under 100 parts per <span class="hlt">billion</span> in air using the Sun as a light source. Analytical modeling of spatial irradiance distributions surrounding the null are presented and compared with photographs of irradiance captured in situ behind candidate starshades.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70026993','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70026993"><span id="translatedtitle">Compound-specific carbon and hydrogen isotope analysis of sub-parts per <span class="hlt">billion</span> level waterborne petroleum hydrocarbons</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wang, Y.; Huang, Y.; Huckins, J.N.; Petty, J.D.</p> <p>2004-01-01</p> <p>Compound-specific carbon and hydrogen isotope analysis (CSCIA and CSHIA) has been increasingly used to study the source, transport, and bioremediation of organic contaminants such as petroleum hydrocarbons. In natural aquatic systems, dissolved contaminants represent the bioavailable fraction that generally is of the greatest toxicological significance. However, determining the isotopic ratios of waterborne hydrophobic contaminants in natural waters is very challenging because of their extremely low concentrations (often at sub-parts ber <span class="hlt">billion</span>, or even lower). To acquire sufficient quantities of polycyclic aromatic hydrocarbons with 10 ng/L concentration for CSHIA, more than 1000 L of water must be extracted. Conventional liquid/liquid or solid-phase extraction is not suitable for such large volume extractions. We have developed a new approach that is capable of efficiently sampling sub-parts per <span class="hlt">billion</span> level waterborne petroleum hydrocarbons for CSIA. We use semipermeable membrane devices (SPMDs) to accumulate hydrophobic contaminants from polluted waters and then recover the compounds in the laboratory for CSIA. In this study, we demonstrate, under a variety of experimental conditions (different concentrations, temperatures, and turbulence levels), that SPMD-associated processes do not induce C and H isotopic fractionations. The applicability of SPMD-CSIA technology to natural systems is further demonstrated by determining the ??13C and ??D values of petroleum hydrocarbons present in the Pawtuxet River, RI. Our results show that the combined SPMD-CSIA is an effective tool to investigate the source and fate of hydrophobic contaminants in the aquatic environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23903747','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23903747"><span id="translatedtitle">An age difference of two <span class="hlt">billion</span> years between a metal-rich and a metal-poor globular cluster.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hansen, B M S; Kalirai, J S; Anderson, J; Dotter, A; Richer, H B; Rich, R M; Shara, M M; Fahlman, G G; Hurley, J R; King, I R; Reitzel, D; Stetson, P B</p> <p>2013-08-01</p> <p>Globular clusters trace the formation history of the spheroidal components of our Galaxy and other galaxies, which represent the bulk of star formation over the history of the Universe. The clusters exhibit a range of metallicities (abundances of elements heavier than helium), with metal-poor clusters dominating the stellar halo of the Galaxy, and higher-metallicity clusters found within the inner Galaxy, associated with the stellar bulge, or the thick disk. Age differences between these clusters can indicate the sequence in which the components of the Galaxy formed, and in particular which clusters were formed outside the Galaxy and were later engulfed along with their original host galaxies, and which were formed within it. Here we report an absolute age of 9.9 ± 0.7 <span class="hlt">billion</span> years (at 95 per cent confidence) for the metal-rich globular cluster 47 Tucanae, determined by modelling the properties of the cluster's white-dwarf cooling sequence. This is about two <span class="hlt">billion</span> years younger than has been inferred for the metal-poor cluster NGC 6397 from the same models, and provides quantitative evidence that metal-rich clusters like 47 Tucanae formed later than metal-poor halo clusters like NGC 6397. PMID:23903747</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25539085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25539085"><span id="translatedtitle">A spin-down clock for cool stars from observations of a 2.5-<span class="hlt">billion</span>-year-old cluster.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meibom, Søren; Barnes, Sydney A; Platais, Imants; Gilliland, Ronald L; Latham, David W; Mathieu, Robert D</p> <p>2015-01-29</p> <p>The ages of the most common stars--low-mass (cool) stars like the Sun, and smaller--are difficult to derive because traditional dating methods use stellar properties that either change little as the stars age or are hard to measure. The rotation rates of all cool stars decrease substantially with time as the stars steadily lose their angular momenta. If properly calibrated, rotation therefore can act as a reliable determinant of their ages based on the method of gyrochronology. To calibrate gyrochronology, the relationship between rotation period and age must be determined for cool stars of different masses, which is best accomplished with rotation period measurements for stars in clusters with well-known ages. Hitherto, such measurements have been possible only in clusters with ages of less than about one <span class="hlt">billion</span> years, and gyrochronology ages for older stars have been inferred from model predictions. Here we report rotation period measurements for 30 cool stars in the 2.5-<span class="hlt">billion</span>-year-old cluster NGC 6819. The periods reveal a well-defined relationship between rotation period and stellar mass at the cluster age, suggesting that ages with a precision of order 10 per cent can be derived for large numbers of cool Galactic field stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011NatGe...4..698W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011NatGe...4..698W"><span id="translatedtitle">Microfossils of sulphur-metabolizing cells in 3.4-<span class="hlt">billion</span>-year-old rocks of Western Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wacey, David; Kilburn, Matt R.; Saunders, Martin; Cliff, John; Brasier, Martin D.</p> <p>2011-10-01</p> <p>Sulphur isotope data from early Archaean rocks suggest that microbes with metabolisms based on sulphur existed almost 3.5 <span class="hlt">billion</span> years ago, leading to suggestions that the earliest microbial ecosystems were sulphur-based. However, morphological evidence for these sulphur-metabolizing bacteria has been elusive. Here we report the presence of microstructures from the 3.4-<span class="hlt">billion</span>-year-old Strelley Pool Formation in Western Australia that are associated with micrometre-sized pyrite crystals. The microstructures we identify exhibit indicators of biological affinity, including hollow cell lumens, carbonaceous cell walls enriched in nitrogen, taphonomic degradation, organization into chains and clusters, and δ13C values of -33 to -46‰ Vienna PeeDee Belemnite (VPDB). We therefore identify them as microfossils of spheroidal and ellipsoidal cells and tubular sheaths demonstrating the organization of multiple cells. The associated pyrite crystals have Δ33S values between -1.65 and +1.43‰ and δ34S values ranging from -12 to +6‰ Vienna Canyon Diablo Troilite (VCDT). We interpret the pyrite crystals as the metabolic by-products of these cells, which would have employed sulphate-reduction and sulphur-disproportionation pathways. These microfossils are about 200 million years older than previously described microfossils from Palaeoarchaean siliciclastic environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25719667','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25719667"><span id="translatedtitle">An ultraluminous quasar with a twelve-<span class="hlt">billion</span>-solar-mass black hole at redshift 6.30.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Xue-Bing; Wang, Feige; Fan, Xiaohui; Yi, Weimin; Zuo, Wenwen; Bian, Fuyan; Jiang, Linhua; McGreer, Ian D; Wang, Ran; Yang, Jinyi; Yang, Qian; Thompson, David; Beletsky, Yuri</p> <p>2015-02-26</p> <p>So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one <span class="hlt">billion</span> solar masses (10(9) M Sun symbol). The existence of such black holes when the Universe was less than one <span class="hlt">billion</span> years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 10(10) M Sun symbol, which is consistent with the 1.3 × 10(10) M Sun symbol derived by assuming an Eddington-limited accretion rate. PMID:25719667</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatGe...9..448S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatGe...9..448S"><span id="translatedtitle">Earth's air pressure 2.7 <span class="hlt">billion</span> years ago constrained to less than half of modern levels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Som, Sanjoy M.; Buick, Roger; Hagadorn, James W.; Blake, Tim S.; Perreault, John M.; Harnmeijer, Jelte P.; Catling, David C.</p> <p>2016-06-01</p> <p>How the Earth stayed warm several <span class="hlt">billion</span> years ago when the Sun was considerably fainter is the long-standing problem of the `faint young Sun paradox'. Because of negligible O2 and only moderate CO2 levels in the Archaean atmosphere, methane has been invoked as an auxiliary greenhouse gas. Alternatively, pressure broadening in a thicker atmosphere with a N2 partial pressure around 1.6-2.4 bar could have enhanced the greenhouse effect. But fossilized raindrop imprints indicate that air pressure 2.7 <span class="hlt">billion</span> years ago (Gyr) was below twice modern levels and probably below 1.1 bar, precluding such pressure enhancement. This result is supported by nitrogen and argon isotope studies of fluid inclusions in 3.0-3.5 Gyr rocks. Here, we calculate absolute Archaean barometric pressure using the size distribution of gas bubbles in basaltic lava flows that solidified at sea level ~2.7 Gyr in the Pilbara Craton, Australia. Our data indicate a surprisingly low surface atmospheric pressure of Patm = 0.23 +/- 0.23 (2σ) bar, and combined with previous studies suggests ~0.5 bar as an upper limit to late Archaean Patm. The result implies that the thin atmosphere was rich in auxiliary greenhouse gases and that Patm fluctuated over geologic time to a previously unrecognized extent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25719667','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25719667"><span id="translatedtitle">An ultraluminous quasar with a twelve-<span class="hlt">billion</span>-solar-mass black hole at redshift 6.30.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Xue-Bing; Wang, Feige; Fan, Xiaohui; Yi, Weimin; Zuo, Wenwen; Bian, Fuyan; Jiang, Linhua; McGreer, Ian D; Wang, Ran; Yang, Jinyi; Yang, Qian; Thompson, David; Beletsky, Yuri</p> <p>2015-02-26</p> <p>So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one <span class="hlt">billion</span> solar masses (10(9) M Sun symbol). The existence of such black holes when the Universe was less than one <span class="hlt">billion</span> years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 10(10) M Sun symbol, which is consistent with the 1.3 × 10(10) M Sun symbol derived by assuming an Eddington-limited accretion rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/132912','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/132912"><span id="translatedtitle"><span class="hlt">Electron</span>-emission yield of Al, Cu, and Au for the impact of swift bare light ions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Benka, O.; Schinner, A.; Fink, T.; Pfaffenlehner, M.</p> <p>1995-11-01</p> <p>The <span class="hlt">electron</span> emission yield induced by mega-<span class="hlt">electron-volt</span> H{sup +}, He{sup 2+}, Li{sup 3+}, B{sup 5+}, and C{sup 6+} impact on aluminum, copper, and gold targets was measured. We found a significant deviation of the results from a simple proportionality to the stopping power, especially for heavier ions and low projectile velocities. Using a slightly modified model by J. E. Borovsky and D. M. Suszcynsky [Phys. Rev. A {bold 43}, 1433 (1991)] our experiments could be well represented. In this model the collective electric field generated along the projectile`s path was taken into account. Consequently, the positive ion channel appears to be the dominant mechanism that leads beyond a projectile-independent yield--to--stopping power ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24585368','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24585368"><span id="translatedtitle">Ab-initio study of structural, <span class="hlt">electronic</span>, and transport properties of zigzag GaP nanotubes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Srivastava, Anurag; Jain, Sumit Kumar; Khare, Purnima Swarup</p> <p>2014-03-01</p> <p>Stability and <span class="hlt">electronic</span> properties of zigzag (3 ≤ n ≤ 16) gallium phosphide nanotubes (GaP NTs) have been analyzed by employing a systematic ab-intio approach based on density functional theory using generalized gradient approximation with revised Perdew Burke Ernzerhoff type parameterization. Diameter dependence of bond length, buckling, binding energy, and band gap has been investigated and the analysis shows that the bond length and buckling decreases with increasing diameter of the tube, highest binding energy of (16, 0) confirms this as the most stable amongst all the NTs taken into consideration. The present GaP NTs shows direct band gap and it increases with diameter of the tubes. Using a two probe model for (4, 0) NT the I-V relationship shows an exponential increase in current on applying bias voltage beyond 1.73 <span class="hlt">volt</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.medicare.gov/Pubs/pdf/11382.pdf','NIH-MEDLINEPLUS'); return false;" href="https://www.medicare.gov/Pubs/pdf/11382.pdf"><span id="translatedtitle"><span class="hlt">Electronic</span> Prescribing</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... 1-877-486-2048 . I went to the pharmacy, and my prescription was ready. <span class="hlt">Electronic</span> eRx Prescribing ... write and send your prescriptions directly to your pharmacy. This means no more prescriptions on paper and ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://betobaccofree.hhs.gov/about-tobacco/Electronic-Cigarettes/index.html','NIH-MEDLINEPLUS'); return false;" href="http://betobaccofree.hhs.gov/about-tobacco/Electronic-Cigarettes/index.html"><span id="translatedtitle"><span class="hlt">Electronic</span> Cigarettes</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... and Figures Tobacco and Nicotine Smoked Tobacco Products Smokeless Tobacco Products <span class="hlt">Electronic</span> Cigarettes New FDA Regulations HEALTH EFFECTS ... Secondhand Smoke Effects of Smoking on Your Health Smokeless Tobacco and Your Health Tobacco Use and Fertility Tobacco ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4681328','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4681328"><span id="translatedtitle"><span class="hlt">Electronic</span> plants</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus</p> <p>2015-01-01</p> <p>The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated <span class="hlt">electronic</span> circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with <span class="hlt">electronics</span>. We report analog and digital organic <span class="hlt">electronic</span> circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed <span class="hlt">electronics</span> in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993aubu.rept.....N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993aubu.rept.....N"><span id="translatedtitle">Design of power <span class="hlt">electronics</span> for TVC EMA systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelms, R. Mark</p> <p>1993-08-01</p> <p>The Composite Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power <span class="hlt">electronic</span> modules capable of modulating several hundred amperes of current at up to 270 <span class="hlt">volts</span>. MSFC has selected the brushless dc motor for implementation in EMA's. This report presents the results of an investigation into the applicability of two new technologies, MOS-controlled thyristors (MCT's) and pulse density modulation (PDM), to the control of brushless dc motors in EMA systems. MCT's are new power semiconductor devices, which combine the high voltage and current capabilities of conventional thyristors and the low gate drive requirements of metal oxide semiconductor field effect transistors (MOSFET's). The commanded signals in a PDM system are synthesized using a series of sinusoidal pulses instead of a series of square pulses as in a pulse width modulation (PWM) system. A resonant dc link inverter is employed to generate the sinusoidal pulses in the PDM system. This inverter permits zero-voltage switching of all semiconductors which reduces switching losses and switching stresses. The objectives of this project are to develop and validate an analytical model of the MCT device when used in high power motor control applications and to design, fabricate, and test a prototype <span class="hlt">electronic</span> circuit employing both MCT and PDM technology for controlling a brushless dc motor.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940015169','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940015169"><span id="translatedtitle">Design of power <span class="hlt">electronics</span> for TVC EMA systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelms, R. Mark</p> <p>1993-01-01</p> <p>The Composite Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power <span class="hlt">electronic</span> modules capable of modulating several hundred amperes of current at up to 270 <span class="hlt">volts</span>. MSFC has selected the brushless dc motor for implementation in EMA's. This report presents the results of an investigation into the applicability of two new technologies, MOS-controlled thyristors (MCT's) and pulse density modulation (PDM), to the control of brushless dc motors in EMA systems. MCT's are new power semiconductor devices, which combine the high voltage and current capabilities of conventional thyristors and the low gate drive requirements of metal oxide semiconductor field effect transistors (MOSFET's). The commanded signals in a PDM system are synthesized using a series of sinusoidal pulses instead of a series of square pulses as in a pulse width modulation (PWM) system. A resonant dc link inverter is employed to generate the sinusoidal pulses in the PDM system. This inverter permits zero-voltage switching of all semiconductors which reduces switching losses and switching stresses. The objectives of this project are to develop and validate an analytical model of the MCT device when used in high power motor control applications and to design, fabricate, and test a prototype <span class="hlt">electronic</span> circuit employing both MCT and PDM technology for controlling a brushless dc motor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17733919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17733919"><span id="translatedtitle">Voyager 2: energetic ions and <span class="hlt">electrons</span> in the jovian magnetosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vogt, R E; Cummings, A C; Garrard, T L; Gehrels, N; Stone, E C; Trainor, J H; Schardt, A W; Conlon, T F; McDonald, F B</p> <p>1979-11-23</p> <p>The Voyager 2 encounter has enhanced our understanding of earlier results and provided measurements beyond 160 Jupiter radii (R(J)) in the magnetotail. Significant fluxes of energetic sulfur and oxygen nuclei (4 to 15 million <span class="hlt">electron</span> <span class="hlt">volts</span> per nucleon) of Jovian origin were observed inside 25 R(J), and the gradient in phase space density at 12 R(J) indicates that the ions are diffusing inward. A substantially longer time delay versus distance was found for proton flux maxima in the active hemisphere in the magnetotail at Jovicentric longitudes lambda(III), = 260 degrees to 320 degrees than in the inactive hemisphere at lambda(III), = 85 degrees to l10 degrees . These delays can be related to the radial motion of plasma expanding into the magnetotail, and differences in the expansion speeds between the active and inactive hemispheres can produce rarefaction regions in trapped particles. It is suggested that the 10-hour modulation of interplanetary Jovian <span class="hlt">electrons</span> may be associated with the arrival at the dawn magnetopause of a rarefaction region each planetary rotation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27620188','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27620188"><span id="translatedtitle"><span class="hlt">Electron</span> Beam Technology for Environmental Pollution Control.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chmielewski, Andrzej G; Han, Bumsoo</p> <p>2016-10-01</p> <p>Worldwide, there are over 1700 <span class="hlt">electron</span> beam (EB) units in commercial use, providing an estimated added value to numerous products, amounting to 100 <span class="hlt">billion</span> USD or more. High-current <span class="hlt">electron</span> accelerators are used in diverse industries to enhance the physical and chemical properties of materials and to reduce undesirable contaminants such as pathogens, toxic byproducts, or emissions. Over the past few decades, EB technologies have been developed aimed at ensuring the safety of gaseous and liquid effluents discharged to the environment. It has been demonstrated that EB technologies for flue gas treatment (SO x and NO x removal), wastewater purification, and sludge hygienization can be effectively deployed to mitigate environmental degradation. Recently, extensive work has been carried out on the use of EB for environmental remediation, which also includes the removal of emerging contaminants such as VOCs, endocrine disrupting chemicals (EDCs), and potential EDCs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2897161','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2897161"><span id="translatedtitle">Integrated <span class="hlt">electronic</span> platforms for weight loss</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McCrady-Spitzer, Shelly K; Levine, James A</p> <p>2010-01-01</p> <p>What can be done to build effective weight loss solutions for the 1.5 <span class="hlt">billion</span> people with obesity? It is self-evident that no one good solution exists for people who are overweight or obese, otherwise it would have been applied across the people who need it worldwide. There is, therefore, an urgent need for approaches that will afford weight loss; what is more, such approaches need to be scalable. For that reason, it is attractive to consider <span class="hlt">electronic</span> platforms as an avenue for scalable weight loss solutions. Such platforms often do not require substantial investments but rather the integration of pre-existing off-the-shelf components. In this article we explore the concepts and design challenges for <span class="hlt">electronic</span> platforms that precipitate weight loss. PMID:20214426</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27620188','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27620188"><span id="translatedtitle"><span class="hlt">Electron</span> Beam Technology for Environmental Pollution Control.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chmielewski, Andrzej G; Han, Bumsoo</p> <p>2016-10-01</p> <p>Worldwide, there are over 1700 <span class="hlt">electron</span> beam (EB) units in commercial use, providing an estimated added value to numerous products, amounting to 100 <span class="hlt">billion</span> USD or more. High-current <span class="hlt">electron</span> accelerators are used in diverse industries to enhance the physical and chemical properties of materials and to reduce undesirable contaminants such as pathogens, toxic byproducts, or emissions. Over the past few decades, EB technologies have been developed aimed at ensuring the safety of gaseous and liquid effluents discharged to the environment. It has been demonstrated that EB technologies for flue gas treatment (SO x and NO x removal), wastewater purification, and sludge hygienization can be effectively deployed to mitigate environmental degradation. Recently, extensive work has been carried out on the use of EB for environmental remediation, which also includes the removal of emerging contaminants such as VOCs, endocrine disrupting chemicals (EDCs), and potential EDCs. PMID:27620188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/991002','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/991002"><span id="translatedtitle">Ion viscous heating in a magnetohydrodynamically unstable Z-pinch at over two <span class="hlt">billion</span> Kelvin.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jones, Brent Manley; Coverdale, Christine Anne; LePell, Paul David; Haines, Malcolm G.; Deeney, Christopher</p> <p>2005-02-01</p> <p>Pulsed power driven metallic wire-array Z pinches are the most powerful and efficient laboratory x-ray sources. Furthermore, under certain conditions the soft x-ray energy radiated in a 5 ns pulse at stagnation can exceed the estimated kinetic energy of the radial implosion phase by a factor of 3 to 4. A theoretical model is developed here to explain this, allowing the rapid conversion of magnetic energy to a very high ion temperature plasma through the generation of fine scale, fast-growing m=0 interchange MHD instabilities at stagnation. These saturate nonlinearly and provide associated ion viscous heating. Next the ion energy is transferred by equipartition to the <span class="hlt">electrons</span> and thus to soft x-ray radiation. Recent time-resolved iron spectra at Sandia confirm an ion temperature T{sub i} of over 200 keV (2 x 10{sup 9} degrees), as predicted by theory. These are believed to be record temperatures for a magnetically confined plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.206..470M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.206..470M"><span id="translatedtitle">Lamellar magnetism and exchange bias in <span class="hlt">billion</span>-year-old titanohematite with nanoscale ilmenite exsolution lamellae: I. Mineral and magnetic characterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McEnroe, Suzanne A.; Robinson, Peter; Miyajima, Nobuyoshi; Fabian, Karl; Dyar, Darby; Sklute, Elizabeth</p> <p>2016-07-01</p> <p>Recent high-resolution aeromagnetic surveys in South Norway have revealed numerous remanent anomalies over Mesoproterozoic metamorphic rocks. Studies on the nature of the minerals that are the remanent carriers has led to discoveries of titanohematite samples with unusual magnetic properties caused by nanoscale exsolution lamellae with their related lamellar magnetism. Here we focus on a rock unit dominated by quartz-plagioclase-biotite granulite containing titanohematite grains with a strong lattice-preferred orientation parallel to regional foliation. When samples with their natural remanent magnetization (NRM), acquired nearly 1 <span class="hlt">billion</span> years ago, are cooled to 10 K and hysteresis loops measured, these loops show bi-modal exchange bias caused by the magnetism induced within the ilmenite by antiferromagnetic coupling with the adjacent lamellar NRM. By contrast when the samples are cooled in a strong magnetic field (1.5 Tesla), this results in unimodal lamellar magnetism, and, below the TN of ilmenite it adopts a consistent negative orientation, giving rise to unimodal negative exchange bias of >500 mT. The results presented here cover the chemical and magnetic properties, Mossbauer results and transmission <span class="hlt">electron</span> microscopy of the titanohematite and ilmenite lamellae. Initial magnetic experiments indicated the shifts found in the exchange-bias experiments were directly related to the orientation of the sample to the applied field and the initial state of the NRM. In most samples with these unusual magnetic properties, ilmenite lamellae could not be seen in an optical or a scanning <span class="hlt">electron</span> microscope. However magnetic experiments gave proof of the presence of ilmenite, later confirmed by Mössbauer spectroscopy. Several attempts were made to identify ilmenite in TEM studies, finally successful in showing ilmenite lamellae parallel to (001) of hematite with thicknesses ˜1.2 to 1.7 nm and aspect ratios 7-13. Here we compare new TEM images and the magnetic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007shep.book.1219P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007shep.book.1219P"><span id="translatedtitle">Molecular <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petty, Michael</p> <p></p> <p>The prospects of using organic materials in <span class="hlt">electronics</span> and optoelectronics applications have attracted scientists and technologists since the 1970s. This field has become known as molecular <span class="hlt">electronics</span>. Some successes have already been achieved, for example the liquid-crystal display. Other products such as organic light-emitting displays, chemical sensors and plastic transistors are developing fast. There is also a keen interest in exploiting technologies at the molecular scale that might eventually replace silicon devices. This chapter provides some of the background physics and chemistry to the interdisciplinary subject of molecular <span class="hlt">electronics</span>. A review of some of the possible application areas for organic materials is presented and some speculation is provided regarding future directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1034165','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1034165"><span id="translatedtitle"><span class="hlt">Electron</span> tube</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Suyama, Motohiro; Fukasawa, Atsuhito; Arisaka, Katsushi; Wang, Hanguo</p> <p>2011-12-20</p> <p>An <span class="hlt">electron</span> tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an <span class="hlt">electron</span> detector arranged on the projection portion, for detecting <span class="hlt">electrons</span> from the photoelectric surface, and made of silicon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/935718','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/935718"><span id="translatedtitle">Taking out 1 <span class="hlt">billion</span> tons of CO2: The magic of China's 11th Five-Year Plan?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhou, Nan; Lin, Jiang; Zhou, Nan; Levine, Mark; Fridley, David</p> <p>2007-07-01</p> <p>China's 11th Five-Year Plan (FYP) sets an ambitious target for energy-efficiency improvement: energy intensity of the country's gross domestic product (GDP) should be reduced by 20% from 2005 to 2010 (NDRC, 2006). This is the first time that a quantitative and binding target has been set for energy efficiency, and signals a major shift in China's strategic thinking about its long-term economic and energy development. The 20% energy intensity target also translates into an annual reduction of over 1.5 <span class="hlt">billion</span> tons of CO2 by 2010, making the Chinese effort one of most significant carbon mitigation effort in the world today. While it is still too early to tell whether China will achieve this target, this paper attempts to understand the trend in energy intensity in China and to explore a variety of options toward meeting the 20% target using a detailed end-use energy model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/925592','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/925592"><span id="translatedtitle">Taking out one <span class="hlt">billion</span> tones of carbon: the magic of China's 11thFive-Year Plan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lin, Jiang; Zhou, Nan; Levine, Mark D.; Fridley, David</p> <p>2007-05-01</p> <p>China's 11th Five-Year Plan (FYP) sets an ambitious targetfor energy-efficiency improvement: energy intensity of the country sgross domestic product (GDP) should be reduced by 20 percent from 2005 to2010 (NDRC, 2006). This is the first time that a quantitative and bindingtarget has been set for energy efficiency, and signals a major shift inChina's strategic thinking about its long-term economic and energydevelopment. The 20 percent energy intensity target also translates intoan annual reduction of over one <span class="hlt">billion</span> tons of CO2 by 2010, making theChinese effort one of most significant carbon mitigation effort in theworld today. While it is still too early to tell whether China willachieve this target, this paper attempts to understand the trend inenergy intensity in China and to explore a variety of options towardmeeting the 20 percent target using a detailed endues energymodel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26858376','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26858376"><span id="translatedtitle">Vaccine Assistance To Low- And Middle-Income Countries Increased To $3.6 <span class="hlt">Billion</span> In 2014.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haakenstad, Annie; Birger, Maxwell; Singh, Lavanya; Liu, Patrick; Lim, Stephen; Ng, Marie; Dieleman, Joseph L</p> <p>2016-02-01</p> <p>In the 2012 Global Vaccine Action Plan, development assistance partners committed to providing sustainable financing for vaccines and expanding vaccination coverage to all children in low- and middle-income countries by 2020. To assess progress toward these goals, the Institute for Health Metrics and Evaluation produced estimates of development assistance for vaccinations. These estimates reveal major increases in the assistance provided since 2000. In 2014, $3.6 <span class="hlt">billion</span> in development assistance for vaccinations was provided for low- and middle-income countries, up from $822 million in 2000. The funding increase was driven predominantly by the establishment of Gavi, the Vaccine Alliance, supported by the Bill & Melinda Gates Foundation and the governments of the United States and United Kingdom. Despite stagnation in total development assistance for health from donors from 2010 onward, development assistance for vaccination has continued to grow. PMID:26858376</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4682852','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4682852"><span id="translatedtitle">1.8 <span class="hlt">Billion</span> Years of Detrital Zircon Recycling Calibrates a Refractory Part of Earth’s Sedimentary Cycle</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hadlari, Thomas; Swindles, Graeme T.; Galloway, Jennifer M.; Bell, Kimberley M.; Sulphur, Kyle C.; Heaman, Larry M.; Beranek, Luke P.; Fallas, Karen M.</p> <p>2015-01-01</p> <p>Detrital zircon studies are providing new insights on the evolution of sedimentary basins but the role of sedimentary recycling remains largely undefined. In a broad region of northwestern North America, this contribution traces the pathway of detrital zircon sand grains from Proterozoic sandstones through Phanerozoic strata and argues for multi-stage sedimentary recycling over more than a <span class="hlt">billion</span> years. As a test of our hypothesis, integrated palynology and detrital zircon provenance provides clear evidence for erosion of Carboniferous strata in the northern Cordillera as a sediment source for Upper Cretaceous strata. Our results help to calibrate Earth's sedimentary cycle by showing that recycling dominates sedimentary provenance for the refractory mineral zircon. PMID:26658165</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11349144','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11349144"><span id="translatedtitle">The Archean Dongwanzi ophiolite complex, North China craton: 2.505-<span class="hlt">billion</span>-year-old oceanic crust and mantle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kusky, T M; Li, J H; Tucker, R D</p> <p>2001-05-11</p> <p>We report a thick, laterally extensive 2505 +/- 2.2-million-year-old (uranium-lead ratio in zircon) Archean ophiolite complex in the North China craton. Basal harzburgite tectonite is overlain by cumulate ultramafic rocks, a mafic-ultramafic transition zone of interlayered gabbro and ultramafic cumulates, compositionally layered olivine-gabbro and pyroxenite, and isotropic gabbro. A sheeted dike complex is rooted in the gabbro and overlain by a mixed dike-pillow lava section, chert, and banded iron formation. The documentation of a complete Archean ophiolite implies that mechanisms of oceanic crustal accretion similar to those of today were in operation by 2.5 <span class="hlt">billion</span> years ago at divergent plate margins and that the temperature of the early mantle was not extremely elevated, as compared to the present-day temperature. Plate tectonic processes similar to those of the present must also have emplaced the ophiolite in a convergent margin setting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11349144','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11349144"><span id="translatedtitle">The Archean Dongwanzi ophiolite complex, North China craton: 2.505-<span class="hlt">billion</span>-year-old oceanic crust and mantle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kusky, T M; Li, J H; Tucker, R D</p> <p>2001-05-11</p> <p>We report a thick, laterally extensive 2505 +/- 2.2-million-year-old (uranium-lead ratio in zircon) Archean ophiolite complex in the North China craton. Basal harzburgite tectonite is overlain by cumulate ultramafic rocks, a mafic-ultramafic transition zone of interlayered gabbro and ultramafic cumulates, compositionally layered olivine-gabbro and pyroxenite, and isotropic gabbro. A sheeted dike complex is rooted in the gabbro and overlain by a mixed dike-pillow lava section, chert, and banded iron formation. The documentation of a complete Archean ophiolite implies that mechanisms of oceanic crustal accretion similar to those of today were in operation by 2.5 <span class="hlt">billion</span> years ago at divergent plate margins and that the temperature of the early mantle was not extremely elevated, as compared to the present-day temperature. Plate tectonic processes similar to those of the present must also have emplaced the ophiolite in a convergent margin setting. PMID:11349144</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1042287','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1042287"><span id="translatedtitle"><span class="hlt">Electron</span> Impedances</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>P Cameron</p> <p>2011-12-31</p> <p>It is only recently, and particularly with the quantum Hall effect and the development of nanoelectronics, that impedances on the scale of molecules, atoms and single <span class="hlt">electrons</span> have gained attention. In what follows the possibility that characteristic impedances might be defined for the photon and the single free <span class="hlt">electron</span> is explored is some detail, the premise being that the concepts of electrical and mechanical impedances are relevant to the elementary particle. The scale invariant quantum Hall impedance is pivotal in this exploration, as is the two body problem and Mach's principle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/4099506','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/4099506"><span id="translatedtitle"><span class="hlt">Electronic</span> system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Robison, G H; Dickson, J F</p> <p>1960-11-15</p> <p>An <span class="hlt">electronic</span> system is designed for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. The system comprises separate input means electrically associated with the events under observation an <span class="hlt">electronic</span> channel associated with each input means, including control means and indicating means; timing means adapted to apply a signal from the input means after a predetermined time to the control means to deactivate each of the channels; and means for resetting the system to its initial condition after the observation of each group of events. (D.L.C.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4112613','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4112613"><span id="translatedtitle"><span class="hlt">ELECTRONIC</span> SYSTEM</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Robison, G.H. et al.</p> <p>1960-11-15</p> <p>An <span class="hlt">electronic</span> system is described for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. It is comprised of separate input means electrically associated with the events under observation: an <span class="hlt">electronic</span> channel associated with each input means including control means and indicating means; timing means associated with each of the input means and the control means and adapted to derive a signal from the input means and apply it after a predetermined time to the control means to effect deactivation of each of the channels; and means for resetting the system to its initial condition after observation of each group of events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvE..87c2701M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvE..87c2701M"><span id="translatedtitle">Nanodosimetry of Auger <span class="hlt">electrons</span>: A case study from the decay of 125I and 0-18-eV <span class="hlt">electron</span> stopping cross sections of cytosine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michaud, M.; Bazin, M.; Sanche, L.</p> <p>2013-03-01</p> <p>Radiopharmaceuticals emitting Auger <span class="hlt">electrons</span> are often injected into patients undergoing cancer treatment with targeted radionuclide therapy (TRT). In this type of radiotherapy, the radiation source is radial and most of the emitted primary particles are low-energy <span class="hlt">electrons</span> (LEEs) having kinetic energies distributed mostly from zero to a few hundred <span class="hlt">electron</span> <span class="hlt">volts</span> with very short ranges in biological media. These LEEs generate a high density of energy deposits and clustered damage, thus offering a relative biological effectiveness comparable to that of alpha particles. In this paper, we present a simple model and corresponding measurements to assess the energy deposited near the site of the radiopharmaceuticals in TRT. As an example, a calculation is performed for the decay of a single 125I radionuclide surrounded by a 1-nm-radius spherical shell of cytosine molecules using the energy spectrum of LEEs emitted by 125I along with their stopping cross sections between 0 and 18 eV. The dose absorbed by the cytosine shell, which occupies a volume of 4 nm3, is extremely high. It amounts to 79 kGy per decay of which 3%, 39%, and 58% is attributed to vibrational excitations, <span class="hlt">electronic</span> excitations, and ionization processes, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24976798','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24976798"><span id="translatedtitle">Nanodosimetry of Auger <span class="hlt">electrons</span>: A case study from the decay of (125)I and 0-18-eV <span class="hlt">electron</span> stopping cross sections of cytosine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Michaud, M; Bazin, M; Sanche, L</p> <p>2013-03-01</p> <p>Radiopharmaceuticals emitting Auger <span class="hlt">electrons</span> are often injected into patients undergoing cancer treatment with targeted radionuclide therapy (TRT). In this type of radiotherapy, the radiation source is radial and most of the emitted primary particles are low-energy <span class="hlt">electrons</span> (LEEs) having kinetic energies distributed mostly from zero to a few hundred <span class="hlt">electron</span> <span class="hlt">volts</span> with very short ranges in biological media. These LEEs generate a high density of energy deposits and clustered damage, thus offering a relative biological effectiveness comparable to that of alpha particles. In this paper, we present a simple model and corresponding measurements to assess the energy deposited near the site of the radiopharmaceuticals in TRT. As an example, a calculation is performed for the decay of a single (125)I radionuclide surrounded by a 1-nm-radius spherical shell of cytosine molecules using the energy spectrum of LEEs emitted by (125)I along with their stopping cross sections between 0 and 18 eV. The dose absorbed by the cytosine shell, which occupies a volume of 4 nm(3), is extremely high. It amounts to 79 kGy per decay of which 3%, 39%, and 58% is attributed to vibrational excitations, <span class="hlt">electronic</span> excitations, and ionization processes, respectively.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850014171','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850014171"><span id="translatedtitle">Average and worst-case specifications of precipitating auroral <span class="hlt">electron</span> environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hardy, D. A.; Burke, W. J.; Gussenhoven, M. S.; Holeman, E.; Yeh, H. C.</p> <p>1985-01-01</p> <p>The precipitation <span class="hlt">electrons</span> in the auroral environment are highly variable in their energy and intensity in both space and time. As such they are a source of potential hazard to the operation of the Space Shuttle and other large spacecraft operating in polar orbit. In order to assess these hazards both the average and extreme states of the precipitating <span class="hlt">electrons</span> must be determined. Work aimed at such a specification is presented. First results of a global study of the average characteristics are presented. In this study the high latitude region was divided into spatial elements in magnetic local time and corrected geomagnetic latitude. The average <span class="hlt">electron</span> spectrum was then determined in each spatial element for seven different levels of activity as measured by K sub p using an extremely large data set of auroral observations. Second a case study of an extreme auroral <span class="hlt">electron</span> environment is presented, in which the <span class="hlt">electrons</span> are accelerated through field aligned potential as high as 30,000 <span class="hlt">volts</span> and in which the spacecraft is seen to charge negatively to a potential approaching .5 kilovolts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=virtual+AND+reality+AND+architecture&pg=2&id=EJ489348','ERIC'); return false;" href="http://eric.ed.gov/?q=virtual+AND+reality+AND+architecture&pg=2&id=EJ489348"><span id="translatedtitle"><span class="hlt">Electronic</span> School.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Executive Educator, 1994</p> <p>1994-01-01</p> <p>This issue of "The <span class="hlt">Electronic</span> School" features a special forum on computer networking. Articles specifically focus on network operating systems, cabling requirements, and network architecture. Tom Wall argues that virtual reality is not yet ready for classroom use. B.J. Novitsky profiles two high schools experimenting with CD-ROM yearbooks. Bill…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED456073.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED456073.pdf"><span id="translatedtitle"><span class="hlt">Electronic</span> Money.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Schilling, Tim</p> <p></p> <p>Thirty years ago a cashless society was predicted for the near future; paper currency and checks would be an antiquated symbol of the past. Consumers would embrace a new alternative for making payments: <span class="hlt">electronic</span> money. But currency is still used for 87% of payments, mainly for "nickel and dime" purchases. And checks are the payment choice for…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760014423','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760014423"><span id="translatedtitle">Optical <span class="hlt">electronics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Javan, A.</p> <p>1976-01-01</p> <p>The development of an optical diode consisting of a metal-dielectric-metal junction in which the high-speed electric conduction process occurs due to quantum mechanical <span class="hlt">electron</span> tunneling across the dielectric barrier is briefly reviewed. Potential applications of the diode are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED317815.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED317815.pdf"><span id="translatedtitle">Basic <span class="hlt">Electronics</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hartman, Lonnie; Huston, Jane, Ed.</p> <p></p> <p>The skills taught in these materials for a seven-unit course were those identified as necessary not only for entry-level <span class="hlt">electronic</span> technicians but for those in other occupations as well, including appliance repair, heating and air conditioning, and auto mechanics. The seven units are on shop orientation and safety principles, introduction to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED405859.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED405859.pdf"><span id="translatedtitle"><span class="hlt">Electronic</span> Homework.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Lee, Fong-lok; Heyworth, Rex M.</p> <p></p> <p>The <span class="hlt">Electronic</span> Homework assistant system is composed of two components: the Computer Tutor and the Homework Administrator. The Computer Tutor is an intelligent tutoring system that can provide personal assistance like supplying hints, checking errors, providing remediation and prioritizing problems. The Homework Administrator is a teacher's…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080005993','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005993"><span id="translatedtitle"><span class="hlt">Electronic</span> tongue</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhlman, Kimberly (Inventor); Buehler, Martin G. (Inventor)</p> <p>2004-01-01</p> <p>An ion selective electrode (ISE) array is described, as well as methods for producing the same. The array can contain multiple ISE which are individually <span class="hlt">electronically</span> addressed. The addressing allows simplified preparation of the array. The array can be used for water quality monitoring, for example.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Realia&pg=4&id=EJ563830','ERIC'); return false;" href="http://eric.ed.gov/?q=Realia&pg=4&id=EJ563830"><span id="translatedtitle"><span class="hlt">Electronic</span> Portfolios.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Purves, Alan C.</p> <p>1996-01-01</p> <p>Outlines three forms of <span class="hlt">electronic</span> portfolio based on a student's work, a class project about a specific topic, and a class seminar on a broad topic. Discusses logistical problems of management, access, and cross-referencing; technical problems of input, access, and copying; and theoretical issues of the lack of realia, of ownership and copyright,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=circuit+AND+test+AND+method&pg=7&id=ED410409','ERIC'); return false;" href="http://eric.ed.gov/?q=circuit+AND+test+AND+method&pg=7&id=ED410409"><span id="translatedtitle">General <span class="hlt">Electronics</span> Technician: Basic <span class="hlt">Electronics</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hilley, Robert</p> <p></p> <p>These instructional materials include a teacher's guide designed to assist instructors in organizing and presenting an introductory course in general <span class="hlt">electronics</span> and a student guide. The materials are based on the curriculum-alignment concept of first stating the objectives, developing instructional strategies for teaching those objectives, and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2869529','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2869529"><span id="translatedtitle"><span class="hlt">Electron</span> Cryotomography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tocheva, Elitza I.; Li, Zhuo; Jensen, Grant J.</p> <p>2010-01-01</p> <p><span class="hlt">Electron</span> cryotomography (ECT) is an emerging technology that allows thin samples such as macromolecular complexes and small bacterial cells to be imaged in 3-D in a nearly native state to “molecular” (∼4 nm) resolution. As such, ECT is beginning to deliver long-awaited insight into the positions and structures of cytoskeletal filaments, cell wall elements, motility machines, chemoreceptor arrays, internal compartments, and other ultrastructures. This article describes the technique and summarizes its contributions to bacterial cell biology. For comparable recent reviews, see (Subramaniam 2005; Jensen and Briegel 2007; Murphy and Jensen 2007; Li and Jensen 2009). For reviews on the history, technical details, and broader application of <span class="hlt">electron</span> tomography in general, see for example (Subramaniam and Milne 2004; Lucić et al. 2005; Leis et al. 2008; Midgley and Dunin-Borkowski 2009). PMID:20516135</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010neof.book...73B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010neof.book...73B"><span id="translatedtitle"><span class="hlt">Electronic</span> Nose and <span class="hlt">Electronic</span> Tongue</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhattacharyya, Nabarun; Bandhopadhyay, Rajib</p> <p></p> <p>Human beings have five senses, namely, vision, hearing, touch, smell and taste. The sensors for vision, hearing and touch have been developed for several years. The need for sensors capable of mimicking the senses of smell and taste have been felt only recently in food industry, environmental monitoring and several industrial applications. In the ever-widening horizon of frontier research in the field of <span class="hlt">electronics</span> and advanced computing, emergence of <span class="hlt">electronic</span> nose (E-Nose) and <span class="hlt">electronic</span> tongue (E-Tongue) have been drawing attention of scientists and technologists for more than a decade. By intelligent integration of multitudes of technologies like chemometrics, microelectronics and advanced soft computing, human olfaction has been successfully mimicked by such new techniques called machine olfaction (Pearce et al. 2002). But the very essence of such research and development efforts has centered on development of customized <span class="hlt">electronic</span> nose and <span class="hlt">electronic</span> tongue solutions specific to individual applications. In fact, research trends as of date clearly points to the fact that a machine olfaction system as versatile, universal and broadband as human nose and human tongue may not be feasible in the decades to come. But application specific solutions may definitely be demonstrated and commercialized by modulation in sensor design and fine-tuning the soft computing solutions. This chapter deals with theory, developments of E-Nose and E-Tongue technology and their applications. Also a succinct account of future trends of R&D efforts in this field with an objective of establishing co-relation between machine olfaction and human perception has been included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4102678','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4102678"><span id="translatedtitle"><span class="hlt">ELECTRONIC</span> MULTIPLIER</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Collier, D.M.; Meeks, L.A.; Palmer, J.P.</p> <p>1961-01-31</p> <p>S>An <span class="hlt">electronic</span> multiplier is described for use in analog computers. Two electrical input signals are received; one controls the slope of a saw-tooth voltage wave while the other controls the time duration of the wave. A condenser and diode clamps are provided to sustain the crest voltage reached by the wave, and for storing that voltage to provide an output signal which is a steady d-c voltage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4163907','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4163907"><span id="translatedtitle"><span class="hlt">ELECTRON</span> GUN</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Christofilos, N.C.; Ehlers, K.W.</p> <p>1960-04-01</p> <p>A pulsed <span class="hlt">electron</span> gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the <span class="hlt">electron</span> source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the <span class="hlt">electron</span> source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030066804&hterms=year+model&qs=N%3D0%26Ntk%3DTitle%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dyear%2Bmodel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030066804&hterms=year+model&qs=N%3D0%26Ntk%3DTitle%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dyear%2Bmodel"><span id="translatedtitle">A One <span class="hlt">Billion</span> Year Martian Climate Model: The Importance of Seasonally Resolved Polar Caps and the Role of Wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Armstrong, J. C.; Leovy, C. B.; Quinn, T. R.; Haberle, R. M.; Schaeffer, J.</p> <p>2003-01-01</p> <p>Wind deflation and deposition are powerful agents of surface change in the present Mars climate regime. Recent studies indicate that, while the distribution of regions of potential deflation (or erosion) and deposition is remarkably insensitive to changes in orbital parameters (obliquity, timing of perihelion passage, etc.), rates of aeolian surface modification may be highly sensitive to these parameters even if the atmospheric mass remains constant. But previous work suggested the atmospheric mass is likely to be sensitive to obliquity, especially if a significant mass of carbon dioxide can be stored in the regolith or deposited in the form of massive polar caps. Deflation and erosion are highly sensitive to surface pressure, so feedback between orbit variations and surface pressure can greatly enhance the sensitivity of aeolian modification rates to orbital parameters. We used statistics derived from a 1 Gyr orbital integration of the spin axis of Mars, coupled with 3D general circulation models (GCMs) at a variety of orbital conditions and pressures, to explore this feedback. We also employed a seasonally resolved 1D energy balance model to illuminate the gross characteristics of the longterm atmospheric evolution, wind erosion and deposition over one <span class="hlt">billion</span> years. We find that seasonal polar cycles have a critical influence on the ability for the regolith to release CO2 at high obliquities, and find that the atmospheric CO2 actually decreases at high obliquities due to the cooling effect of polar deposits at latitudes where seasonal caps form. At low obliquity, the formation of massive, permanent polar caps depends critically on the values of the frost albedo, A(sub frost), and frost emissivity, E(sub frost). Using our 1D model with values of A(sub frost) = 0.67 and E(sub frost) = 0.55, matched to the NASA Ames GCM results, we find that permanent caps only form at low obliquities (< 10 degrees). Thus, contrary to expectations, the Martian atmospheric pressure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060038050&hterms=accelerometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Daccelerometer','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060038050&hterms=accelerometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Daccelerometer"><span id="translatedtitle">(abstract) A Miniature, High-Sensitivity, <span class="hlt">Electron</span>-Tunneling Accelerometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gabrielson, Thomas B.; Rockstad, Howard K.; Tang, Tony K.</p> <p>1994-01-01</p> <p>A prototype low-noise accelerometer has been fabricated with an <span class="hlt">electron</span>-tunneling transducer. By measuring the tunneling current between an electrode on the proof mass and a feedback-controlled monitor electrode, very small accelerations can be detected with high responsivity. This particular prototype (10x10x1.5 mm) was designed for underwater acoustic measurement from a few hertz to 1 kHz. The measured responsivity below the fundamental device resonance at 100 Hz is roughly 1500 <span class="hlt">volts</span> per m/s(sup 2) with a measured noise spectral density of 10(sup -6) m/s(sup 2) per root hertz or less between 30 and 300 Hz. The noise floor is controlled primarily by 1/f noise in the tunneling current although the noise floor reaches the theoretical molecular-agitation limit at 100 hertz. The responsivity and directivity of the device were measured in a standard gradient-hydrophone calibrator; the noise floor was determined in a vacuum-ionization chamber assembled from commercial off-the-shelf components; and the detailed dynamics of the proof-mass motion were examined using a heterodyne laser interferometer that was scanned across the surface and synchronously detected with respect to the excitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150007916','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150007916"><span id="translatedtitle">Gradual Diffusion and Punctuated Phase Space Density Enhancements of Highly Relativistic <span class="hlt">Electrons</span>: Van Allen Probes Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baker, D. N.; Jaynes, A. N.; Li, X.; Henderson, M. G.; Kanekal, S. G.; Reeves, G. D.; Spence, H. E.; Claudepierre, S. G.; Fennell, J. F.; Hudson, M. K.</p> <p>2014-01-01</p> <p>The dual-spacecraft Van Allen Probes mission has provided a new window into mega <span class="hlt">electron</span> <span class="hlt">volt</span> (MeV) particle dynamics in the Earth's radiation belts. Observations (up to E (is) approximately 10MeV) show clearly the behavior of the outer <span class="hlt">electron</span> radiation belt at different timescales: months-long periods of gradual inward radial diffusive transport and weak loss being punctuated by dramatic flux changes driven by strong solar wind transient events. We present analysis of multi-MeV <span class="hlt">electron</span> flux and phase space density (PSD) changes during March 2013 in the context of the first year of Van Allen Probes operation. This March period demonstrates the classic signatures both of inward radial diffusive energization and abrupt localized acceleration deep within the outer Van Allen zone (L (is) approximately 4.0 +/- 0.5). This reveals graphically that both 'competing' mechanisms of multi-MeV <span class="hlt">electron</span> energization are at play in the radiation belts, often acting almost concurrently or at least in rapid succession.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24611581','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24611581"><span id="translatedtitle">Few-<span class="hlt">electron</span> edge-state quantum dots in a silicon nanowire field-effect transistor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Voisin, Benoit; Nguyen, Viet-Hung; Renard, Julien; Jehl, Xavier; Barraud, Sylvain; Triozon, François; Vinet, Maud; Duchemin, Ivan; Niquet, Yann-Michel; de Franceschi, Silvano; Sanquer, Marc</p> <p>2014-01-01</p> <p>We investigate the gate-induced onset of few-<span class="hlt">electron</span> regime through the undoped channel of a silicon nanowire field-effect transistor. By combining low-temperature transport measurements and self-consistent calculations, we reveal the formation of one-dimensional conduction modes localized at the two upper edges of the channel. Charge traps in the gate dielectric cause <span class="hlt">electron</span> localization along these edge modes, creating elongated quantum dots with characteristic lengths of ∼10 nm. We observe single-<span class="hlt">electron</span> tunneling across two such dots in parallel, specifically one in each channel edge. We identify the filling of these quantum dots with the first few <span class="hlt">electrons</span>, measuring addition energies of a few tens of millielectron <span class="hlt">volts</span> and level spacings of the order of 1 meV, which we ascribe to the valley orbit splitting. The total removal of valley degeneracy leaves only a 2-fold spin degeneracy, making edge quantum dots potentially promising candidates for silicon spin qubits. PMID:24611581</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1221156-long-lived-relativistic-electron-storage-ring-embedded-earth-outer-van-allen-belt','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1221156-long-lived-relativistic-electron-storage-ring-embedded-earth-outer-van-allen-belt"><span id="translatedtitle">A long-lived relativistic <span class="hlt">electron</span> storage ring embedded in Earth's Outer Van Allen belt</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Henderson, M. G.; Li, X.; Spence, H. E.; Elkington, S. R.; Friedel, R. H. W.; Goldstein, J.; Hudson, M. K.; et al</p> <p>2013-02-28</p> <p>Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts are thought to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is comprised predominantly of mega-<span class="hlt">electron</span> <span class="hlt">volt</span> (MeV) <span class="hlt">electrons</span> that wax and wane in intensity on time scales ranging from hours to days depending primarily on external forcing by the solar wind. Thus, the spatially separated inner zone is comprised of commingled high-energy <span class="hlt">electrons</span> and very energetic positive ions (mostly protons), the latter being stable in intensity levels over years to decades. In situ energy-specific and temporally resolved spacecraft observations revealmore » an isolated third ring, or torus, of high-energy (E > 2 MeV) <span class="hlt">electrons</span> that formed on 2 September 2012 and persisted largely unchanged in the geocentric radial range of 3.0 to ~3.5 Earth radii for over four weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864337','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864337"><span id="translatedtitle">Neutral beamline with ion energy recovery based on magnetic blocking of <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Stirling, William L.</p> <p>1982-01-01</p> <p>A neutral beamline generator with energy recovery of the full-energy ion ponent of the beam based on magnetic blocking of <span class="hlt">electrons</span> is provided. Ions from a positive ion source are accelerated to the desired beam energy from a slightly positive potential level with respect to ground through a neutralizer cell by means of a negative acceleration voltage. The unneutralized full-energy ion component of the beam exiting the neutralizer are retarded and slightly deflected and the <span class="hlt">electrons</span> in the neutralizer are blocked by a magnetic field generated transverse to the beamline. An <span class="hlt">electron</span> collector in the form of a coaxial cylinder surrounding and protruding axial a few centimeters beyond the neutralizer exit terminates the <span class="hlt">electrons</span> which exit the neutralizer in an E x B drift to the collector when the collector is biased a few hundred <span class="hlt">volts</span> positive with respect to the neutralizer voltage. The neutralizer is operated at the negative acceleration voltage, and the deflected full energy ions are decelerated and the charge collected at ground potential thereby expending none of their energy received from the acceleration power supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1221156','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1221156"><span id="translatedtitle">A long-lived relativistic <span class="hlt">electron</span> storage ring embedded in Earth's Outer Van Allen belt</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Henderson, M. G.; Li, X.; Spence, H. E.; Elkington, S. R.; Friedel, R. H. W.; Goldstein, J.; Hudson, M. K.; Reeves, G. D.; Thorne, R. M.; Kletzing, C. A.; Claudepierre, S. G.</p> <p>2013-02-28</p> <p>Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts are thought to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is comprised predominantly of mega-<span class="hlt">electron</span> <span class="hlt">volt</span> (MeV) <span class="hlt">electrons</span> that wax and wane in intensity on time scales ranging from hours to days depending primarily on external forcing by the solar wind. Thus, the spatially separated inner zone is comprised of commingled high-energy <span class="hlt">electrons</span> and very energetic positive ions (mostly protons), the latter being stable in intensity levels over years to decades. In situ energy-specific and temporally resolved spacecraft observations reveal an isolated third ring, or torus, of high-energy (E > 2 MeV) <span class="hlt">electrons</span> that formed on 2 September 2012 and persisted largely unchanged in the geocentric radial range of 3.0 to ~3.5 Earth radii for over four weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19800052751&hterms=particle+accelerator&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dparticle%2Baccelerator','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19800052751&hterms=particle+accelerator&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dparticle%2Baccelerator"><span id="translatedtitle">POLAR 5 - An <span class="hlt">electron</span> accelerator experiment within an aurora. III - Evidence for significant spacecraft charging by an <span class="hlt">electron</span> accelerator at ionospheric altitudes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacobsen, T. A.; Maynard, N. C.</p> <p>1980-01-01</p> <p>The POLAR 5 rocket experiment carried an <span class="hlt">electron</span> accelerator on a 'daughter' payload which injected a 0.1 A beam of 10 keV <span class="hlt">electrons</span> in a pulsed mode every 410 ms. With spin and precession, injections were made over a wide range of pitch angles. Measurements from a double probe electric field instrument and from particle detectors on the 'mother' payload and from a crude RPA on the 'daughter' payload are interpreted to indicate that the 'daughter' charges to a potential between several hundred <span class="hlt">volts</span> and 1 kV. The neutralizing return current to the 'daughter' is shown to be asymmetrically distributed with the majority being collected from the direction of the beam. The additional <span class="hlt">electrons</span> necessary to neutralize the daughter are thought to be produced and heated through beam-plasma interactions postulated by Maehlum et al. (1980) and Grandal et al. (1980) to explain the particle and optical measurements. Significant electric fields emanating from the charged 'daughter' and the beam are seen at distances exceeding 100 m at the 'mother' payload.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PlPhR..37..628M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PlPhR..37..628M"><span id="translatedtitle">Glow discharge with electrostatic confinement of <span class="hlt">electrons</span> in a chamber bombarded by fast <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Metel, A. S.; Grigoriev, S. N.; Melnik, Yu. A.; Prudnikov, V. V.</p> <p>2011-07-01</p> <p>A metal substrate is immersed in plasma of glow discharge with electrostatic confinement of <span class="hlt">electrons</span> inside the vacuum chamber volume V ≈ 0.12 m3 filled with argon or nitrogen at pressures 0.005-5 Pa, and dependence of discharge characteristics on negative substrate potential is studied. Emitted by the substrate secondary <span class="hlt">electrons</span> bombard the chamber walls and it results in <span class="hlt">electron</span> emission growth of the chamber walls and rise of gas ionization intensity inside the chamber. Increase of voltage U between the chamber and the substrate up to 10 kV at a constant discharge current I d in the anode circuit results in a manifold rise of current I in the substrate circuit and decrease of discharge voltage U d between the anode and the chamber from hundreds to tens of <span class="hlt">volts</span>. At pressure p < 0.05 Pa nonuniformity of plasma density does not exceed ˜10%. Using the Child-Langmuir law, as well as measurement results of sheath width d between homogeneous plasma and a lengthy flat substrate dependent on voltage U ion current density j i on the substrate surface and ion-<span class="hlt">electron</span> emission coefficient γ i are calculated. After the current in circuit of a substrate made of the same material is measured, the γ i values may be used to evaluate the average dose of ion implantation. The rate of dose rise at a constant high voltage U is by an order of magnitude higher than in known systems equipped with generators of square-wave high-voltage pulses. Application to the substrate of 10-ms-wide sinusoidal high-voltage pulses, which follow each other with 100-Hz frequency, results in synchronous oscillations of voltage U and ion current I i in the substrate circuit. In this case variation of the sheath width d due to oscillations of U and Ii is insignificant and d does not exceed several centimeters thus enabling substrate treatment in a comparatively small vacuum chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26933691','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26933691"><span id="translatedtitle">Long-range coupling of <span class="hlt">electron</span>-hole pairs in spatially separated organic donor-acceptor layers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakanotani, Hajime; Furukawa, Taro; Morimoto, Kei; Adachi, Chihaya</p> <p>2016-02-01</p> <p>Understanding exciton behavior in organic semiconductor molecules is crucial for the development of organic semiconductor-based excitonic devices such as organic light-emitting diodes and organic solar cells, and the tightly bound <span class="hlt">electron</span>-hole pair forming an exciton is normally assumed to be localized on an organic semiconducting molecule. We report the observation of long-range coupling of <span class="hlt">electron</span>-hole pairs in spatially separated <span class="hlt">electron</span>-donating and <span class="hlt">electron</span>-accepting molecules across a 10-nanometers-thick spacer layer. We found that the exciton energy can be tuned over 100 megaelectron <span class="hlt">volts</span> and the fraction of delayed fluorescence can be increased by adjusting the spacer-layer thickness. Furthermore, increasing the spacer-layer thickness produced an organic light-emitting diode with an electroluminescence efficiency nearly eight times higher than that of a device without a spacer layer. Our results demonstrate the first example of a long-range coupled charge-transfer state between <span class="hlt">electron</span>-donating and <span class="hlt">electron</span>-accepting molecules in a working device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4771443','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4771443"><span id="translatedtitle">Long-range coupling of <span class="hlt">electron</span>-hole pairs in spatially separated organic donor-acceptor layers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nakanotani, Hajime; Furukawa, Taro; Morimoto, Kei; Adachi, Chihaya</p> <p>2016-01-01</p> <p>Understanding exciton behavior in organic semiconductor molecules is crucial for the development of organic semiconductor-based excitonic devices such as organic light-emitting diodes and organic solar cells, and the tightly bound <span class="hlt">electron</span>-hole pair forming an exciton is normally assumed to be localized on an organic semiconducting molecule. We report the observation of long-range coupling of <span class="hlt">electron</span>-hole pairs in spatially separated <span class="hlt">electron</span>-donating and <span class="hlt">electron</span>-accepting molecules across a 10-nanometers-thick spacer layer. We found that the exciton energy can be tuned over 100 megaelectron <span class="hlt">volts</span> and the fraction of delayed fluorescence can be increased by adjusting the spacer-layer thickness. Furthermore, increasing the spacer-layer thickness produced an organic light-emitting diode with an electroluminescence efficiency nearly eight times higher than that of a device without a spacer layer. Our results demonstrate the first example of a long-range coupled charge-transfer state between <span class="hlt">electron</span>-donating and <span class="hlt">electron</span>-accepting molecules in a working device. PMID:26933691</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatEn...115005H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatEn...115005H"><span id="translatedtitle">Impacts of a 32-<span class="hlt">billion</span>-gallon bioenergy landscape on land and fossil fuel use in the US</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hudiburg, Tara W.; Wang, Weiwei; Khanna, Madhu; Long, Stephen P.; Dwivedi, Puneet; Parton, William J.; Hartman, Melannie; Delucia, Evan H.</p> <p>2016-01-01</p> <p>Sustainable transportation biofuels may require considerable changes in land use to meet mandated targets. Understanding the possible impact of different policies on land use and greenhouse gas emissions has typically proceeded by exploring either ecosystem or economic modelling. Here we integrate such models to assess the potential for the US Renewable Fuel Standard to reduce greenhouse gas emissions from the transportation sector through the use of cellulosic biofuels. We find that 2022 US emissions are decreased by 7.0 ± 2.5% largely through gasoline displacement and soil carbon storage by perennial grasses. If the Renewable Fuel Standard is accompanied by a cellulosic biofuel tax credit, these emissions could be reduced by 12.3 ± 3.4%. Our integrated approach indicates that transitioning to cellulosic biofuels can meet a 32-<span class="hlt">billion</span>-gallon Renewable Fuel Standard target with negligible effects on food crop production, while reducing fossil fuel use and greenhouse gas emissions. However, emissions savings are lower than previous estimates that did not account for economic constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22949693','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22949693"><span id="translatedtitle">Sulfur isotopes of organic matter preserved in 3.45-<span class="hlt">billion</span>-year-old stromatolites reveal microbial metabolism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bontognali, Tomaso R R; Sessions, Alex L; Allwood, Abigail C; Fischer, Woodward W; Grotzinger, John P; Summons, Roger E; Eiler, John M</p> <p>2012-09-18</p> <p>The 3.45-<span class="hlt">billion</span>-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ(33)S and . This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ(33)S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H(2)S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ(33)S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22949693','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22949693"><span id="translatedtitle">Sulfur isotopes of organic matter preserved in 3.45-<span class="hlt">billion</span>-year-old stromatolites reveal microbial metabolism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bontognali, Tomaso R R; Sessions, Alex L; Allwood, Abigail C; Fischer, Woodward W; Grotzinger, John P; Summons, Roger E; Eiler, John M</p> <p>2012-09-18</p> <p>The 3.45-<span class="hlt">billion</span>-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ(33)S and . This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ(33)S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H(2)S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ(33)S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities. PMID:22949693</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24590933','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24590933"><span id="translatedtitle">Early HIV treatment led to life expectancy gains valued at $80 <span class="hlt">billion</span> for people infected in 1996-2009.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Romley, John A; Juday, Timothy; Solomon, Matthew D; Seekins, Daniel; Brookmeyer, Ronald; Goldman, Dana P</p> <p>2014-03-01</p> <p>In late 2009 US guidelines for HIV treatment were revised to recommend the initiation of combination antiretroviral therapy (cART) earlier in the course of the disease. We analyzed the life expectancy gains of people infected with HIV between the introduction of cART in 1996 and the 2009 guideline revisions. Compared to people who initiated cART late (defined as having a CD4 cell count of less than 350 per cubic millimeter of blood), those who initiated treatment early (with a CD4 count of 350-500) could expect to live 6.1 years longer, and the earliest initiators (with a CD4 count of more than 500) could expect an extra 9.0 years of life. The total value of life expectancy gains to the early and earliest initiators of treatment was $80 <span class="hlt">billion</span>, with each life-year valued at $150,000. The value of the survival gains was more than double the increase in drug manufacturers' revenues from early cART initiation. Our results clarify the economic implications of adherence to treatment guidelines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2683128','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2683128"><span id="translatedtitle">The controversial “Cambrian” fossils of the Vindhyan are real but more than a <span class="hlt">billion</span> years older</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bengtson, Stefan; Belivanova, Veneta; Rasmussen, Birger; Whitehouse, Martin</p> <p>2009-01-01</p> <p>The age of the Vindhyan sedimentary basin in central India is controversial, because geochronology indicating early Proterozoic ages clashes with reports of Cambrian fossils. We present here an integrated paleontologic–geochronologic investigation to resolve this conundrum. New sampling of Lower Vindhyan phosphoritic stromatolitic dolomites from the northern flank of the Vindhyans confirms the presence of fossils most closely resembling those found elsewhere in Cambrian deposits: annulated tubes, embryo-like globules with polygonal surface pattern, and filamentous and coccoidal microbial fabrics similar to Girvanella and Renalcis. None of the fossils, however, can be ascribed to uniquely Cambrian or Ediacaran taxa. Indeed, the embryo-like globules are not interpreted as fossils at all but as former gas bubbles trapped in mucus-rich cyanobacterial mats. Direct dating of the same fossiliferous phosphorite yielded a Pb–Pb isochron of 1,650 ± 89 (2σ) million years ago, confirming the Paleoproterozoic age of the fossils. New U–Pb geochronology of zircons from tuffaceous mudrocks in the Lower Vindhyan Porcellanite Formation on the southern flank of the Vindhyans give comparable ages. The Vindhyan phosphorites provide a window of 3-dimensionally preserved Paleoproterozoic fossils resembling filamentous and coccoidal cyanobacteria and filamentous eukaryotic algae, as well as problematic forms. Like Neoproterozoic phosphorites a <span class="hlt">billion</span> years later, the Vindhyan deposits offer important new insights into the nature and diversity of life, and in particular, the early evolution of multicellular eukaryotes. PMID:19416859</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4873660','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4873660"><span id="translatedtitle">Decimetre-scale multicellular eukaryotes from the 1.56-<span class="hlt">billion</span>-year-old Gaoyuzhuang Formation in North China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhu, Shixing; Zhu, Maoyan; Knoll, Andrew H.; Yin, Zongjun; Zhao, Fangchen; Sun, Shufen; Qu, Yuangao; Shi, Min; Liu, Huan</p> <p>2016-01-01</p> <p>Fossils of macroscopic eukaryotes are rarely older than the Ediacaran Period (635–541 million years (Myr)), and their interpretation remains controversial. Here, we report the discovery of macroscopic fossils from the 1,560-Myr-old Gaoyuzhuang Formation, Yanshan area, North China, that exhibit both large size and regular morphology. Preserved as carbonaceous compressions, the Gaoyuzhuang fossils have statistically regular linear to lanceolate shapes up to 30 cm long and nearly 8 cm wide, suggesting that the Gaoyuzhuang fossils record benthic multicellular eukaryotes of unprecedentedly large size. Syngenetic fragments showing closely packed ∼10 μm cells arranged in a thick sheet further reinforce the interpretation. Comparisons with living thalloid organisms suggest that these organisms were photosynthetic, although their phylogenetic placement within the Eukarya remains uncertain. The new fossils provide the strongest evidence yet that multicellular eukaryotes with decimetric dimensions and a regular developmental program populated the marine biosphere at least a <span class="hlt">billion</span> years before the Cambrian Explosion. PMID:27186667</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040090667&hterms=anaerobic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Danaerobic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040090667&hterms=anaerobic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Danaerobic"><span id="translatedtitle">Evidence from massive siderite beds for a CO2-rich atmosphere before approximately 1.8 <span class="hlt">billion</span> years ago</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ohmoto, Hiroshi; Watanabe, Yumiko; Kumazawa, Kazumasa</p> <p>2004-01-01</p> <p>It is generally thought that, in order to compensate for lower solar flux and maintain liquid oceans on the early Earth, methane must have been an important greenhouse gas before approximately 2.2 <span class="hlt">billion</span> years (Gyr) ago. This is based upon a simple thermodynamic calculation that relates the absence of siderite (FeCO3) in some pre-2.2-Gyr palaeosols to atmospheric CO2 concentrations that would have been too low to have provided the necessary greenhouse effect. Using multi-dimensional thermodynamic analyses and geological evidence, we show here that the absence of siderite in palaeosols does not constrain atmospheric CO2 concentrations. Siderite is absent in many palaeosols (both pre- and post-2.2-Gyr in age) because the O2 concentrations and pH conditions in well-aerated soils have favoured the formation of ferric (Fe3+)-rich minerals, such as goethite, rather than siderite. Siderite, however, has formed throughout geological history in subsurface environments, such as euxinic seas, where anaerobic organisms created H2-rich conditions. The abundance of large, massive siderite-rich beds in pre-1.8-Gyr sedimentary sequences and their carbon isotope ratios indicate that the atmospheric CO2 concentration was more than 100 times greater than today, causing the rain and ocean waters to be more acidic than today. We therefore conclude that CO2 alone (without a significant contribution from methane) could have provided the necessary greenhouse effect to maintain liquid oceans on the early Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23698363','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23698363"><span id="translatedtitle">The rapid assembly of an elliptical galaxy of 400 <span class="hlt">billion</span> solar masses at a redshift of 2.3.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fu, Hai; Cooray, Asantha; Feruglio, C; Ivison, R J; Riechers, D A; Gurwell, M; Bussmann, R S; Harris, A I; Altieri, B; Aussel, H; Baker, A J; Bock, J; Boylan-Kolchin, M; Bridge, C; Calanog, J A; Casey, C M; Cava, A; Chapman, S C; Clements, D L; Conley, A; Cox, P; Farrah, D; Frayer, D; Hopwood, R; Jia, J; Magdis, G; Marsden, G; Martínez-Navajas, P; Negrello, M; Neri, R; Oliver, S J; Omont, A; Page, M J; Pérez-Fournon, I; Schulz, B; Scott, D; Smith, A; Vaccari, M; Valtchanov, I; Vieira, J D; Viero, M; Wang, L; Wardlow, J L; Zemcov, M</p> <p>2013-06-20</p> <p>Stellar archaeology shows that massive elliptical galaxies formed rapidly about ten <span class="hlt">billion</span> years ago with star-formation rates of above several hundred solar masses per year. Their progenitors are probably the submillimetre bright galaxies at redshifts z greater than 2. Although the mean molecular gas mass (5 × 10(10) solar masses) of the submillimetre bright galaxies can explain the formation of typical elliptical galaxies, it is inadequate to form elliptical galaxies that already have stellar masses above 2 × 10(11) solar masses at z ≈ 2. Here we report multi-wavelength high-resolution observations of a rare merger of two massive submillimetre bright galaxies at z = 2.3. The system is seen to be forming stars at a rate of 2,000 solar masses per year. The star-formation efficiency is an order of magnitude greater than that of normal galaxies, so the gas reservoir will be exhausted and star formation will be quenched in only around 200 million years. At a projected separation of 19 kiloparsecs, the two massive starbursts are about to merge and form a passive elliptical galaxy with a stellar mass of about 4 × 10(11) solar masses. We conclude that gas-rich major galaxy mergers with intense star formation can form the most massive elliptical galaxies by z ≈ 1.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..MARJ25013S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MARJ25013S"><span id="translatedtitle">Multi million-to-<span class="hlt">Billion</span> Atom Molecular Dynamics Simulations of Cavitation-Induced Damage on a Silica Slab</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shekhar, Adarsh; Nomura, Ken-Ichi; Kalia, Rajiv; Nakano, Aiichiro; Vashishta, Priya</p> <p>2012-02-01</p> <p>Cavitation bubble collapse causes severe damage to materials. For example, cavitation erosion is a major threat to the safety of nuclear power plants. The cavitation bubbles may also be utilized for preventing stress corrosion cracking with water jet peening technology. We have performed multi million-to-<span class="hlt">billion</span> atoms molecular dynamics simulations to investigate the shock-induced cavitation damage mechanism on an amorphous silica slab in water. The system consists of a 60nm thick silica slab immersed in water in an MD box of dimension 285 x 200 x 200 nm3. A nanobubble is created by removing water molecules within a sphere of radius 100 nm. To apply a planar shock, we assign a uniform particle velocity vp on the entire system towards a planar momentum mirror. We have performed the simulation with two kinds of bubbles, an empty bubble and a bubble filled with inert gas. The simulation results reveal nanojet formation during bubble collapse causing damage on the silica surface; however, the damage was significantly reduced in the case of the filled bubble. We will discuss the effect of the presence of inter gas inside the nanobubble on the pressure distribution, the extent of damage, and collapse behavior corresponding the shock front.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3458326','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3458326"><span id="translatedtitle">Sulfur isotopes of organic matter preserved in 3.45-<span class="hlt">billion</span>-year-old stromatolites reveal microbial metabolism</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bontognali, Tomaso R. R.; Sessions, Alex L.; Allwood, Abigail C.; Fischer, Woodward W.; Grotzinger, John P.; Summons, Roger E.; Eiler, John M.</p> <p>2012-01-01</p> <p>The 3.45-<span class="hlt">billion</span>-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ33S and . This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ33S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H2S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ33S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities. PMID:22949693</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110014891','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110014891"><span id="translatedtitle"><span class="hlt">Electronic</span> Router</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crusan, Jason</p> <p>2005-01-01</p> <p><span class="hlt">Electronic</span> Router (E-Router) is an application program for routing documents among the cognizant individuals in a government agency or other organization. E-Router supplants a prior 14 NASA Tech Briefs, May 2005 system in which paper documents were routed physically in packages by use of paper slips, packages could be lost, routing times were unacceptably long, tracking of packages was difficult, and there was a need for much photocopying. E-Router enables a user to create a digital package to be routed. Input accepted by E-Router includes the title of the package, the person(s) to whom the package is to be routed, attached files, and comments to reviewers. <span class="hlt">Electronic</span> mail is used to notify reviewers of needed actions. The creator of the package can, at any time, see the status of the package in the routing structure. At the end of the routing process, E-Router keeps a record of the package and of approvals and/or concurrences of the reviewers. There are commercial programs that perform the general functions of E-Router, but they are more complicated. E-Router is Web-based, easy to use, and does not require the installation or use of client software.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=india&pg=5&id=EJ1042106','ERIC'); return false;" href="http://eric.ed.gov/?q=india&pg=5&id=EJ1042106"><span id="translatedtitle">Developing a <span class="hlt">Billion</span> Leaders</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gergen, Christopher; Rego, Lyndon; Wright, Joel</p> <p>2014-01-01</p> <p>Intentionally developing the leadership capacity of all students is a necessary requirement for schools around the world. The Center for Creative Leadership in Greensboro, N.C., has been at the center of this work and presents three schools as examples: Ravenscroft School in Raleigh, N.C., the African Leadership Academy in Johannesburg, South…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Sci...333..838K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Sci...333..838K"><span id="translatedtitle">Epidermal <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Dae-Hyeong; Lu, Nanshu; Ma, Rui; Kim, Yun-Soung; Kim, Rak-Hwan; Wang, Shuodao; Wu, Jian; Won, Sang Min; Tao, Hu; Islam, Ahmad; Yu, Ki Jun; Kim, Tae-il; Chowdhury, Raeed; Ying, Ming; Xu, Lizhi; Li, Ming; Chung, Hyun-Joong; Keum, Hohyun; McCormick, Martin; Liu, Ping; Zhang, Yong-Wei; Omenetto, Fiorenzo G.; Huang, Yonggang; Coleman, Todd; Rogers, John A.</p> <p>2011-08-01</p> <p>We report classes of <span class="hlt">electronic</span> systems that achieve thicknesses, effective elastic moduli, bending stiffnesses, and areal mass densities matched to the epidermis. Unlike traditional wafer-based technologies, laminating such devices onto the skin leads to conformal contact and adequate adhesion based on van der Waals interactions alone, in a manner that is mechanically invisible to the user. We describe systems incorporating electrophysiological, temperature, and strain sensors, as well as transistors, light-emitting diodes, photodetectors, radio frequency inductors, capacitors, oscillators, and rectifying diodes. Solar cells and wireless coils provide options for power supply. We used this type of technology to measure electrical activity produced by the heart, brain, and skeletal muscles and show that the resulting data contain sufficient information for an unusual type of computer game controller.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790030940&hterms=microwave+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmicrowave%2Bradiation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790030940&hterms=microwave+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmicrowave%2Bradiation"><span id="translatedtitle">Microwave radiation measurements near the <span class="hlt">electron</span> plasma frequency of the NASA Lewis Bumpy Torus plasma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mallavarpu, R.; Roth, J. R.</p> <p>1978-01-01</p> <p>Microwave emission near the <span class="hlt">electron</span> plasma frequency of the NASA Lewis Bumpy Torus plasma has been observed, and its relation to the average <span class="hlt">electron</span> density and the dc toroidal magnetic field was examined. The emission was detected using a spectrum analyzer and a 50-ohm miniature coaxial probe. The radiation appeared as a broad amplitude peak that shifted in frequency as the plasma parameters were varied. The observed radiation scanned an average plasma density ranging from 20 <span class="hlt">billion</span> to 800 <span class="hlt">billion</span> per cu cm. A linear relation was observed between the density calculated from the emission frequency and the average plasma density measured with a microwave interferometer. With the aid of a relative density profile measurement of the plasma, it was determined that the emissions occurred from the outer periphery of the plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhD...48w3001K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhD...48w3001K"><span id="translatedtitle">Glow discharges with electrostatic confinement of fast <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolobov, V. I.; Metel, A. S.</p> <p>2015-06-01</p> <p>This review presents a unified treatment of glow discharges with electrostatic confinement of fast <span class="hlt">electrons</span>. These discharges include hollow cathode discharges, wire and cage discharges, reflect discharges with brush and multirod cathodes, and discharges in crossed electric and magnetic fields. Fast <span class="hlt">electrons</span> bouncing inside electrostatic traps provide efficient ionization of gas at very low gas pressures. The electrostatic trap effect (ETE) was first observed by Paschen in hollow cathode discharges almost a century ago. The key parameters that define fundamental characteristics of ETE discharges are the ionization length λN, the penetration range, Λ, and the diffusion length λ of the fast <span class="hlt">electrons</span>, and two universal geometric parameters of the traps: effective width a and length L. Peculiarities of <span class="hlt">electron</span> kinetics and ion collection mechanism explain experimental observations for different trap geometries. The ETE is observed only at Λ > a, when the penetration range of the γ-<span class="hlt">electrons</span> emitted by the cathode exceeds the trap width. In the optimal pressure range, when λN > a, and Λ < L, the cathode potential fall Uc is independent of gas pressure p. With increasing current, Uc tends to its upper limit W/eβγ, where β is the percentage of ions arriving at the cathode and W is the gas ionization cost. In the low-pressure range, Λ > L, Uc rises from hundreds to thousands of <span class="hlt">volts</span>. The sign of the anode potential fall, Ua, depends on the anode surface Sa and its position. When Sa is large compared to a critical value S*, Ua is negative and small. At Sa < S*, the value of Ua becomes positive and rises up to 0.5-1 kV with decreasing p ultimately causing discharge extinction. Scaling laws indicate common physics between vacuum discharges and atmospheric pressure micro-discharges. We discuss peculiarities of <span class="hlt">electron</span> kinetics under different conditions using semi-analytical models. Recent experimental results and applications of glow</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960013907','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960013907"><span id="translatedtitle">Evaluation testing of a portable vapor detector for Part-Per-<span class="hlt">Billion</span> (PPB) level UDMH and N2H4</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Curran, Dan; Lueck, Dale E.</p> <p>1995-01-01</p> <p>Trace level detection of hydrazine (N2H4), monomethyl hydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH) has been receiving increased attention over the past several years. In May 1995 the American Conference of Government Industrial Hygienists (ACGIH) lowered their acceptable threshold limit value (TLV) from 100 parts-per-<span class="hlt">billion</span> (ppb) to 10 ppb. Several types of ppb-level detectors are being developed by the United States Air Force (USAF) Space and Missile Systems Center (SMSC). A breadboard version of a portable, lightweight hydrazine detection sensor was developed and produced by Giner Corp. for the USAF. This sensor was designed for ppb level UDMH and N2H4 vapor detection in near real-time. This instrument employs electrochemical sensing, utilizing a three electrode cell with an anion-exchange polymer electrolyte membrane as the only electrolyte in the system. The sensing, counter and reference electrodes are bonded to the membrane forming a single component. The only liquid required to maintain the sensor is deionized water which hydrates the membrane. At the request of the USAF SMSC, independent testing and evaluation of the breadboard instrument was performed at NASA's Toxic Vapor Detection Laboratory (TVDL) for response to ppb-level N2H4 and UDMH and MMH. The TVDL, located at Kennedy Space Center (KSC) has the unique ability to generate calibrated sample vapor streams of N2H4, UDMH, and MMH over a range from less than 10 ppb to thousands of parts per million (ppm) with full environmental control of relative humidity (0-90%) and temperature (0-50 C). The TVDL routinely performs these types of tests. Referenced sensors were subjected to extensive testing, including precision, linearity, response/recovery times, zero and span drift, humidity and temperature effects as well as ammonia interference. Results of these tests and general operation characteristics are reported.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22456703','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22456703"><span id="translatedtitle">Air density 2.7 <span class="hlt">billion</span> years ago limited to less than twice modern levels by fossil raindrop imprints.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Som, Sanjoy M; Catling, David C; Harnmeijer, Jelte P; Polivka, Peter M; Buick, Roger</p> <p>2012-04-19</p> <p>According to the 'Faint Young Sun' paradox, during the late Archaean eon a Sun approximately 20% dimmer warmed the early Earth such that it had liquid water and a clement climate. Explanations for this phenomenon have invoked a denser atmosphere that provided warmth by nitrogen pressure broadening or enhanced greenhouse gas concentrations. Such solutions are allowed by geochemical studies and numerical investigations that place approximate concentration limits on Archaean atmospheric gases, including methane, carbon dioxide and oxygen. But no field data constraining ground-level air density and barometric pressure have been reported, leaving the plausibility of these various hypotheses in doubt. Here we show that raindrop imprints in tuffs of the Ventersdorp Supergroup, South Africa, constrain surface air density 2.7 <span class="hlt">billion</span> years ago to less than twice modern levels. We interpret the raindrop fossils using experiments in which water droplets of known size fall at terminal velocity into fresh and weathered volcanic ash, thus defining a relationship between imprint size and raindrop impact momentum. Fragmentation following raindrop flattening limits raindrop size to a maximum value independent of air density, whereas raindrop terminal velocity varies as the inverse of the square root of air density. If the Archaean raindrops reached the modern maximum measured size, air density must have been less than 2.3 kg m(-3), compared to today's 1.2 kg m(-3), but because such drops rarely occur, air density was more probably below 1.3 kg m(-3). The upper estimate for air density renders the pressure broadening explanation possible, but it is improbable under the likely lower estimates. Our results also disallow the extreme CO(2) levels required for hot Archaean climates. PMID:22456703</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22456703','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22456703"><span id="translatedtitle">Air density 2.7 <span class="hlt">billion</span> years ago limited to less than twice modern levels by fossil raindrop imprints.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Som, Sanjoy M; Catling, David C; Harnmeijer, Jelte P; Polivka, Peter M; Buick, Roger</p> <p>2012-04-19</p> <p>According to the 'Faint Young Sun' paradox, during the late Archaean eon a Sun approximately 20% dimmer warmed the early Earth such that it had liquid water and a clement climate. Explanations for this phenomenon have invoked a denser atmosphere that provided warmth by nitrogen pressure broadening or enhanced greenhouse gas concentrations. Such solutions are allowed by geochemical studies and numerical investigations that place approximate concentration limits on Archaean atmospheric gases, including methane, carbon dioxide and oxygen. But no field data constraining ground-level air density and barometric pressure have been reported, leaving the plausibility of these various hypotheses in doubt. Here we show that raindrop imprints in tuffs of the Ventersdorp Supergroup, South Africa, constrain surface air density 2.7 <span class="hlt">billion</span> years ago to less than twice modern levels. We interpret the raindrop fossils using experiments in which water droplets of known size fall at terminal velocity into fresh and weathered volcanic ash, thus defining a relationship between imprint size and raindrop impact momentum. Fragmentation following raindrop flattening limits raindrop size to a maximum value independent of air density, whereas raindrop terminal velocity varies as the inverse of the square root of air density. If the Archaean raindrops reached the modern maximum measured size, air density must have been less than 2.3 kg m(-3), compared to today's 1.2 kg m(-3), but because such drops rarely occur, air density was more probably below 1.3 kg m(-3). The upper estimate for air density renders the pressure broadening explanation possible, but it is improbable under the likely lower estimates. Our results also disallow the extreme CO(2) levels required for hot Archaean climates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6782680','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6782680"><span id="translatedtitle">Guide for preparing annual reports on radiation-safety testing of <span class="hlt">electronic</span> products (general)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1987-10-01</p> <p>For manufacturers of <span class="hlt">electronic</span> products other than those for which a specific guide has been issued, the guide replaces the Guide for the Filing of Annual Reports (21 CFR Subchapter J, Section 1002.11), HHS Publication FDA 82-8127. The <span class="hlt">electronic</span> product (general) annual reporting guide is applicable to the following products: products intended to produce x radiation (accelerators, analytical devices, therapy x-ray machines); microwave diathermy machines; cold-cathode discharge tubes; and vacuum switches and tubes operating at or above 15,000 <span class="hlt">volts</span>. To carry out its responsibilities under Public Law 90-602, the Food and Drug Administration's Center for Devices and Radiological Health (CDRH) has issued a series of regulations contained in Title 21 of the Code of Federal Regulations (CFR). Part 1002 of 21 CFR deals with records and reports. Section 1002.61 categorizes <span class="hlt">electronic</span> products into Groups A through C. Section 1002.30 requires manufacturers of products in Groups B and C to establish and maintain certain records, while Section 1002.11 requires such manufacturers to submit an Annual Report summarizing the contents of the required records. Section 1002.7 requires that reports conform to reporting guides issued by CDRH unless an acceptable justification for an alternate format is provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6533699','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6533699"><span id="translatedtitle">Neutral beamline with ion energy recovery based on magnetic blocking of <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Stirling, W.L.</p> <p>1980-07-01</p> <p>A neutral beamline generator with energy recovery of the full-energy ion component of the beam based on magnetic blocking of <span class="hlt">electrons</span> is provided. Ions from a positive ion source are accelerated to the desired beam energy from a slightly positive potential level with respect to ground through a neutralizer cell by means of a negative acceleration voltage. The unneutralized full-energy ion component of the beam exiting the neutralizer are retarded and slightly deflected and the elecrons in the neutralizer are blocked by a magnetic field generated transverse to the beamline. An <span class="hlt">electron</span> collector in the form of a coaxial cylinder surrounding and protruding axial a few centimeters beyond the neutralizer exit terminates the <span class="hlt">electrons</span> which exit the neutralizer in an E x B drift to the collector when the collector is biased a few hundred <span class="hlt">volts</span> positive with respect to the neutralizer voltage. The neutralizer is operated at the negative acceleration voltage. The neutralizer is operated at the negative acceleration voltage, and the deflected full energy ions are decelerated and the charge collected at ground potential thereby expending none of their energy received from the acceleration power supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010041226&hterms=electronic+information&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectronic%2Binformation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010041226&hterms=electronic+information&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectronic%2Binformation"><span id="translatedtitle">System Miniaturization Via Heterogeneous Integration of <span class="hlt">Electronic</span> Devices for Deep Space Missions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>DelCastillo, L.; Schatzel, D. V.; Graber, R. W.; Mottiwala, A.</p> <p>2001-01-01</p> <p>The scientific devices designed for each of the Outer Planets Program Focuses will likely be groundbreaking not only with respect to their scientific role but also regarding the <span class="hlt">electronics</span> required to perform such investigations. In the past, the performance of packaged <span class="hlt">electronics</span> was limited by the components themselves, with minimal influence of the packaging technology. The rapid development of integrated circuit technology, however, has drastically increased the importance of packaging technology in the ultimate performance of devices. If not carefully considered in the overall design, the packaging may become the limiting factor in the operation of the system. Although industry is responsible for several significant accomplishments in the field of <span class="hlt">electronics</span> packaging, deep space/outer planet missions must take into account additional requirements such as extremely low temperatures, high radiation levels, hermetic sealing, and severe size and weight limitations. Therefore, the present investigation has been designed to meet the needs of NASA's sensor intensive outer planets program by combining (using flip chip technology) an array of devices (including analog, digital, power <span class="hlt">volt</span>-age, passives, and MEMS) into a miniaturized heterogeneous system and utilizing optical buses to enable autonomy. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23450000','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23450000"><span id="translatedtitle">A long-lived relativistic <span class="hlt">electron</span> storage ring embedded in Earth's outer Van Allen belt.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baker, D N; Kanekal, S G; Hoxie, V C; Henderson, M G; Li, X; Spence, H E; Elkington, S R; Friedel, R H W; Goldstein, J; Hudson, M K; Reeves, G D; Thorne, R M; Kletzing, C A; Claudepierre, S G</p> <p>2013-04-12</p> <p>Since their discovery more than 50 years ago, Earth's Van Allen radiation belts have been considered to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is composed predominantly of megaelectron <span class="hlt">volt</span> (MeV) <span class="hlt">electrons</span> that wax and wane in intensity on time scales ranging from hours to days, depending primarily on external forcing by the solar wind. The spatially separated inner zone is composed of commingled high-energy <span class="hlt">electrons</span> and very energetic positive ions (mostly protons), the latter being stable in intensity levels over years to decades. In situ energy-specific and temporally resolved spacecraft observations reveal an isolated third ring, or torus, of high-energy (>2 MeV) <span class="hlt">electrons</span> that formed on 2 September 2012 and persisted largely unchanged in the geocentric radial range of 3.0 to ~3.5 Earth radii for more than 4 weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9591E..0DD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9591E..0DD"><span id="translatedtitle">Gated photocathode design for the P510 <span class="hlt">electron</span> tube used in the National Ignition Facility (NIF) optical streak cameras</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Datte, P.; James, G.; Celliers, P.; Kalantar, D.; Vergel de Dios, G.</p> <p>2015-08-01</p> <p>The optical streak cameras currently used at the National Ignition Facility (NIF) implement the P510 <span class="hlt">electron</span> tube from Photonis1. The existing high voltage <span class="hlt">electronics</span> provide DC bias voltages to the cathode, slot, and focusing electrodes. The sweep deflection plates are driven by a ramp voltage. This configuration has been very successful for the majority of measurements required at NIF. New experiments require that the photocathode be gated or blanked to reduce the effects of undesirable scattered light competing with low light level experimental data. The required ~2500V gate voltage is applied between the photocathode and the slot electrode in response to an external trigger to allow the <span class="hlt">electrons</span> to flow. Otherwise the slot electrode is held approximately 100 <span class="hlt">Volts</span> more negative than the potential of the photocathode, preventing <span class="hlt">electron</span> flow. This article reviews the implementation and performance of the gating circuit that applies an <span class="hlt">electronic</span> gate to the photocathode with a nominal 50ns rise and fall time, and a pulse width between 50ns and 2000ns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AAS...19510004H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AAS...19510004H"><span id="translatedtitle"><span class="hlt">Electronic</span> Preprints</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanisch, R.</p> <p>1999-12-01</p> <p>Despite the tremendous advances in <span class="hlt">electronic</span> publications and the increasing rapidity with which papers are now moving from acceptance into ``print,'' preprints continue to be an important mode of communication within the astronomy community. The Los Alamos e-preprint service, astro-ph, provides for rapid and cost-free (to authors and readers) dissemination of manuscripts. As the use of astro-ph has increased the number of paper preprints in circulation to libraries has decreased, and institutional preprint series appear to be waning. It is unfortunate, however, that astro-ph does not function in collaboration with the refereed publications. For example, there is no systematic tracking of manuscripts from preprint to their final, published form, and as a centralized archive it is difficult to distribute the tracking and maintenance functions. It retains documents that have been superseded or have become obsolete. We are currently developing a distributed preprint and document management system which can support both distributed collections of preprints (e.g., traditional institutional preprint series), can link to the LANL collections, can index other documents in the ``grey'' literature (observatory reports, telescope and instrument user's manuals, calls for proposals, etc.), and can function as a manuscript submission tool for the refereed journals. This system is being developed to work cooperatively with the refereed literature so that, for example, links to preprints are updated to links to the final published papers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Nanot..24L0201D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Nanot..24L0201D"><span id="translatedtitle">EDITORIAL: Synaptic <span class="hlt">electronics</span> Synaptic <span class="hlt">electronics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique</p> <p>2013-09-01</p> <p>Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic <span class="hlt">electronics</span>', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1193217','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1193217"><span id="translatedtitle">Environmental TEM study of <span class="hlt">electron</span> beam induced electro-chemistry of Pr₀̣₆₄Ca₀̣₃₆MnO₃ catalysts for oxygen evolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mildner, Stephanie; Beleggia, Marco; Mierwaldt, Daniel; Hansen, Thoma Willum; Wagner, Jakob Birkedal; Yazdi, Sadegh; Kasama, Takeshi; Ciston, Jim; Zhu, Yimei; Jooss, Christian</p> <p>2015-03-12</p> <p>Environmental Transmission <span class="hlt">Electron</span> Microscopy (ETEM) studies offer great potential for gathering atomic scale information on the <span class="hlt">electronic</span> state of electrodes in contact with reactants but also pose big challenges due to the impact of the high energy <span class="hlt">electron</span> beam. In this article, we present an ETEM study of a Pr₀̣₆₄Ca₀̣₃₆MnO₃ (PCMO) thin film electro-catalyst for water splitting and oxygen evolution in contact with water vapor. We show by means of off-axis <span class="hlt">electron</span> holography and electrostatic modeling that the <span class="hlt">electron</span> beam gives rise to a positive electric sample potential due to secondary <span class="hlt">electron</span> emission. The value of the electric potential depends on the primary <span class="hlt">electron</span> flux, the sample -conductivity and grounding, and gas properties. We present evidence that two observed electro-chemical reactions are driven by a beam induced electrostatic potential of the order of a <span class="hlt">volt</span>. The first reaction is an anodic electrochemical oxidation reaction of oxygen depleted amorphous PCMO which results in recrystallization of the perovskite structure. The second reaction is oxygen evolution which can be detected by the oxidation of a silane additive and formation of SiO<sub>2–x</sub> at catalytically active surfaces. Recently published in-situ XANES observation of subsurface oxygen vacancy formation during oxygen evolution at a positive potential [³²] is confirmed in this work. The quantification of beam induced potentials is an important step for future controlled electro-chemical experiments in an ETEM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1218316','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1218316"><span id="translatedtitle">Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a <span class="hlt">Billion</span>-Ton Annual Supply, April 2005</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2005-04-01</p> <p>The purpose of this report is to determine whether the land resources of the United States are capable of producing a sustainable supply of biomass sufficient to displace 30 percent or more of the country’s present petroleum consumption – the goal set by the Biomass R&D Technical Advisory Committee in their vision for biomass technologies. Accomplishing this goal would require approximately 1 <span class="hlt">billion</span> dry tons of biomass feedstock per year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150003115','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150003115"><span id="translatedtitle">Carbon Nanotube <span class="hlt">Electron</span> Gun</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)</p> <p>2013-01-01</p> <p>An <span class="hlt">electron</span> gun, an <span class="hlt">electron</span> source for an <span class="hlt">electron</span> gun, an extractor for an <span class="hlt">electron</span> gun, and a respective method for producing the <span class="hlt">electron</span> gun, the <span class="hlt">electron</span> source and the extractor are disclosed. Embodiments provide an <span class="hlt">electron</span> source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract <span class="hlt">electrons</span> from the <span class="hlt">electron</span> source, where the aperture may substantially align with the CNT of the <span class="hlt">electron</span> source when the extractor and <span class="hlt">electron</span> source are mated to form the <span class="hlt">electron</span> gun. The <span class="hlt">electron</span> source and extractor may have alignment features for aligning the <span class="hlt">electron</span> source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the <span class="hlt">electron</span> gun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110000773','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110000773"><span id="translatedtitle">Carbon nanotube <span class="hlt">electron</span> gun</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)</p> <p>2010-01-01</p> <p>An <span class="hlt">electron</span> gun, an <span class="hlt">electron</span> source for an <span class="hlt">electron</span> gun, an extractor for an <span class="hlt">electron</span> gun, and a respective method for producing the <span class="hlt">electron</span> gun, the <span class="hlt">electron</span> source and the extractor are disclosed. Embodiments provide an <span class="hlt">electron</span> source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract <span class="hlt">electrons</span> from the <span class="hlt">electron</span> source, where the aperture may substantially align with the CNT of the <span class="hlt">electron</span> source when the extractor and <span class="hlt">electron</span> source are mated to form the <span class="hlt">electron</span> gun. The <span class="hlt">electron</span> source and extractor may have alignment features for aligning the <span class="hlt">electron</span> source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the <span class="hlt">electron</span> gun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23821907','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23821907"><span id="translatedtitle">Medicare overpayments to private plans, 1985-2012: shifting seniors to private plans has already cost Medicare US$282.6 <span class="hlt">billion</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hellander, Ida; Himmelstein, David U; Woolhandler, Steffie</p> <p>2013-01-01</p> <p>Previous research has documented Medicare overpayments to the private Medicare Advantage (MA) plans that compete with traditional fee-for-service Medicare. This research has assessed individual categories of overpayment for, at most, a few years. However, no study has calculated the total overpayments to private plans since the program's inception. Prior to 2004, selective enrollment of healthier seniors was the major source of excess payments. We estimate this has added US$41 <span class="hlt">billion</span> to Medicare's costs since 1985. Medicare adopted a risk-adjustment scheme in 2004, but this has not curbed private plans' ability to game the payment system. This has added US$122.5 <span class="hlt">billion</span> to Medicare's costs since 2004. Congress mandated increased payment to private plans in the 2003 Medicare Modernization Act, which was mitigated, to a degree, by the subsequent Affordable Care Act. In total, we find that Medicare has overpaid private insurers by US$282.6 <span class="hlt">billion</span> since 1985. Risk adjustment does not work in for-profit MA plans, which have a financial incentive, the data, and the ingenuity to game whatever system Medicare devises. It is time to end Medicare's costly experiment with privatization. The U.S. needs to adopt a single-payer national health insurance program with effective methods for controlling costs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUSMGP23A..02E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUSMGP23A..02E"><span id="translatedtitle">Dipolar geomagnetic field and low orbital obliquity during the last two <span class="hlt">billion</span> years: Evidence from paleomagnetism of evaporite basins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evans, D. A.</p> <p>2006-05-01</p> <p>Paleomagnetism of climatically sensitive sedimentary rock types, such as glacial deposits and evaporites, can test the uniformitarianism of ancient geomagnetic fields and paleoclimatic zones. Precambrian glacial deposits laid down in near-equatorial paleomagnetic latitudes indicate a paleoclimatic paradox that can be explained either by Snowball Earth episodes, or high orbital obliquity, or dramatically non-uniformitarian geomagnetic fields. Here I present the first global paleomagnetic compilation of the Earth's entire basin-scale evaporite record. Evaporation exceeds precipitation in today's subtropical desert belts, generally within a zone of 15-35° from the equator. Assuming a geocentric axial dipole (GAD) magnetic field for Cenozoic- Mesozoic time, evaporite basins of the past 250 Myr have a volume-weighted mean paleolatitude of 23±4°, also squarely within the subtropics. Carboniferous-Permian evaporites have an indistinguishable weighted-mean paleolatitude of 22±4°, which does not change significantly when recently hypothesized octupolar field components are included in the calculations. Early Paleozoic (including late Ediacaran) evaporites are lower-latitude (weighted mean 10±5°), but detailed analyses of individual examples show this cannot be attributed solely to nondipolar field components or sedimentary inclination biases; the cause may be due to particular paleogeographic effects on regional tropical climates, or incomplete sampling by the paleomagnetic data. Proterozoic (pre-Ediacaran) evaporite basins have a volume- weighted mean inclination of 33±4°, which would correspond to a mean paleolatitude of 18±3° for a pure GAD field. This latter mean is indistinguishable, within error, from the Cenozoic-Mesozoic mean and demonstrates the success of the GAD model as a first-order description of the geomagnetic field for the last two <span class="hlt">billion</span> years. Also, general circulation climate models of a high-obliquity Earth predict either no strong zonal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22538613','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22538613"><span id="translatedtitle">Deposition of 1.88-<span class="hlt">billion</span>-year-old iron formations as a consequence of rapid crustal growth.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rasmussen, Birger; Fletcher, Ian R; Bekker, Andrey; Muhling, Janet R; Gregory, Courtney J; Thorne, Alan M</p> <p>2012-04-26</p> <p>Iron formations are chemical sedimentary rocks comprising layers of iron-rich and silica-rich minerals whose deposition requires anoxic and iron-rich (ferruginous) sea water. Their demise after the rise in atmospheric oxygen by 2.32 <span class="hlt">billion</span> years (Gyr) ago has been attributed to the removal of dissolved iron through progressive oxidation or sulphidation of the deep ocean. Therefore, a sudden return of voluminous iron formations nearly 500 million years later poses an apparent conundrum. Most late Palaeoproterozoic iron formations are about 1.88 Gyr old and occur in the Superior region of North America. Major iron formations are also preserved in Australia, but these were apparently deposited after the transition to a sulphidic ocean at 1.84 Gyr ago that should have terminated iron formation deposition, implying that they reflect local marine conditions. Here we date zircons in tuff layers to show that iron formations in the Frere Formation of Western Australia are about 1.88 Gyr old, indicating that the deposition of iron formations from two disparate cratons was coeval and probably reflects global ocean chemistry. The sudden reappearance of major iron formations at 1.88 Gyr ago--contemporaneous with peaks in global mafic-ultramafic magmatism, juvenile continental and oceanic crust formation, mantle depletion and volcanogenic massive sulphide formation--suggests deposition of iron formations as a consequence of major mantle activity and rapid crustal growth. Our findings support the idea that enhanced submarine volcanism and hydrothermal activity linked to a peak in mantle melting released large volumes of ferrous iron and other reductants that overwhelmed the sulphate and oxygen reservoirs of the ocean, decoupling atmospheric and seawater redox states, and causing the return of widespread ferruginous conditions. Iron formations formed on clastic-starved coastal shelves where dissolved iron upwelled and mixed with oxygenated surface water. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/885984','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/885984"><span id="translatedtitle">Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasability of a <span class="hlt">Billion</span>-Ton Annual Supply</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Perlack, R.D.</p> <p>2005-12-15</p> <p> land resources of the United States are capable of producing a sustainable supply of biomass sufficient to displace 30 percent or more of the country's present petroleum consumption--the goal set by the Advisory Committee in their vision for biomass technologies. Accomplishing this goal would require approximately 1 <span class="hlt">billion</span> dry tons of biomass feedstock per year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22538613','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22538613"><span id="translatedtitle">Deposition of 1.88-<span class="hlt">billion</span>-year-old iron formations as a consequence of rapid crustal growth.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rasmussen, Birger; Fletcher, Ian R; Bekker, Andrey; Muhling, Janet R; Gregory, Courtney J; Thorne, Alan M</p> <p>2012-04-26</p> <p>Iron formations are chemical sedimentary rocks comprising layers of iron-rich and silica-rich minerals whose deposition requires anoxic and iron-rich (ferruginous) sea water. Their demise after the rise in atmospheric oxygen by 2.32 <span class="hlt">billion</span> years (Gyr) ago has been attributed to the removal of dissolved iron through progressive oxidation or sulphidation of the deep ocean. Therefore, a sudden return of voluminous iron formations nearly 500 million years later poses an apparent conundrum. Most late Palaeoproterozoic iron formations are about 1.88 Gyr old and occur in the Superior region of North America. Major iron formations are also preserved in Australia, but these were apparently deposited after the transition to a sulphidic ocean at 1.84 Gyr ago that should have terminated iron formation deposition, implying that they reflect local marine conditions. Here we date zircons in tuff layers to show that iron formations in the Frere Formation of Western Australia are about 1.88 Gyr old, indicating that the deposition of iron formations from two disparate cratons was coeval and probably reflects global ocean chemistry. The sudden reappearance of major iron formations at 1.88 Gyr ago--contemporaneous with peaks in global mafic-ultramafic magmatism, juvenile continental and oceanic crust formation, mantle depletion and volcanogenic massive sulphide formation--suggests deposition of iron formations as a consequence of major mantle activity and rapid crustal growth. Our findings support the idea that enhanced submarine volcanism and hydrothermal activity linked to a peak in mantle melting released large volumes of ferrous iron and other reductants that overwhelmed the sulphate and oxygen reservoirs of the ocean, decoupling atmospheric and seawater redox states, and causing the return of widespread ferruginous conditions. Iron formations formed on clastic-starved coastal shelves where dissolved iron upwelled and mixed with oxygenated surface water. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013Nanot..24L0201D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013Nanot..24L0201D&link_type=ABSTRACT"><span id="translatedtitle">EDITORIAL: Synaptic <span class="hlt">electronics</span> Synaptic <span class="hlt">electronics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique</p> <p>2013-09-01</p> <p>Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic <span class="hlt">electronics</span>', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24524867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24524867"><span id="translatedtitle">A novel low energy <span class="hlt">electron</span> microscope for DNA sequencing and surface analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mankos, M; Shadman, K; Persson, H H J; N'Diaye, A T; Schmid, A K; Davis, R W</p> <p>2014-10-01</p> <p>Monochromatic, aberration-corrected, dual-beam low energy <span class="hlt">electron</span> microscopy (MAD-LEEM) is a novel technique that is directed towards imaging nanostructures and surfaces with sub-nanometer resolution. The technique combines a monochromator, a mirror aberration corrector, an energy filter, and dual beam illumination in a single instrument. The monochromator reduces the energy spread of the illuminating <span class="hlt">electron</span> beam, which significantly improves spectroscopic and spatial resolution. Simulation results predict that the novel aberration corrector design will eliminate the second rank chromatic and third and fifth order spherical aberrations, thereby improving the resolution into the sub-nanometer regime at landing energies as low as one hundred <span class="hlt">electron-Volts</span>. The energy filter produces a beam that can extract detailed information about the chemical composition and local <span class="hlt">electronic</span> states of non-periodic objects such as nanoparticles, interfaces, defects, and macromolecules. The dual flood illumination eliminates charging effects that are generated when a conventional LEEM is used to image insulating specimens. A potential application for MAD-LEEM is in DNA sequencing, which requires high resolution to distinguish the individual bases and high speed to reduce the cost. The MAD-LEEM approach images the DNA with low <span class="hlt">electron</span> impact energies, which provides nucleobase contrast mechanisms without organometallic labels. Furthermore, the micron-size field of view when combined with imaging on the fly provides long read lengths, thereby reducing the demand on assembling the sequence. Experimental results from bulk specimens with immobilized single-base oligonucleotides demonstrate that base specific contrast is available with reflected, photo-emitted, and Auger <span class="hlt">electrons</span>. Image contrast simulations of model rectangular features mimicking the individual nucleotides in a DNA strand have been developed to translate measurements of contrast on bulk DNA to the detectability of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1257846-novel-low-energy-electron-microscope-dna-sequencing-surface-analysis','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1257846-novel-low-energy-electron-microscope-dna-sequencing-surface-analysis"><span id="translatedtitle">A novel low energy <span class="hlt">electron</span> microscope for DNA sequencing and surface analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Mankos, M.; Shadman, K.; Persson, H. H. J.; N’Diaye, A. T.; Schmid, A. K.; Davis, R. W.</p> <p>2014-01-31</p> <p>Monochromatic, aberration-corrected, dual-beam low energy <span class="hlt">electron</span> microscopy (MAD-LEEM) is a novel technique that is directed towards imaging nanostructures and surfaces with sub-nanometer resolution. The technique combines a monochromator, a mirror aberration corrector, an energy filter, and dual beam illumination in a single instrument. The monochromator reduces the energy spread of the illuminating <span class="hlt">electron</span> beam, which significantly improves spectroscopic and spatial resolution. Simulation results predict that the novel aberration corrector design will eliminate the second rank chromatic and third and fifth order spherical aberrations, thereby improving the resolution into the sub-nanometer regime at landing energies as low as one hundred <span class="hlt">electron-Volts</span>.more » The energy filter produces a beam that can extract detailed information about the chemical composition and local <span class="hlt">electronic</span> states of non-periodic objects such as nanoparticles, interfaces, defects, and macromolecules. The dual flood illumination eliminates charging effects that are generated when a conventional LEEM is used to image insulating specimens. A potential application for MAD-LEEM is in DNA sequencing, which requires high resolution to distinguish the individual bases and high speed to reduce the cost. The MAD-LEEM approach images the DNA with low <span class="hlt">electron</span> impact energies, which provides nucleobase contrast mechanisms without organometallic labels. Furthermore, the micron-size field of view when combined with imaging on the fly provides long read lengths, thereby reducing the demand on assembling the sequence. Finally, experimental results from bulk specimens with immobilized single-base oligonucleotides demonstrate that base specific contrast is available with reflected, photo-emitted, and Auger <span class="hlt">electrons</span>. Image contrast simulations of model rectangular features mimicking the individual nucleotides in a DNA strand have been developed to translate measurements of contrast on bulk DNA to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4117835','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4117835"><span id="translatedtitle">A Novel Low Energy <span class="hlt">Electron</span> Microscope for DNA Sequencing and Surface Analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mankos, M.; Shadman, K.; Persson, H.H.J.; N’Diaye, A.T.; Schmid, A.K.; Davis, R.W.</p> <p>2014-01-01</p> <p>Monochromatic, aberration-corrected, dual-beam low energy <span class="hlt">electron</span> microscopy (MAD-LEEM) is a novel technique that is directed towards imaging nanostructures and surfaces with sub-nanometer resolution. The technique combines a monochromator, a mirror aberration corrector, an energy filter, and dual beam illumination in a single instrument. The monochromator reduces the energy spread of the illuminating <span class="hlt">electron</span> beam, which significantly improves spectroscopic and spatial resolution. Simulation results predict that the novel aberration corrector design will eliminate the second rank chromatic and third and fifth order spherical aberrations, thereby improving the resolution into the sub-nanometer regime at landing energies as low as one hundred <span class="hlt">electron-Volts</span>. The energy filter produces a beam that can extract detailed information about the chemical composition and local <span class="hlt">electronic</span> states of non-periodic objects such as nanoparticles, interfaces, defects, and macromolecules. The dual flood illumination eliminates charging effects that are generated when a conventional LEEM is used to image insulating specimens. A potential application for MAD-LEEM is in DNA sequencing, which requires high resolution to distinguish the individual bases and high speed to reduce the cost. The MAD-LEEM approach images the DNA with low <span class="hlt">electron</span> impact energies, which provides nucleobase contrast mechanisms without organometallic labels. Furthermore, the micron-size field of view when combined with imaging on the fly provides long read lengths, thereby reducing the demand on assembling the sequence. Experimental results from bulk specimens with immobilized single-base oligonucleotides demonstrate that base specific contrast is available with reflected, photo-emitted, and Auger <span class="hlt">electrons</span>. Image contrast simulations of model rectangular features mimicking the individual nucleotides in a DNA strand have been developed to translate measurements of contrast on bulk DNA to the detectability of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1257846','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1257846"><span id="translatedtitle">A novel low energy <span class="hlt">electron</span> microscope for DNA sequencing and surface analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mankos, M.; Shadman, K.; Persson, H. H. J.; N’Diaye, A. T.; Schmid, A. K.; Davis, R. W.</p> <p>2014-01-31</p> <p>Monochromatic, aberration-corrected, dual-beam low energy <span class="hlt">electron</span> microscopy (MAD-LEEM) is a novel technique that is directed towards imaging nanostructures and surfaces with sub-nanometer resolution. The technique combines a monochromator, a mirror aberration corrector, an energy filter, and dual beam illumination in a single instrument. The monochromator reduces the energy spread of the illuminating <span class="hlt">electron</span> beam, which significantly improves spectroscopic and spatial resolution. Simulation results predict that the novel aberration corrector design will eliminate the second rank chromatic and third and fifth order spherical aberrations, thereby improving the resolution into the sub-nanometer regime at landing energies as low as one hundred <span class="hlt">electron-Volts</span>. The energy filter produces a beam that can extract detailed information about the chemical composition and local <span class="hlt">electronic</span> states of non-periodic objects such as nanoparticles, interfaces, defects, and macromolecules. The dual flood illumination eliminates charging effects that are generated when a conventional LEEM is used to image insulating specimens. A potential application for MAD-LEEM is in DNA sequencing, which requires high resolution to distinguish the individual bases and high speed to reduce the cost. The MAD-LEEM approach images the DNA with low <span class="hlt">electron</span> impact energies, which provides nucleobase contrast mechanisms without organometallic labels. Furthermore, the micron-size field of view when combined with imaging on the fly provides long read lengths, thereby reducing the demand on assembling the sequence. Finally, experimental results from bulk specimens with immobilized single-base oligonucleotides demonstrate that base specific contrast is available with reflected, photo-emitted, and Auger <span class="hlt">electrons</span>. Image contrast simulations of model rectangular features mimicking the individual nucleotides in a DNA strand have been developed to translate measurements of contrast on bulk DNA to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22490690','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22490690"><span id="translatedtitle">Trapped <span class="hlt">electron</span> plasma formation and equilibrium with a low-power radio-frequency drive</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Romé, M.; Maero, G.; Paroli, B.; Pozzoli, R.; Chen, S.</p> <p>2015-06-29</p> <p>Penning-Malmberg traps confining <span class="hlt">electron</span> plasmas usually rely on external sources like thermo- and photocathodes. It has been already demonstrated that <span class="hlt">electron</span> plasmas of comparable densities can be produced by applying a radio-frequency (RF) power to any inner electrode of the trap. Such excitation may result in significant <span class="hlt">electron</span> heating and ionization of the residual gas with the formation of a plasma column when the RF frequency is of the order or larger than the typical axial bounce frequencies of few-eV <span class="hlt">electrons</span>, even at RF amplitude of few <span class="hlt">volts</span>. While discharges are common in plasma generation at higher pressures and RF power, this mechanism is not yet well explored in our working conditions, namely ultra-high vacuum and very low RF power. This plasma production mechanism is very sensitive to the experimental conditions. Interesting phenomena can be observed: transition from a diffuse to a narrow-section, denser plasma column; presence of low-order diocotron modes in transient and steady-state plasmas; modulation of the m=1 diocotron mode and suppression of its instability despite the presence of positive ions and resistive loads. These observations are reported here, and possible explanations are discussed. In addition, a possible <span class="hlt">electron</span> heating mechanism is investigated with a single-particle, one-dimensional model described by an area-preserving map where an <span class="hlt">electron</span> bounces within a square potential well and the RF excitation is modelled by a time-oscillating square barrier. The low-energy part of the Poincaré plot includes both quasi-periodic and chaotic regions, where heating up to ionization energies is achievable. Results of a systematic analysis of the map extracting its chaotic properties and scaling laws as a function of the control parameters are reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvS..19b1303C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvS..19b1303C"><span id="translatedtitle">Direct longitudinal laser acceleration of <span class="hlt">electrons</span> in free space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carbajo, Sergio; Nanni, Emilio A.; Wong, Liang Jie; Moriena, Gustavo; Keathley, Phillip D.; Laurent, Guillaume; Miller, R. J. Dwayne; Kärtner, Franz X.</p> <p>2016-02-01</p> <p>Compact laser-driven accelerators are pursued heavily worldwide because they make novel methods and tools invented at national laboratories widely accessible in science, health, security, and technology [V. Malka et al., Principles and applications of compact laser-plasma accelerators, Nat. Phys. 4, 447 (2008)]. Current leading laser-based accelerator technologies [S. P. D. Mangles et al., Monoenergetic beams of relativistic <span class="hlt">electrons</span> from intense laser-plasma interactions, Nature (London) 431, 535 (2004); T. Toncian et al., Ultrafast laser-driven microlens to focus and energy-select mega-<span class="hlt">electron</span> <span class="hlt">volt</span> protons, Science 312, 410 (2006); S. Tokita et al. Single-shot ultrafast <span class="hlt">electron</span> diffraction with a laser-accelerated sub-MeV <span class="hlt">electron</span> pulse, Appl. Phys. Lett. 95, 111911 (2009)] rely on a medium to assist the light to particle energy transfer. The medium imposes material limitations or may introduce inhomogeneous fields [J. R. Dwyer et al., Femtosecond <span class="hlt">electron</span> diffraction: "Making the molecular movie,", Phil. Trans. R. Soc. A 364, 741 (2006)]. The advent of few cycle ultraintense radially polarized lasers [S. Carbajo et al., Efficient generation of ultraintense few-cycle radially polarized laser pulses, Opt. Lett. 39, 2487 (2014)] has ushered in a novel accelerator concept [L. J. Wong and F. X. Kärtner, Direct acceleration of an <span class="hlt">electron</span> in infinite vacuum by a pulsed radially polarized laser beam, Opt. Express 18, 25035 (2010); F. Pierre-Louis et al. Direct-field <span class="hlt">electron</span> acceleration with ultrafast radially polarized laser beams: Scaling laws and optimization, J. Phys. B 43, 025401 (2010); Y. I. Salamin, <span class="hlt">Electron</span> acceleration from rest in vacuum by an axicon Gaussian laser beam, Phys. Rev. A 73, 043402 (2006); C. Varin and M. Piché, Relativistic attosecond <span class="hlt">electron</span> pulses from a free-space laser-acceleration scheme, Phys. Rev. E 74, 045602 (2006); A. Sell and F. X. Kärtner, Attosecond <span class="hlt">electron</span> bunches accelerated and compressed by radially polarized laser</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/897266','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/897266"><span id="translatedtitle"><span class="hlt">Electron</span> beam generation in Tevatron <span class="hlt">electron</span> lenses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.; /Novosibirsk, IYF</p> <p>2006-08-01</p> <p>New type of high perveance <span class="hlt">electron</span> guns with convex cathode has been developed. Three guns described in this article are built to provide transverse <span class="hlt">electron</span> current density distributions needed for <span class="hlt">Electron</span> Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of <span class="hlt">electrons</span>, <span class="hlt">electron</span> guns of this type can be used in <span class="hlt">electron</span> cooling and beam-beam compensation devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/866459','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/866459"><span id="translatedtitle">Optically pulsed <span class="hlt">electron</span> accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Fraser, John S.; Sheffield, Richard L.</p> <p>1987-01-01</p> <p>An optically pulsed <span class="hlt">electron</span> accelerator can be used as an injector for a free <span class="hlt">electron</span> laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive <span class="hlt">electron</span> source emits <span class="hlt">electron</span> bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive <span class="hlt">electron</span> source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the <span class="hlt">electron</span> burst emitted by the photoemissive <span class="hlt">electron</span> source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5456580','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5456580"><span id="translatedtitle">Optically pulsed <span class="hlt">electron</span> accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Fraser, J.S.; Sheffield, R.L.</p> <p>1985-05-20</p> <p>An optically pulsed <span class="hlt">electron</span> accelerator can be used as an injector for a free <span class="hlt">electron</span> laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive <span class="hlt">electron</span> source emits <span class="hlt">electron</span> bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive <span class="hlt">electron</span> source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the <span class="hlt">electron</span> burst emitted by the photoemissive <span class="hlt">electron</span> source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19779150','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19779150"><span id="translatedtitle">Detection of gamma rays from a starburst galaxy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Acero, F; Aharonian, F; Akhperjanian, A G; Anton, G; Barres de Almeida, U; Bazer-Bachi, A R; Becherini, Y; Behera, B; Bernlöhr, K; Bochow, A; Boisson, C; Bolmont, J; Borrel, V; Brucker, J; Brun, F; Brun, P; Bühler, R; Bulik, T; Büsching, I; Boutelier, T; Chadwick, P M; Charbonnier, A; Chaves, R C G; Cheesebrough, A; Chounet, L-M; Clapson, A C; Coignet, G; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubois, F; Dubus, G; Dyks, J; Dyrda, M; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Fegan, S; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Füssling, M; Gabici, S; Gallant, Y A; Gérard, L; Gerbig, D; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Göring, D; Hauser, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Hofverberg, P; Hoppe, S; Horns, D; Jacholkowska, A; de Jager, O C; Jahn, C; Jung, I; Katarzyński, K; Katz, U; Kaufmann, S; Kerschhaggl, M; Khangulyan, D; Khélifi, B; Keogh, D; Klochkov, D; Kluźniak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Lamanna, G; Lenain, J-P; Lohse, T; Marandon, V; Martineau-Huynh, O; Marcowith, A; Masbou, J; Maurin, D; McComb, T J L; Medina, M C; Méhault, J; Moderski, R; Moulin, E; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; de Oña Wilhelmi, E; Orford, K J; Ostrowski, M; Panter, M; Paz Arribas, M; Pedaletti, G; Pelletier, G; Petrucci, P-O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raubenheimer, B C; Raue, M; Rayner, S M; Reimer, O; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Ruppel, J; Sahakian, V; Santangelo, A; Schlickeiser, R; Schöck, F M; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sikora, M; Skilton, J L; Sol, H; Stawarz, Ł; Steenkamp, R; Stegmann, C; Stinzing, F; Superina, G; Szostek, A; Tam, P H; Tavernet, J-P; Terrier, R; Tibolla, O; Tluczykont, M; van Eldik, C; Vasileiadis, G; Venter, C; Venter, L; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A</p> <p>2009-11-20</p> <p>Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of approximately 10(15) <span class="hlt">electron</span> <span class="hlt">volts</span>. We report the detection of gamma rays--tracers of such cosmic rays--from the starburst galaxy NGC 253 using the High Energy Stereoscopic System (H.E.S.S.) array of imaging atmospheric Cherenkov telescopes. The gamma-ray flux above 220 <span class="hlt">billion</span> <span class="hlt">electron</span> <span class="hlt">volts</span> is F = (5.5 +/- 1.0(stat) +/- 2.8(sys)) x 10(-13) cm(-2) s(-1), implying a cosmic-ray density about three orders of magnitude larger than that in the center of the Milky Way. The fraction of cosmic-ray energy channeled into gamma rays in this starburst environment is five times as large as that in our Galaxy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFMSH44C..02S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFMSH44C..02S&link_type=ABSTRACT"><span id="translatedtitle">Backstreaming <span class="hlt">Electrons</span> Associated With Solar <span class="hlt">Electron</span> Bursts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Skoug, R. M.; Steinberg, J. T.; de Koning, C. A.; Gosling, J. T.; McComas, D. J.</p> <p>2007-12-01</p> <p>Solar <span class="hlt">electron</span> bursts are frequently observed in the ACE/SWEPAM suprathermal <span class="hlt">electron</span> measurements at energies below 1.4 keV. A significant fraction of such events show backscattered <span class="hlt">electrons</span>, beginning after the burst onset and traveling back towards the Sun along the magnetic field direction. Such backscattered particles imply a scattering mechanism beyond the spacecraft location. Some bursts also show backstreaming conic distributions, implying mirroring at magnetic field enhancements beyond the spacecraft. Here we present a study of these backstreaming particles during solar <span class="hlt">electron</span> events. We examine the occurrence of backstreaming <span class="hlt">electrons</span> and their relationship to other burst characteristics such as pitch angle width, duration, and energy range. We also investigate the time delay between burst onset and the appearance of backscattered <span class="hlt">electrons</span>, including energy and pitch-angle dispersion. We examine the pitch angle distribution and energy dependence of backstreaming <span class="hlt">electrons</span>, and consider possible origins of these <span class="hlt">electron</span> distributions and their relationship to solar wind structure beyond the spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010089138','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010089138"><span id="translatedtitle">Nano-<span class="hlt">Electronics</span> and Bio-<span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Srivastava, Deepak; Kwak, Dochan (Technical Monitor)</p> <p>2001-01-01</p> <p>Viewgraph presentation on Nano-<span class="hlt">Electronics</span> and Bio-<span class="hlt">Electronics</span> is discussed. Topics discussed include: NASA Ames nanotechnology program, Potential Carbon Nanotube (CNT) application, CNT synthesis,Computational Nanotechnology, and protein nanotubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000APS..OSS..C506M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000APS..OSS..C506M"><span id="translatedtitle">Recrystallized Granite Surface Fissures Of The Wasatch Range, Produced Not Later Than 1/4 <span class="hlt">Billion</span> Years Ago</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDonald, Keith L.</p> <p>2000-05-01</p> <p>Our studies of numerous recrystallized fissures in 4 granite plutons of Wasatch Range, namely, Mount Tuscarora-Wolverine-Millicent,^1,6,7 Bonanza Peak-Midway,^2 Little Cottonwood Canyon and Ferguson Canyon plutons, all of which formed magma chambers reaching Earth-atmosphere interface, establish that they resulted from high thermal gradients rather than passages of earthquake waves. Magma chambers formed, solidified during Permo-Caroniferous Ice Age(roughly, 1/3...1/4 <span class="hlt">billion</span> yr ago, a time interval preceding period of extrusion of Rocky Mountains, 10^8 yr ago), and while fluid, belched lava flows^5 extending over its reservoir walls to run hundred of meters. We have shown how the magma melts, dilutes and replaces overlying metamorphic rock^7 to reach Earth's surface so that a pluton containing large amounts of dross(Fe-ores, etc.) had a short fluid lifetime. We also described how offshoots from a long-running main fissure form acute angles with that fissure.^3 Such recrystallized fissures, reaching depths of perhaps 100 m, have initial fractures near time of solidification of their uppermost portion of magma chamber while still hot(<= 1600^oF), a time when max. stresses occur near granite surface due to high thermal gradients, owing to snow coverage, cold water contacts due to rain, stream flow over granite surface, partial coverage by ocean, etc., wherever heat sinks might occur, during P-C ice age--when region of Wasatch Range existed at sea level, Salt Lake Valley being covered entirely by ocean water and region east of Wasatch Bouleuard rising gently above Pacific Ocean to elevations of possibly 500-1000 ft, say, at a distance of 10-15 mi to east. This fact is implied by Chinese Wall of white limestone on Grandeur Peak, unequivocally, and similarly another in Neff's Canyon running e. from n. ridge of 9200 ft. saddle-summit, as well as a dozen other ancient calcified stream beds emptying into ocean to w., in Salt Lake Valley. This existed prior to regional</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000APS..DFD.PK007M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000APS..DFD.PK007M"><span id="translatedtitle">Recrystallized Granite Surface Fissures of Wasatch Range Produced Not Later Than 1/4<span class="hlt">Billion</span> Years Ago</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDonald, Keith</p> <p>2000-11-01</p> <p>Our studies of numerous recrystallized fissures in 4 granite plutons of Wasatch Range, i.e., Mount T-W-M, (K.L. McDonald, Bul. A.P.S., 32 (4), 1124),(37 (5), 1256-7),(38 (1), 740) Bonanza Pk.-Midway,(35 (9), 2132) Little Cottonwood and Ferguson Canyon plutons, all of which formed magma chambers reaching Earth-atm. interface, estab that they resulted from high thermal gradients and not passages of earthquake waves.(33 (9), 1982-2) Magma chambers formed, solidified during Permo- Carboniferous Ice Age (roughly 1/3...1/4 <span class="hlt">billion</span> yr ago), a time interval preceding extrusion, pf Rocky Mts., 10^8 yr ago, and while fluid, some belched lava flows(36 (9), 2466) extending over its reservoir walls to run hundreds of m. We have shown how the magma melts, dilutes and replaces overlying metamorphic rock(38 (1), 740) to reach Earth's surface, so that a pluton containing large amounts of dross (Fe ores, etc.) had a short fluid lifetime. We also described how offshoots from a long-running main fissure form acute angles with that fissure.(33 (3), 485) Recryst. fissures, reaching depths of perhaps 100 m, had initial fractures near time of solidification of top portion of magma chamber, while still hot (<< 1600 ^oF), a time when max. stresses occur near granite surface due to high thermal gradients, owing to snow coverage, rain water, stream flow over granite surface, partial coverage by ocean, etc., during P-C ice age -- when region of Wasatch Range existed at sea level, S.L. Valley being covered entrely by ocean water and region of Wasatch Boul. rising gently above Pac. Ocean to elev. of possibly 500-1000 ft, say, at a dist. of 10-15 mi to e, as implied by Chinese Wall of limestone on Grandeur Pk, another in Neff's Canyon running e from n ridge of her 9200 ft saddle-summit, as well as a dozen other ancient calcified stream beds emptying into ocean to w., in S.L. Valley. This existed prior to regional uplift (of similar topog.) of over 4000 ft. Details of how earthquake waves form an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002APS..APRB17080M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002APS..APRB17080M"><span id="translatedtitle">Recrystallized Granite Surface Fissures Of Wasatch Range, Produced Not Later Than 1/4 <span class="hlt">Billion</span> Years Ago.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDonald, K. L.</p> <p>2002-04-01</p> <p>Our studies of numerous recrystallized fissures in 4 granite plutons of Wasatch Range, i.e., Mount T-W-M^1,6,7 Bonanza Pk.-Midway,^2 Little Cottonwood and Ferguson Canyon plutons, all of which formed magma chambers reaching Earth-atm. interface, estab. that they resulted from high thermal gradients and not passages of earthquake waves.^4 Magma chambers formed, solidified during Permo-Carboniferous Ice Age (roughly 1/3...1/4 <span class="hlt">billion</span> yr ago), a time interval preceding extrusion of Rocky Mts., 10^8 yr ago, and while fluid, some belched lava flows^5 extending over its reservoir walls to run hundreds of m. We have shown how the magma melts, dilutes and replaces overlying metamorphic rock^7 to reach Earth's surface, so that a pluton containing large amounts of dross (Fe-ores, etc.) had a short fluid lifetime. We also described how offshoots from a long-running main fissure form acute angles with that fissure^3. Recryst. fissures, reaching depths of perhaps 100 m, had initial fractures near time of solidification of top portion of magma chamber, while still hot (<= 1600^oF), a time when max. stresses occur near granite surface due to high thermal gradients, owing to snow coverage, rain water, stream flow over granite surface, partial coverage by ocean, etc., during P-C ice age - when region of Wasatch Range existed at sea level, S. L. Valley being covered entirely by ocean water and region east of Wasatch Boul. rising gently above Pac. Ocean to elev. of possibly 500-1000 ft, say, at a distance of 10-15 mi to e, as implied by Chinese wall of limestone on Grandeur Pk, another in Neff's Canyon running e from n ridge of her 9200 ft saddle-summit, as well as a dozen other ancient calcified stream beds emptying into ocean to w, in S.L. Valley. This existed prior to regional uplift (of similar topog.) of over 4000 ft. Details of how earthquake waves form an epicenter from which propagate 2 stress fields in diam. opp. directions to open up, by a few m, surface granite to form a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100011125','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100011125"><span id="translatedtitle">Interface <span class="hlt">Electronic</span> Circuitry for an <span class="hlt">Electronic</span> Tongue</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keymeulen, Didier; Buehler, Martin</p> <p>2007-01-01</p> <p><span class="hlt">Electronic</span> circuitry has been developed to serve as an interface between an <span class="hlt">electronic</span> tongue and digital input/output boards in a laptop computer that is used to control the tongue and process its readings. <span class="hlt">Electronic</span> tongues can be used for a variety of purposes, including evaluating water quality, analyzing biochemicals, analyzing biofilms, and measuring electrical conductivities of soils.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/883513','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/883513"><span id="translatedtitle"><span class="hlt">Electron</span> Diffraction Experiments using Laser Plasma <span class="hlt">Electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fill, E E; Trushin, S; Tommasini, R; Bruch, R</p> <p>2005-09-07</p> <p>We demonstrate that <span class="hlt">electrons</span> emitted from a laser plasma can be used to generate diffraction patterns in reflection and transmission. The <span class="hlt">electrons</span> are emitted in the direction of laser polarization with energies up to 100 keV. The broad <span class="hlt">electron</span> energy spectrum makes possible the generation of a ''streaked'' diffraction pattern which allows recording fast processes in a single run.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22344953','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22344953"><span id="translatedtitle">Neuromorphic adaptive plastic scalable <span class="hlt">electronics</span>: analog learning systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Srinivasa, Narayan; Cruz-Albrecht, Jose</p> <p>2012-01-01</p> <p>Decades of research to build programmable intelligent machines have demonstrated limited utility in complex, real-world environments. Comparing their performance with biological systems, these machines are less efficient by a factor of 1 million1 <span class="hlt">billion</span> in complex, real-world environments. The Systems of Neuromorphic Adaptive Plastic Scalable <span class="hlt">Electronics</span> (SyNAPSE) program is a multifaceted Defense Advanced Research Projects Agency (DARPA) project that seeks to break the programmable machine paradigm and define a new path for creating useful, intelligent machines. Since real-world systems exhibit infinite combinatorial complexity, <span class="hlt">electronic</span> neuromorphic machine technology would be preferable in a host of applications, but useful and practical implementations still do not exist. HRL Laboratories LLC has embarked on addressing these challenges, and, in this article, we provide an overview of our project and progress made thus far.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4865294','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4865294"><span id="translatedtitle"><span class="hlt">Electron</span> Diffraction Using Transmission <span class="hlt">Electron</span> Microscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bendersky, Leonid A.; Gayle, Frank W.</p> <p>2001-01-01</p> <p><span class="hlt">Electron</span> diffraction via the transmission <span class="hlt">electron</span> microscope is a powerful method for characterizing the structure of materials, including perfect crystals and defect structures. The advantages of <span class="hlt">electron</span> diffraction over other methods, e.g., x-ray or neutron, arise from the extremely short wavelength (≈2 pm), the strong atomic scattering, and the ability to examine tiny volumes of matter (≈10 nm3). The NIST Materials Science and Engineering Laboratory has a history of discovery and characterization of new structures through <span class="hlt">electron</span> diffraction, alone or in combination with other diffraction methods. This paper provides a survey of some of this work enabled through <span class="hlt">electron</span> microscopy. PMID:27500060</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21513122','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21513122"><span id="translatedtitle">Molecular <span class="hlt">Electronics</span> - Current Challenges</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vilan, Ayelet; Cahen, David</p> <p>2010-12-01</p> <p>Molecular <span class="hlt">electronics</span> is a flourishing area of nano-science and -technology, with a promise for cheap <span class="hlt">electronics</span> of novel functionality. Here we outline the major challenges for molecular <span class="hlt">electronics</span> becoming an established scientific discipline, including models with predictive power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/901007','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/901007"><span id="translatedtitle">Energy Doubling of 42 GeV <span class="hlt">Electrons</span> in a Meter-scale Plasma Wakefield Accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Blumenfeld, Ian; Clayton, Christopher E.; Decker, Franz-Josef; Hogan, Mark J.; Huang, Chengkun; Ischebeck, Rasmus; Iverson, Richard; Joshi, Chandrashekhar; Katsouleas, Thomas; Kirby, Neil; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; Muggli, Patric; Oz, Erdem; Siemann, Robert H.; Walz, Dieter; Zhou, Miaomiao; /SLAC /UCLA /Southern California U.</p> <p>2007-03-14</p> <p>The energy frontier of particle physics is several trillion <span class="hlt">electron</span> <span class="hlt">volts</span>, but colliders capable of reaching this regime (such as the Large Hadron Collider and the International Linear Collider) are costly and time-consuming to build; it is therefore important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators, a drive beam (either laser or particle) produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultrahigh accelerating fields over a substantial length to achieve a significant energy gain. Here we show that an energy gain of more than 42 GeV is achieved in a plasma wakefield accelerator of 85 cm length, driven by a 42 GeV <span class="hlt">electron</span> beam at the Stanford Linear Accelerator Center (SLAC). The results are in excellent agreement with the predictions of three-dimensional particle-in-cell simulations. Most of the beam <span class="hlt">electrons</span> lose energy to the plasma wave, but some <span class="hlt">electrons</span> in the back of the same beam pulse are accelerated with a field of {approx} 52GV m{sup -1}. This effectively doubles their energy, producing the energy gain of the 3-km-long SLAC accelerator in less than a meter for a small fraction of the <span class="hlt">electrons</span> in the injected bunch. This is an important step towards demonstrating the viability of plasma accelerators for high-energy physics applications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/569609','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/569609"><span id="translatedtitle"><span class="hlt">Electron</span> beam focusing system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.</p> <p>1997-09-01</p> <p>The high energy <span class="hlt">electron</span> cooling requires a very cold <span class="hlt">electron</span> beam. Thus, the <span class="hlt">electron</span> beam focusing system is very important for the performance of <span class="hlt">electron</span> cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of <span class="hlt">electron</span> beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent <span class="hlt">electron</span> beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5310157','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5310157"><span id="translatedtitle"><span class="hlt">Electron-electron</span> interaction in projectile <span class="hlt">electron</span> loss</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Huelskoetter, H.; Meyerhof, W.E.; Dillard, E.A.; Guardala, N.; Spooner, D.W. ); Feinberg, B. ); Belkacem, A. Sciences Division, Building 71-259, Lawrence Berkeley Laboratory, One Cyclotron Road, Berkeley, CA ); Alonso, J.R.; Krebs, G.F.; McMahan, M.A.; Rude, B.S ); Blumenfeld, L.; Gould, H. ); Rhoades-Brown, M.E. ); Schweppe, J. (Chemical Sciences Division, Building 71-259, Lawrence Berkeley Laboratory, One Cyclotron Road, Berkeley, CA (</p> <p>1991-08-01</p> <p>In ion-atom collisions where the projectile is ionized, target <span class="hlt">electrons</span> act not only coherently by screening the target nucleus but they may also act incoherently by directly ejecting a projectile <span class="hlt">electron</span>. This <span class="hlt">electron-electron</span> interaction should be relatively most important for targets that have a low nuclear charge, since the cross section for a neutral target is roughly proportional to {ital Z}{sub {ital t}}{sup 2}+{ital Z}{sub {ital t}}, where {ital Z}{sub {ital t}}{sup 2} is the contribution due to the target nucleus and {ital Z}{sub {ital t}} comes from the target <span class="hlt">electrons</span>. In order to investigate the <span class="hlt">electron-electron</span> interaction, we have measured and calculated cross sections for Li{sup 2+}, C{sup 5+}, and O{sup 7+} on H{sub 2} and He, Au{sup 52+} on H{sub 2}, He, C, and N{sub 2}, Au{sup 75+} on H{sub 2} and N{sub 2}, U{sup 86+} on H{sub 2} and He, and U{sup 90+} on H{sub 2}. The collision energies range from 0.75 to 405 MeV/nucleon. The calculations have been performed in the plane-wave Born approximation. We demonstrate that for energies where the target <span class="hlt">electrons</span> have sufficient kinetic energy in the projectile frame to ionize the projectile, the <span class="hlt">electron-electron</span> interaction can lead to a significant increase in the total <span class="hlt">electron</span>-loss cross section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7028755','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7028755"><span id="translatedtitle">Age-related degradation of Westinghouse 480-<span class="hlt">volt</span> circuit breakers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Subudhi, M.; Shier, W.; MacDougall, E. )</p> <p>1990-07-01</p> <p>An aging assessment of Westinghouse DS-series low-voltage air circuit breakers was performed as part of the Nuclear Plant Aging Research (NPAR) program. The objectives of this study are to characterize age-related degradation within the breaker assembly and to identify maintenance practices to mitigate their effect. Since this study has been promulgated by the failures of the reactor trip breakers at the McGuire Nuclear Station in July 1987, results relating to the welds in the breaker pole lever welds are also discussed. The design and operation of DS-206 and DS-416 breakers were reviewed. Failure data from various national data bases were analyzed to identify the predominant failure modes, causes, and mechanisms. Additional operating experiences from one nuclear station and two industrial breaker-service companies were obtained to develop aging trends of various subcomponents. The responses of the utilities to the NRC Bulletin 88-01, which discusses the center pole lever welds, were analyzed to assess the final resolution of failures of welds in the reactor trips. Maintenance recommendations, made by the manufacturer to mitigate age-related degradation were reviewed, and recommendations for improving the monitoring of age-related degradation are discussed. As described in Volume 2 of this NUREG, the results from a test program to assess degradation in breaker parts through mechanical cycling are also included. The testing has characterized the cracking of center-pole lever welds, identified monitoring techniques to determine aging in breakers, and provided information to augment existing maintenance programs. Recommendations to improve breaker reliability using effective maintenance, testing, and inspection programs are suggested. 13 refs., 21 figs., 8 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4955802','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4955802"><span id="translatedtitle">Two-<span class="hlt">Volt</span> Josephson Arbitrary Waveform Synthesizer Using Wilkinson Dividers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Flowers-Jacobs, Nathan E.; Fox, Anna E.; Dresselhaus, Paul D.; Schwall, Robert E.; Benz, Samuel P.</p> <p>2016-01-01</p> <p>The root-mean-square (rms) output voltage of the NIST Josephson arbitrary waveform synthesizer (JAWS) has been doubled from 1 V to a record 2 V by combining two new 1 V chips on a cryocooler. This higher voltage will improve calibrations of ac thermal voltage converters and precision voltage measurements that require state-of-the-art quantum accuracy, stability, and signal-to-noise ratio. We achieved this increase in output voltage by using four on-chip Wilkinson dividers and eight inner-outer dc blocks, which enable biasing of eight Josephson junction (JJ) arrays with high-speed inputs from only four high-speed pulse generator channels. This approach halves the number of pulse generator channels required in future JAWS systems. We also implemented on-chip superconducting interconnects between JJ arrays, which reduces systematic errors and enables a new modular chip package. Finally, we demonstrate a new technique for measuring and visualizing the operating current range that reduces the measurement time by almost two orders of magnitude and reveals the relationship between distortion in the output spectrum and output pulse sequence errors. PMID:27453676</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.6833W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.6833W"><span id="translatedtitle">Exceptional preservation of aragonite in a circa 3.3 <span class="hlt">billion</span> year old microbial mat from the Barberton greenstone belt, South Africa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Westall, Frances; Cavalazzi, Barbara; Lemelle, Laurence; Marrochhi, Yves; Rouzaud, Jean-Noel; Simionovici, Alexandre; Andreazza, Caroline; Foucher, Frédéric; Thiel, Volker; Hofmann, Axel</p> <p>2010-05-01</p> <p>Exceptional preservation of aragonite in a circa 3.3 <span class="hlt">billion</span> year old microbial mat from the Barberton greenstone belt, South Africa Frances Westall, Barbara Cavalazzi, Laurence Lemelle, Yves Marrocchi, Jean-Noël Rouzaud, Alexandre Simionovici, Murielle Salomé, Smail Mostefaoui, Caroline Andreazza, Frédéric Foucher, Jan Toporski, Andrea Jauss, Volker Thiel, Axel Hofmann, Anders Meibom, François Robert Aragonite occurs as a biologically-formed mineral precipitate within modern calcifying microbial mats. It is, however, rarely preserved in the geological record because, as one of the least stable polymorphs of calcium carbonate, it readily converts to calcite in present environmental conditions at the Earth's surface. In an in situ investigation at the micro- to nanometer-scale, we show that 5-10 nm sized nanocrystals of aragonite are preserved within the organic framework of a partially calcified microbial mat from the ~ 3.3 <span class="hlt">billion</span> year-old Josefsdal Chert in the Barberton greenstone belt, South Africa. Transformation of the aragonite to calcite was blocked by a combination of chemical inhibitors within the crystal lattice, organic molecules coating the nanocrystals and, in particular, to the precocious permeation of the mat by hydrothermal silica. Apart from its exceptional preservation for 3.3 <span class="hlt">billion</span> years, the identification of aragonite in the Josefsdal microbial mat is the earliest evidence for in situ calcification of a microbial mat. Furthermore, the indications of associated sulphur-reducing bacteria (SRB) activity with calcification strongly support a photosynthetic origin for the mat. This is the most direct evidence for photosynthesis in early Archaean rocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950013493','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950013493"><span id="translatedtitle">Design of power <span class="hlt">electronics</span> for TVC and EMA systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelms, R. Mark; Bell, J. Brett; Shepherd, Michael T.</p> <p>1994-01-01</p> <p>The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power <span class="hlt">electronic</span> modules capable of modulating several hundred amperes of current at up to 270 <span class="hlt">volts</span>. MSFC has selected the brushless dc motor for implementation in EMA's. A previous project performed by Auburn University examined the use of the resonant dc link (RDCL) inverter, pulse density modulation (PDM), and mos-controlled thyristors (MCT's) for speed control of a brushless dc motor. The speed of the brushless dc motor is proportional to the applied stator voltage. In a PDM system, the control system determines the number of resonant voltage pulses which must be applied to the stator to achieve a desired speed. The addition of a waveshaping circuit to the front end of a standard three-phase inverter yields a RDCL inverter; the resonant voltage pulses are produced through the action of this wave shaping circuit and the inverter. This project has focused on the implementation of a system which permits zero-voltage switching with the bus voltage clamped at the input voltage level. In the same manner as the RDCL inverter, the inverter selected for this implementation is a combination of waveshaping circuit and a standard three-phase inverter. In addition, this inverter allows a pulse-width modulated (PWM)-like control scheme instead of a PDM scheme. The operation of waveshaping circuit will be described through analysis and waveforms. Design relationships will also be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994aubu.reptR....N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994aubu.reptR....N"><span id="translatedtitle">Design of power <span class="hlt">electronics</span> for TVC and EMA systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelms, R. Mark; Bell, J. Brett; Shepherd, Michael T.</p> <p>1994-11-01</p> <p>The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power <span class="hlt">electronic</span> modules capable of modulating several hundred amperes of current at up to 270 <span class="hlt">volts</span>. MSFC has selected the brushless dc motor for implementation in EMA's. A previous project performed by Auburn University examined the use of the resonant dc link (RDCL) inverter, pulse density modulation (PDM), and mos-controlled thyristors (MCT's) for speed control of a brushless dc motor. The speed of the brushless dc motor is proportional to the applied stator voltage. In a PDM system, the control system determines the number of resonant voltage pulses which must be applied to the stator to achieve a desired speed. The addition of a waveshaping circuit to the front end of a standard three-phase inverter yields a RDCL inverter; the resonant voltage pulses are produced through the action of this wave shaping circuit and the inverter. This project has focused on the implementation of a system which permits zero-voltage switching with the bus voltage clamped at the input voltage level. In the same manner as the RDCL inverter, the inverter selected for this implementation is a combination of waveshaping circuit and a standard three-phase inverter. In addition, this inverter allows a pulse-width modulated (PWM)-like control scheme instead of a PDM scheme. The operation of waveshaping circuit will be described through analysis and waveforms. Design relationships will also be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARS24005I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARS24005I"><span id="translatedtitle">Attraction by Repulsion: Pairing <span class="hlt">Electrons</span> using <span class="hlt">Electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ilani, Shahal</p> <p></p> <p>One of the fundamental properties of <span class="hlt">electrons</span> is their mutual Columbic repulsion. If <span class="hlt">electrons</span> are placed in a solid, however, this basic property may change. A famous example is that of superconductors, where coupling to lattice vibrations makes <span class="hlt">electrons</span> attractive and leads to the formation of bound pairs. But what if all the degrees of freedom in the solid are <span class="hlt">electronic</span>? Is it possible to make <span class="hlt">electrons</span> attract each other only by their repulsion to other <span class="hlt">electrons</span>? Such an `excitonic' mechanism for attraction was proposed fifty years ago by W. A. Little, with the hope that it could lead to better and more exotic superconductivity. Yet, despite many efforts to synthesize materials that possess this unique property, to date there is still no evidence for <span class="hlt">electronic</span>-based attraction. In this talk I will present our recent experiments that observe this unusual <span class="hlt">electronic</span> attraction using a different, bottom-up approach. Our experiments are based on a new generation of quantum devices made from pristine carbon nanotubes, combined with precision cryogenic manipulation. Using this setup we can now assemble the fundamental building block of the excitonic attraction and demonstrate that two <span class="hlt">electrons</span> that naturally repel each other can be made attractive using an independent <span class="hlt">electronic</span> system as the binding glue. I will discuss the lessons learned from these experiments on what is achievable with plain electrostatics, and on the possibility to use the observed mechanism for creating exotic states of matter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6087405','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6087405"><span id="translatedtitle">Determination of the <span class="hlt">electron</span> velocity distribution from the soft and hard x-ray emission during lower-hybrid current drive on PLT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>von Goeler, S.; Stevens, J.; Karney, C.</p> <p>1983-06-01</p> <p>During lower-hybrid heating in low-density-tokamak discharges, a nonMaxwellian tail of high-energy <span class="hlt">electrons</span> is formed. This tail carries the plasma current. Utilizing the fact that relativistic <span class="hlt">electrons</span> emit bremsstrahlung predominantly in the forward direction, we investigate the shape of the <span class="hlt">electron</span> distribution by measuring the dependence of the x-ray emission on the angle between the magnetic field and the line of sight. The experimental data indicate that the distribution function is predominantly peaked in the forward direction, although a small fraction of the <span class="hlt">electrons</span> is in the backward cone. The energy dependence of the x-ray spectra is consistent with that of a velocity distribution which has a plateau extending out to several hundred kiloelectron <span class="hlt">volts</span>. Radial profiles show that the hot <span class="hlt">electrons</span> are located in the central plasma region and form a high-conductivity plasma with the current profile frozen in. The slope of the spectrum depends on the rf power and on the phasing of the waveguide grill, but not on the externally applied plasma voltage. Relaxation oscillations occur shortly after switching the rf off. They also appear during the rf for low rf power and at the high-density limit of the lower-hybrid current drive. The x-ray spectra confirm that parallel energy is transferred to perpendicular energy during the instability, suggesting an instability due to the anomalous Doppler effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED278417.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED278417.pdf"><span id="translatedtitle"><span class="hlt">Electronic</span> Networking. ERIC Digest.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tucker, Susan</p> <p></p> <p>This digest discusses several aspects of <span class="hlt">electronic</span> networking, including network functions, implementation, and applications in education. <span class="hlt">Electronic</span> networking is defined as including the four basic services of <span class="hlt">electronic</span> mail (E-mail), <span class="hlt">electronic</span> "bulletin boards," teleconferencing, and online databases, and an overview of these four functions…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED320034.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED320034.pdf"><span id="translatedtitle">Introduction to <span class="hlt">Electronic</span> Marketing.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dilbeck, Lettie</p> <p></p> <p>These materials for a five-unit course were developed to introduce secondary and postsecondary students to the use of <span class="hlt">electronic</span> equipment in marketing. The units cover the following topics: <span class="hlt">electronic</span> marketing as a valid marketing approach; telemarketing; radio <span class="hlt">electronic</span> media marketing; television <span class="hlt">electronic</span> media marketing; and cable TV…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AIPC..591..409G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AIPC..591..409G"><span id="translatedtitle"><span class="hlt">Electronic</span> properties of nanohorns</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garaj, Slaven; Gaál, Richard; Bonard, J.-M.; Thien-Nga, L.; Forró, L.; Takahashi, K.; Kokai, F.; Yudasaka, M.; Iijima, S.</p> <p>2001-11-01</p> <p><span class="hlt">Electronic</span> properties of nanohorns were investigated by <span class="hlt">electron</span> spin resonance, resistivity and thermo-electric power measurements. <span class="hlt">Electron</span> transport and spin relaxation is governed by hopping between "dahlia"-like aggregates of conducting nanohorn structures. Upon doping, conduction <span class="hlt">electron</span> part of paramagnetic susceptibility increases significantly. Field emission properties of nanohorns rank them among the best field-emitters currently available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvL.108x6803R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvL.108x6803R"><span id="translatedtitle"><span class="hlt">Electron-Electron</span> Interactions in Artificial Graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Räsänen, E.; Rozzi, C. A.; Pittalis, S.; Vignale, G.</p> <p>2012-06-01</p> <p>Recent advances in the creation and modulation of graphenelike systems are introducing a science of “designer Dirac materials”. In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (quantum dots) arranged in an adjustable honeycomb lattice in the two-dimensional <span class="hlt">electron</span> gas. As our ability to control the quality of artificial graphene samples improves, so grows the need for an accurate theory of its <span class="hlt">electronic</span> properties, including the effects of <span class="hlt">electron-electron</span> interactions. Here we determine those effects on the band structure and on the emergence of Dirac points.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MAR.M3004R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MAR.M3004R"><span id="translatedtitle"><span class="hlt">Electron-electron</span> interactions in artificial graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rasanen, Esa</p> <p>2013-03-01</p> <p>Recent advances in the creation and modulation of graphenelike systems are introducing a science of ``designer Dirac materials.'' In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (quantum dots) arranged in an adjustable honeycomb lattice in the two-dimensional <span class="hlt">electron</span> gas. As our ability to control the quality of artificial graphene samples improves, so grows the need for an accurate theory of its <span class="hlt">electronic</span> properties, including the effects of <span class="hlt">electron-electron</span> interactions. Here we determine those effects on the band structure and on the emergence of Dirac points, and discuss future investigations and challenges in this field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24205812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24205812"><span id="translatedtitle">Microbially induced sedimentary structures recording an ancient ecosystem in the ca. 3.48 <span class="hlt">billion</span>-year-old Dresser Formation, Pilbara, Western Australia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noffke, Nora; Christian, Daniel; Wacey, David; Hazen, Robert M</p> <p>2013-12-01</p> <p>Microbially induced sedimentary structures (MISS) result from the response of microbial mats to physical sediment dynamics. MISS are cosmopolitan and found in many modern environments, including shelves, tidal flats, lagoons, riverine shores, lakes, interdune areas, and sabkhas. The structures record highly diverse communities of microbial mats and have been reported from numerous intervals in the geological record up to 3.2 <span class="hlt">billion</span> years (Ga) old. This contribution describes a suite of MISS from some of the oldest well-preserved sedimentary rocks in the geological record, the early Archean (ca. 3.48 Ga) Dresser Formation, Western Australia. Outcrop mapping at the meter to millimeter scale defined five sub-environments characteristic of an ancient coastal sabkha. These sub-environments contain associations of distinct macroscopic and microscopic MISS. Macroscopic MISS include polygonal oscillation cracks and gas domes, erosional remnants and pockets, and mat chips. Microscopic MISS comprise tufts, sinoidal structures, and laminae fabrics; the microscopic laminae are composed of primary carbonaceous matter, pyrite, and hematite, plus trapped and bound grains. Identical suites of MISS occur in equivalent environmental settings through the entire subsequent history of Earth including the present time. This work extends the geological record of MISS by almost 300 million years. Complex mat-forming microbial communities likely existed almost 3.5 <span class="hlt">billion</span> years ago.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Geomo.238...56B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Geomo.238...56B"><span id="translatedtitle">An efficient and comprehensive method for drainage network extraction from DEM with <span class="hlt">billions</span> of pixels using a size-balanced binary search tree</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bai, Rui; Li, Tiejian; Huang, Yuefei; Li, Jiaye; Wang, Guangqian</p> <p>2015-06-01</p> <p>With the increasing resolution of digital elevation models (DEMs), computational efficiency problems have been encountered when extracting the drainage network of a large river basin at <span class="hlt">billion</span>-pixel scales. The efficiency of the most time-consuming depression-filling pretreatment has been improved by using the O(NlogN) complexity least-cost path search method, but the complete extraction steps following this method have not been proposed and tested. In this paper, an improved O(NlogN) algorithm was proposed by introducing a size-balanced binary search tree (BST) to improve the efficiency of the depression-filling pretreatment further. The following extraction steps, including the flow direction determination and the upslope area accumulation, were also redesigned to benefit from this improvement. Therefore, an efficient and comprehensive method was developed. The method was tested to extract drainage networks of 31 river basins with areas greater than 500,000 km2 from the 30-m-resolution ASTER GDEM and two sub-basins with areas of approximately 1000 km2 from the 1-m-resolution airborne LiDAR DEM. Complete drainage networks with both vector features and topographic parameters were obtained with time consumptions in O(NlogN) complexity. The results indicate that the developed method can be used to extract entire drainage networks from DEMs with <span class="hlt">billions</span> of pixels with high efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24205812','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24205812"><span id="translatedtitle">Microbially induced sedimentary structures recording an ancient ecosystem in the ca. 3.48 <span class="hlt">billion</span>-year-old Dresser Formation, Pilbara, Western Australia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noffke, Nora; Christian, Daniel; Wacey, David; Hazen, Robert M</p> <p>2013-12-01</p> <p>Microbially induced sedimentary structures (MISS) result from the response of microbial mats to physical sediment dynamics. MISS are cosmopolitan and found in many modern environments, including shelves, tidal flats, lagoons, riverine shores, lakes, interdune areas, and sabkhas. The structures record highly diverse communities of microbial mats and have been reported from numerous intervals in the geological record up to 3.2 <span class="hlt">billion</span> years (Ga) old. This contribution describes a suite of MISS from some of the oldest well-preserved sedimentary rocks in the geological record, the early Archean (ca. 3.48 Ga) Dresser Formation, Western Australia. Outcrop mapping at the meter to millimeter scale defined five sub-environments characteristic of an ancient coastal sabkha. These sub-environments contain associations of distinct macroscopic and microscopic MISS. Macroscopic MISS include polygonal oscillation cracks and gas domes, erosional remnants and pockets, and mat chips. Microscopic MISS comprise tufts, sinoidal structures, and laminae fabrics; the microscopic laminae are composed of primary carbonaceous matter, pyrite, and hematite, plus trapped and bound grains. Identical suites of MISS occur in equivalent environmental settings through the entire subsequent history of Earth including the present time. This work extends the geological record of MISS by almost 300 million years. Complex mat-forming microbial communities likely existed almost 3.5 <span class="hlt">billion</span> years ago. PMID:24205812</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3870916','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3870916"><span id="translatedtitle">Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ca. 3.48 <span class="hlt">Billion</span>-Year-Old Dresser Formation, Pilbara, Western Australia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Christian, Daniel; Wacey, David; Hazen, Robert M.</p> <p>2013-01-01</p> <p>Abstract Microbially induced sedimentary structures (MISS) result from the response of microbial mats to physical sediment dynamics. MISS are cosmopolitan and found in many modern environments, including shelves, tidal flats, lagoons, riverine shores, lakes, interdune areas, and sabkhas. The structures record highly diverse communities of microbial mats and have been reported from numerous intervals in the geological record up to 3.2 <span class="hlt">billion</span> years (Ga) old. This contribution describes a suite of MISS from some of the oldest well-preserved sedimentary rocks in the geological record, the early Archean (ca. 3.48 Ga) Dresser Formation, Western Australia. Outcrop mapping at the meter to millimeter scale defined five sub-environments characteristic of an ancient coastal sabkha. These sub-environments contain associations of distinct macroscopic and microscopic MISS. Macroscopic MISS include polygonal oscillation cracks and gas domes, erosional remnants and pockets, and mat chips. Microscopic MISS comprise tufts, sinoidal structures, and laminae fabrics; the microscopic laminae are composed of primary carbonaceous matter, pyrite, and hematite, plus trapped and bound grains. Identical suites of MISS occur in equivalent environmental settings through the entire subsequent history of Earth including the present time. This work extends the geological record of MISS by almost 300 million years. Complex mat-forming microbial communities likely existed almost 3.5 <span class="hlt">billion</span> years ago. Key Words: Archean—Biofilms—Microbial mats—Early Earth—Evolution. Astrobiology 13, 1103–1124. PMID:24205812</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770038256&hterms=precipitation+reactions&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dprecipitation%2Breactions','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770038256&hterms=precipitation+reactions&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dprecipitation%2Breactions"><span id="translatedtitle">Effects of soft <span class="hlt">electron</span> precipitation on the distribution of vibrational energy of N2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Newton, G. P.; Walker, J. C. G.; Mantas, G. P.</p> <p>1977-01-01</p> <p>The paper investigates the direct effect of soft <span class="hlt">electron</span> precipitation on the nitrogen vibrational distribution and on the rate coefficient for the ion-atom interchange reaction between O(+) and N2, using a spectrum of the precipitating <span class="hlt">electrons</span> characteristic of the dayside cusp region. Substantial increases in the nitrogen vibrational temperature and in the rate of the O(+) destruction reaction do not occur unless the flux of incident <span class="hlt">electrons</span> is as large as 1 trillion per sq cm/sec. For such large fluxes, departures of the vibrational distribution from a Boltzmann distribution have a significant effect on the rate coefficient. Incident fluxes less than 100 <span class="hlt">billion</span> per sq cm/sec, such as are usually observed, have little direct effect on nitrogen vibration, although the indirect effect resulting from enhanced <span class="hlt">electron</span> temperatures might be important.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Natur.535..406B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Natur.535..406B"><span id="translatedtitle">Cooperative electrocatalytic alcohol oxidation with <span class="hlt">electron</span>-proton-transfer mediators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badalyan, Artavazd; Stahl, Shannon S.</p> <p>2016-07-01</p> <p>The electrochemical oxidation of alcohols is a major focus of energy and chemical conversion efforts, with potential applications ranging from fuel cells to biomass utilization and fine-chemical synthesis. Small-molecule electrocatalysts for processes of this type are promising targets for further development, as demonstrated by recent advances in nickel catalysts for electrochemical production and oxidation of hydrogen. Complexes with tethered amines that resemble the active site of hydrogenases have been shown both to catalyse hydrogen production (from protons and <span class="hlt">electrons</span>) with rates far exceeding those of such enzymes and to mediate reversible electrocatalytic hydrogen production and oxidation with enzyme-like performance. Progress in electrocatalytic alcohol oxidation has been more modest. Nickel complexes similar to those used for hydrogen oxidation have been shown to mediate efficient electrochemical oxidation of benzyl alcohol, with a turnover frequency of 2.1 per second. These compounds exhibit poor reactivity with ethanol and methanol, however. Organic nitroxyls, such as TEMPO (2,2,6,6-tetramethyl-1-piperidine N-oxyl), are the most widely studied electrocatalysts for alcohol oxidation. These catalysts exhibit good activity (1-2 turnovers per second) with a wide range of alcohols and have great promise for electro-organic synthesis. Their use in energy-conversion applications, however, is limited by the high electrode potentials required to generate the reactive oxoammonium species. Here we report (2,2‧-bipyridine)Cu/nitroxyl co-catalyst systems for electrochemical alcohol oxidation that proceed with much faster rates, while operating at an electrode potential a half-<span class="hlt">volt</span> lower than that used for the TEMPO-only process. The (2,2‧-bipyridine)Cu(II) and TEMPO redox partners exhibit cooperative reactivity and exploit the low-potential, proton-coupled TEMPO/TEMPOH redox process rather than the high-potential TEMPO/TEMPO+ process. The results show how</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Natur.535..406B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Natur.535..406B&link_type=ABSTRACT"><span id="translatedtitle">Cooperative electrocatalytic alcohol oxidation with <span class="hlt">electron</span>-proton-transfer mediators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badalyan, Artavazd; Stahl, Shannon S.</p> <p>2016-07-01</p> <p>The electrochemical oxidation of alcohols is a major focus of energy and chemical conversion efforts, with potential applications ranging from fuel cells to biomass utilization and fine-chemical synthesis. Small-molecule electrocatalysts for processes of this type are promising targets for further development, as demonstrated by recent advances in nickel catalysts for electrochemical production and oxidation of hydrogen. Complexes with tethered amines that resemble the active site of hydrogenases have been shown both to catalyse hydrogen production (from protons and <span class="hlt">electrons</span>) with rates far exceeding those of such enzymes and to mediate reversible electrocatalytic hydrogen production and oxidation with enzyme-like performance. Progress in electrocatalytic alcohol oxidation has been more modest. Nickel complexes similar to those used for hydrogen oxidation have been shown to mediate efficient electrochemical oxidation of benzyl alcohol, with a turnover frequency of 2.1 per second. These compounds exhibit poor reactivity with ethanol and methanol, however. Organic nitroxyls, such as TEMPO (2,2,6,6-tetramethyl-1-piperidine N-oxyl), are the most widely studied electrocatalysts for alcohol oxidation. These catalysts exhibit good activity (1–2 turnovers per second) with a wide range of alcohols and have great promise for electro-organic synthesis. Their use in energy-conversion applications, however, is limited by the high electrode potentials required to generate the reactive oxoammonium species. Here we report (2,2‧-bipyridine)Cu/nitroxyl co-catalyst systems for electrochemical alcohol oxidation that proceed with much faster rates, while operating at an electrode potential a half-<span class="hlt">volt</span> lower than that used for the TEMPO-only process. The (2,2‧-bipyridine)Cu(II) and TEMPO redox partners exhibit cooperative reactivity and exploit the low-potential, proton-coupled TEMPO/TEMPOH redox process rather than the high-potential TEMPO/TEMPO+ process. The results show how</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27350245','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27350245"><span id="translatedtitle">Cooperative electrocatalytic alcohol oxidation with <span class="hlt">electron</span>-proton-transfer mediators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Badalyan, Artavazd; Stahl, Shannon S</p> <p>2016-07-21</p> <p>The electrochemical oxidation of alcohols is a major focus of energy and chemical conversion efforts, with potential applications ranging from fuel cells to biomass utilization and fine-chemical synthesis. Small-molecule electrocatalysts for processes of this type are promising targets for further development, as demonstrated by recent advances in nickel catalysts for electrochemical production and oxidation of hydrogen. Complexes with tethered amines that resemble the active site of hydrogenases have been shown both to catalyse hydrogen production (from protons and <span class="hlt">electrons</span>) with rates far exceeding those of such enzymes and to mediate reversible electrocatalytic hydrogen production and oxidation with enzyme-like performance. Progress in electrocatalytic alcohol oxidation has been more modest. Nickel complexes similar to those used for hydrogen oxidation have been shown to mediate efficient electrochemical oxidation of benzyl alcohol, with a turnover frequency of 2.1 per second. These compounds exhibit poor reactivity with ethanol and methanol, however. Organic nitroxyls, such as TEMPO (2,2,6,6-tetramethyl-1-piperidine N-oxyl), are the most widely studied electrocatalysts for alcohol oxidation. These catalysts exhibit good activity (1–2 turnovers per second) with a wide range of alcohols and have great promise for electro-organic synthesis. Their use in energy-conversion applications, however, is limited by the high electrode potentials required to generate the reactive oxoammonium species. Here we report (2,2′-bipyridine)Cu/nitroxyl co-catalyst systems for electrochemical alcohol oxidation that proceed with much faster rates, while operating at an electrode potential a half-<span class="hlt">volt</span> lower than that used for the TEMPO-only process. The (2,2′-bipyridine)Cu(II) and TEMPO redox partners exhibit cooperative reactivity and exploit the low-potential, proton-coupled TEMPO/TEMPOH redox process rather than the high-potential TEMPO/TEMPO+ process. The results show how</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27350245','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27350245"><span id="translatedtitle">Cooperative electrocatalytic alcohol oxidation with <span class="hlt">electron</span>-proton-transfer mediators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Badalyan, Artavazd; Stahl, Shannon S</p> <p>2016-07-21</p> <p>The electrochemical oxidation of alcohols is a major focus of energy and chemical conversion efforts, with potential applications ranging from fuel cells to biomass utilization and fine-chemical synthesis. Small-molecule electrocatalysts for processes of this type are promising targets for further development, as demonstrated by recent advances in nickel catalysts for electrochemical production and oxidation of hydrogen. Complexes with tethered amines that resemble the active site of hydrogenases have been shown both to catalyse hydrogen production (from protons and <span class="hlt">electrons</span>) with rates far exceeding those of such enzymes and to mediate reversible electrocatalytic hydrogen production and oxidation with enzyme-like performance. Progress in electrocatalytic alcohol oxidation has been more modest. Nickel complexes similar to those used for hydrogen oxidation have been shown to mediate efficient electrochemical oxidation of benzyl alcohol, with a turnover frequency of 2.1 per second. These compounds exhibit poor reactivity with ethanol and methanol, however. Organic nitroxyls, such as TEMPO (2,2,6,6-tetramethyl-1-piperidine N-oxyl), are the most widely studied electrocatalysts for alcohol oxidation. These catalysts exhibit good activity (1–2 turnovers per second) with a wide range of alcohols and have great promise for electro-organic synthesis. Their use in energy-conversion applications, however, is limited by the high electrode potentials required to generate the reactive oxoammonium species. Here we report (2,2′-bipyridine)Cu/nitroxyl co-catalyst systems for electrochemical alcohol oxidation that proceed with much faster rates, while operating at an electrode potential a half-<span class="hlt">volt</span> lower than that used for the TEMPO-only process. The (2,2′-bipyridine)Cu(II) and TEMPO redox partners exhibit cooperative reactivity and exploit the low-potential, proton-coupled TEMPO/TEMPOH redox process rather than the high-potential TEMPO/TEMPO+ process. The results show how</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/968028','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/968028"><span id="translatedtitle">Carbon nanotube <span class="hlt">electron</span> sources for <span class="hlt">electron</span> microscopes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>De Jonge, Niels</p> <p>2009-01-01</p> <p><span class="hlt">Electron</span> sources were made from individual multi-walled carbon nanotubes with closed caps and thoroughly cleaned surfaces. Nanotubes from both chemical vapor deposition growth and arc discharge growth were investigated. These emitters provide a highly stable emission current up to a threshold current of a few microamperes. At too large currents several processes take place such as splitting, breaking and cap closing. The emission process is field emission for a workfunction of 5 eV. The <span class="hlt">electron</span> optical per-formance is highly beneficial for their use as high-brightness point sources in <span class="hlt">electron</span> microscopes and advantageous with respect to state-of-the-art <span class="hlt">electron</span> sources. The life-time is at least two years. We have tested the source successfully in a scanning <span class="hlt">electron</span> microscope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/569607','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/569607"><span id="translatedtitle">High energy <span class="hlt">electron</span> cooling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parkhomchuk, V.</p> <p>1997-09-01</p> <p>High energy <span class="hlt">electron</span> cooling requires a very cold <span class="hlt">electron</span> beam. The questions of using <span class="hlt">electron</span> cooling with and without a magnetic field are presented for discussion at this workshop. The <span class="hlt">electron</span> cooling method was suggested by G. Budker in the middle sixties. The original idea of the <span class="hlt">electron</span> cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both <span class="hlt">electron</span> and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1183853','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1183853"><span id="translatedtitle">RHIC <span class="hlt">electron</span> lenses upgrades</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gu, X.; Altinbas, Z.; Bruno, D.; Binello, S.; Costanzo, M.; Drees, A.; Fischer, W.; Gassner, D. M.; Hock, J.; Hock, K.; Harvey, M.; Luo, Y.; Marusic, A.; Mi, C.; Mernick, K.; Minty, M.; Michnoff, R.; Miller, T. A.; Pikin, A. I.; Robert-Demolaize, G.; Samms, T.; Shrey, T. C.; Schoefer, V.; Tan, Y.; Than, R.; Thieberger, P.; White, S. M.</p> <p>2015-05-03</p> <p>In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two <span class="hlt">electron</span> lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current <span class="hlt">electron</span> lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new <span class="hlt">electron</span> gun with 15-mm diameter cathode is characterized. The <span class="hlt">electron</span> beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the <span class="hlt">electron</span> and proton beams was achieved using the <span class="hlt">electron</span> backscattering detector in conjunction with an automated orbit control program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740061829&hterms=literature+review&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dliterature%2Breview','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740061829&hterms=literature+review&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dliterature%2Breview"><span id="translatedtitle">Cosmic <span class="hlt">electrons</span>. [literature review</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ramaty, R.</p> <p>1974-01-01</p> <p>The published literature on cosmic <span class="hlt">electrons</span> is summarized. The primary and secondary sources of cosmic <span class="hlt">electrons</span> are discussed, and the propagation of the <span class="hlt">electrons</span> in the interstellar medium is studied with respect to energy loss mechanisms, age distributions, and spectral modifications during flight. Various portions of the <span class="hlt">electron</span> and positron spectra are then considered in relation to problems of astrophysics. New information is presented on such topics as the origin of low-energy positrons, the decay kinematics of the pi-mu-e process, the application of age distributions for nuclear cosmic rays to cosmic <span class="hlt">electrons</span>, and the possibility of nonidentical sources for cosmic <span class="hlt">electrons</span> and protons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..GECDTP022B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..GECDTP022B"><span id="translatedtitle">Observation of an <span class="hlt">electron</span> sheath at a large, transiently biassed surface in the GEC cell</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barroy, P. R. J.; Goodyear, A.; Braithwaite, N. St. J.</p> <p>2001-10-01</p> <p>Sheath reversal has been investigated in front of a biassed surface embedded into the ground electrode of a capacitively coupled GEC cell. Radio frequency bursts (several tens of <span class="hlt">volts</span> amplitude) were applied to the surface (20 mm diameter including guard ring) and fast, two dimensional observations made of the light emission using an intensified CCD camera synchronously gated within the succession of bursts. A guard ring, biassed to the same potential, ensures sheath planarity. The evolution of the optical emission has been followed during the dc biassing period. If the applied RF is large enough and the timescale short enough a perturbation of the plasma sheath is observed. At the onset of the RF burst periodic, sheath reversal is achieved as the potential of the surface exceeds that of the plasma. After several cycles of RF, the surface acquires enough negative charge to bias itself negatively, below plasma potential; sheath reversal then stops. The overall effect is accompanied by light emision from species excited by <span class="hlt">electrons</span> accelerated towards the surface. Modelling of the phenomenon has been conducted to account for the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DPPJP9030K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DPPJP9030K"><span id="translatedtitle">Design of an RF System for <span class="hlt">Electron</span> Bernstein Wave Studies in MST</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kauffold, J. X.; Seltzman, A. H.; Anderson, J. K.; Nonn, P. D.; Forest, C. B.</p> <p>2010-11-01</p> <p>Motivated by the possibility of current profile control a 5.5GHz RF system for EBW is being developed. The central component is a standard radar Klystron with 1.2MW peak power and 4μs typical pulse length. Meaningful experiments require RF pulse lengths similar to the characteristic <span class="hlt">electron</span> confinement times in MST necessitating the creation of a power supply providing 80kV at 40A for 10ms. A low inductance IGBT network switches power at 20kHz from an electrolytic capacitor bank into the primary of a three-phase resonant transformer system that is then rectified and filtered. The system uses three magnetically separate transformers with microcrystalline iron cores to provide suitable <span class="hlt">volt</span>-seconds and low hysteresis losses. Each phase has a secondary with a large leakage inductance and a parallel capacitor providing a boost ratio greater than 60:1 with a physical turns ratio of 13.5:1. A microprocessor feedback control system varies the drive frequency around resonance to regulate the boost ratio and provide a stable output as the storage bank discharges. The completed system will deliver RF to the plasma boundary where coupling to the Bernstein mode and subsequent heating and current drive can occur.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/40203178','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/40203178"><span id="translatedtitle">Narrow <span class="hlt">electron</span> injector for ballistic <span class="hlt">electron</span> spectroscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kast, M.; Pacher, C.; Strasser, G.; Gornik, E.</p> <p>2001-06-04</p> <p>A three-terminal hot <span class="hlt">electron</span> transistor is used to measure the normal energy distribution of ballistic <span class="hlt">electrons</span> generated by an <span class="hlt">electron</span> injector utilizing an improved injector design. A triple barrier resonant tunneling diode with a rectangular transmission function acts as a narrow (1 meV) energy filter. An asymmetric energy distribution with its maximum on the high-energy side with a full width at half maximum of {Delta}E{sub inj}=10 meV is derived. {copyright} 2001 American Institute of Physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.youtube.com/watch?v=TIY2BoAmKpQ','SCIGOVIMAGE-NASA'); return false;" href="http://www.youtube.com/watch?v=TIY2BoAmKpQ"><span id="translatedtitle"><span class="hlt">Electron</span> Beam Freeform Fabrication</span></a></p> <p><a target="_blank" href="http://www.nasa.gov/multimedia/videogallery/index.html">NASA Video Gallery</a></p> <p></p> <p></p> <p><span class="hlt">Electron</span> Beam Freeform Fabrication (EBF3) is a process by which NASA hopes to build metal parts in zero gravity environments. It's a layer-additive process that uses an <span class="hlt">electron</span> beam and a solid wi...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=electronic+AND+contract&id=EJ657761','ERIC'); return false;" href="http://eric.ed.gov/?q=electronic+AND+contract&id=EJ657761"><span id="translatedtitle">Copyright of <span class="hlt">Electronic</span> Publishing.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dong, Elaine; Wang, Bob</p> <p>2002-01-01</p> <p>Analyzes the importance of copyright, considers the main causes of copyright infringement in <span class="hlt">electronic</span> publishing, discusses fair use of a copyrighted work, and suggests methods to safeguard copyrighted <span class="hlt">electronic</span> publishing, including legislation, contracts, and technology. (Author/LRW)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/939491','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/939491"><span id="translatedtitle">Chapter 9: <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grupen, Claus; Shwartz, Boris A.</p> <p>2006-12-19</p> <p>Sophisticated front-end <span class="hlt">electronics</span> are a key part of practically all modern radiation detector systems. This chapter introduces the basic principles and their implementation. Topics include signal acquisition, <span class="hlt">electronic</span> noise, pulse shaping (analog and digital), and data readout techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4009411','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4009411"><span id="translatedtitle">Relativistic <span class="hlt">electron</span> beam generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Mooney, L.J.; Hyatt, H.M.</p> <p>1975-11-11</p> <p>A relativistic <span class="hlt">electron</span> beam generator for laser media excitation is described. The device employs a diode type relativistic <span class="hlt">electron</span> beam source having a cathode shape which provides a rectangular output beam with uniform current density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6840632','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6840632"><span id="translatedtitle">Catalac free <span class="hlt">electron</span> laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Brau, C.A.; Swenson, D.A.; Boyd, T.J. Jr.</p> <p>1979-12-12</p> <p>A catalac free <span class="hlt">electron</span> laser using a rf linac (catalac) which acts as a catalyst to accelerate an <span class="hlt">electron</span> beam in an initial pass through the catalac and decelerate the <span class="hlt">electron</span> beam during a second pass through the catalac is described. During the second pass through the catalac, energy is extracted from the <span class="hlt">electron</span> beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add <span class="hlt">electron</span> beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free <span class="hlt">electron</span> laser wiggler to further enhance efficiency of the catalac free <span class="hlt">electron</span> laser. The catalac free <span class="hlt">electron</span> laser can be used in conjunction with a simple resonator, a ring resonator, or as an amplifier in conjunction with a master oscillator laser.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864170','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864170"><span id="translatedtitle">Catalac free <span class="hlt">electron</span> laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Brau, Charles A.; Swenson, Donald A.; Boyd, Jr., Thomas J.</p> <p>1982-01-01</p> <p>A catalac free <span class="hlt">electron</span> laser using a rf linac (catalac) which acts as a catalyst to accelerate an <span class="hlt">electron</span> beam in an initial pass through the catalac and decelerate the <span class="hlt">electron</span> beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the <span class="hlt">electron</span> beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add <span class="hlt">electron</span> beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free <span class="hlt">electron</span> laser wiggler to further enhance efficiency of the catalac free <span class="hlt">electron</span> laser. The catalac free <span class="hlt">electron</span> laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020050543','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020050543"><span id="translatedtitle"><span class="hlt">Electronic</span> Nose: Evaluation of Kamina Prototype Unit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schattke, Nathan</p> <p>2001-01-01</p> <p>The Kamina, Sam and Cyranose <span class="hlt">electronic</span> nose systems were evaluated and partially trained. Much work was performed on the Kamina as it has the ability to respond to low (less than 10 ppb) concentrations of hydrazine compounds. We were able to tell the difference between Hydrazine (Hz) and Monomethylhydrazine (MMH) in standard clean humid air. We were able to detect MMH in reduced pressure (1/3 atm) at about 250 ppb, however the training set was to far from the real situation to be useful now. Various engineering and usability aspects of both the noses was noted, especially the software. One serious physical engineering flaw was remedied in the Kamina system. A gas flow manifold was created for the Sam system. Different chips were evaluated for the Kamina system. It is still unclear if they can be exchanged without retraining the software.The Sam Detect commercial unit was evaluated for solvent detection and evaluation. It was able to successfully identify some solvents. The Cyranose, was observed and evaluated for two days. It has the ability to detect gasses in the 100 parts per million level but not the 10 parts per <span class="hlt">billion</span> level. It is very sensitive to humidity changes; there is software to partially handle this.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22068410','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22068410"><span id="translatedtitle">Six climate change-related events in the United States accounted for about $14 <span class="hlt">billion</span> in lost lives and health costs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Knowlton, Kim; Rotkin-Ellman, Miriam; Geballe, Linda; Max, Wendy; Solomon, Gina M</p> <p>2011-11-01</p> <p>The future health costs associated with predicted climate change-related events such as hurricanes, heat waves, and floods are projected to be enormous. This article estimates the health costs associated with six climate change-related events that struck the United States between 2000 and 2009. The six case studies came from categories of climate change-related events projected to worsen with continued global warming-ozone pollution, heat waves, hurricanes, infectious disease outbreaks, river flooding, and wildfires. We estimate that the health costs exceeded $14 <span class="hlt">billion</span>, with 95 percent due to the value of lives lost prematurely. Actual health care costs were an estimated $740 million. This reflects more than 760,000 encounters with the health care system. Our analysis provides scientists and policy makers with a methodology to use in estimating future health costs related to climate change and highlights the growing need for public health preparedness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/935346','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/935346"><span id="translatedtitle"><span class="hlt">Electron</span> Cyclotron Resonances in <span class="hlt">Electron</span> Cloud Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Celata, Christine; Celata, C.M.; Furman, Miguel A.; Vay, J.-L.; Yu, Jennifer W.</p> <p>2008-06-25</p> <p>We report a previously unknown resonance for <span class="hlt">electron</span> cloud dynamics. The 2D simulation code"POSINST" was used to study the <span class="hlt">electron</span> cloud buildup at different z positions in the International Linear Collider positron damping ring wiggler. An <span class="hlt">electron</span> equilibrium density enhancement of up to a factor of 3 was found at magnetic field values for which the bunch frequency is an integral multiple of the <span class="hlt">electron</span> cyclotron frequency. At low magnetic fields the effects of the resonance are prominent, but when B exceeds ~;;(2 pi mec/(elb)), with lb = bunch length, effects of the resonance disappear. Thus short bunches and low B fields are required for observing the effect. The reason for the B field dependence, an explanation of the dynamics, and the results of the 2D simulations and of a single-particle tracking code used to elucidate details of the dynamics are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16116372','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16116372"><span id="translatedtitle"><span class="hlt">Electronic</span> health record and <span class="hlt">electronic</span> patient record.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dimond, Bridgit</p> <p></p> <p>This article considers the government plans for the development of <span class="hlt">electronic</span> health and patient records as set out in the NHS Plan and the progress and problems which have been encountered in their realization. PMID:16116372</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. Their policies may differ from this site.</small> </div> </center> <div id="footer-wrapper"> <div class="footer-content"> <div id="footerOSTI" class=""> <div class="row"> <div class="col-md-4 text-center col-md-push-4 footer-content-center"><small><a href="http://www.science.gov/disclaimer.html">Privacy and Security</a></small> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center col-md-pull-4 footer-content-left"> <img src="https://www.osti.gov/images/DOE_SC31.png" alt="U.S. Department of Energy" usemap="#doe" height="31" width="177"><map style="display:none;" name="doe" id="doe"><area shape="rect" coords="1,3,107,30" href="http://www.energy.gov" alt="U.S. Deparment of Energy"><area shape="rect" coords="114,3,165,30" href="http://www.science.energy.gov" alt="Office of Science"></map> <a ref="http://www.osti.gov" style="margin-left: 15px;"><img src="https://www.osti.gov/images/footerimages/ostigov53.png" alt="Office of Scientific and Technical Information" height="31" width="53"></a> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center footer-content-right"> <a href="http://www.osti.gov/nle"><img src="https://www.osti.gov/images/footerimages/NLElogo31.png" alt="National Library of Energy" height="31" width="79"></a> <a href="http://www.science.gov"><img src="https://www.osti.gov/images/footerimages/scigov77.png" alt="science.gov" height="31" width="98"></a> <a href="http://worldwidescience.org"><img src="https://www.osti.gov/images/footerimages/wws82.png" alt="WorldWideScience.org" height="31" width="90"></a> </div> </div> </div> </div> </div> <p><br></p> </div><!-- container --> </body> </html>