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Sample records for hh 47c bow

  1. Improved bow shock models for Herbig-Haro objects - application to HH 2A-prime

    International Nuclear Information System (INIS)

    Raymond, J.C.; Hartmann, L.; Hartigan, P.

    1988-01-01

    An improved version of the bow shock theory previously applied to Herbig-Haro objects is presented. The modifications provide a more accurate calculation of the ionization state of material entering the bow shock. The revised preionization does not drastically affect the emission-line predictions for a 200 km/s bow shock model, though the effects will be more severe for slower shock velocities. The line profiles of the new models resemble the observed profiles somewhat more closely, and the relative emission-line intensities typically differ by 30 percent from those predicted by the older models. The models agree well with new IUE spectra and existing optical data for HH 2A-prime. 32 references

  2. Bowed Strings

    Science.gov (United States)

    Rossing, Thomas D.; Hanson, Roger J.

    In the next eight chapters, we consider some aspects of the science of bowed string instruments, old and new. In this chapter, we present a brief discussion of bowed strings, a subject that will be developed much more thoroughly in Chap. 16. Chapters 13-15 discuss the violin, the cello, and the double bass. Chapter 17 discusses viols and other historic string instruments, and Chap. 18 discusses the Hutchins-Schelleng violin octet.

  3. The dynamics of Herbig-Haro objects HH46 and 47A and their remarkable connecting filament HH47B

    International Nuclear Information System (INIS)

    Meaburn, J.; Dyson, J.E.

    1987-01-01

    Echelle observations of the Hα and [S II] line profiles have been made with the Anglo-Australian Telescope along the emission-line filament (HH47B) which connects the Herbig-Haro objects HH46 and 47A. A red continuum source between HH46 and the 10μm peak has a +-200kms -1 wide Hα component centred on the rest velocity of the parent globule. Scattered radiation from an embedded T Tauri star is suggested. HH46 and 47A are receding away from the observer but the connecting filament exhibits some form of velocity ellipse. The bipolar configuration had been previously suggested by the discovery of the counter object HH47C with Vsub(HEL) = 100kms -1 . (author)

  4. HIGH ANGULAR RESOLUTION MULTI-LINE STUDY OF HH 1 AND 2

    Energy Technology Data Exchange (ETDEWEB)

    Raga, A. C.; Castellanos-Ramírez, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ap. 70-543, 04510 D.F., México (Mexico); Reipurth, Bo; Chiang, Hsin-Fang [Institute for Astronomy, University of Hawaii at Manoa, Hilo, HI 96720 (United States); Bally, J., E-mail: raga@nucleares.unam.mx [Center for Astrophysics and Space Astronomy, University of Colorado, UCB 389, Boulder, CO 80309 (United States)

    2015-10-15

    We present new Hubble Space Telescope (HST) narrow band images of the bright Herbig–Haro (HH) objects HH 1 and 2 in the light of the Hα, Hβ, [O i] 6300, [O ii] 3726+28, [O iii] 5007 and [S ii] 6716+30 emission lines. The resulting emission and line ratio maps give an improved picture of the physical structure of these HH objects, showing the presence of spatially limited, high excitation/ionization ridges. We find that HH 1 has a morphology that could be interpreted in terms of a single, asymmetric bow shock, and that many of the clumps of HH 2 fall in two bow-shaped structures of different excitations. We also construct two-line ratio plots showing clear trends, which are much simpler than the highly complex spatial distributions of the emission, and are therefore interesting for testing shock models of HH objects (we only present a comparison with previously published, steady plane-parallel shock models). We have also used the temperature-sensitive [O i]/[S ii] line ratio to evaluate the temperature range and to obtain temperature maps of HH 1 and 2. We find that this line ratio picks out emitting regions with temperatures ≈10{sup 4} K, except along the leading edges of the HH 1 and 2 bow shocks (in which temperatures of ∼3 → 5 × 10{sup 4} K are obtained)

  5. HH 222: A GIANT HERBIG-HARO FLOW FROM THE QUADRUPLE SYSTEM V380 ORI

    Energy Technology Data Exchange (ETDEWEB)

    Reipurth, Bo; Aspin, Colin; Connelley, M. S. [Institute for Astronomy, University of Hawaii at Manoa, 640 North Aohoku Place, Hilo, HI 96720 (United States); Bally, John [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Geballe, T. R. [Gemini Observatory, 670 North Aohoku Place, Hilo, HI 96720 (United States); Kraus, Stefan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States); Appenzeller, Immo [Landessternwarte Heidelberg, Königstuhl 12, D-69117 Heidelberg (Germany); Burgasser, Adam, E-mail: reipurth@ifa.hawaii.edu, E-mail: caa@ifa.hawaii.edu, E-mail: msc@ifa.hawaii.edu, E-mail: John.Bally@colorado.edu, E-mail: tgeballe@gemini.edu, E-mail: stefan.kraus@cfa.harvard.edu, E-mail: iappenze@lsw.uni-heidelberg.de, E-mail: aburgasser@ucsd.edu [Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA 92093 (United States)

    2013-11-01

    HH 222 is a giant shocked region in the L1641 cloud, and is popularly known as the Orion Streamers or ''the waterfall'' on account of its unusual structure. At the center of these streamers are two infrared sources coincident with a nonthermal radio jet aligned along the principal streamer. The unique morphology of HH 222 has long been associated with this radio jet. However, new infrared images show that the two sources are distant elliptical galaxies, indicating that the radio jet is merely an improbable line-of-sight coincidence. Accurate proper motion measurements of HH 222 reveal that the shock structure is a giant bow shock moving directly away from the well-known, very young, Herbig Be star V380 Ori. The already known Herbig-Haro object HH 35 forms part of this flow. A new Herbig-Haro object, HH 1041, is found precisely in the opposite direction of HH 222 and is likely to form part of a counterflow. The total projected extent of this HH complex is 5.3 pc, making it among the largest HH flows known. A second outflow episode from V380 Ori is identified as a pair of HH objects, HH 1031 to the northwest and the already known HH 130 to the southeast, along an axis that deviates from that of HH 222/HH 1041 by only 3.°7. V380 Ori is a hierarchical quadruple system, including a faint companion of spectral type M5 or M6, which at an age of ∼1 Myr corresponds to an object straddling the stellar-to-brown dwarf boundary. We suggest that the HH 222 giant bow shock is a direct result of the dynamical interactions that led to the conversion from an initial non-hierarchical multiple system into a hierarchical configuration. This event occurred no more than 28,000 yr ago, as derived from the proper motions of the HH 222 giant bow shock.

  6. Bulbous Bow Shape Optimization

    OpenAIRE

    Blanchard , Louis; Berrini , Elisa; Duvigneau , Régis; Roux , Yann; Mourrain , Bernard; Jean , Eric

    2013-01-01

    International audience; The aim of this study is to prove the usefulness of a bulbous bow for a fishing vessel, in terms of drag reduction, using an automated shape optimization procedure including hydrodynamic simulations. A bulbous bow is an appendage that is known to reduce the drag, thanks to its influence on the bow wave system. However, the definition of the geometrical parameters of the bulb, such as its length and thickness, is not intuitive, as both parameters are coupled with regard...

  7. Medicine Bow wind project

    Science.gov (United States)

    Nelson, L. L.

    1982-05-01

    The Bureau of Reclamation (Bureau) conducted studies for a wind turbine field of 100 MW at a site near Medicine Bow, WY, one of the windiest areas in the United States. The wind turbine system would be electrically interconnected to the existing Federal power grid through the substation at Medicine Bow. Power output from the wind turbines would thus be integrated with the existing hydroelectric system, which serves as the energy storage system. An analysis based on 'willingness to pay' was developed. Based on information from the Department of Energy's Western Area Power Administration (Western), it was assumed that 90 mills per kWh would represent the 'willingness to pay' for onpeak power, and 45 mills per kWh for offpeak power. The report concludes that a 100-MW wind field at Medicine Bow has economic and financial feasibility. The Bureau's construction of the Medicine Bow wind field could demonstrate to the industry the feasibility of wind energy.

  8. Fuel pin bowing in CAGR

    International Nuclear Information System (INIS)

    Crossland, I.G.

    1982-01-01

    Some of the more important mechanisms by which pin bowing can occur in Advanced Gas Cooled Reactors are examined. These include creep relaxation of the stresses which occur when thermal bowing is restrained and asymmetric axial clad creep. The clad temperature changes which accompany such bowing are also investigated and the theoretical results briefly compared with the empirical behaviour. (author)

  9. COLLISIONALLY EXCITED FILAMENTS IN HUBBLE SPACE TELESCOPE Hα AND Hβ IMAGES OF HH 1/2

    Energy Technology Data Exchange (ETDEWEB)

    Raga, A. C.; Castellanos-Ramírez, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ap. 70-543, 04510 México, D.F. (Mexico); Reipurth, B.; Chiang, Hsin-Fang [Institute for Astronomy, University of Hawaii at Manoa, Hilo, HI 96720 (United States); Bally, J., E-mail: raga@nucleares.unam.mx [Center for Astrophysics and Space Astronomy, University of Colorado, UCB 389, Boulder, CO 80309 (United States)

    2015-01-01

    We present new Hα and Hβ images of the HH 1/2 system, and we find that the Hα/Hβ ratio has high values in ridges along the leading edges of the HH 1 bow shock and of the brighter condensations of HH 2. These ridges have Hα/Hβ = 4 → 6, which is consistent with collisional excitation from the n = 1 to the n = 3 and 4 levels of hydrogen in a gas of temperatures T = 1.5 → 10 × 10{sup 4} K. This is therefore the first direct evidence that the collisional excitation/ionization region of hydrogen just behind Herbig-Haro shock fronts is detected.

  10. Atelier Bow-Wow DELIGHTS

    DEFF Research Database (Denmark)

    Kajita, Masashi

    2011-01-01

    Atelier Bow-Wow bruger det engelske ord 'delights' til at beskrive en arkitektonisk kvalitet, der dækker over fornøjelse, nydelse og glæde. Interviewet med Yoshiharu Tskukamoto, der sammen med Momoyo Kaijima leder Atelier Bow-Wow, udforsker baggrunden for begrebet 'delights', hvordan det spiller...

  11. Analysis of PWR assembly bow

    International Nuclear Information System (INIS)

    Fetterman, Robert J.; Franceschini, Fausto

    2008-01-01

    Excessive out of core assembly bow has been observed during refueling outages of certain PWRs. Assembly bow can take on a rather complex S-shape, and in other cases C-shape bow is prevalent. Concerns have been raised regarding the impact of the observed assembly bow on the in-core power distribution and the safety analyses supporting the plant operations. In response to these concerns, Westinghouse has developed a comprehensive analysis process for determining the effects of assembly bow on core power distributions and plant operating margins. This methodology has been applied to a particular reactor as part of an overall safety reanalysis completed in support of plant modifications. This paper provides a brief description of the methods used and a summary of the pertinent results. (authors)

  12. Analysis of PWR assembly bow

    Energy Technology Data Exchange (ETDEWEB)

    Fetterman, Robert J.; Franceschini, Fausto [Westinghouse Electric Company LLC, Pittsburgh, PA (United States)

    2008-07-01

    Excessive out of core assembly bow has been observed during refueling outages of certain PWRs. Assembly bow can take on a rather complex S-shape, and in other cases C-shape bow is prevalent. Concerns have been raised regarding the impact of the observed assembly bow on the in-core power distribution and the safety analyses supporting the plant operations. In response to these concerns, Westinghouse has developed a comprehensive analysis process for determining the effects of assembly bow on core power distributions and plant operating margins. This methodology has been applied to a particular reactor as part of an overall safety reanalysis completed in support of plant modifications. This paper provides a brief description of the methods used and a summary of the pertinent results. (authors)

  13. The electron density and temperature distributions predicted by bow shock models of Herbig-Haro objects

    International Nuclear Information System (INIS)

    Noriega-Crespo, A.; Bohm, K.H.; Raga, A.C.

    1990-01-01

    The observable spatial electron density and temperature distributions for series of simple bow shock models, which are of special interest in the study of Herbig-Haro (H-H) objects are computed. The spatial electron density and temperature distributions are derived from forbidden line ratios. It should be possible to use these results to recognize whether an observed electron density or temperature distribution can be attributed to a bow shock, as is the case in some Herbig-Haro objects. As an example, the empirical and predicted distributions for H-H 1 are compared. The predicted electron temperature distributions give the correct temperature range and they show very good diagnostic possibilities if the forbidden O III (4959 + 5007)/4363 wavelength ratio is used. 44 refs

  14. Bow shock data analysis

    Science.gov (United States)

    Zipf, Edward C.; Erdman, Peeter W.

    1994-08-01

    The University of Pittsburgh Space Physics Group in collaboration with the Army Research Office (ARO) modeling team has completed a systematic organization of the shock and plume spectral data and the electron temperature and density measurements obtained during the BowShock I and II rocket flights which have been submitted to the AEDC Data Center, has verified the presence of CO Cameron band emission during the Antares engine burn and for an extended period of time in the post-burn plume, and have adapted 3-D radiation entrapment codes developed by the University of Pittsburgh to study aurora and other atmospheric phenomena that involve significant spatial effects to investigate the vacuum ultraviolet (VUV) and extreme ultraviolet (EUV) envelope surrounding the re-entry that create an extensive plasma cloud by photoionization.

  15. H-H interactions in Pd

    DEFF Research Database (Denmark)

    Christensen, O. B.; Ditlevsen, Peter; Jacobsen, Karsten Wedel

    1989-01-01

    -medium theory to calculate total energies we show the same tendency for the short-range part of the H-H interaction when two H atoms are squeezed into a single site in Pd or PdH. At longer range (of the order a lattice constant) there is an attractive, lattice-mediated H-H interaction. On the basis...

  16. Time-dependent bow shocks and the condensation structure of Herbig-Haro objects

    International Nuclear Information System (INIS)

    Raga, A.C.; Bohm, K.H.

    1987-01-01

    Some Herbig-Haro objects show a structure which appears to look like a bow shock, but also show a number of condensations superposed on this bow-shaped structure. In the case of HH 1 and HH 2 considerably different proper motions have been measured for the individual condensations. It is, however, very hard to explain why the condensations remain so close to each other if they are indeed separate entities. In this paper it is shown that an interpretation of the whole Herbig-Haro object as a single, time-dependent bow shock provides a natural explanation for the occurrence of condensations (which in numerical calculations appear to be associated with thermal instabilities in the postshock flow) with different proper motions. To this effect, time-dependent, axisymmetric, nonadiabatic bow shock models have been developed from which predictions were obtained for spatially resolved H-alpha intensity maps, and then these predictions are compared qualitatively with observations of a few Herbig-Haro objects. 57 references

  17. The Three-Dimensional Structure of HH 32 from GMOS IFU Spectroscopy

    Science.gov (United States)

    Beck, Tracy L.; Riera, A.; Raga, A. C.; Aspin, C.

    2004-01-01

    We present new high-resolution spectroscopic observations of the Herbig-Haro object HH 32 from system verification observations made with the GMOS IFU at Gemini North Observatory. The three-dimensional spectral data cover a 8.7"×5.85" spatial field and 4820-7040 Å spectral region centered on the HH 32 A knot complex. We show the position-dependent line profiles and radial velocity channel maps of the Hα line, as well as line ratio velocity channel maps of [O III] λ5007/Hα, [O I] λ6300/Hα, [N II] λ6583/Hα, [S II] λλ(6716+6730)/Hα, and [S II] λ6716/λ6730. We find that the line emission and the line ratios vary significantly on spatial scales of ~1" and over velocities of ~50 km s-1. A ``3/2-dimensional'' bow shock model is qualitatively successful at reproducing the general features of the radial velocity channel maps, but it does not show the same complexity as the data, and it fails to reproduce the line ratios in our high spatial resolution maps. The observations of HH 32 A show two or three superposed bow shocks with separations of ~3", which we interpret as evidence of a line-of-sight superposition of two or three working surfaces located along the redshifted body of the HH 32 outflow. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the NSF, the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

  18. ALMA OBSERVATIONS OF THE HH 46/47 MOLECULAR OUTFLOW

    International Nuclear Information System (INIS)

    Arce, Héctor G.; Mardones, Diego; Garay, Guido; Corder, Stuartt A.; Noriega-Crespo, Alberto; Raga, Alejandro C.

    2013-01-01

    The morphology, kinematics, and entrainment mechanism of the HH 46/47 molecular outflow were studied using new ALMA Cycle 0 observations. Results show that the blue and red lobes are strikingly different. We argue that these differences are partly due to contrasting ambient densities that result in different wind components having a distinct effect on the entrained gas in each lobe. A 29 point mosaic, covering the two lobes at an angular resolution of about 3'', detected outflow emission at much higher velocities than previous observations, resulting in significantly higher estimates of the outflow momentum and kinetic energy than previous studies of this source, using the CO(1-0) line. The morphology and the kinematics of the gas in the blue lobe are consistent with models of outflow entrainment by a wide-angle wind, and a simple model describes the observed structures in the position-velocity diagram and the velocity-integrated intensity maps. The red lobe exhibits a more complex structure, and there is evidence that this lobe is entrained by a wide-angle wind and a collimated episodic wind. Three major clumps along the outflow axis show velocity distribution consistent with prompt entrainment by different bow shocks formed by periodic mass ejection episodes which take place every few hundred years. Position-velocity cuts perpendicular to the outflow cavity show gradients where the velocity increases toward the outflow axis, inconsistent with outflow rotation. Additionally, we find evidence for the existence of a small outflow driven by a binary companion

  19. Gemini-IFU spectroscopy of HH 111

    Energy Technology Data Exchange (ETDEWEB)

    Cerqueira, A. H.; Vasconcelos, M. J.; Feitosa, J.; Plana, H. [LATO-DCET, Universidade Estadual de Santa Cruz Rod. Jorge Amado, km 16, Ilhéus, BA, CEP 45662-900 (Brazil); Raga, A. C., E-mail: hoth@uesc.br [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, 04510 D.F. (Mexico)

    2015-03-01

    We present new optical observations of the Herbig–Haro (HH) 111 jet using the Gemini Multi Object Spectrograph in its Integral Field Unit mode. Eight fields of 5{sup ′′}×3.{sup ′′}5 have been positioned along and across the HH 111 jet, covering the spatial region from knot E to L in HH 111 (namely, knots E, F, G, H, J, K, and L). We present images and velocity channel maps for the [O i] 6300+6360, Hα, [N ii] 6548+6583, and [S ii] 6716+6730 lines, as well as for the [S ii] 6716/6730 line ratio. We find that the HH 111 jet has an inner region with lower excitation and higher radial velocity, surrounded by a broader region of higher excitation and lower radial velocity. Also, we find higher electron densities at lower radial velocities. These results imply that the HH 111 jet has a fast, axial region with lower velocity shocks surrounded by a lower velocity sheath with higher velocity shocks.

  20. New test of bow-shock models of Herbig-Haro objects

    International Nuclear Information System (INIS)

    Raga, A.C.; Bohm, K.H.; Solf, J.; Max-Planck-Institut fuer Astronomie, Heidelberg, West Germany)

    1986-01-01

    Long-slit, high-resolution spectroscopy of the Herbig-Haro oject HH 32 has shown that the emission-line profiles in all four condensations A, B, C, and D show high- and low-velocity components. The spatial maxima of these two components are always arranged in a double-layer pattern, with the maximum of the high-velocity component 0.6-1.0 arcsecs closer to the central star (AS 353A) than the low-velocity maximum. A study of the emission-line profiles predicted from a model of a radiating bow shock shows that such a double-layer structure appears naturally for this type of flow. In this case both the high-velocity and the low-velocity components come from the post-shock gas, in agreement with the theoretical prediction that it should be very difficult to detect the pre-shock gas observationally. The present results agree qualitatively well with observations of HH 32, strengthening the case for a bow-shock interpretation of this Herbig-Haro object. It is shown that the double-layer effect will be more easily observable for bow shocks which move at a relatively large angle with respect to the plane of the sky (i.e., for Herbig-Haro objects which have large radial velocities). 31 references

  1. Luminosity Targets for FCC-hh

    CERN Document Server

    Zimmermann, F.; Buffat, X.; Schulte, D.

    2016-01-01

    We discuss the choice of target values for the peak and integrated luminosity of a future high-energy frontier circular hadron collider (FCC-hh). We review the arguments on the physics reach of a hadron collider. Next we show that accelerator constraints will limit the beam current and the turnaround time. Taking these limits into account, we derive an expression for the ultimate integrated luminosity per year, depending on a possible pile-up limit imposed by the physics experiments. We finally benchmark our result against the planned two phases of FCC-hh [1, 2, 3

  2. The player and the bowed string: coordination of bowing parameters in violin and viola performance.

    Science.gov (United States)

    Schoonderwaldt, E

    2009-11-01

    An experiment was conducted with four violin and viola players, measuring their bowing performance using an optical motion capture system and sensors on the bow. The measurements allowed for a detailed analysis of the use and coordination of the main bowing parameters bow velocity, bow force, and bow-bridge distance. An analysis of bowing strategies in detache playing of notes of three durations (0.2, 2, and 4 s) at three dynamic levels (pp, mf, and f) on all four strings is presented, focusing on the "steady" part of the notes. The results revealed clear trends in the coordinated variations of the bowing parameters depending on the constraints of the task, reflecting a common behavior as well as individual strategies. Furthermore, there were clear indications that the players adapted the bowing parameters to the physical properties of the string and the instrument, respecting the limits of the playable control parameter space.

  3. Simple analytical relations for ship bow waves

    Science.gov (United States)

    Noblesse, Francis; Delhommeau, G.?Rard; Guilbaud, Michel; Hendrix, Dane; Yang, Chi

    Simple analytical relations for the bow wave generated by a ship in steady motion are given. Specifically, simple expressions that define the height of a ship bow wave, the distance between the ship stem and the crest of the bow wave, the rise of water at the stem, and the bow wave profile, explicitly and without calculations, in terms of the ship speed, draught, and waterline entrance angle, are given. Another result is a simple criterion that predicts, also directly and without calculations, when a ship in steady motion cannot generate a steady bow wave. This unsteady-flow criterion predicts that a ship with a sufficiently fine waterline, specifically with waterline entrance angle 2, may generate a steady bow wave at any speed. However, a ship with a fuller waterline (25E) can only generate a steady bow wave if the ship speed is higher than a critical speed, defined in terms of αE by a simple relation. No alternative criterion for predicting when a ship in steady motion does not generate a steady bow wave appears to exist. A simple expression for the height of an unsteady ship bow wave is also given. In spite of their remarkable simplicity, the relations for ship bow waves obtained in the study (using only rudimentary physical and mathematical considerations) are consistent with experimental measurements for a number of hull forms having non-bulbous wedge-shaped bows with small flare angle, and with the authors' measurements and observations for a rectangular flat plate towed at a yaw angle.

  4. Entropy Generation Across Earth's Bow Shock

    Science.gov (United States)

    Parks, George K.; McCarthy, Michael; Fu, Suiyan; Lee E. s; Cao, Jinbin; Goldstein, Melvyn L.; Canu, Patrick; Dandouras, Iannis S.; Reme, Henri; Fazakerley, Andrew; hide

    2011-01-01

    Earth's bow shock is a transition layer that causes an irreversible change in the state of plasma that is stationary in time. Theories predict entropy increases across the bow shock but entropy has never been directly measured. Cluster and Double Star plasma experiments measure 3D plasma distributions upstream and downstream of the bow shock that allow calculation of Boltzmann's entropy function H and his famous H-theorem, dH/dt O. We present the first direct measurements of entropy density changes across Earth's bow shock. We will show that this entropy generation may be part of the processes that produce the non-thermal plasma distributions is consistent with a kinetic entropy flux model derived from the collisionless Boltzmann equation, giving strong support that solar wind's total entropy across the bow shock remains unchanged. As far as we know, our results are not explained by any existing shock models and should be of interests to theorists.

  5. Primary shield displacement and bowing

    International Nuclear Information System (INIS)

    Scott, K.V.

    1978-01-01

    The reactor primary shield is constructed of high density concrete and surrounds the reactor core. The inlet, outlet and side primary shields were constructed in-place using 2.54 cm (1 in) thick steel plates as the forms. The plates remained as an integral part of the shields. The elongation of the pressure tubes due to thermal expansion and pressurization is not moving through the inlet nozzle hardware as designed but is accommodated by outward displacement and bowing of the inlet and outlet shields. Excessive distortion of the shields may result in gas seal failures, intolerable helium gas leaks, increased argon-41 emissions, and shield cooling tube failures. The shield surveillance and testing results are presented

  6. Energetics of the terrestrial bow shock

    Science.gov (United States)

    Hamrin, Maria; Gunell, Herbert; Norqvist, Patrik

    2017-04-01

    The solar wind is the primary energy source for the magnetospheric energy budget. Energy can enter through the magnetopause both as kinetic energy (plasma entering via e.g. magnetic reconnection and impulsive penetration) and as electromagnetic energy (e.g. by the conversion of solar wind kinetic energy into electromagnetic energy in magnetopause generators). However, energy is extracted from the solar wind already at the bow shock, before it encounters the terrestrial magnetopause. At the bow shock the supersonic solar wind is slowed down and heated, and the region near the bow shock is known to host many complex processes, including the accelerating of particles and the generation of waves. The processes at and near the bow shock can be discussed in terms of energetics: In a generator (load) process kinetic energy is converted to (from) electromagnetic energy. Bow shock regions where the solar wind is decelerated correspond to generators, while regions where particles are energized (accelerated and heated) correspond to loads. Recently, it has been suggested that currents from the bow shock generator should flow across the magnetosheath and connect to the magnetospause current systems [Siebert and Siscoe, 2002; Lopez et al., 2011]. In this study we use data from the Magnetospheric MultiScale (MMS) mission to investigate the energetics of the bow shock and the current closure, and we compare with the MHD simulations of Lopez et al., 2011.

  7. Viols and Other Historic Bowed String Instruments

    Science.gov (United States)

    Campbell, Murray; Campbell, Patsy

    While plucked strings have been used for musical purposes since at least the third millennium BCE, the idea of sounding a string by bowing it is a much more recent development. Bowed string instruments seem to have originated in Asia toward the end of the first millennium CE, and were in widespread use in Western Europe by the end of the eleventh century. For the next three centuries many different types of bowed instrument, with a bewildering variety of names, were in common use throughout Europe.

  8. Comparative review of bow shocks and magnetopauses

    International Nuclear Information System (INIS)

    Lepping, R.P.

    1984-04-01

    Bow shock and magnetopauses formation is discussed. Plasma and magnetic field environments of all the planets from Mercury to Saturn were measured. It was found that all the planets have bow shocks and almost all have a magnetopause. Venus is the only planet with no measurable intrinsic magnetic field and the solar wind interacts directly with Venus ionosphere. The bow shock characteristics depend on the changing solar wind conditions. The shape of a magnetopause or any obstacle to flow depends on the three dimensional pressure profile that it presents to the solar wind. Jupiter is unusual because of the considerable amount of plasma which is contained in its magnetosphere. Magentopause boundaries in ecliptic plane projection are modelled by segments of ellipses, matched to straight lines for the magnetotool boundaries or parabolas. Specific properties of known planetary bow shocks and magnetopauses are reviewed

  9. Bow-shaped toroidal field coils

    International Nuclear Information System (INIS)

    Bonanos, P.

    1981-05-01

    Design features of Bow-Shaped Toroidal Field Coils are described and compared with circular and D shaped coils. The results indicate that bow coils can produce higher field strengths, store more energy and be made demountable. The design offers the potential for the production of ultrahigh toroidal fields. Included are representative coil shapes and their engineering properties, a suggested structural design and an analysis of a specific case

  10. True versus apparent shapes of bow shocks

    Science.gov (United States)

    Tarango-Yong, Jorge A.; Henney, William J.

    2018-06-01

    Astrophysical bow shocks are a common result of the interaction between two supersonic plasma flows, such as winds or jets from stars or active galaxies, or streams due to the relative motion between a star and the interstellar medium. For cylindrically symmetric bow shocks, we develop a general theory for the effects of inclination angle on the apparent shape. We propose a new two-dimensional classification scheme for bow shapes, which is based on dimensionless geometric ratios that can be estimated from observational images. The two ratios are related to the flatness of the bow's apex, which we term planitude, and the openness of its wings, which we term alatude. We calculate the expected distribution in the planitude-alatude plane for a variety of simple geometrical and physical models: quadrics of revolution, wilkinoids, cantoids, and ancantoids. We further test our methods against numerical magnetohydrodynamical simulations of stellar bow shocks and find that the apparent planitude and alatude measured from infrared dust continuum maps serve as accurate diagnostics of the shape of the contact discontinuity, which can be used to discriminate between different physical models. We present an algorithm that can determine the planitude and alatude from observed bow shock emission maps with a precision of 10 to 20 per cent.

  11. HH-65A Dolphin digital integrated avionics

    Science.gov (United States)

    Huntoon, R. B.

    1984-01-01

    Communication, navigation, flight control, and search sensor management are avionics functions which constitute every Search and Rescue (SAR) operation. Routine cockpit duties monopolize crew attention during SAR operations and thus impair crew effectiveness. The United States Coast Guard challenged industry to build an avionics system that automates routine tasks and frees the crew to focus on the mission tasks. The HH-64A SAR avionics systems of communication, navigation, search sensors, and flight control have existed independently. On the SRR helicopter, the flight management system (FMS) was introduced. H coordinates or integrates these functions. The pilot interacts with the FMS rather than the individual subsystems, using simple, straightforward procedures to address distinct mission tasks and the flight management system, in turn, orchestrates integrated system response.

  12. IFIN-HH, Scientific Report 2000

    International Nuclear Information System (INIS)

    Dragolici, Felicia; Enescu, Sanda-Elena; Oancea, Margareta; Preda, Mihaela; Prodan, Lucia; Raduta, Adriana; Sandu, Doina; Schiaua, Claudiu

    2001-01-01

    The annual report of the Horia Hulubei National Institute for Physics and Nuclear Engineering, IFIN-HH, on 2000 presents progress reports in the fields of Theoretical Physics (Nuclear and Atomic Physics (1 paper), Mathematical Physics, Field Theory and Elementary Particles (4 papers), Physics of Information (11 papers)), Nuclear Physics (Nuclear Structure (12 papers), Nuclear Reactions (11 papers), Applied Nuclear Physics (6 papers)), Atomic Physics (1 paper), Cosmic Rays and Nuclear Astrophysics (3 papers), Inertial Fusion, Physics of Neutrons and Nuclear Transmutations (3 papers), Nuclear Instruments and Methods (12 papers), Particle Physics (11 papers), Health and Environmental Physics (8 papers), Applied Physics (13 papers), Tracers, Radiopharmaceuticals and Radiometry (8 papers), Waste management and Site Restoration (1 paper) and Standardization (2 papers). Appendices are added listing the publications in journals, monographs and as preprints, contributions to international conferences, PhD theses, and scientific exchanges (foreign visitors, invited seminars, visits abroad, seminars abroad). Finally the Institute scientific board and research staff are listed

  13. IFIN-HH, Scientific Report 1999

    International Nuclear Information System (INIS)

    Carstea, Stefan; Dragulici, Felicia; Enescu, Sanda-Elena; Oancea, Margareta; Preda, Mihaela; Prodan, Lucia; Raduta, Adriana; Sandu, Doina; Schiaua, Claudiu

    2000-01-01

    The annual report of the Horia Hulubei National Institute for Physics and Nuclear Engineering, IFIN-HH, on 1999 presents progress reports in the fields of Theoretical Physics (Nuclear and Atomic Physics (14 papers); Mathematical Physics, Field Theory and Elementary Particles (5 ); Physics of Information (6)), Nuclear Physics (Nuclear Structure (11), Nuclear Reactions (10), Atomic Physics (3), Cosmic Rays and Nuclear Astrophysics (3), Physics of Neutrons (2); Nuclear Instruments and Methods (11)), Particle Physics (7), Health and Environmental Physics (10), Applied Physics (21), Tracers, Radiopharmaceuticals and Radiometry (16), Technological Development (2), Waste management and Site Restoration (2) and Standardization (4). Appendices are added listing the publications in journals, monographs and as preprints, contributions to international conferences, PhD theses, and scientific exchanges (foreign visitors, invited seminars, visits abroad, seminars abroad). Finally the Institute scientific board and research staff are listed

  14. IFIN-HH, Scientific Report 2001 - 2002

    International Nuclear Information System (INIS)

    Oancea, Margareta; Schiaua, Claudiu; Grecu, Dan; Dumitriu, Marinela

    2003-01-01

    The annual report of the Horia Hulubei National Institute for Physics and Nuclear Engineering - IFIN-HH on 2001-2002 presents progress reports in the fields of Theoretical Physics (Nuclear, Atomic and Molecular Physics, Mathematical Physics, Field Theory and Elementary Particles, Computational Physics (Physics of Information) and Solid State Physics), Nuclear Physics (Nuclear Structure, Nuclear Reaction, Atomic Physics, Cosmic Rays and Nuclear Astrophysics, Inertial Fusion, Physics of Neutrons and Nuclear Transmutation, Nuclear Instruments and Methods), Particle Physics, Health and Environmental Physics, Applied Physics, Tracers, Radiopharmaceuticals and Radiometry, Waste Management and Site Restoration and Standardization. Appendices are added listing the publications in journals, books and preprints, participations in international conferences and scientific exchanges (foreign visitors, visits abroad, seminars abroad). Finally, the Institute directorate and research staff are listed

  15. Channel Bow in Boiling Water Reactors - Hot Cell Examination Results and Correlation to Measured Bow

    International Nuclear Information System (INIS)

    Mahmood, S.T.; Lin, Y.P.; Dubecky, M.A.; Edsinger, K.; Mader, E.V.

    2007-01-01

    An increase in frequency of fuel channel-control blade interference has been observed in Boiling Water Reactors (BWR) in recent years. Many of the channels leading to interference were found to bow towards the control blade in a manner that was inconsistent with the expected bow due to other effects. The pattern of bow appeared to indicate a new channel bow mechanism that differed from the predominant bow mechanism caused by differential growth due to fast-fluence gradients. In order to investigate this new type of channel bow, coupons from several channels with varying degrees of bow were returned to the GE Vallecitos Nuclear Center (VNC) for Post-Irradiation Examination (PIE). This paper describes the characteristics of channel corrosion and hydrogen pickup observed, and relates the observations to the channel exposure level, control history, and measured channel bow. The channels selected for PIE had exposures in the range of 36-48 GWd/MTU and covered a wide range of measured bow. The coupons were obtained at 4 elevations from opposing channel sides adjacent and away from the control blade. The PIE performed on these coupons included visual examination, metallography, and hydrogen concentration measurements. A new mechanism of control-blade shadow corrosion-induced channel bow was found to correlate with differences in the extent of corrosion and corresponding differences in the hydrogen concentration between opposite sides of the channels. The increased corrosion on the control blade sides was found to be dependent on the level of control early in the life of the channel. The contributions of other potential factors leading to increased channel bow and channel-control blade interference are also discussed in this paper. (authors)

  16. Ammonia toroid aligned perpendicular to the HH 1 and HH 2 bipolar outflow

    International Nuclear Information System (INIS)

    Torrelles, J.M.; Canto, J.; Rodriguez, L.F.; Ho, P.T.P.; Moran, J.M.; Universidad Nacional Autonoma de Mexico, Mexico City)

    1985-01-01

    The ammonia emission from the region containing the Herbig-Haro objects 1 and 2, which mark the presence of a bipolar outflow, was mapped. The ammonia observations delineate an elongated structure aligned perpendicular to the bipolar outflow. This ammonia condensation is centered between HH 1 and HH 2 and coincides with the recently discovered central radio continuum source. This continuum source has no optical counterpart. The ammonia spectrum at the position of the continuum source shows a remarkable splitting. Based on the orientation of the bipolar outflow, which is known to be oriented nearly perpendicular to the line of sight, and on theoretical considerations, it is concluded that the ammonia source is part of a toroid, viewed edge-on, in slow expansion driven by the wind pressure of the central source. This toroid may be the focusing mechanism for the bipolar outflow. Searches for ammonia condensations in the vicinity of other HH objects may help localize the energy sources of these systems. 26 references

  17. The IFIN-HH triple coincidence liquid scintillation counter

    CSIR Research Space (South Africa)

    Razdolescu, AC

    2006-10-01

    Full Text Available at IFIN-HH using a 3 H standard. The performances of the IFIN-HH TDCR counter was checked against the measurement results of the TDCR counters of CSIR NML (South Africa), RC (Poland) and LNHB (France). A set of ready-to-measure Ni-63 sources in liquid...

  18. Observation of the HH 1 and 2 region with IRAS

    International Nuclear Information System (INIS)

    Pravdo, S.H.; Chester, T.J.

    1987-01-01

    Infrared Astronomical Satellite (IRAS) observations of the region in Orion containing HH 1 and 2 reveal for the first time the large-scale distribution of newly formed stars. New infrared sources discovered in these observations are discussed, and attempts are made to untangle the complex infrared morphology of this field. A major finding of this study is that HH 1 is near the peak of an intense and broad plateau of 60 and 100 micron emission that spatially corresponds well with the boundaries of a previously detected molecular cloud. Other findings include the detection of an emitting circum-HH object dust complex around HH 2, 25 micron emission associated with the putative HH 1 and 2 exciting source discovered with the VLA, a new luminous far-infrared source, and numerous infrared source complexes, some in blank optical fields and others in fields containing optical emission-line stars. 37 references

  19. Effect of Buffer Bow Structure in Ship-Ship Collision

    DEFF Research Database (Denmark)

    Yamada, Yasuhira; Endo, Hisayoshi; Pedersen, Preben Terndrup

    2008-01-01

    tankers, the introduction of buffer bulbous bows has been proposed. Relatively soft buffer bows absorb part of the kinetic energy of the striking ship before penetrating the inner hull of the struck vessel. The purpose of the present paper is to verify the effectiveness of a prototype buffer bulbous bow......) and the forward velocity of the struck ship on the collapse mode of the bow of the striking vessel are investigated. Collapse modes, contact forces and energy absorption capabilities of the buffer bows are compared with those of conventional bows....

  20. Stress relaxation of thermally bowed fuel pins

    International Nuclear Information System (INIS)

    Crossland, I.G.; Speight, M.V.

    1983-01-01

    The presence of cross-pin temperature gradients in nuclear reactor fuel pins produces differential thermal expansion which, in turn, causes the fuel pin to bow elastically. If the pin is restrained in any way, such thermal bowing causes the pin to be stressed. At high temperatures these stresses can relax by creep and it is shown here that this causes the pin to suffer an additional permanent deflection, so that when the cross-pin temperature difference is removed the pin remains bowed. By representing the cylindrical pin by an equivalent I-beam, the present work examines this effect when it takes place by secondary creep. Two restraint systems are considered, and it is demonstrated that the rate of relaxation depends mainly upon the creep equation, and hence the temperature, and also the magnitude of the initial stresses. (author)

  1. PROPER MOTIONS OF THE HH 110/270 SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Kajdic, P. [Instituto de Astronomia, UNAM, Mexico D.F. (Mexico); Reipurth, B.; Walawender, J. [Institute for Astronomy, University of Hawaii at Manoa, 640 N. A' ohoku Place, Hilo, HI 96720 (United States); Raga, A. C. [Instituto de Ciencias Nucleares, UNAM, Mexico D.F. (Mexico); Bally, J., E-mail: primoz@geofisica.unam.mx, E-mail: reipurth@IfA.Hawaii.Edu, E-mail: raga@nucleares.unam.mx, E-mail: John.Bally@casa.colorado.edu, E-mail: joshw@ifa.hawaii.edu [CASA, University of Colorado, 389 UCB, Boulder, CO 80309-0389 (United States)

    2012-05-15

    We present a study of the HH 110/270 system based on three sets of optical images obtained with the ESO New Technology Telescope, the Subaru Telescope, and the Hubble Space Telescope (HST). The ground-based observations are made in the H{alpha} and [S II] emission lines and the HST observations are made in the H{alpha} line only. Ground-based observations reveal the existence of nine knots, which have not been previously discussed and offer some important insight into the HH 110/270 history. We perform a kinematic study of the HH 110/270 system and an analysis of its emission properties. We measure proper motions of all the knots in the system. Four of the newly identified knots belong to the HH 270 jet. Their positions indicate that the jet's axis changed its direction in the past. We speculate that similar changes may have occurred many times in the past and this could be part of the reason for the unusual structure of the HH 110 jet. The HST observations allow us to resolve individual knots into their substructures and to measure their proper motions. These measurements show that the knots are highly turbulent structures. Finally, we report the discovery of four new Herbig-Haro (HH) objects located near the HH 110/270 system.

  2. PROPER MOTIONS OF THE HH 110/270 SYSTEM

    International Nuclear Information System (INIS)

    Kajdič, P.; Reipurth, B.; Walawender, J.; Raga, A. C.; Bally, J.

    2012-01-01

    We present a study of the HH 110/270 system based on three sets of optical images obtained with the ESO New Technology Telescope, the Subaru Telescope, and the Hubble Space Telescope (HST). The ground-based observations are made in the Hα and [S II] emission lines and the HST observations are made in the Hα line only. Ground-based observations reveal the existence of nine knots, which have not been previously discussed and offer some important insight into the HH 110/270 history. We perform a kinematic study of the HH 110/270 system and an analysis of its emission properties. We measure proper motions of all the knots in the system. Four of the newly identified knots belong to the HH 270 jet. Their positions indicate that the jet's axis changed its direction in the past. We speculate that similar changes may have occurred many times in the past and this could be part of the reason for the unusual structure of the HH 110 jet. The HST observations allow us to resolve individual knots into their substructures and to measure their proper motions. These measurements show that the knots are highly turbulent structures. Finally, we report the discovery of four new Herbig-Haro (HH) objects located near the HH 110/270 system.

  3. Traumatic bowing of forearm and lower leg in children

    International Nuclear Information System (INIS)

    Stenstroem, R.; Gripenberg, L.; Bergius, A.-R.

    1978-01-01

    Traumatic bowing of the forearm or lower leg is reported in 31 children. It is a relatively rare condition. Bowing occurs most frequently in combination with fracture of the other bone in the same extremity. In a minority of cases a bowing deformity is a single lesion. Age distribution, degree of deformity, mechanism of origin and therapy are presented and discussed. (Auth.)

  4. Extraction of bowing parameters from violin performance combining motion capture and sensors.

    Science.gov (United States)

    Schoonderwaldt, E; Demoucron, M

    2009-11-01

    A method is described for measurement of a complete set of bowing parameters in violin performance. Optical motion capture was combined with sensors for accurate measurement of the main bowing parameters (bow position, bow velocity, bow acceleration, bow-bridge distance, and bow force) as well as secondary control parameters (skewness, inclination, and tilt of the bow). In addition, other performance features (moments of on/off in bow-string contact, string played, and bowing direction) were extracted. Detailed descriptions of the calculations of the bowing parameters, features, and calibrations are given. The described system is capable of measuring all bowing parameters without disturbing the player, allowing for detailed studies of musically relevant aspects of bow control and coordination of bowing parameters in bowed-string instrument performance.

  5. The earth's foreshock, bow shock, and magnetosheath

    Science.gov (United States)

    Onsager, T. G.; Thomsen, M. F.

    1991-01-01

    Studies directly pertaining to the earth's foreshock, bow shock, and magnetosheath are reviewed, and some comparisons are made with data on other planets. Topics considered in detail include the electron foreshock, the ion foreshock, the quasi-parallel shock, the quasi-perpendicular shock, and the magnetosheath. Information discussed spans a broad range of disciplines, from large-scale macroscopic plasma phenomena to small-scale microphysical interactions.

  6. The earth's foreshock, bow shock, and magnetosheath

    International Nuclear Information System (INIS)

    Onsager, T.G.; Thomsen, M.F.

    1991-01-01

    Studies directly pertaining to the earth's foreshock, bow shock, and magnetosheath are reviewed, and some comparisons are made with data on other planets. Topics considered in detail include the electron foreshock, the ion foreshock, the quasi-parallel shock, the quasi-perpendicular shock, and the magnetosheath. Information discussed spans a broad range of disciplines, from large-scale macroscopic plasma phenomena to small-scale microphysical interactions. 184 refs

  7. The Bowed Tube : a Virtual Violin

    OpenAIRE

    Carrillo, Alfonso P.; Bonada, Jordi

    2010-01-01

    This paper presents a virtual violin for real-time performances consisting of two modules: a violin spectral modeland a control interface. The interface is composed by asensing bow and a tube with drawn strings in substitutionof a real violin. The spectral model is driven by the bowingcontrols captured with the control interface and it is ableto predict spectral envelopes of the sound corresponding tothose controls. The envelopes are filled with harmonic andnoisy content and given to an addit...

  8. Plastic bowing of the ribs in children

    Energy Technology Data Exchange (ETDEWEB)

    Caro, P.A.; Borden, S. IV

    1988-06-01

    Four cases of plastic bowing of the ribs are presented. In three patients with Werdnig-Hoffman disease, plastic curvatures were associated with chronic pneumonia and atelectasis. We postulate that intrapulmonary retractive forces can deform ribs thinned by muscular atrophy. In turn, thoracic collapse can perpetuate lobar and segmental atelectasis. In one case of osteogenesis imperfecta without pneumonia, we believe normal muscle forces bent ribs weakened by deficiency of normal cortical architecture.

  9. Plastic bowing of the ribs in children

    International Nuclear Information System (INIS)

    Caro, P.A.; Borden, S. IV

    1988-01-01

    Four cases of plastic bowing of the ribs are presented. In three patients with Werdnig-Hoffman disease, plastic curvatures were associated with chronic pneumonia and atelectasis. We postulate that intrapulmonary retractive forces can deform ribs thinned by muscular atrophy. In turn, thoracic collapse can perpetuate lobar and segmental atelectasis. In one case of osteogenesis imperfecta without pneumonia, we believe normal muscle forces bent ribs weakened by deficiency of normal cortical architecture. (orig.)

  10. Radiological assessment of the femoral bowing in Japanese population

    Directory of Open Access Journals (Sweden)

    Abdelaal Ahmed Hamed Kassem

    2016-01-01

    Full Text Available Introduction: Differences in the magnitude of bowing between races are well-known characteristics of the femur. Asian races have an increased magnitude of femoral bowing but most of the orthopedic implants designed for the femur do not match this exaggerated bowing. We calculated the sagittal and coronal femoral bowing in the Japanese population at different levels of the femur and addressed its surgical significance. Material and methods: We calculated the sagittal and coronal bowing of 132 Japanese femora using CT scan of the femur. A mathematical calculation of the radius of curvature at proximal, middle, and distal regions of the femur was used to determine the degree of femoral bowing. Results: Mean sagittal bowing of the femur was 581, 188, and 161 mm for the proximal, middle, and distal thirds of the femur and mean lateral bowing was 528, 5092, and 876 mm, respectively. Mean sagittal and coronal bowing for the whole femur was 175 and 2640 mm, respectively. No correlation was found between age, gender, length of femur, and the degree of bowing. Conclusion: Our study reveals that femoral bowing in the Japanese population is 175 mm in the sagittal plane and 2640 mm in the coronal plane; these values are greater than the femoral bowing in other ethnic groups studied in the literature. This may result in varying degrees of mismatch between the western-manufactured femoral intramedullary implants and the Japanese femur. We recommend that orthopedic surgeons to accurately perform preoperative evaluation of the femoral bowing to avoid potential malalignment, rotation, and abnormal stresses between the femur and implant.

  11. Coordination in fast repetitive violin-bowing patterns.

    Science.gov (United States)

    Schoonderwaldt, Erwin; Altenmüller, Eckart

    2014-01-01

    We present a study of coordination behavior in complex violin-bowing patterns involving simultaneous bow changes (reversal of bowing direction) and string crossings (changing from one string to another). Twenty-two violinists (8 advanced amateurs, 8 students with violin as major subject, and 6 elite professionals) participated in the experiment. We investigated the influence of a variety of performance conditions (specific bowing patterns, dynamic level, tempo, and transposition) and level of expertise on coordination behavior (a.o., relative phase and amplitude) and stability. It was found that the general coordination behavior was highly consistent, characterized by a systematic phase lead of bow inclination over bow velocity of about 15° (i.e., string crossings were consistently timed earlier than bow changes). Within similar conditions, a high individual consistency was found, whereas the inter-individual agreement was considerably less. Furthermore, systematic influences of performance conditions on coordination behavior and stability were found, which could be partly explained in terms of particular performance constraints. Concerning level of expertise, only subtle differences were found, the student and professional groups (higher level of expertise) showing a slightly higher stability than the amateur group (lower level of expertise). The general coordination behavior as observed in the current study showed a high agreement with perceptual preferences reported in an earlier study to similar bowing patterns, implying that complex bowing trajectories for an important part emerge from auditory-motor interaction.

  12. Coordination in fast repetitive violin-bowing patterns.

    Directory of Open Access Journals (Sweden)

    Erwin Schoonderwaldt

    Full Text Available We present a study of coordination behavior in complex violin-bowing patterns involving simultaneous bow changes (reversal of bowing direction and string crossings (changing from one string to another. Twenty-two violinists (8 advanced amateurs, 8 students with violin as major subject, and 6 elite professionals participated in the experiment. We investigated the influence of a variety of performance conditions (specific bowing patterns, dynamic level, tempo, and transposition and level of expertise on coordination behavior (a.o., relative phase and amplitude and stability. It was found that the general coordination behavior was highly consistent, characterized by a systematic phase lead of bow inclination over bow velocity of about 15° (i.e., string crossings were consistently timed earlier than bow changes. Within similar conditions, a high individual consistency was found, whereas the inter-individual agreement was considerably less. Furthermore, systematic influences of performance conditions on coordination behavior and stability were found, which could be partly explained in terms of particular performance constraints. Concerning level of expertise, only subtle differences were found, the student and professional groups (higher level of expertise showing a slightly higher stability than the amateur group (lower level of expertise. The general coordination behavior as observed in the current study showed a high agreement with perceptual preferences reported in an earlier study to similar bowing patterns, implying that complex bowing trajectories for an important part emerge from auditory-motor interaction.

  13. The sacred weapon: bow and arrow combat in Iran

    Directory of Open Access Journals (Sweden)

    Manouchehr Moshtagh Khorasani

    2012-07-01

    Full Text Available The following article presents the development of the bow and arrow, and its important role in the history of Iran. The bow always played an important role not only on the battlefield, but also in hunting. It was also considered as a sacred weapon and additionally a royal symbol. Bow and arrow were considered as a superior weapon in comparison with other types of weapons because one could fight with them at a safer distance as one offered by swords, maces and axes. The first part of the article presents a short history of the bow in Iran. Based on historical Persian manuscripts, the next part explains the structure of the composite bow and the materials used for making it. The third part describes some types of bows based on the material, place of production, the usage, and bow type based on the length of the bow and the arrows. The following part talks about different types of arrows based on morphology of arrowheads, the type of plume/feather, the material of the shaft, the material of the arrowhead, the length of arrows, the target of arrows, the place of production of arrowheads and terms for describing its different features of an arrowhead. Then, the article talks about different types of thumb rings, bowstrings, quivers and bow cases and arrow guides for shooting short arrows. The next part discusses different principles of archery as explained in Persian manuscripts. Finally the article describes different archery targets.

  14. The spectrographic orbit of the eclipsing binary HH Carinae

    International Nuclear Information System (INIS)

    Mandrini, C.H.; Mendez, R.H.; Niemela, V.S.; Ferrer, O.E.

    1985-01-01

    We present a radial velocity study of the eclipsing binary system HH Carinae, and determine for the first time its spectrographic orbital elements. Using the results of a previous photometric study by Soderhjelm, we also determine the values of the masses and dimensions of the binary components. (author)

  15. FCC-hh Hadron Collider - Parameter Scenarios and Staging Options

    CERN Document Server

    Benedikt, Michael; Schulte, Daniel; Zimmermann, F; Syphers, M J

    2015-01-01

    FCC-hh is a proposed future energy-frontier hadron collider, based on dipole magnets with a field around 16 T installed in a new tunnel with a circumference of about 100 km, which would provide proton collisions at a centre-of-mass energy of 100 TeV, as well as heavy-ion collisions at the equivalent energy. The FCC-hh should deliver a high integrated proton-proton luminosity at the level of several 100 fb−1 per year, or more. The challenges for operating FCC-hh with high beam current and at high luminosity include the heat load from synchrotron radiation in a cold environment, the radiation from collision debris around the interaction region, and machine protection. In this paper, starting from the FCC-hh design baseline parameters we explore different approaches for increasing the integrated luminosity, and discuss the impact of key individual pa- rameters, such as the turnaround time. We also present some injector considerations and options for early hadron-collider operation.

  16. Evolution of bow-tie architectures in biology.

    Directory of Open Access Journals (Sweden)

    Tamar Friedlander

    2015-03-01

    Full Text Available Bow-tie or hourglass structure is a common architectural feature found in many biological systems. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signaling pathways to regulate multiple output genes. Little is known, however, about how bow-tie architectures evolve. Here, we address the evolution of bow-tie architectures using simulations of multi-layered systems evolving to fulfill a given input-output goal. We find that bow-ties spontaneously evolve when the information in the evolutionary goal can be compressed. Mathematically speaking, bow-ties evolve when the rank of the input-output matrix describing the evolutionary goal is deficient. The maximal compression possible (the rank of the goal determines the size of the narrowest part of the network-that is the bow-tie. A further requirement is that a process is active to reduce the number of links in the network, such as product-rule mutations, otherwise a non-bow-tie solution is found in the evolutionary simulations. This offers a mechanism to understand a common architectural principle of biological systems, and a way to quantitate the effective rank of the goals under which they evolved.

  17. THE POLARIMETRIC AND PHOTOMETRIC VARIABILITY OF HH 30

    International Nuclear Information System (INIS)

    Duran-Rojas, MarIa Carolina; Watson, Alan M.; Stapelfeldt, Karl R.; Hiriart, David

    2009-01-01

    We have obtained ground-based photopolarimetry of the young stellar object HH 30 over the course of one year. Our observations reveal the presence of a dominant periodic modulation of the polarization with a period of 7.49 ± 0.04 days or one of the aliases of this period close to 1 day. There are also suggestions of a weak periodic modulation in the photometry with the same period but a phase displaced by one quarter of a period. These results are in agreement with the lighthouse model for HH 30, in which a beam or shadow from a central source sweeps across the disk. Our observations by themselves appear to be consistent with both of the mechanisms that have been proposed for the lighthouse-asymmetric accretion hot spots on the star or orbiting clumps or voids in the disk-and provide strong quantitative constraints for future models.

  18. First results for a FCC-hh ring optics design

    CERN Document Server

    Chance, Antoine; Payet, Jacques; Alemany Fernandez, Reyes; Holzer, Bernhard; Schulte, Daniel

    2015-01-01

    The first order considerations of the optics for the FCC-hh ring are presented. The arc cell is generated taking into account some general considerations like the whole circumference, maximum gradients and lengths of the elements in the cell. The integration of the insertion regions started. Three types of Dispersion Suppressors (DIS) are studied. The sensitivity of the arc parameters to these layout considerations is studied in more detail. An alternative layout is shown as well.

  19. hh+ {Jet} production at 100 TeV

    Science.gov (United States)

    Banerjee, Shankha; Englert, Christoph; Mangano, Michelangelo L.; Selvaggi, Michele; Spannowsky, Michael

    2018-04-01

    Higgs pair production is a crucial phenomenological process in deciphering the nature of the TeV scale and the mechanism underlying electroweak symmetry breaking. At the Large Hadron Collider, this process is statistically limited. Pushing the energy frontier beyond the LHC's reach will create new opportunities to exploit the rich phenomenology at higher centre-of-mass energies and luminosities. In this work, we perform a comparative analysis of the hh+ {jet} channel at a future 100 TeV hadron collider. We focus on the hh→ b\\bar{b} b\\bar{b} and hh → b\\bar{b} τ ^+τ ^- channels and employ a range of analysis techniques to estimate the sensitivity potential that can be gained by including this jet-associated Higgs pair production to the list of sensitive collider processes in such an environment. In particular, we observe that hh → b\\bar{b} τ ^+τ ^- in the boosted regime exhibits a large sensitivity to the Higgs boson self-coupling and the Higgs self-coupling could be constrained at the 8% level in this channel alone.

  20. Studying the outflow-core interaction with ALMA Cycle 1 observations of the HH 46/47 molecular outflow

    Science.gov (United States)

    Zhang, Yichen; Arce, Hector G.; Mardones, Diego; Dunham, Michael; Garay, Guido; Noriega-Crespo, Alberto; Corder, Stuartt; Offner, Stella; Cabrit, Sylvie

    2016-01-01

    We present ALMA Cycle 1 observations of the HH 46/47 molecular outflow which is driven by a low-mass Class 0/I protostar. Previous ALMA Cycle 0 12CO observation showed outflow cavities produced by the entrainment of ambient gas by the protostellar jet and wide-angle wind. Here we present analysis of observation of 12CO, 13CO, C18O and other species using combined 12m array and ACA observations. The improved angular resolution and sensitivity allow us to detect details of the outflow structure. Specially, we see that the outflow cavity wall is composed of two or more layers of outflowing gas, which separately connect to different shocked regions along the outflow axis inside the cavity, suggesting the outflow cavity wall is composed of multiple shells entrained by a series of jet bow-shock events. The new 13CO and C18O data also allow us to trace relatively denser and slower outflow material than that traced by the 12CO. These species are only detected within about 1 to 2 km/s from the cloud velocity, tracing the outflow to lower velocities than what is possible using only the 12CO emission. Interestingly, the cavity wall of the red lobe appears at very low outflow velocities (as low as ~0.2 km/s). In addition, 13CO and C18O allow us to correct for the CO optical depth, allowing us to obtain more accurate estimates of the outflow mass, momentum and kinetic energy. Applying the optical depth correction significantly increases the previous mass estimate by a factor of 14. The outflow kinetic energy distribution shows that even though the red lobe is mainly entrained by jet bow-shocks, most of the outflow energy is being deposited into the cloud at the base of the outflow cavity rather than around the heads of the bow shocks. The estimated total mass, momentum, and energy of the outflow indicate that the outflow has the ability to disperse the parent core. We found possible evidence for a slowly moving rotating outflow in CS. Our 13CO and C18O observations also trace a

  1. H2 emission from non-stationary magnetized bow shocks

    Science.gov (United States)

    Tram, L. N.; Lesaffre, P.; Cabrit, S.; Gusdorf, A.; Nhung, P. T.

    2018-01-01

    When a fast moving star or a protostellar jet hits an interstellar cloud, the surrounding gas gets heated and illuminated: a bow shock is born that delineates the wake of the impact. In such a process, the new molecules that are formed and excited in the gas phase become accessible to observations. In this paper, we revisit models of H2 emission in these bow shocks. We approximate the bow shock by a statistical distribution of planar shocks computed with a magnetized shock model. We improve on previous works by considering arbitrary bow shapes, a finite irradiation field and by including the age effect of non-stationary C-type shocks on the excitation diagram and line profiles of H2. We also examine the dependence of the line profiles on the shock velocity and on the viewing angle: we suggest that spectrally resolved observations may greatly help to probe the dynamics inside the bow shock. For reasonable bow shapes, our analysis shows that low-velocity shocks largely contribute to H2 excitation diagram. This can result in an observational bias towards low velocities when planar shocks are used to interpret H2 emission from an unresolved bow. We also report a large magnetization bias when the velocity of the planar model is set independently. Our 3D models reproduce excitation diagrams in BHR 71 and Orion bow shocks better than previous 1D models. Our 3D model is also able to reproduce the shape and width of the broad H2 1-0S(1) line profile in an Orion bow shock (Brand et al. 1989).

  2. Structural changes in cuticles on violin bow hair caused by wear.

    Science.gov (United States)

    Yamamoto, Tomoko; Sugiyama, Shigeru

    2010-01-01

    A bow with horse tail hair is used to play the violin. New and worn-out bow hairs were observed by atomic force microscopy. The cuticles of the new bow hair were already damaged by bleach and delipidation, however the worn-out bow hairs were much more damaged and broken off by force, which relates to wearing out.

  3. HH 1158: THE LOWEST LUMINOSITY EXTERNALLY IRRADIATED HERBIG–HARO JET

    International Nuclear Information System (INIS)

    Riaz, B.; Whelan, E. T.

    2015-01-01

    We have identified a new externally irradiated Herbig–Haro (HH) jet, HH 1158, within ∼2 pc of the massive OB type stars in the σ Orionis cluster. At an L bol  ∼ 0.1 L ⊙ , HH 1158 is the lowest luminosity irradiated HH jet identified to date in any cluster. Results from the analysis of high-resolution optical spectra indicate asymmetries in the brightness, morphology, electron density, velocity, and the mass outflow rates for the blue and redshifted lobes. We constrain the position angle of the HH 1158 jet at 102° ± 5°. The mass outflow rate and the mean accretion rate for HH 1158 using multiple diagnostics are estimated to be (5.2 ± 2.6) × 10 −10 M ⊙ yr −1 and (3.0 ± 1.0) × 10 −10 M ⊙ yr −1 , respectively. The properties for HH 1158 are notably similar to the externally irradiated HH 444–HH 447 jets previously identified in σ Orionis. In particular, the morphology is such that the weaker jet beam is tilted toward the massive stars, indicating a higher extent of photo-evaporation. The high value for the Hα/[S ii] ratio is also consistent with the ratios measured in other irradiated jets, including HH 444–HH 447. The presence of an extended collimated jet that is bipolar and the evidence of shocked emission knots make HH 1158 the first unique case of irradiated HH jets at the very low-luminosity end, and provides an opportunity to learn the physical properties of very faint HH jet sources

  4. Laser vibrometry measurements of vibration and sound fields of a bowed violin

    Science.gov (United States)

    Gren, Per; Tatar, Kourosh; Granström, Jan; Molin, N.-E.; Jansson, Erik V.

    2006-04-01

    Laser vibrometry measurements on a bowed violin are performed. A rotating disc apparatus, acting as a violin bow, is developed. It produces a continuous, long, repeatable, multi-frequency sound from the instrument that imitates the real bow-string interaction for a 'very long bow'. What mainly differs is that the back and forward motion of the real bow is replaced by the rotating motion with constant velocity of the disc and constant bowing force (bowing pressure). This procedure is repeatable. It is long lasting and allows laser vibrometry techniques to be used, which measure forced vibrations by bowing at all excited frequencies simultaneously. A chain of interacting parts of the played violin is studied: the string, the bridge and the plates as well as the emitted sound field. A description of the mechanics and the sound production of the bowed violin is given, i.e. the production chain from the bowed string to the produced tone.

  5. Development of the computer network of IFIN-HH

    International Nuclear Information System (INIS)

    Danet, A.; Mirica, M.; Constantinescu, S.

    1998-01-01

    The general computer network of Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), as part of RNC (Romanian National Computer Network for scientific research and technological development), offers the Romanian physics research community an efficient and cost-effective infrastructure to communicate and collaborate with fellow researchers abroad, and to collect and exchange the most up-to-date information in their research area. RNC is the national project co-ordinated and established by the Ministry of Research and Technology targeted on the following main objectives: - setting up a technical and organizational infrastructure meant to provide national and international electronic services for the Romanian scientific research community; - providing a rapid and competitive tool for the exchange information in the framework of R-D community; - using the scientific and technical data bases available in the country and offered by the national networks from other countries through international networks; - providing a support for information, documentation, scientific and technical co-operation. The guiding principle in elaborating the project of general computer network of IFIN-HH was to implement an open system based on OSI standards without technical barriers in communication between different communities using different computing hardware and software. The major objectives achieved in 1997 in the direction of developing the general computer network of IFIN-HH (over 250 computers connected) were: - connecting all the existing and newly installed computer equipment and providing an adequate connectivity; - providing the usual Internet services: e-mail, ftp, telnet, finger, gopher; - providing access to the World Wide Web resources; - providing on-line statistics of IP traffic (input and output) of each node of the domain computer network; - improving the performance of the connection with the central node RNC. (authors)

  6. Improvements, verifications and validations of the BOW code

    International Nuclear Information System (INIS)

    Yu, S.D.; Tayal, M.; Singh, P.N.

    1995-01-01

    The BOW code calculates the lateral deflections of a fuel element consisting of sheath and pellets, due to temperature gradients, hydraulic drag and gravity. the fuel element is subjected to restraint from endplates, neighboring fuel elements and the pressure tube. Many new features have been added to the BOW code since its original release in 1985. This paper outlines the major improvements made to the code and verification/validation results. (author)

  7. Mesoscale Surface Pressure and Temperature Features Associated with Bow Echoes

    Science.gov (United States)

    2010-01-01

    contain several bowing segments. These multiple segments could occur at the same time and be located within the same bow, such as the serial derecho ...Examination of derecho environments using proximity soundings. Wea. Forecasting, 16, 329–342. Fovell, R. G., 2002: Upstream influence of numerically...Se- vere Local Storms, Hyannis, MA, Amer. Meteor. Soc., 4.6. Johns, R. H., and W. D. Hirt, 1987: Derechos : Widespread con- vectively induced

  8. Beam-beam studies for FCC-hh

    CERN Document Server

    AUTHOR|(CDS)2068329; Pieloni, Tatiana; Buffat, Xavier; Furuseth, Sondre Vik

    2017-01-01

    The Future Circular Collider hadron-hadron (FCC-hh) design study is currently exploring different IR design possibilities including round and flat optics or different crossing schemes. The present study intends to evaluate each scenario from the beam-beam effects point of view. In particular the single particle long term stability to maximize beam lifetimes and luminosity reach is used to quantify the differences. The impact of strong head on interactions on the beam quality and lifetime is addressed by means of GPU accelerated simulations code featuring a weak-strong 6-dimensional beam-beam interaction.

  9. EMQN best practice guidelines for the molecular genetic diagnosis of hereditary hemochromatosis (HH)

    Science.gov (United States)

    Porto, Graça; Brissot, Pierre; Swinkels, Dorine W; Zoller, Heinz; Kamarainen, Outi; Patton, Simon; Alonso, Isabel; Morris, Michael; Keeney, Steve

    2016-01-01

    Molecular genetic testing for hereditary hemochromatosis (HH) is recognized as a reference test to confirm the diagnosis of suspected HH or to predict its risk. The vast majority (typically >90%) of patients with clinically characterized HH are homozygous for the p.C282Y variant in the HFE gene, referred to as HFE-related HH. Since 1996, HFE genotyping was implemented in diagnostic algorithms for suspected HH, allowing its early diagnosis and prevention. However, the penetrance of disease in p.C282Y homozygotes is incomplete. Hence, homozygosity for p.C282Y is not sufficient to diagnose HH. Neither is p.C282Y homozygosity required for diagnosis as other rare forms of HH exist, generally referred to as non-HFE-related HH. These pose significant challenges when defining criteria for referral, testing protocols, interpretation of test results and reporting practices. We present best practice guidelines for the molecular genetic diagnosis of HH where recommendations are classified, as far as possible, according to the level and strength of evidence. For clarification, the guidelines' recommendations are preceded by a detailed description of the methodology and results obtained with a series of actions taken in order to achieve a wide expert consensus, namely: (i) a survey on the current practices followed by laboratories offering molecular diagnosis of HH; (ii) a systematic literature search focused on some identified controversial topics; (iii) an expert Best Practice Workshop convened to achieve consensus on the practical recommendations included in the guidelines. PMID:26153218

  10. IRC -10414: a bow-shock-producing red supergiant star

    Science.gov (United States)

    Gvaramadze, V. V.; Menten, K. M.; Kniazev, A. Y.; Langer, N.; Mackey, J.; Kraus, A.; Meyer, D. M.-A.; Kamiński, T.

    2014-01-01

    Most runaway OB stars, like the majority of massive stars residing in their parent clusters, go through the red supergiant (RSG) phase during their lifetimes. Nonetheless, although many dozens of massive runaways were found to be associated with bow shocks, only two RSG bow-shock-producing stars, Betelgeuse and μ Cep, are known to date. In this paper, we report the discovery of an arc-like nebula around the late M-type star IRC -10414 using the SuperCOSMOS H-alpha Survey. Our spectroscopic follow-up of IRC -10414 with the Southern African Large Telescope (SALT) showed that it is a M7 supergiant, which supports previous claims on the RSG nature of this star based on observations of its maser emission. This was reinforced by our new radio- and (sub)millimetre-wavelength molecular line observations made with the Atacama Pathfinder Experiment 12-m telescope and the Effelsberg 100-m radio telescope, respectively. The SALT spectrum of the nebula indicates that its emission is the result of shock excitation. This finding along with the arc-like shape of the nebula and an estimate of the space velocity of IRC -10414 (≈70 ± 20 km s-1) imply the bow shock interpretation for the nebula. Thus, IRC -10414 represents the third case of a bow-shock-producing RSG and the first one with a bow shock visible at optical wavelengths. We discuss the smooth appearance of the bow shocks around IRC -10414 and Betelgeuse and propose that one of the necessary conditions for stability of bow shocks generated by RSGs is the ionization of the stellar wind. Possible ionization sources of the wind of IRC -10414 are proposed and discussed.

  11. X-ray study of bow shocks in runaway stars

    Science.gov (United States)

    De Becker, M.; del Valle, M. V.; Romero, G. E.; Peri, C. S.; Benaglia, P.

    2017-11-01

    Massive runaway stars produce bow shocks through the interaction of their winds with the interstellar medium, with the prospect for particle acceleration by the shocks. These objects are consequently candidates for non-thermal emission. Our aim is to investigate the X-ray emission from these sources. We observed with XMM-Newton a sample of five bow shock runaways, which constitutes a significant improvement of the sample of bow shock runaways studied in X-rays so far. A careful analysis of the data did not reveal any X-ray emission related to the bow shocks. However, X-ray emission from the stars is detected, in agreement with the expected thermal emission from stellar winds. On the basis of background measurements we derive conservative upper limits between 0.3 and 10 keV on the bow shocks emission. Using a simple radiation model, these limits together with radio upper limits allow us to constrain some of the main physical quantities involved in the non-thermal emission processes, such as the magnetic field strength and the amount of incident infrared photons. The reasons likely responsible for the non-detection of non-thermal radiation are discussed. Finally, using energy budget arguments, we investigate the detectability of inverse Compton X-rays in a more extended sample of catalogued runaway star bow shocks. From our analysis we conclude that a clear identification of non-thermal X-rays from massive runaway bow shocks requires one order of magnitude (or higher) sensitivity improvement with respect to present observatories.

  12. Developments of the general computer network of NIPNE-HH

    International Nuclear Information System (INIS)

    Mirica, M.; Constantinescu, S.; Danet, A.

    1997-01-01

    Since 1991 the general computer network of NIPNE-HH was developed and connected to RNCN (Romanian National Computer Network) for research and development and it offers to the Romanian physics research community an efficient and cost-effective infrastructure to communicate and collaborate with fellow researchers abroad, and to collect and exchange the most up-to-date information in their research area. RNCN is targeted on the following main objectives: Setting up a technical and organizational infrastructure meant to provide national and international electronic services for the Romanian scientific research community; - Providing a rapid and competitive tool for the exchange of information in the framework of Research and Development (R-D) community; - Using the scientific and technical data bases available in the country and offered by the national networks from other countries through international networks; - Providing a support for information, scientific and technical co-operation. RNCN has two international links: to EBONE via ACONET (64kbps) and to EuropaNET via Hungarnet (64 kbps). The guiding principle in designing the project of general computer network of NIPNE-HH, as part of RNCN, was to implement an open system based on OSI standards taking into account the following criteria: - development of a flexible solution, according to OSI specifications; - solutions of reliable gateway with the existing network already in use,allowing the access to the worldwide networks; - using the TCP/IP transport protocol for each Local Area Network (LAN) and for the connection to RNCN; - ensuring the integration of different and heterogeneous software and hardware platforms (DOS, Windows, UNIX, VMS, Linux, etc) through some specific interfaces. The major objectives achieved in direction of developing the general computer network of NIPNE-HH are: - linking all the existing and newly installed computer equipment and providing an adequate connectivity. LANs from departments

  13. Numerical Study on the Effect of Buffer Bow Structure in Ship-to-ship Collisions

    DEFF Research Database (Denmark)

    Yamada, Yasuhira; Endo, Hisayoshi; Pedersen, Preben Terndrup

    2005-01-01

    tankers, the introduction of buffer bulbous bows has been proposed. Relatively soft buffer bows absorb part of the kinetic energy of the striking ship before penetrating the inner hull of the struck vessel. The purpose of the present paper is to verify the effectiveness of a prototype buffer bulbous bow......) and the forward velocity of the struck ship on the collapse mode of the bow of the striking vessel are investigated. Collapse modes, contact forces and energy absorption capabilities of the buffer bows are compared with those of conventional bows....

  14. Bowing behavior of subassemblies in experimental fast reactor ''JOYO''

    International Nuclear Information System (INIS)

    Ikegami, T.; Mizoo, N.; Matsuno, Y.; Watari, Y.

    1984-01-01

    In JOYO, the measured power coefficients in the beginning of the operation cycle of MK-I and MK-II cores showed power dependence, while the calculation without taking account of bowing predicted little power dependence. The bowing analysis was performed in order to investigate the power dependence observed in the measured power coefficients and the following conclusions were obtained. (1) The evaluated power coefficients taking account of bowing effect agree better with measured ones than the calculated ones without taking account of bowing effect in MK-I core. (2) In MK-II core, although the analytical results show not so good agreement quantitatively with the measured power coefficients, it is suggested that they agree better depending on the uncertain parameters such as the heat generation in the reflector region, the threshold moment for leaning and the stiffness of the inner reflector. (3) It becomes clear from these results that the power dependence observed in the measured power coefficients in JOYO is due to the bowing effect. (author)

  15. Runaways and weathervanes: The shape of stellar bow shocks

    Science.gov (United States)

    Henney, W. J.; Tarango-Yong, J. A.

    2017-11-01

    Stellar bow shocks are the result of the supersonic interaction between a stellar wind and its environment. Some of these are "runaways": high-velocity stars that have been ejected from a star cluster. Others are "weather vanes", where it is the local interstellar medium itself that is moving, perhaps as the result of a champagne flow of ionized gas from a nearby HII region. We propose a new two-dimensional classification scheme for bow shapes, which is based on dimensionless geometric ratios that can be estimated from observational images. The two ratios are related to the flatness of the bow’s apex, which we term "planitude" and the openness of its wings, which we term "alatude". We calculate the inclination-dependent tracks on the planitude-alatude plane that are predicted by simple models for the bow shock shape. We also measure the shapes of bow shocks from three different observational datasets: mid-infrared arcs around hot main-sequence stars, far-infrared arcs around luminous cool stars, and emission-line arcs around proplyds and other young stars in the Orion Nebula. Clear differences are found between the different datasets in their distributions on the planitude-alatude plane, which can be used to constrain the physics of the bow shock interaction and emission mechanisms in the different classes of object.

  16. Crushing of ship bows in head-on collision

    DEFF Research Database (Denmark)

    Ocakli, H.; Zhang, S.; Pedersen, Preben Terndrup

    2004-01-01

    Semi-analytical methods for analysis of plate crushing and ship bow damage in head-on collisions are developed in this paper. Existing experimental and theoretical studies for crushing analysis of plated structures are summarized and compared. Simple formulae for determining the crushing force....... The approach developed can be used easily to determine the crushing resistance and damage extent of the ship bow when ship length and collision speed are known. The method can be used in probabilistic analysis of damage extents in ship collisions where a large number of calculations are generally required....

  17. A Comparison of the Radio and Optical Time-Evolution of HH 1 and 2

    Science.gov (United States)

    Rodríguez, L. F.; Raga, A. C.; Rodríguez-Kamenetzky, A.; Carrasco-González, C.

    2018-04-01

    We present a comparison between the time-evolution over the past ≍20 years of the radio continuum and Hα emission of HH 1 and 2. We find that the radio continuum and the Hα emission of both objects show very similar trends, with HH 1 becoming fainter and HH 2 brightening quite considerably (by about a factor of 2). We also find that the FHα /Fff (Hα to freefree continuum) ratio of HH 1 and 2 has higher values than the ones typically found in planetary nebulae (PNe), which we interpret as an indication that the Hα and free-free emission of HH 1/2 is produced in emitting regions with lower temperatures (≍2000 K) than the emission of PNe (with ≍104 K).

  18. Narrowband imaging of the Herbig-Haro object HH 46/47

    International Nuclear Information System (INIS)

    Raga, A.C.; Mateo, M.

    1987-01-01

    Narrow-band CCD images of the HH 46/47 system were obtained in the light of the H-alpha, forbidden N II 6583-A forbidden S II 6717-A and forbidden S II 6731-A emission lines. The images include HH 46, HH 47B, and HH 47A. A calibration for these images was carried out that makes it possible to calculate line ratios, and then use these line ratios as diagnostics of the physical conditions in the radiating gas. The study shows that the bright condensation HH 47A has a higher electron density and a lower excitation spectrum than the jet that joins this condensation to the central source. This result does not agree with the observations of other morphologically similar Herbig-Haro objects. 36 references

  19. Fatigue analysis of the bow structure of FPSO

    Science.gov (United States)

    Hu, Zhi-Qiang; Gao, Zhen; Gu, Yong-Ning

    2003-06-01

    The bow structure of FPSO moored by the single mooring system is rather complicated. There are many potential hot spots in connection parts of structures between the mooring support frame and the forecastle. Mooring forces, which are induced by wave excitation and transferred by the YOKE and the mooring support frame, may cause fatigue damage to the bow structure. Different from direct wave-induced-forces, the mooring force consists of wave frequency force (WF) and 2nd draft low frequency force (LF)[3], which are represented by two sets of short-term distribution respectively. Based on two sets of short-term distribution of mooring forces obtained by the model test, the fatigue damage of the bow structure of FPSO is analyzed, with emphasis on two points. One is the procedure and position selection for fatigue check, and the other is the application of new formulae for the calculation of accumulative fatigue damage caused by two sets of short-term distribution of hot spot stress range. From the results distinguished features of fatigue damage to the FPSO’s bow structure can be observed.

  20. Application of Bow-tie methodology to improve patient safety.

    Science.gov (United States)

    Abdi, Zhaleh; Ravaghi, Hamid; Abbasi, Mohsen; Delgoshaei, Bahram; Esfandiari, Somayeh

    2016-05-09

    Purpose - The purpose of this paper is to apply Bow-tie methodology, a proactive risk assessment technique based on systemic approach, for prospective analysis of the risks threatening patient safety in intensive care unit (ICU). Design/methodology/approach - Bow-tie methodology was used to manage clinical risks threatening patient safety by a multidisciplinary team in the ICU. The Bow-tie analysis was conducted on incidents related to high-alert medications, ventilator associated pneumonia, catheter-related blood stream infection, urinary tract infection, and unwanted extubation. Findings - In total, 48 potential adverse events were analysed. The causal factors were identified and classified into relevant categories. The number and effectiveness of existing preventive and protective barriers were examined for each potential adverse event. The adverse events were evaluated according to the risk criteria and a set of interventions were proposed with the aim of improving the existing barriers or implementing new barriers. A number of recommendations were implemented in the ICU, while considering their feasibility. Originality/value - The application of Bow-tie methodology led to practical recommendations to eliminate or control the hazards identified. It also contributed to better understanding of hazard prevention and protection required for safe operations in clinical settings.

  1. Active current sheets near the earth's bow shock

    International Nuclear Information System (INIS)

    Schwartz, S.J.; Kessel, R.L.; Brown, C.C.; Woolliscroft, L.J.C.; Dunlop, M.W.; Farrugia, C.J.; Hall, D.S.

    1988-01-01

    The authors present here an investigation of active current sheets observed by the AMPTE UK spacecraft near the Earth's bow shock, concentrating on their macroscopic features and geometry. Events selected primarily by flow directions which deviate substantially from the Sun-Earth line show similar characteristics, including their association with an underlying macroscopic current sheet and a hot central region whose flow direction is organized, at least in part, by location relative to the inferred initial intersection point between the current sheet and the bow shock. This region is flanked by edges which, according to a Rankine-Hugoniot analysis, are often fast shocks whose orientation is consistent with that expected if a bulge on the bow shock convected past the spacecraft. They have found the magnetosheath manifestations of these events which they study in detail. They suggest that these events are the direct result of the disruption and reformation of the bow shock by the passage of an interplanetary current sheet, most probably a tangential discontinuity

  2. Giotto observations of the bow shock at Comet Halley

    International Nuclear Information System (INIS)

    Formisano, V.; Amata, E.; Wilken, B.

    1986-01-01

    Preliminary results from the JPA instrument on Giotto indicate that Comet Halley, even on the flanks, has a bow shock which moves backwards and forwards over the spacecraft. To understand the structure properly will require more detailed investigation of the relationships between three particle populations, cometary ions, solar wind ions and electrons

  3. Mammotome HH biopsy - the future of minimal invasive breast surgery?

    International Nuclear Information System (INIS)

    Pietrzyk, G.; Nowicki, J.; Bojarski, B.; Kedzierski, B.; Wysocki, A.; Prudlak, E.

    2007-01-01

    Vacuum-assisted breast biopsy / Mammotome HH '' R '' Breast Biopsy System/ is the milestone in the diagnosis of breast lesions. This system has proven to be as diagnostically reliable as open surgery, but without scarring, deformations and hospitalizations associated with an open procedure. The aim of our study was to assess the role and possibilities of using this biopsy in treatment of benign breast lesions like fibroadenoma. From 2001 to 2004, about 1118 Mammotome biopsies were performed in our Department. Among 445 Mammotome biopsies performed under US control there were 211 cases of fibroadenomas. Follow-up was performed in 156 patients with this result at 6 and 12 months after biopsy. In our study we took into considerations the size, localizations as well as performers. In 2002 there were 70.8% patients with total lesion excision, 16.7% with residual lesion and 12.5% women with hematomas or scars. In 2003-2004 there were more women with total lesion excision (84.3%), fewer residual tumors and other lesions. In future, Mammotome breast biopsy can replace scalpel, and will become an alternative method to open surgical excision of fibroadenomas. It is important especially in the cases of young women to prevent cosmetic deformations and scars. (author)

  4. Glacial Meltwater Contirbutions to the Bow River, Alberta, Canada

    Science.gov (United States)

    Bash, E. A.; Marshall, S. J.; White, E. C.

    2009-12-01

    Assessment of glacial melt is critical for water resource management in areas which rely on glacier-fed rivers for agricultural and municipal uses. Changes in precipitation patterns coupled with current glacial retreat are altering the glacial contribution to river flow in areas such as the Andes of South America and the high ranges of Asia, as well as the Rockies of Western Canada. Alberta’s Bow River has its headwaters in the eastern slopes of the Canadian Rockies and contributes to the Nelson drainage system feeding into Hudson Bay. The Bow River basin contains several population centers, including the City of Calgary, and is heavily taxed for agricultural use. The combined effects of rapid glacial retreat in the Canadian Rockies, higher drought frequency, and increased demand are likely to heighten water stress in Southern Alberta. However, there has been little focus to date on the extent and importance of glacial meltwater in the Bow River. The Bow River contains 74.5 km2 of glacier ice, which amounts to only 0.29% of the basin. While this number is not high compared to some glacierized areas, Hopkinson and Young (1998) report that in dry years, glacier melt can provide up to 50% of late summer flows at a station in the upper reaches of the river system. We extend this work with an assessment of monthly and annual glacial contributions to the Bow River farther downstream in Calgary. Our analysis is based on mass balance, meteorological, and hydrological data that has been collected at the Haig Glacier since 2001. This data is used in conjunction with glacier coverage and hypsometric data for the remainder of the basin to estimate seasonal snow and glacial meltwater contributions to the Bow River from the glacierized fraction of the catchment. The results of this study show the percentage of total flow attributed to glacial melt to be highly variable. Glacier runoff contributes up to an order of magnitude more water to the Bow River per unit area of

  5. Small Arms of the Scythians. On the Time of Sigmoid Bow Appearance in Eastern Europe

    Directory of Open Access Journals (Sweden)

    Lukyashko Sergey Ivanovich

    2015-12-01

    Full Text Available Horse archers well-known in the ancient world used composite sigmoid bows for shooting (archery, the specific constructive features of which have been studied by the researchers. This type of a bow was convergently formed in Eastern China in the middle of the 2nd millennium B.C. and in the North Caucasus in the middle of the 4th millennium B.C. It gets transferred to the Northern Black Sea Region by the Scythians in the late 7th - early 6th centuries B.C. that resulted in the dramatic transformation of arrowheads’ types. The Greeks became aware of this weapon in the last third of the 6th century B.C. Bows can be divided into simple and complex ones. The simple bows are made from one solid bar, while the complex bows are made of several layers of different wood species. Composite bows are constructed from a few consequently connected bars. These types also include a reinforced bow – the bow springing qualities of which are reinforced by bone or tendon plates. Since the ancient masters combined different production methods, the definition of a composite reinforced bow can be found in the literature. European small arms development was focused on improving a simple bow. The strength of such bow was achieved by its size. However, massive bows are unsuitable for firing from a horse. Therefore, in cultures associated with the development of riding the search of methods of bow strength increase at the condition of reducing its size, was going on. In Asia, the focus was made on the material rather than shoulders design. As a result, complex composite bows appear in the East, which were made from several pieces of wood, connected with the central part of the handle at an angle. After the appearance of the Scythians in the middle East the angular design of bows was replaced by a sigmoid shape (scythicus acrus.

  6. Comparative evaluation of H&H and WFNS grading scales with modified H&H (sans systemic disease): A study on 1000 patients with subarachnoid hemorrhage.

    Science.gov (United States)

    Aggarwal, Ashish; Dhandapani, Sivashanmugam; Praneeth, Kokkula; Sodhi, Harsimrat Bir Singh; Pal, Sudhir Singh; Gaudihalli, Sachin; Khandelwal, N; Mukherjee, Kanchan K; Tewari, M K; Gupta, Sunil Kumar; Mathuriya, S N

    2018-01-01

    The comparative studies on grading in subarachnoid hemorrhage (SAH) had several limitations such as the unclear grading of Glasgow Coma Scale 15 with neurological deficits in World Federation of Neurosurgical Societies (WFNS), and the inclusion of systemic disease in Hunt and Hess (H&H) scales. Their differential incremental impacts and optimum cut-off values for unfavourable outcome are unsettled. This is a prospective comparison of prognostic impacts of grading schemes to address these issues. SAH patients were assessed using WFNS, H&H (including systemic disease), modified H&H (sans systemic disease) and followed up with Glasgow Outcome Score (GOS) at 3 months. Their performance characteristics were analysed as incremental ordinal variables and different grading scale dichotomies using rank-order correlation, sensitivity, specificity, positive predictive value, negative predictive value, Youden's J and multivariate analyses. A total of 1016 patients were studied. As univariate incremental variable, H&H sans systemic disease had the best negative rank-order correlation coefficient (-0.453) with respect to lower GOS (p H&H sans systemic disease had the greatest adjusted incremental impact of 0.72 (95% confidence interval (CI) 0.54-0.91) against a lower GOS as compared to 0.6 (95% CI 0.45-0.74) and 0.55 (95% CI 0.42-0.68) for H&H and WFNS grades, respectively. In multivariate categorical analysis, H&H grades 4-5 sans systemic disease had the greatest impact on unfavourable GOS with an adjusted odds ratio of 6.06 (95% CI 3.94-9.32). To conclude, H&H grading sans systemic disease had the greatest impact on unfavourable GOS. Though systemic disease is an important prognostic factor, it should be considered distinctly from grading. Appropriate cut-off values suggesting unfavourable outcome for H&H and WFNS were 4-5 and 3-5, respectively, indicating the importance of neurological deficits in addition to level of consciousness.

  7. Magnetic field fluctuations across the Earth’s bow shock

    Directory of Open Access Journals (Sweden)

    A. Czaykowska

    Full Text Available We present a statistical analysis of 132 dayside (LT 0700-1700 bow shock crossings of the AMPTE/IRM spacecraft. We perform a superposed epoch analysis of low frequency, magnetic power spectra some minutes up-stream and downstream of the bow shock. The events are devided into categories depending on the angle θBn between bow shock normal and interplanetary magnetic field, and on plasma-β. In the foreshock upstream of the quasi-parallel bow shock, the power of the magnetic fluctuations is roughly 1 order of magnitude larger (δB ~ 4 nT for frequencies 0.01–0.04 Hz than upstream of the quasi-perpendicular shock. There is no significant difference in the magnetic power spectra upstream and downstream of the quasi-parallel bow shock; only at the shock itself, is the magnetic power enhanced by a factor of 4. This enhancement may be due to either an amplification of convecting upstream waves or to wave generation at the shock interface. On the contrary, downstream of the quasi-perpendicular shock, the magnetic wave activity is considerably higher than upstream. Down-stream of the quasi-perpendicular low-β bow shock, we find a dominance of the left-hand polarized component at frequencies just below the ion-cyclotron frequency, with amplitudes of about 3 nT. These waves are identified as ion-cyclotron waves, which grow in a low-β regime due to the proton temperature anisotropy. We find a strong correlation of this anisotropy with the intensity of the left-hand polarized component. Downstream of some nearly perpendicular (θBn ≈ 90° high-β crossings, mirror waves are identified. However, there are also cases where the conditions for mirror modes are met downstream of the nearly perpendicular shock, but no mirror waves are observed.

    Key words. Interplanetary physics (plasma waves and turbulence – Magnetospheric physics (magnetosheath; plasma waves and

  8. Magnetic field fluctuations across the Earth’s bow shock

    Directory of Open Access Journals (Sweden)

    A. Czaykowska

    2001-03-01

    Full Text Available We present a statistical analysis of 132 dayside (LT 0700-1700 bow shock crossings of the AMPTE/IRM spacecraft. We perform a superposed epoch analysis of low frequency, magnetic power spectra some minutes up-stream and downstream of the bow shock. The events are devided into categories depending on the angle θBn between bow shock normal and interplanetary magnetic field, and on plasma-β. In the foreshock upstream of the quasi-parallel bow shock, the power of the magnetic fluctuations is roughly 1 order of magnitude larger (δB ~ 4 nT for frequencies 0.01–0.04 Hz than upstream of the quasi-perpendicular shock. There is no significant difference in the magnetic power spectra upstream and downstream of the quasi-parallel bow shock; only at the shock itself, is the magnetic power enhanced by a factor of 4. This enhancement may be due to either an amplification of convecting upstream waves or to wave generation at the shock interface. On the contrary, downstream of the quasi-perpendicular shock, the magnetic wave activity is considerably higher than upstream. Down-stream of the quasi-perpendicular low-β bow shock, we find a dominance of the left-hand polarized component at frequencies just below the ion-cyclotron frequency, with amplitudes of about 3 nT. These waves are identified as ion-cyclotron waves, which grow in a low-β regime due to the proton temperature anisotropy. We find a strong correlation of this anisotropy with the intensity of the left-hand polarized component. Downstream of some nearly perpendicular (θBn ≈ 90° high-β crossings, mirror waves are identified. However, there are also cases where the conditions for mirror modes are met downstream of the nearly perpendicular shock, but no mirror waves are observed.Key words. Interplanetary physics (plasma waves and turbulence – Magnetospheric physics (magnetosheath; plasma waves and instabilities

  9. Bovine exome sequence analysis and targeted SNP genotyping of recessive fertility defects BH1, HH2, and HH3 reveal a putative causative mutation in SMC2 for HH3.

    Science.gov (United States)

    McClure, Matthew C; Bickhart, Derek; Null, Dan; Vanraden, Paul; Xu, Lingyang; Wiggans, George; Liu, George; Schroeder, Steve; Glasscock, Jarret; Armstrong, Jon; Cole, John B; Van Tassell, Curtis P; Sonstegard, Tad S

    2014-01-01

    The recent discovery of bovine haplotypes with negative effects on fertility in the Brown Swiss, Holstein, and Jersey breeds has allowed producers to identify carrier animals using commercial single nucleotide polymorphism (SNP) genotyping assays. This study was devised to identify the causative mutations underlying defective bovine embryo development contained within three of these haplotypes (Brown Swiss haplotype 1 and Holstein haplotypes 2 and 3) by combining exome capture with next generation sequencing. Of the 68,476,640 sequence variations (SV) identified, only 1,311 genome-wide SNP were concordant with the haplotype status of 21 sequenced carriers. Validation genotyping of 36 candidate SNP identified only 1 variant that was concordant to Holstein haplotype 3 (HH3), while no variants located within the refined intervals for HH2 or BH1 were concordant. The variant strictly associated with HH3 is a non-synonymous SNP (T/C) within exon 24 of the Structural Maintenance of Chromosomes 2 (SMC2) on Chromosome 8 at position 95,410,507 (UMD3.1). This polymorphism changes amino acid 1135 from phenylalanine to serine and causes a non-neutral, non-tolerated, and evolutionarily unlikely substitution within the NTPase domain of the encoded protein. Because only exome capture sequencing was used, we could not rule out the possibility that the true causative mutation for HH3 might lie in a non-exonic genomic location. Given the essential role of SMC2 in DNA repair, chromosome condensation and segregation during cell division, our findings strongly support the non-synonymous SNP (T/C) in SMC2 as the likely causative mutation. The absence of concordant variations for HH2 or BH1 suggests either the underlying causative mutations lie within a non-exomic region or in exome regions not covered by the capture array.

  10. Bovine exome sequence analysis and targeted SNP genotyping of recessive fertility defects BH1, HH2, and HH3 reveal a putative causative mutation in SMC2 for HH3.

    Directory of Open Access Journals (Sweden)

    Matthew C McClure

    Full Text Available The recent discovery of bovine haplotypes with negative effects on fertility in the Brown Swiss, Holstein, and Jersey breeds has allowed producers to identify carrier animals using commercial single nucleotide polymorphism (SNP genotyping assays. This study was devised to identify the causative mutations underlying defective bovine embryo development contained within three of these haplotypes (Brown Swiss haplotype 1 and Holstein haplotypes 2 and 3 by combining exome capture with next generation sequencing. Of the 68,476,640 sequence variations (SV identified, only 1,311 genome-wide SNP were concordant with the haplotype status of 21 sequenced carriers. Validation genotyping of 36 candidate SNP identified only 1 variant that was concordant to Holstein haplotype 3 (HH3, while no variants located within the refined intervals for HH2 or BH1 were concordant. The variant strictly associated with HH3 is a non-synonymous SNP (T/C within exon 24 of the Structural Maintenance of Chromosomes 2 (SMC2 on Chromosome 8 at position 95,410,507 (UMD3.1. This polymorphism changes amino acid 1135 from phenylalanine to serine and causes a non-neutral, non-tolerated, and evolutionarily unlikely substitution within the NTPase domain of the encoded protein. Because only exome capture sequencing was used, we could not rule out the possibility that the true causative mutation for HH3 might lie in a non-exonic genomic location. Given the essential role of SMC2 in DNA repair, chromosome condensation and segregation during cell division, our findings strongly support the non-synonymous SNP (T/C in SMC2 as the likely causative mutation. The absence of concordant variations for HH2 or BH1 suggests either the underlying causative mutations lie within a non-exomic region or in exome regions not covered by the capture array.

  11. A MULTI-WAVELENGTH STUDY OF THE STAR-FORMING CORE AHEAD OF HH 80N

    International Nuclear Information System (INIS)

    Masque, Josep M.; Estalella, Robert; Osorio, Mayra; Anglada, Guillem; Girart, Josep M.; Garay, Guido; Calvet, Nuria; Beltran, Maria T.

    2011-01-01

    We present observations of continuum emission in the mid-infrared to millimeter wavelength range, complemented with ammonia observations, of the dense core ahead of the radio Herbig-Haro (HH) object HH 80N, found in the GGD 27 region. The continuum emission in all the observed bands peaks at the same position, consistent with the presence of an embedded object, HH 80N-IRS1, within the core. The distribution of the Very Large Array ammonia emission is well correlated with that of the dust, suggesting that photochemical effects caused by the nearby HH object do not play an important role in shaping this particular molecular emission. In order to unveil the nature of HH 80N-IRS1, we analyzed the continuum data of this source, using self-consistent models of protostellar collapse. We find that a young protostar surrounded by a slowly rotating collapsing envelope of radius ∼0.08 pc and 20 M sun plus a circumstellar disk of radius ∼300 AU and 0.6 M sun provide a good fit to the observed spectral energy distribution and to the maps at 350 μm, 1.2 mm, and 3.5 mm of HH 80N-IRS1. Besides, the Atacama Pathfinder Experiment and Plateau de Bure Interferometer continuum maps at 350 μm and 3.5 mm, respectively, reveal additional clumps in the continuum emission. Given the modeling results and the observed morphology of the emission, we propose a scenario consisting of a central embedded Class 0 object, HH 80N-IRS1, with the rest of the material of the HH 80N core possibly undergoing fragmentation that may lead to the formation of several protostars.

  12. Electrostatic and electromagnetic turbulence associated with the Earth's bow shock

    International Nuclear Information System (INIS)

    Rodriguez, P.

    1974-01-01

    The electric and magnetic field spectral densities of plasma waves in the earth's bow shock have been measured in the frequency range 20 Hz to 200 kHz using two 16-channel spectrum analyzers on the IMP-6 spacecraft. Electrostatic noise with a spectrum similar to the turbulence in the shock, but with lower intensities, is observed throughout the magnetosheath region, downstream of the shock. The intensity of the electrostatic component of turbulence in the bow shock increases as the upstream electron to ion temperature ratio increases, and decreases as the upstream sound velocity increases; both of these variations for the electrostatic component are consistent with ion sound wave turbulence. (U.S.)

  13. H2 profiles of C-type bow shocks

    International Nuclear Information System (INIS)

    Smith, M.D.; Brand, P.W.J.L.

    1990-01-01

    We present emission-line profiles of molecular hydrogen from curved C-shocks within molecular clouds. Shock configurations arising from the supersonic motion of jets and bullets within a dense cloud are chosen. Bow shock speeds in the range υ w = 40-200 km s -1 are investigated. Breakdown through dissociation and self-ionization restricts the C-shock section to the bow tail. We find that profiles are essentially single-peaked and narrow with full widths (at 10 per cent maximum intensity, deconvolved) of up to about 50, 40 and 30 km s -1 for cones, hemispherical caps and paraboloids, respectively. Exceptional field alignments can produce lines as wide as 75 km s -1 in the conical shock model. (author)

  14. Arctic Bowyery – The Use of Compression Wood in Bows in the Subarctic and Arctic Regions of Eurasia and America

    Directory of Open Access Journals (Sweden)

    Marcus Lepola

    2015-06-01

    Full Text Available This paper is a study of the traditional use of a special kind of wood in bow construction in Eurasia and North America. This special kind of wood, called compression wood and coming from coniferous trees, has unique qualities that makes it suitable for bow construction. Bows made using this special wood have been referred to as Finno-Ugric bows, Sámi bows, Two-Wood bows and Eurasia laminated bows. These bows appear to have developed from archaic forms of compression wood self bows that were made from a single piece of wood. Recently features similar to the Eurasian compression wood bows have been discovered in bows originating from Alaska, and the use of compression wood for bow manufacture has been known to some Canadian Inuit groups. This paper addresses the origin and possible diffusion pattern of this innovation in bow technology in Eurasia and suggests a timeframe and a possible source for the transfer of this knowledge to North America. This paper also discusses the role of the Asiatic composite bow in the development of bows in Eurasia.

  15. Organizing learning processes on risks by using the bow-tie representation

    Energy Technology Data Exchange (ETDEWEB)

    Chevreau, F.R. [Ecole des Mines de Paris, 06904 Sophia-Antipolis (France)]. E-mail: chevreau@cindy.ensmp.fr; Wybo, J.L. [Ecole des Mines de Paris, 06904 Sophia-Antipolis (France)]. E-mail: wybo@cindy.ensmp.fr; Cauchois, D. [Process Safety Department, Sanofi-Aventis, Site de Production de Vitry sur Seine, 9 Quai Jules Guesdes, 94400 Vitry sur Seine (France)]. E-mail: didier.cauchois@sanofi-aventis.com

    2006-03-31

    The Aramis method proposes a complete and efficient way to manage risk analysis by using the bow-tie representation. This paper shows how the bow-tie representation can also be appropriate for experience learning. It describes how a pharmaceutical production plant uses bow-ties for incident and accident analysis. Two levels of bow-ties are constructed: standard bow-ties concern generic risks of the plant whereas local bow-ties represent accident scenarios specific to each workplace. When incidents or accidents are analyzed, knowledge that is gained is added to existing local bow-ties. Regularly, local bow-ties that have been updated are compared to standard bow-ties in order to revise them. Knowledge on safety at the global and at local levels is hence as accurate as possible and memorized in a real time framework. As it relies on the communication between safety experts and local operators, this use of the bow-ties contributes therefore to organizational learning for safety.

  16. Organizing learning processes on risks by using the bow-tie representation

    International Nuclear Information System (INIS)

    Chevreau, F.R.; Wybo, J.L.; Cauchois, D.

    2006-01-01

    The Aramis method proposes a complete and efficient way to manage risk analysis by using the bow-tie representation. This paper shows how the bow-tie representation can also be appropriate for experience learning. It describes how a pharmaceutical production plant uses bow-ties for incident and accident analysis. Two levels of bow-ties are constructed: standard bow-ties concern generic risks of the plant whereas local bow-ties represent accident scenarios specific to each workplace. When incidents or accidents are analyzed, knowledge that is gained is added to existing local bow-ties. Regularly, local bow-ties that have been updated are compared to standard bow-ties in order to revise them. Knowledge on safety at the global and at local levels is hence as accurate as possible and memorized in a real time framework. As it relies on the communication between safety experts and local operators, this use of the bow-ties contributes therefore to organizational learning for safety

  17. Thermally-induced bowing of CANDU fuel elements

    International Nuclear Information System (INIS)

    Suk, H.C.; Sim, K.S.; Park, J.H.; Park, G.S.

    1995-01-01

    Considering only the thermally-induced bending moments which are generated both within the sheath and between the fuel and sheath by an asymmetric temperature distribution with respect to the axis of an element, a generalized and explicit analytical formula for the thermally-induced bending is developed in this paper, based on the cases of 1) the bending of an empty tube treated by neglecting of the fuel/sheath mechanical interaction and 2) the fuel/sheath interaction due to the pellet and sheath temperature variations. In each of the cases, the temperature asymmetries in sheath are modelled to be caused by the combined effects of (i) non-uniform coolant temperature due to imperfect coolant mixing, (ii) variable sheath/coolant heat transfer coefficient, (iii) asymmetric heat generation due to neutron flux gradients across an element and so as to inclusively cover the uniform temperature distributions within the fuel and sheath with respect to the axial centerline. Investigating the relative importance of the various parameters affecting fuel element bowing, the element bowing is found to be greatly affected with the variations of element length, sheath diameter, pellet/sheath mechanical interaction and neutron flux depression factors, pellet thermal expansion coefficient, pellet/sheath heat transfer coefficient in comparison with those of other parameters such as sheath thickness, film heat transfer coefficient, sheath thermal expansion coefficient, and sheath and pellet thermal conductivities. Also, the element bowing of the standard 37-element bundle and CANFLEX 43-element bundle for the use in CANDU-6 reactors was analyzed with the formula, which could help to demonstrate the integrity of the fuel. All the required input data for the analyses were generated in terms of the reactor operation conditions on the reactor physics, thermal hydraulics and fuel performance by using various CANDU computer codes. The analysis results indicate that the CANFLEX 43-element

  18. Bowing to the Dharma: Japanese Buddhist Women Leaders & Healers

    Directory of Open Access Journals (Sweden)

    Paula Arai

    2017-11-01

    Full Text Available The prodigious stream of Japanese Buddhist women in roles of leadership and healing extends the length of Japanese Buddhist history. This article will highlight the transformative power of bowing that helped galvanize Sōtō Zen nuns on the eve of the twentieth century and feature twentieth-century leaders who institutionalized their disciplined commitments. It will also offer a window into the creative healing practices that characterizes women’s activity in the home.

  19. Plasma waves in the Earth's foreshock, bow shock, and magnetosheath

    International Nuclear Information System (INIS)

    Onsager, T.G.

    1988-01-01

    The research presented in this dissertation is a detailed analysis of electrostatic waves in the Earth's foreshock, bow shock, and magnetosheath. The wave modes measured in these regions, the possible generation mechanisms, and the process which drive the plasma to its unstable state are investigated. The measurements used in this study were obtained from the plasma wave receiver, the particle instrument, and the magnetometer on board the Active Magnetospheric Particle Tracer Explorer (AMPTE) Ion Release Module (IRM). Electron beam mode waves have been identified in the Earth's foreshock. A technique is developed which allows the rest frame frequency and wave number of the electron beam mode waves to be determined from the measurements. The experimentally determined values are compared with theoretical predictions, and approximate limits are put on the beam temperatures. It is demonstrated that electrostatic waves are present in the bow shock and magnetosheath with frequencies above the maximum frequency for Doppler shifted ion acoustic waves, yet below the Langmuir frequency. Waves in this frequency range are tentatively identified as electron beam mode waves. This identification is based on the measured frequencies and electric field polarization directions. Data from 45 bow shock crossings are then used to investigate possible correlations between the electron beam mode waves and the near shock plasma parameters. The best correlations are found with Alfven Mach number and electron beta. Possible mechanism which might produce electron beams in the shock and magnetosheath are discussed in terms of the correlation study results

  20. PLANETARY EMBRYO BOW SHOCKS AS A MECHANISM FOR CHONDRULE FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Christopher R.; Boley, Aaron C. [Department of Physics and Astronomy University of British Columbia Vancouver, BC V6T 1Z1 (Canada); Morris, Melissa A. [Physics Department State University of New York at Cortland Cortland, NY 13045 (United States)

    2016-02-20

    We use radiation hydrodynamics with direct particle integration to explore the feasibility of chondrule formation in planetary embryo bow shocks. The calculations presented here are used to explore the consequences of a Mars-size planetary embryo traveling on a moderately excited orbit through the dusty, early environment of the solar system. The embryo’s eccentric orbit produces a range of supersonic relative velocities between the embryo and the circularly orbiting gas and dust, prompting the formation of bow shocks. Temporary atmospheres around these embryos, which can be created via volatile outgassing and gas capture from the surrounding nebula, can non-trivially affect thermal profiles of solids entering the shock. We explore the thermal environment of solids that traverse the bow shock at different impact radii, the effects that planetoid atmospheres have on shock morphologies, and the stripping efficiency of planetoidal atmospheres in the presence of high relative winds. Simulations are run using adiabatic and radiative conditions, with multiple treatments for the local opacities. Shock speeds of 5, 6, and 7 km s{sup −1} are explored. We find that a high-mass atmosphere and inefficient radiative conditions can produce peak temperatures and cooling rates that are consistent with the constraints set by chondrule furnace studies. For most conditions, the derived cooling rates are potentially too high to be consistent with chondrule formation.

  1. Observations of high-velocity molecular gas near Herbig-Haro objects: HH 24--27 and HH 1--2

    International Nuclear Information System (INIS)

    Snell, R.L.; Edwards, S.

    1982-01-01

    High-velocity CO has been detected in the vicinity of the Herbig-Haro objects HH 24--27. These observations indicate that there are two sources of high-velocity outflow; one centered on an infrared source near HH 26, and the second centered roughly 2' south of HH 24. The redshifted and blueshifted wings in both sources are spatially separated suggesting that the high-velocity gas is due to energetic bipolar outflow from young stars embedded in the molecular cloud. The association of Herbig-Haro objects with regions of high-velocity gas suggests a common origin for both in the interaction of a stellar wind with the ambient molecular cloud. The mass loss rates implied by our observations, assuming that the rate of mass loss has been constant throughout the dynamical lifetime of the bipolar lobes, are roughly 10 -6 M/sub sun/ yr -1 for both sources. We have also searched for high-velocity gas near HH 1--2 but found no evidence for mass outflow in this region

  2. Dependence of sound characteristics on the bowing position in a violin

    Science.gov (United States)

    Roh, YuJi; Kim, Young H.

    2014-12-01

    A quantitative analysis of violin sounds produced for different bowing positions over the full length of a violin string has been carried out. An automated bowing machine was employed in order to keep the bowing parameters constant. A 3-dimensional profile of the frequency spectrum was introduced in order to characterize the violin's sound. We found that the fundamental frequency did not change for different bowing positions, whereas the frequencies of the higher harmonics were different. Bowing the string at 30 mm from the bridge produced musical sounds. The middle of the string was confirmed to be a dead zone, as reported in previous works. In addition, the quarter position was also found to be a dead zone. Bowing the string 90 mm from the bridge dominantly produces a fundamental frequency of 864 Hz and its harmonics.

  3. On the stability of bow shocks generated by red supergiants: the case of IRC -10414

    Science.gov (United States)

    Meyer, D. M.-A.; Gvaramadze, V. V.; Langer, N.; Mackey, J.; Boumis, P.; Mohamed, S.

    2014-03-01

    In this Letter, we explore the hypothesis that the smooth appearance of bow shocks around some red supergiants (RSGs) might be caused by the ionization of their winds by external sources of radiation. Our numerical simulations of the bow shock generated by IRC -10414 (the first-ever RSG with an optically detected bow shock) show that the ionization of the wind results in its acceleration by a factor of 2, which reduces the difference between the wind and space velocities of the star and makes the contact discontinuity of the bow shock stable for a range of stellar space velocities and mass-loss rates. Our best-fitting model reproduces the overall shape and surface brightness of the observed bow shock and suggests that the space velocity and mass-loss rate of IRC -10414 are ≈50 km s-1 and ≈10-6 M⊙ yr-1, respectively, and that the number density of the local interstellar medium is ≈3 cm-3. It also shows that the bow shock emission comes mainly from the shocked stellar wind. This naturally explains the enhanced nitrogen abundance in the line-emitting material, derived from the spectroscopy of the bow shock. We found that photoionized bow shocks are ≈15-50 times brighter in optical line emission than their neutral counterparts, from which we conclude that the bow shock of IRC -10414 must be photoionized.

  4. PROPER MOTIONS OF THE OUTER KNOTS OF THE HH 80/81/80N RADIO-JET

    Energy Technology Data Exchange (ETDEWEB)

    Masqué, Josep M.; Rodriguez, Luis F.; Carrasco-González, Carlos [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58089, México (Mexico); Araudo, Anabella [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Estalella, Robert [Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos (IEEC-UB), Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Catalunya (Spain); Anglada, Guillem; Osorio, Mayra [Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, E-18080 Granada (Spain); Girart, Josep M. [Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193 Cerdanyola del Vallès, Catalunya (Spain)

    2015-11-20

    The radio-knots of the Herbig–Haro (HH) 80/81/80N jet extend from the HH 80 object to the recently discovered Source 34 and has a total projected jet size of 10.3 pc, constituting the largest collimated radio-jet system known so far. It is powered by the bright infrared source IRAS 18162−2048 associated with a massive young stellar object. We report 6 cm JVLA observations that, compared with previous 6 cm VLA observations carried out in 1989, allow us to derive proper motions of the HH 80, HH 81, and HH 80N radio knots located about 2.5 pc away in projection from the powering source. For the first time, we measure proper motions of the optically obscured HH 80N object providing evidence that this knot, along with HH 81 and HH 80 are associated with the same radio-jet. We also confirm the presence of Source 34, located further north of HH 80N, previously proposed to belong to the jet.We derived that the tangential velocity of HH 80N is 260 km s{sup −1} and has a direction in agreement with the expected direction of a ballistic precessing jet. The HH 80 and HH 81 objects have tangential velocities of 350 and 220 km s{sup −1}, respectively, but their directions are somewhat deviated from the expected jet path. The velocities of the HH objects studied in this work are significantly lower than those derived for the radio knots of the jet close to the powering source (600–1400 km s{sup −1}) suggesting that the jet is slowing down due to a strong interaction with the ambient medium. As a result, since HH 80 and HH 81 are located near the edge of the cloud, the inhomogeneous and low density medium may contribute to skew the direction of their determined proper motions. The HH 80 and HH 80N emission at 6 cm is, at least in part, probably synchrotron radiation produced by relativistic electrons in a magnetic field of 1 mG. If these electrons are accelerated in a reverse adiabatic shock, we estimate a jet total density of ≲1000 cm{sup −3}. All of these

  5. Effective Maxillary Protraction with Tandem Traction Bow Appliance

    Directory of Open Access Journals (Sweden)

    Pravin Kumar S Marure

    2014-01-01

    Full Text Available Tandem traction bow appliance (TTBA promotes patient compliance, because it is more esthetic and comfortable than extraoral appliances. TTBA should be used only in case where maxillary deficiency and normal mandible is present. Advantages of it includes good oral hygiene, early treatment of any Class III malocclusion, optimal retention, distribution of the forces for protraction to all maxillary teeth, free mandibular movement. It can be used in conjunction with fixed appliances if necessary. This paper includes two case reports. The treatment results in both the cases demonstrated significant skeletal and dental response to TTBA therapy. Skeletal change was primarily a result of anterior movement of the maxilla.

  6. Electromagnetic ion beam instability upstream of the earth's bow shock

    International Nuclear Information System (INIS)

    Gary, S.P.; Gosling, J.T.; Forslund, D.W.

    1981-01-01

    The linear theory of the electromagnetic ion beam instability for arbitrary angles of propagation has been studied. The parameters considered in the theory are typical of the solar wind upstream of the earth's bow shock when a 'reflected' proton beam is present. Maximum growth occurs for propagation parallel to the ambient field B, but this instability also displays significant growth at wave-vectors oblique to B, Oblique, unstable modes seem to be the likely source of the compressive magnetic fluctuations recently observed in conjunction with 'diffuse' ion population. An energetic ion beam does not directly give rise to linear growth of either ion acoustic or whistler mode instabilities

  7. Relative locations of the bow shocks of the terrestrial planets

    International Nuclear Information System (INIS)

    Russell, C.T.

    1977-01-01

    The observed bow shock encounters at Mercury, Venus and Mars are least square fit using the same technique so that their sizes and shapes can be intercompared. The shock front of Mercury most resembles the terrestrial shock in shape, and the shock stand off distance is consistent with the observed moment. The shapes of the Venus and Mars shock fronts more resemble each other than the earth's and the stand off distances are consistent with direct interaction of the solar wind with the ionosphere on the dayside. The Venus shock is closer to the planet than the Mars shock suggesting more absorption of the solar wind at Venus

  8. Cross-talk studies between FCC-hh Experimental Interaction Regions

    CERN Document Server

    AUTHOR|(CDS)2081283; Seryi, Andrei; Appleby, Robert Barrie; Rafique, Haroon; Besana, Maria Ilaria

    2017-01-01

    Debris from 50 TeV proton-proton collisions at the main interaction point in the FCC-hh may contribute to the background in the subsequent detector. This cross-talk is of possible concern for the FCC-hh due to the high luminosity and energy of the collider. DPMJET-III is used as a collision debris generator in order to assess the muon cross-talk contribution. An analytical calculation of muon range in rock is performed. This is followed by a full Monte Carlo simulation using FLUKA, where the accelerator tunnel has been modelled. The muon cross talk between the adjacent interaction points is assessed and its implications for FCC-hh design are discussed.

  9. First Design of a Proton Collimation System for 50 TeV FCC-hh

    CERN Document Server

    Fiascaris, Maria; Mirarchi, Daniele; Redaelli, Stefano

    2016-01-01

    We present studies aimed at defining a first conceptual solution for a collimation system for the hadron-hadron option for the Future Circular Collider (FCC-hh). The baseline collimation layout is based on the scaling of the present LHC collimation system to the FCC-hh energy. It currently includes a dedicated betatron cleaning insertion as well as collimators in the experimental insertions to protect the inner triplets. An aperture model for the FCC-hh is defined and the geometrical acceptance is calculated at top energy taking into account mechanical and optics imperfections. Based on these studies the collimator settings needed to protect the machine are defined. The performance of the collimation system is then assessed with particle tracking simulation tools assuming a perfect machine.

  10. Considerations on operation schedule and maintenance aspects of FCC-hh

    CERN Document Server

    Niemi, Arto; Foraz, Katy

    2018-01-01

    The Future Circular Hadron Collider (FCC-hh) has ambitious goals for integrated luminosity production. Reaching these goals requires reducing the time for planned technical stops and commissioning, compared to the LHC. This note describes potential options for an FCC-hh operation schedule. Special attention is given to considerations on how to accomplish the required maintenance activities in a limited time frame. The note recommends to study further the feasibility and cost-efficiency of operating without annual stops and longer intervals between long shutdowns.

  11. Updates on the optics of the future hadron-hadron collider FCC-hh

    CERN Document Server

    AUTHOR|(CDS)2093721; Boutin, David Jean Henri; Dalena, Barbara; Holzer, Bernhard; Langner, Andy Sven; Schulte, Daniel

    2017-01-01

    The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the three options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The layout of FCC-hh has been optimized to a more compact design following recommendations from civil engineering aspects. The updates on the first order and second order optics of the ring will be shown for collisions at the required centre-of-mass energy of 100 TeV. Special emphasis is put on the dispersion suppressors and general beam cleaning sections as well as first considerations of injection and extraction sections.

  12. The bowing potential of granitic rocks: rock fabrics, thermal properties and residual strain

    Science.gov (United States)

    Siegesmund, S.; Mosch, S.; Scheffzük, Ch.; Nikolayev, D. I.

    2008-10-01

    The bowing of natural stone panels is especially known for marble slabs. The bowing of granite is mainly known from tombstones in subtropical humid climate. Field inspections in combination with laboratory investigations with respect to the thermal expansion and the bowing potential was performed on two different granitoids (Cezlak granodiorite and Flossenbürg granite) which differ in the composition and rock fabrics. In addition, to describe and explain the effect of bowing of granitoid facade panels, neutron time-of-flight diffraction was applied to determine residual macro- and microstrain. The measurements were combined with investigations of the crystallographic preferred orientation of quartz and biotite. Both samples show a significant bowing as a function of panel thickness and destination temperature. In comparison to marbles the effect of bowing is more pronounced in granitoids at temperatures of 120°C. The bowing as well as the thermal expansion of the Cezlak sample is also anisotropic with respect to the rock fabrics. A quantitative estimate was performed based on the observed textures. The effect of the locked-in stresses may also have a control on the bowing together with the thermal stresses related to the different volume expansion of the rock-forming minerals.

  13. Quasi-perpendicular/quasi-parallel divisions of Earth's bow shock

    International Nuclear Information System (INIS)

    Greenstadt, E.W.

    1991-01-01

    Computer-drawn diagrams of the boundaries between quasi-perpendicular and quasi-parallel areas of Earth's bow shock are displayed for a few selected cone angles of static interplanetary magnetic field (IMF). The effect on the boundary of variable IMF in the foreshock is also discussed and shown for one nominal case. The boundaries demand caution in applying them to the realistic, dynamic conditions of the solar wind and in interpreting the effects of small cone angles on the distributions of structures at the shock. However, the calculated, first-order boundaries are helpful in defining areas of the shock where contributions from active structures inherent in quasi-parallel geometry may be distinguishable from those derived secondarily from upstream reflected ion dynamics. The boundaries are also compatible with known behavior of daytime ULF geomagnetic waves and pulsations according to models postulating that cone angle-controlled, time-dependent ULF activity around the subsolar point of the bow shock provides the source of geomagnetic excitation

  14. Quasilinear simulations of interplanetary shocks and Earth's bow shock

    Science.gov (United States)

    Afanasiev, Alexandr; Battarbee, Markus; Ganse, Urs; Vainio, Rami; Palmroth, Minna; Pfau-Kempf, Yann; Hoilijoki, Sanni; von Alfthan, Sebastian

    2016-04-01

    We have developed a new self-consistent Monte Carlo simulation model for particle acceleration in shocks. The model includes a prescribed large-scale magnetic field and plasma density, temperature and velocity profiles and a self-consistently computed incompressible ULF foreshock under the quasilinear approximation. Unlike previous analytical treatments, our model is time dependent and takes full account of the anisotropic particle distributions and scattering in the wave-particle interaction process. We apply the model to the problem of particle acceleration at traveling interplanetary (IP) shocks and Earth's bow shock and compare the results with hybrid-Vlasov simulations and spacecraft observations. A qualitative agreement in terms of spectral shape of the magnetic fluctuations and the polarization of the unstable mode is found between the models and the observations. We will quantify the differences of the models and explore the region of validity of the quasilinear approach in terms of shock parameters. We will also compare the modeled IP shocks and the bow shock, identifying the similarities and differences in the spectrum of accelerated particles and waves in these scenarios. The work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA). The Academy of Finland is thanked for financial support. We acknowledge the computational resources provided by CSC - IT Centre for Science Ltd., Espoo.

  15. Lunar Surface Potential Increases during Terrestrial Bow Shock Traversals

    Science.gov (United States)

    Collier, Michael R.; Stubbs, Timothy J.; Hills, H. Kent; Halekas, Jasper; Farrell, William M.; Delory, Greg T.; Espley, Jared; Freeman, John W.; Vondrak, Richard R.; Kasper, Justin

    2009-01-01

    Since the Apollo era the electric potential of the Moon has been a subject of interest and debate. Deployed by three Apollo missions, Apollo 12, Apollo 14 and Apollo 15, the Suprathermal Ion Detector Experiment (SIDE) determined the sunlit lunar surface potential to be about +10 Volts using the energy spectra of lunar ionospheric thermal ions accelerated toward the Moon. We present an analysis of Apollo 14 SIDE "resonance" events that indicate the lunar surface potential increases when the Moon traverses the dawn bow shock. By analyzing Wind spacecraft crossings of the terrestrial bow shock at approximately this location and employing current balancing models of the lunar surface, we suggest causes for the increasing potential. Determining the origin of this phenomenon will improve our ability to predict the lunar surface potential in support of human exploration as well as provide models for the behavior of other airless bodies when they traverse similar features such as interplanetary shocks, both of which are goals of the NASA Lunar Science Institute's Dynamic Response of the Environment At the Moon (DREAM) team.

  16. Electron velocity distributions near the earth's bow shock

    International Nuclear Information System (INIS)

    Feldman, W.C.; Anderson, R.C.; Bame, S.J.; Gary, S.P.; Gosling, J.T.; McComas, D.J.; Thomsen, M.F.; Paschmann, G.; Hoppe, M.M.

    1983-01-01

    A survey of two-dimensional electron velocity distributions, f(V), measured near the earth's bow shock using Los Alamos/Garching plasma instrumentation aboard ISEE 2 is presented. This survey provides clues to the mechanisms of electron thermalization within the shock and the relaxation of both the upsteam and downstream velocity distributions. First, near the foreshock boundary, fluxes of electrons having a power law shape at high energies backstream from the shock. Second, within the shock, cuts through f(V) along B. f(V), often show single maxima offset toward the magnetosheath by speeds comparable to, but larger than, the upstream thermal speed.Third, magnetosheath distributions generally have flat tops out to an energy, E 0 , with maxima substantially lower than that in the solar wind. Occasionally, cuts through f(V) along B show one and sometimes two small peaks at the edge of the flat tops making them appear concave upward. The electron distributions characteristic of these three regions are interpreted as arising from the effects of macroscopic (scale size comparable to or larger than the shock width) electric and magnetic fields and the subsequent effects of microscopic (scale size small in comparison with the shock width) fields. In particular, our results suggest that field-aligned instabilities are likely to be present in the earth's bow shock

  17. Dynamic risk analysis using bow-tie approach

    International Nuclear Information System (INIS)

    Khakzad, Nima; Khan, Faisal; Amyotte, Paul

    2012-01-01

    Accident probability estimation is a common and central step to all quantitative risk assessment methods. Among many techniques available, bow-tie model (BT) is very popular because it represent the accident scenario altogether including causes and consequences. However, it suffers a static structure limiting its application in real-time monitoring and probability updating which are key factors in dynamic risk analysis. The present work is focused on using BT approach in a dynamic environment in which the occurrence probability of accident consequences changes. In this method, on one hand, failure probability of primary events of BT, leading to the top event, are developed using physical reliability models, and constantly revised as physical parameters (e.g., pressure, velocity, dimension, etc) change. And, on the other hand, the failure probability of safety barriers of the BT are periodically updated using Bayes’ theorem as new information becomes available over time. Finally, the resulting, updated BT is used to estimate the posterior probability of the consequences which in turn results in an updated risk profile. - Highlights: ► A methodology is proposed to make bow-tie method adapted for dynamic risk analysis. ► Physical reliability models are used to revise the top event. ► Bayes’ theorem is used to update the probability of safety barriers. ► The number of accidents in sequential time intervals is used to form likelihood function. ► The risk profile is updated for varying physical parameters and for different times.

  18. Dissipation Mechanisms and Particle Acceleration at the Earth's Bow Shock

    Science.gov (United States)

    Desai, M. I.; Burch, J. L.; Broll, J. M.; Genestreti, K.; Torbert, R. B.; Ergun, R.; Wei, H.; Giles, B. L.; Russell, C. T.; Phan, T.; Chen, L. J.; Lai, H.; Wang, S.; Schwartz, S. J.; Allen, R. C.; Mauk, B.; Gingell, I.

    2017-12-01

    NASA's Magnetospheric Multiscale (MMS) mission has four spacecraft equipped with identical state-of-the-art instruments that acquire magnetic and electric field, plasma wave, and particle data at unprecedented temporal resolution to study the fundamental physics of magnetic reconnection in the Earth's magnetosphere. During Phase 1a, MMS also encountered and crossed the Earth's bow shock more than 300 times. We use burst data during 2 bow shock crossings to shed new light on key open questions regarding the formation, evolution, and dissipation mechanisms at collisionless shocks. Specifically, we focus on two events that exhibit clear differences in the ion and electron properties, the associated wave activity, and, therefore in the nature of the dissipation. In the case of a quasi-perpendicular, low beta shock crossing, we find that the dissipation processes are most likely associated with field-aligned electron beams that are coincident with high frequency electrostatic waves. On the other hand, the dissipation processes at an oblique, high beta shock crossing are largely governed by the quasi-static electric field and generation of magnetosonic whistler waves that result in perpendicular temperature anisotropy for the electrons. We also discuss the implications of these results for ion heating, reflection, and particle acceleration.

  19. Multispacecraft observations of the terrestrial bow shock and magnetopause during extreme solar wind disturbances

    DEFF Research Database (Denmark)

    Tatrallyay, M.; Erdos, G.; Nemeth, Z.

    2012-01-01

    by the Cluster spacecraft were best predicted by the 3-D model of Lin et al. (2010). The applied empirical bow shock models and the 3-D semi-empiric bow shock model combined with magnetohydrodynamic (MHD) solution proved to be insufficient for predicting the observed unusual bow shock locations during large...... interplanetary disturbances. The results of a global 3-D MHD model were in good agreement with the Cluster observations on 17 January 2005, but they did not predict the bow shock crossings on 31 October 2003....... of three magnetopause and four bow shock models which describe them in considerably different ways using statistical methods based on observations. A new 2-D magnetopause model is introduced (based on Verigin et al., 2009) which takes into account the pressure of the compressed magnetosheath field raised...

  20. 76 FR 78234 - Medicine Bow-Routt National Forests and Thunder Basin National Grassland, Campbell County, WY...

    Science.gov (United States)

    2011-12-16

    ... DEPARTMENT OF AGRICULTURE Forest Service Medicine Bow-Routt National Forests and Thunder Basin... Supervisor, Medicine Bow-Routt National Forests and Thunder Basin National Grassland, 2250 East Richards.... Responsible Official Richard Cooksey, Deputy Forest Supervisor, Medicine Bow-Routt National Forests and...

  1. Overview of design development of FCC-hh Experimental Interaction Regions

    CERN Document Server

    AUTHOR|(CDS)2082479; Abelleira, Jose; Cruz Alaniz, Emilia; Van Riesen-Haupt, Leon; Benedikt, Michael; Besana, Maria Ilaria; Buffat, Xavier; Burkhardt, Helmut; Cerutti, Francesco; Langner, Andy Sven; Martin, Roman; Riegler, Werner; Schulte, Daniel; Tomas Garcia, Rogelio; Appleby, Robert Barrie; Rafique, Haroon; Barranco Garcia, Javier; Pieloni, Tatiana; Boscolo, Manuela; Collamati, Francesco; Nevay, Laurence James; Hofer, Michael

    2017-01-01

    The experimental interaction region (EIR) is one of the key areas that define the performance of the Future Circular Collider. In this overview we will describe the status and the evolution of the design of EIR of FCC-hh, focusing on design of the optics, energy deposition in EIR elements, beam-beam effects and machine detector interface issues.

  2. HH-MIP: An Enhancement of Mobile IP by Home Agent Handover

    Directory of Open Access Journals (Sweden)

    Yang Chun-Chuan

    2010-01-01

    Full Text Available We propose an enhancement of Mobile IP (MIP called MIP with Home Agent Handover (HH-MIP to enjoy most of the advantages of Route Optimization MIP (ROMIP but with only a small increase of signaling overhead. In HH-MIP, the concept of Temporary HA (THA is proposed and the mobile host (MH registers the new CoA with its THA rather than its original HA. Since the THA of an MH is selected to be close to the current location of MH, HH-MIP reduces the handoff latency and shortens the signaling path of registration as well. Moreover, HH-MIP adopts an aggressive approach in selecting THA for an MH, that is, whenever an MH is moving away from its HA or previous THA, the MH triggers the handover of THA. Theoretical analysis demonstrates that the proposed scheme enjoys small handoff latency as well as routing efficiency, and the signaling cost of the proposed scheme is significantly less than that in ROMIP.

  3. THE MOLECULAR EMISSION OF THE IRRADIATED STAR-FORMING CORE AHEAD OF HH 80N

    International Nuclear Information System (INIS)

    Masque, Josep M.; Beltran, Maria T.; Estalella, Robert; Girart, Josep M.; Viti, Serena

    2009-01-01

    We present a Berkeley-Illinois-Maryland Association Array molecular survey of the star-forming core ahead of HH 80N, the optically obscured northern counterpart of the Herbig-Haro objects HH 80/81. Continuum emission at 1.4 mm and 8 μm is detected at the center of the core, which confirms the presence of an embedded very young stellar object in the core. All detected molecular species arise in a ringlike structure, which is most clearly traced by CS (2-1) emission. This molecular ring suggests that strong molecular depletion occurs in the inner part of the core (at a radius of ≅0.1 pc and densities higher than ∼5 x 10 4 cm -3 ). Despite the overall morphology and kinematic similarity between the different species, there is significant molecular differentiation along the ringlike structure. The analysis of the chemistry along the core shows that part of this differentiation may be caused by the UV irradiation of the nearby HH 80N object that illuminates the part of the core facing HH 80N, which results in an abundance enhancement of some of the detected species.

  4. Crustacean hyperglycemic hormone (cHH as a modulator of aggression in crustacean decapods.

    Directory of Open Access Journals (Sweden)

    Laura Aquiloni

    Full Text Available Biogenic amines, particularly serotonin, are recognised to play an important role in controlling the aggression of invertebrates, whereas the effect of neurohormones is still underexplored. The crustacean Hyperglycemic Hormone (cHH is a multifunctional member of the eyestalk neuropeptide family. We expect that this neuropeptide influences aggression either directly, by controlling its expression, or indirectly, by mobilizing the energetic stores needed for the increased activity of an animal. Our study aims at testing such an influence and the possible reversion of hierarchies in the red swamp crayfish, Procambarus clarkii, as a model organism. Three types of pairs of similarly sized males were formed: (1 'control pairs' (CP, n = 8: both individuals were injected with a phosphate saline solution (PBS; (2 'reinforced pairs' (RP, n = 9: the alpha alone was injected with native cHH, and the beta with PBS; (3 'inverted pairs' (IP, n = 9: the opposite of (2. We found that, independently of the crayfish's prior social experience, cHH injections induced (i the expression of dominance behaviour, (ii higher glycemic levels, and (iii lower time spent motionless. In CP and RP, fight intensity decreased with the establishment of dominance. On the contrary, in IP, betas became increasingly likely to initiate and escalate fights and, consequently, increased their dominance till a temporary reversal of the hierarchy. Our results demonstrate, for the first time, that, similarly to serotonin, cHH enhances individual aggression, up to reverse, although transitorily, the hierarchical rank. New research perspectives are thus opened in our intriguing effort of understanding the role of cHH in the modulation of agonistic behaviour in crustaceans.

  5. CRISPR/Cas9-mediated Dax1 knockout in the monkey recapitulates human AHC-HH.

    Science.gov (United States)

    Kang, Yu; Zheng, Bo; Shen, Bin; Chen, Yongchang; Wang, Lei; Wang, Jianying; Niu, Yuyu; Cui, Yiqiang; Zhou, Jiankui; Wang, Hong; Guo, Xuejiang; Hu, Bian; Zhou, Qi; Sha, Jiahao; Ji, Weizhi; Huang, Xingxu

    2015-12-20

    Mutations in the DAX1 locus cause X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH), which manifest with primary adrenal insufficiency and incomplete or absent sexual maturation, respectively. The associated defects in spermatogenesis can range from spermatogenic arrest to Sertoli cell only syndrome. Conclusions from Dax1 knockout mouse models provide only limited insight into AHC/HH disease mechanisms, because mouse models exhibit more extensive abnormalities in testicular development, including disorganized and incompletely formed testis cords with decreased number of peritubular myoid cells and male-to-female sex reversal. We previously reported successful clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated genome targeting in cynomolgus monkeys. Here, we describe a male fetal monkey in which targeted genome editing using CRISPR/Cas9 produced Dax1-null mutations in most somatic tissues and in the gonads. This DAX1-deficient monkey displayed defects in adrenal gland development and abnormal testis architecture with small cords, expanded blood vessels and extensive fibrosis. Sertoli cell formation was not affected. This phenotype strongly resembles findings in human patients with AHC-HH caused by mutations in DAX1. We further detected upregulation of Wnt/β-catenin-VEGF signaling in the fetal Dax1-deficient testis, suggesting abnormal activation of signaling pathways in the absence of DAX1 as one mechanism of AHC-HH. Our study reveals novel insight into the role of DAX1 in HH and provides proof-of-principle for the generation of monkey models of human disease via CRISPR/Cas9-mediated gene targeting. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Hedgehog Pathway Inhibitor HhAntag691 Is a Potent Inhibitor of ABCG2/BCRP and ABCB1/Pgp

    Directory of Open Access Journals (Sweden)

    Yimao Zhang

    2009-01-01

    Full Text Available HhAntag691 (GDC-0449, a low-molecular weight inhibitor of the tumor-promoting hedgehog (Hh signaling pathway, has been used to treat medulloblastoma in animal models and has recently entered clinical trials for a variety of solid tumors. Here, we show that HhAntag691 inhibits multiple ATP-binding cassette (ABC transporters. ATP-binding cassette transporters are within a family of membrane proteins, the overexpression of which is associated with multidrug resistance, a major impediment to successful cancer treatment. HhAntag691 is a potent inhibitor of two ABC transporters, ABCG2/BCRP and ABCB1/Pgp, and is a mild inhibitor of ABCC1/MRP1. In ABCG2-overexpressing HEK293 cells, HhAntag691 increased retention of the fluorescent ABCG2 substrate BODIPY-prazosin and resensitized these cells to mitoxantrone, an antineoplastic ABCG2 substrate. In Madin-Darby canine kidney II cells engineered to overexpress Pgp or MRP1, HhAntag691 increased the retention of calcein-AM and resensitized them to colchicine. HhAntag691 also resensitized human non-small cell lung carcinoma cells NCI-H460/par and NCI-H460/MX20, which overexpress ABCG2 in response to mitoxantrone, to mitoxantrone, and to topotecan or SN-38. The IC50 values of HhAntag691 for inhibition of ABCG2 and Pgp were ∼1.4 and ∼3.0 µM, respectively. Because ABC transporters are highly expressed at the blood-brain barrier and on many tumor cells, they contribute significantly to treatment failure of many types of cancer, particularly of those within the neuraxis. In addition to its effect on Hh signaling, the ability of HhAntag691 and related compounds to inhibit two key ABC transporters could contribute to their effectiveness in treating malignancies.

  7. Hybrid simulation techniques applied to the earth's bow shock

    Science.gov (United States)

    Winske, D.; Leroy, M. M.

    1985-01-01

    The application of a hybrid simulation model, in which the ions are treated as discrete particles and the electrons as a massless charge-neutralizing fluid, to the study of the earth's bow shock is discussed. The essentials of the numerical methods are described in detail; movement of the ions, solution of the electromagnetic fields and electron fluid equations, and imposition of appropriate boundary and initial conditions. Examples of results of calculations for perpendicular shocks are presented which demonstrate the need for a kinetic treatment of the ions to reproduce the correct ion dynamics and the corresponding shock structure. Results for oblique shocks are also presented to show how the magnetic field and ion motion differ from the perpendicular case.

  8. The bowed catheter sign: a risk for pericardial tamponade

    International Nuclear Information System (INIS)

    Towbin, Richard

    2008-01-01

    The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

  9. The bowed catheter sign: a risk for pericardial tamponade

    Energy Technology Data Exchange (ETDEWEB)

    Towbin, Richard [Phoenix Children' s Hospital, Department of Radiology, Phoenix, AZ (United States)

    2008-03-15

    The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

  10. Violin Pedagogy and the Physics of the Bowed String

    Science.gov (United States)

    McLeod, Alexander Rhodes

    The paper describes the mechanics of violin tone production using non-specialist language, in order to present a scientific understanding of tone production accessible to a broad readership. As well as offering an objective understanding of tone production, this model provides a powerful tool for analyzing the technique of string playing. The interaction between the bow and the string is quite complex. Literature reviewed for this study reveals that scientific investigations have provided important insights into the mechanics of string playing, offering explanations for factors which both contribute to and limit the range of tone colours and dynamics that stringed instruments can produce. Also examined in the literature review are significant works of twentieth century violin pedagogy exploring tone production on the violin, based on the practical experience of generations of teachers and performers. Hermann von Helmholtz described the stick-slip cycle which drives the string in 1863, which replaced earlier ideas about the vibration of violin strings. Later, scientists such as John Schelleng and Lothar Cremer were able to demonstrate how the mechanics of the bow-string interaction can create different tone colours. Recent research by Anders Askenfelt, Knut Guettler, and Erwin Schoonderwaldt have continued to refine earlier research in this area. The writings of Lucien Capet, Leopold Auer, Carl Flesch, Paul Rolland, Kato Havas, Ivan Galamian, and Simon Fischer are examined and analyzed. Each author describes a different approach to tone production on the violin, representing a different understanding of the underlying mechanism. Analyzing these writings within the context of a scientific understanding of tone production makes it possible to compare these approaches more consistently, and to synthesize different concepts drawn from the diverse sources evaluated.

  11. SUPRATHERMAL ELECTRONS AT SATURN'S BOW SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Masters, A.; Dougherty, M. K. [The Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Sulaiman, A. H. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Sergis, N. [Office of Space Research and Technology, Academy of Athens, Soranou Efesiou 4, 11527 Athens (Greece); Stawarz, L. [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Krakow (Poland); Fujimoto, M. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Coates, A. J., E-mail: a.masters@imperial.ac.uk [Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom)

    2016-07-20

    The leading explanation for the origin of galactic cosmic rays is particle acceleration at the shocks surrounding young supernova remnants (SNRs), although crucial aspects of the acceleration process are unclear. The similar collisionless plasma shocks frequently encountered by spacecraft in the solar wind are generally far weaker (lower Mach number) than these SNR shocks. However, the Cassini spacecraft has shown that the shock standing in the solar wind sunward of Saturn (Saturn's bow shock) can occasionally reach this high-Mach number astrophysical regime. In this regime Cassini has provided the first in situ evidence for electron acceleration under quasi-parallel upstream magnetic conditions. Here we present the full picture of suprathermal electrons at Saturn's bow shock revealed by Cassini . The downstream thermal electron distribution is resolved in all data taken by the low-energy electron detector (CAPS-ELS, <28 keV) during shock crossings, but the higher energy channels were at (or close to) background. The high-energy electron detector (MIMI-LEMMS, >18 keV) measured a suprathermal electron signature at 31 of 508 crossings, where typically only the lowest energy channels (<100 keV) were above background. We show that these results are consistent with the theory in which the “injection” of thermal electrons into an acceleration process involves interaction with whistler waves at the shock front, and becomes possible for all upstream magnetic field orientations at high Mach numbers like those of the strong shocks around young SNRs. A future dedicated study will analyze the rare crossings with evidence for relativistic electrons (up to ∼1 MeV).

  12. SUPRATHERMAL ELECTRONS AT SATURN'S BOW SHOCK

    International Nuclear Information System (INIS)

    Masters, A.; Dougherty, M. K.; Sulaiman, A. H.; Sergis, N.; Stawarz, L.; Fujimoto, M.; Coates, A. J.

    2016-01-01

    The leading explanation for the origin of galactic cosmic rays is particle acceleration at the shocks surrounding young supernova remnants (SNRs), although crucial aspects of the acceleration process are unclear. The similar collisionless plasma shocks frequently encountered by spacecraft in the solar wind are generally far weaker (lower Mach number) than these SNR shocks. However, the Cassini spacecraft has shown that the shock standing in the solar wind sunward of Saturn (Saturn's bow shock) can occasionally reach this high-Mach number astrophysical regime. In this regime Cassini has provided the first in situ evidence for electron acceleration under quasi-parallel upstream magnetic conditions. Here we present the full picture of suprathermal electrons at Saturn's bow shock revealed by Cassini . The downstream thermal electron distribution is resolved in all data taken by the low-energy electron detector (CAPS-ELS, <28 keV) during shock crossings, but the higher energy channels were at (or close to) background. The high-energy electron detector (MIMI-LEMMS, >18 keV) measured a suprathermal electron signature at 31 of 508 crossings, where typically only the lowest energy channels (<100 keV) were above background. We show that these results are consistent with the theory in which the “injection” of thermal electrons into an acceleration process involves interaction with whistler waves at the shock front, and becomes possible for all upstream magnetic field orientations at high Mach numbers like those of the strong shocks around young SNRs. A future dedicated study will analyze the rare crossings with evidence for relativistic electrons (up to ∼1 MeV).

  13. SPITZER OBSERVATIONS OF BOW SHOCKS AND OUTFLOWS IN RCW 38

    Energy Technology Data Exchange (ETDEWEB)

    Winston, E. [ESA-ESTEC (SRE-SA), Keplerlaan 1, 2201 AZ Noordwijk ZH (Netherlands); Wolk, S. J.; Bourke, T. L.; Spitzbart, B. [Harvard Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Megeath, S. T. [Ritter Observatory, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Ave., Toledo, OH 43606 (United States); Gutermuth, R., E-mail: ewinston@rssd.esa.int [Five Colleges Astronomy Department, Smith College, Northampton, MA 01027 (United States)

    2012-01-10

    We report Spitzer observations of five newly identified bow shocks in the massive star-forming region RCW 38. Four are visible at Infrared Array Camera (IRAC) wavelengths, the fifth is only visible at 24 {mu}m. Chandra X-ray emission indicates that winds from the central O5.5 binary, IRS 2, have caused an outflow to the northeast and southwest of the central subcluster. The southern lobe of hot ionized gas is detected in X-rays; shocked gas and heated dust from the shock front are detected with Spitzer at 4.5 and 24 {mu}m. The northern outflow may have initiated the present generation of star formation, based on the filamentary distribution of the protostars in the central subcluster. Further, the bow-shock driving star, YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are identified within this pillar at near- to mid-IR wavelengths. We also report on IRAC 3.6 and 5.8 {mu}m observations of the cluster DBS2003-124, northeast of RCW 38, where 33 candidate young stellar objects (YSOs) are identified. One star associated with the cluster drives a parsec-scale jet. Two Herbig-Haro objects associated with the jet are visible at IRAC and Multiband Imaging Photometer for Spitzer (MIPS) wavelengths. The jet extends over a distance of {approx}3 pc. Assuming a velocity of 100 km s{sup -1} for the jet material gives an age of 3 Multiplication-Sign 10{sup 4} yr, indicating that the star (and cluster) are likely to be very young, with a similar or possibly younger age than RCW 38, and that star formation is ongoing in the extended RCW 38 region.

  14. SPITZER OBSERVATIONS OF BOW SHOCKS AND OUTFLOWS IN RCW 38

    International Nuclear Information System (INIS)

    Winston, E.; Wolk, S. J.; Bourke, T. L.; Spitzbart, B.; Megeath, S. T.; Gutermuth, R.

    2012-01-01

    We report Spitzer observations of five newly identified bow shocks in the massive star-forming region RCW 38. Four are visible at Infrared Array Camera (IRAC) wavelengths, the fifth is only visible at 24 μm. Chandra X-ray emission indicates that winds from the central O5.5 binary, IRS 2, have caused an outflow to the northeast and southwest of the central subcluster. The southern lobe of hot ionized gas is detected in X-rays; shocked gas and heated dust from the shock front are detected with Spitzer at 4.5 and 24 μm. The northern outflow may have initiated the present generation of star formation, based on the filamentary distribution of the protostars in the central subcluster. Further, the bow-shock driving star, YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are identified within this pillar at near- to mid-IR wavelengths. We also report on IRAC 3.6 and 5.8 μm observations of the cluster DBS2003-124, northeast of RCW 38, where 33 candidate young stellar objects (YSOs) are identified. One star associated with the cluster drives a parsec-scale jet. Two Herbig-Haro objects associated with the jet are visible at IRAC and Multiband Imaging Photometer for Spitzer (MIPS) wavelengths. The jet extends over a distance of ∼3 pc. Assuming a velocity of 100 km s –1 for the jet material gives an age of 3 × 10 4 yr, indicating that the star (and cluster) are likely to be very young, with a similar or possibly younger age than RCW 38, and that star formation is ongoing in the extended RCW 38 region.

  15. Modelling the bending/bowing of composite beams such as nuclear fuel

    International Nuclear Information System (INIS)

    Tayal, M.

    1989-01-01

    Arrays of tubes are used in many engineered structures, such as in nuclear fuel bundles and in steam generators. The tubes can bend (bow) due to in-service temperatures and loads. Assessments of bowing of nuclear fuel elements can help demonstrate the integrity of fuel and of surrounding components, as a function of operating conditions such as channel power. The BOW code calculates the bending of composite beams such as fuel elements, due to gradients of temperature and due to hydraulic forces. The deflections and rotations are calculated in both lateral directions, for given conditions of temperatures. Wet and dry operation of the sheath can be simulated. BOW accounts for the following physical phenomena: circumferential and axial variations in the temperatures of the sheath and of the pellet; cracking of pellets; grip and slip between the pellets and the sheath; hydraulic drag; restraint from endplates, from neighbouring elements, and from the pressure-tube; gravity; concentric or eccentric welds between endcaps and endplate; neutron flux gradients; and variations of material properties with temperature. The code is based on fundamental principles of mechanics. The governing equations are solved numerically using the finite element method. Several comparisons with closed-form equations shoe that the solutions of BOW are accurate. BOW's predictions for initial in-reactor bow are also consistent with two post-irradiation measurements

  16. Dominant acceleration processes of ambient energetic protons (E>= 50 keV) at the bow shock: conditions and limitations

    International Nuclear Information System (INIS)

    Anagnostopoulos, G.C.; Sarris, E.T.

    1983-01-01

    Energetic proton (Esub(p)>= 50 keV) and magnetic field observations during crossings of the Earth's Bow Shock by the IMP-7 and 8 spacecraft are incorporated in this work in order to examine the effect of the Bow Shock on a pre-existing proton population under different ''interplanetary magnetic field-Bow Shock'' configurations, as well as the conditions for the presence of the Bow Shock associated energetic proton intensity enhancements. The presented observations indicate that the dominant process for the efficient acceleration of ambient energetic particles to energies exceeding approximately 50 keV is by ''gradient-B'' drifting parallel to the induced electric field at quasi-perpendicular Bow Shocks under certain well defined limitations deriving from the finite and curved Bow Shock surface. It is shown that the proton acceleration at the Bow Shock is most efficient for high values of the upstream magnetic field (in general B 1 > 8#betta#), high upstream plasma speed and expanded Bow Shock fronts, as well as for direction of the induced electric field oriented almost parallel to the flanks of the Bow Shock, i.e. when the drift distance of protons parallel to the electric field at the shock front is considerably smaller than the local radius of curvature of the Bow Shock. The implications of the presented observations of Bow Shock crossings as to the source of the energetic proton intensity enhancements are discussed. (author)

  17. Square and bow-tie configurations in the cyclic evasion problem

    Science.gov (United States)

    Arnold, M. D.; Golich, M.; Grim, A.; Vargas, L.; Zharnitsky, V.

    2017-05-01

    Cyclic evasion of four agents on the plane is considered. There are two stationary shapes of configurations: square and degenerate bow-tie. The bow-tie is asymptotically attracting while the square is of focus-center type. Normal form analysis shows that square is nonlinearly unstable. The stable manifold consists of parallelograms that all converge to the square configuration. Based on these observations and numerical simulations, it is conjectured that any non-parallelogram non-degenerate configuration converges to the bow-tie.

  18. Bowing-reactivity trends in EBR-II assuming zero-swelling ducts

    International Nuclear Information System (INIS)

    Meneghetti, D.

    1994-01-01

    Predicted trends of duct-bowing reactivities for the Experimental Breeder Reactor II (EBR-II) are correlated with predicted row-wise duct deflections assuming use of idealized zero-void-swelling subassembly ducts. These assume no irradiation induced swellings of ducts but include estimates of the effects of irradiation-creep relaxation of thermally induced bowing stresses. The results illustrate the manners in which at-power creeps may affect subsequent duct deflections at zero power and thereby the trends of the bowing component of a subsequent power reactivity decrement

  19. Familial congenital bowing with short thick bones and metaphyseal changes, a distinct entity

    International Nuclear Information System (INIS)

    Rezza, E.; Lendvai, D.; Iannaccone, G.

    1984-01-01

    The authors describe two siblings, a male and a female, with disproportionate short stature, rhizomelic-mesomelic shortening of the limb bones, marked bowing of the femora, moderate bowing of the humeri, radii and ulnae, straight tibiae and fibulae, normal hands, flared cupped metaphyses of the tibiae, ulnae, raddi and ribs, and narrow chest. There was some improvement of the bone changes with advancing age. These two patients are similar to five other cases from the literature and strongly support Hall and Spranger's view that this pseudocampomelic condition most likely represents a distinct familial bowing syndrome. The differential diagnosis and the hereditary aspects in the two patients, are also briefly discussed. (orig.)

  20. AIRBORNE X-HH INCIDENCE ANGLE IMPACT ON CANOPY HEIGHT RETREIVAL: IMPLICATIONS FOR SPACEBORNE X-HH TANDEM-X GLOBAL CANOPY HEIGHT MODEL

    Directory of Open Access Journals (Sweden)

    M. L. Tighe

    2012-07-01

    Full Text Available To support international climate change mitigation efforts, the United Nations REDD+ initiative (Reducing Emissions from Deforestation and Degradation seeks to reduce land use induced greenhouse gas emissions to the atmosphere. It requires independent monitoring of forest cover and forest biomass information in a spatially explicit form. It is widely recognised that remote sensing is required to deliver this information. Synthetic Aperture Radar interferometry (InSAR techniques have gained traction in the last decade as a viable technology from which vegetation canopy height and bare earth elevations can be derived. The viewing geometry of a SAR sensor is side-looking where the radar pulse is transmitted out to one side of the aircraft or satellite, defining an incidence angle (θ range. The incidence angle will change from near-range (NR to far-range (FR across of the track of the SAR platform. InSAR uses image pairs and thus, contain two set of incidence angles. Changes in the InSAR incidence angles can alter the relative contributions from the vegetation canopy and the ground surface and thus, affect the retrieved vegetation canopy height. Incidence angle change is less pronounced in spaceborne data than in airborne data and mitigated somewhat when multiple InSAR-data takes are combined. This study uses NEXTMap® single- and multi-pass X-band HH polarized InSAR to derive vegetation canopy height from the scattering phase centre height (hspc. Comparisons with in situ vegetation canopy height over three test sites (Arizona-1, Minnesota-2; the effect of incidence angle changes across swath on the X-HH InSAR hspc was examined. Results indicate at steep incidence angles (θ = 35º, more exposure of lower vegetation canopy structure (e.g. tree trunks led to greater lower canopy double bounce, increased ground scattering, and decreased volume scattering. This resulted in a lower scattering phase centre height (hspc or a greater underestimation of

  1. Luminous Herbig-Haro objects from a massive protostar: The unique case of HH 80/81

    Science.gov (United States)

    Reipurth, Bo

    2017-08-01

    Herbig-Haro (HH) objects are the optical manifestations of shock waves excited by outflows from young stars. They represent one of the few classes of spatially extended astronomical objects where both structural changes and proper motions can be measured on time scales of years to decades. HH 80/81 is a pair of HH objects in Sagittarius which are the intrinsically most luminous HH objects known. The driving source of HH 80/81 is the embedded star IRAS 18162-2048, which has a luminosity of 20,000 Lsun and excites a compact HII region, suggesting that it is a newborn massive star. HH objects associated with massive young stars are very rare, only a handful of cases are known, but what makes the HH 80/81 source unique among massive protostars is that it produces a finely collimated bipolar radio jet with extremely high velocity and pointing straight to HH 80/81. We propose to observe the HH 80/81 complex with WFC3 and the following four filters: Halpha 6563, Hbeta 4861, [SII] 6717/31, and [OIII] 5007. First epoch HST images were obtained 22 years ago, which now allows a very precise determination of proper motions. Groundbased optical and radio proper motions are not only uncertain, but actually contradict each other, a controversy that will be resolved by HST. The fine resolution of WFC3 allows a study of both fine structural details and structural changes of the shocks. Finally we will use a sophisticated adaptive grid code to interpret the (de-reddened) line ratios across the shocks.

  2. Ultraboosted Zt and γt production at the HL-LHC and FCC-hh

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Saavedra, J.A. [Universidad de Granada, Departamento de Fisica Teorica y del Cosmos, Granada (Spain)

    2017-11-15

    Searches for anomalous Zt and γt production provide an excellent probe of flavour-changing top interactions when the energies considered are very large. In this note we estimate the sensitivity to these interactions at the high-luminosity phase of the LHC and a future 100 TeV pp collider (FCC-hh). For the LHC, the expected limits on t → uZ/uγ branching ratios from Zt and γt production will reach the 10{sup -5} level, one order of magnitude better than the existing projections for t → uZ from t anti t production. For the FCC-hh, the limits on t → uZ/uγ could reach an impressive sensitivity at the 10{sup -6} level, with limits on t → cZ/cγ at the 10{sup -5} level. (orig.)

  3. The Time-Dependent Wavelet Spectrum of HH 1 and 2

    Science.gov (United States)

    Raga, A. C.; Reipurth, B.; Esquivel, A.; González-Gómez, D.; Riera, A.

    2018-04-01

    We have calculated the wavelet spectra of four epochs (spanning ≍20 yr) of Hα and [S II] HST images of HH 1 and 2. From these spectra we calculated the distribution functions of the (angular) radii of the emission structures. We found that the size distributions have maxima (corresponding to the characteristic sizes of the observed structures) with radii that are logarithmically spaced with factors of ≍2→3 between the successive peaks. The positions of these peaks generally showed small shifts towards larger sizes as a function of time. This result indicates that the structures of HH 1 and 2 have a general expansion (seen at all scales), and/or are the result of a sequence of merging events resulting in the formation of knots with larger characteristic sizes.

  4. Sudden rotation reactive scattering: Theory and application to 3-D H+H2

    International Nuclear Information System (INIS)

    Bowman, J.M.; Lee, K.T.

    1980-01-01

    An approximate quantum mechanical theory of reactive scattering is presented and applied to the H+H 2 reaction in three dimensions. Centrifugal sudden and rotational sudden approximations are made in each arrangement channel, however, vibrational states are treated in a fully coupled manner. Matching of arrangement channel wave functions is done where the arrangement channel centrifugal potentials are equal. This matching is particularly appropriate for collinearly favored reactions. Integral and differential cross sections are calculated for the H+H 2 reaction for H 2 in the ground and first excited vibrational states. These calculations employ the Porter--Karplus potential energy surface mainly to allow for comparisons with previous accurate and approximate quantal and quasiclassical calculations

  5. Exploring the $Z' \\rightarrow t\\overline{t}$ heavy resonance at FCC-hh

    CERN Document Server

    Smith, Rachel Emma Clarke

    2017-01-01

    My summer student project explored the feasibility of detecting final states with boosted top quarks at 100 TeV with the baseline FCC-hh detector. I focused specifically on the $Z' \\rightarrow t\\overline{t}$ hadronic process. I determined the exclusion cross-section of $Z' \\rightarrow t\\overline{t}$ and the integrated luminosity required to make a discovery at the baseline FCC detector at 95% confidence level.

  6. 20 years of cosmic muons research performed in IFIN-HH

    International Nuclear Information System (INIS)

    Mitrica, Bogdan

    2012-01-01

    During the last two decades a modern direction in particle physics research has been developed in IFIN-HH Bucharest, Romania. The history started with the WILLI detector built in IFIN-HH Bucharest in collaboration with KIT Karlsruhe (formerly Forschungszentrum Karlsruhe). The detector was designed for measurements of the low energy muon charge ratio ( 0.4GeV, show a diurnal modulation of the muon flux. The analysis of the muon events for energies 15 eV. Simulation studies and preliminary experimental tests, regarding the performances of the mini-array, have been performed using H and Fe primaries, with energies in a range 10 13 eV - 10 15 eV. The results show detailed effects of the direction of EAS incidence relative to the geomagnetic field, depending, in particular, of the primary mass. Based on the results, we can say that WILLI-EAS experiment could be used for testing the hadronic interaction models. Measurements of the high energy muon flux in underground of the salt mine from Slanic Prahova, Romania was performed using a new mobile detector developed in IFIN-HH, Bucharest. Consisting of 2 scintillator plates measuring in coincidence, the detector is installed on a van which facilitates measurements on different positions at surface or in underground. The detector was used to measure muon fluxes in different locations at surface or in underground. The detector was used to measure muon fluxes at different sites of Romania and in the underground of the salt mines from Slanic Prahova, Romania where IFIN-HH has a modern underground laboratory. New methods for the detection of cosmic ray muons are investigated in our institute based on scintillator techniques using optical fiber and MPPC photodyodes.

  7. An empirical model of the Earth's bow shock based on an artificial neural network

    Science.gov (United States)

    Pallocchia, Giuseppe; Ambrosino, Danila; Trenchi, Lorenzo

    2014-05-01

    All of the past empirical models of the Earth's bow shock shape were obtained by best-fitting some given surfaces to sets of observed crossings. However, the issue of bow shock modeling can be addressed by means of artificial neural networks (ANN) as well. In this regard, here it is presented a perceptron, a simple feedforward network, which computes the bow shock distance along a given direction using the two angular coordinates of that direction, the bow shock predicted distance RF79 (provided by Formisano's model (F79)) and the upstream alfvénic Mach number Ma. After a brief description of the ANN architecture and training method, we discuss the results of the statistical comparison, performed over a test set of 1140 IMP8 crossings, between the prediction accuracies of ANN and F79 models.

  8. 76 FR 13666 - Pitney Bowes, Inc., Mailing Solutions Management, Global Engineering Group, Including On-Site...

    Science.gov (United States)

    2011-03-14

    ...., Mailing Solutions Management, Global Engineering Group, Including On-Site Leased Workers From Guidant... workers and former workers of Pitney Bowes, Inc., Mailing Solutions Management Division, Engineering... reviewed the certification to clarify the subject worker group's identity. Additional information revealed...

  9. Design and performance studies of a hadronic calorimeter for a FCC-hh experiment

    Science.gov (United States)

    Faltova, J.

    2018-03-01

    The hadron-hadron Future Circular Collider (FCC-hh) project studies the physics reach of a proton-proton machine with a centre-of-mass-energy of 100 TeV and five times greater peak luminosities than at the High-Luminosity LHC (HL-LHC). The high-energy regime of the FCC-hh opens new opportunities for the discovery of physics beyond the standard model. At 100 TeV a large fraction of the W, Z, H bosons and top quarks are produced with a significant boost. It implies an efficient reconstruction of very high energetic objects decaying hadronically. The reconstruction of those boosted objects sets the calorimeter performance requirements in terms of energy resolution, containment of highly energetic hadron showers, and high transverse granularity. We present the current baseline technologies for the calorimeter system in the barrel region of the FCC-hh reference detector: a liquid argon electromagnetic and a scintillator-steel hadronic calorimeters. The focus of this paper is on the hadronic calorimeter and the performance studies for hadrons. The reconstruction of single particles and the achieved energy resolution for the combined system of the electromagnetic and hadronic calorimeters are discussed.

  10. Analytical parametrization and shape classification of anomalous HH production in the EFT approach

    CERN Document Server

    Carvalho, Alexandra; Manzano, Pablo de Castro; Dorigo, Tommaso; Goertz, Florian; Gouzevich, Maxime; Tosi, Mia

    2016-01-01

    In this document we study the effect of anomalous Higgs boson couplings on non-resonant pair production of Higgs bosons ($HH$) at the LHC. We explore the space of the five parameters $\\kappa_{\\lambda}$, $\\kappa_{t}$, $c_2$, $c_g$, and $c_{2g}$ in terms of the corresponding kinematics of the final state, and describe a partition of the space into a limited number of regions featuring similar phenomenology in the kinematics of $HH$ final state. We call clusters the sets of points belonging to the same region; to each cluster corresponds a representative point which we call a benchmark. We discuss a possible technique to estimate the sensitivity of an experimental search to the kinematical differences between the phenomenology of the benchmark points and the rest of the parameter space contained in the corresponding cluster. We also provide an analytical parametrization of the cross-section modifications that the variation of anomalous couplings produces with respect to standard model $HH$ production along with ...

  11. The Intricate Structure of HH 508, the Brightest Microjet in the Orion Nebula

    Science.gov (United States)

    Wu, Ya-Lin; Close, Laird M.; Kim, Jinyoung Serena; Males, Jared R.; Morzinski, Katie M.

    2018-02-01

    We present Magellan adaptive optics Hα imaging of HH 508, which has the highest surface brightness among protostellar jets in the Orion Nebula. We find that HH 508 actually has a shorter component to the west, and a longer and knotty component to the east. The east component has a kink at 0.″3 from the jet-driving star θ 1 Ori B2, so it may have been deflected by the wind/radiation from the nearby θ 1 Ori B1B5. The origin of both components is unclear, but if each of them is a separate jet, then θ 1 Ori B2 may be a tight binary. Alternatively, HH 508 may be a slow-moving outflow, and each component represents an illuminated cavity wall. The ionization front surrounding θ 1 Ori B2B3 does not directly face θ 1 Ori B1B5, suggesting that the EUV radiation from θ 1 Ori C plays a dominant role in affecting the morphology of proplyds even in the vicinity of θ 1 Ori B1B5. Finally, we report an Hα blob that might be ejected by the binary proplyd LV 1.

  12. On numerical simulation of fuel assembly bow in pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Horváth, Ákos, E-mail: akoshorvath@t-online.hu [AREVA, AREVA NP GmbH, Paul-Gossen-Str. 100, 91052 Erlangen (Germany); Budapest University of Technology and Economics, Department of Aircraft and Ships, Stoczek Street 6, Building J, H-1111 Budapest (Hungary); Dressel, Bernd [AREVA, AREVA NP GmbH, Paul-Gossen-Str. 100, 91052 Erlangen (Germany)

    2013-12-15

    Highlights: • Simulation of fuel assembly bow by coupled CFD and finite element method. • Comparison of calculated and experimentally measured bow shapes. • Investigation of boundary condition effect on bow pattern of a fuel assembly row. • Highlighting importance of consideration of fluid–structure interaction. • Assessment of flow redistribution within the fuel assembly row model. - Abstract: Fuel assembly bow in pressurized water reactor cores is largely triggered by lateral hydraulic forces together with creep processes generated by neutron flux. A detailed understanding of the flow induced bow behaviour is, therefore, an important issue. The experimental feedbacks and laboratory tests on fuel assembly bow show that it is characterized to a high degree by fluid–structure interaction (FSI) effects, therefore, consideration of FSI is essential and indispensable in full comprehension of the bow mechanism. In the present study, coupled computational fluid dynamics (CFD) and finite element simulations are introduced, calculating fuel assembly deformation under different conditions as a quasi-stationary phenomenon. The aim has been, on the one hand, to develop such a simplified fuel assembly CFD model, which allows set up of fuel assembly rows without loosing its main hydraulic characteristic; on the other hand, to investigate the bow pattern of a given fuel assembly row under different boundary conditions. The former one has been achieved by comparing bow shapes obtained with different fuel assembly (spacer grid) modelling approaches and mesh resolutions with experimental data. In the second part of the paper a row model containing 7.5 fuel assemblies is introduced, investigating the effect of flow distribution at inlet and outlet boundary regions on fuel assembly bow behaviour. The post processing has been focused on the bow pattern, lateral hydraulic forces, and horizontal flow distribution. The results have revealed importance of consideration of

  13. Effect of loading pattern on longitudinal bowing in flexible roll forming

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hyun; Woo, Young Yun; Hwang, Tae Woo; Han, Sang Wook; Moon, Young Hoon [School of Mechanical Engineering, Engineering Research Center for Net Shape and Die Manufacturing, Pusan National University,Busan (Korea, Republic of)

    2016-12-15

    The flexible roll forming process can be used to fabricate products with a variable cross-section profile in the longitudinal direction. Transversal nonuniformity of the longitudinal strain is one of the fundamental characteristics of blank deformation in flexible roll forming. Longitudinal bowing is a shape defect caused by transversal nonuniformity of the longitudinal strain. In this study, loading patterns in flexible roll forming are investigated in order to reduce the longitudinal bowing in a roll-formed blank. To analyze the effects of loading patterns on longitudinal bowing, two different forming schedules are implemented. In schedule 1, loading patterns with different bending angle increments are designed under fixed initial and final bending angles. In schedule 2, loading patterns with different initial bending angles under the fixed final bending angle are designed. Our results show that the bowing heights are significantly affected by the loading patterns. The bowing susceptibilities vary with blank shape such as trapezoid, convex, and concave shapes. In addition to the peak longitudinal strain at the respective roll stands, the cumulative longitudinal strain from the initial to final stands is shown to be a reliable index in predicting the tendency of longitudinal bowing.

  14. Flow performance of highly loaded axial fan with bowed rotor blades

    International Nuclear Information System (INIS)

    Chen, L; Liu, X J; Yang, A L; Dai, R

    2013-01-01

    In this paper, a partial bowed rotor blade was proposed for a newly designed high loaded axial fan. The blade was positively bowed 30 degrees from hub to 30 percent spanwise position. Flows of radial blade and bowed blade fans were numerically compared for various operation conditions. Results show that the fan's performance is improved. At the designed condition with flow coefficient of 0.52, the efficiency of the bowed blade fan is increased 1.44% and the static pressure rise is increased 11%. Comparing the flow structures, it can be found that the separated flow in the bowed fan is reduced and confined within 20 percent span, which is less than the 35 percent in the radial fan. It means that the bowed blade generates negative blade force and counteracts partial centrifugal force. It is alleviates the radial movements of boundary layers in fan's hub region. Flow losses due to 3D mixing are reduced in the rotor. Inlet flow to downstream stator is also improved

  15. Flow performance of highly loaded axial fan with bowed rotor blades

    Science.gov (United States)

    Chen, L.; Liu, X. J.; Yang, A. L.; Dai, R.

    2013-12-01

    In this paper, a partial bowed rotor blade was proposed for a newly designed high loaded axial fan. The blade was positively bowed 30 degrees from hub to 30 percent spanwise position. Flows of radial blade and bowed blade fans were numerically compared for various operation conditions. Results show that the fan's performance is improved. At the designed condition with flow coefficient of 0.52, the efficiency of the bowed blade fan is increased 1.44% and the static pressure rise is increased 11%. Comparing the flow structures, it can be found that the separated flow in the bowed fan is reduced and confined within 20 percent span, which is less than the 35 percent in the radial fan. It means that the bowed blade generates negative blade force and counteracts partial centrifugal force. It is alleviates the radial movements of boundary layers in fan's hub region. Flow losses due to 3D mixing are reduced in the rotor. Inlet flow to downstream stator is also improved.

  16. Anterior Femoral Bow and Possible Effect on the Stifle Joint: A Comparison between Humans and Dogs.

    Science.gov (United States)

    Ocal, M K; Sabanci, S S; Cobanoglu, M; Enercan, M

    2017-08-01

    The aim of the study was to compare the anterior bow of the femur between dogs and humans in terms of the possible impact on the stifle joint. The femoral radiographs obtained retrospectively were used to determine the angles and positions of the anterior bow in both dogs (n = 135) and humans (n = 57). Descriptive statistics and Pearson's correlation analysis were used for the statistical analyses of the variables. The mean anterior bow angle (ABA) was 18.3 ± 2.02° and 4.88 ± 1.24° in dogs and humans, respectively. The bow position was at the distal shaft in dogs (64.9 ± 2.04%) and almost at the mid-shaft of the bone (46.5 ± 5.52%) in humans. The ABA was related to the bow position in both humans and dogs. Additionally, the angle correlated with age in humans, while it was correlated with weight and breed in dogs. In conclusion, it is suggested that the anterior bow should be used as a landmark on the femoral axis for the biomechanical research of stifle joint, and dog stifle could be used as a suitable model for human knee in experimental studies for clinicians, while making sure that ethical principles are fully respected. © 2017 Blackwell Verlag GmbH.

  17. Binary energy source of the HH 250 outflow and its circumstellar environment

    Science.gov (United States)

    Comerón, Fernando; Reipurth, Bo; Yen, Hsi-Wei; Connelley, Michael S.

    2018-04-01

    Aims: Herbig-Haro flows are signposts of recent major accretion and outflow episodes. We aim to determine the nature and properties of the little-known outflow source HH 250-IRS, which is embedded in the Aquila clouds. Methods: We have obtained adaptive optics-assisted L-band images with the NACO instrument on the Very Large Telescope (VLT), together with N- and Q-band imaging with VISIR also on the VLT. Using the SINFONI instrument on the VLT we carried out H- and K-band integral field spectroscopy of HH 250-IRS, complemented with spectra obtained with the SpeX instrument at the InfraRed Telescope Facility (IRTF) in the JHKL bands. Finally, the SubMillimeter Array (SMA) interferometer was used to study the circumstellar environment of HH 250-IRS at 225 and 351 GHz with CO (2-1) and CO (3-2) maps and 0.9 mm and 1.3 mm continuum images. Results: The HH 250-IRS source is resolved into a binary with 0.''53 separation, corresponding to 120 AU at the adopted distance of 225 pc. The individual components show heavily veiled spectra with weak CO absorption indicative of late-type stars. Both are Class I sources, but their spectral energy distributions between 1.5 μm and 19 μm differ markedly and suggest the existence of a large cavity around one of the components. The millimeter interferometric observations indicate that the gas mainly traces a circumbinary envelope or disk, while the dust emission is dominated by one of the circumstellar envelopes. Conclusions: HH 250-IRS is a new addition to the handful of multiple systems where the individual stellar components, the circumstellar disks and a circumbinary disk can be studied in detail, and a rare case among those systems in which a Herbig-Haro flow is present. Based on observations obtained with the VLT (Cerro Paranal, Chile) in programs 089.C-0196(A), 095.C-0488(A), and 095.C-0488(B), as well as with IRTF (Mauna Kea, Hawaii), SMA (Mauna Kea, Hawaii), and the Nordic Optical Telescope (La Palma, Canary Islands, Spain

  18. The electronic structure and bonding of a H-H pair in the vicinity of a BCC Fe bulk vacancy

    Energy Technology Data Exchange (ETDEWEB)

    Juan, A.; Pistonesi, C.; Brizuela, G. [Universidad Nacional del Sur, Bahia Blanca (Argentina). Departamento de Fisica; Garcia, A.J. [Universidad Nacional del Sur, Bahia Blanca (Argentina). Departamento de Ciencias de la Computacion

    2003-09-01

    The H-Fe interaction near a bcc Fe vacancy is analysed using a semi-empirical theoretical method. Calculations were performed using a Fe{sub 86} cluster with a vacancy. Hydrogen atoms are positioned in their local energy minima configurations. Changes in the electronic structure of Fe atoms near a vacancy were analysed for the system without H, with one H and with two H atoms. Fe atoms surrounding the vacancy weaken their bond when hydrogen is present. This is due to the formation of H-Fe bonds. Hydrogen influences only its nearest-neighbour Fe atoms. The H-H interaction was also analysed. For H-H distance of 0.82 Angstrom an H-H association is formed, while H-Fe interaction and Fe-Fe weakening is markedly reduced, when compared with other H-H interactions. (author)

  19. A study of the Herbig-Haro object HH 120 and the associated cometary globule CG 30

    International Nuclear Information System (INIS)

    Pettersson, B.

    1984-01-01

    Infrared and spectroscopic observations are presented of a new Herbig-Haro object, here named HH 120, in the cometary globule CG 30. The emission line spectrum indicates a very low degree of excitation of the same order as that found for HH 47, HH 7, and HH 11. From several spectra a radial velocity of -42 km -1 +-12 km s -1 is deduced and the electron temperature, Tsub(e), and electron number density, Nsub(e), are found to be 9100 K+-400 K and 1700 cm -3 +-600 cm -3 , respectively. A prominent continuum is shown to be composed of a collisionally enhanced two-photon continuum and a reflected late-type stellar component, probably originating in the hidden source of energy. Infrared scans of CG 30 revealed five sources, two of which are very close to HH 120. It is argued that one of them, CG 30-IRS4, is the source of energy producing HH 120 and an associated reflection nebula. The bolometric luminosity of CG 30-IRS4 is estimated to be at least 0.9 Lsub(sun), its mass 1.1 Msub(sun) and its radius 1.6 Rsub(sun). (orig.)

  20. Comparison of accelerated ion populations observed upstream of the bow shocks at Venus and Mars

    Directory of Open Access Journals (Sweden)

    M. Yamauchi

    2011-03-01

    Full Text Available Foreshock ions are compared between Venus and Mars at energies of 0.6~20 keV using the same ion instrument, the Ion Mass Analyser, on board both Venus Express and Mars Express. Venus Express often observes accelerated protons (2~6 times the solar wind energy that travel away from the Venus bow shock when the spacecraft location is magnetically connected to the bow shock. The observed ions have a large field-aligned velocity compared to the perpendicular velocity in the solar wind frame, and are similar to the field-aligned beams and intermediate gyrating component of the foreshock ions in the terrestrial upstream region. Mars Express does not observe similar foreshock ions as does Venus Express, indicating that the Martian foreshock does not possess the intermediate gyrating component in the upstream region on the dayside of the planet. Instead, two types of gyrating protons in the solar wind frame are observed very close to the Martian quasi-perpendicular bow shock within a proton gyroradius distance. The first type is observed only within the region which is about 400 km from the bow shock and flows tailward nearly along the bow shock with a similar velocity as the solar wind. The second type is observed up to about 700 km from the bow shock and has a bundled structure in the energy domain. A traversal on 12 July 2005, in which the energy-bunching came from bundling in the magnetic field direction, is further examined. The observed velocities of the latter population are consistent with multiple specular reflections of the solar wind at the bow shock, and the ions after the second reflection have a field-aligned velocity larger than that of the de Hoffman-Teller velocity frame, i.e., their guiding center has moved toward interplanetary space out from the bow shock. To account for the observed peculiarity of the Martian upstream region, finite gyroradius effects of the solar wind protons compared to the radius of the bow shock curvature and

  1. Polarized bow shocks reveal features of the winds and environments of massive stars

    Science.gov (United States)

    Shrestha, Manisha

    2018-01-01

    Massive stars strongly affect their surroundings through their energetic stellar winds and deaths as supernovae. The bow shock structures created by fast-moving massive stars contain important information about the winds and ultimate fates of these stars as well as their local interstellar medium (ISM). Since bow shocks are aspherical, the light scattered in the dense shock material becomes polarized. Analyzing this polarization reveals details of the bow shock geometry as well as the composition, velocity, density, and albedo of the scattering material. With these quantities, we can constrain the properties of the stellar wind and thus the evolutionary state of the star, as well as the dust composition of the local ISM.In my dissertation research, I use a Monte Carlo radiative transfer code that I optimized to simulate the polarization signatures produced by both resolved and unresolved stellar wind bow shocks (SWBS) illuminated by a central star and by shock emission. I derive bow shock shapes and densities from published analytical calculations and smooth particle hydrodynamic (SPH) models. In the case of the analytical SWBS and electron scattering, I find that higher optical depths produce higher polarization and position angle rotations at specific viewing angles compared to theoretical predictions for low optical depths. This is due to the geometrical properties of the bow shock combined with multiple scattering effects. For dust scattering, the polarization signature is strongly affected by wavelength, dust grain properties, and viewing angle. The behavior of the polarization as a function of wavelength in these cases can distinguish among different dust models for the local ISM. In the case of SPH density structures, I investigate how the polarization changes as a function of the evolutionary phase of the SWBS. My dissertation compares these simulations with polarization data from Betelgeuse and other massive stars with bow shocks. I discuss the

  2. The existence and nature of the interstellar bow shock

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Jaffel, Lotfi [UPMC Univ Paris 06, UMR7095, Institut d' Astrophysique de Paris, F-75014, Paris (France); Strumik, M.; Ratkiewicz, R.; Grygorczuk, J., E-mail: bjaffel@iap.fr [Space Research Centre, Polish Academy of Sciences, Bartycka 18A, 00-716 Warsaw (Poland)

    2013-12-20

    We report a new diagnosis of two different states of the local interstellar medium (LISM) near our solar system by using a sensitivity study constrained by several distinct and complementary observations of the LISM, solar wind, and inner heliosphere. Assuming the Interstellar Boundary Explorer (IBEX) He flow parameters for the LISM, we obtain a strength of ∼2.7 ± 0.2 μG and a direction pointing away from galactic coordinates (28, 52) ± 3° for the interstellar magnetic field as a result of fitting Voyager 1 and Voyager 2 in situ plasma measurements and IBEX energetic neutral atoms ribbon. When using Ulysses parameters for the LISM He flow, we recently reported the same direction but with a strength of 2.2 ± 0.1 μG. First, we notice that with Ulysses He flow, our solution is in the expected hydrogen deflection plane (HDP). In contrast, for the IBEX He flow, the solution is ∼20° away from the corresponding HDP plane. Second, the long-term monitoring of the interplanetary H I flow speed shows a value of ∼26 km s{sup –1} measured upwind from the Doppler shift in the strong Lyα sky background emission line. All elements of the diagnosis seem therefore to support Ulysses He flow parameters for the interstellar state. In that frame, we argue that reliable discrimination between superfast, subfast, or superslow states of the interstellar flow should be based on most existing in situ and remote observations used together with global modeling of the heliosphere. For commonly accepted LISM ionization rates, we show that a fast interstellar bow shock should be standing off upstream of the heliopause.

  3. Electric field measurements at subcritical, oblique bow shock crossings

    International Nuclear Information System (INIS)

    Wygant, J.R.; Bensadoun, M.; Mozer, F.S.

    1987-01-01

    Electric field measurements at oblique, subcritical bow shock crossings are presented from the ISEE 1 University of California, Berkeley, double-probe electric field experiment. The measurements averaged over the 3-s spin period of the spacecraft provide the first observations of the large-scale (100 km) laminar oscillations in the longitudinal component of the electric field associated with the whistler precursor which is characteristic of these dispersive shocks. The amplitude of the oscillations increases from ∼0.5 mV/m to a maximum of 6 mV/m across the magnetic ramp of the shock (directed along the shock normal). The calculated electric potential drops across the shocks varied from 340 to 550 volts, which is 40-60% of the observed loss of kinetic energy associated with the bulk flow of the ions. These measurements suggest that at these shocks the additional deceleration of incident ions is due to the Lorentz force. The contributions to the normal component of the large-scale electric field at the shock due to the parallel and perpendicular components (relative to the magnetic field) of the electric field are evaluated. It is shown that the perpendicular component of the electric field dominates, accounting for most of the cross-shock potential, but that there is a nonnegligible parallel component. This large-scale parallel component has a magnitude of 1-2 mV/m which sometimes results in a potential well for electrons with a depth of ∼150 eV. It is experimentally demonstrated that the dominance of the perpendicular over the parallel component of the electric field resulted in a correlation between the longitudinal component of the large-scale electric field and the fluctuations in the magnetic field component perpendicular to the coplanarity plane

  4. Observing and Reducing IFUs: INTEGRAL and PMAS—Properties of the Ionized Gas in HH 202

    Directory of Open Access Journals (Sweden)

    Luis López-Martín

    2014-01-01

    Full Text Available The reduction of integral field spectroscopy (IFS data requires several stages and many repetitive operations to convert raw data into, typically, a large number of spectra. Instead there are several semiautomatic data reduction tools and here we present this data reduction process using some of the Image Reduction and Analysis Facility (IRAF tasks devoted to reduce spectroscopic data. After explaining the whole process, we illustrate the power of this instrumental technique with some results obtained for the object HH202 in the Orion Nebula (Mesa-Delgado et al., 2009.

  5. Exploring the triplet parameters space to optimise the final focus of the FCC-hh

    CERN Document Server

    AUTHOR|(CDS)2141109; Abelleira, Jose; Seryi, Andrei; Cruz Alaniz, Emilia

    2017-01-01

    One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation and MADX for more precise calculations. In cooperation with radiation studies, this algorithm was then applied to design an alternative triplet for the final focus of the Future Circular Collider (FCC-hh).

  6. Radiation Load Optimization in the Final Focus System of FCC-hh

    CERN Document Server

    Martin, Roman; Cerutti, Francesco; Tomás, Rogelio

    2016-01-01

    With a center-of-mass energy of up to 100 TeV, FCC-hh will produce highly energetic collision debris at the Interaction Point (IP). Protecting the final focus quadrupoles from this radiation is challenging, since the required amount of shielding placed inside the magnets will reduce the free aperture, thereby limiting the β^{*} reach and luminosity. Hence, radiation mitigation strategies that make best use of the available aperture are required. In this paper, we study the possibility to split the first quadrupole Q1 into two quadrupoles with individual apertures, in order to distribute the radiation load more evenly and reduce the peak dose.

  7. High velocity molecular gas near Herbig-Haro objects HH 7--11

    International Nuclear Information System (INIS)

    Snell, R.L.; Edwards, S.

    1981-01-01

    Observations of the J = 2-1 and J = 1-0 transitions of 12 CO and 13 CO reveal the presence of high velocity molecular gas associated with a low luminosity infrared source in the vicinity of the Herbig-Haro objects HH 7--11. The blueshifted and redshifted wings show peak intensities spatially separated by 1X5 (0.2 pc), suggesting an energetic bipolar outflow of gas from a young low mass star. The mass loss rate implied by these observations is 8 x 10 -6 M/sub sun/ yr -1

  8. Scattering of field-aligned beam ions upstream of Earth's bow shock

    Directory of Open Access Journals (Sweden)

    A. Kis

    2007-03-01

    Full Text Available Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

  9. Scattering of field-aligned beam ions upstream of Earth's bow shock

    Directory of Open Access Journals (Sweden)

    A. Kis

    2007-03-01

    Full Text Available Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

  10. Blade bowing effects on radial equilibrium of inlet flow in axial compressor cascades

    Directory of Open Access Journals (Sweden)

    Han XU

    2017-10-01

    Full Text Available The circumferentially averaged equation of the inlet flow radial equilibrium in axial compressor was deduced. It indicates that the blade inlet radial pressure gradient is closely related to the radial component of the circumferential fluctuation (CF source item. Several simplified cascades with/without aerodynamic loading were numerically studied to investigate the effects of blade bowing on the inlet flow radial equilibrium. A data reduction program was conducted to obtain the CF source from three-dimensional (3D simulation results. Flow parameters at the passage inlet were focused on and each term in the radial equilibrium equation was discussed quantitatively. Results indicate that the inviscid blade force is the inducement of the inlet CF due to geometrical asymmetry. Blade bowing induces variation of the inlet CF, thus changes the radial pressure gradient and leads to flow migration before leading edge (LE in the cascades. Positive bowing drives the inlet flow to migrate from end walls to mid-span and negative bowing turns it to the reverse direction to build a new equilibrium. In addition, comparative studies indicate that the inlet Mach number and blade loading can efficiently impact the effectiveness of blade bowing on radial equilibrium in compressor design.

  11. Multispacecraft observations of energetic ions upstream and downstream of the bow shock

    International Nuclear Information System (INIS)

    Scholer, M.; Mobius, E.; Kistler, L.M.; Klecker, B.; Ipavich, F.M.; Department of Physics and Astronomy, University of Maryland, College Park)

    1989-01-01

    We present simultaneous measurements of energetic protons and alpha particles inside and outside of the magnetopause, immediately upstream, and downstream as well as further upstream of the bow shock. A comparison between the intensity at the bow shock and further upstream results in an e-folding distance at 30 keV of similar to 6.2 R/sub E/. After transformation of the angular distribution into the solar wind frame a diffusion coefficeint of κ/sub parallel/similar to 3 R/sub E/ is obtained from the anisotropy and the intensity gradient. Immediately downstream of the bow shock the anisotropy in the shock frame is directed toward the magnetopause. After transformation into the plasma rest frame the distribution is isotropic. The intensity in the magnetosheath just outside the magnetopause is smaller than the intensity behind the bow shock. Thus, in the magnetosheath there is no gradient or streaming in the upstream direction. The spectra, intensities, and relative abundances in the magnetosheath and inside the magnetosphere are totally different. These observations are consistent with first order Fermi acceleration at the bow shock and subsequent downstream convection, and exclude a magnetospheric source for these particles. Copyright American Geophysical Union 1989

  12. BOWS (bioinformatics open web services) to centralize bioinformatics tools in web services.

    Science.gov (United States)

    Velloso, Henrique; Vialle, Ricardo A; Ortega, J Miguel

    2015-06-02

    Bioinformaticians face a range of difficulties to get locally-installed tools running and producing results; they would greatly benefit from a system that could centralize most of the tools, using an easy interface for input and output. Web services, due to their universal nature and widely known interface, constitute a very good option to achieve this goal. Bioinformatics open web services (BOWS) is a system based on generic web services produced to allow programmatic access to applications running on high-performance computing (HPC) clusters. BOWS intermediates the access to registered tools by providing front-end and back-end web services. Programmers can install applications in HPC clusters in any programming language and use the back-end service to check for new jobs and their parameters, and then to send the results to BOWS. Programs running in simple computers consume the BOWS front-end service to submit new processes and read results. BOWS compiles Java clients, which encapsulate the front-end web service requisitions, and automatically creates a web page that disposes the registered applications and clients. Bioinformatics open web services registered applications can be accessed from virtually any programming language through web services, or using standard java clients. The back-end can run in HPC clusters, allowing bioinformaticians to remotely run high-processing demand applications directly from their machines.

  13. BOW SHOCK FRAGMENTATION DRIVEN BY A THERMAL INSTABILITY IN LABORATORY ASTROPHYSICS EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki-Vidal, F.; Lebedev, S. V.; Pickworth, L. A.; Swadling, G. F.; Skidmore, J.; Hall, G. N.; Bennett, M.; Bland, S. N.; Burdiak, G.; De Grouchy, P.; Music, J.; Suttle, L. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Ciardi, A. [Sorbonne Universités, UPMC Univ. Paris 6, UMR 8112, LERMA, F-75005, Paris (France); Rodriguez, R.; Gil, J. M.; Espinosa, G. [Departamento de Fisica de la Universidad de Las Palmas de Gran Canaria, E-35017 Las Palmas de Gran Canaria (Spain); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Hansen, E.; Frank, A., E-mail: f.suzuki@imperial.ac.uk [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

    2015-12-20

    The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the collision of two counterstreaming, supersonic plasma jets produced by an opposing pair of radial foil Z-pinches driven by the current pulse from the MAGPIE pulsed-power generator. The jets have different flow velocities in the laboratory frame, and the experiments are driven over many times the characteristic cooling timescale. The initially smooth bow shock rapidly develops small-scale nonuniformities over temporal and spatial scales that are consistent with a thermal instability triggered by strong radiative cooling in the shock. The growth of these perturbations eventually results in a global fragmentation of the bow shock front. The formation of a thermal instability is supported by analysis of the plasma cooling function calculated for the experimental conditions with the radiative packages ABAKO/RAPCAL.

  14. The Milky Way Project: A Citizen Science Catalog of Infrared Bow Shock Nebulae

    Science.gov (United States)

    Dixon, Don; Jayasinghe, Tharindu; Povich, Matthew S.

    2017-01-01

    We present preliminary results from the first citizen-science search for infrared stellar-wind bow shock candidates. This search uses the Milky Way project, hosted by the Zooniverse, an online platform with over 1 million volunteer citizen scientists. Milky Way Project volunteers examine 77,000 randomly-distributed Spitzer image cutouts at varying zoom levels. Volunteers mark the infrared arc of potential bow shock candidates as well as the star likely driving the nebula. We produce lists of candidates from bow shocks flagged by multiple volunteers, which after merging and final visual review form the basis for our catalog. Comparing our new catalog to a recently-published catalog of 709 infrared bow shock candidates identified by a small team of (primarily undergraduate) researchers will allow us to assess the effectiveness of citizen science for this type of search and should yield a more complete catalog. Planned studies using these large catalogs will improve constraints on the mass-loss rates for the massive stars that create these bow shock nebulae. Mass-loss rates are highly uncertain but are a critical component of evolutionary models for massive stars. This work is supported by the National Science Foundation under grants CAREER-1454334, AST-1411851 (RUI) and AST-1412845.

  15. Physics and life-business: Participation of IFIN-HH in ConvEX-3 Exercise

    International Nuclear Information System (INIS)

    Vamanu, D.; Slavnicu, D.; Gheorghiu, Dorina; Acasandrei, V.; Vamanu, B.

    2005-01-01

    The paper illustrates a less popular yet by no means less consequential task within IFIN-HH's public mission, namely - to provide scientific advice and technical support in the management of nuclear accidents and radiological emergencies. The case in point is ConvEX-3, a 36-hour, 41-actor-countries international alert exercise conducted, May 2005, by the International Atomic Energy Agency in Vienna and targeting a virtual accident at Cernavoda Nuclear Power Plant, Romania. A comprehensive Technical Report compiled in the aftermath of the exercise covers the results, as well as the ways and means at work, highlighting the productive complementarities of the two chief tools employed as assessment and decision support: RODOS (Real Time On-line Decision Support) - a 'major league' expert system based on fixed workstations, in development under an EC project and vying for a position of comprehensive, reference European tool 160 in nuclear emergency crises - for which IFIN-HH is the sole licensed operator in Romania; and RAT (Radiological Assessment Toolkit), a 'minor league' domestic counterpart operating at PC level, assembling a vademecum of, mainly U.S.-originated, reference models dwelling in radioactive inventories, source terms, environmental dispersion, dose and derived response levels, cadastral evaluation of impacts, and countermeasure assessment. (authors)

  16. Optimizing laboratory animal stress paradigms: The H-H* experimental design.

    Science.gov (United States)

    McCarty, Richard

    2017-01-01

    Major advances in behavioral neuroscience have been facilitated by the development of consistent and highly reproducible experimental paradigms that have been widely adopted. In contrast, many different experimental approaches have been employed to expose laboratory mice and rats to acute versus chronic intermittent stress. An argument is advanced in this review that more consistent approaches to the design of chronic intermittent stress experiments would provide greater reproducibility of results across laboratories and greater reliability relating to various neural, endocrine, immune, genetic, and behavioral adaptations. As an example, the H-H* experimental design incorporates control, homotypic (H), and heterotypic (H*) groups and allows for comparisons across groups, where each animal is exposed to the same stressor, but that stressor has vastly different biological and behavioral effects depending upon each animal's prior stress history. Implementation of the H-H* experimental paradigm makes possible a delineation of transcriptional changes and neural, endocrine, and immune pathways that are activated in precisely defined stressor contexts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 20 years of cosmic muons research performed in IFIN-HH

    Energy Technology Data Exchange (ETDEWEB)

    Mitrica, Bogdan [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Bucharest, P.O.B.MG-6 (Romania)

    2012-11-20

    During the last two decades a modern direction in particle physics research has been developed in IFIN-HH Bucharest, Romania. The history started with the WILLI detector built in IFIN-HH Bucharest in collaboration with KIT Karlsruhe (formerly Forschungszentrum Karlsruhe). The detector was designed for measurements of the low energy muon charge ratio (< 1GeV) based on a delayed coincidence method, measuring the decay time of the muons stopped in the detector: the positive muons decay freely, but the negative muons are captured in the atom thus creating muonic atoms and decay depending on the nature of the host atom. In a first configuration, the WILLI detector was placed in a fixed position for measuring vertical muons. Further WILLI has been transformed in a rotatable device which allows directional measurements of muon charge ratio and muon flux. The results exhibit a pronounced azimuthal asymmetry (East-West effect) due to the different in fluence of the geomagnetic field on the trajectories of positive and negative muons in air. In parallel, flux measurement, taking into account muon events with nergies > 0.4GeV, show a diurnal modulation of the muon flux. The analysis of the muon events for energies < 0.6GeV reveals an aperiodic variation of the muon flux. A new detection system performing coincidence measurements between the WILLI calorimeter and a small array of 12 scintillators plates has been installed in IFIN-HH starting from the autumn of 2010. The aim of the system is to investigate muon charge ratio from individual EAS by using the mini-array as trigger for the WILLI calorimeter. Such experimental studies could provide detailed information on hadronic interaction models and primary cosmic ray composition at energies around 10{sup 15}eV. Simulation studies and preliminary experimental tests, regarding the performances of the mini-array, have been performed using H and Fe primaries, with energies in a range 10{sup 13}eV - 10{sup 15}eV. The results show

  18. A matched Bow-tie antenna at 433MHz for use in underwater wireless sensor networks

    International Nuclear Information System (INIS)

    Abdou, A A; Shaw, A; Mason, A; Al-Shamma'a, A; Cullen, J; Wylie, S; Diallo, M

    2013-01-01

    Electromagnetic (EM) wave propagation underwater is been disregarded because of attenuation at high frequencies, however the theory predicts that propagation is possible at some useful distance in the lower Industrial, Scientific and Medical (ISM) band. Common transceivers rely on narrowband antennas and matching circuit. The aim of this paper is to design a broadband 433MHz bow-tie antenna and experiment it in air and water without a matching circuit. This antenna could be attached to wireless transceivers and form a Wireless Sensor Network for deployment in various underwater applications. The bow-tie antennas were designed, simulated and constructed in laboratory. Experiments were setup carefully by using a completely isolated transmitter from electronics to avoid airborne transmission. The 433MHz. bow-tie proved its suitability for use in Underwater.

  19. Sedentism, social change, warfare, and the bow in the ancient Pueblo Southwest.

    Science.gov (United States)

    Reed, Paul F; Geib, Phil R

    2013-01-01

    In the ancient American Southwest, use of the bow developed relatively rapidly among Pueblo people by the fifth century AD. This new technology replaced the millennia-old atlatl and dart weaponry system. Roughly 150 years later in the AD 600s, Pueblo socioeconomic organization began to evolve rapidly, as many groups adopted a much more sedentary life. Multiple factors converged to allow this sedentary pattern to emerge, but the role of the bow in this process has not been fully explored. In this paper, we trace the development of the bow and discuss its role as sedentism emerged and social changes occurred in ancient Puebloan society from the fifth through seventh centuries AD. Copyright © 2013 Wiley Periodicals, Inc.

  20. Reliability of the input admittance of bowed-string instruments measured by the hammer method.

    Science.gov (United States)

    Zhang, Ailin; Woodhouse, Jim

    2014-12-01

    The input admittance at the bridge, measured by hammer testing, is often regarded as the most useful and convenient measurement of the vibrational behavior of a bowed string instrument. However, this method has been questioned, due especially to differences between human bowing and hammer impact. The goal of the research presented here is to investigate the reliability and accuracy of this classic hammer method. Experimental studies were carried out on cellos, with three different driving conditions and three different boundary conditions. Results suggest that there is nothing fundamentally different about the hammer method, compared to other kinds of excitation. The third series of experiments offers an opportunity to explore the difference between the input admittance measuring from one bridge corner to another and that of single strings. The classic measurement is found to give a reasonable approximation to that of all four strings. Some possible differences between the hammer method and normal bowing and implications of the acoustical results are also discussed.

  1. A numerical study on bow shocks around the lightning return stroke channel

    International Nuclear Information System (INIS)

    Chen, Qiang; Chen, Bin; Yi, Yun; Chen, P. F.; Mao, Yunfei; Xiong, Run

    2015-01-01

    Bow shock structures are important to various hydrodynamics and magnetohydrodynamics (MHD) phenomena in geophysics and astrophysics. The formation and propagation of bow shocks around the lightning return stroke channel are investigated based on the self-similar motion theory and simulated with a two-dimensional Eulerian finite volume resistive radiation MHD code. In this framework, as verification of theoretical models, the evolving structures of many quantities, such as the plasma density, temperature, pressure, shock velocity, and magnetic field, can be obtained, which present all the characteristics of bow shocks in the lightning return stroke processes. The evolution characteristics and the configuration of the curved return stroke channels, e.g., the non-ideal effects and the scaling laws, are discussed in detail. The results may have applications for some observed features of the return stroke channels and other phenomena in the lightning discharge plasmas

  2. An IRAS/ISSA Survey of Bow Shocks Around Runaway Stars

    Science.gov (United States)

    Buren, David Van

    1995-01-01

    We searched for bow shock-like objects like those known around Oph and a Cam near the positions of 183 runaway stars. Based primarily on the presence and morphology of excess 60 micron emission we identify 56 new candidate bow shocks, for which we determine photometric and morphological parameters. Previously only a dozen or so were known. Well resolved structures are present around 25 stars. A comparison of the distribution of symmetry axes of the infrared nebulae with that of their proper motion vectors indicates that these two directions are very significantly aligned. The observed alignment strongly suggests that the structures we see arise from the interaction of stellar winds with the interstellar medium, justifying the identification of these far-infrared objects as stellar wind bow shocks.

  3. Prenatal diagnosis of metatropic dysplasia: beware of the pseudo-bowing sign

    International Nuclear Information System (INIS)

    Garel, Catherine; Dhouib, Amira; Sileo, Chiara; Ducou le Pointe, Hubert; Cormier-Daire, Valerie

    2014-01-01

    Metatropic dysplasia is a very rare form of osteochondrodysplasia with only one case of prenatal diagnosis described in the literature. It is characterized by marked shortening of the long bones with severe platyspondyly and dumbbell-shape metaphyses. We report a case of metatropic dysplasia that was diagnosed prenatally and describe the findings on US and CT. The pregnancy was terminated and the post-mortem radiographs are shown. The woman had been referred for short and bowed long bones. Severe metaphyseal enlargement was a misleading finding because it had been misinterpreted as limb bowing. Thus when abnormal curvature of the long bones is observed at prenatal US, attention should be drawn not only to the diaphyses but also to the metaphyses because severe metaphyseal enlargement might be responsible for pseudo-bowing. (orig.)

  4. Prenatal diagnosis of metatropic dysplasia: beware of the pseudo-bowing sign

    Energy Technology Data Exchange (ETDEWEB)

    Garel, Catherine [Trousseau Hospital, University Hospitals of the East of Paris, Department of Radiology, Paris (France); Hopital d' Enfants Armand-Trousseau, Department of Radiology, Paris (France); Dhouib, Amira; Sileo, Chiara; Ducou le Pointe, Hubert [Trousseau Hospital, University Hospitals of the East of Paris, Department of Radiology, Paris (France); Cormier-Daire, Valerie [Paris Descartes University, Sorbonne Paris Cite, Necker-Enfants-Malades Hospital, Department of Genetics, Paris (France)

    2014-03-15

    Metatropic dysplasia is a very rare form of osteochondrodysplasia with only one case of prenatal diagnosis described in the literature. It is characterized by marked shortening of the long bones with severe platyspondyly and dumbbell-shape metaphyses. We report a case of metatropic dysplasia that was diagnosed prenatally and describe the findings on US and CT. The pregnancy was terminated and the post-mortem radiographs are shown. The woman had been referred for short and bowed long bones. Severe metaphyseal enlargement was a misleading finding because it had been misinterpreted as limb bowing. Thus when abnormal curvature of the long bones is observed at prenatal US, attention should be drawn not only to the diaphyses but also to the metaphyses because severe metaphyseal enlargement might be responsible for pseudo-bowing. (orig.)

  5. A Possible Buried Impact Structure Near Bow City, Alberta

    Science.gov (United States)

    Xie, W.; Glombick, P.; Schmitt, D. R.; Bown, T. D.

    2012-12-01

    In recent years, improved exploration techniques have resulted in the serendipitous discoveries of increasing numbers of extraterrestrial impact structures in sedimentary basins around the world. Following in this tradition, a new potential impact structure centered near 50.4°N, 112.35°N in SE Alberta has been identified. The first indications of this structure appeared in careful systematic mapping of Cretaceous age sediments using public domain well log information that showed overturned and missing components in what regionally is a simple layered stratigraphy. This motivated the examination of legacy 2D seismic profiles over the area that confirmed the stratigraphic anomalies and provided new details that further supported interpretation of a potential impact structure. Further, the existence of unexpected faults through the Cretaceous Bearpaw formation had been noted as early as the 1940's in the limited outcrop available in coulees, and these as well as other complex fault structures along the Bow River outcrops were confirmed in recent field visits to the site. The 2D seismic data displays a number of listric and rose-petal faulting consistent with late stage collapse of the impact crater. Further, a seismically transparent central uplift peak is visible. Based on the results, the structure is recognized as a complex crater with a diameter of approximately 8 kilometers and, today, bottoming at a depth of 900 meters from the current surface. Currently, the age of the feature is grossly estimated to be less than 70 my on the basis of underlying undisturbed seismic reflectors. The structure may be somewhat unique in that weak coals surrounding the feature are clearly thickened indicating outward lateral sliding along shear planes through weaker layers. Work in progress includes acquisition of a high resolution seismic profile and detailed mapping of the magnetic and gravity potential fields. More detailed mapping will include searches for shock metamorphism

  6. Magnetic field fluctuations across the Earth's bow shock

    Energy Technology Data Exchange (ETDEWEB)

    Czaykowska, A.; Bauer, T.M. [Max-Planck-Institut fuer Extraterrestrische Physik, Garching (Germany); Treumann, R.A. [Max-Planck-Institut fuer Extraterrestrische Physik, Garching (Germany); Centre for Interdisciplinary Plasma Science, Garching (Germany); International Space Science Inst. (ISSI), Bern (Switzerland); Baumjohann, W. [Max-Planck-Institut fuer Extraterrestrische Physik, Garching (Germany); Inst. fuer Weltraumforschung der Oesterreichischen Akademie der Wissenschaften, Graz (Austria)

    2001-03-01

    We present a statistical analysis of 132 dayside (LT 0700-1700) bow shock crossings of the AMPTE/IRM spacecraft. We perform a superposed epoch analysis of low frequency, magnetic power spectra some minutes upstream and downstream of the bow shock. The events are devided into categories depending on the angle {theta}{sub Bn} between bow shock normal and interplanetary magnetic field, and on plasma-{beta}. In the foreshock upstream of the quasi-parallel bow shock, the power of the magnetic fluctuations is roughly 1 order of magnitude larger ({delta}B {proportional_to} 4 nT for frequencies 0.01-0.04 Hz) than upstream of the quasi-perpendicular shock. There is no significant difference in the magnetic power spectra upstream and downstream of the quasi-parallel bow shock; only at the shock itself, is the magnetic power enhanced by a factor of 4. This enhancement may be due to either an amplification of convecting upstream waves or to wave generation at the shock interface. On the contrary, downstream of the quasi-perpendicular shock, the magnetic wave activity is considerably higher than upstream. Downstream of the quasi-perpendicular low-{beta} bow shock, we find a dominance of the left-hand polarized component at frequencies just below the ion-cyclotron frequency, with amplitudes of about 3 nT. These waves are identified as ion-cyclotron waves, which grow in a low-{beta} regime due to the proton temperature anisotropy. We find a strong correlation of this anisotropy with the intensity of the left-hand polarized component. Downstream of some nearly perpendicular ({theta}{sub Bn} {approx} 90 ) high-{beta} crossings, mirror waves are identified. However, there are also cases where the conditions for mirror modes are met downstream of the nearly perpendicular shock, but no mirror waves are observed. (orig.)

  7. NUMERICAL SIMULATION OF THE SVS 13 MICROJET AND BOW SHOCK BUBBLE

    International Nuclear Information System (INIS)

    Gardner, Carl L.; Jones, Jeremiah R.; Hodapp, Klaus W.

    2016-01-01

    Numerical simulations of the SVS 13 microjet and bow shock bubble are performed using the WENO method that reproduces the main features and dynamics of data from the Keck Telescope/OSIRIS velocity-resolved integral field spectrograph: an expanding, cooler bow shock bubble, with the bubble center moving at approximately 50 km s −1 with a radial expansion velocity of 11 km s −1 , surrounding the fast, hotter jet, which is propagating at 156 km s −1 . Contact and bow shock waves are visible in the simulations both from the initial short jet pulse that creates the nearly spherical bow shock bubble and from the fast microjet, while a terminal Mach disk shock is visible near the tip of the continuous microjet, which reduces the velocity of the jet gas down to the flow velocity of the contact discontinuity at the leading edge of the jet. At 21.1 years after the launch of the initial bubble pulse, the jet has caught up with and penetrated almost all the way across the bow shock bubble of the slower initial pulse. At times later than about 22 years, the jet has penetrated through the bubble and thereafter begins to subsume its spherical form. Emission maps from the simulations of the jet—traced by the emission of the shock-excited 1.644 μ m [Fe ii] line—and the bow shock bubble—traced in the lower excitation 2.122 μ m H 2 1–0 S(1) line—projected onto the plane of the sky are presented, and are in good agreement with the Keck observations.

  8. Numerical Simulation of the SVS 13 Microjet and Bow Shock Bubble

    Science.gov (United States)

    Gardner, Carl L.; Jones, Jeremiah R.; Hodapp, Klaus W.

    2016-10-01

    Numerical simulations of the SVS 13 microjet and bow shock bubble are performed using the WENO method that reproduces the main features and dynamics of data from the Keck Telescope/OSIRIS velocity-resolved integral field spectrograph: an expanding, cooler bow shock bubble, with the bubble center moving at approximately 50 km s-1 with a radial expansion velocity of 11 km s-1, surrounding the fast, hotter jet, which is propagating at 156 km s-1. Contact and bow shock waves are visible in the simulations both from the initial short jet pulse that creates the nearly spherical bow shock bubble and from the fast microjet, while a terminal Mach disk shock is visible near the tip of the continuous microjet, which reduces the velocity of the jet gas down to the flow velocity of the contact discontinuity at the leading edge of the jet. At 21.1 years after the launch of the initial bubble pulse, the jet has caught up with and penetrated almost all the way across the bow shock bubble of the slower initial pulse. At times later than about 22 years, the jet has penetrated through the bubble and thereafter begins to subsume its spherical form. Emission maps from the simulations of the jet—traced by the emission of the shock-excited 1.644 μm [Fe II] line—and the bow shock bubble—traced in the lower excitation 2.122 μm H2 1-0 S(1) line—projected onto the plane of the sky are presented, and are in good agreement with the Keck observations.

  9. Accuracy of two face-bow/semi-adjustable articulator systems in transferring the maxillary occlusal cant

    Directory of Open Access Journals (Sweden)

    Nazia Nazir

    2012-01-01

    Full Text Available Context: The precision of an arbitrary face-bow in accurately transferring the orientation of the maxillary cast to the articulator has been questioned because the maxillary cast is mounted in relation to arbitrary measurements and anatomic landmarks that vary among individuals. Aim: This study was intended to evaluate the sagittal inclination of mounted maxillary casts on two semi-adjustable articulator/face-bow systems in comparison to the occlusal cant on lateral cephalograms. Materials and Methods: Maxillary casts were mounted on the Hanau and Girrbach semi-adjustable articulators following face-bow transfer with their respective face-bows. The sagittal inclination of these casts was measured in relation to the fixed horizontal reference plane using physical measurements. Occlusal cant was measured on lateral cephalograms. SPSS software (version 11.0, Chicago, IL, USA was used for statistical analysis. Repeated measures analysis of variance and Tukey′s tests were used to evaluate the results (P < 0.05. Results: Comparison of the occlusal cant on the articulators and cephalogram revealed statistically significant differences. Occlusal plane was steeper on Girrbach Artex articulator in comparison to the Hanau articulator. Conclusion: Within the limitations of this study, it was found that the sagittal inclination of the mounted maxillary cast achieved with Hanau articulator was closer to the cephalometric occlusal cant as compared to that of the Girrbach articulator. Among the two articulators and face-bow systems, the steepness of sagittal inclination was greater on Girrbach semi-adjustable articulator. Different face-bow/articulator systems could result in different orientation of the maxillary cast, resulting in variation in stability, cuspal inclines and cuspal heights.

  10. Accuracy of two face-bow/semi-adjustable articulator systems in transferring the maxillary occlusal cant.

    Science.gov (United States)

    Nazir, Nazia; Sujesh, M; Kumar, Ravi; Sreenivas, P

    2012-01-01

    The precision of an arbitrary face-bow in accurately transferring the orientation of the maxillary cast to the articulator has been questioned because the maxillary cast is mounted in relation to arbitrary measurements and anatomic landmarks that vary among individuals. This study was intended to evaluate the sagittal inclination of mounted maxillary casts on two semi-adjustable articulator/face-bow systems in comparison to the occlusal cant on lateral cephalograms. Maxillary casts were mounted on the Hanau and Girrbach semi-adjustable articulators following face-bow transfer with their respective face-bows. The sagittal inclination of these casts was measured in relation to the fixed horizontal reference plane using physical measurements. Occlusal cant was measured on lateral cephalograms. SPSS software (version 11.0, Chicago, IL, USA) was used for statistical analysis. Repeated measures analysis of variance and Tukey's tests were used to evaluate the results (P occlusal cant on the articulators and cephalogram revealed statistically significant differences. Occlusal plane was steeper on Girrbach Artex articulator in comparison to the Hanau articulator. Within the limitations of this study, it was found that the sagittal inclination of the mounted maxillary cast achieved with Hanau articulator was closer to the cephalometric occlusal cant as compared to that of the Girrbach articulator. Among the two articulators and face-bow systems, the steepness of sagittal inclination was greater on Girrbach semi-adjustable articulator. Different face-bow/articulator systems could result in different orientation of the maxillary cast, resulting in variation in stability, cuspal inclines and cuspal heights.

  11. 76 FR 2710 - Pitney Bowes, Inc., Mailing Solutions Management Division Including On-Site Leased Workers of...

    Science.gov (United States)

    2011-01-14

    ...., Mailing Solutions Management Division Including On-Site Leased Workers of Guidant Group, and Teleworkers... Bowes, Inc., Mailing Solutions Management Division, Engineering Quality Assurance, Shelton, Connecticut... identity of the subject worker group. The worker group consists of workers of Pitney Bowes, Inc., the...

  12. Wrist muscle activity of khatrah approach in Mameluke technique using traditional bow archery

    Science.gov (United States)

    Ariffin, Muhammad Shahimi; Rambely, Azmin Sham; Ariff, Noratiqah Mohd

    2018-04-01

    An investigation of khatrah technique in archery was carried out. An electromyography (EMG) experiment was conducted towards six wrist muscles which are flexor carpi radialis, extensor carpi ulnaris and extensor digitorum communis for both arms. The maximum voluntary contraction (MVC) and activity data were recorded. The bow arm produced a higher muscle force compared to draw arm muscles during release phase. However, the muscle forces produced by bow arm had a consistency in term of pattern throughout the phases. In conclusion, the forces generated by the professional archer produced a force benchmark at the wrist joint to alleviate the risk of injury.

  13. ASYMPTOTIC STEADY-STATE SOLUTION TO A BOW SHOCK WITH AN INFINITE MACH NUMBER

    Energy Technology Data Exchange (ETDEWEB)

    Yalinewich, Almog; Sari, Re’em [Racah Institute of Physics, the Hebrew University, 91904, Jerusalem (Israel)

    2016-08-01

    The problem of a cold gas flowing past a stationary obstacle is considered. We study the bow shock that forms around the obstacle and show that at large distances from the obstacle the shock front forms a parabolic solid of revolution. The profiles of the hydrodynamic variables in the interior of the shock are obtained by solution of the hydrodynamic equations in parabolic coordinates. The results are verified with a hydrodynamic simulation. The drag force on the obstacle is also calculated. Finally, we use these results to model the bow shock around an isolated neutron star.

  14. A conceptual solution for a beam halo collimation system for the Future Circular hadron-hadron Collider (FCC-hh)

    Science.gov (United States)

    Fiascaris, M.; Bruce, R.; Redaelli, S.

    2018-06-01

    We present the first conceptual solution for a collimation system for the hadron-hadron option of the Future Circular Collider (FCC-hh). The collimation layout is based on the scaling of the present Large Hadron Collider collimation system to the FCC-hh energy and it includes betatron and momentum cleaning, as well as dump protection collimators and collimators in the experimental insertions for protection of the final focus triplet magnets. An aperture model for the FCC-hh is defined and the geometrical acceptance is calculated at injection and collision energy taking into account mechanical and optics imperfections. The performance of the system is then assessed through the analysis of normalized halo distributions and complete loss maps for an ideal lattice. The performance limitations are discussed and a solution to improve the system performance with the addition of dispersion suppression collimators around the betatron cleaning insertion is presented.

  15. Latest developments in the predisposal of radioactive waste at the radioactive waste management department from ifin-hh

    International Nuclear Information System (INIS)

    Dragolici, F.; Dogaru, G.; Neacsu, E.

    2016-01-01

    The Radioactive Waste Management Department (DMDR) from IFIN-HH has a wide experience in the management of the non-fuel cycle radioactive wastes from all over Romania generated from nuclear techniques and technologies application, assuring the radiological safety and security of operators, population and environment. During 2011-2015 was implemented a major upgrading programme applied both on the technological systems of the building and on equipment. The paper describes the facility developments having the scope to share to the public and stakeholders the radioactive waste predisposal capabilities available at DMDR-IFIN-HH. As a whole, today DMDR-IFIN-HH represents a complete and complex infrastructure, assuring high quality services in all the steps related to the management of the institutional radioactive waste in Romania. (authors)

  16. 177Lu-DOTA-HH1, a novel anti-CD37 radio-immunoconjugate: a study of toxicity in nude mice.

    Directory of Open Access Journals (Sweden)

    Ada H V Repetto-Llamazares

    Full Text Available CD37 is an internalizing B-cell antigen expressed on Non-Hodgkin lymphoma (NHL and chronic lymphocytic leukemia cells (CLL. The anti-CD37 monoclonal antibody HH1 was conjugated to the bifunctional chelator p-SCN-Bn-DOTA and labelled with the beta-particle emitting radionuclide 177Lu creating the radio-immunoconjugate (RIC 177Lu-DOTA-HH1 (177Lu-HH1, trade name Betalutin. The present toxicity study was performed prior to initiation of clinical studies with 177Lu-HH1.Nude mice with or without tumor xenografts were treated with 50 to 1000 MBq/kg 177Lu- HH1 and followed for clinical signs of toxicity up to ten months. Acute, life threatening bone marrow toxicity was observed in animals receiving 800 and 1000 MBq/kg 177Lu-HH1. Significant changes in serum concentrations of liver enzymes were evident for treatment with 1000 MBq/kg 177Lu-HH1. Lymphoid depletion, liver necrosis and atrophy, and interstitial cell hyperplasia of the ovaries were also observed for mice in this dose group.177Lu-DOTA-HH1 was well tolerated at dosages about 10 times above those considered relevant for radioimmunotherapy in patients with B-cell derived malignancies.The toxicity profile was as expected for RICs. Our experimental results have paved the way for clinical evaluation of 177Lu-HH1 in NHL patients.

  17. THE COUNTERJET OF HH 30: NEW LIGHT ON ITS BINARY DRIVING SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Estalella, Robert; Lopez, Rosario; Riera, Angels [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E-08028 Barcelona (Spain); Anglada, Guillem; Carrasco-Gonzalez, Carlos [Instituto de Astrofisica de Andalucia, CSIC, Glorieta de la Astronomia s/n, E-18008 Granada (Spain); Gomez, Gabriel, E-mail: robert.estalella@am.ub.es, E-mail: rosario.lopez@am.ub.es, E-mail: guillem@iaa.es, E-mail: ggv@iac.es, E-mail: gabriel.gomez@gtc.iac.es, E-mail: angels.riera@upc.edu, E-mail: carrasco@mpifr-bonn.mpg.de [Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain)

    2012-08-15

    We present new [S II] images of the Herbig-Haro (HH) 30 jet and counterjet observed in 2006, 2007, and 2010 that, combined with previous data, allowed us to measure with improved accuracy the positions and proper motions of the jet and counterjet knots. Our results show that the motion of the knots is essentially ballistic, with the exception of the farthest knots, which trace the large-scale 'C'-shape bending of the jet. The observed bending of the jet can be produced by a relative motion of the HH 30 star with respect to its surrounding environment, caused either by a possible proper motion of the HH 30 star, or by the entrainment of environment gas by the red lobe of the nearby L1551-IRS5 outflow. Alternatively, the bending can be produced by the stellar wind from a nearby classical T Tauri star, identified in the Two Micron All Sky Survey catalog as J04314418+181047. The proper motion velocities of the knots of the counterjet show more variations than those of the jet. In particular, we identify two knots of the counterjet that have the same kinematic age but whose velocities differ by almost a factor of two. Thus, it appears from our observations that counterjet knots launched simultaneously can be ejected with very different velocities. We confirm that the observed wiggling of the jet and counterjet arises from the orbital motion of the jet source in a binary system. Precession, if present at all, is of secondary importance in shaping the jet. We derive an orbital period of {tau}{sub o} = 114 {+-} 2 yr and a mass function of m{mu}{sup 3}{sub c} = 0.014 {+-} 0.006 M{sub Sun }. For a mass of the system of m = 0.45 {+-} 0.04 M{sub Sun} (the value inferred from observations of the CO kinematics of the disk), we obtain a mass of m{sub j} = 0.31 {+-} 0.04 M{sub Sun} for the jet source, a mass of m{sub c} = 0.14 {+-} 0.03 M{sub Sun} for the companion, and a binary separation of a = 18.0 {+-} 0.6 AU. This binary separation coincides with the value required

  18. A new AMS facility based on a Cockcroft-Walton type 1 MV tandetron at IFIN-HH Magurele, Romania

    Science.gov (United States)

    Stan-Sion, C.; Enachescu, M.; Ghita, D. G.; Calinescu, C. I.; Petre, A.; Mosu, D. V.; Klein, M.

    2014-01-01

    A 1 MV AMS machine was recently installed in the National Institute for Physics and Nuclear Engineering IFIN-HH, Bucharest Romania. It is the second AMS facility at IFIN-HH having the goal not only to continue but mainly to enlarge the research area of this highly sensitive analyzing method. The multi-element AMS was developed by HVEE to measure 14C, 10Be, and 26Al, and 129I. The results of an acceptance test are presented and demonstrate that this machine is capable of routine 14C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as a low background level.

  19. Model for collimated outflows in molecular clouds and the case of HH 7-11

    Energy Technology Data Exchange (ETDEWEB)

    Silvestro, G; Ferrari, A; Rosner, R; Trussoni, E; Tsinganos, K

    1987-01-15

    Modelling is carried out for collimated outflows of high-velocity gas in molecular clouds, which is often observed to be associated with linear chains of optical emission knots. A wind-flow model is proposed to account for the phenomenon, based on the structural similarities between the outflows and jets from active galactic nuclei and quasars. The chain of Herbig-Haro objects HH7-11 is used to illustrate the proposal. The model is based on flows in a channel of variable cross-sectional area due to Kelvin-Helmholtz instabilities between the flow and the ambient medium. Solutions of the Mach number equation for such a channel are presented, which possess multiple critical points and shocks identified with observed optical knots. (U.K.).

  20. Evidence for CP violation in time-integrated $D^0 \\rightarrow h^-h^+$ decay rates

    CERN Document Server

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Comerma-Montells, A; Constantin, F; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; Elsby, D; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koopman, R; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalorav Goicochea, J M; Owen, P; Pal, K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrella, A; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, A C; Smith, N A; Smith, E; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Topp-Joergensen, S; Torr, N; Tournefier, E; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urquijo, P; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Viaud, B; Videau, I; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Voss, H; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yushchenko, O; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zverev, E; Zvyagin, A

    2012-01-01

    A search for time-integrated $CP$ violation in $D^0 \\rightarrow h^-h^+$ ($h=K$, $\\pi$) decays is presented using 0.62~fb$^{-1}$ of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the slow pion in the $D^{*+} \\rightarrow D^0 \\pi^+$ and $D^{*-} \\rightarrow \\overline{D}^0 \\pi^-$ decay chains. The difference in $CP$ asymmetry between $D^0 \\rightarrow K^- K^+$ and $D^0 \\rightarrow \\pi^- \\pi^+$, $\\Delta A_{CP} \\equiv A_{CP}(K^-K^+) \\, - \\, A_{CP}(\\pi^-\\pi^+)$, is measured to be $\\left[ -0.82 \\pm 0.21 (\\mathrm{stat.}) \\pm 0.11 (\\mathrm{syst.}) \\right]\\%$. This differs from the hypothesis of $CP$ conservation by $3.5$ standard deviations.

  1. Proton cross-talk and losses in the dispersion suppressor regions at the FCC-hh

    CERN Document Server

    AUTHOR|(CDS)2100784; Appleby, Robert Barrie; Krainer, Alexander; Langner, Andy Sven; Abelleira, Jose

    2017-01-01

    Protons that collide at the interaction points of the FCC-hh may contribute to the background in the subsequent detector. Due to the high luminosity of the proton beams this may be of concern. Using DPMJET-III to model 50 TeV proton-proton collisions, tracking studies have been performed with PTC and MERLIN in order to gauge the elastic and inelastic proton cross-talk. High arc losses, particularly in the dispersion suppressor regions, have been revealed. These losses originate mainly from particles with a momentum deviation, either from interaction with a primary collimator in the betatron cleaning insertion, or from the proton-proton collisions. This issue can be mitigated by introducing additional collimators in the dispersion suppressor region. The specific design, lattice integration, and the effect of these collimators on cross-talk is assessed.

  2. ATLAS searches for VH, HH, VV, V+$\\gamma$/$\\gamma\\gamma$ resonances

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00441490; The ATLAS collaboration

    2017-01-01

    The discovery of a Higgs boson at the Large Hadron Collider motivates searches for physics beyond the Standard Model in channels involving coupling to the Higgs boson. A search for massive resonances decaying into couples of bosons is described. The considered final states are: $HH$, $VH$, $VV$, $V\\gamma$ and $\\gamma\\gamma$ with $V$ indicating either the $W$ or the $Z$ boson. Final states with different number of leptons or photons and where, in many cases, at least one Higgs decays into a b-quark pair are studied using different jet reconstruction techniques which allow to optimize the signal acceptance for low or high Higgs boson transverse momentum. The most recent diboson resonance searches using LHC Run 2 data are described.

  3. Betatron-collimation Studies for Heavy Ions in the FCC-hh

    CERN Multimedia

    Logothetis Agaliotis, Efstathios

    2018-01-01

    One of the biggest challenges in the design of the FCC-hh is the collimation system. From LHC experience it is known that a collimation system optimized for proton cleaning has a significantly reduced efficiency for heavy ions. The study presented in this contribution evaluates the betatron-collimation efficiency for the heavy-ion operation with lead nuclei at a beam energy of 50 Z TeV in the system designed for proton operation. The fragmentation processes of the main beam particles in the primary collimator are simulated with FLUKA and fragments are individually tracked with SixTrack until being lost in the downstream aperture. In this way a first-impact loss-map is obtained, identifying locations where high energy deposition are to be expected. This provides a first-level assessment of feasibility and allows to include countermeasures in the conceptual accelerator design.

  4. Itinerant deaf educator and general educator perceptions of the D/HH push-in model.

    Science.gov (United States)

    Rabinsky, Rebecca J

    2013-01-01

    A qualitative case study using the deaf and hard of hearing (D/HH) push-in model was conducted on the perceptions of 3 itinerant deaf educators and 3 general educators working in 1 school district. Participants worked in pairs of 1 deaf educator and 1 general educator at 3 elementary schools. Open-ended research questions guided the study, which was concerned with teachers' perceptions of the model in general and with the model's advantages, disadvantages, and effectiveness. Data collected from observations, one-to-one interviews, and a focus group interview enabled the investigator to uncover 4 themes: Participants (a) had an overall positive experience, (b) viewed general education immersion as an advantage, (c) considered high noise levels a disadvantage, and (d) believed the effectiveness of the push-in model was dependent on several factors, in particular, the needs of the student and the nature of the general education classroom environment.

  5. Physics at the FCC-hh, a 100 TeV pp collider

    CERN Document Server

    2017-01-01

    A 100 TeV pp collider is under consideration, by the high-energy physics community, as an important step for the future development of our field, following the completion of the LHC and High-luminosity LHC physics programmes. In particular, CERN is considering 100 TeV pp collisions as the key target of a Future Circular Collider facility, built around a 100 km tunnel and designed to deliver pp, e+e- and ep collisions, in addition to a programme with heavy ion beams and with the injector complex. CERN is coordinating an international study tasked with the completion, by the end of 2018, of a Conceptual Design Report (CDR) for this facility. This document presents the first results of the assessment of the physics potential of the hadronic part of this research programme (FCC-hh).

  6. Spitzer spectral line mapping of the HH211 outflow

    DEFF Research Database (Denmark)

    Dionatos, Odyssefs; Nisini, Brunella; Cabrit, Sylvie

    2010-01-01

    of emission line diagnostics and an existing grid of molecular shock models. The physical properties of the warm gas are compared against other molecular jet tracers and to the results of a similar study towards the L1448-C outflow. Results: We have detected and mapped the v=0-0 S(0) - S(7) H2 lines and fine...... compared to solar abundances by a factor ~10-50. Conclusions: Spitzer spectral mapping observations reveal for the first time a cool H$_2$ component towards the CO jet of HH211 consistent with the CO material being fully molecular and warm at ~ 300 K. The maps also reveal for the first time the existence...... uncertainties on jet speed and shock conditions are too large for a definite conclusion....

  7. Neutral competition of stem cells is skewed by proliferative changes downstream of Hh and Hpo.

    Science.gov (United States)

    Amoyel, Marc; Simons, Benjamin D; Bach, Erika A

    2014-10-16

    Neutral competition, an emerging feature of stem cell homeostasis, posits that individual stem cells can be lost and replaced by their neighbors stochastically, resulting in chance dominance of a clone at the niche. A single stem cell with an oncogenic mutation could bias this process and clonally spread the mutation throughout the stem cell pool. The Drosophila testis provides an ideal system for testing this model. The niche supports two stem cell populations that compete for niche occupancy. Here, we show that cyst stem cells (CySCs) conform to the paradigm of neutral competition and that clonal deregulation of either the Hedgehog (Hh) or Hippo (Hpo) pathway allows a single CySC to colonize the niche. We find that the driving force behind such behavior is accelerated proliferation. Our results demonstrate that a single stem cell colonizes its niche through oncogenic mutation by co-opting an underlying homeostatic process. © 2014 The Authors.

  8. Performance assessment of the SIMFAP parallel cluster at IFIN-HH Bucharest

    International Nuclear Information System (INIS)

    Adam, Gh.; Adam, S.; Ayriyan, A.; Dushanov, E.; Hayryan, E.; Korenkov, V.; Lutsenko, A.; Mitsyn, V.; Sapozhnikova, T.; Sapozhnikov, A; Streltsova, O.; Buzatu, F.; Dulea, M.; Vasile, I.; Sima, A.; Visan, C.; Busa, J.; Pokorny, I.

    2008-01-01

    Performance assessment and case study outputs of the parallel SIMFAP cluster at IFIN-HH Bucharest point to its effective and reliable operation. A comparison with results on the supercomputing system in LIT-JINR Dubna adds insight on resource allocation for problem solving by parallel computing. The solution of models asking for very large numbers of knots in the discretization mesh needs the migration to high performance computing based on parallel cluster architectures. The acquisition of ready-to-use parallel computing facilities being beyond limited budgetary resources, the solution at IFIN-HH was to buy the hardware and the inter-processor network, and to implement by own efforts the open software concerning both the operating system and the parallel computing standard. The present paper provides a report demonstrating the successful solution of these tasks. The implementation of the well-known HPL (High Performance LINPACK) Benchmark points to the effective and reliable operation of the cluster. The comparison of HPL outputs obtained on parallel clusters of different magnitudes shows that there is an optimum range of the order N of the linear algebraic system over which a given parallel cluster provides optimum parallel solutions. For the SIMFAP cluster, this range can be inferred to correspond to about 1 to 2 x 10 4 linear algebraic equations. For an algorithm of polynomial complexity N α the task sharing among p processors within a parallel solution mainly follows an (N/p)α behaviour under peak performance achievement. Thus, while the problem complexity remains the same, a substantial decrease of the coefficient of the leading order of the polynomial complexity is achieved. (authors)

  9. Reconsidering the process for bow-stave removal from juniper trees in the Great Basin

    Science.gov (United States)

    Constance I. Millar; Kevin T. Smith

    2017-01-01

    We question the growth arrestment hypothesis for bow stave removal used by indigenous people in the western Great Basin. Using modern understanding of tree growth and wound response, we suggest that growth would not be arrested by one or two transverse notches along a juniper stem. Rather these would trigger compartmentalization, which limits cambial death to within 10...

  10. Beacon: A three-dimensional structural analysis code for bowing history of fast breeder reactor cores

    International Nuclear Information System (INIS)

    Miki, K.

    1979-01-01

    The core elements of an LMFBR are bowed due to radial gradients of both temperature and neutron flux in the core. Since all hexagonal elements are multiply supported by adjacent elements or the restraint system, restraint forces and bending stresses are induced. In turn, these forces and stresses are relaxed by irradiation enhanced creep of the material. The analysis of the core bowing behavior requires a three-dimensional consideration of the mechanical interactions among the core elements, because the core consists of different kinds of elements and of fuel assemblies with various burnup histories. A new computational code BEACON has been developed for analyzing the bowing behavior of an LMFBR's core in three dimensions. To evaluate mechanical interactions among core elements, the code uses the analytical method of the earlier SHADOW code. BEACON analyzes the mechanical interactions in three directions, which form angles of 60 0 with one another. BEACON is applied to the 60 0 sector of a typical LMFBR's core for analyzing the bowing history during one equilibrium cycle. 120 core elements are treated, assuming the boundary condition of rotational symmetry. The application confirms that the code can be an effective tool for parametric studies as well as for detailed structural analysis of LMFBR's core. (orig.)

  11. 26 CFR 48.4161(b)-1 - Imposition and rates of tax; bows and arrows.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Imposition and rates of tax; bows and arrows. 48.4161(b)-1 Section 48.4161(b)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Sporting Goods § 48.4161(b)-1...

  12. Computing the Dust Distribution in the Bow Shock of a Fast-moving, Evolved Star

    NARCIS (Netherlands)

    van Marle, A. -J; Meliani, Z.; Keppens, R.; Decin, L.

    2011-01-01

    We study the hydrodynamical behavior occurring in the turbulent interaction zone of a fast-moving red supergiant star, where the circumstellar and interstellar material collide. In this wind–interstellar-medium collision, the familiar bow shock, contact discontinuity, and wind termination shock

  13. The role of the umrhubhe bow as transmitter of cultural knowledge ...

    African Journals Online (AJOL)

    The focus is also on Madosini's responses to several questions regarding her method of playing umrhubhe, with a view to understanding the indigenous use of technical language in its description of the process of producing musical sound on an unbraced,4 mouth-resonated bow. Journal of Musical Arts in Africa Vol.

  14. Historic range of variability for upland vegetation in the Medicine Bow National Forest, Wyoming

    Science.gov (United States)

    Gregory K. Dillon; Dennis H. Knight; Carolyn B. Meyer

    2005-01-01

    An approach for synthesizing the results of ecological research pertinent to land management is the analysis of the historic range of variability (HRV) for key ecosystem variables that are affected by management activities. This report provides an HRV analysis for the upland vegetation of the Medicine Bow National Forest in southeastern Wyoming. The variables include...

  15. Photo series for quantifying forest residues in managed lands of the Medicine Bow National Forest

    Science.gov (United States)

    John B. Popp; John E. Lundquist

    2006-01-01

    This photo series presents a visual representation of a range of fuel loading conditions specifically found on the Medicine Bow National Forest. The photos are grouped by forest type and past management practices. This field guide describes the distribution of different types of woody fuels and includes some vegetation data.

  16. Transient bowing of core assemblies in advanced liquid metal fast reactors

    International Nuclear Information System (INIS)

    Kamal, S.A.; Orechwa, Y.

    1986-01-01

    Two alternative core restraint concepts are considered for a conceptual design of a 900 MWth liquid metal fast reactor core with a heterogeneous layout. The two concepts, known as limited free bowing and free flowering, are evaluated based on core bowing criteria that emphasize the enhancement of inherent reactor safety. The core reactivity change during a postulated loss of flow transient is calculated in terms of the lateral displacements and displacement-reactivity-worths of the individual assemblies. The NUBOW-3D computer code is utilized to determine the assembly deformations and interassembly forces that arise when the assemblies are subjected to temperature gradients and irradiation induced creep and swelling during the reactor operation. The assembly ducts are made of the ferritic steel HT-9 and remain in the reactor core for four-years at full power condition. Whereas both restraint systems meet the bowing criteria, a properly designed limited free bowing system appears to be more advantageous than a free flowering system from the point of view of enhancing the reactor inherent safety

  17. Modelling of bow-tie microstrip antennas using modified locally conformal FDTD method

    NARCIS (Netherlands)

    George, J.

    2000-01-01

    An analysis of bow-tie microstrip antennas is presented based on the use of the modified locally conformal finite-difference time-domain (FDTD) method. This approach enables the number of cells along the antenna length and width to be chosen independently of the antenna central width, which helps to

  18. Application of the Bow Tie method for evaluation of safety in the procedure of logging wells

    International Nuclear Information System (INIS)

    Alfonso Pallares, C; Perez Reyes, Y.; Sarabia Molina, I.I.

    2013-01-01

    This work consists of an assessment of security in the practice of logging of oil wells, using the method of Bow Tie for being a simple method of evaluation of the risk, which makes it possible in a structured way to set priorities to manage risk

  19. Calculation modelling of the RCCA movement through bowed FA guide tubes

    International Nuclear Information System (INIS)

    Razoumovsky, D.V.; Lihkachev, Yu.I.; Troyanov, V.M.

    2000-01-01

    Rod control cluster assembly movement through the bowed guide tubes is considered. The movement equation is presented with some of the assumptions and special attention is paid to the determination of the mechanical friction force. The numerical algorithm is described and some results of parametric studies are presented. (author)

  20. A benchmark study of procedures for analysis of axial crushing of bulbous bows

    DEFF Research Database (Denmark)

    Yamada, Yasuhira; Pedersen, Preben Terndrup

    2008-01-01

    Simplified methods to estimate mean axial crushing forces of plated structures are reviewed and applied to a series of experimental results for axial crushing of large-scale bulbous bow models. Methods based on intersection unit elements such as L-, T- and X-type elements as well as methods based...

  1. Modification of the ANC Nodal Code for analysis of PWR assembly bow

    International Nuclear Information System (INIS)

    Franceschini, Fausto; Fetterman, Robert J.; Little, David C.

    2008-01-01

    Refueling operations at certain PWR cores have revealed fuel assemblies with assembly bow that was higher than expected. As the fuel assemblies bow, the gaps between assemblies change from the uniform nominal configuration. This causes a change in the water volume which affects neutron moderation and thereby power distribution, fuel depletion history, rod internal pressure, etc., with non-trivial impacts on the safety analysis. Westinghouse has developed a new methodology for incorporation of assembly bow in its reload safety analysis package. As part of the new process, the standard Westinghouse reactor physics tool for core analysis, the Advanced Nodal Code ANC, has been modified. The modified ANC, ANCGAP, enables explicit treatment of three-dimensional gap distributions in its neutronic calculations; its accuracy is similar to that of the standard ANC, as demonstrated through an extensive benchmark campaign conducted over a variety of fuel compositions and challenging gap configurations. These features make ANCGAP a crucial tool in the Westinghouse assembly bow package. (authors)

  2. Modification of the ANC Nodal Code for analysis of PWR assembly bow

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, Fausto; Fetterman, Robert J.; Little, David C. [Westinghouse Electric Company LLC, Pittsburgh PA (United States)

    2008-07-01

    Refueling operations at certain PWR cores have revealed fuel assemblies with assembly bow that was higher than expected. As the fuel assemblies bow, the gaps between assemblies change from the uniform nominal configuration. This causes a change in the water volume which affects neutron moderation and thereby power distribution, fuel depletion history, rod internal pressure, etc., with non-trivial impacts on the safety analysis. Westinghouse has developed a new methodology for incorporation of assembly bow in its reload safety analysis package. As part of the new process, the standard Westinghouse reactor physics tool for core analysis, the Advanced Nodal Code ANC, has been modified. The modified ANC, ANCGAP, enables explicit treatment of three-dimensional gap distributions in its neutronic calculations; its accuracy is similar to that of the standard ANC, as demonstrated through an extensive benchmark campaign conducted over a variety of fuel compositions and challenging gap configurations. These features make ANCGAP a crucial tool in the Westinghouse assembly bow package. (authors)

  3. The value of the absent bow tie sign in MRI of bucket-handle tears

    International Nuclear Information System (INIS)

    Watt, Andrew J.B.; Halliday, Tonya; Raby, Nigel

    2000-01-01

    AIM: To assess the accuracy of the absent bow tie sign in diagnosing bucket handle meniscal tears (BHT) of the knee menisci. MATERIALS AND METHODS: During a 3-year period, we correlated the MRI and arthroscopic findings and the presence of the various signs. One hundred and seven knees were reviewed: 74 where either MRI or arthroscopy had identified a BHT and 33 which were either normal (31), or a simple tear was identified (2). All cases were reviewed by a single radiologist with a musculoskeletal interest blinded to the original results. Each was assessed for the presence of (1) a central meniscal fragment, (2) the double posterior cruciate ligament (PCL) sign, (3) the bow tie sign and (4) the contribution of a 3D-volume sequence. RESULTS: Optimal results were obtained using standard sequences and a 3D-volume sequence, giving a sensitivity of 74% and positive predictive value of 89%. The bow tie sign gave a sensitivity of 71% and positive predictive value of 76%, significantly less than previous reports. The 18 BHTs diagnosed by arthroscopy but missed by MRI showed other abnormal findings at MRI and were not reported as normal. CONCLUSION: We were not able to reproduce the previously reported high sensitivity and specificity of the absent bow tie sign. Despite optimization of all factors, the accurate diagnosis of a bucket handle tear remains difficult, and is most reliably made by identifying a central meniscal fragment, rather than relying on secondary signs such as the absent bow tie sign. Watt, A.J.B. (2000)

  4. THEMIS satellite observations of hot flow anomalies at Earth's bow shock

    Directory of Open Access Journals (Sweden)

    C. Chu

    2017-03-01

    Full Text Available Hot flow anomalies (HFAs at Earth's bow shock were identified in Time History of Events and Macroscale Interactions During Substorms (THEMIS satellite data from 2007 to 2009. The events were classified as young or mature and also as regular or spontaneous hot flow anomalies (SHFAs. The dataset has 17 young SHFAs, 49 mature SHFAs, 15 young HFAs, and 55 mature HFAs. They span a wide range of magnetic local times (MLTs from approximately 7 to 16.5 MLT. The largest ratio of solar wind to HFA core density occurred near dusk and at larger distances from the bow shock. In this study, HFAs and SHFAs were observed up to 6.3 RE and 6.1 RE (Earth radii, respectively, upstream from the model bow shock. HFA–SHFA occurrence decreases with distance upstream from the bow shock. HFAs of the highest event core ion temperatures were not seen at the flanks. The ratio of HFA ion temperature increase to HFA electron temperature increase is highest around 12 MLT and slightly duskward. For SHFAs, (Tihfa∕Tisw/(Tehfa∕Tesw generally increased with distance from the bow shock. Both mature and young HFAs are more prevalent when there is an approximately radial interplanetary magnetic field. HFAs occur most preferentially for solar wind speeds from 550 to 600 km s−1. The correlation coefficient between the HFA increase in thermal energy density from solar wind values and the decrease in kinetic energy density from solar wind values is 0.62. SHFAs and HFAs do not show major differences in this study.

  5. Diagnostic value of progesterone receptor, p16, p53 and pHH3 expression in uterine atypical leiomyoma.

    Science.gov (United States)

    Liang, Yun; Zhang, Xiaofei; Chen, Xiaoduan; Lü, Weiguo

    2015-01-01

    The differential diagnosis between atypical leiomyoma and leiomyosarcoma may be hard based on morphological criterion at times. It would be helpful to find out biomarkers that can be used to distinguish them. The aim of the study was to investigate the diagnostic value of progesterone receptor (PR), p16, p53 and pHH3 expression in a series of uterine smooth muscle tumors. Immunohistochemical expression of PR, p16, p53 and pHH3 was investigated on 32 atypical leiomyomas, 15 leiomyosarcomas and 15 usual leomyomas. The difference in expression was compared between atypical leiomyoma and other groups. The expression of PR, p16, and pHH3 was found significantly different between atypical leiomyomas and leiomyosarcomas, but lack of significant difference between atypical leiomyomas and usual leiomyomas. There was no significant difference with regard to p53 distribution among these uterine smooth muscle tumors. High p16, pHH3 expression and low PR expression preferred the diagnosis of leiomyosarcoma. The panel of antibodies used in this study is a useful complementary analysis in the assessment of problematic uterine smooth muscle tumors.

  6. Sequential application of ligand and structure based modeling approaches to index chemicals for their hH4R antagonism.

    Directory of Open Access Journals (Sweden)

    Matteo Pappalardo

    Full Text Available The human histamine H4 receptor (hH4R, a member of the G-protein coupled receptors (GPCR family, is an increasingly attractive drug target. It plays a key role in many cell pathways and many hH4R ligands are studied for the treatment of several inflammatory, allergic and autoimmune disorders, as well as for analgesic activity. Due to the challenging difficulties in the experimental elucidation of hH4R structure, virtual screening campaigns are normally run on homology based models. However, a wealth of information about the chemical properties of GPCR ligands has also accumulated over the last few years and an appropriate combination of these ligand-based knowledge with structure-based molecular modeling studies emerges as a promising strategy for computer-assisted drug design. Here, two chemoinformatics techniques, the Intelligent Learning Engine (ILE and Iterative Stochastic Elimination (ISE approach, were used to index chemicals for their hH4R bioactivity. An application of the prediction model on external test set composed of more than 160 hH4R antagonists picked from the chEMBL database gave enrichment factor of 16.4. A virtual high throughput screening on ZINC database was carried out, picking ∼ 4000 chemicals highly indexed as H4R antagonists' candidates. Next, a series of 3D models of hH4R were generated by molecular modeling and molecular dynamics simulations performed in fully atomistic lipid membranes. The efficacy of the hH4R 3D models in discrimination between actives and non-actives were checked and the 3D model with the best performance was chosen for further docking studies performed on the focused library. The output of these docking studies was a consensus library of 11 highly active scored drug candidates. Our findings suggest that a sequential combination of ligand-based chemoinformatics approaches with structure-based ones has the potential to improve the success rate in discovering new biologically active GPCR drugs and

  7. Sequential application of ligand and structure based modeling approaches to index chemicals for their hH4R antagonism.

    Science.gov (United States)

    Pappalardo, Matteo; Shachaf, Nir; Basile, Livia; Milardi, Danilo; Zeidan, Mouhammed; Raiyn, Jamal; Guccione, Salvatore; Rayan, Anwar

    2014-01-01

    The human histamine H4 receptor (hH4R), a member of the G-protein coupled receptors (GPCR) family, is an increasingly attractive drug target. It plays a key role in many cell pathways and many hH4R ligands are studied for the treatment of several inflammatory, allergic and autoimmune disorders, as well as for analgesic activity. Due to the challenging difficulties in the experimental elucidation of hH4R structure, virtual screening campaigns are normally run on homology based models. However, a wealth of information about the chemical properties of GPCR ligands has also accumulated over the last few years and an appropriate combination of these ligand-based knowledge with structure-based molecular modeling studies emerges as a promising strategy for computer-assisted drug design. Here, two chemoinformatics techniques, the Intelligent Learning Engine (ILE) and Iterative Stochastic Elimination (ISE) approach, were used to index chemicals for their hH4R bioactivity. An application of the prediction model on external test set composed of more than 160 hH4R antagonists picked from the chEMBL database gave enrichment factor of 16.4. A virtual high throughput screening on ZINC database was carried out, picking ∼ 4000 chemicals highly indexed as H4R antagonists' candidates. Next, a series of 3D models of hH4R were generated by molecular modeling and molecular dynamics simulations performed in fully atomistic lipid membranes. The efficacy of the hH4R 3D models in discrimination between actives and non-actives were checked and the 3D model with the best performance was chosen for further docking studies performed on the focused library. The output of these docking studies was a consensus library of 11 highly active scored drug candidates. Our findings suggest that a sequential combination of ligand-based chemoinformatics approaches with structure-based ones has the potential to improve the success rate in discovering new biologically active GPCR drugs and increase the

  8. Efficient heterologous expression and secretion in Aspergillus oryzae of a llama variable heavy-chain antibody fragment V(HH) against EGFR.

    Science.gov (United States)

    Okazaki, Fumiyoshi; Aoki, Jun-ichi; Tabuchi, Soichiro; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

    2012-10-01

    We have constructed a filamentous fungus Aspergillus oryzae that secretes a llama variable heavy-chain antibody fragment (V(HH)) that binds specifically to epidermal growth factor receptor (EGFR) in a culture medium. A major improvement in yield was achieved by fusing the V(HH) with a Taka-amylase A signal sequence (sTAA) and a segment of 28 amino acids from the N-terminal region of Rhizopus oryzae lipase (N28). The yields of secreted, immunologically active anti-EGFR V(HH) reached 73.8 mg/1 in a Sakaguchi flask. The V(HH) fragments were released from the sTAA or N28 proteins by an indigenous A. oryzae protease during cultivation. The purified recombinant V(HH) fragment was specifically recognized and could bind to the EGFR with a high affinity.

  9. THE ROLE OF PICKUP IONS ON THE STRUCTURE OF THE VENUSIAN BOW SHOCK AND ITS IMPLICATIONS FOR THE TERMINATION SHOCK

    International Nuclear Information System (INIS)

    Lu Quanming; Shan Lican; Zhang Tielong; Wu Mingyu; Wang Shui; Zank, Gary P.; Yang Zhongwei; Du Aimin

    2013-01-01

    The recent crossing of the termination shock by Voyager 2 has demonstrated the important role of pickup ions (PUIs) in the physics of collisionless shocks. The Venus Express (VEX) spacecraft orbits Venus in a 24 hr elliptical orbit that crosses the bow shock twice a day. VEX provides a unique opportunity to investigate the role of PUIs on the structure of collisionless shocks more generally. Using VEX observations, we find that the strength of the Venusian bow shock is weaker when solar activity is strong. We demonstrate that this surprising anti-correlation is due to PUIs mediating the Venusian bow shock

  10. CENTIMETER CONTINUUM OBSERVATIONS OF THE NORTHERN HEAD OF THE HH 80/81/80N JET: REVISING THE ACTUAL DIMENSIONS OF A PARSEC-SCALE JET

    Energy Technology Data Exchange (ETDEWEB)

    Masque, Josep M.; Estalella, Robert [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Marti i Franques 1, E-08028 Barcelona, Catalunya (Spain); Girart, Josep M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 3-72, 58090 Morelia, Michoacan (Mexico); Beltran, Maria T. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2012-10-10

    We present 6 and 20 cm Jansky Very Large Array/Very Large Array observations of the northern head of the HH 80/81/80N jet, one of the largest collimated jet systems known so far, aimed to look for knots farther than HH 80N, the northern head of the jet. Aligned with the jet and 10' northeast of HH 80N, we found a radio source not reported before, with a negative spectral index similar to that of HH 80, HH 81, and HH 80N. The fit of a precessing jet model to the knots of the HH 80/81/80N jet, including the new source, shows that the position of this source is close to the jet path resulting from the modeling. If the new source belongs to the HH 80/81/80N jet, its derived size and dynamical age are 18.4 pc and >9 Multiplication-Sign 10{sup 3} yr, respectively. If the jet is symmetric, its southern lobe would expand beyond the cloud edge resulting in an asymmetric appearance of the jet. Based on the updated dynamical age, we speculate on the possibility that the HH 80/81/80N jet triggered the star formation observed in a dense core found ahead of HH 80N, which shows signposts of interaction with the jet. These results indicate that parsec-scale radio jets can play a role in the stability of dense clumps and the regulation of star formation in the molecular cloud.

  11. New cosmic rays experiments in the underground laboratory of IFIN-HH from Slanic Prahova, Romania

    Science.gov (United States)

    Mitrica, Bogdan; Stanca, Denis; Brancus, Iliana; Margineanu, Romul; Blebea-Apostu, Ana-Maria; Gomoiu, Claudia; Saftoiu, Alexandra; Toma, Gabriel; Rebel, Heinigerd; Haungs, Andreas; Sima, Octavian; Gherghel-Lascu, Alexandru; Niculescu-Oglinzanu, Mihai

    2015-02-01

    Since 2006 a modern laboratory has been developed by IFIN-HH in the underground of Slanic Prahova salt ore. This work presents a short review of previous scientific activities performed in the underground laboratory, in parallel with some plans for the future. A mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania. The device is used to measure the muon flux on different locations at the surface and underground and it consists of two detection layers, each one including four large scintillator plates. A new rotatable detector for measurements of the directional variation of the muon flux has been designed and it is presently under preliminary tests. Built from four layers of sensitive material and using for collecting the signals and directing them to the micro PMTs a new technique, through optical fibers instead wave length shifters, it allows an easy discrimination of the moun flux on the arrival directions of muons. Combining the possibility to rotate and the directionality properties, the underground muon detector is acting like a muon tomography device, being able to scan, using cosmic muons, the rock material above the detector. In parallel new detection system based on SiPM will be also installed in the following weeks. It should be composed by four layers, each layer consisting in 4 scintillator plates what we consider in the following as a module of detection. For this purpose, first two scintillator layers, with the optical fibers positioned on perpendicular directions are put in coincidence with other two layers, 1 m distance from the first two, with similar optical fiber arrangement, thus allowing reconstructing muon trajectory. It is intended also to design and construct an experimental device for the investigation of such radio antennas and the behavior of the signal in rock salt at the Slanic salt mine in Romania. Another method to detect high energy neutrinos is based on the detection of secondary particles resulting

  12. New cosmic rays experiments in the underground laboratory of IFIN-HH from Slanic Prahova, Romania

    Energy Technology Data Exchange (ETDEWEB)

    Mitrica, Bogdan; Stanca, Denis; Brancus, Iliana; Margineanu, Romul; Blebea-Apostu, Ana-Maria; Gomoiu, Claudia; Saftoiu, Alexandra; Toma, Gabriel; Gherghel-Lascu, Alexandru; Niculescu-Oglinzanu, Mihai [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, P.O.B. MG-6, Bucharest (Romania); Rebel, Heinigerd; Haungs, Andreas [Institute of Experimental Nuclear Physics, Karlsruhe Institute of Technology-Campus North, 76021 Karlsruhe (Germany); Sima, Octavian [Department of Physics, University of Bucharest, 077125 Magurele (Romania)

    2015-02-24

    Since 2006 a modern laboratory has been developed by IFIN-HH in the underground of Slanic Prahova salt ore. This work presents a short review of previous scientific activities performed in the underground laboratory, in parallel with some plans for the future. A mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania. The device is used to measure the muon flux on different locations at the surface and underground and it consists of two detection layers, each one including four large scintillator plates. A new rotatable detector for measurements of the directional variation of the muon flux has been designed and it is presently under preliminary tests. Built from four layers of sensitive material and using for collecting the signals and directing them to the micro PMTs a new technique, through optical fibers instead wave length shifters, it allows an easy discrimination of the moun flux on the arrival directions of muons. Combining the possibility to rotate and the directionality properties, the underground muon detector is acting like a muon tomography device, being able to scan, using cosmic muons, the rock material above the detector. In parallel new detection system based on SiPM will be also installed in the following weeks. It should be composed by four layers, each layer consisting in 4 scintillator plates what we consider in the following as a module of detection. For this purpose, first two scintillator layers, with the optical fibers positioned on perpendicular directions are put in coincidence with other two layers, 1 m distance from the first two, with similar optical fiber arrangement, thus allowing reconstructing muon trajectory. It is intended also to design and construct an experimental device for the investigation of such radio antennas and the behavior of the signal in rock salt at the Slanic salt mine in Romania. Another method to detect high energy neutrinos is based on the detection of secondary particles resulting

  13. MULTI-COMPONENT ANALYSIS OF POSITION-VELOCITY CUBES OF THE HH 34 JET

    International Nuclear Information System (INIS)

    Rodríguez-González, A.; Esquivel, A.; Raga, A. C.; Cantó, J.; Curiel, S.; Riera, A.; Beck, T. L.

    2012-01-01

    We present an analysis of Hα spectra of the HH 34 jet with two-dimensional spectral resolution. We carry out multi-Gaussian fits to the spatially resolved line profiles and derive maps of the intensity, radial velocity, and velocity width of each of the components. We find that close to the outflow source we have three components: a high (negative) radial velocity component with a well-collimated, jet-like morphology; an intermediate velocity component with a broader morphology; and a positive radial velocity component with a non-collimated morphology and large linewidth. We suggest that this positive velocity component is associated with jet emission scattered in stationary dust present in the circumstellar environment. Farther away from the outflow source, we find only two components (a high, negative radial velocity component, which has a narrower spatial distribution than an intermediate velocity component). The fitting procedure was carried out with the new AGA-V1 code, which is available online and is described in detail in this paper.

  14. Design and performance of an electromagnetic calorimeter for a FCC-hh experiment

    Science.gov (United States)

    Zaborowska, A.

    2018-03-01

    The physics reach and feasibility of the Future Circular Collider are currently under investigation. The goal is to collide protons with centre-of-mass energies up to 100 TeV, extending the research carried out at the current HEP facilities. The detectors designed for the FCC experiments need to tackle harsh conditions of the unprecedented collision energy and luminosity. The baseline technology for the calorimeter system of the FCC-hh detector is described. The electromagnetic calorimeter in the barrel, as well as the electromagnetic and hadronic calorimeters in the endcaps and the forward regions, are based on the liquid argon as active material. The detector layout in the barrel region combines the concept of a high granularity calorimeter with precise energy measurements. The calorimeters have to meet the requirements of high radiation hardness and must be able to deal with a very high number of collisions per bunch crossings (pile-up). A very good energy and angular resolution for a wide range of electrons' and photons' momentum is needed in order to meet the demands based on the physics benchmarks. First results of the performance studies with the new liquid argon calorimeter are presented, meeting the energy resolution goal.

  15. Vibrational inelastic and charge transfer processes in H++H2 system: An ab initio study

    Science.gov (United States)

    Amaran, Saieswari; Kumar, Sanjay

    2007-12-01

    State-resolved differential cross sections, total and integral cross sections, average vibrational energy transfer, and the relative probabilities are computed for the H++H2 system using the newly obtained ab initio potential energy surfaces at the full CI/cc-pVQZ level of accuracy which allow for both the direct vibrational inelastic and the charge transfer processes. The quantum dynamics is treated within the vibrational close-coupling infinite-order-sudden approximation approach using the two ab initio quasidiabatic potential energy surfaces. The computed collision attributes for both the processes are compared with the available state-to-state scattering experiments at Ec.m.=20eV. The results are in overall good agreement with most of the observed scattering features such as rainbow positions, integral cross sections, and relative vibrational energy transfers. A comparison with the earlier theoretical study carried out on the semiempirical surfaces (diatomics in molecules) is also made to illustrate the reliability of the potential energy surfaces used in the present work.

  16. RESOLVING THE CIRCUMSTELLAR DISK AROUND THE MASSIVE PROTOSTAR DRIVING THE HH 80-81 JET

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco-Gonzalez, Carlos [Max-Planck-Institut fuer Radioastronomie (MPIfR), Auf dem Huegel 69, 53121 Bonn (Germany); Galvan-Madrid, Roberto [European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching (Germany); Anglada, Guillem; Osorio, Mayra [Instituto de Astrofisica de Andalucia, CSIC, Camino Bajo de Huetor 50, E-18008 Granada (Spain); D' Alessio, Paola; Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacan (Mexico); Hofner, Peter [Physics Department, New Mexico Tech, 801 Leroy Pl., Socorro, NM 87801 (United States); Linz, Hendrik [Max-Planck-Institut fuer Astronomie (MPIA), Koenigstuhl 17, 69117 Heidelberg (Germany); Araya, Esteban D., E-mail: carrasco@mpifr-bonn.mpg.de [Physics Department, Western Illinois University, 1 University Circle, Macomb, IL 61455 (United States)

    2012-06-20

    We present new high angular resolution observations toward the driving source of the HH 80-81 jet (IRAS 18162-2048). Continuum emission was observed with the Very Large Array at 7 mm and 1.3 cm, and with the Submillimeter Array at 860 {mu}m, with angular resolutions of {approx}0.''1 and {approx}0.''8, respectively. Submillimeter observations of the sulfur oxide (SO) molecule are reported as well. At 1.3 cm the emission traces the well-known radio jet, while at 7 mm the continuum morphology is quadrupolar and seems to be produced by a combination of free-free and dust emission. An elongated structure perpendicular to the jet remains in the 7 mm image after subtraction of the free-free contribution. This structure is interpreted as a compact accretion disk of {approx}200 AU radius. Our interpretation is favored by the presence of rotation in our SO observations observed at larger scales. The observations presented here add to the small list of cases where the hundred-AU scale emission from a circumstellar disk around a massive protostar has been resolved.

  17. A new ion beam facility based on a 3 MV Tandetron™ at IFIN-HH, Romania

    Science.gov (United States)

    Burducea, I.; Straticiuc, M.; Ghiță, D. G.; Moșu, D. V.; Călinescu, C. I.; Podaru, N. C.; Mous, D. J. W.; Ursu, I.; Zamfir, N. V.

    2015-09-01

    A 3 MV Tandetron™ accelerator system has been installed and commissioned at the "Horia Hulubei" National Institute for Physics and Nuclear Engineering - IFIN-HH, Măgurele, Romania. The main purpose of this machine is to strengthen applied nuclear physics research ongoing in our institute for more than four decades. The accelerator system was developed by High Voltage Engineering Europa B.V. (HVE) and comprises three high energy beam lines. The first beam line is dedicated to ion beam analysis (IBA) techniques: Rutherford Backscattering Spectrometry - RBS, Nuclear Reaction Analysis - NRA, Particle Induced X-ray and γ-ray Emission - PIXE and PIGE and micro-beam experiments - μ-PIXE. The second beam line is dedicated to high energy ion implantation experiments and the third beam line was designed mainly for nuclear cross-sections measurements used in nuclear astrophysics. A unique feature, the first time in operation at an accelerator facility is the Na charge exchange canal (CEC), which is used to obtain high intensity beams of He- of at least 3 μA. The results of the acceptance tests demonstrate the huge potential of this new facility in various fields, from IBA to radiation hardness studies and from medical or environmental applications to astrophysics. The main features of the accelerator are presented in this paper.

  18. Systematic search for very-high-energy gamma-ray emission from bow shocks of runaway stars

    Science.gov (United States)

    H.E.S.S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Coffaro, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'C.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Richter, S.; Rieger, F.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stycz, K.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.

    2018-04-01

    Context. Runaway stars form bow shocks by ploughing through the interstellar medium at supersonic speeds and are promising sources of non-thermal emission of photons. One of these objects has been found to emit non-thermal radiation in the radio band. This triggered the development of theoretical models predicting non-thermal photons from radio up to very-high-energy (VHE, E ≥ 0.1 TeV) gamma rays. Subsequently, one bow shock was also detected in X-ray observations. However, the data did not allow discrimination between a hot thermal and a non-thermal origin. Further observations of different candidates at X-ray energies showed no evidence for emission at the position of the bow shocks either. A systematic search in the Fermi-LAT energy regime resulted in flux upper limits for 27 candidates listed in the E-BOSS catalogue. Aim. Here we perform the first systematic search for VHE gamma-ray emission from bow shocks of runaway stars. Methods: Using all available archival H.E.S.S. data we search for very-high-energy gamma-ray emission at the positions of bow shock candidates listed in the second E-BOSS catalogue release. Out of the 73 bow shock candidates in this catalogue, 32 have been observed with H.E.S.S. Results: None of the observed 32 bow shock candidates in this population study show significant emission in the H.E.S.S. energy range. Therefore, flux upper limits are calculated in five energy bins and the fraction of the kinetic wind power that is converted into VHE gamma rays is constrained. Conclusions: Emission from stellar bow shocks is not detected in the energy range between 0.14 and 18 TeV.The resulting upper limits constrain the level of VHE gamma-ray emission from these objects down to 0.1-1% of the kinetic wind energy.

  19. Ion distributions in the Earth's foreshock upstream from the bow shock

    Science.gov (United States)

    Fuselier, S. A.

    1995-01-01

    A variety of suprathermal and energetic ion distributions are found upstream from shocks. Some distributions, such as field-aligned beams, are generated directly at the shock either through reflection processes or through leakage from the hotter downstream region. Other distributions, such as intermediate distributions, evolve from these parent distributions through wave-particle interactions. This paper reviews our current understanding of the creation and evolution of suprathermal distributions at shocks. Examples of suprathermal ion distributions are taken from observations at the Earth's bow shock. Particular emphasis is placed on the creation of field-aligned beams and specularly reflected ion distributions and on the evolution of these distributions in the Earth's ion foreshock. However, the results from this heavily studied region are applicable to interplanetary shocks, bow shocks at other planets, and comets.

  20. Ion distributions upstream and downstream of the Earth's bow shock: first results from Vlasiator

    Directory of Open Access Journals (Sweden)

    D. Pokhotelov

    2013-12-01

    Full Text Available A novel hybrid-Vlasov code, Vlasiator, is developed for global simulations of magnetospheric plasma kinetics. The code is applied to model the collisionless bow shock on scales of the Earth's magnetosphere in two spatial dimensions and three dimensions in velocity space retrieving ion distribution functions over the entire foreshock and magnetosheath regions with unprecedented detail. The hybrid-Vlasov approach produces noise-free uniformly discretized ion distribution functions comparable to those measured in situ by spacecraft. Vlasiator can reproduce features of the ion foreshock and magnetosheath well known from spacecraft observations, such as compressional magnetosonic waves generated by backstreaming ion populations in the foreshock and mirror modes in the magnetosheath. An overview of ion distributions from various regions of the bow shock is presented, demonstrating the great opportunities for comparison with multi-spacecraft observations.

  1. Analysis of Silver Ink Bow-Tie RFID Tag Antennas Printed on Paper Substrates

    Directory of Open Access Journals (Sweden)

    Sari Merilampi

    2007-01-01

    Full Text Available In this study, polymeric silver inks, paper substrates, and screen printing were used to produce prototype Bow-Tie tags. Because of increasing interest in applying passive UHF-RFID systems in paper industry, the Bow-Tie antenna used in this study was designed to work through paper. The maximum reliable read ranges of the tags were measured thorough stacked paper and also in air. The analysis and functioning of the antenna design are also discussed. All inks and paper substrates were suitable as antenna material and the prototype tag antennas had good reading performance. The maximum reliable read ranges were quite the same as for copper and aluminum tags studied elsewhere. This means that printed UHF tags are competitive solutions for the identification of simple mass products.

  2. Predictions of lithium interactions with earth's bow shock in the presence of wave activity

    Science.gov (United States)

    Decker, R. B.; Lui, A. T. Y.; Vlahos, L.

    1984-01-01

    The results of a test-particle simulation studying the movement of a lithium tracer ion injected upstream of the bow shock are reported. Wave activity consists of parallel and antiparallel propagating Alfven waves characterized by a frequency power spectrum within a frequency or range of amplitudes defined separately in the upstream and downstream regions. The results show that even a moderate level of wave activity can substantially change the results obtained in the absence of waves. Among the effects observed are: (1) increased ion transmission; (2) both the average energy gain and spread about the average are increased for transmitted and reflected particles; (3) the average final pitch angle for transmitted particles tends to 90 deg, and the spread of reflected particles is reduced; and (4) the spatial dispersion of the ions on the bow shock after a single encounter is increased.

  3. Sensitivity of reactivity feedback due to core bowing in a metallic-fueled core

    International Nuclear Information System (INIS)

    Nakagawa, Masatoshi; Kawashima, Masatoshi; Endo, Hiroshi; Nishimura, Tomohiro

    1991-01-01

    A sensitivity study has been carried out on negative reactivity feedback caused by core bowing to assess the potential effectiveness of FBR passive safety features in regard to withstanding an anticipated transient without scram (ATWS). In the present study, an analysis has been carried to obtain the best material and geometrical conditions concerning the core restraint system out for several power to flow rates (P/F), up to 2.0 for a 300 MWe metallic-fueled core. From this study, it was clarified that the pad stiffness at an above core loading pads (ACLP) needs to be large enough to ensure negative reactivity feedback against ATWS. It was also clarified that there is an upper limit for the clearances between ducts at ACLP. A new concept, in regard to increasing the absolute value for negative reactivity feedback due to core bowing at ATWS, is proposed and discussed. (author)

  4. Nonthermal ions and associated magnetic field behavior at a quasi-parallel earth's bow shock

    Science.gov (United States)

    Wilkinson, W. P.; Pardaens, A. K.; Schwartz, S. J.; Burgess, D.; Luehr, H.; Kessel, R. L.; Dunlop, M.; Farrugia, C. J.

    1993-01-01

    Attention is given to ion and magnetic field measurements at the earth's bow shock from the AMPTE-UKS and -IRM spacecraft, which were examined in high time resolution during a 45-min interval when the field remained closely aligned with the model bow shock normal. Dense ion beams were detected almost exclusively in the midst of short-duration periods of turbulent magnetic field wave activity. Many examples of propagation at large elevation angles relative to the ecliptic plane, which is inconsistent with reflection in the standard model shock configuration, were discovered. The associated waves are elliptically polarized and are preferentially left-handed in the observer's frame of reference, but are less confined to the maximum variance plane than other previously studied foreshock waves. The association of the wave activity with the ion beams suggests that the former may be triggered by an ion-driven instability, and possible candidates are discussed.

  5. Bimanual coordination of bowing and fingering in violinists--effects of position changes and string changes.

    Science.gov (United States)

    Kazennikov, Oleg; Wiesendanger, Mario

    2009-07-01

    Music performance is based on demanding motor control with much practice from young age onward. We have chosen to investigate basic bimanual movements played by violin amateurs and professionals. We posed the question whether position and string changes, two frequent mechanisms, may influence the time interval bowing (right)-fingering (left) coordination. The objective was to measure bimanual coordination, i.e., with or without position changes and string changes. The tendency was that the bimanual coordination was statistically only slightly increased or even unchanged but not perceptible. We conclude that the coordination index is limited up to 100 ms intervals, without any erroneous perception. Although the mentioned position changes and string changes are movements with their timing, they are executed in parallel rather than in series with the bow-fingering coordination.

  6. Observations of two distinct populations of bow shock ions in the upstream solar wind

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.; Bame, S.J.; Paschmann, G.; Sckopke, N.

    1978-01-01

    Observations upstream of the earth's bow shock with the LASL/MPI fast plasma experiments on ISEE 1 and 2 reveal the presence of two distinct and mutually exclusive populations of low energy (< or approx. =40keV) ions apparently accelerated at the bow shock. The first of these, the ''reflected'' population, is characterized by 1) sharply peaked spectra seldom extending much above approx. 10 keV/ion and 2) relatively collimated flow coming from the direction of the shock. On the other hand, the ''diffuse'' ions are distinguished by relatively flat energy spectra above approx. 10 keV and broad angular distributions. They are by far the most commonly observed upstream ion event. A close causal association is suggested between the diffuse ion population in the upstream solar wind and energetic plasma ions observed within the magnetosheath

  7. MMS Observation of Shock-Reflected He++ at Earth's Quasi-Perpendicular Bow Shock

    Science.gov (United States)

    Broll, Jeffrey Michael; Fuselier, S. A.; Trattner, K. J.; Schwartz, S. J.; Burch, J. L.; Giles, B. L.; Anderson, B. J.

    2018-01-01

    Specular reflection of protons at Earth's supercritical quasi-perpendicular bow shock has long been known to lead to the thermalization of solar wind particles by velocity-space dispersion. The same process has been proposed for He++ but could not be confirmed previously due to insufficient time resolution for velocity distribution measurements. We present observations and simulations of a bow shock crossing by the Magnetospheric Multiscale (MMS) mission on 20 November 2015 indicating that a very similar reflection process for He++ is possible, and further that the part of the incoming distribution with the highest probability of reflecting is the same for H+ and He++. However, the reflection process for He++ is accomplished by deeper penetration into the downstream magnetic fields.

  8. Risk assessment in gas and oil pipelines based on the fuzzy Bow-tie technique

    OpenAIRE

    P. Heyrani; A. Baghaei

    2016-01-01

    Introduction: Nowadays, gas and oil account for 60 percent of world energy resources. Transporting crude oil and its products are accomplished through a number of ways among which pipelines are of the utmost significance. Considering the extent of pipelines in installation and residential areas and also high potential for damage, the safety of these pipes and application of risk management principles have undeniable importance. Bow-tie risk assessment method is one of the ways to determine sa...

  9. Coupled hydromagnetic wave excitation and ion acceleration upstream of the earth's bow shock

    International Nuclear Information System (INIS)

    Lee, M.A.

    1982-01-01

    A self-consistent theory is presented for the excitation of hydromagnetic waves and the acceleration of diffuse ions upstream of the earth's bow shock in the quasi-equilibrium that results when the solar wind velocity and the interplanetary magnetic field are nearly parallel. For the waves the quasi-equilibrium results from a balance between excitation by the ions, which stream relative to the solar wind plasma, and convective loss to the magnetosheath. For the diffuse ions the quasi-equilibrium results from a balance between injection at the shock front, confinement to the foreshock by pitch angle scattering on the waves, acceleration by compression at the shock front, loss to the magnetosheath, loss due to escape upstream of the foreshock, and loss via diffusion perpendicular to the average magnetic field onto field lines that do not connect to the shock front. Diffusion equations describing the ion transport and wave kinetic equations describing the hydromagnetic wave transport are solved self-consistently to yield analytical expressions for the differential wave intensity spectrum as a function of frequency and distance from the bow shock z and for the ion omnidirectional distribution functions and anisotropies as functions of energy and z, In quantitative agreement with observations, the theory predicts (1) exponential spectra at the bow shock in energy per charge, (2) a decrease in intensity and hardening of the ion spectra with increasing z, (3) a 30-keV proton anisotropy parallel to z increasing from -0.28 at the bow shock to +0.51 as z→infinity (4) a linearly polarized wave intensity spectrum with a minimum at approx.6 x 10 -3 Hz and a maximum at approx.2--3 x 10 -2 Hz, (5) a decrease in the wave intensity spectrum with increasing z, (6) a total energy density in protons with energies >15 keV about eight times that in the hydromagnetic waves

  10. Observation of Motion of Bowed Strings and Resonant Strings in Violin Performances

    Science.gov (United States)

    Matsutani, Akihiro

    2013-10-01

    The motion of a bowed string and a resonant string of a violin were simultaneously observed for the first time. The results of the direct observation of string motion in double stops and harmonics are also presented. The importance of the resonance was experimentally demonstrated from these observations. It is suggested that players should take account of the resonance and ideal Helmholtz motion in violin performances.

  11. The Fruits of Adversity: Technical Refinements of the Turkish Composite Bow during the Crusading Era

    Science.gov (United States)

    1991-01-01

    period. Depictions of these two bows are found in the detailed reproductions of sculptures, architectural reliefs, metalworkings, bone carvings, ivory...34 Ecclesiastical History of 12 In European battles at this time, heavy cavalry was unchallenged as the offensive arm in battle.4 Since the time of...Marzial, Great Britain: Aldine Press, 1965. Vitalis, Ordericus, The Ecclesiastical History of England and Normandy, trans. by Thomas Forester, London

  12. Laboratory studies of stagnating plasma flows with applications to inner solar system and stellar bow shocks

    Science.gov (United States)

    Weber, T. E.; Smith, R. J.; Hsu, S. C.

    2016-10-01

    Supercritical magnetized collisionless shocks are thought to play a dominant role in the overall partition of energy throughout the universe by converting flow kinetic energy to other forms such as thermal and supra-thermal populations, magnetic field enhancement, turbulence, and energetic particles. The Magnetized Shock Experiment (MSX) at LANL creates conditions similar to those of inner solar system and stellar bow shocks by accelerating hot (100s of eV during translation) dense (1022 - 1023 m-3) Field Reversed Configuration (FRC) plasmoids to 100s of km/s; resulting in β 1, collisionless plasma flows with Msonic and MAlfvén 10. The drifting FRC can be made to impinge upon a variety of static obstacles including: a strong mirror or cusp magnetic field (mimicking magnetically excited shocks such as the Earth's bow shock), plasma pileup from a solid obstacle (similar to the bow shocks of Mercury and the Moon), and a neural gas puff (bow shocks of Venus or the comets). Characteristic shock length and time scales that are both large enough to observe yet small enough to fit within the experiment, enabling study of the complex interplay of kinetic and fluid processes that mediate cosmic shocks and can generate non-thermal distributions, produce density and magnetic field enhancements much greater than predicted by fluid theory, and accelerate particles. An overview of the experimental program will be presented, including recent results. This work is supported by the U.S. DOE, Office of Science, Office of Fusion Energy Sciences under Contract No. DE-AC52-06NA25369.

  13. Serendipitous discovery of an infrared bow shock near PSR J1549–4848 with Spitzer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhongxiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Kaplan, David L. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Morrell, Nidia [Las Campanas Observatory, Observatories of the Carnegie Institution of Washington, La Serena (Chile); Kaspi, Victoria M. [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada)

    2013-06-01

    We report on the discovery of an infrared cometary nebula around PSR J1549–4848 in our Spitzer survey of a few middle-aged radio pulsars. Following the discovery, multi-wavelength imaging and spectroscopic observations of the nebula were carried out. We detected the nebula in Spitzer Infrared Array Camera 8.0, Multiband Imaging Photometer for Spitzer 24 and 70 μm imaging, and in Spitzer IRS 7.5-14.4 μm spectroscopic observations, and also in the Wide-field Infrared Survey Explorer all-sky survey at 12 and 22 μm. These data were analyzed in detail, and we find that the nebula can be described with a standard bow shock shape, and that its spectrum contains polycyclic aromatic hydrocarbon and H{sub 2} emission features. However, it is not certain which object drives the nebula. We analyze the field stars and conclude that none of them can be the associated object because stars with a strong wind or mass ejection that usually produce bow shocks are much brighter than the field stars. The pulsar is approximately 15'' away from the region in which the associated object is expected to be located. In order to resolve the discrepancy, we suggest that a highly collimated wind could be emitted from the pulsar and produce the bow shock. X-ray imaging to detect the interaction of the wind with the ambient medium- and high-spatial resolution radio imaging to determine the proper motion of the pulsar should be carried out, which will help verify the association of the pulsar with the bow shock nebula.

  14. Wafer bowing control of free-standing heteroepitaxial diamond (100) films grown on Ir(100) substrates via patterned nucleation growth

    International Nuclear Information System (INIS)

    Yoshikawa, Taro; Kodama, Hideyuki; Kono, Shozo; Suzuki, Kazuhiro; Sawabe, Atsuhito

    2015-01-01

    The potential of patterned nucleation growth (PNG) technique to control the wafer bowing of free-standing heteroepitaxial diamond films was investigated. The heteroepitaxial diamond (100) films were grown on an Ir(100) substrate via PNG technique with different patterns of nucleation regions (NRs), which were dot-arrays with 8 or 13 μm pitch aligned to < 100 > or < 110 > direction of the Ir(100) substrate. The wafer bows and the local stress distributions of the free-standing films were measured using a confocal micro-Raman spectrometer. For each NR pattern, the stress evolutions within the early stage of diamond growth were also studied together with a scanning electron microscopic observation of the coalescing diamond particles. These investigations revealed that the NR pattern, in terms of pitch and direction of dot-array, strongly affects the compressive stress on the nucleation side of the diamond film and dominantly contributes to the elastic deformation of the free-standing film. This indicates that the PNG technique with an appropriate NR pattern is a promising solution to fabricate free-standing heteroepitaxial diamond films with extremely small bows. - Highlights: • Wafer bowing control of free-standing heteroepitaxial diamond (100) films • Effect of patterned nucleation and growth (PNG) technique on wafer bowing reduction • Influence of nucleation region patterns of PNG on wafer bowing • Internal stress analysis of PNG films via confocal micro-Raman spectroscopy

  15. The Procedure for Determination of Special Margin Factors to Account for a Bow of the VVER-1000 Fuel Assemblies

    International Nuclear Information System (INIS)

    Tsyganov, Sergey V.; Marin, Stanislav V.; Shishkov, Lev K.

    2008-01-01

    Starting from 1980's, the problem of bow of the VVER-1000 reactor FAs and the effect of that on the operational safety is being discussed. At the initial period of time, the extension of time for dropping control rods of the control and protection system associated with this bow posed the highest threat. Later on, new more rigid structures were developed for FAs that eliminated the problems of control rods. However, bow of the VVER-1000 reactor FAs is observed up to now. The scale of this bow reduced significantly but it still effects safety. Even a minor bow available may lead to the noticeable increase of power of individual fuel pins associated with the local variation of the coolant amount. This effect must be taken into account on designing fuel loadings to eliminate the exceeding of set limitations. The introduction of additional special margins is the standard method for taking this effect into account. The present paper describes the conservative technique for the assessment of additional margins for bow of FAs of state-of-the-art designs. This technique is employed in the VVER-1000 reactor designing. The chosen conservatism degree is discussed as well as the method for its assurance and acceptable ways for its slackening. The example of the margin evaluation for the up-to-date fuel loading is given. (authors)

  16. The procedure for determination of special margin factors to account for a bow of the WWER-1000 fuel assemblies

    International Nuclear Information System (INIS)

    Tsyganov, S. V.; Marin, S. V.; Shishkov, L. K.

    2008-01-01

    Starting from 1980s, the problem of bow of the WWER-1000 reactor fuel assemblies and the effect of that on the operational safety is being discussed. At the initial period of time, the extension of time for dropping control rods of the control and protection system associated with this bow posed the highest threat. Later on, new more rigid structures were developed for fuel assemblies that eliminated the problems of control rods. However, bow of the WWER-1000 reactor fuel assemblies is observed up to now. The scale of this bow reduced significantly but it still effects safety. Even a minor bow available may lead to the noticeable increase of power of individual fuel pins associated with the local variation of the coolant amount. This effect must be taken into account on designing fuel loadings to eliminate the exceeding of set limitations. The introduction of additional special margins is the standard method for taking this effect into account. The present paper describes the conservative technique for the assessment of additional margins for bow of fuel assemblies of state-of-the-art designs. This technique is employed in the WWER-1000 reactor designing. The chosen conservatism degree is discussed as well as the method for its assurance and acceptable ways for its slackening. The example of the margin evaluation for the up-to-date fuel loading is given. (authors)

  17. The Procedure for Determination of Special Margin Factors to Account for a Bow of the VVER-1000 Fuel Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Tsyganov, Sergey V.; Marin, Stanislav V.; Shishkov, Lev K. [Russian Research Center ' Kurchatov Institute' , 1., Kurchatov sq., 123182 Moscow (Russian Federation)

    2008-07-01

    Starting from 1980's, the problem of bow of the VVER-1000 reactor FAs and the effect of that on the operational safety is being discussed. At the initial period of time, the extension of time for dropping control rods of the control and protection system associated with this bow posed the highest threat. Later on, new more rigid structures were developed for FAs that eliminated the problems of control rods. However, bow of the VVER-1000 reactor FAs is observed up to now. The scale of this bow reduced significantly but it still effects safety. Even a minor bow available may lead to the noticeable increase of power of individual fuel pins associated with the local variation of the coolant amount. This effect must be taken into account on designing fuel loadings to eliminate the exceeding of set limitations. The introduction of additional special margins is the standard method for taking this effect into account. The present paper describes the conservative technique for the assessment of additional margins for bow of FAs of state-of-the-art designs. This technique is employed in the VVER-1000 reactor designing. The chosen conservatism degree is discussed as well as the method for its assurance and acceptable ways for its slackening. The example of the margin evaluation for the up-to-date fuel loading is given. (authors)

  18. Risk analysis of urban gas pipeline network based on improved bow-tie model

    Science.gov (United States)

    Hao, M. J.; You, Q. J.; Yue, Z.

    2017-11-01

    Gas pipeline network is a major hazard source in urban areas. In the event of an accident, there could be grave consequences. In order to understand more clearly the causes and consequences of gas pipeline network accidents, and to develop prevention and mitigation measures, the author puts forward the application of improved bow-tie model to analyze risks of urban gas pipeline network. The improved bow-tie model analyzes accident causes from four aspects: human, materials, environment and management; it also analyzes the consequences from four aspects: casualty, property loss, environment and society. Then it quantifies the causes and consequences. Risk identification, risk analysis, risk assessment, risk control, and risk management will be clearly shown in the model figures. Then it can suggest prevention and mitigation measures accordingly to help reduce accident rate of gas pipeline network. The results show that the whole process of an accident can be visually investigated using the bow-tie model. It can also provide reasons for and predict consequences of an unfortunate event. It is of great significance in order to analyze leakage failure of gas pipeline network.

  19. Upstream pressure variations associated with the bow shock and their effects on the magnetosphere

    International Nuclear Information System (INIS)

    Fairfield, D.H.; Baumjohann, W.; Paschmann, G.; Luehr, H.; Sibeck, D.G.

    1990-01-01

    Magnetic field enhancements and depressions on the time scales of minutes were frequently observed simultaneously by the AMPTE CCE, GOES 5, and GOES 6 spacecraft in the subsolar magnetosphere. The source of these perturbations has been detected in the high time resolution AMPTE IRM measurements of the kinetic pressure of the solar wind upstream of the bow shock. It is argued that these upstream pressure variations are not inherent in the solar wind but rather are associated with the bow shock. This conclusion follows from the facts that (1) the upstream field strength and the density associated with the perturbations are highly correlated with each other whereas these quantities tend to be anticorrelated in the undisturbed solar wind, and (2) the upstream perturbations occur within the foreshock or at its boundary. The results imply a mode of interaction between the solar wind and the magnetosphere whereby density changes produced in the foreshock subsequently convect through the bow shock and impinge on the magnetosphere. Also velocity decreases deep within the foreshock sometimes reach many tens of kilometers per second and may be associated with further pressure variations as a changing interplanetary field direction changes the foreshock geometry. Upstream pressure perturbations should create significant effects on the magnetopause and at the foot of nearby field lines that lead to the polar cusp ionosphere

  20. Upstream region, foreshock and bow shock wave at Halley's Comet from plasma electron measurements

    International Nuclear Information System (INIS)

    Anderson, K.A.; Carlson, C.W.; Curtis, D.W.

    1986-01-01

    Halley plasma electron parameters from 2.7 million km from the comet nucleus to the bow shock wave at 1.1 million km and beyond are surveyed. The features of the electron foreshock lying outside the shock to a distance of 230,000 km are described. It is a region of intense solar wind-comet plasma interaction in which energetic electrons are prominent. Several spikes of electrons whose energies extend to 2.5 keV appear in front of the shock. These energetic electrons may be accelerated in the same way electrons are accelerated at the Earth's bow shock to energies of 1 to 10 keV. The direction of the electron bulk flow direction changes abruptly between 1920 and 1922 UT, and the flow speed begins a sharp decline at the same time. It is suggested that the spacecraft entered the bow shock wave between 1920 and 1922 UT. Electron density variations at Halley are very much smaller than those at Giacobini-Zinner

  1. Interaction of single-pulse laser energy with bow shock in hypersonic flow

    Directory of Open Access Journals (Sweden)

    Hong Yanji

    2014-04-01

    Full Text Available Pressure sensing and schlieren imaging with high resolution and sensitivity are applied to the study of the interaction of single-pulse laser energy with bow shock at Mach 5. An Nd:YAG laser operated at 1.06 μm, 100 mJ pulse energy is used to break down the hypersonic flow in a shock tunnel. Three-dimensional Navier–Stokes equations are solved with an upwind scheme to simulate the interaction. The pressure at the stagnation point on the blunt body is measured and calculated to examine the pressure variation during the interaction. Schlieren imaging is used in conjunction with the calculated density gradients to examine the process of the interaction. The results show that the experimental pressure at the stagnation point on the blunt body and schlieren imaging fit well with the simulation. The pressure at the stagnation point on the blunt body will increase when the transmission shock approaches the blunt body and decrease with the formation of the rarefied wave. Bow shock is deformed during the interaction. Quasi-stationary waves are formed by high rate laser energy deposition to control the bow shock. The pressure and temperature at the stagnation point on the blunt body and the wave drag are reduced to 50%, 75% and 81% respectively according to the simulation. Schlieren imaging has provided important information for the investigation of the mechanism of the interaction.

  2. Recoil and Vibration in an Archery Bow Equipped with a Multi-Rod Stabilizer

    Directory of Open Access Journals (Sweden)

    Igor Zaniewski

    2012-01-01

    Full Text Available The aim of this research is to create a mechanical and mathematical model of a multi-rod stabilizer for the sport archery bow and to analyze its capability to damp disagreeable recoil and vibration of the bow during internal ballistic motion. The research methods are based on the Euler-Bernoulli theory of beam bending, Lagrange equations of the second kind, the Cauchy problem, and the Runge-Kutta method. A mathematical software package was used to analyze the problem. The approach to the problem of sport-bow stabilization in the vertical plane that is proposed in this paper addresses the practical needs both of applied engineering mechanics and of the sport of archery. Numerical results from computer simulation are presented in both tabular and graphical form. The common motion of the string and arrow (internal ballistic motion is accompanied by intense vibration which is caused by disruption of the static force balance at the moment of string release.

  3. PSR J2124-3358: A Bow Shock Nebula with an X-ray Tail

    Science.gov (United States)

    Chatterjee, S.; Gaensler, B. M.; Vigelius, M.; Cordes, J. M.; Arzoumanian, Z.; Stappers, B.; Ghavamian, P.; Melatos, A.

    2005-12-01

    As neutron stars move supersonically through the interstellar medium, their relativistic winds are confined by the ram pressure of the interstellar medium. The outer shocked layers may emit in Hα , producing a visible bow shock nebula, while the confined relativistic wind may produce radio or X-ray emission. The Hα bow shock nebula powered by the recycled pulsar J2124-3358 is asymmetric about the velocity vector and shows a marked kink. In recent observations with the Chandra X-ray Observatory, we have detected a long, curved X-ray tail associated with the pulsar. The tail is not aligned with the pulsar velocity, but is confined within the optical bow shock. The X-ray spectrum of the tail is well-fit by a power law, consistent with synchrotron emission from the wind termination shock and the post-shock flow. The presence of Hα and X-ray emission allows us to trace both the external ambient medium and the confined wind. In magnetohydrodynamic simulations, we verify that a bulk flow and non-uniformities in the ambient medium can produce the observed shape of the nebula, possibly in combination with an anisotropic pulsar wind. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number GO5-6075X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060.

  4. Speciation in the aqueous H+/H2VO4-/H2O2/citrate system of biomedical interest.

    Science.gov (United States)

    Gorzsás, András; Getty, Kendra; Andersson, Ingegärd; Pettersson, Lage

    2004-09-21

    The speciation in the quaternary aqueous H+/H2VO4-/H2O2/citrate (Cit3-) and H+/H2VO4-/Cit3-/L-(+)-lactate (Lac-) systems has been determined at 25 degrees C in the physiological medium of 0.150 M Na(Cl). A combination of 51V NMR integral intensities and chemical shift (Bruker AMX500) as well as potentiometric data (glass electrode) have been collected and evaluated with the computer program LAKE, which is able to treat multimethod data simultaneously. The pKa-values for citric acid have been determined as 2.94, 4.34 and 5.61. Altogether six vanadate-citrate species have been found in the ternary H+/H2VO4-/Cit3- system in the pH region 2-10, only two of which are mononuclear. Reduction of vanadium(V) becomes more pronounced at pH acidic solutions limited the final model to pH > 4. In the quaternary H+/H2VO4-/Cit3-/Lac- system, two mixed-ligand species have been determined, with the compositions V2CitLac2- and V2CitLac3- (pKa = 5.0). To our knowledge, this is the first time such complexes have been reported for vanadium(V). 51V NMR chemical shifts, compositions and formation constants are given, and equilibrium conditions are illustrated in distribution diagrams as well as the fit of the model to the experimental data. When suitable, structural proposals are given, based on 13C NMR measurements and available literature data of related compounds.

  5. Structure-guided mutational analysis of the OB, HhH, and BRCT domains of Escherichia coli DNA ligase.

    Science.gov (United States)

    Wang, Li Kai; Nair, Pravin A; Shuman, Stewart

    2008-08-22

    NAD(+)-dependent DNA ligases (LigAs) are ubiquitous in bacteria and essential for growth. LigA enzymes have a modular structure in which a central catalytic core composed of nucleotidyltransferase and oligonucleotide-binding (OB) domains is linked via a tetracysteine zinc finger to distal helix-hairpin-helix (HhH) and BRCT (BRCA1-like C-terminal) domains. The OB and HhH domains contribute prominently to the protein clamp formed by LigA around nicked duplex DNA. Here we conducted a structure-function analysis of the OB and HhH domains of Escherichia coli LigA by alanine scanning and conservative substitutions, entailing 43 mutations at 22 amino acids. We thereby identified essential functional groups in the OB domain that engage the DNA phosphodiester backbone flanking the nick (Arg(333)); penetrate the minor grove and distort the nick (Val(383) and Ile(384)); or stabilize the OB fold (Arg(379)). The essential constituents of the HhH domain include: four glycines (Gly(455), Gly(489), Gly(521), Gly(553)), which bind the phosphate backbone across the minor groove at the outer margins of the LigA-DNA interface; Arg(487), which penetrates the minor groove at the outer margin on the 3 (R)-OH side of the nick; and Arg(446), which promotes protein clamp formation via contacts to the nucleotidyltransferase domain. We find that the BRCT domain is required in its entirety for effective nick sealing and AMP-dependent supercoil relaxation.

  6. INTERFEROMETRIC OBSERVATIONS OF NITROGEN-BEARING MOLECULAR SPECIES IN THE STAR-FORMING CORE AHEAD OF HH 80N

    Energy Technology Data Exchange (ETDEWEB)

    Masqué, Josep M.; Estalella, Robert [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Catalunya (Spain); Girart, Josep M. [Institut de Ciències de l' Espai (CSIC-IEEC), Campus UAB, Facultat de Ciències, Torre C5 - parell 2, E-08193 Bellaterra, Catalunya (Spain); Anglada, Guillem; Osorio, Mayra [Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain); Beltrán, Maria T. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2013-10-10

    We present Very Large Array NH{sub 3} and Plateau de Bure Interferometer NH{sub 2}D and HN{sup 13}C observations of the star-forming core ahead of HH 80N, the optically obscured northern counterpart of the Herbig-Haro objects HH 80/81. The main goal is to determine the kinematical information of the high density regions of the core (n ∼> 10{sup 5} cm{sup –3}) missed in previous works due to the depletion of the species observed (e.g., CS). The obtained maps show different kinematical signatures between the eastern and western parts of the core, suggesting a possible dynamical interaction of the core with the HH 80/81/80N outflow. The analysis of the position-velocity (P-V) plots of these species rules out a previous interpretation of having a molecular ring-like structure with a radius of 6 × 10{sup 4} AU traced by CS infalling onto a central protostar found in the core (IRS1). A high degree of NH{sub 3} deuteration, with respect to the central part of the core harboring IRS1, is derived in the eastern part, where a dust condensation (SE) is located. This deuteration trend of NH{sub 3} suggests that SE is in a pre-stellar evolutionary stage, earlier than that of IRS1. Since SE is the closest condensation to the HH 80N/81/80N outflow, in a case of outflow-core dynamical interaction, it should be perturbed first and be the most evolved condensation in the core. Therefore, the derived evolutionary sequence for SE and IRS1 makes outflow triggered star formation on IRS1 unlikely.

  7. Design of an Automated System for Synthesis of [18 F] FDG for PET Investigation at IFIN-HH Bucharest

    International Nuclear Information System (INIS)

    Craciun, Liviu Stefan; Cimpeanu, Catalina; Constantinescu, Olimpiu; Dudu, Dorin; Ionescu, Cristina; Negoita, Nicolae; Racolta, Petru Mihai; Rusen, Ion

    2009-01-01

    A novel apparatus constructed at IFIN-HH is described for automated synthesis of radiopharmaceuticals labeled with 18 F for use in positron emission tomography (PET) investigations. [18 F] fluoride was produced at the IFIN-HH cyclotron by irradiation of H 2 O enriched 97% in 18 O with 13 MeV deuterons, or 8 MeV protons. The irradiated H 2 O was transferred (injected) into the radiochemical fully-automated processing systems which ensured the separation of 18 F from H 2 O, the labeling with 18 F, and finally purified by filtration with selective absorbants. The system is easy to operate and contains a programmable logical controller that manages the entire operation program stored in its internal memory. The computer is used to assist the operator during the different steps of synthesis and to allow visualization of the process and printing the report. The device was used for used for the production of 2-[18 F] FLUORO-2-DEOXY-D-GLUCOSE at the IFIN-HH cyclotron, one of the most used radiopharmaceutical in PET investigations. The synthesis module is configured so that is flexible enough to accomplish other nucleophile reactions of labeling with short lived radioisotopes.

  8. Design of an Automated System for Synthesis of [18 F] FDG for PET Investigation at IFIN-HH Bucharest

    Science.gov (United States)

    Craciun, Liviu Stefan; Cimpeanu, Catalina; Constantinescu, Olimpiu; Dudu, Dorin; Ionescu, Cristina; Negoita, Nicolae; Racolta, Petru Mihai; Rusen, Ion

    2009-03-01

    A novel apparatus constructed at IFIN-HH is described for automated synthesis of radiopharmaceuticals labeled with 18F for use in positron emission tomography (PET) investigations. [18 F] fluoride was produced at the IFIN-HH cyclotron by irradiation of H2O enriched 97% in 18O with 13 MeV deuterons, or 8 MeV protons. The irradiated H2O was transferred (injected) into the radiochemical fully-automated processing systems which ensured the separation of 18F from H2O, the labeling with 18F, and finally purified by filtration with selective absorbants. The system is easy to operate and contains a programmable logical controller that manages the entire operation program stored in its internal memory. The computer is used to assist the operator during the different steps of synthesis and to allow visualization of the process and printing the report. The device was used for used for the production of 2-[18 F] FLUORO-2-DEOXY-D-GLUCOSE at the IFIN-HH cyclotron, one of the most used radiopharmaceutical in PET investigations. The synthesis module is configured so that is flexible enough to accomplish other nucleophile reactions of labeling with short lived radioisotopes.

  9. Formation and Atmosphere of Complex Organic Molecules of the HH 212 Protostellar Disk

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chin-Fei; Ho, Paul T. P.; Hirano, Naomi; Shang, Hsien [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China); Li, Zhi-Yun [Astronomy Department, University of Virginia, Charlottesville, VA 22904 (United States); Zhang, Qizhou, E-mail: cflee@asiaa.sinica.edu.tw [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-07-01

    HH 212 is a nearby (400 pc) Class 0 protostellar system recently found to host a “hamburger”-shaped dusty disk with a radius of ∼60 au, deeply embedded in an infalling-rotating flattened envelope. We have spatially resolved this envelope-disk system with the Atacama Large Millimeter/submillimeter Array at up to ∼16 au (0.″04) resolution. The envelope is detected in HCO{sup +} J = 4–3 down to the dusty disk. Complex organic molecules (COMs) and doubly deuterated formaldehyde (D{sub 2}CO) are detected above and below the dusty disk within ∼40 au of the central protostar. The COMs are methanol (CH{sub 3}OH), deuterated methanol (CH{sub 2}DOH), methyl mercaptan (CH{sub 3}SH), and formamide (NH{sub 2}CHO, a prebiotic precursor). We have modeled the gas kinematics in HCO{sup +} and COMs and found a centrifugal barrier (CB) at a radius of ∼44 au, within which a Keplerian rotating disk is formed. This indicates that HCO{sup +} traces the infalling-rotating envelope down to the CB and COMs trace the atmosphere of a Keplerian rotating disk within the CB. The COMs are spatially resolved for the first time, both radially and vertically, in the atmosphere of a disk in the earliest, Class 0 phase of star formation. Our spatially resolved observations of COMs favor their formation in the disk rather than a rapidly infalling (warm) inner envelope. The abundances and spatial distributions of the COMs provide strong constraints on models of their formation and transport in low-mass star formation.

  10. A dedicated beam line for Rutherford backscattering analysis at IFIN-HH cyclotron

    International Nuclear Information System (INIS)

    Ivanov, E. A.; Dudu, D.; Plostinaru, D.; Catana, D.; Vata, I.

    2003-01-01

    Rutherford back-scattering technique (RBS) is an analytical tool that uses elastic scattering of 1-5 MeV charged particles for analysis of the surface and the outer few micrometers of solids. IFIN-HH RBS system consists of the U-120 Cyclotron, a dedicated beam line and a scattering chamber with sample manipulators and particle detectors. In our RBS system the samples are bombarded with 2-5 alpha particles accelerated by U-120 Cyclotron (in 3-rd subharmonic regime) while the scattered particles are detected by a surface barrier detector. The signal from the detector is processed by common nuclear electronics and the particle energy spectra are stored in a computer based multichannel analyser. The data evaluation is accomplished using standard procedures and computer codes. The necessary vacuum inside chamber is obtained with an oil-free turbo pump. The beam spot dimension on the target is 1x1 mm. The standard measurement are done at Θ = 165 angle. The samples are electrically insulated and can be rotated around a vertical axis. The advantage of the RBS technique lies in the quantitative analysis of major and minor constituents lying in the first 0.5 to 2.0 micrometers of a material. Depending on the sample structure and composition, the detection limits vary from 10 11 to 10 15 at. cm -2 for heavy and light elements, respectively. The depth distribution of constituents can be reconstructed with a depth resolution of 10-20 nm. The RBS technique is non-destructive since the erosion and the radiation degradation of the sample material by the particle impact is negligible. The most extensive use of the RBS technique is in the field of electronic and optical materials, special coatings and in the study of various physico-chemical processes on the solid surfaces. (authors)

  11. Status and Perspectives for a Slow Positron Beam Facility at the HH-NIPNE Bucharest

    Science.gov (United States)

    Straticiuc, Mihai; Craciun, Liviu Stefan; Constantinescu, Olimpiu; Ghita, Ionica Alina; Ionescu, Cristina; Racolta, Petru Mihai; Vasilescu, Angela; Braic, Viorel; Zoita, Catalin; Kiss, Adrian; Bojin, Dionezie

    2009-03-01

    The development of a positron annihilation spectroscopy laboratory at the HH-NIPNE Bucharest-to be used for material studies and applications was started in the last 10 years. In the framework of a national research project extended over the last 3 years, was designed a low energy positron accelerator, as a high-vacuum dedicated beam line with two options: a 25 mCi 22NaCl source and in line with the NIPNE-cyclotron or a new intense compact cyclotron. The construction of the beam line was planned as a sequence of modules: source- moderator system; magnetical filter for fast positrons in order to select the positrons energies in the range 0.8-1 keV; a modular system for focusing, transport and acceleration of monoenergetic positrons in the energy range 0.8-50 keV and a CDBS analysis chamber. The moderator proposed-is tungsten as a foil of about 3 μm prepared at the Optoelectronics Institute were put into a thermal treatment vacuum chamber and bombarded with electrons from a 100 W electron gun After the treatment, they were tested for changes of elemental composition of the surface and structure at the Polytechnic University. The structure tests were performed on a DRON 3 M diffractometer, with a Co tube (λKα = 1.7903 A)-the angular regions studied were around 34° (1 0 0) and 69° (2 0 0). In the present time, the trajectories of the positron are going to be simulated with dedicated software (an ion and electron optics simulator). For the coincidence measurements (CDBS) set-up we used a home-made 22NaCl source, by separation without carrier from a metallic Mg target irradiated with 12 MeV protons and separated by columnar cation exchange. A home- made biparametric system for CDBS measurements will be reported, also.

  12. Martian Bow Shock and Magnetic Pile-Up Barrier Formation Due to the Exosphere Ion Mass-Loading

    Directory of Open Access Journals (Sweden)

    Eojin Kim

    2011-03-01

    Full Text Available Bow shock, formed by the interaction between the solar wind and a planet, is generated in different patterns depending on the conditions of the planet. In the case of the earth, its own strong magnetic field plays a critical role in determining the position of the bow shock. However, in the case of Mars of which has very a small intrinsic magnetic field, the bow shock is formed by the direct interaction between the solar wind and the Martian ionosphere. It is known that the position of the Martian bow shock is affected by the mass loading-effect by which the supersonic solar wind velocity becomes subsonic as the heavy ions originating from the planet are loaded on the solar wind. We simulated the Martian magnetosphere depending on the changes of the density and velocity of the solar wind by using the three-dimensional magnetohydrodynamic model built by modifying the comet code that includes the mass loading effect. The Martian exosphere model of was employed as the Martian atmosphere model, and only the photoionization by the solar radiation was considered in the ionization process of the neutral atmosphere. In the simulation result under the normal solar wind conditions, the Martian bow shock position in the subsolar point direction was consistent with the result of the previous studies. The three-dimensional simulation results produced by varying the solar wind density and velocity were all included in the range of the Martian bow shock position observed by Mariner 4, Mars 2, 3, 5, and Phobos 2. Additionally, the simulation result also showed that the change of the solar wind density had a greater effect on the Martian bow shock position than the change of the solar wind velocity. Our result may be useful in analyzing the future observation data by Martian probes.

  13. Observational test of shock drift and Fermi acceleration on a seed particle population upstream of earth's bow shock

    Science.gov (United States)

    Anagnostopoulos, G. C.; Sarris, E. T.; Krimigis, S. M.

    1988-01-01

    The efficiency of proposed shock acceleration mechanisms as they operate at the bow shock in the presence of a seed energetic particle population was examined using data from simultaneous observations of energetic solar-origin protons, carried out by the IMP 7 and 8 spacecraft in the vicinity of the quasi-parallel (dawn) and quasi-perpendicular (dusk) regions of the earth's bow shock, respectively. The results of observations (which include acceleration effects in the intensities of the energetic protons with energies as high as 4 MeV observed at the vicinity of the dusk bow shock, but no evidence for any particle acceleration at the energy equal to or above 50 keV at the dawn side of the bow shock) indicate that the acceleration of a seed particle population occurs only at the quasi-perpendicular bow shock through shock drift acceleration and that the major source of observed upstream ion populations is the leakage of magnetospheric ions of energies not less than 50 keV, rather than in situ acceleration.

  14. Ionospheric Bow Wave Induced by the Moon Shadow Ship Over the Continent of United States on 21 August 2017

    Science.gov (United States)

    Sun, Yang-Yi; Liu, Jann-Yenq; Lin, Charles Chien-Hung; Lin, Chi-Yen; Shen, Ming-Hsueh; Chen, Chieh-Hung; Chen, Chia-Hung; Chou, Min-Yang

    2018-01-01

    A moon shadow of the total solar eclipse swept through the continent of United States (CONUS) from west to east on 21 August 2017. Massive total electron content (integration of electron density from 0 km to 20,200 km altitude) observations from 2,255 ground-based Global Navigation Satellite System receivers show that the moon shadow ship generates a great ionospheric bow wave front which extends 1,500 km away from the totality path covering the entire CONUS. The bow wave front consists of the acoustic shock wave due to the supersonic/near-supersonic moon shadow ship and the significant plasma recombination due to the reduction in solar irradiation within the shadow area. The deep bow wave trough (-0.02 total electron content unit (1 TECU = 1016 el m-2) area) nearly coincides with the 100% obscuration moving along the totality path over the CONUS through the entire eclipse period. The supersonic moon shadow ship induces a bow wave crest in front of the ship ( 80% obscuration). It is the first time to find the acoustic shock wave-formed bow wave trough and crest near the totality.

  15. Thermal/hydraulic bowing stability analysis of grid-supported multi-pin bundles with differential swelling and irradiation creep

    International Nuclear Information System (INIS)

    McAreavey, G.

    1977-01-01

    Azimuthal variations of clad temperature in fuel pin bundles leads to pin bowing by differential thermal expansion. During irradiation in a fast flux further possibly more severe bowing is caused by differential neutron induced voidage swelling, which, being temperature sensitive, will also vary azimuthally. The problem of pin bowing in a fuel element cluster involves consideration of the thermal/hydraulic behaviour, allowing for both inherent and induced clad temperature non-uniformities, coupled with the restrained bowing behaviour, including differential thermal expansion, differential swelling, and irradiation creep. All pins must be considered simultaneously. In the temperature and stress ranges of interest thermal creep may be neglected. An existing computer code, IAMBIC solves the zero time thermal bowing problem for a cluster of up to 61 pins on hexagonal pitch, with up to 21 supports at arbitrary axial spacing. The present paper describes the basis of TRIAMBIC, a time dependent code which analyses the irradiation induced effects in fuel pin bunbles due to fast neutrons. (Auth.)

  16. On the failure behaviour to striking bow penetration of impacted marine-steel structures

    Science.gov (United States)

    Prabowo, Aditya Rio; Muttaqie, Teguh; Sohn, Jung Min; Bae, Dong Myung; Setiyawan, Agus

    2018-04-01

    Demands for water transportation modes are continuously increasing as rapid economic and industrial growths in the recent decade. Ship as representative of the water transportation is generally needed to carry various products from one location to another. Besides as product carrier, ship also acts as public facility to transport human across islands for number of reasons, such as tourism and vehicle. Considering its importance, structural damage due to accidental loads or so-called impact can cause unacceptable casualties which threat ship passenger, shipping industry and maritime environment in same time. The most frequent impact phenomena occur in forms of collision and grounding, which are targeting side structure and double bottom consecutively. However, since responses of the impacts on structure are highly nonlinear and vary due to development of ship structures, sustainable analysis as an update of pioneer calculation can be beneficial as rational reference for improving safety and navigational instruments. This work aims to assess failures of the side structures subjected to penetration of striking bow in ship-ship collision scenario. Locations of impact are idealized to happen on after-end, midsection and fore-end to provide complete assessment. Striking bow is to be deployed by varying input velocity to observe significance of the fractures on the side structure. This configuration is implemented on the designed collision scenario, and later calculated using nonlinear finite element method (NLFEM). Summary of the solution indicated that the midsection produced the highest resistance against side collision. Breaching of the inner shell was successfully avoided on the fore-end, but the critical damage to the cargo was observed during bow penetration to the after-end region. This location was recommended to be added by longitudinal framing to increase its resistance against ship collision.

  17. On the failure behaviour to striking bow penetration of impacted marine-steel structures

    Directory of Open Access Journals (Sweden)

    Prabowo Aditya Rio

    2018-04-01

    Full Text Available Demands for water transportation modes are continuously increasing as rapid economic and industrial growths in the recent decade. Ship as representative of the water transportation is generally needed to carry various products from one location to another. Besides as product carrier, ship also acts as public facility to transport human across islands for number of reasons, such as tourism and vehicle. Considering its importance, structural damage due to accidental loads or so-called impact can cause unacceptable casualties which threat ship passenger, shipping industry and maritime environment in same time. The most frequent impact phenomena occur in forms of collision and grounding, which are targeting side structure and double bottom consecutively. However, since responses of the impacts on structure are highly nonlinear and vary due to development of ship structures, sustainable analysis as an update of pioneer calculation can be beneficial as rational reference for improving safety and navigational instruments. This work aims to assess failures of the side structures subjected to penetration of striking bow in ship-ship collision scenario. Locations of impact are idealized to happen on after-end, midsection and fore-end to provide complete assessment. Striking bow is to be deployed by varying input velocity to observe significance of the fractures on the side structure. This configuration is implemented on the designed collision scenario, and later calculated using nonlinear finite element method (NLFEM. Summary of the solution indicated that the midsection produced the highest resistance against side collision. Breaching of the inner shell was successfully avoided on the fore-end, but the critical damage to the cargo was observed during bow penetration to the after-end region. This location was recommended to be added by longitudinal framing to increase its resistance against ship collision.

  18. Plasma electron signature of magnetic connection to the earth's bow shock: ISEE 3

    International Nuclear Information System (INIS)

    Feldman, W.C.; Anderson, R.C.; Asbridge, J.R.; Bame, S.J.; Gosling, J.T.; Zwickl, R.D.

    1982-01-01

    Enhanced fluxes of low-energy electrons backstreaming from the earth's bow shock have been identified at ISEE 3. When present, these fluxes modify ambient solar wind electron velocity distributions f(v) in characteristic ways that depends on whether ISEE 3 is near the edge, or within the interior of the earth's electron foreshock. Near the edge, energy peaks in f(v) are observed. Such distributions should be locally unstable to electron plasma oscillations. Well within the interior of the foreshock, enhanced fluxes of electrons with energies up to the maximum detected by the Los Alamos electron analyzer (approx.1 keV) are observed over the full backward hemisphere. These electrons can be modelled with an asymptotic power law distribution having index in the range 4< or approx. =p/sub b/s< or approx. =6. At intermediate energies (approx.20--50 eV), twin angular peaks are observed centered on the magnetic field direction B. Also observed at these times are depressions in f(v) at energies less than approx.20 eV that are centered on B. Such distributions having a perpendicular temperature greater than their parallel temperature may be locally unstable to the generation of whistler waves. Analysis of a particularly clean example of connection to the bow shock is consistent with the possiblility that the observed electron fluxes emerge from the forward foot of the electron heating region within bow shock where the electron density and temperature are larger than that of the uperturbed upstream solar wind by a factor of approx.1.2. This analysis also indicates that the electrostatic potential within the forward foot of the shock is between approx.5 and 50 V more positive than that within plasma far upstream at ISEE 3. However, these interpretations depend on the assumption of nearly scatter-free propagation, which may not hold

  19. Anomalous band-gap bowing of AlN1−xPx alloy

    International Nuclear Information System (INIS)

    Winiarski, M.J.; Polak, M.; Scharoch, P.

    2013-01-01

    Highlights: •Structural and electronic properties of AlN 1−x P x from first principles. •The supercell and the virtual crystall approximation methods applied and compared. •Anomalously high band-gap bowing found. •Similarities of band-gap behavior to that in BN 1−x P x noticed. •Performance of MBJLDA with the pseudopotential approach discussed. -- Abstract: Electronic structure of zinc blende AlN 1−x P x alloy has been calculated from first principles. Structural optimization has been performed within the framework of LDA and the band-gaps calculated with the modified Becke–Jonson (MBJLDA) method. Two approaches have been examined: the virtual crystal approximation (VCA) and the supercell-based calculations (SC). The composition dependence of the lattice parameter obtained from the SC obeys Vegard’s law whereas the volume optimization in the VCA leads to an anomalous bowing of the lattice constant. A strong correlation between the band-gaps and the structural parameter in the VCA method has been observed. On the other hand, in the SC method the supercell size and atoms arrangement (clustered vs. uniform) appear to have a great influence on the computed band-gaps. In particular, an anomalously big band-gap bowing has been found in the case of a clustered configuration with relaxed geometry. Based on the performed tests and obtained results some general features of MBJLDA are discussed and its performance for similar systems predicted

  20. Reflection of the solar wind ions at the earth's bow shock: energization

    International Nuclear Information System (INIS)

    Bonifazi, C.; Moreno, G.; Russell, C.T.

    1983-01-01

    The energies of the field-aligned proton beams observed upstream of the earth's bow shock are tested, on a statistical basis, against a simple reflection model. The comparison is carried out using both plasma and magnetic field data collected by the ISEE 2 spacecraft. The observations refer to the period from November 5 to December 20, 1977. According to this model, some of the solar wind protons incident upon the earth's shock front when reflected upstream gain energy by displacement parallel to the interplanetary electric field. The energy gained in the reflection can be described as a function of the angles between the interplanetary magnetic field, the solar wind bulk velocity, and the local shock normal. The task of finding these angles, i.e., the expected source point of the reflected ions at the earth's shock front, has been resolved using both the measured magnetic field direction and actual beam trajectory. The latter method, which takes into account the ion drift velocity, leads to a better agreement between theory and observations when far from the shock. In particular, it allows us to check the energies of the field-aligned beams even when they are observed far from the earth's bow shock (at distances up to 10-15 R/sub E/). We confirm, on a statistical basis, the test of the model recently carried out using the Los Alamos National Laboratory/Max-Planck-extraterrestrische observations on ISEE 1 and 2. We infer that reflected beams can sometimes propagate far upstream of the earth's bow shock without changing their energy properties

  1. Astrophysically relevant radiatively cooled hypersonic bow shocks in nested wire arrays

    Science.gov (United States)

    Ampleford, David

    2009-11-01

    We have performed laboratory experiments which introduce obstructions into hypersonic plasma flows to study the formation of shocks. Astrophysical observations have demonstrated many examples of equivalent radiatively cooled bow shocks, for example the head of protostellar jets or supernova remnants passing through the interstellar medium or between discrete clumps in jets. Wire array z-pinches allow us to study quasi-planar radiatively cooled flows in the laboratory. The early stage of a wire array z-pinch implosion consists of a steady flow of the wire material towards the axis. Given a high rate of radiative cooling, these flows reach high sonic- Mach numbers, typically up to 5. The 2D nature of this configuration allows the insertion of obstacles into the flow, such as a concentric ``inner'' wire array, as has previously been studied for ICF research. Here we study the application of such a nested array to laboratory astrophysics where the inner wires act as obstructions perpendicular to the flow, and induce bow shocks. By varying the wire array material (W/Al), the significance of radiative cooling on these shocks can be controlled, and is shown to change the shock opening angle. As multiple obstructions are present, the experiments show the interaction of multiple bow shocks. It is also possible to introduce a magnetic field around the static object, increasing the opening angle of the shocks. Further experiments can be designed to control the flow density, magnetic field structure and obstruction locations. In collaboration with: S.V. Lebedev, M.E. Cuneo, C.A. Jennings, S.N. Bland, J.P. Chittenden, A. Ciardi, G.N. Hall, S.C. Bott, M. Sherlock, A. Frank, E. Blackman

  2. Survey of coherent ion reflection at the quasi-parallel bow shock

    International Nuclear Information System (INIS)

    Onsager, T.G.; Thomsen, M.F.; Gosling, J.T.; Bame, S.J.; Russell, C.T.

    1990-01-01

    Ions coherently reflected off the Earth's bow shock have previously been observed both when the upstream geometry is quasi-perpendicular and when it is quasi-parallel. In the case of quasiperpendicular geometry, the ions are reflected in a nearly specular manner and are quickly carried back into the shock by the convecting magnetic field. In the quasi-parallel geometry, however, near-specularly reflected ions' guiding center velocities would on the average be directed away from the shock, allowing the ions to escape into the upstream region. The conditions under which coherent reflection occurs and the subsequent coupling of the reflected ions to the incoming solar wind plasma are important factors when assessing the contribution of the reflected ions to the downstream temperature increase and the shock structure. The survey presented in this paper, along with previously reported observations, suggests that near-specularly reflected ions are indeed an important aspect of energy dissipation at the Earth's quasi-parallel bow shock. The authors find that (1) cool, coherent, near-specularly reflected ion beams are detected over nearly the full range of upstream plasma paraameters commonly found at the Earth's bow shock; (2) the beams are typically observed only near the shock ramp or some shock-like feature; and (3) the observed beam velocities are almost always consistent with what one would expect for near-specularly reflected ions after only a small fraction of a gyroperiod following reflection. The second and third points indicate that the beams spread very quickly in velocity space. This spread in velocities could be due either to interactions between the beam and incoming solar wind ions or to some initially small velocity spread in the beam

  3. GYROSURFING ACCELERATION OF IONS IN FRONT OF EARTH's QUASI-PARALLEL BOW SHOCK

    International Nuclear Information System (INIS)

    Kis, Arpad; Lemperger, Istvan; Wesztergom, Viktor; Agapitov, Oleksiy; Krasnoselskikh, Vladimir; Khotyaintsev, Yuri V.; Dandouras, Iannis

    2013-01-01

    It is well known that shocks in space plasmas can accelerate particles to high energies. However, many details of the shock acceleration mechanism are still unknown. A critical element of shock acceleration is the injection problem; i.e., the presence of the so called seed particle population that is needed for the acceleration to work efficiently. In our case study, we present for the first time observational evidence of gyroresonant surfing acceleration in front of Earth's quasi-parallel bow shock resulting in the appearance of the long-suspected seed particle population. For our analysis, we use simultaneous multi-spacecraft measurements provided by the Cluster spacecraft ion (CIS), magnetic (FGM), and electric field and wave instrument (EFW) during a time period of large inter-spacecraft separation distance. The spacecraft were moving toward the bow shock and were situated in the foreshock region. The results show that the gyroresonance surfing acceleration takes place as a consequence of interaction between circularly polarized monochromatic (or quasi-monochromatic) transversal electromagnetic plasma waves and short large amplitude magnetic structures (SLAMSs). The magnetic mirror force of the SLAMS provides the resonant conditions for the ions trapped by the waves and results in the acceleration of ions. Since wave packets with circular polarization and different kinds of magnetic structures are very commonly observed in front of Earth's quasi-parallel bow shock, the gyroresonant surfing acceleration proves to be an important particle injection mechanism. We also show that seed ions are accelerated directly from the solar wind ion population.

  4. GYROSURFING ACCELERATION OF IONS IN FRONT OF EARTH's QUASI-PARALLEL BOW SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Kis, Arpad; Lemperger, Istvan; Wesztergom, Viktor [Research Centre for Astronomy and Earth Sciences, Geodetic and Geophysical Institute, Sopron (Hungary); Agapitov, Oleksiy; Krasnoselskikh, Vladimir [LPC2E/CNRS, F-45071 Orleans (France); Khotyaintsev, Yuri V. [Swedish Institute of Space Physics, SE- 751 21 Uppsala (Sweden); Dandouras, Iannis, E-mail: akis@ggki.hu, E-mail: Kis.Arpad@csfk.mta.hu [CESR, F-31028 Toulouse (France)

    2013-07-01

    It is well known that shocks in space plasmas can accelerate particles to high energies. However, many details of the shock acceleration mechanism are still unknown. A critical element of shock acceleration is the injection problem; i.e., the presence of the so called seed particle population that is needed for the acceleration to work efficiently. In our case study, we present for the first time observational evidence of gyroresonant surfing acceleration in front of Earth's quasi-parallel bow shock resulting in the appearance of the long-suspected seed particle population. For our analysis, we use simultaneous multi-spacecraft measurements provided by the Cluster spacecraft ion (CIS), magnetic (FGM), and electric field and wave instrument (EFW) during a time period of large inter-spacecraft separation distance. The spacecraft were moving toward the bow shock and were situated in the foreshock region. The results show that the gyroresonance surfing acceleration takes place as a consequence of interaction between circularly polarized monochromatic (or quasi-monochromatic) transversal electromagnetic plasma waves and short large amplitude magnetic structures (SLAMSs). The magnetic mirror force of the SLAMS provides the resonant conditions for the ions trapped by the waves and results in the acceleration of ions. Since wave packets with circular polarization and different kinds of magnetic structures are very commonly observed in front of Earth's quasi-parallel bow shock, the gyroresonant surfing acceleration proves to be an important particle injection mechanism. We also show that seed ions are accelerated directly from the solar wind ion population.

  5. 3-D Hybrid Simulation of Quasi-Parallel Bow Shock and Its Effects on the Magnetosphere

    International Nuclear Information System (INIS)

    Lin, Y.; Wang, X.Y.

    2005-01-01

    A three-dimensional (3-D) global-scale hybrid simulation is carried out for the structure of the quasi-parallel bow shock, in particular the foreshock waves and pressure pulses. The wave evolution and interaction with the dayside magnetosphere are discussed. It is shown that diamagnetic cavities are generated in the turbulent foreshock due to the ion beam plasma interaction, and these compressional pulses lead to strong surface perturbations at the magnetopause and Alfven waves/field line resonance in the magnetosphere

  6. Analytic MHD Theory for Earth's Bow Shock at Low Mach Numbers

    Science.gov (United States)

    Grabbe, Crockett L.; Cairns, Iver H.

    1995-01-01

    A previous MHD theory for the density jump at the Earth's bow shock, which assumed the Alfven M(A) and sonic M(s) Mach numbers are both much greater than 1, is reanalyzed and generalized. It is shown that the MHD jump equation can be analytically solved much more directly using perturbation theory, with the ordering determined by M(A) and M(s), and that the first-order perturbation solution is identical to the solution found in the earlier theory. The second-order perturbation solution is calculated, whereas the earlier approach cannot be used to obtain it. The second-order terms generally are important over most of the range of M(A) and M(s) in the solar wind when the angle theta between the normal to the bow shock and magnetic field is not close to 0 deg or 180 deg (the solutions are symmetric about 90 deg). This new perturbation solution is generally accurate under most solar wind conditions at 1 AU, with the exception of low Mach numbers when theta is close to 90 deg. In this exceptional case the new solution does not improve on the first-order solutions obtained earlier, and the predicted density ratio can vary by 10-20% from the exact numerical MHD solutions. For theta approx. = 90 deg another perturbation solution is derived that predicts the density ratio much more accurately. This second solution is typically accurate for quasi-perpendicular conditions. Taken together, these two analytical solutions are generally accurate for the Earth's bow shock, except in the rare circumstance that M(A) is less than or = 2. MHD and gasdynamic simulations have produced empirical models in which the shock's standoff distance a(s) is linearly related to the density jump ratio X at the subsolar point. Using an empirical relationship between a(s) and X obtained from MHD simulations, a(s) values predicted using the MHD solutions for X are compared with the predictions of phenomenological models commonly used for modeling observational data, and with the predictions of a

  7. Critical experiment tests of bowing and expansion reactivity calculations for LMRS

    International Nuclear Information System (INIS)

    Schaefer, R.W.

    1988-01-01

    Experiments done in several LMR-type critical assemblies simulated core axial expansion, core radial expansion and bowing, coolant expansion, and control driveline expansion. For the most part new experimental techniques were developed to do these experiments. Calculations of the experiments basically used design-level methods, except when it was necessary to investigate complexities peculiar to the experiments. It was found that these feedback reactivities generally are overpredicted, but the predictions are within 30% of the experimental values. 14 refs., 2 figs., 4 tabs

  8. Beam-Steerable Microstrip-Fed Bow-Tie Antenna Array for Fifth Generation Cellular Communications

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert Frølund

    2016-01-01

    The design and performance of mm-wave phased array antenna for 5G mobile broadband communication systems has been provided in this manuscript. The antenna is designed on a N9000 PTFE substrate with 0.787 mm thickness and 2.2 dielectric constant and 65×130 mm2 overall dimension. Eight elements...... of bow-tie antennas have been used at the top-edge region of mobile phone PCB. The antenna elements fed by microstrip lines are designed to operate at 17 GHz. The simulated results give good performances in terms of different antenna parameters. In addition, an investigation on the distance between...

  9. Estimation of violin bowing features from Audio recordings with Convolutional Networks

    DEFF Research Database (Denmark)

    Perez-Carillo, Alfonso; Purwins, Hendrik

    The acquisition of musical gestures and particularly of instrument controls from a musical performance is a field of increasing interest with applications in many research areas. In the last years, the development of novel sensing technologies has allowed the fine measurement of such controls...... and low-cost of the acquisition and its nonintrusive nature. The main challenge is designing robust detection algorithms to be as accurate as the direct approaches. In this paper, we present an indirect acquisition method to estimate violin bowing controls from audio signal analysis based on training...

  10. Do we really observe a bow shock in N157B...?

    OpenAIRE

    van der Swaluw, Eric

    2003-01-01

    I present a model of a pulsar wind interacting with its associated supernova remnant. I will use the model to argue that one can explain the morphology of the pulsar wind nebula inside N157B, a supernova remnant in the Large Magellanic Cloud, without the need for a bow shock interpretation. The model uses a hydrodynamics code which simulates the evolution of a pulsar wind nebula, when the pulsar is moving at a high velocity (1000 km/sec) through the expanding supernova remnant. The simulation...

  11. Discovery of an optical bow-shock around pulsar B0740-28

    OpenAIRE

    Jones, D.H.; Stappers, B.W.; Gaensler, B.M.

    2002-01-01

    We report the discovery of a faint H-alpha pulsar wind nebula (PWN) powered by the radio pulsar B0740-28. The characteristic bow-shock morphology of the PWN implies a direction of motion consistent with the previously measured velocity vector for the pulsar. The PWN has a flux density more than an order of magnitude lower than for the PWNe seen around other pulsars, but, for a distance 2 kpc, it is consistent with propagation through a medium of atomic density n_H ~ 0.25 cm^{-3}, and neutral ...

  12. Liquid Crystal Bow-Tie Microstrip antenna for Wireless Communication Applications

    Directory of Open Access Journals (Sweden)

    B.T.P.Madhav

    2014-06-01

    Full Text Available In this paper we presented the design and analysis of Bow-Tie antenna on liquid crystal substrate, which is suitable for the Bluetooth/WLAN-2.4/WiBree/ZigBee applications. The Omni-directional radiation patterns along with moderate gain make the proposed antenna suitable for above mentioned applications. Details of the antenna design and simulated results Return loss, Input impedance, Radiation Patterns, E-Field, H-Field and Current Distributions, VSWR are presented and discussed. The proposed antenna is simulated at 2.4 GHz using Ansoft HFSS-11.

  13. Comparison of theory with atomic oxygen 130.4 nm radiation data from the Bow Shock ultraviolet 2 rocket flight

    Science.gov (United States)

    Levin, Deborah A.; Candler, Graham V.; Collins, Robert J.; Howlett, Carl L.; Espy, Patrick; Whiting, Ellis; Park, Chul

    1993-01-01

    Comparison is made between the results obtained from a state-of-the-art flow and radiative model and bow shock vacuum ultraviolet (VUV) data obtained the recent Bow Shock 2 Flight Experiment. An extensive data set was obtained from onboard rocket measurements at a reentry speed of 5 km/sec between the altitudes of approximately 65-85 km. A description of the NO photoionization cell used, the data, and the interpretation of the data will be presented. The primary purpose of the analyses is to assess the utility of the data and to propose a radiation model appropriate to the flight conditions of Bow Shock 2. Theoretical predictions based on flow modeling discussed in earlier work and a new radiation model are compared with data.

  14. Terahertz-wave near-field imaging with subwavelength resolution using surface-wave-assisted bow-tie aperture

    Science.gov (United States)

    Ishihara, Kunihiko; Ohashi, Keishi; Ikari, Tomofumi; Minamide, Hiroaki; Yokoyama, Hiroyuki; Shikata, Jun-ichi; Ito, Hiromasa

    2006-11-01

    We demonstrate the terahertz-wave near-field imaging with subwavelength resolution using a bow-tie shaped aperture surrounded by concentric periodic structures in a metal film. A subwavelength aperture with concentric periodic grooves, which are known as a bull's eye structure, shows extremely large enhanced transmission beyond the diffraction limit caused by the resonant excitation of surface waves. Additionally, a bow-tie aperture exhibits extraordinary field enhancement at the sharp tips of the metal, which enhances the transmission and the subwavelength spatial resolution. We introduced a bow-tie aperture to the bull's eye structure and achieved high spatial resolution (˜λ/17) in the near-field region. The terahertz-wave near-field image of the subwavelength metal pattern (pattern width=20μm) was obtained for the wavelength of 207μm.

  15. [Development Of 25-Year Imp 8 Bow Shock Crossing "List, Ingestion Of This List To Cdaweb, & Enhancement"

    Science.gov (United States)

    Merka, J.; Szabo, A.; Narock, T. W.; King, J. H.; Paularena, K. I.; Richardson, J. D.

    2003-01-01

    The MIT portion of this project was to use the plasma data from IMP 8 to identify bow shock crossings for construction of a bow shock data base. In collaboration with Goddard, we determined which shock parameters would be included in the catalog and developed a set of flags for characterizing the data. IMP 8 data from 1973-2001 were surveyed for bow shock crossings; the crossings apparent in the plasma data were compared to a list of crossing chosen in the magnetometer data by Goddard. Differences were reconciled to produce a single list. The data were then provided to the NSSDC for archiving. All the work ascribed to MIT in the proposal was completed.

  16. Multicentre randomised double bind crossover trial on contamination of conventional ties and bow ties in routine obstetric and gynaecological practice.

    Science.gov (United States)

    Biljan, M M; Hart, C A; Sunderland, D; Manasse, P R; Kingsland, C R

    1993-01-01

    OBJECTIVE--To assess level of contamination of neckwear worn by gynaecologists and obstetricians during routine working week. DESIGN--Multicentre randomised double blind crossover trial. Participants wore the same conventional ties for three days in one week and bow ties for the same period in second week. SETTING--Two teaching and three district general hospitals in the midlands, Wales, and north England. SUBJECTS--15 registrars and senior registrars. INTERVENTIONS--A swab soaked in sterile saline was taken from specific area on ties at end of first and third working days and sent in transport medium for culture on chocolatised blood and MacConkey agar for 48 hours. MAIN OUTCOME MEASURES--Level of bacteriological growth assessed semiquantitatively (0 for no contamination; for heavy contamination) after swabs had been cultured. At end of study the participants completed a questionnaire to assess their attitude toward wearing different types of necktie. RESULTS--12 doctors (80%) completed the study. Although bow ties were significantly less contaminated at end of first working day (z = -2.354, p = 0.019), this difference was not maintained; there was no difference in level of contamination on third day. Level of contamination did not increase between first and third day of wearing the same garment. One of the 10 doctors who returned the questionnaire found the bow tie very uncomfortable. All participants would consider wearing a bow tie if it proved to be less contaminated than a conventional tie. CONCLUSIONS--Although a significant difference in contamination was established between conventional and bow ties on first day of study, this difference was not confirmed on third day and there is unlikely to be any real association between tie type and bacterial contamination. Because of its negative image and difficulty to tie, the bow tie will probably remain a minority fashion. Images p1583-a PMID:8292945

  17. A new technique to characterize CT scanner bow-tie filter attenuation and applications in human cadaver dosimetry simulations

    Science.gov (United States)

    Li, Xinhua; Shi, Jim Q.; Zhang, Da; Singh, Sarabjeet; Padole, Atul; Otrakji, Alexi; Kalra, Mannudeep K.; Xu, X. George; Liu, Bob

    2015-01-01

    Purpose: To present a noninvasive technique for directly measuring the CT bow-tie filter attenuation with a linear array x-ray detector. Methods: A scintillator based x-ray detector of 384 pixels, 307 mm active length, and fast data acquisition (model X-Scan 0.8c4-307, Detection Technology, FI-91100 Ii, Finland) was used to simultaneously detect radiation levels across a scan field-of-view. The sampling time was as short as 0.24 ms. To measure the body bow-tie attenuation on a GE Lightspeed Pro 16 CT scanner, the x-ray tube was parked at the 12 o’clock position, and the detector was centered in the scan field at the isocenter height. Two radiation exposures were made with and without the bow-tie in the beam path. Each readout signal was corrected for the detector background offset and signal-level related nonlinear gain, and the ratio of the two exposures gave the bow-tie attenuation. The results were used in the geant4 based simulations of the point doses measured using six thimble chambers placed in a human cadaver with abdomen/pelvis CT scans at 100 or 120 kV, helical pitch at 1.375, constant or variable tube current, and distinct x-ray tube starting angles. Results: Absolute attenuation was measured with the body bow-tie scanned at 80–140 kV. For 24 doses measured in six organs of the cadaver, the median or maximum difference between the simulation results and the measurements on the CT scanner was 8.9% or 25.9%, respectively. Conclusions: The described method allows fast and accurate bow-tie filter characterization. PMID:26520720

  18. BOW. A computer code to predict lateral deflections of composite beams. A computer code to predict lateral deflections of composite beams

    Energy Technology Data Exchange (ETDEWEB)

    Tayal, M.

    1987-08-15

    Arrays of tubes are used in many engineered structures, such as in nuclear fuel bundles and in steam generators. The tubes can bend (bow) due to in-service temperatures and loads. Assessments of bowing of nuclear fuel elements can help demonstrate the integrity of fuel and of surrounding components, as a function of operating conditions such as channel power. The BOW code calculates the bending of composite beams such as fuel elements, due to gradients of temperature and due to hydraulic forces. The deflections and rotations are calculated in both lateral directions, for given conditions of temperatures. Wet and dry operation of the sheath can be simulated. Bow accounts for the following physical phenomena: circumferential and axial variations in the temperatures of the sheath and of the pellet; cracking of pellets; grip and slip between the pellets and the sheath; hydraulic drag; restraints from endplates, from neighbouring elements, and from the pressure-tube; gravity; concentric or eccentric welds between endcap and endplate; neutron flux gradients; and variations of material properties with temperature. The code is based on fundamental principles of mechanics. The governing equations are solved numerically using the finite element method. Several comparisons with closed-form equations show that the solutions of BOW are accurate. BOW`s predictions for initial in-reactor bow are also consistent with two post-irradiation measurements.

  19. TH-CD-207B-05: Measurement of CT Bow-Tie Profiles Using a Linear Array Detector

    Energy Technology Data Exchange (ETDEWEB)

    Yang, K; Li, X; Liu, B [Massachusetts General Hospital, Boston, MA (United States)

    2016-06-15

    Purpose: To accurately measure CT bow-tie profiles from various manufacturers and to provide non-proprietary information for CT system modeling. Methods: A GOS-based linear detector (0.8 mm per pixel and 51.2 cm in length) with a fast data sampling speed (0.24 ms/sample) was used to measure the relative profiles of bow-tie filters from a collection of eight CT scanners by three different vendors, GE (LS Xtra, LS VCT, Discovery HD750), Siemens (Sensation 64, Edge, Flash, Force), and Philips (iBrilliance 256). The linear detector was first calibrated for its energy response within typical CT beam quality ranges and compared with an ion chamber and analytical modeling (SPECTRA and TASMIP). A geometrical calibration process was developed to determine key parameters including the distance from the focal spot to the linear detector, the angular increment of the gantry at each data sampling, the location of the central x-ray on the linear detector, and the angular response of the detector pixel. Measurements were performed under axial-scan modes for most representative bow-tie filters and kV selections from each scanner. Bow-tie profiles were determined by re-binning the measured rotational data with an angular accuracy of 0.1 degree using the calibrated geometrical parameters. Results: The linear detector demonstrated an energy response as a solid state detector, which is close to the CT imaging detector. The geometrical calibration was proven to be sufficiently accurate (< 1mm in error for distances >550 mm) and the bow-tie profiles measured from rotational mode matched closely to those from the gantry-stationary mode. Accurate profiles were determined for a total of 21 bow-tie filters and 83 filter/kV combinations from the abovementioned scanner models. Conclusion: A new improved approach of CT bow-tie measurement was proposed and accurate bow-tie profiles were provided for a broad list of CT scanner models.

  20. Detailed study of electron plasma waves upstream of the earth's bow shock

    International Nuclear Information System (INIS)

    Etcheto, J.; Faucheux, M.

    1984-01-01

    A detailed study of electron plasma waves observed upstream of the earth's bow shock and of their relationships to the position of the satellite in the foreshock and to the electron measurements has been carried out. The wave characteristics depend on the position in the electron foreshock: a narrow-bnd (a few percent) and intense (a few millivolts per meter) noise is observed at the plasma frequency at the edge of the foreshock while the spectrum widens (Δf/fapprox. =0.3) at the same time as the power decreases (hundreds of microvolts per meter) deeper (a few earth radii) inside the foreshock. Signals below the plasma frequency are also observed. These waves are polarized along the magnetic field, with long wavelengths below and at the plasma frequency and short wavelengths above it. They appear as short bursts, the duration of which depends on the frequency: longer close to the plasma frequency (50 ms), they shorten with increasing separation from the plasma frequency, the usual duration being 15 ms. While the correlation of the wave characteristics with the reflected electrons is good as the satellite moves inside the foreshock, no evolution is found with the distance to the bow shock, neither for the noise nor for the particles. These results are discussed in the frame of various mechanisms which have been proposed to explain these upstream waves but no satisfactory agreement is found with any of them

  1. Structure of oblique subcritical bow shocks: ISEE 1 and 2 observations

    International Nuclear Information System (INIS)

    Mellott, M.M.; Greenstadt, E.W.

    1984-01-01

    We have studied the structural elements, including shock ramps and precursor wave trains, of a series of oblique low-Mach number terrestrial bow shocks. We used magnetic field data from the dual ISEE 1 and 2 spacecraft to determine the scale lengths of various elements of shock structure as well as wavelengths and wave polarizations. Bow shocks structure under these conditions is esstentially that of a large-amplitude damped whistler mode wave which extends upstream in the form of a precursor wave train. Shock thicknesses, which are determined by the dispersive properties of the ambient plasma, are too broad to support current-driven electrostatic waves, ruling out such turbulence as the source of dissipation in these shocks. Dissipative processes are reflected in the damping of the precursors, and dissipative scale lengths are approx.200--800 km (several times greater than shock thicknesses). Precursor damping is not related to shock normal angle or Mach number, but is correlated with T/sub e//T/sub t/. The source of the dissipation in the shocks does not appear to be wave-wave decay of the whistlers, for which no evidence is found. We cannot rule out the possibility of contribution to the dissipation from ion acoustic and, or lower hybrid mode turbulence, but interaction of the whistler itself with upstream electrons offers a simpler and more self-consistent explanation for the observed wave train damping

  2. COMPUTING THE DUST DISTRIBUTION IN THE BOW SHOCK OF A FAST-MOVING, EVOLVED STAR

    International Nuclear Information System (INIS)

    Van Marle, A. J.; Meliani, Z.; Keppens, R.; Decin, L.

    2011-01-01

    We study the hydrodynamical behavior occurring in the turbulent interaction zone of a fast-moving red supergiant star, where the circumstellar and interstellar material collide. In this wind-interstellar-medium collision, the familiar bow shock, contact discontinuity, and wind termination shock morphology form, with localized instability development. Our model includes a detailed treatment of dust grains in the stellar wind and takes into account the drag forces between dust and gas. The dust is treated as pressureless gas components binned per grain size, for which we use 10 representative grain size bins. Our simulations allow us to deduce how dust grains of varying sizes become distributed throughout the circumstellar medium. We show that smaller dust grains (radius <0.045 μm) tend to be strongly bound to the gas and therefore follow the gas density distribution closely, with intricate fine structure due to essentially hydrodynamical instabilities at the wind-related contact discontinuity. Larger grains which are more resistant to drag forces are shown to have their own unique dust distribution, with progressive deviations from the gas morphology. Specifically, small dust grains stay entirely within the zone bound by shocked wind material. The large grains are capable of leaving the shocked wind layer and can penetrate into the shocked or even unshocked interstellar medium. Depending on how the number of dust grains varies with grain size, this should leave a clear imprint in infrared observations of bow shocks of red supergiants and other evolved stars.

  3. The upstream escape of energized solar wind protons from the bow shock

    International Nuclear Information System (INIS)

    Greenstadt, E.W.

    1975-01-01

    Recently, there have been some systematic observations of backstreaming protons at the Earth's bow shock with parallel velocity components and total energies much too high to be associated with the usual long-period upstream waves or to be produced by Sonnerup's simple reflection process (Lin et al., 1974), and these protons (30-100keV) were attributed to some unknown acceleration mechanism in the upstream region. The observations of Lof et al. involved protons in high pitch angle, and, although their reasons for favoring an upstream acceleration were quite different, it may seem intuitive that high pitch angle particles would have difficulty escaping the shock, especially at large field-normal angles. Such an inference would superficially support the notion of energization outside the bow shock. It seems worthwhile therefore to examine the extent to which the geometry of individual particle motion alone might select among reflected particles those that can escape upstream and those that cannot. In this paper the geometry of escape is described and some simple numerical examples are worked out for a few special cases. It is found that protons with rather high energies and pitch angles can escape the shock at only marginally quasi-parallel field orientations (i.e., thetasub(nB) approximately 50 0 ), even if they have quite moderate speeds parallel to B. (Auth.)

  4. Ionospheric Bow Waves and Perturbations Induced by the 21 August 2017 Solar Eclipse

    Science.gov (United States)

    Zhang, Shun-Rong; Erickson, Philip J.; Goncharenko, Larisa P.; Coster, Anthea J.; Rideout, William; Vierinen, Juha

    2017-12-01

    During solar eclipses, the Moon's shadow causes a large reduction in atmospheric energy input, including not only the stratosphere but also the thermosphere and ionosphere. The eclipse shadow has a supersonic motion which is theoretically expected to generate atmospheric bow waves, similar to a fast-moving river boat, with waves starting in the lower atmosphere and propagating into the ionosphere. However, previous geographically limited observations have had difficulty detecting these weak waves within the natural background atmospheric variability, and the existence of eclipse-induced ionospheric waves and their evolution in a complex coupling system remain controversial. During the 21 August 2017 eclipse, high fidelity and wide coverage ionospheric observations provided for the first time an oversampled set of eclipse data, using a dense network of Global Navigation Satellite System receivers at ˜2,000 sites in North America. We show the first unambiguous evidence of ionospheric bow waves as electron content disturbances over central/eastern United States, with ˜1 h duration, 300-400 km wavelength and 280 m/s phase speed emanating from and tailing the totality region. We also identify large ionospheric perturbations moving at the supersonic speed of the maximum solar obscuration which are too fast to be associated with known gravity wave or large-scale traveling ionospheric disturbance processes. This study reveals complex interconnections between the Sun, Moon, and Earth's neutral atmosphere and ionosphere and demonstrates persistent coupling processes between different components of the Earth's atmosphere, a topic of significant community interest.

  5. High-order harmonics from bow wave caustics driven by a high-intensity laser

    International Nuclear Information System (INIS)

    Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.

    2012-01-01

    We propose a new mechanism of high-order harmonic generation during an interaction of a high-intensity laser pulse with underdense plasma. A tightly focused laser pulse creates a cavity in plasma pushing electrons aside and exciting the wake wave and the bow wave. At the joint of the cavity wall and the bow wave boundary, an annular spike of electron density is formed. This spike surrounds the cavity and moves together with the laser pulse. Collective motion of electrons in the spike driven by the laser field generates high-order harmonics. A strong localization of the electron spike, its robustness to oscillations imposed by the laser field and, consequently, its ability to produce high-order harmonics is explained by catastrophe theory. The proposed mechanism explains the experimental observations of high-order harmonics with the 9 TW J-KAREN laser (JAEA, Japan) and the 120 TW Astra Gemini laser (CLF RAL, UK) [A. S. Pirozhkov, et al., arXiv:1004.4514 (2010); A. S. Pirozhkov et al, AIP Proceedings, this volume]. The theory is corroborated by high-resolution two-and three-dimensional particle-in-cell simulations.

  6. Bow Shock Generator Current Systems: MMS Observations of Possible Current Closure

    Science.gov (United States)

    Hamrin, M.; Gunell, H.; Lindkvist, J.; Lindqvist, P.-A.; Ergun, R. E.; Giles, B. L.

    2018-01-01

    We use data from the first two dayside seasons of the Magnetospheric Multiscale (MMS) mission to study current systems associated with quasi-perpendicular bow shocks of generator type. We have analyzed 154 MMS bow shock crossings near the equatorial plane. We compute the current density during the crossings and conclude that the component perpendicular to the shock normal (J⊥) is consistent with a pileup of the interplanetary magnetic field (IMF) inside the magnetosheath. For predominantly southward IMF, we observe a component Jn parallel (antiparallel) to the normal for GSM Y > 0 (MMS probing region. For IMF clock angles near 90∘, we find indications of the current system being tilted toward the north-south direction, obtaining a significant Jz component, and we suggest that the current closes off the equatorial plane at higher latitudes where the spacecraft are not probing. The observations are complicated for several reasons. For example, variations in the solar wind and the magnetospheric currents and loads affect the closure, and Jn is distributed over large regions, making it difficult to resolve inside the magnetosheath proper.

  7. The cometary H II regions of DR 21: Bow shocks or champagne flows or both?

    Science.gov (United States)

    Immer, K.; Cyganowski, C.; Reid, M. J.; Menten, K. M.

    2014-03-01

    We present deep Very Large Array H66α radio recombination line (RRL) observations of the two cometary H II regions in DR 21. With these sensitive data, we test the "hybrid" bow shock/champagne flow model previously proposed for the DR 21 H II regions. The ionized gas down the tail of the southern H II region is redshifted by up to ~30 km s-1 with respect to the ambient molecular gas, as expected in the hybrid scenario. The RRL velocity structure, however, reveals the presence of two velocity components in both the northern and southern H II regions. This suggests that the ionized gas is flowing along cone-like shells, swept-up by stellar winds. The observed velocity structure of the well-resolved southern H II region is most consistent with a picture that combines a stellar wind with stellar motion (as in bow shock models) along a density gradient (as in champagne flow models). The direction of the implied density gradient is consistent with that suggested by maps of dust continuum and molecular line emission in the DR 21 region. The image cubes are only available as a FITS file at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/563/A39Table 2, Fig. 4, and Appendices A and B are available in electronic form at http://www.aanda.org

  8. Woods with physical, mechanical and acoustic properties similar to those of Caesalpinia echinata have high potential as alternative woods for bow makers

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz Longui

    2014-09-01

    Full Text Available For nearly two hundred years, Caesalpinia echinata wood has been the standard for modern bows. However, the threat of extinction and the enforcement of trade bans have required bow makers to seek alternative woods. The hypothesis tested was that woods with physical, mechanical and acoustic properties similar to those of C. echinata would have high potential as alternative woods for bows. Accordingly, were investigated Handroanthus spp., Mezilaurus itauba, Hymenaea spp., Dipteryx spp., Diplotropis spp. and Astronium lecointei. Handroanthus and Diplotropis have the greatest number of similarities with C. echinata, but only Handroanthus spp. showed significant results in actual bow manufacture, suggesting the importance of such key properties as specific gravity, speed of sound propagation and modulus of elasticity. In practice, Handroanthus and Dipteryx produced bows of quality similar to that of C. echinata.

  9. Adapting National Water Model Forecast Data to Local Hyper-Resolution H&H Models During Hurricane Irma

    Science.gov (United States)

    Singhofen, P.

    2017-12-01

    The National Water Model (NWM) is a remarkable undertaking. The foundation of the NWM is a 1 square kilometer grid which is used for near real-time modeling and flood forecasting of most rivers and streams in the contiguous United States. However, the NWM falls short in highly urbanized areas with complex drainage infrastructure. To overcome these shortcomings, the presenter proposes to leverage existing local hyper-resolution H&H models and adapt the NWM forcing data to them. Gridded near real-time rainfall, short range forecasts (18-hour) and medium range forecasts (10-day) during Hurricane Irma are applied to numerous detailed H&H models in highly urbanized areas of the State of Florida. Coastal and inland models are evaluated. Comparisons of near real-time rainfall data are made with observed gaged data and the ability to predict flooding in advance based on forecast data is evaluated. Preliminary findings indicate that the near real-time rainfall data is consistently and significantly lower than observed data. The forecast data is more promising. For example, the medium range forecast data provides 2 - 3 days advanced notice of peak flood conditions to a reasonable level of accuracy in most cases relative to both timing and magnitude. Short range forecast data provides about 12 - 14 hours advanced notice. Since these are hyper-resolution models, flood forecasts can be made at the street level, providing emergency response teams with valuable information for coordinating and dispatching limited resources.

  10. Application of the Bow Tie method for evaluation of safety in the procedure of logging wells; Aplicacion del metodo de Bow Tie para la evaluacion de seguridad en la practica de perfilaje de pozos

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso Pallares, C; Perez Reyes, Y.; Sarabia Molina, I.I. [Centro Nacional de Seguridad Nuclear (CNSN), La Habana (Cuba)

    2013-07-01

    This work consists of an assessment of security in the practice of logging of oil wells, using the method of Bow Tie for being a simple method of evaluation of the risk, which makes it possible in a structured way to set priorities to manage risk.

  11. Bow tie methodology: a tool to enhance the visibility and understanding of nuclear safety cases

    International Nuclear Information System (INIS)

    Vannerem, Marc

    2013-01-01

    There is much common ground between the nuclear industry and other major hazard industries such as those subject to the Seveso II regulations, e.g. oil, gas and chemicals. They are all subject to legal requirements to identify and control hazards, and to demonstrate that all necessary measures have been taken to minimise risks posed by the site with regard to people and the environment. This places a requirement on the Operators of major hazard installations, whether nuclear or conventional, to understand and identify the hazards of their operations, the initiating events, the consequences, the prevention and mitigation measures. However, in the UK, nuclear and 'Seveso' type facilities seem to adopt a different approach to the presentation of their safety cases. Given the magnitude of the hazards, safety cases developed for nuclear fuel cycle facilities are rigorous, detailed and complex, which can have the effect of reducing the visibility of the key hazards and corresponding protective measures. In contrast, on installations in the oil and gas and chemical industries, a real attempt has been made over recent years to improve the visibility and accessibility of the safety case to all operating personnel, through the use of visual aids / diagrams. In particular, many Operators are choosing to use 'bow tie methodology', in which very simple overview diagrams are produced to illustrate, in a form understandable by all: - what the key hazards are; - the initiating events; - the consequences of an incident; - the barriers or 'Layers of Protection' which prevent an initiating event from developing into an incident; - the barriers or 'Layers of Defence' which mitigate the consequences of an incident, i.e. which prevent the incident from escalating into major consequences. The bow tie method is one of a number of methodologies that can be used to make safety cases more accessible. It is used in this paper to illustrate ways to

  12. Effect of an isotropic outflow from the Galactic Centre on the bow-shock evolution along the orbit

    Czech Academy of Sciences Publication Activity Database

    Zajaček, Michal; Eckart, A.; Karas, Vladimír; Kunneriath, Devaky; Shahzamanian, B.; Sabha, N.; Muzic, K.; Valencia-S, M.

    2016-01-01

    Roč. 455, č. 2 (2016), s. 1257-1274 ISSN 0035-8711 R&D Projects: GA ČR(CZ) GC13-00070J Institutional research plan: CEZ:AV0Z1003909 Institutional support: RVO:67985815 Keywords : galactic centre * black hole * bow-shock Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.961, year: 2016

  13. Atelier Bow-Wow on the Representation of Behaviorology: Yosiharu Tsukamoto in conversation with Anne Elisabeth Toft and Christina Capetillo

    DEFF Research Database (Denmark)

    Toft, Anne Elisabeth; Capetillo, Christina

    2015-01-01

    Yoshiharu Tsukamoto discussing the representational practices of Atelier Bow-Wow and its work on “Behaviorology”: How do you represent the seemingly un-representable? How do you depict and illustrate what is not tangible? How do you represent social practices, time-based processes, situations...

  14. Role of In-segregation in anomalously large band-gap bowings of (In,Al,Ga)N

    DEFF Research Database (Denmark)

    Gorczyka, I.; Suski, T.; Christensen, Niels Egede

    2011-01-01

    Large bowings of the band gap and its pressure coefficient in In-containing nitride semiconductor alloys are observed. Photoluminescence measurements for InxGa1-xN and InxAl1-xN combined with other experimental data show large scatter of the results. A comparison with ab-initio calculations sugge...

  15. Identification of the nonlinear excitation force acting on a bowed string using the dynamical responses at remote locations

    International Nuclear Information System (INIS)

    Debut, V.; Antunes, J.; Delaune, X.

    2010-01-01

    For achieving realistic numerical simulations of bowed string instruments, based on physical modeling, a good understanding of the actual friction interaction phenomena is of great importance. Most work published in the field including our own has assumed that bow/string frictional forces behave according to the classical Coulomb stick-slip model, with an empirical velocity-dependent sliding friction coefficient. Indeed, the basic self-excited string motions (such as the Helmholtz regime) are well captured using such friction model. However, recent work has shown that the tribological behavior of the bow/string rosin interface is rather complex, therefore the basic velocity-dependent Coulomb model may be an over-simplistic representation of the friction force. More specifically, it was suggested that a more accurate model of the interaction force can be achieved by coupling the system dynamical equations with a thermal model which encapsulates the complex interface phenomena. In spite of the interesting work performed by Askenfelt, a direct measurement of the actual dynamical friction forces without disturbing the string motion is quite difficult. Therefore, in this work we develop a modal-based identification technique making use of inverse methods and optimization techniques, which enables the identification of the interface force, as well as the string self-excited motion, from the dynamical reactions measured at the string end supports. The method gives convincing results using simulated data originated from nonlinear computations of a bowed string. Furthermore, in cases where the force identifications are very sensitive to errors in the transfer function modal parameters, we suggest a method to improve the modal frequencies used for the identifications. Preliminary experimental results obtained using a basic bowing device, by which the string is excited with the stick of the bow, are then presented. Our identifications, from the two dynamical string reactions

  16. 4D display of the outflow track of embryonic-chick hearts (HH 14-19) using a high speed streak mode OCT

    Science.gov (United States)

    Ma, Siyu; Wang, Rui; Goodwin, Richard L.; Markwald, Roger R.; Borg, Thomas K.; Runyan, Raymond B.; Gao, Zhi

    2013-02-01

    Congenital Heart Disease (CHD) is the most common congenital malformation in newborns in the US. Although knowledge of CHD is limited, altered hemodynamic conditions are suspected as the factor that stimulates cardiovascular cell response, resulting in the heart morphology remodeling that ultimately causes CHDs. Therefore, one of recent efforts in CHD study is to develop high-speed imaging tools to correlate the rapidly changing hemodynamic condition and the morphological adaptations of an embryonic heart in vivo. We have developed a high-speed streak mode OCT that works at the center wavelength of 830 nm and is capable of providing images (292x220 μm2) of the outflow tract of an embryonic chick heart at the rate of 1000 Hz. The modality can provide a voxel resolution in the range of 10 μm3, and the spectral resolution allows a depth range of 1.63 mm. In the study reported here, each of the 4D images of an outflow tract was recorded for 2 seconds. The recording was conducted every 2 hours (HH17 to HH18), 3 hours (HH14 to HH17), and 4 hours (HH18 to HH19). Because of the fast scan speed, there is no need for postacquisition processing such as use of gating techniques to provide a fine 3D structure. In addition, more details of the outflow tract are preserved in the recorded images. The 4D images can be used in the future to determine the role of blood flow in CHD development.

  17. From Bows to Sound-Chests: Tracing the Ancestry of the Violin

    Directory of Open Access Journals (Sweden)

    Janelle R. Finley

    2016-04-01

    Full Text Available The ancestry of the violin is a subject that has been studied, researched, debated, and written about in great detail. However, despite all of the research and study, the ancestry of the violin is still not certain. This paper presents two schools of thought that propose different theories as to how the ancestry of the violin should be determined and what instruments should be included in the ancestry of the violin. The first school of thought proposes that the violin’s ancestry should be traced through the bow. The second theory proposes that the violin’s ancestry should be traced through the sound-chest of the violin. This paper also presents the different arguments for and against each theory, the importance of this topic, and the paper’s position on this topic. Research for this paper was accomplished through the use of scholarly books on the subject of the history of the violin.

  18. Short term memory bowing effect is consistent with presentation rate dependent decay.

    Science.gov (United States)

    Tarnow, Eugen

    2010-12-01

    I reanalyze the free recall data of Murdock, J Exp Psychol 64(5):482-488 (1962) and Murdock and Okada, J Verbal Learn and Verbal Behav 86:263-267 (1970) which show the famous bowing effect in which initial and recent items are recalled better than intermediate items (primacy and recency effects). Recent item recall probabilities follow a logarithmic decay with time of recall consistent with the tagging/retagging theory. The slope of the decay increases with increasing presentation rate. The initial items, with an effectively low presentation rate, decay with the slowest logarithmic slope, explaining the primacy effect. The finding that presentation rate limits the duration of short term memory suggests a basis for memory loss in busy adults, for the importance of slow music practice, for long term memory deficiencies for people with attention deficits who may be artificially increasing the presentation rates of their surroundings. A well-defined, quantitative measure of the primacy effect is introduced.

  19. ULF/ELF electromagnetic waves associated with the quasi-perpendicular earth's bow shock crossings

    International Nuclear Information System (INIS)

    Nozdrachev, M.N.; Petrukovich, A.A.

    1992-01-01

    The present paper is dedicated to the analysis of electromagnetic turbulence in the frequency range 0.1-75 Hz, associated with crossing of Earth's Bow Shock recorded by the Prognoz-8 and -10 satellites. The quasimonochromatic waves are identified in the shock transition region. Their frequencies, laying in the range from 2 Hz to 6 Hz upstream the shock ramp shift to the values less than 1 Hz in the downstream region. The amplitudes of these narrow emissions are high enough to provide the dissipation in the flow of the solar wind plasma. It is argued that spectra shapes in this frequency range 0.1-75 Hz are strongly affected by the Doppler shift

  20. Ion acceleration at the earth's bow shock: A review of observations in the upstream region

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

    1979-01-01

    Positive ions are accelerated at or near the earth's bow shock and propagate into the upstream region. Two distinctly different population of these ions, distinguished by their greatly different spectral and angular widths, can be identified there. The type of ion population observed in the upstream region is strongly correlated with the presence or absence of long-period compresive waves in the solar wind. Very few ions are accelerated in the vicinity of the shock to energies much above about 100 keV. It is not yet clear whether the most energetic ions (i.e. those near 100 keV) are accelerated at the shock or in the broad disturbed region upstream from the shock. In either case stochastic acceleration by turbulent electrostatic fields seems to be the most viable candidate for the acceleration of the most energetic particles

  1. First-order Fermi acceleration of the diffuse ion population near the earth's bow shock

    Science.gov (United States)

    Forman, M. A.

    1981-01-01

    The flux of 30-65 keV particles observed by the ISEE-3 200 earth radii upstream is shown to be an upstream escape of the energetic ions in the earth's bow shock. A formal solution to the transport equation for the distribution function of energetic particles upstream from an isotropic monoenergetic source of particles/sq cm at a plane shock where the plasma changes speed is found, and escape conditions are defined. The efficiency of the acceleration is calculated to depend on the charge/particle, and fluxes near and far upstream of the shock are described analytically. Any model which takes into account shock acceleration by diffusive scattering with significant escape losses produces the observed spectrum close to the shock. The escape loss upstream is demonstrated to control the spectrum and the variation of flux and anisotropy with distance from the shock.

  2. Oxidation of graphene 'bow tie' nanofuses for permanent, write-once-read-many data storage devices.

    Science.gov (United States)

    Pearson, A C; Jamieson, S; Linford, M R; Lunt, B M; Davis, R C

    2013-04-05

    We have fabricated nanoscale fuses from CVD graphene sheets with a 'bow tie' geometry for write-once-read-many data storage applications. The fuses are programmed using thermal oxidation driven by Joule heating. Fuses that were 250 nm wide with 2.5 μm between contact pads were programmed with average voltages and powers of 4.9 V and 2.1 mW, respectively. The required voltages and powers decrease with decreasing fuse sizes. Graphene shows extreme chemical and electronic stability; fuses require temperatures of about 400 °C for oxidation, indicating that they are excellent candidates for permanent data storage. To further demonstrate this stability, fuses were subjected to applied biases in excess of typical read voltages; stable currents were observed when a voltage of 10 V was applied to the devices in the off state and 1 V in the on state for 90 h each.

  3. Electron bulk acceleration and thermalization at Earth's quasi-perpendicular bow shock

    Science.gov (United States)

    Chen, L.-J.; Wang, S.; Wilson, L. B., III; Schwartz, S. J.; Bessho, N.; Moore, T. E.; Gershman, D. J.; Giles, B. L.; Malaspina, D. M.; Wilder, F. D.; Ergun, R. E.; Hesse, M.; Lai, H.; Russell, C. T.; Strangeway, R. J.; Torbert, R. B.; Vinas, A. F.-; Burch, J. L.; Lee, S.; Pollock, C.; Dorelli, J.; Paterson, W. R.; Ahmadi, N.; Goodrich, K. A.; Lavraud, B.; Le Contel, O.; Khotyaintsev, Yu. V.; Lindqvist, P.-A.; Boardsen, S.; Wei, H.; Le, A.; Avanov, L. A.

    2018-05-01

    Electron heating at Earth's quasiperpendicular bow shock has been surmised to be due to the combined effects of a quasistatic electric potential and scattering through wave-particle interaction. Here we report the observation of electron distribution functions indicating a new electron heating process occurring at the leading edge of the shock front. Incident solar wind electrons are accelerated parallel to the magnetic field toward downstream, reaching an electron-ion relative drift speed exceeding the electron thermal speed. The bulk acceleration is associated with an electric field pulse embedded in a whistler-mode wave. The high electron-ion relative drift is relaxed primarily through a nonlinear current-driven instability. The relaxed distributions contain a beam traveling toward the shock as a remnant of the accelerated electrons. Similar distribution functions prevail throughout the shock transition layer, suggesting that the observed acceleration and thermalization is essential to the cross-shock electron heating.

  4. Method for measuring violin sound radiation based on bowed glissandi and its application to sound synthesis.

    Science.gov (United States)

    Perez Carrillo, Alfonso; Bonada, Jordi; Patynen, Jukka; Valimaki, Vesa

    2011-08-01

    This work presents a method for measuring and computing violin-body directional frequency responses, which are used for violin sound synthesis. The approach is based on a frame-weighted deconvolution of excitation and response signals. The excitation, consisting of bowed glissandi, is measured with piezoelectric transducers built into the bridge. Radiation responses are recorded in an anechoic chamber with multiple microphones placed at different angles around the violin. The proposed deconvolution algorithm computes impulse responses that, when convolved with any source signal (captured with the same transducer), produce a highly realistic violin sound very similar to that of a microphone recording. The use of motion sensors allows for tracking violin movements. Combining this information with the directional responses and using a dynamic convolution algorithm, helps to improve the listening experience by incorporating the violinist motion effect in stereo.

  5. High time resolution characteristics of intermediate ion distributions upstream of the earth's bow shock

    Science.gov (United States)

    Potter, D. W.

    1985-01-01

    High time resolution particle data upstream of the bow shock during time intervals that have been identified as having intermediate ion distributions often show high amplitude oscillations in the ion fluxes of energy 2 and 6 keV. These ion oscillations, observed with the particle instruments of the University of California, Berkeley, on the ISEE 1 and 2 spacecraft, are at the same frequency (about 0.04 Hz) as the magnetic field oscillations. Typically, the 6-keV ion flux increases then the 2-keV flux increases followed by a decrease in the 2-keV flux and then the 6-keV flux decreases. This process repeats many times. Although there is no entirely satisfactory explanation, the presence of these ion flux oscillations suggests that distributions often are misidentified as intermediate ion distributions.

  6. Nowcasting and forecasting of the magnetopause and bow shock—A status update

    Science.gov (United States)

    Petrinec, S. M.; Redmon, R. J.; Rastaetter, L.

    2017-01-01

    There has long been interest in knowing the shape and location of the Earth's magnetopause and of the standing fast-mode bow shock upstream of the Earth's magnetosphere. This quest for knowledge spans both the research and operations arenas. Pertinent to the latter, nowcasting and near-term forecasting are important for determining the extent to which the magnetosphere is compressed or expanded due to the influence of the solar wind bulk plasma and fields and the coupling to other magnetosphere-ionosphere processes with possible effects on assets. This article provides an update to a previous article on the same topic published 15 years earlier, with focus on studies that have been conducted, the current status of nowcasting and forecasting of geophysical boundaries, and future endeavors.

  7. A Multi-wavelength Study of an Isolated MSP Bow Shock

    Science.gov (United States)

    Romani, Roger W.; Slane, Patrick; Green, Andrew

    2017-08-01

    PSR J2124-3358 is the only single MSP known to sport an Halpha bow shock. This shock, now also seen in the UV, encloses an unusual X-ray pulsar wind nebula (PWN) with a long off-axis trail. Combining the X-ray and UV images with AAT/KOALA integral field spectroscopy of the Halpha emission, we have an unusually complete picture of the pulsar's (101 km/s transverse) motion and the latitudinal distribution of its wind flux. These images reveal the 3-D orientation of a hard-spectrum PWN jet and a softer equatorial outflow. Within the context of a thin shock model, we can constrain the total energy output of the pulsar and the neutron star moment of inertia. The IFU spectra show extreme Balmer dominance, which also constrains the nature of the UV shock emission.

  8. Ion acceleration at the earth's bow shock: a review of observations in the upstream region

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

    1979-01-01

    Positive ions are accelerated at or near the earth's bow shock and propagate into the upstream region. Two distinctly different populations of these ions, distinguished by their greatly different spectral and angular widths, can be identified there. The type of ion population observed in the upstream region is strongly correlated with the presence or absence of long-period compressive waves in the solar wind. Very few ions are accelerated in the vicinity of the shock to energies much above about 100 keV. It is not yet clear whether the most energetic ions (i.e., those near 100 keV) are accelerated at the shock or in broad disturbed region upstream from the shock. In either case stochastic acceleration by turbulent electrostatic fields seems to be the most viable candidate for the acceleration of the most energetic particles

  9. On nonstationarity and rippling of the quasiperpendicular zone of the Earth bow shock: Cluster observations

    Directory of Open Access Journals (Sweden)

    V. V. Lobzin

    2008-09-01

    Full Text Available A new method for remote sensing of the quasiperpendicular part of the bow shock surface is presented. The method is based on analysis of high frequency electric field fluctuations corresponding to Langmuir, upshifted, and downshifted oscillations in the electron foreshock. Langmuir waves usually have maximum intensity at the upstream boundary of this region. All these waves are generated by energetic electrons accelerated by quasiperpendicular zone of the shock front. Nonstationary behavior of the shock, in particular due to rippling, should result in modulation of energetic electron fluxes, thereby giving rise to variations of Langmuir waves intensity. For upshifted and downshifted oscillations, the variations of both intensity and central frequency can be observed. For the present study, WHISPER measurements of electric field spectra obtained aboard Cluster spacecraft are used to choose 48 crossings of the electron foreshock boundary with dominating Langmuir waves and to perform for the first time a statistical analysis of nonstationary behavior of quasiperpendicular zone of the Earth's bow shock. Analysis of hidden periodicities in plasma wave energy reveals shock front nonstationarity in the frequency range 0.33 fBiBi, where fBi is the proton gyrofrequency upstream of the shock, and shows that the probability to observe such a nonstationarity increases with Mach number. The profiles observed aboard different spacecraft and the dominating frequencies of the periodicities are usually different. Hence nonstationarity and/or rippling seem to be rather irregular both in space and time rather than resembling a quasiregular wave propagating on the shock surface.

  10. On nonstationarity and rippling of the quasiperpendicular zone of the Earth bow shock: Cluster observations

    Directory of Open Access Journals (Sweden)

    V. V. Lobzin

    2008-09-01

    Full Text Available A new method for remote sensing of the quasiperpendicular part of the bow shock surface is presented. The method is based on analysis of high frequency electric field fluctuations corresponding to Langmuir, upshifted, and downshifted oscillations in the electron foreshock. Langmuir waves usually have maximum intensity at the upstream boundary of this region. All these waves are generated by energetic electrons accelerated by quasiperpendicular zone of the shock front. Nonstationary behavior of the shock, in particular due to rippling, should result in modulation of energetic electron fluxes, thereby giving rise to variations of Langmuir waves intensity. For upshifted and downshifted oscillations, the variations of both intensity and central frequency can be observed. For the present study, WHISPER measurements of electric field spectra obtained aboard Cluster spacecraft are used to choose 48 crossings of the electron foreshock boundary with dominating Langmuir waves and to perform for the first time a statistical analysis of nonstationary behavior of quasiperpendicular zone of the Earth's bow shock. Analysis of hidden periodicities in plasma wave energy reveals shock front nonstationarity in the frequency range 0.33 fBi

  11. ION ACCELERATION AT THE QUASI-PARALLEL BOW SHOCK: DECODING THE SIGNATURE OF INJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Torbjörn; Haynes, Christopher T.; Burgess, D. [School of Physics and Astronomy, Queen Mary University of London, London, E1 4NS (United Kingdom); Mazelle, Christian X. [IRAP, Université Paul Sabatier Toulouse III-CNRS, 31028 Toulouse Cedex 4 (France)

    2016-03-20

    Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can accelerate ions into cosmic-ray energies. This energization is attributed to diffusive shock acceleration; however, for this process to become active, the ions must first be sufficiently energized. How and where this initial acceleration takes place has been one of the key unresolved issues in shock acceleration theory. Using Cluster spacecraft observations, we study the signatures of ion reflection events in the turbulent transition layer upstream of the terrestrial bow shock, and with the support of a hybrid simulation of the shock, we show that these reflection signatures are characteristic of the first step in the ion injection process. These reflection events develop in particular in the region where the trailing edge of large-amplitude upstream waves intercept the local shock ramp and the upstream magnetic field changes from quasi-perpendicular to quasi-parallel. The dispersed ion velocity signature observed can be attributed to a rapid succession of ion reflections at this wave boundary. After the ions’ initial interaction with the shock, they flow upstream along the quasi-parallel magnetic field. Each subsequent wavefront in the upstream region will sweep the ions back toward the shock, where they gain energy with each transition between the upstream and the shock wave frames. Within three to five gyroperiods, some ions have gained enough parallel velocity to escape upstream, thus completing the injection process.

  12. The CHESS survey of the L1157-B1 bow-shock: Dissecting the water content

    Science.gov (United States)

    Busquet, Gemma; Lefloch, Bertrand; Benedettini, Milena; Ceccarelli, Cecilia; Codella, Claudio; Cabrit, Sylvie; Nisini, Brunella; Viti, Serena; Gómez-Ruiz, Arturo; Gusdorf, Antoine; Di Giorgio, Anna Maria; Wiesenfeld, Laurent

    2013-07-01

    Molecular outflows powered by young protostars strongly affect the kinematics and chemistry of the natal molecular cloud through strong shocks, resulting in an increase of the abundance of several species. In particular, water is a powerful tracer of shocked material due to its sensitivity to both physical conditions and chemical processes. The observations of the "Chemical Herschel Survey of Star forming regions" (CHESS) key program towards the shock region L1157-B1 offered a unique and comprehensive view of the water emission in a typical protostellar bow shock across the submillimeter and far-infrared window. A grand total of 13 water lines have been detected with the PACS and HIFI instruments, probing a wide range of excitation conditions and providing us with a detailed picture on both the kinematics and the spatial distribution of water emission. Several gas components have been identified coexisting in the L1157-B1 shock region. Large Velocity Gradient (LVG) analysis reveals that these components have different excitation conditions: i) a warm (T~250 K) and dense (n(H2)~10^6 cm-3) gas component seen also with the CO lines and associated with the partly dissociative shock produced by the impact of the protostellar jet against the bow shock; ii) a compact (size~5''), hot (T~700 K), and less dense (n(H2)~10^4 cm-3) gas component, and iii) an extended component associated with the B1 outflow cavity. These three components present clear differences in terms of water enrichment. Finally, we confront the physical and chemical properties of the H2O emission to the predictions of current shock models.

  13. Injection and acceleration of H+ and He2+ at Earth's bow shock

    Directory of Open Access Journals (Sweden)

    K.-H. Trattner

    Full Text Available We have performed a number of one-dimensional hybrid simulations (particle ions, massless electron fluid of quasi-parallel collisionless shocks in order to investigate the injection and subsequent acceleration of part of the solar wind ions at the Earth's bow shock. The shocks propagate into a medium containing magnetic fluctuations, which are initially superimposed on the background field, as well as generated or enhanced by the electromagnetic ion/ion beam instability between the solar wind and backstreaming ions. In order to study the mass (M and charge (Q dependence of the acceleration process He2+ is included self-consistently. The upstream differential intensity spectra of H+ and He2+ can be well represented by exponentials in energy. The e-folding energy Ec is a function of time: Ec increases with time. Furthermore the e-folding energy (normalized to the shock ramming energy Ep increases with increasing Alfvén Mach number of the shock and with increasing fluctuation level of the initially superimposed turbulence. When backstreaming ions leave the shock after their first encounter they exhibit already a spectrum which extends to more than ten times the shock ramming energy and which is ordered in energy per charge. From the injection spectrum it is concluded that leakage of heated downstream particles does not contribute to ion injection. Acceleration models that permit thermal particles to scatter like the non-thermal population do not describe the correct physics.Key words. Interplanetary physics (planetary bow shocks · Space plasma physics (charged particle motion and acceleration; numerical simulation studies

  14. Injection and acceleration of H+ and He2+ at Earth's bow shock

    Directory of Open Access Journals (Sweden)

    M. Scholer

    1999-05-01

    Full Text Available We have performed a number of one-dimensional hybrid simulations (particle ions, massless electron fluid of quasi-parallel collisionless shocks in order to investigate the injection and subsequent acceleration of part of the solar wind ions at the Earth's bow shock. The shocks propagate into a medium containing magnetic fluctuations, which are initially superimposed on the background field, as well as generated or enhanced by the electromagnetic ion/ion beam instability between the solar wind and backstreaming ions. In order to study the mass (M and charge (Q dependence of the acceleration process He2+ is included self-consistently. The upstream differential intensity spectra of H+ and He2+ can be well represented by exponentials in energy. The e-folding energy Ec is a function of time: Ec increases with time. Furthermore the e-folding energy (normalized to the shock ramming energy Ep increases with increasing Alfvén Mach number of the shock and with increasing fluctuation level of the initially superimposed turbulence. When backstreaming ions leave the shock after their first encounter they exhibit already a spectrum which extends to more than ten times the shock ramming energy and which is ordered in energy per charge. From the injection spectrum it is concluded that leakage of heated downstream particles does not contribute to ion injection. Acceleration models that permit thermal particles to scatter like the non-thermal population do not describe the correct physics.Key words. Interplanetary physics (planetary bow shocks · Space plasma physics (charged particle motion and acceleration; numerical simulation studies

  15. Plasma and wave properties downstream of Martian bow shock: Hybrid simulations and MAVEN observations

    Science.gov (United States)

    Dong, Chuanfei; Winske, Dan; Cowee, Misa; Bougher, Stephen W.; Andersson, Laila; Connerney, Jack; Epley, Jared; Ergun, Robert; McFadden, James P.; Ma, Yingjuan; Toth, Gabor; Curry, Shannon; Nagy, Andrew; Jakosky, Bruce

    2015-04-01

    Two-dimensional hybrid simulation codes are employed to investigate the kinetic properties of plasmas and waves downstream of the Martian bow shock. The simulations are two-dimensional in space but three dimensional in field and velocity components. Simulations show that ion cyclotron waves are generated by temperature anisotropy resulting from the reflected protons around the Martian bow shock. These proton cyclotron waves could propagate downward into the Martian ionosphere and are expected to heat the O+ layer peaked from 250 to 300 km due to the wave-particle interaction. The proton cyclotron wave heating is anticipated to be a significant source of energy into the thermosphere, which impacts atmospheric escape rates. The simulation results show that the specific dayside heating altitude depends on the Martian crustal field orientations, solar cycles and seasonal variations since both the cyclotron resonance condition and the non/sub-resonant stochastic heating threshold depend on the ambient magnetic field strength. The dayside magnetic field profiles for different crustal field orientation, solar cycle and seasonal variations are adopted from the BATS-R-US Mars multi-fluid MHD model. The simulation results, however, show that the heating of O+ via proton cyclotron wave resonant interaction is not likely in the relatively weak crustal field region, based on our simplified model. This indicates that either the drift motion resulted from the transport of ionospheric O+, or the non/sub-resonant stochastic heating mechanism are important to explain the heating of Martian O+ layer. We will investigate this further by comparing the simulation results with the available MAVEN data. These simulated ion cyclotron waves are important to explain the heating of Martian O+ layer and have significant implications for future observations.

  16. Search for lepton-flavor and lepton-number-violating τ→ℓhh{sup ′} decay modes

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Y. [Graduate School of Science, Nagoya University, Nagoya (Japan); Hayasaka, K., E-mail: hayasaka@hepl.phys.nagoya-u.ac.jp [Kobayashi-Maskawa Institute, Nagoya University, Nagoya (Japan); Adachi, I. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Aihara, H. [Department of Physics, University of Tokyo, Tokyo (Japan); Asner, D.M. [Pacific Northwest National Laboratory, Richland, WA (United States); Aulchenko, V. [Budker Institute of Nuclear Physics SB RAS and Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Aushev, T. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bakich, A.M. [School of Physics, University of Sydney, NSW 2006 (Australia); Bay, A. [École Polytechnique Fédérale de Lausanne, EPFL, Lausanne (Switzerland); Bhardwaj, V. [Nara Women' s University, Nara (Japan); Bhuyan, B. [Indian Institute of Technology Guwahati, Guwahati (India); Bischofberger, M. [Nara Women' s University, Nara (Japan); Bozek, A. [H. Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Bračko, M. [University of Maribor, Maribor (Slovenia); J. Stefan Institute, Ljubljana (Slovenia); Browder, T.E. [University of Hawaii, Honolulu, HI (United States); Chang, M.-C. [Department of Physics, Fu Jen Catholic University, Taipei, Taiwan (China); Chen, A. [National Central University, Chung-li, Taiwan (China); Chen, P. [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Cheon, B.G. [Hanyang University, Seoul (Korea, Republic of); Chistov, R. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); and others

    2013-02-26

    We search for lepton-flavor and lepton-number-violating τ decays into a lepton (ℓ= electron or muon) and two charged mesons (h,h{sup ′}=π{sup ±} or K{sup ±}) using 854 fb{sup −1} of data collected with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup −} collider. We obtain 90% confidence level upper limits on the τ→ℓhh{sup ′} branching fractions in the range (2.0–8.4)×10{sup −8}. These results improve upon our previously published upper limits by factors of about 1.8 on average.

  17. A ROTATING MOLECULAR DISK TOWARD IRAS 18162-2048, THE EXCITING SOURCE OF HH 80-81

    International Nuclear Information System (INIS)

    Fernandez-Lopez, M.; Curiel, S.; Girart, J. M.; Gomez, Y.; Ho, P. T. P.; Patel, N.

    2011-01-01

    We present several molecular line emission arcsecond and subarcsecond observations obtained with the Submillimeter Array in the direction of the massive protostar IRAS 18162-2048, the exciting source of HH 80-81. The data clearly indicate the presence of a compact (radius ∼425-850 AU) SO 2 structure, enveloping the more compact (radius ∼ sun . The SO 2 spectral line data also allow us to constrain the structure temperature between 120 and 160 K and the volume density ∼> 2 x 10 9 cm -3 . We also find that such a rotating flattened system could be unstable due to gravitational disturbances. The data from C 17 O line emission show a dense core within this star-forming region. Additionally, the H 2 CO and SO emissions appear clumpy and trace the disk-like structure, a possible interaction between a molecular core and the outflows, and in part, the cavity walls excavated by the thermal radio jet.

  18. Cellulose-dependent expression and antibacterial characteristics of surfactin from Bacillus subtilis HH2 isolated from the giant panda

    Science.gov (United States)

    Zhong, Zhijun; Su, Huaiyi; Li, Jin; Li, Haozhou; Feng, Fan; Lan, Jingchao; Zhang, Zhihe; Fu, Hualin; Hu, Yanchun; Cao, Suizhong; Chen, Weigang; Deng, Jiabo; Yu, Jianqiu; Zhang, Wenping

    2018-01-01

    Surfactin secreted by Bacillus subtilis can confer strong, diverse antipathogenic effects, thereby benefitting the host. Carbon source is an important factor for surfactin production. However, the mechanism that bacteria utilize cellulose, the most abundant substance in the intestines of herbivores, to produce surfactin remains unclear. Here, we used B. subtilis HH2, isolated from the feces of a giant panda, as a model to determine changes in surfactin expression in the presence of different concentrations of cellulose by quantitative polymerase chain reaction and high-performance liquid chromatography. We further investigated the antimicrobial effects of surfactin against three common intestinal pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella enterica) and its resistance to high temperature (60–121°C), pH (1–12), trypsin (100–300 μg/mL, pH 8), and pepsin (100–300 μg/mL, pH 2). The results showed that the surfactin expressed lowest in bacteria cultured in the presence of 1% glucose medium as the carbon source, whereas increased in an appropriate cellulose concentration (0.67% glucose and 0.33% cellulose). The surfactin could inhibit E. coli and Staphylococcus aureus, but did not affect efficiently for Salmonella enterica. The antibacterial ability of surfactin did not differ according to temperature (60–100°C), pH (2–11), trypsin (100–300 μg/mL), and pepsin (100–300 μg/mL; P > 0.05), but decreased significantly at extreme environments (121°C, pH 1 or 12; P < 0.05) compared with that in the control group (37°C, pH = 7, without any protease). In conclusion, our findings indicated that B. subtilis HH2 could increase surfactin expression in an appropriate cellulose environment and thus provide benefits to improve the intestinal health of herbivores. PMID:29385201

  19. Cellulose-dependent expression and antibacterial characteristics of surfactin from Bacillus subtilis HH2 isolated from the giant panda.

    Directory of Open Access Journals (Sweden)

    Ziyao Zhou

    Full Text Available Surfactin secreted by Bacillus subtilis can confer strong, diverse antipathogenic effects, thereby benefitting the host. Carbon source is an important factor for surfactin production. However, the mechanism that bacteria utilize cellulose, the most abundant substance in the intestines of herbivores, to produce surfactin remains unclear. Here, we used B. subtilis HH2, isolated from the feces of a giant panda, as a model to determine changes in surfactin expression in the presence of different concentrations of cellulose by quantitative polymerase chain reaction and high-performance liquid chromatography. We further investigated the antimicrobial effects of surfactin against three common intestinal pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella enterica and its resistance to high temperature (60-121°C, pH (1-12, trypsin (100-300 μg/mL, pH 8, and pepsin (100-300 μg/mL, pH 2. The results showed that the surfactin expressed lowest in bacteria cultured in the presence of 1% glucose medium as the carbon source, whereas increased in an appropriate cellulose concentration (0.67% glucose and 0.33% cellulose. The surfactin could inhibit E. coli and Staphylococcus aureus, but did not affect efficiently for Salmonella enterica. The antibacterial ability of surfactin did not differ according to temperature (60-100°C, pH (2-11, trypsin (100-300 μg/mL, and pepsin (100-300 μg/mL; P > 0.05, but decreased significantly at extreme environments (121°C, pH 1 or 12; P < 0.05 compared with that in the control group (37°C, pH = 7, without any protease. In conclusion, our findings indicated that B. subtilis HH2 could increase surfactin expression in an appropriate cellulose environment and thus provide benefits to improve the intestinal health of herbivores.

  20. Resonant Higgs boson pair production in the $hh\\rightarrow b\\bar{b} \\; WW \\rightarrow b\\bar{b} \\ell^+ \

    CERN Document Server

    Martín Lozano, Víctor; Park, Chan Beom

    2015-01-01

    Adding a scalar singlet provides one of the simplest extensions of the Standard Model. In this work we briefly review the latest constraints on the mass and mixing of the new Higgs boson and study its production and decay at the LHC. We mainly focus on double Higgs production in the $hh \\rightarrow b \\bar{b} WW \\rightarrow b \\bar{b} \\ell^+ \

  1. Production of bifunctional proteins by Aspergillus awamori: Llama variable heavy chain antibody fragment (V-HH) R9 coupled to Arthromyces ramosus peroxidase (ARP)

    NARCIS (Netherlands)

    Joosten, V.; Roelofs, M.S.; Dries, van den N.; Goosen, T.; Verrips, C.T.; Hondel, van den C.A.M.J.J.; Lokman, B.C.

    2005-01-01

    The Arthromyces ramosus peroxidase gene (arp) was genetically fused to either the 5'- or 3'-terminal ends of the gene encoding llama variable heavy chain antibody fragment V-HH R9, resulting in the fusion expression cassettes ARP-R9 or R9-ARP. Aspergillus awamori transformants were obtained which

  2. Two-Polarisation Physical Model of Bowed Strings with Nonlinear Contact and Friction Forces, and Application to Gesture-Based Sound Synthesis

    Directory of Open Access Journals (Sweden)

    Charlotte Desvages

    2016-05-01

    Full Text Available Recent bowed string sound synthesis has relied on physical modelling techniques; the achievable realism and flexibility of gestural control are appealing, and the heavier computational cost becomes less significant as technology improves. A bowed string sound synthesis algorithm is designed, by simulating two-polarisation string motion, discretising the partial differential equations governing the string’s behaviour with the finite difference method. A globally energy balanced scheme is used, as a guarantee of numerical stability under highly nonlinear conditions. In one polarisation, a nonlinear contact model is used for the normal forces exerted by the dynamic bow hair, left hand fingers, and fingerboard. In the other polarisation, a force-velocity friction curve is used for the resulting tangential forces. The scheme update requires the solution of two nonlinear vector equations. The dynamic input parameters allow for simulating a wide range of gestures; some typical bow and left hand gestures are presented, along with synthetic sound and video demonstrations.

  3. Bowing and expansion of natural stone panels: marble and limestone testing and assessment

    Directory of Open Access Journals (Sweden)

    Grelk, Bent

    2008-06-01

    Full Text Available Natural stone has been used as a building material for centuries. In the past, load bearing members were made of entirely of stone, but in the last 50 years new processing techniques have made the production and use of thin facade cladding a profitable venture. Unfortunately however, marble facades on buildings in Europe and elsewhere have undergone severe deterioration. The EC-financed TEAM project (2000-2005 studied the bowing observed on marble facades in both cold and warm climates. TEAM’s main objectives were to understand and explain the expansion, bowing, and strength loss mechanisms governing the decay of marble- and limestone-clad facades, and to draft new European standards to prevent the use of marble and limestone poorly suited to outdoor cladding. A survey of some 200 buildings afforded a clear picture of the geographical, geological and climatic scope of the problem. Detailed case studies of six buildings resulted in a facade assessment methodology that included a monitoring system and risk assessment. Both laboratory and field research was conducted on almost 100 different types of stone from different countries and in place in different climates. The outcome was the determination of the decay mechanisms and critical factors. Two test methods and respective precision statements, one for bowing and the other for irreversible thermal expansion in high humidity conditions, were prepared for submission to CEN TC 246.La piedra natural se ha empleado como material de construcción durante siglos. En el pasado, se solía utilizar en elementos de carga, pero en los últimos 50 años las nuevas técnicas de procesamiento han permitido que sea comercialmente rentable producir y utilizar revestimientos para fachadas de espesor reducido. Desafortunadamente, numerosas fachadas de mármol de edificios tanto en Europa como fuera de ella han sufrido graves problemas derivados del deterioro de la piedra. El proyecto TEAM (2000

  4. Study on the effect of the CANFLEX-NU fuel element bowing on the critical heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Suk, Ho Chun; Cho, Moon Sung; Jeon, Ji Su

    2001-01-01

    The effect of the CANFLEX-NU fuel element bowing on the critical heat flux is reviewed and analyzed, which is requested by KINS as the Government design licensing condition for the use of the fuel bundles in CANDU power reactors. The effect of the gap between two adjacent fuel elements on the critical heat flux and onset-of-dryout power is studied. The reduction of the width of a single inter-rod gap from its nominal size to the minimum manufacture allowance of 1 mm has a negligible effects on the thermal-hydraulic performance of the bundle for the given set of boundary conditions applied to the CANFLEX-43 element bundle in an uncrept channel. As expected, the in-reactor irradiation test results show that there are no evidence of the element bow problems on the bundle performance.

  5. ROLE OF FCA WELDING PROCESS PARAMETERS ON BEAD PROFILE, ANGULAR AND BOWING DISTORTION OF FERRITIC STAINLESS STEEL SHEETS

    Directory of Open Access Journals (Sweden)

    VENKATESAN M. V.

    2014-02-01

    Full Text Available This paper discusses the influence of flux cored arc welding (FCAW process parameters such as welding current, travel speed, voltage and CO2 shielding gas flow rate on bead profile, bowing distortion and angular distortion of 409 M ferritic stainless steel sheets of 2 mm thickness. The bowing and angular distortions of the welded plates were measured using a simple device called profile tracer and Vernier bevel protractor respectively. The study revealed that the FCAW process parameters have significant effect on bead profile, and distortion. The relationship between bead profile and distortions were analyzed. Most favorable process parameters that give uniform bead profile and minimum distortion for the weld are recommended for fabrication.

  6. Non-stationarity of the quasi-perpendicular bow shock: comparison between Cluster observations and simulations

    Directory of Open Access Journals (Sweden)

    H. Comişel

    2011-02-01

    Full Text Available We have performed full particle electromagnetic simulations of a quasi-perpendicular shock. The shock parameters have been chosen to be appropriate for the quasi-perpendicular Earth's bow shock observed by Cluster on 24 January 2001 (Lobzin et al., 2007. We have performed two simulations with different ion to electron mass ratio: run 1 with mi/me=1840 and run 2 with mi/me=100. In run 1 the growth rate of the modified two-stream instability (MTSI is large enough to get excited during the reflection and upstream gyration of part of the incident solar wind ions. The waves due to the MTSI are on the whistler mode branch and have downstream directed phase velocities in the shock frame. The Poynting flux (and wave group velocity far upstream in the foot is also directed in the downstream direction. However, in the density and magnetic field compression region of the overshoot the waves are refracted and the Poynting flux in the shock frame is directed upstream. The MTSI is suppressed in the low mass ratio run 2. The low mass ratio run shows more clearly the non-stationarity of the shock with a larger time scale of the order of an inverse ion gyrofrequency (Ωci: the magnetic field profile flattens and steepens with a period of ~1.5Ωci−1. This non-stationarity is different from reformation seen in previous simulations of perpendicular or quasi-perpendicular shocks. Beginning with a sharp shock ramp the large electric field in the normal direction leads to high reflection rate of solar wind protons. As they propagate upstream, the ion bulk velocity decreases and the magnetic field increases in the foot, which results in a flattening of the magnetic field profile and in a decrease of the normal electric field. Subsequently the reflection rate decreases and the whole shock profile steepens again. Superimposed on this 'breathing' behavior are in the realistic mass ratio case the waves due to the MTSI. The simulations lead us to a re-interpretation of

  7. Quantified Energy Dissipation Rates in the Terrestrial Bow Shock. 2; Waves and Dissipation

    Science.gov (United States)

    Wilson, L. B., III; Sibeck, D. G.; Breneman, A. W.; Le Contel, O.; Cully, C.; Turner, D. L.; Angelopoulos, V.; Malaspina, D. M.

    2014-01-01

    We present the first quantified measure of the energy dissipation rates, due to wave-particle interactions, in the transition region of the Earth's collision-less bow shock using data from the Time History of Events and Macro-Scale Interactions during Sub-Storms spacecraft. Our results show that wave-particle interactions can regulate the global structure and dominate the energy dissipation of collision-less shocks. In every bow shock crossing examined, we observed both low-frequency (less than 10 hertz) and high-frequency (approximately or greater than10 hertz) electromagnetic waves throughout the entire transition region and into the magnetosheath. The low-frequency waves were consistent with magnetosonic-whistler waves. The high-frequency waves were combinations of ion-acoustic waves, electron cyclotron drift instability driven waves, electrostatic solitary waves, and whistler mode waves. The high-frequency waves had the following: (1) peak amplitudes exceeding delta B approximately equal to 10 nanoteslas and delta E approximately equal to 300 millivolts per meter, though more typical values were delta B approximately equal to 0.1-1.0 nanoteslas and delta E approximately equal to 10-50 millivolts per meter (2) Poynting fluxes in excess of 2000 microWm(sup -2) (micro-waves per square meter) (typical values were approximately 1-10 microWm(sup -2) (micro-waves per square meter); (3) resistivities greater than 9000 omega meters; and (4) associated energy dissipation rates greater than 10 microWm(sup -3) (micro-waves per cubic meter). The dissipation rates due to wave-particle interactions exceeded rates necessary to explain the increase in entropy across the shock ramps for approximately 90 percent of the wave burst durations. For approximately 22 percent of these times, the wave-particle interactions needed to only be less than or equal to 0.1 percent efficient to balance the nonlinear wave steepening that produced the shock waves. These results show that wave

  8. Risk Analysis on Leakage Failure of Natural Gas Pipelines by Fuzzy Bayesian Network with a Bow-Tie Model

    OpenAIRE

    Shan, Xian; Liu, Kang; Sun, Pei-Liang

    2017-01-01

    Pipeline is the major mode of natural gas transportation. Leakage of natural gas pipelines may cause explosions and fires, resulting in casualties, environmental damage, and material loss. Efficient risk analysis is of great significance for preventing and mitigating such potential accidents. The objective of this study is to present a practical risk assessment method based on Bow-tie model and Bayesian network for risk analysis of natural gas pipeline leakage. Firstly, identify the potential...

  9. Perspectives on grizzly bear management in Banff National Park and the Bow River Watershed, Alberta: A Q methodology study

    OpenAIRE

    Chamberlain, Emily Carter

    2006-01-01

    Conserving populations of large carnivores such as grizzly bears (Ursus arctos) requires not only biophysical research, but also an understanding of the values and beliefs of the people involved with and affected by carnivore management. I used Q methodology to examine views of stakeholders concerning grizzly bear management in the Banff-Bow Valley region of Alberta, Canada. In recent years, decision-making about bears in this region has been characterized by acrimonious disputes over scienti...

  10. Bow shock studies at Mercury, Venus, Earth, and Mars with applications to the solar-planetary interaction problem

    International Nuclear Information System (INIS)

    Slavin, J.A.

    1982-01-01

    A series of bow shock studies conducted for the purpose of investigating the interaction between the solar wind and the terrestrial planets is presented. Toward this end appropriate modeling techniques have been developed and applied to the bow wave observations at Venus, Earth, and Mars. For Mercury the measurements are so few in number that no accurate determination of shock shape was deemed possible. Flow solutions generated using the observed bow wave surface as a boundary condition in a single fluid variable obstacle shape gasdynamic model produced excellent fits to the measured width and shape of the earth's magnetosheath. This result and the observed ordering of shock shape and position by upstream sonic Mach number provide strong support for the validity of the gasdynamic approximation. At Mercury the application of earth type models to the individual Mariner 10 boundry crossings has led to the determination of an effective planetary magnetic moment of 6+-2 x 10 22 G-cm 3 . Consistent with the presence of a small terrestrial style magnetosphere, southward interplanetary magnetic fields were found to significantly reduce the solar wind stand-off distance most probably through the effects of dayside magnetic reconnection. For Venus the low altitude solar wind flow field derived from gasdynamic modeling of bow shock location and shape indicates that a fraction of the incident streamlines are absorbed by the neutral atmosphere near the ionopause; approximately 1% and 8%, respectively, in the solar maximum Pioneer Venus and solar minimum Venera measurements. Accordingly, it appears that cometary processes must be included in model calculations of the solar wind flow about Venus. At Mars the moderate height of the gasdynamic solar wind-obstacle interface and the weakness of the Martian ionosphere/atmosphere are found to be incompatible with a Venus type interaction

  11. Kaguya observations of the lunar wake in the terrestrial foreshock: Surface potential change by bow-shock reflected ions

    Science.gov (United States)

    Nishino, Masaki N.; Harada, Yuki; Saito, Yoshifumi; Tsunakawa, Hideo; Takahashi, Futoshi; Yokota, Shoichiro; Matsushima, Masaki; Shibuya, Hidetoshi; Shimizu, Hisayoshi

    2017-09-01

    There forms a tenuous region called the wake behind the Moon in the solar wind, and plasma entry/refilling into the wake is a fundamental problem of the lunar plasma science. High-energy ions and electrons in the foreshock of the Earth's magnetosphere were detected at the lunar surface in the Apollo era, but their effects on the lunar night-side environment have never been studied. Here we show the first observation of bow-shock reflected protons by Kaguya (SELENE) spacecraft in orbit around the Moon, confirming that solar wind plasma reflected at the terrestrial bow shock can easily access the deepest lunar wake when the Moon stays in the foreshock (We name this mechanism 'type-3 entry'). In a continuous type-3 event, low-energy electron beams from the lunar night-side surface are not obvious even though the spacecraft location is magnetically connected to the lunar surface. On the other hand, in an intermittent type-3 entry event, the kinetic energy of upward-going field-aligned electron beams decreases from ∼ 80 eV to ∼ 20 eV or electron beams disappear as the bow-shock reflected ions come accompanied by enhanced downward electrons. According to theoretical treatment based on electric current balance at the lunar surface including secondary electron emission by incident electron and ion impact, we deduce that incident ions would be accompanied by a few to several times higher flux of an incident electron flux, which well fits observed downward fluxes. We conclude that impact by the bow-shock reflected ions and electrons raises the electrostatic potential of the lunar night-side surface.

  12. Quasiparticle self-consistent GW theory of III-V nitride semiconductors: Bands, gap bowing, and effective masses

    DEFF Research Database (Denmark)

    Svane, Axel; Christensen, Niels Egede; Gorczyca, I.

    2010-01-01

    on the basis of the local approximation to density functional theory, although generally overestimated by 0.2–0.3 eV in comparison with experimental gap values. Details of the electronic energies and the effective masses including their pressure dependence are compared with available experimental information....... The band gap of InGaN2 is considerably smaller than what would be expected by linear interpolation implying a significant band gap bowing in InGaN alloys....

  13. Assessing the potential for rainbow trout reproduction in tributaries of the Mountain Fork River below Broken Bow Dam, southeastern Oklahoma

    Science.gov (United States)

    Long, James M.; Starks, Trevor A.; Farling, Tyler; Bastarache, Robert

    2016-01-01

    Stocked trout (Salmonidae) in reservoir tailwater systems in the Southern United States have been shown to use tributary streams for spawning and rearing. The lower Mountain Fork of the Little River below Broken Bow Dam is one of two year-round tailwater trout fisheries in Oklahoma, and the only one with evidence of reproduction by stocked rainbow trout (Oncorhynchus mykiss). Whether stocked trout use tributaries in this system for spawning is unknown. Furthermore, an

  14. First simultaneous measurements of waves generated at the bow shock in the solar wind, the magnetosphere and on the ground

    Science.gov (United States)

    Clausen, L. B. N.; Yeoman, T. K.; Fear, R. C.; Behlke, R.; Lucek, E. A.; Engebretson, M. J.

    2009-01-01

    On 5 September 2002 the Geotail satellite observed the cone angle of the Interplanetary Magnetic Field (IMF) change to values below 30° during a 56 min interval between 18:14 and 19:10 UT. This triggered the generation of upstream waves at the bow shock, 13 RE downstream of the position of Geotail. Upstream generated waves were subsequently observed by Geotail between 18:30 and 18:48 UT, during times the IMF cone angle dropped below values of 10°. At 18:24 UT all four Cluster satellites simultaneously observed a sudden increase in wave power in all three magnetic field components, independent of their position in the dayside magnetosphere. We show that the 10 min delay between the change in IMF direction as observed by Geotail and the increase in wave power observed by Cluster is consistent with the propagation of the IMF change from the Geotail position to the bow shock and the propagation of the generated waves through the bow shock, magnetosheath and magnetosphere towards the position of the Cluster satellites. We go on to show that the wave power recorded by the Cluster satellites in the component containing the poloidal and compressional pulsations was broadband and unstructured; the power in the component containing toroidal oscillations was structured and shows the existence of multi-harmonic Alfvénic continuum waves on field lines. Model predictions of these frequencies fit well with the observations. An increase in wave power associated with the change in IMF direction was also registered by ground based magnetometers which were magnetically conjunct with the Cluster satellites during the event. To the best of our knowledge we present the first simultaneous observations of waves created by backstreaming ions at the bow shock in the solar wind, the dayside magnetosphere and on the ground.

  15. Energy time dispersion of a new class of magnetospheric ion events observed near the Earth's bow shock

    Directory of Open Access Journals (Sweden)

    G. C. Anagnostopoulos

    2000-01-01

    Full Text Available We have analyzed high time resolution (\\geq6 s data during the onset and the decay phase of several energetic (\\geq35 keV ion events observed near the Earth's bow shock by the CCE/AMPTE and IMP-7/8 spacecraft, during times of intense substorm/geomagnetic activity. We found that forward energy dispersion at the onset of events (earlier increase of middle energy ions and/or a delayed fall of the middle energy ion fluxes at the end of events are often evident in high time resolution data. The energy spectra at the onset and the decay of this kind of events show a characteristic hump at middle (50-120 keV energies and the angular distributions display either anisotropic or broad forms. The time scale of energy dispersion in the ion events examined was found to range from several seconds to \\sim1 h depending on the ion energies compared and on the rate of variation of the Interplanetary Magnetic Field (IMF direction. Several canditate processes are discussed to explain the observations and it is suggested that a rigidity dependent transport process of magnetospheric particles within the magnetosheath is most probably responsible for the detection of this new type of near bow shock magnetospheric ion events. The new class of ion events was observed within both the magnetosheath and the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

  16. Enhanced Scattering of Diffuse Ions on Front of the Earth's Quasi-Parallel Bow Shock: a Case Study

    Science.gov (United States)

    Kis, A.; Matsukiyo, S.; Otsuka, F.; Hada, T.; Lemperger, I.; Dandouras, I. S.; Barta, V.; Facsko, G. I.

    2017-12-01

    In the analysis we present a case study of three energetic upstream ion events at the Earth's quasi-parallel bow shock based on multi-spacecraft data recorded by Cluster. The CIS-HIA instrument onboard Cluster provides partial energetic ion densities in 4 energy channels between 10 and 32 keV.The difference of the partial ion densities recorded by the individual spacecraft at various distances from the bow shock surface makes possible the determination of the spatial gradient of energetic ions.Using the gradient values we determined the spatial profile of the energetic ion partial densities as a function of distance from the bow shock and we calculated the e-folding distance and the diffusion coefficient for each event and each ion energy range. Results show that in two cases the scattering of diffuse ions takes place in a normal way, as "by the book", and the e-folding distance and diffusion coefficient values are comparable with previous results. On the other hand, in the third case the e-folding distance and the diffusion coefficient values are significantly lower, which suggests that in this case the scattering process -and therefore the diffusive shock acceleration (DSA) mechanism also- is much more efficient. Our analysis provides an explanation for this "enhanced" scattering process recorded in the third case.

  17. TRANSPORT OF SOLAR WIND H{sup +} AND He{sup ++} IONS ACROSS EARTH’S BOW SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Parks, G. K.; Lin, N. [Space Sciences Laboratory, University of California, Berkeley, CA (United States); Lee, E. [School of Space Research and Institute of Natural Sciences, Kyung Hee University, Yongin (Korea, Republic of); Fu, S. Y.; Ma, Y. Q. [Institute of Space Science, Peking University, Beijing (China); Kim, H. E.; Hong, J. [School of Space Research, Kyung Hee University, Yongin (Korea, Republic of); Yang, Z. W.; Liu, Y. [Key Laboratory for Space Weather, Chinese Academy of Sciences, Beijing (China); Canu, P. [Plasma Physics Laboratory, Ecole Polytechnique, Paris (France); Dandouras, I.; Rème, H. [IRAP, Paul Sabatier University and CNRS, Toulouse (France); Goldstein, M. L., E-mail: parks@ssl.berkeley.edu [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    2016-07-10

    We have investigated the dependence of mass, energy, and charge of solar wind (SW) transport across Earth’s bow shock. An examination of 111 crossings during quiet SW in both quasi-perpendicular and quasi-parallel shock regions shows that 64 crossings had various degrees of heating and thermalization of SW. We found 22 crossings where the SW speed was <400 km s{sup −1}. The shock potential of a typical supercritical quasi-perpendicular shock estimated from deceleration of the SW and cutoff energy of electron flat top distribution is ∼50 Volts. We find that the temperatures of H{sup +} and He{sup ++} beams that penetrate the shock can sometimes be nearly the same in the upstream and downstream regions, indicating little or no heating had occurred crossing the bow shock. None of the models predict that the SW can cross the bow shock without heating. Our observations are important constraints for new models of collisionless shocks.

  18. A lower-limb training program to improve balance in healthy elderly women using the T-bow device.

    Science.gov (United States)

    Chulvi-Medrano, Iván; Colado, Juan C; Pablos, Carlos; Naclerio, Fernando; García-Massó, Xavier

    2009-06-01

    Ageing impairs balance, which increases the risk of falls. Fall-related injuries are a serious health problem associated with dependency and disability in the elderly and results in high costs to public health systems. This study aims to determine the effects of a training program to develop balance using a new device called the T-Bow. A total of 28 women > 65 years were randomly assigned to an experimental group (EG) (n = 18; 69.50 [0.99] years), or a control group (CG) (n = 10; 70.70 [2.18] years). A program for lower limbs was applied for 8 weeks using 5 exercises on the T-Bow: squat, lateral and frontal swings, lunges, and plantarflexions. The intensity of the exercises was controlled by time of exposure, support base, and ratings of perceived exertion. Clinical tests were used to evaluate variables of balance. Static balance was measured by a 1-leg balance test (unipedal stance test), dynamic balance was measured by the 8-foot-up-and-go test, and overall balance was measured using the Tinetti test. Results for the EG showed an increase of 35.2% in static balance (P 0.05). Results for the CG showed a decline of 5.79% in static balance (P > 0.05) but no change in the other balance variables. Thus the data suggest that implementing a training program using the T-Bow could improve balance in healthy older women.

  19. Análisis del entorno sinóptico asociado con eventos de Bow-Echo en la Provincia de Buenos Aires Synoptic Environment Analysis Associated With Bow - Echo Events In The Province Of Buenos Aires

    Directory of Open Access Journals (Sweden)

    Marcela Torres Brizuela

    2011-06-01

    Full Text Available Durante la madrugada del día 21 de Octubre de 2008 se desarrollaron tres líneas convectivas en la provincia de Buenos Aires, captadas por los radares meteorológicos de las localidades de Ezeiza y Pergamino. La estructura espacial y evolución temporal del campo de reflectividad de estos sistemas, configuración de línea en arco, responde al modo convectivo conocido con el nombre de “bow-echo”. La imagen doppler del radar de Ezeiza registró un fenómeno típico en la parte posterior de estas líneas en arco: los vientos intensos mayores a 20 m.s-1. El objetivo principal de este estudio es comprender las condiciones sinópticas que acompañaron la ocurrencia de estos sistemas para poder contribuir al pronóstico de su ocurrencia. En este evento las condiciones de humedad especifica en la zona del norte de la provincia de Buenos Aires (q≥ 12-14 g.kg-1, así como la de cortante vertical del viento por debajo del nivel de 700 hPa (Us>15 m.s-1 coinciden en indicar al entorno como favorable al desarrollo del mismo, aunque no así los valores disponibles de CAPE evaluados para parcelas que se elevan desde superficie.During the morning hours on October 21 2008, three convective lines developed over the Buenos Aires province, and were captured by the meteorological radars located at Ezeiza and Pergamino. The spatial structure and temporal evolution of the reflectivity field of these convective systems present the attributes of the particular convective system referred to as a “bow-echo”. Ezeiza doppler radar images, captured winds stronger than 20 m.s-1 behind these arc lines, a phenomenon that frequently characterizes the presence of a bow-echo. The main objective of this study is to understand the synoptic weather conditions accompanying the occurrence of these bow echo events to enhance the weather forecasting of these systems. On this particular case the specific humidity field over the northern part of the Buenos Aires province (q

  20. A semiquantitative theory for the 2fp radiation observed upstream from the earth's bow shock

    International Nuclear Information System (INIS)

    Cairns, I.H.

    1988-01-01

    A semiquantitative theory for the 2f p radiation observed upstream from the Earth's bow shock is presented: the radiation is produced by the process L + L → T + S, proceeding as two sequential three-wave steps L → L' + S and L + L' → T, in the foreshock where nonthermal L and S waves are observed. (Here L, S, and T denote Langmuir, ion acoustic, and transverse electromagnetic waves, respectively.) This theory is consistent with all the available wave data, including the characteristics and levels of a class of low-frequency waves identified as S wave products of the process L → L' + S, and the brightness temperature and bandwidth of the 2f p radiation. Indeed the theory could account for higher 2f p brightness temperatures if required. Predictions of the theory suitable for observational testing include (1) the existence of two 2f p sources, one to each wing of the foreshock, (2) the spatial location of the source regions, and (3) the characteristics and levels of the product L' and S waves in the source regions. The radiation should (4) have intrinsic bandwidths of the order of 1 kHz or less, (5) be less than 0.1% circularly polarized, and (6) have a limiting brightness temperature equal to the effective temperature T L of the L waves producing the radiation

  1. Relativistic Electrons Produced by Foreshock Disturbances Observed Upstream of Earth's Bow Shock

    Science.gov (United States)

    Wilson, L. B., III; Sibeck, D. G.; Turner, D. L.; Osmane, A.; Caprioli, D.; Angelopoulos, V.

    2016-01-01

    Charged particles can be reflected and accelerated by strong (i.e., high Mach number) astrophysical collisionless shock waves, streaming away to form a foreshock region in communication with the shock. Foreshocks are primarily populated by suprathermal ions that can generate foreshock disturbances-largescale (i.e., tens to thousands of thermal ion Larmor radii), transient (approximately 5-10 per day) structures. They have recently been found to accelerate ions to energies of several keV. Although electrons in Saturn's high Mach number (M > 40) bow shock can be accelerated to relativistic energies (nearly 1000 keV), it has hitherto been thought impossible to accelerate electrons beyond a few tens of keV at Earth's low Mach number (1 =M foreshock disturbances to energies up to at least approximately 300 keV. Although such energetic electrons have been previously observed, their presence has been attributed to escaping magnetospheric particles or solar events. These relativistic electrons are not associated with any solar or magnetospheric activity. Further, due to their relatively small Larmor radii (compared to magnetic gradient scale lengths) and large thermal speeds (compared to shock speeds), no known shock acceleration mechanism can energize thermal electrons up to relativistic energies. The discovery of relativistic electrons associated with foreshock structures commonly generated in astrophysical shocks could provide a new paradigm for electron injections and acceleration in collisionless plasmas.

  2. Modeling of direct wafer bonding: Effect of wafer bow and etch patterns

    Science.gov (United States)

    Turner, K. T.; Spearing, S. M.

    2002-12-01

    Direct wafer bonding is an important technology for the manufacture of silicon-on-insulator substrates and microelectromechanical systems. As devices become more complex and require the bonding of multiple patterned wafers, there is a need to understand the mechanics of the bonding process. A general bonding criterion based on the competition between the strain energy accumulated in the wafers and the surface energy that is dissipated as the bond front advances is developed. The bonding criterion is used to examine the case of bonding bowed wafers. An analytical expression for the strain energy accumulation rate, which is the quantity that controls bonding, and the final curvature of a bonded stack is developed. It is demonstrated that the thickness of the wafers plays a large role and bonding success is independent of wafer diameter. The analytical results are verified through a finite element model and a general method for implementing the bonding criterion numerically is presented. The bonding criterion developed permits the effect of etched features to be assessed. Shallow etched patterns are shown to make bonding more difficult, while it is demonstrated that deep etched features can facilitate bonding. Model results and their process design implications are discussed in detail.

  3. Spectroscopic Analysis to Characterize Finishing Treatments of Ancient Bowed String Instruments.

    Science.gov (United States)

    Fiocco, Giacomo; Rovetta, Tommaso; Gulmini, Monica; Piccirillo, Anna; Licchelli, Maurizio; Malagodi, Marco

    2017-11-01

    Historical bowed string instruments exhibit acoustic features and aesthetic appeal that are still considered inimitable. These characteristics seem to be in large part determined by the materials used in the ground and varnishing treatments after the assembly of the instrument. These finishing processes were kept secret by the violinmakers and the traditional methods were handed down orally from master craftsmen to apprentices. Today, the methods of the past can represent a secret to be revealed through scientific investigations. The "Cremonese" methods used in the 17th and 18th centuries were lost as the last Great Masters from the Amati, Guarneri, and Stradivari families passed away. In this study, we had the chance of combining noninvasive and microinvasive techniques on six fragments of historical musical instruments. The fragments were detached from different instruments during extraordinary maintenance and restoration treatments, which involved the substitution of severely damaged structural parts like top plates, back plates, or ribs. Therefore, the fragments can offer to the scientists a valuable overview on the materials and techniques used by the violinmakers. The results obtained by portable X-ray fluorescence, optical microscopy, scanning electron microscopy coupled with energy dispersive X-ray spectrometry, and Fourier transform infrared microscopy allowed us to: (1) determine the stratigraphy of six instruments; (2) obtain new information about the materials involved in the finishing processes employed in Cremona; and (3) elucidate the technological relationship among the procedures adopted in the violin making workshops during the considered period.

  4. Bow hull-form optimization in waves of a 66,000 DWT bulk carrier

    Directory of Open Access Journals (Sweden)

    Jin-Won Yu

    2017-09-01

    Full Text Available This paper uses optimization techniques to obtain bow hull form of a 66,000 DWT bulk carrier in calm water and in waves. Parametric modification functions of SAC and section shape of DLWL are used for hull form variation. Multi-objective functions are applied to minimize the wave-making resistance in calm water and added resistance in regular head wave of λ/L = 0.5. WAVIS version 1.3 is used to obtain wave-making resistance. The modified Fujii and Takahashi's formula is applied to obtain the added resistance in short wave. The PSO algorithm is employed for the optimization technique. The resistance and motion characteristics in calm water and regular and irregular head waves of the three hull forms are compared. It has been shown that the optimal brings 13.2% reduction in the wave-making resistance and 13.8% reduction in the added resistance at λ/L = 0.5; and the mean added resistance reduces by 9.5% at sea state 5.

  5. ANALISA PENGARUH BENTUK LAMBUNG AXE BOW PADA KAPAL HIGH SPEED CRAFT TERHADAP HAMBATAN TOTAL

    Directory of Open Access Journals (Sweden)

    Romadhoni Oni

    2015-06-01

    Full Text Available Hambatan merupakan salah satu faktor utama yang mempengaruhi proses perancangan sebuah kapal. Kapal dengan bentuk lambung yang baik akan menghasilkan hambatan yang efisiensi sehingga operasional kapal dan pergerakan kapal lebih baik. Pada ini penelitian dilakukan dengan memodelkan kapal high speed craft tipe Crew boat panjang 38 meter, lebar 7.6 meter, tinggi 3.65 meter dan draft 1.89 meter. Selanjutnya diselidiki model lambung kapal yang menghasilkan hambatan total paling kecil menggunakan pendekatan studi numerik software (maxsuft hullspeed metode savitsky dan holtrop dan software Computational Fluid Dynamics (CFD. Hasil penelitian berdasarkan analisa numerik (Maxsuft –Hullspeed dan CFD menujukkan pada kecepatan sevice bentuk lambung model AXE Bow memiliki nilai hambatan yang lebih kecil dibandingkan model kapal planing hull chine (HPC dan rounded hull (RH. Hasil perhitungan numerik dan CFD memiliki nilai yang hampir sama pada setiap variasi model. Hasil komparisi yang dilakukan didapatkan selisih total hambatan pada kecepatan 25 knot yaitu  model HPC 1.8 kN, model HPCAB 5.2 kN, model RH 4.8 kN dan model 5.1 kN. Dari perbandingan kedua metode tersebut memiliki selisih cukup kecil yaitu  kurang dari 5%. Selain mendapatkan nilai hambatan Software CFD akan menghasilkan nilai  perbandingan gaya angkat (lift force, dan total pressure yang terdistribusi  pada permukaan model setiap variasi kecepatan.

  6. Reflected and diffuse ions backstreaming from the earth's bow shock 1. Basic properties

    International Nuclear Information System (INIS)

    Bonifazi, C.; Moreno, G.

    1981-01-01

    Plasma data supplied by the ISEE 2 solar wind experiment are used to perform the first extended statistical analysis of the basic moments of the ions backstream from the earth's bow shock. The analysis is based on 3253 ion spectra, corresponding to a total observation time of approx. =87 hours. It turns out that the density and total energy density of the backstream ions are, on the average, equal to approx. =1% and approx. =10% of those of the solar wind, respectively. The distinction between the 'reflected' and 'diffuse' populations has been confirmed and put on a quantitive basis using the ratio A = V /sub B/P/w/sub B/P between the bulk velocity and the rms thermal speed of the ions. The reflected ions are characterized by a bulk velocity V/sub B/P of the order of 2 times the solar wind velocity and by a temperature of approx.7 x 10 6 K. In contrast, the diffuse ions have, on the average, a bulk velocity 1.2 times the solar wind velocity and a temperature of 40 x 10 6 K. Therefore the total energy density of the diffuse ions is approx. =30% larger than that of the reflected ions. Finally, the kinetic and thermal energy densities are distributed quite differently in the two ion populations: in fact, approx. =70% of the total energy density is kinetic for the reflected ions, while this percentage decreases to approx. =20% for the diffuse ions

  7. Experimental Study on Behavior of Bow-tie Tree Generation by Using Heavy Water

    Science.gov (United States)

    Kumazawa, Takao; Nakagawa, Wataru; Tsurumaru, Hidekazu

    Bow-tie tree (BTT) generated from contaminant, e.g., metal, carbon, amber(over cured resin) or void in insulator is a significant deterioration factor of XLPE power cable. However, essential role of water in generation and progress of BTT is not yet sufficiently cleared. In order to investigate the role of water we paid attention to difference in chemical properties of light water (H2O) and heavy water (D2O), moreover we evaluated influence of isotopic effect due to hydrogen and deuterium on behavior of BTT generation. In accelerated aging test the number of BTT in XLPE sample, in which copper powder of 500ppm was contaminated as BTT cores, dipped in heavy water (D2O:100wt%) decreased to one third compared with light water(D2O:0wt%). Furthermore, the maximum length of BTT decreased with increase in concentration of heavy water. The experimental results show that heavy water exerted a depression effect on generation and progress of BTT. We considered that the depression effect due to hydrogen isotope appeared by inhibiting ionization and elution of BTT cores, because salt-solubility and ionic mobility of heavy water are about 15 to 20% smaller than those of light water. Therefore, the essential role of water seemed to be production and transport of ions in XLPE.

  8. Correlated wave and particle observations upstream of the earth's bow shock

    International Nuclear Information System (INIS)

    Harvey, C.C.; Bavassano-Cattaneo, M.B.; Dobrowolny, M.; Orsini, S.; Mangeney, A.; Russell, C.T.

    1981-01-01

    Data from three ISEE experiments has been analyzed during several periods of turbulence observed in the solar wind upstream of the earth's quasi-parallel bow shock. Radio observations are used to validate a shock model, which is subsequently used to compute various geometrical parameters during all the periods studied. One typical 9-hour period on November 4, 1977, is discussed in some detail to illustrate the parameters studied and the correlations found. It is shown that during this period, the radio noise spectrum has two components, one centered around the local electron plasma frequency and the other at somewhat lower frequencies; the latter component has a shorter wavelength and correlates with the level of MHD turbulence. A multivariate canonical statistical analysis of particle and MHD data during a 2-week period shows that the proton anisotropy and turbulence level correlate well with the minimum backstreaming proton parallel velocity p/sub min/ which, as defined here, is a purely geometrical parameter. Trivariate analysis shows that the correlation of particles and turbulence with the angle between the magnetic field and the shock normal have their sense reversed when allowance is made for the strong correlations with p/sub min/. A very good correlation has been found between power and compressibility in magnetic fluctuations

  9. Stratigraphy and uranium potential of early proterozoic metasedimentary rocks in the Medicine Bow Mountains, Wyoming

    International Nuclear Information System (INIS)

    Karlstrom, K.E.; Houston, R.S.

    1979-01-01

    The Medicine Bow Mountains of southeastern Wyoming contain an eight mile (13 km) thick section of Early Proterozoic (2500 to 1700 My b.p.) metasedimentary rocks which is subdivided into three successions: the Phantom Lake Metamorphic Suite (oldest), Deep Lake Group, and Libby Creek Group. The most promising units are the basal conglomerate of the upper Phantom Lake Suite, which appears to unconformably overlie metavolcanics of the lower Phantom Lake Suite, and the Magnolia Formation, which unconformably overlies the upper Phantom Lake Suite. Outcrops of the former have yielded assays of up to 141 ppM U and 916 ppM Th, with no appreciable gold. Outcrops of the Magnolia Formation have yielded up to 8.4 ppM U and 38 ppM Th. Several factors indicate that these units deserve further study. First, the lithologies of the radioactive and nonradioactive units are remarkably similar to those found in known uranium fossil-placers. Second, the paleogeography was favorable for placer accumulation if the conglomerates are fluvial sediments in an epicontinental clastic succession which was deposited during several transgressive-regressive cycles, as interpreted to be, Third, the age of the conglomerates may be similar to the age of other known uranium placers-i.e., more than 2000 My b.p. And fourth, geological and geochemical studies indicate that both uranium and pyrite have been strongly leached from outcrops and that subsurface rocks contain more uranium than surface rocks do

  10. CFD analyses of the rod bowing effect on the subchannel outlet temperature distribution

    Energy Technology Data Exchange (ETDEWEB)

    Ekstroem, Karoliina; Toppila, Timo [Fortum Power and Heat, Fortum (Finland)

    2017-09-15

    In the Loviisa 1 and 2 nuclear power plants the subcooling margin of the hottest subchannel of the fuel assembly is monitored. The temperature of the coolant in the hottest subchannel is limited to the constant saturation temperature. Bending of the fuel rods occurs during normal operation due to the differences in the heat profiles of the rods. The coolant temperature will rise more in the subchannel with smaller flow area due to the bending and this has to be taken into account in the safety margin of subchannel enthalpy rise. Computational Fluid Dynamics (CFD) simulations are used to estimate how much the estimated maximum bow of a rod affects the temperature rise of the subchannel. The quantitative uncertainty of the predicted enthalpy rise in fuel bundle subchannel is estimated based on the uncertainty of modelling of mixing between subchannels. The measured turbulence quantities from LDA measurements of cold test assembly made in 1990s in Fortum are compared with CFD results to give uncertainty estimation for turbulence, which is further used for uncertainty estimation of mixing and simulated subchannel enthalpy rise.

  11. Radiative bow shock wave (?) driven by nuclear ejecta in a Seyfert galaxy

    International Nuclear Information System (INIS)

    Wilson, A.S.; Ulvestad, J.S.; California Institute of Technology, Pasadena)

    1987-01-01

    New VLA maps at 2 cm of the 13-arcsec-scale linear radio source in the center of NGC 1068 are described. The northeast lobe shows a limb-brightened conical morphology, very sharp leading edges, and a magnetic field running parallel to these edges. The spectral index between 2 and 6 cm in these line-brightened regions is near 1.0. The northeast subpeak has a very steep radio spectrum between 18 and 2 cm which is attributed to inverse Compton losses of the relativistic electrons on the infrared photons. The spectral indices in the southwest lobe lie in the range 0.9-1.5 except in its northern parts, where a much larger index is found. The northeast lobe radio emission could arise in either the cocoon of old jet material which has passed through the internal shock in the ejecta and blown out to either side, or in interstellar material compressed by a bow shock wave driven into the galactic ISM. 45 references

  12. A Laminar Model for the Magnetic Field Structure in Bow-Shock Pulsar Wind Nebulae

    Science.gov (United States)

    Bucciantini, N.

    2018-05-01

    Bow Shock Pulsar Wind Nebulae are a class of non-thermal sources, that form when the wind of a pulsar moving at supersonic speed interacts with the ambient medium, either the ISM or in a few cases the cold ejecta of the parent supernova. These systems have attracted attention in recent years, because they allow us to investigate the properties of the pulsar wind in a different environment from that of canonical Pulsar Wind Nebulae in Supernova Remnants. However, due to the complexity of the interaction, a full-fledged multidimensional analysis is still laking. We present here a simplified approach, based on Lagrangian tracers, to model the magnetic field structure in these systems, and use it to compute the magnetic field geometry, for various configurations in terms of relative orientation of the magnetic axis, pulsar speed and observer direction. Based on our solutions we have computed a set of radio emission maps, including polarization, to investigate the variety of possible appearances, and how the observed emission pattern can be used to constrain the orientation of the system, and the possible presence of turbulence.

  13. A 100 au Wide Bipolar Rotating Shell Emanating from the HH 212 Protostellar Disk: A Disk Wind?

    Science.gov (United States)

    Lee, Chin-Fei; Li, Zhi-Yun; Codella, Claudio; Ho, Paul T. P.; Podio, Linda; Hirano, Naomi; Shang, Hsien; Turner, Neal J.; Zhang, Qizhou

    2018-03-01

    HH 212 is a Class 0 protostellar system found to host a “hamburger”-shaped dusty disk with a rotating disk atmosphere and a collimated SiO jet at a distance of ∼400 pc. Recently, a compact rotating outflow has been detected in SO and SO2 toward the center along the jet axis at ∼52 au (0.″13) resolution. Here we resolve the compact outflow into a small-scale wide-opening rotating outflow shell and a collimated jet, with the observations in the same S-bearing molecules at ∼16 au (0.″04) resolution. The collimated jet is aligned with the SiO jet, tracing the shock interactions in the jet. The wide-opening outflow shell is seen extending out from the inner disk around the SiO jet and has a width of ∼100 au. It is not only expanding away from the center, but also rotating around the jet axis. The specific angular momentum of the outflow shell is ∼40 au km s‑1. Simple modeling of the observed kinematics suggests that the rotating outflow shell can trace either a disk wind or disk material pushed away by an unseen wind from the inner disk or protostar. We also resolve the disk atmosphere in the same S-bearing molecules, confirming the Keplerian rotation there.

  14. Assessment of Snow Status Changes Using L-HH Temporal-Coherence Components at Mt. Dagu, China

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2015-09-01

    Full Text Available Multitemporal Phased Array type L-band Synthetic Aperture Radar (PALSAR horizontally transmitted and horizontally received (HH coherence data was decomposed into temporal-coherence, spatial-coherence, and thermal noise components. The multitemporal data spanned between February and May of 2008, and consisted of two pairs of interferometric SAR (InSAR images formed by consecutive repeat passes. With the analysis of ancillary data, a snow increase process and a snow decrease process were determined. Then, the multiple temporal-coherence components were used to study the variation of thawing and freezing statuses of snow because the components can mostly reflect the temporal change of the snow that occurred between two data acquisitions. Compared with snow mapping results derived from optical images, the outcomes from the snow increase process and the snow decrease process reached an overall accuracy of 71.3% and 79.5%, respectively. Being capable of delineating not only the areas with or without snow cover but also status changes among no-snow, wet snow, and dry snow, we have developed a critical means to assess the water resource in alpine areas.

  15. Two Component Decomposition of Dual Polarimetric HH/VV SAR Data: Case Study for the Tundra Environment of the Mackenzie Delta Region, Canada

    Directory of Open Access Journals (Sweden)

    Tobias Ullmann

    2016-12-01

    Full Text Available This study investigates a two component decomposition technique for HH/VV-polarized PolSAR (Polarimetric Synthetic Aperture Radar data. The approach is a straight forward adaption of the Yamaguchi decomposition and decomposes the data into two scattering contributions: surface and double bounce under the assumption of a negligible vegetation scattering component in Tundra environments. The dependencies between the features of this two and the classical three component Yamaguchi decomposition were investigated for Radarsat-2 (quad and TerraSAR-X (HH/VV data for the Mackenzie Delta Region, Canada. In situ data on land cover were used to derive the scattering characteristics and to analyze the correlation among the PolSAR features. The double bounce and surface scattering features of the two and three component scattering model (derived from pseudo-HH/VV- and quad-polarized data showed similar scattering characteristics and positively correlated-R2 values of 0.60 (double bounce and 0.88 (surface scattering were observed. The presence of volume scattering led to differences between the features and these were minimized for land cover classes of low vegetation height that showed little volume scattering contribution. In terms of separability, the quad-polarized Radarsat-2 data offered the best separation of the examined tundra land cover types and will be best suited for the classification. This is anticipated as it represents the largest feature space of all tested ones. However; the classes “wetland” and “bare ground” showed clear positions in the feature spaces of the C- and X-Band HH/VV-polarized data and an accurate classification of these land cover types is promising. Among the possible dual-polarization modes of Radarsat-2 the HH/VV was found to be the favorable mode for the characterization of the aforementioned tundra land cover classes due to the coherent acquisition and the preserved co-pol. phase. Contrary, HH/HV-polarized and VV

  16. Femoral shaft bowing in the coronal plane has more significant effect on the coronal alignment of TKA than proximal or distal variations of femoral shape.

    Science.gov (United States)

    Kim, Jong-Min; Hong, Soo-Heon; Kim, Jong-Min; Lee, Bum-Sik; Kim, Dong-Eun; Kim, Kyung-Ah; Bin, Seong-Il

    2015-07-01

    The aim of this study was to determine (1) variations in the shape of the proximal, middle, and distal femur in a series of Korean patients who had undergone total knee arthroplasty (TKA), (2) the preoperative relationship between these three parameters and the distal valgus cutting angle referenced off the femoral intramedullary guide, and (3) whether there was any relationship between femoral bowing and variations in the shape of the proximal or distal femur in the coronal plane. The preoperative long-standing anteroposterior radiographs of 316 consecutive osteoarthritis patients who underwent primary TKA from 2009 to 2011 were examined. The femoral neck shaft angle, the femoral shaft bowing angle, and the mechanical lateral distal femoral angle were measured to assess the shape of the proximal, middle, and distal femur, respectively. The valgus cutting angle of the femur was defined as the angle between the distal anatomical and mechanical axes of the femur. The study population showed large variations in femoral shape. The mean femoral intramedullary guide angle was 6.5° ± 1.3° (range: 4°-13°). The femoral shaft bowing angle was the factor that showed the strongest correlation with this angle (P shaft angle showed no correlation (n.s.). The femoral shaft bowing angle showed a weak correlation with the mechanical lateral distal femoral angle (P = 0.001), but was not significantly correlated with the femoral neck shaft angle (n.s.). Apparent femoral bowing (>3° of lateral or medial bowing) was found in 42 (13.3 %) of cases (37 cases of lateral bowing and five of medial bowing). Cases with lateral apparent femoral bowing >3° had a distal cutting angle of 8.6° ± 2.2° relative to the femoral intramedullary guide. The femoral intramedullary guide angle was mainly influenced by femoral shaft bowing among femoral deformities in the coronal plane. Therefore, to increase the accuracy of distal femoral cut during TKA, it is necessary to confirm femoral

  17. Determination of trace elements in the human hair reference material, HH-I, by neutron activation analysis and atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Coetzee, P.; Pieterse, H.

    1986-01-01

    Analytical procedures are presented and problem areas identified with regard to the determination of trace elements in IAEA powdered human hair reference material, HH-I, of limited sample size (100-200 mg), by NAA and graphite furnace AAS. Results obtained for the twelve elements As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Sb, Se, and Zn studied in human hair and other biological reference material like orchard leaves, seaplant material, and copepod compare satisfactorily with the certified values

  18. Nonlinear wave-particle interaction upstream from the Earth's bow shock

    Directory of Open Access Journals (Sweden)

    C. Mazelle

    2000-01-01

    Full Text Available Well-defined ring-like backstreaming ion distributions have been recently reported from observations made by the 3DP/PESA-High analyzer onboard the WIND spacecraft in the Earth's foreshock at large distances from the bow shock, which suggests a local production mechanism. The maximum phase space density for these distributions remains localized at a nearly constant pitch-angle value for a large number of gyroperiods while the shape of the distribution remains very steady. These distributions are also observed in association with quasi-monochromatic low frequency (~ 50 mHz waves with substantial amplitude (δB/B>0.2. The analysis of the magnetic field data has shown that the waves are propagating parallel to the background field in the right-hand mode. Parallel ion beams are also often observed in the same region before the observation of both the ring-like distributions and the waves. The waves appear in cyclotron resonance with the ion parallel beams. We investigate first the possibility that the ion beams could provide the free energy source for driving an ion/ion instability responsible for the ULF wave occurrence. For that, we solve the wave dispersion relation with the observed parameters. Second, we show that the ring-like distributions could then be produced by a coherent nonlinear wave-particle interaction. It tends to trap the ions into narrow cells in velocity space centered on a well-defined pitch-angle, directly related to the saturation wave amplitude in the analytical theory. The theoretical predictions are in good quantitative agreement with the observations

  19. Ions upstream of the earth's bow shock: a theoretical comparison of alternative source populations

    International Nuclear Information System (INIS)

    Schwartz, S.J.; Thomsen, M.F.; Gosling, J.T.

    1983-01-01

    A theoretical framework is developed for studying trajectories of ions reflected or leaked upstream from the earth's bow shock and subject solely to the Lorentz force in a steady interplanetary magnetic field B and the V x B electric field. We include the effects of a sharp shock potential rise. Expressions are derived for the guiding center motion and gyromotion in a frame (the Hoffman-Teller frame) moving parallel to the shock surface with sufficient speed to transform the incident solar wind velocity into motion entirely along the interplanetary magnetic field: the appropriate equations are also provided to transform these motions back to the observer's frame. The utility of these expressions is illustrated by comparing the predicted upstream motions for four different source models for upstream ions: magnetic moment-conserving reflection of the solar wind ions, specular reflection of solar wind ions, magnetic moment-conserving leakage of magnetosheath ions, and leakage of magnetosheath ions parallel to the shock normal. This comparison reveals that, for identical geometries, the reflection models produce higher energies and/or gyromotion than do the leakage models. We further argue that in a single simple encounter with the shock, an ion should behave in an unmagnetized manner and hence should not conserve its magnetic moment. Conservation of magnetic moment, if it is to occur, would seem to require multiple encounters with the shock. We investigate the conditions under which such multiple encounters can occur and find that under most quasi-parallel geometries neither leaked nor reflected ions should probably conserve their magnetic moments

  20. Magnetic Field Orientation Effects on the Standoff Distance of Earth's Bow Shock

    Science.gov (United States)

    Cairns, Iver H.; Lyon, J. G.

    1996-01-01

    Three-dimensional, global MHD simulations of solar wind flow onto a prescribed magnetopause obstacle are used to show that a bow shock's nose location a(sub s), and the relative subsolar magnetosheath thickness Delta(sub ms)/a(sub mp) are strong functions of the IMF cone angle theta (between v(sub sw) and B(sub sw)) and the Alfven Mach number M(sub A). For a given M(sub A) the shock is more distant for higher theta (restricted to the interval 0-90deg by symmetries), while a(sub s)/a(sub mp) and Delta(sub ms/a(sub mp) increase with decreasing M(sub A) for theta greater than or approximately 20deg but decrease with decreasing M(sub A) for theta approximately Odeg. Large differences in Delta(sub ms/a(sub mp) are predicted between theta = Odeg and 90deg at low M(sub A), with smaller differences remaining even at M(sub A) approximately 10. The theta = Odeg results confirm and extend the previous work of Spreiter and Rizzi [1974]. The simulations show that successful models for the subsolar shock location cannot subsume the dependences on M(sub A) and theta into a sole dependence on M(ms). Instead, they confirm a recent prediction [Cairns and Grabbe, 1994] that a(sub s)/a(sub mp) and Delta(sub ms)/a(sub mp) should depend strongly on theta and M(sub A) for M(sub A) less than or approximately 10 (as well as on other MHD variables). Detailed comparisons between theory and data remain to be done. However, preliminary comparisons show good agreement, with distant shock locations found for low M(sub A) and large theta greater than or approximately 45deg and closer locations found for theta less than or approximately 20deg even at M/A approximately 8.

  1. Revisit the landscape of protonated water clusters H+(H2O)n with n = 10-17: An ab initio global search

    Science.gov (United States)

    Shi, Ruili; Li, Keyao; Su, Yan; Tang, Lingli; Huang, Xiaoming; Sai, Linwei; Zhao, Jijun

    2018-05-01

    Using a genetic algorithm incorporated with density functional theory, we explore the ground state structures of protonated water clusters H+(H2O)n with n = 10-17. Then we re-optimize the isomers at B97-D/aug-cc-pVDZ level of theory. The extra proton connects with a H2O molecule to form a H3O+ ion in all H+(H2O)10-17 clusters. The lowest-energy structures adopt a monocage form at n = 10-16 and core-shell structure at n = 17 based on the MP2/aug-cc-pVTZ//B97-D/aug-cc-pVDZ+ZPE single-point-energy calculation. Using second-order vibrational perturbation theory, we further calculate the infrared spectra with anharmonic correction for the ground state structures of H+(H2O)10-17 clusters at the PBE0/aug-cc-pVDZ level. The anharmonic correction to the spectra is crucial since it reproduces the experimental results quite well. The extra proton weakens the O-H bond strength in the H3O+ ion since the Wiberg bond order of the O-H bond in the H3O+ ion is smaller than that in H2O molecules, which causes a red shift of the O-H stretching mode in the H3O+ ion.

  2. Resolving the Polarized Dust Emission of the Disk around the Massive Star Powering the HH 80–81 Radio Jet

    Science.gov (United States)

    Girart, J. M.; Fernández-López, M.; Li, Z.-Y.; Yang, H.; Estalella, R.; Anglada, G.; Áñez-López, N.; Busquet, G.; Carrasco-González, C.; Curiel, S.; Galvan-Madrid, R.; Gómez, J. F.; de Gregorio-Monsalvo, I.; Jiménez-Serra, I.; Krasnopolsky, R.; Martí, J.; Osorio, M.; Padovani, M.; Rao, R.; Rodríguez, L. F.; Torrelles, J. M.

    2018-04-01

    Here we present deep (16 μJy beam‑1), very high (40 mas) angular resolution 1.14 mm, polarimetric, Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protostar driving the HH 80–81 radio jet. The observations clearly resolve the disk oriented perpendicularly to the radio jet, with a radius of ≃0.″171 (∼291 au at 1.7 kpc distance). The continuum brightness temperature, the intensity profile, and the polarization properties clearly indicate that the disk is optically thick for a radius of R ≲ 170 au. The linear polarization of the dust emission is detected almost all along the disk, and its properties suggest that dust polarization is produced mainly by self-scattering. However, the polarization pattern presents a clear differentiation between the inner (optically thick) part of the disk and the outer (optically thin) region of the disk, with a sharp transition that occurs at a radius of ∼0.″1 (∼170 au). The polarization characteristics of the inner disk suggest that dust settling has not occurred yet with a maximum dust grain size between 50 and 500 μm. The outer part of the disk has a clear azimuthal pattern but with a significantly higher polarization fraction compared to the inner disk. This pattern is broadly consistent with the self-scattering of a radiation field that is beamed radially outward, as expected in the optically thin outer region, although contribution from non-spherical grains aligned with respect to the radiative flux cannot be excluded.

  3. Clinicians' perceptions of usefulness of the PubMed4Hh mobile device application for clinical decision making at the point of care: a pilot study.

    Science.gov (United States)

    Gartrell, Kyungsook; Brennan, Caitlin W; Wallen, Gwenyth R; Liu, Fang; Smith, Karen G; Fontelo, Paul

    2018-05-08

    Although evidence-based practice in healthcare has been facilitated by Internet access through wireless mobile devices, research on the effectiveness of clinical decision support for clinicians at the point of care is lacking. This study examined how evidence as abstracts and the bottom-line summaries, accessed with PubMed4Hh mobile devices, affected clinicians' decision making at the point of care. Three iterative steps were taken to evaluate the usefulness of PubMed4Hh tools at the NIH Clinical Center. First, feasibility testing was conducted using data collected from a librarian. Next, usability testing was carried out by a postdoctoral research fellow shadowing clinicians during rounds for one month in the inpatient setting. Then, a pilot study was conducted from February, 2016 to January, 2017, with clinicians using a mobile version of PubMed4Hh. Invitations were sent via e-mail lists to clinicians (physicians, physician assistants and nurse practitioners) along with periodic reminders. Participants rated the usefulness of retrieved bottom-line summaries and abstracts and indicated their usefulness on a 7-point Likert scale. They also indicated location of use (office, rounds, etc.). Of the 166 responses collected in the feasibility phase, more than half of questions (57%, n = 94) were answerable by both the librarian using various resources and by the postdoctoral research fellow using PubMed4Hh. Sixty-six questions were collected during usability testing. More than half of questions (60.6%) were related to information about medication or treatment, while 21% were questions regarding diagnosis, and 12% were specific to disease entities. During the pilot study, participants reviewed 34 abstracts and 40 bottom-line summaries. The abstracts' usefulness mean scores were higher (95% CI [6.12, 6.64) than the scores of the bottom-line summaries (95% CI [5.25, 6.10]). The most frequent reason given was that it confirmed current or tentative diagnostic or

  4. Bow shock specularly reflected ions in the presence of low-frequency electromagnetic waves: a case study

    Directory of Open Access Journals (Sweden)

    K. Meziane

    2004-07-01

    Full Text Available An energetic ion (E≤40 event observed by the CLUSTER/CIS experiment upstream of the Earth's bow shock is studied in detail. The ion event is observed in association with quasi-monochromatic ULF MHD-like waves, which we show modulate the ion fluxes. According to three statistical bow shock position models, the Cluster spacecrafts are located at ~0.5 Re from the shock and the averaged bow shock θBn0 is about ~30°. The analysis of the three-dimensional angular distribution indicates that ions propagating roughly along the magnetic field direction are observed at the onset of the event. Later on, the angular distribution is gyrophase-bunched and the pitch-angle distribution is peaked at α0~θBn0, consistent with the specular reflection production mechanism. The analysis of the waves shows that they are left-handed in the spacecraft frame of reference (right-handed in the solar wind frame and propagate roughly along the ambient magnetic field; we have found that they are in cyclotron-resonance with the field-aligned beam observed just upstream. Using properties of the waves and particles, we explain the observed particle flux-modulation in the context of θBn changes at the shock caused by the convected ULF waves. We have found that the high count rates coincide with particles leaving the shock when θBn angles are less than ~40°, consistent with the specular reflection hypothesis as the production mechanism of ions.

  5. A Cometary Bow Shock and Mid-Infrared Emission Variations Revealed in Spitzer Observations of HD 34078 and IC 405

    OpenAIRE

    France, Kevin; McCandliss, Stephan R.; Lupu, Roxana E.

    2006-01-01

    We present new infrared observations of the emission/reflection nebula IC 405 obtained with the Spitzer Space Telescope. Infrared images in the four IRAC bands (3.6, 4.5, 5.8, and 8.0 um) and two MIPS bands (24 and 70 um) are complemented by IRS spectroscopy (5-30 um) of two nebular filaments. The IRAC (8.0 um) and MIPS imaging shows evidence of a bow shock associated with the runaway O9.5V star, HD 34078, created by the interaction between the star and nebular material. The ratio of emission...

  6. Frequency of occurrence of knock-kneed and bow-legged knees for children and young people in school age

    OpenAIRE

    Siminska, Joanna; Bukowska, Weronika; Ratuszek–Sadowska, Dorota; Nowacka, Krystyna; Hagner, Wojciech

    2017-01-01

    Siminska Joanna, Bukowska Weronika, Ratuszek–Sadowska Dorota, Nowacka Krystyna, Hagner Wojciech. FREQUENCY OF OCCURRENCE OF KNOCK-KNEED AND BOW-LEGGED KNEES FOR CHILDREN AND YOUNG PEOPLE IN SCHOOL AGE. Journal of Education, Health and Sport. 2017;7(6):317-322. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.814970 http://ojs.ukw.edu.pl/index.php/johs/article/view/4545 The journal has had 7 points in Ministry of Science and Higher Education parametric eval...

  7. A Lower-Limb Training Program to Improve Balance in Healthy Elderly Women Using the T-Bow (R) Device

    OpenAIRE

    Chulvi-Medrano, Iván; Colado, Juan Carlos; Pablos Abella, Carlos; Naclerio Ayllón, Fernando José; Garcia-Massó, Xavier

    2009-01-01

    Ageing impairs balance, which increases the risk of falls. Fall-related injuries are a serious health problem associated with dependency and disability in the elderly and results in high costs to public health systems. This study aims to determine the effects of a training program to develop balance using a new device called the T-Bow (R). A total of 28 women > 65 years were randomly assigned to an experimental group (EG) (n = 18; 69.50 [0.99] years), or a control group (CG) (n = 10; 70.70 [2...

  8. Hydrologic and Isotopic Sensitivity of Alpine Lakes to Climate Change in the Medicine Bow Mountains, Wyoming

    Science.gov (United States)

    Liefert, D. T.; Shuman, B. N.; Mercer, J.; Parsekian, A.; Williams, D. G.

    2017-12-01

    Climate reconstructions show that global average temperatures were 0.5°C higher than today during the mid-Holocene, falling well within projections for increases in global average temperature presented in the latest Intergovernmental Panel on Climate Change report. Despite the consensus for the prediction of a warmer climate, however, it is unclear how snowmelt from high-elevation watersheds will be affected by such a change. Snowmelt contributes substantially to major rivers in the western United States, and much of the water flows through lakes in the highest-elevation watersheds. Our water balance models show that modern alpine lakes with seasonably unstable water levels can desiccate primarily through groundwater outflow, resulting in increased groundwater storage that likely sustains baseflow in mountain streams once snowmelt has subsided in late summer. However, contribution of freshwater from alpine lakes to streams may vary over time as changes in climate alters snowpack, rates of evaporation, and the abundance of snowmelt-fed lakes. As such, alpine lakes with seasonally unstable water levels today may have dried out entirely during the mid-Holocene warm period and may dry out in the future as temperatures increase. To investigate the response of alpine lakes to temperatures of the mid-Holocene, we collected 9 sediment cores from closed-basin alpine lakes in the Medicine Bow Mountains of southern Wyoming that lose most their volumes each summer. We use radiocarbon-dating of charcoal in basal sediments to determine lake formation age, abundance of conifer needles to infer relative forest cover, and a δ18O carbonate record to determine changes in the ratio of evaporation to precipitation in an alpine lake that existed throughout the Holocene. Warming likely changed watershed hydrology through a) decreased snowpack and earlier snowmelt, b) increased evaporation, and c) increased transpiration associated with expanded forest cover and longer growing seasons

  9. ROTATION AND OUTFLOW MOTIONS IN THE VERY LOW-MASS CLASS 0 PROTOSTELLAR SYSTEM HH 211 AT SUBARCSECOND RESOLUTION

    International Nuclear Information System (INIS)

    Lee, C.-F.; Hirano, Naomi; Ho, Paul T. P.; Shang, Hsien; Palau, Aina; Bourke, Tyler L.; Zhang Qizhou

    2009-01-01

    HH 211 is a nearby young protostellar system with a highly collimated jet. We have mapped it in 352 GHz continuum, SiO (J = 8 - 7), and HCO + (J = 4 - 3) emission at up to ∼0.''2 resolution with the Submillimeter Array (SMA). The continuum source is now resolved into two sources, SMM1 and SMM2, with a separation of ∼ 84 AU. SMM1 is seen at the center of the jet, probably tracing a (inner) dusty disk around the protostar driving the jet. SMM2 is seen to the southwest of SMM1 and may trace an envelope-disk around a small binary companion. A flattened envelope-disk is seen in HCO + around SMM1 with a radius of ∼ 80 AU perpendicular to the jet axis. Its velocity structure is consistent with a rotation motion and can be fitted with a Keplerian law that yields a mass of ∼50 ± 15 M Jup (a mass of a brown dwarf) for the protostar. Thus, the protostar could be the lowest mass source known to have a collimated jet and a rotating flattened envelope-disk. A small-scale (∼200 AU) low-speed (∼2 km s -1 ) outflow is seen in HCO + around the jet axis extending from the envelope-disk. It seems to rotate in the same direction as the envelope-disk and may carry away part of the angular momentum from the envelope-disk. The jet is seen in SiO close to ∼100 AU from SMM1. It is seen with a 'C-shaped' bending. It has a transverse width of ∼ -1 . A possible velocity gradient is seen consistently across its innermost pair of knots, ∼0.5 km s -1 at ∼10 AU, consistent with the sense of rotation of the envelope-disk. If this gradient is an upper limit of the true rotational gradient of the jet, then the jet carries away a very small amount of angular momentum of ∼ -1 and thus must be launched from the very inner edge of the disk near the corotation radius.

  10. Status and perspectives for the Pd-103 radioactive seeds production at the cyclotron IFIN-HH from Bucharest

    International Nuclear Information System (INIS)

    Dudu, D.; Popa, V.; Racolta, P.M.; Tetcu, N.; Voiculescu, Dana

    2001-01-01

    Historically, 103 Pb, a short-lived isotope for permanent implant treatment of early stage prostate cancer, was generated via the 102 Pd(n,γ) 103 Pd reaction which relied on the availability of 1% naturally abundant 102 Pd in an enriched form and its moderately high neutron capture cross section. For the last 12 years, the accelerator production method for 103 Pd has been based on the irradiation of the rhodium metal with rather low energy protons via the reaction 103 Rh(p,n) 103 Pd. Big corporations from USA operate more than 10 dedicated accelerators to produce this nuclide. The prostate cancer market with 180,000 new cases reported annually justifies the effort for this radionuclide production. Recently, a manufacture in Europe also brought the USA patented type of 103 Pd seed implants on the world market. Our interest for this radioisotope production was started in 2000, as a result of the demand of two big hospitals from Bucharest and the opportunity to participate in a research programme (333-F2-RC 832) co-ordinated by the IAEA in Vienna. The U-120 Cyclotron, made in 1956 and brought from Russia, was quite a reliable machine. The accelerator is a classical cyclotron with adjustable energy. Now at the level of our technology, we can maintain it by ourselves and operate it quite independently. The experiments for the first year were focused on obtaining homemade data on cross-section, thick target yields and possible contaminants for the nuclear reaction 103 Rh (p,n) 103 Pb in the proton energy region 5-14 MeV. The experiments were performed at our Van de Graaff HV Tandem FN 15 accelerator (8 MV on terminal) by using proton beams up to 14 MeV with a current intensity of 100 nA. Design and adaptation of a dedicated beam line at IFIN-HH Cyclotron for the 103 production was a priority in our work planning for the first year

  11. Ion distribution dynamics near the Earth's bow shock: first measurements with the 2D ion energy spectrometer CORALL on the INTERBALL/Tail-probe satellite

    Directory of Open Access Journals (Sweden)

    Yu. I. Yermolaev

    1997-05-01

    Full Text Available The dynamics of the ion distribution function near the Earth's bow shock is studied on the basis of quasi-3D measurements of ion energy spectra in the range of 30–24200 eV/q with the Russian-Cuban CORALL instrument on the INTERBALL/Tail-probe satellite. The instrument was designed for observations of magnetospheric plasma and measures ions, in an angular range of 36°–144° from the Earth-Sun direction. Ion populations generated by the Earth bow shock are often observed upstream from the bow shock. In the solar-wind stream compressed and heated by the passing of very dense magnetic cloud (CME, two types of these ion populations were measured upstream and before the bow shock crossing on 25 August 1995 at 07:37 UT. Both populations were observed in the energy range above 2 keV. At ~06:20 UT, when the angle between the direction of the interplanetary magnetic field and normal to the bow shock VBn was ≃ 43° the instrument observed a narrow, fast (~800 km/s field-aligned beam moving from the Earth. At ~07:30, when Bn ≃ 28°, the wide ion pitch-angle distribution was observed. A similar suprathermal ion population is observed in the magnetosheath simultaneously with the solar-wind ion population being heated and deflected from the Sun-Earth direction. The similarity of observations during the mentioned time-interval and under usual solar-wind conditions allows us to conclude that types of suprathermal ion populations upstream and downstream from the bow shock do not depend on the solar-wind disturbance generated by magnetic cloud.

  12. Recent H-alpha Results on Pulsar B2224+65’s Bow-Shock Nebula, the “Guitar”

    Directory of Open Access Journals (Sweden)

    Timothy Dolch

    2016-09-01

    Full Text Available We used the 4 m Discovery Channel Telescope (DCT at Lowell observatory in 2014 to observe the Guitar Nebula, an Hα bow-shock nebula around the high-velocity radio pulsar B2224+65. Since the nebula's discovery in 1992, the structure of the bow-shock has undergone significant dynamical changes. We have observed the limb structure, targeting the “body” and “neck” of the guitar. Comparing the DCT observations to 1995 observations with the Palomar 200-inch Hale telescope, we found changes in both spatial structure and surface brightness in the tip, head, and body of the nebula.

  13. Risk Analysis on Leakage Failure of Natural Gas Pipelines by Fuzzy Bayesian Network with a Bow-Tie Model

    Directory of Open Access Journals (Sweden)

    Xian Shan

    2017-01-01

    Full Text Available Pipeline is the major mode of natural gas transportation. Leakage of natural gas pipelines may cause explosions and fires, resulting in casualties, environmental damage, and material loss. Efficient risk analysis is of great significance for preventing and mitigating such potential accidents. The objective of this study is to present a practical risk assessment method based on Bow-tie model and Bayesian network for risk analysis of natural gas pipeline leakage. Firstly, identify the potential risk factors and consequences of the failure. Then construct the Bow-tie model, use the quantitative analysis of Bayesian network to find the weak links in the system, and make a prediction of the control measures to reduce the rate of the accident. In order to deal with the uncertainty existing in the determination of the probability of basic events, fuzzy logic method is used. Results of a case study show that the most likely causes of natural gas pipeline leakage occurrence are parties ignore signage, implicit signage, overload, and design defect of auxiliaries. Once the leakage occurs, it is most likely to result in fire and explosion. Corresponding measures taken on time will reduce the disaster degree of accidents to the least extent.

  14. Occurrence of high-beta superthermal plasma events in the close environment of Jupiter's bow shock as observed by Ulysses

    International Nuclear Information System (INIS)

    Marhavilas, P. K.; Sarris, E. T.; Anagnostopoulos, G. C.

    2011-01-01

    The ratio of the plasma pressure to the magnetic field pressure (or of their energy densities) which is known as the plasma parameter 'beta'(β) has important implications to the propagation of energetic particles and the interaction of the solar wind with planetary magnetospheres. Although in the scientific literature the contribution of the superthermal particles to the plasma pressure is generally assumed negligible, we deduced, by analyzing energetic particles and magnetic field measurements recorded by the Ulysses spacecraft, that in a series of events, the energy density contained in the superthermal tail of the particle distribution is comparable to or even higher than the energy density of the magnetic field, creating conditions of high-beta plasma. More explicitly, in this paper we analyze Ulysses/HI-SCALE measurements of the energy density ratio (parameter β ep ) of the energetic ions'(20 keV to ∼5 MeV) to the magnetic field's in order to find occurrences of high-beta (β ep >1) superthermal plasma conditions in the environment of the Jovian magnetosphere, which is an interesting plasma laboratory and an important source of emissions in our solar system. In particular, we examine high-beta ion events close to Jupiter's bow shock, which are produced by two processes: (a) bow shock ion acceleration and (b) ion leakage from the magnetosphere.

  15. Anti-slamming bulbous bow and tunnel stern applications on a novel Deep-V catamaran for improved performance

    Directory of Open Access Journals (Sweden)

    Mehmet Atlar

    2013-06-01

    Full Text Available While displacement type Deep-V mono hulls have superior seakeeping behaviour at speed, catamarans typically have modest behaviour in rough seas. It is therefore a logical progression to combine the superior seakeeping performance of a displacement type Deep-V mono-hull with the high-speed benefits of a catamaran to take the advantages of both hull forms. The displacement Deep-V catamaran concept was developed in Newcastle University and Newcastle University's own multi-purpose research vessel, which was launched in 2011, pushed the design envelope still further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. This paper presents the hullform development of this unique vessel to understand the contribution of the novel bow and stern features on the performance of the Deep-V catamaran. The study is also a further validation of the hull resistance by using advanced numerical analysis methods in conjunction with the model test. An assessment of the numerical predictions of the hull resistance is also made against physical model test results and shows a good agreement between them.

  16. Origin of 30 approximately 100 keV protons observed in the upstream region of the earth's bow shock

    International Nuclear Information System (INIS)

    Terasawa, T.

    1979-01-01

    A Fermi-type acceleration model is constructed to explain the origin of energetic protons (30 approximately 100 keV) which have been observed upstream of the bow shock. It is shown that the suprathermal protons (with energy of several keV) can be accelerated up to several tens of keV through the Fermi-type process in which the reflection at the shock front and the scattering in the upstream region are coupled. The efficiency of the scattering process is estimated by using the results of Barnes' quasilinear treatment of the wave excitation. The resultant energy spectrum and flux intensity (10 3 approximately 10 4 protons/(cm 2 s ster keV) in 32 approximately 45.3 keV) are consistent with the observation, and the softening of the energy spectrum observed in the dawn region can be explained by the decrease in the efficiency of the acceleration process in the dawn region due to the curvature of the bow shock and the reduction of shock strength. The spatial distribution of the flux predicted by the model is also consistent with the observation. In view of these consistencies of the Fermi-type acceleration process is suggested as a possible candidate mechanism to explain the upstream protons although it is not intended to exclude other possibilities. (author)

  17. Features in the Behavior of the Solar Wind behind the Bow Shock Front near the Boundary of the Earth's Magnetosphere

    Science.gov (United States)

    Grib, S. A.; Leora, S. N.

    2017-12-01

    Macroscopic discontinuous structures observed in the solar wind are considered in the framework of magnetic hydrodynamics. The interaction of strong discontinuities is studied based on the solution of the generalized Riemann-Kochin problem. The appearance of discontinuities inside the magnetosheath after the collision of the solar wind shock wave with the bow shock front is taken into account. The propagation of secondary waves appearing in the magnetosheath is considered in the approximation of one-dimensional ideal magnetohydrodynamics. The appearance of a compression wave reflected from the magnetopause is indicated. The wave can nonlinearly break with the formation of a backward shock wave and cause the motion of the bow shock towards the Sun. The interaction between shock waves is considered with the well-known trial calculation method. It is assumed that the velocity of discontinuities in the magnetosheath in the first approximation is constant on the average. All reasonings and calculations correspond to consideration of a flow region with a velocity less than the magnetosonic speed near the Earth-Sun line. It is indicated that the results agree with the data from observations carried out on the WIND and Cluster spacecrafts.

  18. Analytic models for beam propagation and far-field patterns in slab and bow-tie x-ray lasers

    International Nuclear Information System (INIS)

    Chandler, E.A.

    1994-06-01

    Simplified analytic models for beam propagation in slab and bow-tie x-ray lasers yield convenient expressions that provide both a framework for guidance in computer modeling and useful approximates for experimenters. In unrefracted bow-tie lasers, the laser shape in conjunction with the nearly-exponential weighting of rays according to their length produces a small effective aperture for the signal. We develop an analytic expression for the aperture and the properties of the far-field signal. Similarly, we develop the view that the far-field pattern of refractive slab lasers is the result of effective apertures that are created by the interplay of refraction and exponential amplification. We present expressions for the size of this aperture as a function of laser parameters as well as for the intensity and position of the far-field lineout. This analysis also yields conditions for the refraction limit in slab lasers and an estimate for the signal loss due to refraction

  19. The jumps of physical quantities at fast shocks under pressure anisotropy: theory versus observations at the bow shock

    International Nuclear Information System (INIS)

    Vogl, D.F.

    2000-10-01

    The interaction of the solar wind with magnetized planets leads to the formation of the so-called magnetosphere, a cavity generated by the geomagnetic field. The supersonic, superalfvenic, and magnetized solar wind flow interacting with blunt bodies produces a detached bow shock, separating the solar wind from the magnetosheath, the region between the shock wave and the magnetopause. On approach to a planetary obstacle, the solar wind becomes subsonic at the bow shock and then flows past the planet in the magnetosheath. At the bow shock, the plasma parameters and the magnetic field strength change from upstream to downstream, i.e., an increase of plasma density, temperature, pressure, and magnetic field strength, and a decrease of the velocity across the shock. In this PhD thesis we mainly concentrate on the variations of all physical quantities across the bow shock taking into account pressure anisotropy, which is an important feature in space plasma physics and observed by various spacecraft missions in the solar wind as well as in the magnetosheath. Dealing with anisotropic plasma conditions, one has to introduce the so-called pressure tensor, characterized by two scalar pressures, the pressure perpendicular (P p erp) and the pressure parallel (P p arallel) with respect to the magnetic field and in general one speaks of anisotropic conditions for P p erp is not P p arallel. Many spacecraft observations of the solar wind show P p arallel > P p erp, whereas observations of the magnetosheath show the opposite case, P p arallel p erp. Therefore, dissipation of kinetic energy into thermal energy plays an important role in studying the variations of the relevant physical quantities across the shock. It has to be mentioned that planetary bow shocks are good examples for fast MHD shock waves. Therefore, the basic equations for describing the changes across the shock can be obtained by integrating the MHD equations in conservative form. We note that these equations, the

  20. High resolution HH-XRF scanning and XRD modelling as a tool in sedimentological analysis - A case study from the Enreca-3 core, Bach Long Vi Island, Vietnam

    Science.gov (United States)

    Rizzi, Malgorzata; Hemmingsen Schovsbo, Niels; Korte, Christoph; Bryld Wessel Fyhn, Michael

    2017-04-01

    To improve the understanding and interpretation of the depositional environment of a late Oligocene lacustrine organic rich oil-prone source rock succession, 2464 hand held (HH)-XRF measurements were made systematically on the 500 m long, continuous core from the fully cored Enreca-3 well. This core, drilled on the remote Bach Long Vi Island, northern Gulf of Tonkin, offshore Vietnam, represents a deep lake succession alternating between lacustrine pelagic dominated sediments interrupted by hyperpycnal turbidites, high density turbidites and debris flows [1, 2]. From a combined HH-XRF-XRD data set, multivariate data analysis and regression models are used to type the rock and to predict the XRD mineral composition based on HH-XRF composition. The rock types and the modelled mineral composition highlight the geochemical variations of the sediment and allows for direct comparison with sedimentological processes and facies changes. The modeling also depicts the cyclic alteration of rock types that are present on many different scales ranging from centimeters to hundreds of meters [1, 2]. The sedimentological and geochemical variations observed throughout the cored section reflects fluctuating paleoclimate, tectonism and hinterland condition controlling the depositional setting, which may provide a deeper understanding of the deposition of this and similar Paleogene syn-rift succession in the South China Sea region. It allows furthermore the development of a more generalized depositional model relevant for other deep-lacustrine syn-rift basins. [1] Petersen et al. (2014) Journal of Petroleum Geology, 37: 373-389. [2] Hovikoski et al. (2016) Journal of Sedimentary Research, 86(8): 982-1007.

  1. Deep VLA images of the HH 124 IRS radio cluster and its surroundings, and a new determination of the distance to NGC 2264

    Energy Technology Data Exchange (ETDEWEB)

    Dzib, Sergio A. [Max Planck Institut für Radioastronomie, Auf del Hügel 69, D-53121 Bonn (Germany); Loinard, Laurent; Rodríguez, Luis F. [Centro de Radioastronomía y Astrofísica, Universidad NacionalAutónoma de México Apartado Postal 3-72, 58090 Morelia, Michoacán (Mexico); Galli, Phillip, E-mail: sdzib@mpifr-bonn.mpg.de [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, 05508-900 São Paulo, SP (Brazil)

    2014-06-20

    We present new deep (σ ∼ 6 μJy) radio images of the HH 124 IRS radio cluster at 4.8 and 7.5 GHz. We detect a total of 50 radio sources, most of them compact. Variability and spectral indices were analyzed in order to determine the nature of the sources and of their radio emission. A proper motion study was also performed for several of these radio sources using previously reported radio observations. Our analysis shows that 11 radio sources can be associated with Galactic objects, most of them probably young stars. Interestingly, 8 of these sources are in an area less than 1 arcmin{sup 2} in size. The importance of such compact clusters resides in that all of its members can be observed in a single pointing with most telescopes and are, therefore, ideal for multi-wavelength studies of variability. Another 4 of the detected sources are clearly extragalactic. Finally, we propose from statistical arguments that out of the remaining sources, about 10 are Galactic, but our study does not allow us to identify which of the sources fall in that specific category. The relatively large proper motions observed for the sources in HH 124 IRS suggest that this region is located at about 400 pc from the Sun. This is significantly smaller than the ∼800-900 pc distance usually assigned to the nearby open cluster NGC 2264 with which HH 124 is thought to be associated. However, a reanalysis of the Hipparcos parallaxes for members of NGC 2264, a convergent point approach, and a kinematic analysis all argue in favor of a distance of the order of 400 pc for NGC 2264 as well.

  2. Study of the physics potential of the FCC-hh machine to measure the coupling of the Higgs boson to b quarks

    CERN Document Server

    Rodríguez, Arturo

    2016-01-01

    The FCC project as well as the Pythia + Delphes analysis within the FCC software are introduced. The ROOT analysis carried out to reconstruct main observables, such the invariant mass of the bb system, transverse mass and momentum of the W boson together with the lepton pT and distribution is explained. The resulting reconstructed invariant mass of the bb system showed a peak near the 125 GeV in correspondence with the Higgs boson. Future steps towards estimating the physics potential of the FCC-hh machine in this channel are discussed.

  3. Observations and measurements of dynamic effects due to beam-beam interactions in the LHC and extrapolation to the FCC-hh

    CERN Document Server

    Goncalves Jorge, Patrik

    The Future Circular hadron-hadron Collider (FCC-hh) is a design study for a 100 TeV centre-of-mass energy. The dynamics of the beams in such a collider poses many challenges, in particular the amount of energy stored in each beam (8.4 GJ) makes them very destructive and therefore requires a tight control of the machine and beam parameters during the full cycle in order to avoid damages and reach the collider designed performances. The FCC-hh features an increase of the beam brightness during the cycle due to the presence of synchrotron radiation damping at high energy. As a result, the electromagnetic forces that the two beams exert on each other, the so-called beam-beam forces, are enhanced and might become an issue for the safe operation of the machine. In this new regime, the impact of the beam-beam interaction on the optics becomes non-negligible. In this master thesis, for the first time, the impact of the beam-beam interaction on the optics ($\\beta$-beating) is measured in a hadron collider (LHC). The e...

  4. Development of design technology on thermal-hydraulic performance in tight-lattice rod bundles. II-rod bowing effect on boiling transition

    International Nuclear Information System (INIS)

    Liu, Wei; Tamai, Hidesada; Kureta, Masatoshi; Ohnuki, Akira; Takase, Kazuyuki; Akimoto, Hajime

    2007-01-01

    A thermal-hydraulic feasibility project for an Innovative Water Reactor for Flexible fuel cycle (FLWR) has been performed since 2002. In this R and D project, large-scale thermal-hydraulic tests, several model experiments and development of advanced numerical analysis codes have been carried out. In this paper, we will describe the critical power characteristics in a 37-rod tight-lattice bundle with rod-bowing under both steady and transient states. It is observed that no matter it is run under a steady or a transient state, boiling transition (BT) always occurs axially at exit elevation of upper high-heat-flux region and transversely in the central area of the bundle. Steady critical power increases monotonically with the increase of mass velocity, with the decrease of inlet water temperature and with the decrease of exit pressure. These trends are same as those in the base case test without rod-bowing. The steady critical power with rod-bowing is about 10% lower than that without rod-bowing. For the postulated power increase and flow decrease cases that may be possibly met in a normal operation of the FLWR, it is confirmed that no BT occurs when Initial Critical Power Ratio (ICPR) is 1.3. Moreover, when the transitions are run under severer ICPR that causes BT, the transient critical powers are generally same as the steady ones. The experiments are analyzed with TRAC-BF1 code. The TRAC-BF1 code shows good prediction for the occurrence or the non occurrence of the BT and predicts the BT starting time within the accuracy of critical power correlation. Traditional quasi - steady state prediction of the transient BT is confirmed being applicable for the postulated abnormal transient processes in the tight lattice bundle with rod - bowing. (author)

  5. Remote sensing of local structure of the quasi-perpendicular Earth's bow shock by using field-aligned beams

    Directory of Open Access Journals (Sweden)

    B. Miao

    2009-03-01

    Full Text Available Field-aligned ion beams (FABs originate at the quasi-perpendicular Earth's bow shock and constitute an important ion population in the foreshock region. The bulk velocity of these FABs depends significantly on the shock normal angle, which is the angle between shock normal and upstream interplanetary magnetic field (IMF. This dependency may therefore be taken as an indicator of the local structure of the shock. Applying the direct reflection model to Cluster measurements, we have developed a method that uses proton FABs in the foreshock region for remote sensing of the local shock structure. The comparison of the model results with the multi-spacecraft observations of FAB events shows very good agreement in terms of wave amplitude and frequency of surface waves at the shock front.

  6. Electrostatic quasi-monochromatic waves in the downstream region of the Earth's bow shock based on Geotail observations

    Science.gov (United States)

    Shin, K.; Kojima, H.; Matsumoto, H.; Mukai, T.

    2007-02-01

    Geotail plasma wave observations show the existence of intense electrostatic quasi-monochromatic (EQM) waves in the downstream region of the Earth's bow shock. They oscillate parallel to the ambient magnetic field and appear at frequencies between the electron plasma and ion plasma frequencies. Although these waves have been believed to be Doppler-shifted ion acoustic waves, the typical plasma parameters observed in the downstream region do not support the generation conditions for ion acoustic waves. In this paper, the existence of cold electron beam-like components accompanying EQM waves is considered based on waveform and statistical analyses. Linear dispersion analyses using realistic plasma parameters revealed that the cold electron beams cause destabilization of electron acoustic waves at frequencies consistent with those of observed EQM waves. The results of observations and linear analyses suggest that EQM waves are generated by the destabilization of the electron acoustic mode.

  7. ULF Waves Upstream from Planetary Bow Shocks: Application to the Interball-Tail Observations at the Earth

    International Nuclear Information System (INIS)

    Trotignon, J.G.; Rauch, J.L.; Klimov, S.; Nozdrachev, M.; Romanov, S.; Savin, S.; Skalsky, A.; Blecki, J.; Juchniewicz, J.; Amata, E.

    1999-01-01

    One of the outstanding problems in solar system plasma physics is the morphology of planetary and cometary foreshocks. A large variety of electron and ion velocity distribution functions, as well as electrostatic and electromagnetic waves phenomena, are indeed currently observed in these regions located upstream from, and magnetically connected to, bow shocks. Foreshocks being complex and highly dynamic, it is not easy to get a comprehensive description of them. Nevertheless, simple geometrical considerations can be of help to order foreshock structures. In light of the great number of results obtained in planetary foreshocks, which are briefly reviewed, we present an ongoing study of the upstream waves observed by the INTERBALL-TAIL magnetometers in the Ultra Low Frequency range. (author)

  8. Feasibility evaluation of x-ray imaging for measurement of fuel rod bowing in CFTL test bundles

    International Nuclear Information System (INIS)

    Baker, S.P.

    1980-06-01

    The Core Flow Test Loop (CFTL) is a high temperature, high pressure, out-of-reactor helium-circulating system. It is designed for detailed study of the thermomechanical performance, at prototypic steady-state and transient operating conditions, of electrically heated rods that simulate segments of core assemblies in the Gas-Cooled Fast Breeder reactor demonstration plant. Results are presented of a feasibility evaluation of x-ray imaging for making measurements of the displacement (bowing) of fuel rods in CFTL test bundles containing electrically heated rods. A mock-up of a representative CFTL test section consisting of a test bundle and associated piping was fabricated to assist in this evaluation

  9. Oxidation of graphene ‘bow tie’ nanofuses for permanent, write-once-read-many data storage devices

    International Nuclear Information System (INIS)

    Pearson, A C; Jamieson, S; Davis, R C; Linford, M R; Lunt, B M

    2013-01-01

    We have fabricated nanoscale fuses from CVD graphene sheets with a ‘bow tie’ geometry for write-once-read-many data storage applications. The fuses are programmed using thermal oxidation driven by Joule heating. Fuses that were 250 nm wide with 2.5 μm between contact pads were programmed with average voltages and powers of 4.9 V and 2.1 mW, respectively. The required voltages and powers decrease with decreasing fuse sizes. Graphene shows extreme chemical and electronic stability; fuses require temperatures of about 400 °C for oxidation, indicating that they are excellent candidates for permanent data storage. To further demonstrate this stability, fuses were subjected to applied biases in excess of typical read voltages; stable currents were observed when a voltage of 10 V was applied to the devices in the off state and 1 V in the on state for 90 h each. (paper)

  10. Oxidation of graphene ‘bow tie’ nanofuses for permanent, write-once-read-many data storage devices

    Science.gov (United States)

    Pearson, A. C.; Jamieson, S.; Linford, M. R.; Lunt, B. M.; Davis, R. C.

    2013-04-01

    We have fabricated nanoscale fuses from CVD graphene sheets with a ‘bow tie’ geometry for write-once-read-many data storage applications. The fuses are programmed using thermal oxidation driven by Joule heating. Fuses that were 250 nm wide with 2.5 μm between contact pads were programmed with average voltages and powers of 4.9 V and 2.1 mW, respectively. The required voltages and powers decrease with decreasing fuse sizes. Graphene shows extreme chemical and electronic stability; fuses require temperatures of about 400 °C for oxidation, indicating that they are excellent candidates for permanent data storage. To further demonstrate this stability, fuses were subjected to applied biases in excess of typical read voltages; stable currents were observed when a voltage of 10 V was applied to the devices in the off state and 1 V in the on state for 90 h each.

  11. Large Scale Earth's Bow Shock with Northern IMF as Simulated by PIC Code in Parallel with MHD Model

    Science.gov (United States)

    Baraka, Suleiman

    2016-06-01

    In this paper, we propose a 3D kinetic model (particle-in-cell, PIC) for the description of the large scale Earth's bow shock. The proposed version is stable and does not require huge or extensive computer resources. Because PIC simulations work with scaled plasma and field parameters, we also propose to validate our code by comparing its results with the available MHD simulations under same scaled solar wind (SW) and (IMF) conditions. We report new results from the two models. In both codes the Earth's bow shock position is found to be ≈14.8 R E along the Sun-Earth line, and ≈29 R E on the dusk side. Those findings are consistent with past in situ observations. Both simulations reproduce the theoretical jump conditions at the shock. However, the PIC code density and temperature distributions are inflated and slightly shifted sunward when compared to the MHD results. Kinetic electron motions and reflected ions upstream may cause this sunward shift. Species distributions in the foreshock region are depicted within the transition of the shock (measured ≈2 c/ ω pi for Θ Bn = 90° and M MS = 4.7) and in the downstream. The size of the foot jump in the magnetic field at the shock is measured to be (1.7 c/ ω pi ). In the foreshocked region, the thermal velocity is found equal to 213 km s-1 at 15 R E and is equal to 63 km s -1 at 12 R E (magnetosheath region). Despite the large cell size of the current version of the PIC code, it is powerful to retain macrostructure of planets magnetospheres in very short time, thus it can be used for pedagogical test purposes. It is also likely complementary with MHD to deepen our understanding of the large scale magnetosphere.

  12. THE CHESS SURVEY OF THE L1157-B1 SHOCK REGION: CO SPECTRAL SIGNATURES OF JET-DRIVEN BOW SHOCKS

    International Nuclear Information System (INIS)

    Lefloch, B.; Codella, C.; Ceccarelli, C.; Cabrit, S.; Busquet, G.; Benedettini, M.; Cernicharo, J.; Pardo, J. R.; Lis, D. C.; Nisini, B.

    2012-01-01

    The unprecedented sensitivity of Herschel coupled with the high resolution of the HIFI spectrometer permits studies of the intensity-velocity relationship I(v) in molecular outflows, over a higher excitation range than possible up to now. Over the course of the CHESS Key Program, we have observed toward the bright bow shock region L1157-B1, the CO rotational transitions between J = 5-4 and J = 16-15 with HIFI, and the J = 1-0, 2-1, and 3-2 with the IRAM 30 m and the Caltech Submillimeter Observatory telescopes. We find that all the line profiles I CO (v) are well fit by a linear combination of three exponential laws ∝exp (– |v/v 0 |) with v 0 = 12.5, 4.4, and 2.5 km s –1 . The first component dominates the CO emission at J ≥ 13, as well as the high-excitation lines of SiO and H 2 O. The second component dominates for 3 ≤ J up ≤ 10 and the third one for J up ≤ 2. We show that these exponentials are the signature of quasi-isothermal shocked gas components: the impact of the jet against the L1157-B1 bow shock (T k ≅ 210 K), the walls of the outflow cavity associated with B1 (T k ≅ 64 K), and the older cavity L1157-B2 (T k ≅ 23 K), respectively. Analysis of the CO line flux in the large-velocity gradient approximation further shows that the emission arises from dense gas (n(H 2 ) ≥ 10 5 -10 6 cm –3 ) close to LTE up to J = 20. We find that the CO J = 2-1 intensity-velocity relation observed in various other molecular outflows is satisfactorily fit by similar exponential laws, which may hold an important clue to their entrainment process.

  13. Delineating functional principles of the bow tie structure of a kinase-phosphatase network in the budding yeast.

    Science.gov (United States)

    Abd-Rabbo, Diala; Michnick, Stephen W

    2017-03-16

    Kinases and phosphatases (KP) form complex self-regulating networks essential for cellular signal processing. In spite of having a wealth of data about interactions among KPs and their substrates, we have very limited models of the structures of the directed networks they form and consequently our ability to formulate hypotheses about how their structure determines the flow of information in these networks is restricted. We assembled and studied the largest bona fide kinase-phosphatase network (KP-Net) known to date for the yeast Saccharomyces cerevisiae. Application of the vertex sort (VS) algorithm on the KP-Net allowed us to elucidate its hierarchical structure in which nodes are sorted into top, core and bottom layers, forming a bow tie structure with a strongly connected core layer. Surprisingly, phosphatases tend to sort into the top layer, implying they are less regulated by phosphorylation than kinases. Superposition of the widest range of KP biological properties over the KP-Net hierarchy shows that core layer KPs: (i), receive the largest number of inputs; (ii), form bottlenecks implicated in multiple pathways and in decision-making; (iii), and are among the most regulated KPs both temporally and spatially. Moreover, top layer KPs are more abundant and less noisy than those in the bottom layer. Finally, we showed that the VS algorithm depends on node degrees without biasing the biological results of the sorted network. The VS algorithm is available as an R package ( https://cran.r-project.org/web/packages/VertexSort/index.html ). The KP-Net model we propose possesses a bow tie hierarchical structure in which the top layer appears to ensure highest fidelity and the core layer appears to mediate signal integration and cell state-dependent signal interpretation. Our model of the yeast KP-Net provides both functional insight into its organization as we understand today and a framework for future investigation of information processing in yeast and eukaryotes

  14. Lithium and boron analysis by LA-ICP-MS results from a bowed PWR rod with contact

    Directory of Open Access Journals (Sweden)

    Puranen Anders

    2017-01-01

    Full Text Available A previously published investigation of an irradiated fuel rod from the Ringhals 2 PWR, which was bowed to contact with an adjacent rod, identified a significant but highly localised thinning of the clad wall and increased corrosion. Rod fretting was deemed unlikely due to the adhering oxide covering the surfaces. Local overheating in itself was also deemed insufficient to account for the accelerated corrosion. Instead, an enhanced concentration of lithium due to conditions of local boiling was hypothesised to explain the accelerated corrosion. Studsvik has developed a hot cell coupled LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectrometer equipment that enables a flexible means of isotopic analysis of irradiated fuel and other highly active surfaces. In this work, the equipment was used to investigate the distribution of lithium (7Li and boron (11B in the outer oxide at the bow contact area. Depth profiling in the clad oxide at the opposite side of the rod to the point of contact, which is considered to have experienced normal operating conditions and which has a typical oxide thickness, evidenced levels of ∼10–20 ppm 7Li and a 11B content reaching hundreds of ppm in the outer parts of the oxide, largely in agreement with the expected range of Li and B clad oxide concentrations from previous studies. In the contact area, the 11B content was similar to the reference condition at the opposite side. The 7Li content in the outermost oxide closest to the contact was, however, found to be strongly elevated, reaching several hundred ppm. The considerable and highly localised increase in lithium content at the area of enhanced corrosion thus offers strong evidence for a case of lithium induced breakaway corrosion during power operation, when rod-to-rod contact and high enough surface heat flux results in a very local increase in lithium concentration.

  15. Constraining Genome-Scale Models to Represent the Bow Tie Structure of Metabolism for 13C Metabolic Flux Analysis

    Directory of Open Access Journals (Sweden)

    Tyler W. H. Backman

    2018-01-01

    Full Text Available Determination of internal metabolic fluxes is crucial for fundamental and applied biology because they map how carbon and electrons flow through metabolism to enable cell function. 13 C Metabolic Flux Analysis ( 13 C MFA and Two-Scale 13 C Metabolic Flux Analysis (2S- 13 C MFA are two techniques used to determine such fluxes. Both operate on the simplifying approximation that metabolic flux from peripheral metabolism into central “core” carbon metabolism is minimal, and can be omitted when modeling isotopic labeling in core metabolism. The validity of this “two-scale” or “bow tie” approximation is supported both by the ability to accurately model experimental isotopic labeling data, and by experimentally verified metabolic engineering predictions using these methods. However, the boundaries of core metabolism that satisfy this approximation can vary across species, and across cell culture conditions. Here, we present a set of algorithms that (1 systematically calculate flux bounds for any specified “core” of a genome-scale model so as to satisfy the bow tie approximation and (2 automatically identify an updated set of core reactions that can satisfy this approximation more efficiently. First, we leverage linear programming to simultaneously identify the lowest fluxes from peripheral metabolism into core metabolism compatible with the observed growth rate and extracellular metabolite exchange fluxes. Second, we use Simulated Annealing to identify an updated set of core reactions that allow for a minimum of fluxes into core metabolism to satisfy these experimental constraints. Together, these methods accelerate and automate the identification of a biologically reasonable set of core reactions for use with 13 C MFA or 2S- 13 C MFA, as well as provide for a substantially lower set of flux bounds for fluxes into the core as compared with previous methods. We provide an open source Python implementation of these algorithms at https://github.com/JBEI/limitfluxtocore.

  16. Reversible Heterolytic Cleavage of the H-H Bond by Molybdenum Complexes: Controlling the Dynamics of Exchange Between Proton and Hydride

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shaoguang; Appel, Aaron M.; Bullock, R. Morris

    2017-05-18

    Controlling the heterolytic cleavage of the H-H bond of dihydrogen is critically important in catalytic hydrogenations and in the catalytic oxidation of H2. We show how the rate of reversible heterolytic cleavage of H2 can be controlled over nearly four orders of magnitude at 25 °C, from 2.1 × 103 s-1 to ≥107 s-1. Bifunctional Mo complexes, [CpMo(CO)(κ3-P2N2)]+ (P2N2 = 1,5-diaza-3,7-diphosphacyclooctane with alkyl/aryl groups on N and P), have been developed for heterolytic cleavage of H2 into a proton and a hydride, akin to Frustrated Lewis Pairs. The H-H bond cleavage is enabled by the basic amine in the second coordination sphere. The products of heterolytic cleavage of H2, Mo hydride complexes bearing protonated amines, [CpMo(H)(CO)(P2N2H)]+, were characterized by spectroscopic studies and by X-ray crystallography. Variable temperature 1H, 15N and 2-D 1H-1H ROESY NMR spectra indicated rapid exchange of the proton and hydride. The exchange rates are in the order [CpMo(H)(CO)(PPh2NPh2H)]+ > [CpMo(H)(CO)(PtBu2NPh2H)]+ > [CpMo(H)(CO)(PPh2NBn2H)]+ > [CpMo(H)(CO)(PtBu2NBn2H)]+ > [CpMo(H)(CO)(PtBu2NtBu2H)]+. The pKa values determined in acetonitrile range from 9.3 to 17.7, and show a linear correlation with the logarithm of the exchange rates. Thus the exchange dynamics are controlled through the relative acidity of the [CpMo(H)(CO)(P2N2H)]+ and [CpMo(H2)(CO)(P2N2)]+ isomers, providing a design principle for controlling heterolytic cleavage of H2.

  17. Quality assurance for measurements of the radioactivity in the area of the"Horia Hulubei" National Institute for Physics and Nuclear Engineering, IFIN-HH.

    Science.gov (United States)

    Stochioiu, Ana; Luca, Aurelian; Sahagia, Maria; Margineanu, Romul Mircea; Tudor, Ion

    2012-10-01

    This paper presents one part of the activities deployed by the Laboratory for Environment and Personnel Dosimetry (LDPM) of IFIN-HH, namely the radiological monitoring of the environment within the Institute's area and its surrounding influence zone, according to the program approved by the National Regulatory Body for Nuclear Activities, CNCAN. The representative reports regard the radioactive content of soil, surface and underground water, cultivated and spontaneous vegetation, aerosols and atmospheric fallout, sediments. The common requirement is that the measured quantities be precise and the reported values be reliable and credible. This goal is achieved by maintaining a Quality System, verified within the obtaining and maintaining of the laboratory accreditation, according to the international standard ISO/IEC 17025:2005.The LDPM is accredited by the Romanian accreditation body, RENAR, member of the European Accreditation, EA and is designed by CNCAN as a notified testing laboratory. Many measurements were performed in collaboration with the Radionuclide Metrology Laboratory (RML) from IFIN-HH, RENAR accredited and CNCAN notified for calibration and for testing in the field of radioactivity measurement. This paper proposes a short presentation of the important aspects in our activity: i. description of equipment, samplingmethods, processing and measurement of environmental samples; ii. validation of equipment and methods by participation in international and national proficiency tests; iii. a five year follow chart, containing the results in measurement of samples; iv. a recent application, with a wide impact in Romanian mass media: the credible daily report on the possible influence of Fukushima accident over the Romanian environmental radioactivity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Transcriptional regulation and adaptation to a high-fiber environment in Bacillus subtilis HH2 isolated from feces of the giant panda.

    Directory of Open Access Journals (Sweden)

    Ziyao Zhou

    Full Text Available In the giant panda, adaptation to a high-fiber environment is a first step for the adequate functioning of intestinal bacteria, as the high cellulose content of the gut due to the panda's vegetarian appetite results in a harsh environment. As an excellent producer of several enzymes and vitamins, Bacillus subtilis imparts various advantages to animals. In our previous study, we determined that several strains of B. subtilis isolated from pandas exhibited good cellulose decomposition ability, and we hypothesized that this bacterial species can survive in and adapt well to a high-fiber environment. To evaluate this hypothesis, we employed RNA-Seq technology to analyze the differentially expressed genes of the selected strain B. subtilis HH2, which demonstrates significant cellulose hydrolysis of different carbon sources (cellulose and glucose. In addition, we used bioinformatics software and resources to analyze the functions and pathways of differentially expressed genes. Interestingly, comparison of the cellulose and glucose groups revealed that the up-regulated genes were involved in amino acid and lipid metabolism or transmembrane transport, both of which are involved in cellulose utilization. Conversely, the down-regulated genes were involved in non-essential functions for bacterial life, such as toxin and bacteriocin secretion, possibly to conserve energy for environmental adaptation. The results indicate that B. subtilis HH2 triggered a series of adaptive mechanisms at the transcriptional level, which suggests that this bacterium could act as a probiotic for pandas fed a high-fiber diet, despite the fact that cellulose is not a very suitable carbon source for this bacterial species. In this study, we present a model to understand the dynamic organization of and interactions between various functional and regulatory networks for unicellular organisms in a high-fiber environment.

  19. X-RAY OBSERVATIONS OF BOW SHOCKS AROUND RUNAWAY O STARS. THE CASE OF ζ OPH AND BD+43°3654

    Energy Technology Data Exchange (ETDEWEB)

    Toalá, J. A.; Guerrero, M. A. [Instituto de Astrofísica de Andalucía, IAA-CSIC, Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Oskinova, L. M.; González-Galán, A. [Institute for Physics and Astronomy, University of Potsdam, D-14476 Potsdam (Germany); Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States); Pohl, M., E-mail: toala@iaa.es [Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), Taipei 10617,Taiwan (China)

    2016-04-20

    Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations toward the runaway stars ζ Oph by Chandra and Suzaku and of BD+43°3654 by XMM-Newton to search for the presence of non-thermal X-ray emission. We found no evidence of non-thermal emission spatially coincident with the bow shocks; nonetheless, diffuse emission was detected in the vicinity of ζ Oph. After a careful analysis of its spectral characteristics, we conclude that this emission has a thermal nature with a plasma temperature of T ≈ 2 × 10{sup 6} K. The cometary shape of this emission seems to be in line with recent predictions of radiation-hydrodynamic models of runaway stars. The case of BD+43°3654 is puzzling, as non-thermal emission has been reported in a previous work for this source.

  20. Simulated solar wind plasma interaction with the Martian exosphere: influence of the solar EUV flux on the bow shock and the magnetic pile-up boundary

    Directory of Open Access Journals (Sweden)

    R. Modolo

    2006-12-01

    Full Text Available The solar wind plasma interaction with the Martian exosphere is investigated by means of 3-D multi-species hybrid simulations. The influence of the solar EUV flux on the bow shock and the magnetic pile-up boundary is examined by comparing two simulations describing the two extreme states of the solar cycle. The hybrid formalism allows a kinetic description of each ions species and a fluid description of electrons. The ionization processes (photoionization, electron impact and charge exchange are included self-consistently in the model where the production rate is computed locally, separately for each ionization act and for each neutral species. The results of simulations are in a reasonable agreement with the observations made by Phobos 2 and Mars Global Surveyor spacecraft. The position of the bow shock and the magnetic pile-up boundary is weakly dependent of the solar EUV flux. The motional electric field creates strong asymmetries for the two plasma boundaries.

  1. [Individual difference of coronal bowing of femur and its influence on the lower limbs alignment after the total knee arthroplasty].

    Science.gov (United States)

    Wu, W; Guo, W S; Cheng, L M; Liu, Z H; Zhang, Q D; Zhang, N F

    2017-04-04

    Objective: To disclose the correlation between the femur bowing angle(FBA) and vulgas correction angle(VCA), anlysys its influence on the total knee arthroplasty and the lower limbs alignment. Methods: From Janurary 2013 to December 2015, 699 patients who had received total knee arthroplasty(TKA)were collected in the Department of Joint Surgery, China-Japan Friendship. The FBA, VCA, offset of the proximal femur, the lengh of the femur, the neck shaft angle of the femur of the eligible cases from the long leg X-ray were measured.All the data were analysed for the following steps: the FBA's mean value and characteristics of distributation of all the cases; the VCA's mean value and characteristics of distributation of all the cases; correlations between the VCA and the other parameters; divide all the cases into four groups based on the value of FBA : group A(FBA3°, 236)and then plan to cut the distal femur with 5° and 6°, respectively. The percent of ideal alignmental outcome's percentage of every group were compared. Results: The mean Value of the FBA is -7.1--12.1(1.4±2.4)°; the mean Value of the VCA is 2.5--11.9(6.5±1.3)°. The correlation index between VCA and FBA, the neck shaft angle of the femur , offset of the hip joint, the lengh of the femur is 0.72, -0.26, 0.45 and -0.08, perspectively. The theoretical ideal alignment percentage of the 5 degree-valgus-bone cut and 6 degree-valgus-bone cut in every group is group A: 89.7% and 66.5%; group B: 93.7% and 95.7%; group C: 71.9% and 94.6%; group D: 21.2% and 50.8%, respectively. Conclusion: The cases whose femur bowing angles are outliers are common in daily medical practice, so the vulgas correction angles need be ajusted for its significant correlation with FBA. 5 degree-valgus-bone cut or 6 degree-valgus-bone cut could not get the ideal alignment some times.

  2. THE CHESS SURVEY OF THE L1157-B1 SHOCK REGION: CO SPECTRAL SIGNATURES OF JET-DRIVEN BOW SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Lefloch, B.; Codella, C.; Ceccarelli, C. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et dAstrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Cabrit, S. [Observatoire de Paris, LERMA, UMR 8112 du CNRS, ENS, UPMC, UCP, 61 Av. de l' Observatoire, F-75014 Paris (France); Busquet, G.; Benedettini, M. [INAF, Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Cernicharo, J.; Pardo, J. R. [Centro de Astrobiologia, INTA, Ctra de Torrejon a Ajalvir, km 4, E-28850 Torrejon de Ardoz, E-28850 Madrid (Spain); Lis, D. C. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Nisini, B., E-mail: lefloch@obs.ujf-grenoble.fr [INAF, Osservatorio Astronomico di Roma, Via di Frascati 33, I-00040 Monte, Porzio Catone (Italy)

    2012-10-01

    The unprecedented sensitivity of Herschel coupled with the high resolution of the HIFI spectrometer permits studies of the intensity-velocity relationship I(v) in molecular outflows, over a higher excitation range than possible up to now. Over the course of the CHESS Key Program, we have observed toward the bright bow shock region L1157-B1, the CO rotational transitions between J = 5-4 and J = 16-15 with HIFI, and the J = 1-0, 2-1, and 3-2 with the IRAM 30 m and the Caltech Submillimeter Observatory telescopes. We find that all the line profiles I{sub CO}(v) are well fit by a linear combination of three exponential laws {proportional_to}exp (- |v/v{sub 0}|) with v{sub 0} = 12.5, 4.4, and 2.5 km s{sup -1}. The first component dominates the CO emission at J {>=} 13, as well as the high-excitation lines of SiO and H{sub 2}O. The second component dominates for 3 {<=} J{sub up} {<=} 10 and the third one for J{sub up} {<=} 2. We show that these exponentials are the signature of quasi-isothermal shocked gas components: the impact of the jet against the L1157-B1 bow shock (T{sub k} {approx_equal} 210 K), the walls of the outflow cavity associated with B1 (T{sub k} {approx_equal} 64 K), and the older cavity L1157-B2 (T{sub k} {approx_equal} 23 K), respectively. Analysis of the CO line flux in the large-velocity gradient approximation further shows that the emission arises from dense gas (n(H{sub 2}) {>=} 10{sup 5}-10{sup 6} cm{sup -3}) close to LTE up to J = 20. We find that the CO J = 2-1 intensity-velocity relation observed in various other molecular outflows is satisfactorily fit by similar exponential laws, which may hold an important clue to their entrainment process.

  3. Large amplitude solitary waves in and near the Earth’s magnetosphere, magnetopause and bow shock: Polar and Cluster observations

    Directory of Open Access Journals (Sweden)

    C. Cattell

    2003-01-01

    Full Text Available Solitary waves with large electric fields (up to 100's of mV/m have been observed throughout the magnetosphere and in the bow shock. We discuss observations by Polar at high altitudes ( ~ 4-8 RE , during crossings of the plasma sheet boundary and cusp, and new measurements by Polar at the equatorial magnetopause and by Cluster near the bow shock, in the cusp and at the plasma sheet boundary. We describe the results of a statistical study of electron solitary waves observed by Polar at high altitudes. The mean solitary wave duration was ~ 2 ms. The waves have velocities from ~ 1000 km/s to  > 2500 km/s. Observed scale sizes (parallel to the magnetic field are on the order of 1-10lD, with eF/kTe from ~ 0.01 to O(1. The average speed of solitary waves at the plasma sheet boundary is faster than the average speed observed in the cusp and at cusp injections. The amplitude increases with both velocity and scale size. These observations are all consistent with the identification of the solitary waves as electron hole modes. We also report the discovery of solitary waves at the magnetopause, observed in Polar data obtained at the subsolar equatorial magnetopause. Both positive and negative potential structures have been observed with amplitudes up to ~ 25 mV/m. The velocities range from 150 km/s to >2500 km/s, with scale sizes the order of a kilometer (comparable to the Debye length. Initial observations of solitary waves by the four Cluster satellites are utilized to discuss the scale sizes and time variability of the regions where the solitary waves occur. Preliminary results from the four Cluster satellites have given a glimpse of the spatial and temporal variability of the occurrence of solitary waves and their association with other wave modes. In all the events studied, significant differences were observed in the waveforms observed simultaneously at the four locations separated by ~ 1000 km. When solitary waves were seen at one satellite, they

  4. Experimental validation of a method characterizing bow tie filters in CT scanners using a real-time dose probe

    International Nuclear Information System (INIS)

    McKenney, Sarah E.; Nosratieh, Anita; Gelskey, Dale; Yang Kai; Huang Shinying; Chen Lin; Boone, John M.

    2011-01-01

    Purpose: Beam-shaping or ''bow tie'' (BT) filters are used to spatially modulate the x-ray beam in a CT scanner, but the conventional method of step-and-shoot measurement to characterize a beam's profile is tedious and time-consuming. The theory for characterization of bow tie relative attenuation (COBRA) method, which relies on a real-time dosimeter to address the issues of conventional measurement techniques, was previously demonstrated using computer simulations. In this study, the feasibility of the COBRA theory is further validated experimentally through the employment of a prototype real-time radiation meter and a known BT filter. Methods: The COBRA method consisted of four basic steps: (1) The probe was placed at the edge of a scanner's field of view; (2) a real-time signal train was collected as the scanner's gantry rotated with the x-ray beam on; (3) the signal train, without a BT filter, was modeled using peak values measured in the signal train of step 2; and (4) the relative attenuation of the BT filter was estimated from filtered and unfiltered data sets. The prototype probe was first verified to have an isotropic and linear response to incident x-rays. The COBRA method was then tested on a dedicated breast CT scanner with a custom-designed BT filter and compared to the conventional step-and-shoot characterization of the BT filter. Using basis decomposition of dual energy signal data, the thickness of the filter was estimated and compared to the BT filter's manufacturing specifications. The COBRA method was also demonstrated with a clinical whole body CT scanner using the body BT filter. The relative attenuation was calculated at four discrete x-ray tube potentials and used to estimate the thickness of the BT filter. Results: The prototype probe was found to have a linear and isotropic response to x-rays. The relative attenuation produced from the COBRA method fell within the error of the relative attenuation measured with the step-and-shoot method

  5. Saturation of backward stimulated scattering of laser in kinetic regime: Wavefront bowing, trapped particle modulational instability, and trapped particle self-focusing of plasma waves

    International Nuclear Information System (INIS)

    Yin, L.; Albright, B. J.; Bowers, K. J.; Daughton, W.; Rose, H. A.

    2008-01-01

    Backward stimulated Raman and Brillouin scattering (SRS and SBS) of laser are examined in the kinetic regime using particle-in-cell simulations. The SRS reflectivity measured as a function of the laser intensity in a single hot spot from two-dimensional (2D) simulations shows a sharp onset at a threshold laser intensity and a saturated level at higher intensities, as obtained previously in Trident experiments [D. S. Montgomery et al., Phys. Plasmas 9, 2311 (2002)]. In these simulations, wavefront bowing of electron plasma waves (ion acoustic waves) due to the trapped particle nonlinear frequency shift, which increases with laser intensity, is observed in the SRS (SBS) regime for the first time. Self-focusing from trapped particle modulational instability (TPMI) [H. A. Rose, Phys. Plasmas 12, 12318 (2005)] is shown to occur in both two- and three-dimensional SRS simulations. The key physics underlying nonlinear saturation of SRS is identified as a combination of wavefront bowing, TPMI, and self-focusing of electron plasma waves. The wavefront bowing marks the beginning of SRS saturation and self-focusing alone is sufficient to terminate the SRS reflectivity, both effects resulting from cancellation of the source term for SRS and from greatly increased dissipation rate of the electron plasm waves. Ion acoustic wave bowing also contributes to the SBS saturation. Velocity diffusion by transverse modes and rapid loss of hot electrons in regions of small transverse extent formed from self-focusing lead to dissipation of the wave energy and an increase in the Landau damping rate in spite of strong electron trapping that reduces Landau damping initially. The ranges of wavelength and growth rate associated with transverse breakup of the electron-plasma wave are also examined in 2D speckle simulations as well as in 2D periodic systems from Bernstein-Greene-Kruskal equilibrium and are compared with theory predictions

  6. FEASIBILITY OF WIND TO SERVE UPPER SKAGIT'S BOW HILL TRIBAL LANDS AND FEASIBILITY UPDATE FOR RESIDENTIAL RENEWABLE ENERGY.

    Energy Technology Data Exchange (ETDEWEB)

    RICH, LAUREN

    2013-09-30

    A two year wind resource assessment was conducted to determine the feasibility of developing a community scale wind generation system for the Upper Skagit Indian Tribe's Bow Hill land base, and the project researched residential wind resource technologies to determine the feasibility of contributing renewable wind resource to the mix of energy options for our single and multi-family residential units.

  7. Observations of Lambda(0)(b) -> Lambda K+pi(-) and Lambda(0)(b) -> Lambda K+K- decays and searches for other Lambda(0)(b) and Xi(0)(b) decays to Lambda h(+)h '(-) final states

    NARCIS (Netherlands)

    Aaij, R.; Beteta, C. Abelian; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrechtl, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A.; Arnato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Onderwater, C. J. G.; Pellegrino, A.; Tolk, S.

    2016-01-01

    A search is performed for the charmless three-body decays of the Lambda(0)(b) and Xi(0)(b) baryons to the final states Lambda h(+)h'(-), where h(') = pi or K. The analysis is based on a data sample, corresponding to an integrated luminosity of 3 fb-1 of pp collisions, collected by the LHCb

  8. Theory for the radiation at the third to fifth harmonics of the plasma frequency upstream from the Earth's bow shock

    International Nuclear Information System (INIS)

    Cairns, I.H.

    1988-01-01

    A theory is presented for the radiation at the third to fifth harmonics of the plasma frequency observed upstream from the Earth's bow shock: the radiation is produced by the process L+T'→T in the foreshock, with the initial T' radiation being the frequently observed second harmonic radiation (generated by another process) and the L waves being products of the decay L'→L+S of L' waves generated by a streaming instability. (Here L, S, and T denote Langmuir, ion acoustic, and 'transverse electromagnetic waves, respectively.) The theory can account for the observed radiation when unusually large levels (electric fields in excess of 10 mV/m) of suitable L waves are present. Such levels of L waves are possible, in principle, but have not been reported before; the radiation is observed quite infrequently, thereby implying a requirement for unusual foreshock conditions. Predictions for the characteristics of the source regions (one to each wing of the foreshock) and the bandwidth of the radiation are given. Potential problems for the theory, relating to the large levels of L waves required to account for the radiation, are discussed. copyright American Geophysical Union 1988

  9. The CHESS Survey of the L1157-B1 Shock Region: CO Spectral Signatures of Jet-driven Bow Shocks

    Science.gov (United States)

    Lefloch, B.; Cabrit, S.; Busquet, G.; Codella, C.; Ceccarelli, C.; Cernicharo, J.; Pardo, J. R.; Benedettini, M.; Lis, D. C.; Nisini, B.

    2012-10-01

    The unprecedented sensitivity of Herschel coupled with the high resolution of the HIFI spectrometer permits studies of the intensity-velocity relationship I(v) in molecular outflows, over a higher excitation range than possible up to now. Over the course of the CHESS Key Program, we have observed toward the bright bow shock region L1157-B1, the CO rotational transitions between J = 5-4 and J = 16-15 with HIFI, and the J = 1-0, 2-1, and 3-2 with the IRAM 30 m and the Caltech Submillimeter Observatory telescopes. We find that all the line profiles I CO(v) are well fit by a linear combination of three exponential laws vpropexp (- |v/v 0|) with v 0 = 12.5, 4.4, and 2.5 km s-1. The first component dominates the CO emission at J >= 13, as well as the high-excitation lines of SiO and H2O. The second component dominates for 3 = 105-106 cm-3) close to LTE up to J = 20. We find that the CO J = 2-1 intensity-velocity relation observed in various other molecular outflows is satisfactorily fit by similar exponential laws, which may hold an important clue to their entrainment process.

  10. Plasma wave profiles of Earth's bow shock at low Mach number: ISEE 3 observations on the far flank

    International Nuclear Information System (INIS)

    Greenstadt, E.W.; Coroniti, F.V.; Moses, S.L.; Smith, E.J.

    1992-01-01

    The Earth's bow shock is weak along its distant flanks where the projected component of solar wind velocity normal to the hyperboloidal surface is only a fraction of the total free stream velocity, severely reducing the local Mach number. The authors present a survey of selected crossings far downstream from the subsolar shock, delineating the overall plasma wave (pw) behavior of a selected set of nearly perpendicular crossings and another set of limited Mach number but broad geometry; they include their immediate upstream regions. The result is a generalizable pw signature, or signatures, of low Mach number shocks and some likely implications of those signatures for the weak shock's plasma physical processes on the flank. They find the data consistent with the presence of ion beam interactions producing noise ahead of the shock in the ion acoustic frequency range. One subcritical case was found whose pw noise was presumably related to a reflected ion population just as in stronger events. The presence or absence, and the amplitudes, of pw activity are explainable by the presence or absence of a population of upstream ions controlled by the component of interplanetary magnetic field normal to the solar wind flow

  11. Magnetosheath plasma stability and ULF wave occurrence as a function of location in the magnetosheath and upstream bow shock parameters

    Science.gov (United States)

    Soucek, Jan; Escoubet, C. Philippe; Grison, Benjamin

    2015-04-01

    We present the results of a statistical study of the distribution of mirror and Alfvén-ion cyclotron (AIC) waves in the magnetosheath together with plasma parameters important for the stability of ULF waves, specifically ion temperature anisotropy and ion beta. Magnetosheath crossings registered by Cluster spacecraft over the course of 2 years served as a basis for the statistics. For each observation we used bow shock, magnetopause, and magnetosheath flow models to identify the relative position of the spacecraft with respect to magnetosheath boundaries and local properties of the upstream shock crossing. A strong dependence of both plasma parameters and mirror/AIC wave occurrence on upstream ΘBn and MA is identified. We analyzed a joint dependence of the same parameters on ΘBn and fractional distance between shock and magnetopause, zenith angle, and length of the flow line. Finally, the occurrence of mirror and AIC modes was compared against the respective instability thresholds. We noted that AIC waves occurred nearly exclusively under mirror stable conditions. This is interpreted in terms of different characters of nonlinear saturation of the two modes.

  12. Morphology of channels and channel-sand bodies in the Glauconitic sandstone member (Upper Mannville), Little Bow area, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, J.C.; Hermanson, S.W.; Lawton, D.C.

    1982-12-01

    Large channels in the Glauconitic sandstone member of southern Alberta have proved to be difficult exploration targets because of an irregular distribution of reservoir sands within the channels. In the Little Bow area, two channels are present in the lower part of the Glauconitic member and have cut into the underlying Calcareous member. The channels can be recognized where they truncate regional markers of the Calcareous member -- the Bantry shale and Ostracod limestone, and where channel-fill deposits exhibit uniform geophysical log characters, indicating sandstone- or mudstone-filled reaches. Sediments of the Glauconitic member adjacent to the channels comprise a series of splay sandstones and mudstones that prograded into interdistributary bays of the lower delta plain. The two channels associated with these deposits are interpreted as distributary channels. Sand bodies within the channels formed as lateral bars and are isolated by mudstones which mark the abandoned stream course. Geological exploration for these discontinuous channel sandstones is difficult, and high-resolutio seismic data integrated with sound geologic modelling are critical for successful prospect delineation.

  13. Generation of the problem-dependent data libraries for IFIN-HH WWR-S spent fuel storage criticality and dose calculation

    International Nuclear Information System (INIS)

    Ene, Daniela; Tigau, F.

    1998-01-01

    The methods used for the radioactivity inventory calculation and dose evaluation of the fuel elements irradiated in the WWR-S IFIN-HH reactor are discussed in this work. A particular attention is paid to the processed problem-dependent nuclear libraries. SAS2H, a complex sequence of the SCALE-4.3 code system containing the modules BONAMI - NITAWL - XSDRNPM - COUPLE - ORIGEN-S - XSDOSE, has been assimilated on the IFIN-HH computer and applied to update the ORIGEN-S libraries by producing problem-dependent processed data libraries needed to perform the depletion and shielding analysis. This sequence uses one of the eight associated data libraries of the SCALE-4.3 system according to the choice of the user. The method consists in the following analysis processes: i) lattice cell neutron analysis to produce the flux weighting spectrum for activation library updating; ii) update of the nuclear data constants of the ORIGEN-S libraries; iii) depletion and decay analysis for a specified fuel assembly and irradiation history in order to generate gamma and neutron source strength and spectra. iv) one-dimensional radial shielding calculation for the evaluation of the angular neutron and gamma flux at the surface of a spent fuel shipping cask and further calculation of the dose rates at various points outside the cask. An efficient alternative of the calculation sequence mentioned above is the ARP (Automatic Rapid Processing) method conceived in order to generate independently ORIGEN-S libraries and to reduce substantially the running time. The substance of this method is the generation of the problem-dependent libraries from basis libraries a priori created by SAS2H for specific fuel assembly type and further interpolation of two independent variables, enrichment and burnup. Specific applications concerning WWR-S spent fuel were performed: i) generation of three problem-dependent libraries for the S-36 fuel assembly taking into account the maximum value of the burnup of this

  14. Temperature-dependent transitions between normal and inverse isotope effects pertaining to the interaction of H-H and C-H bonds with transition metal centers.

    Science.gov (United States)

    Parkin, Gerard

    2009-02-17

    Deuterium kinetic isotope effects (KIEs) serve as versatile tools to infer details about reaction mechanisms and the nature of transition states, while equilibrium isotope effects (EIEs) associated with the site preferences of hydrogen and deuterium enable researchers to study aspects of molecular structure. Researchers typically interpret primary deuterium isotope effects based on two simple guidelines: (i) the KIE for an elementary reaction is normal (k(H)/k(D) > 1) and (ii) the EIE is dictated by deuterium preferring to be located in the site corresponding to the highest frequency oscillator. In this Account, we evaluate the applicability of these rules to the interactions of H-H and C-H bonds with a transition metal center. Significantly, experimental and computational studies question the predictability of primary EIEs in these systems based on the notion that deuterium prefers to occupy the highest frequency oscillator. In particular, the EIEs for (i) formation of sigma-complexes by coordination of H-H and C-H bonds and (ii) oxidative addition of dihydrogen exhibit unusual temperature dependencies, such that the same system may demonstrate both normal (i.e., K(H)/K(D) > 1) and inverse (i.e., K(H)/K(D) ZPE (where SYM is the symmetry factor, MMI is the mass-moment of inertia term, EXC is the excitation term, and ZPE is the zero-point energy term), and the distinctive temperature profile results from the inverse ZPE (enthalpy) and normal [SYM x MMI x EXC] (entropy) components opposing each other and having different temperature dependencies. At low temperatures, the ZPE component dominates and the EIE is inverse, while at high temperatures, the [SYM x MMI x EXC] component dominates and the EIE is normal. The inverse nature of the ZPE term is a consequence of the rotational and translational degrees of freedom of RH (R = H, CH(3)) becoming low-energy isotopically sensitive vibrations in the product, while the normal nature of the [SYM x MMI x EXC] component

  15. Neural network prediction of carbonate lithofacies from well logs, Big Bow and Sand Arroyo Creek fields, Southwest Kansas

    Science.gov (United States)

    Qi, L.; Carr, T.R.

    2006-01-01

    In the Hugoton Embayment of southwestern Kansas, St. Louis Limestone reservoirs have relatively low recovery efficiencies, attributed to the heterogeneous nature of the oolitic deposits. This study establishes quantitative relationships between digital well logs and core description data, and applies these relationships in a probabilistic sense to predict lithofacies in 90 uncored wells across the Big Bow and Sand Arroyo Creek fields. In 10 wells, a single hidden-layer neural network based on digital well logs and core described lithofacies of the limestone depositional texture was used to train and establish a non-linear relationship between lithofacies assignments from detailed core descriptions and selected log curves. Neural network models were optimized by selecting six predictor variables and automated cross-validation with neural network parameters and then used to predict lithofacies on the whole data set of the 2023 half-foot intervals from the 10 cored wells with the selected network size of 35 and a damping parameter of 0.01. Predicted lithofacies results compared to actual lithofacies displays absolute accuracies of 70.37-90.82%. Incorporating adjoining lithofacies, within-one lithofacies improves accuracy slightly (93.72%). Digital logs from uncored wells were batch processed to predict lithofacies and probabilities related to each lithofacies at half-foot resolution corresponding to log units. The results were used to construct interpolated cross-sections and useful depositional patterns of St. Louis lithofacies were illustrated, e.g., the concentration of oolitic deposits (including lithofacies 5 and 6) along local highs and the relative dominance of quartz-rich carbonate grainstone (lithofacies 1) in the zones A and B of the St. Louis Limestone. Neural network techniques are applicable to other complex reservoirs, in which facies geometry and distribution are the key factors controlling heterogeneity and distribution of rock properties. Future work

  16. MicroHH 1.0: a computational fluid dynamics code for direct numerical simulation and large-eddy simulation of atmospheric boundary layer flows

    Science.gov (United States)

    van Heerwaarden, Chiel C.; van Stratum, Bart J. H.; Heus, Thijs; Gibbs, Jeremy A.; Fedorovich, Evgeni; Mellado, Juan Pedro

    2017-08-01

    This paper describes MicroHH 1.0, a new and open-source (www.microhh.org) computational fluid dynamics code for the simulation of turbulent flows in the atmosphere. It is primarily made for direct numerical simulation but also supports large-eddy simulation (LES). The paper covers the description of the governing equations, their numerical implementation, and the parameterizations included in the code. Furthermore, the paper presents the validation of the dynamical core in the form of convergence and conservation tests, and comparison of simulations of channel flows and slope flows against well-established test cases. The full numerical model, including the associated parameterizations for LES, has been tested for a set of cases under stable and unstable conditions, under the Boussinesq and anelastic approximations, and with dry and moist convection under stationary and time-varying boundary conditions. The paper presents performance tests showing good scaling from 256 to 32 768 processes. The graphical processing unit (GPU)-enabled version of the code can reach a speedup of more than an order of magnitude for simulations that fit in the memory of a single GPU.

  17. Comportamiento de las aleaciones termorresistentes AISI HH y HK-40 ante los procesos de carburización y nitruración

    Directory of Open Access Journals (Sweden)

    Eleno Alfonso-Brindis

    2001-03-01

    Full Text Available Se evalúa el comportamiento de los aceros austeníticos fundidos AISI HH y HK- 40 (de producción nacional ante los procesos de carburización y nitruración en los rangos de temperaturas desde 750 hasta 1 000 °C. Se estudia la cinética y la termodinámica de las posibles reacciones y los productos de las mismas se caracterizan mediante técnicas de Microscopía Óptica, Microscopía Electrónica de Barrido y Microanálisis (MEB-EDAX. En el análisis microscópico se observó la formación de carburos de cromo después de la carburización, mientras que la nitruración dio lugar a la formación de nitruros de cromo. Se concluye que la aleación AISI HK-40 posee una elevada resistencia intrínseca a la carburización y a la nitruración, que hace factible su empleo en componentes de hornos de soleras múltiples para la reducción de minerales lateríticos

  18. Nicotinamide nucleotide transhydrogenase from Rhodobacter capsulatus; the H+/H- ratio and the activation state of the enzyme during reduction of acetyl pyridine adenine dinucleotide.

    Science.gov (United States)

    Palmer, T; Jackson, J B

    1992-02-21

    Chromatophores from Rhodobacter capsulatus were incubated in the dark with NADPH and acetylpyridineadenine dinucleotide (AcPdAD+) in the presence of different concentrations of myxothiazol. The transhydrogenase activity was monitored until an appropriate mass action ratio, [AcPdAD+][NADPH]/[AcPdADH][NADP+], was reached. The sample was then illuminated and the initial rate of either AcPdAD+ reduction by NADPH or AcPdADH oxidation by NADP+ was recorded. The ratio of H+ translocated per H- equivalent transferred by transhydrogenase was calculated from the value of the membrane potential (delta pH = 0) at which illumination caused no net reaction in either direction. The mean value for the H+/H- ratio was 0.55. At greater values of [AcPdAD+][NADPH]/[AcPdADH][NADP+] than were employed in the above experiments and over a wider range of concentrations of myxothiazol, it was found that incremental increases in the membrane potential always gave rise to a decrease, never an increase in the rate of AcPdAD+ reduction. In contrast to the H(+)-ATP synthase, there is no evidence of any activation/deactivation of H(+)-transhydrogenase by the protonmotive force.

  19. Risk analysis using AS/NZS 4360:2004, Bow-Tie diagram and ALARP on construction projects of Banyumanik Hospital

    Science.gov (United States)

    Sari, Diana Puspita; Pujotomo, Darminto; Wardani, Nadira Kusuma

    2017-11-01

    The Determination of risk is an uncertain event. Risks can have negative or positive impacts on project objectives. A project was defined as a series of activities and tasks that have a purpose, specifications, and limits of cost. Banyumanik Hospital Development Project is one of the construction projects in Semarang which have experienced some problems. The first problem is project delays on building stake. The second problem is delay of material supply. Finally, the problem that occurs is less management attention to health safety as evidenced by the unavailability of PPE for the workers. These problems will pose a risk to be a very important risk management performed by contractors at the Banyumanik Hospital Development Project to reduce the impact that would be caused by the risk borne by the provider of construction services. This research aim to risk identification, risk assessment and risk mitigation. Project risk management begins with the identification of risks based on the project life cycle. The risk assessment carried out by AS I NZS 4360: 2004 to the impacts of cost, time and quality. The results obtained from the method of AS I NZS 4360: 2004 is the risk that requires the handling of mitigation. Mitigated risk is the risk that had significant and high level. There are four risks that require risk mitigation with Bow-Tie diagrams which is work accidents, contract delays, material delays and design changes. Bow-Tie diagram method is a method for identifying causal and preventive action and recovery of a risk. Results obtained from Bow-Tie diagram method is a preventive action and recovery. This action is used as input to the ALARP method. ALARP method is used to determine the priority of the strategy proposed in the category broadly acceptable, tolerable, and unacceptable.

  20. Evidence of the correlation between a strong 4d-As/2p-N orbitals coupling and the bowing effect in GaAsN

    International Nuclear Information System (INIS)

    Mehnane, N.; Badi, F.; Abid, H.; Reda Aced, M.; Sekkal, N.

    2008-05-01

    By means of a simple physical argumentation, we give the proof that the giant bowing observed in GaAsN is correlated to a strong interaction between 4d-As and 2p-N orbitals. The calculations were carried out within the first principles full potential linear muffin-tin orbitals method (FPLMTO) method in its plane wave approximation (PLW) which enables an accurate treatment of the interstitial regions. The choice of this method ensures our work to be free from adjustable parameters and enables us to perform a microscopic study. (author)

  1. Coal rank, distribution, and coalbed methane potential of the Lower Cretaceous Luscar Group, Bow River to Blackstone River, central Alberta foothills

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, F M; Kalkreuth, W D

    1994-12-31

    Mapping data on Lower Cretaceous Luscar Group coals in the central Alberta foothills is presented. The coals outcrop in the Inner Foothills from the Bow River to the boundary between Alberta and British Columbia, north of Grande Cache. Both subsurface and surface mapping data is presented. The coal rank is highly variable and depends on sample location and depth, as established by vitrinite reflectance studies on trench samples and cuttings gathered from petroleum exploration wells. The conventional coal resource potential and the coalbed methane potential for the area are discussed with reference to the map sheets provided. 29 refs., 45 figs., 3 tabs., 3 apps.

  2. ROBOT3: a computer program to calculate the in-pile three-dimensional bowing of cylindrical fuel rods (AWBA Development Program)

    International Nuclear Information System (INIS)

    Kovscek, S.E.; Martin, S.E.

    1982-10-01

    ROBOT3 is a FORTRAN computer program which is used in conjunction with the CYGRO5 computer program to calculate the time-dependent inelastic bowing of a fuel rod using an incremental finite element method. The fuel rod is modeled as a viscoelastic beam whose material properties are derived as perturbations of the CYGRO5 axisymmetric model. Fuel rod supports are modeled as displacement, force, or spring-type nodal boundary conditions. The program input is described and a sample problem is given

  3. Social-value maps for Arapaho, Roosevelt, Medicine Bow, Routt, and White River National Forests, Colorado and Wyoming

    Science.gov (United States)

    Ancona, Zachary H.; Semmens, Darius J.; Sherrouse, Benson C.

    2016-03-25

    Executive SummaryThe continued pressures of population growth on the life-sustaining, economic, and cultural ecosystem services provided by our national forests, particularly those located near rapidly growing urban areas, present ongoing challenges to forest managers. Achieving an effective assessment of these ecosystem services includes a proper accounting of the ecological, economic, and social values attributable to them. However, assessments of ecosystem goods and services notably lack information describing the spatial distribution and relative intensity of social values—the perceived, nonmarket values derived particularly from cultural ecosystem services. A geographic information system (GIS) tool developed to fill this need, Social Values for Ecosystem Services (SolVES; http://solves.cr.usgs.gov), now provides the capability to generate social-value maps at a range of spatial scales. This report presents some of the methods behind SolVES, procedures needed to apply the tool, the first formal map products resulting from its application at a regional scale, and a discussion of the management implications associated with this type of information.In this study, we use SolVES to identify the location and relative intensity of social values as derived from survey responses gathered from residents living in counties adjacent to Arapaho, Roosevelt, Medicine Bow, Routt, and White River National Forests. The results, presented as a series of social-value maps, represent the first publicly available spatial data on social-value intensity for the southern Rocky Mountain region. Our analysis identified high-value areas for social values including aesthetic, biodiversity, and life sustaining within wilderness areas. Other values, like recreation, show high-value areas both within wilderness and throughout the general forest areas, which can be attributed to people using the forests for a diverse set of recreational activities. The economic social-value type was lower

  4. Air quality monitoring in the Bow Corridor : final report December 1999 to August 2001. On-line ed.

    International Nuclear Information System (INIS)

    2001-01-01

    Alberta Environment monitored the air quality of the Bow Corridor and the Cochrane area from December 1999 to August 2001 in an effort to address recent concerns about particulate emissions from industrial, natural and domestic sources as well as concerns about air pollution from traffic along Highway 1 and in communities in the corridor. The Mobile Air Monitoring Laboratory (MAML) monitored air quality at 22 sites in the Cochrane, Exshaw, Canmore and Banff areas. The work included monitoring for sulphur dioxide, particulates, oxides of nitrogen, ozone, hydrocarbons, carbon monoxide, hydrogen sulphide and ammonia using continuous analyzers. In addition, a stationary particulate sampler was used to monitor very small, respirable particulates (PM2.5) as well as larger, inhalable particulates (PM10). Weather parameters such as wind, temperature and relative humidity were also monitored. A passive (no power required) air quality monitoring network was also set up to collect monthly samples of sulphur dioxide at 7 sites and nitrogen dioxide and ozone at 11 different sites. The pollutant levels were compared with air quality levels to Alberta's Ambient Air Quality Guidelines which are some of the most stringent in North America. Maximum one-hour concentrations were : 53 per cent of the one-hour guideline for sulphur dioxide; 15 per cent of the one-hour guideline for nitrogen dioxide; 68 per cent of the one-hour guideline for ozone; 8 per cent of the one-hour guideline for carbon monoxide; 20 per cent of the one-hour guideline for hydrogen sulphide; and 2 per cent of the one-hour guideline for ammonia. These air quality levels were compared to other locations in Alberta. The sources of airborne particulates were wind-blown dust from natural sources, limestone mining operations, manufacturing plants (cement, lime and magnesia), vehicle exhaust from local traffic and Highway 1, and smoke from recreational burning and forest fires. The sources of oxides of nitrogen are

  5. Fuel pin bowing and related investigation of WWER-440 control rod influence on power release inside of neighbouring fuel pins

    International Nuclear Information System (INIS)

    Mikus, J.

    2005-01-01

    The purpose of this work consists in investigation of the WWER-440 control rod (CR) influence on space power distribution, especially from viewpoint of the values and gradient occurrence that could result in static and cyclic loads with some consequences, e.g. fuel pin bowing. As known, CR can cause power peaks in periphery fuel pins of adjacent operating assemblies because of the butt joint design of the absorbing adapter to the CR fuel part, that is, presence of the water cavity resulting in a flash up of thermal neutrons. As a consequence, beside well-known peaks in axial power distribution, above power gradients can occur inside of mentioned fuel pins. Because of complicated geometry and material composition of the CR, the detailed calculations concerning both above phenomena are complicated, too. Therefore it is useful to acquire appropriate experimental data to investigate mentioned influence and compare them with calculations. Since detailed power distributions cannot be obtained in the NPP, needed information is provided by means of experiments on research reactors. In case of measurements inside of fuel pins, special (e.g. track) detectors placed between fuel pellets are used. Such works are relatively complicated and time consuming, therefore an evaluation based on mathematical modelling and numerical approximation was proposed by means of that, and using measured power release in some selected fuel pins, information about power release inside of one of these fuel pins, can be obtained. For this purpose, an experiment on light water, zero-power research reactor LR-0 was realized and axial power distribution measurements were performed in a WWER-440 type core near to an authentic CR model. Application of the above evaluation method is demonstrated on one ''investigated'' fuel pin neighbouring CR by means of following results: 1. Axial power distribution inside of investigated fuel pin in two opposite positions on its pellets surface that are situated to

  6. Observations of the spatial and temporal structure of field-aligned beam and gyrating ring distributions at the quasi-perpendicular bow shock with Cluster CIS

    Directory of Open Access Journals (Sweden)

    E. Möbius

    2001-09-01

    Full Text Available During the early orbit phase, the Cluster spacecraft have repeatedly crossed the perpendicular Earth’s bow shock and provided the first multi-spacecraft measurements. We have analyzed data from the Cluster Ion Spectrometry experiment (CIS, which observes the 3D-ion distribution function of the major species in the energy range of 5 eV to 40 keV with a 4 s resolution. Beams of reflected ions were observed simultaneously at all spacecraft locations and could be tracked from upstream to the shock itself. They were found to originate from the same distribution of ions that constitutes the reflected gyrating ions, which form a ring distribution in the velocity space immediately upstream and downstream of the shock. This observation suggests a common origin of ring and beam populations at quasi-perpendicular shocks in the form of specular reflection and immediate pitch angle scattering. Generally, the spatial evolution across the shock is very similar on all spacecraft, but phased in time according to their relative location. However, a distinct temporal structure of the ion fluxes in the field-aligned beam is observed that varies simultaneously on all spacecraft. This is likely to reflect the variations in the reflection and scattering efficiencies.Key words. Interplanetary physics (planetary bow shocks; energetic particles; instruments and techniques

  7. MMS observations of the Earth bow shock during magnetosphere compression and expansion: comparison of whistler wave properties around the shock ramp

    Science.gov (United States)

    Russell, C. T.; Strangeway, R. J.; Schwartz, S. J.

    2017-12-01

    The Magnetospheric Multiscale (MMS) spacecraft, with their state-of-the-art plasma and field instruments onboard, allow us to investigate electromagnetic waves at the bow shock and their association with small-scale disturbances in the shocked plasmas. Understanding these waves could improve our knowledge on the heating of electrons and ions across the shock ramp and the energy dissipation of supercritical shocks. We have found broad-band and narrow band waves across the shock ramp and slightly downstream. The broad-band waves propagate obliquely to the magnetic field direction and have frequencies up to the electron cyclotron frequency, while the narrow-band waves have frequencies of a few hundred Hertz, durations under a second, and are right-handed circularly polarized and propagate along the magnetic field lines. Both wave types are likely to be whistler mode with different generation mechanisms. When the solar wind pressure changes, MMS occasionally observed a pair of bow shocks when the magnetosphere was compressed and then expanded. We compare the wave observations under these two situations to understand their roles in the shock ramp as well as the upstream and downstream plasmas.

  8. Influence of fuel pin bowing on the temperature distribution in fuel pin cladding tubes in case of sodium cooling; experimental results

    International Nuclear Information System (INIS)

    Moeller, R.; Tschoeke, H.; Kolodziej, M.

    1978-09-01

    The influence of rod bowing on the local temperature distribution was measured with turbulent sodium flow in the cladding tubes of a 19-rod bundle mock-up of the SNR 300 Mark Ia fuel element. Such measurements have been carried out for the first time. The results presented in this report are part 1 of the experimental evaluation not yet completed. The major results are: 1. When a rod on the first ring gets deformed towards a neighbour on the second ring with a gap reduction from the nominal value of 100 % down to 20 %, the maximum azimuthal temperature difference of the outer rod increases by about 60 %. 2. The maximum azimuthal temperature difference of a rod on the first ring increases by a factor of 2, if it is approached by a neighbour on the same ring. 3. The reduction in cross section of a subchannel by rod bowing results only locally in distinct temperature rises, i.e. in the adjacent cladding tubes. Rods of the next but one row are no more subject to noticeable changes in temperature [de

  9. ARAMIS project: a more explicit demonstration of risk control through the use of bow-tie diagrams and the evaluation of safety barrier performance.

    Science.gov (United States)

    de Dianous, Valérie; Fiévez, Cécile

    2006-03-31

    Over the last two decades a growing interest for risk analysis has been noted in the industries. The ARAMIS project has defined a methodology for risk assessment. This methodology has been built to help the industrialist to demonstrate that they have a sufficient risk control on their site. Risk analysis consists first in the identification of all the major accidents, assuming that safety functions in place are inefficient. This step of identification of the major accidents uses bow-tie diagrams. Secondly, the safety barriers really implemented on the site are taken into account. The barriers are identified on the bow-ties. An evaluation of their performance (response time, efficiency, and level of confidence) is performed to validate that they are relevant for the expected safety function. At last, the evaluation of their probability of failure enables to assess the frequency of occurrence of the accident. The demonstration of the risk control based on a couple gravity/frequency of occurrence is also possible for all the accident scenarios. During the risk analysis, a practical tool called risk graph is used to assess if the number and the reliability of the safety functions for a given cause are sufficient to reach a good risk control.

  10. DESY: ARGUS bows out

    International Nuclear Information System (INIS)

    Wagner, Albrecht

    1993-01-01

    Last year the ARGUS experiment at DESY's DORIS electron-positron storage ring stopped taking data after ten years of fruitful physics. Analysis and new results will continue for some time, but members of the group are already looking to new physics horizons. The ARGUS collaboration was formed in 1978 by groups from DESY, Dortmund, Heidelberg (IHEP), Lund, Moscow (ITEP), and South Carolina under the leadership of Walter Schmidt-Parzefall. Later groups joined from IPP Canada, Kansas, Ljubljana, Karlsruhe, Erlangen/Nurnberg, Heidelberg (MPI) and Dresden. The detector was conceived to investigate the physics of the beauty and charm quarks and the tau lepton at the upgraded DORIS II electronpositron storage ring. With a similar programme started by the CLEO collaboration at Cornell's CESR electron-positron collider, the resulting competition ensured good physics. ARGUS rolled into the beam in October 1982 and took data until October 1992. In May 1993 the decision was taken to stop further ARGUS running. During those ten years a broad spectrum of physics has been covered, including weak decays of beauty and charm quarks and tau leptons, hadron spectroscopy, quark/gluon mechanisms, photon-photon interactions and particle searches. In particular, ARGUS has made valuable contributions to determination of many fundamental constants of the Standard Model. These comprise measurements of quark transitions (CKM matrix elements) in the decays of B mesons (containing the beauty quark), the determination of the properties of the tau lepton and its neutrino, as well as a measurement of the quark coupling constant. The charm study has resulted in first observations of many charmed hadrons and decay modes. The study of quark and gluon mechanisms (fragmentation) has yielded valuable input for future experiments, while the first observations of new final states in photon-photon interactions have created much interest. A total luminosity of 520 inverse picobarns has been collected at collision energies around 10 GeV

  11. The CHESS survey of the L1157-B1 bow-shock: high and low excitation water vapor

    Science.gov (United States)

    Busquet, G.; Lefloch, B.; Benedettini, M.; Ceccarelli, C.; Codella, C.; Cabrit, S.; Nisini, B.; Viti, S.; Gómez-Ruiz, A. I.; Gusdorf, A.; di Giorgio, A. M.; Wiesenfeld, L.

    2014-01-01

    Context. Molecular outflows powered by young protostars strongly affect the kinematics and chemistry of the natal molecular cloud through strong shocks. This results in substantial modifications of the abundance of several species. In particular, water is a powerful tracer of shocked material because of its sensitivity to both physical conditions and chemical processes. Aims: As part of the Chemical HErschel Surveys of Star-forming regions (CHESS) guaranteed time key program, we aim at investigating the physical and chemical conditions of H2O in the brightest shock region B1 of the L1157 molecular outflow. Methods: We observed several ortho- and para-H2O transitions using the HIFI and PACS instruments on board Herschel toward L1157-B1, providing a detailed picture of the kinematics and spatial distribution of the gas. We performed a large velocity gradient (LVG) analysis to derive the physical conditions of H2O shocked material, and ultimately obtain its abundance. Results: We detected 13 H2O lines with both instruments probing a wide range of excitation conditions. This is the largest data set of water lines observed in a protostellar shock and it provides both the kinematics and the spatial information of the emitting gas. The PACS maps reveal that H2O traces weak and extended emission associated with the outflow identified also with HIFI in the o-H2O line at 556.9 GHz, and a compact (~10'') bright, higher excitation region. The LVG analysis of H2O lines in the bow-shock show the presence of two gas components with different excitation conditions: a warm (Tkin ≃ 200-300 K) and dense (n(H2) ≃ (1-3) × 106 cm-3) component with an assumed extent of 10'', and a compact (~2''-5'') and hot, tenuous (Tkin ≃ 900-1400 K, n(H2) ≃ 103-4 cm-3) gas component that is needed to account for the line fluxes of high Eu transitions. The fractional abundance of the warm and hot H2O gas components is estimated to be (0.7-2) × 10-6 and (1-3) × 10-4, respectively. Finally, we

  12. Development of design technology on thermal-hydraulic performance in tight-lattice rod bundle. III - Numerical estimation on rod bowing effect based on X-ray CT data

    International Nuclear Information System (INIS)

    Misawa, Takeharu; Ohnuki, Akira; Katsuyama, Kozo; Nagamine, Tsuyoshi; Nakamura, Yasuo; Akimoto, Hajime; Mitsutake, Toru; Misawa, Susumu

    2007-01-01

    Design studies of the Innovative Water Reactor for Flexible Fuel Cycle (FLWR) are being carried out at the Japan Atomic Energy Agency (JAEA) as one candidate for the future reactors. In actual core design, it is precondition to prevent fuel rods contact due to fuel rod bowing. However, the FLWR cores have nonconventional characteristics such as a hexagonal tight lattice arrangement and a high enrichment fuel loading. Therefore, as conservative evaluation, it is important to investigate influence of fuel rod bowing upon the boiling transition. In the JAEA, a 37-rod bundle experiments (base case test section (1.3mm gap width), gap width effect test section (1.0mm gap width), and rod bowing test section) were performed in order to investigate the thermal hydraulic characteristics in the tight lattice bundle. In this paper, the rod bowing effect test is paid attention. It is suspected that the actual fuel rod positions in the rod bowing test section may be different from the design-based positions. Even a slight displacement from the design-based position of fuel rod may occur variation of flow area, and give influence upon the thermal hydraulic characteristics in the rod bundle. Therefore, if the critical power in the rod bundle is evaluated by an analytical approach, the analysis based on more correct input can be performed by using actual fuel rod position data. In this study, the rod positions in the rod bowing test section were measured using the high energy X-ray computer tomography (Xray-CT). Based on the measured rod positions data, the subchannel analysis by the NASCA code was performed, in order to investigate applicability of the NASCA code to BT estimation of the rod bowing test section, and influence of displacement from design-based rod position upon BT estimation by the NASCA code. The predicted critical powers are agreement with those obtained by the experiment. The analysis based on the design-based rod positions is also performed, and the result is

  13. Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC. Crystal structure of [Cu(PLITSC−HH2O]Br•H2O

    Directory of Open Access Journals (Sweden)

    Leovac Vukadin M.

    2014-01-01

    Full Text Available The synthesis and structural characterization of a square-planar copper(II complex with pyridoxal S-methylisothiosemicarbazone (PLITSC of the formula [Cu(PLITSC−HH2O]Br•H2O (1 as the first Cu(II complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSCBr2] (2 and [Cu(PLITSCBr(MeOH]Br (3 were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry. [Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine i Ministarstva nauke Republike Srbije, br. 172014

  14. Do nonbonded H--H interactions in phenanthrene stabilize it relative to anthracene? A possible resolution to this question and its implications for ligands such as 2,2'-bipyridyl.

    Science.gov (United States)

    Hancock, Robert D; Nikolayenko, Igor V

    2012-08-23

    The problem of whether interactions between the hydrogen atoms at the 1,10-positions in the "cleft" of the "bent" phenanthrene stabilize the latter molecule thermodynamically relative to "linear" anthracene, or whether the higher stability of phenanthrene is due to a more energetically favorable π-system, is considered. DFT calculations at the X3LYP/cc-pVTZ(-f)++ level of the ground state energies (E) of anthracene, phenanthrene, and the set of five benzoquinolines are reported. In the gas phase, "bent" phenanthrene was computed to be thermodynamically more stable than "linear" anthracene by -28.5 kJ mol(-1). This fact was attributed predominantly to the phenomenon of higher aromatic stabilization of the π-system of phenanthrene relative to anthracene, and not to the stabilizing influence of the nonbonding H--H interactions in its cleft. In fact, these interactions in phenanthrene were shown to be destabilizing. Similar calculations for five benzoquinolines (bzq) indicate that ΔE values vary as: 6,7-bzq (linear) ≤ 2,3-bzq (linear) < 5,6-bzq (bent) ≤ 3,4-bzq (bent) < 7,8-bzq (bent, no H--H nonbonding interactions in cleft), supporting the idea that it is a more stable π-system that favors 7,8-bzq over 2,3-bzq and 6,7-bzq, and that the H--H interactions in the clefts of 3,4-bzq and 5,6-bzq are destabilizing. Intramolecular hydrogen bonding in the cleft of 7,8-bzq plays a secondary role in its stabilization relative 6,7-bzq. The question of whether H--H nonbonded interactions between H atoms at the 3 and 3' positions of 2,2'-bipyridyl (bpy) coordinated to metal ions are stabilizing or destabilizing is then considered. The energy of bpy is scanned as a function of N-C-C-N torsion angle (χ) in the gas-phase, and it is found that the trans form is 32.8 kJ mol(-1) more stable than the cis conformer. A relaxed coordinate scan of energy of bpy in aqueous solution as a function of χ is modeled using the PBF approach, and it is found that the trans conformer is

  15. Remote sensing of local structure of the quasi-perpendicular Earth's bow shock by using field-aligned beams

    Directory of Open Access Journals (Sweden)

    B. Miao

    2009-03-01

    Full Text Available Field-aligned ion beams (FABs originate at the quasi-perpendicular Earth's bow shock and constitute an important ion population in the foreshock region. The bulk velocity of these FABs depends significantly on the shock normal angle, which is the angle between shock normal and upstream interplanetary magnetic field (IMF. This dependency may therefore be taken as an indicator of the local structure of the shock. Applying the direct reflection model to Cluster measurements, we have developed a method that uses proton FABs in the foreshock region for remote sensing of the local shock structure. The comparison of the model results with the multi-spacecraft observations of FAB events shows very good agreement in terms of wave amplitude and frequency of surface waves at the shock front.

  16. Ribbon-wise customized lingual appliance and orthodontic anchor screw for the treatment of skeletal high-angle maxillary protrusion without bowing effect.

    Science.gov (United States)

    Inami, Toru; Ito, Goshi; Miyazawa, Ken; Tabuchi, Masako; Goto, Shigemi

    2018-05-02

    This case report demonstrates the treatment of a skeletal Class II high-angle adult patient with bimaxillary protrusion, angle Class I occlusion, and crowded anterior teeth. A ribbon-wise arch wire and a customized lingual appliance with anterior vertical slots were used to achieve proper torque control of the maxillary anterior teeth. An orthodontic anchor screw and a palatal bar were used for vertical control to avoid increasing the Frankfort-mandibular plane angle (FMA) by maxillary molar extrusion. Through the combined use of the ribbon-wise customized lingual appliance, palatal bar, and orthodontic anchor screw, vertical control and an excellent treatment result were achieved without the vertical and horizontal bowing effects peculiar to conventional lingual treatment.

  17. Coal rank, distribution and coalbed methane potential of the lower cretaceous luscar group, Bow River to Blackstone River, Central Alberta Foothills. Bulletin No. 473

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, F M

    1994-12-31

    Renewed interest in coal for alternative sources of energy such as coalbed methane have led to an expansion of exploration efforts into areas where the distribution and characterization of the coal resources is not well documented. This paper provides a geological compilation and assessment of the coal distribution and characterization of the Lower Cretaceous Luscar Group for the foothills area from the Bow River to Blackstone River in west-central Alberta. Included with the report are a series of geological maps and cross-sections that highlight the distribution of the coal-bearing strata and potential coalbed methane exploration targets. Field mapping of the area was carried out during the summers of 1988, 1989, and 1990.

  18. On the impact of isoelectric impurities on band bowing and disorder of compound semiconductors; Ueber den Einfluss von isoelektronischen Stoerstellen auf Bandbiegung und Unordnung in Verbindungshalbleitern

    Energy Technology Data Exchange (ETDEWEB)

    Karcher, Christian

    2012-03-16

    Isolectronic impurities and their impact on the properties of compound semiconductors is discussed in two systems: Nitrogen in Ga(As,P) quantum wells on the one hand and Sulfur and Selenium in bulk ZnTe. The properties are reduced to two experimentally observable aspects: Band Bowing, i.e. the non-linearity of the band gap of the compound semiconductor and disorder, i.e. in particular the formation of a strongly localized density of states beneath the fundamental band gap. Apart of the pure experimental studies an insight into the theoretical model of disorder-induced temperature dependent luminescence properties of the compound semiconductors by means of Monte Carlo Simulations is given.

  19. Which Bow Shock Theory, Gasdynamic or Magnetohydrodynamic, Better Explains CME Stand-off Distance Ratios from LASCO-C2 Observations ?

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Ok; Moon, Y.-J. [School of Space Research Kyung Hee University Yongin 17104 (Korea, Republic of); Lee, Jin-Yi [Department of Astronomy and Space Science Kyung Hee University Yongin 17104 (Korea, Republic of); Kim, R.-S.; Cho, K.-S. [Korea Astronomy and Space Science Institute Daejeon 34055 (Korea, Republic of)

    2017-03-20

    It is generally believed that fast coronal mass ejections (CMEs) can generate their associated shocks, which are characterized by faint structures ahead of CMEs in white-light coronagraph images. In this study, we examine whether the observational stand-off distance ratio, defined as the CME stand-off distance divided by its radius, can be explained by bow shock theories. Of 535 SOHO /LASCO CMEs (from 1996 to 2015) with speeds greater than 1000 km s{sup −1} and angular widths wider than 60°, we select 18 limb CMEs with the following conditions: (1) their Alfvénic Mach numbers are greater than one under Mann’s magnetic field and Saito’s density distributions; and (2) the shock structures ahead of the CMEs are well identified. We determine observational CME stand-off distance ratios by using brightness profiles from LASCO-C2 observations. We compare our estimates with theoretical stand-off distance ratios from gasdynamic (GD) and magnetohydrodynamic (MHD) theories. The main results are as follows. Under the GD theory, 39% (7/18) of the CMEs are explained in the acceptable ranges of adiabatic gamma ( γ ) and CME geometry. Under the MHD theory, all the events are well explained when we consider quasi-parallel MHD shocks with γ = 5/3. When we use polarized brightness (pB) measurements for coronal density distributions, we also find similar results: 8% (1/12) under GD theory and 100% (12/12) under MHD theory. Our results demonstrate that the bow shock relationships based on MHD theory are more suitable than those based on GD theory for analyzing CME-driven shock signatures.

  20. Interaction of a finite-length ion beam with a background plasma: Reflected ions at the quasi-parallel bow shock

    International Nuclear Information System (INIS)

    Onsager, T.G.; Winske, D.; Thomsen, M.F.

    1991-01-01

    The coupling of a finite-length, field-aligned, ion beam with a uniform background plasma is investigated using one-dimensional hybrid computer simulations. The finite-length beam is used to study the interaction between the incident solar wind and ions reflected from the Earth's quasi-parallel bow shock, where the reflection process may vary with time. The coupling between the reflected ions and the solar wind is relevant to ion heating at the bow shock and possibly to the formation of hot, flow anomalies and re-formation of the shock itself. The authors find that although there are many similarities between the instabilities driven by the finite-length beam and those predicted by linear theory for an infinite, homogeneous beam, there are also some important differences. Consistent with linear theory, the waves which dominate the interaction are the electromagnetic right-hand polarized resonant and nonresonant modes. However, in addition to the instability growth rates, the length of time that the waves are in contact with the beam is also an important factor in determining which wave mode will dominate the interaction. Whereas linear theory predicts the nonresonant mode to have the larger growth rate for the parameters they investigate, with finite-length beam they find that both the nonresonant and resonant modes contribute to the interaction. They find that the interaction will result in strong coupling, where a significant fraction of the available free energy is converted into thermal energy in a short time, provided the beam is sufficiently dense or sufficiently long

  1. Six potencial woods for bows of stringed instruments: organoleptic properties, machining and commercial availability. Seis madeiras potenciais para arcos de instrumentos de corda: propriedades organolépticas, trababilidade e disponibilidade comercial.

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz LONGUI

    2011-12-01

    Full Text Available In this paper it was investigated the organoleptic properties and machining of six potential woods for bows of stringed instruments and compared the results with those mentioned for the Caesalpinia echinata wood, the reference for modern bows. Thirty wood stores were visited in different cities of the São Paulo state to verify the commercial availability of these woods. We concluded that despite the traditionalism of the red tones in the woods for bows, woods with yellowish tones such as Handroanthus spp. and Dipteryx spp. or brownish such as Diplotropis spp. with appropriate properties, may offer alternative colors and textures to the musicians. It was observed that the Mezilaurus itauba and Astronium lecointei, woods with easy machining, have no potential suitable for bows. Regarding to availability, all woods tested are relatively easy to find nowadays in the wood market. Handroanthus spp. and Dipteryx spp. showed greater potential for making bows for professional musicians.The woods of Mezilaurus itauba and Astronium lecointei did not show good potentialfor bows.Neste trabalho foram investigadas as propriedades organolépticas e a trabalhabilidade de seis madeiras potenciais para arcos de instrumentos de corda e os resultados comparados com os da madeira de Caesalpinia echinata, referência para arcos modernos. Foram visitadas 30 madeireiras em diferentes cidades do Estado de São Paulo para observar a disponibilidade das seis madeiras. Conclui-se que apesar do tradicionalismo dos tons de vermelhos na madeira para arcos, outras madeiras com tons amarelados como Handroanthus spp. e Dipteryx spp. ou acastanhados como Diplotropis spp., desde que possuam propriedades adequadas, podem oferecer alternativas de cores e texturas para os músicos. Madeiras de fácil trabalhabilidade, como Mezilaurus itauba e Astronium lecointei não são adequadas para a fabricação dos arcos. Atualmente, todas as madeiras testadas são relativamente fáceis de

  2. Drill-hole data, drill-site geology, and geochemical data from the study of Precambrian uraniferous conglomerates of the Medicine Bow Mountains and Sierra Madre of southeastern Wyoming

    International Nuclear Information System (INIS)

    Karlstrom, K.E.; Houston, R.S.; Schmidt, T.G.; Inlow, D.; Flurkey, A.J.; Kratochvil, A.L.; Coolidge, C.M.; Sever, C.K.; Quimby, W.F.

    1981-02-01

    This volume is presented as a companion to Volume 1: The Geology and Uranium Potential of Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 3: Uranium Assessment for Precambrian Pebble Conglomerates in Southeastern Wyoming. Volume 1 summarized the geologic setting and geologic and geochemical characteristics of uranium-bearing conglomerates in Precambrian metasedimentary rocks of southeastern Wyoming. Volume 3 is a geostatistical resource estimate of U and Th in quartz-pebble conglomerates. This volume contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks of the Medicine Bow Mountains and Sierra Madre, and drill site geologic maps and cross-sections from most of the holes

  3. Drill-hole data, drill-site geology, and geochemical data from the study of Precambrian uraniferous conglomerates of the Medicine Bow Mountains and Sierra Madre of southeastern Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Karlstrom, K.E.; Houston, R.S.; Schmidt, T.G.; Inlow, D.; Flurkey, A.J.; Kratochvil, A.L.; Coolidge, C.M.; Sever, C.K.; Quimby, W.F.

    1981-02-01

    This volume is presented as a companion to Volume 1: The Geology and Uranium Potential of Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 3: Uranium Assessment for Precambrian Pebble Conglomerates in Southeastern Wyoming. Volume 1 summarized the geologic setting and geologic and geochemical characteristics of uranium-bearing conglomerates in Precambrian metasedimentary rocks of southeastern Wyoming. Volume 3 is a geostatistical resource estimate of U and Th in quartz-pebble conglomerates. This volume contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks of the Medicine Bow Mountains and Sierra Madre, and drill site geologic maps and cross-sections from most of the holes.

  4. Fuel pin bowing and related investigation of the gadolinium fuel pin influence on power release inside of neighbouring fuel pins in a WWER-440 type core

    International Nuclear Information System (INIS)

    Mikus, J.

    2006-01-01

    As known both the WWER-440 and WWER-1000 reactors are systematically modernized to enhance their safety and economical parameters of operation. For this purpose new fuel assemblies (FAs) were designed with improved technical parameters, e.g., containing fuel pins (FPs) in which Gd 2 O 3 burnable absorber is integrated into fuel. Presence of such FPs in reactor core results in a strong depression of thermal neutrons in their positions and corresponding high gradients in neighbouring FPs. Consequently, similar situation in neighbouring FPs can be expected as for both the power release and temperature gradients. The purpose of this work consists in investigation of the gadolinium FP influence on space power distribution, especially from viewpoint of the values and gradient occurrence inside of the neighbouring FPs that could result in static loads with some consequences, e.g., a contribution to FP/FA bowing. Since detailed power distributions cannot be obtained in the NPPs, needed information is provided by means of experiments on research reactors. As for the power release measurement inside of FPs, some special (e.g. track) detectors placed between fuel pellets are usually used. Since such works are relatively complicated and time consuming, an evaluation method based on mathematical modelling and numerical approximation was proposed by means of that, and using measured (integral) power release in selected FPs, needed power release values inside of investigated FPs, can be estimated. For this purpose, experimental results from light water, zero-power research reactor LR-0 obtained by measurements in a WWER-440 type core with 19 FAs at zero boron concentration and containing some FPs with gadolinium (Gd FPs) were utilized. Application of the proposed evaluation method is demonstrated on investigated FPs neighbouring a Gd FP by means of the: relative azimuthal power distribution estimation inside of investigated FPs on their fuel pellet surface in horizontal plane

  5. Mo-Mo Quintuple Bond is Highly Reactive in H-H, C-H, and O-H σ-Bond Cleavages Because of the Polarized Electronic Structure in Transition State.

    Science.gov (United States)

    Chen, Yue; Sakaki, Shigeyoshi

    2017-04-03

    The recently reported high reactivity of the Mo-Mo quintuple bond of Mo 2 (N ∧ N) 2 (1) {N ∧ N = μ-κ 2 -CH[N(2,6-iPr 2 C 6 H 3 )] 2 } in the H-H σ-bond cleavage was investigated. DFT calculations disclosed that the H-H σ-bond cleavage by 1 occurs with nearly no barrier to afford the cis-dihydride species followed by cis-trans isomerization to form the trans-dihydride product, which is consistent with the experimental result. The O-H and C-H bond cleavages by 1 were computationally predicted to occur with moderate (ΔG° ⧧ = 9.0 kcal/mol) and acceptable activation energies (ΔG° ⧧ = 22.5 kcal/mol), respectively, suggesting that the Mo-Mo quintuple bond can be applied to various σ-bond cleavages. In these σ-bond cleavage reactions, the charge-transfer (CT Mo→XH ) from the Mo-Mo quintuple bond to the X-H (X = H, C, or O) bond and that (CT XH→Mo ) from the X-H bond to the Mo-Mo bond play crucial roles. Though the HOMO (dδ-MO) of 1 is at lower energy and the LUMO + 2 (dδ*-MO) of 1 is at higher energy than those of RhCl(PMe 3 ) 2 (LUMO and LUMO + 1 of 1 are not frontier MO), the H-H σ-bond cleavage by 1 more easily occurs than that by the Rh complex. Hence, the frontier MO energies are not the reason for the high reactivity of 1. The high reactivity of 1 arises from the polarization of dδ-type MOs of the Mo-Mo quintuple bond in the transition state. Such a polarized electronic structure enhances the bonding overlap between the dδ-MO of the Mo-Mo bond and the σ*-antibonding MO of the X-H bond to facilitate the CT Mo→XH and reduce the exchange repulsion between the Mo-Mo bond and the X-H bond. This polarized electronic structure of the transition state is similar to that of a frustrated Lewis pair. The easy polarization of the dδ-type MOs is one of the advantages of the metal-metal multiple bond, because such polarization is impossible in the mononuclear metal complex.

  6. Hierarchical self-assembly of a bow-shaped molecule bearing self-complementary hydrogen bonding sites into extended supramolecular assemblies.

    Science.gov (United States)

    Ikeda, Masato; Nobori, Tadahito; Schmutz, Marc; Lehn, Jean-Marie

    2005-01-07

    The bow-shaped molecule 1 bearing a self-complementary DAAD-ADDA (D=donor A=acceptor) hydrogen-bonding array generates, in hydrocarbon solvents, highly ordered supramolecular sheet aggregates that subsequently give rise to gels by formation of an entangled network. The process of hierarchical self-assembly of compound 1 was investigated by the concentration and temperature dependence of UV-visible and (1)H NMR spectra, fluorescence spectra, and electron microscopy data. The temperature dependence of the UV-visible spectra indicates a highly cooperative process for the self-assembly of compound 1 in decaline. The electron micrograph of the decaline solution of compound 1 (1.0 mM) revealed supramolecular sheet aggregates forming an entangled network. The selected area electronic diffraction patterns of the supramolecular sheet aggregates were typical for single crystals, indicative of a highly ordered assembly. The results exemplify the generation, by hierarchical self-assembly, of highly organized supramolecular materials presenting novel collective properties at each level of organization.

  7. Structural phase change and optical band gap bowing in hot wall deposited CdSe{sub x}Te{sub 1-x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore, Tamilnadu (India); Jayakumar, S.; Kannan, M.D.; Balasundaraprabhu, R. [Thin Film Center, PSG College of Technology, Coimbatore, Tamilnadu (India)

    2009-04-15

    CdSe{sub x}Te{sub 1-x} thin films of different compositions have been deposited on glass substrates by hot wall deposition method under conditions very close to thermodynamical equilibrium with minimum loss of material. The structural studies carried out on the deposited films revealed that they are crystalline in nature and exhibit either cubic zinc blende or hexagonal phase or both depending on the composition of the material. The lattice parameter values for both cubic and hexagonal phases have been determined and are observed to vary with composition according to Vegard's law. The optical properties of the deposited CdSe{sub x}Te{sub 1-x} thin films have been studied using transmittance spectra. The spectra shows a sharp fall in transmittance at wavelength corresponding to the band gap of the material. The optical band gap has been determined and found to be direct allowed. The band gap has been observed to strongly depend on film composition. The variation of band gap with composition has been observed to be quadratic in nature exhibiting a bowing behaviour. (author)

  8. On the origin of field-aligned beams at the quasi-perpendicular bow shock: multi-spacecraft observations by Cluster

    Directory of Open Access Journals (Sweden)

    H. Kucharek

    2004-07-01

    Full Text Available Two distinct populations of reflected and accelerated ions are known to originate from quasi-perpendicular shocks, gyrating ions and reflected ion beams. Recent observations under such bow shock conditions with Cluster have shown strong evidence that both particle distributions appear to emerge from the same reflection process. In this paper the basic production mechanism of field-aligned beams has been investigated by using CLUSTER multi-spacecraft measurements. We have analyzed several quasi-perpendicular shocks with the Cluster Ion Spectrometry experiment (CIS and followed the spatial and temporal evolution of the reflected and transmitted ion populations across the shock. These observations show that the field-aligned beams most likely result from effective scattering in pitch angle during reflection in the shock ramp. Investigating a low Mach number shock, leakage of a fraction of the thermalized ion distribution in the downstream region does not appear to be the source as the volume in phase space occupied by beam ions is empty downstream of the shock ramp.

  9. Profiling Radar Observations and Numerical Simulations of a Downslope Wind Storm and Rotor on the Lee of the Medicine Bow Mountains in Wyoming

    Directory of Open Access Journals (Sweden)

    Binod Pokharel

    2017-02-01

    Full Text Available This study describes a downslope wind storm event observed over the Medicine Bow range (Wyoming, USA on 11 January 2013. The University of Wyoming King Air (UWKA made four along-wind passes over a five-hour period over the mountain of interest. These passes were recognized as among the most turbulent ones encountered in many years by crew members. The MacCready turbulence meter aboard the UWKA measured moderate to severe turbulence conditions on each pass in the lee of the mountain range, with eddy dissipation rate values over 0.5 m2/3 s−1. Three rawinsondes were released from an upstream location at different times. This event is simulated using the non-hydrostatic Weather Research and Forecast (WRF model at an inner- domain resolution of 1 km. The model produces a downslope wind storm, notwithstanding some discrepancies between model and rawinsonde data in terms of upstream atmospheric conditions. Airborne Wyoming Cloud Radar (WCR vertical-plane Doppler velocity data from two beams, one pointing to the nadir and one pointing slant forward, are synthesized to obtain a two-dimensional velocity field in the vertical plane below flight level. This synthesis reveals the fine-scale details of an orographic wave breaking event, including strong, persistent downslope acceleration, a strong leeside updraft (up to 10 m·s−1 flanked by counter-rotating vortices, and deep turbulence, extending well above flight level. The analysis of WCR-derived cross-mountain flow in 19 winter storms over the same mountain reveals that cross-mountain flow acceleration and downslope wind formation are difficult to predict from upstream wind and stability profiles.

  10. Logs and paleoseismic interpretations from trenches 14C and 14D on the Bow Ridge fault, northeastern Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    Menges, C.M.; Taylor, E.M.; Vadurro, G.; Oswald, J.A.; Cress, R.; Murray, M.; Lundstrom, S.C.; Paces, J.B.; Mahan, S.A.

    1997-01-01

    Detailed studies of trenches 14D and 14C on the Bow Ridge fault indicate two to three displacements and long recurrence intervals during the middle to late Quaternary. The main trace of the fault is marked by a thick (20--40 centimeters wide) subvertical shear zone coated with multiple carbonate-silica laminae and several generations of fine-grained fissure-fill debris. Exposed in the trenches is a vertically stacked sequence of thin (0.3--1.5 meters thick) fine-grained colluvial, alluvial, and eolian deposits that commonly contain smaller wedge-shaped units or several weakly to strongly developed buried paleosols, or both. The two to three surface-rupture events are recognized at discrete stratigraphic intervals in the sequence based on (1) incremental up-section decreases in offset of marker horizons, (b) upward terminations of shear zones, fissure fills, and fractures, and (c) the position of small scarp-derived colluvial wedges deposited adjacent to the fault above downfaulted marker horizons. Preferred estimates of the vertical displacement per event are 12 and 40 centimeters. Left-oblique striations are observed on carbonate fault laminae, which, if tectonic in origin, increase the vertical displacement by factors of 1.1 to 1.7, yielding preferred net slip displacements per event of 13 to 70 centimeters. Thermoluminescence ages of 48 ± 20 and 132 ± 23 thousand years bracket the ages of the events, which probably occurred near the bounding ages of the time interval. These age constraints suggest long, average recurrence intervals between the three events of 75 to 210 ky; the preferred values range between 100 to 140 ky. The small net cumulative displacement of two dated reference horizons yield very low fault slip rates of 0.002 to 0.007 millimeters per year; the preferred value is 0.003 millimeters per year

  11. Use of safety case to accomplish with Brazilian regulations for drilling units; Uso de caso de seguranca para cumprir com as normas brasileiras para unidades de perfuracao: metodologia Bow Tie

    Energy Technology Data Exchange (ETDEWEB)

    Bardy, Mariana; Silveira, Paula Dias; Oliveira, Katia [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil). Risk Advisory

    2012-07-01

    The last accidents on the industry, mainly after BP accident in Texas City and Macondo blowout, showed and increased the importance of safety barriers on prevention of such events. The safety barriers can be identified in risk analysis studies such as Preliminary Hazard Analysis or HAZOP. But, the identification of safety barriers is not enough, it is necessary to maintain their integrity to guarantee that when demanded they work properly as expected. The methodology presented in this document aim to evaluate the integrity condition of safety barriers and their compliance with the project original characteristics using the Bow Tie and an audit process, and searching for actions that can guarantee the barriers integrity when demanded in a proactive way. The Bow Tie diagrams provide a graphic picture of accidental scenarios, join a relational perspective between event, cause, consequence and barriers, and additionally provide a clear view of possible threats and consequences related with events with high damage potential. The application of methodology described in this document is presented based on a case study related to an accidental release of flammable liquid due to dropped objects on the topside of an offshore unit. Among the benefits identified using this proposed methodology it can be highlighted the possibility to form an integrated overview of management system and of factors that can reduce losses. The Bow Tie diagram provides an overview of process accidents, in several different organization levels, and the integration between different areas responsible for management of different barriers groups. Complementing those diagrams with an audit process it can be determined the real image of company management system related to process safety, which make possible the identification of main points for improvement. (author)

  12. Another string.... but no bow.

    LENUS (Irish Health Repository)

    Green, Connor

    2011-04-01

    Based on a positive personal experience, the authors advocate the use of a wound protector\\/retractor such as the Alexis system in total hip arthroplasty, to avoid intra-operative bacterial contamination from the skin, while avoiding damage to the skin and other soft tissues.

  13. Sailing comfort through axe bow

    NARCIS (Netherlands)

    Verdult, E.

    2012-01-01

    Every year, the Royal Netherlands Sea Rescue Institution (KNRM) heads out to sea 2000 times to rescue people. In conditions with high waves, the lifeboats hit the water so hard that the crew have diffilty keeping upright in the pilot house. Sailing slowly is therefore the only option. But the boats

  14. BASEMAP, SILVER BOW COUNTY, MONTANA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — FEMA Framework Basemap datasets comprise six of the seven FGDC themes of geospatial data that are used by most GIS applications (Note: the seventh framework theme,...

  15. SURVEY, SILVER BOW COUNTY, MT

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  16. Effects of variation in background mixing ratios of N2, O2, and Ar on the measurement of δ18O-H2O and δ2H-H2O values by cavity ring-down spectroscopy

    Science.gov (United States)

    Johnson, Jennifer E.; Rella, Chris W.

    2017-08-01

    Cavity ring-down spectrometers have generally been designed to operate under conditions in which the background gas has a constant composition. However, there are a number of observational and experimental situations of interest in which the background gas has a variable composition. In this study, we examine the effect of background gas composition on a cavity ring-down spectrometer that measures δ18O-H2O and δ2H-H2O values based on the amplitude of water isotopologue absorption features around 7184 cm-1 (L2120-i, Picarro, Inc.). For background mixtures balanced with N2, the apparent δ18O values deviate from true values by -0.50 ± 0.001 ‰ O2 %-1 and -0.57 ± 0.001 ‰ Ar %-1, and apparent δ2H values deviate from true values by 0.26 ± 0.004 ‰ O2 %-1 and 0.42 ± 0.004 ‰ Ar %-1. The artifacts are the result of broadening, narrowing, and shifting of both the target absorption lines and strong neighboring lines. While the background-induced isotopic artifacts can largely be corrected with simple empirical or semi-mechanistic models, neither type of model is capable of completely correcting the isotopic artifacts to within the inherent instrument precision. The development of strategies for dynamically detecting and accommodating background variation in N2, O2, and/or Ar would facilitate the application of cavity ring-down spectrometers to a new class of observations and experiments.

  17. FCC-hh turn-around cycle

    CERN Document Server

    Alemany Fernandez, Reyes; Bartmann, Wolfgang; Buffat, Xavier; Niemi, Arto; Schulte, Daniel; Solfaroli Camillocci, Matteo; Stoel, Linda

    2016-01-01

    The turn-around cycle time of a collider is defined as the time spent between the end of stable beams and the start of the next stable beams period, and its calculation is of fundamental importance. On one side it is a crucial ingredient for the computation of the optimal time spent in luminosity production, which defines the integrated luminosity per fill or store. On the other side, combined with the availability and reliability of the machine, it allows to perform a detailed breakdown of the operational performance of the collider over an operational season, i.e. percentage of time in stable beams and beam in the machine with respect to down time. This paper presents a preliminary operational cycle definition for the hadron-hadron Future Circular Collider, as a base line for estimating the corresponding turn-around time. The cycle definition is based on the Large Hadron Collider (LHC) operational cycle. Two turn-around times are presented, the theoretical one and a more realistic one based on the LHC exper...

  18. IFIN-HH, Scientific Report 1998

    International Nuclear Information System (INIS)

    Andries, Mihai; Dragulici, Cristian; Enescu, Sanda-Elena; Oancea, Margareta; Preda, Mihaela; Prodan, Lucia; Raduta, Adriana; Sandu, Doina; Schiaua, Claudiu

    1999-01-01

    The annual report on 1998 of the Horia Hulubei National Institute for Physics and Nuclear Engineering, presents the Institute's activity in the fields of Theoretical Physics (Nuclear and Atomic Physics, Mathematical Physics, Field Theory, and Particle Physics, and Physics of Information), Experimental Physics (Nuclear Structure, Nuclear Reactions, Atomic Physics, Particle Physics, Cosmic Rays and Nuclear Astrophysics, Inertial Physics, Neutron Physics, and Nuclear Transmutations and Nuclear Instruments and Methods), Biophysics, Applied Physics, Radiation Processing, Tracers and Radiometry, Technological Development, Waste Management and Site Restoration, Standardization. Also, data concerning the Publications, Conferences, Patents, PhD Theses, Scientific Exchanges, Visitors, Invited Seminars, Visits and Seminars abroad are given in appendices. The Report gives also the Directorate, the Heads of Departments and the Research Staff

  19. Madeiras utilizadas na fabricação de arcos para instrumentos de corda: aspectos anatômicos Anatomical features of woods used in the manufacture of bows for stringed instruments

    Directory of Open Access Journals (Sweden)

    Veronica Angyalossy

    2005-12-01

    Full Text Available A madeira de pau-brasil (Caesalpinia echinata Lam. é mundialmente empregada na confecção de arcos para instrumentos de corda, uma vez que apresenta características únicas de ressonância, densidade, durabilidade, beleza, entre outras qualidades, que a tornam ideal para tal uso. Diferentes amostras de pau-brasil, contudo, fornecem arcos com qualidades distintas. No comércio nacional outras madeiras estão sendo empregadas na produção de arcos. Realizou-se, neste estudo, uma análise qualitativa e quantitativa de diferentes amostras de pau-brasil com o objetivo de apontar diferenças na estrutura da madeira que possam contribuir para o entendimento das causas da variação na qualidade do arco, além da análise de outras espécies objetivando determinar, do ponto de vista estrutural, semelhanças ou diferenças com o pau-brasil. Conclui-se que variações no diâmetro dos vasos, distribuição e quantidade de parênquima axial e orientação dos elementos axiais e radiais são parâmetros que devem ser considerados quando se busca determinar as causas das diferenças na qualidade dos arcos de pau-brasil. Constatou-se que arcos de boa qualidade apresentam grã linheira e textura fina. Esta última característica decorre da menor proporção de vasos cujo diâmetro é reduzido, raios homogêneos e fibras com paredes espessas e/ou muito espessas. Assim, a relação entre a estrutura e a qualidade do arco está diretamente relacionada com as dimensões, a distribuição e a proporção das células do lenho.Pernambuco wood (Caesalpinia echinata Lam. has special characteristics like resonance, density, durability, and beauty; for this reason, it is considered the best material for stringed instruments bows. Besides pernambuco wood has been used around the world, some samples, and consequently some bows, are better than others. In Brazil, others woody species have been used in the manufacture of bows. In this paper some wood samples of

  20. Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada

    International Nuclear Information System (INIS)

    Taylor, E.M.; Huckins, H.E.

    1995-01-01

    Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ''carbonate'' in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes

  1. FLOODPLAIN, SILVER BOW COUNTY, MONTANA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

  2. NIH bows to part of Rifkin suit.

    Science.gov (United States)

    Sun, M

    1984-11-30

    Having lost a round in its legal battle with Jeremy Rifkin over field tests of genetically engineered bacteria, the National Institutes of Health will conduct the simpler of two ecological analyses required by the National Environmental Policy Act on three proposed experiments. In May 1984 a federal district court ruling halted a University of California field test pending a decision on Rifkin's 1983 suit, which alleged that NIH had violated the Act by approving experiments without studying the ecological consequences. Still to be decided by the U.S. Court of Appeals is whether NIH must also issue full-scale environmental impact statements.

  3. Integrated Bow Waterjet for Amphibious Vehicles.

    Science.gov (United States)

    1983-01-01

    8217 Davidson Laboratory Report 2276, October 1982. 3. J. D. van Manen , "Open-Water Test Series with Propellers in Nozzles," International Shipbuilding Progress...Volume 1, No. 2, 1954, pg. 99. 4. W.P.A. van Lammeren, J. D. van Manen and M.W.C. Oosterveld, "The Wageningen B-Screw Series," Trans. SNAME 1969, pg

  4. Leaders bow heads for synagogue tragedy

    Index Scriptorium Estoniae

    2005-01-01

    4. juulil 1941 põletasid natsid Riias maha sünagoogi, mille käigus võis hukkuda kuni 2000 juuti. 4. juuli mälestustseremoonial osales hulk tipp-poliitikuid ja väliskülalisi, kellele Iisraeli suursaadik Gary Koren pani südamele propageerida antisemitismi null-tolerantsi Lätis

  5. Retraction RETRACTION of "Methylation of the RASSFIA promoter in breast cancer" by Y. Ji, H.H. Jin, M.D. Wang, W.X. Cao, J.L. Bao - Genet. Mol. Res. 15 (2): gmr.15028261 (2016) - DOI: 10.4238/gmr.15028261.

    Science.gov (United States)

    Ji, Y; Jin, H H; Wang, M D; Cao, W X; Bao, J L

    2016-10-07

    The retracted article is: Ji Y, Jin HH, Wang MD, Cao WX, et al. (2016). Methylation of the RASSFIA promoter in breast cancer. Genet. Mol. Res. 15: gmr.15028261. There are significant parts of this article (particularly, in the discussion section) that are copied from "Methylation of HIN-1, RASSF1A, RIL and CDH13 in breast cancer is associated with clinical characteristics, but only RASSF1A methylation is associated with outcome", by Jia Xu, Priya B Shetty, Weiwei Feng, Carol Chenault, Robert C Bast Jr, Jean-Pierre J Issa, Susan G Hilsenbeck and Yinhua Yu, published in BMC Cancer 2012; 12: 243. DOI: 10.1186/1471-2407-12-243. The first paragraphs of both discussions are identical. This is concerning. The abstract and introduction sections have much of their text plagiarized. Overall, there is high plagiarism detected. The GMR editorial staff was alerted and after a thorough investigation, we have strong reason to believe that the peer review process was failure and, after review and contacting the authors, the editors of Genetics and Molecular Research decided to retract the article in accordance with the recommendations of the Committee on Publication Ethics (COPE). The authors and their institutions were advised of this serious breach of ethics.

  6. Organización del mercado de generación de electricidad colombiano. Una aplicación de los índices de diversificación tecnológica y de concentración H-H y C-4, 1995-2004

    Directory of Open Access Journals (Sweden)

    Gustavo Castillo

    2005-06-01

    Full Text Available El objetivo de este artículo es analizar la evolución de la concentración del mercado de generación de electricidad colombiano, con base en los índices de diversificación tecnológica y de concentración H-H y C-4, en el período 1995-2004. Se entiende la concentración como un comportamiento empresarial que, desde la perspectiva del regulador, puede atentar contra los resultados de eficiencia esperados con la reforma de las reglas de juego para la industria. Del análisis se concluye, por un lado, que los niveles de concentración han disminuido en el período de estudio, pasando de oligopolio fuerte a moderado; sin embargo, por el otro, al agrupar las empresas por vínculos empresariales los índices se elevan. Curiosamente, las empresas generadoras que apuntalan los índices son aquellas con diversificación tecnológica alta.

  7. Organización del mercado de generación de electricidad colombiano.: Una aplicación de los índices de diversificación tecnológica y de concentración H-H y C-4, 1995-2004

    Directory of Open Access Journals (Sweden)

    David Tobón Orozco

    2005-01-01

    Full Text Available El objetivo de este artículo es analizar la evolución de la concentración del mercado de generación de electricidad colombiano, con base en los índices de diversificación tecnológica y de concentración H-H y C-4, en el período 1995-2004. Se entiende la concentración como un comportamiento empresarial que, desde la perspectiva del regulador, puede atentar contra los resultados de eficiencia esperados con la reforma de las reglas de juego para la industria. Del análisis se concluye, por un lado, que los niveles de concentración han disminuido en el periodo de estudio, pasando de oligopolio fuerte a moderado; sin embargo, por el otro, al agrupar las empresas por vínculos empresariales los índices se elevan. Curiosamente, las empresas generadoras que apuntalan los índices son aquellas con diversificación tecnológica alta.

  8. Observing shape resonances in ultraslow H^++H elastic scattering

    Science.gov (United States)

    Macek, J. H.; Schultz, D. R.; Ovchinnikov, S. Yu.; Krstic, P. S.

    2004-05-01

    We have calculated highly accurate elastic and charge transfer cross sections for proton-hydrogen scattering at energies 0.0001-10 eV, using fully quantal approach (P.S. Krstic and D.R. Schultz, J. Phys. B 32, 3485 (1999)). A number of resonances are observed. We calculate the positions and widths of the shape resonances in the effective potentials for various orbital angular momenta (J. H. Macek and S. Yu. Ovchinnikov, Phys. Rev. A 50, 468 (1994)). These correlate well with the observed resonances. We acknowledge support from the US DOE through ORNL, managed by UT-Battelle, LLC under contract DE-AC05-00OR22725.

  9. Autocrine and Paracrine Hh Signaling Regulate Prostate Development

    Science.gov (United States)

    2010-09-01

    Rev. Mol. Cell. Biol. 6, 306–317 7. Wang, B. E., Shou, J., Ross, S., Koeppen, H., De Sauvage, F. J., and Gao, W. Q. (2003) J. Biol. Chem. 278, 18506...and Placzek, M. (2006) Nat. Rev. Genet. 7, 841–850 13. Callahan, C. A., Ofstad, T., Horng, L.,Wang, J. K., Zhen, H. H., Coulombe , P. A., and Oro, A. E...Albig, A. R., and Schiemann, W. P. (2005)Mol. Biol. Cell 16, 609–625 45. Olsen, M. W., Ley , C. D., Junker, N., Hansen, A. J., Lund, E. L., and Krist

  10. On the structure and origin of HH jets.

    Science.gov (United States)

    De Colle, Fabio

    2011-10-01

    The goal of this proposal is to study the structure and origin of jets from young stellar objects by using HST observations of T Tauri jets. To this end, we propose to use three different but complementary approaches: tomographic reconstruction to recover the jet velocity cross-section, numerical simulations to compare the predictions of jet ejection models with the observations, and a statistical analysis of the data. First, we plan to use standard tomographic reconstruction techniques to derive the cross-section {i.e. perpendicular to the jet axis} velocity and physical parameters {electron density, temperature and ionization fraction} of the jets. This will allow a reliable estimation of mass- and momentum-flux from the central star-disk system, which, together with the cross-sectional velocity constraints, will help to distinguish between different jet ejection models. Second, we will focus our study on understanding recent observations of stellar jets showing transverse velocity shifts in several emission lines. The origin of these velocity shift is still debated: they can be interpreted as evidence of rotation, or they can be originated by side-to-side asymmetries in the flow or in the ambient medium. To distinguish between these two scenarios, we plan to uncover the origin of transverse velocity shift by a statistical approach based on the presence {or absence} of correlations between the velocity shifts and the degree of asymmetries in the flow. Finally, we will use our adaptive mesh refinement code to compare the observations with a large number of numerical simulations constructed on different jet ejection mechanisms.

  11. Accelerator mass spectrometry at IFIN-HH in Bucharest

    International Nuclear Information System (INIS)

    Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.

    1999-01-01

    An AMS (Accelerator Mass Spectrometry) facility was constructed at the FN - 8 MV Tandem Accelerator of the National Institute for Physics and Nuclear Engineering in Bucharest. It represents the first experimental setup of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarised at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses), a double focussing, 90 angle analysing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight stack magazine attached to the ion source. On the exit side of the Tandem Accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high energy side, is optically achromatic and contains two 90 angle analysing magnets of 150 MEP. For particle detection a Bragg-curve Spectroscopy Detector (ionisation chamber) is used and a multi-anode gas detector with TOF discrimination is under construction. The research programme at this new facility is focused on using 26 Al for medical applications. In future it will be use for 129 I - AMS measurements as a nuclear safeguard. This long lived isotope will be used to monitor and investigate the transport of 129 I in vicinity of three nuclear power plants in Eastern Europe: Kozloduy (Bulgaria), Cernavoda (Romania) and Chernobyl (Ukraine). Measurements will concern soil, precipitation and air samples. Water samples will be collected along the flow of rivers Danube and Dnieper, from the Danube Delta and from coastal areas of the Black Sea. (authors)

  12. Resonant charge exchange for H-H+ in Debye plasmas

    Science.gov (United States)

    Laricchiuta, Annarita; Colonna, Gianpiero; Capitelli, Mario; Kosarim, Alexander; Smirnov, Boris M.

    2017-11-01

    The dynamics of resonant charge exchange in proton-hydrogen collisions embedded in plasma is investigated in the framework of the asymptotic approach, modified to account for the effect of Debye-Hückel screening in particle interactions. The cross sections exhibit a marked dependence on the Debye length in regimes of severe plasma confinement. Processes involving excited states H( n)-H+ are also discussed.

  13. Optimising A Read Out for A Possible FCC hh Collision

    CERN Document Server

    Alagaraisamy, Revathy

    2017-01-01

    The Future Circular Collider Study (FCC) aims to provide a conceptual design for an accelerator to possibly be constructed in the 2040s-2050s. The most ambitious design proposed is a 100 km-circumference proton-proton collider (FCChh), designed to achieve a centre-of-mass energy of 100 TeV and exceeding . Thus,along with this the precision of the detector is increased via many ways,e.g: calculation and reduction of electronic noise with PCB readout in detector.

  14. Orientation and alignment in H+-H collisions

    International Nuclear Information System (INIS)

    Hansen, J.P.; Dubois, A.; Nielsen, S.E.

    1991-01-01

    We have calculated probabilities, orientation parameters, and alignment angles for 2p excitation and capture in proton-hydrogen collisions at 50- and 100-keV projectile energy. The results, obtained from solving the Schroedinger equation in a multistate atomic-orbital expansion, are compared to those of a similar, recently published investigation. In both studies, similar results for excitation are found, and also for capture at large impact parameters. The origin of different predictions for capture at intermediate impact parameters is discussed

  15. High spectral resolution observations of the H2 2.12 micron line in Herbig-Haro objects

    International Nuclear Information System (INIS)

    Zinnecker, H.; Mundt, R.; Geballe, T.R.; Zealey, W.J.

    1989-01-01

    High-spectral-resolution Fabry-Perot observations of the H 2 2.12-micron line emissions of several Herbig-Haro (HH) objects are discussed. It is shown that H 2 emission by the shock heating of external molecular gas in the wings of the bow shock associated with the working surface of a high-velocity jet may occur for HH objects associated with the jet's end. The shock heating of external molecular gas entrained in the flow by internal shocks occurring in the jet itself and/or in its boundary layer may be the H 2 emission mechanism for HH objects observed along the flow axis. 59 refs

  16. Molecular hydrogen mapping of Herbig-Haro 7-11; a filamentary bullet

    International Nuclear Information System (INIS)

    Lightfoot, J.F.; Glencross, W.M.

    1986-01-01

    A map is presented of the Q-branch H 2 line emission associated with Herbig-Haro 7-11. The molecules are shock-excited and the emitting area stretches 4 arcmin north-west from HH7-11 in a fairly sharp and straight line. The evidence suggests that the emission occurs where a spine of dense molecular gas is being struck by a jet from the young star SVS13. The origin of the Herbig-Haro objects is discussed. It is suggested that HH7-11 are the bow-shocks formed around a helical filament of dense gas moving at 200 km s -1 through the molecular cloud. The filament could be produced by a well-collimated precessing jet from SVS13. HH2. HH12 and HH101 may be explained in a similar way. (author)

  17. GIANT HERBIG-HARO FLOWS IN L1228: A SECOND LOOK

    International Nuclear Information System (INIS)

    Devine, D.; Chiriboga, D.; Smart, K.; Bally, J.

    2009-01-01

    We present second epoch narrowband Hα and [S II] images of the giant Herbig-Haro flows HH199 and HH200 in the L1228 molecular cloud. Proper motions for several members of the HH200 flow were determined by comparing the new images to similar narrowband images taken 13 years earlier. Based on our measurements, the HH200 flow is inclined by 15 deg. to the plane of the sky and has a steady, fixed outflow axis with P.A. = 49 deg. There is a general nonlinear decline in the proper motions with increasing distance from the source, and it appears that successive eruption episodes have cleared out a relatively free channel through the L1228 cloud. The bright knot HH200B6 is located at the end of the channel along the edge of L1228, and appears to be tracing the location where the outflow erupts from the cloud. We did not detect any proper motions for HH200B6, and suggest that it is the plug of material that has been bored out by the cumulative effects of numerous eruptions along a steady outflow axis. The proper motions combined with the spacing of the HH200 knots along the flow axis are consistent with a velocity variable outflow, which erupts periodically on timescales of the order of 600 years. The relatively small size of the knots combined with the large proper motions and derived bow-shock speeds would seem to rule out the presence of a less collimated wind component. We also discuss the HH199 flow, which is radically different from HH200. The members of the HH199 flow exhibited large changes in the morphology and emission, and were not suitable for determining proper motions. The HH200 and HH199 flows appear to be the opposite ends of the spectrum of giant HH flows.

  18. THE SPINDLE: AN IRRADIATED DISK AND BENT PROTOSTELLAR JET IN ORION

    Energy Technology Data Exchange (ETDEWEB)

    Bally, John; Youngblood, Allison; Ginsburg, Adam, E-mail: John.Bally@colorado.edu, E-mail: Allison.Youngblood@colorado.edu, E-mail: Adam.Ginsburg@colorado.edu [Department of Astrophysical and Planetary Sciences, University of Colorado, UCB 389, Boulder, CO 80309 (United States)

    2012-09-10

    We present Hubble Space Telescope observations of a bent, pulsed Herbig-Haro jet, HH 1064, emerging from the young star Parenago 2042 embedded in the H II region NGC 1977 located about 30' north of the Orion Nebula. This outflow contains eight bow shocks in the redshifted western lobe and five bow shocks in the blueshifted eastern lobe. Shocks within a few thousand AU of the source star exhibit proper motions of {approx}160 km s{sup -1} but motions decrease with increasing distance. Parenago 2042 is embedded in a proplyd-a photoevaporating protoplanetary disk. A remarkable set of H{alpha} arcs resembling a spindle surround the redshifted (western) jet. The largest arc with a radius of 500 AU may trace the ionized edge of a circumstellar disk inclined by {approx}30 Degree-Sign . The spindle may be the photoionized edge of either a {approx}3 km s{sup -1} FUV-driven wind from the outer disk or a faster MHD-powered flow from an inner disk. The HH 1064 jet appears to be deflected north by photoablation of the south-facing side of a mostly neutral jet beam. V2412 Ori, located 1' west of Parenago 2042 drives a second bent flow, HH 1065. Both HH 1064 and 1065 are surrounded by LL Ori-type bows marking the boundary between the outflow cavity and the surrounding nebula.

  19. Two dimensional hybrid simulation of a curved bow shock

    International Nuclear Information System (INIS)

    Thomas, V.A.; Winske, D.

    1990-01-01

    Results are presented from two dimensional hybrid simulations of curved collisionless supercritical shocks, retaining both quasi-perpendicular and quasi-parallel sections of the shock in order to study the character and origin of the foreshock ion population. The simulations demonstrate that the foreshock ion population is dominated by ions impinging upon the quasi-parallel side of the shock, while nonlocal transport from the quasi-perpendicular side of the shock into the foreshock region is minimal. Further, it is shown that the ions gain energy by drifting significantly in the direction of the convection electric field through multiple shock encounters

  20. Bell's Spaceships: The Views from Bow and Stern

    Science.gov (United States)

    Lewis, Geraint F.; Barnes, Luke A.; Sticka, Martin J.

    2018-01-01

    Unravelling apparent paradoxes has proven to be a powerful tool for understanding the complexities of special relativity. In this paper, we focus upon one such paradox, namely Bell's spaceship paradox, examining the relative motion of two uniformly accelerating spaceships. We consider the view from either spaceship, with the exchange of photons between the two. This recovers the well-known result that the leading spaceship loses sight of the trailing spaceship as it is redshifted and disappears behind what is known as the `Rindler horizon'. An immediate impact of this is that if either spaceship tries to measure the separation through `radar ranging', bouncing photons off one another, they would both eventually fail to receive any of the photon `pings' that they emit. We find that the view from this trailing spaceship is, however, starkly different, initially, seeing the leading spaceship with an increasing blueshift, followed by a decreasing blueshift. We conclude that, while the leading spaceship loses sight of the trailing spaceship, for the trailing spaceship the view of the separation between the two spaceships, and the apparent angular size of the leading spaceship, approach asymptotic values. Intriguingly, for particular parameterisation of the journey of the two spaceships, these asymptotic values are identical to those properties seen before the spaceships began accelerating, and the view from the trailing spaceship becomes identical to when the two spaceships were initially at rest.