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Sample records for external ion ejection

  1. Ejection of Coulomb Crystals from a Linear Paul Ion Trap for Ion-Molecule Reaction Studies.

    Science.gov (United States)

    Meyer, K A E; Pollum, L L; Petralia, L S; Tauschinsky, A; Rennick, C J; Softley, T P; Heazlewood, B R

    2015-12-17

    Coulomb crystals are being increasingly employed as a highly localized source of cold ions for the study of ion-molecule chemical reactions. To extend the scope of reactions that can be studied in Coulomb crystals-from simple reactions involving laser-cooled atomic ions, to more complex systems where molecular reactants give rise to multiple product channels-sensitive product detection methodologies are required. The use of a digital ion trap (DIT) and a new damped cosine trap (DCT) are described, which facilitate the ejection of Coulomb-crystallized ions onto an external detector for the recording of time-of-flight (TOF) mass spectra. This enables the examination of reaction dynamics and kinetics between Coulomb-crystallized ions and neutral molecules: ionic products are typically cotrapped, thus ejecting the crystal onto an external detector reveals the masses, identities, and quantities of all ionic species at a selected point in the reaction. Two reaction systems are examined: the reaction of Ca(+) with deuterated isotopologues of water, and the charge exchange between cotrapped Xe(+) with deuterated isotopologues of ammonia. These reactions are examples of two distinct types of experiment, the first involving direct reaction of the laser-cooled ions, and the second involving reaction of sympathetically-cooled heavy ions to form a mixture of light product ions. Extensive simulations are conducted to interpret experimental results and calculate optimal operating parameters, facilitating a comparison between the DIT and DCT approaches. The simulations also demonstrate a correlation between crystal shape and image shape on the detector, suggesting a possible means for determining crystal geometry for nonfluorescing ions.

  2. Successive Resonances for Ion Ejection at Arbitrary Frequencies in an Ion Trap

    Science.gov (United States)

    Snyder, Dalton T.; Cooks, R. Graham

    2016-09-01

    The use of successive resonances for ion ejection is demonstrated here as a method of scanning quadrupole ion traps with improvement in both resolution and sensitivity compared with single frequency resonance ejection. The conventional single frequency resonance ejection waveform is replaced with a dual-frequency waveform. The two included frequencies are spaced very closely and their relative amplitudes are adjusted so that the first frequency that ions encounter excites them to higher amplitudes where space charge effects are less prominent, thereby giving faster and more efficient ejection when the ions come into resonance with the second frequency. The method is applicable at any arbitrary frequency, unlike double and triple resonance methods. However, like double and triple resonance ejection, ejection using successive resonances requires the rf and AC waveforms to be phase-locked in order to retain mass accuracy and mass precision. The improved performance is seen in mass spectra acquired by rf amplitude scans (resonance ejection) as well as by secular frequency scans.

  3. Reducing Space Charge Effects in a Linear Ion Trap by Rhombic Ion Excitation and Ejection

    Science.gov (United States)

    Zhang, Xiaohua; Wang, Yuzhuo; Hu, Lili; Guo, Dan; Fang, Xiang; Zhou, Mingfei; Xu, Wei

    2016-07-01

    Space charge effects play important roles in ion trap operations, which typically limit the ion trapping capacity, dynamic range, mass accuracy, and resolving power of a quadrupole ion trap. In this study, a rhombic ion excitation and ejection method was proposed to minimize space charge effects in a linear ion trap. Instead of applying a single dipolar AC excitation signal, two dipolar AC excitation signals with the same frequency and amplitude but 90° phase difference were applied in the x- and y-directions of the linear ion trap, respectively. As a result, mass selective excited ions would circle around the ion cloud located at the center of the ion trap, rather than go through the ion cloud. In this work, excited ions were then axially ejected and detected, but this rhombic ion excitation method could also be applied to linear ion traps with ion radial ejection capabilities. Experiments show that space charge induced mass resolution degradation and mass shift could be alleviated with this method. For the experimental conditions in this work, space charge induced mass shift could be decreased by ~50%, and the mass resolving power could be improved by ~2 times at the same time.

  4. Detection of Isotopes of Mercury Ions by Resonant Ejection in Paul Trap

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-Ming; SHE Lei; LI Jiao-Mei; GAO Ke-Lin

    2007-01-01

    A simple method to detect mercury ions confined in a Paul trap has been developed by resonant ejection. In this method, frequency of the additional ejection ac voltage is scanned instead of the amplitude of the rf drive voltage in conventional methods. It is possible not only to observe the spectra of the secular oscillation of the trapped ions directly, but also to eject the confined ions from the trap mass-selectively.

  5. Ion Trapping, Storage, and Ejection in Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Zhang, Xinyu; Garimella, Sandilya V B; Prost, Spencer A; Webb, Ian K; Chen, Tsung-Chi; Tang, Keqi; Tolmachev, Aleksey V; Norheim, Randolph V; Baker, Erin S; Anderson, Gordon A; Ibrahim, Yehia M; Smith, Richard D

    2015-06-16

    A new Structures for Lossless Ion Manipulations (SLIM) module, having electrode arrays patterned on a pair of parallel printed circuit boards (PCB), was constructed and utilized to investigate capabilities for ion trapping at a pressure of 4 Torr. Positive ions were confined by application of RF voltages to a series of inner rung electrodes with alternating phase on adjacent electrodes, in conjunction with positive DC potentials on surrounding guard electrodes on each PCB. An axial DC field was also introduced by stepwise varying the DC potentials applied to the inner rung electrodes to control the ion transport and accumulation inside the ion trapping region. We show that ions can be trapped and accumulated with up to 100% efficiency, stored for at least 5 h with no significant losses, and then could be rapidly ejected from the SLIM trap. The present results provide a foundation for the development of much more complex SLIM devices that facilitate extended ion manipulations.

  6. Negative ion source with external RF antenna

    Science.gov (United States)

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  7. Analysis of Nonlinear Dispersion of a Pollutant Ejected by an External Source into a Channel Flow

    Directory of Open Access Journals (Sweden)

    T. Chinyoka

    2010-01-01

    Full Text Available This paper focuses on the transient analysis of nonlinear dispersion of a pollutant ejected by an external source into a laminar flow of an incompressible fluid in a channel. The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation, and the nonlinear governing equations of momentum and pollutant concentration are obtained. The problem is solved numerically using a semi-implicit finite difference method. Solutions are presented in graphical form and given in terms of fluid velocity, pollutant concentration, skin friction, and wall mass transfer rate for various parametric values. The model can be a useful tool for understanding the polluting situations of an improper discharge incident and evaluating the effects of decontaminating measures for the water body.

  8. Ion Plasma Responses to External Electromagnetic Fields

    NARCIS (Netherlands)

    Naus, H.W.L.

    2010-01-01

    The response of ion plasmas to external radiation fields is investigated in a quantum mechanical formalism.We focus on the total electric field within the plasma. For general bandpass signals three frequency regions can be distinguished in terms of the plasma frequency. For low frequencies, the exte

  9. The SNS External Antenna H- Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Welton, Robert F [ORNL; Stockli, Martin P [ORNL; Murray Jr, S N [ORNL; Crisp, Danny W [ORNL; Carmichael, Justin R [ORNL; Goulding, Richard Howell [ORNL; Han, Baoxi [ORNL; Pennisi, Terry R [ORNL; Santana, Manuel [ORNL

    2010-01-01

    The U.S. Spallation Neutron Source (SNS) is an accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure that we will meet our operational commitments as well as provide for future facility upgrades with high reliability, we have developed an RF-driven, H- ion source based on a ceramic aluminum nitride (AlN) plasma chamber [1]. This source is expected to be utilized by the SNS for neutron production starting in 2009. This report details the design of the production source which features an AlN plasma chamber, 2-layer external antenna, cooled-multicusp magnet array, Cs2CrO4 cesium system and a Molybdenum plasma ignition gun. Performance of the production source both on the SNS accelerator and SNS test stand is reported. The source has also been designed to accommodate an elemental Cs system with an external reservoir which has demonstrated unanalyzed beam currents up to ~100mA (60Hz, 1ms) on the SNS ion source test stand.

  10. Liquid metal ion source assembly for external ion injection into an electron string ion source (ESIS)

    Energy Technology Data Exchange (ETDEWEB)

    Segal, M. J., E-mail: mattiti@gmail.com [iThemba LABS, P.O. Box 722, Somerset West 7130 (South Africa); University of Cape Town, Rondebosch, Cape Town 7700 (South Africa); Bark, R. A.; Thomae, R. [iThemba LABS, P.O. Box 722, Somerset West 7130 (South Africa); Donets, E. E.; Donets, E. D.; Boytsov, A.; Ponkin, D.; Ramsdorf, A. [Joint Institute for Nuclear Research, Joloit-Curie 6, 141980 Dubna, Moscow Region (Russian Federation)

    2016-02-15

    An assembly for a commercial Ga{sup +} liquid metal ion source in combination with an ion transportation and focusing system, a pulse high-voltage quadrupole deflector, and a beam diagnostics system has been constructed in the framework of the iThemba LABS (Cape Town, South Africa)—JINR (Dubna, Russia) collaboration. First, results on Ga{sup +} ion beam commissioning will be presented. Outlook of further experiments for measurements of charge breeding efficiency in the electron string ion source with the use of external injection of Ga{sup +} and Au{sup +} ion beams will be reported as well.

  11. Rapid crystallization of externally produced ions in a Penning trap

    CERN Document Server

    Murboeck, T; Birkl, G; Noertershaeuser, W; Thompson, R C; Vogel, M

    2016-01-01

    We have studied the cooling dynamics, formation process and geometric structure of mesoscopic crystals of externally produced magnesium ions in a Penning trap. We present a cooling model and measurements for a combination of buffer gas cooling and laser cooling which has been found to reduce the ion kinetic energy by eight orders of magnitude from several hundreds of eV to micro-eV and below within seconds. With ion numbers of the order of 1000 to 100000, such cooling leads to the formation of ion Coulomb crystals which display a characteristic shell structure in agreement with theory of non-neutral plasmas. We show the production and characterization of two-species ion crystals as a means of sympathetic cooling of ions lacking a suitable laser-cooling transition.

  12. External Second Gate-Fourier Transform Ion Mobility Spectrometry.

    Energy Technology Data Exchange (ETDEWEB)

    Tarver, Edward E., III

    2005-01-01

    Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and versatile techniques for the detection of trace levels of organic vapors. IMS is widely used for detecting contraband narcotics, explosives, toxic industrial compounds and chemical warfare agents. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention treaty verification as well as humanitarian de-mining efforts has mandated that equal importance be placed on the analysis time as well as the quality of the analytical data. (1) IMS is unrivaled when both speed of response and sensitivity has to be considered. (2) With conventional (signal averaging) IMS systems the number of available ions contributing to the measured signal to less than 1%. Furthermore, the signal averaging process incorporates scan-to-scan variations decreasing resolution. With external second gate Fourier Transform ion mobility spectrometry (FT-IMS), the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters to increase the spectral resolution. The FT-IMS entrance gate operates with a 50% duty cycle and so affords a 7 to 10-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system.

  13. Multicusp ion source with external RF antenna for production of H- ions

    Science.gov (United States)

    Kalvas, T.; Hahto, S. K.; Vainionpää, J. H.; Leung, K. N.; Wilde, S. B.; Mandrillon, P.

    2007-08-01

    A multicusp ion source with modular design was developed at LBNL for production of H- ions. The source consists of a front plate, two multicusp front chambers, a quartz flange with external 3-loop RF antenna and a rear multicusp chamber. The source has LaB6 sputtering target at the rear chamber to lower the work function of the surfaces by coating them with LaB6 and an external cesium oven on the front plate. The front plate also has an integrated collar and filter magnets to cool plasma near the extraction. The collar also enables the use of cesium and LaB6 surface effects. The rear chamber is equipped with three vacuum feed-throughs for operation with two gases and a pressure measurement. Current density of over 10 mA/cm2 of H- has been measured with e/I- ratio being ˜100 when the source was operated with only 1000 W of cw RF power. Negative ion production was enhanced using cesium, Xe gas mixing and LaB6 deposition to the source surfaces. When the front plate with filter magnets is removed, the source produces large amounts of H+. Current density of 110 mA/cm2 with 1800 W RF power at 2.3 Pa source pressure was measured with over 90 % atomic species. A long operation lifetime is excepted as the external RF antenna is not exposed to plasma.

  14. Development of a Kingdon ion trap system for trapping externally injected highly charged ions.

    Science.gov (United States)

    Numadate, Naoki; Okada, Kunihiro; Nakamura, Nobuyuki; Tanuma, Hajime

    2014-10-01

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar(q+) (q = 5-7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar(q+) (q = 5-7) under a constant number density of H2 and determined the charge-transfer cross sections of Ar(q+)(q = 5, 6)-H2 collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula.

  15. The p-H symmetry breaking in dissociative ionization of H2 due to the molecular ion interaction with the ejected electron

    CERN Document Server

    Serov, Vladislav V

    2014-01-01

    We propose a novel mechanism of electron localization and molecular symmetry breaking in dissociative photoionization of the \\H molecule. The Coulomb field of the ejected electron can induce transition of the remaining H$_2^+$ ion from the gerade $^2\\Sigma_g^1(1s\\sigma_g)$ to the ungerade $^2\\Sigma_u^1(2p\\sigma_u)$ electronic state when the nuclei in a bound vibrational state are near the outer turning point. The superposition of this process with a direct transition to vibrational continuum should produce a non-gerade ionic state which results in observed asymmetry in the $p$-H ejection relative to the electron ejection direction at a small kinetic energy release.

  16. Ejecting intact large molecular structures by C{sub 60} ion impact upon bio-organic solids; Ejection de tres grandes structures moleculaires intactes par impact de C{sub 60} sur des solides bioorganiques

    Energy Technology Data Exchange (ETDEWEB)

    Brunelle, A.; Della Negra, S.; Deprun, C.; Depauw, J.; Jacquet, D.; Le Beyec, Y.; Pautrat, N. [Experimental Research Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Haakansson, P. [Division of Ion Physics, Angstrom Laboratory, Uppsala Univ. Uppsala (Sweden)

    1999-11-01

    C{sub 60} molecules accelerated to MeV energies (20 MeV) have been used to induce the desorption-ionization of large bio-molecules from solid samples. In the case of the trypsin molecules, the secondary molecular ion emission yield is about two orders of magnitude larger than with MeV atomic ions. This is a consequence of the very high energy density deposited in solids by 20 MeV C{sub 60} projectiles that gives rise to a large amount of matter ejected after each impact. Although time-of-flight mass spectra can be recorded within a few seconds, it is more the mechanistic aspects in comparison with other particle induced desorption methods, which are the objective of these first results with energetic fullerenes. (authors) 1 fig.

  17. External-field shifts in precision spectroscopy of hydrogen molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [INRNE, Bulgarian Academy of Sciences (Bulgaria); Korobov, Vladimir [Joint Institute for Nuclear Research (Russian Federation); Schiller, Stephan [Heinrich-Heine-Universitat Dusseldorf, Institut fur Experimentalphysik (Germany)

    2015-08-15

    The Effective Hamiltonian of the hydrogen molecular ions is a convenient tool for the evaluation of the shift of the energy levels of the ro-vibrational states and the frequencies of the transitions between them, due to external electric and magnetic fields. Using the Effective Hamiltonian, composite frequencies of suppressed susceptibility to external fields are constructed.

  18. Ion Microprobe U-Th Ages of Zircon From Plutonic Rock Fragments Ejected by Mount Veniaminof Volcano, Alaska Peninsula

    Science.gov (United States)

    Bacon, C. R.; Sisson, T. W.; Mazdab, F. K.

    2006-05-01

    Mount Veniaminof volcano in the Aleutian arc provides an unusual opportunity to directly relate volcanic rocks to a coeval shallow pluton. Fragments of medium- to coarse-grained plutonic rock were ejected during Veniaminof's 3700 14C yr B.P. caldera-forming eruption. The gabbro, diorite, and miarolitic granodiorite fragments are direct evidence of assembly of a shallow pluton consisting of cumulate mush and vapor- saturated residual melt segregations. We used the USGS-Stanford SHRIMP RG (Sensitive High-Resolution Ion MicroProbe with Reverse Geometry) to analyze ~30-μm-diameter areas a few μm deep on individual polished 40-150 μm zircons separated from these plutonic rocks. Samples were sputtered with a 16-22 nA primary beam of 16O- ions and secondary ion intensities were measured for 90Zr216O, 180Hf16O, 238U, 230Th16O, background, 232Th16O, and 238U16O. Crystallization ages for the single zircon populations in each rock were determined by fitting isochrons to SHRIMP RG data plotted on (230Th/232Th) versus (238U/232Th) activity ratio diagrams, after rejecting analyses affected by contamination from the epoxy mounting medium (combination of 232Th and epoxy constituents that overlaps 230Th16O). The SHRIMP RG analyses define 238U-230Th isochron ages of 17.5 ± 1.8 ka and 11.7 +4.7/-4.5 ka for zircon crystallization in granodiorite and diorite, respectively (±2σ). Sparse zircons from two gabbro samples give 238U-230Th model ages of 36.6 +7.1/-6.7 ka and 26.4 +6.7/-6.4 ka using initial activity ratios defined by the granodiorite and diorite isochrons. Zircons from granodiorite and diorite, commonly bearing ~0.2-5 μm fluid inclusions, have exceptionally high U and Th contents (up to 2 and 5 wt.%, respectively) that may be explained by crystallization in the presence of late-magmatic aqueous fluid during passive degassing in the shallow subsurface. Veniaminof erupted medium- K basaltic through dacitic magmas over the past ~250 kyr that define an arc tholeiitic trend

  19. Ion mobility-mass spectrometry of charge-reduced protein complexes reveals general trends in the collisional ejection of compact subunits.

    Science.gov (United States)

    Bornschein, Russell E; Ruotolo, Brandon T

    2015-10-21

    Multiprotein complexes have been shown to play critical roles across a wide range of cellular functions, but most probes of protein quaternary structure are limited in their ability to analyze complex mixtures and polydisperse structures using small amounts of total protein. Ion mobility-mass spectrometry offers a solution to many of these challenges, but relies upon gas-phase measurements of intact multiprotein complexes, subcomplexes, and subunits that correlate well with solution structures. The greatest bottleneck in such workflows is the generation of representative subcomplexes and subunits. Collisional activation of complexes can act to produce product ions reflective of protein complex composition, but such product ions are typically challenging to interpret in terms of their relationship to solution structure due to their typically string-like conformations following activation and subsequent dissociation. Here, we used ion-ion chemistry to perform a broad survey of the gas-phase dissociation of charge-reduced protein complex ions, revealing general trends associated with the collisional ejection of compact, rather than unfolded, protein subunits. Furthermore, we also discover peptide and co-factor dissociation channels that dominate the product ion populations generated for such charge reduced complexes. We assess both sets of observations and discuss general principles that can be extended to the analysis of protein complex ions having unknown structures.

  20. The selectivity of different external binding sites for quaternary ammonium ions in cloned potassium channels.

    Science.gov (United States)

    Jarolimek, W; Soman, K V; Brown, A M; Alam, M

    1995-09-01

    Tetraethylammonium (TEA) is thought to be the most effective quaternary ammonium (QA) ion blocker at the external site of K+ channels, and small changes to the TEA ion reduce its potency. To examine the properties of the external QA receptor, we applied a variety of QA ions to excised patches from human embryonic kidney cells or Xenopus oocytes transfected with the delayed rectifying K+ channels Kv 2.1 and Kv 3.1. In outside-out patches of Kv 3.1, the relative potencies were TEA > tetrapropylammonium (TPA) > tetrabutylammonium (TBA). In contrast to Kv 3.1, the relative potencies in Kv 2.1 were TBA > TEA > TPA. In Kv 3.1 and Kv 2.1, external tetrapentylammonium (TPeA) blocked K+ currents in a fast, reversible and, in contrast to TEA, time-dependent manner. The external binding of TPeA appeared to be voltage independent, unlike the effects of TPeA applied to inside-out patches. External n-alkyl-triethylammonium compounds (C8, C10 chain length) had a lower affinity than TEA in Kv 3.1, but a higher affinity than TEA in Kv 2.1. In Kv 3.1, the decrease in QA affinity was large when one or two methyl groups were substituted for ethyl groups in TEA, but minor when propyl groups replaced ethyl groups. Changes in the free energy of binding could be correlated to changes in the free energy of hydration of TEA derivatives calculated by continuum methodology. These results reveal a substantial hydrophobic component of external QA ion binding to Kv 2.1, and to a lesser degree to Kv 3.1, in addition to the generally accepted electrostatic interactions. The chain length of hydrophobic TEA derivatives affects the affinity for the hydrophobic binding site, whereas the hydropathy of QA ions determines the electrostatic interaction energy.

  1. PS, septum magnet for ejection of antiprotons

    CERN Multimedia

    1980-01-01

    Antiprotons circulated in the PS in the sense opposite to that of the so far normal protons (or positive ions). A new ejection system with a new septum magnet was installed in straight section 58 for antiproton ejection, first towards the ISR and then to the principal customer, the SPS p-pbar Collider. Later on, when the PS delivered leptons for LEP, the antiproton ejection system was use for the ejection of electrons.

  2. Formation mechanism and yield of molecules ejected from ZnS, CdS, and FeS{sub 2} during ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Nikzad, S.; Calaway, W.F.; Pellin, M.J.; Young, C.E.; Gruen, D.M. [Argonne National Lab., IL (United States); Tombrello, T.A. [California Inst. of Technology, Pasadena, CA (United States). Div. of Physics, Mathematics, and Astronomy

    1994-03-01

    Neutral species ejected from single crystals of ZnS, CdS, and FeS{sub 2} during ion bombardment by 3 keV Ar{sup +} were detected by laser post-ionization followed by time-of-flight mass spectrometry. While metal atoms (Fe, Zn, Cd) and S{sub 2} were the dominant species observed, substantial amounts of S, FeS, Zn{sub 2}, ZnS, Cd{sub 2}, and CdS were also detected. The experimental results demonstrate that molecules represent a larger fraction of the sputtered yield than was previously believed from secondary ion mass spectrometry experiments. In addition, the data suggest that the molecules are not necessarily formed from adjacent atoms in the solid and that a modified form of the recombination model could provide a mechanism for their formation.

  3. Multicusp ion source with external rf antenna for production of protons

    Science.gov (United States)

    Hahto, S. K.; Hahto, S. T.; Ji, Q.; Leung, K. N.; Wilde, S.; Foley, E. L.; Grisham, L. R.; Levinton, F. M.

    2004-02-01

    Proton beams are needed in neutral-beam injection for diagnostic development of an internal magnetic field measurement. High proton fraction, low axial energy spread, current density in excess of 30 mA/cm2, and a parallel ion beam with cw operation are the requirements for the ion source/extraction system. A multicusp-type ion source with an external rf antenna was constructed at Lawrence Berkeley National Laboratory. A proton fraction of 85% and proton current density of 32 mA/cm2 were achieved at 1.8 kW of rf power. Plasma parameters were measured with a rf compensated Langmuir probe.

  4. Deterministic delivery of externally cold and precisely positioned single molecular ions

    CERN Document Server

    Leschhorn, G; Schaetz, T

    2011-01-01

    We present the preparation and deterministic delivery of a selectable number of externally cold molecular ions. A laser cooled ensemble of Mg^+ ions subsequently confined in several linear Paul traps inter-connected via a quadrupole guide serves as a cold bath for a single or up to a few hundred molecular ions. Sympathetic cooling embeds the molecular ions in the crystalline structure. MgH^+ ions, that serve as a model system for a large variety of other possible molecular ions, are cooled down close to the Doppler limit and are positioned with an accuracy of one micrometer. After the production process, severely compromising the vacuum conditions, the molecular ion is efficiently transfered into nearly background-free environment. The transfer of a molecular ion between different traps as well as the control of the molecular ions in the traps is demonstrated. Schemes, optimized for the transfer of a specific number of ions, are realized and their efficiencies are evaluated. This versatile source applicable f...

  5. Mass Spectra and Yields of Intact Charged Biomolecules Ejected by Massive Cluster Impact for Bioimaging in a Time-of-Flight Secondary Ion Microscope.

    Science.gov (United States)

    Zhang, Jitao; Franzreb, Klaus; Aksyonov, Sergei A; Williams, Peter

    2015-11-03

    Impacts of massive, highly charged glycerol clusters (≳10(6) Da, ≳ ± 100 charges) have been used to eject intact charged molecules of peptides, lipids, and small proteins from pure solid samples, enabling imaging using these ion species in a time-of-flight secondary ion microscope with few-micrometer spatial resolution. Here, we report mass spectra and useful ion yields (ratio of intact charged molecules detected to molecules sputtered) for several molecular species-two peptides, bradykinin and angiotensin II; two lipids, phosphatidylcholine and sphingomyelin; Irganox 1010 (a detergent); insulin; and rhodamine B-and show that useful ion yields are high enough to enable bioimaging of peptides and lipids in biological samples with few-micrometer resolution and acceptable signals. For example, several hundred molecular ion counts should be detectable from a 3 × 3 μm(2) area of a pure lipid bilayer given appropriate instrumentation or tens of counts from a minor constituent of such a layer.

  6. Possible role of external radial electric field on ion heating in an FRC

    Science.gov (United States)

    Gupta, Deepak; Trask, E.; Korepanov, S.; Granstedt, E.; Osin, D.; Roche, T.; Deng, B.; Beall, M.; Zhai, K.; TAE Team

    2016-10-01

    In C-2/C-2U FRCs, a radial electric field is applied by either plasma guns or biased electrodes inside the divertors, at both ends of the machine. The electric field plays an important role in stabilizing the FRC; thus, providing a favorable target condition to a neutral beam injection. In addition, it is also observed that the application of radial electric field may lead to a heating of ions. Radial profile of impurity ion emission, azimuthal velocity and temperature are measured under different configurations. The conditions and evidences of ion heating due to the electric field biasing will be presented and discussed. Radial momentum balance equation of oxygen impurity ions is used with these measurements to estimate the radial electric field profile. Parameters affecting the ion heating due to biasing will also be discussed with some correlations. The external radial electric field is planned to be applied by biased electrodes and plasma guns in C-2W inner/outer divertors.

  7. Improvements to the internal and external antenna H(-) ion sources at the Spallation Neutron Source.

    Science.gov (United States)

    Welton, R F; Dudnikov, V G; Han, B X; Murray, S N; Pennisi, T R; Pillar, C; Santana, M; Stockli, M P; Turvey, M W

    2014-02-01

    The Spallation Neutron Source (SNS), a large scale neutron production facility, routinely operates with 30-40 mA peak current in the linac. Recent measurements have shown that our RF-driven internal antenna, Cs-enhanced, multi-cusp ion sources injects ∼55 mA of H(-) beam current (∼1 ms, 60 Hz) at 65-kV into a Radio Frequency Quadrupole (RFQ) accelerator through a closely coupled electrostatic Low-Energy Beam Transport system. Over the last several years a decrease in RFQ transmission and issues with internal antennas has stimulated source development at the SNS both for the internal and external antenna ion sources. This report discusses progress in improving internal antenna reliability, H(-) yield improvements which resulted from modifications to the outlet aperture assembly (applicable to both internal and external antenna sources) and studies made of the long standing problem of beam persistence with the external antenna source. The current status of the external antenna ion source will also be presented.

  8. Students' Understanding of External Representations of the Potassium Ion Channel Protein Part II: Structure-Function Relationships and Fragmented Knowledge

    Science.gov (United States)

    Harle, Marissa; Towns, Marcy H.

    2012-01-01

    Research that has focused on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations. This study focuses on students' understanding of three external representations (ribbon diagram, wireframe, and hydrophobic/hydrophilic) of the potassium ion channel protein. Analysis…

  9. Energy-resolved angular distributions and the population partition of excited state Rh atoms ejected from ion bombarded Rh [l brace]001[r brace

    Energy Technology Data Exchange (ETDEWEB)

    He, C.; Postawa, Z.; El-Maazawi, M.; Rosencrance, S.; Garrison, B.J.; Winograd, N. (Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States))

    1994-10-01

    The energy-resolved angular distributions of Rh atoms ejected from Rh [l brace]001[r brace] by bombardment with 5.0 keV Ar[sup +] ions have been measured for the ground state ([ital a] [sup 4][ital F][sub 9/2]) and the two lowest lying excited state ([ital a] [sup 4][ital F][sub 7/2],[ital a] [sup 4][ital F][sub 5/2]). Simultaneous measurements on these electronic states provide us an opportunity to examine the influence of electronic interactions on desorbed particles. The experimental results show that there is a sequential variation in the angular distributions as the excitation energy increases. These variations are attributed to the interaction between the substrate electrons and the excited state atom as it is being ejected from the surface. Since the measurements are performed using multiphoton ionization via a single intermediate state, the population partition among the three lowest states is obtained as well. The excitation probabilities of the [ital a] [sup 4][ital F][sub 7/2] and [ital a] [sup 4][ital F][sub 5/2] states are compared with those predicted from the expression exp([minus][ital A]/[ital av][sub [perpendicular

  10. Computer simulations for rf design of a Spallation Neutron Source external antenna H ion source

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung-Woo [ORNL; Goulding, Richard Howell [ORNL; Kang, Yoon W [ORNL; Shin, Ki [ORNL; Welton, Robert F [ORNL

    2010-01-01

    Electromagnetic modeling of the multicusp external antenna H ion source for the Spallation Neutron Source SNS has been performed in order to optimize high-power performance. During development of the SNS external antenna ion source, antenna failures due to high voltage and multicusp magnet holder rf heating concerns under stressful operating conditions led to rf characteristics analysis. In rf simulations, the plasma was modeled as an equivalent lossy metal by defining conductivity as . Insulation designs along with material selections such as ferrite and Teflon could be included in the computer simulations to compare antenna gap potentials, surface power dissipations, and input impedance at the operating frequencies, 2 and 13.56 MHz. Further modeling and design improvements are outlined in the conclusion.

  11. Effects of external magnetic field on oblique propagation of ion acoustic cnoidal wave in nonextensive plasma

    Science.gov (United States)

    Farhad Kiyaei, Forough; Dorranian, Davoud

    2017-01-01

    Effects of the obliqueness and the strength of external magnetic field on the ion acoustic (IA) cnoidal wave in a nonextensive plasma are investigated. The reductive perturbation method is employed to derive the corresponding KdV equation for the IA wave. Sagdeev potential is extracted, and the condition of generation of IA waves in the form of cnoidal waves or solitons is discussed in detail. In this work, the domain of allowable values of nonextensivity parameter q for generation of the IA cnoidal wave in the plasma medium is considered. The results show that only the compressive IA wave may generate and propagate in the plasma medium. Increasing the strength of external magnetic field will increase the frequency of the wave and decrease its amplitude, while increasing the angle of propagation will decrease the frequency of the wave and increase its amplitude.

  12. Simultaneous ion luminescence imaging and spectroscopy of individual aerosol particles with external proton or helium microbeams

    Energy Technology Data Exchange (ETDEWEB)

    Kada, Wataru, E-mail: kada.wataru@gunma-u.ac.jp [Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Satoh, Takahiro; Yokoyama, Akihito; Koka, Masashi; Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2014-08-01

    Simultaneous microscopic imaging and spectroscopy of individual aerosol particles were performed with an external microbeam. Visible luminescence induced by the external microbeam was successfully used as a probe to detect organic contaminants in the targets. Combined ion luminescence (IL)/particle-induced X-ray emission (PIXE) analysis of the aerosol targets revealed microscopic chemical and elemental composition distributions under ambient atmospheric conditions. The simple confocal micro-optics for the IL spectroscopy and microscopic imaging were sufficiently sensitive for detecting these molecules at sub-parts per million concentrations and at a wavelength resolution of less than 5 nm. The IL spectra were monitored to prevent severe damage to the samples. Furthermore, our IL system has the advantage that it is simple to add to a conventional micro-PIXE system.

  13. Mass transport model of ions within biofilms under the effect of external field

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; TANG Xue-xi

    2006-01-01

    A mass transport model was developed to predict the transport rate of ions within biofilms, which was experimentally verified using the fluxes ofNH4+ and Ca2+ through the heterotrophic biofilms with the thickness varying from 230 to 1430 μm under the effect of external field in the range of-20 V/m to 60 V/m. It is found that the result predicted by the model is in agreement with the experimentally obtained one, with the error less than 5 percent for the thin biofilms. The error increases with the increase of the biofilm thickness. The transport rate of ions caused by electric migration is affected by the charges, field strength, and biofilm thickness and so on.

  14. Chaotic behavior of collective ion dynamics in the presence of an external static magnetic field

    Science.gov (United States)

    Poria, Swarup; Ghosh, Samiran

    2016-06-01

    The two-dimensional nonlinear collective ion dynamics in the presence of external magnetic field in an electron-ion plasma is investigated. The analysis is performed for traveling plane waves to elucidate the various aspects of the phase-space dynamics. The presence of magnetic field makes the dynamics of the nonlinear wave complex with a complicated phase-space behavior. Thus, the nonlinear wave supports a wide class of nonlinear structures viz., single soliton, multi-soliton, periodic, and quasi-periodic oscillations depending on the values of M (Mach number) and Ω (the ratio of ion gyro-frequency to the ion plasma frequency). The computational results predict the chaotic behavior of the nonlinear wave and the transition to chaos takes place when Ω ≳ 0.35 depending on the direction of propagation and the value of M. The amplitude of the wave depends on the obliqueness of the propagation and Mach number, whereas the magnetic field changes the dispersion properties of the wave.

  15. The design of high power, external antennas for radio frequency multicusp ion sources

    Science.gov (United States)

    Welton, R. F.; Stockli, M. P.; Roseberry, R. T.; Kang, Y.; Keller, R.

    2004-05-01

    The ion source for the Spallation Neutron Source (SNS) is a radio-frequency, multicusp source designed to deliver H- beam pulses of 45 mA to the SNS accelerator, with a pulse length of 1 ms and a repetition rate of 60 Hz. In order to achieve this performance the source must operate with both high peak rf power, ˜45 kW, and high average rf power, ˜3 kW, over an operational run period of 3 weeks. The most critical source component in this respect is the plasma-immersed, porcelain coated rf antenna which can be susceptible to damage during high power operation. The DESY group has developed an external antenna configuration utilizing an Al2O3 plasma chamber which has demonstrated a very long operational period exceeding 25 000 h. Their source operates with peak rf powers comparable to the SNS source but with greatly reduced average rf powers, ˜50 W. In order to explore the applicability of this external antenna concept to high average power ion sources like the SNS source, we have performed thermal, mechanical, and electromagnetic analyses of the Al2O3 plasma chamber. This article discusses the final design which has resulted from these studies as well as estimates of the power limitations of such devices.

  16. The status of the SNS external antenna ion source and spare RFQ test facility

    Energy Technology Data Exchange (ETDEWEB)

    Welton, R. F., E-mail: welton@ornl.gov; Aleksandrov, A. V.; Han, B. X.; Kang, Y.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Stockli, M. P. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471 (United States); Dudnikov, V. G. [Muons, Inc., 552 N. Batavia Avenue, Batavia, Illinois 60510 (United States)

    2016-02-15

    The Oak Ridge National Laboratory operates the Spallation Neutron Source, consisting of a H{sup −} ion source, a 1 GeV linac and an accumulator ring. The accumulated <1 μs-long, ∼35 A beam pulses are extracted from the ring at 60 Hz and directed onto a liquid Hg target. Spalled neutrons are directed to ∼20 world class instruments. Currently, the facility operates routinely with ∼1.2 MW of average beam power, which soon will be raised to 1.4 MW. A future upgrade with a second target station calls for raising the power to 2.8 MW. This paper describes the status of two accelerator components expected to play important roles in achieving these goals: a recently acquired RFQ accelerator and the external antenna ion source. Currently, the RFQ is being conditioned in a newly constructed 2.5 MeV Integrated Test Facility (ITF) and the external antenna source is also being tested on a separate test stand. This paper presents the results of experiments and the testing of these systems.

  17. Action as ejection.

    Science.gov (United States)

    Franco, Daisy

    2006-01-01

    The systematic analysis of acting-out episodes can be used in assessing analytic progress. Variables to be considered are the nature of the wish, the type of defense, and the degree of concreteness (versus symbolization) of the mental processes used in attempting actualization (as distinct from the resort to action). Two acting-out episodes of a borderline patient who acted out as a character trait, both occurring outside the analytic setting, are presented as illustrations. In the first one, occurring relatively early in the analysis, when split-off negative and positive self-images had to be rigidly maintained, ejection of the negative self-image was actualized via the regressive use of a symbolic equation and the mechanism of displacement, obliterating the distinction between an internal feeling and an external thing that here was literally thrown out. The later episode, occurring after the split was healed and within the context of a frustrating heterosexual involvement, contained an acted-out allusion to identification and competition with the mother. As in a dream, via associations, an unconscious wish for oedipal victory was revealed. Whereas in the first episode the goal of ejection was central, with splitting and denial the underlying defenses, it was absent from the second, in which an attempt was made to actualize a repressed infantile wish and made greater use of symbolization. It is concluded that acting-out episodes at different periods of the analysis, when systematically analyzed, can serve in assessing a patient's progress.

  18. Phase space generation for proton and carbon ion beams for external users’ applications at the Heidelberg Ion Therapy Center

    Directory of Open Access Journals (Sweden)

    Thomas eTessonnier

    2016-01-01

    Full Text Available In the field of radiation therapy, accurate and robust dose calculation is required. For this purpose, precise modeling of the irradiation system and reliable computational platforms are needed. At the Heidelberg Ion Therapy Center (HIT, the beamline has been already modeled in the FLUKA Monte Carlo code. However, this model was kept confidential for disclosure reasons and was not available for any external team. The main goal of this study was to create efficiently phase space (PS files for proton and carbon ion beams, for all energies and foci available at HIT. PS are representing the characteristics of each particle recorded (charge, mass, energy, coordinates, direction cosines, generation at a certain position along the beam path. In order to achieve this goal, keeping a reasonable data size but maintaining the requested accuracy for the calculation, we developed a new approach of beam PS generation with the Monte-Carlo code FLUKA. The generated PS were obtained using an infinitely narrow beam and recording the desired quantities after the last element of the beamline, with a discrimination of primaries or secondaries. In this way, a unique PS can be used for each energy to accommodate the different foci by combining the narrow-beam scenario with a random sampling of its theoretical Gaussian beam in vacuum. PS can also reproduce the different patterns from the delivery system, when properly combined with the beam scanning information. MC simulations using PS have been compared to simulations including the full beamline geometry and have been found in very good agreement for several cases (depth dose distributions, lateral dose profiles, with relative dose differences below 0.5%. This approach has also been compared with measured data of ion beams with different energies and foci, resulting in a very satisfactory agreement. Hence, the proposed approach was able to fulfill the different requirements and has demonstrated its capability for

  19. Effect of dust ion collision on dust ion acoustic waves in the framework of damped Zakharov-Kuznetsov equation in presence of external periodic force

    Science.gov (United States)

    Kanti Das, Tushar; Ali, Rustam; Chatterjee, Prasanta

    2017-10-01

    The dynamics of dust ion acoustic waves (DIAWs) is investigated in a magnetized dusty plasma whose constituents are cold ions, superthermal electrons, and dust particles in the framework of a damped Zakharov-Kuznetsov (dZK) equation in the presence of externally applied periodic force. The dZK equation is derived employing the standard reductive perturbation technique. The effect of dust ion collision on the quasiperiodic and chaotic motion of dust ion acoustic waves is discussed. It is observed that the collision frequency νid 0 plays the role of a switching parameter from the quasiperiodic route to chaos for the DIAWs.

  20. Ion permeabilities in mouse sperm reveal an external trigger for SLO3-dependent hyperpolarization.

    Directory of Open Access Journals (Sweden)

    Julio C Chávez

    Full Text Available Unlike most cells of the body which function in an ionic environment controlled within narrow limits, spermatozoa must function in a less controlled external environment. In order to better understand how sperm control their membrane potential in different ionic conditions, we measured mouse sperm membrane potentials under a variety of conditions and at different external K(+ concentrations, both before and after capacitation. Experiments were undertaken using both wild-type, and mutant mouse sperm from the knock-out strain of the sperm-specific, pH-sensitive, SLO3 K(+ channel. Membrane voltage data were fit to the Goldman-Hodgkin-Katz equation. Our study revealed a significant membrane permeability to both K(+ and Cl(- before capacitation, as well as Na(+. The permeability to both K(+ and Cl(- has the effect of preventing large changes in membrane potential when the extracellular concentration of either ion is changed. Such a mechanism may protect against undesired shifts in membrane potential in changing ionic environments. We found that a significant portion of resting membrane potassium permeability in wild-type sperm was contributed by SLO3 K(+ channels. We also found that further activation of SLO3 channels was the essential mechanism producing membrane hyperpolarization under two separate conditions, 1 elevation of external pH prior to capacitation and 2 capacitating conditions. Both conditions produced a significant membrane hyperpolarization in wild-type which was absent in SLO3 mutant sperm. Hyperpolarization in both conditions may result from activation of SLO3 channels by raising intracellular pH; however, demonstrating that SLO3-dependent hyperpolarization is achieved by an alkaline environment alone shows that SLO3 channel activation might occur independently of other events associated with capacitation. For example sperm may undergo stages of membrane hyperpolarization when reaching alkaline regions of the female genital tract

  1. Internal and External Temperature Monitoring of a Li-Ion Battery with Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Susana Novais

    2016-08-01

    Full Text Available The integration of fiber Bragg grating (FBG sensors in lithium-ion cells for in-situ and in-operando temperature monitoring is presented herein. The measuring of internal and external temperature variations was performed through four FBG sensors during galvanostatic cycling at C-rates ranging from 1C to 8C. The FBG sensors were placed both outside and inside the cell, located in the center of the electrochemically active area and at the tab-electrode connection. The internal sensors recorded temperature variations of 4.0 ± 0.1 °C at 5C and 4.7 ± 0.1 °C at 8C at the center of the active area, and 3.9 ± 0.1 °C at 5C and 4.0 ± 0.1 °C at 8C at the tab-electrode connection, respectively. This study is intended to contribute to detection of a temperature gradient in real time inside a cell, which can determine possible damage in the battery performance when it operates under normal and abnormal operating conditions, as well as to demonstrate the technical feasibility of the integration of in-operando microsensors inside Li-ion cells.

  2. Internal and External Temperature Monitoring of a Li-Ion Battery with Fiber Bragg Grating Sensors.

    Science.gov (United States)

    Novais, Susana; Nascimento, Micael; Grande, Lorenzo; Domingues, Maria Fátima; Antunes, Paulo; Alberto, Nélia; Leitão, Cátia; Oliveira, Ricardo; Koch, Stephan; Kim, Guk Tae; Passerini, Stefano; Pinto, João

    2016-08-30

    The integration of fiber Bragg grating (FBG) sensors in lithium-ion cells for in-situ and in-operando temperature monitoring is presented herein. The measuring of internal and external temperature variations was performed through four FBG sensors during galvanostatic cycling at C-rates ranging from 1C to 8C. The FBG sensors were placed both outside and inside the cell, located in the center of the electrochemically active area and at the tab-electrode connection. The internal sensors recorded temperature variations of 4.0 ± 0.1 °C at 5C and 4.7 ± 0.1 °C at 8C at the center of the active area, and 3.9 ± 0.1 °C at 5C and 4.0 ± 0.1 °C at 8C at the tab-electrode connection, respectively. This study is intended to contribute to detection of a temperature gradient in real time inside a cell, which can determine possible damage in the battery performance when it operates under normal and abnormal operating conditions, as well as to demonstrate the technical feasibility of the integration of in-operando microsensors inside Li-ion cells.

  3. Ejection Tower Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Ejection Tower Facility's mission is to test and evaluate new ejection seat technology being researched and developed for future defense forces. The captive and...

  4. Ion-cage interpretation for the structural and dynamic changes of ionic liquids under an external electric field.

    Science.gov (United States)

    Shi, Rui; Wang, Yanting

    2013-05-01

    In many applications, ionic liquids (ILs) work in a nonequilibrium steady state driven by an external electric field. However, how the electric field changes the structure and dynamics of ILs and its underlying mechanism still remain poorly understood. In this paper, coarse-grained molecular dynamics simulations were performed to investigate the structure and dynamics of 1-ethyl-3-methylimidazolium nitrate ([EMIm][NO3]) under a static electric field. The ion cage structure was found to play an essential role in determining the structural and dynamic properties of the IL system. With a weak or moderate electric field (0-10(7) V/m), the external electric field is too weak to modify the ion cage structure in an influential way and thus the changes of structural and dynamic properties are negligible. With a strong electric field (10(7)-10(9) V/m) applied, ion cages expand and deform apparently, leading to the increase of ion mobility and self-diffusion coefficient with electric field, and the self-diffusion of ions along the electric field becomes faster than the other two directions due to the anisotropic deformation of ion cages. In addition, the Einstein relation connecting diffusion and mobility breaks down at strong electric fields, and it also breaks down for a single ion species even at moderate electric fields (linear-response region).

  5. Proton ejection project for Saturne; Projet d'ejection des protons de saturne

    Energy Technology Data Exchange (ETDEWEB)

    Bronca, G.; Gendreau, G

    1959-07-01

    The reasons for choosing the ejection system are given. The characteristics required for the ejected beam are followed by a description of the ejection process, in chronological order from the viewpoint of the protons: movement of the particles, taking into account the various elements which make up the system (internal magnet, external magnet, quadrupoles, ejection correction coils, thin and thick cables,...) and specification of these elements. Then follows an estimation of the delay in manufacture and the cost of the project. Finally, the characteristics of the magnets and quadrupoles are listed in an appendix. (author) [French] On donne d'abord les raisons du choix du systeme d'ejection, puis le principe. Apres les caracteristiques requises pour le faisceau ejecte, on decrit le processus d'ejection selon l'ordre chronologique vu par les protons: mouvement des particules compte tenu des divers elements composant le systeme (aimant interne, aimant externe, quadrupoles, enroulements correcteurs ejection, cibles mince et epaisse,. ..) et cahier de charge de ces elements. On estime, ensuite les delais de realisation et le cout du projet. Enfin, un resume des caracteristiques des aimants et quadrupoles est donne en appendice. (auteur)

  6. Improvements to the internal and external antenna H{sup −} ion sources at the Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Welton, R. F., E-mail: welton@ornl.gov; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Pillar, C.; Santana, M.; Stockli, M. P. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471 (United States); Dudnikov, V. G. [Muons, Inc., 552 N. Batavia Avenue, Batavia, Illinois 60510 (United States); Turvey, M. W. [Villanova University, 800E. Lancaster Ave, Villanova, Pennsylvania 19085 (United States)

    2014-02-15

    The Spallation Neutron Source (SNS), a large scale neutron production facility, routinely operates with 30–40 mA peak current in the linac. Recent measurements have shown that our RF-driven internal antenna, Cs-enhanced, multi-cusp ion sources injects ∼55 mA of H{sup −} beam current (∼1 ms, 60 Hz) at 65-kV into a Radio Frequency Quadrupole (RFQ) accelerator through a closely coupled electrostatic Low-Energy Beam Transport system. Over the last several years a decrease in RFQ transmission and issues with internal antennas has stimulated source development at the SNS both for the internal and external antenna ion sources. This report discusses progress in improving internal antenna reliability, H{sup −} yield improvements which resulted from modifications to the outlet aperture assembly (applicable to both internal and external antenna sources) and studies made of the long standing problem of beam persistence with the external antenna source. The current status of the external antenna ion source will also be presented.

  7. Students' Understanding of External Representations of the Potassium Ion Channel Protein, Part I: Affordances and Limitations of Ribbon Diagrams, Vines, and Hydrophobic/Polar Representations

    Science.gov (United States)

    Harle, Marissa; Towns, Marcy H.

    2012-01-01

    Research on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations. This project focuses on students' understanding of three external representations of the potassium ion channel protein. This is part I of a two-part study, which focuses on the affordances and…

  8. State-selective energy and angular resolved detection of neutral species ejected from keV ion bombarded C{sub 6}H{sub 6}/Ag{l_brace}1 1 1{r_brace}

    Energy Technology Data Exchange (ETDEWEB)

    Vandeweert, E.; Meserole, C.A.; Sostarecz, A.; Dou, Y.; Winograd, N. E-mail: nxw@psu.edunxw@psuvm.psu.edu; Postawa, Z

    2000-04-01

    We investigated the desorption of neutral benzene (C{sub 6}H{sub 6}) molecules and silver atoms from C{sub 6}H{sub 6}/Ag{l_brace}1 1 1{r_brace} upon bombardment by 8 keV Ar{sup +} ions. Using state-selective resonant ionization spectroscopy, substrate atoms sputtered in the ground and a high-lying metastable state, and ground-state and vibrationally excited molecules could be probed separately. The silver atom yield, kinetic energy and polar angle distributions were found to be modified upon benzene dosing. From these results, it was inferred that a large fraction of the metastable silver atoms de-excite during collisions with adsorbates. Also the ejection of benzene molecules depends strongly both on the internal energy of the molecules and the degree of coverage of the Ag surface. Up to monolayer thickness, the benzene molecules are mainly ejected during collisions with departing substrate particles. Molecules with higher internal energy leave the surface with a distribution shifted towards higher kinetic energies. At multi-layer coverages, a slow desorption mechanism becomes dominant. It is suggested that only benzene molecules vibrationally excited near the benzene-vacuum interface can survive the ejection process without de-excitation.

  9. Black Hole Induced Ejections

    OpenAIRE

    Pelletier, G.

    2004-01-01

    Black Holes generate a particular kind of environments dominated by an accretion flow which concentrates a magnetic field. The interplay of gravity and magnetism creates this paradoxical situation where relativistic ejection is allowed and consequently high energy phenomena take place. Therefore Black Holes, which are very likely at the origin of powerfull astrophysical phenomena such as AGNs, micro- quasars and GRBs where relativistic ejections are observed, are at the heart of high energy a...

  10. Control of Internal and External Short Circuits in Lithium Ion and Lithium Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has identified needs for compact high-energy-density primary and secondary batteries. Lithium and Lithium Ion cells, respectively, are meeting these needs for...

  11. Integration of XRF spectrometer for simultaneous and/or complementary use with PIXE at the external ion beam analysis setup

    Energy Technology Data Exchange (ETDEWEB)

    Fazinic, S.; Cosic, D.; Jaksic, M. [Laboratory for lon Beam Interactions, Division of Experimental Physics, Rudjer Boskovic Institute, Zagreb (Croatia); Migliori, A.; Karydas, A.G. [Nuclear Spectrometry and Applications Laboratory, International Atomic Energy Agency (IAEA), Vienna (Austria); Desnica, V. [Laboratory for Science and Technology in Art, Academy of Fine Arts in Zagreb, Zagreb (Croatia); Mudronja, D. [Natural Science Laboratory, Croatian Conservation Institute, Zagreb (Croatia)

    2013-07-01

    Full text: The Rudjer Boskovic Institute Tandem Accelerator Facility is equipped with a number of end-stations dedicated to ion beam analysis (IBA), modification of materials and nuclear physics experiments. IBA is performed at the: (1) nuclear microbeam, (2) broad-beam in-vacuum and (3) external beam end-stations. Several lBA techniques can be used simultaneously, Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE) at the external beam end-station, and additionally Rutherford Backscattering Spectroscopy (RBS) at the in-vacuum end-station. X-ray fluorescence (XRF) analysis is a technique complementary to PIXE. Both techniques offer high analytical potential for multi-elemental investigations and material characterization. Due to different excitation mechanisms, PIXE generally exhibits higher sensitivity for lighter elements and XRF for heavier, whereas they also have different in-sample depth sensitivities. Although they use different excitation sources, both techniques can use the same data acquisition modules. With the development of miniature, low power and lightweight X-ray tubes it is possible to incorporate an X-ray source within the IBA setup and combine the two techniques for simultaneous use. In this work, the unification of the PIXE and XRF techniques at the RBI external ion beam analysis setup has been investigated and the results are discussed. This has been done by installing a transmission miniature X-ray tube at the end-station. The tube has been properly positioned in order to irradiate the same spot on the sample as the ion beam used for PIXE/PIGE measurements. Our home made data acquisition system SPECTOR, used regularly for the IBA measurements, has been also used to acquire the XRF spectra. At first, the X-ray tube has been installed at the in-vacuum IBA station, and then to the external beam end-station. Test measurements have been carried out on various standard reference materials using both systems and the

  12. Recent developments of ion beam induced luminescence at the external scanning microbeam facility of the LABEC laboratory in Florence

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, E. [INFN sezione di Torino, via P.Giuria 1, 10125 Torino (Italy); Dipartimento di Fisica and Centro di Eccellenza NIS, Universita di Torino, via P. Giuria 1, 10125 Torino (Italy); Calusi, S. [INFN sezione di Torino, via P.Giuria 1, 10125 Torino (Italy); Dipartimento di Fisica, Universita and INFN Sez.di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Firenze (Italy); Cossio, R. [Dipartimento di Scienze Mineralogiche e Petrologiche, via Valperga Caluso, 35, 10125 Torino (Italy); Giuntini, L. [Dipartimento di Fisica, Universita and INFN Sez.di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Firenze (Italy); Giudice, A. [Dipartimento di Fisica and Centro di Eccellenza NIS, Universita di Torino, via P. Giuria 1, 10125 Torino (Italy); Lo Mando, P.A. [Dipartimento di Fisica, Universita and INFN Sez.di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Firenze (Italy); Manfredotti, C. [INFN sezione di Torino, via P.Giuria 1, 10125 Torino (Italy); Dipartimento di Fisica and Centro di Eccellenza NIS, Universita di Torino, via P. Giuria 1, 10125 Torino (Italy); Massi, M.; Mirto, F.A. [Dipartimento di Fisica, Universita and INFN Sez.di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Firenze (Italy); Vittone, E. [INFN sezione di Torino, via P.Giuria 1, 10125 Torino (Italy); Dipartimento di Fisica and Centro di Eccellenza NIS, Universita di Torino, via P. Giuria 1, 10125 Torino (Italy)], E-mail: vittone@to.infn.it

    2008-04-15

    A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps. The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage.

  13. Recent developments of ion beam induced luminescence at the external scanning microbeam facility of the LABEC laboratory in Florence

    Science.gov (United States)

    Colombo, E.; Calusi, S.; Cossio, R.; Giuntini, L.; Giudice, A. Lo; Mandò, P. A.; Manfredotti, C.; Massi, M.; Mirto, F. A.; Vittone, E.

    2008-04-01

    A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps. The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage.

  14. Biological Effects of Drug-Free Alginate Beads Cross-Linked by Copper Ions Prepared Using External Ionotropic Gelation.

    Science.gov (United States)

    Pavelková, M; Kubová, K; Vysloužil, J; Kejdušová, M; Vetchý, D; Celer, V; Molinková, D; Lobová, D; Pechová, A; Vysloužil, J; Kulich, P

    2016-08-08

    External ionotropic gelation offers a unique possibility to entrap multivalent ions in a polymer structure. The aim of this experimental study was to prepare new drug-free sodium alginate (ALG) particles cross-linked by Cu(2+) ions and to investigate their technological parameters (particle size, sphericity, surface topology, swelling capacity, copper content, release of Cu(2+) ions, mucoadhesivity) and biological activity (cytotoxicity and efficiency against the most common vaginal pathogens-Herpes simplex, Escherichia coli, Candida albicans) with respect to potential vaginal administration. Beads prepared from NaALG dispersions (3 or 4%) were cross-linked by Cu(2+) ions (0.5 or 1.0 M CuCl2) using external ionotropic gelation. Prepared mucoadhesive beads with particle size over 1000 μm exhibited sufficient sphericity (all ˃0.89) and copper content (214.8-249.07 g/kg), which increased with concentration of polymer and hardening solution. Dissolution behaviour was characterized by extended burst effect, followed by 2 h of copper release. The efficiency of all samples against the most common vaginal pathogens was observed at cytotoxic Cu(2+) concentrations. Anti-HSV activity was demonstrated at a Cu(2+) concentration of 546 mg/L. Antibacterial activity of beads (expressed as minimum inhibition concentration, MIC) was influenced mainly by the rate of Cu(2+) release which was controlled by the extent of swelling capacity. Lower MIC values were found for E. coli in comparison with C. albicans. Sample ALG-3_1.0 exhibited the fastest copper release and was proved to be the most effective against both bacteria. This could be a result of its lower polymer concentration in combination with smaller particle size and thus larger surface area.

  15. Effect of external electric fields on the dielectronic recombination cross section of lithium and sodium like ions

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.C.; Pindzola, M.S.; Bottcher, C.

    1985-03-01

    The effect of external electric fields on the dielectronic recombination cross section associated with the 2s ..-->.. 2p excitation in the Li like ions B/sup 2 +/, C/sup 3 +/, O/sup 5 +/, and Fe/sup 23 +/, and the 3s ..-->.. 3p excitation in the Na like ions Mg/sup +/, S/sup 5 +/, Cl/sup 6 +/, and Fe/sup 15 +/ has been studied in the configuration-average, distorted-wave approximation. By applying the linear-Stark approximation to the doubly-excited 2pnl and 3pnl Rydberg states in the presence of an external electric field, we study the systematics of field mixing effects on dielectronic recombination and determine the maximum field enhancement of the dielectronic recombination cross section. We find that the magnitude of the field enhancement decreases as we move up an isoelectronic sequence and is of the order of a factor of two or three in highly-ionized systems. In addition, we show that dielectronic recombination transitions through doubly-excited states near threshold can produce large narrow peaks in the cross section at low energies, which are especially prominent in high stages of ionization, and are not affected by the electric field.

  16. Ion confinement and transport in a toroidal plasma with externally imposed radial electric fields

    Science.gov (United States)

    Roth, J. R.; Krawczonek, W. M.; Powers, E. J.; Kim, Y. C.; Hong, H. Y.

    1979-01-01

    Strong electric fields were imposed along the minor radius of the toroidal plasma by biasing it with electrodes maintained at kilovolt potentials. Coherent, low-frequency disturbances characteristic of various magnetohydrodynamic instabilities were absent in the high-density, well-confined regime. High, direct-current radial electric fields with magnitudes up to 135 volts per centimeter penetrated inward to at least one-half the plasma radius. When the electric field pointed radially toward, the ion transport was inward against a strong local density gradient; and the plasma density and confinement time were significantly enhanced. The radial transport along the electric field appeared to be consistent with fluctuation-induced transport. With negative electrode polarity the particle confinement was consistent with a balance of two processes: a radial infusion of ions, in those sectors of the plasma not containing electrodes, that resulted from the radially inward fields; and ion losses to the electrodes, each of the which acted as a sink and drew ions out of the plasma. A simple model of particle confinement was proposed in which the particle confinement time is proportional to the plasma volume. The scaling predicted by this model was consistent with experimental measurements.

  17. Influence of an external magnetic field on damage by self-ion irradiation in Fe90Cr10 alloy

    Directory of Open Access Journals (Sweden)

    Fernando José Sánchez

    2016-12-01

    Full Text Available The effect of an external magnetic field (B=0.5 T on Fe90Cr10 specimens during Fe ion irradiation, has been investigated by means of Conversion Electron Mössbauer Spectroscopy (CEMS. The analysis has revealed significant differences in the average hyperfine magnetic field (=0.3 T between non-irradiated and irradiated samples as well as between irradiations made with B (w/ B and without B (w/o B. It is considered that these variations can be due to changes in the local environment around the probe nuclei (57Fe; where vacancies and Cr distribution play a role. The results indicate that the Cr distribution in the neighbourhood of the iron atoms could be changed by the application of an external field. This would imply that an external magnetic field may be an important parameter to take into account in predictive models for Cr behaviour in Fe–Cr alloys, and especially in fusion conditions where intense magnetic fields are required for plasma confinement.

  18. A look ahead: Status of the SNS external antenna ion source and the new RFQ test stand

    Science.gov (United States)

    Welton, R. F.; Aleksandrov, A.; Dudnikov, V. G.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, M.; Kang, Y.; Santana, M.; Stockli, M. P.

    2015-04-01

    The U.S. Spallation Neutron Source (SNS) now operates with ˜1 MW of beam power to target with the near-term goal of delivering 1.4 MW. Plans are being considered to incorporate a second target station into the facility which will require ˜2.8 MW of beam power. Presently, H- beam pulses (˜1 ms, 60 Hz) are produced by an RF-driven, Cs-enhanced, multi-cusp ion source which injects beam into an RFQ (Radio Frequency Quadrupole) accelerator that, in turn, feeds the SNS Linac. Currently the source/RFQ system delivers ˜35 mA of pulsed current to the linac which is mostly sufficient for 1.4 MW operations while ˜50 mA are needed for the second target station upgrade. This paper provides a look forward for the SNS by providing (i) the present and future SNS source/RFQ beam requirements and our plans to achieve these, (ii) a description and status of the external antenna ion source being developed for the replacement of the current internal antenna ion source, and (iii) a description and status of the newly constructed RFQ test facility.

  19. A look ahead: Status of the SNS external antenna ion source and the new RFQ test stand

    Energy Technology Data Exchange (ETDEWEB)

    Welton, R. F., E-mail: welton@ornl.gov; Aleksandrov, A.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, M.; Kang, Y.; Santana, M.; Stockli, M. P. [Spallation Neutron Source, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37830-647 (United States); Dudnikov, V. G. [Muons, Inc. 552 N. Batavia Avenue, Batavia, IL 60510 (United States)

    2015-04-08

    The U.S. Spallation Neutron Source (SNS) now operates with ∼1 MW of beam power to target with the near-term goal of delivering 1.4 MW. Plans are being considered to incorporate a second target station into the facility which will require ∼2.8 MW of beam power. Presently, H{sup −} beam pulses (∼1 ms, 60 Hz) are produced by an RF-driven, Cs-enhanced, multi-cusp ion source which injects beam into an RFQ (Radio Frequency Quadrupole) accelerator that, in turn, feeds the SNS Linac. Currently the source/RFQ system delivers ∼35 mA of pulsed current to the linac which is mostly sufficient for 1.4 MW operations while ∼50 mA are needed for the second target station upgrade. This paper provides a look forward for the SNS by providing (i) the present and future SNS source/RFQ beam requirements and our plans to achieve these, (ii) a description and status of the external antenna ion source being developed for the replacement of the current internal antenna ion source, and (iii) a description and status of the newly constructed RFQ test facility.

  20. THE CONTINUED DEVELOPMENT OF THE SNS EXTERNAL ANTENNA H- ION SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Welton, Robert F [ORNL; Carmichael, Justin R [ORNL; Desai, Nandishkumar J [ORNL; Fuja, Raymond E [ORNL; Goulding, Richard Howell [ORNL; Han, Baoxi [ORNL; Kang, Yoon W [ORNL; Lee, Shyh-Yuan [ORNL; Murray Jr, S N [ORNL; Pennisi, Terry R [ORNL; Potter, Kerry G [ORNL; Santana, Manuel [ORNL; Stockli, Martin P [ORNL

    2010-01-01

    The U.S. Spallation Neutron Source (SNS) is an accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure that the SNS will meet operational commitments as well as provide for future facility upgrades with high reliability, we are developing an RF-driven, H- ion source based on a water-cooled, ceramic aluminum nitride (AlN) plasma chamber. To date, early versions of this source has delivered up to 42 mA to the SNS Front End (FE) and unanalyzed beam currents up to ~ 100mA (60Hz, 1ms) to the ion source test stand. This source was operated on the SNS accelerator from February to April 2009 and produced ~35mA (beam current required by the ramp up plan) with availability of ~97%. During this run several ion source failures identified reliability issues which must be addressed before the source re-enters routine operation: plasma ignition, antenna lifetime, magnet cooling and cooling jacket integrity. This report discusses these issues, details proposed engineering solutions and notes progress to date.

  1. Resonance methods in quadrupole ion traps

    Science.gov (United States)

    Snyder, Dalton T.; Peng, Wen-Ping; Cooks, R. Graham

    2017-01-01

    The quadrupole ion trap is widely used in the chemical physics community for making measurements on dynamical systems, both intramolecular (e.g. ion fragmentation reactions) and intermolecular (e.g. ion/molecule reactions). In this review, we discuss linear and nonlinear resonances in quadrupole ion traps, an understanding of which is critical for operation of these devices and interpretation of the data which they provide. The effect of quadrupole field nonlinearity is addressed, with important implications for promoting fragmentation and achieving unique methods of mass scanning. Methods that depend on ion resonances (i.e. matching an external perturbation with an ion's induced frequency of motion) are discussed, including ion isolation, ion activation, and ion ejection.

  2. Coronal Mass Ejections

    Science.gov (United States)

    Crooker, Nancy; Joselyn, Jo Ann; Feynman, Joan

    The early 1970's can be said to mark the beginning of The Enlightenment in the history of the Space Age, literally as well as by analogy to European history. Instruments blinded by Earth's atmosphere were lifted above and, for the first time, saw clearly and continuously the ethereal white light and sparkling x-rays from the solar corona. From these two bands of the light spectrum came images of coronal mass ejections and coronal holes, respectively. But whereas coronal holes were immediately identified as the source of high-speed solar wind streams, at first coronal mass ejections were greeted only by a sense of wonder. It took years of research to identify their signatures in the solar wind before the fastest ones could be identified with the well-known shock disturbances that cause the most violent space storms.

  3. Coronal Mass Ejections

    CERN Document Server

    Kunow, H; Linker, J. A; Schwenn, R; Steiger, R

    2006-01-01

    It is well known that the Sun gravitationally controls the orbits of planets and minor bodies. Much less known, however, is the domain of plasma fields and charged particles in which the Sun governs a heliosphere out to a distance of about 15 billion kilometers. What forces activates the Sun to maintain this power? Coronal Mass Ejections (CMEs) and their descendants are the troops serving the Sun during high solar activity periods. This volume offers a comprehensive and integrated overview of our present knowledge and understanding of Coronal Mass Ejections (CMEs) and their descendants, Interplanetary CMEs (ICMEs). It results from a series of workshops held between 2000 and 2004. An international team of about sixty experimenters involved e.g. in the SOHO, ULYSSES, VOYAGER, PIONEER, HELIOS, WIND, IMP, and ACE missions, ground observers, and theoreticians worked jointly on interpreting the observations and developing new models for CME initiations, development, and interplanetary propagation. The book provides...

  4. Black Hole Induced Ejections

    CERN Document Server

    Pelletier, G

    2004-01-01

    Black Holes generate a particular kind of environments dominated by an accretion flow which concentrates a magnetic field. The interplay of gravity and magnetism creates this paradoxical situation where relativistic ejection is allowed and consequently high energy phenomena take place. Therefore Black Holes, which are very likely at the origin of powerfull astrophysical phenomena such as AGNs, micro- quasars and GRBs where relativistic ejections are observed, are at the heart of high energy astrophysics. The combination of General Relativity and Magneto-HydroDynamics (MHD) makes theory difficult; however great pionneers opened beautiful tracks in the seventies and left important problems to be solved for the next decades. These lectures will present the status of these issues. They have a tutorial aspect together with critical review aspect and contain also some new issues. Most of these lectures has been presented at the "School on Black Hole in the Universe" at Cargese, in May 2003.

  5. The new external ion beam analysis setup at the Demokritos Tandem accelerator and first applications in cultural heritage

    Science.gov (United States)

    Sokaras, Dimosthenis; Bistekos, Euthimios; Georgiou, Lambros; Salomon, Joseph; Bogovac, Mladen; Aloupi-Siotis, Eleni; Paschalis, Vasilis; Aslani, Ioanna; Karabagia, Sofia; Lagoyannis, Anastasios; Harissopulos, Sotirios; Kantarelou, Vasiliki; Karydas, Andreas-Germanos

    2011-03-01

    At the 5.5 MV Tandem VdG accelerator of the Institute of Nuclear Physics of N.C.S.R. "Demokritos", Athens, Greece, an external ion-beam set-up has been recently developed and installed. The aim of this development was to integrate the analytical capabilities of the PIXE, RBS and PIGE ion beam techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. A careful 3D mechanical drawing optimized the set-up experimental parameters achieving probe dimensions at the millimeter range (1 mm 2) and fulfilling the special requirements imposed for optimum performance of the aforementioned techniques, including the possibility to use heavier, than protons, ion beams. For the digital pulse processing of the X-ray, γ-ray and charged particle detector signals, novel hardware and software tools were developed based on a custom FPGA configuration. The first applications were focused in the quality control of materials that have been intentionally contaminated with a particular tracer-element ("tagged" materials). The tagged materials which were developed and tested are technologically authentic replicas of ancient attic ceramics with black glazed decoration. Analytical diagnostic studies were carried out for a few representative paintings of contemporary Greek painters in order to identify and document materials/pigments and techniques and eventually to prevent trade of fakes. Finally, ancient glass beads were also examined with respect to the sodium concentration and its in-depth homogeneity.

  6. The new external ion beam analysis setup at the Demokritos Tandem accelerator and first applications in cultural heritage

    Energy Technology Data Exchange (ETDEWEB)

    Sokaras, Dimosthenis, E-mail: dsokaras@inp.demokritos.g [Institute of Nuclear Physics, N.C.S.R. ' Demokritos' , Aghia Paraskevi, 15310 Athens (Greece); Bistekos, Euthimios; Georgiou, Lambros [Philon Models, 18541 Piraeus (Greece); Salomon, Joseph [Laboratoire du C2RMF, Centre de Rechereche et de Restauration des Musees du France, 75001 Paris (France); Bogovac, Mladen [Institute Ruder Boskovic, 10002 Zagreb (Croatia); Aloupi-Siotis, Eleni [Thetis Authentics Ltd., 11636 Athens (Greece); Paschalis, Vasilis [Benaki Museum, 10674 Athens (Greece); Aslani, Ioanna [Thetis Authentics Ltd., 11636 Athens (Greece); Karabagia, Sofia; Lagoyannis, Anastasios; Harissopulos, Sotirios; Kantarelou, Vasiliki [Institute of Nuclear Physics, N.C.S.R. ' Demokritos' , Aghia Paraskevi, 15310 Athens (Greece); Karydas, Andreas-Germanos [Institute of Nuclear Physics, N.C.S.R. ' Demokritos' , Aghia Paraskevi, 15310 Athens (Greece); Nuclear Spectrometry and Applications Laboratory, International Atomic Energy Agency (IAEA), 2444 Seibersdorf (Austria)

    2011-03-01

    At the 5.5 MV Tandem VdG accelerator of the Institute of Nuclear Physics of N.C.S.R. 'Demokritos', Athens, Greece, an external ion-beam set-up has been recently developed and installed. The aim of this development was to integrate the analytical capabilities of the PIXE, RBS and PIGE ion beam techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. A careful 3D mechanical drawing optimized the set-up experimental parameters achieving probe dimensions at the millimeter range (1 mm{sup 2}) and fulfilling the special requirements imposed for optimum performance of the aforementioned techniques, including the possibility to use heavier, than protons, ion beams. For the digital pulse processing of the X-ray, {gamma}-ray and charged particle detector signals, novel hardware and software tools were developed based on a custom FPGA configuration. The first applications were focused in the quality control of materials that have been intentionally contaminated with a particular tracer-element ('tagged' materials). The tagged materials which were developed and tested are technologically authentic replicas of ancient attic ceramics with black glazed decoration. Analytical diagnostic studies were carried out for a few representative paintings of contemporary Greek painters in order to identify and document materials/pigments and techniques and eventually to prevent trade of fakes. Finally, ancient glass beads were also examined with respect to the sodium concentration and its in-depth homogeneity.

  7. External Second Gate, Fourier Transform Ion Mobility Spectrometry: Parametric Optimization for Detection of Weapons of Mass Destruction

    Directory of Open Access Journals (Sweden)

    Edward E. Tarver

    2004-03-01

    Full Text Available Abstract: Ion mobility spectrometry (IMS is recognized as one of the most sensitive and robust techniques for the detection of narcotics, explosives and chemical warfare agents. IMS is widely used in forensic, military and security applications. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention (CWC treaty verification as well as humanitarian de-mining efforts have mandated that equal importance be placed on the time required to obtain results as well as the quality of the analytical data. [1] In this regard IMS is virtually unrivaled when both speed of response and sensitivity have to be considered. [2] The problem with conventional (signal averaging IMS systems is the fixed duty cycle of the entrance gate that restricts to less than 1%, the number of available ions contributing to the measured signal. Furthermore, the signal averaging process incorporates scan-to-scan variations that degrade the spectral resolution contributing to misidentifications and false positives. With external second gate, Fourier Transform ion mobility spectrometry (FT-IMS the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters (scan time and sampling rate to increase the spectral resolution to reduce false alarms and improve the sensitivity for early warning and contamination avoidance. In addition, with FT-IMS the entrance gate operates with a 50% duty cycle and so affords a seven-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system.

  8. Ejection Fraction Heart Failure Measurement

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Ejection Fraction Heart Failure Measurement Updated:Feb 15,2017 The ejection fraction ( ... failure This content was last reviewed April 2015. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  9. Coronal Mass Ejections: Observations

    Directory of Open Access Journals (Sweden)

    David F. Webb

    2012-06-01

    Full Text Available Solar eruptive phenomena embrace a variety of eruptions, including flares, solar energetic particles, and radio bursts. Since the vast majority of these are associated with the eruption, development, and evolution of coronal mass ejections (CMEs, we focus on CME observations in this review. CMEs are a key aspect of coronal and interplanetary dynamics. They inject large quantities of mass and magnetic flux into the heliosphere, causing major transient disturbances. CMEs can drive interplanetary shocks, a key source of solar energetic particles and are known to be the major contributor to severe space weather at the Earth. Studies over the past decade using the data sets from (among others the SOHO, TRACE, Wind, ACE, STEREO, and SDO spacecraft, along with ground-based instruments, have improved our knowledge of the origins and development of CMEs at the Sun and how they contribute to space weather at Earth. SOHO, launched in 1995, has provided us with almost continuous coverage of the solar corona over more than a complete solar cycle, and the heliospheric imagers SMEI (2003 – 2011 and the HIs (operating since early 2007 have provided us with the capability to image and track CMEs continually across the inner heliosphere. We review some key coronal properties of CMEs, their source regions and their propagation through the solar wind. The LASCO coronagraphs routinely observe CMEs launched along the Sun-Earth line as halo-like brightenings. STEREO also permits observing Earth-directed CMEs from three different viewpoints of increasing azimuthal separation, thereby enabling the estimation of their three-dimensional properties. These are important not only for space weather prediction purposes, but also for understanding the development and internal structure of CMEs since we view their source regions on the solar disk and can measure their in-situ characteristics along their axes. Included in our discussion of the recent developments in CME

  10. Magnetic structure of Coronal Mass Ejections

    CERN Document Server

    Lyutikov, Maxim

    2012-01-01

    We present several models of the magnetic structure of solar coronal mass ejections (CMEs). First, we model CMEs as expanding force-free magnetic structures. While keeping the internal magnetic field structure of the stationary solutions, expansion leads to complicated internal velocities and rotation, while the field structures remain force-free. Second, expansion of a CME can drive resistive dissipation within the CME changing the ionization states of different ions. We fit in situ measurements of ion charge states to the resistive spheromak solutions. Finally, we consider magnetic field structures of fully confined stable magnetic clouds containing both toroidal and poloidal magnetic fields and having no surface current sheets. Expansion of such clouds may lead to sudden onset of reconnection events.

  11. Design and Experimental Study of the External H~- Ion Source for a 10 MeV Medical Cyclotron

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A 10 MeV medical cyclotron has been designed by the BRIF Division at CIAE, for which the H- beam is axially injected to the machine. To satisfy the requirement for the cyclotron with H- ion source, a compact multicusp H- ion source has

  12. Coronal Mass Ejections An Introduction

    CERN Document Server

    Howard, Timothy

    2011-01-01

    In times of growing technological sophistication and of our dependence on electronic technology, we are all affected by space weather. In its most extreme form, space weather can disrupt communications, damage and destroy spacecraft and power stations, and increase radiation exposure to astronauts and airline passengers. Major space weather events, called geomagnetic storms, are large disruptions in the Earth’s magnetic field brought about by the arrival of enormous magnetized plasma clouds from the Sun. Coronal mass ejections (CMEs) contain billions of tons of plasma and hurtle through space at speeds of several million miles per hour. Understanding coronal mass ejections and their impact on the Earth is of great interest to both the scientific and technological communities. This book provides an introduction to coronal mass ejections, including a history of their observation and scientific revelations, instruments and theory behind their detection and measurement, and the status quo of theories describing...

  13. Response behavior of ZrO{sub 2} under swift heavy ion irradiation with and without external pressure

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, B., E-mail: bea.schuster@gsi.de [Technische Universitaet Darmstadt, Hochschulstr. 6, 64289 Darmstadt (Germany); Helmholtz Centre for Heavy Ion Reseach (GSI), Planckstr. 1, 64291 Darmstadt (Germany); Fujara, F. [Technische Universitaet Darmstadt, Hochschulstr. 6, 64289 Darmstadt (Germany); Merk, B. [Technische Universitaet Darmstadt, Hochschulstr. 6, 64289 Darmstadt (Germany); Helmholtz Centre for Heavy Ion Reseach (GSI), Planckstr. 1, 64291 Darmstadt (Germany); Neumann, R. [Helmholtz Centre for Heavy Ion Reseach (GSI), Planckstr. 1, 64291 Darmstadt (Germany); Seidl, T. [Technische Universitaet Darmstadt, Hochschulstr. 6, 64289 Darmstadt (Germany); Helmholtz Centre for Heavy Ion Reseach (GSI), Planckstr. 1, 64291 Darmstadt (Germany); Trautmann, C. [Helmholtz Centre for Heavy Ion Reseach (GSI), Planckstr. 1, 64291 Darmstadt (Germany)

    2012-04-15

    In this study, we demonstrate that the combination of relativistic heavy ions with pressure can influence the phase behavior of ZrO{sub 2} in ways none of those two extreme conditions alone could. The response behavior of ZrO{sub 2} towards ion irradiation under different pressure conditions is investigated. ZrO{sub 2} exposed to energetic particles is known to undergo a crystalline-to-crystalline phase transition from the monoclinic to the tetragonal phase. In agreement with earlier findings, this structural change requires also for heaviest ions, such as Au, Pb, and U, a multiple ion impact. If the irradiation is performed under high pressure, the monoclinic-to-tetragonal transformation occurs at a fluence that is more than one order of magnitude lower suggesting a single impact process. Raman measurements at ambient conditions and X-ray diffraction analysis of the samples irradiated under pressure revealed that the monoclinic-to-tetragonal transformation under pressure is not a direct process but involves a transition into the cubic high-temperature structure, before the tetragonal structure becomes stable under decompression. At even higher pressures, the additional ion irradiation forces ZrO{sub 2} to transform to the higher orthorhombic-II phase that is far away from its stability field.

  14. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform.

    Science.gov (United States)

    Sun, Gongchen; Senapati, Satyajyoti; Chang, Hsueh-Chia

    2016-04-07

    A microfluidic ion exchange membrane hybrid chip is fabricated using polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (>100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems.

  15. Compressed wormlike chain moving out of confined space: A model of DNA ejection from bacteriophage

    Institute of Scientific and Technical Information of China (English)

    Ji-Zeng Wang; Long Li; Hua-Jian Gao

    2012-01-01

    The molecular biomechanics of DNA ejection from bacteriophage is of interest to not only fundamental biological understandings but also practical applications such as the design of advanced site-specific and controllable drug delivery systems.In this paper,we analyze the viscous motion of a semiflexible polymer chain coming out of a strongly confined space as a model to investigate the effects of various structure confinements and frictional resistances encountered during the DNA ejection process.The theoretically predicted relations between the ejection speed,ejection time,ejection length,and other physical parameters,such as the phage type,total genome length and ionic state of external buffer solutions,show excellent agreement with in vitro experimental observations in the literature.

  16. Coronal Mass Ejections travel time

    Science.gov (United States)

    Braga, Carlos Roberto; Souza de Mendonça, Rafael Rodrigues; Dal Lago, Alisson; Echer, Ezequiel

    2017-10-01

    Coronal mass ejections (CMEs) are the main source of intense geomagnetic storms when they are earthward directed. Studying their travel time is a key-point to understand when the disturbance will be observed at Earth. In this work, we study the CME that originated the interplanetary disturbance observed on 2013/10/02. According to the observations, the CME that caused the interplanetary disturbance was ejected on 2013/09/29. We obtained the CME speed and estimate of the time of arrival at the Lagrangian Point L1 using the concept of expansion speed. We found that observed and estimated times of arrival of the shock differ between 2 and 23 hours depending on method used to estimate the radial speed.

  17. Impurity ion flow and temperature measured in a detached divertor with externally applied non-axisymmetric fields on DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Briesemeister, A.R., E-mail: briesemeister@fusion.gat.com [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Isler, R.C. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Allen, S.L. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States); Ahn, J.-W. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); McLean, A.G. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States); Unterberg, E.A.; Hillis, D.L. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Fenstermacher, M.E.; Meyer, W.H. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States)

    2015-08-15

    Externally applied non-axisymmetric magnetic fields are shown to have little effect on the impurity ion flow velocity and temperature as measured by the multichord divertor spectrometer in the DIII-D divertor for both attached and detached conditions. These experiments were performed in H-mode plasmas with the grad-B drift toward the target plates, with and without n = 3 resonant magnetic perturbations (RMPs). The flow velocity in the divertor is shown to change by as much as 30% when deuterium gas puffing is used to create detachment of the divertor plasma. No measurable changes in the C III flow were observed in response to the RMP fields for the conditions used in this work. Images of the C III emission are used along with divertor Thomson scattering to show that the local electron and C III temperatures are equilibrated for the conditions shown.

  18. Anatomy of Depleted Interplanetary Coronal Mass Ejections

    Science.gov (United States)

    Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.; Manchester, W. B., IV

    2017-01-01

    We report a subset of interplanetary coronal mass ejections (ICMEs) containing distinct periods of anomalous heavy-ion charge state composition and peculiar ion thermal properties measured by ACE/SWICS from 1998 to 2011. We label them “depleted ICMEs,” identified by the presence of intervals where C6+/C5+ and O7+/O6+ depart from the direct correlation expected after their freeze-in heights. These anomalous intervals within the depleted ICMEs are referred to as “Depletion Regions.” We find that a depleted ICME would be indistinguishable from all other ICMEs in the absence of the Depletion Region, which has the defining property of significantly low abundances of fully charged species of helium, carbon, oxygen, and nitrogen. Similar anomalies in the slow solar wind were discussed by Zhao et al. We explore two possibilities for the source of the Depletion Region associated with magnetic reconnection in the tail of a CME, using CME simulations of the evolution of two Earth-bound CMEs described by Manchester et al.

  19. Influence of changes in external potassium and chloride ions on membrane potential and intracellular potassium ion activity in rabbit ventricular muscle.

    Science.gov (United States)

    Fozzard, H A; Lee, C O

    1976-04-01

    1. The membrane responses of rabbit papillary muscles to rapid changes in [K](o) and [Cl](o) were measured with open-tipped micropipettes and with closed micropipettes made from K-selective glass.2. The muscle cells behaved primarily as a K electrode, and responses to changes in [K](o) with constant [Cl](o) or with constant [K](o) x [Cl](o) were substantially the same.3. When [Cl](o) was changed at a constant [K](o) the membrane potentials changed rapidly and symmetrically by a small value and remained constant for 30 min.4. Measurement of potential with K(+)-selective micro-electrodes in these experiments showed no change in intracellular K activity. In addition to permitting calculation of K permeability, these measurements reassured us that the K(+)-selective electrodes were well insulated and not influenced by electrical shunts at the impalement site.5. Although the membrane response to changes in [Cl](o) was small, it was possible to calculate that the permeability ratio (P(Cl)/P(K)), was 0.11. The Cl and K conductances were about 0.015 mmho/cm(2) and 0.09 mmho/cm(2) respectively, resulting in a conductance ratio (g(Cl)/g(K)) of about 0.17.6. The time course of depolarization by increase in [K](o) was rapid (half-time 5 sec), but repolarization on return to lower [K](o) was much slower (half-time 50 sec). The depolarization time course was easily fitted by the potential change calculated by assuming the need for K diffusion into the extracellular spaces and taking account of the logarithmic relation between membrane potential and [K](o). These calculations did not fit the time course of repolarization, which was slowed in the fashion expected from an inward-rectifying membrane.7. The influence of [K](i) on membrane potential was investigated by changes in tonicity of the external solution. Hypotonic solution produced a change in intracellular K activity close to that produced by ideal water movement. However, in hypertonic solution, intracellular K activity

  20. Effects of pulling forces, osmotic pressure, condensing agents and viscosity on the thermodynamics and kinetics of DNA ejection from bacteriophages to bacterial cells: a computational study

    Science.gov (United States)

    Petrov, Anton S.; Douglas, Scott S.; Harvey, Stephen C.

    2013-03-01

    In this work, we report on simulations of double-stranded DNA (dsDNA) ejection from bacteriophage ϕ29 into a bacterial cell. The ejection was studied with a coarse-grained model, in which viral dsDNA was represented by beads on a torsion-less string. The bacteriophage’s capsid and the bacterial cell were defined by sets of spherical constraints. To account for the effects of the viscous medium inside the bacterial cell, the simulations were carried out using a Langevin dynamics protocol. Our simplest simulations (involving constant viscosity and no external biasing forces) produced results compatible with the push-pull model of DNA ejection, with an ejection rate significantly higher in the first part of ejection than in the latter parts. Additionally, we performed more complicated simulations, in which we included additional factors such as external forces, osmotic pressure, condensing agents and ejection-dependent viscosity. The effects of these factors (independently and in combination) on the thermodynamics and kinetics of DNA ejection were studied. We found that, in general, the dependence of ejection forces and ejection rates on the amount of DNA ejected becomes more complex if the ejection is modeled with a broader, more realistic set of parameters and influences (such as variation in the solvent’s viscosity and the application of an external force). However, certain combinations of factors and numerical parameters led to the opposition of some ejection-driving and ejection-inhibiting influences, ultimately causing an apparent simplification of the ejection profiles.

  1. COMPARATIVE STUDY OF HEART FAILURE WITH PRESERVED EJECTION FRACTION VERSUS DECREASED EJECTION FRACTION

    Directory of Open Access Journals (Sweden)

    Chandrashekar

    2015-03-01

    Full Text Available BACKGROUND AND OBJECTIVES : To study the socio demographic profile , risk factors , clinical presentation and comorbidies in patients with heart failure. To compare the socio demographic profile , risk factors , clinical presentation and comorbidities in patients with Heart failure with normal ejection fraction (HFnEF and Heart failure with reduced ejection fraction (HFrEF. METHODS: The primary study population consisted of 100 cases of adult men and women aged more than 18 years with symptoms of Hea rt failure diagnosed by Framingham’s criteria . The study population was selected from inpatients and outpatients attending Department of Medicine of KIMS hospital between January to December 2012. The study was a hospital based observatory and comparative study. RESULTS: Out of 100 cases included in our study 50% cases had HFrEF & 50% cases had HFnEF as confirmed by echocardiographic parameters. There was no statistically significant difference between the two groups with respect to age and sex. However the re were significant statistical significant differences between the groups with respect to clinical features , risk factors and co morbidities. Clinical features like oedema , hepatomegaly and rales were common in HFrEF group (P<0.05. Also LVESD & LVEDD wer e increased in patients with HFrEF. Risk factors like prior MI/IHD were more common in patients with HfrEF (P<0.05 . History of hypertension and left ventricular hypertrophy were common in patients with HFnEF (P< 0.05. Among the comorbidities: IHD Conduct ion abnormalities were common in HFrEF group. Pericardial effusion was more common in HFnEFgroup.

  2. Characteristics of Coronal Mass Ejections

    Science.gov (United States)

    Talukder, F.; Marchese, A. K.; Tulsee, T.

    2014-12-01

    A coronal mass ejection (CME) is a release of charged particles resulting from solar activity. These charged particles can affect electronics on spacecraft, airplanes, global positioning systems, and communication satellites. The purpose of this research was to study CME data from satellites and correlate these to other properties. Solar wind data collected by STEREO A/B and ACE satellites were analyzed. The data consisted of solar wind flux for various elements (helium through iron), as well as the components of the interplanetary magnetic field. CME events are known to cause a surge in the helium flux, as well as other particles. It is hypothesized that a CME event will cause an increase in the number of lighter elements relative to heavier particles. This is because for a given input of energy, lighter elements are expected to be accelerated to a greater extent than heavier elements. A significant increase was observed in the ratio between helium to oxygen (He/O) prior to intense CMEs. A CME event on November 4, 2003 caused an eleven-fold increase in the He/O ratio, while for another event on April 2, 2001 the He/O ratio increased from 80 to 700. A significant increase in He/O ratio is not observed during weaker CMEs. Furthermore, it was also observed that not all increases in the ratio were accompanied by CMEs. The increase in He/O ratio prior to the CME arrival might be used as a way to predict future events.

  3. Excitation of radial ion motion in an rf-only multipole ion guide immersed in a strong magnetic field gradient.

    Science.gov (United States)

    Beu, Steven C; Hendrickson, Christopher L; Marshall, Alan G

    2011-03-01

    Radiofrequency (rf) multipole ion guides are widely used to transfer ions through the strong magnetic field gradient between source and analyzer regions of external source Fourier transform ion cyclotron resonance mass spectrometers. Although ion transfer as determined solely by the electric field in a multipole ion guide has been thoroughly studied, transfer influenced by immersion in a strong magnetic field gradient has not been as well characterized. Recent work has indicated that the added magnetic field can have profound effects on ion transfer, ultimately resulting in loss of ions initially contained within the multipole. Those losses result from radial ejection of ions due to transient cyclotron resonance that occurs when ions traverse a region in which the magnetic field results in an effective cyclotron frequency equal to the multipole rf drive frequency divided by the multipole order (multipole order is equal to one-half the number of poles). In this work, we describe the analytical basis for ion resonance in a rf multipole ion guide with superposed static magnetic field and compare with results of numerical trajectory simulations. © American Society for Mass Spectrometry, 2011

  4. Space weather and coronal mass ejections

    CERN Document Server

    Howard, Tim

    2013-01-01

    Space weather has attracted a lot of attention in recent times. Severe space weather can disrupt spacecraft, and on Earth can be the cause of power outages and power station failure. It also presents a radiation hazard for airline passengers and astronauts. These ""magnetic storms"" are most commonly caused by coronal mass ejections, or CMES, which are large eruptions of plasma and magnetic field from the Sun that can reach speeds of several thousand km/s. In this SpringerBrief, Space Weather and Coronal Mass Ejections, author Timothy Howard briefly introduces the coronal mass ejection, its sc

  5. Nanodust dynamics during a coronal mass ejection

    Science.gov (United States)

    Czechowski, Andrzej; Kleimann, Jens

    2017-09-01

    The dynamics of nanometer-sized grains (nanodust) is strongly affected by electromagnetic forces. High-velocity nanodust was proposed as an explanation for the voltage bursts observed by STEREO. A study of nanodust dynamics based on a simple time-stationary model has shown that in the vicinity of the Sun the nanodust is trapped or, outside the trapped region, accelerated to high velocities. We investigate the nanodust dynamics for a time-dependent solar wind and magnetic field configuration in order to find out what happens to nanodust during a coronal mass ejection (CME). The plasma flow and the magnetic field during a CME are obtained by numerical simulations using a 3-D magnetohydrodynamic (MHD) code. The equations of motion for the nanodust particles are solved numerically, assuming that the particles are produced from larger bodies moving in near-circular Keplerian orbits within the circumsolar dust cloud. The charge-to-mass ratios for the nanodust particles are taken to be constant in time. The simulation is restricted to the region within 0.14 AU from the Sun. We find that about 35 % of nanodust particles escape from the computational domain during the CME, reaching very high speeds (up to 1000 km s-1). After the end of the CME the escape continues, but the particle velocities do not exceed 300 km s-1. About 30 % of all particles are trapped in bound non-Keplerian orbits with time-dependent perihelium and aphelium distances. Trapped particles are affected by plasma ion drag, which causes contraction of their orbits.

  6. AD Ejection Line Studies and Optics Improvements

    CERN Document Server

    Belochitskii, P

    2013-01-01

    This paper is a summary of the work we made to understand and improve the AD ejection line optics. In 2011 significant differences were noticed between the optical properties of the AD ejection line and the MAD model. Investigations started to find out the sources of discrepancy. Better understanding of the ejection line optics was obtained and corrections were applied to the model of ejection line. The beam delivery to the experiments is better understood now. The results obtained might be useful as well for the optics design of AD to ELENA transfer line. Potential problems with the fringing field model in MAD were pointed out, when bending magnets with large bending angles and small bending radius are involved.

  7. CFD Simulations of Vibration Induced Droplet Ejection.

    Science.gov (United States)

    James, Ashley; Smith, Marc K.; Glezer, Ari

    1998-11-01

    Vibration-induced droplet ejection is a process that occurs when a liquid droplet is placed on a vibrating membrane. Above a critical value of the excitation amplitude, Faraday waves form on the surface of the drop. As the amplitude is increased secondary drops are ejected from the wave crests. A Navier-Stokes solver designed to simulate the transient fluid mechanics of the process is presented. The solver is based on a MAC method on a staggered grid. A volume of fluid method is implemented to track the free surface. The volume fraction is advected via a second-order, unsplit method that minimizes numerical diffusion of the interface. Surface tension is incorporated as a continuum surface force. This work is intended to provide a comprehensive description of the fluid dynamics involved in vibration-induced droplet ejection, with the aim of understanding the mechanism behind the ejection process. The evolution of the interface through droplet ejection will be simulated. The dependence of the ejection process on the driving parameters will be evaluated and the resonance characteristics of the drop will be determined. The results of the computations will be compared with experimental results.

  8. Classification of the ejection mechanisms of charged macromolecules from liquid droplets

    Science.gov (United States)

    Consta, Styliani; Malevanets, Anatoly

    2013-01-01

    The relation between the charge state of a macromolecule and its ejection mechanism from droplets is one of the important questions in electrospray ionization methods. In this article, effects of solvent-solute interaction on the manifestation of the charge induced instability in a droplet are examined. We studied the instabilities in a prototype system of a droplet comprised of charged poly(ethylene glycol) and methanol, acetonitrile, and water solvents. We observed instances of three, previously only conjectured, [S. Consta, J. Phys. Chem. B 114, 5263 (2010), 10.1021/jp912119v] mechanisms of macroion ejection. The mechanism of ejection of charged macroion in methanol is reminiscent of "pearl" model in polymer physics. In acetonitrile droplets, the instability manifests through formation of solvent spines around the solvated macroion. In water, we find that the macroion is ejected from the droplet through contiguous extrusion of a part of the chain. The difference in the morphology of the instabilities is attributed to the interplay between forces arising from the macroion solvation energy and the surface energy of the droplet interface. For the contiguous extrusion of a charged macromolecule from a droplet, we demonstrate that the proposed mechanism leads to ejection of the macromolecule from droplets with sizes well below the Rayleigh limit. The ejected macromolecule may hold charge significantly higher than that suggested by prevailing theories. The simulations reveal new mechanisms of macroion evaporation that differ from conventional charge residue model and ion evaporation mechanisms.

  9. Numerical Simulations of a Flux Rope Ejection

    Indian Academy of Sciences (India)

    P. Pagano; D. H. Mackay; S. Poedts

    2015-03-01

    Coronal mass ejections (CMEs) are the most violent phenomena observed on the Sun. One of the most successful models to explain CMEs is the flux rope ejection model, where a magnetic flux rope is expelled from the solar corona after a long phase along which the flux rope stays in equilibrium while magnetic energy is being accumulated. However, still many questions are outstanding on the detailed mechanism of the ejection and observations continuously provide new data to interpret and put in the context. Currently, extreme ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) are providing new insights into the early phase of CME evolution. In particular, observations show the ejection of magnetic flux ropes from the solar corona and how they evolve into CMEs. However, these observations are difficult to interpret in terms of basic physical mechanisms and quantities, thus, we need to compare equivalent quantities to test and improve our models. In our work, we intend to bridge the gap between models and observations with our model of flux rope ejection where we consistently describe the full life span of a flux rope from its formation to ejection. This is done by coupling the global non-linear force-free model (GNLFFF) built to describe the slow low- formation phase, with a full MHD simulation run with the software MPI-AMRVAC, suitable to describe the fast MHD evolution of the flux rope ejection that happens in a heterogeneous regime. We also explore the parameter space to identify the conditions upon which the ejection is favoured (gravity stratification and magnetic field intensity) and we produce synthesised AIA observations (171 Å and 211 Å). To carry this out, we run 3D MHD simulation in spherical coordinates where we include the role of thermal conduction and radiative losses, both of which are important for determining the temperature distribution of the solar corona during a CME. Our model of flux

  10. Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets.

    Science.gov (United States)

    Bünermann, Oliver; Kornilov, Oleg; Haxton, Daniel J; Leone, Stephen R; Neumark, Daniel M; Gessner, Oliver

    2012-12-07

    The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 ± 0.2 eV, Rydberg atoms in n = 3 and n = 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n = 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n = 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He(2) (+) and He(3) (+) ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n = 3 Rydberg atoms.

  11. Effect of Basic Residue on the Kinetics of Peptide Fragmentation Examined Using Surface-Induced Dissociation Combined with Resonant Ejection

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia

    2015-11-30

    In this work, resonant ejection coupled with surface-induced dissociation (SID) in a Fourier transform ion cyclotron resonance mass spectrometer is used to examine fragmentation kinetics of two singly protonated hexapeptides, RYGGFL and KYGGFL, containing the basic arginine residue and less basic lysine residue at the N-terminus. The kinetics of individual reaction channels at different collision energies are probed by applying a short ejection pulse (1 ms) in resonance with the cyclotron frequency of a selected fragment ion and varying the delay time between ion-surface collision and resonant ejection while keeping total reaction delay time constant. Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental data provides accurate threshold energies and activation entropies of individual reaction channels. Substitution of arginine with less basic lysine has a pronounced effect on the observed fragmentation kinetics of several pathways, including the b2 ion formation, but has little or no effect on formation of the b5+H2O fragment ion. The combination of resonant ejection SID, time- and collision energy-resolved SID, and RRKM modeling of both types of experimental data provides a detailed mechanistic understanding of the primary dissociation pathways of complex gaseous ions.

  12. Effect of arc current on droplet ejection from tungsten-based electrode in multiphase AC arc

    Science.gov (United States)

    Hashizume, Taro; Tanaka, Manabu; Watanabe, Takayuki

    2017-05-01

    The dynamic behavior of droplet ejection from a tungsten electrode was successfully visualized using a high-speed camera and an appropriate band-pass filter. The effect of arc current on droplet ejection was investigated to understand the electrode erosion mechanism in the multiphase AC arc. The rate of erosion by droplet ejection increased with increasing current. This result was examined on the basis of the time variation in forces on a pending droplet at the electrode tip during the AC cycle. The relationship among electromagnetic force, surface tension, and ion pressure on the molten tip during the cathodic period is crucial for controling droplet ejection. The molten tip becomes hemispherical forming the pending droplet with an increase in the instantaneous value of arc current during the AC cycle. The pending droplet detaches from the electrode surface when electromagnetic force becomes the dominant force. Consequently, a higher rate of erosion by droplet ejection with a higher arc current resulted from a stronger electromagnetic force.

  13. Runaway Massive Binaries and Cluster Ejection Scenarios

    CERN Document Server

    McSwain, M V; Boyajian, T S; Grundstrom, E D; Roberts, M S E; Ransom, Scott M.; Boyajian, Tabetha S.; Grundstrom, Erika D.

    2006-01-01

    The production of runaway massive binaries offers key insights into the evolution of close binary stars and open clusters. The stars HD 14633 and HD 15137 are rare examples of such runaway systems, and in this work we investigate the mechanism by which they were ejected from their parent open cluster, NGC 654. We discuss observational characteristics that can be used to distinguish supernova ejected systems from those ejected by dynamical interactions, and we present the results of a new radio pulsar search of these systems as well as estimates of their predicted X-ray flux assuming that each binary contains a compact object. Since neither pulsars nor X-ray emission are observed in these systems, we cannot conclude that these binaries contain compact companions. We also consider whether they may have been ejected by dynamical interactions in the dense environment where they formed, and our simulations of four-body interactions suggest that a dynamical origin is possible but unlikely. We recommend further X-ra...

  14. Ion funnel ion trap and process

    Science.gov (United States)

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  15. Characterization of defect growth structures in ion plated films by scanning electron microscopy

    Science.gov (United States)

    Spalvins, T.

    1979-01-01

    Gold and copper films (0.2-2 micron thick) are ion plated on very smooth stainless steel 304 and mica surfaces. The deposited films are examined by SEM to identify the morphological growth of defects. Three types of coating defects are distinguished: nodular growth, abnormal or runaway growth, and spits. The potential nucleation sites for defect growth are analyzed to determine the cause of defect formation. It is found that nuclear growth is due to inherent surface microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation and ejection of droplets. All these defects have adverse effects on the coatings.

  16. Characterization of defect growth structures in ion plated films by scanning electron microscopy

    Science.gov (United States)

    Spalvins, T.

    1979-01-01

    Gold and copper films (0.2-2 micron thick) are ion plated on very smooth stainless steel 304 and mica surfaces. The deposited films are examined by SEM to identify the morphological growth of defects. Three types of coating defects are distinguished: nodular growth, abnormal or runaway growth, and spits. The potential nucleation sites for defect growth are analyzed to determine the cause of defect formation. It is found that nuclear growth is due to inherent surface microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation and ejection of droplets. All these defects have adverse effects on the coatings.

  17. Pilot ejection, parachute, and helicopter crash injuries.

    Science.gov (United States)

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. 2014.

  18. Coronal Mass Ejections of Solar Cycle 23

    Indian Academy of Sciences (India)

    Nat Gopalswamy

    2006-06-01

    I summarize the statistical, physical, and morphological properties of coronal mass ejections (CMEs) of solar cycle 23, as observed by the Solar and Heliospheric Observatory (SOHO) mission. The SOHO data is by far the most extensive data, which made it possible to fully establish the properties of CMEs as a phenomenon of utmost importance to Sun–Earth connection as well as to the heliosphere. I also discuss various subsets of CMEs that are of primary importance for their impact on Earth.

  19. Observational Properties of Coronal Mass Ejections

    Science.gov (United States)

    2006-01-01

    2003. Peameis, D.V., Magntetic topology of imspumlsive assd gradutal solar energetic particle Xic. H., L. Ofmran, and G. Lawvrence, Cone model for...425, 1097, 2004. Yashiro, S., N. Gopalssvamy, G. Michalek, assd R.A. Hosvard, Properties of narrow coronal Sltatstnigara~jU, A., Y.-i. Mootn, M. Dryer...G.M.,’FTit relatiomtslip hetwseen prominence ermtptions assd coronal mnass ejections.. 107(A8), 1223, doi: 10. 1029/2001 JAOO9 143, 2002. .1. Atssnn.s

  20. Potential Method of Predicting Coronal Mass Ejection

    Science.gov (United States)

    Imholt, Timothy

    2001-10-01

    Coronal Mass Ejections (CME) may be described as a blast of gas and highly charged solar mass fragments ejected into space. These ejections, when directed toward Earth, have many different effects on terrestrial systems ranging from the Aurora Borealis to changes in wireless communication. The early prediction of these solar events cannot be overlooked. There are several models currently accepted and utilized to predict these events, however, with earlier prediction of both the event and the location on the sun where the event occurs allows us to have earlier warnings as to when they will affect man-made systems. A better prediction could perhaps be achieved by utilizing low angular resolution radio telescope arrays to catalog data from the sun at different radio frequencies on a regular basis. Once this data is cataloged a better predictor for these CME’s could be found. We propose a model that allows a prediction to be made that appears to be longer than 24 hours.

  1. Spontaneous Capillarity-Driven Droplet Ejection

    CERN Document Server

    Wollman, Andrew; Pettit, Donald; Weislogel, Mark

    2012-01-01

    The first large length-scale capillary rise experiments were conducted by R. Siegel using a drop tower at NASA LeRC shortly after the 1957 launch of Sputnik I. Siegel was curious if the wetting fluid would expel from the end of short capillary tubes in a low-gravity environment. He observed that although the fluid partially left the tubes, it was always pulled back by surface tension, which caused the fluid to remain pinned to the tubes' end. By exploiting tube geometry and fluid properties, we demonstrate that such capillary flows can in fact eject a variety of jets and drops. This fluid dynamics video provides a historical overview of such spontaneous capillarity-driven droplet ejection. Footage of terrestrial and low earth orbit experiments are also shown. Droplets generated in a microgravity environment are $10^6$ times larger than those ejected in a terrestrial environment. The accompanying article provides a summary of the critical parameters and experimental procedures. Scaling the governing equations ...

  2. Gas Ejection from Spiral Galaxy Disks

    Science.gov (United States)

    Durelle, Jeremy

    We present the results of three proposed mechanisms for ejection of gas from a spiral arm into the halo. The mechanisms were modelled using magnetohydrodynamics (MHD) as a theoretical template. Each mechanism was run through simulations using a Fortran code: ZEUS-3D, an MHD equation solver. The first mechanism modelled the gas dynamics with a modified Hartmann flow which describes the fluid flow between two parallel plates. We initialized the problem based on observation of lagging halos; that is, that the rotational velocity falls to a zero at some height above the plane of the disk. When adopting a density profile which takes into account the various warm and cold H I and HII molecular clouds, the system evolves very strangely and does not reproduce the steady velocity gradient observed in edge-on galaxies. This density profile, adopted from Martos and Cox (1998), was used in the remaining models. However, when treating a system with a uniform density profile, a stable simulation can result. Next we considered supernova (SN) blasts as a possible mechanism for gas ejection. While a single SN was shown to be insufficient to promote vertical gas structures from the disk, multiple SN explosions proved to be enough to promote gas ejection from the disk. In these simulations, gas ejected to a height of 0.5 kpc at a velocity of 130 km s--1 from 500 supernovae, extending to an approximate maximum height of 1 kpc at a velocity of 6.7 x 103 km s--1 from 1500 supernovae after 0.15 Myr, the approximate time of propagation of a supernova shock wave. Finally, we simulated gas flowing into the spiral arm at such a speed to promote a jump in the disk gas, termed a hydraulic jump. The height of the jump was found to be slightly less than a kiloparsec with a flow velocity of 41 km s--1 into the halo after 167 Myr. The latter models proved to be effective mechanisms through which gas is ejected from the disk whereas the Hartmann flow (or toy model) mechanism remains unclear as the

  3. A METHOD IN SYSTEM DESIGN OF EJECTING DEVICES OF MISSILES

    Institute of Scientific and Technical Information of China (English)

    DaiLongcheng; XuanYimin

    2002-01-01

    Anew method in system design of ejecting devices of missiles is first presented.Some important points are dis-cussed,which guid the research and development of new ejecting devices of missileg,amd provid the foundation flr thw design of mew ejecting device is provided.The system design includes the distribution of techmology specifica-tion,3-D solid modeling of ejecting devices of missiles im-ported from abroad,the design of pmeumatic device sys-tem,the design of ejecting mechanism system,the predic-tion of reliability and the experimental analysis,etc.

  4. Osmotic pressure: resisting or promoting DNA ejection from phage

    CERN Document Server

    Jeembaeva, Meerim; Larsson, Frida; Evilevitch, Alex

    2008-01-01

    Recent in vitro experiments have shown that DNA ejection from bacteriophage can be partially stopped by surrounding osmotic pressure when ejected DNA is digested by DNase I on the course of ejection. We argue in this work by combination of experimental techniques (osmotic suppression without DNaseI monitored by UV absorbance, pulse-field electrophoresis, and cryo-EM visualization) and simple scaling modeling that intact genome (i.e. undigested) ejection in a crowded environment is, on the contrary, enhanced or eventually complete with the help of a pulling force resulting from DNA condensation induced by the osmotic stress itself. This demonstrates that in vivo, the osmotically stressed cell cytoplasm will promote phage DNA ejection rather than resisting it. The further addition of DNA-binding proteins under crowding conditions is shown to enhance the extent of ejection. We also found some optimal crowding conditions for which DNA content remaining in the capsid upon ejection is maximum, which correlates well...

  5. Role of osmotic and hydrostatic pressures in bacteriophage genome ejection

    CERN Document Server

    Lemay, Serge G; Molineux, Ian J

    2012-01-01

    A critical step in the bacteriophage life cycle is genome ejection into host bacteria. The ejection process for double-stranded DNA phages has been studied thoroughly \\textit{in vitro}, where after triggering with the cellular receptor the genome ejects into a buffer. The experimental data have been interpreted in terms of the decrease in free energy of the densely packed DNA associated with genome ejection. Here we detail a simple model of genome ejection in terms of the hydrostatic and osmotic pressures inside the phage, a bacterium, and a buffer solution/culture medium. We argue that the hydrodynamic flow associated with the water movement from the buffer solution into the phage capsid and further drainage into the bacterial cytoplasm, driven by the osmotic gradient between the bacterial cytoplasm and culture medium, provides an alternative mechanism for phage genome ejection \\textit{in vivo}; the mechanism is perfectly consistent with phage genome ejection \\textit{in vitro}.

  6. On Subthreshold Ionization of Helium Droplets, Ejection of He+, and the Role of Anions

    CERN Document Server

    Renzler, Michael; Weinberger, Nikolaus; Denifl, Stephan; Scheier, Paul; Echt, Olof

    2016-01-01

    The mechanism of ionization of helium droplets has been investigated in numerous reports but one observation has not found a satisfactory explanation: How are $He^+$ ions formed and ejected from undoped droplets at electron energies below the ionization threshold of the free atom? Does this path exist at all? A measurement of the ion yields of $He^+$ and $He_2^+$ as a function of electron energy, electron emission current, and droplet size reveals that metastable $He^{*-}$ anions play a crucial role in the formation of free $He^+$ at subthreshold energies. The proposed model is testable.

  7. Bending and turbulent enhancement phenomena of neutral gas flow containing an atmospheric pressure plasma by applying external electric fields measured by schlieren optical method

    Science.gov (United States)

    Yamada, Hiromasa; Yamagishi, Yusuke; Sakakita, Hajime; Tsunoda, Syuichiro; Kasahara, Jiro; Fujiwara, Masanori; Kato, Susumu; Itagaki, Hirotomo; Kim, Jaeho; Kiyama, Satoru; Fujiwara, Yutaka; Ikehara, Yuzuru; Ikehara, Sanae; Nakanishi, Hayao; Shimizu, Nobuyuki

    2016-01-01

    To understand the mechanism of turbulent enhancement phenomena of a neutral gas flow containing plasma ejected from the nozzle of plasma equipment, the schlieren optical method was performed to visualize the neutral gas behavior. It was confirmed that the turbulent starting point became closer to the nozzle exit, as the amplitude of discharge voltage (electric field) increased. To study the effect of electric field on turbulent enhancement, two sets of external electrodes were arranged in parallel, and the gas from the nozzle was allowed to flow between the upper and lower electrodes. It was found that the neutral gas flow was bent, and the bending angle increased as the amplitude of the external electric field increased. The results obtained using a simple model analysis roughly coincide with experimental data. These results indicate that momentum transport from drifted ions induced by the electric field to neutral particles is an important factor that enhances turbulence.

  8. Particle Ejection and Levitation Technology (PELT)

    Science.gov (United States)

    2008-01-01

    Each of the six Apollo landers touched down at unique sites on the lunar surface. Aside from the Apollo 12 landing site located 180 meters from the Surveyor III lander, plume impingement effects on ground hardware during the landings were not a problem. The planned return to the Moon requires numerous landings at the same site. Since the top few centimeters of lunar soil are loosely packed regolith, plume impingement from the lander will eject the granular material at high velocities. A picture shows what the astronauts viewed from the window of the Apollo 14 lander. There was tremendous dust excavation beneath the vehicle. With high-vacuum conditions on the Moon (10 (exp -14) to 10 (exp -12) torr), motion of all particles is completely ballistic. Estimates derived from damage to Surveyor III caused by the Apollo 12 lander show that the speed of the ejected regolith particles varies from 100 m/s to 2,000 m/s. It is imperative to understand the physics of plume impingement to safely design landing sites for future Moon missions. Aerospace scientists and engineers have examined and analyzed images from Apollo video extensively in an effort to determine the theoretical effects of rocket exhaust impingement. KSC has joined the University of Central Florida (UCF) to develop an instrument that will measure the 3-D vector of dust flow caused by plume impingement during descent of landers. The data collected from the instrument will augment the theoretical studies and analysis of the Apollo videos.

  9. Energetics of Solar Coronal Mass Ejections

    CERN Document Server

    Subramanian, P; Subramanian, Prasad; Vourlidas, Angelos

    2007-01-01

    Aims: To investigate if solar coronal mass ejections are driven mainly by coupling to the ambient solar wind, or through the release of internal magnetic energy. Methods: We examine the energetics of 39 flux-rope like coronal mass ejections (CMEs) from the Sun using data in the distance range $\\sim$ 2--20 $R_{{\\o}dot}$ from the Large Angle Spectroscopic Coronograph (LASCO) aboard the Solar and Heliospheric Observatory (SOHO). This comprises a complete sample of the best examples of flux-rope CMEs observed by LASCO in 1996-2001. Results: We find that 69% of the CMEs in our sample experience a clearly identifiable driving power in the LASCO field of view. For these CMEs which are driven, we examine if they might be deriving most of their driving power by coupling to the solar wind. We do not find conclusive evidence in favor of this hypothesis. On the other hand, we find that their internal magnetic energy is a viable source of the required driving power. We have estimated upper and lower limits on the power th...

  10. MAVEN observations of the response of Mars to an interplanetary coronal mass ejection.

    Science.gov (United States)

    Jakosky, B M; Grebowsky, J M; Luhmann, J G; Connerney, J; Eparvier, F; Ergun, R; Halekas, J; Larson, D; Mahaffy, P; McFadden, J; Mitchell, D F; Schneider, N; Zurek, R; Bougher, S; Brain, D; Ma, Y J; Mazelle, C; Andersson, L; Andrews, D; Baird, D; Baker, D; Bell, J M; Benna, M; Chaffin, M; Chamberlin, P; Chaufray, Y-Y; Clarke, J; Collinson, G; Combi, M; Crary, F; Cravens, T; Crismani, M; Curry, S; Curtis, D; Deighan, J; Delory, G; Dewey, R; DiBraccio, G; Dong, C; Dong, Y; Dunn, P; Elrod, M; England, S; Eriksson, A; Espley, J; Evans, S; Fang, X; Fillingim, M; Fortier, K; Fowler, C M; Fox, J; Gröller, H; Guzewich, S; Hara, T; Harada, Y; Holsclaw, G; Jain, S K; Jolitz, R; Leblanc, F; Lee, C O; Lee, Y; Lefevre, F; Lillis, R; Livi, R; Lo, D; Mayyasi, M; McClintock, W; McEnulty, T; Modolo, R; Montmessin, F; Morooka, M; Nagy, A; Olsen, K; Peterson, W; Rahmati, A; Ruhunusiri, S; Russell, C T; Sakai, S; Sauvaud, J-A; Seki, K; Steckiewicz, M; Stevens, M; Stewart, A I F; Stiepen, A; Stone, S; Tenishev, V; Thiemann, E; Tolson, R; Toublanc, D; Vogt, M; Weber, T; Withers, P; Woods, T; Yelle, R

    2015-11-01

    Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

  11. A Subpath Ejection Method for the Vehicle Routing Problem

    OpenAIRE

    1998-01-01

    Generically, ejection chains are methods conceived to allow solution transformations to be efficiently carried out by modifying a variable number of their components at each step of a local search algorithm. We consider a subpath ejection chain method for the vehicle routing problem (VRP) under capacity and route length restrictions. The method undertakes the identification of a substructure named the flower reference structure which, besides coordinating moves during an ejection chain constr...

  12. Acoustic and aerodynamic characteristics of ejectives in Amharic

    Science.gov (United States)

    Demolin, Didier

    2004-05-01

    This paper invetsigates the main phonetic characteristics that distinguishes ejectives from pulmonic sounds in Amharic. In this language, there are five ejectives that can be phonemically singleton or geminate. Duration measurements have been made in intervocalic position for pulmonic stops and for each type of ejective, taking into account the overall duration and VOT. Results show that ejective stops have a higher amplitude burst than pulmonic stops. The duration of the noise is shorter for ejective fricatives compared to pulmonic fricatives. At the end of ejective fricatives, there is a 30-ms glottal lag that is not present in pulmonic fricatives. Geminate ejectives are realized by delaying the elevation of the larynx. This can be observed on the spectrographic data by an increase of the noise at the end of the geminate ejectives. Aerodynamic data have been collected in synchronization with the acoustic recordings. The main observations are that pharyngeal pressures values are much higher than what is usually assumed (up to 40 CmH2O for velars) and that the delayed command in the elevation of the larynx of geminate ejectives is shown by two phases in the rise of pharyngeal pressure.

  13. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... to Pneumococcal Vaccine Additional Content Medical News External Otitis (Swimmer's Ear) By Bradley W. Kesser, MD, Associate ... the Outer Ear Ear Blockages Ear Tumors External Otitis (Swimmer's Ear) Malignant External Otitis Perichondritis External otitis ...

  14. Coronal Mass Ejections: From Sun to Earth

    Science.gov (United States)

    Patsourakos, S.

    2016-06-01

    Coronal Mass Ejections (CMEs) are gigantic expulsions of magnetized plasmas from the solar corona into the interplanetary (IP) space. CMEs spawn ~ 1015 gr of mass and reach speeds ranging between several hundred to a few thousand km/s (e.g., Gopalswamy et al. 2009; Vourlidas et al. 2010). It takes 1-5 days for a CME to reach Earth. CMEs are one of the most energetic eruptive manifestations in the solar system and are major drivers of space weather via their magnetic fields and energetic particles, which are accelerated by CME-driven shocks. In this review we give a short account of recent, mainly observational, results on CMEs from the STEREO and SDO missions which include the nature of their pre-eruptive and eruptive configurations and the CME propagation from Sun to Earth. We conclude with a discussion of the exciting capabilities in CME studies that will soon become available from new solar and heliospheric instrumentation.

  15. Periodicities in Solar Coronal Mass Ejections

    CERN Document Server

    Lou, Y Q; Fan, Z; Wang, S; Wang, J

    2003-01-01

    Mid-term quasi-periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four-year data (February 5, 1999 to February 10, 2003) of the Large Angle Spectrometric Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). In parallel, mid-term quasi-periodicities in solar X-ray flares (class >M5.0) from the Geosynchronous Operational Environment Satellites (GOES) and in daily averages of Ap index for geomagnetic disturbances from the World Data Center (WDC) at the International Association for Geomagnetism and Aeronomy (IAGA) are also examined for the same four-year time span. Several conceptual aspects of possible equatorially trapped Rossby-type waves at and beneath the solar photosphere are discussed.

  16. Kinematical properties of coronal mass ejections

    CERN Document Server

    Temmer, Manuela

    2016-01-01

    Coronal mass ejections (CMEs) are the most dynamic phenomena in our solar system. They abruptly disrupt the continuous outflow of solar wind by expelling huge clouds of magnetized plasma into interplanetary space with velocities enabling to cross the Sun-Earth distance within a few days. Earth-directed CMEs may cause severe geomagnetic storms when their embedded magnetic fields and the shocks ahead compress and reconnect with the Earth's magnetic field. The transit times and impacts in detail depend on the initial CME velocity, size, and mass, as well as on the conditions and coupling processes with the ambient solar wind flow in interplanetary space. The observed CME parameters may be severly affected by projection effects and the constant changing environmental conditions are hard to derive. This makes it difficult to fully understand the physics behind CME evolution, preventing to do a reliable forecast of Earth-directed events. This short review focusing on observational data, shows recent methods which w...

  17. Planet Scattering Around Binaries: Ejections, Not Collisions

    CERN Document Server

    Smullen, Rachel A; Shannon, Andrew

    2016-01-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically effects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Asid...

  18. Solar Eruptions: Coronal Mass Ejections and Flares

    Science.gov (United States)

    Gopalswamy, Nat

    2012-01-01

    This lecture introduces the topic of Coronal mass ejections (CMEs) and solar flares, collectively known as solar eruptions. During solar eruptions, the released energy flows out from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. Flares can be eruptive or confined. Eruptive flares accompany CMEs, while confined flares hav only electromagnetic signature. CMEs can drive MHD shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. CMEs heading in the direction of Earth arrive in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currnts that can disrupt power grids, railroads, and underground pipelines

  19. Boulders Ejected From Small Impact Craters

    Science.gov (United States)

    Bart, Gwendolyn D.; Melosh, H. J.

    2006-09-01

    We investigate the distribution of boulders ejected from lunar craters by analyzing high resolution Lunar Orbiter images. Our previous study (DPS 2004) of four small craters indicated that larger boulders are more frequently found close to the crater rim rather than far away, and that the size of the ejecta drops off as a power law with distance from the crater. Our current study adds more than ten new bouldery craters that range in size from 200 m to several kilometers and are found on a variety of terrain (mare, highlands, and the Copernicus ejecta blanket.) For each crater we plot the boulder diameter as a function of the ejection velocity of the boulder. We compare this size-velocity distribution with the size-velocity distribution of ejecta from large craters (Vickery 1986, 1987) to ascertain the mechanism of fracture of the substrate in the impact. We also make cumulative plots of the boulders, indicating the number of boulders of each size present around the crater. The cumulative plots allow us to compare our boulder distributions with the distributions of secondary craters from large impacts. Material thrown from a several-hundred-meter diameter crater may land intact as boulders, but material thrown from a tens-of-kilometers diameter crater will travel at a significantly higher velocity, and will form a secondary crater when it impacts the surface. Our data helps elucidate whether the upturn, at small diameters, of the cratering curve of the terrestrial planets is due to secondary impacts or to the primary population. This work is funded by NASA PGG grant NNG05GK40G.

  20. Photoprocess of molecules encapsulated in porous solids X: Photosensitization of zeolite-Y encapsulated tris(2,2'-bipyridine-nickel-(II)ion by phenosafranine adsorbed onto the external surface of the nanoporous host

    Indian Academy of Sciences (India)

    Karuppannan Senthil Kumar; Sudha T; Paramasivam Natarajan

    2014-07-01

    Tris-(2,2'-bipyridine)-nickel-(II) complex ion encapsulated by zeolite-Y host has been synthesized by ship-in-a-bottle method. Photosensitization of nickel(II) complex (Ni(bpy)$^{2+}_{3}$) in the zeolite host by surface adsorbed phenosafranine dye was investigated by time-resolved fluorescence and absorption spectral measurements. Formation of nickel (II)-complex in the super cage of the host was ascertained by XRD, FTIR, solidstate NMR, diffuse reflectance UV-visible absorption spectroscopic techniques and ICP-OES measurements. Phenosafranine dye adsorbed on the external surface of zeolite-Y shows a decrease in fluorescence intensity with increased loading of the nickel(II) complex in zeolite-Y. Time-resolved emission studies show two excited state lifetimes for the photoexcited phenosafranine dye. Average fluorescence lifetimes of the dye in this case do not change with increase in the loading of the nickel(II) complex. However, relative contribution of short lifetime component increases when the amount of encapsulated nickel(II) complex is increased. The zeolite-Y host containing only bipyridyl ligand shows a marked decrease in fluorescence intensity. Fluorescence lifetimes of the dye however do not change with increased loading of bipyridyl while relative contribution of short lifetime component increases with an increase in the loading of bipyridyl in the host. This observation is interpreted to be due to electron transfer from the excited state of phenosafranine dye to the bipyridine. Picosecond pump-probe investigations confirm that the photoinduced electron transfer occurs from the surfaceadsorbed phenosafranine in the excited state to the nickel(II) complex within zeolite-Y cavity and also to the Ni(bpy)$^{2+}_{3}$ complex in contact with the phenosafranine dye co-adsorbed on the external surface of the host.

  1. Externally Wetted Ionic Liquid Thruster

    Science.gov (United States)

    Lozano, P.; Martinez-Sanchez, M.; Lopez-Urdiales, J. M.

    2004-10-01

    This paper presents initial developments of an electric propulsion system based on ionic liquid ion sources (ILIS). Propellants are ionic liquids, which are organic salts with two important characteristics; they remain in the liquid state at room temperature and have negligible vapor pressure, thus allowing their use in vacuum. The working principles of ILIS are similar to those of liquid metal ion sources (LMIS), in which a Taylor cone is electrostatically formed at the tip of an externally wetted needle while ions are emitted directly from its apex. ILIS have the advantage of being able to produce negative ions that have similar masses than their positive counterparts with similar current levels. This opens up the possibility of achieving plume electrical neutrality without electron emitters. The possible multiplexing of these emitters is discussed in terms of achievable thrust density for applications other than micro-propulsion.

  2. Animal models of heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    G. Conceição; I. Heinonen (Ilkka); A.P. Lourenço; D.J.G.M. Duncker (Dirk); I. Falcão-Pires

    2016-01-01

    textabstractHeart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function

  3. Fighter Pilot Ejection Study as an Educational Tool

    Science.gov (United States)

    Robinson, Garry; Jovanoski, Zlatko

    2010-01-01

    In this article, we apply the well-known equations of projectile motion to the case of a fighter pilot ejecting from an aircraft, the aim being to establish under what conditions there is danger of impact with the rear vertical stabilizer. The drag force on the pilot after ejection is assumed to vary as the velocity squared and the aircraft motion…

  4. Fast ejection chain algorithms for vehicle routing with time windows

    NARCIS (Netherlands)

    Sontrop, Herman; Blesa, M.J.; Blum, C.; van der Horn, Pieter; Uetz, Marc Jochen; Roli, A.; Sampels, M.

    This paper introduces a new algorithm, based on the concept of ejection chains, to effectively target vehicle routing problems with time window constraints (VRPTW). Ejection chains create powerful compound moves within Local Search algorithms. Their potential to yield state of the art algorithms has

  5. Polymer ejection from bacteriophages is fully determined by confinement energy

    CERN Document Server

    Piili, J

    2015-01-01

    The ejection dynamics through a nanoscale pore of a flexible polymer that is initially strongly confined inside a spherical capsid is examined. By extensive simulations using the stochastic rotation dynamics method we show that the time for an individual monomer to eject grows exponentially with the number of ejected monomers under constant initial monomer density. This dependence is a consequence of the excess free energy of the polymer due to confinement growing exponentially with the initial monomer number inside the capsid, which we address to strong monomer-monomer interactions. Consequently, for sufficiently strong initial confinement and long polymers ejection times for polymers of different lengths depend linearly on the length. At polymer lengths amenable to computer simulations the dependence is superlinear due to the finite-size effect related to the retraction of polymer tails at final stages of ejection.

  6. Summoning the wind: Hydrodynamic cooperation of forcibly ejected fungal spores

    CERN Document Server

    Roper, Marcus; Cobb, Ann; Dillard, Helene R; Pringle, Anne

    2009-01-01

    The forcibly launched spores of the crop pathogen \\emph{Sclerotinia sclerotiorum} must eject through many centimeters of nearly still air to reach the flowers of the plants that the fungus infects. Because of their microscopic size, individually ejected spores are quickly brought to rest by drag. In the accompanying fluid dynamics video we show experimental and numerical simulations that demonstrate how, by coordinating the nearly simultaneous ejection of hundreds of thousands of spores,\\emph{Sclerotinia} and other species of apothecial fungus are able to sculpt a flow of air that carries spores across the boundary layer and around intervening obstacles. Many spores are sacrificed to create this flow of air. Although high speed imaging of spore launch in a wild isolate of the dung fungus \\emph{Ascobolus} shows that the synchronization of spore ejections is self-organized, which could lead to spores delaying their ejection to avoid being sacrificed, simulations and asymptotic analysis show that, close the frui...

  7. Ejection experience in Serbian air force, 1990-2010

    Directory of Open Access Journals (Sweden)

    Pavlović Miroslav

    2014-01-01

    Full Text Available Background/Aim. Ejection injuries are the problem for air forces. The present risk for injuries is still too high, approximately 30-50%. This study was an effort to determine factors responsible for and contributing to injuries in the Serbian Air Force (SAF in the last two decades. Methods. All ejection cases in the SAF between 1990 and 2010 were analyzed. The collected data were: aircraft type, ejection seat generation, pilots ´ age and experience, causes of ejection, aeronautical parameters, the condition of aircraft control and types of injuries. For ease of comparison the U.S. Air Force Safety Regulation was used to define of major injuries: hospitalization for 5 days or more, loss of consciousness for over 5 min, bone fracture, joint dislocation, injury to any internal organ, any third-degree burn, or second-degree burn over 5% of the body surface area. Results. There were 52 ejections (51 pilots and 1 mechanic on 44 airplanes. The ejected persons were from 22 to 46 years, average 32 years. Major injuries were present in 25.49% cases. Of all the ejected pilots 9.61% had fractures of thoracic spine, 11.53% fractures of legs, 3.48% fractures of arms. Of all major injuries, fractures of thoracic spine were 38.46%. None of the pilots had experienced ejection previously. Conclusion. Our results suggest to obligatory take preventive measures: magnetic resonance imaging (MRI scan must be included in the standard pilot selection procedure and procedure after ejection. Physical conditioning of pilots has to be improved. Training on ejection trainer has to be accomplished, too.

  8. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Georg, Dietmar, E-mail: Dietmar.Georg@akhwien.at [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hopfgartner, Johannes [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Gòra, Joanna [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kuess, Peter [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kragl, Gabriele [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Berger, Daniel [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hegazy, Neamat [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Goldner, Gregor; Georg, Petra [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria)

    2014-03-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ({sup 192}Ir) and LDR-BT ({sup 125}I) were D{sub 90%} ≥34 Gy in 8.5 Gy per fraction and D{sub 90%} ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D{sub mean} around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques

  9. Morphology of gold and copper ion-plated coatings

    Science.gov (United States)

    Spalvins, T.

    1978-01-01

    Copper and gold films (0.2 to 2 microns thick) were ion plated onto polished 304-stainless-steel, glass, mica surfaces. These coatings were examined by SEM for defects in their morphological growth. Three types of defects were distinguished: nodular growth, abnormal or runaway growth, and spits. The cause for each type of defect was investigated. Nodular growth is due to inherent substrate microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation (ejection of droplets). All these defects induce stresses and produce porosity in the coatings and thus weaken their mechanical properties. During surface rubbing, large nodules are pulled out, leaving vacancies in the coatings.

  10. Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

    Science.gov (United States)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2017-01-01

    Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

  11. Radio-quiet Fast Coronal Mass Ejections

    Science.gov (United States)

    Gopalswamy, N.; Aguilar-Rodriguez, E.; Kaiser, M. L.; Howard, R. A.

    2004-12-01

    Coronal mass ejections (CMEs) drive shocks in the interplanetary medium that produce type II radio emission. These CMEs are faster and wider on the average, than the general population of CMEs. However, when we start from fast (speed > 900 km/s) and wide (angular width > 60 degrees), more than half of them are not associated with radio bursts. In order to understand why these CMEs are radio quiet, we collected all the fast and wide (FW) CMEs detected by the Solar and Heliospheric Observatory (SOHO) mission's Large Angle and Spectrometric Coronagraph (LASCO) and isolated those without associated type II radio bursts. The radio bursts were identified in the dynamic spectra of the Radio and Plasma Wave (WAVES) Experiment on board the Wind spacecraft. We also checked the list against metric type II radio bursts reported in Solar Geophysical Data and isolated those without any radio emission. This exercise resulted in about 140 radio-quiet FW CMEs. We identified the source regions of these CMEs using the Solar Geophysical Data listings, cross-checked against the eruption regions in the SOHO/EIT movies. We explored a number of possibilities for the radio-quietness: (i) Source region being too far behind the limb, (ii) flare size, (iii) brightness of the CME, and (iv) the density of the ambient medium. We suggest that a combination of CME energy and the Alfven speed profile of the ambient medium is primarily responsible for the radio-quietness of these FW CMEs.

  12. Planet scattering around binaries: ejections, not collisions

    Science.gov (United States)

    Smullen, Rachel A.; Kratter, Kaitlin M.; Shannon, Andrew

    2016-09-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary star and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically affects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Systems similar to the only observed multiplanet circumbinary system, Kepler-47, can arise from much more tightly packed, unstable systems. Only extreme initial conditions introduce differences in the final planet populations. Thus, we suggest that any intrinsic differences in the populations are imprinted by formation.

  13. Anisotropic mass ejection in binary mergers

    CERN Document Server

    Morris, T; Podsiadlowski, Ph.

    2006-01-01

    We investigate the mass loss from a rotationally distorted envelope following the early, rapid in-spiral of a companion star inside a common envelope. For initially wide, massive binaries (M_1+M_2=20M_{\\odot}, P\\sim 10 yr), the primary has a convective envelope at the onset of mass transfer and is able to store much of the available orbital angular momentum in its expanded envelope. Three-dimensional SPH calculations show that mass loss is enhanced at mid-latitudes due to shock reflection from a torus-shaped outer envelope. Mass ejection in the equatorial plane is completely suppressed if the shock wave is too weak to penetrate the outer envelope in the equatorial direction (typically when the energy deposited in the star is less than about 1/3 of the binding energy of the envelope). We present a parameter study to show how the geometry of the ejecta depends on the angular momentum and the energy deposited in the envelope during a merging event. Applications to the nearly axisymmetric, but very non-spherical ...

  14. Reconnection in a slow Coronal Mass Ejection

    Directory of Open Access Journals (Sweden)

    G. Poletto

    2008-10-01

    Full Text Available This paper aims at studying reconnection occurring in the aftermath of the 28 May 2004, CME, first imaged by the LASCO (Large Angle and Spectrometric Coronagraph C2 at 11:06 UT. The CME was observed in White Light and UV radiation: images acquired by the LASCO C2 and C3 coronagraphs and spectra acquired by UVCS (Ultraviolet Coronagraph Spectrometer allowed us to identify the level at which field lines, stretched outwards by the CME ejection, reconnect below the CME bubble. As the CME propagates outwards, reconnection occurs at increasingly higher levels. The process goes on at a low pace for several hours: here we give the profile of the reconnection rate vs. heliocentric distance over a time interval of ≈14 h after the CME onset, extending estimates of the reconnection rate to larger distances than previously inferred by other authors. The reconnection rate appears to decrease with time/altitude. We also calculate upper and lower limits to the density in the diffusion region between 4 and 7 R and conclude by comparing estimates of the classical and anomalous resistivity in the diffusion region with the value inferred from the data. The latter turns out to be ≥5 order of magnitudes larger than predicted by classical or anomalous theories, pointing to the need of identifying the process responsible for the observed value.

  15. Why are halo coronal mass ejections faster?

    Institute of Scientific and Technical Information of China (English)

    Qing-Min Zhang; Yang Guo; Peng-Fei Chen; Ming-De Ding; Cheng Fang

    2010-01-01

    Halo coronal mass ejections(CMEs)have been to be significantly faster than normal CMEs,which is a long-standing puzzle.In order to solve the puzzle,we first investigate the observed properties of 31 limb CMEs that clearly display loopshaped frontal loops.The observational results show a strong tendency that slower CMEs are weaker in white-light intensity.Then,we perform a Monte Carlo simulation of 20000 artificial limb CMEs that have an average velocity of~523 km s-1.The Thomson scattering of these events is calculated when they are assumed to be observed as limb and halo events,respectively.It is found that the white-light intensity of many slow CMEs becomes remarkably reduced when they turn from being viewed as a limb event to being viewed as a halo event.When the intensity is below the background solar wind fluctuation,it is assumed that they would be missed by coronagraphs.The average velocity of"detectable"halo CMEs is~922 km s-1,very close to the observed value.This also indicates that wider events are more likely to be recorded.The results soundly suggest that the higher average velocity of halo CMEs is due to that a majority of slow events and some of narrow fast events carrying less material are so faint that they are blended with the solar wind fluctuations,and therefore are not observed.

  16. Active Longitude and Coronal Mass Ejection Occurrences

    Science.gov (United States)

    Gyenge, N.; Singh, T.; Kiss, T. S.; Srivastava, A. K.; Erdélyi, R.

    2017-03-01

    The spatial inhomogeneity of the distribution of coronal mass ejection (CME) occurrences in the solar atmosphere could provide a tool to estimate the longitudinal position of the most probable CME-capable active regions in the Sun. The anomaly in the longitudinal distribution of active regions themselves is often referred to as active longitude (AL). In order to reveal the connection between the AL and CME spatial occurrences, here we investigate the morphological properties of active regions. The first morphological property studied is the separateness parameter, which is able to characterize the probability of the occurrence of an energetic event, such as a solar flare or CME. The second morphological property is the sunspot tilt angle. The tilt angle of sunspot groups allows us to estimate the helicity of active regions. The increased helicity leads to a more complex buildup of the magnetic structure and also can cause CME eruption. We found that the most complex active regions appear near the AL and that the AL itself is associated with the most tilted active regions. Therefore, the number of CME occurrences is higher within the AL. The origin of the fast CMEs is also found to be associated with this region. We concluded that the source of the most probably CME-capable active regions is at the AL. By applying this method, we can potentially forecast a flare and/or CME source several Carrington rotations in advance. This finding also provides new information for solar dynamo modeling.

  17. Pulse Ejection Presentation System Synchronized with Breathing

    Science.gov (United States)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  18. Ejection of small droplet from microplate using focused ultrasound

    Science.gov (United States)

    Tanaka, Hiroki; Mizuno, Yosuke; Nakamura, Kentaro

    2017-08-01

    We discussed an ultrasonic system for single-droplet ejection from a microplate, which is one of the basic and important procedures in the noncontact handling of droplets in air. In this system, a 1.5 MHz concave transducer located below the microplate is used for chasing the liquid surface through a pulse echo method, and also for the ejection of a 1 µL single droplet by the burst of focused ultrasound. We investigated the relationship between the droplet ejection characteristics, the distance from the transducer to the surface of liquid, the material property, and the excitation condition of the focused ultrasonic transducer. It was verified that the optimal position of the transducer was off the focal point of sound pressure by ±1 mm, because the sound intensity had to be controlled to eject a single droplet. Subsequently, we confirmed experimentally that the ejected droplet volume linearly depended on the surface tension of the liquid, and that the droplet volume and ejection velocity were determined by the Webber number, Reynolds number, and Ohnesolge number. In addition, by optimizing the duration of the burst ultrasound, the droplet volume and ejection velocity were controlled.

  19. Interplanetary Coronal Mass Ejection (ICME) and Cosmic rays transmission during Forbush decreases

    Science.gov (United States)

    Okpala, K. C.

    2015-12-01

    Forbush decrease (FD) is an observed reduction in galactic cosmic ray (GCR) intensity as measured by ground neutron monitors often associated energetic events on the Sun such as coronal mass ejections (CME). FD is associated with increased activity of the sun as reflected in the size of the interplanetary coronal mass ejections passing around the Earth and the corotating regions in the Heliosphere. Since the interplanetary anisotropy evolves itself during a geomagnetic storm in addition to the reconfiguration of external magnetospheric currents, it is expected that changes in transmissivity of cosmic rays of galactic origin will occur during Geomagnetic storms. In this study we examine sixty-three (63) FD events and associated geomagnetic storms over the last three solar cycles from 1970 to 2013. The negative peaks of the FDs and the Dst coincided for most of the events (~70%). There was good correlation (>0.67) between the FDs and Dst. Signatures of influence of external magnetospheric currents on the count rates of the neutron monitors stations during periods of Forbush decreases (FDs) is provided. This evidence is observed as sudden increases in the count rates during the main phase of simultaneous FD. The magnitude of the sudden rise in the count rates of Neutron monitors and peak dst correlated well (>0.50) both for high latitude and mid latitude stations.

  20. Improved Measurement of Ejection Velocities From Craters Formed in Sand

    Science.gov (United States)

    Cintala, Mark J.; Byers, Terry; Cardenas, Francisco; Montes, Roland; Potter, Elliot E.

    2014-01-01

    A typical impact crater is formed by two major processes: compression of the target (essentially equivalent to a footprint in soil) and ejection of material. The Ejection-Velocity Measurement System (EVMS) in the Experimental Impact Laboratory has been used to study ejection velocities from impact craters formed in sand since the late 1990s. The original system used an early-generation Charge-Coupled Device (CCD) camera; custom-written software; and a complex, multicomponent optical system to direct laser light for illumination. Unfortunately, the electronic equipment was overtaken by age, and the software became obsolete in light of improved computer hardware.

  1. External ionization mechanisms for advanced thermionic converters

    Science.gov (United States)

    Hatziprokopiou, M. E.

    Ion generation and recombination mechanisms in the cesium plasma were investigated as they pertain to the advanced mode thermionic energy converters. The changes in plasma density and temperature within the converter were studied under the influence of several promising auxiliary ionization candidate sources. Three novel approaches of external cesium ion generation were investigated in some detail, namely vibrationally excited N2 as an energy source of ionization of Cs ions in a DC discharge, microwave power as a means of resonant sustenance of the cesium plasma, and ion generation in a pulse N2-Cs mixture. The experimental data obtained and discussed in this work show that all three techniques--i.e. the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave power--have considerable promise as schemes in auxiliary ion generation applicable to the advanced thermionic energy converter.

  2. Stealthy but Geoeffective Coronal Mass Ejections

    Science.gov (United States)

    Nitta, Nariaki; Mulligan, Tamitha

    2017-08-01

    We have long known about the existence of "problem" geomagnetic storms whose origins are elusive. In more general terms, not all the 1 AU disturbances can be clearly attributed to coronal mass ejections (CMEs), high speed streams (HSSs) or corotation interaction regions (CIRs.) When interplanetary CME (ICME) signatures are found in in situ data, there is not always a flare or filament eruption on the Sun or even an obvious CME observed close to the Sun that correlates with the ICME within a reasonable time range. These ICMEs sometimes result in intense storms. Furthermore, there is a possibility that some of the more severe storms could be partly contributed by such ICMEs of unclear origin. Therefore space weather prediction will remain incomplete without properly understanding these ICMEs. Even if the ICME is paired with a CME, it is sometimes difficult to find where the latter comes from. This is often called the “stealth CME” that apparently lacks low coronal signatures (LCSs). STEREO's second and third view points have tremendously helped us determine its front-side origin and find when and where it forms and accelerates, which is important for isolating possible LCSs. Although SDO/AIA has been continuously taking full-disk EUV images in a wide temperature range since 2010, there are still a number of stealthy CMEs whose LCSs are unclear or ambiguous. It is assumed that they start at high altitudes, leaving weak or negligible LCSs. Some of them seem to involve multiple magnetic domains, and weak or open field regions. We present AIA observations of several stealthy CMEs, including recent ones, that were responsible for geomagnetic storms, emphasizing the need to compare images with long time differences and to find the periods at which the CME forms and accelerates. We also discuss uncertainties in interpreting in situ data as to whether a CME is present when data are dominated by other solar wind features, such as HSS and CIR.

  3. Forecasting Coronal Mass Ejections from Vector Magnetograms

    Science.gov (United States)

    Falconer, D. A.; Moore, R. L.; Gary, G. A.; Six, N. Frank (Technical Monitor)

    2002-01-01

    In a 17 vector magnetogram study of 12 bipolar active regions (Falconer, Moore, & Gary, 2002, ApJ in press), we correlated four quantitative global magnetic measures with the Coronal Mass Ejections (CME) productivity of the active region. The global measures included a measure of active region size, the total magnetic flux phi and three measures of an active region global nonpotentiality 1) the net current (I (sub N)), 2) the length of the strong-shear, strong-field main neutral line (L(sub SS)) and 3) and the normalized twist (alpha = muIN/PHI). The CME productivity was determined from YOHKOH/SXT observations, Geostationary Operational Environmental Satellite (GOES), and when possible Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph Experiment (SOHO/LASCO) observations within 12 days of the day of the magnetogram. We found that the three measures of global nonpotentiality (I(sub N), L(sub SS), alpha) were all well correlated (greater than 99% confidence level) with an active region's CME productivity. The sample size was to small to confirm if there was a statistical significant correlation of the globally nonscientist measures with future CME activity (i.e. from the date of the magnetogram forward). We are doubling our sample, and will report on the statistical significance of global nonpotentiality as a predictor of future CME productivity. The new active regions are all from the first year of the upgraded MSFC vector magnetograms. This work, is funded by NSF through the Space Weather Program, by NASA through the Living with the Star, Targeted Research and Technology, and by NASA Solar Physics Supporting Research and Technology Program. The upgrade to the MSFC vector magnetograph was supported by the High Energy Solar Spectroscopic Imager (HESSI) mission.

  4. Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?

    CERN Document Server

    Cloutier, Ryan; Valencia, Diana

    2015-01-01

    Models of the dynamical evolution of the early solar system following the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant mass, which gets ejected by a gas giant during the early solar system's proposed instability phase. We investigate the likelihood of an ice giant ejection event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus respectively. We show that planetary encounters that are sufficient to eject an ice giant, often provide excessive perturbations to the orbits of Callisto and Iapetus making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite ...

  5. Anticipating the Geoeffectiveness of Coronal Mass Ejections Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Coronal Mass Ejections (CMEs) are responsible for some of the most severe space weather at Earth. Major geomagnetic storms arise when CMEs carry large amounts of...

  6. "Paradoxical" reduction in postexercise ejection time and increased transthoracic impedance.

    Science.gov (United States)

    Nakamura, Y; Kotilainen, P; Haffty, B; Jolda, R; Bishop, R; Spodick, D

    1978-12-01

    Despite decreasing heart rate, left ventricular ejection time (LVET) transiently falls immediately following bicycle exercise. In seven normal, untrained subjects LVET decreases at 15 s postexercise corresponded (r = 0.78) with an increase in transthoracic electrical impedance (Z) consistent with decreased venous return to the thorax. Because the determinants of LVET are stroke volume (SV) and ejection rate, the deltaZ implies that decreased SV contributed to the "paradoxical" fall in LVET.

  7. Animal models of heart failure with preserved ejection fraction

    OpenAIRE

    Conceição, G.; Heinonen, I.; Lourenço, A. P.; Duncker, D. J.; Falcão-Pires, I.

    2016-01-01

    Heart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function is impaired. Although it now represents over 50 % of all patients with heart failure, the mechanisms of HFpEF remain understood, precluding effective therapy. Understanding the pathophysiology of HFpEF has be...

  8. The External Degree.

    Science.gov (United States)

    Houle, Cyril O.

    This book examines the external degree in relation to the extremes of attitudes, myths, and data. Emphasis is placed on the emergence of the American external degree, foreign external-degree programs, the purpose of the external degree, the current scene, institutional issues, and problems of general policy. (MJM)

  9. Chromospheric Plasma Ejections in a Light Bridge of a Sunspot

    Science.gov (United States)

    Song, Donguk; Chae, Jongchul; Yurchyshyn, Vasyl; Lim, Eun-Kyung; Cho, Kyung-Suk; Yang, Heesu; Cho, Kyuhyoun; Kwak, Hannah

    2017-02-01

    It is well-known that light bridges (LBs) inside a sunspot produce small-scale plasma ejections and transient brightenings in the chromosphere, but the nature and origin of such phenomena are still unclear. Utilizing the high-spatial and high-temporal resolution spectral data taken with the Fast Imaging Solar Spectrograph and the TiO 7057 Å broadband filter images installed at the 1.6 m New Solar Telescope of Big Bear Solar Observatory, we report arcsecond-scale chromospheric plasma ejections (1.″7) inside a LB. Interestingly, the ejections are found to be a manifestation of upwardly propagating shock waves as evidenced by the sawtooth patterns seen in the temporal-spectral plots of the Ca ii 8542 Å and Hα intensities. We also found a fine-scale photospheric pattern (1″) diverging with a speed of about 2 km s‑1 two minutes before the plasma ejections, which seems to be a manifestation of magnetic flux emergence. As a response to the plasma ejections, the corona displayed small-scale transient brightenings. Based on our findings, we suggest that the shock waves can be excited by the local disturbance caused by magnetic reconnection between the emerging flux inside the LB and the adjacent umbral magnetic field. The disturbance generates slow-mode waves, which soon develop into shock waves, and manifest themselves as the arcsecond-scale plasma ejections. It also appears that the dissipation of mechanical energy in the shock waves can heat the local corona.

  10. An Experimental Investigation of Vibration-Induced Single Droplet Ejection.

    Science.gov (United States)

    Range, Kai; Smith, Marc K.; Glezer, Ari

    1998-11-01

    Vibration-induced droplet atomization occurs when small secondary droplets are ejected from the free surface of a larger droplet placed on a vibrating membrane. To model a single ejection event, a liquid droplet is placed on a small piston and vibrated using an electromagnetic driver. The droplet oscillates in a characteristic mode shape that depends on the driving frequency and amplitude, the properties of the liquid, and the size of the droplet. When the excitation amplitude is large enough, a small secondary droplet is ejected from the primary droplet. Observations of this process using high-speed digital video imaging show that droplet ejection occurs when a small liquid column or jet appears on the primary droplet and a secondary droplet forms on the column by a capillary-pinching mechanism. The liquid column or jet emanates from a crater in the primary droplet. As the driving frequency increases, this crater becomes smaller and the diameter of the ejected droplet decreases. We shall present results showing how the ejected droplet diameter and speed depends on the driving frequency and amplitude, the liquid properties, and the primary droplet volume.

  11. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline Rose

    2017-05-01

    Coronal mass ejections (CMEs) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many M dwarfs. Theoretical predictions of such effects are limited by the lack of observations of stellar CMEs. This thesis addresses this gap through a search for the spectral and spatial radio signatures of CMEs on active M dwarfs. Solar CMEs produce radio bursts with a distinctive spectral signature, narrow-band plasma emission that drifts to lower frequency as a CME expands outward. To search for analogous events on nearby stars, I worked on system design, software, and commissioning for the Starburst project, a wideband single-baseline radio interferometry backend dedicated to stellar observations. In addition, I led a survey of nearby active M dwarfs with the Karl G. Jansky Very Large Array (VLA), detecting coherent radio bursts in 13 out of 23 epochs, over a total of 58 hours. This survey's ultra-wide bandwidth (0.23-6.0 GHz) dynamic spectroscopy, unprecedented for stellar observations, revealed diverse behavior in the time-frequency plane. Flare star UV Ceti produced complex, luminous events reminiscent of brown dwarf aurorae; AD Leo sustained long-duration, intense, narrow-band "storms"; and YZ CMi emitted a burst with substructure with rapid frequency drift, resembling solar Type III bursts, which are attributed to electrons moving at speeds of order 10% of the speed of light. To search for the spatial signature of CMEs, I led 8.5-GHz observations with the Very Long Baseline Array simultaneous to 24 hours of the VLA survey. This program detected non-thermal continuum emission from the stars in all epochs, as well as continuum flares on AD Leo and coherent bursts on UV Ceti, enabling measurement of the spatial offset between flaring and quiescent emission. These observations demonstrate the diversity of stellar transients that can be expected in time-domain radio surveys, especially

  12. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline; Hallinan, Gregg; Monroe, Ryan; Bourke, Stephen; Starburst Program Team

    2017-01-01

    Coronal mass ejections (CMEs) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many M dwarfs. Theoretical predictions of such effects are limited by the lack of observations of stellar CMEs. My thesis addresses this gap through a search for the spectral and spatial radio signatures of CMEs on active M dwarfs.Solar CMEs produce radio bursts with a distinctive spectral signature, narrow-band plasma emission that drifts to lower frequency as a CME expands outward. To search for analogous events on nearby stars, I worked on system design, software, and commissioning for the Starburst project, a wideband single-baseline radio interferometry backend dedicated to stellar observations. In addition, I led a survey of nearby active M dwarfs with the Karl G. Jansky Very Large Array (JVLA), detecting 12 bright (>10 mJy) radio bursts in 58 hours. This survey’s ultra-wide bandwidth (0.23-6.0 GHz) dynamic spectroscopy, unprecedented for stellar observations, revealed diverse behavior in the time-frequency plane. Flare star UV Ceti produced complex, luminous events reminiscent of brown dwarf aurorae; AD Leo sustained long-duration, intense, narrow-band "storms"; and YZ CMi emitted a burst with substructure with rapid frequency drift, resembling solar Type III bursts, which are attributed to electrons moving at speeds of order 10% of the speed of light.To search for the spatial signature of CMEs, I led 8.5-GHz observations with the Very Long Baseline Array simultaneous to 24 hours of the JVLA survey. This program detected non-thermal continuum emission from the stars in all epochs, as well as continuum flares on AD Leo and coherent bursts on UV Ceti, enabling measurement of the spatial offset between flaring and quiescent emission.These observations demonstrate the diversity of stellar transients that can be expected in time-domain radio surveys, especially with the advent of large low

  13. Microfabricated ion frequency standard

    Science.gov (United States)

    Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.

    2010-12-28

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  14. Characterizing the original ejection velocity field of the Koronis family

    Science.gov (United States)

    Carruba, V.; Nesvorný, D.; Aljbaae, S.

    2016-06-01

    An asteroid family forms as a result of a collision between an impactor and a parent body. The fragments with ejection speeds higher than the escape velocity from the parent body can escape its gravitational pull. The cloud of escaping debris can be identified by the proximity of orbits in proper element, or frequency, domains. Obtaining estimates of the original ejection speed can provide valuable constraints on the physical processes occurring during collision, and used to calibrate impact simulations. Unfortunately, proper elements of asteroids families are modified by gravitational and non-gravitational effects, such as resonant dynamics, encounters with massive bodies, and the Yarkovsky effect, such that information on the original ejection speeds is often lost, especially for older, more evolved families. It has been recently suggested that the distribution in proper inclination of the Koronis family may have not been significantly perturbed by local dynamics, and that information on the component of the ejection velocity that is perpendicular to the orbital plane (vW), may still be available, at least in part. In this work we estimate the magnitude of the original ejection velocity speeds of Koronis members using the observed distribution in proper eccentricity and inclination, and accounting for the spread caused by dynamical effects. Our results show that (i) the spread in the original ejection speeds is, to within a 15% error, inversely proportional to the fragment size, and (ii) the minimum ejection velocity is of the order of 50 m/s, with larger values possible depending on the orbital configuration at the break-up.

  15. Regulating multiple externalities

    DEFF Research Database (Denmark)

    Waldo, Staffan; Jensen, Frank; Nielsen, Max

    2016-01-01

    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  16. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  17. Peristaltic ion source

    Energy Technology Data Exchange (ETDEWEB)

    Brown, I.G.; Anders, A.; Anders, S.; Dickinson, M.R.; MacGill, R.A.

    1995-08-01

    Conventional ion sources generate energetic ion beams by accelerating the plasma-produced ions through a voltage drop at the extractor, and since it is usual that the ion beam is to propagate in a space which is at ground potential, the plasma source is biased at extractor voltage. For high ion beam energy the plasma source and electrical systems need to be raised to high voltage, a task that adds considerable complexity and expense to the total ion source system. The authors have developed a system which though forming energetic ion beams at ground potential as usual, operates with the plasma source and electronics at ground potential also. Plasma produced by a nearby source streams into a grided chamber that is repetitively pulsed from ground to high positive potential, sequentially accepting plasma into its interior region and ejecting it energetically. They call the device a peristaltic ion source. In preliminary tests they`ve produced nitrogen and titanium ion beams at energies from 1 to 40 keV. Here they describe the philosophy behind the approach, the test embodiment that they have made, and some preliminary results.

  18. Failure and Ejection Behavior of Concrete Materials under Internal Blast

    Directory of Open Access Journals (Sweden)

    Haifu Wang

    2016-01-01

    Full Text Available In order to investigate the failure and ejection behavior of concrete materials under internal blast, the default Riedel-Hiermaier-Thoma (RHT concrete model in AUTODYN and a meshfree processor called SPH are employed in this numerical simulation. It is shown that the failure mechanisms are significantly different in these damaged zones. Crushed zone is caused by shear failure while fractured zone is induced by tensile failure, and spalled zone is formed by a combination of shear and tensile failure. In addition, the ejection velocity distribution of the fragmented concrete mass on free surface is examined. The results indicate that the ejection velocity declines monotonously with the increase of the distance to symmetry axis of computational model. On the wall of the prefabricated borehole, two types of fragmented concrete mass are analyzed, and bottom initiation is recommended to eject the fragmented concrete mass effectively. Moreover, an algorithm of average ejection speed is developed to effectively estimate the drill capacity of high velocity, energetic (HE projectiles. At last, the validity of numerical simulation is verified by physical experiments.

  19. Analysis of melt ejection during long pulsed laser drilling

    Science.gov (United States)

    Ting-Zhong, Zhang; Zhi-Chao, Jia; Hai-Chao, Cui; De-Hua, Zhu; Xiao-Wu, Ni; Jian, Lu

    2016-05-01

    In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations based on 304 stainless steel and aluminum targets are performed to study the effects of material parameters on melt ejection. The numerical method is employed to predict the temperatures, velocity fields in the solid, liquid, and vapour front, and melt pool dynamics of targets as well. The experimental methods include the shadow-graphic technique, weight method, and optical microscope imaging, which are applied to real-time observations of melt ejection phenomena, measurements of collected melt and changes of target mass, observations of surface morphology and the cross-section of the keyhole, respectively. Numerical and experimental results show that the metallic material with high thermal diffusivity like aluminum is prone to have a thick liquid zone and a large quantity of melt ejection. Additionally, to the best of our knowledge, the liquid zone is used to illustrate the relations between melt ejection and material thermal diffusivity for the first time. The research result in this paper is useful for manufacturing optimization and quality control in laser-material interaction. Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. KYLX_0341) and the National Natural Science Foundation of China (Grant No. 61405147).

  20. Hypervelocity intracluster stars ejected by supermassive black hole binaries

    CERN Document Server

    Holley-Bockelmann, K; Mihos, J C; Feldmeier, J J; Ciardullo, R; McBride, C; Holley-Bockelmann, Kelly; Sigurdsson, Steinn; Feldmeier, John J.; Ciardullo, Robin; Bride, Cameron Mc

    2005-01-01

    Hypervelocity stars have been recently discovered in the outskirts of galaxies, such as the unbound star in the Milky Way halo, or the three anomalously fast intracluster planetary nebulae (ICPNe) in the Virgo Cluster. These may have been ejected by close 3-body interactions with a binary supermassive black hole (SMBBH), where a star which passes within the semimajor axis of the SMBBH can receive enough energy to eject it from the system. Stars ejected by SMBBHs may form a significant sub-population with very different kinematics and mean metallicity than the bulk of the intracluster stars. The number, kinematics, and orientation of the ejected stars may constrain the mass ratio, semimajor axis, and even the orbital plane of the SMBBH. We investigate the evolution of the ejected debris from a SMBBH within a clumpy and time-dependent cluster potential using a high resolution, self-consistent cosmological N-body simulation of a galaxy cluster. We show that the predicted number and kinematic signature of the fas...

  1. Ejection of gaseous clumps from gravitationally unstable protostellar disks

    CERN Document Server

    Vorobyov, Eduard I

    2016-01-01

    We investigate the dynamics of gaseous clumps formed via gravitational fragmentation in young protostellar disks, focusing on the fragments that are ejected from the disk via many-body gravitational interaction. Numerical hydrodynamics simulations were employed to study the evolution of young protostellar disks formed from the collapse of rotating pre-stellar cores with mass in the 1.1-1.6 M_sun range. Protostellar disks formed in our models undergo gravitational fragmentation driven by continuing mass loading from parental collapsing cores. A few fragments can be ejected from the disk during the early evolution, but the low-mass fragments (< 15~M_Jup) disperse creating spectacular bow-type structures while passing through the disk and collapsing core. The least massive fragment that survived the ejection (21 M_Jup) straddles the planetary-mass limit, while the most massive ejected fragments (145 M_Jup) can break up into several pieces, leading to the ejection of wide separation binary clumps in the brown-...

  2. ASH External Web Portal (External Portal) -

    Data.gov (United States)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  3. Capstan friction model for DNA ejection from bacteriophages

    Science.gov (United States)

    Ghosal, Sandip

    2013-01-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell. The phage DNA is then transcribed by the cell’s transcription machinery. A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection. In recent in vitro experiments, the speed of DNA translocation from a λ phage capsid has been measured as a function of ejected length over the entire duration of the event. Here a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid. PMID:23368388

  4. Constraints on the original ejection velocity fields of asteroid families

    CERN Document Server

    Carruba, Valerio

    2016-01-01

    Asteroid families form as a result of large-scale collisions among main belt asteroids. The orbital distribution of fragments after a family-forming impact could inform us about their ejection velocities. Unfortunately, however, orbits dynamically evolve by a number of effects, including the Yarkovsky drift, chaotic diffusion, and gravitational encounters with massive asteroids, such that it is difficult to infer the ejection velocities eons after each family's formation. Here we analyze the inclination distribution of asteroid families, because proper inclination can remain constant over long time intervals, and could help us to understand the distribution of the component of the ejection velocity that is perpendicular to the orbital plane ($v_{W}$). From modeling the initial breakup, we find that the distribution of $v_{W}$ of the fragments, which manage to escape the parent body's gravity, should be more peaked than a Gaussian distribution (i.e., be leptokurtic) even if the initial distribution was Gaussia...

  5. Characterizing the original ejection velocity field of the Koronis family

    CERN Document Server

    Carruba, Valerio; Aljbaae, Safwan

    2016-01-01

    An asteroid family forms as a result of a collision between an impactor and a parent body. The fragments with ejection speeds higher than the escape velocity from the parent body can escape its gravitational pull. The cloud of escaping debris can be identified by the proximity of orbits in proper element, or frequency, domains. Obtaining estimates of the original ejection speed can provide valuable constraints on the physical processes occurring during collision, and used to calibrate impact simulations. Unfortunately, proper elements of asteroids families are modified by gravitational and non-gravitational effects, such as resonant dynamics, encounters with massive bodies, and the Yarkovsky effect, such that information on the original ejection speeds is often lost, especially for older, more evolved families. It has been recently suggested that the distribution in proper inclination of the Koronis family may have not been significantly perturbed by local dynamics, and that information on the component of th...

  6. Capstan Friction Model for DNA Ejection from Bacteriophages

    Science.gov (United States)

    Ghosal, Sandip

    2012-12-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell. The phage DNA is then transcribed by the cell’s transcription machinery. A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection. In recent in vitro experiments, the speed of DNA translocation from a λ phage capsid has been measured as a function of ejected length over the entire duration of the event. Here, a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid.

  7. Fluctuation Pressure Assisted Ejection of DNA From Bacteriophage

    CERN Document Server

    Harrison, Michael J

    2010-01-01

    The role of thermal pressure fluctuation excited within tightly packaged DNA prior to ejection from protein capsid shells is discussed in a model calculation. At equilibrium before ejection we assume the DNA is folded many times into a bundle of parallel segments that forms an equilibrium conformation at minimum free energy, which presses tightly against internal capsid walls. Using a canonical ensemble at temperature T we calculate internal pressure fluctuations against a slowly moving or static capsid mantle for an elastic continuum model of the folded DNA bundle. It is found that fluctuating pressure on the capsid internal wall from thermal excitation of longitudinal acoustic vibrations in the bundle may have root-mean-square values which are several tens of atmospheres for typically small phage dimensions. Comparisons are given with measured data on three mutants of lambda phage with different base pair lengths and total genome ejection pressures.

  8. Capstan friction model for DNA ejection from bacteriophages

    CERN Document Server

    Ghosal, Sandip

    2013-01-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell.The phage DNA is then transcribed by the cell's transcription machinery.A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection.In recent in vitro experiments, the speed of DNA translocation from a lambda phage capsid has been measured as a function of ejected length over the entire duration of the event.Here a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid.

  9. Stoichiometric relationship between energy-dependent proton ejection and electron transport in mitochondria.

    Science.gov (United States)

    Brand, M D; Reynafarje, B; Lehninger, A L

    1976-02-01

    The number of protons ejected during electron transport per pair of electrons per energy-conserving site (the H+/site ratio) was measured in rat liver mitochondria by three different methods under conditions in which transmembrane movements of endogenous phosphate were minized or eliminated. (1) In the Ca2+ pulse method, between 3.5 and 4.0 molecules of 3-hydroxybutyrate and 1.75 to 2.0 Ca2+ ions were accumulated per 2 e- per site during Ca2+ induced electron transport in the presence of rotenone, when measured under conditions in which movements of endogenous phosphate were negligible. Since entry of 3-hydroxybutyrate requires its protonation to the free acid these data correspond to an H+/site ratio of 3.5-4.0 (2) In the oxygen pulse method addition of known amounts of oxygen to anaerobic mitochondria in the presence of substrate yielded H+/site ratios of 3.0 when phosphate transport was eliminated by addition of N-ethylmaleimide or by anaerobic washing to remove endogenous phosphate. In the absence of such measures the observed H+/site ratio was 2.0. (3) In the reductant pulse method measurement of the initial steady rates of H+ ejection and oxygen consumption by mitochondria in an aerobic medium after addition of substrate gave H+/site near 4.0 in the presence of N-ethylmaleimide; in the absence of the inhibitor the observed ratio was only 2.0. These and other experiments reported indicate that the values of 2.0 earlier obtained for the H+/site ratio by Mitchell and Moyle [Biochem J. (1967) 105, 1147-1162] and others were underestimates due to the unrecognized masking of H+ ejection by movements of endogenous phosphate. The results presented here show that the H+/site ratio of mitochondrial electron transport is at least 3.0 and may be as high as 4.0.

  10. The interplanetary mass ejections behaviour in the heliosphere

    CERN Document Server

    Dumitrache, Cristiana

    2014-01-01

    We present here an overview of an important solar phenomenon with major implication for space weather and planetary life. The coronal mass ejections (CMEs) come from the Sun and expand in the heliosphere, becoming interplanetary coronal mass ejections (ICMEs). They represent huge clouds of plasma and magnetic fields that travel with velocities reaching even 2000 km/s and perturbing the planetary and interplanetary field. The magnetic clouds (MC) are a special class of ICMEs. We summarize some aspects as the ICMEs identification, propagation and track back to the Sun, where the solar source could be found. We notice here few known catalogs of the ICMEs and magnetic clouds.

  11. The beam diagnostic system, serving the Serpukhov fast ejection

    CERN Document Server

    Cupérus, J; Kamber, I; Nuttall, J

    1973-01-01

    A set of beam transformers measures the intensity of each bunch, circulating or ejected. Five electrostatic pick-ups measure the radial position of one selected bunch. Secondary emission grids and luminescent screens give the profile and position of the beam at relevant points. Gated radiation detectors monitor beam loss in the ejection area. All signals are digitalized and fed to a minicomputer on line. Readout is via nixies, CRT analogue displays, pen recorders and a teletype. Statistics can be made over a chosen number of acceleration cycles. (5 refs).

  12. Development of a Backpack Survival Kit for Ejection Seats.

    Science.gov (United States)

    1982-02-08

    7 AD-A113 653 NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT -ETC F/6 6/7 DEVELOP04ENT OF A BACKPACK SURVIVAL KIT FOR EJECTION SEATS. (U) FEB...82 T J ZENOBI, 6 F WHITMAN UNCLASSIFIED NADC 22216 NL EEEEEE -EuJ REPORT NO. NADC-82024.60 DEVELOPMENT OF A BACKPACK SURVIVAL KIT FOR EJECTION SEATS...RECIPIENT’S CATALOG NUMBER NADC-82024-60 - I" J 4. TITLE (and Subtitle) S. TYPE OF REPORT A PERIOD COVERED Development of a Backpack Survival Kit Phase Report

  13. Diagnosis of heart failure with preserved ejection fraction.

    Science.gov (United States)

    Wachter, Rolf; Edelmann, Frank

    2014-07-01

    Heart failure with preserved ejection fraction (HFpEF) constitutes a growing health care burden worldwide. Although definitions vary somewhat among guidelines, in general the presence of typical heart failure symptoms and signs in combination with a preserved left ventricular ejection fraction (≥50%) and functional and/or structural left ventricular changes makes the diagnosis likely. This review focuses on the current understanding of diagnostic criteria, as presented in current guidelines and consensus recommendations, and on new insights from recent papers. The role of comorbidities that often contribute to symptoms and hamper the HFpEF diagnostics is also reviewed.

  14. Characterization of Boulders Ejected from Small Impact Craters

    NARCIS (Netherlands)

    Bart, G.D.; Melosh, H.J.; Strom, R.G.

    2004-01-01

    When an asteroid or comet impacts the surface of a solid body, some of the surface material is often ejected from the crater in the form of blocks. We are characterizing the size and location of such blocks around craters on the Moon and Mars. The lunar craters were observed in Lunar Orbiter III ima

  15. 78 FR 55137 - Federal Motor Vehicle Safety Standards; Ejection Mitigation

    Science.gov (United States)

    2013-09-09

    ... Part 571 Federal Motor Vehicle Safety Standards; Ejection Mitigation; Final Rule #0;#0;Federal Register... TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL40 Federal Motor Vehicle... document responds to petitions for reconsideration of a 2011 final rule that established Federal...

  16. Certain optimal parameters of high-velocity Venturi ejection tubes

    Science.gov (United States)

    Stark, S. B.; Reznichenko, I. G.; Pavlenko, Y. P.

    1984-11-01

    The influence of the geometrical characteristics of centrifugal nozzles in high velocity Venturi ejection tubes for atomizing liquid in gas cleaning plant is analyzed. An optimal value of the nozzle geometrical characteristic, which is a function of the degree of filling of the nozzle outlet opening by the liquid, is given, at which the throat length is independent of water pressure before the nozzle.

  17. Galectin-3 in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    de Boer, Rudolf A.; Edelmann, Frank; Cohen-Solal, Alain; Mamas, Mamas A.; Maisel, Alan; Pieske, Burkert

    2013-01-01

    In the last decades it has been appreciated that many patients with heart failure (HF) suffer from HF with preserved ejection fraction (HFpEF). The diagnosis and treatment of HFpEF is difficult, as we lack specific markers of the disease and no specific treatments have been identified. Galectin-3 ha

  18. Characterization of Boulders Ejected from Small Impact Craters

    NARCIS (Netherlands)

    Bart, G.D.; Melosh, H.J.; Strom, R.G.

    2004-01-01

    When an asteroid or comet impacts the surface of a solid body, some of the surface material is often ejected from the crater in the form of blocks. We are characterizing the size and location of such blocks around craters on the Moon and Mars. The lunar craters were observed in Lunar Orbiter III ima

  19. The physics of accretion-ejection with LOFT

    CERN Document Server

    Casella, P; Coriat, M; Kalemci, E; Motta, S; Neilsen, J; Ponti, G; Begelman, M; Belloni, T; Koerding, E; Maccarone, T J; Petrucci, P -O; Rodriguez, J; Tomsick, J; Bhattacharyya, S; Bianchi, S; Del Santo, M; Donnarumma, I; Gandhi, P; Homan, J; Jonker, P; Kalamkar, M; Malzac, J; Markoff, S; Migliari, S; Miller, J; Miller-Jones, J; Poutanen, J; Remillard, R; Russell, D M; Uttley, P; Zdziarski, A

    2015-01-01

    This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of the physics of accretion and ejection around compact objects. For a summary, we refer to the paper.

  20. A Filament-Associated Halo Coronal Mass Ejection

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    There are only a few observations published so far that show the initiation of a coronal mass ejection (CME) and illustrate the magnetic changes in the surface origin of a CME. Any attempt to connect a CME with its local solar activities is meaningful. In this paper we present a clear instance of a halo CME initiation. A careful analysis of magnetograms shows that the only obvious magnetic changes in the surface region of the CME is a magnetic flux cancellation underneath a quiescent filament. The early disturbance was seen as the slow upward motion in segments of the quiescent filament. Four hours later, the filament was accelerated to about 50 km s-1 and erupted. While a small part of the material in the filament was ejected into the upper corona, most of the mass was transported to a nearby region. About forty minutes later, the transported mass was also ejected partially to the upper corona. The eruption of the filament triggered a two-ribbon flare, with post-flare loops connecting the flare ribbons. A halo CME, which is inferred to be associated with the eruptive filament, was observed from LASCO/C2 and C3. The halo CME contained two CME events, each event corresponded to a partial mass ejection of the filament. We suggest that the magnetic reconnection at the lower atmosphere is responsible for the filament eruption and the halo CME.

  1. Experimental Investigation of the Dispersion of Liquids by Ejection Atomizers

    Science.gov (United States)

    Arkhipov, V. A.; Bondarchuk, S. S.; Evsevleev, M. Ya.; Zharova, I. K.; Zhukov, A. S.; Zmanovskii, S. V.; Kozlov, E. A.; Konovalenko, A. I.; Trofimov, V. F.

    2013-11-01

    This paper presents the results of an experimental investigation of the dispersivity of liquid droplets in the spray cone of ejection atomizers. The calculational droplet size distribution function was measured by the method of low angles of the probe laser radiation scattering indicatrix on a pneumohydraulic bench under cold blow conditions. The efficiency of the proposed circuit designs of atomizers has been analyzed.

  2. External radiation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  3. Ion optics of RHIC electron beam ion source

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Kuznetsov, G. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2012-02-15

    RHIC electron beam ion source has been commissioned to operate as a versatile ion source on RHIC injection facility supplying ion species from He to Au for Booster. Except for light gaseous elements RHIC EBIS employs ion injection from several external primary ion sources. With electrostatic optics fast switching from one ion species to another can be done on a pulse to pulse mode. The design of an ion optical structure and the results of simulations for different ion species are presented. In the choice of optical elements special attention was paid to spherical aberrations for high-current space charge dominated ion beams. The combination of a gridded lens and a magnet lens in LEBT provides flexibility of optical control for a wide range of ion species to satisfy acceptance parameters of RFQ. The results of ion transmission measurements are presented.

  4. Anomalous-plasmoid-ejection-induced secondary magnetic reconnection: modeling solar flares and coronal mass ejections by laser–plasma experiments

    Institute of Scientific and Technical Information of China (English)

    Quanli; Dong; Dawei; Yuan; Shoujun; Wang; Xun; Liu; Yutong; Li; Xiaoxuan; Lin; Huigang; Wei; Jiayong; Zhong; Shaoen; Jiang; Yongkun; Ding; Bobin; Jiang; Kai; Du; Yongjian; Tang; Mingyang; Yu; Xiantu; He; Neng; Hua; Zhanfeng; Qiao; Kuixi; Huang; Ming; Chen; Jianqiang; Zhu; Gang; Zhao; Zhengming; Sheng; Jie; Zhang

    2013-01-01

    The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings.In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense,and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.

  5. Angular distributions of very low energy recoil ions

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Lepera, C.E.; Breinig, M.; Burgdoerfer, J.; DeSerio, R.; Elston, S.B.; Gibbons, J.P.; Huelskoetter, H.P.; Liljeby, L.; Vane, C.R.; Sellin, I.A.

    1986-01-01

    We present the first measurements of the angular distribution of recoil ions near 90/sup 0/ with respect to the incident projectile direction. Beams of 22.5 and 33 MeV chlorine ions (incident charge states q =4,5,8) have been used as ''hammer'' beams incident on Ne atoms. We confirm the long standing assumption that these recoil ions are ejected preferentially at angles near 90/sup 0/ with respect to the primary beam direction and with energies typically less than 5 eV. Recoil ions ejected around 90/sup 0/ have an energy distribution appreciably wider than those ejected at either larger or smaller angles. 9 refs., 6 figs.

  6. Parallel Molecular Dynamics Simulations of Ejection from the Metal Cu and Al Under Shock Loading

    Institute of Scientific and Technical Information of China (English)

    CHEN Qi-Feng; CAO Xiao-Lin; ZHANG Ying; CAI Ling-Cang; CHEN Dong-Quan

    2005-01-01

    @@ Large-scale non-equilibrium molecular dynamics simulations are used to investigate the ejection of the metal under a shock loading. The present work focus on the dynamic process of ejection from the metal Cu and Al surface groove under shock loading, using parallel MD implementation and the Morse potential. The ejected mass coefficient and the size distribution of ejected particles (cluster for atoms) are investigated with changes of the half-angle or the depth of groove and shock strength.

  7. 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer: A National Resource for Ultrahigh Resolution Mass Analysis.

    Science.gov (United States)

    Hendrickson, Christopher L; Quinn, John P; Kaiser, Nathan K; Smith, Donald F; Blakney, Greg T; Chen, Tong; Marshall, Alan G; Weisbrod, Chad R; Beu, Steven C

    2015-09-01

    We describe the design and initial performance of the first 21 tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The 21 tesla magnet is the highest field superconducting magnet ever used for FT-ICR and features high spatial homogeneity, high temporal stability, and negligible liquid helium consumption. The instrument includes a commercial dual linear quadrupole trap front end that features high sensitivity, precise control of trapped ion number, and collisional and electron transfer dissociation. A third linear quadrupole trap offers high ion capacity and ejection efficiency, and rf quadrupole ion injection optics deliver ions to a novel dynamically harmonized ICR cell. Mass resolving power of 150,000 (m/Δm(50%)) is achieved for bovine serum albumin (66 kDa) for a 0.38 s detection period, and greater than 2,000,000 resolving power is achieved for a 12 s detection period. Externally calibrated broadband mass measurement accuracy is typically less than 150 ppb rms, with resolving power greater than 300,000 at m/z 400 for a 0.76 s detection period. Combined analysis of electron transfer and collisional dissociation spectra results in 68% sequence coverage for carbonic anhydrase. The instrument is part of the NSF High-Field FT-ICR User Facility and is available free of charge to qualified users.

  8. Deactivation in the rabbit left ventricle induced by constant ejection flow

    NARCIS (Netherlands)

    Wijkstra, Hessel; Boom, H.B.K.

    1989-01-01

    A study of pressure generated by the left ventricle after ejection with constant flow for different values of the ejection flow, flow duration, time of flow arrest, and ventricular volume is discussed. It was found that pressure after ejection, normalized with respect to isovolumic pressure, is

  9. Noncardiac Comorbidities in Heart Failure With Reduced Versus Preserved Ejection Fraction

    NARCIS (Netherlands)

    Mentz, Robert J.; Kelly, Jacob P.; von Lueder, Thomas G.; Voors, Adriaan A.; Lam, Carolyn S. P.; Cowie, Martin R.; Kjeldsen, Keld; Jankowska, Ewa A.; Atar, Dan; Butler, Javed; Fiuzat, Mona; Zannad, Faiez; Pitt, Bertram; O'Connor, Christopher M.

    2014-01-01

    Heart failure patients are classified by ejection fraction (EF) into distinct groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Although patients with heart failure commonly have multiple comorbidities that complicate management a

  10. Noncardiac Comorbidities in Heart Failure With Reduced Versus Preserved Ejection Fraction

    NARCIS (Netherlands)

    Mentz, Robert J.; Kelly, Jacob P.; von Lueder, Thomas G.; Voors, Adriaan A.; Lam, Carolyn S. P.; Cowie, Martin R.; Kjeldsen, Keld; Jankowska, Ewa A.; Atar, Dan; Butler, Javed; Fiuzat, Mona; Zannad, Faiez; Pitt, Bertram; O'Connor, Christopher M.

    2014-01-01

    Heart failure patients are classified by ejection fraction (EF) into distinct groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Although patients with heart failure commonly have multiple comorbidities that complicate management

  11. Deactivation in the rabbit left ventricle induced by constant ejection flow

    NARCIS (Netherlands)

    Wijkstra, Hessel; Boom, Herman B.K.

    1989-01-01

    A study of pressure generated by the left ventricle after ejection with constant flow for different values of the ejection flow, flow duration, time of flow arrest, and ventricular volume is discussed. It was found that pressure after ejection, normalized with respect to isovolumic pressure, is rege

  12. Coronal Mass Ejections and Non-recurrent Forbush Decreases

    Science.gov (United States)

    Belov, A.; Abunin, A.; Abunina, M.; Eroshenko, E.; Oleneva, V.; Yanke, V.; Papaioannou, A.; Mavromichalaki, H.; Gopalswamy, N.; Yashiro, S.

    2014-10-01

    Coronal mass ejections (CMEs) and their interplanetary counterparts (interplanetary coronal mass ejections, ICMEs) are responsible for large solar energetic particle events and severe geomagnetic storms. They can modulate the intensity of Galactic cosmic rays, resulting in non-recurrent Forbush decreases (FDs). We investigate the connection between CME manifestations and FDs. We used specially processed data from the worldwide neutron monitor network to pinpoint the characteristics of the recorded FDs together with CME-related data from the detailed online catalog based upon the Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) data. We report on the correlations of the FD magnitude to the CME initial speed, the ICME transit speed, and the maximum solar wind speed. Comparisons between the features of CMEs (mass, width, velocity) and the characteristics of FDs are also discussed. FD features for halo, partial halo, and non-halo CMEs are presented and discussed.

  13. Dynamics of bacteriophage genome ejection in vitro and in vivo

    Science.gov (United States)

    Panja, Debabrata; Molineux, Ian J.

    2010-12-01

    Bacteriophages, phages for short, are viruses of bacteria. The majority of phages contain a double-stranded DNA genome packaged in a capsid at a density of ~500 mg ml-1. This high density requires substantial compression of the normal B-form helix, leading to the conjecture that DNA in mature phage virions is under significant pressure, and that pressure is used to eject the DNA during infection. A large number of theoretical, computer simulation and in vitro experimental studies surrounding this conjecture have revealed many—though often isolated and/or contradictory—aspects of packaged DNA. This prompts us to present a unified view of the statistical physics and thermodynamics of DNA packaged in phage capsids. We argue that the DNA in a mature phage is in a (meta)stable state, wherein electrostatic self-repulsion is balanced by curvature stress due to confinement in the capsid. We show that in addition to the osmotic pressure associated with the packaged DNA and its counterions, there are four different pressures within the capsid: pressure on the DNA, hydrostatic pressure, the pressure experienced by the capsid and the pressure associated with the chemical potential of DNA ejection. Significantly, we analyze the mechanism of force transmission in the packaged DNA and demonstrate that the pressure on DNA is not important for ejection. We derive equations showing a strong hydrostatic pressure difference across the capsid shell. We propose that when a phage is triggered to eject by interaction with its receptor in vitro, the (thermodynamic) incentive of water molecules to enter the phage capsid flushes the DNA out of the capsid. In vivo, the difference between the osmotic pressures in the bacterial cell cytoplasm and the culture medium similarly results in a water flow that drags the DNA out of the capsid and into the bacterial cell.

  14. EUV and Coronagraphic Observations of Coronal Mass Ejections

    Indian Academy of Sciences (India)

    Durgesh Tripathi

    2006-06-01

    The Large Angle Spectrometric Coronagraph (LASCO) and Extreme-ultraviolet Imaging Telescope (EIT) onboard Solar and Heliospheric Observatory (SOHO) provide us with unprecedented multi-wavelength observations helping us to understand different dynamic phenomena on the Sun and in the corona. In this paper we discuss the association between post-eruptive arcades (PEAs) detected by EIT and white-light coronal mass ejections (CMEs) detected by LASCO/C2 telescope.

  15. Multinucleon Ejection Model for Two Body Current Neutrino Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sobczyk, Jan T.; /Fermilab

    2012-06-01

    A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.

  16. Characterization of Boulders Ejected from Small Impact Craters

    Science.gov (United States)

    Bart, G. D.; Melosh, H. J.; Strom, R. G.

    2004-11-01

    When an asteroid or comet impacts the surface of a solid body, some of the surface material is often ejected from the crater in the form of blocks. We are characterizing the size and location of such blocks around craters on the Moon and Mars. The lunar craters were observed in Lunar Orbiter III images from P-12 and S-18. The Mars crater was observed in Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) Release No. MOC2-712. The craters range in size from 300 m to 3 km diameter. We measured the diameters of boulders observed around the craters, and also measured the distance between the boulder and the crater center. We then calculate the ejection velocity of each boulder based on how far the block was from the crater. The data indicate that larger boulders are more frequently found close to the crater rim rather than far away. The size of the ejecta drops off as a power law with distance from the crater. Our results are consistent with studies by Vickery (1986, 1987), which indirectly found the distribution of ejecta sizes from large craters by analyzing the size and distribution of their secondary craters. Our work characterizes the other end of the ejecta spectrum --- low velocity boulders ejected from small craters. We have also constructed R-plots of the boulder diameters for each crater. We found that the R-plot for the boulders has a dependence remarkably similar to an R-plot of the diameters of secondary craters. This similarity supports the already accepted idea that the impactors that produce secondaries are blocks ejected from larger craters. It is also consistent with the interpretation that the upturn of the cratering curve at small diameters on the terrestrial planets is due to secondary impacts rather than a primary population as some have proposed.

  17. Phenotypic Spectrum of Heart Failure with Preserved Ejection Fraction

    OpenAIRE

    Sanjiv J Shah; Katz, Daniel H.; Rahul C Deo

    2014-01-01

    Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome, with several underlying etiologic and pathophysiologic factors. While prior heart failure clinical trials have used a “one size fits all” approach, this approach has not proven successful for HFpEF. Furthermore, with the aging population and epidemics of obesity, diabetes, and hypertension, the prevalence of HFpEF will continue to grow over the foreseeable future. Coupled with the high morbidity and mortality ...

  18. The Emerging Epidemic of Heart Failure with Preserved Ejection Fraction

    OpenAIRE

    Oktay, A. Afşin; Rich, Jonathan D.; Sanjiv J Shah

    2013-01-01

    Heart failure with preserved ejection fraction (HFpEF), which currently represents approximately 50 % of heart failure (HF) cases, is common and associated with high morbidity and mortality. Understanding the epidemiology of HFpEF has been difficult due to the challenges in HFpEF diagnosis and the heterogeneous etiologies and pathophysiologies that underlie HFpEF. Nevertheless, several high-quality epidemiology and observational registry studies of HFpEF demonstrate that an increasing prevale...

  19. Survivability rate among pilots in case of ejection

    Directory of Open Access Journals (Sweden)

    Alexandru GHEORGHIU

    2015-06-01

    Full Text Available The current paper presents a statistical analysis of a recent research made by the author [1], showing the factors causing the accidents that happened in Romanian Air Force from 1952 to 2014. Also the decision of ejection is analyzed. The study contains 225 events: 110 catastrophes and 115 accidents. 280 fighter pilots and 235 aircraft were involved in this analysis. The below information is a personal one and does not reflect an official position of the Ministry of National Defence.

  20. Mergers and ejections of black holes in globular clusters

    CERN Document Server

    Aarseth, Sverre

    2012-01-01

    We report on results of fully consistent N-body simulations of globular cluster models with N = 100 000 members containing neutron stars and black holes. Using the improved `algorithmic regularization' method of Hellstrom and Mikkola for compact subsystems, the new code NBODY7 enables for the first time general relativistic coalescence to be achieved for post-Newtonian terms and realistic parameters. Following an early stage of mass segregation, a few black holes form a small dense core which usually leads to the formation of one dominant binary. The subsequent evolution by dynamical shrinkage involves the competing processes of ejection and mergers by radiation energy loss. Unless the binary is ejected, long-lived triple systems often exhibit Kozai cycles with extremely high inner eccentricity (e > 0.999) which may terminate in coalescence at a few Schwarzschild radii. A characteristic feature is that ordinary stars as well as black holes and even BH binaries are ejected with high velocities. On the basis of...

  1. Episodic AGB Mass Ejection and the Creation of Fallback Shells

    CERN Document Server

    Chen, Zhuo; Blackman, Eric

    2015-01-01

    The short duration of mass ejection events during the Ascending Giant Branch (AGB) phase of stellar evolution can take different forms ranging thermal pulses to regular stellar pulsations. In most cases the shells ejected by the star are assumed to reach the escape velocity and expand into circumstellar space until they dissipate or merge with the surrounding gas. In this paper we investigate the case of an AGB star that emits a pulse of material below the escape velocity as may occur during a Common Envelope event. We explore the evolution of the shell created by this short mass loss event. We seek to determine when the shell falls back onto the star as opposed to being driven to escape velocity by the action of winds which occur after shell ejection. The problem is solved via 2.5D AMR AstroBEAR hydrodynamic simulations and a simplified one dimensional analytic model. We find that for given set of initial wind characteristics there is a critical shell velocity that distinguishes between shell fallback and sh...

  2. Droplet ejection and sliding on a flapping film

    Science.gov (United States)

    Chen, Xi; Doughramaji, Nicole; Betz, Amy Rachel; Derby, Melanie M.

    2017-03-01

    Water recovery and subsequent reuse are required for human consumption as well as industrial, and agriculture applications. Moist air streams, such as cooling tower plumes and fog, represent opportunities for water harvesting. In this work, we investigate a flapping mechanism to increase droplet shedding on thin, hydrophobic films for two vibrational cases (e.g., ± 9 mm and 11 Hz; ± 2 mm and 100 Hz). Two main mechanisms removed water droplets from the flapping film: vibrational-induced coalescence/sliding and droplet ejection from the surface. Vibrations mobilized droplets on the flapping film, increasing the probability of coalescence with neighboring droplets leading to faster droplet growth. Droplet departure sizes of 1-2 mm were observed for flapping films, compared to 3-4 mm on stationary films, which solely relied on gravity for droplet removal. Additionally, flapping films exhibited lower percentage area coverage by water after a few seconds. The second removal mechanism, droplet ejection was analyzed with respect to surface wave formation and inertia. Smaller droplets (e.g., 1-mm diameter) were ejected at a higher frequency which is associated with a higher acceleration. Kinetic energy of the water was the largest contributor to energy required to flap the film, and low energy inputs (i.e., 3.3 W/m2) were possible. Additionally, self-flapping films could enable novel water collection and condensation with minimal energy input.

  3. Pharmacotherapy of heart failure with preserved ejection fraction.

    Science.gov (United States)

    Basaraba, Jade E; Barry, Arden R

    2015-04-01

    Heart failure with preserved ejection fraction (HFpEF) constitutes ~50% of all heart failure diagnoses and is associated with considerable morbidity and mortality. The treatment of HFpEF can be challenging due to a lack of evidence supporting the benefit of various drug therapies. In practice, treatment can be divided into acute and chronic management. Acute therapy for decompensated heart failure is similar for both HFpEF and heart failure with reduced ejection fraction. The mainstay of treatment is diuretics to reduce volume overload and improve dyspnea. Patients with an acute exacerbation of HFpEF and rapid atrial fibrillation (AF) should be rate controlled with negative chronotropic agents. For chronic therapy, patients with HFpEF should not be treated like patients with heart failure with reduced ejection fraction. Chronic management of HFpEF can be simplified by using three strategies based on applicability: treat precipitating conditions (e.g., hypertension, AF), control symptoms by maintaining euvolemia with diuretics, and avoid therapies that have been shown not to be beneficial unless another compelling indication exists. Nondrug interventions for HFpEF include salt and fluid restriction, regular physical activity, and referral to a heart function clinic, if appropriate.

  4. Pathfinder landing sites at candidate SNC impact ejection sites

    Science.gov (United States)

    Golombek, Matthew P.

    1994-01-01

    If Mars Pathfinder were able to land at a site on Mars from which the SNC meteorites were ejected by impact, the Pathfinder mission would essentially represent a very inexpensive sample return mission. Geologic units that contain four potential impact craters from which SNC meteorites could have been ejected from Mars are accessible to the Mars Pathfinder lander. Determining that SNC meteorites came from a particular spot on Mars raises the intriguing possibility of using Pathfinder as a sample return mission and providing a radiometric age for the considerably uncertain martian crater-age timescale. Pathfinder instruments are capable of determining if the rock type at the landing site is similar to that of one or more of the SNC meteorites, which would strengthen the hypothesis that the SNC meteorites did, in fact, come from Mars. Unfortunately, instrument observations from Pathfinder are probably not capable of determining if the geologic unit sampled by the lander is definitively the unit from which a SNC meteorite came from as opposed to Mars in general or perhaps a particular region on Mars. This abstract evaluates the possibility of landing at potential SNC ejection sites and the ability of Pathfinder to identify the landing site as the place from which an SNC meteorite came.

  5. Ge and Ti post-ion acceleration from laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, L., E-mail: Lorenzo.Torrisi@unime.i [INFN-LNS di Catania, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica, Universita di Messina, Ctr. Papardo 31, 98166 S. Agata, Messina (Italy); Giuffrida, L. [INFN-LNS di Catania, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica, Universita di Messina, Ctr. Papardo 31, 98166 S. Agata, Messina (Italy); Rosinski, M. [Institute of Plasma Physics and Laser Microfusion, 23 Hery Str. 01-497 Warsaw (Poland); Schallhorn, C. [Department of Physics, University of California, Portola Plaza 430, 90095 Los Angeles, CA (United States)

    2010-09-15

    Laser ion sources (LIS) are employed with success to generate, in vacuum, Ge and Ti ion beams with high current, ion energy, charge states and directivity. Nanoseconds infrared laser pulses, with intensities of the order of 10{sup 10} W/cm{sup 2}, induce high ablation in Ge and Ti targets. Ions are produced in vacuum with energy distribution following the Coulomb-Boltzmann-shifted distribution and they are ejected mainly along the normal to the target surface. The free ion expansion process occurs in a constant-potential chamber placed at 30 kV positive voltage. An electric field of 5 kV/cm was used to accelerate the ions emitted from the plasma at INFN-LNS laser facility. Time-of-flight technique is employed to measure the mean ion energies of the post-accelerated particles. Ion charge states and energy distributions were measured through an ion energy spectrometer.

  6. Ge and Ti post-ion acceleration from laser ion source

    Science.gov (United States)

    Torrisi, L.; Giuffrida, L.; Rosinski, M.; Schallhorn, C.

    2010-09-01

    Laser ion sources (LIS) are employed with success to generate, in vacuum, Ge and Ti ion beams with high current, ion energy, charge states and directivity. Nanoseconds infrared laser pulses, with intensities of the order of 10 10 W/cm 2, induce high ablation in Ge and Ti targets. Ions are produced in vacuum with energy distribution following the Coulomb-Boltzmann-shifted distribution and they are ejected mainly along the normal to the target surface. The free ion expansion process occurs in a constant-potential chamber placed at 30 kV positive voltage. An electric field of 5 kV/cm was used to accelerate the ions emitted from the plasma at INFN-LNS laser facility. Time-of-flight technique is employed to measure the mean ion energies of the post-accelerated particles. Ion charge states and energy distributions were measured through an ion energy spectrometer.

  7. Externally Verifiable Oblivious RAM

    Directory of Open Access Journals (Sweden)

    Gancher Joshua

    2017-04-01

    Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

  8. External Beam Therapy (EBT)

    Science.gov (United States)

    ... Esophageal Cancer Treatment Head and Neck Cancer Treatment Lung Cancer Treatment Prostate Cancer Treatment Brain Tumor Treatment Why is ... Radiation Oncology) Breast Cancer Treatment Esophageal Cancer Treatment Lung Cancer Treatment Images related to External Beam Therapy (EBT) Sponsored ...

  9. MALIGNANT EXTERNAL OTITIS

    OpenAIRE

    Massoud Moghaddam

    1993-01-01

    Two case reports of malignant external otitis in the elderly diabetics and their complications and management with regard to our experience at Amir Alam Hospital, Department of ENT will be discussed here.

  10. Checklists for external validity

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke;

    2014-01-01

    RATIONALE, AIMS AND OBJECTIVES: The quality of the current literature on external validity varies considerably. An improved checklist with validated items on external validity would aid decision-makers in judging similarities among circumstances when transferring evidence from a study setting...... to an implementation setting. In this paper, currently available checklists on external validity are identified, assessed and used as a basis for proposing a new improved instrument. METHOD: A systematic literature review was carried out in Pubmed, Embase and Cinahl on English-language papers without time restrictions....... The retrieved checklist items were assessed for (i) the methodology used in primary literature, justifying inclusion of each item; and (ii) the number of times each item appeared in checklists. RESULTS: Fifteen papers were identified, presenting a total of 21 checklists for external validity, yielding a total...

  11. Photospheric magnetic field of an eroded-by-solar-wind coronal mass ejection

    Science.gov (United States)

    Palacios, J.; Cid, C.; Saiz, E.; Guerrero, A.

    2017-10-01

    We have investigated the case of a coronal mass ejection that was eroded by the fast wind of a coronal hole in the interplanetary medium. When a solar ejection takes place close to a coronal hole, the flux rope magnetic topology of the coronal mass ejection (CME) may become misshapen at 1 AU as a result of the interaction. Detailed analysis of this event reveals erosion of the interplanetary coronal mass ejection (ICME) magnetic field. In this communication, we study the photospheric magnetic roots of the coronal hole and the coronal mass ejection area with HMI/SDO magnetograms to define their magnetic characteristics.

  12. Migration with fiscal externalities.

    Science.gov (United States)

    Hercowitz, Z; Pines, D

    1991-11-01

    "This paper analyses the distribution of a country's population among regions when migration involves fiscal externalities. The main question addressed is whether a decentralized decision making [by] regional governments can produce an optimal population distribution...or a centralized intervention is indispensable, as argued before in the literature.... It turns out that, while with costless mobility the fiscal externality is fully internalized by voluntary interregional transfers, with costly mobility, centrally coordinated transfers still remain indispensable for achieving the socially optimal allocation."

  13. Sen cycles and externalities

    OpenAIRE

    Piggins, Ashley; Salerno, Gillian

    2016-01-01

    It has long been understood that externalities of some kind are responsible for Sen’s (1970) theorem on the impossibility of a Paretian liberal. However, Saari and Petron (2006) show that for any social preference cycle generated by combining the weak Pareto principle and individual decisiveness, every decisive individual must suffer at least one strong negative externality. We show that this fundamental result only holds when individual preferences are strict. Building on their contribution,...

  14. Field induced anomalous spreading, oscillation, ejection, spinning, and breaking of oil droplets on a strongly slipping water surface.

    Science.gov (United States)

    Kumar, Sunny; Sarma, Bhaskarjyoti; Dasmahapatra, Ahsok Kumar; Dalal, Amaresh; Basu, Dipankar Narayan; Bandyopadhyay, Dipankar

    2017-07-01

    Application of an electric field on an oil droplet floating on the surface of a deionized water bath showed interesting motions such as spreading, oscillation, and ejection. The electric field was generated by connecting a pointed platinum cathode at the top of the oil droplet and a copper anode coated with polymer at the bottom of the water layer. The experimental setup mimicked a conventional electrowetting setup with the exception that the oil was spread on a soft and deformable water isolator. While at relatively lower field intensities we observed spreading of the droplet, at intermediate field intensities the droplet oscillated around the platinum cathode, before ejecting out at a speed as high as ∼5 body lengths per second at even stronger field intensities. The experiments suggested that when the electric field was ramped up abruptly to a particular voltage, any of the spreading, oscillation, or ejection motions of the droplet could be engendered at lower, intermediate and higher field intensities, respectively. However, when the field was ramped up progressively by increasing by a definite amount of voltage per unit time, all three aforementioned motions could be generated simultaneously with the increase in the field intensity. Interestingly, when the aforementioned setup was placed on a magnet, the droplet showed a rotational motion under the influence of the Lorentz force, which was generated because of the coupling of the weak leakage current with the externally applied magnetic field. The spreading, oscillation, ejection, and rotation of the droplet were found to be functions of the oil-water interfacial tension, viscosity, and size of the oil droplet. We developed simple theoretical models to explain the experimental results obtained. Importantly, rotating at a higher speed broke the droplet into a number of smaller ones, owing to the combined influence of the spreading due to the centripetal force and the shear at the oil-water interface. While

  15. The Effect on the Lunar Exosphere of a Coroual Mass Ejection Passage

    Science.gov (United States)

    Killen, R. M.; Hurley, D. M.; Farrell, W. M.

    2011-01-01

    Solar wind bombardment onto exposed surfaces in the solar system produces an energetic component to the exospheres about those bodies. The solar wind energy and composition are highly dependent on the origin of the plasma. Using the measured composition of the slow wind, fast wind, solar energetic particle (SEP) population, and coronal mass ejection (CME), broken down into their various components, we have estimated the total sputter yield for each type of solar wind. We show that the heavy ion component, especially the He++ and 0+7 can greatly enhance the total sputter yield during times when the heavy ion population is enhanced. Folding in the flux, we compute the source rate for several species during different types of solar wind. Finally, we use a Monte Carlo model developed to simulate the time-dependent evolution of the lunar exosphere to study the sputtering component of the exosphere under the influence of a CME passage. We simulate the background exosphere of Na, K, Ca, and Mg. Simulations indicate that sputtering increases the mass of those constituents in the exosphere a few to a few tens times the background values. The escalation of atmospheric density occurs within an hour of onset The decrease in atmospheric density after the CME passage is also rapid, although takes longer than the increase, Sputtered neutral particles have a high probability of escaping the moon,by both Jeans escape and photo ionization. Density and spatial distribution of the exosphere can be tested with the LADEE mission.

  16. Stoichiometry of H+ ejection during respiration-dependent accumulation of Ca2+ by rat liver mitochondria.

    Science.gov (United States)

    Brand, M D; Chen, C H; Lehninger, A L

    1976-02-25

    We have investigated the energy-dependent uptake of Ca2+ by rat liver mitochondria with succinate as respiratory substrate with rotenone added to block NAD-linked electron transport. In the presence of 3-hydroxybutyric or other permeant monocarboxylic acids Ca2+ was taken up to extents approaching those seen in the presence of phosphate. The quantitative relationship between cation and anion uptake was determined from the slope of a plot of 3-hydroxybutyrate uptake against Ca2+ uptake, a method which allowed determination of the stoichiometry without requiring ambiguous corrections for early nonenergized or nonstoichiometric binding events. This procedure showed that 2 molecules of 3-hydroxtbutyrate were accumulated with each Ca2+ ion. Under these conditions close to 2 Ca2+ ions and 4 molecules of 3-hydroxybutyrate were accumulated per pair of electrons per energy-conserving site of the respiratory chain. Since 3-hydroxybutyrate must be protonated to pass the membrane as the undissociated free acid, it is concluded that 4 protons were ejected (and subsequently reabsorbed) per pair of electrons per energy-conserving site, in contrast to the value 2.0 postulated by the chemiosmotic hypothesis.

  17. Characterization of plasma jet ejected from a parallel-plate rail gun for simulating edge localized mode

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K.S., E-mail: alsk3@snu.ac.kr; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr; Jung, B.K.; Hwang, Y.S., E-mail: yhwang@snu.ac.kr

    2013-10-15

    Highlights: • A small plasma gun is constructed to study edge localized mode. • A plasma jet ejected from the gun is characterized with a quadruple Langmuir probe. • The device and diagnostics are suitable for research about the control of plasma jet. -- Abstract: A small plasma gun with parallel-plate configuration is fabricated to generate a bunch of plasma which is similar to ELM (edge localized mode) plasma, by taking advantages of its simplicity and cost-effectiveness. Prior to explore how to control the ELM-like plasma so as to relieve heat load on the divertor target, characteristics of a plasma jet ejected from the plasma gun are investigated using a quadruple Langmuir probe which is appropriate for measuring rapidly varying plasma parameters such as electron density, temperature, and ion velocity at the same time. The plasma density and ion velocity measured at 112 mm away from the exit are 3 × 10{sup 19} m{sup −3} and 11 km/s, respectively, which seem to be suitable for investigating next step research on the control of ELM-like plasma using various methods such as electromagnetic waves and high-voltage pulses. Also, the quadruple Langmuir probe is proven to be adequate for use in such experiments.

  18. Maximum Velocity of a Boulder Ejected From an Impact Crater Formed on a Regolith Covered Surface

    Science.gov (United States)

    Bart, G. D.; Melosh, H. J.

    2007-12-01

    We investigate the effect of regolith depth on boulder ejection velocity. A "boulder" refers to an apparently intact rock or rock fragment lying on a planetary surface, regardless of emplacement mechanism. Boulders appear in planetary images as positive relief features --- bright, sun-facing pixels adjacent to dark, shadowed pixels. We studied 12 lunar craters in high resolution (1~m) photographs from Lunar Orbiter III and V. Local regolith depth was measured using the method of small crater morphology. Ejection velocities of boulders were calculated assuming a ballistic trajectory to the final boulder location. A plot of regolith depth/crater diameter vs. maximum boulder ejection velocity shows that craters formed in deeper regolith (with respect to crater size) eject boulders at lower velocities. When ejection velocity (EjV) is in m/s, and regolith depth (Dr) and crater diameter (Dc) are in meters, the data fit the relation Dr / Dc = 1053 × EjVmax-2.823. To explain the data, we turn to impact cratering theory. An ejected particle will follow a streamline from its place of origin to its ejection point (the Z-model), and then follow a ballistic trajectory. Material ejected along more shallow streamlines is ejected at greater velocities. If shallow regolith covers the surface, the most shallow (greatest velocity) streamlines will travel only through the regolith. Boulders, however, must be ejected from the bedrock below the regolith. Thus, the boulder ejected with the greatest velocity originates just below the regolith, along the most shallow streamline through the bedrock. If the regolith is deeper, the most shallow streamline through the bedrock will be deeper, and the maximum velocity of an ejected boulder will be lower. Hence, the regolith depth and maximum ejection velocity of a boulder are correlated: greater boulder ejection velocities correspond to thinner regolith. We observe this correlation in the data.

  19. Atomic excitation and recombination in external fields

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, M.H.; Clark, C.W.

    1985-01-01

    This volume offers a timely look at Rydberg states of atoms in external fields and dielectronic recombination. Each topic provides authoritative coverage, presents a fresh account of a flourishing field of current atomic physics and introduces new opportunities for discovery and development. Topics considered include electron-atom scattering in external fields; observations of regular and irregular motion as exemplified by the quadratic zeeman effect and other systems; Rydberg atoms in external fields and the Coulomb geometry; crossed-field effects in the absorption spectrum of lithium in a magnetic field; precise studies of static electric field ionization; widths and shapes of stark resonances in sodium above the saddle point; studies of electric field effects and barium autoionizing resonances; autoionization and dielectronic recombination in plasma electric microfields; dielectronic recombination measurements on multicharged ions; merged beam studies of dielectronic recombination; Rydberg atoms and dielectronic recombination in astrophysics; and observations on dielectronic recombination.

  20. Amplification of an electromagnetic field at the scattering of the nonrelativistic electron by an ion in the external field of medium intensity for an arbitrary angle of the initial electron

    Science.gov (United States)

    Tsybul'nik, V. A.; Roshchupkin, S. P.

    2014-08-01

    We theoretically study the gain coefficient for a electromagnetic field, in the scattering of nonrelativistic electrons by ions in a elliptically polarized light wave. We obtain a simple analytical expression for a field amplification constant in logarithmic approach to an arbitrary angle of the initial electron. The formula supplements and extends the domain of applicability of the known Marcuse formula for the linear polarization in the presence of a weak field. It is demonstrated that the maximum gain is reached when the initial electron velocity directs along the major semi-axis of the polarization ellipse. In the range of optical frequencies, the gain coefficient of the laser radiation can be significant for relatively high powers of electron beams. Obtained results may be experimentally verified, for example, by the scientific facilities at the SLAC National Accelerator Laboratory and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany).

  1. Enhanced secondary ion emission with a bismuth cluster ion source

    Science.gov (United States)

    Nagy, G.; Walker, A. V.

    2007-04-01

    We have investigated the mechanism of secondary ion yield enhancement using Bin+ (n = 1-6) primary ions and three different samples - dl-phenylalanine, Irganox 1010 and polystyrene - adsorbed on Al, Si and Ag substrates. The largest changes in secondary ion yields are observed for Bi2+ and Bi3+ primary ions. Smaller increases in secondary ion yield are found using Bi4+, Bi5+ and Bi6+ projectiles. The secondary ion yield enhancements are generally larger on Si than on Al. Using Bin+ structures obtained from density functional theory (DFT) calculations we demonstrate that the yield enhancements cannot be explained by an increase in the deposited energy density (energy per area) into the substrate. These data show that the mechanism of Bin+ sputtering is very similar to that for Aun+ primary ion beams. When a polyatomic primary ion strikes the substrate, its constituent atoms are likely to remain near to each other, and so a substrate atom can be struck simultaneously by multiple atoms. The action of these multiple concerted impacts leads to efficient energy transfer in the near surface region and an increase in the number of secondary ions ejected from the surface. Such concerted impacts involve one, two or three projectile atoms, which explains well the nonlinear yield enhancements observed going from Bi+ to Bi2+ to Bi3+.

  2. Environmental external effects from wind power based on the EU ExternE methodology

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1998-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective...

  3. Quantification of the relative contribution of the different right ventricular wall motion components to right ventricular ejection fraction: the ReVISION method.

    Science.gov (United States)

    Lakatos, Bálint; Tősér, Zoltán; Tokodi, Márton; Doronina, Alexandra; Kosztin, Annamária; Muraru, Denisa; Badano, Luigi P; Kovács, Attila; Merkely, Béla

    2017-03-27

    Three major mechanisms contribute to right ventricular (RV) pump function: (i) shortening of the longitudinal axis with traction of the tricuspid annulus towards the apex; (ii) inward movement of the RV free wall; (iii) bulging of the interventricular septum into the RV and stretching the free wall over the septum. The relative contribution of the aforementioned mechanisms to RV pump function may change in different pathological conditions.Our aim was to develop a custom method to separately assess the extent of longitudinal, radial and anteroposterior displacement of the RV walls and to quantify their relative contribution to global RV ejection fraction using 3D data sets obtained by echocardiography.Accordingly, we decomposed the movement of the exported RV beutel wall in a vertex based manner. The volumes of the beutels accounting for the RV wall motion in only one direction (either longitudinal, radial, or anteroposterior) were calculated at each time frame using the signed tetrahedron method. Then, the relative contribution of the RV wall motion along the three different directions to global RV ejection fraction was calculated either as the ratio of the given direction's ejection fraction to global ejection fraction and as the frame-by-frame RV volume change (∆V/∆t) along the three motion directions.The ReVISION (Right VentrIcular Separate wall motIon quantificatiON) method may contribute to a better understanding of the pathophysiology of RV mechanical adaptations to different loading conditions and diseases.

  4. EPISODIC EJECTION FROM ACTIVE ASTEROID 311P/PANSTARRS

    Energy Technology Data Exchange (ETDEWEB)

    Jewitt, David [Department of Earth and Space Sciences, University of California at Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States); Agarwal, Jessica [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Gottingen (Germany); Weaver, Harold [The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Mutchler, Max [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Larson, Stephen, E-mail: jewitt@ucla.edu [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson AZ 85721-0092 (United States)

    2015-01-10

    We examine the development of the active asteroid 311P/PANSTARRS (formerly, 2013 P5) in the period from 2013 September to 2014 February using high resolution images from the Hubble Space Telescope. This multi-tailed object is characterized by a single, reddish nucleus of absolute magnitude H ≥ 18.98 ± 0.10, corresponding to an equal-area sphere of radius ≤200 ± 20 m (for assumed geometric albedo 0.29 ± 0.09). We set an upper limit to the radii of possible companion nuclei at ∼10 m. The nucleus ejected debris in nine discrete episodes, spread irregularly over a nine month interval, each time forming a distinct tail. Particles in the tails range from about 10 μm to at least 80 mm in radius, and were ejected at speeds <1 m s{sup –1}. The ratio of the total ejected dust mass to the nucleus mass is ∼3×10{sup –5}, corresponding to a global surface layer ∼2 mm thick, or to a deeper layer covering a smaller fraction of the surface. The observations are incompatible with an origin of the activity by impact or by the sublimation of entrapped ice. This object appears to be shedding its regolith by rotational (presumably YORP-driven) instability. Long-term fading of the photometry (months) is attributed to gradual dissipation of near-nucleus dust. Photometric variations on short timescales (<0.7 hr) are probably caused by fast rotation of the nucleus. However, because of limited time coverage and dilution of the nucleus signal by near-nucleus dust, we have not been able to determine the rotation period.

  5. Informed Heuristics for Guiding Stem-and-Cycle Ejection Chains

    CERN Document Server

    Harabor, Daniel

    2011-01-01

    The state of the art in local search for the Traveling Salesman Problem is dominated by ejection chain methods utilising the Stem-and-Cycle reference structure. Though effective such algorithms employ very little information in their successor selection strategy, typically seeking only to minimise the cost of a move. We propose an alternative approach inspired from the AI literature and show how an admissible heuristic can be used to guide successor selection. We undertake an empirical analysis and demonstrate that this technique often produces better results than less informed strategies albeit at the cost of running in higher polynomial time.

  6. Geoeffectiveness of Coronal Mass Ejections in the SOHO Era

    DEFF Research Database (Denmark)

    Dumbovic, M.; Devos, A.; Vrsnak, B.;

    2014-01-01

    The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the geomagnetic storm intensity. Several CME...... and flare parameters as well as the effect of successive-CME occurrence in changing the probability for a certain range of Dst index values, were examined. The results confirm some of already known relationships between remotely-observed properties of solar eruptive events and geomagnetic storms, namely...

  7. Invasive hemodynamic characterization of heart failure with preserved ejection fraction

    DEFF Research Database (Denmark)

    Andersen, Mads Jønsson; Borlaug, Barry A

    2014-01-01

    Recent hemodynamic studies have advanced our understanding of heart failure with preserved ejection fraction (HFpEF). Despite improved pathophysiologic insight, clinical trials have failed to identify an effective treatment for HFpEF. Invasive hemodynamic assessment can diagnose or exclude HFpEF......, making it invaluable in understanding the basis of the disease. This article reviews the hemodynamic mechanisms underlying HFpEF and how they manifest clinically, discusses invasive hemodynamic assessment as a diagnostic tool, and explores how invasive hemodynamic profiling may allow understanding...

  8. Exercise physiology in heart failure and preserved ejection fraction.

    Science.gov (United States)

    Haykowsky, Mark J; Kitzman, Dalane W

    2014-07-01

    Recent advances in the pathophysiology of exercise intolerance in patients with heart failure with preserved ejection fraction (HFPEF) suggest that noncardiac peripheral factors contribute to the reduced peak V(o2) (peak exercise oxygen uptake) and to its improvement after endurance exercise training. A greater understanding of the peripheral skeletal muscle vascular adaptations that occur with physical conditioning may allow for tailored exercise rehabilitation programs. The identification of specific mechanisms that improve whole body and peripheral skeletal muscle oxygen uptake could establish potential therapeutic targets for medical therapies and a means to follow therapeutic response.

  9. Plasmoid ejections driven by dynamo action underneath a spherical surface

    CERN Document Server

    Warnecke, Jörn; Mitra, Dhrubaditya

    2010-01-01

    We present a unified three-dimensional model of the convection zone and upper atmosphere of the Sun in spherical geometry. In this model, magnetic fields, generated by a helically forced dynamo in the convection zone, emerge without the assistance of magnetic buoyancy. We use an isothermal equation of state with gravity and density stratification. Recurrent plasmoid ejections, which rise through the outer atmosphere, is observed. In addition, the current helicity of the small--scale field is transported outwards and form large structures like magnetic clouds.

  10. Epidemiology of heart failure with preserved ejection fraction

    DEFF Research Database (Denmark)

    Andersson, Charlotte; Vasan, Ramachandran S

    2014-01-01

    Heart failure with preserved ejection fraction (HFPEF) is a common condition, and the prevalence is projected to increase further. Studies differ in the reported incidence and mortality associated with this condition, although there is agreement that between a third and one-half of all patients...... with heart failure have HFPEF. Although several consensus statements and guidelines have been published, some recent randomized clinical trials have reported low mortality, raising doubts about whether all patients diagnosed with HFPEF have HFPEF or whether the condition is heterogeneous in its cause...

  11. Externality or sustainability economics?

    Energy Technology Data Exchange (ETDEWEB)

    Bergh, Jeroen C.J.M. van den [ICREA, Barcelona (Spain); Department of Economics and Economic History and Institute for Environmental Science and Technology, Universitat Autonoma de Barcelona (Spain)

    2010-09-15

    In an effort to develop 'sustainability economics' Baumgaertner and Quaas (2010) neglect the central concept of environmental economics-'environmental externality'. This note proposes a possible connection between the concepts of environmental externality and sustainability. In addition, attention is asked for other aspects of 'sustainability economics', namely the distinction weak/strong sustainability, spatial sustainability and sustainable trade, distinctive sustainability policy, and the ideas of early 'sustainability economists'. I argue that both sustainability and externalities reflect a systems perspective and propose that effective sustainability solutions require that more attention is given to system feedbacks, notably other-regarding preferences and social interactions, and energy and environmental rebound. The case of climate change and policy is used to illustrate particular statements. As a conclusion, a list of 20 insights and suggestions for research is offered. (author)

  12. Metasurface external cavity laser

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  13. Dynamical mass ejection from black hole-neutron star binaries

    CERN Document Server

    Kyutoku, Koutarou; Okawa, Hirotada; Shibata, Masaru; Taniguchi, Keisuke

    2015-01-01

    We investigate properties of material ejected dynamically in the merger of black hole-neutron star binaries by numerical-relativity simulations. We systematically study dependence of ejecta properties on the mass ratio of the binary, spin of the black hole, and equation of state of the neutron-star matter. Dynamical mass ejection is driven primarily by tidal torque, and the ejecta is much more anisotropic than that from binary neutron star mergers. In particular, the dynamical ejecta is concentrated around the orbital plane with a half opening angle of 10deg--20deg and often sweeps only a half of the plane. The ejecta mass can be as large as ~0.1M_sun, and the velocity is subrelativistic with ~0.2--0.3c for typical cases. The ratio of the ejecta mass to the bound mass (disk and fallback components) becomes high and the ejecta velocity is large when the binary mass ratio is large, i.e., the black hole is massive. The remnant black hole-disk system receives a kick velocity of O(100)km/s due to the ejecta linear...

  14. Models for grains and gas ejection dynamics from a silo

    Science.gov (United States)

    Zhou, Yixian; Aussillous, Pascale; Ruyer, Pierre; Iusti/Gep Team; Semia/Limar Team

    2015-11-01

    In the hypothetical conditions of a reactivity initiated accident in a nuclear power plant, some of the fuel rods could break. If fuel fragmentation occurs, hot fuel particles and pressurized gas could interact with the surrounding fluid. The violence of this interaction depends on the discharge rate toward the fluid. In the present work, we study the discharge dynamics and identify the parameters governing this flow. In this paper, we focus on the experimental study of the discharge of a silo composed of spherical glass beads, with an orifice either lateral or at the bottom, with or without air flow. The measured parameters are the mass flow rate and the pressure along the silo, whereas the controlled parameters are the size of particles, the size of orifices, and the flow rate of air. For the case without air flow we found that the flow rate of particles ejected from the bottom orifice is 3 times greater than from the lateral orifice. For the case of a lateral orifice, when the form of the orifice is rectangular with width W and height D, we identify two regimes which depend on the ratio of width to height W / D . For the case with air flow, we found that the flow rate increases with the air flow. A simple physical model is proposed to describe the grains and gas ejection.

  15. Full Halo Coronal Mass Ejections: Arrival at the Earth

    CERN Document Server

    Shen, Chenglong; Pan, Zonghao; Miao, Bin; Ye, Pinzhong; Wang, S

    2014-01-01

    A geomagnetic storm is mainly caused by a front-side coronal mass ejection (CME) hitting the Earth and then interacting with the magnetosphere. However, not all front-side CMEs can hit the Earth. Thus, which CMEs hit the Earth and when they do so are important issues in the study and forecasting of space weather. In our previous work (Shen et al., 2013), the de-projected parameters of the full-halo coronal mass ejections (FHCMEs) that occurred from 2007 March 1 to 2012 May 31 were estimated, and there are 39 front-side events could be fitted by the GCS model. In this work, we continue to study whether and when these front-side FHCMEs (FFHCMEs) hit the Earth. It is found that 59\\% of these FFHCMEs hit the Earth, and for central events, whose deviation angles $\\epsilon$, which are the angles between the propagation direction and the Sun-Earth line, are smaller than 45 degrees, the fraction increases to 75\\%. After checking the deprojected angular widths of the CMEs, we found that all of the Earth-encountered CM...

  16. On the role of recombination in common-envelope ejections

    CERN Document Server

    Ivanova, N; Podsiadlowski, Ph

    2014-01-01

    The energy budget in common-envelope events (CEEs) is not well understood, with substantial uncertainty even over to what extent the recombination energy stored in ionised hydrogen and helium might be used to help envelope ejection. We investigate the reaction of a red-giant envelope to heating which mimics limiting cases of energy input provided by the orbital decay of a binary during a CEE, specifically during the post-plunge-in phase during which the spiral-in has been argued to occur on a time-scale longer than dynamical. We show that the outcome of such a CEE depends less on the total amount of energy by which the envelope is heated than on how rapidly the energy was transferred to the envelope and on where the envelope was heated. The envelope always becomes dynamically unstable before receiving net heat energy equal to the envelope's initial binding energy. We find two types of outcome, both of which likely lead to at least partial envelope ejection: "runaway" solutions in which the expansion of the ra...

  17. A Solar Coronal Jet Event Triggers A Coronal Mass Ejection

    CERN Document Server

    Liu, Jiajia; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S

    2015-01-01

    We present the multi-point and multi-wavelength observation and analysis on a solar coronal jet and coronal mass ejection (CME) event in this paper. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it propagate in a high speed over 1000 km/s . The jet erupted before and shared the same source region with the CME. The temporal and spacial relation- ship between them guide us the possibility that the jet triggered the CME and became its core. This scenario could promisingly enrich our understanding on the triggering mechanism of coronal mass ejections and their relations with coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the SDO/HMI instrument and the off- limb inverse Y-shaped configuration observed by SDO/AIA 171 A passband, together provide the first detailed observation on the three-dimensional reconnection process of large-scale jets as simulated in Pariat et al. 2009. ...

  18. The initiation of coronal mass ejections by magnetic flux emergence

    Science.gov (United States)

    Dubey, G.; van der Holst, B.; Poedts, S.

    2006-12-01

    Aims.The initiation of solar Coronal Mass Ejections (CMEs) is studied in the framework of computational Magneto-Hydro-Dynamics (MHD). Methods: .The initial configuration includes a magnetic flux rope that is embedded in a gravitationally stratified solar atmosphere with a background dipole magnetic field in spherical, axi-symmetric geometry. The flux rope is in equilibrium due to an image current below the photosphere. An emerging magnetic flux triggering mechanism is used to make this equilibrium configuration unstable. Results: . When the magnetic flux emerges within the filament below the flux rope this results in a catastrophic behavior similar to earlier, more simple models. As a result, the flux rope rises and a current sheet forms below it. It is shown that the magnetic reconnection in the current sheet below the flux rope in combination with the outward curvature forces results in a fast ejection of the flux rope as observed for solar CMEs. We have done a parameter study of the effect of the flux emergence rate on the velocity and the acceleration of the resulting CMEs.

  19. Physical properties of erupting plasma associated with coronal mass ejections

    Science.gov (United States)

    Lee, J.; Raymond, J. C.; Reeves, K. K.; Moon, Y.; Kim, K.

    2013-12-01

    We investigate the physical properties (temperature, density, and mass) of erupting plasma observed in X-rays and EUV, which are all associated with coronal mass ejections observed by SOHO/LASCO. The erupting plasmas are observed as absorption or emission features in the low corona. The absorption feature provides a lower limit to the cold mass while the emission feature provides an upper limit to the mass of observed plasma in X-ray and EUV. We compare the mass constraints for each temperature response and find that the mass estimates in EUV and XRT are smaller than the total mass in the coronagraph. Several events were observed by a few passbands in the X-rays, which allows us to determine the temperature of the eruptive plasma using a filter ratio method. The temperature of one event is estimated at about 8.6 MK near the top of the erupting plasma. This measurement is possibly an average temperature for higher temperature plasma because the XRT is more sensitive at higher temperatures. In addition, a few events show that the absorption features of a prominence or a loop change to emission features with the beginning of their eruptions in all EUV wavelengths of SDO/AIA, which indicates the heating of the plasma. By estimating the physical properties of the erupting plasmas, we discuss the heating of the plasmas associated with coronal mass ejections in the low corona.

  20. Spontaneous Aerosol Ejection: Origin of Inorganic Particles in Biomass Pyrolysis.

    Science.gov (United States)

    Teixeira, Andrew R; Gantt, Rachel; Joseph, Kristeen E; Maduskar, Saurabh; Paulsen, Alex D; Krumm, Christoph; Zhu, Cheng; Dauenhauer, Paul J

    2016-06-08

    At high thermal flux and temperatures of approximately 500 °C, lignocellulosic biomass transforms to a reactive liquid intermediate before evaporating to condensable bio-oil for downstream upgrading to renewable fuels and chemicals. However, the existence of a fraction of nonvolatile compounds in condensed bio-oil diminishes the product quality and, in the case of inorganic materials, catalyzes undesirable aging reactions within bio-oil. In this study, ablative pyrolysis of crystalline cellulose was evaluated, with and without doped calcium, for the generation of inorganic-transporting aerosols by reactive boiling ejection from liquid intermediate cellulose. Aerosols were characterized by laser diffraction light scattering, inductively coupled plasma spectroscopy, and high-speed photography. Pyrolysis product fractionation revealed that approximately 3 % of the initial feed (both organic and inorganic) was transported to the gas phase as aerosols. Large bubble-to-aerosol size ratios and visualization of significant late-time ejections in the pyrolyzing cellulose suggest the formation of film bubbles in addition to the previously discovered jet formation mechanism.

  1. Ejection Dynamics in Vibration-Induced Droplet Atomization

    Science.gov (United States)

    Vukasinovic, Bojan; Smith, Marc K.; Glezer, Ari

    2001-11-01

    A primary sessile liquid drop is atomized into a fine spray of secondary droplets using vibration-induced atomization (VIDA) resulting from forced waves on a free surface of the primary drop. The mechanism of free surface breakup during the VIDA process is investigated using high-speed imaging and laser vibrometry. Secondary droplets result from a localized collapse of surface troughs and the ejection and ultimate breakup of momentary liquid spikes. The characteristic breakup time of these liquid spikes scales with the vibration period and the spike length initially varies like t0.5. The breakup begins with a capillary pinch-off from the tip of the spike that can be followed by additional pinching of liquid droplets. For relatively low-viscosity liquid (e.g., water) a capillary-wave instability of a jet is observed in some cases, while in very viscous liquid (e.g., glycerin-water solution) the first breakup occurs near the stem of the jet. The mechanisms of secondary droplet ejection and the influence of the operating parameters and fluid properties are discussed.

  2. Subdwarf B stars from the common envelope ejection channel

    CERN Document Server

    Xiong, H; Podsiadlowski, P; Han, Z

    2016-01-01

    From the canonical binary scenario, the majority of sdBs are produced from low-mass stars with degenerate cores where helium is ignited in a way of flashes. Due to numerical difficulties, the models of produced sdBs are generally constructed from more massive stars with non-degenerate cores, leaving several uncertainties on the exact characteristics of sdB stars. Employing MESA, we systematically studied the characteristics of sdBs produced from the common envelope (CE) ejection channel, and found that the sdB stars produced from the CE ejection channel appear to form two distinct groups on the effective temperature-gravity diagram. One group (the flash-mixing model) almost has no H-rich envelope and crows at the hottest temperature end of the extremely horizontal branch (EHB), while the other group has significant H-rich envelope and spreads over the whole canonical EHB region. The key factor for the dichotomy of the sdB properties is the development of convection during the first helium flash, which is dete...

  3. Forbush decreases associated to Stealth Coronal Mass Ejections

    Science.gov (United States)

    Heber, B.; Wallmann, C.; Galsdorf, D.; Herbst K.; Kühl, P.; Dumbovic, M.; Vršnak, B.; Veronig, A.; Temmer, M.; Möstl, C.; Dalla, S.

    Interplanetary coronal mass ejections (ICMEs) are structures in the solar wind that are the counterparts of coronal mass ejections (CMEs) at the Sun. It is commonly believed that enhanced magnetic fields in interplanetary shocks and solar ejecta as well as the increased turbulence in the solar wind sheath region are the cause of Forbush decreases (FDs) representing decreases of galactic cosmic ray (GCR) intensities. Recently, stealth CMEs i.e.~CMEs with no apparent solar surface association have become a subject in recent studies of solar activity. Whether all of such stealth CMEs can drive a FD is difficult to investigate on the basis of neutron monitor NM measurements because these measurements not only reflect the GCR intensity variation in interplanetary space but also the variation of the geomagnetic field as well as the conditions in the Earth atmosphere. Single detector counter from spacecraft instrumentation, here SOHO and Chandra EPHIN, exceed counting statistic of NMs allowing to determine intensity variation of less than 1 permil in interplanetary space on the basis of 30 minute count rate averages. Here we present the ongoing analysis of eleven stealth CMEs.

  4. Right heart dysfunction in heart failure with preserved ejection fraction

    Science.gov (United States)

    Melenovsky, Vojtech; Hwang, Seok-Jae; Lin, Grace; Redfield, Margaret M.; Borlaug, Barry A.

    2014-01-01

    Aim Right heart function is not well characterized in patients with heart failure and preserved ejection fraction (HFpEF). The goal of this study was to examine the haemodynamic, clinical, and prognostic correlates of right ventricular dysfunction (RVD) in HFpEF. Methods and results Heart failure and preserved ejection fraction patients (n = 96) and controls (n = 46) underwent right heart catheterization, echocardiographic assessment, and follow-up. Right and left heart filling pressures, pulmonary artery (PA) pressures, and right-sided chamber dimensions were higher in HFpEF compared with controls, while left ventricular size and EF were similar. Right ventricular dysfunction (defined by RV fractional area change, FAC Right ventricular function was impaired in HFpEF compared with controls using both load-dependent (FAC: 40 ± 10 vs. 53 ± 7%, P Right heart dysfunction is common in HFpEF and is caused by both RV contractile impairment and afterload mismatch from pulmonary hypertension. Right ventricular dysfunction in HFpEF develops with increasing PA pressures, atrial fibrillation, male sex, and left ventricular dysfunction, and may represent a novel therapeutic target. PMID:24875795

  5. Dynamical Mass Ejection from Binary Neutron Star Mergers

    CERN Document Server

    Radice, David; Lippuner, Jonas; Roberts, Luke F; Ott, Christian D; Rezzolla, Luciano

    2016-01-01

    We present fully general-relativistic simulations of binary neutron star mergers with a temperature and composition dependent nuclear equation of state. We study the dynamical mass ejection from both quasi-circular and dynamical-capture eccentric mergers. We systematically vary the level of our treatment of the microphysics to isolate the effects of neutrino cooling and heating and we compute the nucleosynthetic yields of the ejecta. We find that eccentric binaries can eject significantly more material than quasi-circular binaries and generate bright infrared and radio emission. In all our simulations the outflow is composed of a combination of tidally- and shock-driven ejecta, mostly distributed over a broad $\\sim 60^\\circ$ angle from the orbital plane, and, to a lesser extent, by thermally driven winds at high latitudes. Ejecta from eccentric mergers are typically more neutron rich than those of quasi-circular mergers. This is the effect of the strong tidal torques exerted on the neutron stars during their ...

  6. Stochastic Control - External Models

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad

    2005-01-01

    This note is devoted to control of stochastic systems described in discrete time. We are concerned with external descriptions or transfer function model, where we have a dynamic model for the input output relation only (i.e.. no direct internal information). The methods are based on LTI systems...

  7. Productivity Change and Externalities

    DEFF Research Database (Denmark)

    Kravtsova, Victoria

    2014-01-01

    firms and the economy as a whole. The approach used in the current research accounts for different internal as well as external factors that individual firms face and evaluates the effect on changes in productivity, technology as well as the efficiency of domestic firms. The empirical analysis focuses...... change in different types of firms and sectors of the economy...

  8. Multiple external root resorption.

    Science.gov (United States)

    Yusof, W Z; Ghazali, M N

    1989-04-01

    Presented is an unusual case of multiple external root resorption. Although the cause of this resorption was not determined, several possibilities are presented. Trauma from occlusion, periodontal and pulpal inflammation, and resorption of idiopathic origin are all discussed as possible causes.

  9. The Role of Overlying Magnetic Field in Modeling Coronal Mass Ejections

    Science.gov (United States)

    Olmedo, Oscar; Zhang, J.

    2009-05-01

    Recent models and observations have revealed that the magnetic fields overlying active regions play an important role in the eruption or confinement of flux ropes due to the torus instability. Flux ropes are now generally accepted to be the magnetic configuration of coronal mass ejections (CMEs) but their initiation is still not clear. In this study the external magnetic field profile of the well-developed flux rope model as proposed by James Chen (see J.Chen 1989, 1996) is examined. This external magnetic field represents overlying coronal loops, that may be of bipolar or complex topology with footpoints assumed to originate from an active region, and it is assumed that the only magnetic field component that affects the flux rope evolution is the one that is perpendicular to the flux ropes major axis. In this type of flux rope model, it has been suggested that the flux ropes initiation is driven by poloidal flux injection either of photospheric or coronal origin. Several test profiles are investigated, such as a power law profile, and a polynomial profile that could be thought of as a summation of magnetic multipoles. The gradient index for the prescribed magnetic field profile is studied and it is found that above a critical value the flux rope is eruptive and below this value it is confined, in agreement with observations and simulations. Implications of the results are that the torus instability is the most likely candidate in driving the eruption of flux rope CMEs, and that the distribution of magnetic field has a significant effect on the initiation and acceleration of CMEs.

  10. Solar filament eruptions and their physical role in triggering Coronal Mass Ejections

    CERN Document Server

    Schmieder, B; Aulanier, G

    2012-01-01

    Solar filament eruptions play a crucial role in triggering coronal mass ejections (CMEs). More than 80 % of eruptions lead to a CME. This correlation has been studied extensively during the past solar cycles and the last long solar minimum. The statistics made on events occurring during the rising phase of the new solar cycle 24 is in agreement with this finding. Both filaments and CMEs have been related to twisted magnetic fields. Therefore, nearly all the MHD CME models include a twisted flux tube, called a flux rope. Either the flux rope is present long before the eruption, or it is built up by reconnection of a sheared arcade from the beginning of the eruption. In order to initiate eruptions, different mechanisms have been proposed: new emergence of flux, and/or dispersion of the external magnetic field, and/or reconnection of field lines below or above the flux rope. These mechanisms reduce the downward magnetic tension and favor the rise of the flux rope. Another mechanism is the kink instability when t...

  11. Experimental Research on Influence of Some Factors on Ejection Height of Cargo Projectile

    Institute of Scientific and Technical Information of China (English)

    郁浩; 王晓天; 李欣; 李纪敏

    2012-01-01

    Some factors influencing the cargo projectile's ejection height in different conditions were analyzed by using harmonic curve diagram and cluster method.The test results of the ejection height for a certain cargo projectile show that the wind speed and direction are the main influence factors.For given meteorological conditions,the applied environmental stress becomes the main cause,while the launching angle does not influence the ejection height.

  12. Modeling MHD accretion-ejection: episodic ejections of jets triggered by a mean-field disk dynamo

    Energy Technology Data Exchange (ETDEWEB)

    Stepanovs, Deniss; Fendt, Christian; Sheikhnezami, Somayeh, E-mail: deniss@stepanovs.org, E-mail: fendt@mpia.de [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-11-20

    We present MHD simulations exploring the launching, acceleration, and collimation of jets and disk winds. The evolution of the disk structure is consistently taken into account. Extending our earlier studies, we now consider the self-generation of the magnetic field by an α{sup 2}Ω mean-field dynamo. The disk magnetization remains on a rather low level, which helps to evolve the simulations for T > 10, 000 dynamical time steps on a domain extending 1500 inner disk radii. We find the magnetic field of the inner disk to be similar to the commonly found open field structure, favoring magneto-centrifugal launching. The outer disk field is highly inclined and predominantly radial. Here, differential rotation induces a strong toroidal component, which plays a key role in outflow launching. These outflows from the outer disk are slower, denser, and less collimated. If the dynamo action is not quenched, magnetic flux is continuously generated, diffuses outward through the disk, and fills the entire disk. We have invented a toy model triggering a time-dependent mean-field dynamo. The duty cycles of this dynamo lead to episodic ejections on similar timescales. When the dynamo is suppressed as the magnetization falls below a critical value, the generation of the outflows and also accretion is inhibited. The general result is that we can steer episodic ejection and large-scale jet knots by a disk-intrinsic dynamo that is time-dependent and regenerates the jet-launching magnetic field.

  13. ExternE transport methodology for external cost evaluation of air pollution

    DEFF Research Database (Denmark)

    Jensen, S. S.; Berkowicz, R.; Brandt, J.

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summaris...

  14. The External Mind

    DEFF Research Database (Denmark)

    The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism......, Extended Mind and Distributed Cognition by Claudio Paolucci pp. 69-96 The Social Horizon of Embodied Language and Material Symbols by Riccardo Fusaroli pp. 97-123 Semiotics and Theories of Situated/Distributed Action and Cognition: a Dialogue and Many Intersections by Tommaso Granelli pp. 125-167 Building...... Action in Public Environments with Diverse Semiotic Resources by Charles Goodwin pp. 169-182 How Marking in Dance Constitutes Thinking with the Body by David Kirsh pp. 183-214 Ambiguous Coordination: Collaboration in Informal Science Education Research by Ivan Rosero, Robert Lecusay, Michael Cole pp. 215-240...

  15. External-Memory Multimaps

    CERN Document Server

    Angelino, Elaine; Mitzenmacher, Michael; Thaler, Justin

    2011-01-01

    Many data structures support dictionaries, also known as maps or associative arrays, which store and manage a set of key-value pairs. A \\emph{multimap} is generalization that allows multiple values to be associated with the same key. For example, the inverted file data structure that is used prevalently in the infrastructure supporting search engines is a type of multimap, where words are used as keys and document pointers are used as values. We study the multimap abstract data type and how it can be implemented efficiently online in external memory frameworks, with constant expected I/O performance. The key technique used to achieve our results is a combination of cuckoo hashing using buckets that hold multiple items with a multiqueue implementation to cope with varying numbers of values per key. Our external-memory results are for the standard two-level memory model.

  16. The Research and Development of the External Magnetic Field Acting on Electro-Deposition Process

    OpenAIRE

    Wu Menghua; Jia Weiping

    2016-01-01

    The research and development status of the electro-deposition technology under the action of external magnetic field are introduced. The basic characteristics and applied manners of external magnetic field in electro-deposition process are summarized. The acting principle of external magnetic field, the effects of magnetic hydrodynamics (MHD) caused by the Lorentz force, and the acting of magnetic force on the metal ions and particles are described. The main actions of external magnetic field...

  17. On interplanetary coronal mass ejection identification at 1 AU

    Science.gov (United States)

    Mulligan, T.; Russell, C. T.; Gosling, J. T.

    1999-06-01

    Coronal mass ejections are believed to be produced in the corona from closed magnetic regions not previously participating in the solar wind expansion. At 1 AU their interplanetary counterparts (ICMEs) generally have a number of distinct plasma and field signatures that distinguish them from the ambient solar wind. These include heat flux dropouts, bi-directional streaming, enhanced alpha particle events, times of depressed proton temperatures, intervals of distorted or enhanced magnetic field, and times of large magnetic field rotations characteristic of magnetic clouds. The first three of these signatures are phenomena that occur at some point within the ICME, but do not necessarily persist throughout the entire ICME. The large scale magnetic field rotations, distortions and enhancements, and the proton temperature depressions tend to mark more accurately the beginning and end of the ICME proper. We examine herein the reliability with which each of these markers identifies ICMEs utilizing ISEE-3 data from 1978-1980.

  18. An ice-cream cone model for coronal mass ejections

    Science.gov (United States)

    Xue, X. H.; Wang, C. B.; Dou, X. K.

    2005-08-01

    In this study, we use an ice-cream cone model to analyze the geometrical and kinematical properties of the coronal mass ejections (CMEs). Assuming that in the early phase CMEs propagate with near-constant speed and angular width, some useful properties of CMEs, namely the radial speed (v), the angular width (α), and the location at the heliosphere, can be obtained considering the geometrical shapes of a CME as an ice-cream cone. This model is improved by (1) using an ice-cream cone to show the near real configuration of a CME, (2) determining the radial speed via fitting the projected speeds calculated from the height-time relation in different azimuthal angles, (3) not only applying to halo CMEs but also applying to nonhalo CMEs.

  19. On Sun-to-Earth Propagation of Coronal Mass Ejections

    CERN Document Server

    Liu, Ying D; Lugaz, Noé; Möstl, Christian; Davies, Jackie A; Bale, Stuart D; Lin, Robert P

    2013-01-01

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation. Our comparison between different techniques (and data sets) also has important implications for CME observations and their interpretations. Future CME observations and space weather forecasting are discussed based on these results. See detail in the PDF.

  20. MHD Remote Numerical Simulations: Evolution of Coronal Mass Ejections

    CERN Document Server

    Hernandez-Cervantes, L; Gonzalez-Ponce, A R

    2008-01-01

    Coronal mass ejections (CMEs) are solar eruptions into interplanetary space of as much as a few billion tons of plasma, with embedded magnetic fields from the Sun's corona. These perturbations play a very important role in solar--terrestrial relations, in particular in the spaceweather. In this work we present some preliminary results of the software development at the Universidad Nacional Autonoma de Mexico to perform Remote MHD Numerical Simulations. This is done to study the evolution of the CMEs in the interplanetary medium through a Web-based interface and the results are store into a database. The new astrophysical computational tool is called the Mexican Virtual Solar Observatory (MVSO) and is aimed to create theoretical models that may be helpful in the interpretation of observational solar data.

  1. The Kinematics and Morphology of Solar Coronal Mass Ejections

    CERN Document Server

    Byrne, Jason P

    2012-01-01

    Solar coronal mass ejections (CMEs) are large-scale eruptions of plasma and magnetic field from the Sun into the corona and interplanetary space. They are the most significant drivers of adverse space weather at Earth and other locations in the heliosphere, so it is important to understand the physics governing their eruption and propagation. However the diffuse morphology and transient nature of CMEs makes them difficult to identify and track using traditional image processing techniques. In this thesis the implementation of multiscale image processing techniques to identify and track the CME front through coronagraph images is detailed. An ellipse characterisation of the CME front is used to determine the CME kinematics and morphology with increased precision as compared to techniques used in current CME catalogues, and efforts are underway to automate this procedure for applying to a large number of CME observations for future analysis. It was found that CMEs do not simply undergo constant acceleration, bu...

  2. Dynamo generated field emergence through recurrent plasmoid ejections

    CERN Document Server

    Warnecke, Jörn

    2010-01-01

    Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmosphere. In this paper we use helical forcing to produce a large-scale dynamo-generated magnetic field, which rises even without magnetic buoyancy. A two layer system is used as computational domain where the upper part represents the solar atmosphere. Here, the evolution of the magnetic field is solved with the stress--and--relax method. Below this region a magnetic field is produced by a helical forcing function in the momentum equation, which leads to dynamo action. We find twisted magnetic fields emerging frequently to the outer layer, forming arch-like structures. In addition, recurrent plasmoid ejections can be found by looking at space--time diagrams of the magnetic field. Recent simulations in spherical coordinates show similar results.

  3. Flux Rope Formation Preceding Coronal Mass Ejection Onset

    CERN Document Server

    Green, L M

    2009-01-01

    We analyse the evolution of a sigmoidal (S shaped) active region toward eruption, which includes a coronal mass ejection (CME) but leaves part of the filament in place. The X-ray sigmoid is found to trace out three different magnetic topologies in succession: a highly sheared arcade of coronal loops in its long-lived phase, a bald-patch separatrix surface (BPSS) in the hours before the CME, and the first flare loops in its major transient intensity enhancement. The coronal evolution is driven by photospheric changes which involve the convergence and cancellation of flux elements under the sigmoid and filament. The data yield unambiguous evidence for the existence of a BPSS, and hence a flux rope, in the corona prior to the onset of the CME.

  4. Plasma Heating Suring a Coronal Mass Ejection Observed by SOHO

    CERN Document Server

    Murphy, N A; Korreck, K E

    2011-01-01

    We perform a time-dependent ionization analysis to constrain plasma heating requirements during a fast partial halo coronal mass ejection (CME) observed on 2000 June 28 by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO). We use two methods to derive densities from the UVCS measurements, including a density sensitive O V line ratio at 1213.85 and 1218.35 Angstroms, and radiative pumping of the O VI 1032,1038 doublet by chromospheric emission lines. The most strongly constrained feature shows cumulative plasma heating comparable to or greater than the kinetic energy, while features observed earlier during the event show cumulative plasma heating comparable to or less than the kinetic energy. SOHO Michelson Doppler Imager (MDI) observations are used to estimate the active region magnetic energy. We consider candidate plasma heating mechanisms and provide constraints when possible. Because this CME was associated with a relatively weak flare, the contribution b...

  5. Geoeffectiveness of Coronal Mass Ejections in the SOHO era

    CERN Document Server

    Dumbovic, Mateja; Vrsnak, Bojan; Sudar, Davor; Rodriguez, Luciano; Ruzdjak, Domagoj; Leer, Kristoffer; Vennerstrom, Susanne; Veronig, Astrid

    2014-01-01

    The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the geomagnetic storm intensity. Several CME and flare parameters as well as the effect of successive-CME occurrence in changing the probability for a certain range of Dst index values, were examined. The results confirm some of already known relationships between remotely-observed properties of solar eruptive events and geomagnetic storms, namely the importance of initial CME speed, apparent width, source position, and the associated solar flare class. In this paper we quantify these relationships in a form to be used for space weather forecasting in future. The results of the statistical study are employed to construct an empirical statistical model for predicting the probability of the geomagnetic storm intensity based on remote solar observations of CMEs and fl...

  6. Application of particle trajectory model in 1D planar ejection

    Institute of Scientific and Technical Information of China (English)

    刘坤; 柏劲松; 李平

    2008-01-01

    A simple one-dimensional planar model for ejection was set up based on experiments.And numerical simulation was performed on this model with particle trajectory model method.An Eulerian finite volume method was conducted to resolve gas field.And Lagrangian method was imposed to track each particle.The interaction between gas and particles was responded as source terms in governing equations which were induced by forces.The effects of total spraying mass,particle size and other factors on the mixture of particles and gas were investigated.The spatial distributions of particle mass and velocity at different time were presented.The result shows that the numerical results are qualitatively consistent to those of experiments.

  7. Raman activated cell ejection for isolation of single cells.

    Science.gov (United States)

    Wang, Yun; Ji, Yuetong; Wharfe, Emma S; Meadows, Roger S; March, Peter; Goodacre, Royston; Xu, Jian; Huang, Wei E

    2013-11-19

    We have optimized a Raman microscope to obtain a single cell Raman spectrum (SCRS) with 0.1 s acquisition time. SCRS with such short acquisition time has sufficient discriminatory ability and spectral reproducibility to differentiate cells incorporated with (13)C and (15)N and to classify five different types of bacteria isolated from the oral cavity. We also developed Raman activated cell ejection (RACE) that is assisted by laser induced forward transfer (LIFT). We have shown, for the first time, that the single cells of interest can be identified and then accurately isolated from complex microbial communities based on their SCRS. This approach can be used to sort single cells of target traits from complex samples (e.g., biofilms, soils, sludge, tissues).

  8. Interplanetary Coronal Mass Ejections observed by MESSENGER and Venus Express

    CERN Document Server

    Good, S W

    2015-01-01

    Interplanetary coronal mass ejections (ICMEs) observed by the MESSENGER (MES) and Venus Express (VEX) spacecraft have been catalogued and analysed. The ICMEs were identified by a relatively smooth rotation of the magnetic field direction consistent with a flux rope structure, coinciding with a relatively enhanced magnetic field strength. A total of 35 ICMEs were found in the surveyed MES data (primarily from March 2007 to April 2012), and 84 ICMEs in the surveyed VEX data (from May 2006 to December 2013). The ICME flux rope configurations have been determined. Ropes with northward leading edges were about four times more common than ropes with southward leading edges, in agreement with a previously established solar cycle dependence. Ropes with low inclinations to the solar equatorial plane were about four times more common than ropes with high inclinations, possibly an observational effect. Left and right-handed ropes were observed in almost equal numbers. In addition, data from MES, VEX, STEREO-A, STEREO-B ...

  9. Final common envelope ejection by migration and jets

    CERN Document Server

    Soker, Noam

    2014-01-01

    I summarize recent analytical and numerical studies of the common envelope (CE) process and suggest to replace the commonly used alpha-prescription for the CE ejection by a prescription based on final migration and jets launched by the companion or the core of the giant stellar primary. In the migration process the core-companion binary systems is surrounded by a highly oblate (flatten) envelope, a thick circumbinary disk, formed by the large angular momentum transferred from the core-companion system to the envelope. I then show that the energy that can be released by an accreting main sequence companion can surpass the mutual gravitational energy of the core and the companion. An efficient channel to leash the accretion energy to expel the CE is through jets operating via a feedback mechanism (JFM).

  10. Close Binary Progenitors and Ejected Companions of Thermonuclear Supernovae

    Science.gov (United States)

    Geier, S.; Kupfer, T.; Heber, U.; Nemeth, P.; Ziegerer, E.; Irrgang, A.; Schindewolf, M.; Marsh, T. R.; Gänsicke, B. T.; Barlow, B. N.; Bloemen, S.

    2017-03-01

    Hot subdwarf stars (sdO/Bs) are evolved core helium-burning stars with very thin hydrogen envelopes, which can be formed by common envelope ejection. Close sdB binaries with massive white dwarf (WD) companions are potential progenitors of thermonuclear supernovae type Ia (SN Ia). We discovered such a progenitor candidate as well as a candidate for a surviving companion star, which escapes from the Galaxy. More candidates for both types of objects have been found by cross-matching known sdB stars with proper motion and light curve catalogues. We found 72 sdO/B candidates with high Galactic restframe velocities, 12 of them might be unbound to our Galaxy. Furthermore, we discovered the second-most compact sdB+WD binary known. However, due to the low mass of the WD companion, it is unlikely to be a SN Ia progenitor.

  11. Predicting Coronal Mass Ejections Using Machine Learning Methods

    CERN Document Server

    Bobra, Monica G

    2016-01-01

    Of all the activity observed on the Sun, two of the most energetic events are flares and Coronal Mass Ejections (CMEs). Usually, solar active regions that produce large flares will also produce a CME, but this is not always true (Yashiro et al., 2005). Despite advances in numerical modeling, it is still unclear which circumstances will produce a CME (Webb & Howard, 2012). Therefore, it is worthwhile to empirically determine which features distinguish flares associated with CMEs from flares that are not. At this time, no extensive study has used physically meaningful features of active regions to distinguish between these two populations. As such, we attempt to do so by using features derived from [1] photospheric vector magnetic field data taken by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager instrument and [2] X-ray flux data from the Geostationary Operational Environmental Satellite's X-ray Flux instrument. We build a catalog of active regions that either produced both a flare and a...

  12. Heart failure with preserved ejection fraction: emerging drug strategies.

    Science.gov (United States)

    Zouein, Fouad A; de Castro Brás, Lisandra E; da Costa, Danielle V; Lindsey, Merry L; Kurdi, Mazen; Booz, George W

    2013-07-01

    Approximately half of heart failure patients have a normal ejection fraction, a condition designated as heart failure with preserved ejection fraction (HFpEF). This heart failure subtype disproportionately affects women and the elderly and is commonly associated with other cardiovascular comorbidities, such as hypertension and diabetes. HFpEF is increasing at a steady rate and is predicted to become the leading cause of heart failure within a decade. HFpEF is characterized by impaired diastolic function, thought to be due to concentric remodeling of the heart along with increased stiffness of both the extracellular matrix and myofilaments. In addition, oxidative stress and inflammation are thought to have a role in HFpEF progression, along with endothelial dysfunction and impaired nitric oxide-cyclic guanosine monophosphate-protein kinase G signaling. Surprisingly a number of clinical studies have failed to demonstrate any benefit of drugs effective in heart failure with systolic dysfunction in HFpEF patients. Thus, HFpEF is one of the largest unmet needs in cardiovascular medicine, and there is a substantial need for new therapeutic approaches and strategies that target mechanisms specific for HFpEF. This conclusion is underscored by the recently reported disappointing results of the RELAX trial, which assessed the use of phosphodiesterase-5 inhibitor sildenafil for treating HFpEF. In animal models, endothelial nitric oxide synthase activators and If current inhibitors have shown benefit in improving diastolic function, and there is a rationale for assessing matrix metalloproteinase 9 inhibitors and nitroxyl donors. LCZ696, a combination drug of angiotensin II receptor blocker and neprilysin inhibitor, and the aldosterone receptor antagonist spironolactone are currently in clinical trial for treating HFpEF. Here we present an overview of the etiology and diagnosis of HFpEF that segues into a discussion of new therapeutic approaches emerging from basic research and

  13. Episodic mass ejections from common-envelope objects

    Science.gov (United States)

    Clayton, Matthew; Podsiadlowski, Philipp; Ivanova, Natasha; Justham, Stephen

    2017-09-01

    After the initial fast spiral-in phase experienced by a common-envelope binary, the system may enter a slow, self-regulated phase, possibly lasting hundreds of years, in which all the energy released by orbital decay can be efficiently transported to the surface, where it is radiated away. If the remaining envelope is to be removed during this phase, this removal must occur through some as-yet-undetermined mechanism. We carried out 1D hydrodynamic simulations of a low-mass red giant undergoing a synthetic common-envelope event in such a slow spiral-in phase, using the stellar evolutionary code mesa. We simulated the heating of the envelope due to frictional dissipation from a binary companion's orbit in multiple configurations and investigated the response of the giant's envelope. We find that our model envelopes become dynamically unstable and develop large-amplitude pulsations, with periods in the range 3-20 yr and very short growth time-scales of similar order. The shocks and associated rebounds that emerge as these pulsations grow are in some cases strong enough to dynamically eject shells of matter of up to 0.1 M⊙, ∼10 per cent of the mass of the envelope, from the stellar surface at above escape velocity. These ejections are seen to repeat within a few decades, leading to a time-averaged mass-loss rate of the order of 10-3 M⊙ yr-1, which is sufficiently high to represent a candidate mechanism for removing the entire envelope over the duration of the slow spiral-in phase.

  14. Metabolomic fingerprint of heart failure with preserved ejection fraction.

    Directory of Open Access Journals (Sweden)

    Beshay N Zordoky

    Full Text Available Heart failure (HF with preserved ejection fraction (HFpEF is increasingly recognized as an important clinical entity. Preclinical studies have shown differences in the pathophysiology between HFpEF and HF with reduced ejection fraction (HFrEF. Therefore, we hypothesized that a systematic metabolomic analysis would reveal a novel metabolomic fingerprint of HFpEF that will help understand its pathophysiology and assist in establishing new biomarkers for its diagnosis.Ambulatory patients with clinical diagnosis of HFpEF (n = 24, HFrEF (n = 20, and age-matched non-HF controls (n = 38 were selected for metabolomic analysis as part of the Alberta HEART (Heart Failure Etiology and Analysis Research Team project. 181 serum metabolites were quantified by LC-MS/MS and 1H-NMR spectroscopy. Compared to non-HF control, HFpEF patients demonstrated higher serum concentrations of acylcarnitines, carnitine, creatinine, betaine, and amino acids; and lower levels of phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins. Medium and long-chain acylcarnitines and ketone bodies were higher in HFpEF than HFrEF patients. Using logistic regression, two panels of metabolites were identified that can separate HFpEF patients from both non-HF controls and HFrEF patients with area under the receiver operating characteristic (ROC curves of 0.942 and 0.981, respectively.The metabolomics approach employed in this study identified a unique metabolomic fingerprint of HFpEF that is distinct from that of HFrEF. This metabolomic fingerprint has been utilized to identify two novel panels of metabolites that can separate HFpEF patients from both non-HF controls and HFrEF patients.ClinicalTrials.gov NCT02052804.

  15. Metabolomic Fingerprint of Heart Failure with Preserved Ejection Fraction

    Science.gov (United States)

    Zordoky, Beshay N.; Sung, Miranda M.; Ezekowitz, Justin; Mandal, Rupasri; Han, Beomsoo; Bjorndahl, Trent C.; Bouatra, Souhaila; Anderson, Todd; Oudit, Gavin Y.; Wishart, David S.; Dyck, Jason R. B.

    2015-01-01

    Background Heart failure (HF) with preserved ejection fraction (HFpEF) is increasingly recognized as an important clinical entity. Preclinical studies have shown differences in the pathophysiology between HFpEF and HF with reduced ejection fraction (HFrEF). Therefore, we hypothesized that a systematic metabolomic analysis would reveal a novel metabolomic fingerprint of HFpEF that will help understand its pathophysiology and assist in establishing new biomarkers for its diagnosis. Methods and Results Ambulatory patients with clinical diagnosis of HFpEF (n = 24), HFrEF (n = 20), and age-matched non-HF controls (n = 38) were selected for metabolomic analysis as part of the Alberta HEART (Heart Failure Etiology and Analysis Research Team) project. 181 serum metabolites were quantified by LC-MS/MS and 1H-NMR spectroscopy. Compared to non-HF control, HFpEF patients demonstrated higher serum concentrations of acylcarnitines, carnitine, creatinine, betaine, and amino acids; and lower levels of phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins. Medium and long-chain acylcarnitines and ketone bodies were higher in HFpEF than HFrEF patients. Using logistic regression, two panels of metabolites were identified that can separate HFpEF patients from both non-HF controls and HFrEF patients with area under the receiver operating characteristic (ROC) curves of 0.942 and 0.981, respectively. Conclusions The metabolomics approach employed in this study identified a unique metabolomic fingerprint of HFpEF that is distinct from that of HFrEF. This metabolomic fingerprint has been utilized to identify two novel panels of metabolites that can separate HFpEF patients from both non-HF controls and HFrEF patients. Clinical Trial Registration ClinicalTrials.gov NCT02052804 PMID:26010610

  16. Dynamical mass ejection from binary neutron star mergers

    Science.gov (United States)

    Radice, David; Galeazzi, Filippo; Lippuner, Jonas; Roberts, Luke F.; Ott, Christian D.; Rezzolla, Luciano

    2016-08-01

    We present fully general-relativistic simulations of binary neutron star mergers with a temperature and composition dependent nuclear equation of state. We study the dynamical mass ejection from both quasi-circular and dynamical-capture eccentric mergers. We systematically vary the level of our treatment of the microphysics to isolate the effects of neutrino cooling and heating and we compute the nucleosynthetic yields of the ejecta. We find that eccentric binaries can eject significantly more material than quasi-circular binaries and generate bright infrared and radio emission. In all our simulations the outflow is composed of a combination of tidally- and shock-driven ejecta, mostly distributed over a broad ˜60° angle from the orbital plane, and, to a lesser extent, by thermally driven winds at high latitudes. Ejecta from eccentric mergers are typically more neutron rich than those of quasi-circular mergers. We find neutrino cooling and heating to affect, quantitatively and qualitatively, composition, morphology, and total mass of the outflows. This is also reflected in the infrared and radio signatures of the binary. The final nucleosynthetic yields of the ejecta are robust and insensitive to input physics or merger type in the regions of the second and third r-process peaks. The yields for elements on the first peak vary between our simulations, but none of our models is able to explain the Solar abundances of first-peak elements without invoking additional first-peak contributions from either neutrino and viscously-driven winds operating on longer time-scales after the mergers, or from core-collapse supernovae.

  17. Enhancement of Terrestrial Diffuse X-ray Emission Associated With Coronal Mass Ejection and Geomagnetic Storm

    CERN Document Server

    Ezoe, Yuichiro; Yoshitake, Hiroshi; Mitsuda, Kazuhisa; Terada, Naoki; Oishi, Shihoko; Ohashi, Takaya

    2011-01-01

    We present an analysis of a Suzaku observation taken during the geomagnetic storm of 2005 August 23-24. We found time variation of diffuse soft X-ray emission when a coronal mass ejection hit Earth and caused a geomagnetic storm. The diffuse emission consists of fluorescent scattering of solar X-rays and exospheric solarwind charge exchange. The former is characterized by a neutral oxygen emission line due to strong heating of the upper atmosphere during the storm time, while the latter is dominated by a sum of C V, C VI, N VI, N VII, O VII, and O VIII emission lines due to the enhanced solar wind flux in the vicinity of the exosphere. Using the solar wind data taken with the ACE and WIND satellites,a time correlation between the solar wind and the strong O VII line flux were investigated. We estimated necessary column densities for the solar X-ray scattering and exospheric SWCX. From these results, we argue that a part of the solar wind ions enter inside the magnetosphere and cause the SWCX reaction.

  18. Energy and angular distributions of excited rhodium atoms ejected from the rhodium (100) surface

    Energy Technology Data Exchange (ETDEWEB)

    El-Maazawi, M.; Maboudian, R.; Postawa, Z.; Winograd, N. (Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 (US))

    1991-05-15

    Multiphoton resonance ionization spectroscopy has been used to determine the polar-angle and the kinetic-energy distribution of Rh atoms desorbed from the ion-bombarded Rh{l brace}100{r brace} surface in the fine-structure components of the {ital a}{sup 4}{ital F}{sub {ital J}} ground-state multiplet ({ital J}=9/2 and 7/2). The overall behavior is found to be very similar to that observed for higher-lying metastable levels. The energy distribution of the metastable level ({sup 4}{ital F}{sub 7/2} with excitation energy of {similar to}0.2 eV) is found to be broader than the ground-state ({sup 4}{ital F}{sub 9/2}) distribution. The energy distribution of the excited ejected atoms is shown to depend mainly on the electron configuration of the excited state. The measured spectra have also been used to investigate the dependence of the excitation probability on the emission velocity. It is shown that the excitation probability depends strongly on this parameter, approaching an exponential dependence on the reciprocal of the normal component of velocity at higher velocities ({gt}5{times}10{sup 5} cm/sec).

  19. The cardio-renal-anemia syndrome in elderly subjects with heart failure and a normal ejection fraction: a comparison with heart failure and low ejection fraction.

    Science.gov (United States)

    Cohen, Rose S; Mubashir, Asyia; Wajahat, Raja; Mani, Susan; Hummel, Scott; Maurer, Mathew S

    2006-01-01

    The prevalence and severity of anemia and renal dysfunction in heart failure patients with a normal ejection fraction (HFNEF) is uncharacterized. Two hundred eighty-five consecutive patients admitted to a community hospital with heart failure were stratified by the presence or absence of anemia and a normal or reduced ejection fraction. Comparisons of clinical variables were performed. In this sample, 62% of subjects were anemic, with no difference between those with a normal and a reduced ejection fraction (63% vs. 61%). Anemic HFNEF subjects had a lower glomerular filtration rate (37 +/- 21 mL/min vs. 52 +/- 35 mL/min; p renal dysfunction and anemia. The authors conclude that the degree and magnitude of anemia in elderly inpatients with heart failure does not differ by ejection fraction. Worse symptoms and more severe renal dysfunction were seen in HFNEF subjects with anemia than in HFNEF subjects without anemia.

  20. Space-time evolution of ejected plasma for the triggering of gas switch

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shanhong, E-mail: liushanhong108098@163.com; Liu, Xuandong; Shen, Xi; Feng, Lei; Zhang, Qiaogen [State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Institute of High Voltage Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Tie, Weihao [Xi' an Electrical Engineering Research Institute, Xi' an 710049 (China)

    2016-06-15

    Ejected plasma has been widely applied to the discharge process of gas spark switches as a trigger technology, and the development process of ejected plasma has a direct and important effect on the discharge characteristics of gas switches. In this paper, both the injection characteristics and space-time evolution of ejected plasma for the triggering of gas spark switch with different stored energies, pulse polarities, and pressures are studied. The discharge characteristics and breakdown process of a gas switch ignited by ejected plasma under different working coefficients are also discussed briefly. The results show that stored energy has significant influence on the characteristics of ejected plasma. With the increase of stored energy, the propulsion mode of ejected plasma in the axial direction transforms from “plasmoid” to “plasma flow,” and the distribution of the ejected plasma goes through “cloud,” “core-cloud,” and “branch” in sequence. The velocity of ejected plasma under negative pulse polarity is obviously higher than that under positive pulse polarity, especially at the very beginning time. The radial dimensions of ejected plasma under two kinds of pulse polarities follow the similar varying pattern over time, which increase first and then decrease, assuming an inverted “U”-shaped curve. With the increase of pressure, the velocity of ejected plasma significantly decreases and the “branch” channels droop earlier. Applying the ejected plasma to the triggering of a gas switch, the switch can be triggered reliably in a much wide working coefficient range of 10%–90%. With the increase of working coefficient, the breakdown process of the switch translates from slow working mode to fast working mode, and the delay time reduces from tens of μs to hundreds of ns.

  1. Space-time evolution of ejected plasma for the triggering of gas switch

    Science.gov (United States)

    Liu, Shanhong; Liu, Xuandong; Shen, Xi; Feng, Lei; Tie, Weihao; Zhang, Qiaogen

    2016-06-01

    Ejected plasma has been widely applied to the discharge process of gas spark switches as a trigger technology, and the development process of ejected plasma has a direct and important effect on the discharge characteristics of gas switches. In this paper, both the injection characteristics and space-time evolution of ejected plasma for the triggering of gas spark switch with different stored energies, pulse polarities, and pressures are studied. The discharge characteristics and breakdown process of a gas switch ignited by ejected plasma under different working coefficients are also discussed briefly. The results show that stored energy has significant influence on the characteristics of ejected plasma. With the increase of stored energy, the propulsion mode of ejected plasma in the axial direction transforms from "plasmoid" to "plasma flow," and the distribution of the ejected plasma goes through "cloud," "core-cloud," and "branch" in sequence. The velocity of ejected plasma under negative pulse polarity is obviously higher than that under positive pulse polarity, especially at the very beginning time. The radial dimensions of ejected plasma under two kinds of pulse polarities follow the similar varying pattern over time, which increase first and then decrease, assuming an inverted "U"-shaped curve. With the increase of pressure, the velocity of ejected plasma significantly decreases and the "branch" channels droop earlier. Applying the ejected plasma to the triggering of a gas switch, the switch can be triggered reliably in a much wide working coefficient range of 10%-90%. With the increase of working coefficient, the breakdown process of the switch translates from slow working mode to fast working mode, and the delay time reduces from tens of μs to hundreds of ns.

  2. Simulation of Foam Divot Weight on External Tank Utilizing Least Squares and Neural Network Methods

    Science.gov (United States)

    Chamis, Christos C.; Coroneos, Rula M.

    2007-01-01

    Simulation of divot weight in the insulating foam, associated with the external tank of the U.S. space shuttle, has been evaluated using least squares and neural network concepts. The simulation required models based on fundamental considerations that can be used to predict under what conditions voids form, the size of the voids, and subsequent divot ejection mechanisms. The quadratic neural networks were found to be satisfactory for the simulation of foam divot weight in various tests associated with the external tank. Both linear least squares method and the nonlinear neural network predicted identical results.

  3. Miniature Bipolar Electrostatic Ion Thruster

    Science.gov (United States)

    Hartley, Frank T.

    2006-01-01

    The figure presents a concept of a bipolar miniature electrostatic ion thruster for maneuvering a small spacecraft. The ionization device in the proposed thruster would be a 0.1-micron-thick dielectric membrane with metal electrodes on both sides. Small conical holes would be micromachined through the membrane and electrodes. An electric potential of the order of a volt applied between the membrane electrodes would give rise to an electric field of the order of several mega-volts per meter in the submicron gap between the electrodes. An electric field of this magnitude would be sufficient to ionize all the molecules that enter the holes. In a thruster-based on this concept, one or more propellant gases would be introduced into such a membrane ionizer. Unlike in larger prior ion thrusters, all of the propellant molecules would be ionized. This thruster would be capable of bipolar operation. There would be two accelerator grids - one located forward and one located aft of the membrane ionizer. In one mode of operation, which one could denote the forward mode, positive ions leaving the ionizer on the backside would be accelerated to high momentum by an electric field between the ionizer and an accelerator grid. Electrons leaving the ionizer on the front side would be ejected into free space by a smaller accelerating field. The equality of the ion and electron currents would eliminate the need for an additional electron- or ion-emitting device to keep the spacecraft charge-neutral. In another mode of operation, which could denote the reverse mode, the polarities of the voltages applied to the accelerator grids and to the electrodes of the membrane ionizer would be the reverse of those of the forward mode. The reversal of electric fields would cause the ion and electrons to be ejected in the reverse of their forward mode directions, thereby giving rise to thrust in the direction opposite that of the forward mode.

  4. Ion current rectification inversion in conic nanopores: nonequilibrium ion transport biased by ion selectivity and spatial asymmetry.

    Science.gov (United States)

    Yan, Yu; Wang, Lin; Xue, Jianming; Chang, Hsueh-Chia

    2013-01-28

    We show both theoretically and experimentally that the ion-selectivity of a conic nanopore, as defined by a normalized density of the surface charge, significantly affects ion current rectification across the pore. For weakly selective negatively charged pores, intra-pore ion transport controls the current and internal ion enrichment/depletion at positive/reverse biased voltage (current enters/leaves through the tip, respectively), which is responsible for current rectification. For strongly selective negatively charged pores under positive bias, the current can be reduced by external field focusing and concentration depletion at the tip at low ionic strengths and high voltages, respectively. These external phenomena produce a rectification inversion for highly selective pores at high (low) voltage (ionic strength). With an asymptotic analysis of the intra-pore and external ion transport, we derive simple scaling laws to quantitatively capture empirical and numerical data for ion current rectification and rectification inversion of conic nanopores.

  5. Charge Breeding of Radioactive Ions

    CERN Document Server

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  6. Regularization by External Variables

    DEFF Research Database (Denmark)

    Bossolini, Elena; Edwards, R.; Glendinning, P. A.

    2016-01-01

    Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula...... of regularization, by external variables that shadow either the state or the switch of the original system. The shadow systems are derived from and inspired by various applications in electronic control, predator-prey preference, time delay, and genetic regulation....

  7. Left ventricular dyssynchrony in patients with heart failure and preserved ejection fraction

    NARCIS (Netherlands)

    Santos, Angela B. S.; Kraigher-Krainer, Elisabeth; Bello, Natalie; Claggett, Brian; Zile, Michael R.; Pieske, Burkert; Voors, Adriaan A.; McMurray, John J. V.; Packer, Milton; Bransford, Toni; Lefkowitz, Marty; Shah, Amil M.; Solomon, Scott D.

    2014-01-01

    Aims Mechanical dyssynchrony has been postulated to play a pathophysiologic role in heart failure with preserved ejection fraction (HFpEF). Methods and results We quantified left ventricular (LV) systolic dyssynchrony in 130 HFpEF patients with NYHA class II-IV symptoms, ejection fraction (EF) 45, a

  8. Septum magnet for ejection from the PS to the E-Hall

    CERN Multimedia

    1977-01-01

    Pulsed septum magnet for ejection from PS straight sections 61/62 to the East-Hall. This septum magnet, for ss 61, had only 1 turn, for minimum thickness. It was followed by another septum in ss 62, with 2 turns, as there the ejected beam was already farther away from the circulating beam. Both septa were water-cooled.

  9. Imaging of the Ejection Process of Nanosecond Laser-induced forward Transfer of Gold

    NARCIS (Netherlands)

    Pohl, R.; Visser, C.W.; Römer, G.R.B.E.; Sun, C.; Huis in 't Veld, A.J.; Lohse, D.

    2015-01-01

    Laser-induced forward transfer is a direct-write process suitable for high precision 3D printing of several materials. However, the driving forces related to the ejection mechanism of the donor ma-terial are still under debate. To gain further insights into the ejection dynamics, this article presen

  10. Speeds of coronal mass ejections: SMM observations from 1980 and 1984-1989

    Science.gov (United States)

    Hundhausen, A. J.; Burkepile, J. T.; St. Cyr, O. C.

    1994-01-01

    The speeds of 936 features in 673 coronal mass ejections have been determined from trajectories observed with the Solar Maximum Mission (SMM) coronagraph in 1980 and 1984 to 1989. The distribution of observed speeds has a range (from 5th to 95th percentile) of 35 to 911 km/s; the average and median speeds are 349 and 285 km/s. The speed distributions of some selected classes of mass ejections are significantly different. For example, the speeds of 331 'outer loops' range from 80 to 1042 km/s; the average and median speeds for this class of ejections are 445 and 372 km/s. The speed distributions from each year of SMM observations show significant changes, with the annual average speeds varying from 157 (1984) to 458 km/s (1985). These variations are not simply related to the solar activity cycle; the annual averages from years near the sunspot maxima and minimum are not significantly different. The widths, latitudes, and speeds of mass ejections determined from the SMM observations are only weakly correlated. In particular, mass ejection speeds vary only slightly with the heliographic latitudes of the ejection. High-latitude ejections, which occur well poleward of the active latitudes, have speeds similar to active latitude ejections.

  11. Uniform description of polymer ejection dynamics from capsid with and without hydrodynamics

    Science.gov (United States)

    Piili, J.; Suhonen, P. M.; Linna, R. P.

    2017-05-01

    We use stochastic rotation dynamics (SRD) to examine the dynamics of the ejection of an initially strongly confined flexible polymer from a spherical capsid with and without hydrodynamics. The results obtained using stochastic rotation dynamics (SRD) are compared to similar Langevin simulations. Inclusion of hydrodynamic modes speeds up the ejection but also allows the part of the polymer outside the capsid to expand closer to equilibrium. This shows as higher values of radius of gyration when hydrodynamics are enabled. By examining the waiting times of individual polymer beads, we find that the waiting time tw grows with the number of ejected monomers s as a sum of two exponents. When ≈63 % of the polymer has ejected, the ejection enters the regime of slower dynamics. The functional form of tw versus s is universal for all ejection processes starting from the same initial monomer densities. Inclusion of hydrodynamics only reduces its magnitude. Consequently, we define a universal scaling function h such that the cumulative waiting time t =N0h (s /N0) for large N0. Our unprecedentedly precise measurements of force indicate that this form for tw(s ) originates from the corresponding force toward the pore decreasing superexponentially at the end of the ejection. Our measured tw(s ) explains the apparent superlinear scaling of the ejection time with the polymer length for short polymers. However, for asymptotically long polymers, tw(s ) predicts linear scaling.

  12. Heart failure with preserved ejection fraction in women : The dutch queen of hearts program

    NARCIS (Netherlands)

    den Ruijter, H.; Pasterkamp, G.; Rutten, F. H.; Lam, C. S P; Chi, C.; Tan, K. H.; van Zonneveld, A. J.; Spaanderman, M.; de Kleijn, D. P V

    2015-01-01

    Heart failure (HF) poses a heavy burden on patients, their families and society. The syndrome of HF comes in two types: with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). The latter is on the increase and predominantly present in women, especially the older ones. There i

  13. Ejection Regimes in Picosecond Laser-Induced Forward Transfer of Metals

    NARCIS (Netherlands)

    Pohl, Ralph; Visser, Claas Willem; Römer, Gert-Willem; Lohse, Detlef; Sun, Chao; Huis in 't Veld, Bert

    2015-01-01

    Laser-induced forward transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials, including pure metals. To understand the ejection mechanism and thereby improve deposition, here we present visualizations of ejection events at high-spatial (submicrometer) and hi

  14. Oxidation of methionine residues in polypeptide ions via gas-phase ion/ion chemistry.

    Science.gov (United States)

    Pilo, Alice L; McLuckey, Scott A

    2014-06-01

    The gas-phase oxidation of methionine residues is demonstrated here using ion/ion reactions with periodate anions. Periodate anions are observed to attach in varying degrees to all polypeptide ions irrespective of amino acid composition. Direct proton transfer yielding a charge-reduced peptide ion is also observed. In the case of methionine and, to a much lesser degree, tryptophan-containing peptide ions, collisional activation of the complex ion generated by periodate attachment yields an oxidized peptide product (i.e., [M + H + O](+)), in addition to periodic acid detachment. Detachment of periodic acid takes place exclusively for peptides that do not contain either a methionine or tryptophan side chain. In the case of methionine-containing peptides, the [M + H + O](+) product is observed at a much greater abundance than the proton transfer product (viz., [M + H](+)). Collisional activation of oxidized Met-containing peptides yields a signature loss of 64 Da from the precursor and/or product ions. This unique loss corresponds to the ejection of methanesulfenic acid from the oxidized methionine side chain and is commonly used in solution-phase proteomics studies to determine the presence of oxidized methionine residues. The present work shows that periodate anions can be used to 'label' methionine residues in polypeptides in the gas phase. The selectivity of the periodate anion for the methionine side chain suggests several applications including identification and location of methionine residues in sequencing applications.

  15. THE VERY UNUSUAL INTERPLANETARY CORONAL MASS EJECTION OF 2012 JULY 23: A BLAST WAVE MEDIATED BY SOLAR ENERGETIC PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Russell, C. T. [University of California, Los Angeles, CA 90095-1567 (United States); Mewaldt, R. A.; Cohen, C. M. S.; Leske, R. A. [California Institute of Technology, Pasadena, CA 91125 (United States); Luhmann, J. G. [University of California, Berkeley, CA 94720 (United States); Mason, G. M. [Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States); Von Rosenvinge, T. T. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gomez-Herrero, R. [University of Alcala, E-28871 Alcala de Henares (Spain); Klassen, A. [Kiel University, D-24118 Kiel (Germany); Galvin, A. B.; Simunac, K. D. C., E-mail: ctrussell@igpp.ucla.edu [University of New Hampshire, Durham, NH 03824 (United States)

    2013-06-10

    The giant, superfast, interplanetary coronal mass ejection, detected by STEREO A on 2012 July 23, well away from Earth, appears to have reached 1 AU with an unusual set of leading bow waves resembling in some ways a subsonic interaction, possibly due to the high pressures present in the very energetic particles produced in this event. Eventually, a front of record high-speed flow reached STEREO. The unusual behavior of this event is illustrated using the magnetic field, plasma, and energetic ion observations obtained by STEREO. Had the Earth been at the location of STEREO, the large southward-oriented magnetic field component in the event, combined with its high speed, would have produced a record storm.

  16. Sizes and locations of coronal mass ejections - SMM observations from 1980 and 1984-1989

    Science.gov (United States)

    Hundhausen, A. J.

    1993-01-01

    A statistical description of the sizes and locations of 1209 mass ejections observed with the SMM coronagraph/polarimeter in 1980 and 1984-1989 is presented. The average width of the coronal mass ejections detected with this instrument was close to 40 deg in angle for the entire period of SMM observations. No evidence was found for a significant change in mass ejection widths as reported by Howard et al. (1986). There is clear evidence for changes in the latitude distribution of mass ejections over this epoch. Mass ejections occurred over a much wider range of latitudes at the times of high solar activity (1980 and 1989) than at times of low activity (1985-1986).

  17. Two billion years of magmatism recorded from a single Mars meteorite ejection site

    Science.gov (United States)

    Lapen, Thomas J.; Righter, Minako; Andreasen, Rasmus; Irving, Anthony J.; Satkoski, Aaron M.; Beard, Brian L.; Nishiizumi, Kunihiko; Jull, A. J. Timothy; Caffee, Marc W.

    2017-01-01

    The timing and nature of igneous activity recorded at a single Mars ejection site can be determined from the isotope analyses of Martian meteorites. Northwest Africa (NWA) 7635 has an Sm-Nd crystallization age of 2.403 ± 0.140 billion years, and isotope data indicate that it is derived from an incompatible trace element–depleted mantle source similar to that which produced a geochemically distinct group of 327- to 574-million-year-old “depleted” shergottites. Cosmogenic nuclide data demonstrate that NWA 7635 was ejected from Mars 1.1 million years ago (Ma), as were at least 10 other depleted shergottites. The shared ejection age is consistent with a common ejection site for these meteorites. The spatial association of 327- to 2403-Ma depleted shergottites indicates >2 billion years of magmatism from a long-lived and geochemically distinct volcanic center near the ejection site. PMID:28164153

  18. Type Ia supernova bolometric light curves and ejected mass estimates from the Nearby Supernova Factory

    CERN Document Server

    Scalzo, R; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Cellier-Holzem, F; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Guy, J; Kim, A; Kowalski, M; Kromer, M; Nordin, J; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Runge, K; Saunders, C; Sim, S A; Smadja, G; Tao, C; Taubenberger, S; Thomas, R C; Weaver, B A

    2014-01-01

    We present a sample of normal type Ia supernovae from the Nearby Supernova Factory dataset with spectrophotometry at sufficiently late phases to estimate the ejected mass using the bolometric light curve. We measure $^{56}$Ni masses from the peak bolometric luminosity, then compare the luminosity in the $^{56}$Co-decay tail to the expected rate of radioactive energy re- lease from ejecta of a given mass. We infer the ejected mass in a Bayesian context using a semi-analytic model of the ejecta, incorporating constraints from contemporary numerical models as priors on the density structure and distribution of $^{56}$Ni throughout the ejecta. We find a strong correlation between ejected mass and light curve decline rate, and consequently $^{56}$Ni mass, with ejected masses in our data ranging from 0.9-1.4 $M_\\odot$. Most fast-declining (SALT2 $x_1 < -1$) normal SNe Ia have significantly sub-Chandrasekhar ejected masses in our fiducial analysis.

  19. Femtosecond pulse-width dependent trapping and directional ejection dynamics of dielectric nanoparticles

    KAUST Repository

    Chiang, Weiyi

    2013-09-19

    We demonstrate that laser pulse duration, which determines its impulsive peak power, is an effective parameter to control the number of optically trapped dielectric nanoparticles, their ejections along the directions perpendicular to polarization vector, and their migration distances from the trapping site. This ability to controllably confine and eject the nanoparticle is explained by pulse width-dependent optical forces exerted on nanoparticles in the trapping site and ratio between the repulsive and attractive forces. We also show that the directional ejections occur only when the number of nanoparticles confined in the trapping site exceeds a definite threshold. We interpret our data by considering the formation of transient assembly of the optically confined nanoparticles, partial ejection of the assembly, and subsequent filling of the trapping site. The understanding of optical trapping and directional ejections by ultrashort laser pulses paves the way to optically controlled manipulation and sorting of nanoparticles. © 2013 American Chemical Society.

  20. Right Ventricular Ejection Fraction Is Incremental to Left Ventricular Ejection Fraction for the Prediction of Future Arrhythmic Events in Patients With Systolic Dysfunction.

    Science.gov (United States)

    Mikami, Yoko; Jolly, Umjeet; Heydari, Bobak; Peng, Mingkai; Almehmadi, Fahad; Zahrani, Mohammed; Bokhari, Mahmoud; Stirrat, John; Lydell, Carmen P; Howarth, Andrew G; Yee, Raymond; White, James A

    2017-01-01

    Left ventricular ejection fraction remains the primary risk stratification tool used in the selection of patients for implantable cardioverter defibrillator therapy. However, this solitary marker fails to identify a substantial portion of patients experiencing sudden cardiac arrest. In this study, we examined the incremental value of considering right ventricular ejection fraction for the prediction of future arrhythmic events in patients with systolic dysfunction using the gold standard of cardiovascular magnetic resonance. Three hundred fourteen consecutive patients with ischemic cardiomyopathy or nonischemic dilated cardiomyopathy undergoing cardiovascular magnetic resonance were followed for the primary outcome of sudden cardiac arrest or appropriate implantable cardioverter defibrillator therapy. Blinded quantification of left ventricular and right ventricular (RV) volumes was performed from standard cine imaging. Quantification of fibrosis from late gadolinium enhancement imaging was incrementally performed. RV dysfunction was defined as right ventricular ejection fraction ≤45%. Among all patients (164 ischemic cardiomyopathy, 150 nonischemic dilated cardiomyopathy), the mean left ventricular ejection fraction was 32±12% (range, 6-54%) with mean right ventricular ejection fraction of 48±15% (range, 7-78%). At a median of 773 days, 49 patients (15.6%) experienced the primary outcome (9 sudden cardiac arrest, 40 appropriate implantable cardioverter defibrillator therapies). RV dysfunction was independently predictive of the primary outcome (hazard ratio=2.98; P=0.002). Among those with a left ventricular ejection fraction >35% (N=121; mean left ventricular ejection fraction, 45±6%), RV dysfunction provided an adjusted hazard ratio of 4.2 (P=0.02). RV dysfunction is a strong, independent predictor of arrhythmic events. Among patients with mild to moderate LV dysfunction, a cohort greatly contributing to global sudden cardiac arrest burden, this marker

  1. Abnormal calcium homeostasis in heart failure with preserved ejection fraction is related to both reduced contractile function and incomplete relaxation: an electromechanically detailed biophysical modeling study

    Science.gov (United States)

    Adeniran, Ismail; MacIver, David H.; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF) accounts for about 50% of heart failure cases. It has features of incomplete relaxation and increased stiffness of the left ventricle. Studies from clinical electrophysiology and animal experiments have found that HFpEF is associated with impaired calcium homeostasis, ion channel remodeling and concentric left ventricle hypertrophy (LVH). However, it is still unclear how the abnormal calcium homeostasis, ion channel and structural remodeling affect the electro-mechanical dynamics of the ventricles. In this study we have developed multiscale models of the human left ventricle from single cells to the 3D organ, which take into consideration HFpEF-induced changes in calcium handling, ion channel remodeling and concentric LVH. Our simulation results suggest that at the cellular level, HFpEF reduces the systolic calcium level resulting in a reduced systolic contractile force, but elevates the diastolic calcium level resulting in an abnormal residual diastolic force. In our simulations, these abnormal electro-mechanical features of the ventricular cells became more pronounced with the increase of the heart rate. However, at the 3D organ level, the ejection fraction of the left ventricle was maintained due to the concentric LVH. The simulation results of this study mirror clinically observed features of HFpEF and provide new insights toward the understanding of the cellular bases of impaired cardiac electromechanical functions in heart failure. PMID:25852567

  2. Abnormal calcium homeostasis in heart failure with preserved ejection fraction is related to both reduced contractile function and incomplete relaxation: An electromechanically detailed biophysical modelling study

    Directory of Open Access Journals (Sweden)

    Ismail eAdeniran

    2015-03-01

    Full Text Available Heart failure with preserved ejection fraction (HFpEF accounts for about 50% of heart failure cases. It has features of incomplete relaxation and increased stiffness of the left ventricle. Studies from clinical electrophysiology and animal experiments have found that HFpEF is associated with impaired calcium homeostasis, ion channel remodelling and concentric left ventricle hypertrophy (LVH. However, it is still unclear how the abnormal calcium homeostasis, ion channel and structural remodelling affect the electro-mechanical dynamics of the ventricles. In this study we have developed multiscale models of the human left ventricle from single cells to the 3D organ, which take into consideration HFpEF-induced changes in calcium handling, ion channel remodelling and concentric LVH. Our simulation results suggest that at the cellular level, HFpEF reduces the systolic calcium level resulting in a reduced systolic contractile force, but elevates the diastolic calcium level resulting in an abnormal residual diastolic force. In our simulations, these abnormal electro-mechanical features of the ventricular cells became more pronounced with the increase of the heart rate. However, at the 3D organ level, the ejection fraction of the left ventricle was maintained due to the concentric LVH. The simulation results of this study mirror clinically observed features of HFpEF and provide new insights towards the understanding of the cellular bases of impaired cardiac electromechanical functions in heart failure.

  3. External Measures of Cognition

    Directory of Open Access Journals (Sweden)

    Osvaldo eCairo

    2011-10-01

    Full Text Available The human brain is undoubtedly the most impressive, complex and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind.

  4. Coronal ``Wave'': Magnetic Footprint of a Coronal Mass Ejection?

    Science.gov (United States)

    Attrill, Gemma D. R.; Harra, Louise K.; van Driel-Gesztelyi, Lidia; Démoulin, Pascal

    2007-02-01

    We investigate the properties of two ``classical'' EUV Imaging Telescope (EIT) coronal waves. The two source regions of the associated coronal mass ejections (CMEs) possess opposite helicities, and the coronal waves display rotations in opposite senses. We observe deep core dimmings near the flare site and also widespread diffuse dimming, accompanying the expansion of the EIT wave. We also report a new property of these EIT waves, namely, that they display dual brightenings: persistent ones at the outermost edge of the core dimming regions and simultaneously diffuse brightenings constituting the leading edge of the coronal wave, surrounding the expanding diffuse dimmings. We show that such behavior is consistent with a diffuse EIT wave being the magnetic footprint of a CME. We propose a new mechanism where driven magnetic reconnections between the skirt of the expanding CME magnetic field and quiet-Sun magnetic loops generate the observed bright diffuse front. The dual brightenings and the widespread diffuse dimming are identified as innate characteristics of this process.

  5. Global Energetics of Solar Flares: IV. Coronal Mass Ejection Energetics

    CERN Document Server

    Aschwanden, Markus J

    2016-01-01

    This study entails the fourth part of a global flare energetics project, in which the mass $m_{\\mathrm{cme}}$, kinetic energy $E_{\\mathrm{kin}}$, and the gravitational potential energy $E_{\\mathrm{grav}}$ of coronal mass ejections (CMEs) is measured in 399 M and X-class flare events observed during the first 3.5 yrs of the Solar Dynamics Observatory (SDO) mission, using a new method based on the EUV dimming effect. The EUV dimming is modeled in terms of a radial adiabatic expansion process, which is fitted to the observed evolution of the total emission measure of the CME source region. The model derives the evolution of the mean electron density, the emission measure, the bulk plasma expansion velocity, the mass, and the energy in the CME source region. The EUV dimming method is truly complementary to the Thomson scattering method in white light, which probes the CME evolution in the heliosphere at $r > 2 R_{\\odot}$, while the EUV dimming method tracks the CME launch in the corona. We compare the CME paramet...

  6. Coronal mass ejections and geomagnetic storms: Seasonal variations

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-07-01

    The well-established semiannual geomagnetic cycle, with peak activity near the equinoxes, has been attributed to the angle between the solar rotation axis and the geomagnetic dipole, which modulates the GSM Bz component in the interplanetary magnetic field (MF). This effect is predicted to be accentuated in the shocked plasma ahead of fast coronal mass ejections (CMESs); its relevance to the internal fields of the ejecta is unclear. CMEs, particularly fast events driving interplanetary shocks, are the cause of almost all large geomagnetic storms near solar maximum. We use a set of CMEs identified by ISEE-3 observations of bidirectional electron streaming, plus IMF and geomagnetic data, to investigate the semiannual geomagnetic variation and its relation to CMEs. We find that the geomagnetic effectiveness of CMEs and post-shock solar wind is well-ordered by speed and by the southward component of the IMF in GSM coordinates, as well as by preexisting geomagnetic conditions. The post-shock seasonal effect, with geomagnetic effectiveness maximizing near April 5 for negative GSEQ By and near October 5 for positive GSEQ By, is identifiable in shock and shock/CME events, but not for CME events without leading shocks. When used to complement the more fundamental causal parameter of CME speed, the seasonal effect appears to have value for prediction of geomagnetic storms.

  7. Coronal mass ejections and geomagnetic storms: Seasonal variations

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

    The well-established semiannual geomagnetic cycle, with peak activity near the equinoxes, has been attributed to the angle between the solar rotation axis and the geomagnetic dipole, which modulates the GSM Bz component in the interplanetary magnetic field (MF). This effect is predicted to be accentuated in the shocked plasma ahead of fast coronal mass ejections (CMESs); its relevance to the internal fields of the ejecta is unclear. CMEs, particularly fast events driving interplanetary shocks, are the cause of almost all large geomagnetic storms near solar maximum. We use a set of CMEs identified by ISEE-3 observations of bidirectional electron streaming, plus IMF and geomagnetic data, to investigate the semiannual geomagnetic variation and its relation to CMEs. We find that the geomagnetic effectiveness of CMEs and post-shock solar wind is well-ordered by speed and by the southward component of the IMF in GSM coordinates, as well as by preexisting geomagnetic conditions. The post-shock seasonal effect, with geomagnetic effectiveness maximizing near April 5 for negative GSEQ By and near October 5 for positive GSEQ By, is identifiable in shock and shock/CME events, but not for CME events without leading shocks. When used to complement the more fundamental causal parameter of CME speed, the seasonal effect appears to have value for prediction of geomagnetic storms.

  8. On interplanetary coronal mass ejection identification at 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, T.; Russell, C.T. [Institute of Geophysics and Planetary Physics and the Department of Earth and Space Sciences University of California Los Angeles (United States); Gosling, J.T. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

    1999-06-01

    Coronal mass ejections are believed to be produced in the corona from closed magnetic regions not previously participating in the solar wind expansion. At 1 AU their interplanetary counterparts (ICMEs) generally have a number of distinct plasma and field signatures that distinguish them from the ambient solar wind. These include heat flux dropouts, bi-directional streaming, enhanced alpha particle events, times of depressed proton temperatures, intervals of distorted or enhanced magnetic field, and times of large magnetic field rotations characteristic of magnetic clouds. The first three of these signatures are phenomena that occur at some point within the ICME, but do not necessarily persist throughout the entire ICME. The large scale magnetic field rotations, distortions and enhancements, and the proton temperature depressions tend to mark more accurately the beginning and end of the ICME proper. We examine herein the reliability with which each of these markers identifies ICMEs utilizing ISEE-3 data from 1978{endash}1980. {copyright} {ital 1999 American Institute of Physics.}

  9. Large Geomagnetic Storms Associated with Limb Halo Coronal Mass Ejections

    CERN Document Server

    Gopalswamy, Nat; Xie, Hong; Akiyama, Sachiko; Makela, Pertti

    2009-01-01

    Solar cycle 23 witnessed the observation of hundreds of halo coronal mass ejections (CMEs), thanks to the high dynamic range and extended field of view of the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO) mission. More than two thirds of halo CMEs originating on the front side of the Sun have been found to be geoeffective (Dst = 45deg) have a 20% shorter delay time on the average. It was suggested that the geomagnetic storms due to limb halos must be due to the sheath portion of the interplanetary CMEs (ICMEs) so that the shorter delay time can be accounted for. We confirm this suggestion by examining the sheath and ejecta portions of ICMEs from Wind and ACE data that correspond to the limb halos. Detailed examination showed that three pairs of limb halos were interacting events. Geomagnetic storms following five limb halos were actually produced by other disk halos. The storms followed by four isolated limb halos and the ones associated with interact...

  10. The Relationship of Coronal Mass Ejections to Streamers

    CERN Document Server

    Subramanian, P; Rich, N B; Howard, R A; Subramanian, Prasad

    1999-01-01

    We have examined images from the Large Angle Spectroscopic Coronagraph (LASCO) to study the relationship of Coronal Mass Ejections (CMEs) to coronal streamers. We wish to test the suggestion (Low 1996) that CMEs arise from flux ropes embedded in a streamer erupting, thus disrupting the streamer. The data span a period of two years near sunspot minimum through a period of increased activity as sunspot numbers increased. We have used LASCO data from the C2 coronagraph which records Thomson scattered white light from coronal electrons at heights between 1.5 and 6R_sun. Maps of the coronal streamers have been constructed from LASCO C2 observations at a height of 2.5R_sun at the east and west limbs. We have superposed the corresponding positions of CMEs observed with the C2 coronagraph onto the synoptic maps. We identified the different kinds of signatures CMEs leave on the streamer structure at this height (2.5R_sun). We find four types of CMEs with respect to their effect on streamers: 1. CMEs that disrupt the s...

  11. The 3D structure of Coronal Mass Ejections

    Science.gov (United States)

    Patsourakos, Spiros

    2016-07-01

    Coronal Mass Ejections (CMEs) represent one of the most powerful energy release phenomena in the entire solar system and are a major driver of space weather. Prior to 2006, our observational access to CMEs was limited to single viewpoint remote sensing observations in the inner/outer corona, and in-situ observations further away, e.g. at 1 AU. Taking all these factors together, turned out to be a major obstacle in our understanding and characterizing of the 3D structure and evolution of CMEs. The situation improved dramatically with the availability of multi-viewpoint imaging observations of CMEs, all way through from the Sun to 1 AU, from the STEREO mission since 2006, combined with observations from other missions (SOHO, Hinode, SDO, IRIS). With this talk we will discuss several key recent results in CME science resulting from the analysis of multi-viewpoint observations. This includes: (1) shape and structure; (2) kinematics and energetics; (3) trajectories, deflections and rotations; (4) arrival times and velocities at 1 AU; (5) magnetic field structure; (6) relationships with coronal and interplanetary shocks and solar energetic particles. The implications of these results in terms of CME theories and models will be also addressed. We will conclude with a discussion of important open issues in our understanding of CMEs and how these could be addressed with upcoming (Solar Orbiter, Solar Probe Plus) and under-study missions (e.g., L5).

  12. A numerical study of two interacting coronal mass ejections

    Directory of Open Access Journals (Sweden)

    J. M. Schmidt

    2004-06-01

    Full Text Available The interaction in the solar wind between two coronal mass ejections (CMEs is investigated using numerical simulations. We show that the nature of the interaction depends on whether the CME magnetic structures interact, but in all cases the result is an equilisation of the speed of the two CMEs. In the absence of magnetic interaction, the forward shock of the faster trailing CME interacts with the slow leading CME, and accelerates it. When the two CMEs have magnetic fields with the same sense of rotation, magnetic reconnection occurs between the two CMEs, leading to the formation of a single magnetic structure: in the most extreme cases, one CME "eats" the other. When the senses of rotation are opposite, reconnection does not occur, but the CMEs collide in a highly non-elastic manner, again forming a single structure. The possibility of enhanced particle acceleration in such processes is assessed. The presence of strong magnetic reconnection provides excellent opportunities for the acceleration of thermal particles, which then form a seed population for further acceleration at the CME shocks. The presence of a large population of seed particles will thus lead to an overall increase in energetic particle fluxes, as suggested by some observations.

  13. Regarding the detectability and measurement of coronal mass ejections

    Directory of Open Access Journals (Sweden)

    Howard Timothy A.

    2015-01-01

    Full Text Available In this review I discuss the problems associated with the detection and measurement of coronal mass ejections (CMEs. CMEs are important phenomena both scientifically, as they play a crucial role in the evolution of the solar corona, and technologically, as their impact with the Earth leads to severe space weather activity in the form of magnetic storms. I focus on the observation of CMEs using visible white light imagers (coronagraphs and heliospheric imagers, as they may be regarded as the binding agents between different datasets and different models that are used to reconstruct them. Our ability to accurately measure CMEs observed by these imagers is hampered by many factors, from instrumental to geometrical to physical. Following a brief review of the history of CME observation and measurement, I explore the impediments to our ability to measure them and describe possible means for which we may be able to mitigate those impediments. I conclude with a discussion of the claim that we have reached the limit of the information that we can extract from the current generation of white light imagers, and discuss possible ways forward regarding future instrument capabilities.

  14. Dust Ejection from Planetary Bodies by Temperature Gradients: Laboratory Experiments

    CERN Document Server

    Kelling, Thorben; Kocifaj, Miroslav; Klacka, Jozef; Reiss, Dennis

    2011-01-01

    Laboratory experiments show that dusty bodies in a gaseous environment eject dust particles if they are illuminated. We find that even more intense dust eruptions occur when the light source is turned off. We attribute this to a compression of gas by thermal creep in response to the changing temperature gradients in the top dust layers. The effect is studied at a light flux of 13 kW/(m*m) and 1 mbar ambient pressure. The effect is applicable to protoplanetary disks and Mars. In the inner part of protoplanetary disks, planetesimals can be eroded especially at the terminator of a rotating body. This leads to the production of dust which can then be transported towards the disk edges or the outer disk regions. The generated dust might constitute a significant fraction of the warm dust observed in extrasolar protoplanetary disks. We estimate erosion rates of about 1 kg/s for 100 m parent bodies. The dust might also contribute to subsequent planetary growth in different locations or on existing protoplanets which ...

  15. Data Constrained Coronal Mass Ejections in A Global Magnetohydrodynamics Model

    CERN Document Server

    Jin, M; van der Holst, B; Sokolov, I; Toth, G; Mullinix, R E; Taktakishvili, A; Chulaki, A; Gombosi, T I

    2016-01-01

    We present a first-principles-based coronal mass ejection (CME) model suitable for both scientific and operational purposes by combining a global magnetohydrodynamics (MHD) solar wind model with a flux rope-driven CME model. Realistic CME events are simulated self-consistently with high fidelity and forecasting capability by constraining initial flux rope parameters with observational data from GONG, SOHO/LASCO, and STEREO/COR. We automate this process so that minimum manual intervention is required in specifying the CME initial state. With the newly developed data-driven Eruptive Event Generator Gibson-Low (EEGGL), we present a method to derive Gibson-Low (GL) flux rope parameters through a handful of observational quantities so that the modeled CMEs can propagate with the desired CME speeds near the Sun. A test result with CMEs launched with different Carrington rotation magnetograms are shown. Our study shows a promising result for using the first-principles-based MHD global model as a forecasting tool, wh...

  16. Automatic Determination of the Conic Coronal Mass Ejection Model Parameters

    Science.gov (United States)

    Pulkkinen, A.; Oates, T.; Taktakishvili, A.

    2009-01-01

    Characterization of the three-dimensional structure of solar transients using incomplete plane of sky data is a difficult problem whose solutions have potential for societal benefit in terms of space weather applications. In this paper transients are characterized in three dimensions by means of conic coronal mass ejection (CME) approximation. A novel method for the automatic determination of cone model parameters from observed halo CMEs is introduced. The method uses both standard image processing techniques to extract the CME mass from white-light coronagraph images and a novel inversion routine providing the final cone parameters. A bootstrap technique is used to provide model parameter distributions. When combined with heliospheric modeling, the cone model parameter distributions will provide direct means for ensemble predictions of transient propagation in the heliosphere. An initial validation of the automatic method is carried by comparison to manually determined cone model parameters. It is shown using 14 halo CME events that there is reasonable agreement, especially between the heliocentric locations of the cones derived with the two methods. It is argued that both the heliocentric locations and the opening half-angles of the automatically determined cones may be more realistic than those obtained from the manual analysis

  17. A spectacular coronal mass ejection event and associated phenomena

    Science.gov (United States)

    Ma, Yuan; Li, Chun-Sheng; Song, Qian

    Based on the data taken from S. G. D. and relevant simultaneous observations of solar radio bursts, gamma-ray emission and geophysical effects on June 15, 1991 the relationships among these phenomena are discussed in this paper. Through the analyses it is considered that proton events and GLE events occurred on June 15 in 1991, which were the geophysic responses caused by CME (V>=750 km/s). Simultaneous observation of the bursts at the centimetric and decimetric wavelengths can obtain the U-shape spectrum of speak fluxes, which is still one of the effective tools for predicting proton events and its production mechanism can be explained by using the acceleration of the direct current field parallel to the magnetic field in the electric current sheet formed in the process of the production of spray prominences. However, the process in which electrons are accelerated up to the high energy state remains to be explained. The whole event of June 15 1991, from the coronal matter ejection (or the spray prominences in active regions) to the production of various geophysic effects, has explained and verified.

  18. Spironolactone in patients with heart failure and preserved ejection fraction.

    Science.gov (United States)

    Sánchez-Sánchez, C; Mendoza-Ruiz de Zuazu, H F; Formiga, F; Manzano, L; Ceresuela, L M; Carrera-Izquierdo, M; González Franco, Á; Epelde-Gonzalo, F; Cerqueiro-González, J M; Montero-Pérez-Barquero, M

    2015-01-01

    Aldosterone inhibitors have been shown to be beneficial for patients with systolic heart failure. However, the evidence from patients with heart failure and preserved ejection fraction (HFPEF) is limited. We evaluated the role of spironolactone in the prognosis of a cohort of patients with HFPEF. We analyzed the outcomes of patients hospitalized for HFPEF in 52 departments of internal medicine of the Spanish RICA registry according to those who did and did not take spironolactone. We recorded the posthospital mortality rate and readmissions at 1 year and performed a multivariate survival analysis. We included 1212 patients with HFPEF, with a mean age of 79 years (standard deviation, 7.9), (64.1% women), the majority of whom had hypertensive heart disease (50.7%). The patients treated with spironolactone, compared with those who were not treated with this diuretic, had a more advanced functional class, a higher number of readmissions (44.3 vs. 29.1%; p<0.001) and a higher rate in the combined variable of readmissions/mortality (39.0 vs. 29.0%; p=0.001). In the multivariate analysis, the administration of spironolactone was associated with an increase in readmissions (RR, 1.4; 95% CI, 1.16-1.78; p=0.001). For patients with HFPEF, the administration of spironolactone was associated with an increase in all-cause readmission, perhaps due to the higher rate of hyperpotassemia. Copyright © 2015. Published by Elsevier España, S.L.U.

  19. [Heart failure with preserved left ventricular ejection fraction].

    Science.gov (United States)

    Maeder, Micha T; Rickli, Hans

    2013-10-16

    Heart failure with preserved left ventricular ejection fraction (LVEF; HFpEF) is a common type of heart failure in the elderly, and it typically represents advanced hypertensive heart disease. The left ventricle in patients with HFpEF is characterized by concentric remodeling, normal LVEF, but reduced left longitudinal shortening, and importantly diastolic dysfunction. Dyspnoe and fatigue in patients with HFpEF are due to impaired left ventricular filling with a rapid increase in filling pressures and the lack of an increase in stroke volume during exercise. The diagnosis of HFpEF requires the careful exclusion of non-cardiac causes of dyspnoe as well as cardiac causes of dyspnoe associated with preserved LVEF other than HFpEF, primarily coronary artery disease and valve disease. Then, the following findings are required to make a diagnosis of HFpEF: a non-dilated left ventricle with an LVEF >50% and the presence of a significant diastolic impairment, which can be assessed using invasive haemodynamics, echocardiography, natriuretic peptides, or a combination of these tools. In contrast to patients with heart failure and reduced LVEF there is still no established treatment for patients with HFpEF, which prolongs survival or reduces the rate of hospitalizations for heart failure. There is currently however intense research going on in this field, and results from large trials evaluating the effects of various interventions on clinical endpoints are expected within the next years.

  20. Survivability of bacteria ejected from icy surfaces after hypervelocity impact.

    Science.gov (United States)

    Burchell, Mark J; Galloway, James A; Bunch, Alan W; Brandão, Pedro F B

    2003-02-01

    Both the Saturnian and Jovian systems contain satellites with icy surfaces. If life exists on any of these icy bodies (in putative subsurface oceans for example) then the possibility exists for transfer of life from icy body to icy body. This is an application of the idea of Panspermia, wherein life migrates naturally through space. A possible mechanism would be that life, here taken as bacteria, could become frozen in the icy surface of one body. If a high-speed impact occurred on that surface, ejecta containing the bacteria could be thrown into space. It could then migrate around the local region of space until it arrived at a second icy body in another high-speed impact. In this paper we consider some of the necessary steps for such a process to occur, concentrating on the ejection of ice bearing bacteria in the initial impact, and on what happens when bacteria laden projectiles hit an icy surface. Laboratory experiments using high-speed impacts with a light gas gun show that obtaining icy ejecta with viable bacterial loads is straightforward. In addition to demonstrating the viability of the bacteria carried on the ejecta, we have also measured the angular and size distribution of the ejecta produced in hypervelocity impacts on ice. We have however been unsuccessful at transferring viable bacteria to icy surfaces from bacteria laden projectiles impacting at hypervelocities.

  1. Global Energetics in Solar Flares and Coronal Mass Ejections

    Science.gov (United States)

    Aschwanden, Markus J.

    2017-08-01

    We present a statistical study of the energetics of coronal mass ejections (CME) and compare it with the magnetic, thermal, and nonthermal energy dissipated in flares. The physical parameters of CME speeds, mass, and kinetic energies are determined with two different independent methods, i.e., the traditional white-light scattering method using LASCO/SOHO data, and the EUV dimming method using AIA/SDO data. We analyze all 860 GOES M- and X-class flare events observed during the first 7 years (2010-2016) of the SDO mission. The new ingredients of our CME modeling includes: (1) CME geometry in terms of a self-similar adiabatic expansion, (2) DEM analysis of CME mass over entire coronal temperature range, (3) deceleration of CME due to gravity force which controls the kinetic and potentail CME energy as a function of time, (4) the critical speed that controls eruptive and confined CMEs, (5) the relationship between the center-of-mass motion during EUV dimming and the leading edge motion observed in white-light coronagraphs. Novel results are: (1) Physical parameters obtained from both the EUV dimming and white-light method can be reconciled; (2) the equi-partition of CME kinetic and thermal flare energy; (3) the Rosner-Tucker-Vaiana scaling law. We find that the two methods in EUV and white-light wavelengths are highly complementary and yield more complete models than each method alone.

  2. The coronal mass ejection waiting-time distribution

    CERN Document Server

    Wheatland, M S

    2003-01-01

    The distribution of times $\\Delta t$ between coronal mass ejections (CMEs) in the Large Angle and Spectrometric Coronagraph (LASCO) CME catalog for the years 1996-2001 is examined. The distribution exhibits a power-law tail $\\propto (\\Delta t)^{\\gamma}$ with an index $\\gamma\\approx -2.36\\pm 0.11$ for large waiting times ($\\Delta t>10 {\\rm hours}$). The power-law index of the waiting-time distribution varies with the solar cycle: for the years 1996-1998 (a period of low activity), the power-law index is $\\gamma\\approx-1.86\\pm 0.14$, and for the years 1999-2001 (a period of higher activity), the index is $\\gamma\\approx-2.98\\pm 0.20$. The observed CME waiting-time distribution, and its variation with the cycle, may be understood in terms of CMEs occurring as a time-dependent Poisson process. The CME waiting-time distribution is compared with that for greater than C1 class solar flares in the Geostationary Operational Environmental Satellite (GOES) catalog for the same years. The flare and CME waiting-time distri...

  3. Ensemble Modeling of the 23 July 2012 Coronal Mass Ejection

    Science.gov (United States)

    Cash, M. D.; Biesecker, D. A.; Pizzo, V.; Koning, C. A.; Millward, G.; Arge, C. N.; Henney, C. J.; Odstrcil, D.

    2015-10-01

    On 23 July 2012 a significant and rapid coronal mass ejection (CME) was detected in situ by the Solar Terrestrial Relations Observatory (STEREO) A. This CME was unusual due to its extremely brief Sun-to-1 AU transit time of less than 21 h and its exceptionally high impact speed of 2246 km/s. If this CME had been Earth directed, it would have produced a significant geomagnetic storm with potentially serious consequences. To protect our ground- and space-based assets, there is a clear need to accurately forecast the arrival times of such events using realistic input parameters and models run in near real time. Using Wang-Sheely-Arge (WSA)-Enlil, the operational model currently employed at the NOAA Space Weather Prediction Center, we investigate the sensitivity of the 23 July CME event to model input parameters. Variations in the initial CME speed, angular width, and direction, as well as the ambient solar wind background, are investigated using an ensemble approach to study the effect on the predicted arrival time of the CME at STEREO A. Factors involved in the fast transit time of this large CME are discussed, and potential improvements to modeling such events with the WSA-Enlil model are presented.

  4. A Type II Radio Burst without a Coronal Mass Ejection

    CERN Document Server

    Su, W; Ding, M D; Chen, P F; Sun, J Q

    2015-01-01

    Type II radio bursts are thought to be a signature of coronal shocks. In this paper, we analyze a short-lived type II burst that started at 07:40 UT on 2011 February 28. By carefully checking white-light images, we find that the type II radio burst is not accompanied by a coronal mass ejection, only with a C2.4 class flare and narrow jet. However, in the extreme-ultraviolet (EUV) images provided by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), we find a wave-like structure that propagated at a speed of $\\sim$ 600 km s$^{-1}$ during the burst. The relationship between the type II radio burst and the wave-like structure is in particular explored. For this purpose, we first derive the density distribution under the wave by the differential emission measure (DEM) method, which is used to restrict the empirical density model. We then use the restricted density model to invert the speed of the shock that produces the observed frequency drift rate in the dynamic spectrum. The ...

  5. INTERCOMPARISON OF RESULTS FOR A PWR ROD EJECTION ACCIDENT

    Energy Technology Data Exchange (ETDEWEB)

    DIAMOND,D.J.; ARONSON,A.; JO,J.; AVVAKUMOV,A.; MALOFEEV,V.; SIDOROV,V.; FERRARESI,P.; GOUIN,C.; ANIEL,S.; ROYER,M.E.

    1999-10-01

    This study is part of an overall program to understand the uncertainty in best-estimate calculations of the local fuel enthalpy during the rod ejection accident. Local fuel enthalpy is used as the acceptance criterion for this design-basis event and can also be used to estimate fuel damage for the purpose of determining radiological consequences. The study used results from neutron kinetics models in PARCS, BARS, and CRONOS2, codes developed in the US, the Russian Federation, and France, respectively. Since BARS uses a heterogeneous representation of the fuel assembly as opposed to the homogeneous representations in PARCS and CRONOS, the effect of the intercomparison was primarily to compare different intra-assembly models. Quantitative comparisons for core power, reactivity, assembly fuel enthalpy and pin power were carried out. In general the agreement between methods was very good providing additional confidence in the codes and providing a starting point for a quantitative assessment of the uncertainty in calculated fuel enthalpy using best-estimate methods.

  6. A Study of Fast Flareless Coronal Mass Ejections

    CERN Document Server

    Song, H Q; Ye, D D; Han, G Q; Du, G H; Li, G; Zhang, J; Hu, Q

    2013-01-01

    Two major processes have been proposed to convert the coronal magnetic energy into the kinetic energy of a coronal mass ejection (CME): resistive magnetic reconnection and ideal macroscopic magnetohydrodynamic instability of magnetic flux rope. However, it remains elusive whether both processes play a comparable role or one of them prevails during a particular eruption. To shed light on this issue, we carefully studied energetic but flareless CMEs, \\textit{i.e.}, fast CMEs not accompanied by any flares. Through searching the Coordinated Data Analysis Workshops (CDAW) database of CMEs observed in Solar Cycle 23, we found 13 such events with speeds larger than 1000 km s$^{-1}$. Other common observational features of these events are: (1) none of them originated in active regions; they were associated with eruptions of well-developed long filaments in quiet-Sun regions, (2) no apparent enhancement of flare emissions was present in soft X-ray, EUV and microwave data. Further studies of two events reveal that (1) ...

  7. VLA Measurements of Faraday Rotation through Coronal Mass Ejections

    CERN Document Server

    Kooi, Jason E; Buffo, Jacob J; Spangler, Steven R

    2016-01-01

    Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun that play an important role in space weather. Faraday rotation (FR) is the rotation of the plane of polarization that results when a linearly polarized signal passes through a magnetized plasma such as a CME. FR observations of a source near the Sun can provide information on the plasma structure of a CME shortly after launch. We report on simultaneous white-light and radio observations made of three CMEs in August 2012. We made sensitive Very Large Array (VLA) full-polarization observations using 1 - 2 GHz frequencies of a "constellation" of radio sources through the solar corona at heliocentric distances that ranged from 6 - 15 solar radii. Of the nine sources observed, three were occulted by CMEs: two sources (0842+1835 and 0900+1832) were occulted by a single CME and one source (0843+1547) was occulted by two CMEs. In addition to our radioastronomical observations, which represent one of the first active hunts for CME Faraday r...

  8. A multiple sampling ionization chamber for the External Target Facility

    Science.gov (United States)

    Zhang, X. H.; Tang, S. W.; Ma, P.; Lu, C. G.; Yang, H. R.; Wang, S. T.; Yu, Y. H.; Yue, K.; Fang, F.; Yan, D.; Zhou, Y.; Wang, Z. M.; Sun, Y.; Sun, Z. Y.; Duan, L. M.; Sun, B. H.

    2015-09-01

    A multiple sampling ionization chamber used as a particle identification device for high energy heavy ions has been developed for the External Target Facility. The performance of this detector was tested with a 239Pu α source and RI beams. A Z resolution (FWHM) of 0.4-0.6 was achieved for nuclear fragments of 18O at 400 AMeV.

  9. The Accretion Flow - Discrete Ejection Connection in GRS 1915+105

    CERN Document Server

    Punsly, Brian; Trushkin, Sergei A

    2016-01-01

    The microquasar GRS~1915+105 is known for its spectacular discrete ejections. They occur unexpectedly, thus their inception escapes direct observation. It has been shown that the X-ray flux increases in the hours leading up to a major ejection. In this article, we consider the serendipitous interferometric monitoring of a modest version of a discrete ejection described in Reid et al. (2014) that would have otherwise escaped detection in daily radio light curves. The observation begins $\\sim 1$ hour after the onset of the ejection, providing unprecedented accuracy on the estimate of the ejection time. The astrometric measurements allow us to determine the time of ejection as $\\rm{MJD}\\, 56436.274^{+0.016}_{-0.013}$, i.e., within a precision of 41 minutes (95\\% confidence). Just like larger flares, we find that the X-ray luminosity increases in last 2 - 4 hours preceding ejection. Our finite temporal resolution indicates that this elevated X-ray flux persists within $21.8^{+22.6}_{-19.1}$ minutes of the ejectio...

  10. Multiple Plasmoid Ejections and Associated Hard X-ray Bursts in the 2000 November 24 Flare

    CERN Document Server

    Nishizuka, N; Asai, A; Shibata, K; 10.1088/0004-637X/711/2/1062

    2013-01-01

    The Soft X-ray Telescope (SXT) on board Yohkoh revealed that the ejection of X-ray emitting plasmoid is sometimes observed in a solar flare. It was found that the ejected plasmoid is strongly accelerated during a peak in the hard X-ray emission of the flare. In this paper we present an examination of the GOES X 2.3 class flare that occurred at 14.51 UT on 2000 November 24. In the SXT images we found multiple plasmoid ejections with velocities in the range of 250-1500 km/s, which showed blob-like or loop-like structures. Furthermore, we also found that each plasmoid ejection is associated with an impulsive burst of hard X-ray emission. Although some correlation between plasmoid ejection and hard X-ray emission has been discussed previously, our observation shows similar behavior for multiple plasmoid ejection such that each plasmoid ejection occurs during the strong energy release of the solar flare. As a result of temperature-emission measure analysis of such plasmoids, it was revealed that the apparent veloc...

  11. Evidence for direct geographic influences on linguistic sounds: the case of ejectives.

    Directory of Open Access Journals (Sweden)

    Caleb Everett

    Full Text Available We present evidence that the geographic context in which a language is spoken may directly impact its phonological form. We examined the geographic coordinates and elevations of 567 language locations represented in a worldwide phonetic database. Languages with phonemic ejective consonants were found to occur closer to inhabitable regions of high elevation, when contrasted to languages without this class of sounds. In addition, the mean and median elevations of the locations of languages with ejectives were found to be comparatively high. The patterns uncovered surface on all major world landmasses, and are not the result of the influence of particular language families. They reflect a significant and positive worldwide correlation between elevation and the likelihood that a language employs ejective phonemes. In addition to documenting this correlation in detail, we offer two plausible motivations for its existence. We suggest that ejective sounds might be facilitated at higher elevations due to the associated decrease in ambient air pressure, which reduces the physiological effort required for the compression of air in the pharyngeal cavity--a unique articulatory component of ejective sounds. In addition, we hypothesize that ejective sounds may help to mitigate rates of water vapor loss through exhaled air. These explications demonstrate how a reduction of ambient air density could promote the usage of ejective phonemes in a given language. Our results reveal the direct influence of a geographic factor on the basic sound inventories of human languages.

  12. Electrolytic silver ion cell sterilizes water supply

    Science.gov (United States)

    Albright, C. F.; Gillerman, J. B.

    1968-01-01

    Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water.

  13. Ion-Ion Neutralization.

    Science.gov (United States)

    1980-12-31

    plasma were identified using a downstream quadrupole mass spectrometer. In these experimento it is a simple matter to establish H+(H 2 0):f as the...pressure as predicted by the Thomson t2rnary mechanism whicK hzr been suownr to be valid experimentally at hiTh rrsurs (,han and Peron, 1:EI4 hereafter t...of NO , NO2 ions in various gases and the ternary recombination coefficients of these ions in the higher pres:;ure ( Thomson ) re"ie. Equation (5) cr>n

  14. Dynamical ejections of massive stars from young star clusters under diverse initial conditions

    Science.gov (United States)

    Oh, Seungkyung; Kroupa, Pavel

    2016-05-01

    We study the effects that initial conditions of star clusters and their massive star population have on dynamical ejections of massive stars from star clusters up to an age of 3 Myr. We use a large set of direct N-body calculations for moderately massive star clusters (Mecl ≈ 103.5 M⊙). We vary the initial conditions of the calculations, such as the initial half-mass radius of the clusters, initial binary populations for massive stars and initial mass segregation. We find that the initial density is the most influential parameter for the ejection fraction of the massive systems. The clusters with an initial half-mass radius rh(0) of 0.1 (0.3) pc can eject up to 50% (30)% of their O-star systems on average, while initially larger (rh(0) = 0.8 pc) clusters, that is, lower density clusters, eject hardly any OB stars (at most ≈ 4.5%). When the binaries are composed of two stars of similar mass, the ejections are most effective. Most of the models show that the average ejection fraction decreases with decreasing stellar mass. For clusters that are efficient at ejecting O stars, the mass function of the ejected stars is top-heavy compared to the given initial mass function (IMF), while the mass function of stars that remain in the cluster becomes slightly steeper (top-light) than the IMF. The top-light mass functions of stars in 3 Myr old clusters in our N-body models agree well with the mean mass function of young intermediate-mass clusters in M 31, as reported previously. This implies that the IMF of the observed young clusters is the canonical IMF. We show that the multiplicity fraction of the ejected massive stars can be as high as ≈ 60%, that massive high-order multiple systems can be dynamically ejected, and that high-order multiples become common especially in the cluster. We also discuss binary populations of the ejected massive systems. Clusters that are initially not mass-segregated begin ejecting massive stars after a time delay that is caused by mass

  15. Cavitation dynamics and directional microbubble ejection induced by intense femtosecond laser pulses in liquids.

    Science.gov (United States)

    Faccio, D; Tamošauskas, G; Rubino, E; Darginavičius, J; Papazoglou, D G; Tzortzakis, S; Couairon, A; Dubietis, A

    2012-09-01

    We study cavitation dynamics when focusing ring-shaped femtosecond laser beams in water. This focusing geometry reduces detrimental nonlinear beam distortions and enhances energy deposition within the medium, localized at the focal spot. We observe remarkable postcollapse dynamics of elongated cavitation bubbles with high-speed ejection of microbubbles out of the laser focal region. Bubbles are ejected along the laser axis in both directions (away and towards the laser). The initial shape of the cavitation bubble is also seen to either enhance or completely suppress jet formation during collapse. In the absence of jetting, microbubble ejection occurs orthogonal to the laser propagation axis.

  16. Burden of Recurrent Hospitalizations Following an Admission for Acute Heart Failure: Preserved Versus Reduced Ejection Fraction.

    Science.gov (United States)

    Santas, Enrique; Valero, Ernesto; Mollar, Anna; García-Blas, Sergio; Palau, Patricia; Miñana, Gema; Núñez, Eduardo; Sanchis, Juan; Chorro, Francisco Javier; Núñez, Julio

    2017-04-01

    Heart failure with preserved ejection fraction and reduced ejection fraction share a high mortality risk. However, differences in the rehospitalization burden over time between these 2 entities remains unclear. We prospectively included 2013 consecutive patients discharged for acute heart failure. Of these, 1082 (53.7%) had heart failure with preserved ejection fraction and 931 (46.2%) had heart failure with reduced ejection fraction. Cox and negative binomial regression methods were used to evaluate the risks of death and repeat hospitalizations, respectively. At a median follow-up of 2.36 years (interquartile range: 0.96-4.65), 1018 patients (50.6%) died, and 3804 readmissions were registered in 1406 patients (69.8%). Overall, there were no differences in mortality between heart failure with preserved ejection fraction and heart failure with reduced ejection fraction (16.7 vs 16.1 per 100 person-years, respectively; P=0794), or all-cause repeat hospitalization rates (62.1 vs 62.2 per 100 person-years, respectively; P=.944). After multivariable adjustment, and compared with patients with heart failure with reduced ejection fraction, patients with heart failure with preserved ejection fraction exhibited a similar risk of all-cause readmissions (incidence rate ratio=1.04; 95%CI, 0.93-1.17; P=.461). Regarding specific causes, heart failure with preserved ejection fraction showed similar risks of cardiovascular and heart failure-related rehospitalizations (incidence rate ratio=0.93; 95%CI, 0.82-1.06; P=.304; incidence rate ratio=0.96; 95% confidence interval, 0.83-1.13; P=.677, respectively), but had a higher risk of noncardiovascular readmissions (incidence rate ratio=1.24; 95%CI, 1.04-1.47; P=.012). Following an admission for acute heart failure, patients with heart failure with preserved ejection fraction have a similar rehospitalization burden to those with heart failure with reduced ejection fraction. However, patients with heart failure with preserved ejection

  17. New Classification for Heart Failure with Mildly Reduced Ejection Fraction; Greater clarity or more confusion?

    Directory of Open Access Journals (Sweden)

    Sunil Nadar

    2017-03-01

    Full Text Available The latest European Society of Cardiology (ESC guidelines for the diagnosis and management of heart failure include a new patient group for those with heart failure with mildly reduced ejection fraction (HFmrEF. By defining this group of patients as a separate entity, the ESC hope to encourage more research focusing on patients with HFmrEF. Previously, patients with this condition were caught between two classifications—heart failure with reduced ejection fraction and heart failure with preserved ejection fraction. Hopefully, the inclusion of new terminology will not increase confusion, but rather aid our understanding of heart failure, a complex clinical syndrome.

  18. External fixators in haemophilia.

    Science.gov (United States)

    Lee, V; Srivastava, A; PalaniKumar, C; Daniel, A J; Mathews, V; Babu, N; Chandy, M; Sundararaj, G D

    2004-01-01

    External fixators (EF) are not commonly used for patients with haemophilia. We describe the use of EF (Ilizarov, AO- uni- and bi-planar fixators and Charnley clamp) in nine patients (mean age: 19.2 years; range: 9-37) with haemophilia for the following indications - arthrodesis of infected joints, treatment of open fractures and osteoclasis. EF required an average of nine skin punctures [range: 4-17 were maintained for a period of 15 weeks (range: 8-29.5), without regular factor replacement, till bone healing was adequate and were removed with a single dose of factor infusion]. The mean preoperative factor level achieved was 85% (range: 64-102%). Much lower levels were subsequently maintained till wound healing. The average total factor consumption was 430 IU kg(-1) (range: 240-870), administered over a period of 17 days (range: 9-44). There were no major complications related to EF except in a patient who developed inhibitors. In conclusion, EF can be used safely in haemophilic patients who do not have inhibitors and does not require prolonged factor replacement.

  19. Magnetic reconnection in the interior of interplanetary coronal mass ejections.

    Science.gov (United States)

    Fermo, R L; Opher, M; Drake, J F

    2014-07-18

    Recent in situ observations of interplanetary coronal mass ejections (ICMEs) found signatures of reconnection exhausts in their interior or trailing edge. Whereas reconnection on the leading edge of an ICME would indicate an interaction with the coronal or interplanetary environment, this result suggests that the internal magnetic field reconnects with itself. In light of this data, we consider the stability properties of flux ropes first developed in the context of astrophysics, then further elaborated upon in the context of reversed field pinches (RFPs). It was shown that the lowest energy state of a flux rope corresponds to ∇ × B = λB with λ a constant, the so-called Taylor state. Variations from this state will result in the magnetic field trying to reorient itself into the Taylor state solution, subject to the constraints that the toroidal flux and magnetic helicity are invariant. In reversed field pinches, this relaxation is mediated by the reconnection of the magnetic field, resulting in a sawtooth crash. If we likewise treat the ICME as a flux rope, any deviation from the Taylor state will result in reconnection within the interior of the flux tube, in agreement with the observations by Gosling et al. Such a departure from the Taylor state takes place as the flux tube cross section expands in the latitudinal direction, as seen in magnetohydrodynamic (MHD) simulations of flux tubes propagating through the interplanetary medium. We show analytically that this elongation results in a state which is no longer in the minimum energy Taylor state. We then present magnetohydrodynamic simulations of an elongated flux tube which has evolved away from the Taylor state and show that reconnection at many surfaces produces a complex stochastic magnetic field as the system evolves back to a minimum energy state configuration.

  20. A SOLAR CORONAL JET EVENT TRIGGERS A CORONAL MASS EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S. [CAS Key Laboratory of Geospace Environment, Earh and Space Science School, University of Science and Technology of China, No. 96, JinZhai Road, Hefei, Anhui 230026 (China)

    2015-11-10

    In this paper, we present multi-point, multi-wavelength observations and analysis of a solar coronal jet and coronal mass ejection (CME) event. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it to propagate at a high speed of over 1000 km s{sup −1}. The jet erupted before the CME and shared the same source region. The temporal and spacial relationship between these two events lead us to the possibility that the jet triggered the CME and became its core. This scenario hold the promise of enriching our understanding of the triggering mechanism of CMEs and their relations to coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the Solar Dynamics Observatory (SDO)/HMI instrument along with the off-limb inverse Y-shaped configuration observed by SDO/AIA in the 171 Å passband provide the first detailed observation of the three-dimensional reconnection process of a large-scale jet as simulated in Pariat et al. The eruption process of the jet highlights the importance of filament-like material during the eruption of not only small-scale X-ray jets, but likely also of large-scale EUV jets. Based on our observations and analysis, we propose the most probable mechanism for the whole event, with a blob structure overlaying the three-dimensional structure of the jet, to describe the interaction between the jet and the CME.

  1. Ejection of Supernova-Enriched Gas From Dwarf Disk Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Fragile, P C; Murray, S D; Lin, D C

    2004-06-15

    We examine the efficiency with which supernova-enriched gas may be ejected from dwarf disk galaxies, using a methodology previously employed to study the self-enrichment efficiency of dwarf spheroidal systems. Unlike previous studies that focused on highly concentrated starbursts, in the current work we consider discrete supernova events spread throughout various fractions of the disk. We model disk systems having gas masses of 10{sup 8} and 10{sup 9} M{sub {circle_dot}} with supernova rates of 30, 300, and 3000 Myr{sup -1}. The supernova events are confined to the midplane of the disk, but distributed over radii of 0, 30, and 80% of the disk radius, consistent with expectations for Type II supernovae. In agreement with earlier studies, we find that the enriched material from supernovae is largely lost when the supernovae are concentrated near the nucleus, as expected for a starburst event. In contrast, we find the loss of enriched material to be much less efficient (as low as 21%) when the supernovae occur over even a relatively small fraction of the disk. The difference is due to the ability of the system to relax following supernova events that occur over more extended regions. Larger physical separations also reduce the likelihood of supernovae going off within low-density ''chimneys'' swept out by previous supernovae. We also find that, for the most distributed systems, significant metal loss is more likely to be accompanied by significant mass loss. A comparison with theoretical predications indicates that, when undergoing self-regulated star formation, galaxies in the mass range considered shall efficiently retain the products of Type II supernovae.

  2. Heart failure with preserved ejection fraction: uncertainties and dilemmas.

    Science.gov (United States)

    Ferrari, Roberto; Böhm, Michael; Cleland, John G F; Paulus, Walter J S; Pieske, Burkert; Rapezzi, Claudio; Tavazzi, Luigi

    2015-07-01

    Many uncertainties surround the syndrome of heart failure with preserved ejection fraction (HFpEF), which was the topic reviewed in an Expert Meeting at the University of Ferrara. This concluded that the absence of clear diagnostic clinical criteria was the major barrier to progress. There was general agreement that symptoms or signs of heart failure, normal LVEF despite an elevated plasma concentration of natriuretic peptides, and signs of abnormal LV relaxation, LV filling, LV hypertrophy, or left atrial enlargement, or diastolic dysfunction supported the diagnosis. However, HFpEF, like all heart failure syndromes, is heterogeneous in aetiology and pathophysiology, rather than being a single disease. HFpEF may account for about half of all patients with heart failure. The classical risk factors for developing HFpEF include age and co-morbidities, notably hypertension, atrial fibrillation, and the metabolic syndrome. When complicated by increasing congestion requiring hospital admission, the prognosis is poor; 30% or more of patients will die within 1 year (nearly two-thirds die from cardiovascular causes). Patients with chronic stable symptoms have a much better prognosis. Despite many clinical trials, there is no solid evidence that any treatment alters the natural history of HFpEF. Several treatments have shown promising early results and are now being tested in substantial randomized clinical trials. Further basic research is required to better characterize the disease and accelerate progress. Our review highlights the many difficulties encountered in performing randomized clinical trials in HFpEF, often due to difficulties in characterizing HFpEF itself.

  3. Reproducibility of gallbladder ejection fraction measured by fatty meal cholescintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Muqbel, Kusai M.; Hani, M. N. Hani; Elheis, M. A.; Al-Omari, M. H. [School of Medicine, Jordan University of Science and Technology, Irbid (Jordan)

    2010-12-15

    There are conflicting data in the literature regarding the reproducibility of the gallbladder ejection fraction (GBEF) measured by fatty meal cholescintigraphy (CS). We aimed to test the reproducibility of GBEF measured by fatty meal CS. Thirty-five subjects (25 healthy volunteers and 10 patients with chronic abdominal pain) underwent fatty meal CS twice in order to measure GBEF1 and GBEF2. The healthy volunteers underwent a repeat scan within 1-13 months from the first scan. The patients underwent a repeat scan within 1-4 years from the first scan and were not found to have chronic acalculous cholecystitis (CAC). Our standard fatty meal was composed of a 60-g Snickers chocolate bar and 200 ml full-fat yogurt. The mean {+-} SD values for GBEF1 and GBEF2 were 52{+-}17% and 52{+-}16%, respectively. There was a direct linear correlation between the values of GBEF1 and GBEF2 for the subjects, with a correlation coefficient of 0.509 (p=0.002). Subgroup data analysis of the volunteer group showed that there was significant linear correlation between volunteer values of GBEF1 and GBEF2, with a correlation coefficient of 0.473 (p=0.017). Subgroup data analysis of the non-CAC patient group showed no significant correlation between patient values of GBEF1 and GBEF2, likely due to limited sample size. This study showed that fatty meal CS is a reliable test in gallbladder motility evaluation and that GBEF measured by fatty meal CS is reproducible

  4. Earth's polar cap ionization patches lead to ion upflow

    Science.gov (United States)

    Zhang, Q. H.; Zong, Q.; Lockwood, M. M.; Liang, J.; Zhang, B.; Moen, J. I.; Zhang, S.; Zhang, Y.; Ruohoniemi, J. M.; Thomas, E. G.; Liu, R.; Dunlop, M. W.; Yang, H. G.; Hu, H.; Liu, Y.; Lester, M.

    2014-12-01

    The Earth constantly losses matter through ions escaping from the polar ionosphere. This makes the ionosphere as an important source of plasma for the magnetosphere and could modulate atmospheric isotope abundances on geological timescales, depending on what fraction of the upflowing ions subsequently return to the ionosphere and what fraction are ejected into interplanetary space. It has been proposed that the magnetosphere is dynamically modulated by the presence of the ionospheric ions, particularly heavy ions O+, during magnetic substorms and storms. The origin and formation mechanism of ionospheric ion upflow is, however, poorly understood, particularly under disturbed space weather conditions. We report simultaneous direct observations of ion upflow and a patch of ionization at the center of the polar cap region during a geomagnetic storm. Our observations indicate enhanced fluxes of upwelling O+ ions originate from the patch and were accelerated by the enhanced ambipolar electric field. This enhancement is caused by soft electron precipitations. Polar cap patches therefore provide an important source of upwelling ions for accelerations mechanisms at greater altitudes which can eject the ions. These observations give new insight into the processes of ionosphere-magnetosphere coupling and the potential loss of terrestrial water dissociation products into space which, although extremely slow in the case of Earth, may be significant for other planets and moons.

  5. Skepticism, contextualism, externalism and modality

    National Research Council Canada - National Science Library

    Ron Wilburn

    2006-01-01

    .... However, because efforts to contextualize externalism via subjunctive conditional analysis court circularity, it is only on an internalistic interpretation that contextualist strategies can even be motivated...

  6. Exercise hemodynamics in patients with and without diastolic dysfunction and preserved ejection fraction after myocardial infarction

    DEFF Research Database (Denmark)

    Andersen, Mads J; Ersbøll, Mads; Bro-Jeppesen, John

    2012-01-01

    Left ventricular diastolic dysfunction (DD) is common after myocardial infarction (MI) despite preservation of left ventricular ejection fraction, yet it remains unclear how or whether DD affects cardiac hemodynamics with stress....

  7. On pulsar-driven mass ejection in low-mass X-ray binaries

    Institute of Scientific and Technical Information of China (English)

    Lei Fu; Xiang-Dong Li

    2011-01-01

    There is accumulating evidence for mass ejection in low-mass X-ray binaries (LMXBs) driven by radio pulsar activity during X-ray quiescence.We consider the condition for mass ejection by comparing the radiation pressure from a millisecond pulsar,and the gas pressure at the inner Lagrange point or at the surrounding accretion disk.We calculate the critical spin period of the pulsar below which mass ejection is allowed.Combining with the evolution of the mass transfer rate,we present constraints on the orbital periods of the systems.We show that mass ejection could happen in both wide and compact LMXBs.It may be caused by transient accretion due to thermal instability in the accretion disks in the former,and irradiation-driven mass-transfer cycles in the latter.

  8. Improved Rock Core Sample Break-off, Retention and Ejection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort advances the design of an innovative core sampling and acquisition system with improved core break-off, retention and ejection features. Phase 1...

  9. Improved Rock Core Sample Break-off, Retention and Ejection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort advances the design of an innovative core sampling and acquisition system with improved core break-off, retention and ejection features. The...

  10. Impaired myocardial oxygen availability contributes to abnormal exercise hemodynamics in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    van Empel, Vanessa P M; Mariani, Justin; Borlaug, Barry A; Kaye, David M

    2014-01-01

    BACKGROUND: Hypertension is a frequent risk factor for the development of heart failure with preserved ejection fraction (HFPEF). Progressive extracellular matrix accumulation has been presumed to be the fundamental pathophysiologic mechanism that leads to the transition to impaired diastolic reserv

  11. Individual and objective methods for preventing ejections in oil and gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Hoznek, I.

    1984-01-01

    The use of different methods for preventing ejections is noted and, along with an analysis of their effectiveness, attention is focused on the possibility of using a number of newer methods towards increasing labor safety.

  12. Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction : integrating evidence into clinical practice

    NARCIS (Netherlands)

    Zannad, Faiez; Stough, Wendy Gattis; Rossignol, Patrick; Bauersachs, Johann; McMurray, John J. V.; Swedberg, Karl; Struthers, Allan D.; Voors, Adriaan A.; Ruilope, Luis M.; Bakris, George L.; O'Connor, Christopher M.; Gheorghiade, Mihai; Mentz, Robert J.; Cohen-Solal, Alain; Maggioni, Aldo P.; Beygui, Farzin; Filippatos, Gerasimos S.; Massy, Ziad A.; Pathak, Atul; Pina, Ileana L.; Sabbah, Hani N.; Sica, Domenic A.; Tavazzi, Luigi; Pitt, Bertram

    2012-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HFREF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These

  13. Predictors and progression of aortic stenosis in patients with preserved left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Schulte, Phillip J; Al Enezi, Fawaz

    2015-01-01

    We aimed to characterize the hemodynamic progression of aortic stenosis (AS) in a contemporary unselected cohort of patients with preserved left ventricular ejection fraction. Current guidelines recommend echocardiographic surveillance of hemodynamic progression. However, limited data exist on th...

  14. Relationships between egg-recognition and egg-ejection in a grasp-ejector species

    Science.gov (United States)

    Soler, Manuel; Ruiz-Raya, Francisco; Roncalli, Gianluca; Ibáñez-Álamo, Juan Diego

    2017-01-01

    Brood parasitism frequently leads to a total loss of host fitness, which selects for the evolution of defensive traits in host species. Experimental studies have demonstrated that recognition and rejection of the parasite egg is the most common and efficient defence used by host species. Egg-recognition experiments have advanced our knowledge of the evolutionary and coevolutionary implications of egg recognition and rejection. However, our understanding of the proximate mechanisms underlying both processes remains poor. Egg rejection is a complex behavioural process consisting of three stages: egg recognition, the decision whether or not to reject the putative parasitic egg and the act of ejection itself. We have used the blackbird (Turdus merula) as a model species to explore the relationship between egg recognition and the act of egg ejection. We have manipulated the two main characteristics of parasitic eggs affecting egg ejection in this grasp-ejector species: the degree of colour mimicry (mimetic and non-mimetic, which mainly affects the egg-recognition stage of the egg-rejection process) and egg size (small, medium and large, which affects the decision to eject), while maintaining a control group of non-parasitized nests. The behaviour of the female when confronted with an experimental egg was filmed using a video camera. Our results show that egg touching is an indication of egg recognition and demonstrate that blackbirds recognized (i.e., touched) non-mimetic experimental eggs significantly more than mimetic eggs. However, twenty per cent of the experimental eggs were touched but not subsequently ejected, which confirms that egg recognition does not necessarily mean egg ejection and that accepting parasitic eggs, at least sometimes, is the consequence of acceptance decisions. Regarding proximate mechanisms, our results show that the delay in egg ejection is not only due to recognition problems as usually suggested, given that experimental eggs are not

  15. Laser in situ keratomileusis flap stability in an aviator following aircraft ejection.

    Science.gov (United States)

    Richmond, Christopher J; Barker, Patrick D; Levine, Edgar M; Hofmeister, Elizabeth M

    2016-11-01

    We present the case of a 28-year-old male F/A-18F Super Hornet naval flight officer who ejected from an aircraft at 13 000 feet at a speed in excess of 350 knots 7 years after uneventful laser in situ keratomileusis (LASIK). The patient was evaluated the day after the ejection. No LASIK flap complications or epithelial defects were found, and the corrected distance visual acuity was 20/15 in both eyes.

  16. Simulation of 3D Flow in Turbine Blade Rows including the Effects of Coolant Ejection

    Institute of Scientific and Technical Information of China (English)

    Jian-Jun LIU; Bai-Tao AN; Yun-Tao ZENG

    2008-01-01

    This paper describes the numerical simulation of three-dimensional viscous flows in air-cooled turbine blade rows with the effects of coolant ejection. A TVD Navier-Stokes flow solver incorporated with Baldwin-Lomax turbulence model and multi-grid convergence acceleration algorithm are used for the simulation. The influences of coolant ejection on the main flow are accounted by volumetric coolant source terms. Numerical results for a four-stage turbine are presented and discussed.

  17. The survival of patients with heart failure with preserved or reduced left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Boesgaard, Søren

    2012-01-01

    A substantial proportion of patients with heart failure have preserved left ventricular ejection fraction (HF-PEF). Previous studies have reported mixed results whether survival is similar to those patients with heart failure and reduced EF (HF-REF).......A substantial proportion of patients with heart failure have preserved left ventricular ejection fraction (HF-PEF). Previous studies have reported mixed results whether survival is similar to those patients with heart failure and reduced EF (HF-REF)....

  18. Heart Failure with Preserved Ejection Fraction in the Elderly: Scope of the Problem

    OpenAIRE

    Upadhya, Bharathi; Taffet, George E.; Cheng, Che Ping; Kitzman, Dalane W.

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure (HF) in older adults, particularly women, and is increasing in prevalence as the population ages. With morbidity and mortality on par with HF with reduced ejection fraction, it remains a most challenging clinical syndrome for the practicing clinician and basic research scientist. Originally considered to be predominantly caused by diastolic dysfunction, more recent insights indicate that HFpEF in o...

  19. Understanding heart failure with preserved ejection fraction: where are we today?

    OpenAIRE

    van Heerebeek, L.; Paulus, W.J.

    2016-01-01

    Heart failure with preserved ejection fraction (HFpEF) represents a complex and heterogeneous clinical syndrome, which is increasingly prevalent and associated with poor outcome. In contrast to heart failure with reduced ejection fraction (HFrEF), modern heart failure pharmacotherapy did not improve outcome in HFpEF, which was attributed to incomplete understanding of HFpEF pathophysiology, patient heterogeneity and lack of insight into primary pathophysiological processes. HFpEF patients are...

  20. Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Acampa, Wanda; Liuzzi, Raffaele; De Luca, Serena; Capasso, Enza; Luongo, Luca; Cuocolo, Alberto [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages, National Council of Research, Naples (Italy); Caprio, Maria Grazia [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages, National Council of Research, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Nicolai, Emanuele [SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Petretta, Mario [University Federico II, Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Naples (Italy)

    2010-02-15

    We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients. Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest {sup 99m}Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest. In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress. In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography. (orig.)

  1. Left ventricular ejection fraction is determined by both global myocardial strain and wall thickness

    Directory of Open Access Journals (Sweden)

    David H. MacIver

    2015-06-01

    Conclusion: The findings of this study explain the coexistence of reduced global myocardial strain and normal ejection fraction seen in clinical observational studies. Our understanding of the pathophysiological processes in heart failure and associated conditions is substantially enhanced. These results provide a much better insight into the biophysical inter-relationship between myocardial strain and ejection fraction. This improved understanding provides an essential foundation for the design and interpretation of future clinical mechanistic and prognostic studies.

  2. Motion Law Analysis and Structural Optimization of the Ejection Device of Tray Seeder

    Science.gov (United States)

    Luo, Xin; Hu, Bin; Dong, Chunwang; Huang, Lili

    An ejection mechanism consisting four reset springs, an electromagnet and a seed disk was designed for tray seeder. The motion conditions of seeds in the seed disk were theoretical analyzed and intensity and height of seed ejection were calculated. The motions of the seeds and seed disk were multi-body dynamic simulated using Cosmos modules plug-in SolidWorks software package. The simulation results showed the consistence with the theoretical analysis.

  3. Rollover Car Crashes with Ejection: A Deadly Combination—An Analysis of 719 Patients

    Directory of Open Access Journals (Sweden)

    Rifat Latifi

    2014-01-01

    Full Text Available Rollover car crashes (ROCs are serious public safety concerns worldwide. Objective. To determine the incidence and outcomes of ROCs with or without ejection of occupants in the State of Qatar. Methods. A retrospective study of all patients involved in ROCs admitted to Level I trauma center in Qatar (2011-2012. Patients were divided into Group I (ROC with ejection and Group II (ROC without ejection. Results. A total of 719 patients were evaluated (237 in Group I and 482 in Group II. The mean age in Group I was lower than in Group II (24.3±10.3 versus 29±12.2; P=0.001. Group I had higher injury severity score and sustained significantly more head, chest, and abdominal injuries in comparison to Group II. The mortality rate was higher in Group I (25% versus 7%; P=0.001. Group I patients required higher ICU admission rate (P=0.001. Patients in Group I had a 5-fold increased risk for age-adjusted mortality (OR 5.43; 95% CI 3.11–9.49, P=0.001. Conclusion. ROCs with ejection are associated with higher rate of morbidity and mortality compared to ROCs without ejection. As an increased number of young Qatari males sustain ROCs with ejection, these findings highlight the need for research-based injury prevention initiatives in the country.

  4. Material ejection from shock-loaded free surfaces of aluminum and lead

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J.R.

    1976-10-01

    A discussion is presented regarding interferometer experiments conducted on free surfaces which are impulsively loaded with high amplitude shock waves. It is shown that material ejection from shocked surfaces can significantly degrade interferometer experiments. In particular, loss of both light intensity and contrast of interferometer signals can result from various scattering and absorption processes occurring in a cloud of ejected material. An experimental technique is presented which allows determination of the mass and velocity of material ejected from free surfaces during shock loading. The technique has been applied to a study of mass ejection occurring naturally from shocked surfaces of two aluminium alloys and from lead. These results show that the total ejected mass ranges from a few ..mu..g/cm/sup 2/ in the aluminum alloys studied to a few mg/cm/sup 2/ in lead, for shock pressures ranging from about 10 to 50 GPa (100 to 500 kbar). Surface defects, such as pits and scratches, are thought to strongly influence mass ejection in aluminum; whereas in lead, localized shock-induced melting and vaporization are thought to be the dominant mechanisms at the higher shock pressures. Experimental results are also presented for aluminum surfaces which contain artificial defects in the form of wedge-shaped cavities. These results show that the maximum ejecta velocities of approximately two to four times the free surface velocity which are observed in these experiments can be correlated with predictions of steady jetting theory.

  5. Dynamical ejections of massive stars from young star clusters under diverse initial conditions

    CERN Document Server

    Oh, Seungkyung

    2016-01-01

    We study the effects of initial conditions of star clusters and their massive star population on dynamical ejections of stars from star clusters up to an age of 3 Myr, particularly focusing on massive systems, using a large set of direct N-body calculations for moderately massive star clusters (Mecl=$10^{3.5}$ Msun). We vary the initial conditions of the calculations such as the initial half-mass radius of the clusters, initial binary populations for massive stars and initial mass segregation. We find that the initial density is the most influential parameter for the ejection fraction of the massive systems. The clusters with an initial half-mass radius of 0.1 (0.3) pc can eject up to 50% (30)% of their O-star systems on average. Most of the models show that the average ejection fraction decreases with decreasing stellar mass. For clusters efficient at ejecting O stars, the mass function of the ejected stars is top-heavy compared to the given initial mass function (IMF), while the mass function of stars remai...

  6. Pyroclast Tracking Velocimetry illuminates bomb ejection and explosion dynamics at Stromboli (Italy) and Yasur (Vanuatu) volcanoes

    Science.gov (United States)

    Gaudin, Damien; Taddeucci, Jacopo; Scarlato, Piergiorgio; Moroni, Monica; Freda, Carmela; Gaeta, Mario; Palladino, Danilo Mauro

    2014-07-01

    A new image processing technique—Pyroclast Tracking Velocimetry—was used to analyze a set of 30 high-speed videos of Strombolian explosions from different vents at Stromboli (Italy) and Yasur (Vanuatu) volcanoes. The studied explosions invariably appear to result from the concatenation of up to a hundred individual pyroclast ejection pulses. All these pulses share a common evolution over time, including (1) a non-linear decrease of the pyroclast ejection velocity, (2) an increasing spread of ejection angle, and (3) an increasing size of the ejected pyroclasts. These features reflect the dynamic burst of short-lived gas pockets, in which the rupture area enlarges while pressure differential decreases. We estimated depth of pyroclast release to be approximately 1 and 8 m below the surface at Stromboli and Yasur, respectively. In addition, explosions featuring more frequent pulses also have higher average ejection velocities and larger total masses of pyroclasts. These explosions release a larger overall amount of energy stored in the pressurized gas by a combination of more frequent and stronger ejection pulses. In this context, the associated kinetic energy per explosion, ranging 103-109 J appears to be a good proxy for the explosion magnitude. Differences in the pulse-defining parameters among the different vents suggest that this general process is modulated by geometrical factors in the shallow conduit, as well as magma-specific rheology. Indeed, the more viscous melt of Yasur, compared to Stromboli, is associated with larger vents producing fewer pulses but larger pyroclasts.

  7. Linear theory on temporal instability of megahertz faraday waves for monodisperse microdroplet ejection.

    Science.gov (United States)

    Tsai, Shirley C; Tsai, Chen S

    2013-08-01

    A linear theory on temporal instability of megahertz Faraday waves for monodisperse microdroplet ejection based on mass conservation and linearized Navier-Stokes equations is presented using the most recently observed micrometer- sized droplet ejection from a millimeter-sized spherical water ball as a specific example. The theory is verified in the experiments utilizing silicon-based multiple-Fourier horn ultrasonic nozzles at megahertz frequency to facilitate temporal instability of the Faraday waves. Specifically, the linear theory not only correctly predicted the Faraday wave frequency and onset threshold of Faraday instability, the effect of viscosity, the dynamics of droplet ejection, but also established the first theoretical formula for the size of the ejected droplets, namely, the droplet diameter equals four-tenths of the Faraday wavelength involved. The high rate of increase in Faraday wave amplitude at megahertz drive frequency subsequent to onset threshold, together with enhanced excitation displacement on the nozzle end face, facilitated by the megahertz multiple Fourier horns in resonance, led to high-rate ejection of micrometer- sized monodisperse droplets (>10(7) droplets/s) at low electrical drive power (<;1 W) with short initiation time (<;0.05 s). This is in stark contrast to the Rayleigh-Plateau instability of a liquid jet, which ejects one droplet at a time. The measured diameters of the droplets ranging from 2.2 to 4.6 μm at 2 to 1 MHz drive frequency fall within the optimum particle size range for pulmonary drug delivery.

  8. ExternE transport methodology for external cost evaluation of air pollution

    DEFF Research Database (Denmark)

    Jensen, S. S.; Berkowicz, R.; Brandt, J.

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summaris...... how the methodology has been applied so far in a previous Danish study. Finally, results of a case study are reported. Exposure factors have been calculated for various urban categories in the Greater Copenhagen Area...

  9. ExternE transport methodology for external cost evaluation of air pollution (DK)

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.; Berkowicz, R.; Brandt, J. [National Environmental Research Inst., Dept. of Atmospheric Environment (Denmark); Willumsen, E.; Kristensen, N.B. [COWI (Denmark)

    2004-07-01

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AiGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Inititally, a brief description of the ExternE Transport methodology is given and it is summarised how the methodology has been applied so far in a previous Danish study. Finally, results of a case study are reported. Exposure factors have been calculated for various urban categories in the Greater Copenhagen Area. (au)

  10. Electron and ion induced electron emission from metals and insulators

    CERN Document Server

    Steinbatz, M

    2001-01-01

    gradually exposed to oxygen as an experimental probe. The experimental data are fitted with an analytical model, that is able to describe the observed kinetics. The fit parameters give absolute values of sticking probabilities and of surface reaction rates. During oxidation of aluminum and magnesium also spontaneous emission of electrons (exoelectrons) is observed. This effect is quantitatively studied for different oxygen partial pressures. The experimental data also indicate a significant influence of the surface morphology on the exoemission process. An important consequence of atomic collisions in solids is ionization leading to electron ejection from the target atoms with subsequent migration through the solid. A certain fraction of these electrons finally reaches the surface and is ejected into vacuum. A standard measurement of this phenomenon is the observation of the particle (electron, ion) induced electron emission yield g, defined as the average number of ejected electrons per incoming projectile. ...

  11. ON SUN-TO-EARTH PROPAGATION OF CORONAL MASS EJECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Luhmann, Janet G.; Moestl, Christian; Bale, Stuart D.; Lin, Robert P. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Lugaz, Noe [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Davies, Jackie A., E-mail: liuxying@ssl.berkeley.edu [Space Science and Technology Department, Rutherford Appleton Laboratory, Didcot (United Kingdom)

    2013-05-20

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts, and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of fast CMEs can be approximately formulated into three phases: an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation (or gradual deceleration); (2) the CMEs studied here are still accelerating even after the flare maximum, so energy must be continuously fed into the CME even after the time of the maximum heating and radiation has elapsed in the corona; (3) the rapid deceleration, presumably due to interactions with the ambient medium, mainly occurs over a relatively short timescale following the acceleration phase; and (4) CME-CME interactions seem a common phenomenon close to solar maximum. Our comparison between different techniques (and data sets) has important implications for CME observations and their interpretations: (1) for the current cases, triangulation assuming a compact CME geometry is more reliable than triangulation assuming a spherical front attached to the Sun for distances below 50-70 solar radii from the Sun, but beyond about 100 solar radii we would trust the latter more; (2) a proper treatment of CME geometry must be performed in determining CME Sun-to-Earth kinematics, especially when the CME propagation direction is far away from the

  12. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  13. Retrofitting Systems for External Walls

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report, 9 different external and internal retrofitting systems are analyzed using numerical calculations. The analysis focuses on the thermal bridge effects in the different systems, and on this basis it is discussed whether internal or external retrofitting has the most advantages...

  14. Performance Targets and External Benchmarking

    DEFF Research Database (Denmark)

    Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

    Research on relative performance measures, transfer pricing, beyond budgeting initiatives, target costing, piece rates systems and value based management has for decades underlined the importance of external benchmarking in performance management. Research conceptualises external benchmarking...... the conditions upon which the market mechanism is performing within organizations. This paper aims to contribute to research by providing more insight to the conditions for the use of external benchmarking as an element in performance management in organizations. Our study explores a particular type of external...... towards the conditions for the use of the external benchmarks we provide more insights to some of the issues and challenges that are related to using this mechanism for performance management and advance competitiveness in organizations....

  15. External costs related to power production technologies. ExternE national implementation for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Schleisner, L.; Sieverts Nielsen, P.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs.

  16. Effects of Potassium Currents upon Action Potential of Cardiac Cells Exposed to External Electric fields

    Institute of Scientific and Technical Information of China (English)

    An-Ying Zhang; Xiao-Feng Pang

    2008-01-01

    Previous studies show that exposure to high-voltage electric fields would influence the electro cardiogram both in experimental animate and human beings. The effects of the external electric fields upon action potential of cardiac cells are studied in this paper based on the dynamical model, LR91. Fourth order Runger-Kuta is used to analyze the change of potassium ion channels exposed to external electric fields in detail. Results indicate that external electric fields could influence the current of potassium ion by adding an induced component voltage on membrane. This phenomenon might be one of the reasons of heart rate anomaly under the high-voltage electric fields.

  17. Internal standard versus external standard calibration: an uncertainty case study of a liquid chromatography analysis

    Directory of Open Access Journals (Sweden)

    Elcio Cruz de Oliveira

    2010-01-01

    Full Text Available Traditionally, in the cigarettes industry, the determination of ammonium ion in the mainstream smoke is performed by ion chromatography. This work studies this determination and compares the results of this technique with the use of external and internal standard calibration. A reference cigarette sample presented measurement uncertainty of 2.0 μg/cigarette and 1.5 μg/cigarette, with external and internal standard, respectively. It is observed that the greatest source of uncertainty is the bias correction factor and that it is even more significant when using external standard, confirming thus the importance of internal standardization for this correction.

  18. Better Visual Outcome by Intraocular Lens Ejection in Geriatric Patients with Ruptured Ocular Injuries

    Science.gov (United States)

    Sugita, Tadasu; Tsunekawa, Taichi; Matsuura, Toshiyuki; Takayama, Kei; Yamamoto, Kentaro; Kachi, Shu; Ito, Yasuki; Ueno, Shinji; Nonobe, Norie; Kataoka, Keiko; Suzumura, Ayana; Iwase, Takeshi; Terasaki, Hiroko

    2017-01-01

    Ocular trauma is one of the leading causes of visual impairment worldwide. Because of the popularity of cataract surgeries, aged individuals with ocular trauma commonly have a surgical wound in their eyes. The purpose of this study was to evaluate the visual outcome of cases that were coincident with intraocular lens (IOL) ejection in the eyes with ruptured open-globe ocular injuries. Consecutive patients with open-globe ocular injuries were first reviewed. Patients’ characteristics, corrected distance visual acuities (CDVAs) over 3 years after the trauma, causes of injuries, traumatic wound patterns, and coexistence of retinal detachment were examined. The relationships between poor CDVA and the other factors, including the complications of crystalline lens and IOL ejection, were examined. A total of 105 eyes/patients [43 eyes with rupture, 33 with penetrating, 28 with intraocular foreign body (IOFB), and 1 with perforating injuries] were included. Rupture injuries were common in aged patients and were mostly caused by falls, whereas penetrating and IOFB injuries were common in young male patients. CDVAs of the eyes with rupture injuries were significantly worse than those of the eyes with penetrating or IOFB injuries. CDVA from more than 50% of the ruptured eyes resulted in no light perception or light perception to 20/500. CDVA of the ruptured eyes complicated by crystalline lens ejection was significantly worse than that of those complicated by IOL ejection. The wounds of the ruptured eyes complicated by IOL ejection were mainly located at the superior corneoscleral limbus, whereas those of the eyes complicated by crystalline lens ejection were located at the posterior sclera. There were significant correlations between poor CDVA and retinal detachment and crystalline lens ejection. These results proposed a new trend in the ocular injuries that commonly occur in aged patients; history of cataract surgery might affect the final visual outcome after open

  19. Value of left ventricular ejection fraction during exercise in predicting the extent of coronary artery disease.

    Science.gov (United States)

    DePace, N L; Iskandrian, A S; Hakki, A H; Kane, S A; Segal, B L

    1983-04-01

    To determine the relation between left ventricular performance during exercise and the extent of coronary artery disease, the results of exercise radionuclide ventriculography were analyzed in 65 patients who also underwent cardiac catheterization. A scoring system was used to quantitate the extent of coronary artery disease. This system takes into account the number and site of stenoses of the major coronary vessels and their secondary branches. The conventional method of interpreting the coronary angiograms indicated that 26 patients had significant coronary artery disease (defined as 70% or more narrowing of luminal diameter) of one vessel, 21 had multivessel disease and 18 had no significant coronary artery disease. Although the exercise left ventricular ejection fraction was significantly higher in patients with no coronary artery disease than in patients with one or multivessel disease (probability [p] less than 0.001), there was considerable overlap among the three groups. With the scoring system, a good correlation was found between the coronary artery disease score and the exercise left ventricular ejection fraction (r = -0.70; p less than 0.001). If the exercise heart rate was 130 beats/min or greater or the age of the patient was 50 years or less, an even better correlation was found (r = -0.73 and r = -0.82, respectively). The exercise ejection fraction (but not the change in ejection fraction, end-diastolic volume and end-systolic volume from rest to exercise) correlated with the extent of coronary artery disease. The exercise ejection fraction is the most important exercise variable that correlates with the extent of coronary artery disease when the latter is assessed quantitatively by a scoring system rather than the conventional method of reporting coronary angiograms. Young age and greater exercise heart rate strengthened the correlation. The change in ejection fraction from rest to exercise is useful in the diagnosis of coronary artery disease

  20. Coronal Mass Ejections, Interplanetary Shocks In Relation With Forbush Decreases Associated With Intense Geomagnetic Storms

    Science.gov (United States)

    Verma, P. L.; Patel, Nand Kumar; Prajapati, Mateswari

    2014-05-01

    Coronal mass ejections (CMEs} are the most energetic solar events in which large amount of solar plasma materials are ejected from the sun into heliosphere, causing major disturbances in solar wind plasma, Interplanetary shocks, Forbush decrease(Fds) in cosmic ray intensity and geomagnetic storms. We have studied Forbush decreases associated with intense geomagnetic storms observed at Oulu super neutron monitor, during the period of May 1998-Dec 2006 with coronal mass ejections (CMEs), X-ray solar flares and interplanetary shocks. We have found that all the (100%) Forbush decreases associated with intense geomagnetic storms are associated with halo and partial halo coronal mass ejections (CMEs). The association rate between halo and partial halo coronal mass ejections are found 96.00%and 04.00% respectively. Most of the Forbush decreases associated with intense geomagnetic storms (96.29%) are associated with X-ray solar flares of different categories . The association rates for X-Class, M-Class, and C- Class X -ray solar flares are found 34.62%, 50.00% and 15.38% respectively .Further we have concluded that majority of the Forbush decrease associated with intense geomagnetic storms are related to interplanetary shocks (92.30 %) and the related shocks are forward shocks. We have found positive co-relation with co-relation co-efficient .7025 between magnitudes of Forbush decreases associated with intense geomagnetic storms and speed of associated coronal mass ejections. Positive co-relation with co-relation co-efficient 0.48 has also been found between magnitudes of intense geomagnetic storms and speed of associated coronal mass ejections.

  1. External fuel thermionic reactor system.

    Science.gov (United States)

    Mondt, J. F.; Peelgren, M. L.

    1971-01-01

    Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.

  2. Combination of external loads

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S.; Tarp Johansen, N.J.; Joergensen, H. [Forskningscenter Risoe, Roskilde (Denmark); Gravesen, H.; Soerensen, S.L. [Carl Bro, Glostrup (Denmark); Pedersen, J. [Elsam Engineering, Fredericia (Denmark); Zorn, R.; Hvidberg Knudsen, M. [DHI Water and Environment, Hoersholm (Denmark); Voelund, P. [Energi E2, Koebenhavn (Denmark)

    2003-09-01

    The project onbectives have been: To improve and consequently opimise the basis for design of offshore wind turbines. This is done through 1) mapping the wind, wave ice and current as well as correlations of these, and 2) by clarifyring how these external conditions transform into loads. A comprehensive effort has been made to get a thorough understanding of the uncertainties that govern the reliability of wind turbines with respect to wind and wave loading. One of the conclusions is that the reliability of wind turbines is generally lower, than the average reliability of building structures that are subject not only to environmental loads, which are very uncertain, but also imposed loads and self weight, which are less uncertain than the environmental loads. The implication is that, at the moment lower load partial safety factors for onshore wind turbines cannot be recommended. For the combination of wind and wave design loads the problem is twofold: 1). A very conservative design will be generated by simply adding the individual wind and wave design loads disregarding the independence of the short-term fluctuations of wind and wave loads. 2). Characteristic values and partial safety factors for wind and wave loads are not defined similarly. This implies that the reliability levels of turbine support structures subject to purely aerodynamic loads and subject to purely hydrodynamic loads are not identical. For the problem of combining aerodynamic design loads and hydrodynamic design loads two results have been obtained in the project: 1). By simple means a site specific wave load safety factor rendering the same safety level for hydrodynamic loads as for aerodynamic loads is derived, and next, by direct square summation of extreme fluctuations, the wind and wave load safety factors are weighted. 2). Under the assumptions that a deep water site is considered and that the wave loading is a fifty-fifty mix of drag and inertia the same wind and wave load safety factor

  3. Calculation of the ionization differential effective cross sections in fast ion-atom collisions

    CERN Document Server

    Kaminskij, A K

    2002-01-01

    The method of the calculations of the ionization effective cross sections d sigma/d OMEGA differential in the incident ion scattering angle is described in fast collisions of light ions and atoms. The calculated values of angular distributions of the ions Al, Mg (for the different values of charge and energy of ions) after their collisions with the Ne, Mg atoms being ionized are reported. The dependence of such angular distributions on the incident ion charge and energy and the initial state of ejected electron is investigated

  4. External costs related to power production technologies. ExternE national implementation for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Schleisner, L.; Sieverts Nielsen, P. [eds.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs.

  5. Externality and burnout among dentists.

    Science.gov (United States)

    St-Yves, A; Freeston, M H; Godbout, F; Poulin, L; St-Amand, C; Verret, M

    1989-12-01

    This study investigates the relationship between burnout as measured by the Maslach Burnout Inventory and locus of control as measured by the Adult Nowicki-Strickland Internal-External Locus of Control (ANS-IE) for 82 dentists. Significant Pearson correlations between two Maslach subscales and locus of control show Personal Accomplishment to be negatively associated -.31 and Emotional Exhaustion to be positively correlated .21 to externality.

  6. Relatie interne en externe audit

    OpenAIRE

    Ghys, Emelie

    2011-01-01

    In het eerste hoofdstuk wordt de probleemstelling van deze eindverhandeling besproken. Interne en externe audit worden de laatste jaren internationaal en nationaal meer en meer erkend in het bedrijfsleven. Aanleiding voor de toenemende belangstelling van de interne en externe auditfunctie zijn de verschillende boekhoudschandalen rond corporate governance of deugdelijk bestuur. Deze financiële mislukkingen leidden wereldwijd tot diverse wetten, nieuwe regels en verbeterde standaarden om zo een...

  7. Performance Targets and External Benchmarking

    DEFF Research Database (Denmark)

    Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

    as a market mechanism that can be brought inside the firm to provide incentives for continuous improvement and the development of competitive advances. However, whereas extant research primarily has focused on the importance and effects of using external benchmarks, less attention has been directed towards...... towards the conditions for the use of the external benchmarks we provide more insights to some of the issues and challenges that are related to using this mechanism for performance management and advance competitiveness in organizations....

  8. Parallel External Memory Graph Algorithms

    DEFF Research Database (Denmark)

    Arge, Lars Allan; Goodrich, Michael T.; Sitchinava, Nodari

    2010-01-01

    In this paper, we study parallel I/O efficient graph algorithms in the Parallel External Memory (PEM) model, one o f the private-cache chip multiprocessor (CMP) models. We study the fundamental problem of list ranking which leads to efficient solutions to problems on trees, such as computing lowest...... an optimal speedup of ¿(P) in parallel I/O complexity and parallel computation time, compared to the single-processor external memory counterparts....

  9. THE NATURE OF HYPERVELOCITY STARS AND THE TIME BETWEEN THEIR FORMATION AND EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Cohen, Judith G., E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: jlc@astro.caltech.edu [Palomar Observatory, Mail Stop 249-17, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-07-20

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 {+-} 0.11 M{sub Sun} main-sequence B star at a distance of 50 {+-} 5 kpc. The difference between its age and its flight time from the Galactic center is 105 {+-} 18 (stat) {+-}30 (sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10{sup 8} yr 'arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10{sup 7} yr. For comparison, we derive arrival times of 10{sup 7} yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10{sup 7} yr of its lifetime is ruled out at the 3{sigma} level. Together with the 10{sup 8} yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Galactic center origin for the HVSs. If the HVSs were indeed ejected by the central black hole, then the Galactic center was forming stars {approx_equal}200 Myr ago, and the progenitors of the HVSs took {approx_equal}100 Myr to enter the black hole's loss cone.

  10. Activity associated with coronal mass ejections at solar minimum - SMM observations from 1984-1986

    Science.gov (United States)

    St. Cyr, O. C.; Webb, D. F.

    1991-01-01

    Seventy-three coronal mass ejections (CMEs) observed by the coronagraph aboard SMM between 1984 and 1986 were examined in order to determine the distribution of various forms of solar activity that were spatially and temporally associated with mass ejections during solar minimum phase. For each coronal mass ejection a speed was measured, and the departure time of the transient from the lower corona estimated. Other forms of solar activity that appeared within 45 deg longitude and 30 deg latitude of the mass ejection and within +/-90 min of its extrapolated departure time were explored. The statistical results of the analysis of these 73 CMEs are presented, and it is found that slightly less than half of them were infrequently associated with other forms of solar activity. It is suggested that the distribution of the various forms of activity related to CMEs does not change at different phases of the solar cycle. For those CMEs with associations, it is found that eruptive prominences and soft X-rays were the most likely forms of activity to accompany the appearance of mass ejections.

  11. Probability of rebound and eject of sand particles in wind-blown sand movement

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Xiaojing Zheng

    2007-01-01

    When incident particles impact into a sand bed in wind-blown sand movement, rebound of the incident particles and eject of the sand particles by the incident particles affect directly the development of wind sand flux. In order to obtain rebound and eject lift-off probability of the sand particles, we apply the particle-bed stochastic collision model presented in our pervious works to derive analytic solutions of velocities of the incident and impacted particles in the postcollision bed. In order to describe randomness inherent in the real particle-bed collision, we take the incident angle, theimpact position and the direction of resultant action of sand particles in sand bed on the impacted sand particle as random variables, and calculate the rebound and eject velocities,angles and coefficients (ratio of rebound and eject velocity to incident velocity). Numerical results are found in accordance with current experimental results. The rebound and eject lift-off probabilities versus the incident and creeping velocities are predicted.

  12. Ejection of the corona at State transitions: a common behaviour in microquasars?

    CERN Document Server

    Prat, Lionel

    2009-01-01

    The onset of most microquasar outbursts is characterized by a state transition between a Low/Hard State (LHS) and a High/Soft State (HSS). Besides drastic spectral and timing changes, this transition often shows a discrete ejection event detectable in the radio range. However, the exact nature of the ejected material and the mechanisms that give birth to these phenomena are yet to be unraveled. Recent simultaneous radio and X-ray observations on several sources point to a coronal nature of the ejected material. In the cases of GRS 1915+105, XTE J1550-564, and the 2002 outburst of GX 339-4, the flux of the Compton component decreases sharply just before an ejection is detected in the radio range. Finally, in the case of H1743-322, drastic physical changes occurred in the corona just before the state transition, compatible with the disappearance of part of this medium. Thus, the behaviour of at least 4 microquasars points in the direction of an ejection of the corona at the state transition, feature that is yet...

  13. Simulations of Emerging Magnetic Flux. II. The Formation of Unstable Coronal Flux Ropes and the Initiation of Coronal Mass Ejections

    Science.gov (United States)

    Leake, James E.; Linton, Mark G.; Antiochos, Spiro K.

    2014-01-01

    We present results from three-dimensional magnetohydrodynamic simulations of the emergence of a twisted convection zone flux tube into a pre-existing coronal dipole field. As in previous simulations, following the partial emergence of the sub-surface flux into the corona, a combination of vortical motions and internal magnetic reconnection forms a coronal flux rope. Then, in the simulations presented here, external reconnection between the emerging field and the pre-existing dipole coronal field allows further expansion of the coronal flux rope into the corona. After sufficient expansion, internal reconnection occurs beneath the coronal flux rope axis, and the flux rope erupts up to the top boundary of the simulation domain (approximately 36 Mm above the surface).We find that the presence of a pre-existing field, orientated in a direction to facilitate reconnection with the emerging field, is vital to the fast rise of the coronal flux rope. The simulations shown in this paper are able to self-consistently create many of the surface and coronal signatures used by coronal mass ejection (CME) models. These signatures include surface shearing and rotational motions, quadrupolar geometry above the surface, central sheared arcades reconnecting with oppositely orientated overlying dipole fields, the formation of coronal flux ropes underlying potential coronal field, and internal reconnection which resembles the classical flare reconnection scenario. This suggests that proposed mechanisms for the initiation of a CME, such as "magnetic breakout," are operating during the emergence of new active regions.

  14. Ion trap system for radioactive ions at JYFL

    Energy Technology Data Exchange (ETDEWEB)

    Kolhinen, V.S.; Jokinen, A.; Rinta-Antila, S.; Szerypo, J. [University of Jyvaeskylae, Department of Physics (Finland); Aeystoe, J. [CERN, Geneva (Switzerland)

    2001-07-01

    The goal of the ion trap project in Jyvaeskylae is to improve the quality of radioactive beams at IGISOL (Ion Guide Isotope Separator On-Line), in terms of transverse emittance, energy spread and purity. This improvement is achieved with an aid of an RFQ cooler/buncher and a mass-selective cylindrical Penning trap (mass resolving power up to 10{sup 5}). Their final purpose is to produce cooled isobarically pure beams of exotic radioactivities mainly of exotic neutron-rich isotopes from fission (including refractory elements). In the Penning trap ions are confined in three dimensions in a superposition of static quadrupole electric and homogeneous magnetic fields. The magnetic field confines the ions in two dimensions in a plane perpendicular to the field direction. A confinement in the third, magnetic field direction (parallel to the trap axis) is done by a quadrupole electric field. The Penning trap system in Jyvaeskylae (JYFLTRAP) will contain two cylindrical Penning traps placed inside the same superconducting magnet (B=7 T). The first, purification trap, will accept cooled (continuous or bunched) beams from the RFQ cooler/buncher and perform the isobaric purification. The latter is - done using a combination of a buffer gas cooling and an azimuthal quadrupole RF-field providing mass- dependent centering of ions. This, in turn, allows mass-selective ejection of ions in short pulses. Clean monoisotopic bunched beams will be delivered for the nuclear spectroscopy studies, collinear laser spectroscopy experiments and precise nuclear mass measurements (10{sup -7} precision). The latter will be performed in the second, precision Penning trap (author)

  15. External Costs Related to Power Production Technologies

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective...

  16. External Costs Related to Power Production Technologies

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective of...

  17. The trapped ion-electron instability in an electron storage ring with a gap in the bunch train

    Science.gov (United States)

    Bosch, R. A.

    2000-08-01

    The trapped ion-electron instability in an electron storage ring is studied for a broad distribution of natural ion oscillation frequencies, termed ion bounce frequencies. A gap in the train of electron bunches may be used to create bands of unstable ion bounce frequencies, so that an ion species is ejected from regions of the ring where its horizontal or vertical bounce frequency is unstable. Expressions are obtained for the reduction in the incoherent tune shifts and trapped ion-electron instability growth rates resulting from the gap.

  18. The trapped ion-electron instability in an electron storage ring with a gap in the bunch train

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, R.A. E-mail: bosch@src.wisc.edu

    2000-08-11

    The trapped ion-electron instability in an electron storage ring is studied for a broad distribution of natural ion oscillation frequencies, termed ion bounce frequencies. A gap in the train of electron bunches may be used to create bands of unstable ion bounce frequencies, so that an ion species is ejected from regions of the ring where its horizontal or vertical bounce frequency is unstable. Expressions are obtained for the reduction in the incoherent tune shifts and trapped ion-electron instability growth rates resulting from the gap.

  19. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  20. A multiple sampling ionization chamber for the External Target Facility

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.H., E-mail: zhxh@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Tang, S.W.; Ma, P.; Lu, C.G.; Yang, H.R.; Wang, S.T.; Yu, Y.H.; Yue, K.; Fang, F. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yan, D.; Zhou, Y.; Wang, Z.M.; Sun, Y. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Sun, Z.Y.; Duan, L.M. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, B.H. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China)

    2015-09-21

    A multiple sampling ionization chamber used as a particle identification device for high energy heavy ions has been developed for the External Target Facility. The performance of this detector was tested with a {sup 239}Pu α source and RI beams. A Z resolution (FWHM) of 0.4–0.6 was achieved for nuclear fragments of {sup 18}O at 400 AMeV.

  1. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  2. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    Science.gov (United States)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  3. Miniaturized Linear Wire Ion Trap Mass Analyzer.

    Science.gov (United States)

    Wu, Qinghao; Li, Ailin; Tian, Yuan; Zare, Richard N; Austin, Daniel E

    2016-08-02

    We report a linear ion trap (LIT) in which the electric field is formed by fine wires held under tension and accurately positioned using holes drilled in two end plates made of plastic. The coordinates of the hole positions were optimized in simulation. The stability diagram and mass spectra using boundary ejection were compared between simulation and experiment and good agreement was found. The mass spectra from experiments show peak widths (fwhm) in units of mass-to-charge of around 0.38 Th using a scan rate of 3830 Th/s. The limits of detection are 137 ppbv and 401 ppbv for benzene and toluene, respectively. Different sizes of the wire ion trap can be easily fabricated by drilling holes in scaled positions. Other distinguishing features, such as high ion and photon transmission, low capacitance, high tolerance to mechanical and assembly error, and low weight, are discussed.

  4. Global Energetics of Solar Flares. V. Energy Closure in Flares and Coronal Mass Ejections

    Science.gov (United States)

    Aschwanden, Markus J.; Caspi, Amir; Cohen, Christina M. S.; Holman, Gordon; Jing, Ju; Kretzschmar, Matthieu; Kontar, Eduard P.; McTiernan, James M.; Mewaldt, Richard A.; O’Flannagain, Aidan; Richardson, Ian G.; Ryan, Daniel; Warren, Harry P.; Xu, Yan

    2017-02-01

    In this study we synthesize the results of four previous studies on the global energetics of solar flares and associated coronal mass ejections (CMEs), which include magnetic, thermal, nonthermal, and CME energies in 399 solar M- and X-class flare events observed during the first 3.5 yr of the Solar Dynamics Observatory (SDO) mission. Our findings are as follows. (1) The sum of the mean nonthermal energy of flare-accelerated particles ({E}{nt}), the energy of direct heating ({E}{dir}), and the energy in CMEs ({E}{CME}), which are the primary energy dissipation processes in a flare, is found to have a ratio of ({E}{nt}+{E}{dir}+{E}{CME})/{E}{mag}=0.87+/- 0.18, compared with the dissipated magnetic free energy {E}{mag}, which confirms energy closure within the measurement uncertainties and corroborates the magnetic origin of flares and CMEs. (2) The energy partition of the dissipated magnetic free energy is: 0.51 ± 0.17 in nonthermal energy of ≥slant 6 {keV} electrons, 0.17 ± 0.17 in nonthermal ≥slant 1 {MeV} ions, 0.07 ± 0.14 in CMEs, and 0.07 ± 0.17 in direct heating. (3) The thermal energy is almost always less than the nonthermal energy, which is consistent with the thick-target model. (4) The bolometric luminosity in white-light flares is comparable to the thermal energy in soft X-rays (SXR). (5) Solar energetic particle events carry a fraction ≈ 0.03 of the CME energy, which is consistent with CME-driven shock acceleration. (6) The warm-target model predicts a lower limit of the low-energy cutoff at {e}c≈ 6 {keV}, based on the mean peak temperature of the differential emission measure of T e = 8.6 MK during flares. This work represents the first statistical study that establishes energy closure in solar flare/CME events.

  5. Clinical utility of semi-automated estimation of ejection fraction at the point-of-care

    DEFF Research Database (Denmark)

    Frederiksen, Christian Alcaraz; Juhl-Olsen, Peter; Hermansen, Johan Fridolf

    2015-01-01

    INTRODUCTION: To compare estimation of ejection fraction at the bedside by AutoEF compared with conventional methods and to assess feasibility and time consumption. METHODS: A total of 102 relatively hemodynanically stable mixed medical and surgical patients were included. All patients underwent...... ultrasonography of the heart at the bedside performed by a novice examiner. Three assessments of ejection fraction were made: 1) Expert eyeballing by a single specialist in cardiology and expert in echocardiography; 2) Manual planimetry by an experienced examiner; 3) AutoEF by a novice examiner with limited...... experience in echocardiography. RESULTS: Expert eyeballing of ejection fraction was performed in 100% of cases. Manual planimetry was possible in 89% of cases and AutoEF was possible in 83% of cases. The correlation between expert eyeballing and AutoEF was r=0.82, p manual planimetry...

  6. Determination of ejection velocity of rock fragments during rock burst in consideration of damage

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-jun; LI Xi-bing; ZHOU Zi-long

    2005-01-01

    The ejection velocity of rock fragments during rock burst, one of the important indexes representing the rock burst strength, is used most conveniently in the supporting design of tunnel with rock burst tendency and is often determined by means of observation devices. In order to calculate the average ejection velocity of rock fragments theoretically, the energy of rock burst was divided into damage consuming energy and kinetic energy gained by unit volume of rock firstly, and then the rock burst kinetic proportional coefficient η was brought up which could be determined according to the rock-burst damage energy index WD , at last the expression of the average ejection velocity of rock fragments during rock burst was obtained and one deep level underground tunnel was researched using the mentioned method. The results show that the calculation method is valid with or without considering the tectonic stress of tunnels, and that the method can be a reference for supporting design of deep mining.

  7. Chip-ejection interference in cutting processes of modern cutting tools

    Institute of Scientific and Technical Information of China (English)

    师汉民

    1999-01-01

    Based on the “principle of minimum energy”, the basic characteristics of non-free cutting are studied; the phenomenon and the nature of chip-ejection interference commonly existing in the cutting process of modem cutting tools are explored. A "synthesis method of elementary cutting tools" is suggested for modeling the cutting process of modem complex cutting tools. The general equation governing the chip-ejection motion is deduced. Real examples of non-free cutting are analyzed and the theoretically predicted results are supported by the experimental data or facts. The sufficient and necessary conditions for eliminating chip-ejection interference and for realizing free cutting are given; the idea and the technical approach of "the principle of free cutting" are also discussed, and a feasible way for improving or optimizing the cutting performance of modem cutting tools is, therefore, found.

  8. Effect of shock wave risetime on material ejection from aluminum surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J.R.

    1977-09-15

    The effect of shock wave risetime on material ejection in aluminum has been studied for loading stresses of 21 GPa. Uniform loading was accomplished with plate impact techniques by mounting specimens on a ramp wave generator. Projectile impact on one side of the wave generator produced a wave which dispersed with propagation distance. This wave was then made incident to an aluminum specimen, so that the specimen experienced non-shock loading. It was found that mass ejection from aluminum surfaces can be reduced by over two orders of magnitude relative to shock loading conditions by accelerating the surface with a wave risetime greater than about 35 ns. These results suggest an explanation for the apparent discrepancies which are sometimes observed in mass ejection measurements utilizing either plate impact or electron beam deposition to generate stress waves.

  9. Model for estimating the effects of surface roughness on mass ejection from shocked materials

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J R; Bertholf, L D

    1978-10-01

    A statistical model is presented for estimating the effects of surface roughness on mass ejection from shocked surfaces. In the model, roughness is characterized by the total volume of defects, such as pits, scratches and machine marks, on a surface. The amount of material ejected from these defects during shock loading can be estimated by assuming that jetting from surface depressions is the primary mode of ejection and by making simplifying assumptions about jetting processes. Techniques are discussed for estimating the effects of distribution in defect size and shape, and results are presented for several different geometries of defects. The model is used to compare predicted and measured ejecta masses from six different materials. Surface defects in these materials range from pits and scratches on polished surfaces to prepared defects such as machined or porous surfaces. Good agreement is achieved between predicted and measured results which suggests general applicability of the model.

  10. Quantitative uncertainty and sensitivity analysis of a PWR control rod ejection accident

    Energy Technology Data Exchange (ETDEWEB)

    Pasichnyk, I.; Perin, Y.; Velkov, K. [Gesellschaft flier Anlagen- und Reaktorsicherheit - GRS mbH, Boltzmannstasse 14, 85748 Garching bei Muenchen (Germany)

    2013-07-01

    The paper describes the results of the quantitative Uncertainty and Sensitivity (U/S) Analysis of a Rod Ejection Accident (REA) which is simulated by the coupled system code ATHLET-QUABOX/CUBBOX applying the GRS tool for U/S analysis SUSA/XSUSA. For the present study, a UOX/MOX mixed core loading based on a generic PWR is modeled. A control rod ejection is calculated for two reactor states: Hot Zero Power (HZP) and 30% of nominal power. The worst cases for the rod ejection are determined by steady-state neutronic simulations taking into account the maximum reactivity insertion in the system and the power peaking factor. For the U/S analysis 378 uncertain parameters are identified and quantified (thermal-hydraulic initial and boundary conditions, input parameters and variations of the two-group cross sections). Results for uncertainty and sensitivity analysis are presented for safety important global and local parameters. (authors)

  11. Synergistic effects in radiation-induced particle ejection from solid surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Noriaki (Nagoya Univ. (Japan). Dept. of Physics)

    1990-01-01

    A description is given on radiation-induced particle ejection from solid surfaces, emphasizing synergistic effects arising from multi-species particle irradiation and from irradiation under complex environments. First, it is pointed out that synergisms can be treated by introducing the effects of material modification on radiation-induced particle ejection. As examples of the effects of surface modification on the sputtering induced by elastic encounters, sputtering of alloys and chemical sputtering of graphite are briefly discussed. Then the particle ejection induced by electronic encounters is explained emphasizing the difference in the behaviors from materials to materials. The possible synergistic effects of electronic and elastic encounters are also described. Lastly, we point out the importance of understanding the elementary processes of material-particle interaction and of developing computer codes describing material behaviors under irradiation. (author).

  12. COMET 22P/KOPFF: DUST ENVIRONMENT AND GRAIN EJECTION ANISOTROPY FROM VISIBLE AND INFRARED OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Fernando; Pozuelos, Francisco; Aceituno, Francisco; Casanova, Victor; Sota, Alfredo [Instituto de Astrofisica de Andalucia, CSIC, Glorieta de la Astronomia s/n, 18008 Granada (Spain); Castellano, Julio; Reina, Esteban, E-mail: fernando@iaa.es [Amateur Association Cometas-Obs (Spain)

    2012-06-20

    We present optical observations and Monte Carlo models of the dust coma, tail, and trail structures of the comet 22P/Kopff during the 2002 and 2009 apparitions. Dust loss rates, ejection velocities, and power-law size distribution functions are derived as functions of the heliocentric distance using pre- and post-perihelion imaging observations during both apparitions. The 2009 post-perihelion images can be accurately fitted by an isotropic ejection model. On the other hand, strong dust ejection anisotropies are required to fit the near-coma regions at large heliocentric distances (both inbound at r{sub h} = 2.5 AU and outbound at r{sub h} = 2.6 AU) for the 2002 apparition. These asymmetries are compatible with a scenario where dust ejection is mostly seasonally driven, coming mainly from regions near subsolar latitudes at far heliocentric distances inbound and outbound. At intermediate to near-perihelion heliocentric distances, the outgassing would affect much more extended latitude regions, the emission becoming almost isotropic near perihelion. We derived a maximum dust production rate of 260 kg s{sup -1} at perihelion, and an averaged production rate over one orbit of 40 kg s{sup -1}. An enhanced emission rate, also accompanied by a large ejection velocity, is predicted at r{sub h} > 2.5 pre-perihelion. The model has also been extended to the thermal infrared in order to be applied to available trail observations of this comet taken with IRAS and Infrared Space Observatory spacecrafts. The modeled trail intensities are in good agreement with those observations, which is remarkable taking into account that those data are sensitive to dust ejection patterns corresponding to several orbits before the 2002 and 2009 apparitions.

  13. Left-ventricular peak ejection rate, filling rate, and ejection fraction--frame rate requirements at rest and exercise: concise communication.

    Science.gov (United States)

    Bacharach, S L; Green, M V; Borer, J S; Hyde, J E; Farkas, S P; Johnston, G S

    1979-03-01

    The effect of framing rate on the measurement of left-ventricular (LV) ejection fraction (EF), peak ejection rate (PER), and peak filling rate (PFR) was evaluated at rest and during exercise in 11 normal subjects and 21 patients who underwent gated equilibrium blood-pool imaging. Left-ventricular time-activity curves were obtained in each subject, at rest and during stress, at temporal resolutions of 10, 20, 30, 40, and 50 msec per frame. Ejection fraction, PER, and PFR were determined for each frame duration. By observing changes in the measured values of these quantities with framing rate we conclude that: a) for the measurement of EF, 50 msec per frame at rest and 40 msec per frame at exercise is sufficient; b) PER requires 40 msec per frame at rest and 20 msec per frame during exercise; and c) for the measurement of PFR, at least 40 msec per frame at rest and 20 msec per frame during exercise are needed. These results should hold for both first-pass and gated equilibrium studies.

  14. Tolvaptan Improves the Long-Term Prognosis in Patients With Congestive Heart Failure With Preserved Ejection Fraction as Well as in Those With Reduced Ejection Fraction.

    Science.gov (United States)

    Imamura, Teruhiko; Kinugawa, Koichiro

    2016-09-28

    Tolvaptan (TLV), an arginine vasopressin type 2 antagonist, has been shown to play a role in ameliorating symptomatic congestion and normalizing diluted hyponatremia in patients with congestive heart failure (HF). However, most evidence was derived from patients with HF with reduced ejection fraction (HFrEF), and the clinical efficacy of TLV in patients with HF with preserved ejection fraction (HFpEF) remains uncertain. In this study, we retrospectively enrolled 60 in-hospital patients with stage D HF, who had received TLV to treat symptomatic congestion at our institute between 2011 and 2013. As a control group, we also enrolled 60 background-matched HF patients who did not receive TLV therapy. Patients with HFpEF (n = 29), whose left ventricular ejection fraction was > 45%, had higher age and a lower urine aquaporin-2 level relative to the plasma arginine vasopressin concentration compared with those with HFrEF (n = 91). TLV therapy significantly reduced the 2-year readmission rates in both the HFrEF and HFpEF populations (P < 0.05 for both), indicating that TLV therapy may improve the long-term prognosis not only in patients with HFrEF but also in those with HFpEF.

  15. Ejection fraction and outcomes in patients with atrial fibrillation and heart failure

    DEFF Research Database (Denmark)

    Banerjee, Amitava; Taillandier, Sophie; Olesen, Jonas Bjerring;

    2012-01-01

    Heart failure (HF) increases the risk of stroke and thrombo-embolism (TE) in non-valvular atrial fibrillation (NVAF), and is incorporated in stroke risk stratification scores. We aimed to establish the role of ejection fraction (EF) in risk prediction in patients with NVAF and HF.......Heart failure (HF) increases the risk of stroke and thrombo-embolism (TE) in non-valvular atrial fibrillation (NVAF), and is incorporated in stroke risk stratification scores. We aimed to establish the role of ejection fraction (EF) in risk prediction in patients with NVAF and HF....

  16. Novel plasma and imaging biomarkers in heart failure with preserved ejection fraction

    Directory of Open Access Journals (Sweden)

    Prathap Kanagala

    2015-12-01

    Full Text Available Existing diagnostic guidelines for heart failure with preserved ejection fraction (HFPEF primarily comprise natriuretic peptides and echocardiographic assessment, highlighting the role of diastolic dysfunction. However, recent discoveries of novel plasma markers implicated in pathophysiology of heart failure and technological advances in imaging provide additional biomarkers which are potentially applicable to HFPEF. The evidence base for plasma extra-cellular matrix (ECM peptides, galectin-3, ST2, GDF-15 and pentraxin-3 is reviewed. Furthermore, the capabilities of novel imaging techniques to assess existing parameters (e.g. left ventricular ejection fraction, systolic & diastolic function, chamber size and additional derangements of the ECM, myocardial mechanics and ischaemia evaluation are addressed.

  17. Thermodynamic cost of external control

    Science.gov (United States)

    Barato, Andre C.; Seifert, Udo

    2017-07-01

    Artificial molecular machines are often driven by the periodic variation of an external parameter. This external control exerts work on the system of which a part can be extracted as output if the system runs against an applied load. Usually, the thermodynamic cost of the process that generates the external control is ignored. Here, we derive a refined second law for such small machines that include this cost, which is, for example, generated by free energy consumption of a chemical reaction that modifies the energy landscape for such a machine. In the limit of irreversible control, this refined second law becomes the standard one. Beyond this ideal limiting case, our analysis shows that due to a new entropic term unexpected regimes can occur: the control work can be smaller than the extracted work and the work required to generate the control can be smaller than this control work. Our general inequalities are illustrated by a paradigmatic three-state system.

  18. Leveraging External Sources of Innovation

    DEFF Research Database (Denmark)

    West, Joel; Bogers, Marcel

    2014-01-01

    This paper reviews research on open innovation that considers how and why firms commercialize external sources of innovations. It examines both the “outside-in” and “coupled” modes of open innovation. From an analysis of prior research on how firms leverage external sources of innovation...... cited work beyond those journals. A review of 291 open innovation-related publications from these sources shows that the majority of these articles indeed address elements of this inbound open innovation process model. Specifically, it finds that researchers have front-loaded their examination...... external innovations create value rather than how firms capture value from those innovations. Finally, the interaction phase considers both feedback for the linear process and reciprocal innovation processes such as cocreation, network collaboration, and community innovation. This review and synthesis...

  19. Effects of Plasma Drag on Low Earth Orbiting Satellites due to Heating of Earth's Atmosphere by Coronal Mass Ejections

    CERN Document Server

    Nwankwo, Victor U J

    2013-01-01

    Solar events, such as coronal mass ejections (CMEs) and solar flares, heat up the upper atmosphere and near-Earth space environment. Due to this heating and expansion of the outer atmosphere by the energetic ultraviolet, X-ray and particles expelled from the sun, the low Earth-Orbiting satellites (LEOS) become vulnerable to an enhanced drag force by the ions and molecules of the expanded atmosphere. Out of various types of perturbations, Earth directed CMEs play the most significant role. They are more frequent and intense during the active (solar maximum) phase of the sun's approximately 11-year cycle. As we are approaching another solar maximum later in 2013, it may be instructive to analyse the effects of the past solar cycles on the orbiting satellites using the archival data of space environment parameters as indicators. In this paper, we compute the plasma drag on a model LEOS due to the atmospheric heating by CMEs and other solar events as a function of the solar parameters. Using the current forecast ...

  20. Propagation of Plasma Generated by Intense Pulsed Ion Beam Irradiation

    Institute of Scientific and Technical Information of China (English)

    WU Di; GONG Ye; LIU Jin-Yuan; WANG Xiao-Gang; LIU Yue; MA Teng-Cai

    2006-01-01

    @@ Taking the calculation results based on the established two-dimensional ablation model of the intense-pulsed-ion-beam (IPIB) irradiation process as initial conditions, we build a two-dimensional hydrodynamic ejection model of plasma produced by an IPIB-irradiated metal titanium target into ambient gas. We obtain the conclusions that shock waves generate when the background pressure is around 133 mTorr and also obtain the plume splitting phenomenon that has been observed in the experiments.

  1. Inverted battery design as ion generator for interfacing with biosystems

    Science.gov (United States)

    Wang, Chengwei; Fu, Kun (Kelvin); Dai, Jiaqi; Lacey, Steven D.; Yao, Yonggang; Pastel, Glenn; Xu, Lisha; Zhang, Jianhua; Hu, Liangbing

    2017-07-01

    In a lithium-ion battery, electrons are released from the anode and go through an external electronic circuit to power devices, while ions simultaneously transfer through internal ionic media to meet with electrons at the cathode. Inspired by the fundamental electrochemistry of the lithium-ion battery, we envision a cell that can generate a current of ions instead of electrons, so that ions can be used for potential applications in biosystems. Based on this concept, we report an `electron battery' configuration in which ions travel through an external circuit to interact with the intended biosystem whereas electrons are transported internally. As a proof-of-concept, we demonstrate the application of the electron battery by stimulating a monolayer of cultured cells, which fluoresces a calcium ion wave at a controlled ionic current. Electron batteries with the capability to generate a tunable ionic current could pave the way towards precise ion-system control in a broad range of biological applications.

  2. Ion desorption from frozen H 2O irradiated by MeV heavy ions

    Science.gov (United States)

    Collado, V. M.; Farenzena, L. S.; Ponciano, C. R.; Silveira, E. F. da; Wien, K.

    2004-10-01

    Nitrogen (0.13-0.85 MeV) and 252Cf fission fragments (˜65 MeV) beams are employed to sputter positive and negative secondary ions from frozen water. Desorption yields are measured for different ice temperatures and projectile energies. Target surface is continuously refreshed by condensed water while the target temperature varies and ice thickness changes. In both projectile energy ranges, the preferentially ejected ions are H +, H2+ and (H 2O) nH +-cluster ions. The yields of the corresponding negative ions H - and (H 2O) nO - or (H 2O) nOH - are 1-2 orders of magnitude lower. The (H 2O) nH + desorption yields decrease exponentially as the cluster size, n, increases. In the low energy range, the desorption of positive ion clusters may occur in a two-step process: first, desorption of preformed H 2O clusters and, then, ionization by H + or H 3O + capture. For 0.81 MeV N + projectile ions, the cluster ion emission contributes with 0.05% to the total H 2O desorbed yield. There are indications that emission of the (H 2O) nH + disappears for an electronic energy loss lower than 20 eV/Å. For the high energy range, desorption of small ion clusters is particularly enhanced, revealing that a fragmentation process also exists.

  3. Coulomb crystal mass spectrometry in a digital ion trap

    CERN Document Server

    Deb, Nabanita; Smith, Alexander D; Keller, Matthias; Rennick, Christopher J; Heazlewood, Brianna R; Softley, Timothy P

    2015-01-01

    We present a mass spectrometric technique for identifying the masses and relative abundances of Coulomb-crystallized ions held in a linear Paul trap. A digital radiofrequency waveform is employed to generate the trapping potential, as this can be cleanly switched off, and static dipolar fields subsequently applied to the trap electrodes for ion ejection. Excellent detection efficiency is demonstrated for Ca+ and CaF+ ions from bi-component Ca+/CaF+ Coulomb crystals prepared by reaction of Ca+ with CH3F. A quantitative linear relationship is observed between ion number and the corresponding integrated TOF peak, independent of the ionic species. The technique is applicable to a diverse range of multi-component Coulomb crystals - demonstrated here for Ca+/NH3+/NH4+ and Ca+/CaOH+/CaOD+ crystals - and will facilitate the measurement of ion-molecule reaction rates and branching ratios in complicated reaction systems.

  4. Gamma-Ray Burst Afterglows with Energy Injection: Homogeneous VersusWind External Media

    Institute of Scientific and Technical Information of China (English)

    王伟; 戴子高

    2001-01-01

    Assuming an adiabatic evolution of a gamma-ray burst (GRB) fireball interacting with an external medium,we calculate the hydrodynamics of the fireball with an energy injection from a strongly magnetic millisecond pulsar through magnetic dipole radiation, and obtain the light curve of the optical afterglow from the fireball by synchrotron radiation. The results are given both for an homogeneous external medium and for a wind ejected by GRB progenitor. Our calculations are also available in both ultra-relativistic and non-relativistic phases.Furthermore, the observed R-band light curve of GRB000301C can be well fitted in our model, which might provide a probe of the properties of GRB progenitors.

  5. Impact of ejection fraction on the clinical response to cardiac resynchronization therapy in mild heart failure

    DEFF Research Database (Denmark)

    Linde, Cecilia; Daubert, Claude; Abraham, William T;

    2013-01-01

    Current guidelines recommend cardiac resynchronization therapy (CRT) in mild heart failure (HF) patients with QRS prolongation and ejection fraction (EF) ≤30%. To assess the effect of CRT in less severe systolic dysfunction, outcomes in the REsynchronization reVErses Remodeling in Systolic left v...

  6. Ejection of Hyper-Velocity Stars from the Galactic Centre by Intermediate-Mass Black Holes

    CERN Document Server

    Baumgardt, H; Zwart, S P; Baumgardt, Holger; Gualandris, Alessia; Zwart, Simon Portegies

    2006-01-01

    We have performed N-body simulations of the formation of hyper-velocity stars (HVS) in the centre of the Milky Way due to inspiralling intermediate-mass black holes (IMBHs). We considered IMBHs of different masses, all starting from circular orbits at an initial distance of 0.1 pc. We find that the IMBHs sink to the centre of the Galaxy due to dynamical friction, where they deplete the central cusp of stars. Some of these stars become HVS and are ejected with velocities sufficiently high to escape the Galaxy. Since the HVS carry with them information about their origin, in particular in the moment of ejection, the velocity distribution and the direction in which they escape the Galaxy, detecting a population of HVS will provide insight in the ejection processes and could therefore provide indirect evidence for the existence of IMBHs. Our simulations show that HVS are generated in short bursts which last only a few Myrs until the IMBH is swallowed by the supermassive black hole (SMBH). HVS are ejected almost i...

  7. A study on the core analysis methodology for SMART CEA ejection accident-I

    Energy Technology Data Exchange (ETDEWEB)

    Zee, Sung Kyun; Lee, Chung Chan; Kim, Kyo Yoon; Cho, Byung Oh

    1999-04-01

    A methodology to analyze the fuel enthalpy is developed based on MASTER that is a time dependent 3 dimensional core analysis code. Using the proposed methodology, SMART CEA ejection accident is analyzed. Moreover, radiation doses are estimated at the exclusion area boundary and low population zone to confirm the criteria for the accident. (Author). 31 refs., 13 tabs., 18 figs.

  8. Impact on porous targets: penetration, crater formation, target compaction, and ejection.

    Science.gov (United States)

    Ringl, Christian; Bringa, Eduardo M; Urbassek, Herbert M

    2012-12-01

    Using a granular-mechanics code, we study the impact of a sphere into a porous adhesive granular target, consisting of monodisperse silica grains. The model includes elastic repulsive, adhesive, and dissipative forces, as well as sliding, rolling, and twisting friction. Impact velocities of up to 30 m/s and target filling factors (densities) between 19% and 35% have been systematically studied. We find that the projectile is stopped by an effective drag force which is proportional to the square of its velocity. Target adhesion influences projectile stopping only below a critical velocity, which increases with adhesion. The penetration depth depends approximately logarithmically on the impact velocity and is inversely proportional to the target density. The excavated crater is of conical form and is surrounded by a compaction zone whose width increases but whose maximum value decreases with increasing target density. Grain ejection increases in proportion with impactor velocity. Grains are ejected which have originally been buried to a depth of 8R(grain) below the surface; the angular distribution favors oblique ejection with a maximum around 45°. The velocity distribution of ejected grains features a broad low-velocity maximum around 0.5-1 m/s but exhibits a high-velocity tail up to ~15% of the projectile impact velocity.

  9. Injury pattern as an indication of seat belt failure in ejected vehicle occupants.

    Science.gov (United States)

    Freeman, Michael D; Eriksson, Anders; Leith, Wendy

    2014-09-01

    Prior authors have suggested that when occupant ejection occurs in association with a seat belt failure, entanglement of the outboard upper extremity (OUE) with the retracting shoulder belt will invariably occur, leaving injury pattern evidence of belt use. In the present investigation, the authors assessed this theory using data accessed from the NASS-CDS for ejected front seat occupants of passenger vehicles. Logistic regression models were used to assess the associations between seat belt failure status and injuries. Injury types associated with seat belt failure were significant OUE and head injuries (OR = 3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The two injury types were found to be a predictor of seat belt use and subsequent failure only if combined with a high (≥0.8) precrash probability of belt use. The injury pattern associated with a seat belt failure-related ejection has limited use in the forensic investigation of crash-related ejections.

  10. Angular distribution of electrons ejected by charged particles. IV. Combined classical and quantum-mechanical treatment

    NARCIS (Netherlands)

    Boesten, L.G.J.; Bonsen, T.F.M.

    1975-01-01

    Angular distributions of electrons ejected from helium by 100 and 300 keV protons have been calculated by a method which is a comination of the classical three-body collision theory and the quantum-mechanical Born approximation. The results of this theory have been compared with the corresponding ex

  11. Comparative Influences of Fluid and Shell on Modeled Ejection Performance of a Piezoelectric Micro-Jet

    Directory of Open Access Journals (Sweden)

    Kai Li

    2017-01-01

    Full Text Available The piezoelectric micro-jet, which can achieve the drop-on-demand requirement, is based on ink-jet technology and small droplets can be ejected out by precise control. The droplets are driven out of the nozzle by the acoustic pressure waves which are generated by the piezoelectric vibrator. The propagation processes of the acoustic pressure waves are affected by the acoustic properties of the fluid and the shell material of the micro-jet, as well as the excitations and the structure sizes. The influences of the fluid density and acoustic velocity in the fluid on the nozzle pressure and support reaction force of the vibrator are analyzed in this paper. The effects of the shell material on the ejection performance are studied as well. In order to improve the ejection performance of the micro-jet, for ejecting a given fluid, the recommended methods of selecting the shell material and adjusting excitations are provided based on the results, and the influences of the factors on working frequencies are obtained as well.

  12. The Nature of Hypervelocity Stars and the Time Between Their Formation and Ejection

    CERN Document Server

    Brown, Warren R; Geller, Margaret J; Kenyon, Scott J

    2012-01-01

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 +- 0.11 Msun main sequence B star at a distance of 50 +- 5 kpc. The difference between its age and its flight time from the Galactic center is 105 +-18(stat)+-30(sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10^8 yr `arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10^7 yr. For comparison, we derive arrival times of 10^7 yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10^7 yr of its lifetime is ruled out at the 3-sigma level. Together with the 10^8 yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Ga...

  13. The Solar Atmosphere at Three Temperatures During a Coronal Mass Ejection

    Science.gov (United States)

    Zhitnik, I.; Pertzov, A.; Oparin, S.; Oraevsky, V.; Slemzin, V.; Sobelman, I.; Feynman, J.; Goldstein, B.

    1998-01-01

    On April 14, 1994 a major coronal mass ejection (CME) occured while the solar atmosphere was being observed in XUV by the Terek C instrument aboard the CORONAS spacecraft. We here compare the TEREK data before and after the CME with the Yohkoh soft x-ray data and the National Solar Observatory He I 10830 data from April 13 and 14.

  14. Association between Hypotension, Low Ejection Fraction and Cognitive Performance in Cardiac Patients

    Directory of Open Access Journals (Sweden)

    Rebecca F. Gottesman

    2010-01-01

    Full Text Available Background and Purpose: Impaired cardiac function can adversely affect the brain via decreased perfusion. The purpose of this study was to determine if cardiac ejection fraction (EF is associated with cognitive performance, and whether this is modified by low blood pressure.

  15. Ejection Systems and the Human Factor: A Guide for Flight Surgeons and Aeromedical Trainers

    Science.gov (United States)

    1988-05-01

    from when I regained consciousness, as soon as I realised where I was, there was a lot of pain in the leg..." b. CF104: (Ejection at 400 KIAS, 3,500 feet...201-209. 31. YEAGER, R.R.; Gross Behaviour of the Body’s Gluteal Region; Technology Inc; Dayton, Ohio, December 1971. 32. ZELLER, AF.; Human Reaction

  16. Rapid estimation of left ventricular ejection fraction in acute myocardial infarction by echocardiographic wall motion analysis

    DEFF Research Database (Denmark)

    Berning, J; Rokkedal Nielsen, J; Launbjerg, J

    1992-01-01

    Echocardiographic estimates of left ventricular ejection fraction (ECHO-LVEF) in acute myocardial infarction (AMI) were obtained by a new approach, using visual analysis of left ventricular wall motion in a nine-segment model. The method was validated in 41 patients using radionuclide...

  17. High-resolution imaging of ejection dynamics in laser-induced forward transfer

    NARCIS (Netherlands)

    Pohl, R.; Visser, C.W.; Römer, G.R.B.E.; Sun, C.; Huis in 't Veld, A.J.; Lohse, D.; Nakata, Yoshiki; Xianfan, Xianfan; Roth, Stephan; Neuenschwander, Beat

    2014-01-01

    Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental

  18. Imaging of the ejection process of nanosecond laser-induced forward transfer of gold

    NARCIS (Netherlands)

    Pohl, R.; Visser, C.W.; Römer, G.R.B.E.; Sun, C.; Huis in 't Veld, A.J.; Lohse, D.

    2014-01-01

    Laser-induced forward transfer is a direct-write process suitable for high precision 3D printing of several materials. However, the driving forces related to the ejection mechanism of the donor ma-terial are still under debate. So far, most of the experimental studies of nanosecond LIFT, are based o

  19. Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction : integrating evidence into clinical practice

    NARCIS (Netherlands)

    Zannad, Faiez; Stough, Wendy Gattis; Rossignol, Patrick; Bauersachs, Johann; McMurray, John J. V.; Swedberg, Karl; Struthers, Allan D.; Voors, Adriaan A.; Ruilope, Luis M.; Bakris, George L.; O'Connor, Christopher M.; Gheorghiade, Mihai; Mentz, Robert J.; Cohen-Solal, Alain; Maggioni, Aldo P.; Beygui, Farzin; Filippatos, Gerasimos S.; Massy, Ziad A.; Pathak, Atul; Pina, Ileana L.; Sabbah, Hani N.; Sica, Domenic A.; Tavazzi, Luigi; Pitt, Bertram

    2012-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HFREF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These cl

  20. High-resolution imaging of ejection dynamics in laser-induced forward transfer

    NARCIS (Netherlands)

    Pohl, Ralph; Visser, C.W.; Römer, Gerardus Richardus, Bernardus, Engelina; Sun, C.; Huis in 't Veld, Bert; Lohse, Detlef; Nakata, Yoshiki; Xianfan, Xianfan; Roth, Stephan; Neuenschwander, Beat

    2014-01-01

    Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental

  1. Awake craniotomy in a patient with ejection fraction of 10%: considerations of cerebrovascular and cardiovascular physiology.

    Science.gov (United States)

    Meng, Lingzhong; Weston, Stephen D; Chang, Edward F; Gelb, Adrian W

    2015-05-01

    A 37-year-old man with nonischemic 4-chamber dilated cardiomyopathy and low-output cardiac failure (estimated ejection fraction of 10%) underwent awake craniotomy for a low-grade oligodendroglioma resection under monitored anesthesia care. The cerebrovascular and cardiovascular physiologic challenges and our management of this patient are discussed.

  2. On Retaining the Seat Pack After Ejection when Landing in Trees

    Science.gov (United States)

    2010-11-01

    escape over the past 20 years works at the Aerospace Engineering Test Establishment ( AETE ) in Cold Lake. Therefore, it was unclear how complete the...equipment use & utility, rations, materials found, first aid, shelter, travel. H. Rescue WFSO Aircraft signals use & performance ( visual ...ACES II Second generation advanced concept ejection seat AETE Aerospace Engineering and Test Establishment AFP Rdns Aerospace and Force Protection

  3. The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

    DEFF Research Database (Denmark)

    Vršnak, B.; Žic, T.; Falkenberg, Thea Vilstrup;

    2010-01-01

    Context. The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast of their arrival on Earth is one of the central issues of space weather studies. Aims. We investigate to which degree various ICME parameters (mass, size, take-off speed) and the ambient solar-wind paramete...

  4. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  5. Predicting Heart Failure With Preserved and Reduced Ejection Fraction : The International Collaboration on Heart Failure Subtypes

    NARCIS (Netherlands)

    Ho, Jennifer E; Enserro, Danielle; Brouwers, Frank P; Kizer, Jorge R; Shah, Sanjiv J; Psaty, Bruce M; Bartz, Traci M; Santhanakrishnan, Rajalakshmi; Lee, Douglas S; Chan, Cheeling; Liu, Kiang; Blaha, Michael J; Hillege, Hans L; van der Harst, Pim; van Gilst, Wiek H; Kop, Willem J; Gansevoort, Ron T; Vasan, Ramachandran S; Gardin, Julius M; Levy, Daniel; Gottdiener, John S; de Boer, Rudolf A; Larson, Martin G

    2016-01-01

    BACKGROUND: Heart failure (HF) is a prevalent and deadly disease, and preventive strategies focused on at-risk individuals are needed. Current HF prediction models have not examined HF subtypes. We sought to develop and validate risk prediction models for HF with preserved and reduced ejection fract

  6. Automatic detection of the optimal ejecting direction based on a discrete Gauss map

    Directory of Open Access Journals (Sweden)

    Masatomo Inui

    2014-01-01

    Full Text Available In this paper, the authors propose a system for assisting mold designers of plastic parts. With a CAD model of a part, the system automatically determines the optimal ejecting direction of the part with minimum undercuts. Since plastic parts are generally very thin, many rib features are placed on the inner side of the part to give sufficient structural strength. Our system extracts the rib features from the CAD model of the part, and determines the possible ejecting directions based on the geometric properties of the features. The system then selects the optimal direction with minimum undercuts. Possible ejecting directions are represented as discrete points on a Gauss map. Our new point distribution method for the Gauss map is based on the concept of the architectural geodesic dome. A hierarchical structure is also introduced in the point distribution, with a higher level “rough” Gauss map with rather sparse point distribution and another lower level “fine” Gauss map with much denser point distribution. A system is implemented and computational experiments are performed. Our system requires less than 10 seconds to determine the optimal ejecting direction of a CAD model with more than 1 million polygons.

  7. The classification of ambiguity in polarimetric reconstruction of coronal mass ejection

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Xinghua; Wang, Huaning; Huang, Xin; Du, Zhanle; He, Han, E-mail: xhdai@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-01-10

    The Thomson scattering theory indicates that there exist explicit and implicit ambiguities in polarimetric analyses of coronal mass ejection (CME) observations. We suggest a classification for these ambiguities in CME reconstruction. Three samples, including double explicit, mixed, and double implicit ambiguity, are shown with the polarimetric analyses of STEREO CME observations. These samples demonstrate that this classification is helpful for improving polarimetric reconstruction.

  8. Impaired left atrial function in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    Santos, Angela B. S.; Kraigher-Krainer, Elisabeth; Gupta, Deepak K.; Claggett, Brian; Zile, Michael R.; Pieske, Burkert; Voors, Adriaan A.; Lefkowitz, Marty; Bransford, Toni; Shi, Victor; Packer, Milton; McMurray, John J. V.; Shah, Amil M.; Solomon, Scott D.

    2014-01-01

    AimsLeft atrial (LA) enlargement is present in the majority of heart failure with preserved ejection fraction (HFpEF) patients and is a marker of risk. However, the importance of LA function in HFpEF is less well understood. Methods and resultsThe PARAMOUNT trial enrolled HFpEF patients (LVEF 45%, N

  9. Heart Failure With Preserved Ejection Fraction and Atrial Fibrillation : Vicious Twins

    NARCIS (Netherlands)

    Kotecha, Dipak; Lam, Carolyn S. P.; Van Veldhuisen, Dirk J.; Van Gelder, Isabelle C.; Voors, Adriaan A.; Rienstra, Michiel

    2016-01-01

    Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are age-related conditions that are increasing in prevalence, commonly coexist, and share clinical features. This review provides a practical update on the epidemiology, pathophysiology, diagnosis, and management of

  10. Impaired Systolic Function by Strain Imaging in Heart Failure With Preserved Ejection Fraction

    NARCIS (Netherlands)

    Kraigher-Krainer, Elisabeth; Shah, Amil M.; Gupta, Deepak K.; Santos, Angela; Claggett, Brian; Pieske, Burkert; Zile, Michael R.; Voors, Adriaan A.; Lefkowitz, Marty P.; Packer, Milton; McMurray, John J. V.; Solomon, Scott D.

    2014-01-01

    Objectives This study sought to determine the frequency and magnitude of impaired systolic deformation in heart failure with preserved ejection fraction (HFpEF). Background Although diastolic dysfunction is widely considered a key pathophysiologic mediator of HFpEF, the prevalence of concomitant sys

  11. Predicting Heart Failure With Preserved and Reduced Ejection Fraction : The International Collaboration on Heart Failure Subtypes

    NARCIS (Netherlands)

    Ho, Jennifer E.; Enserro, Danielle; Brouwers, Frank P.; Kizer, Jorge R.; Shah, Sanjiv J.; Psaty, Bruce M.; Bartz, Traci M.; Santhanakrishnan, Rajalakshmi; Lee, Douglas S.; Chan, Cheeling; Liu, Kiang; Blaha, Michael J.; Hillege, Hans L.; van der Harst, Pim; van Gilst, Wiek H.; Kop, Willem J.; Gansevoort, Ron T.; Vasan, Ramachandran S.; Gardin, Julius M.; Levy, Daniel; Gottdiener, John S.; de Boer, Rudolf A.; Larson, Martin G.

    2016-01-01

    Background-Heart failure (HF) is a prevalent and deadly disease, and preventive strategies focused on at-risk individuals are needed. Current HF prediction models have not examined HF subtypes. We sought to develop and validate risk prediction models for HF with preserved and reduced ejection fracti

  12. Clinical validation of fully automated computation of ejection fraction from gated equilibrium blood-pool scintigrams

    NARCIS (Netherlands)

    J.H.C. Reiber (Johan); S.P. Lie; M.L. Simoons (Maarten); C. Hoek; J.J. Gerbrands (Jan); W. Wijns (William); W.H. Bakker (Willem); P.P.M. Kooij (Peter)

    1983-01-01

    textabstractA fully automated procedure for the computation of left-ventricular ejection fraction (EF) from cardiac-gated Tc-99m blood-pool (GBP) scintigrams with fixed, dual, and variable ROI methods is described. By comparison with EF data from contrast ventriculography in 68 patients, the dual-RO

  13. Observation of two coronal mass ejections on April 7, 2011 by radio telescope URAN-2

    Science.gov (United States)

    Brazhenko, A.; Melnik, V.; Konovalenko, A.; Dorovskyy, V.; Vashchishin, V.; Franzusenko, A.; Rucker, H.

    2012-09-01

    Two CME's (coronal mass ejection) were registered by SOHO and STEREO on April 7, 2011. The results of observations obtained by radio telescope URAN-2 of different CME manifestations in radio emission at decameter wavelengths are discussed in this paper. Particularly we report about registration of new type of fine structure of type II bursts.

  14. Vanadate oligoanions interact with the proton ejection by the Ca2+ pump of sarcoplasmic reticulum.

    Science.gov (United States)

    Aureliano, M; Madeira, V M

    1994-11-30

    Decameric vanadate differs from other oligomeric vanadate species in inhibiting Ca2+ uptake and H+ ejection promoted by sarcoplasmic reticulum ATPase. A decavanadate solution, 2 mM in total vanadium, containing about 200 microM decameric species, inhibits by about 50% the uptake of Ca2+ and by 75% the H+ ejection, whereas 2 mM nominal monovanadate slightly increases the uptake of Ca2+ and inhibits the ejection of H+ by 25%. Moreover, decavanadate linearly increases the Ca2+/H+ ratio, whereas monovanadate mimicks decavanadate behavior only at concentrations up to 1.2 mM. For higher concentrations of monovanadate, this effect is reversed probably due to the formation of metavanadates, namely tetravandate. It is concluded that Ca2+ uptake is tightly coupled to proton ejection through molecular events that are sensitive to the interaction of vanadate species. Apparently, the stoichiometry is variable and modulated by molecular events involved in vanadate interaction suggesting alterations in the energetic coupling associated with Ca2+ translocation.

  15. Impact-driven ejection of micro metal droplets on-demand

    NARCIS (Netherlands)

    Luo, Jun; Qi, Lehua; Tao, Yuan; Ma, Qian; Visser, Claas Willem

    2016-01-01

    On-demand metal droplet deposition will be a cornerstone technology in 3D metal printing. However, suitable small nozzles are hardly available, limiting the resolution and surface finish of final products. Here, the ejection of record-small metal droplets with a diameter of only 0.55±0.07 times the

  16. Bi-temporal 3D active appearance models with applications to unsupervised ejection fraction estimation

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Pedersen, Dorthe

    2005-01-01

    Rapid and unsupervised quantitative analysis is of utmost importance to ensure clinical acceptance of many examinations using cardiac magnetic resonance imaging (MRI). We present a framework that aims at fulfilling these goals for the application of left ventricular ejection fraction estimation i...

  17. Optimal Auctions with Financial Externalities

    NARCIS (Netherlands)

    Maasland, E.; Onderstal, A.M.

    2002-01-01

    We construct optimal auctions when bidders face financial externalities.In a Coasean World, in which the seller cannot prevent a perfect resale market, nor withhold the object, the lowest-price all-pay auction is optimal.In a Myersonean World, in which the seller can both prevent resale after the au

  18. Organizing for External Knowledge Sourcing

    DEFF Research Database (Denmark)

    Rabbiosi, Larissa; Reichstein, Toke

    2011-01-01

    The aim of this article is to provide an introduction to the special issue. We briefly consider the external knowledge sourcing and organizing for innovation literatures, which offer a background for the special issue, and we highlight their mutual dialogue. We then illustrate the main findings...

  19. Measuring Externalities in Program Evaluation

    NARCIS (Netherlands)

    Janssens, Wendy

    2005-01-01

    Impact evaluations of development programmes usually focus on a comparison of participants with a control group. However, if the programme generates externalities for non-participants such an approach will capture only part of the programme's impact. Based on a unique large-scale quantitative survey

  20. Lupus vulgaris of external nose.

    Science.gov (United States)

    Bhandary, Satheesh Kumar; Ranganna, B Usha

    2008-12-01

    Lupus vulgaris is the commonest form of cutaneous tuberculosis which commonly involve trunk and buttocks. Lupus vulgaris affecting nose and face, are rarely reported in India. This study reports an unusual case of lupus vulgaris involving the external nose that showed dramatic outcome after six months of anti- tubercular treatment.

  1. [Treatment by external insulin pump].

    Science.gov (United States)

    Clavel, Sylvaine

    2010-12-01

    Since the recent recommendations by the French speaking association for research on diabetes and metabolic illnesses (Alfediam), treatment by insulin pump has found itself in competition with basal-bolus, a procedure using similar injections of insulin which has become a benchmark treatment. The latest Alfediam guidelines focus on defining ways of treating diabetics with an external insulin pump.

  2. Matchings with Externalities and Attitudes

    DEFF Research Database (Denmark)

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal;

    2013-01-01

    Two-sided matchings are an important theoretical tool used to model markets and social interactions. In many real-life problems the utility of an agent is influenced not only by their own choices, but also by the choices that other agents make. Such an influence is called an externality. Whereas ...

  3. Post-external dacryocystorhinostomy lagophthalmos.

    Science.gov (United States)

    Odat, Thabit A; Odat, Haitham A; Khraisat, Heba; Odat, Mohannad A; Alzoubi, Firas Q

    2015-06-01

    To describe lagophthalmos and eyelid closure abnormality after external dacryocystorhinostomy (DCR). A retrospective review of medical records and postoperative photographs of 79 patients who underwent external DCR for nasolacrimal duct obstruction and developed eyelid closure abnormality and lagophthalmos with or without exposure keratopathy was conducted. Collected data included age, sex, indication for surgery, laterality, length and type of incision, length of follow-up duration, presence of punctate epithelial keratopathy, and time for resolution of eyelid closure abnormalities. Twenty-seven patients with 28 external dacryocystorhinostomy had postoperative eyelid closure abnormalities. Male to female ratio was 1:6. The mean age was 40.1 years (range 9-80 years). All surgeries were performed through diagonal skin incision. Lagophthalmos involving the medial third of the palpebral fissure was noticed in 28.6 % of cases. All patients had hypometric blink mainly of the upper eyelid. One patient had punctate epithelial keratopathy. Resolution of lagophthalmos was noticed over a period of 1-5 weeks with an average of 3 weeks. None of the patients continued to have residual hypometric blink or punctate keratopathy at the last follow-up time. The mean follow-up period was 4.2 months (range 3-6 months). Eyelid closure abnormality and lagophthalmos after external DCR are underestimated problems. Spontaneous resolution is seen in all cases weeks to months after surgery.

  4. Femoral Reconstruction Using External Fixation

    Directory of Open Access Journals (Sweden)

    Yevgeniy Palatnik

    2011-01-01

    Full Text Available Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD, limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD and lateral distal femoral angle (LDFA for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

  5. Surface Modification of Polymer Substrates by Oxygen Ion Irradiation

    Science.gov (United States)

    Takaoka, G. H.; Ryuto, H.; Araki, R.; Yakushiji, T.

    2008-11-01

    Oxygen cluster ions and/or monomer ions were used for the sputtering and the surface modification of polymers such as polycarbonate (PC) and polyethylene terephthalate (PET). For the case of oxygen cluster ion irradiation, the sputtered depth increased with increase of the acceleration voltage, and the sputtering yield was much larger than that by the monomer ion irradiation. The sputtered particles represented the polymer structure, which indicated that the bond scission by the cluster ion irradiation resulted in an ejection of monomer molecule through the intermolecular collision. On the other hand, for the oxygen monomer ion irradiation, the implanted depth increased with increase of the acceleration voltage, and the bond scission occurred at the deep region through the binary collision with the high energetic ions. Therefore, the sputtering yield for the polymer surfaces decreased, and the sputtering effect became very small. Furthermore, the simultaneous use of oxygen cluster and monomer ions was more effective for oxidation of the PET surfaces rather than the monomer ion irradiation or the cluster ion irradiation. As a result, the contact angle measurement showed that the wettability of the PET surfaces irradiated by the simultaneous use of oxygen cluster and monomer ions was much enhanced.

  6. The relationship between mitral regurgitation and ejection fraction as predictors for the prognosis of patients with heart failure

    DEFF Research Database (Denmark)

    Thune, Jens Jakob; Torp-Pedersen, Christian; Hassager, Christian;

    2011-01-01

    To study whether there is interaction between mitral regurgitation (MR) and left ventricular ejection fraction (LVEF) in the mortality risk of heart failure (HF) patients.......To study whether there is interaction between mitral regurgitation (MR) and left ventricular ejection fraction (LVEF) in the mortality risk of heart failure (HF) patients....

  7. Study of the fluence dependent interplay between laser induced material removal mechanisms in metals: Vaporization, melt displacement and melt ejection

    Science.gov (United States)

    Fishburn, J. M.; Withford, M. J.; Coutts, D. W.; Piper, J. A.

    2006-05-01

    Three quantitative methods, namely profilometry, high speed imaging and recoil momentum measurements using a ballistic pendulum, are used to determine the interplay of vaporization, melt displacement and melt ejection on nanosecond laser induced material removal. At low to moderate fluences (7 J cm -2), material removal occurs predominantly via the explosive ejection of liquid droplets from the melt pool.

  8. Differing prognostic value of pulse pressure in patients with heart failure with reduced or preserved ejection fraction

    DEFF Research Database (Denmark)

    Jackson, Colette E.; Castagno, Davide; Maggioni, Aldo P.

    2015-01-01

    AIMS: Low pulse pressure is a marker of adverse outcome in patients with heart failure (HF) and reduced ejection fraction (HF-REF) but the prognostic value of pulse pressure in patients with HF and preserved ejection fraction (HF-PEF) is unknown. We examined the prognostic value of pulse pressure...

  9. Linear mass scans in quadrupole ion traps using the inverse Mathieu q scan.

    Science.gov (United States)

    Snyder, Dalton T; Pulliam, Christopher J; Cooks, R Graham

    2016-11-30

    Secular frequency scanning is a method of mass selectively scanning ions out of a quadrupole ion trap by linearly ramping the frequency of the resonance ejection signal through ion secular frequencies at constant rf amplitude and frequency. The method is electronically much simpler than resonance ejection but it requires a complex nonlinear calibration procedure to correlate mass-to-charge with time. A method of secular frequency scanning in quadrupole ion traps is described in which mass-to-charge is linear with time. This method, termed an "inverse Mathieu q scan", contrasts with linear frequency sweeping which requires a complex nonlinear mass calibration procedure. In the current method, mass scans are forced to be linear with time by scanning the frequency of the supplementary ac so that there is an inverse relationship between the ejected ion's Mathieu q parameter and time. In all cases, excellent mass spectral linearity is observed. The rf amplitude is shown to control both the scan range and the scan rate, whereas the ac amplitude and scan rate influence the mass resolution. The scan rate depends linearly on the rf amplitude, a unique feature of this scan. Although changes in either rf or ac amplitude affect the positions of peaks in time, they do not change the mass calibration procedure since this only requires a simple linear fit of m/z vs time. Space charge effects are shown to give rise to significant changes in resolution as well as to mass shifts. A method of secular frequency scanning which provides a linear mass scale has been demonstrated. The inverse Mathieu q scan offers a significant increase in mass range and power savings while maintaining access to linearity, paving the way for a mass spectrometer based completely on ac waveforms for ion isolation, ion activation, and ion ejection. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Molecular dynamic simulation of secondaryion ion emission from an Al sample bombarded with MeV heavy ions

    Institute of Scientific and Technical Information of China (English)

    薛建明; 今西信嗣

    2002-01-01

    Sputtering yields and kinetic energy distributions (KED) of Al atomic ions ejected from a pure aluminium sampleunder MeV silicon ion bombardment were simulated with the molecular dynamic method. Since the electronic energyloss Se is much higher than the nuclear energy loss Sn when the incident ion energy is as high as several MeV, the Seeffect was also taken into consideration in the simulation. It was found that the simulated sputtering yield fits well withthe experimental data and the electronic energy loss has a slight effect at incident ion energies higher than 4 MeV. Thesimulated secondary ion KED spectrum is a little lower in the peak energy and narrower in the peak width than thatin the experiment.

  11. Ion Chromatography.

    Science.gov (United States)

    Mulik, James D.; Sawicki, Eugene

    1979-01-01

    Accurate for the analysis of ions in solution, this form of analysis enables the analyst to directly assay many compounds that previously were difficult or impossible to analyze. The method is a combination of the methodologies of ion exchange, liquid chromatography, and conductimetric determination with eluant suppression. (Author/RE)

  12. Investigating pyroclast ejection dynamics using shock-tube experiments: temperature, grain size and vent geometry effects.

    Science.gov (United States)

    Cigala, V.; Kueppers, U.; Dingwell, D. B.

    2015-12-01

    Explosive volcanic eruptions eject large quantities of gas and particles into the atmosphere. The portion directly above the vent commonly shows characteristics of underexpanded jets. Understanding the factors that influence the initial pyroclast ejection dynamics is necessary in order to better assess the resulting near- and far-field hazards. Field observations are often insufficient for the characterization of volcanic explosions due to lack of safe access to such environments. Fortunately, their dynamics can be simulated in the laboratory where experiments are performed under controlled conditions. We ejected loose natural particles from a shock-tube while controlling temperature (25˚ and 500˚C), overpressure (15MPa), starting grain size distribution (1-2 mm, 0.5-1 mm and 0.125-0.250 mm), sample-to-vent distance and vent geometry. For each explosion we quantified the velocity of individual particles, the jet spreading angle and the production of fines. Further, we varied the setup to allow for different sample-to-gas ratios and deployed four different vent geometries: 1) cylindrical, 2) funnel with a flaring of 30˚, 3) funnel with a flaring of 15˚ and 4) nozzle. The results showed maximum particle velocities up to 296 m/s, gas spreading angles varying from 21˚ to 37˚ and particle spreading angles from 3˚ to 40˚. Moreover we observed dynamically evolving ejection characteristics and variations in the production of fines during the course of individual experiments. Our experiments mechanistically mimic the process of pyroclast ejection. Thus the capability for constraining the effects of input parameters (fragmentation conditions) and conduit/vent geometry on ballistic pyroclastic plumes has been clearly established. These data obtained in the presence of well-documented conduit and vent conditions, should greatly enhance our ability to numerically model explosive ejecta in nature.

  13. Exact Quantum Logic Gates with a Single Trapped Cold Ion

    Institute of Scientific and Technical Information of China (English)

    韦联福; 刘世勇; 雷啸霖

    2001-01-01

    We present an alternative scheme to exactly implement one-qubit and two-qubit quantum gates with a single trapped cold ion driven by a travelling laser field. The internal degree of freedom of the ion acts as the target qubit and the control qubit is encoded by two Fock states of the external vibration of the ion. The conditions to realize these operations, including the duration of each applied laser pulse and Lamb-Dicke parameter, are derived. In our scheme neither the auxiliary atomic level nor the Lamb-Dicke approximation is required. The multiquantum transition between the internal and external degrees of freedom of the ion is considered.

  14. Defensive externality and blame projection following failure.

    Science.gov (United States)

    Hochreich, D J

    1975-09-01

    This study focuses upon the relationship between internal-external control and defensive blame projection. Trust was used as a moderator variable for making differential predictions concerning the behavior of two subgroups of externals: defensive externals, whose externality is presumed to reflect primarily a verbal technique of defense, and congruent externals, whose externality reflects a more genuine belief that most outcomes are determined by forces beyond their personal control. As predicted, defensive externals showed a stronger tendency than did congruent externals and internals to resort to blame projection following failure at an achievement task. There were no group differences in attribution following task success. Defensive externals were found to be more responsive to negative feedback than were congruent externals.

  15. Hydrodynamic ion sound instability in systems of a finite length

    Science.gov (United States)

    Koshkarov, O.; Chapurin, O.; Smolyakov, A.; Kaganovich, I.; Ilgisonis, V.

    2016-09-01

    Plasmas permeated by an energetic ion beam is prone to the kinetic ion-sound instability that occurs as a result of the inverse Landau damping for ion velocity. It is shown here that in a finite length system there exists another type of the ion sound instability which occurs for v02 excitation of the lower-hybrid waves in Hall thruster. It is expected that this mechanism of ion sound and lower hybrid instabilities may be operative in E × B plasma discharges in which the ion beam is created by the application of the external voltage.

  16. Dipolar fluids under external perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Klapp, Sabine H L [Stranski-Laboratorium fuer Physikalische und Theoretische Chemie Sekretariat TC7, Technische Universitaet Berlin, Strasse des 17. Juni 124, D-10623 Berlin (Germany)

    2005-04-20

    We discuss recent developments and present new findings on the structural and phase properties of dipolar model fluids influenced by various external perturbations. We concentrate on systems of spherical particles with permanent (point) dipole moments. Starting from what is known about the three-dimensional systems, particular emphasis is given to dipolar fluids in different confining situations involving both simple and complex (disordered) pore geometries. Further topics concern the effect of quenched positional disorder, the influence of external (electric or magnetic) fields, and the fluid-fluid phase behaviour of various dipolar mixtures. It is demonstrated that due to the translational-orientational coupling and due to the long range of dipolar interactions even simple perturbations such as hard walls can have a profound impact on the systems. (topical review)

  17. External observer reflections on QBism

    CERN Document Server

    Khrennikov, Andrei

    2015-01-01

    In this short review I present my personal reflections on QBism. I have no intrinsic sympathy neither to QBism nor to subjective interpretation of probability in general. However, I have been following development of QBism from its very beginning, observing its evolution and success, sometimes with big surprise. Therefore my reflections on QBism can be treated as "external observer" reflections. I hope that my representation of this interpretation of quantum mechanics (QM) has some degree of objectivity. It may be useful for researchers who are interested in quantum foundations, but do not belong to the QBism-community, because I tried to analyze essentials of QBism critically (i.e., not just emphasizing its advantages, as in a typical publication of QBists). QBists may be interested as well - in comments of an external observer who monitored development of this approach to QM during last 16 years. The second part of the paper is devoted to interpretations of probability, objective versus subjective, and view...

  18. Firm Search for External Knowledge

    DEFF Research Database (Denmark)

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    The innovation performance of modern firms is increasingly determined by their ability to search and absorb external knowledge. However, after a certain threshold firms "oversearch" their environment and innovation performance declines. In this paper, we argue that prior literature has largely...... ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin...... to experience the negative performance effects of oversearch. Based on a comprehensive sample of almost 8,000 firms from ten European countries, we find that institutions matter considerably for firms' search activity. Higher market orientation of institutions increases the effectiveness of firms' search...

  19. MGR External Events Hazards Analysis

    Energy Technology Data Exchange (ETDEWEB)

    L. Booth

    1999-11-06

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses.

  20. Network externalities across financial institutions

    OpenAIRE

    Castro Iragorri, Carlos Alberto; Preciado Pua, Sergio Andrés; Ordóñez Herrera, Juan Sebastián

    2016-01-01

    We propose and estimate a financial distress model that explicitly accounts for the interactions or spill-over effects between financial institutions, through the use of a spatial continuity matrix that is build from financial network data of inter bank transactions. Such setup of the financial distress model allows for the empirical validation of the importance of network externalities in determining financial distress, in addition to institution specific and macroeconomic covariates. The re...

  1. Externe Kosten in der Energiewirtschaft

    OpenAIRE

    Voß, Alfred; Friedrich, Rainer

    1994-01-01

    Als externe Effekte werden unbeteiligte Dritte betreffende Zusatzkosten oder Zusatznutzen verstanden, die sich in den jeweiligen Güterpreisen nicht wiederfinden und denen die Betroffenen nicht indifferent gegenüberstehen. Die gegenwärtige Energiebereitstellung und -nutzung ist in vielen Bereichen eine wesentliche Quelle der Belastung von Umwelt und Natur. Begriffe und Schlagworte wie Waldsterben, Tankerunglücke, Tschernobyl und Treibhauseffekt seien in diesem Zusammenhang erwähnt.

  2. Matching Games with Additive Externalities

    DEFF Research Database (Denmark)

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal

    2012-01-01

    Two-sided matchings are an important theoretical tool used to model markets and social interactions. In many real life problems the utility of an agent is influenced not only by their own choices, but also by the choices that other agents make. Such an influence is called an externality. Whereas......, optimistic, and pessimistic behaviour, and provide both computational hardness results and polynomial-time algorithms for computing stable outcomes....

  3. ENDOSCOPIC DCR VERSUS EXTERNAL DCR

    Directory of Open Access Journals (Sweden)

    Rukma

    2015-04-01

    Full Text Available PURPOSE: To compare success rates of endoscopic dacryocystorhinostomy (DCR and external DCR for acquired nasolacrimal duct obstruction (NLDO. MATERIALS AND METHODS: A prospective comparative non randomized study of 64 patients who presented with acquired NLD obstruction to a tertiary hospital. They were fully evaluated to ascertain the site of obstruction and patients with distal obstruction were included in the study. 34 patients underwent endoscopic DCR and 30 patients underwent external DCR RESULTS: 64 patients were included in the study and 72 procedures carried out. Success was achieved in 65 cases and failure in 7. Of the 7 failed cases, anatomical obstruction at the fistula site was found in 3, whereas functional failure was found in 4. In our patients, endoscopic DCR had a significantly higher success rate than external DCR, 95.23% versus 83.33% (P = 0.03. CONCLUSIONS: The success rate of Endoscopic DCR for acquired NLDO in our group of patients was 95.23%, with endoscopic surgery showing better results.

  4. Conceptual challenges for internalising externalities

    DEFF Research Database (Denmark)

    Miguel, Brandão; Weidema, Bo Pedersen

    2013-01-01

    We analyse a number of different externalities to identify conceptual challenges for the practical implementation of their internalisation. Three issues were identified: i) The balance between compensation and technology change and the respective effects on the nominal and real GDP; ii) The relev......We analyse a number of different externalities to identify conceptual challenges for the practical implementation of their internalisation. Three issues were identified: i) The balance between compensation and technology change and the respective effects on the nominal and real GDP; ii......) The relevance and efficiency of different instruments for internalisation and compensation; and iii) Implementing internalisation over large geographical and temporal distances. We find taxation to be a more relevant and efficient tool for internalisation than insurance and litigation. With increasing...... geographical and especially temporal distance between the benefitting actor and the victim of the external cost, the involvement of a non-governmental intermediate actor becomes increasingly necessary to provide the short-term capital required to ensure a successful implementation....

  5. Individuals' insight into intrapersonal externalities

    Directory of Open Access Journals (Sweden)

    David J. Stillwell

    2012-07-01

    Full Text Available An intrapersonal externality exists when an individual's decisions affect the outcomes of her future decisions. It can result in decreasing or increasing average returns to the rate of consumption, as occurs in addiction or exercise. Experimentation using the Harvard Game, which models intrapersonal externalities, has found differences in decision making between drug users and control subjects, leading to the argument that these externalities influence the course of illicit drug use. Nevertheless, it is unclear how participants who behave optimally conceptualise the problem. We report two experiments using a simplified Harvard Game, which tested the differences in contingency knowledge between participants who chose optimally and participants who did not. Those who demonstrated optimal performance exhibited both a pattern of correct responses and systematic errors to questions about the payoff schedules. The pattern suggested that they learned explicit knowledge of the change in reinforcement on a trail-by-trial basis. They did not have, or need, a full knowledge of the historical interaction leading to each payoff. We also found no evidence of choice differences between participants who were given a guaranteed payment and participants who were paid contingent on their performance, but those given a guaranteed payment were able to report more contingency knowledge as the experiment progressed, suggesting that they explored more rather than settling into a routine. Experiment 2 showed that using a fixed inter-trial interval did not change the results.

  6. Capillarity ion concentration polarization as spontaneous desalting mechanism

    Science.gov (United States)

    Park, Sungmin; Jung, Yeonsu; Son, Seok Young; Cho, Inhee; Cho, Youngrok; Lee, Hyomin; Kim, Ho-Young; Kim, Sung Jae

    2016-04-01

    To overcome a world-wide water shortage problem, numerous desalination methods have been developed with state-of-the-art power efficiency. Here we propose a spontaneous desalting mechanism referred to as the capillarity ion concentration polarization. An ion-depletion zone is spontaneously formed near a nanoporous material by the permselective ion transportation driven by the capillarity of the material, in contrast to electrokinetic ion concentration polarization which achieves the same ion-depletion zone by an external d.c. bias. This capillarity ion concentration polarization device is shown to be capable of desalting an ambient electrolyte more than 90% without any external electrical power sources. Theoretical analysis for both static and transient conditions are conducted to characterize this phenomenon. These results indicate that the capillarity ion concentration polarization system can offer unique and economical approaches for a power-free water purification system.

  7. Capillarity ion concentration polarization as spontaneous desalting mechanism.

    Science.gov (United States)

    Park, Sungmin; Jung, Yeonsu; Son, Seok Young; Cho, Inhee; Cho, Youngrok; Lee, Hyomin; Kim, Ho-Young; Kim, Sung Jae

    2016-04-01

    To overcome a world-wide water shortage problem, numerous desalination methods have been developed with state-of-the-art power efficiency. Here we propose a spontaneous desalting mechanism referred to as the capillarity ion concentration polarization. An ion-depletion zone is spontaneously formed near a nanoporous material by the permselective ion transportation driven by the capillarity of the material, in contrast to electrokinetic ion concentration polarization which achieves the same ion-depletion zone by an external d.c. bias. This capillarity ion concentration polarization device is shown to be capable of desalting an ambient electrolyte more than 90% without any external electrical power sources. Theoretical analysis for both static and transient conditions are conducted to characterize this phenomenon. These results indicate that the capillarity ion concentration polarization system can offer unique and economical approaches for a power-free water purification system.

  8. Preparation of Cluster States with Trapped Ions in Thermal Motion

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-Xing

    2007-01-01

    @@ A potential scheme is proposed for generating cluster states of many trapped ions in thermal motion, in which the effective Hamiltonian does not involve the external degree of freedom and thus the scheme is insensitive to the external state, allowing it to be thermal state. The required experimental techniques of the schemes are within the scope that can be obtained in the ion-trap setup.

  9. An unusual giant spiral arc in the polar cap region during the northward phase of a Coronal Mass Ejection

    Directory of Open Access Journals (Sweden)

    L. Rosenqvist

    2007-03-01

    Full Text Available The shock arrival of an Interplanetary Coronal Mass Ejection (ICME at ~09:50 UT on 22 November 1997 resulted in the development of an intense (Dst<−100 nT geomagnetic storm at Earth. In the early, quiet phase of the storm, in the sheath region of the ICME, an unusual large spiral structure (diameter of ~1000 km was observed at very high latitudes by the Polar UVI instrument. The evolution of this structure started as a polewardly displaced auroral bulge which further developed into the spiral structure spreading across a large part of the polar cap. This study attempts to examine the cause of the chain of events that resulted in the giant auroral spiral. During this period the interplanetary magnetic field (IMF was dominantly northward (Bz>25 nT with a strong duskward component (By>15 nT resulting in a highly twisted tail plasma sheet. Geotail was located at the equatorial dawnside magnetotail flank and observed accelerated plasma flows exceeding the solar wind bulk velocity by almost 60%. These flows are observed on the magnetosheath side of the magnetopause and the acceleration mechanism is proposed to be typical for strongly northward IMF. Identified candidates to the cause of the spiral structure include a By induced twisted magnetotail configuration, the development of magnetopause surface waves due to the enhanced pressure related to the accelerated magnetosheath flows aswell as the formation of additional magnetopause deformations due to external solar wind pressure changes. The uniqeness of the event indicate that most probably a combination of the above effects resulted in a very extreme tail topology. However, the data coverage is insufficient to fully investigate the physical mechanism behind the observations.

  10. Ion focusing

    Energy Technology Data Exchange (ETDEWEB)

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2017-01-17

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  11. In vivo dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mijnheer, Ben [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam 1066 CX (Netherlands); Beddar, Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Izewska, Joanna [Division of Human Health, International Atomic Energy Agency, Vienna 1400 (Austria); Reft, Chester [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois 60637 (United States)

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  12. Vibration-induced drop atomization and the numerical simulation of low-frequency single-droplet ejection

    Science.gov (United States)

    James, Ashley J.; Smith, Marc K.; Glezer, Ari

    2003-02-01

    Vibration-induced droplet ejection is a novel way to create a spray. In this method, a liquid drop is placed on a vertically vibrating solid surface. The vibration leads to the formation of waves on the free surface. Secondary droplets break off from the wave crests when the forcing amplitude is above a critical value. When the forcing frequency is small, only low-order axisymmetric wave modes are excited, and a single secondary droplet is ejected from the tip of the primary drop. When the forcing frequency is high, many high-order non-axisymmetric modes are excited, the motion is chaotic, and numerous small secondary droplets are ejected simultaneously from across the surface of the primary drop. In both frequency regimes a crater may form that collapses to create a liquid spike from which droplet ejection occurs. An axisymmetric, incompressible, Navier Stokes solver was developed to simulate the low-frequency ejection process. A volume-of-fluid method was used to track the free surface, with surface tension incorporated using the continuum-surface-force method. A time sequence of the simulated interface shape compared favourably with an experimental sequence. The dynamics of the droplet ejection process was investigated, and the conditions under which ejection occurs and the effect of the system parameters on the process were determined.

  13. Enhancement of a sunspot light wall with external disturbances

    CERN Document Server

    Yang, Shuhong; Erdélyi, Robert

    2016-01-01

    Based on the \\emph{Interface Region Imaging Spectrograph} observations, we study the response of a solar sunspot light wall to external disturbances. A flare occurrence near the light wall caused material to erupt from the lower solar atmosphere into the corona. Some material falls back to the solar surface, and hits the light bridge (i.e., the base of the light wall), then sudden brightenings appear at the wall base followed by the rise of wall top, leading to an increase of the wall height. Once the brightness of the wall base fades, the height of the light wall begins to decrease. Five hours later, another nearby flare takes place, a bright channel is formed that extends from the flare towards the light bridge. Although no obvious material flow along the bright channel is found, some ejected material is conjectured to reach the light bridge. Subsequently, the wall base brightens and the wall height begins to increase again. Once more, when the brightness of the wall base decays, the wall top fluctuates to ...

  14. Fully variational average atom model with ion-ion correlations.

    Science.gov (United States)

    Starrett, C E; Saumon, D

    2012-02-01

    An average atom model for dense ionized fluids that includes ion correlations is presented. The model assumes spherical symmetry and is based on density functional theory, the integral equations for uniform fluids, and a variational principle applied to the grand potential. Starting from density functional theory for a mixture of classical ions and quantum mechanical electrons, an approximate grand potential is developed, with an external field being created by a central nucleus fixed at the origin. Minimization of this grand potential with respect to electron and ion densities is carried out, resulting in equations for effective interaction potentials. A third condition resulting from minimizing the grand potential with respect to the average ion charge determines the noninteracting electron chemical potential. This system is coupled to a system of point ions and electrons with an ion fixed at the origin, and a closed set of equations is obtained. Solution of these equations results in a self-consistent electronic and ionic structure for the plasma as well as the average ionization, which is continuous as a function of temperature and density. Other average atom models are recovered by application of simplifying assumptions.

  15. Scaling of cross-sections for asymmetric (, 3) process on helium-like ions by fast electrons

    Indian Academy of Sciences (India)

    M K Srivastava

    2004-11-01

    An approximate simple scaling law is obtained for asymmetric (, 3) process on helium-like ions for double ionization by fast electrons. It is based on the equation $(Z'^{3} /)$ exp$[−Z' (r_{1} + r_{2})]$, $Z' = Z − (5/16)$ for ground state wave function of helium- like ions and $Z'^{2}$ scaling of energies. The scaling law is found to work very well if the lower energy electron is ejected along the momentum transfer direction and the other one is ejected in the opposite direction. It also works quite well if this electron is ejected within about 90° of the momentum transfer direction with the other electron going in the opposite direction. The scaling law becomes increasingly accurate as the target nuclear charge and the energy increase.

  16. Redefining the boundaries of interplanetary coronal mass ejections from observations at the ecliptic plane

    CERN Document Server

    Cid, C; Saiz, E; Guerrero, A

    2016-01-01

    On 2015 January 6-7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss on the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME offers a unique opportunity to check the boundaries' process definition and to explain differences between them. Using Wind and ACE data, we perform a complementary analysis involving compositional, magnetic, and kinematic observations providing relevant information regarding the evolution of the ICME as travelling away from the Sun. We propose erosion, at least at the front boundary of the ICME, as the main reason for the difference between the boundaries, and compositional signatures as the most precise diagnostic tool for the boundaries of ICMEs.

  17. Predicting the magnetic vectors within coronal mass ejections arriving at Earth

    CERN Document Server

    Savani, N P; Szabo, A; Mays, M L; Thompson, B J; Richardson, I G; Evans, R; Pulkkinen, A; Nieves-Chinchilla, T

    2015-01-01

    The process by which the Sun affects the terrestrial environment on short timescales is predominately driven by the amount of magnetic reconnection between the solar wind and Earth's magnetosphere. Reconnection occurs most efficiently when the solar wind magnetic field has a southward component. The most severe impacts are during the arrival of a coronal mass ejection (CME) when the magnetosphere is both compressed and magnetically connected to the heliospheric environment, leading to disruptions to, for example, power grids and satellite navigation. Unfortunately, forecasting magnetic vectors within coronal mass ejections remains elusive. Here we report how, by combining a statistically robust helicity rule for a CME's solar origin with a simplified flux rope topology the magnetic vectors within the Earth-directed segment of a CME can be predicted. In order to test the validity of this proof-of-concept architecture for estimating the magnetic vectors within CMEs, a total of eight CME events (between 2010 and...

  18. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova

    CERN Document Server

    Geier, S; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C

    2015-01-01

    Hypervelocity stars (HVS) travel with velocities so high, that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US\\,708. Travelling with a velocity of $\\sim1200\\,{\\rm km\\,s^{-1}}$, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVS. Furthermore, we discovered US\\,708 to be a fast rotator. According to our binary evolution model it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.

  19. Stellar dynamics. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova.

    Science.gov (United States)

    Geier, S; Fürst, F; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C

    2015-03-06

    Hypervelocity stars (HVSs) travel with velocities so high that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US 708. Traveling with a velocity of ~1200 kilometers per second, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVSs. Furthermore, we detected that US 708 is a fast rotator. According to our binary evolution model, it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.

  20. DNA heats up : Energetics of genome ejection from phage revealed by isothermal titration calorimetry

    CERN Document Server

    Jeembaeva, Meerim; Castelnovo, Martin; Evilevitch, Alex

    2010-01-01

    Most bacteriophages are known to inject their double-stranded DNA into bacteria upon receptor binding in an essentially spontaneous way. This downhill thermodynamic process from the intact virion toward the empty viral capsid plus released DNA is made possible by the energy stored during active packaging of the genome into the capsid. Only indirect measurements of this energy have been available until now using either single-molecule or osmotic suppression techniques. In this paper, we describe for the first time the use of isothermal titration calorimetry to directly measure the heat released (or equivalently the enthalpy) during DNA ejection from phage lambda, triggered in solution by a solubilized receptor. Quantitative analyses of the results lead to the identification of thermodynamic determinants associated with DNA ejection. The values obtained were found to be consistent with those previously predicted by analytical models and numerical simulations. Moreover, the results confirm the role of DNA hydrat...