Science.gov

Sample records for forbidden line intensities

  1. Effect of deuteron temperature on iron forbidden line intensities in rf-heated tokamak plasmas

    SciTech Connect

    Sato, K.; Suckewer, S.; Wouters, A.

    1987-05-01

    Two line ratios, the forbidden line at 845.5 A (2s/sup 2/2p /sup 2/P/sub 1/2/ - 2s/sup 2/2p /sup 2/P/sub 3/2/) to the allowed line at 135.7 A (2s/sup 2/2p /sup 2/P/sub 1/2/ - 2s2p/sup 2/ /sup 2/D/sub 3/2/) in Fe XXII and the forbidden line at 592.1 A (2s/sup 2/2p/sup 4/ /sup 3/P/sub 2/ - 2s/sup 2/2p/sup 4/ /sup 1/D/sub 2/) to the forbidden line at 1118.2 A (2s/sup 2/2p/sup 4/ /sup 3/P/sub 2/ - 2s/sup 2/2p/sup 4/ /sup 3/P/sub 1/) in Fe XIX, have been measured as the ion temperature-sensitive line ratios during rf heating in the Princeton Large Torus. The results indicate that deuteron collisions in plasmas of high deuteron temperature have a noticeable effect on the intensity of the forbidden lines. Measured relative intensities are compared with values from level population calculations, which include deuteron collisional excitation between the levels of the ground configuration. The agreement between the observed and calculated ratios is within 30%. A method for deuteron (or proton) temperature measurement in tokamak plasmas is discussed. 37 refs.

  2. Revisiting Forbidden Lines in T Tauri stars

    NASA Astrophysics Data System (ADS)

    Feng, Wanda; Edwards, Suzan; Pascucci, Ilaria; Rigliaco, Elisabetta

    2015-01-01

    Low excitation forbidden lines of [O I], [S II], and [N II] in the spectra of accreting young stars have long been recognized as mass outflow tracers due to their primarily blueshifted emission. The profiles often possess two kinematic components, a high velocity component (centroids from -50 to -200 km/s) arising in an extended collimated jet and a low velocity component (centroids from -5 to -10 km/s) possibly arising in some form of disk wind. Moreover, a recent paper by Rigliaco et al. (2013) explores the possibility that the low velocity component may itself be comprised of distinct broad and narrow kinematic contributions. Using high-resolution spectra acquired with the Keck I HIRES spectrograph, at a velocity resolution of 5 km/s, we aim to separate the various kinematic components in T Tauri forbidden lines. Observed profiles from lines of [O I] 6300, [0 I] 5577, and [S II] 6731 are decomposed via Gaussian fits into components that share kinematic features across multiple lines. For the high velocity components, we modernize the relation between mass ejection in the jets and mass accretion rates onto the star, originally found by Hartigan, Edwards, and Ghandor (1995). For the low velocity components, we confirm that a combination of broad and narrow components is commonly observed, and line ratios of each component are compared to those expected from models of slow photo-evaporative flows from the disk.

  3. The detection of the 5577.3 A forbidden line of O I in comets

    NASA Technical Reports Server (NTRS)

    Krishna Swamy, K. S.; Spinrad, H.

    1984-01-01

    The spectral synthesis of C2 Swan band sequence Delta V = -1 indicates the intensity of the forbidden green oxygen line of 5577.3 A to be about 3 to 5 percent of the 6300 A line. Therefore, it appears that the green line should be observable in high-resolution spectra of a bright comet. Festou and Feldman suggest red/green greater than or equal to 10 means a water parent origin.

  4. Modeling Asymmetric Forbidden Line Emission Profiles in Supernovae with Clumping

    NASA Astrophysics Data System (ADS)

    Herrington, Jessica; Ignace, R.; Hole, K. T.

    2010-01-01

    There are some supernovae that display emission line profiles that are asymmetric in shape. One cause for asymmetry could be an in-homogeneous density distribution, or "clumps". We explore the effects of clumps on the emission line profiles of forbidden lines. Our model assumes the ejecta shell is spherically symmetric in velocity, with a central cavity. The model assigns density perturbations to conical sections in the ejecta. To model the emission profile for a forbidden line, we use Sobolev theory. Our model gives asymmetric profiles when the clumping is introduced. The amount of asymmetry varies with the range of density perturbations allowed, and the relative asymmetry evolves in time. This project was funded by a partnership between the National Science Foundation (NSF AST-0552798), Research Experiences for Undergraduates (REU), and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs.

  5. Collision strengths and transition probabilities for Co III forbidden lines

    NASA Astrophysics Data System (ADS)

    Storey, P. J.; Sochi, Taha

    2016-07-01

    In this paper we compute the collision strengths and their thermally averaged Maxwellian values for electron transitions between the 15 lowest levels of doubly ionized cobalt, Co2+, which give rise to forbidden emission lines in the visible and infrared region of spectrum. The calculations also include transition probabilities and predicted relative line emissivities. The data are particularly useful for analysing the thermodynamic conditions of supernova ejecta.

  6. The optical depth of the 158 micron forbidden C-12 II line - Detection of the F = 1 - 0 forbidden C-13 II hyperfine-structure component. [in Orion nebula

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Townes, C. H.; Geis, N.; Madden, S. C.; Herrmann, F.; Genzel, R.; Poglitsch, A.; Jackson, J. M.

    1991-01-01

    The detection of the F = 1 - 0 hyperfine component of the 158-micron forbidden C-13 II fine-structure line in the interstellar medium is reported. A 12-point intensity map was obtained of the forbidden C-13 distribution over the inner 190-arcsec (R.A.) X 190-arcsec (decl.) regions of the Orion Nebula using an imaging Fabry-Perot interferometer. The forbidden C-12 II/C-13 II line intensity ratio varies significantly over the region mapped. It is highest (86 +/-0) in the core of the Orion H II region, and significantly lower (62 +/-7) in the outer regions of the map, reflecting higher optical depth in the forbidden C-12 II line here. It is suggested that this enhanced optical depth is the result of limb brightening of the optically thin forbidden C-13 II line at the edges of the bowl-shaped H II region blister.

  7. Forbidden lines of highly ionized ions for localized plasma diagnostics

    SciTech Connect

    Hinnov, E.; Fonck, R.; Suckewer, S.

    1980-06-01

    Numerous optically forbidden lines resulting from magnetic dipole transitions in low-lying electron configurations of highly ionized Fe, Ti and Cr atoms have been identified in PLT and PDX tokamak discharges, and applied for localized diagnostics in the high-temperature (0.5 to 3.0 keV) interior of these plasmas. The measurements include determination of local ion densities and their variation in time, and of ion motions (ion temperature, plasma rotations) through Doppler effect of the lines. These forbidden lines are particularly appropriate for such measurements because under typical tokamak conditions their emissivities are quite high (10/sup 11/ to 10/sup 14/ photons/cm/sup 3/-sec), and their relatively long wavelengths allow the use of intricate optical techniques and instrumentation. The spatial location of the emissivity is directly measurable, and tends to occur near radii where the ionization potential of the ion in question is equal to the local electron temperature. In future larger and presumably higher-temperature tokamaks analogous measurements with somewhat heavier atoms, particularly krypton, and perhaps zirconium appear both feasible and desirable.

  8. Ion temperature measurements in the ATF torsatron using titanium forbidden lines (abstract)

    NASA Astrophysics Data System (ADS)

    Crume, E. C., Jr.; Horton, L. D.; Isler, R. C.; Morita, S.

    1990-10-01

    Several forbidden lines of titanium have recently become strong enough to be identified in ATF plasmas in the ultraviolet and in the visible. The increase in intensity has resulted from gettering of the vacuum vessel with titanium both to suppress light impurities and to control hydrogen recycling. Three orders of the forbidden Ti xiv line at 2117.1 Å have been observed in vacuum, and the second and third orders have been observed in air using two different Czerny-Turner spectrometers. Doppler broadening of this line has been used to infer ion temperatures in the interior of ATF plasmas. These data supplement ion temperature measurements employing lines from carbon, nitrogen, and oxygen reported earlier [R. C. Isler et al., Nucl. Fusion 29, 1391 (1989)]. Tentative identifications of other forbidden lines such as Ti vii at 1938.4 Å, Ti xv at 2544.8 Å, Ti xvii at 3370.8 Å and 3834.4 Å, and Ti xviii at 1778.1 Å have also been made. Research was sponsored by the Office of Fusion Energy, U.S. Department of Energy, under contract DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc.

  9. Magellanic cloud planetary nebula with suspected strong forbidden iron lines.

    PubMed

    Aller, L H; Czyzak, S J

    1983-03-01

    The relatively high-excitation nebula (Westerlund-Smith object 25) in the large Magellanic cloud shows prominent forbidden lines of [Ar IV], the close [Ne IV] pair lambda4724, 4726, [Ca V] lambda5309, [Fe V] lambda4227, and probably [Fe VI] and [Fe VII], as well. A conventional interpretation of observations secured with a vidicon detector at the Cerro Tololo 4-m telescopes indicates an essentially "normal" helium abundance but depletions of N, O, Ne, and other elements with respect to our own galaxy. When a comparison is made with diffuse nebulae or H II regions in the large Magellanic cloud, we find helium to be more abundant, oxygen to be depleted, and nitrogen, neon, and argon to be comparable. The abundance of sulfur is uncertain. Iron in the gaseous phase is certainly more plentiful than in conventional planetaries. PMID:16593294

  10. Magellanic cloud planetary nebula with suspected strong forbidden iron lines

    PubMed Central

    Aller, L. H.; Czyzak, S. J.

    1983-01-01

    The relatively high-excitation nebula (Westerlund-Smith object 25) in the large Magellanic cloud shows prominent forbidden lines of [Ar IV], the close [Ne IV] pair λ4724, 4726, [Ca V] λ5309, [Fe V] λ4227, and probably [Fe VI] and [Fe VII], as well. A conventional interpretation of observations secured with a vidicon detector at the Cerro Tololo 4-m telescopes indicates an essentially “normal” helium abundance but depletions of N, O, Ne, and other elements with respect to our own galaxy. When a comparison is made with diffuse nebulae or H II regions in the large Magellanic cloud, we find helium to be more abundant, oxygen to be depleted, and nitrogen, neon, and argon to be comparable. The abundance of sulfur is uncertain. Iron in the gaseous phase is certainly more plentiful than in conventional planetaries. PMID:16593294

  11. Forbidden oxygen lines at various nucleocentric distances in comets

    NASA Astrophysics Data System (ADS)

    Decock, A.; Jehin, E.; Rousselot, P.; Hutsemékers, D.; Manfroid, J.; Raghuram, S.; Bhardwaj, A.; Hubert, B.

    2015-01-01

    Aims: We study the formation of the [OI] lines - that is, 5577.339 Å (the green line), 6300.304 Å and 6363.776 Å (the two red lines) - in the coma of comets and determine the parent species of the oxygen atoms using the ratio of the green-to-red-doublet emission intensity, I5577/(I6300 + I6364), (hereafter the G/R ratio) and the line velocity widths. Methods: We acquired high-resolution spectroscopic observations at the ESO Very Large Telescope of comets C/2002 T7 (LINEAR), 73P-C/Schwassmann-Wachmann 3, 8P/Tuttle, and 103P/Hartley 2 when they were close to Earth (<0.6 au). Using the observed spectra, which have a high spatial resolution (<60 km/pixel), we determined the intensities and widths of the three [OI] lines. We spatially extracted the spectra to achieve the best possible resolution of about 1-2'', that is, nucleocentric projected distances of 100 to 400 km depending on the geocentric distance of the comet. We decontaminated the [OI] green line from C2 lines blends that we identified. Results: The observed G/R ratio in all four comets varies as a function of nucleocentric projected distance (between ~0.25 to ~0.05 within 1000 km). This is mainly due to the collisional quenching of O(1S) and O(1D) by water molecules in the inner coma. The observed green emission line width is about 2.5 km s-1 and decreases as the distance from the nucleus increases, which can be explained by the varying contribution of CO2 to the O(1S) production in the innermost coma. The photodissociation of CO2 molecules seem to produce O(1S) closer to the nucleus, while the water molecule forms all the O(1S) and O(1D) atoms beyond 103 km. Thus we conclude that the main parent species producing O(1S) and O(1D) in the inner coma is not always the same. The observations have been interpreted in the framework of the previously described coupled-chemistry-emission model, and the upper limits of the relative abundances of CO2 were derived from the observed G/R ratios. Measuring the [OI

  12. Detection of Forbidden Line Components of Lithium-like Carbon in Stellar Spectra

    NASA Astrophysics Data System (ADS)

    Werner, Klaus; Rauch, Thomas; Hoyer, Denny; Quinet, Pascal

    2016-08-01

    We report the first identification of forbidden line components from an element heavier than helium in the spectrum of astrophysical plasmas. So far, these components were identified only in laboratory plasmas and not in astrophysical objects. Forbidden components are well known for neutral helium lines in hot stars, particularly in helium-rich post-AGB stars and white dwarfs. We discovered that two hitherto unidentified lines in the ultraviolet spectra of hot hydrogen-deficient (pre-) white dwarfs can be identified as forbidden line components of triply ionized carbon (C iv). The forbidden components (3p-4f and 3d-4d) appear in the blue and red wings of the strong, Stark broadened 3p-4d and 3d-4f lines at 1108 Å and 1169 Å, respectively. They are visible over a wide effective temperature range (60,000-200,000 K) in helium-rich (DO) white dwarfs and PG 1159 stars that have strongly oversolar carbon abundances.

  13. Detection of Forbidden Line Components of Lithium-like Carbon in Stellar Spectra

    NASA Astrophysics Data System (ADS)

    Werner, Klaus; Rauch, Thomas; Hoyer, Denny; Quinet, Pascal

    2016-08-01

    We report the first identification of forbidden line components from an element heavier than helium in the spectrum of astrophysical plasmas. So far, these components were identified only in laboratory plasmas and not in astrophysical objects. Forbidden components are well known for neutral helium lines in hot stars, particularly in helium-rich post-AGB stars and white dwarfs. We discovered that two hitherto unidentified lines in the ultraviolet spectra of hot hydrogen-deficient (pre-) white dwarfs can be identified as forbidden line components of triply ionized carbon (C iv). The forbidden components (3p–4f and 3d–4d) appear in the blue and red wings of the strong, Stark broadened 3p–4d and 3d–4f lines at 1108 Å and 1169 Å, respectively. They are visible over a wide effective temperature range (60,000–200,000 K) in helium-rich (DO) white dwarfs and PG 1159 stars that have strongly oversolar carbon abundances.

  14. The interacting winds of Eta Carinae: Observed forbidden line changes and the Forbidden Blue(-Shifted) Crab

    NASA Astrophysics Data System (ADS)

    Gull, Theodore R.; Madura, Thomas; Corcoran, Michael F.; Teodoro, Mairan; Richardson, Noel; Hamaguchi, Kenji; Groh, Jose H.; Hillier, Desmond John; Damineli, Augusto; Weigelt, Gerd

    2015-01-01

    The massive binary, Eta Carinae (EC), produces such massive winds that strong forbidden line emission of singly- and doubly-ionized iron traces wind-wind interactions from the current cycle plus fossil interactions from one, two and three 5.54-year cycles ago.With an eccentricity of >0.9, the >90 solar mass primary (EC-A) and >30 solar mass secondary (EC-B) approach to within 1.5 AU during periastron and recede to nearly 30 AU across apastron. The wind-wind structures move outward driven by the 420 km/s primary wind interacting with the ~3000 km/s secondary wind yielding partially-accelerated compressed primary wind shells that are excited by mid-UV from EC-A and in limited lines of sight, FUV from EC-B.These structures are spectroscopically and spatially resolved by HST's Space Telescope Imaging Spectrograph. At critical binary phases, we have mapped the central 2'x2' region in the light of [Fe III] and [Fe II] with spatial resolution of 0.12' and velocity resolution of 40 km/s.1) The bulk of forbidden emission originates from the large cavity northwest of EC and is due to ionization of massive ejecta from the 1840s and 1890s eruptions. The brightest clumps are the Weigelt Blobs C and D, but there are additionally multiple, fainter emission clumps. Weigelt B appears to have faded.2) Three concentric, red-shifted [FeII] arcs expand at ~470 km/s excited by mid-UV of EC-A.3) The structure of primarily blue-shifted [Fe III] emission resembles a Maryland Blue Crab. The claws appear at the early stages of the high-excitation recovery from the periastron passage, expand at radial velocities exceeding the primary wind terminal velocity, 420 km/s and fade as the binary system approaches periastron with the primary wind enveloping the FUV radiation from EC-B.4) All [Fe III] emission faded by late June 2014 and disappeared by August 2, 2014, the beginning of periastron passage.Comparisons to HST/STIS observations between 1998 to 2004.3 indicate long-term fading of [Fe II

  15. Detection of forbidden line O I 63 micron emission from the galactic center

    NASA Technical Reports Server (NTRS)

    Lester, D. F.; Werner, M. W.; Storey, J. W. V.; Watson, D. M.; Townes, C. H.

    1981-01-01

    The detection of the 63 micron line of forbidden line O I is reported for three positions in the H II region complex Sgr A at the galactic center. Velocity resolution of the line indicates that the emitting material has both rotational and radial motion of magnitude similar to that of the ionized gas in the core, and that a substantial amount of the emitting material lies within the central few parsecs of the Galaxy. A model in which forbidden line O I is collisionally excited by neutral hydrogen, either from the warm region ahead of an ionization front or behind a shock, is proposed and gives a total mass of hot, neutral gas within the central 3 pc of the Galaxy of between 10 and 1000 solar mass. A limit on the flux of this line has been set for Sgr B2.

  16. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    NASA Astrophysics Data System (ADS)

    Cheng, X.; Ding, M. D.

    2016-05-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s‑1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  17. A Far Ultraviolet Spectroscopic Explorer Survey of Coronal Forbidden Lines in Late-Type Stars

    NASA Astrophysics Data System (ADS)

    Redfield, Seth; Ayres, Thomas R.; Linsky, Jeffrey L.; Ake, Thomas B.; Dupree, A. K.; Robinson, Richard D.; Young, Peter R.

    2003-03-01

    We present a survey of coronal forbidden lines detected in Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of nearby stars. Two strong coronal features, Fe XVIII λ974 and Fe XIX λ1118, are observed in 10 of the 26 stars in our sample. Various other coronal forbidden lines, observed in solar flares, also were sought but not detected. The Fe XVIII feature, formed at logT=6.8 K, appears to be free of blends, whereas the Fe XIX line can be corrupted by a C I multiplet. FUSE observations of these forbidden iron lines at spectral resolution λ/Δλ~15,000 provides the opportunity to study dynamics of hot coronal plasmas. We find that the velocity centroid of the Fe XVIII feature deviates little from the stellar rest frame, confirming that the hot coronal plasma is confined. The observed line widths generally are consistent with thermal broadening at the high temperatures of formation and show little indication of additional turbulent broadening. The fastest rotating stars, 31 Com, α Aur Ab, and AB Dor, show evidence for excess broadening beyond the thermal component and the photospheric vsini. The anomalously large widths in these fast-rotating targets may be evidence for enhanced rotational broadening, consistent with emission from coronal regions extending an additional ΔR~0.4-1.3R* above the stellar photosphere, or represent the turbulent broadening caused by flows along magnetic loop structures. For the stars in which Fe XVIII is detected, there is an excellent correlation between the observed Röntgensatellit (ROSAT) 0.2-2.0 keV soft X-ray flux and the coronal forbidden line flux. As a result, Fe XVIII is a powerful new diagnostic of coronal thermal conditions and dynamics that can be utilized to study high-temperature plasma processes in late-type stars. In particular, FUSE provides the opportunity to obtain observations of important transition region lines in the far-UV, as well as simultaneous measurements of soft X-ray coronal emission, using the Fe

  18. Accurate Ritz Wavelengths of Parity-forbidden [Co II] and [V II] Lines of Astrophysical Interest

    NASA Astrophysics Data System (ADS)

    Ruffoni, M. P.; Pickering, J. C.

    2013-08-01

    We report a comprehensive list of accurate Ritz wavelengths for parity-forbidden [Co II] and [V II] lines obtained from the analysis of energy levels measured in the laboratory with Fourier transform emission spectroscopy. Such lines, particularly those in the infrared, are in demand for the analysis of low-density astrophysical plasmas in and around objects such as planetary nebulae, star-forming regions, and active galactic nuclei. Transitions between all known metastable levels of Co II and V II are included in our analysis, producing wavelengths for 1477 [V II] lines and 782 [Co II] lines. Of these, 170 [V II] lines and 171 [Co II] lines arise from transitions with calculated transition probabilities greater than 1 × 10-2 s-1 and upper level excitations of less than 5 eV, and thus are likely to be observed in astrophysical spectra.

  19. ACCURATE RITZ WAVELENGTHS OF PARITY-FORBIDDEN [Co II] AND [V II] LINES OF ASTROPHYSICAL INTEREST

    SciTech Connect

    Ruffoni, M. P.; Pickering, J. C.

    2013-08-15

    We report a comprehensive list of accurate Ritz wavelengths for parity-forbidden [Co II] and [V II] lines obtained from the analysis of energy levels measured in the laboratory with Fourier transform emission spectroscopy. Such lines, particularly those in the infrared, are in demand for the analysis of low-density astrophysical plasmas in and around objects such as planetary nebulae, star-forming regions, and active galactic nuclei. Transitions between all known metastable levels of Co II and V II are included in our analysis, producing wavelengths for 1477 [V II] lines and 782 [Co II] lines. Of these, 170 [V II] lines and 171 [Co II] lines arise from transitions with calculated transition probabilities greater than 1 Multiplication-Sign 10{sup -2} s{sup -1} and upper level excitations of less than 5 eV, and thus are likely to be observed in astrophysical spectra.

  20. Improved low-lying energy levels determined from solar coronal forbidden and spin-forbidden lines in the 500-1500 A range

    SciTech Connect

    Feldman, U.; Doschek, G.A. . E-mail: george.doschek@nrl.navy.mil

    2007-09-15

    We list observed parity-forbidden and spin-forbidden lines in the 500-1600 A range emitted by solar coronal plasmas and derive improved energy levels from their wavelengths. The lines, emitted by astrophysical abundant elements, belong to transitions within the ground configurations of the type ns{sup 2} np {sup k}, for n = 2, 3 and k = 0-5, and between the lowest term of the first excited configuration 2s2p {sup k+1} and the 2s{sup 2}2p {sup k} ground configurations for k = 0, 1, 2. For each line we give the newly measured wavelength, and the measured or predicted wavelength from the NIST Atomic Spectra Database (ASD) (which except for a few cases includes the previously reported compilation of Kaufman and Sugar [J. Phys. Chem. Ref. Data 15 (1986) 321]), and the values of the transition probability taken from the ASD and CHIANTI database. The list contains measured wavelengths of 136 lines of which over 100 were not available for the Kaufman and Sugar compilation. In addition we provide energy levels that were derived from the reported lines.

  1. Enhancement of the Forbidden Line in the Southwestern Knot of the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Uchida, Hiroyuki; Tanaka, Takaaki; Katsuda, Satoru; Mori, Koji; Koyama, Katsuji; Tsunemi, Hiroshi

    We observed the southwestern knot (SW-K) of the Cygnus Loop supernova remnant with XMM-Newton RGS. The SW-K is one of the brightest and the most compact region in this remnant. The high energy resolution of RGS enables us to resolve details of the line complex of SW-K below ˜1 keV. We particularly focus on the OVII triplet in which the forbidden line is significantly enhanced relative to the resonance line. The measured forbidden-to-resonance line ratio is 1.75±0.13 which can not be explained by standard thermal plasma models such as collisional ionization equilibrium or ionizing plasmas. Recently, our comprehensive study of the Cygnus Loop with Suzaku XIS has found a possible sign of charge exchange (CX) from some points of its rim; their spectra always show a strong excess at ˜0.7 keV whose origin is likely a complex of cascade lines of He-like Oxygen (Kgamma+delta+epsilon). Since the SW-K is one of these regions, the RGS spectrum provides a conclusive information about the presence of the CX emission. It will also resolve a problem of the abundance inhomogeneity which is extensively seen in the Cygnus Loop and more importantly, will give us direct evidence for an interaction between ambient neutrals and ionized materials existing behind the shock. In this talk, we will also discuss other important possibilities such as the recombination or the resonance scattering for the SW-K spectrum. The RGS observation will cast a new light on the X-ray studies of shock-cloud interactions in SNRs ahead of the ASTRO-H era.

  2. Separation between Allowed and Forbidden Component of the He I 447 nm Line in High Electron Density Plasma

    SciTech Connect

    Ivkovic, M.; Jovicevic, S.; Konjevic, N.; Gonzalez, M. A.; Gigosos, M. A.

    2008-10-22

    Stark broadened He I 447.1 nm line is measured and the dependence of the separation between its allowed and forbidden components upon electron density is analyzed. Experimental results are compared with computer simulation results and with former experimental results.

  3. Upgrading electron temperature and electron density diagnostic diagrams of forbidden line emission

    NASA Astrophysics Data System (ADS)

    Proxauf, B.; Öttl, S.; Kimeswenger, S.

    2014-01-01

    Context. Diagnostic diagrams of forbidden lines have been a useful tool for observers for many decades now. They are used to obtain information on the basic physical properties of thin gaseous nebulae. Some diagnostic diagrams are in wavelength domains that were difficult to apply either due to missing wavelength coverage or the low resolution of older spectrographs. Furthermore, most of the diagrams were calculated using just the species involved as a single atom gas, although several are affected by well-known fluorescence mechanisms as well. Additionally, the atomic data have improved up to the present time. Aims: The aim of this work is to recalculate well-known, but also sparsely used, unnoted diagnostics diagrams. The new diagrams provide observers with modern, easy-to-use recipes for determining electron temperature and densities. Methods: The new diagnostic diagrams were calculated using large grids of parameter space in the photoionization code CLOUDY. For a given basic parameter (e.g., electron density or temperature), the solutions with cooling-heating-equilibrium were chosen to derive the diagnostic diagrams. Empirical numerical functions were fitted to provide formulas usable in, e.g., data reduction pipelines. Results: The resulting diagrams differ significantly from those used up to now and will improve thermodynamic calculations. To our knowledge, detailed, directly applicable fit formulas are given for the first time, leading to the calculation of electron temperature or density from the line ratios.

  4. Spectrally-resolved forbidden emission lines: new EXES constraints on accelerating flows from cool evolved stars

    NASA Astrophysics Data System (ADS)

    Harper, Graham

    2015-10-01

    Mass loss from cool evolved stars is important for both stellar evolution and galactic chemical evolution, but it still remains poorly understood. Early-M supergiants are important for mass loss studies because they have little dust and molecules in their winds and yet still are able to drive high mass-loss rates like their dusty cousins of later spectral-types. We propose to use SOFIA-EXES to spectrally-resolve with R=50,000 two 25 micron forbidden emission lines from the ground terms of [Fe II] and [S I] in order to trace the wind acceleration and turbulence in the outflows of cool evolved M stars. For early-M supergiants these species will be the dominant ionization stages and trace the outflow mass, and the emission diagnostics can be used to test theoretical models in the crucial wind acceleration region. We also seek to refine the intrinsic wavelength of the [S I] 25.249 micron line so that it can be used as a new astrophysical velocity diagnostic.

  5. Abundances of argon, sulfur, and neon in six galactic H II regions from infrared forbidden lines

    NASA Technical Reports Server (NTRS)

    Herter, T.; Helfer, H. L.; Forrest, W. J.; Mccarthy, J.; Houck, J. R.; Willner, S. P.; Puetter, R. C.; Rudy, R. J.; Soifer, B. T.; Pipher, J. L.

    1981-01-01

    Airborne measurements of the Ar II (6.99 micron) and S III (18.71 micron) forbidden lines for six compact H II regions are presented, as well as ground-based 2-4 micron and 8-13 micron spectroscopy if not already published. From these data and radio data, lower limits to the elemental abundances of Ar, Ne, and S are deduced. G29.9-0.0, at 5 kpc from the galactic center, is overabundant in all these elements. The other five regions (at distances 6-13 kpc from the center) mainly appear to be consistent with standard abundances, with the exception of G75.84 + 0.4 at 10 kpc from the galactic center, which is overabundant in S. However, preliminary results on G12.8-0.2 at 6 kpc from the galactic center suggest a possible underabundance. A large statistical sample of H II regions is required in order to determine if there is a radial gradient in the heavy element abundances of the Galaxy.

  6. Improved collision strengths and line ratios for forbidden [O III] far-infrared and optical lines

    NASA Astrophysics Data System (ADS)

    Palay, Ethan; Nahar, Sultana N.; Pradhan, Anil K.; Eissner, Werner

    2012-06-01

    Far-infrared and optical [O III] lines are useful temperature-density diagnostics of nebular as well as dust obscured astrophysical sources. Fine-structure transitions among the ground state levels 1 s22 s22 p33 P 0,1,2 give rise to the 52- and 88-?m lines, whereas transitions among the 3 P 0,1,2, 1 D 2, 1 S 0 levels yield the well-known optical lines λλ4363, 4959 and 5007 Å. These lines are excited primarily by electron impact excitation. However, despite their importance in nebular diagnostics collision strengths for the associated fine-structure transitions have not been computed taking full account of relativistic effects. We present Breit-Pauli R-matrix calculations for the collision strengths with highly resolved resonance structures. We find significant differences of up to 20 per cent in the Maxwellian averaged rate coefficients from previous works. We also tabulate these to lower temperatures down to 100 K to enable determination of physical conditions in cold dusty environments such photodissociation regions and ultraluminous infrared galaxies observed with the Herschel Space Observatory. We also examine the effect of improved collision strengths on temperature- and density-sensitive line ratios.

  7. Tracing Slow Winds from T Tauri Stars via Low Velocity Forbidden Line Emission

    NASA Astrophysics Data System (ADS)

    Simon, Molly; Pascucci, Ilaria; Edwards, Suzan; Feng, Wanda; Rigliaco, Elisabetta; Gorti, Uma; Hollenbach, David J.; Tuttle Keane, James

    2016-06-01

    Protoplanetary disks are a natural result of star formation, and they provide the material from which planets form. The evolutional and eventual dispersal of protoplanetary disks play critical roles in determining the final architecture of planetary systems. Models of protoplanetary disk evolution suggest that viscous accretion of disk gas onto the central star and photoevaporation driven by high-energy photons from the central star are the main mechanisms that drive disk dispersal. Understanding when photoevaporation begins to dominate over viscous accretion is critically important for models of planet formation and planetary migration. Using Keck/HIRES (resolution of ~ 7 km/s) we analyze three low excitation forbidden lines ([O I] 6300 Å, [O I] 5577 Å, and [S II] 6731 Å) previously determined to trace winds (including photoevaporative winds). These winds can be separated into two components, a high velocity component (HVC) with blueshifts between ~30 - 150 km/s, and a low velocity component (LVC) with blueshifts on the order of ~5 km/s (Hartigan et al. 1995). We selected a sample of 32 pre-main sequence T Tauri stars in the Taurus-Auriga star-forming region (plus TW Hya) with disks that span a range of evolutionary stages. We focus on the origin of the LVC specifically, which we are able to separate into a broad component (BC) and a narrow component (NC) due to the high resolution of our optical spectra. We focus our analysis on the [O I] 6300 Å emission feature, which is detected in 30/33 of our targets. Interestingly, we find wind diagnostics consistent with photoevaporation for only 21% of our sample. We can, however, conclude that a specific component of the LVC is tracing a magnetohydrodynamic (MHD) wind rather than a photoevaporative wind. We will present the details behind these findings and the implications they have for planet formation more generally.

  8. Tracing Slow Winds from T Tauri Stars via Low Velocity Forbidden Line Emission

    NASA Astrophysics Data System (ADS)

    Simon, Molly; Pascucci, Ilaria; Edwards, Suzan; Feng, Wanda; Rigliaco, Elisabetta; Gorti, Uma; Hollenbach, David J.; Tuttle Keane, James

    2016-06-01

    Protoplanetary disks are a natural result of star formation, and they provide the material from which planets form. The evolutional and eventual dispersal of protoplanetary disks play critical roles in determining the final architecture of planetary systems. Models of protoplanetary disk evolution suggest that viscous accretion of disk gas onto the central star and photoevaporation driven by high-energy photons from the central star are the main mechanisms that drive disk dispersal. Understanding when photoevaporation begins to dominate over viscous accretion is critically important for models of planet formation and planetary migration. Using Keck/HIRES (resolution of ~ 7 km/s) we analyze three low excitation forbidden lines ([O I] 6300 Å, [O I] 5577 Å, and [S II] 6731 Å) previously determined to trace winds (including photoevaporative winds). These winds can be separated into two components, a high velocity component (HVC) with blueshifts between ~30 – 150 km/s, and a low velocity component (LVC) with blueshifts on the order of ~5 km/s (Hartigan et al. 1995). We selected a sample of 32 pre-main sequence T Tauri stars in the Taurus-Auriga star-forming region (plus TW Hya) with disks that span a range of evolutionary stages. We focus on the origin of the LVC specifically, which we are able to separate into a broad component (BC) and a narrow component (NC) due to the high resolution of our optical spectra. We focus our analysis on the [O I] 6300 Å emission feature, which is detected in 30/33 of our targets. Interestingly, we find wind diagnostics consistent with photoevaporation for only 21% of our sample. We can, however, conclude that a specific component of the LVC is tracing a magnetohydrodynamic (MHD) wind rather than a photoevaporative wind. We will present the details behind these findings and the implications they have for planet formation more generally.

  9. Towards Perfect Water Line Intensities

    NASA Astrophysics Data System (ADS)

    Lodi, L.; Tennyson, J.

    2012-06-01

    Over the last ten years the increased availability of computational resources and the steady refinement of theoretical methods have permitted more and more accurate first principle calculations of water-vapor spectra as exemplified, e.g., by the very successful BT2 line list both line positions and intensities, a reliable dipole moment surface (DMS), affecting line intensities. It is also very useful to several application to give reasonable uncertainty bars for computed quantities, an aspect which traditionally has received little attention. We report here recent progress leading to very accurate room-temperature linelists covering the range 0.05-20 000 cm-1, complete with uncertainty bars, for the H_218O and H_217O water isotopologues Line intensities were produced using a recent DMS produced by our group which is capable of giving line intensites accurate to 1% for most medium and strong transitions. Line positions are based if possible on the experimentally derived energy levels recently produced by a IUPAC task group and have a typical accuracy of 0.0002 cm-1; when experimentally derived energy levels are unavailable calculated line position are provided, with an accuracy of the order of 0.2 cm-1. An extension to the main isotopologue H_216O is currently underway. R. J. Barber, J. Tennyson, G. J. Harris and R. N. Tolchenov, Mon. Not. R. Astron. Soc. {368}, 1087-1094 (2006). L. Lodi and J. Tennyson, J. Quant. Spectrosc. Radiat. Trans. (2012), doi:10.1016/j.jqsrt.2012.02.023 L. Lodi, J. Tennyson and O. L. Polyansky, J. Chem. Phys. {135}, 034113 (2011). J. Tennyson at al., J. Quant. Spectrosc. Radiat. Trans. {110}, 573-96 (2009).

  10. Infrared spectrum involving forbidden transitions & coriolis interaction and identification of optically pumped far infrared laser lines in asymmetrically mono-deuterated methanol (Methanol-D1)

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Indra

    2016-05-01

    In this paper new type of ΔK = 2 and 0 transitions have been identified in the Fourier Transform spectrum of Methanol-D1 (CH2DOH). These transitions are normally forbidden but a "Coriolis" type interaction with nearby states is believed to be contributing sufficient transition strength through intensity borrowing effect. This is the first time such forbidden transitions are reported to be identified in the excited states, in this molecule. The present conjecture is supported by observation of a many strong allowed transitions to upper terminating levels which are seen to be highly perturbed. This conclusion has been reached by comparing calculated energy levels using known molecular parameters (Pearson et al., 2012; Coudert et al., 2014; El Hilali et al., 2011; Quade et al., 1998; Richard Quade, 1998, 1999; Mukhopadhyay, 1997) and the actually observed FIR lines. The upper levels are seen to be upshifted from expected position. A closer look at the calculated energy values seems to indicate a possible interaction between the above states and other proximate torsional-rotational states could occur. The possible candidates for the interacting level manifolds are narrowed down through the presence of the forbidden transition. We also take the opportunity to propose alternate rotational quantum numbers for some of the assignments recently reported in the literature (El Hilali et al., 2011). Some ambiguities are pointed out on the data and the reported analysis. There remain too many such irregularities and we propose to gather a large body assigned transitions in a future catalog. Assignments and relevant comments on optically pumped FIR laser radiation are also made.

  11. The photospheric solar oxygen project. II. Non-concordance of the oxygen abundance derived from two forbidden lines

    NASA Astrophysics Data System (ADS)

    Caffau, E.; Ludwig, H.-G.; Malherbe, J.-M.; Bonifacio, P.; Steffen, M.; Monaco, L.

    2013-06-01

    Context. In the Sun, the two forbidden [O i] lines at 630 and 636 nm were previously found to provide discrepant oxygen abundances. Aims: We investigate whether this discrepancy is peculiar to the Sun or whether it is also observed in other stars. Methods: We make use of high-resolution, high signal-to-noise ratio spectra of four dwarf to turn-off stars, five giant stars, and one sub-giant star observed with THEMIS, HARPS, and UVES to investigate the coherence of the two lines. Results: The two lines provide oxygen abundances that are consistent, within observational errors, in all the giant stars examined by us. On the other hand, for the two dwarf stars for which a measurement was possible, for Procyon, and for the sub-giant star Capella, the 636 nm line provides systematically higher oxygen abundances, as already seen for the Sun. Conclusions: The only two possible reasons for the discrepancy are a serious error in the oscillator strength of the Ni i line blending the 630 nm line or the presence of an unknown blend in the 636 nm line, which makes the feature stronger. The CN lines blending the 636 nm line cannot be responsible for the discrepancy. The Ca i autoionisation line, on the red wing of which the 636 nm line is formed, is not well modelled by our synthetic spectra. However, a better reproduction of this line would result in even higher abundances from the 636 nm, thus increasing the discrepancy. Based on observations collected at ESO Paranal Observatory, Programme 182.D-5053(A).

  12. The N(^2D - ^4S) 520 nm forbidden doublet transition in the nightglow: An experimental test of the theoretical intensity ratio

    NASA Astrophysics Data System (ADS)

    Slanger, T. G.; Cosby, P. C.; Huestis, D. L.

    2003-04-01

    N(^2D) is an important species in the nighttime ionosphere, as its reaction with O_2 is a principal source of NO. Its modeled concentration peaks near 200 km, at approximately 4 × 10^5 cm-3. Nightglow emission in the optically forbidden lines at 519.8 and 520.0 nm is quite weak, a consequence of the combination of an extremely long radiative lifetime, about 10^5 sec, and quenching by O-atoms, O_2, and N_2. The radiative lifetime is known only from theory, and various calculations lead to a range of possible values for the intensity ratio R = I(519.8)/I(520.0) of 1.5-2.5. On the observational side, Hernandez and Turtle [1969] determined a range of R = 1.3-1.9 in the nightglow, and Sivjee et al. [1981] reported a variable ratio in aurorae, between 1.2 and 1.6. From sky spectra obtained at the Keck II telescope on Mauna Kea, we have accumulated eighty-five 30-60 minute data sets, from March and October, 2000, and April, 2001, over 13 nights of astronomical observations. We find R to have a quite precise value of 1.760± 0.012 (2-σ). There is no difference between the three data sets in terms of the extracted ratio, which therefore seems to be independent of external conditions. At the same time, determination of the O(^1D - ^3P) doublet intensity ratio, I(630.0)/I(636.4), gives a value of 3.03 ± 0.01, the statistical expectation. G. Hernandez and J. P. Turtle, Planet. Space Sci. 17, 675, 1969. G. G. Sivjee, C. S. Deehr, and K. Henricksen, J. Geophys. Res. 86, 1581, 1981.

  13. The neutral oxygen spectrum. 1: Collisionally excited level populations and line intensities under optically thin conditions

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Kastner, S. O.

    1995-01-01

    This is the first paper in a projected program to produce quantitative information on the spectrum of the neutral oxygen atom under a variety of excitation conditions. Radiative rates and effective collision strengths are assembled from the recent literature where available, or are calculated for as yet untreated transitions using the University College superstructure/distorted-wave computer package, to produce a complete set of atomic data for a 13 hybrid level model of neutral oxygen. Level populations and relative intensities for 28 allowed, inter-combination, and forbidden oxygen lines are computed, under optically thin conditions, for the electron density range 4.0 less than log N(sub e) less than 12.0 and the electron temperature values T(sub e) = 5000, 10,000, 20,000, 50,000, and 100,000 K. Preliminary applications to observed intercombination/allowed and forbidden/allowed line ratios are discussed.

  14. Transition moments, Franck-Condon factors, and lifetimes of forbidden transitions - Calculation of the intensity of the Cameron system of CO.

    NASA Technical Reports Server (NTRS)

    James, T. C.

    1971-01-01

    Discussion of the factors affecting the intensity of forbidden transitions in diatomic molecules. It is shown that using Franck-Condon factors to predict relative band intensities is less reliable for forbidden transitions than it is for allowed transitions. The intensity of the 0,0 and 1,0 bands of the a super 3 pi-super 1 sigma Cameron system of CO are calculated using perturbation theory. The intensity arises from spin-orbit mixing of the A super 1 pi state with the a super 3 pi state. From the known spin-orbit coupling constant of the a super 1 pi state and the known intensity of the fourth positive A super 1 pi-super 1 sigma transition, the oscillator strengths of the 0,0 and 1,0 bands are calculated to be 1.63 x 10 to the minus 7th power and 1.99 x 10 to the minus 7th power. Lifetimes of various rotational levels are shown to range from 2.9 to several hundred milliseconds.-

  15. 2D-photochemical model for forbidden oxygen line emission for comet 1P/Halley

    NASA Astrophysics Data System (ADS)

    Cessateur, G.; De Keyser, J.; Maggiolo, R.; Rubin, M.; Gronoff, G.; Gibbons, A.; Jehin, E.; Dhooghe, F.; Gunell, H.; Vaeck, N.; Loreau, J.

    2016-08-01

    We present here a 2D-model of photochemistry for computing the production and loss mechanisms of the O(1S) and O(1D) states, which are responsible for the emission lines at 577.7 nm, 630 nm, and 636.4 nm, in case of the comet 1P/Halley. The presence of O2 within cometary atmospheres, measured by the in-situ ROSETTA and GIOTTO missions, necessitates a revision of the usual photochemical models. Indeed, the photodissociation of molecular oxygen also leads to a significant production of oxygen in excited electronic states. In order to correctly model the solar UV flux absorption, we consider here a 2D configuration. While the green to red-doublet ratio is not affected by the solar UV flux absorption, estimates of the red-doublet and green lines emissions are, however, overestimated by a factor of two in the 1D model compared to the 2D model. Considering a spherical symmetry, emission maps can be deduced from the 2D model in order to be directly compared to ground and/or in-situ observations.

  16. Observations of the 63 micron forbidden OI emission line in the Orion and Omega Nebulae

    NASA Technical Reports Server (NTRS)

    Melnick, G.; Gull, G. E.; Harwit, M.

    1979-01-01

    Observations of 63-micron neutral oxygen emission from the Orion and Omega Nebulae are reported which were carried out from the NASA Lear Jet flying at an altitude of approximately 13.7 km. The best estimate for the 3 P 1 - 3 P 2 transition wavelength is shown to be 63.2 microns, and the detected fluxes are found to be extraordinarily high (amounting to approximately 600 suns in M42 at 0.5 kpc and to about 2900 suns in the line in M17 at 2 kpc). Attempts are made to estimate the minimum temperature and other parameters of the emitting region in Orion. It is concluded that conditions not too different from those permitted by some current models appear to provide fluxes that agree in order of magnitude with those observed.

  17. Hyperfine structure and isotope shifts in 733.2 nm mixed forbidden line of Pb I

    NASA Astrophysics Data System (ADS)

    Wąsowicz, T. J.; Drozdowski, R.; Kwela, J.

    2007-05-01

    Studies of the hyperfine structure and isotope shifts in 733.2 nm mixed (M1+E2) multipole line of Pb I are presented. As a light source the electrodeless discharge tube was used. The high resolution spectral apparatus consisted of a silver coated Fabry-Perot etalon and a grating spectrograph combined with a CCD camera used as a detector. In the analysis of the spectra a computer simulation technique was used. The experiments with the isotope 207Pb yielded the hyperfine structure splitting constant A for the 3P1 and 1D2 levels of the 6s26p2 ground configuration. In the experiment with natural lead the isotope shifts between four stable isotopes (204, 206, 207, 208) were measured.

  18. Optical line intensities in the Trifid nebula

    SciTech Connect

    Lynds, B.T.; Oneil, E.J. Jr.

    1985-07-01

    Observations of the Trifid nebula (M20) obtained in H-alpha; He I (587.6 nm); and the forbidden lines of N II (658.3 nm), S II (671.6 and 673 nm), O III (500.7 nm), and O II (272.6 and 372.9 nm) using either the CIT long-slit spectrograph or a direct-mode CCD with narrow-band interference filters on the 92-cm telescope at KPNO are reported. The data are presented in extensive graphs and characterized in detail and a model is proposed to explain the scattering measurements. Findings discussed include a single central O7 V star with Teff = about 37,500 K, a dusty plasma ionized by this star, mean nebular electron density 150/cu cm, a central hole of radius 0.2 times that of the ionized zone, dust extending beyond the ionized region, overall temperature 7000-8000 K, filament temperatures up to 9000 K, dust optical depth 1.5 at H-beta, dust albedo 0.5, emission-nebula radius 2.8 pc, and total mass about 1700 solar mass (comprising 340 solar mass ionized material, about 800 solar mass unionized cloud material, and about 600 solar mass in an outer dust sphere). 18 references.

  19. Optical line intensities in the Trifid nebula

    NASA Astrophysics Data System (ADS)

    Lynds, B. T.; Oneil, E. J., Jr.

    1985-07-01

    Observations of the Trifid nebula (M20) obtained in H-alpha; He I (587.6 nm); and the forbidden lines of N II (658.3 nm), S II (671.6 and 673 nm), O III (500.7 nm), and O II (272.6 and 372.9 nm) using either the CIT long-slit spectrograph or a direct-mode CCD with narrow-band interference filters on the 92-cm telescope at KPNO are reported. The data are presented in extensive graphs and characterized in detail and a model is proposed to explain the scattering measurements. Findings discussed include a single central O7 V star with Teff = about 37,500 K, a dusty plasma ionized by this star, mean nebular electron density 150/cu cm, a central hole of radius 0.2 times that of the ionized zone, dust extending beyond the ionized region, overall temperature 7000-8000 K, filament temperatures up to 9000 K, dust optical depth 1.5 at H-beta, dust albedo 0.5, emission-nebula radius 2.8 pc, and total mass about 1700 solar mass (comprising 340 solar mass ionized material, about 800 solar mass unionized cloud material, and about 600 solar mass in an outer dust sphere).

  20. Computer program for determining rotational line intensity factors for diatomic molecules

    NASA Technical Reports Server (NTRS)

    Whiting, E. E.

    1973-01-01

    A FORTRAN IV computer program, that provides a new research tool for determining reliable rotational line intensity factors (also known as Honl-London factors), for most electric and magnetic dipole allowed diatomic transitions, is described in detail. This users manual includes instructions for preparing the input data, a program listing, detailed flow charts, and three sample cases. The program is applicable to spin-allowed dipole transitions with either or both states intermediate between Hund's case (a) and Hund's case (b) coupling and to spin-forbidden dipole transitions with either or both states intermediate between Hund's case (c) and Hund's case (b) coupling.

  1. Line Positions, Intensities And Line Shape Parameters Of PH3 Near 4.4 µm

    NASA Astrophysics Data System (ADS)

    Venkataraman, Malathy; Benner, D. C.; Kleiner, I.; Brown, L. R.; Sams, R. L.; Fletcher, L. N.

    2012-10-01

    Accurate knowledge of spectral line parameters in the 2000 to 2400 cm-1 region of PH3 is important for the CASSINI/VIMS exploration of dynamics and chemistry of Saturn and for the correct interpretation of future Jovian observations by JUNO and ESA’s newly-selected mission JUICE. Since the available intensity information for phosphine is inconsistent, we measured line positions and intensities for over 4000 individual transitions in the 2ν2, ν2+ν4, 2ν4, ν1 and the ν3 bands from analyzing high-resolution, high S/N spectra recorded at room temperature using two Fourier transform spectrometers (FTS); the Bruker IFS 125 HR FTS at PNNL and the Kitt Peak FTS at the National Solar Observatory in Arizona. In addition to line positions and intensities, self-broadened half width and self-induced pressure-shift coefficients were also measured for about 800 transitions for the various bands. The strong Coriolis and other types of interactions occurring among the various vibrational levels result in a large number of forbidden transitions as well as cause A+A- splittings in transitions with K″ that are multiples of 3. Line mixing was detected between several A+A- pairs of transitions; and self- line mixing coefficients were measured for several such pairs of transitions by applying the off-diagonal relaxation matrix formalism of Levy et al.1 A multispectrum nonlinear least squares technique2 employing a non-Voigt line shape including line mixing and speed dependence was used in fitting all the spectra simultaneously. Present results are compared with other reported values. This research is supported by NASA’s Outer Planets Research Program. References [1] A. Lévy et al., In “Spectroscopy of the Earth’s Atmosphere and Interstellar Medium”, Ed. K, Narahari Rao and A. Weber, Boston, Academic Press; p, 261-337 (1992). [2] D. C. Benner et al., J Quant. Spectrosc. Radiat. Transfer 53, 705, 1995.

  2. Direct CW - NMR observation of forbidden transitions at double larmor frequency in hydrogen

    NASA Astrophysics Data System (ADS)

    Skrbek, L.; Sebek, J.; Safrata, R. S.

    1990-08-01

    By means of the classical transverse continuous wave nuclear magnetic resonance (NMR) the forbidden transitions at double Larmor frequency for hydrogen have been observed. The NMR spectra have been measured directly by scanning the external magnetic field up to 10 mT at temperatures about 30 mK. The intensity of the forbidden transition at double Larmor frequency I 2 is of the same order of magnitude as the intensity I 1 of the main Larmor line under these conditions. The intensity ratio I 1/I 2 depends on the external magnetic field in accordance with Cheng theory and NMR-SQUID measurements of Kohl and coworkers.

  3. Theoretical study of the intensity of the spin- or dipole forbidden transitions between the c1∑

    NASA Astrophysics Data System (ADS)

    Klotz, Rainer; Peyerimhoff, Sigrid D.

    The transition moments between the three lowest gerade X3∑-g, a1Δg and b1∑+g and ungerade states c1∑-u, A'3Δu and A3∑+u of the oxygen molecule have been calculated as a function of internuclear separation from 2·1 a.u. to 3·5 a.u. The wavefunctions have thereby been expanded in a perturbation sum whereby the individual terms are large-scale MRD-CI wavefunctions and the expansion coefficients are the spin-orbit coupling coefficients obtained by using the Breit-Pauli one- and two-particle operator. A total of 18 states has been considered in the perturbation expansions; the corresponding potential energy curves are also given for all states. The AO basis set was of double-zeta plus polarization and Rydberg quality and involves a total of 56 contracted gaussians. The absorption oscillator strengths are also determined; the predicted values are 0·06 × 10-7 for c1∑-u - X3∑-g, 0·32 × 10-7 for A'3Δu(Ω = ± 1) - X3∑-g and 1·6 × 10-7 calculated for the strongest A3∑+u - X3∑-g transition, whereby the latter is in excellent agreement with the measured value of 1 × 10-7. The radiative lifetimes for the upper three ungerade states are calculated to be 6 s for c1∑-u, 1 s for A'3Δu and 0·07s for the A3∑+u state. A vibrational analysis of the various emission systems c1∑-u - X3∑-q (Herzberg II), A'3Δu - X3∑-g (Herzberg III), A'3Δu - a1Δg (Chamberlain) and A3∑+u - X3∑-g (Herzberg I system) is also undertaken and the most likely transition mechanisms are analysed. The strongest Herzberg I system borrows its intensity from the Schumann-Runge (B3∑-u - X3∑-g) system since the B state occurs as perturber in the A3∑+u wavefunction.

  4. Study of Milli-Jansky Seyfert Galaxies with Strong Forbidden High-Ionization Lines Using the Very Large Array Survey Images

    NASA Astrophysics Data System (ADS)

    Lal, Dharam V.

    2015-12-01

    We study the radio properties at 1.4 GHz of Seyfert galaxies with strong forbidden high-ionization lines (FHILs), selected from the Sloan Digital Sky Survey - a large-sized sample containing nearly equal proportion of diverse range of Seyfert galaxies showing similar redshift distributions compiled by tet{GMW2009} using the Very Large Array survey images. The radio detection rate is low, 49%, which is lower than the detection rate of several other known Seyfert galaxy samples. These galaxies show low star formation rates and the radio emission is dominated by the active nucleus with ≤10% contribution from thermal emission, and possibly, none show evidence for relativistic beaming. The radio detection rate, distributions of radio power, and correlations between radio power and line luminosities or X-ray luminosity for narrow-line Seyfert 1 (NLS1), Seyfert 1 and Seyfert 2 galaxies are consistent with the predictions of the unified scheme hypothesis. Using correlation between radio and [O III] λ 5007 Å luminosities, we show that ˜8% sample sources are radio-intermediate and the remaining are radio-quiet. There is possibly an ionization stratification associated with clouds on scales of 0.1-1.0 kpc, which have large optical depths at 1.4 GHz, and it seems these clouds are responsible for free-free absorption of radio emission from the core; hence, leading to low radio detection rate for these FHIL-emitting Seyfert galaxies.

  5. Measurements of the intercombination and forbidden lines from helium-like ions in Tokamaks and Electron Beam Ion Traps

    SciTech Connect

    Bitter, M; Hill, K W; von Goeler, S; Stodiek, W; Beiersdorfer, P; Rice, J E; Ince-Cushman, A

    2007-08-22

    The paper reviews the results from tokamak experiments for the line ratios x/w, y/w, and z/w from helium-like ions with Z in the range from 14 to 28. With exception of the DITE experiments, where these line ratios were found to be in agreement with theoretical predictions, all other tokamak experiments yielded values that were significantly larger than predicted. The reasons for these discrepancies are not yet understood. It is possible that radial profile effects were not properly taken into account in the majority of the tokamak experiments. The paper also gives a short historical review of the X-ray diagnostic developments and also presents very recent data from a new type of X-ray imaging crystal spectrometer, which records spatially resolved spectra with a spatial resolution of about 1 cm in the plasma. These new data can be Abel inverted, so that it will be possible to determine line ratios at each radial position in the plasma. Effects of radial profiles, which may have affected the chord-integrated measurements of the past, will thus be eliminated in the future.

  6. Forbidden Iron Lines and Dust Destruction in Supernova Remnant Shocks: The Case of N49 in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Seitenzahl, Ivo R.; Sutherland, Ralph S.; Vogt, Frédéric P. A.; Winkler, P. Frank; Blair, William P.

    2016-08-01

    We present the results of a complete integral-field survey of the bright supernova remnant (SNR) N49 in the Large Magellanic Cloud, obtained with the WiFeS instrument mounted on the ANU 2.3 m telescope at Siding Spring Observatory. From theoretical shock modeling with the new MAPPINGS 5.1 code, we have, for the first time, subjected the optical Fe emission line spectrum of an SNR to a detailed abundance and dynamical analysis covering eight separate stages of ionization. This allows us to derive the dust depletion factors as a function of ionization stage. We have shown that there is substantial (30%-90%) destruction of Fe-bearing dust grains in these fast shocks (v s ˜ 250 km s-1), and we have confirmed that the dominant dust destruction occurs through the non-thermal sputtering and grain-grain collision mechanisms developed in a number of theoretical works.

  7. Forbidden Iron Lines and Dust Destruction in Supernova Remnant Shocks: The Case of N49 in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Seitenzahl, Ivo R.; Sutherland, Ralph S.; Vogt, Frédéric P. A.; Winkler, P. Frank; Blair, William P.

    2016-08-01

    We present the results of a complete integral-field survey of the bright supernova remnant (SNR) N49 in the Large Magellanic Cloud, obtained with the WiFeS instrument mounted on the ANU 2.3 m telescope at Siding Spring Observatory. From theoretical shock modeling with the new MAPPINGS 5.1 code, we have, for the first time, subjected the optical Fe emission line spectrum of an SNR to a detailed abundance and dynamical analysis covering eight separate stages of ionization. This allows us to derive the dust depletion factors as a function of ionization stage. We have shown that there is substantial (30%–90%) destruction of Fe-bearing dust grains in these fast shocks (v s ˜ 250 km s‑1), and we have confirmed that the dominant dust destruction occurs through the non-thermal sputtering and grain–grain collision mechanisms developed in a number of theoretical works.

  8. Gamma-ray line intensities for depleted uranium

    SciTech Connect

    Moss, C.E.

    1985-01-01

    Measurements of the gamma-ray line intensities from depleted uranium allowed us to determine which of two conflicting previous experiments was correct. For the 1001-keV line we obtain a branching ratio of 0.834 +- 0.007, in good agreement with one of the previous experiments. A table compares our intensities for several lines with those obtained in previous experiments. 5 refs., 2 figs., 1 tab.

  9. Study of NH3 Line Intensities in the THz and Far-IR Region

    NASA Astrophysics Data System (ADS)

    Yu, Shanshan

    Ammonia (NH3) exists in the interstellar medium, late-type stars and giant planets of our solar system. Its temperature and abundance profiles in these environments, which are derived with its line parameters as fixed input , are commonly used to provide constraints on retrieving minor species. Therefore NH3 line parameters are essential for interpreting astrophysical and planetary spectra from Herschel, SOFIA, ALMA and JWST. However, our work under a predecessor grant with the APRA program revealed significant deficiencies in NH3 intensities in the terahertz and FIR region, including some weak Delta(K)=3 forbidden transitions predicted to be 100 times stronger. The Delta(K)=3 transitions are the ones connecting levels with different K values and therefore the only way other than collisions and l-doubled states to excite NH3 to K>0 levels. Their intensities have to be corrected to explain the observed high K excitation, such as the detection of NH3 (J,K) = (1,1), (2,2)&(14,14) and (18,18) transitions toward the galactic center star forming region Sgr B2, and to provide insights into the radiative- transfer vs. collision excitation mechanics of interstellar NH3. This proposal will remedy the serious deficiencies in the current databases involving NH3 line parameters in the terahertz and FIR region. We will target transitions with intensities greater than 10^{-23} cm-1/ (molecule/cm2) at 296 K, which will be among new astrophysical detections made by SOFIA, ALMA and JWST, and are 1000 times weaker than the strongest ground state transitions. We will retrieve new positions and intensities from existing laboratory spectra, use them to evaluate the current databases and ab initio calculations, and repair the line positions and intensities by replacing poorly calculated values with our new measurements. The proposed research will result in (1) a validated linelist containing the positions, intensities and lower state energies for the very important Delta(K)=3 NH3 FIR

  10. Line Intensities of the Phosphine Dyad at 10 mu m

    SciTech Connect

    Brown, Linda R.; Sams, Robert L.; Kleiner, Isabelle; Cottaz, C; Sagui, L

    2002-10-01

    Over 1000 measured line intensities of phosphine (PH3) are reported for the 830 to 1310 cm-1 region that contains the two lowest fundamentals in Coriolis interaction. These measurements are fitted to 1.5% for v2 at 992.13 cm-1 for v4 at 1118.31 cm-1, respectively, using five intensity parameters that include three Herman-Wallis type terms. In addition, some 60 intensities of the 2v2-v2 hot band are modeled. The corresponding assignments and line positions of the dyad from previous work [L. Fusina and G. Di Lonardo, J. Mol. Struct. 517-518, 67-78 (2000)] are combined with the present intensity study to provide an improved PH3 database for planetary studies. The total integrated intensity for the dyad is 156.(4) cm-2atm-1 at 296 K.

  11. [Physical meaning of temperature measured by spectral line intensity method].

    PubMed

    Zhao, Wen-Hua; Tang, Huang-Zai; Shen, Yan; Shi, Yong; Hou, Ling-Yun

    2007-11-01

    The difference between electron temperature and excitation temperature is analyzed in the aspect of statistics thermodynamics. It is presented clearly that the temperature acquired by spectral line intensity method is not free electron temperature, but internal electronic excitation temperature of heavy particle. Under thermal equilibrium condition, the excitation temperature is equal to the electron temperature, while under non-thermal equilibrium condition, the excitation temperature is not equal to the electron temperature. In the study of arc jet plume in vacuum chamber, spectral line intensity method was employed to measure the apparent excitation temperature of arc jet plume, and Langmuir probe was employed to measure the electron temperature of arcjet plume. The big difference between the excitation temperature and the electron temperature proved that the temperature acquired by spectral line intensity method is not free electron temperature.

  12. Sharp intense line in the bioluminescence emission of the firefly.

    PubMed

    Barua, A Gohain; Sharma, U; Phukan, M; Hazarika, S

    2014-06-01

    Numerous investigations have been carried out on the spectral distribution of the light of different species of fireflies. Here we record the emission spectrum of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) on a color film. Green and red color-sectors, with an intense yellow one in between, appear in this spectrum. Intensity profile of this spectrum reveals a hitherto undetected strong narrow yellow line, which lies within the full-width-at-half maximum (FWHM) of the intensity profile. The spectrum recorded in a high-resolution spectrometer confirms the presence of this sharp intense line. This finding lends support to an earlier drawn analogy between the in vivo emission of the firefly and laser light.

  13. The Forbidden Quantum Adder

    NASA Astrophysics Data System (ADS)

    Alvarez-Rodriguez, U.; Sanz, M.; Lamata, L.; Solano, E.

    2015-07-01

    Quantum information provides fundamentally different computational resources than classical information. We prove that there is no unitary protocol able to add unknown quantum states belonging to different Hilbert spaces. This is an inherent restriction of quantum physics that is related to the impossibility of copying an arbitrary quantum state, i.e., the no-cloning theorem. Moreover, we demonstrate that a quantum adder, in absence of an ancillary system, is also forbidden for a known orthonormal basis. This allows us to propose an approximate quantum adder that could be implemented in the lab. Finally, we discuss the distinct character of the forbidden quantum adder for quantum states and the allowed quantum adder for density matrices.

  14. Ion source and injection line for high intensity medical cyclotron

    SciTech Connect

    Jia, XianLu Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

    2014-02-15

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H− ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H− ion source (CIAE-CH-I type) and a short injection line, which the H− ion source of 3 mA/25 keV H− beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

  15. Ion source and injection line for high intensity medical cyclotron

    NASA Astrophysics Data System (ADS)

    Jia, XianLu; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

    2014-02-01

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H- ion source (CIAE-CH-I type) and a short injection line, which the H- ion source of 3 mA/25 keV H- beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

  16. Observations and modelling of line intensity ratios of OV multiplet lines for ? - ?

    NASA Astrophysics Data System (ADS)

    Kato, T.; Rachlew-Källne, E.; Hörling, P.; Zastrow, K.-D.

    1996-09-01

    Line intensity ratios of OV multiplet lines for the 0953-4075/29/18/019/img3 (J = 2,1,0) transitions are studied using a collisional radiative model and the results are compared with measurements from the reversed field pinch experiments Extrap T1 and T2 at KTH. The measured line intensity ratios deviate from the predictions of the model and the possible causes for the discrepancy are discussed with regard to errors in rate coefficients and non-quasi-steady state.

  17. Empowering line intensity mapping to study early galaxies

    NASA Astrophysics Data System (ADS)

    Comaschi, P.; Ferrara, A.

    2016-09-01

    Line intensity mapping is a superb tool to study the collective radiation from early galaxies. However, the method is hampered by the presence of strong foregrounds, mostly produced by low-redshift interloping lines. We present here a general method to overcome this problem which is robust against foreground residual noise and based on the cross-correlation function ψαL(r) between diffuse line emission and Lyα emitters (LAE). We compute the diffuse line (Lyα is used as an example) emission from galaxies in a (800Mpc)3 box at z = 5.7 and 6.6. We divide the box in slices and populate them with 14000(5500) LAEs at z = 5.7(6.6), considering duty cycles from 10-3 to 1. Both the LAE number density and slice volume are consistent with the expected outcome of the Subaru HSC survey. We add gaussian random noise with variance σN up to 100 times the variance of the Lyα emission, σα, to simulate residual foregrounds and compute ψαL(r). We find that the signal-to-noise of the observed ψαL(r) does not change significantly if σN ≤ 10σα and show that in these conditions the mean line intensity, ILyα, can be precisely recovered independently of the LAE duty cycle. Even if σN = 100σα, Iα can be constrained within a factor 2. The method works equally well for any other line (e.g. [CII], HeII) used for the intensity mapping experiment.

  18. High intensity line source for x-ray spectrometer calibration

    SciTech Connect

    Thoe, R.S.

    1986-06-01

    A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

  19. Spectral line intensity irreversibility in circulatory plasma magnetization processes

    SciTech Connect

    Qu, Z. Q.; Dun, G. T.

    2012-01-23

    Spectral line intensity variation is found to be irreversible in circulatory plasma magnetization process by experiments described in this paper, i.e., the curves illustrating spectral line photon fluxes irradiated from a light source immerged in a magnetic field by increasing the magnetic induction cannot be reproduced by decreasing the magnetic induction within the errors. There are two plasma magnetization patterns found. One shows that the intensities are greater at the same magnetic inductions during the magnetic induction decreasing process after the increasing, and the other gives the opposite effect. This reveals that the magneto-induced excitation and de-excitation process is irreversible like ferromagnetic magnetization. But the two irreversible processes are very different in many aspects stated in the text.

  20. INTERPRETING THE UNRESOLVED INTENSITY OF COSMOLOGICALLY REDSHIFTED LINE RADIATION

    SciTech Connect

    Switzer, E. R.; Chang, T.-C.; Pen, U.-L.; Voytek, T. C.

    2015-12-10

    Intensity mapping experiments survey the spectrum of diffuse line radiation rather than detect individual objects at high signal-to-noise ratio. Spectral maps of unresolved atomic and molecular line radiation contain three-dimensional information about the density and environments of emitting gas and efficiently probe cosmological volumes out to high redshift. Intensity mapping survey volumes also contain all other sources of radiation at the frequencies of interest. Continuum foregrounds are typically ∼10{sup 2}–10{sup 3} times brighter than the cosmological signal. The instrumental response to bright foregrounds will produce new spectral degrees of freedom that are not known in advance, nor necessarily spectrally smooth. The intrinsic spectra of foregrounds may also not be well known in advance. We describe a general class of quadratic estimators to analyze data from single-dish intensity mapping experiments and determine contaminated spectral modes from the data themselves. The key attribute of foregrounds is not that they are spectrally smooth, but instead that they have fewer bright spectral degrees of freedom than the cosmological signal. Spurious correlations between the signal and foregrounds produce additional bias. Compensation for signal attenuation must estimate and correct this bias. A successful intensity mapping experiment will control instrumental systematics that spread variance into new modes, and it must observe a large enough volume that contaminant modes can be determined independently from the signal on scales of interest.

  1. Interpreting The Unresolved Intensity Of Cosmologically Redshifted Line Radiation

    NASA Technical Reports Server (NTRS)

    Switzer, E. R.; Chang, T.-C.; Masui, K. W.; Pen, U.-L.; Voytek, T. C.

    2016-01-01

    Intensity mapping experiments survey the spectrum of diffuse line radiation rather than detect individual objects at high signal-to-noise ratio. Spectral maps of unresolved atomic and molecular line radiation contain three-dimensional information about the density and environments of emitting gas and efficiently probe cosmological volumes out to high redshift. Intensity mapping survey volumes also contain all other sources of radiation at the frequencies of interest. Continuum foregrounds are typically approximately 10(sup 2)-10(Sup 3) times brighter than the cosmological signal. The instrumental response to bright foregrounds will produce new spectral degrees of freedom that are not known in advance, nor necessarily spectrally smooth. The intrinsic spectra of fore-grounds may also not be well known in advance. We describe a general class of quadratic estimators to analyze data from single-dish intensity mapping experiments and determine contaminated spectral modes from the data themselves. The key attribute of foregrounds is not that they are spectrally smooth, but instead that they have fewer bright spectral degrees of freedom than the cosmological signal. Spurious correlations between the signal and foregrounds produce additional bias. Compensation for signal attenuation must estimate and correct this bias. A successful intensity mapping experiment will control instrumental systematics that spread variance into new modes, and it must observe a large enough volume that contaminant modes can be determined independently from the signal on scales of interest.

  2. Measurement of electric fields in a helium micro-hollow cathode discharge by forbidden transitions

    NASA Astrophysics Data System (ADS)

    Namba, Shinichi; Maki, Daisuke; Takiyama, Ken

    2013-09-01

    Micro-hollow cathode discharges operated at high pressure has been attracting a great deal of interest for various application, such as, excimer light sources, medical/biological fields and microchemical reactor. In the plasmas, the electric (E) field in the sheath region plays an important role to generate and sustain the plasmas. In order to determine the E field in the He microplasma, the emissions of allowed (He I 2P-4D: 492.19 nm) and forbidden (2P-4F: 492.06 nm) lines were observed. The cathode and anode were both made of brass, and ceramic disks were used to electrically insulate the electrodes. The cathode disk had inner hole diameter of 1.0 mm (length: 2.0 mm). The gas with a flow rate was 1.0 L/min. The discharge was operated at voltages of 250 V, currents of 8 mA and gas pressures up to 100 kPa. The plasmas in the cathode opening were observed using a visible spectrometer. The forbidden line associated with the level mixing of upper levels was observed in the cathode surface, indicating that the high E field was formed. As the intensity ratio of forbidden to the allowed lines is a function of the E field which is calculated by perturtabation theory, we derived the field strength of 18 kV/cm at 1.0 mm cathode surface.

  3. EUV line intensities above the limb measured by CDS

    NASA Technical Reports Server (NTRS)

    Fludra, A.; DelZanna, G.; Bromage, B. J. I.; Thomas, R. J.

    1997-01-01

    The extreme ultraviolet (EUV) above the limb observed with the coronal diagnostic spectrometer (CDS) are discussed. The CDS spectra were obtained up to 0.3 solar radii above the east and west limb, and above the polar coronal holes. A large data set was acquired during the campaign in August 1996. The intensities of the chromospheric, transition region and coronal lines were derived as a function of the radial distance. The density-sensitive line ratios of Si IX 350/342 A and Si X 356/347 A were used to derive an average electron density. The temperature and density in the coronal holes were found to be lower than in the closed field regions.

  4. Atomic Data and Spectral Line Intensities for Ne III

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Thomas, R. J.; Landi, E.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Electron impact collision strengths, energy levels, oscillator strengths and spontaneous radiative decay rates are calculated for Ne III. The configurations used are 2s(sup 2) 2p(sup 4),2s2p(sup 5),2s(sup 2) 2p(sup 3)3s, and 2s(sup 2)3p(sup 3)3d giving rise to 57 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies, 5, 10, 15, 20, and 25 Ry. Excitation rate coefficients are calculated by assuming a Maxwellian electron velocity distribution at an electron temperature of logT,(K)=5.0, corresponding to maximum abundance of Ne III. Using the excitation rate coefficients and the radiative transition rates, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10(exp 8)-10(exp 14) per cubic centimeter. Relative spectral line intensities are calculated. Proton excitation rates between the lowest three levels have been included in the statistical equilibrium equations. The predicted Ne III line intensities are compared with SERTS rocket measurements of a solar active region and of a laboratory EUV light source.

  5. [Line intensities of upsilon2 perpendicular band and the change of intensities with temperature for H12C14N].

    PubMed

    Song, Xiao-Shu; Cheng, Xin-Lu; Yang, Xiang-Dong; Li, De-Hua; Ge, Su-Hong

    2008-04-01

    The total internal partition sums (TIPS) were calculated for H12C14N with the product approximation. For rotational partition sums Q(rot), the centrifugal distortion corrections were taken into account. The calculation method for the vibrational partition sums Q(vib) is the harmonic oscillator approximation. The line intensities of upsilon2 perpendicular band (0110-0000 transition) of H12C14N were calculated at normal temperatures and several high temperatures by using the calculated partition functions and experimental transition moment squared and Herman-Waills factor coefficients. Results showed that our line intensities data at 296 and 3 000 K are in excellent agreement with the data in HITRAN, which provide a strong support for the calculations of partition function and line intensity at high temperature. Thereby, the line intensities and spectral simulations of upsilon2 perpendicular band at the higher temperatures 4 000 and 5 000 K were presented and the chang in line intensities with the temperature was discussed. For those transitions corresponding to rotational quantum number J > or = 32 (including P, Q and R branch), the line intensities increase when temperature gradually increase from 296 K. The line intensities are up to the largest at around 1000 K and then weaken rapidly. For J < 32 (also including P, Q and R branch), the line intensities are the largest at 296 K and then weaken rapidly as temperature gradually increase. PMID:18619284

  6. Atomic Data and Spectral Line Intensities for Ni XXI

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Landi, E.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Electron impact collision strengths, energy levels, oscillator strengths and spontaneous radiative decay rates are calculated for Ni XXI. The configurations used are 2s(sup 2)2p(sup 4), 2s2p(sup 5), 2p(sup 6), 2s(sup 2)2p(sup 3)3s, and 2s(sup 2)3p(sup 3)3d giving rise to 58 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies, 85, 170, 255, 340, and 425 Ry. Excitation rate coefficients are calculated by assuming a Maxwellian electron velocity distribution at an electron temperature of log T(sub e)(K)=6.9, corresponding to maximum abundance of Ni XXI. Using the excitation rate coefficients and the radiative transition rates, statistical equilibrium equations for level populations are solved at electron densities 10(exp 8)-10(exp 14) per cubic centimeter. Relative spectral line intensities are calculated. Proton excitation rates between the lowest three levels have been included in the statistical equilibrium equations. The predicted intensity ratios are compared with available observations.

  7. Ft-Ir Measurements of NH_3 Line Intensities in the 60 - 550 CM-1 Using Soleil/ailes Beamline

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Yu, Shanshan; Pearson, John; Manceron, Laurent; Kwabia Tchana, F.; Pirali, Olivier

    2015-06-01

    Ammonia (NH_3) has been found ubiquitous, e.g., in the interstellar medium, low-mass stars, Jovian planets of our solar system, and possibly in the low temperature exoplanets. Their spectroscopic line parameters are essential in the accurate interpretation of the planetary and astrophysical spectra observed with Herschel, SOFIA, ALMA, and JWST. In our previous paper, the NH_3 line positions in the far-IR region were studied for the ground state and ν_2 in an unprecedented accuracy, which revealed significant deficiencies in the NH_3 intensities, for instance, some weak ΔK = 3 lines were predicted to be ~100 times stronger. Measurement of line intensity for these lines in a consistent manner is demanded because the ΔK = 3 forbidden lines are only way other than collisions and l-doubled states to excite NH_3 to K > 0 levels. Recalling that NH_3 transition lines in the high J and K up to 18 were detected toward the galactic center in the star forming region of Sgr B_2, their accurate intensity measurements are critical in explaining the observed high K excitation, which will provide insights into radiative-transfer vs.levels. The interaction between a large amplitude torsional motion and the hyperfine coupling may also lead to a less known hyperfine effect, the so-called magnetic spin-torsion coupling, which was first studied by Heuvel and Dymanus and which has not yet been conclusively evidenced. In this talk, the magnetic hyperfine structure of the non-rigid methanol molecule will be investigated experimentally and theoretically. 13 hyperfine patterns were recorded using two molecular beam microwave spectrometers. These patterns, along with previously recorded ones,^c were analyzed in an attempt to evidence the effects of the magnetic spin-torsion coupling. The theoretical approach setup to analyze the observed data accounts for the spin-torsion coupling, in addition to the familiar magnetic spin-rotation and spin-spin couplings, and relies on symmetry

  8. a Nonhydrostatic Modeling Analysis of AN Intense Midlatitude Squall Line.

    NASA Astrophysics Data System (ADS)

    Yang, Ming-Jen

    1995-01-01

    Nonhydrostatic modeling shows that the convective cells of a squall line, which occurred over Kansas and Oklahoma on 10-11 June 1985, behaves as gravity waves. In the simulation, the gust front generates a continuous low -level updraft. Updraft cells periodically break away from the gust-front updraft and move at their associated gravity -wave phase speeds. Linear theory shows that waves are trapped in the troposphere because of the strong decrease of Scorer parameter with height. Linear theory predicts the gravity-wave amplitudes, quadrature relations, and the gravity-wave periods. The stronger front-to-rear propagation mode dominates in the mature stage of the storm. The decrease of Scorer parameter with height encountered by the rearward propagating waves is a product of the storm circulation. The drop-off in Scorer parameter with height is a manifestation of the shear between ascending front-to-rear and descending rear-to-front flows of the squall-line system. The squall line produces an environment conducive to trapping rearward propagating gravity waves generated at the gust front. Numerical experiments show that the rear inflow and related aspects of storm structure are sensitive to hydrometer types, ice-phase microphysics, and the midlevel environmental humidity. Ice-phase microphysics is important for the model to produce realistic air motions and precipitation in the stratiform region. With the occurrence of heavy hailstones, there is no enhanced rear-to-front flow at the back edge of the storm. Evaporation is the most important latent cooling process determining the structure and strength of the descending rear inflow and the mesoscale downdraft. Latent cooling by melting snow enhances the strength of the rear -to-front flow at the back edge of storm and the intensity of mesoscale downdraft. Mesoscale downdraft is initiated above the rm 0^circC level by sublimational cooling. With the environmental midlevel moisture reduced by half, mesoscale downdrafts

  9. Atomic Data and Spectral Line Intensities for NI XVII

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Landi, E.

    2011-01-01

    Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ni XVII. We include in the calculations the 23 lowest configurations, corresponding to 159 fine-structure levels: 3l3l', 3l4l0'' , and 3s5l0''' , with l,l' = s,p,d, l'' = s,p,d, f, and l''' = s,p,d. Collision strengths are calculated at five incident energies for all transitions at varying energies above the threshold of each transition. One additional energy, very close to the threshold of each transition, has also been included. Calculations have been carried out using the Flexible Atomic Code in the distorted wave approximation. Additional calculations have been performed with the University College London suite of codes for comparison. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates of the present work, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10(exp 8) - 10(exp 14) / cubic cm and at an electron temperature of logT(sub e)e(K) = 6.5, corresponding to the maximum abundance of Ni XVII. Spectral line intensities are calculated, and their diagnostic relevance is discussed. This dataset will be made available in the next version of the CHIANTI database

  10. Atomic Data and Spectral Line Intensities for Ca IX

    NASA Technical Reports Server (NTRS)

    Landi, E.; Bhatia, A. K.

    2012-01-01

    Electron impact collision strengths, energy levels, oscillator strengths and spontaneous radiative decay rates are calculated for Ca IX. We include in the calculations the 33 lowest configurations in the n = 3, 4, 5 complexes, corresponding to 283 fine structure levels in the 3l3l ', 3l4l'' and 3l4l''' configurations, where l,l' = s, p, d, l '' = s, p, d, f and l''' = s, p, d, f, g. Collision strengths are calculated at five incident energies for all transitions: 5.8, 13.6, 24.2, 38.6 and 57.9 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.0055 Ry and 0.23 Ry depending on the levels involved. Calculations have been carried out using the Flexible Atomic Code and the distorted wave approximation. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates calculated in the present work, statistical equilibrium equations for level populations are solved at electron densities covering the 10(exp 8)-10(exp 14)/cubic cm range and at an electron temperature of log T(sub e)(K)=5.8, corresponding to the maximum abundance of Ca IX. Spectral line intensities are calculated, and their diagnostic relevance is discussed.

  11. Atomic Data and Spectral Line Intensities for Ni XV

    NASA Technical Reports Server (NTRS)

    Landi, E.; Bhatia, A. K.

    2011-01-01

    Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ni XV.Weinclude in the calculations the 9 lowest configurations, corresponding to 126 fine structure levels: 3s23p2, 3s3p3, 3s23p3d, 3p4, 3s3p23d, and 3s2 3p4l with l =, s, p, d, f. Collision strengths are calculated at five incident energies for all transitions: 7.8, 18.5, 33.5, 53.5, and 80.2 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.004 and 0.28 Ry depending on the levels involved. Calculations have been carried out using the Flexible Atomic Code and the distorted-wave approximation. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates calculated in the present work, statistical equilibrium equations for level populations are solved at electron densities covering the 10(exp 8)-10(exp 14)/cu cm range and at an electron temperature of log T(sub e)(K) = 6.4, corresponding to the maximum abundance of Ni XV. Spectral line intensities are calculated, and their diagnostic relevance is discussed. This dataset will be made available in the next version of the CHIANTI database.

  12. Distribution of forbidden neutral carbon emission in the ring nebula (NGC 6720)

    NASA Technical Reports Server (NTRS)

    Jewitt, D. C.; Danielson, G. E.; Kupferman, P. N.; Maran, S. P.

    1983-01-01

    The spatial distribution of forbidden C I 9823, 9850 A emission in NGC 6720 is reported. Like forbidden O I, the forbidden C I radiation appears enhanced in the region of the bright filaments. A few percent of the carbon atoms in the filaments are neutral. The neutral fraction is consistent with ionization equilibrium calculations made under the assumption of complete shielding of direct stellar radiation by hydrogen. The observed carbon lines are excited by photoelectrons produced from hydrogen by the nebular diffuse radiation field. The forbidden C I observations confirm that the filaments in NGC 6720 are regions of locally enhanced shielding.

  13. Determination of vibration-rotation lines intensities from absorption Fourier spectra

    NASA Technical Reports Server (NTRS)

    Mandin, J. Y.

    1979-01-01

    The method presented allows the line intensities to be calculated from either their equivalent widths, heights, or quantities deduced from spectra obtained by Fourier spectrometry. This method has proven its effectiveness in measuring intensities of 60 lines of the molecule H2O with a precision of 10%. However, this method cannot be applied to isolated lines.

  14. Atomic data and spectral line intensities for Ca IX

    SciTech Connect

    Landi, E.; Bhatia, A.K.

    2014-11-15

    Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ca IX. We include in the calculations the 33 lowest configurations in the n=3,4, and 5 complexes, corresponding to 283 fine-structure levels in the 3l3l{sup ′}, 3l4l{sup ″}, and 3l5l{sup ‴} configurations, where l,l{sup ′}=s,p,d, l{sup ″}=s,p,d,f and l{sup ‴}=s,p,d,f,g. Collision strengths are calculated at five incident energies for all transitions: 5.8, 13.6, 24.2, 38.6, and 57.9 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.0055 Ry and 0.23 Ry depending on the levels involved. Calculations have been carried out using the Flexible Atomic Code and the distorted wave approximation. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates calculated in the present work, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10{sup 8}–10{sup 14}  cm{sup −3} and at an electron temperature of logT{sub e}(K)=5.8, corresponding to the maximum abundance of Ca IX. Spectral line intensities are calculated, and their diagnostic relevance is discussed.

  15. Atomic Data and Spectral Line Intensities for Ni XI

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Landi, E.

    2010-01-01

    Electron impact collision strengths, energy levels, oscillator strengths and spontaneous radiative decay rates are calculated for Ni XI. We include in the calculations the 10 lowest configurations, corresponding to 164 fine structure levels: 3s(sup 2)3p(sup 6), 3s(sup 2)3p(sup 5)3d, 3s(sup 2)3p(sup 4)3d(sup 2), 3s3p(sup 6)3d, 3s(sup 2)3p(sup 5)4l and 3s3p6 4l with l =.s, p, d. Collision strengths are calculated at five incident energies for all transitions: 7.1, 16.8, 30.2, 48.7 and 74.1 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.06 Ry and 0.25 Ry depending on the lower level. Calculations have been carried out using the Flexible Atomic Code and the distorted wave approximation. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates of the present work, combined with Close Coupling collision excitation rate coefficient available in the literature for the lowest 17 levels, statistical equilibrium equations for level populations are solved at electron densities covering the 10(exp 8)-10(exp 14) cu cm range and at an electron temperature of logT(sub c)(K)=6.1, corresponding to the maximum abundance of Ni XI. Spectral line intensities are calculated, and their diagnostic relevance is discussed. This dataset will be made available in the next version of the CHIANTI database.

  16. Effect of Sodium Chloride on the Intensity of the Spectral Lines of Elements During ARC Discharge

    NASA Astrophysics Data System (ADS)

    Strunina, N. N.; Baisova, B. T.

    2016-01-01

    The effect of the carrier (NaCl) during arc discharge on the intensity of the lines for elements with various ionization potentials (Al, Ca, Fe, Mg, Si, Ti, Zn) was investigated. It was found that the intensity of the spectral lines of the elements increases with increase in the concentration of the carrier. The relative roles of the factors responsible for the increase in the intensity of the spectral lines (the plasma temperature, the intensity of the spectral lines of the elements, and the degree of ionization of the elements, the fl ow rate and residence time of the atoms in the plasma) were analyzed.

  17. Solar Forbidden Oxygen, Revisited

    NASA Astrophysics Data System (ADS)

    Ayres, Thomas R.

    2008-10-01

    Recent large reductions in the solar oxygen abundance, based on synthesis of photospheric O I, OH, and CO absorptions with 3D convection models, have provoked consternation in the helioseismology community: the previous excellent agreement between measured p-mode oscillation frequencies and predictions based on the recommended epsilonO of a decade ago (680 parts per million [ppm] relative to hydrogen) unravels at the new low value (460 ppm). In an attempt to reconcile these conflicting results, the formation of pivotal [O I] λ6300, which is blended with a weak Ni I line, has been reconsidered, exploiting an alternative 3D model (albeit only a single temporal snapshot). And while there are several areas of agreement with the earlier [O I] studies of Allende Prieto, Asplund, and others, there is one crucial point of disagreement: the epsilonO derived here is significantly larger, 650 +/- 65 ppm (although at the expense of a ~30% weaker Ni I line than expected from the recommended nickel abundance). One innovation is a more robust treatment of the solar wavelengths: the balance between the components of the [O I] + Ni I blend is sensitive to velocity errors of only a few hundred m s-1. A second improvement is enforcement of a "continuum calibration" to ensure a self-consistent 3D temperature scale. Because of the renewed agreement between the linchpin tracer [O I] and seismic oxygen, the proposed downward slump of the solar metallicity and the perceived "oxygen crisis" now can be said to rest on less secure footings.

  18. Spectrum line intensity as a surrogate for solar irradiance variations.

    PubMed

    Livingston, W C; Wallace, L; White, O R

    1988-06-24

    Active Cavity Radiometer Irradiance Monitor (ACRIM) solar constant measurements from 1980 to 1986 are compared with ground-based, irradiance spectrophotometry of selected Fraunhofer lines. Both data sets were identically sampled and smoothed with an 85-day running mean, and the ACRIM total solar irradiance (S) values were corrected for sunspot blocking (S(c)). The strength of the mid-photospheric manganese 539.4-nanometer line tracks almost perfectly with ACRIM S(e), Other spectral features formed high in the photosphere and chromosphere also track well. These comparisons independently confirm the variability in the ACRIM S(e), signal, indicate that the source of irradiance is faculae, and indicate that ACRIM S(e), follows the 11-year activity cycle. PMID:17842428

  19. Far-infrared 14NH3 line positions and intensities measured with a FT-IR and AILES beamline, Synchrotron SOLEIL

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Yu, Shanshan; Pearson, John; Pirali, Olivier; Kwabia Tchana, Fridolin; Manceron, Laurent

    2016-09-01

    Extensive measurements of line positions and intensities are reported for the inversion-rotation and rovibrational transitions of 14NH3 in the 50-660 cm-1 region. This study analyzes high-resolution (0.00167 cm-1, unapodized) Fourier-transform spectra of high purity (99.5%) normal ammonia sample obtained using the AILES beamline of Synchrotron SOLEIL. The experimental conditions are designed to study transitions with intensities weaker than 1 × 10-22 cm-1/(molecule cm-2) at room temperature. Line positions and intensities of more than 2830 transitions of 14NH3 are measured and compiled after proper quality control; the features from minor isotopologues (15NH3 and NH2D) and H2O are identified and excluded. Based on the predictions of recent work from the empirical Hamiltonian modeling, systematic quantum assignments are made for 2047 transitions from eight bands including four inversion-rotation (gs, v2, 2v2, and v4) and four ro-vibrational bands (v2-gs, 2v2-v2, v4-v2, and 2v2-v4), as well as covering their ΔK = 3 forbidden transitions. The measured line positions for the assigned transitions are in an excellent agreement (typically better than 0.001 cm-1) with the predictions in a wide range of J and K for all the eight bands. The comparison with the HITRAN 2012 database is also satisfactory, although systematic offsets are seen for transitions with high J and K and those from weak bands. Also we note that out of the eight bands, the 2v2-v4 has not been listed in the HITRAN 2012 database. Differences of 20% are seen between our measured and calculated intensities depending on the bands. For line positions, greater differences are found for some NH3 bands in HITRAN 2012 than recent predictions. Measurements of the individual line positions and intensities are presented for the eight bands, and the final spectroscopic line positions and intensities are compiled as an electronic supplement.

  20. Atomic Data and Spectral Line Intensities for Ne III

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Thomas, R. J.; Landi, E.; Fisher, Richard R. (Technical Monitor)

    2002-01-01

    A number of satellites and rockets have been launched to observe radiation from the Sun and other astrophysical objects. Line radiation is emitted when the electron impact excited levels decay to the lower levels by photon emission. From this radiation, the physical parameters such as electron temperature and density of the astrophysical plasma, elemental abundance, and opacity can be inferred. Ne III lines have been observed in H II regions, Ne-rich filaments in supernovae, and planetary nebulae. The allowed line at 489.50 Angstroms due to the transition 2s(sup 2) 2p(sup 5) (sup 3) P2 (goes to) 2s(sup 2)2p(sup 4)(sup 3)P2 has been identified in the solar spectrum by Vernazza and Reeves using Skylab observations. Other Ne III lines in the solar EUV spectrum have been reported by Thomas and Neupert based on observations from the Solar EUV Rocket Telescope and Spectrograph (SERTS) instrument. Atomic data for Ne III have been calculated by using a set of programs developed at, University College, London. The Superstructure and Distorted Wave (DW) programs have been updated over the years. In the Superstructure program, configuration interaction can be taken into account and radial functions are calculated in a modified Thomas-Fermi-Amaldi potential. This is a statistical potential and depends on parameters lambda 1 which are determined by optimizing the weighted sum of term energies. They are found to be lambda(sub 0)=1.2467, lambda(sub 1)=1.1617, and lambda(sub 2)=1.0663. The relativistic corrections are included by using the Breit-Pauli Hamiltonian as a perturbation to the nonrelativistic Hamiltonian. The same potential is used to calculate reactance matrices in the DW approximation in LS coupling. Collision strengths in intermediate coupling are obtained by using term coupling coefficients obtained from the Superstructure program. In this calculation, the configurations used are 2s(sup 2)2p(sup 4), 2s2p(sup 5), 2s(sup 2)2p(sup 3)3s, 2s(sup 2)p(sup 3)3d giving rise

  1. E1-forbidden transition rates in ions of astrophysical interest

    NASA Astrophysics Data System (ADS)

    Träbert, E.

    2014-11-01

    Transition rates in atomic systems may appear to be of little importance in steady-state plasmas that are observed at great distances from Earth. However, some of the transition rates compete with collision rates, and in these cases certain line intensity ratios are affected and can serve as remote indicators of density. In the low-density environments of stellar coronae and planetary nebulae, the transition rates of interest are mostly spin-forbidden E1 decays, higher-multipole order transitions (M1, E2, M2, M3), and hyperfine-induced transitions. On Earth, measurements of the long upper level lifetimes of these atomic systems require the use of ion traps. A fair number of test cases with lifetimes in the range from nanoseconds to many seconds have been treated successfully, and the evolution of calculations along with the experimental progress is notable. A new generation of cold ion traps is expected to extend the atomic lifetime measurements on multiply charged ions into the range of many minutes.

  2. Room Temperature Line Lists for CO_2 Isotopologues with AB Initio Computed Intensities

    NASA Astrophysics Data System (ADS)

    Zak, Emil; Tennyson, Jonathan; Polyansky, Oleg; Lodi, Lorenzo; Zobov, Nikolay Fedorovich; Tashkun, Sergey; Perevalov, Valery

    2016-06-01

    We report 13 room temperature line lists for all major CO_2 isotopologues, covering 0-8000 wn. These line lists are a response to the need for line intensities of high, preferably sub-percent, accuracy by remote sensing experiments. Our scheme encompasses nuclear motion calculations supported by critical reliability analysis of the generated line intensities. Rotation-vibration wavefunctions and energy levels are computed using DVR3D and a high quality semi-empirical potential energy surface (PES) [1], followed by computation of intensities using a fully ab initio dipole moment surface (DMS). Cross comparison of line lists calculated using pairs of high-quality PES's and DMS's is used to assess imperfections in the PES, which lead to unreliable transition intensities between levels involved in resonance interactions. Four line lists are computed for each isotopologue to quantify sensitivity to minor distortions of the PES/DMS. This provides an estimate of the contribution to the overall line intensity error introduced by the underlying PES. Reliable lines are benchmarked against recent state-of-the-art measurements [2] and HITRAN-2012 supporting the claim that the majority of line intensities for strong bands are predicted with sub-percent accuracy [3]. Accurate line positions are generated using an effective Hamiltonian [4]. We recommend use of these line lists for future remote sensing studies and inclusions in databases. X. Huang, D. W. Schwenke, S. A. Tashkun, T. J. Lee, J. Chem. Phys. 136, 124311, 2012. O. L. Polyansky, K. Bielska, M. Ghysels, L. Lodi, N. F. Zobov, J. T. Hodges, J. Tennyson, PRL, 114, 243001, 2015. E. Zak, J. Tennyson, O. L. Polyansky, L. Lodi, S. A. Tashkun, V. I. Perevalov, JQSRT, in press and to be submitted. S. A. Tashkun, V. I. Perevalov, R. R. Gamache, J. Lamouroux, JQSRT, 152, 45-73, 2015.

  3. A room temperature CO2 line list with ab initio computed intensities

    NASA Astrophysics Data System (ADS)

    Zak, Emil; Tennyson, Jonathan; Polyansky, Oleg L.; Lodi, Lorenzo; Zobov, Nikolay F.; Tashkun, Sergey A.; Perevalov, Valery I.

    2016-07-01

    Atmospheric carbon dioxide concentrations are being closely monitored by remote sensing experiments which rely on knowing line intensities with an uncertainty of 0.5% or better. We report a theoretical study providing rotation-vibration line intensities substantially within the required accuracy based on the use of a highly accurate ab initio dipole moment surface (DMS). The theoretical model developed is used to compute CO2 intensities with uncertainty estimates informed by cross comparing line lists calculated using pairs of potential energy surfaces (PES) and DMS's of similar high quality. This yields lines sensitivities which are utilized in reliability analysis of our results. The final outcome is compared to recent accurate measurements as well as the HITRAN2012 database. Transition frequencies are obtained from effective Hamiltonian calculations to produce a comprehensive line list covering all 12C16O2 transitions below 8000cm-1 and stronger than 10-30 cm/molecule at T = 296 K.

  4. Expected intensities of solar neon-like ions

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Kastner, S. O.

    1985-01-01

    A study of the expected intensities of the stronger solar neon-like ion emission lines, some not yet observed, is carried out to compare with the observational situation. The potential usefulness of the 2p5 3s(3P2) - 2p6 forbidden line as a density diagnostic is discussed, and new electric quadrupole lines in the soft X-ray range are noted. 'Observability diagrams' are presented as a convenient overview of the known and unobserved lines. The S VII resonance lines appear to have anomalous intensities.

  5. 49 CFR 173.54 - Forbidden explosives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... loaded firearm (except as provided in 49 CFR 1544.219). (g) Fireworks that combine an explosive and a... 49 Transportation 2 2013-10-01 2013-10-01 false Forbidden explosives. 173.54 Section 173.54... SHIPMENTS AND PACKAGINGS Definitions, Classification and Packaging for Class 1 § 173.54 Forbidden...

  6. 49 CFR 173.54 - Forbidden explosives.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... loaded firearm (except as provided in 49 CFR 1544.219). (g) Fireworks that combine an explosive and a... 49 Transportation 2 2014-10-01 2014-10-01 false Forbidden explosives. 173.54 Section 173.54... SHIPMENTS AND PACKAGINGS Definitions, Classification and Packaging for Class 1 § 173.54 Forbidden...

  7. 49 CFR 173.54 - Forbidden explosives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... loaded firearm (except as provided in 49 CFR 1544.219). (g) Fireworks that combine an explosive and a... 49 Transportation 2 2010-10-01 2010-10-01 false Forbidden explosives. 173.54 Section 173.54... SHIPMENTS AND PACKAGINGS Definitions, Classification and Packaging for Class 1 § 173.54 Forbidden...

  8. 49 CFR 173.54 - Forbidden explosives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... loaded firearm (except as provided in 49 CFR 1544.219). (g) Fireworks that combine an explosive and a... 49 Transportation 2 2011-10-01 2011-10-01 false Forbidden explosives. 173.54 Section 173.54... SHIPMENTS AND PACKAGINGS Definitions, Classification and Packaging for Class 1 § 173.54 Forbidden...

  9. 49 CFR 173.54 - Forbidden explosives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... loaded firearm (except as provided in 49 CFR 1544.219). (g) Fireworks that combine an explosive and a... 49 Transportation 2 2012-10-01 2012-10-01 false Forbidden explosives. 173.54 Section 173.54... SHIPMENTS AND PACKAGINGS Definitions, Classification and Packaging for Class 1 § 173.54 Forbidden...

  10. Measurements of absolute line intensities in carbon dioxide bands near 5.2 microns

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Benner, D. C.; Devi, V. M.

    1985-01-01

    A nonlinear least-squares spectral fitting procedure has been used to derive experimental absolute intensities for over 300 unblended lines belonging to twelve CO2 bands in the 5.2-micron region. The spectral data were recorded at 0.01/cm resolution and room temperature with the Fourier transform spectrometer in the McMath solar telescope complex at the National Solar Observatory on Kitt Peak and have a signal-to-rms noise ratio of 2000-4000. A natural sample of carbon dioxide was used as the sample gas. For each band, the measured line intensities have been analyzed to derive the vibrational band intensity and coefficients of the F factor. The results are compared to the values used to calculate the intensities in the 1982 Air Force Geophysics Laboratory line parameters compilation.

  11. 14NH_3 Line Positions and Intensities in the Far-Infrared Comparison of Ft-Ir Measurements to Empirical Hamiltonian Model Predictions

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Yu, Shanshan; Pearson, John; Pirali, Olivier; Kwabia Tchana, F.; Manceron, Laurent

    2016-06-01

    We have analyzed multiple spectra of high purity (99.5%) normal ammonia sample recorded at room temperatures using the FT-IR and AILES beamline at Synchrotron SOLEIL, France. More than 2830 line positions and intensities are measured for the inversion-rotation and rovibrational transitions in the 50 - 660 wn region. Quantum assignments were made for 2047 transitions from eight bands including four inversion-rotation bands (gs(a-s), νb{2}(a-s), 2νb{2}(a-s), and νb{4}(a-s)) and four ro-vibrational bands (νb{2} - gs, 2νb{2} - gs, νb{4} - νb{2}, and 2νb{2} -νb{4}), as well as covering more than 300 lines of ΔK = 3 forbidden transitions. Out of the eight bands, we note that 2νb{2} - νb{4} has not been listed in the HITRAN 2012 database. The measured line positions for the assigned transitions are in an excellent agreement (typically better than 0.001 wn) with the predictions from the empirical Hamiltonian model [S. Yu, J.C. Pearson, B.J. Drouin, et al.(2010)] in a wide range of J and K for all the eight bands. The comparison with the HITRAN 2012 database is also satisfactory, although systematic offsets are seen for transitions with high J and K and those from weak bands. However, differences of 20% or so are seen in line intensities for allowed transitions between the measurements and the model predictions, depending on the bands. We have also noticed that most of the intensity outliers in the Hamiltonian model predictions belong to transitions from gs(a-s) band. We present the final results of the FT-IR measurements of line positions and intensities, and their comparisons to the model predictions and the HITRAN 2012 database. Research described in this paper was performed at the Jet Propulsion Laboratory and California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration.

  12. Forbidden Ca II in the sun unmasked by way of Venus

    NASA Technical Reports Server (NTRS)

    Schorn, R. A.; Young, A. T.; Barker, E. S.

    1975-01-01

    Eleven high dispersion spectra of Venus, taken with blue Doppler shifts, have been used to unmask the 7323.88 angstrom forbidden line of Ca II from the earth atmospheric H2O absorption line at 7323.972 angstroms. An equivalent width for the Ca II line has been obtained in integrated sunlight. A model giving the solar calcium abundance is presented.

  13. Line intensity enhancements in stellar coronal X-ray spectra due to opacity effects

    NASA Astrophysics Data System (ADS)

    Rose, S. J.; Matranga, M.; Mathioudakis, M.; Keenan, F. P.; Wark, J. S.

    2008-06-01

    Context: The I(15.01 Å)/I(16.78 Å) emission line intensity ratio in Fe xvii has been reported to deviate from its theoretical value in solar and stellar X-ray spectra. This is attributed to opacity in the 15.01 Å line, leading to a reduction in its intensity, and was interpreted in terms of a geometry in which the emitters and absorbers are spatially distinct. Aims: We study the I(15.01 Å)/I(16.78 Å) intensity ratio for the active cool dwarf EV Lac, in both flare and quiescent spectra. Methods: The observations were obtained with the Reflection Grating Spectrometer on the XMM-Newton satellite. The emission measure distribution versus temperature reconstruction technique is used for our analysis. Results: We find that the 15.01 Å line exhibits a significant enhancement in intensity over the optically thin value. To our knowledge, this is the first time that such an enhancement has been detected on such a sound statistical basis. We interpret this enhancement in terms of a geometry in which the emitters and absorbers are not spatially distinct, and where the geometry is such that resonant pumping of the upper level has a greater effect on the observed line intensity than resonant absorption in the line-of-sight.

  14. Excitation of emission lines by fluorescence and recombination in IC 418

    NASA Astrophysics Data System (ADS)

    Escalante, Vladimir; Morisset, Cristophe; Georgiev, Leonid

    2012-08-01

    We predict intensities of lines of CII, NI, NII, OI and OII and compare them with a deep spectroscopic survey of IC 418 to test the effect of excitation of nebular emission lines by continuum fluorescence of starlight. Our calculations use a nebular model and a synthetic spectrum of its central star to take into account excitation of the lines by continuum fluorescence and recombination. The NII spectrum is mostly produced by fluorescence due to the low excitation conditions of the nebula, but many CII and OII lines have more excitation by fluorescence than recombination. In the neutral envelope, the NI permitted lines are excited by fluorescence, and almost all the OI lines are excited by recombination. Electron excitation produces the forbidden optical lines of OI, but continuum fluorescence excites most of the NI forbidden line intensities. Lines excited by fluorescence of light below the Lyman limit thus suggest a new diagnostic to explore the photodissociation region of a nebula.

  15. Operation of the intensity monitors in beam transport lines at Fermilab during Run II¹

    SciTech Connect

    Crisp, J.; Fellenz, B.; Fitzgerald, J.; Heikkinen, D.; Ibrahim, M. A.

    2011-10-06

    The intensity of charged particle beams at Fermilab must be kept within pre-determined safety and operational envelopes in part by assuring all beam within a few percent has been transported from any source to destination. Beam instensity monitors with toroidial pickups provide such beam intensity measurements in the transport lines between accelerators at FNAL. With Run II, much effort was made to continually improve the resolution and accuracy of the system.

  16. Enhancement of Ion Line Intensity in the Analytical Zone of an Arc Dual-Jet Plasmatron

    NASA Astrophysics Data System (ADS)

    Smirnova, E. V.; Chumakova, N. L.

    2015-07-01

    We show that the effect of enhancement of the intensity (Ii) of ion lines, observed in atomic emission analysis when using an arc dual-jet plasmatron, is not an anomalous phenomenon compared with an arc plasma. For total ion energy <15 eV, it corresponds to a thermal mechanism for excitation of the spectra. At higher energy, we observe an increase in the intensity Ii relative to the equilibrium values that is due to the phenomenon of nonresonant charge exchange.

  17. Absolute line intensities in CO2 bands near 4.8 microns

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Benner, D. C.; Devi, V. M.

    1986-01-01

    Absolute intensities for 726 unblended lines in 20 bands of C-12(O-16)2, C-13(O-16)2, O-16C-12O-18, and O-16C-12O-17 in the 4.8-micron spectral region have been determined using a natural sample of ultrahigh-purity CO2. Spectral data were recorded at low pressure (less than 10 torr) and room temperature with the Fourier transform spectrometer in the McMath solar telescope complex on Kitt Peak. Derived vibrational band intensities and coefficients of the F factor for each band were compared to values of the 1982 Air Force Geophysics Laboratory line parameters compilation. The present work fills out the CO2 lines in the 5-micron band systems. Lines in the strongest of these measured bands are being used to infer atmospheric pressure from high-resolution stratospheric spectra recorded during the Spacelab 3 Atmospheric Trace Molecule Spectroscopy experiment.

  18. Global fitting of line intensities of acetylene molecule in the infrared using the effective operator approach

    NASA Astrophysics Data System (ADS)

    Perevalov, V. I.; Lyulin, O. M.; Jacquemart, D.; Claveau, C.; Teffo, J.-L.; Dana, V.; Mandin, J.-Y.; Valentin, A.

    2003-04-01

    The method of effective operators has been applied to the global fitting of line intensities of the acetylene molecule in the middle infrared. Simultaneous fittings of recently observed line intensities in the cold and hot bands lying in the 13.6, 7.8, and 5 μm regions have been performed. The eigenfunctions of the effective Hamiltonian developed for the global treatment of the vibration-rotation line positions of acetylene [O.M. Lyulin, V.I. Perevalov, S.A. Tashkun, J.-L. Teffo, in: Leonid N. Sinitsa (Ed.), 13th Symposium and School on High Resolution Molecular Spectroscopy, Proceedings of SPIE, vol. 4063, 2000, pp. 126-133] have been used in the calculations. The sets of effective dipole moment parameters obtained reproduce the observed line intensities within the experimental accuracy. The importance of l-type resonance, responsible for some large differences between intensities of the same lines in subbands having opposite parities, is exhibited and discussed.

  19. Intensity increases of actin layer-lines on activation of the Limulus muscle.

    PubMed Central

    Maéda, Y; Boulin, C; Gabriel, A; Sumner, I; Koch, M H

    1986-01-01

    Small angle x-ray diffraction patterns were recorded from isometrically contracting Limulus (horseshoe crab) telson levator muscle using a multiwire proportional-area detector on the storage ring DORIS. In the pattern a substantial increase in intensity is observed on the thin-filament-associated layer-line at 1/38 nm-1 (the first actin layer-line) with a maximum increase at a radial spacing of R = 0.07 nm-1 but there is a much smaller change in the intensity of the 5.9-nm layer-line, which also arises from the thin filament structure. The results suggest that during contraction the myosin heads, presumably being attached to the thin filaments, are arranged along the long-stranded helical tracks of the thin filaments but that the spatial relationship between the heads and the actin monomers varies. Intensity increases have also been observed (Maéda et al., manuscript in preparation) in the part of the patterns from frog muscle and barnacle muscle, which are attributable to the first actin layer-line. It is thus likely that the intensity increase of the first actin layer-line on the Limulus pattern is associated not with structural features which are special to Limulus muscle, but with the tension generating processes that are shared by muscles in general. Images FIGURE 1 FIGURE 2 PMID:3801566

  20. Analysis of the plasma radiation spectra with lines of significantly varying intensity

    NASA Astrophysics Data System (ADS)

    Kostrin, D. K.; Lisenkov, A. A.; Uhov, A. A.; Ramazanov, A. N.

    2016-07-01

    Range of charge accumulation times for the charge-coupled device photodetector, in which there is linearity of its signal characteristics, is demonstrated. The influence of the blooming effect during the saturation of a signal on the form of spectral lines is shown. Method of simultaneous analysis of lines of significantly different intensity using multiple summations of the emission spectra, obtained with a small time of charge accumulation, is proposed.

  1. Ratios of molecular hydrogen line intensities in shocked gas - Evidence for cooling zones

    NASA Technical Reports Server (NTRS)

    Brand, P. W. J. L.; Moorhouse, A.; Bird, M.; Burton, M. G.; Geballe, T. R.

    1988-01-01

    Column densities of molecular hydrogen have been calculated from 19 infrared vibration-rotation and pure rotational line intensities measured at peak 1 of the Orion molecular outflow. The run of column density with energy level is similar to a simple coolng zone model of the line-emitting region, but is not well fitted by predictions of C-shock models current in the literature.

  2. The Labile Limits of Forbidden Interactions.

    PubMed

    González-Varo, Juan P; Traveset, Anna

    2016-09-01

    Forbidden links are defined as pairwise interactions that are prevented by the biological traits of the species. We focus here on the neglected importance of intraspecific trait variation in the forbidden link concept. We show how intraspecific trait variability at different spatiotemporal scales, and through ontogeny, reduces the expected prevalence of forbidden interactions. We also highlight how behavior can foster interactions that, from traits, would be predicted to be forbidden. We therefore discuss the drawbacks of frameworks recently developed to infer biotic interactions using available trait data (mean values). Mispredictions can have disproportionate effects on inferences about community dynamics. Thus, we suggest including intraspecific variability in trait-based models and using them to guide the sampling of real interactions in the field for validation. PMID:27471077

  3. Cluster physics and the importance of forbiddenness

    NASA Astrophysics Data System (ADS)

    Hess, P. O.; Yépez-Martínez, H.

    2016-07-01

    We review the concept of forbiddenness as introduced by Smirnov and Yu M. Tchuvil'sky [1], which states that most of the properties of nuclear reactions and cluster structure is based on structural effects (Pauli exclusion principle). This becomes also clear when one tries to obtain the ground state of the united nucleus by two heavy clusters, which is not possible when all excitations are put into the relative motion. Smirnov et al. introduced the concept of forbiddenness, which is defined as the minimal number of relative oscillation quanta which have to be shifted to internal excitations of the clusters, such that the ground state can be reached. We show that Smirnov et al. committed and error in the derivation, leading us to reevaluate the derivation of the forbiddenness. We deduce the correct expression for the forbiddenness, leading to a simple interpretation and implementation in a cluster model and some applications are presented.

  4. Forbidden patterns in financial time series

    NASA Astrophysics Data System (ADS)

    Zanin, Massimiliano

    2008-03-01

    The existence of forbidden patterns, i.e., certain missing sequences in a given time series, is a recently proposed instrument of potential application in the study of time series. Forbidden patterns are related to the permutation entropy, which has the basic properties of classic chaos indicators, such as Lyapunov exponent or Kolmogorov entropy, thus allowing to separate deterministic (usually chaotic) from random series; however, it requires fewer values of the series to be calculated, and it is suitable for using with small datasets. In this paper, the appearance of forbidden patterns is studied in different economical indicators such as stock indices (Dow Jones Industrial Average and Nasdaq Composite), NYSE stocks (IBM and Boeing), and others (ten year Bond interest rate), to find evidence of deterministic behavior in their evolutions. Moreover, the rate of appearance of the forbidden patterns is calculated, and some considerations about the underlying dynamics are suggested.

  5. Long-term variations of the oxygen red 630 nm line nightglow intensity

    NASA Astrophysics Data System (ADS)

    Gudadze, N. B.; Didebulidze, G. G.; Javakhishvili, G. Sh.; Shepherd, M. G.; Vardosanidze, M. V.

    2007-02-01

    The long-term data set of total nightglow intensity of the oxygen red 630.0 nm line observed at Abastumani (41.8 degrees N, 42.8 degrees E) between 1957-1993 is investigated. The long-term trend and characteristic variations in solar radiation during an 11 year cycle of the red-line intensity are different after astronomical twilight (premidnight) and at midnight. The amplitude of deviation of the red-line intensity from its mean value at solar maximum and (or) minimum phase is greatest after astronomical twilight and decreases toward midnight. The long-term trend of these variations changes from its value about 0.74 R/year premidnight to its minimum negative value of about -1.92 R/year at and after midnight. This behavior of the long-term trend is considered as a possible result of an increase in electron density below the peak height (h(m)F2) of the ionospheric F2 layer and lowering of the height h(m)F2 after midnight predicted by the TIME-GCM model on the assumption of an increase in density of greenhouse gases in the lower atmosphere. The third-order regression equation (with different solar activity indices) is considered to be convenient for describing long-term variations in the mean annual red-line intensity.

  6. Theoretical rovibrational line intensities in the electronic ground state of ozone

    NASA Astrophysics Data System (ADS)

    Diehr, Matthieu; Rosmus, Pavel; Carter, Stuart; Knowles, Peter J.

    2004-01-01

    First-principles calculations of absolute line intensities and rovibrational energies of ozone (16O3) are reported using potential energy and electric dipole moment functions calculated by the internally contracted MRCI approach. The rovibrational energies and eigenfunctions (up to about 8500 cm-1 and J = 64) were obtained variationally with an exact Hamiltonian in internal valence coordinates. More than 4.8 × 106 electric dipole transition matrix elements were calculated for the absolute rovibrational line intensities. They are compared with the values of the HITRAN database. The purely rotational absolute line intensities in the (000) state and the rovibrational intensities for the (001)-(000) band agree to within about 0.3 to 1% for the (010)-(000) band to within about 3 to 4%. Excellent agreement with experiment is also achieved for low-lying overtone and combination bands. Inconsistencies are found for the (100)-(000) band overlapping with the antisymmetric stretching fundamental and also for the (002)-(000) antisymmetric stretching overtone. The generated dipole moment function can be used for predicting the absorption intensities in any of the heavier isotopomers, hot bands or the rates of spontaneous emission.

  7. The safety of obstetric acupuncture: forbidden points revisited

    PubMed Central

    2015-01-01

    Background/aim Although the safety of acupuncture per se in pregnancy is reasonably well accepted, there remains debate regarding needling at points historically considered to be ‘forbidden’ during pregnancy. This article reviews the scientific literature on this topic. Main findings There is no objective evidence of harm following needling at forbidden points, summarised by the following four lines of evidence. (1) In 15 clinical trials (n=823 women receiving n=4549–7234 acupuncture treatments at one or more forbidden points) rates of preterm birth (PTB) and stillbirth following are equivalent to those in untreated control groups and consistent with background rates of these complications in the general population. (2) Observational studies, including a large cohort of 5885 pregnant women needled at forbidden points at all stage of pregnancy, demonstrate that rates of miscarriage, PTB, preterm prelabour rupture of membranes (PPROM), and preterm contractions (preterm labour (PTL) or threatened PTL) are comparable with untreated controls and/or consistent with their anticipated incidence. (3) There is no reliable evidence that acupuncture/electroacupuncture (EA) can induce miscarriage/labour, even under otherwise favourable circumstances such as post-dates pregnancy or intrauterine fetal death. (4) Laboratory experiments using pregnant rats have demonstrated that repeated EA at forbidden points throughout gestation does not influence rates of post-implantation embryonic demise or cause miscarriage, fetal loss or resorption. Conclusions These findings are reassuring and will help individualised risk:benefit assessment before treating pregnant women. Given the numerous evidence-based indications for obstetric acupuncture and lack of evidence of harm, risk:benefit assessments will often fall in favour of treatment. PMID:26362792

  8. Line intensities and self-broadening coefficients for the ν2 band of methyl chloride

    NASA Astrophysics Data System (ADS)

    Barbouchi Ramchani, A.; Jacquemart, D.

    2016-08-01

    The present report concerns measurements of lines intensities and self-broadening coefficients for 170 transitions of the ν2 band of both 12CH335Cl and 12CH337Cl isotopologues between 1291 and 1403 cm-1. This work is the continuation of a previous effort on the ν5 band (Barbouchi Ramchani et al., 2013). For these studies, spectra of CH3Cl have been recorded at room temperature using a rapid scan Bruker IFS120 HR interferometer. The line parameters have been retrieved using a Voigt profile and a multispectrum fitting procedure. The average accuracy of the line parameters obtained in this work has been estimated to be between 2% and 5% for line intensities and between 5% and 10% for self-broadening coefficients depending on the transitions. A global comparison with the experimental values existing in the literature has been performed. The measurements of line intensities have also been compared to calculated values from HITRAN and GEISA databases.

  9. Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experiment Spherical Torus

    NASA Astrophysics Data System (ADS)

    Kim, YooSung; Shi, Yue-Jiang; Yang, Jeong-hun; Kim, SeongCheol; Kim, Young-Gi; Dang, Jeong-Jeung; Yang, Seongmoo; Jo, Jungmin; Oh, Soo-Ghee; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-11-01

    Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of Hα and Hβ radiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.

  10. Examining Helium Line Intensities and Ratios in a Linear Helium Plasma to Identify Te and ne

    NASA Astrophysics Data System (ADS)

    Ray, H.; Biewer, T. M.; Unterberg, E. A.; Fehling, D. T.; Isler, R. C.

    2015-11-01

    Oak Ridge National Laboratory's prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma device dedicated to the understanding of plasma material interaction physics. A photomultiplier tube (PMT) based diagnostic system called a filterscope examines the visible light emission from Proto-MPEX. The filterscope is a non-invasive, high sensitivity, and high temporal resolution compact system with multiple PMT channels. Three PMTs contain He I narrow bandpass filters of wavelengths 667.9, 723.6, and 706.7 nm for line ratio analysis. Helium line intensities and ratios have been widely applied on astrophysical plasmas and machines such as JET and NSTX to determine profiles of electron temperatures, Te, and densities, ne. Ratios of the He I intensities measured by the filterscope are compared to calculated intensity ratios determined through a collisional radiative model (CRM) as follows: An excited He atom in state P will de-excite to a lower energy level Q by emitting a photon of a specific wavelength. A CRM uses the interactions P has with Q and other energy levels to calculate the population density of P. The calculated population density is used to determine the spectral line intensity of the wavelength analyzed. The aforementioned process is performed for each of the He I bandpass filters, and ratios dependent on Te and ne are calculated and compared to the filterscopes measured ratios. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725.

  11. INTENSITY ENHANCEMENT OF O VI ULTRAVIOLET EMISSION LINES IN SOLAR SPECTRA DUE TO OPACITY

    SciTech Connect

    Keenan, F. P.; Mathioudakis, M.; Doyle, J. G.; Madjarska, M. S.; Rose, S. J.; Bowler, L. A.; Britton, J.; McCrink, L.

    2014-04-01

    Opacity is a property of many plasmas. It is normally expected that if an emission line in a plasma becomes optically thick, then its intensity ratio to that of another transition that remains optically thin should decrease. However, radiative transfer calculations undertaken both by ourselves and others predict that under certain conditions the intensity ratio of an optically thick to an optically thin line can show an increase over the optically thin value, indicating an enhancement in the former. These conditions include the geometry of the emitting plasma and its orientation to the observer. A similar effect can take place between lines of differing optical depths. While previous observational studies have focused on stellar point sources, here we investigate the spatially resolved solar atmosphere using measurements of the I(1032 Å)/I(1038 Å) intensity ratio of O VI in several regions obtained with the Solar Ultraviolet Measurements of Emitted Radiation instrument on board the Solar and Heliospheric Observatory satellite. We find several I(1032 Å)/I(1038 Å) ratios observed on the disk to be significantly larger than the optically thin value of 2.0, providing the first detection (to our knowledge) of intensity enhancement in the ratio arising from opacity effects in the solar atmosphere. The agreement between observation and theory is excellent and confirms that the O VI emission originates from a slab-like geometry in the solar atmosphere, rather than from cylindrical structures.

  12. Determination of sulfur in biodiesel microemulsions using the summation of the intensities of multiple emission lines.

    PubMed

    Young, Carl G; Amais, Renata S; Schiavo, Daniela; Garcia, Edivaldo E; Nóbrega, Joaquim A; Jones, Bradley T

    2011-05-15

    A method for the determination of sulfur in biodiesel samples by inductively coupled plasma optical emission spectrometry which uses microemulsion for sample preparation and the summation of the intensities of multiple emission lines has been developed. Microemulsions were prepared using 0.5 mL of 20% v/v HNO(3), 0.5 mL of Triton X-100, 2-3 mL of biodiesel sample, and diluted with n-propanol to a final volume of 10 mL. Summation of the emission intensities of multiple sulfur lines allowed for increased accuracy and sensitivity. The amounts of sulfur determined experimentally were between 2 and 7 mg L(-1), well below legislative standards for many countries. Recoveries obtained ranged from 72 to 119%, and recoveries obtained for the 182.562 nm line were slightly lower. This is most likely due to its lower sensitivity. Using microemulsion for sample preparation and the summation of the intensities of multiple emission lines for the successful determination of sulfur in biodiesel has been demonstrated. PMID:21482315

  13. Detection of far-infrared forbidden O I and forbidden O III emission from the galaxy M82

    NASA Technical Reports Server (NTRS)

    Watson, D. M.; Genzel, R.; Townes, C. H.; Werner, M. W.; Storey, J. W. V.

    1984-01-01

    Observations in M82 of the lowest-lying transitions of neutral and doubly ionized oxygen, forbidden O I 63.2 microns and forbidden O III 88.4 microns, which have wavelengths at which the extinction toward M82 is negligible, are reported. For O III, the +220 km/s velocity of the line center with respect to the local standard of rest, the 300 km/s intrinsic line width, and the asymmetry of the profile are consistent with the systemic velocity and rotational broadening seen in other ionic lines in the nucleus of M82. The fraction of oxygen that is present in doubly ionized form, indicates that the ionization state is similar to that found in H II regions in the disk of the Milky Way Galaxy. The central velocity of the O I line is +130 km/s, and no broadening in excess of instrumental resolution is seen. This result appears to rule out association of this emission with the periphery of the central H II region.

  14. Electron-impact excitation collision strengths and theoretical line intensities for transitions in S III

    SciTech Connect

    Grieve, M. F. R.; Ramsbottom, C. A.; Hudson, C. E.; Keenan, F. P.

    2014-01-01

    We present Maxwellian-averaged effective collision strengths for the electron-impact excitation of S III over a wide range of electron temperatures of astrophysical importance, log T{sub e} (K) = 3.0-6.0. The calculation incorporates 53 fine-structure levels arising from the six configurations—3s {sup 2}3p {sup 2}, 3s3p {sup 3}, 3s {sup 2}3p3d, 3s {sup 2}3p4s, 3s {sup 2}3p4p, and 3s {sup 2}3p4d—giving rise to 1378 individual lines and is undertaken using the recently developed RMATRX II plus FINE95 suite of codes. A detailed comparison is made with a previous R-matrix calculation and significant differences are found for some transitions. The atomic data are subsequently incorporated into the modeling code CLOUDY to generate line intensities for a range of plasma parameters, with emphasis on allowed ultraviolet extreme-ultraviolet emission lines detected from the Io plasma torus. Electron density-sensitive line ratios are calculated with the present atomic data and compared with those from CHIANTI v7.1, as well as with Io plasma torus spectra obtained by Far-Ultraviolet Spectroscopic Explorer and Extreme-Ultraviolet Explorer. The present line intensities are found to agree well with the observational results and provide a noticeable improvement on the values predicted by CHIANTI.

  15. Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory

    SciTech Connect

    Petrignani, Annemieke; Berg, Max H.; Grussie, Florian; Wolf, Andreas; Mizus, Irina I.; Zobov, Nikolai F.; Polyansky, Oleg L.; Tennyson, Jonathan; Pavanello, Michele; Adamowicz, Ludwik

    2014-12-28

    The visible spectrum of H{sub 3}{sup +} is studied using high-sensitivity action spectroscopy in a cryogenic radiofrequency multipole trap. Advances are made to measure the weak ro-vibrational transitions from the lowest rotational states of H{sub 3}{sup +} up to high excitation energies providing visible line intensities and, after normalisation to an infrared calibration line, the corresponding Einstein B coefficients. Ab initio predictions for the Einstein B coefficients are obtained from a highly precise dipole moment surface of H{sub 3}{sup +} and found to be in excellent agreement, even in the region where states have been classified as chaotic.

  16. Does Velocity Redistribution Really Enhance the HE 304 A Line to Observed Intensities?

    NASA Technical Reports Server (NTRS)

    Jordan, Stuart; Andretta, Vincenzo; Garcia, Adriana; Brosius, Jeffrey; Behring, William

    1999-01-01

    Previous work by this group has demonstrated that small-scale nonthermal velocities probably play a significant role in enhancing the intensity of the He II 304 A line above values predicted by the static atmosphere NLTE theories, and more in conformity with Skylab and SOHO observations. This presentation briefly summarizes the evidence for this conclusion, emphasizing SOHO and correlated groundbased observations, of which examples are presented. However, in contrast to the previous studies, the tact taken here is more critical, asking the question "Can velocity redistribution fully explain the observations of the 304 A line, and what counter-indications and problems remain?" The conclusion reached is that, while velocity redistribution plays a significant role in the intensity enhancement, it may not be the whole story. Some other mechanism, associated with velocity filtration, may be at work.

  17. Line Positions and Intensities for the ν12 Band of 13C12CH_6

    NASA Astrophysics Data System (ADS)

    Devi, V. Malathy; Benner, D. Chris; Sung, Keeyoon; Crawford, Timothy J.; Mantz, Arlan; Smith, Mary Ann H.

    2014-06-01

    High-resolution, high signal-to-noise spectra of mono-substituted 13C-ethane (13C12CH_6) in the 12.2 μm region were recorded with a Bruker IFS 125HR Fourier transform spectrometer. The spectra were obtained for four sample pressures at three different temperatures between 130 and 208 K using a 99% 13C-enriched ethane sample contained in a 20.38-cm long coolable absorption cell. A multispectrum nonlinear least squares fitting technique was used to fit the same intervals in the four spectra simultaneously to determine line positions and intensities. Similar to our previous analyses of 12C_2H_6 spectra in this same region, constraints were applied to accurately fit each pair of doublet components arising from torsional Coriolis interaction of the excited ν12 = 1 state with the nearby torsional ν_6 = 3 state. Line intensities corresponding to each spectrum temperature (130 K, 178 K and 208 K) are reported for 1660 ν12 absorption lines for which the assignments are known, and integrated intensities are estimated as the summation of the measured values. The measured line positions and intensities (re-scaled to 296 K) are compared with values in recent editions of spectroscopic databases. K. Sung, A. W. Mantz, L. R. Brown, et al., J. Mol. Spectrosc., 162 (2010) 124-134. D. C. Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith and D. Atkins, JQSRT, 53 (1995) 705-721. V. Malathy Devi, C. P. Rinsland, D. Chris Benner, et al., JQSRT, 111 (2010) 1234-1251 V. Malathy Devi, D. Chris Benner, C. P. Rinsland, et al., JQSRT, 111 (2010) 2481-2504. Research described in this paper was performed at Connecticut College, the College of William and Mary, NASA Langley Research Center and the Jet Propulsion Laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration.

  18. Line Positions and Intensities of Monodeuterated Methane Between 2.2 and 2.5 Microns

    NASA Astrophysics Data System (ADS)

    Brown, Linda R.; Sung, K.; Nikitin, A. V.; Smith, M. H.; Mantz, A. W.; Tyuterev, V. G.; Rey, M.

    2012-10-01

    A new study of 12CH3D line positions and intensities was performed for the upper portion of the Enneadecad polyad between 4000 and 4550 cm-1. For this, FTIR spectra were recorded with D-enriched methane samples (at 80 K with a Bruker 125 IFS at 0.005 cm-1 resolution and at 291 K with the McMath-Pierce FTS at 0.011 cm-1 resolution, respectively). Line positions and intensities were retrieved by least square curve-fitting procedures and analyzed using the effective Hamiltonian and the effective Dipole moment expressed in terms of irreducible tensors operators adapted to symmetric top molecules. Initially, only the cold spectrum was used to identify quantum assignments and predict 12CH3D relative intensities in this region. Combining the two temperature datasets confirmed the assumed quantum assignments and also demonstrated the relative accuracies to be better than ±0.0002 cm-1 for line positions and at least ±6% for 1160 selected features. Including additional assignments from the room temperature spectra alone permitted 1362 line intensities of 12 bands (involving 23 vibrational symmetry components) to be reproduced with an RMS of 9%. Over 4085 selected positions for 12 bands were modeled to 0.008 cm-1. More work is needed to obtain a complete characterization of this complex polyad. This work is part of the ANR project "CH4@Titan" (ref: BLAN08-2_321467). Research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, the NASA Langley Research Center and Connecticut College under contracts and grants with the National Aeronautics and Space Administration. We acknowledge the LEFE-CHAT INSU project APOA1 (CNRS, France); the Groupement de Recherche International SAMIA between CNRS (France), RFBR (Russia) and CAS (China).

  19. Generalized in-line digital holographic technique based on intensity measurements at two different planes

    NASA Astrophysics Data System (ADS)

    Situ, Guohai; Ryle, James P.; Gopinathan, Unnikrishnan; Sheridan, John T.

    2008-02-01

    In-line digital holography based on two-intensity measurements [Zhang et al. Opt. Lett. 29, 1787 (2004)], is modified by introducing a π shifting in the reference phase. Such an improvement avoids the assumption that the object beam must be much weaker than the reference beam in strength and results in a simplified experimental implementation. Computer simulations and optical experiments are carried out to validate the method, which we refer to as position-phase-shifting digital holography.

  20. Line Intensities in the Far-Infrared Spectrum of H 2O 2

    NASA Astrophysics Data System (ADS)

    Perrin, A.; Flaud, J.-M.; Camy-Peyret, C.; Schermaul, R.; Winnewisser, M.; Mandin, J.-Y.; Dana, V.; Badaoui, M.; Koput, J.

    1996-04-01

    Using high resolution Fourier transform spectra (resolution 0.002 cm -1) recorded at the Instituto Ricerca Onde Electromagnetiche Firenze and at the Justus Liebig University Giessen, it has been possible to measure the relative intensities of lines in the far-infrared spectrum of H 2O 2in the 25-400 cm -1spectral region. These intensities were used as input data in a least-squares fit calculation in order to obtain the expansion parameters of the transition moment operator of the pure torsional-rotational transitions of H 2O 2. For these intensity calculations, the theoretical model takes into account the cos γ-type dependence of the dipole moment due to the large amplitude motion of the H atoms relative to the O-O bond, where 2γ is the torsion angle. The value of the dipole moment obtained from the fit of the observed intensities was then scaled to the value obtained from Stark effect measurements. Finally, a synthetic spectrum of the far infrared band of H 2O 2was generated, using the dipole moment expansion determined in this work for the line intensities and the parameters and the Hamiltonian matrix given in a previous analysis (C. Camy-Peyret, J.-M. Flaud, J. W. C. Johns, and M. Noel, J. Mol. Spectrosc.155,84-104 (1992)) for the line positions. In addition to the (Δ n= ±1, Δ Ka= ∓2) torsional-rotational resonances within the ground vibrational state, which are usually observed for H 2O 2, the Hamiltonian model takes explicitly into account both the vibration-rotation resonances involving the ground state and the v3= 1 vibrational state and the "staggering" effect which is due to the cispotential barrier.

  1. K-line spectra from tungsten heated by an intense pulsed electron beam.

    PubMed

    Pereira, N R; Weber, B V; Apruzese, J P; Mosher, D; Schumer, J W; Seely, J F; Szabo, C I; Boyer, C N; Stephanakis, S J; Hudson, L T

    2010-10-01

    The plasma-filled rod-pinch diode (PFRP) is an intense source of x-rays ideal for radiography of dense objects. In the PRFP megavoltage electrons from a pulsed discharge concentrate at the pointed end of a 1 mm diameter tapered tungsten rod. Ionization of this plasma might increase the energy of tungsten's Kα(1) fluorescence line, at 59.3182 keV, enough for the difference to be observed by a high-resolution Cauchois transmission crystal spectrograph. When the PFRP's intense hard bremsstrahlung is suppressed by the proper shielding, such an instrument gives excellent fluorescence spectra, albeit with as yet insufficient resolution to see any effect of tungsten's ionization. Higher resolution is possible with various straightforward upgrades that are feasible thanks to the radiation's high intensity.

  2. K-line spectra from tungsten heated by an intense pulsed electron beam

    SciTech Connect

    Pereira, N. R.; Weber, B. V.; Apruzese, J. P.; Mosher, D.; Schumer, J. W.; Seely, J. F.; Szabo, C. I.; Boyer, C. N.; Stephanakis, S. J.; Hudson, L. T.

    2010-10-15

    The plasma-filled rod-pinch diode (PFRP) is an intense source of x-rays ideal for radiography of dense objects. In the PRFP megavoltage electrons from a pulsed discharge concentrate at the pointed end of a 1 mm diameter tapered tungsten rod. Ionization of this plasma might increase the energy of tungsten's K{alpha}{sub 1} fluorescence line, at 59.3182 keV, enough for the difference to be observed by a high-resolution Cauchois transmission crystal spectrograph. When the PFRP's intense hard bremsstrahlung is suppressed by the proper shielding, such an instrument gives excellent fluorescence spectra, albeit with as yet insufficient resolution to see any effect of tungsten's ionization. Higher resolution is possible with various straightforward upgrades that are feasible thanks to the radiation's high intensity.

  3. Unique forbidden beta decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-28

    The measurement of the electron energy spectrum in single β decays close to the endpoint provides a direct determination of the neutrino masses. The most sensitive experiments use β decays with low Q value, e.g. KATRIN (tritium) and MARE (rhenium). We present the theoretical spectral shape of electrons emitted in the first, second, and fourth unique forbidden β decays. Our findings show that the Kurie functions for these unique forbidden β transitions are linear in the limit of massless neutrinos like the Kurie function of the allowed β decay of tritium.

  4. Radiative and magnetic properties of solar active regions. I. Global magnetic field and EUV line intensities

    NASA Astrophysics Data System (ADS)

    Fludra, A.; Ireland, J.

    2008-05-01

    Context: The relationships between the photospheric magnetic flux and either the X-ray or extreme ultraviolet emission from the solar atmosphere have been studied by several authors. Power-law relations have been found between the total magnetic flux and X-ray flux or intensities of the chromospheric, transition region, and coronal emission lines in solar active regions. These relations were then used to infer the mechanism of the coronal heating. Aims: We derive accurate power laws between EUV line intensities and the total magnetic flux in solar active regions and discuss their applications. We examine whether these global power laws are capable of providing the diagnostics of the coronal heating mechanism. Methods: This analysis is based on EUV lines recorded by the Coronal Diagnostic Spectrometer (CDS) on SOHO for 48 solar active regions, as they crossed the central meridian in years 1996-1998. Four spectral lines are used: He I 584.3 Å (3×104 K), O V 629.7 Å (2.2×105 K), Mg IX 368.06 Å (9.5×105 K), and Fe XVI 360.76 Å (2.0×106 K). In particular, the Fe XVI 360.76 Å line, seen only in areas of enhanced heating in active regions or bright points, has not been used before for this analysis. Results: Empirical power laws are established between the total active region intensity in the lines listed above and the total magnetic flux. We demonstrate the usefulness of some spatially integrated EUV line intensities, I_T, as a proxy for the total magnetic flux, Φ, in active regions. We point out the approximate, empirical nature of the I_T-Φ relationships and discuss the interpretation of the global power index. Different power index values for transition region and coronal lines are explained by their different dependence on pressure under the assumption of hydrostatic loop models. However, the global power laws are dominated by the size of the active regions, and we demonstrate for the first time the difficulties in uniquely relating the power index in the

  5. The effect of line roughness on the diffraction intensities in angular resolved scatterometry

    NASA Astrophysics Data System (ADS)

    Kato, Akiko; Scholze, Frank

    2011-05-01

    Scatterometry is a common technique for the characterization of nano-structured surfaces. It is an indirect measuring method, where a chosen set of parameters describing the scattering object is fitted numerically to the data obtained from a scattering experiment. In order to detect several diffraction orders with an angular resolved measurement, it is necessary to choose the wavelength of the light to be of the same order or smaller than the size of the scattering structure. At PTB, detailed scatterometric investigations of an EUV photomask with periodic absorber line gratings on an EUV multilayer mirror have been performed using EUV and DUV radiation. Multiple propagating diffraction orders could be observed and it was possible to derive information about the line profile by means of rigorous numerical modeling. A comparison with microscopic measurements yields consistent results regarding the line width. The sidewall angle of the line profile, however, as determined in the scatterometry measurements performed in the EUV spectral range as well as in the DUV, was distinctly lower than the angle provided by atomic force microscopy. Analyzing different sources of uncertainty, it could be shown that structure disturbances such as line edge or line width roughness cause significant impact on the angular distribution of the diffraction intensity. This effect can be formulated analytically. On the one hand, this can be used to investigate the consequences of roughness for the structure reconstruction algorithm. For instance, a considerable variation of the reconstructed sidewall angle can be observed as a function of roughness. On the other hand, it is possible to determine a roughness parameter through an appropriate evaluation of the scatterometry experimental data. In this paper we will sum up the sources of uncertainty involved in scatterometry and focus on the line roughness and on how it affects the profile reconstruction.

  6. Data-Model Comparisons of Photoelectron Flux Intensities on the Strong Crustal Field Lines at Mars

    NASA Astrophysics Data System (ADS)

    Liemohn, Michael; Trantham, Matthew; Mitchell, David

    2010-05-01

    This study quantifies the factors controlling photoelectron fluxes on strong crustal field lines in the Martian ionosphere. Using data from Mars Global Surveyor's Magnetometer and Electron Reflectometer instruments, dayside electron populations near the strong crustal fields in the southern hemisphere are analyzed versus various controlling parameters. These parameters include a Mars F10.7 proxy, a solar wind pressure proxy, local solar zenith angle, magnetic elevation angle, magnetic field strength. It was found that solar EUV radiation (corrected for solar zenith angle and the Mars-Sun distance) has the strongest influence on the photoelectron fluxes, and during different time periods this radiation has a stronger influence than at others times. Second, fluxes show a slight enhancement when the magnetic elevation angle is near zero degrees (horizontal field lines). Finally, other parameters, such as pressure and magnetic field strength, seem to have no major influence. These measurement-based results are then compared against numerical modeling flux intensities to quantify the physical mechanisms behind the observed relationships. The numerical code used for this study is our superthermal electron transport model, which solves for the electric distribution function along a magnetic field line. The code includes the influence of a variable magnetic field strength, pitch angle scattering and mirror trapping, and collisional energy cascading. The influence of solar EUV flux, atmospheric composition, solar wind dynamic pressure, and the local magnetic field are systematically investigated with this code to understand why some of these parameters have a strong influence on photoelectron flux intensity while others do not.

  7. Measuring galaxy clustering and the evolution of [C II] mean intensity with far-IR line intensity mapping during 0.5 < z < 1.5

    SciTech Connect

    Uzgil, B. D.; Aguirre, J. E.; Lidz, A.; Bradford, C. M.

    2014-10-01

    Infrared fine-structure emission lines from trace metals are powerful diagnostics of the interstellar medium in galaxies. We explore the possibility of studying the redshifted far-IR fine-structure line emission using the three-dimensional (3D) power spectra obtained with an imaging spectrometer. The intensity mapping approach measures the spatio-spectral fluctuations due to line emission from all galaxies, including those below the individual detection threshold. The technique provides 3D measurements of galaxy clustering and moments of the galaxy luminosity function. Furthermore, the linear portion of the power spectrum can be used to measure the total line emission intensity including all sources through cosmic time with redshift information naturally encoded. Total line emission, when compared to the total star formation activity and/or other line intensities, reveals evolution of the interstellar conditions of galaxies in aggregate. As a case study, we consider measurement of [C II] autocorrelation in the 0.5 < z < 1.5 epoch, where interloper lines are minimized, using far-IR/submillimeter balloon-borne and future space-borne instruments with moderate and high sensitivity, respectively. In this context, we compare the intensity mapping approach to blind galaxy surveys based on individual detections. We find that intensity mapping is nearly always the best way to obtain the total line emission because blind, wide-field galaxy surveys lack sufficient depth and deep pencil beams do not observe enough galaxies in the requisite luminosity and redshift bins. Also, intensity mapping is often the most efficient way to measure the power spectrum shape, depending on the details of the luminosity function and the telescope aperture.

  8. Absolute intensities of CO2 lines in the 3140-3410/cm spectral region

    NASA Technical Reports Server (NTRS)

    Benner, D. Chris; Devi, V. Malathy; Ferry-Leeper, Penelope S.; Rinsland, Curtis P.

    1988-01-01

    Absolute intensities for 430 transitions belonging to eleven rotation-vibration bands of (C-12)(O-16)2, (C-13)(O-16)2, and (O-16)(C-18)(O-18) in the 3140-3410/cm spectral region have been determined by analyzing spectra recorded at 0.01/cm resolution with the Fourier transform spectrometer in the McMath solar telescope complex at the National Solar Observatory on Kitt Peak. The data were recorded at room temperature and low pressures (less than 10 torr) using a natural sample of carbon dioxide. Intensities were derived using a nonlinear least-squares spectral fitting procedure, and the values obtained for each band have been analyzed to determine the vibrational band intensity and nonrigid rotor coefficients. An alternative mathematical formulation is shown in the case of bands for which the Coriolis effect is large and the Q-branch line intensities were not determinable either because they were severely blended or absent from the spectra. Comparison are made between the results obtained in this study and other published values.

  9. Absolute intensities of CO(2) lines in the 3140-3410-cm(-1) spectral region.

    PubMed

    Benner, D C; Devi, V M; Rinsland, C P; Ferry-Leeper, P S

    1988-04-15

    Absolute intensities for 430 transitions belonging to eleven rotation-vibration bands of (12)C(16)O(2),(13)C(16)O(2) and(16)O(12)C(18)O in the 3140-3410-cm(-1) spectral region have been determined by analyzing spectra recorded at 0.01-cm(-1) resolution with the Fourier transform spectrometer in the McMath solar telescope complex at the National Solar Observatory on Kitt Peak. The data were recorded at room temperature and low pressures (<10 Torr) using a natural sample of carbon dioxide. Intensities were derived using a nonlinear least-squares spectral fitting procedure, and the values obtained for each band have been analyzed to determine the vibrational band intensity and nonrigid rotor coefficients. An alternative mathematical formulation is shown in the case of bands for which the Coriolis effect is large and the Q-branch line intensities were not determinate either because they were severely blended or absent from the spectra. Comparisons are made between the results obtained in this study and other published values.

  10. Remote Interrogation of WDM Fiber-Optic Intensity Sensors Deploying Delay Lines in the Virtual Domain

    PubMed Central

    Montero, David Sánchez; Vázquez, Carmen

    2013-01-01

    In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility. PMID:23653054

  11. Low intensity noise and narrow line-width diode laser light at 540 nm

    NASA Astrophysics Data System (ADS)

    Wang, Lirong; Tamaki, Ryo; Kasai, Katsuyuki; Okada-Shudo, Yoshiko; Watanabe, Masayoshi; Zhang, Yun

    2015-05-01

    We present a convenient method to generate high quality single-frequency green light at a wavelength of 540 nm. It consists of a noise suppressed external cavity diode laser at a wavelength of 1080 nm by optical filtering and resonant optical feedback, and a frequency doubling of the fundamental light with an a-cut KTP crystal. Highly efficient conversion is realized by type II non-critical phase matching. A stable single-frequency operation with a maximum power of about 20 mW is performed for more than 3 h. Both the intensity noise and line-width reach the level of a monolithic nonplanar ring laser, which is well known for its extraordinarily narrow line-width and extremely low noise among available single-frequency operating lasers.

  12. Temperature Measurements in the Solar Transition Region Using N III Line Intensity Ratios

    NASA Technical Reports Server (NTRS)

    Doron, R.; Doschek, G. A.; Laming, J. M.; Feldman, U.; Bhatia, A. K.

    2003-01-01

    UV emission from B-like N and O ions a rather rare opportunity for recording spectral lines in a narrow wavelength range that can potentially be used to derive temperatures relevant to the solar transition region. In these ions, the line intensity ratios of the type (2s2p(sup 2) - 2p(sup 3)) / (2s(sup 2)2p - 2s2p(sup 2)) are very sensitive to the electron temperature. Additionally, the lines involving the ratios fall within a range of only - 12 A; in N III the lines fall in the 980 - 992 A range and in O IV in the 780 - 791 A range. In this work, we explore the use of these atomic systems, primarily in N III, for temperature diagnostics of the transition region by analyzing UV spectra obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer flown on the Solar and Heliospheric Observatory (SOHO). The N III temperature-sensitive line ratios are measured in more than 60 observations. Most of the measured ratios correspond to temperatures in the range 5.7x10(exp 4) - 6.7x10(exp 4) K. This range is considerably lower than the calculated temperature of maximum abundance of N III, which is approx. 7.6x10(exp 4) K. Detailed analysis of the spectra further indicates that the measured ratios are probably somewhat overestimated due to resonant scattering effects in the 2s(sup 2)2p - 2s2p(sup 2) lines and small blends in the 2s2p(sup 2) - 2p3 lines. Actual lower ratios would only increase the disagreement between the ionization balance calculations and present temperature measurements based on a collisional excitation model. In the case of the O IV spectra, we determined that due to the close proximity in wavelength of the weak line (2s2p(sup 2)-2p3 transitions) to a strong Ne VIII line, sufficiently accurate ratio measurements cannot be obtained. Subject headings: atomic data --- atomic processes --- Sun: transition region --- Sun: U V radiation --- techniques: spectroscopic

  13. The relative line strength and intensity of the N II 2143 doublet

    NASA Technical Reports Server (NTRS)

    Bucsela, Eric J.; Sharp, William E.

    1989-01-01

    The doublet emission from N II at 2139.7 A and 2143.6 A was observed by a 1.4-m scanning spectrometer with 3.1 A resolution in the daytime, high-altitude thermosphere during moderate levels of solar activity. The spectrometer viewed the earth's limb 5 deg below the local horizontal to give a nominal tangent height of 152 km. Both sub band heads of the nitric oxide gamma band system were resolved in the data at the resolution used. The emission features from N II are clearly evident on the short wavelength shoulder of the (1, 0) band. Synthetic profiles of the (1, 0) gamma band and the (0, 3) delta band of nitric oxide were fitted to the data using a chi-square analysis. These contributions were removed from the data leaving a residual emission, considered to be the N II doublet. A chi-square minimization of the data relative to a synthetic intensity profile was done. The minimum was for a line strength ratio between the 2139 A and 2143 A lines of 0.58 + or - 0.08. The mean solar EUV flux deduced from the intensity of the N II emission in this experiment is lower than other reported observations, consistent with a lower solar activity level.

  14. Line Intensities of Isotopic Carbonyl Sulfide (ocs) at 2.5 Micrometer

    NASA Astrophysics Data System (ADS)

    Toth, Robert A.; Sung, Keeyoon; Brown, Linda R.; Crawford, Timothy J.

    2009-06-01

    We have measured line intensities of ^{16}O^{12}C^{32}S, ^{16}O^{13}C^{32}S, ^{16}O^{12}C^{33}S, ^{16}O^{12}C^{34}S, and ^{18}O^{12}C^{32}S in the 2.5 μm region for the first time to support planetary studies of the Venus atmosphere. Laboratory absorption spectra of OCS were recorded at 0.0033 cm^{-1} resolution at room temperature using a Bruker IFS 125-HR Fourier transform spectrometer at the Jet Propulsion Laboratory. Normal samples of OCS were used in this study, and sample impurities and isotopic abundances were determined from mass spectrum analysis. Optical densities sufficient to observe isotopic bands and weaker hot bands were achieved by using a multi-pass White cell and single pass gas cells in various path lengths, which were validated by analyzing near-IR CO_2 spectra. We present line intensities for almost 30 bands of the OCS isotopes excluding ground state bands of ^{16}O^{12}C^{32}S, which we have reported recently. We have Herman-Wallis factors determined for the individual bands. In some cases, it has been observed that band intensities normalized to 100% isotopic species show a significant deviation from that of the primary isotopic species (up to by 12.5%). No earlier measurements have been reported for these bands. Measurement precision and accuracies will be discussed. Research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration. We thank Drs. Stojan Madzunkov, John A. MacAskill, and Murray R. Darrach from the Atomic and Molecular Collision Group at Jet Propulsion Laboratory for recording mass spectrum of the OCS sample used in this work.

  15. Line position and line intensity analyses of the high-resolution spectrum of H218O up to the First Triad and J = 17

    NASA Astrophysics Data System (ADS)

    Coudert, L. H.; Chelin, P.

    2016-08-01

    Line position and line intensity analyses of the high-resolution spectrum of the H218O isotopic species of the water molecule are performed with the Bending-Rotation approach up to J = 17 and the First Triad of interacting states, (0 2 0), (1 0 0), and (0 0 1). The line position analysis involves microwave and terahertz transitions, ground state combination differences, far infrared and infrared lines, and experimental energy levels which were reproduced with a 1.2 unitless standard deviation. The data set considered in the line intensity analysis consists of 3707 infrared transitions recorded using absorption spectroscopy at room temperature which were fitted with a 1.4 unitless standard deviation. The results of both analyses are compared with previous investigations and are used to build a line position and line intensity database to update the HITRAN and GEISA databases. A comparison with the HITRAN 2012 database reveals that the new database yields intensity values closer to the experimental ones.

  16. A Straightforward Way to Determine Relative Intensities of Spin-Spin Splitting Lines of Equivalent Nuclei in NMR Spectra.

    ERIC Educational Resources Information Center

    Orcutt, Ronald H.

    1987-01-01

    Describes a simple way of obtaining a set of relative intensities of spin-spin splitting lines using Pascal's triangle rather than calculating binomial coefficients. Provides tables showing Pascal's triangle and the relative intensities of multiplets for a range of nuclear spins. (TW)

  17. Forbidden Ca 2 in the sun unmasked by way of Venus

    NASA Technical Reports Server (NTRS)

    Schorn, R. A.; Young, A. T.; Barker, E. S.

    1975-01-01

    Eleven high-dispersion spectra of Venus, taken with blue Doppler shifts have permitted the unmasking of the 7323.88A forbidden line of Ca II from terrestrial absorption. An equivalent width is obtained of 7.4 + or - 0.4mA for this line in integrated sunlight. Our value of W sub lambda is smaller than previous values and much more accurate. The HSRA solar model gives a solar calcium abundance of A sub Ca = 6.21.

  18. The holographic recording in photopolymer by excitation forbidden singlet-triplet transitions

    NASA Astrophysics Data System (ADS)

    Shelkovnikov, V. V.; Pen, E. F.; Russkich, V. V.; Vasiliev, E. V.; Kovalevsky, V. I.

    2006-05-01

    The possibility and features of the holographic recording by excitation of the forbidden singlet-triplet transitions are considered in the report. The experimental demonstration of the hologram recording on forbidden transition is carried out in thick photopolymer material sensitized by Erithrozine dye. The single hologram with diffraction efficiency DE=50% and 16 angle multiplexing hologram were recorded by irradiation of the low intensity He-Ne laser (632 nm) at high concentration of the sensitizing dye and at high optical density in allowed absorption band of dye. The growth of DE of transition hologram depending on the Kr+(647 nm) laser irradiation intensity of was studied. The observed linear dependence of the maximal rate of DE growth on the intensity of recording irradiation was explained by two steps-two photon excitation (T I<--S 0, T II<--T I) of the dye in the photopolymer samples.

  19. Hydrogen Balmer alpha intensity distributions and line profiles from multiple scattering theory using realistic geocoronal models

    NASA Technical Reports Server (NTRS)

    Anderson, D. E., Jr.; Meier, R. R.; Hodges, R. R., Jr.; Tinsley, B. A.

    1987-01-01

    The H Balmer alpha nightglow is investigated by using Monte Carlo models of asymmetric geocoronal atomic hydrogen distributions as input to a radiative transfer model of solar Lyman-beta radiation in the thermosphere and atmosphere. It is shown that it is essential to include multiple scattering of Lyman-beta radiation in the interpretation of Balmer alpha airglow data. Observations of diurnal variation in the Balmer alpha airglow showing slightly greater intensities in the morning relative to evening are consistent with theory. No evidence is found for anything other than a single sinusoidal diurnal variation of exobase density. Dramatic changes in effective temperature derived from the observed Balmer alpha line profiles are expected on the basis of changing illumination conditions in the thermosphere and exosphere as different regions of the sky are scanned.

  20. Measurements of electric field intensity under 750 kV over head lines in an orchard zone

    SciTech Connect

    Aleksandrov, G.N.; Kashina, V.A.; Lisochkina, T.V.; Podporkin, G.V.

    1980-01-01

    The maximum electric field intensity was found to take place in the middle of the space between the rows of apple trees and did not exceed 3 kV/m. The orchard layout and the intensity both through the orchard and under the lines where no trees grew (max intensity 10 kV/m) are given. Unpleasant sensations were experienced in the place where no trees grew due to discharges on contact with plants; the discharge currents in the orchard were too low to feel. Determining the suitability of using trees to ensure ecological safety of extrahigh and ultrahigh voltage overhead lines passing near cities is discussed.

  1. Absolute integrated intensity and individual line parameters for the 6.2-micron band of NO2. [in solar spectrum

    NASA Technical Reports Server (NTRS)

    Goldman, A.; Bonomo, F. S.; Williams, W. J.; Murcray, D. G.; Snider, D. E.

    1975-01-01

    The absolute integrated intensity of the 6.2-micron band of NO2 at 40 C was determined from quantitative spectra at about 10 per cm resolution by the spectral band model technique. A value of 1430 plus or minus 300 per sq cm per atm was obtained. Individual line parameters, positions, intensities, and ground-state energies were derived, and line-by-line calculations were compared with the band model results and with the quantitative spectra obtained at about 0.5 per cm resolution.

  2. Line intensities and collisional-broadening parameters for the nu4 and nu6 bands of carbonyl fluoride

    NASA Technical Reports Server (NTRS)

    May, Randy D.

    1992-01-01

    Line intensities, air- and self-broadening parameters have been measured for selected lines in the nu4 (1243/cm) and nu6 (774/cm) bands of carbonyl fluoride at 296 and 215 K using a tunable diode-laser spectrometer. Measured line intensities are in good agreement +/- 6 percent with recently reported values derived from rotational analyses of the nu4 and nu6 bands. The measured average air-broadening coefficient at 296 K also agrees well (+/- 5 percent) with N2-broadening coefficients determined from microwave studies, while the average self-broadening coefficient reported here is smaller than a previously reported value by 45 percent.

  3. Are plasma satellites present among chromospheric lines?

    NASA Astrophysics Data System (ADS)

    Ohman, Y.

    1983-05-01

    Published literature is examined for evidence of the presence of plasma satellites among the solar chromospheric lines. Indications are found that first-order plasma satellites sometimes appear as a pair of faint chromospheric emission lines in places where forbidden lines, mainly of metals, should be located. Evidence is seen that second-order plasma satellites are present among lines for which emission wings show asymmetry with respect to the distances from the line center and with respect to intensity. Indications are found that fourth-order plasma satellites are present as unidentified diffuse lines situated near parent lines of food strength either in emission or in absorption. All three types of satellites show electron densities on the order of a trillion/cu cm. Indications that plasma satellites may sometimes appear as faint absorption lines in the solar spectrum are discussed.

  4. Intense gamma-ray lines from hidden vector dark matter decay

    SciTech Connect

    Arina, Chiara; Hambye, Thomas; Ibarra, Alejandro; Weniger, Christoph E-mail: thambye@ulb.ac.be E-mail: christoph.weniger@desy.de

    2010-03-01

    Scenarios with hidden, spontaneously broken, non-abelian gauge groups contain a natural dark matter candidate, the hidden vector, whose longevity is due to an accidental custodial symmetry in the renormalizable Lagrangian. Nevertheless, non-renormalizable dimension six operators break the custodial symmetry and induce the decay of the dark matter particle at cosmological times. We discuss in this paper the cosmic ray signatures of this scenario and we show that the decay of hidden vector dark matter particles generically produce an intense gamma ray line which could be observed by the Fermi-LAT experiment, if the scale of custodial symmetry breaking is close to the Grand Unification scale. This gamma line proceeds directly from a tree level dark matter 2-body decay in association with a Higgs boson. Within this model we also perform a determination of the relic density constraints taking into account the dark matter annihilation processes with one dark matter particle in the final state. The corresponding direct detection rates can be easily of order the current experimental sensitivities.

  5. Fourier transform spectroscopy of CO2 isotopologues at 1.6 μm: Line positions and intensities

    NASA Astrophysics Data System (ADS)

    Jacquemart, D.; Borkov, Yu. G.; Lyulin, O. M.; Tashkun, S. A.; Perevalov, V. I.

    2015-07-01

    The line positions and intensities of carbon dioxide isotopologues have been retrieved between 5900 and 6400 cm-1 region from Fourier transform spectra of 17O- and 18O-enriched carbon dioxide recorded in LADIR (Paris, France) with the Bruker IFS 125-HR. In total 1634 line positions and intensities of 20 bands of the 5 major CO2 isotopologues present in our sample 16O12C17O (39.48%), 17O12C17O (27.73%), 16O12C16O (15.20%), 16O12C18O (7.32%) and 17O12C18O (8.25%) are retrieved. All studied bands belong to the ΔP=8 (only for asymmetric species) and 9 series of transitions, where P = 2V1 +V2 + 3V3 is the polyad number (Vi are vibrational quantum numbers). The accuracy of the line position determination is about 0.3×10-3 cm-1 for the unblended and not very weak lines and the accuracy for the line intensities varies from 4% to 30% depending on the intensity of the line and on the extent of the line overlapping. For the 16O12C17O, 17O12C17O, 16O12C18O and 17O12C18O isotopologues the systematic comparisons have been performed with the recent CRDS measurements.

  6. Use of Six Sigma strategies to pull the line on central line-associated bloodstream infections in a neurotrauma intensive care unit.

    PubMed

    Loftus, Kelli; Tilley, Terry; Hoffman, Jason; Bradburn, Eric; Harvey, Ellen

    2015-01-01

    The creation of a consistent culture of safety and quality in an intensive care unit is challenging. We applied the Six Sigma Define-Measure-Analyze-Improve-Control (DMAIC) model for quality improvement (QI) to develop a long-term solution to improve outcomes in a high-risk neurotrauma intensive care unit. We sought to reduce central line utilization as a cornerstone in preventing central line-associated bloodstream infections (CLABSIs). This study describes the successful application of the DMAIC model in the creation and implementation of evidence-based quality improvement designed to reduce CLABSIs to below national benchmarks. PMID:25768963

  7. Quantitative extraction of spectral line intensities and widths from x-ray spectra recorded with gated microchannel plate detectors

    SciTech Connect

    Dunham, Greg; Bailey, J. E.; Rochau, G. A.; Lake, P. W.; Nielsen-Weber, L. B.

    2007-06-15

    Plasma spectroscopy requires determination of spectral line intensities and widths. At Sandia National Laboratories Z facility we use elliptical crystal spectrometers equipped with gated microchannel plate detectors to record time and space resolved spectra. We collect a large volume of data typically consisting of five to six snapshots in time and five to ten spectral lines with 30 spatial elements per frame, totaling to more than 900 measurements per experiment. This large volume of data requires efficiency in processing. We have addressed this challenge by using a line fitting routine to automatically fit each spectrum using assumed line profiles and taking into account photoelectron statistics to efficiently extract line intensities and widths with uncertainties. We verified that the random data noise obeys Poisson statistics. Rescale factors for converting film exposure to effective counts required for understanding the photoelectron statistics are presented. An example of the application of these results to the analysis of spectra recorded in Z experiments is presented.

  8. Missing and forbidden links in mutualistic networks.

    PubMed

    Olesen, Jens M; Bascompte, Jordi; Dupont, Yoko L; Elberling, Heidi; Rasmussen, Claus; Jordano, Pedro

    2011-03-01

    Ecological networks are complexes of interacting species, but not all potential links among species are realized. Unobserved links are either missing or forbidden. Missing links exist, but require more sampling or alternative ways of detection to be verified. Forbidden links remain unobservable, irrespective of sampling effort. They are caused by linkage constraints. We studied one Arctic pollination network and two Mediterranean seed-dispersal networks. In the first, for example, we recorded flower-visit links for one full season, arranged data in an interaction matrix and got a connectance C of 15 per cent. Interaction accumulation curves documented our sampling of interactions through observation of visits to be robust. Then, we included data on pollen from the body surface of flower visitors as an additional link 'currency'. This resulted in 98 new links, missing from the visitation data. Thus, the combined visit-pollen matrix got an increased C of 20 per cent. For the three networks, C ranged from 20 to 52 per cent, and thus the percentage of unobserved links (100 - C) was 48 to 80 per cent; these were assumed forbidden because of linkage constraints and not missing because of under-sampling. Phenological uncoupling (i.e. non-overlapping phenophases between interacting mutualists) is one kind of constraint, and it explained 22 to 28 per cent of all possible, but unobserved links. Increasing phenophase overlap between species increased link probability, but extensive overlaps were required to achieve a high probability. Other kinds of constraint, such as size mismatch and accessibility limitations, are briefly addressed.

  9. Numerical and experimental study of atomic transport and Balmer line intensity in Linac4 negative ion source

    SciTech Connect

    Shibata, T. Nishida, K.; Hatayama, A.; Mattei, S.; Lettry, J.

    2015-04-08

    Time structure of Balmer H{sub α} line intensity in Linac4 RF plasma has been analyzed by the combined simulation model of atomic transport and Collisional-Radiative models. As a preliminary result, time variation of the line intensity in the ignition phase of RF plasma is calculated and compared with the experimental results by photometry. For the comparison, spatial distribution of the local H{sub α} photon emission rate at each time is calculated from the numerical model. The contribution of the local photon emission rates to the observed line intensity via optical viewing port is also investigated by application of the mock-up of the optical viewing port and the known light source. It has been clarified from the analyses that the higher and the lower peaks of the H{sub α} line intensity observed during 1 RF cycle is mainly due to the different spatial distributions in the electron energy distribution function and the resultant local photon emission rate. These results support previous suggestion that the existence of the capacitive electric field in axial direction leads to the higher/lower peaks of the line intensity.

  10. Light Dark Matter from Forbidden Channels.

    PubMed

    D'Agnolo, Raffaele Tito; Ruderman, Joshua T

    2015-08-01

    Dark matter (DM) may be a thermal relic that annihilates into heavier states in the early universe. This forbidden DM framework accommodates a wide range of DM masses from keV to weak scales. An exponential hierarchy between the DM mass and the weak scale follows from the exponential suppression of the thermally averaged cross section. Stringent constraints from the cosmic microwave background are evaded because annihilations turn off at late times. We provide an example where DM annihilates into dark photons, which is testable through large DM self-interactions and direct detection.

  11. Absolute Line Intensities in the ν 3Band of 12CH 3F by Diode-Laser Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lepère, Muriel; Blanquet, Ghislain; Walrand, Jacques

    1996-06-01

    Infrared absolute line intensities of the ν 3band of 12CH 3F have been measured around 9.5 μm using a diode-laser spectrometer. These line strengths were obtained from the equivalent width method and, for a few lines, by fitting a Rautian profile to the measured shape of the lines. From these results, we have deduced the vibrational bandstrength ( Sv0= 379.2 ± 5.9 cm -2·atm -1at 296 K) and the first Herman-Wallis factor (α = 0.35 × 10 -3± 0.10 × 10 -3).

  12. Absolute Line Intensities in the 2ν 02 Band of Cyanogen Chloride at 12.8 μm

    NASA Astrophysics Data System (ADS)

    Lepère, Muriel; Blanquet, Ghislain; Walrand, Jacques

    2000-05-01

    Absolute line intensities were measured at high resolution with a tunable diode laser. This work concerns the 2ν02 band of cyanogen chloride ClCN in the region 780 cm-1. Thirty-two absorption lines were recorded for the isotopomer 35ClCN and 26 lines for 37ClCN. From the analysis of these lines, we determined the bandstrengths: S0v = 19.14 cm-2 atm-1 for 35ClCN and S0v = 17.84 cm-2 atm-1 for 37ClCN.

  13. Coupling between meridional wind nightly behavior and mid-latitude oxygen red 630.0 nm line intensity predawn enhancement

    NASA Astrophysics Data System (ADS)

    Didebulidze, Goderdzi; Gudadze, Nikoloz; Lomidze, Levan; Todua, Maya

    The coupling between meridional wind nightly behavior and winter time predawn enhancement (PE) in the mid-latitude oxygen red 630.0 nm line intensity at Abastumani (41.75 N, 42.82 E) is investigated. It is shown that red line intensity PE, which was considered as a result of increase in the photoelectron flux from magnetically conjugate regions, also can be caused by increase in the mid-latitude northward wind (or decrease in the southward one). In this case the observed mean monthly/seasonal nightly behavior of the red line intensity can be verified by the ionosphere F2 layer parameters observed at Tbilisi ionosphere station (41.65 N, 44.75 E -neighboring Abastumani) and the meridional component of the thermosphere wind given by Horizontal Wind Model 93 (HWM93). The estimation shows that the mean monthly/seasonal northward wind for 1957-1993 and the observed F2 layer peak density NmF2 and height hmF2 can be responsible for the PE in the red line intensity (LT 03 h-05 h), which is also noticeable in early spring and later fall. The observed seasonal midnight negative trend in the red line intensity is accompanied by its wintertime positive trend before morning twilight, which includes the PE and can be explained by long-term increase in the northward wind velocity. In these cases, the increase in the mid-latitude northward wind or decrease in the southward one following to the equatorial midnight temperature maximum (MTM) or similar phenomena could be important in the observed mid-latitude PE of the red line intensity.

  14. Extended line positions, intensities, empirical lower state energies and quantum assignments of NH3 from 6300 to 7000 cm-1

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Brown, Linda R.; Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.; Coy, Stephen L.; Lehmann, Kevin K.

    2012-07-01

    Nearly 4800 features of ammonia between 6300 and 7000 cm-1 with intensities ≥4×10-24 cm-1/(molecule·cm-2) at 296 K were measured using 16 pure NH3 spectra recorded at various temperatures (296-185 K) with the McMath-Pierce Fourier Transform Spectrometer at Kitt Peak National Observatory, AZ. The line positions and intensities were retrieved by fitting individual spectra based on a Voigt line shape profile and then averaging the values to form the experimental linelist. The integrated intensity of the region was 4.68×10-19 cm-1/(molecule·cm-2) at 296 K. Empirical lower state energies were also estimated for 3567 absorption line features using line intensities retrieved from 10 spectra recorded at gas temperature between 185 and 233 K. Finally, using Ground State Combination Differences (GSCDs) and the empirical lower state energy estimates, the quantum assignments were determined for 1096 transitions in the room temperature linelist, along with empirical upper state energies for 434 levels. The assignments correspond to seven vibrational states, as confirmed from recent ab initio calculations. The resulting composite database of 14NH3 line parameters will provide experimental constraints to ab initio calculations and support remote sensing of gaseous bodies including the atmospheres of Earth, (exo)planets, brown dwarfs, and other astrophysical environments.

  15. Discovery of Time Variation of the Intensity of Molecular Lines in IRC+10216 in The Submillimeter and Far Infrared Domains

    PubMed Central

    Cernicharo, J.; Teyssier, D.; Quintana-Lacaci, G.; Daniel, F.; Agúndez, M.; Prieto, L. Velilla; Decin, L.; Guélin, M.; Encrenaz, P.; García-Lario, P.; de Beck, E.; Barlow, M.J.; Groenewegen, M.A.T.; Neufeld, D.; Pearson, J.

    2015-01-01

    We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species towards the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the HIFI instrument on board Herschel1 and with the IRAM2 30-m telescope. They cover several observing periods spreading over 3 years. The line intensity variations for molecules produced in the external layers of the envelope most probably result from time variations in the infrared pumping rates. We analyze the main implications this discovery has on the interpretation of molecular line emission in the envelopes of Mira-type stars. Radiative transfer calculations have to take into account both the time variability of infrared pumping and the possible variation of the dust and gas temperatures with stellar phase in order to reproduce the observation of molecular lines at different epochs. The effect of gas temperature variations with stellar phase could be particularly important for lines produced in the innermost regions of the envelope. Each layer of the circumstellar envelope sees the stellar light radiation with a different lag time (phase). Our results show that this effect must be included in the models. The sub-mm and FIR lines of AGB stars cannot anymore be considered as safe intensity calibrators. PMID:26722620

  16. 158 micron forbidden C II mapping of NGC 6946 - Probing the atomic medium

    NASA Technical Reports Server (NTRS)

    Madden, S. C.; Geis, N.; Genzel, R.; Herrmann, F.; Jackson, J.; Poglitsch, A.; Stacey, G. J.; Townes, C. H.

    1993-01-01

    A well-sampled map (23 x 17 kpc) of the strong 158 micron forbidden C II cooling line in the Scd galaxy NGC 6946 at 55 arcsec resolution is presented which was taken with the MPE/UCB Far-infrared Imaging Fabry-Perot Interferometer (FIFI) in the Kuiper Airborne Observatory. It is concluded that the line emission in NGC 6946 is present in three spatially distinct components including nucleus, spiral arms, and extended region. An extended emission region is a source of most of the forbidden C II luminosity in NGC 6946. The 1 arcmin nuclear component has a line luminosity of 1.5 x 10 exp 7 solar luminosity and contributes 0.15 percent of the galaxy's total FIR luminosity. An extended component of forbidden C II emission is found to exist past the molecular extent of the galaxy and to be present to at least the full dimensions of the map. This component is attributed to a mixture of neutral and atomic clouds.

  17. Line Positions and Intensities of (73)C(189)CH(6) in the 12.2 µm Region

    NASA Astrophysics Data System (ADS)

    Smith, M. A. H.; Devi, V. Malathy; Benner, D. Chris; Sung, K.; Crawford, T. J.; Mantz, A. W.

    2014-06-01

    High-resolution, high signal-to-noise spectra of mono-substituted 13C-ethane (13C12CH6) in the 12.2 µm region have been recorded with a Bruker IFS 125HR Fourier transform spectrometer. Four of these spectra were recorded at three different temperatures between 130 and 208 K using a 99% 13C-enriched ethane sample contained in a 20.38-cm long coolable absorption cell1. A multispectrum nonlinear least squares fitting technique2 was used to fit the same intervals in these four spectra simultaneously to determine line positions and intensities. Similar to our previous analyses of 12C2H6 spectra in this same region3, constraints were applied to accurately fit each pair of doublet components arising from torsional Coriolis interaction of the excited ν12 = 1 state with the nearby torsional ν6 = 3 state. Line intensities are reported for 1660 ν12 absorption lines for which the assignments are known, and integrated intensities are estimated as the summation of the measured values. The measured line positions and intensities are compared with values in recent editions of spectroscopic databases.4

  18. Contribution of inner shell Compton ionization to the X-ray fluorescence line intensity

    NASA Astrophysics Data System (ADS)

    Fernández, Jorge E.; Scot, Viviana; Di Giulio, Eugenio

    2016-10-01

    The Compton effect is a potential ionization mechanism of atoms. It produces vacancies in inner shells that are filled with the same mechanism of atomic relaxation as the one following photo-absorption. This contribution to X-ray fluorescence emission is frequently neglected because the total Compton cross-section is apparently much lower than the photoelectric one at useful X-ray energies. However, a more careful analysis suggests that is necessary to consider single shell cross sections (instead of total cross sections) as a function of energy. In this article these Compton cross sections are computed for the shells K, L1-L3 and M1-M5 in the framework of the impulse approximation. By comparing the Compton and the photoelectric cross-section for each shell it is then possible to determine the extent of the Compton correction to the intensity of the corresponding characteristic lines. It is shown that for the K shell the correction becomes relevant for excitation energies which are too high to be influent in X-ray spectrometry. In contrast, for L and M shells the Compton contribution is relevant for medium-Z elements and medium energies. To illustrate the different grades of relevance of the correction, for each ionized shell, the energies for which the Compton contribution reaches the extent levels of 1, 5, 10, 20, 50 and 100% of the photoelectric one are determined for all the elements with Z = 11-92. For practical applications it is provided a simple formula and fitting coefficients to compute average correction levels for the shells considered.

  19. Real Distribution of the Coronal Green Line Intensity and Modelling Study of Galactic Cosmic Ray Propagation

    NASA Astrophysics Data System (ADS)

    Gushchina, R. T.; Alania, M. V.; Gil, A.; Iskra, K.; Siluszyk, M.

    2003-07-01

    transport equation of galactic cosmic rays (GCR) has been numerically solved for different qA>0 (1996) and qA<0 (1987) epochs assuming that free path of GCR scattering in the interplanetary space is controlled by the Sun's coronal green line intensity (CGLI). We found some distinctions in the distribution of the expected heliolatitudinal gradients of GCR for two and three dimensional interplanetary magnetic field. INTRODUCTION. modulation of GCR in the interplanetary space is generally determined by four processesdiffusion, convection, drift and energy change of GCR particles due to interaction with the solar wind. The joint effect of all above mentioned processes result the 11year variation of GCR. In papers [1-3] are assumed that the general reason of the 11-year variation of GCR in the energy range more than 1 GeV is different structure of the irregularities of the IMF in the maxima and minima epochs of solar activity (SA) caused the radical changes of the dependence of diffusion coefficient on the rigidity of GCR particles. EXPERIMENTAL DATA AND METHOD OF INVESTIGATION. experimental data of sunspot numbers, sunspots' areas and CGLI (λ = 5303˚) show a considerable changes during the 11-year cycle of SA, while e.g. A the changes of the solar wind velocity are not so noticeable [4, 5]. An attempt to take into account influences of the real distributions of the sunspot's areas and the Sun's CGLI on the modulation of GCR considering delay time of the phenomena in the interplanetary space with respect to the processes on the Sun have been undertaken in papers [6-8]. One of parameters of SA contentiously observed on the Earth is the Sun's CGLI. One can suppose that a modulation of GCR by some means is controlled by the changes of the CGLI; particularly there is assumed that a scattering free path of GCR transport is related with the

  20. Forbidden friends as forbidden fruit: parental supervision of friendships, contact with deviant peers, and adolescent delinquency.

    PubMed

    Keijsers, Loes; Branje, Susan; Hawk, Skyler T; Schwartz, Seth J; Frijns, Tom; Koot, Hans M; van Lier, Pol; Meeus, Wim

    2012-01-01

    Spending leisure time with deviant peers may have strong influences on adolescents' delinquency. The current 3-wave multi-informant study examined how parental control and parental prohibition of friendships relate to these undesirable peer influences. To this end, annual questionnaires were administered to 497 Dutch youths (283 boys, mean age = 13 years at baseline), their best friends, and both parents. Cross-lagged panel analyses revealed strong longitudinal links from contacts with deviant peers to adolescent delinquency, but not vice versa. Parent-reported prohibition of friendships positively predicted contacts with deviant peers and indirectly predicted higher adolescent delinquency. Similar indirect effects were not found for parental control. The results suggest that forbidden friends may become "forbidden fruit," leading to unintended increases in adolescents' own delinquency.

  1. Comparing Administrative and Clinical Data for Central Line Associated Blood Stream Infections in Pediatric Intensive Care Unit and Pediatric Cardiothoracic Intensive Care Unit

    PubMed Central

    Bond, Jory; Issa, Mohamed; Nasrallah, Ali; Bahroloomi, Sheena; Blackwood, Roland A.

    2016-01-01

    Central line associated bloodstream infections (CLABSIs) are a frequent source of health complication for patients of all ages, including for patients in the pediatric intensive care unit (PICU) and Pediatric Cardiothoracic Intensive Care Unit (PCTU). Many hospitals, including the University of Michigan Health System, currently use the International Classification of Disease (ICD) coding system when coding for CLABSI. The purpose of this study was to determine the accuracy of coding for CLABSI infections with ICD-9CM codes in PICU and PCTU patients. A retrospective chart review was conducted for 75 PICU and PCTU patients with 90 events of hospital acquired central line infections at the University of Michigan Health System (from 2007-2011). The different variables examined in the chart review included the type of central line the patient had, the duration of the stay of the line, the type of organism infecting the patient, and the treatment the patient received. A review was conducted to assess if patients had received the proper ICD-9CM code for their hospital acquired infection. In addition, each patient chart was searched using Electronic Medical Record Search Engine to determine if any phrases that commonly referred to hospital acquired CLABSIs were present in their charts. Our review found that in most CLABSI cases the hospital’s administrative data diagnosis using ICD-9CM coding systems did not code for the CLABSI. Our results indicate a low sensitivity of 32% in the PICU and an even lower sensitivity of 12% in the PCTU. Using these results, we can conclude that the ICD-9CM coding system cannot be used for accurately defining hospital acquired CLABSIs in administrative data. With the new use of the ICD-10CM coding system, further research is needed to assess the effects of the ICD-10CM coding system on the accuracy of administrative data.

  2. Infrared line intensity measurements in the v = 0-1 band of the ClO radical

    NASA Technical Reports Server (NTRS)

    Burkholder, James B.; Howard, Carleton J.; Hammer, Philip D.; Goldman, Aaron

    1989-01-01

    Integrated line intensity measurements in the ClO-radical fundamental vibrational v = 0-1 band were carried out using a high-resolution Fourier transform spectrometer coupled to a long-path-length absorption cell. The results of a series of measurements designed to minimize systematic errors, yielded a value of the fundamental IR band intensity of the ClO-radical equal to 9.68 + or - 1.45/sq cm per atm at 296 K. This result is consistent with all the earlier published results, with the exception of measurements reported by Kostiuk et al. (1986) and Lang et al. (1988).

  3. Measurement of multiplet intensities and noble gas-broadened line widths in the nu 3 fundamental of methane

    NASA Technical Reports Server (NTRS)

    Varanasi, P.; Pugh, L. A.; Bangaru, B. R. P.

    1974-01-01

    Presented integrated intensity data at 300 K for J multiplets between P(11) and R(11) in the nu-3 fundamental of C-12 methane are shown to be in good agreement with most previously published pertinent values. Also, line widths measured at 100 K, 130 K, 190 K, 250 K, and 300 K for R(0), R(1), and R(2) broadened by He, Ne, and Ar are presented, and the line-width temperature dependence is discussed for the three cases of broadening.

  4. ANALYSIS OF BREIT-PAULI TRANSITION PROBABILITIES FOR LINES IN O III

    SciTech Connect

    Fischer, C. Froese; Tachiev, G.; Rubin, R. H.; Rodriguez, M.

    2009-09-20

    Accurate atomic data are essential for understanding the properties of both O III lines produced by the Bowen fluorescence mechanism and [O III] forbidden lines observed in numerous gaseous nebulae. Improved Breit-Pauli transition probabilities have been published for the carbon sequence. Included were revised data for O III. The present paper analyzes the accuracy of the data specifically for O III by comparison with other theory as well as some recent experiments and observations. For the electric dipole transition probabilities, good agreement is found for allowed Bowen fluorescence lines between predictions of intensity ratios with observed data. For forbidden transitions, the Breit-Pauli magnetic dipole transition operator requires corrections that often are neglected. Good agreement is found when these transition probabilities are computed with multiconfiguration Dirac-Hartree-Fock methods.

  5. Use of emission-line intensities for a self-consistent determination of the particle densities in a transient plasma.

    PubMed

    Gregorian, L; Bernshtam, V A; Kroupp, E; Davara, G; Maron, Y

    2003-01-01

    A method for a self-consistent determination of the time history of the electron density, electron temperature, and ionic charge-state composition in a multicomponent plasma, using time-dependent measurements and calculations of absolute emission-line intensities, is presented. The method is applied for studying the properties of an imploding gas-puff Z-pinch plasma that contains several oxygen ions up to the fifth ionization stage. Furthermore, by using intensity ratios of lines from different ion species, the electron temperature was determined with a much improved accuracy, in comparison to previous spectroscopic studies of the same plasma. The ion-density history obtained, together with the known time-dependent radial boundaries of the plasma shell, allowed for tracking the rise in time of the mass swept by the magnetic field during the implosion. PMID:12636608

  6. Use of emission-line intensities for a self-consistent determination of the particle densities in a transient plasma.

    PubMed

    Gregorian, L; Bernshtam, V A; Kroupp, E; Davara, G; Maron, Y

    2003-01-01

    A method for a self-consistent determination of the time history of the electron density, electron temperature, and ionic charge-state composition in a multicomponent plasma, using time-dependent measurements and calculations of absolute emission-line intensities, is presented. The method is applied for studying the properties of an imploding gas-puff Z-pinch plasma that contains several oxygen ions up to the fifth ionization stage. Furthermore, by using intensity ratios of lines from different ion species, the electron temperature was determined with a much improved accuracy, in comparison to previous spectroscopic studies of the same plasma. The ion-density history obtained, together with the known time-dependent radial boundaries of the plasma shell, allowed for tracking the rise in time of the mass swept by the magnetic field during the implosion.

  7. Use of generalized population ratios to obtain Fe XV line intensities and linewidths at high electron densities

    NASA Technical Reports Server (NTRS)

    Kastner, S. O.; Bhatia, A. K.

    1980-01-01

    A generalized method for obtaining individual level population ratios is used to obtain relative intensities of extreme ultraviolet Fe XV emission lines in the range 284-500 A, which are density dependent for electron densities in the tokamak regime or higher. Four lines in particular are found to attain quite high intensities in the high-density limit. The same calculation provides inelastic contributions to linewidths. The method connects level populations and level widths through total probabilities t(ij), related to 'taboo' probabilities of Markov chain theory. The t(ij) are here evaluated for a real atomic system, being therefore of potential interest to random-walk theorists who have been limited to idealized systems characterized by simplified transition schemes.

  8. A computer program for fast non-LTE analysis of interstellar line spectra. With diagnostic plots to interpret observed line intensity ratios

    NASA Astrophysics Data System (ADS)

    van der Tak, F. F. S.; Black, J. H.; Schöier, F. L.; Jansen, D. J.; van Dishoeck, E. F.

    2007-06-01

    Aims:The large quantity and high quality of modern radio and infrared line observations require efficient modeling techniques to infer physical and chemical parameters such as temperature, density, and molecular abundances. Methods: We present a computer program to calculate the intensities of atomic and molecular lines produced in a uniform medium, based on statistical equilibrium calculations involving collisional and radiative processes and including radiation from background sources. Optical depth effects are treated with an escape probability method. The program is available on the World Wide Web at http://www.sron.rug.nl/~vdtak/radex/index.shtml. The program makes use of molecular data files maintained in the Leiden Atomic and Molecular Database (LAMDA), which will continue to be improved and expanded. Results: The performance of the program is compared with more approximate and with more sophisticated methods. An Appendix provides diagnostic plots to estimate physical parameters from line intensity ratios of commonly observed molecules. Conclusions: This program should form an important tool in analyzing observations from current and future radio and infrared telescopes. Appendices A-D, are only available in electronic form at http://www.aanda.org

  9. Proposed rocket experiments to measure the profile and intensity of the solar He1584A resonance line

    NASA Technical Reports Server (NTRS)

    Judge, D. L.

    1978-01-01

    The intensity and profile of the helium resonance line at 584 A from the entire disc of the sun was investigated using a rocket-borne helium-filled spectrometer and a curve of growth technique. The line profile was found to be accurately represented by a Gaussian profile with full width at half maximum of 122 plus or minus 10m A while the integrated intensity was measured to be (2.6 plus or minus 1.3) x 10 to the 9th power/photons sec sq cm at solar levels of F sub 10.7 = 90.8 x 10 to the minus 22th power/sq m H sub z and R sub z = 27. The measured linewidth is in good agreement with previous spectrographic measurement but the integrated intensity is larger than most previous photoelectric measurements. However, the derived line center flux of (2.0 plus or minus 1.0) x 10 to the 10th power/photons sec sq cm A is in good agreement with values inferred from airglow measurements.

  10. Intensity ratios of H lines: departures from the ideal conditions in the range of laser-induced breakdown spectroscopy experiments.

    PubMed

    Cruzado, A; Di Rocco, H O

    2007-10-01

    In the present paper we analyze the behavior of H line intensity ratios with electron density and electron temperature in intermediate-density plasmas. We analyze the influence on the line intensity ratios of (1) the departures from local thermodynamic equilibrium (LTE) of the level population ratios, (2) the plasma opacity, and (3) the lowering of the ionization potential. We look, particularly, at the lines H(alpha), H(beta), H(gamma), and H(delta) and the energy levels involved in the corresponding atomic transitions for their use as diagnostics in laser-induced breakdown spectroscopy (LIBS) experiments. One important conclusion is that, for typical values of the plasma dimension and the electron temperature taking place in LIBS, i.e., L = 1 mm and T(e) = 10 000 K, respectively, the intensity ratios H(beta)/H(alpha), H(gamma)/H(alpha), and H(delta)/H(alpha) depart from the ideal values by less than 10% in the interval 0.65 x 10(14) part/cm(3)

  11. Power lines, roads, and avian nest survival: effects on predator identity and predation intensity

    PubMed Central

    DeGregorio, Brett A; Weatherhead, Patrick J; Sperry, Jinelle H

    2014-01-01

    1 Anthropogenic alteration of landscapes can affect avian nest success by influencing the abundance, distribution, and behavior of predators. Understanding avian nest predation risk necessitates understanding how landscapes affect predator distribution and behavior. 2 From a sample of 463 nests of 17 songbird species, we evaluated how landscape features (distance to forest edge, unpaved roads, and power lines) influenced daily nest survival. We also used video cameras to identify nest predators at 137 nest predation events and evaluated how landscape features influenced predator identity. Finally, we determined the abundance and distribution of several of the principal predators using surveys and radiotelemetry. 3 Distance to power lines was the best predictor of predator identity: predation by brown-headed cowbirds (Molothrus ater), corvids (Corvus sp. and Cyanocitta cristata), racers (Coluber constrictor), and coachwhips (Masticophis flagellum) increased with proximity to power lines, whereas predation by rat snakes (Elaphe obsoleta) and raptors decreased. In some cases, predator density may reliably indicate nest predation risk because racers, corvids, and cowbirds frequently used power line right-of-ways. 4 Of five bird species with enough nests to analyze individually, daily nest survival of only indigo buntings (Passerina cyanea) decreased with proximity to power lines, despite predation by most predators at our site being positively associated with power lines. For all nesting species combined, distance to unpaved road was the model that most influenced daily nest survival. This pattern is likely a consequence of rat snakes, the locally dominant nest predator (28% of predation events), rarely using power lines and associated areas. Instead, rat snakes were frequently associated with road edges, indicating that not all edges are functionally similar. 5 Our results suggest that interactions between predators and landscape features are likely to be specific to

  12. Line intensities and temperature-dependent line broadening coefficients of Q-branch transitions in the v2 band of ammonia near 10.4 μm

    NASA Astrophysics Data System (ADS)

    Sur, Ritobrata; Spearrin, R. Mitchell; Peng, Wen Y.; Strand, Christopher L.; Jeffries, Jay B.; Enns, Gregory M.; Hanson, Ronald K.

    2016-05-01

    We report measured line intensities and temperature-dependent broadening coefficients of NH3 with Ar, N2, O2, CO2, H2O, and NH3 for nine sQ(J,K) transitions in the ν2 fundamental band in the frequency range 961.5-967.5 cm-1. This spectral region was chosen due to the strong NH3 absorption strength and lack of spectral interference from H2O and CO2 for laser-based sensing applications. Spectroscopic parameters were determined by multi-line fitting using Voigt lineshapes of absorption spectra measured with two quantum cascade lasers in thermodynamically-controlled optical cells. The temperature dependence of broadening was measured over a range of temperatures between 300 and 600 K. These measurements aid the development of mid-infrared NH3 sensors for a broad range of gas mixtures and at elevated temperatures.

  13. Line positions and intensities of the phosphine (PH3) Pentad near 4.5μm

    SciTech Connect

    Malathy Devi, V.; Kleiner, Isabelle; Sams, Robert L.; Brown, Linda R.; Benner, D. Chris; Fletcher, Leigh N.

    2014-04-01

    In order to improve the spectroscopic database for remote sensing of the giant planets, line positions and intensities are determined for the five bands (2ν2, ν2 + ν4, 2ν4, ν1 and ν3) that comprise the Pentad of PH3 between 1950 and 2450 cm-1. Knowledge of PH3 spectral line parameters in this region is important for the exploration of dynamics and chemistry on Saturn, (using existing Cassini/VIMS observations) and future near-IR data of Jupiter from Juno and ESA’s Jupiter Icy Moons Explorer (JUICE). For this study, spectra of pure PH3 from two Fourier transform spectrometers were obtained: (a) five high-resolution (0.00223 cm-1), high signal-to-noise (~1800) spectra recorded at room temperature (298.2 K) with the Bruker IFS 125HR Fourier transform spectrometer (FTS) at the Pacific Northwest National Laboratory (PNNL), Richland, Washington and (b) four high-resolution (at 0.0115 cm-1 resolution), high signal-to-noise (~700) spectra recorded at room temperature in the region 1800–5200 cm-1 using the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory (NSO) on Kitt Peak. Individual line parameters above 2150 cm-1 were retrieved by simultaneous multispectrum fittings of all five Bruker spectra, while retrievals with the four Kitt Peak spectra were done in the 1938–2168 cm-1 range spectrum by spectrum and averaged. In all, positions and intensities were obtained for more than 4400 lines. These included 53 A+A- split pairs of transitions (arising due to vibration–rotation interactions (Coriolis-type interaction) between the ν3 and ν1 fundamental bands) for K" = 3, 6, and 9. Over 3400 positions and 1750 intensities of these lines were ultimately identified as relatively unblended and modeled up to J = 14 and K = 12 with rms values of 0

  14. Line positions and intensities of the phosphine (PH3) Pentad near 4.5 μm

    NASA Astrophysics Data System (ADS)

    Malathy Devi, V.; Kleiner, Isabelle; Sams, Robert L.; Brown, Linda R.; Benner, D. Chris; Fletcher, Leigh N.

    2014-04-01

    In order to improve the spectroscopic database for remote sensing of the giant planets, line positions and intensities are determined for the five bands (2ν2, ν2 + ν4, 2ν4, ν1 and ν3) that comprise the Pentad of PH3 between 1950 and 2450 cm-1. Knowledge of PH3 spectral line parameters in this region is important for the exploration of dynamics and chemistry on Saturn, (using existing Cassini/VIMS observations) and future near-IR data of Jupiter from Juno and ESA's Jupiter Icy Moons Explorer (JUICE). For this study, spectra of pure PH3 from two Fourier transform spectrometers were obtained: (a) five high-resolution (0.00223 cm-1), high signal-to-noise (∼1800) spectra recorded at room temperature (298.2 K) with the Bruker IFS 125HR Fourier transform spectrometer (FTS) at the Pacific Northwest National Laboratory (PNNL), Richland, Washington and (b) four high-resolution (at 0.0115 cm-1 resolution), high signal-to-noise (∼700) spectra recorded at room temperature in the region 1800-5200 cm-1 using the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory (NSO) on Kitt Peak. Individual line parameters above 2150 cm-1 were retrieved by simultaneous multispectrum fittings of all five Bruker spectra, while retrievals with the four Kitt Peak spectra were done in the 1938-2168 cm-1 range spectrum by spectrum and averaged. In all, positions and intensities were obtained for more than 4400 lines. These included 53 A+A- split pairs of transitions (arising due to vibration-rotation interactions (Coriolis-type interaction) between the ν3 and ν1 fundamental bands) for K″ = 3, 6, and 9. Over 3400 positions and 1750 intensities of these lines were ultimately identified as relatively unblended and modeled up to J = 14 and K = 12 with rms values of 0.00133 cm-1 and 7.7%, respectively. The PH3 line parameters (observed positions and measured intensities with known quantum assignments) and Hamiltonian constants are reported. Comparisons

  15. Formaldehyde Emission in Comet C/2002 T7 (LINEAR) at Infrared Wavelengths: Line-by-Line Validation of Modeled Fluorescent Intensities

    NASA Astrophysics Data System (ADS)

    DiSanti, Michael A.; Bonev, B. P.; Dello Russo, N.; Magee-Sauer, K.; Mumma, M. J.; Reuter, D. C.; Villanueva, G. L.; Anderson, W. M.; Gibb, E. L.

    2006-09-01

    Cometary nuclei are the most primitive remnants of the early Solar System, so measuring abundances of their ices allows a glimpse into the conditions in which icy bodies formed. Only in the last several years has it become possible to routinely study native cometary volatiles at infrared wavelengths. In spring 2004, we observed comet C/2002 T7 (LINEAR, hereafter C/T7) using the CSHELL spectrometer at the NASA-IRTF 3-m telescope. CSHELL offers sufficiently high spectral resolving power (λ/δλ 2.5 x 104) to permit line-by-line intensities to be measured. Emission lines from multiple molecular species were targeted in the 2.9 - 5.0 micron spectral region, and our observations revealed an extremely rich chemistry in C/T7, including formaldehyde (H2CO). H2CO is ubiquitous in dense interstellar clouds, so its presence is expected in comets if they contain interstellar material. These bodies delivered enormous quantities of pre-biotic chemicals to the young Earth, thus the abundance of H2CO in comets is of keen astrobiological interest. C/T7 provided the best opportunity to date to compare H2CO line intensities predicted by an existing fluorescence model1 with high-resolution comet spectra. We present results2 showing a high degree of correlation between model and data. This work validates the model and permits highly reliable measures of rotational temperature and production rate of H2CO, for comparison with chemically related molecules (CO, methyl alcohol) in C/T7 and other comets in our database. This research was supported by the NASA Planetary Atmospheres (RTOP 344-33-55), Astrobiology (RTOP 344-53-51), and Planetary Astronomy (RTOP 344-32-98) Programs. References: 1Reuter, D. C., et al. 1989 Ap J 341:1045-1058; 2DiSanti, M. A., et al. 2006 Ap J (in press)

  16. Recombination line intensities for hydrogenic ions. III - Effects of finite optical depth and dust

    NASA Technical Reports Server (NTRS)

    Hummer, D. G.; Storey, P. J.

    1992-01-01

    The effect on the recombination spectrum of hydrogen arising from: (1) finite optical thickness in the Lyman lines; (2) the overlapping of Lyman lines near the series limit; (3) the absorption of Lyman lines by dust or photoionization, and (4) the long-wave radiation emitted by dust is examined. Full account is taken of electron and heavy particle collisions in redistributing energy and angular momentum. It is seen that each of these deviations from the classical Case B leads to observable effects, and that dust influences the recombination spectrum in characteristic ways that may make possible new observational constraints on dust properties in nebulosities. On the basis of these calculations it is believed that the uncertainty in the determination of the helium-to-hydrogen abundance ratio in the universe may be larger than currently claimed.

  17. Recovery of acetylene absorption line profile basing on tunable diode laser spectroscopy with intensity modulation and photoacoustic spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Li; Thursby, Graham; Stewart, George; Arsad, Norhana; Uttamchandani, Deepak; Culshaw, Brian; Wang, Yiding

    2010-04-01

    A novel and direct absorption line recovery technique based on tunable diode laser spectroscopy with intensity modulation is presented. Photoacoustic spectroscopy is applied for high sensitivity, zero background and efficient acoustic enhancement at a low modulation frequency. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used for generating laser intensity modulation (without wavelength modulation) through the external reflection. The MEMS mirror with 10μm thick structure material layer and 100nm thick gold coating is formed as a circular mirror of 2mm diameter attached to an electrothermal actuator and is fabricated on a chip that is wire-bonded and placed on a PCB holder. Low modulation frequency is adopted (since the resonant frequencies of the photoacoustic gas cell and the electrothermal actuator are different) and intrinsic high signal amplitude characteristics in low frequency region achieved from measured frequency responses for the MEMS mirror and the gas cell. Based on the property of photoacoustic spectroscopy and Beer's law that detectable sensitivity is a function of input laser intensity in the case of constant gas concentration and laser path length, a Keopsys erbium doped fibre amplifier (EDFA) with opto-communication C band and high output power up to 1W is chosen to increase the laser power. High modulation depth is achieved through adjusting the MEMS mirror's reflection position and driving voltage. In order to scan through the target gas absorption line, the temperature swept method is adopted for the tunable distributed feed-back (DFB) diode laser working at 1535nm that accesses the near-infrared vibration-rotation spectrum of acetylene. The profile of acetylene P17 absorption line at 1535.39nm is recovered ideally for ~100 parts-per-million (ppm) acetylene balanced by nitrogen. The experimental signal to noise ratio (SNR) of absorption line recovery for 500mW laser power was ~80 and hence the

  18. Excitation of emission lines by fluorescence and recombination in IC 418

    NASA Astrophysics Data System (ADS)

    Escalante, V.; Morisset, C.; Georgiev, L.

    2012-11-01

    We compare calculated intensities of lines of C II, N I, N II, O I and O II with a published deep spectroscopic survey of IC 418. Our calculations use a self-consistent nebular model and a synthetic spectrum of the central star atmosphere to take into account line excitation by continuum fluorescence and electron recombination. We found that the N II spectrum of the s, p and most d states is excited by fluorescence due to the low-excitation conditions of the nebula. Many C II and O II lines have significant amount of excitation by fluorescence. Recombination excites all the lines from the f and g states and most O II lines. In the neutral-ionized boundary, the N I quartet and O I triplet dipole-allowed lines are excited by fluorescence, while the quintet O I lines are excited by recombination. Electron excitation produces the forbidden optical lines of O I, and continuum fluorescence enhances the N I forbidden line intensities. Lines excited by fluorescence of light below the Lyman limit thus suggest a new diagnostic to explore the inner boundary of the photodissociation region of the nebula.

  19. Environmental sensitivity differs between rabbit lines selected for reproductive intensity and longevity.

    PubMed

    Savietto, D; Cervera, C; Blas, E; Baselga, M; Larsen, T; Friggens, N C; Pascual, J J

    2013-12-01

    To better understand the mechanisms that allow some animals to sustain their productive effort in harsh environmental conditions, rabbit does from two selection lines (LP and V) were housed in normal (NC), nutritional (NF) or heat (HC) challenging environmental conditions from first to third partum. The LP line (n=85) was founded on reproductive longevity criteria by selecting does from commercial farms that had a minimum of 25 partum with more than 7.5 kits born alive per parity. Line V (n=79) was constituted from four specialised maternal lines into a composite synthetic line and then selected by litter size at weaning for 36 generations. Female rabbits in NC and NF environments were housed at normal room temperature (18°C to 24°C) and fed with control [11.6 MJ digestible energy (DE)/kg dry matter (DM)] or low-energy diets (9.1 MJ DE/kg DM). HC does were housed at high room temperatures (25°C to 35°C) and fed the control diet. Female rabbits in the HC and NF environments ingested 11.5% and 6% less DE than NC does, respectively (P<0.05). These differences between environments occurred in both lines, with the differences being higher for LP than for V does (+6%; P<0.05). Milk yield responses followed those of energy intake also being higher for LP does (+21.3 g/day; P<0.05). The environmental conditions did not affect the perirenal fat thickness (PFT), but a genotype by environment interaction was observed. In NC and HC, the PFT was higher for line V (+0.23 and +0.35 mm, respectively; P<0.05) than for LP does, but this was not the case at NF (-0.01 mm). Moreover, the PFT evolution was different between them. In the NC environment, LP does used the accreted PFT in late lactation (-0.29 mm), whereas V does did not (-0.08 mm). Conversely, in the HC environment, LP does showed a flat PFT evolution in late lactation, whereas V does accumulated PFT. In the NF environment, LP and V does had a similar PFT evolution. There was also a litter size reduction for V does of

  20. Monitoring the Intensity of Ice Formation on Overhead Electric Power Lines and Contact Networks

    SciTech Connect

    Titov, D. E.; Ugarov, G. G.; Soshinov, A. G.

    2015-05-15

    The conditions for ice to form on a conductor are explained. A hypothesis on the existence of a functional relation between the rate of growth of a mass deposited on a non-live conductor, the dew and desublimation points, and the temperature of the wire surface when there is no wind is suggested and proved. Equations for determining the density, maximum possible mass of the coating and the intensity with which they are formed are proposed, which take into account the temperature of the conductor, the temperature and humidity of the air, the direction and velocity of the wind and the electric field strength of the conductor. The equations are the basis of a proposed thermodynamic method of monitoring the intensity of ice formation. Versions of a technical method and algorithms of the functioning of ice-formation monitoring are proposed.

  1. A brief review of the intensity of lines 3C and 3D in neon-like Fe XVII

    SciTech Connect

    Brown, G V

    2007-06-13

    X-ray emission from neon-like Fe XVII has been measured with high-resolution spectrometers from laboratory or celestial sources for nearly seven decades. Two of the strongest lines regularly identified in these spectra are the {sup 1}P{sub 1} {yields} {sup 1}S{sub 0} resonance, and {sup 3}D{sub 1} {yields} {sup 1}S{sub 0} intercombination line, known as 3C and 3D, respectively. This paper gives a brief overview of measurements of the intensities of the lines 3C and 3D from laboratory and celestial sources, and their comparison to model calculations, with an emphasis on measurements completed using an electron beam ion trap. It includes a discussion of the measured absolute cross sections compared to results from modern atomic theory calculations, as well as the diagnostic utility of the relative intensity, R = I{sub 3C}/I{sub 3D}, as it applies to the interpretation of spectra measured from the Sun and extra-Solar sources.

  2. Atomic Data and Spectral Line Intensities for Be-like Ions

    NASA Technical Reports Server (NTRS)

    Bhatia, Anand; Landi, E.

    2008-01-01

    Atomic data and collision rates are needed to model the spectrum of optically thin astrophysical sources. Recent observations from solar instrumentation such as SOH0 and Hinode have revealed the presence of hosts of lines emitted by high-energy configurations from ions belonging to the Be-like to the 0-like isoelectronic sequences. Data for such configurations are often unavailable in the literature. We have started a program to calculate the atomic parameters and rates for the high-energy configurations of Be-like ions of the type ls2.21.nl' where n=3,4,5. We report on the results of this project and on the diagnostic application of the predicted spectral lines.

  3. Laser-driven beam lines for delivering intensity modulated radiation therapy with particle beams

    SciTech Connect

    Hofmann, K. M.; Schell, S.; Wilkens, J. J.

    2013-07-26

    Laser-accelerated particles can provide a promising opportunity for radiation therapy of cancer. Potential advantages arise from combining a compact, cost-efficient treatment unit with the physical advantages in dose delivery of charged particle beams. We consider different dose delivery schemes and the required devices to design a possible treatment unit. The secondary radiation produced in several beam line elements remains a challenge to be addressed.

  4. On-line depth measurement for laser-drilled holes based on the intensity of plasma emission

    NASA Astrophysics Data System (ADS)

    Ho, Chao-Ching; Chiu, Chih-Mu; Chang, Yuan-Jen; Hsu, Jin-Chen; Kuo, Chia-Lung

    2014-09-01

    The direct time-resolved depth measurement of blind holes is extremely difficult due to the short time interval and the limited space inside the hole. This work presents a method that involves on-line plasma emission acquisition and analysis to obtain correlations between the machining processes and the optical signal output. Given that the depths of laser-machined holes can be estimated on-line using a coaxial photodiode, this was employed in our inspection system. Our experiments were conducted in air under normal atmospheric conditions without gas assist. The intensity of radiation emitted from the vaporized material was found to correlate with the depth of the hole. The results indicate that the estimated depths of the laser-drilled holes were inversely proportional to the maximum plasma light emission measured for a given laser pulse number.

  5. Mood and forbidden foods' influence on perceptions of binge eating.

    PubMed

    Guertin, T L; Conger, A J

    1999-01-01

    This study consists of two experiments investigating the effects of induced mood and food type on perceptions of eating in imagined and real eating situations. A total of 212 female undergraduates representing the continuum of bulimic symptomatology were induced with either elated or depressed moods using a standardized mood-induction procedure. They were then either asked to imagine themselves in a situation with either forbidden or non-forbidden foods (Experiment 1) or else were presented with a buffet of forbidden or non-forbidden foods and asked to eat (Experiment 2). Participants subsequently reported their perception of their eating behavior (i.e., amount of control, meal rating: from a snack to a binge; and meal feeling: from great to bad). Results revealed limited support for affect regulation models of bulimia nervosa when the participants consumed food, but no support for the theory when they imagined eating. Conversely, forbidden foods were found to influence perceptions in the imagined eating situation, but not when the participants ate. Implications of these results are discussed.

  6. Aerodynamic Mixing Downstream from Line Source of Heat in High-intensity Sound Field

    NASA Technical Reports Server (NTRS)

    Mickelson, William R; Baldwin, Lionel V

    1956-01-01

    Theory and measurement showed that the heat wake downstream from a line source is displaced by a transverse standing sound wave in a manner similar to a flag waving in a harmonic mode. With a 147 db, 104 cps standing wave, time-mean temperatures were reduced by an order of magnitude except near the displacement-pattern nodal points. The theory showed that a 161 db, 520 cps standing wave considerably increased the mixing in both the time-mean and instantaneous senses.

  7. Quantitative Kα line spectroscopy for energy transport in ultra-intense laser plasma interaction

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Nishimura, H.; Fujioka, S.; Arikawa, Y.; Nakai, M.; Chen, H.; Park, J.; Williams, G. J.; Ozaki, T.; Shiraga, H.; Kojima, S.; Johzaki, T.; Sunahara, A.; Miyanaga, N.; Kawanaka, J.; Nakata, Y.; Jitsuno, T.; Azechi, H.

    2016-03-01

    Absolute Ka line spectroscopy is proposed for studying laser-plasma interactions taking place in the cone-guided fast ignition targets. X-ray spectra ranging from 20 to 100 keV were quantitatively measured with a Laue spectrometer. The absolute sensitivities of the Laue spectrometer system were calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency, is derived as a consequence of this work. The absolute yield of Au and Ta Ka lines were measured in the fast ignition experimental campaign performed at Institute of Laser Engineering, Osaka University. Applying the hot electron spectrum information from the electron spectrometer, an energy transfer efficiency of the incident LFEX [1], a kJ-class PW laser, to hot electrons was derived for a planar and cone-guided geometry.

  8. Tracking objects outside the line of sight using 2D intensity images

    NASA Astrophysics Data System (ADS)

    Klein, Jonathan; Peters, Christoph; Martín, Jaime; Laurenzis, Martin; Hullin, Matthias B.

    2016-08-01

    The observation of objects located in inaccessible regions is a recurring challenge in a wide variety of important applications. Recent work has shown that using rare and expensive optical setups, indirect diffuse light reflections can be used to reconstruct objects and two-dimensional (2D) patterns around a corner. Here we show that occluded objects can be tracked in real time using much simpler means, namely a standard 2D camera and a laser pointer. Our method fundamentally differs from previous solutions by approaching the problem in an analysis-by-synthesis sense. By repeatedly simulating light transport through the scene, we determine the set of object parameters that most closely fits the measured intensity distribution. We experimentally demonstrate that this approach is capable of following the translation of unknown objects, and translation and orientation of a known object, in real time.

  9. Tracking objects outside the line of sight using 2D intensity images.

    PubMed

    Klein, Jonathan; Peters, Christoph; Martín, Jaime; Laurenzis, Martin; Hullin, Matthias B

    2016-08-31

    The observation of objects located in inaccessible regions is a recurring challenge in a wide variety of important applications. Recent work has shown that using rare and expensive optical setups, indirect diffuse light reflections can be used to reconstruct objects and two-dimensional (2D) patterns around a corner. Here we show that occluded objects can be tracked in real time using much simpler means, namely a standard 2D camera and a laser pointer. Our method fundamentally differs from previous solutions by approaching the problem in an analysis-by-synthesis sense. By repeatedly simulating light transport through the scene, we determine the set of object parameters that most closely fits the measured intensity distribution. We experimentally demonstrate that this approach is capable of following the translation of unknown objects, and translation and orientation of a known object, in real time.

  10. Tracking objects outside the line of sight using 2D intensity images.

    PubMed

    Klein, Jonathan; Peters, Christoph; Martín, Jaime; Laurenzis, Martin; Hullin, Matthias B

    2016-01-01

    The observation of objects located in inaccessible regions is a recurring challenge in a wide variety of important applications. Recent work has shown that using rare and expensive optical setups, indirect diffuse light reflections can be used to reconstruct objects and two-dimensional (2D) patterns around a corner. Here we show that occluded objects can be tracked in real time using much simpler means, namely a standard 2D camera and a laser pointer. Our method fundamentally differs from previous solutions by approaching the problem in an analysis-by-synthesis sense. By repeatedly simulating light transport through the scene, we determine the set of object parameters that most closely fits the measured intensity distribution. We experimentally demonstrate that this approach is capable of following the translation of unknown objects, and translation and orientation of a known object, in real time. PMID:27577969

  11. Tracking objects outside the line of sight using 2D intensity images

    PubMed Central

    Klein, Jonathan; Peters, Christoph; Martín, Jaime; Laurenzis, Martin; Hullin, Matthias B.

    2016-01-01

    The observation of objects located in inaccessible regions is a recurring challenge in a wide variety of important applications. Recent work has shown that using rare and expensive optical setups, indirect diffuse light reflections can be used to reconstruct objects and two-dimensional (2D) patterns around a corner. Here we show that occluded objects can be tracked in real time using much simpler means, namely a standard 2D camera and a laser pointer. Our method fundamentally differs from previous solutions by approaching the problem in an analysis-by-synthesis sense. By repeatedly simulating light transport through the scene, we determine the set of object parameters that most closely fits the measured intensity distribution. We experimentally demonstrate that this approach is capable of following the translation of unknown objects, and translation and orientation of a known object, in real time. PMID:27577969

  12. Generation of undamped stokes radiation under resonant pumping of the dipole-forbidden transition in a {Xi}-atom

    SciTech Connect

    Kochanov, V. P.

    2009-12-15

    We have developed a theory of the nonlinear ring interaction of three intense fields in the scheme of resonant Raman scattering on the dipole-allowed transition from the ground state to the first excited state of a cascade three-level quantum system. We show that the backward Stokes radiation generated by a pump resonant to the dipole-forbidden transition can be used in remote laser sensing of metal vapors.

  13. First on-line isotopic characterization of N2O emitted from intensively managed grassland

    NASA Astrophysics Data System (ADS)

    Wolf, B.; Merbold, L.; Decock, C.; Tuzson, B.; Harris, E.; Six, J.; Emmenegger, L.; Mohn, J.

    2015-01-01

    The analysis of the four main isotopic N2O species (14N14N16O, 14N15N16O, 15N14N16O, 14N14N18O) and especially the intramolecular distribution of 15N (site preference, SP) has been suggested as a tool to distinguish source processes and to help constrain the global N2O budget. However, current studies suffer from limited spatial and temporal resolution capabilities due to the combination of discrete flask sampling with subsequent laboratory-based mass spectrometric analysis. Quantum cascade laser absorption spectroscopy (QCLAS) allows selective high-precision analysis of N2O isotopic species at trace levels and is suitable for in situ measurements. Here, we present results from the first field campaign, conducted on an intensively managed grassland in central Switzerland. N2O mole fractions and isotopic composition were determined in the atmospheric surface layer (2 m height) at high temporal resolution with a modified state-of-the-art laser spectrometer connected to an automated N2O preconcentration unit. The analytical performance was determined from repeated measurements of a compressed air tank and resulted in measurement repeatability of 0.20, 0.12 and 0.11‰ for δ15Nα, δ15Nβ and δ18O, respectively. Simultaneous eddy-covariance N2O flux measurements were used to determine the flux-averaged isotopic signature of soil-emitted N2O. Our measurements indicate that in general, nitrifier-denitrification and denitrification were the prevalent sources of N2O during the campaign, and that variations in isotopic composition were rather due to alterations in the extent to which N2O was reduced to N2, than other pathways such as hydroxylamine oxidation. Management and rewetting events were characterized by low values of the intra-molecular 15N site preference (SP), δ15Nbulk and δ18O, suggesting nitrifier denitrification and incomplete heterotrophic bacterial denitrification responded most strongly to the induced disturbances. Flux-averaged isotopic composition of N

  14. First on-line isotopic characterization of N2O above intensively managed grassland

    NASA Astrophysics Data System (ADS)

    Wolf, B.; Merbold, L.; Decock, C.; Tuzson, B.; Harris, E.; Six, J.; Emmenegger, L.; Mohn, J.

    2015-04-01

    The analysis of the four main isotopic N2O species (14N14N16O, 14N15N16O, 15N14N16O, 14N14N18O) and especially the intramolecular distribution of 15N ("site preference", SP) has been suggested as a tool to distinguish source processes and to help constrain the global N2O budget. However, current studies suffer from limited spatial and temporal resolution capabilities due to the combination of discrete flask sampling with subsequent laboratory-based mass-spectrometric analysis. Quantum cascade laser absorption spectroscopy (QCLAS) allows the selective high-precision analysis of N2O isotopic species at trace levels and is suitable for in situ measurements. Here, we present results from the first field campaign, conducted on an intensively managed grassland site in central Switzerland. N2O mole fractions and isotopic composition were determined in the atmospheric surface layer (at 2.2 m height) at a high temporal resolution with a modified state-of-the-art laser spectrometer connected to an automated N2O preconcentration unit. The analytical performance was determined from repeated measurements of a compressed air tank and resulted in measurement repeatability of 0.20, 0.12 and 0.11‰ for δ15Nα, δ15Nβ and δ18O, respectively. Simultaneous eddy-covariance N2O flux measurements were used to determine the flux-averaged isotopic signature of soil-emitted N2O. Our measurements indicate that, in general, nitrifier-denitrification and denitrification were the prevalent sources of N2O during the campaign and that variations in isotopic composition were due to alterations in the extent to which N2O was reduced to N2 rather than to other pathways, such as hydroxylamine oxidation. Management and rewetting events were characterized by low values of the intramolecular 15N site preference (SP), δ15Nbulk and δ18O, suggesting that nitrifier-denitrification and incomplete heterotrophic bacterial denitrification responded most strongly to the induced disturbances. The flux

  15. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    NASA Astrophysics Data System (ADS)

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  16. Implementation of intensity ratio change and line-of-sight rate change algorithms for imaging infrared trackers

    NASA Astrophysics Data System (ADS)

    Viau, C. R.

    2012-06-01

    The use of the intensity change and line-of-sight (LOS) change concepts have previously been documented in the open-literature as techniques used by non-imaging infrared (IR) seekers to reject expendable IR countermeasures (IRCM). The purpose of this project was to implement IR counter-countermeasure (IRCCM) algorithms based on target intensity and kinematic behavior for a generic imaging IR (IIR) seeker model with the underlying goal of obtaining a better understanding of how expendable IRCM can be used to defeat the latest generation of seekers. The report describes the Intensity Ratio Change (IRC) and LOS Rate Change (LRC) discrimination techniques. The algorithms and the seeker model are implemented in a physics-based simulation product called Tactical Engagement Simulation Software (TESS™). TESS is developed in the MATLAB®/Simulink® environment and is a suite of RF/IR missile software simulators used to evaluate and analyze the effectiveness of countermeasures against various classes of guided threats. The investigation evaluates the algorithm and tests their robustness by presenting the results of batch simulation runs of surface-to-air (SAM) and air-to-air (AAM) IIR missiles engaging a non-maneuvering target platform equipped with expendable IRCM as self-protection. The report discusses how varying critical parameters such track memory time, ratio thresholds and hold time can influence the outcome of an engagement.

  17. Effects of low intensity static electromagnetic radiofrequency fields on leiomyosarcoma and smooth muscle cell lines.

    PubMed

    Karkabounas, Spyridon; Havelas, Konstantinos; Kostoula, Olga K; Vezyraki, Patra; Avdikos, Antonios; Binolis, Jayne; Hatziavazis, George; Metsios, Apostolos; Verginadis, Ioannis; Evangelou, Angelos

    2006-01-01

    In this study we investigated the effects of low intensity static radiofrequency electromagnetic field (EMF) causing no thermal effects, on leiomyosarcoma cells (LSC), isolated from tumors of fifteen Wistar rats induced via a 3,4-benzopyrene injection. Electromagnetic resonance frequencies measurements and exposure of cells to static EMF were performed by a device called multi channel dynamic exciter 100 V1 (MCDE). The LSC were exposed to electromagnetic resonance radiofrequencies (ERF) between 10 kHz to 120 kHz, for 45 min. During a 24h period, after the exposure of the LSC to ERF, there was no inhibition of cells proliferation. In contrast, at the end of a 48 h incubation period, LSC proliferation dramatically decreased by more than 98% (P<0.001). At that time, the survived LSC were only 2% of the total cell population exposed to ERF, and under the same culture conditions showed significant decrease of proliferation. These cells were exposed once again to ERF for 45 min (totally 4 sessions of exposure, of 45 min duration each) and tested using a flow cytometer. Experiments as above were repeated five times. It was found that 45% of these double exposed to ERF, LSC (EMF cells) were apoptotic and only a small percentage 2%, underwent mitosis. In order to determinate their metastatic potential, these EMF cells were also counted and tested by an aggregometer for their ability to aggregate platelets and found to maintain this ability., since they showed no difference in platelet aggregation ability compared to the LSC not exposed to ERF (control cells). In conclusion, exposure of LSC to specific ERF, decreases their proliferation rate and induces cell apoptosis. Also, the LSC that survived after exposed to ERF, had a lower proliferation rate compared to the LSC controls (P<0.05) but did not loose their potential for metastases (platelet aggregation ability). The non-malignant SMC were not affected by the EMF exposure (P<0.4). The specific ERF generated from the MCDE

  18. RHESSI Observations of Particle Acceleration and Energy Release in an Intense Solar Gamma-Ray Line Flare

    NASA Astrophysics Data System (ADS)

    Lin, R. P.; Krucker, S.; Hurford, G. J.; Smith, D. M.; Hudson, H. S.; Holman, G. D.; Schwartz, R. A.; Dennis, B. R.; Share, G. H.; Murphy, R. J.; Emslie, A. G.; Johns-Krull, C.; Vilmer, N.

    2003-10-01

    We summarize Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) hard X-ray (HXR) and γ-ray imaging and spectroscopy observations of the intense (X4.8) γ-ray line flare of 2002 July 23. In the initial rise, a new type of coronal HXR source dominates that has a steep double-power-law X-ray spectrum and no evidence of thermal emission above 10 keV, indicating substantial electron acceleration to tens of keV early in the flare. In the subsequent impulsive phase, three footpoint sources with much flatter double-power-law HXR spectra appear, together with a coronal superhot (T~40 MK) thermal source. The north footpoint and the coronal source both move systematically to the north-northeast at speeds up to ~50 km s-1. This footpoint's HXR flux varies approximately with its speed, consistent with magnetic reconnection models, provided the rate of electron acceleration varies with the reconnection rate. The other footpoints show similar temporal variations but do not move systematically, contrary to simple reconnection models. The γ-ray line and continuum emissions show that ions and electrons are accelerated to tens of MeV during the impulsive phase. The prompt de-excitation γ-ray lines of Fe, Mg, Si, Ne, C, and O-resolved here for the first time-show mass-dependent redshifts of 0.1%-0.8%, implying a downward motion of accelerated protons and α-particles along magnetic field lines that are tilted toward the Earth by ~40°. For the first time, the positron annihilation line is resolved, and the detailed high-resolution measurements are obtained for the neutron-capture line. The first ever solar γ-ray line and continuum imaging shows that the source locations for the relativistic electron bremsstrahlung overlap the 50-100 keV HXR sources, implying that electrons of all energies are accelerated in the same region. The centroid of the ion-produced 2.223 MeV neutron-capture line emission, however, is located ~20''+/-6'' away, implying that the acceleration and

  19. HST imaging of the inner 3 arcseconds of NGC 1068 in the light of forbidden O III 5007 A

    SciTech Connect

    Evans, I.N.; Kinney, A.L.; Ford, H.C.; Antonucci, R.R.J.; Armus, L. California Univ., Santa Barbara Johns Hopkins Univ., Baltimore, MD )

    1991-03-01

    The Planetary Camera aboard HST has been used to obtain a high spatial resolution forbidden O III 5007 A image of the nucleus of the barred spiral galaxy NGC 1068. This image shows more detail than any previously published images and resolves the NLR into several distinct clouds arranged in an apparently conical geometry. The individual emission-line regions appear to be resolved with sizes of 0.1-0.2 arcsec. There is a strong apparent correspondence between the 1.3 cm radio structure and several of the forbidden O III 5007 A clouds, although there are also bright emission-line clouds for which there are no radio counterparts. In particular, the radio triple of Ulvestad et al. (1987) appears to correspond directly to the forbidden O III 5007 A clouds A-D. It is concluded that the distribution of the clouds is consistent with ionization core models. The hidden nucleus is located somewhere in the southern radio component and may be coincident with the H2O megamaser. 33 refs.

  20. HST imaging of the inner 3 arcseconds of NGC 1068 in the light of forbidden O III 5007 A

    NASA Technical Reports Server (NTRS)

    Evans, I. N.; Kinney, A. L.; Ford, H. C.; Antonucci, R. R. J.; Armus, L.

    1991-01-01

    The Planetary Camera aboard HST has been used to obtain a high spatial resolution forbidden O III 5007 A image of the nucleus of the barred spiral galaxy NGC 1068. This image shows more detail than any previously published images and resolves the NLR into several distinct clouds arranged in an apparently conical geometry. The individual emission-line regions appear to be resolved with sizes of 0.1-0.2 arcsec. There is a strong apparent correspondence between the 1.3 cm radio structure and several of the forbidden O III 5007 A clouds, although there are also bright emission-line clouds for which there are no radio counterparts. In particular, the radio 'triple' of Ulvestad et al. (1987) appears to correspond directly to the forbidden O III 5007 A clouds A-D. It is concluded that the distribution of the clouds is consistent with ionization core models. The hidden nucleus is located somewhere in the southern radio component and may be coincident with the H2O megamaser.

  1. FE-XIII Infrared / FE-XIV Green Line Ratio Diagnostics (P55)

    NASA Astrophysics Data System (ADS)

    Srivastava, A. K.; et al.

    2006-11-01

    aks.astro.itbhu@gmail.com We consider the first 27-level atomic model of Fe XIII (5.9 < log Te < 6.4 K) to estimate its ground level populations, taking account of electron as well as proton collisional excitations and de-excitations, radiative cascades, radiative excitations and de-excitations. Radiative cascade is important but the effect of dilution factor is negligible at higher electron densities. The 3 P1-3P0 and 3P2-3P1 transitions in the ground configuration 3s2 3p2 of Fe XIII result in two forbidden coronal emission lines in the infrared region, namely 10747 Å and 10798 Å., while the 5303 Å green line is formed in the 3s2 3p 2 2 ground configuration of Fe XIV as a result of P3 / 2 - P1 / 2 magnetic dipole transition. The line-widths of appropriate pair of forbidden coronal emission lines observed simultaneously can be useful diagnostic tool to deduce temperature and non-thermal velocity in the large scale coronal structures using intensity ratios of the lines as the temperature signature, instead of assuming ion temperature to be equal to the electron temperature. Since the line intensity ratios IG5303/IIR10747 and IG5303/IIR10798 have very week density dependence, they are ideal monitors of temperature mapping in the solar corona.

  2. Improving the output voltage waveform of an intense electron-beam accelerator based on helical type Blumlein pulse forming line

    NASA Astrophysics Data System (ADS)

    Cheng, Xin-Bing; Liu, Jin-Liang; Zhang, Hong-Bo; Feng, Jia-Huai; Qian, Bao-Liang

    2010-07-01

    The Blumlein pulse forming line (BPFL) consisting of an inner coaxial pulse forming line (PFL) and an outer coaxial PFL is widely used in the field of pulsed power, especially for intense electron-beam accelerators (IEBA). The output voltage waveform determines the quality and characteristics of the output beam current of the IEBA. Comparing with the conventional BPFL, an IEBA based on a helical type BPFL can increase the duration of the output voltage in the same geometrical volume. However, for the helical type BPFL, the voltage waveform on a matched load may be distorted which influences the electron-beam quality. In this paper, an IEBA based on helical type BPFL is studied theoretically. Based on telegrapher equations of the BPFL, a formula for the output voltage of IEBA is obtained when the transition section is taken into account, where the transition section is between the middle cylinder of BPFL and the load. From the theoretical analysis, it is found that the wave impedance and transit time of the transition section influence considerably the main pulse voltage waveform at the load, a step is formed in front of the main pulse, and a sharp spike is also formed at the end of the main pulse. In order to get a well-shaped square waveform at the load and to improve the electron-beam quality of such an accelerator, the wave impedance of the transition section should be equal to that of the inner PFL of helical type BPFL and the transit time of the transition section should be designed as short as possible. Experiments performed on an IEBA with the helical type BPFL show reasonable agreement with theoretical analysis.

  3. Shape of solitons in classically forbidden states - 'Lorentz expansion'

    NASA Technical Reports Server (NTRS)

    Guinea, F.; Peierls, R. E.; Schrieffer, R.

    1986-01-01

    The shape of extended objects in classically forbidden regions is shown to undergo expansion analogous to Lorentz contraction of a relativistic body of finite velocities. The problem of two interacting Dirac particles moving in one dimension is solved explicitly and the results are generalized to soliton solutions of field theories. An estimate of the effect on tunneling rates is also given, including solitons in (CH)z.

  4. The rise and fall of horror autotoxicus and forbidden clones.

    PubMed

    Jennette, J Charles; Falk, Ronald J

    2010-09-01

    Cui and associates show that healthy individuals have natural autoantibodies (NAAs) specific for myeloperoxidase, proteinase 3, and glomerular basement membrane (GBM) with the same specificity as anti-neutrophil cytoplasmic antibodies and anti-GBM antibodies that are pathogenic. Although Ehrlich proposed horror autotoxicus and Burnet envisioned elimination of forbidden clones, NAAs are present in all healthy individuals and play beneficial homeostatic roles. Pathogenic autoimmunity is dysregulation of natural homeostatic autoimmunity rather than onset of a previously absent self-recognition.

  5. The rise and fall of horror autotoxicus and forbidden clones.

    PubMed

    Jennette, J Charles; Falk, Ronald J

    2010-09-01

    Cui and associates show that healthy individuals have natural autoantibodies (NAAs) specific for myeloperoxidase, proteinase 3, and glomerular basement membrane (GBM) with the same specificity as anti-neutrophil cytoplasmic antibodies and anti-GBM antibodies that are pathogenic. Although Ehrlich proposed horror autotoxicus and Burnet envisioned elimination of forbidden clones, NAAs are present in all healthy individuals and play beneficial homeostatic roles. Pathogenic autoimmunity is dysregulation of natural homeostatic autoimmunity rather than onset of a previously absent self-recognition. PMID:20805814

  6. A Experimental Study of Ion Dynamic Effects on Helium Line Profiles.

    NASA Astrophysics Data System (ADS)

    Pease, Dennis Carl

    Time-resolved spectral line profiles for several neutral helium lines were determined in the afterglow of a linear z-discharge. The plasma temperature ((TURNEQ)10,000(DEGREES)K) was derived from both absolute and relative line intensities and was nearly constant during the afterglow. A monotonically decreasing electron density (5 x 10('14) > N(,e) > 4 x 10('13) cm('-3)) was measured using H(,(beta)) profile fitting and laser interferometry. Additional diagnostics indicated that the afterglow plasma was homogeneous and reproducible, and thereby confirmed its usefulness for detailed spectroscopic investigations. Detailed profiles were obtained for five neutral helium lines with nearby forbidden (i.e. (DELTA)l (NOT=) (+OR-)1) components: 2('3)P-4('3)D,('3)F ((lamda) 4471(ANGSTROM)); 2('3)P-5('3)D,('3)F,('3)G ((lamda) 4026(ANGSTROM)); 2('3)P -6('3)D,('3)F,('3)G,('3)H ((lamda) 3819(ANGSTROM)); 2('1)P -4('1)D,('1)F ((lamda) 4921(ANGSTROM)); and 2('1)P-5('1)D,('1)F,('1)G ((lamda) 4388(ANGSTROM)). Comparison of these profiles was made to published theoretical Stark broadening calculations which assumed either static ions or dynamic ions. Substantial discrepancies were found when comparing static ion calculations to the experimental profiles. The observed differences, a forbidden line which was too broad and a filled-in dip between the allowed and forbidden lines, agreed qualitatively with the results of published experimental data at higher densities. Excellent agreement was found between experimental profiles and those Stark broadening calculations which included the effects of ion dynamics. The high instrumental resolution used ((delta)(lamda)(,FWHM)(TURNEQ) .08(ANGSTROM)), the low electron densities, and the good plasma reproducibility enabled a number of subtle contributors to the line profile structure to be discerned including: hydrogen molecular lines, which had integrated intensities < 10('-4) that of the principal helium lines; intercombination lines, which were

  7. Infrared spectroscopy of 17O- and 18O-enriched carbon dioxide: Line positions and intensities in the 4681-5337 cm-1 region

    NASA Astrophysics Data System (ADS)

    Borkov, Yu. G.; Jacquemart, D.; Lyulin, O. M.; Tashkun, S. A.; Perevalov, V. I.

    2015-07-01

    The line positions and intensities of carbon dioxide isotopologues have been retrieved in the 4681-5337 cm-1 spectral range from Fourier transform spectra of carbon dioxide recorded in LADIR (Paris, France) with the Bruker IFS 125-HR [Jacquemart D, et al., J Quant Spectrosc Radiat Transf 2012;113:961-975]. In total 6386 line positions and intensities of 89 bands of 12 isotopologues 16O12C16O, 16O13C16O, 16O12C18O, 16O12C17O, 16O13C18O, 16O13C17O, 18O12C18O, 17O12C18O, 17O12C17O, 18O13C18O, 17O13C18O, and 17O13C17O have been retrieved. 23 bands were newly assigned. All studied bands belong to the ΔP=7 series of transitions, where P = 2V1 +V2 + 3V3 is the polyad number (Vi are vibrational quantum numbers). The accuracy of the line position measurement is about 0.3×10-3 cm-1 for the unblended and not very weak lines. The accuracy of the line intensities varies from 4% to 15% depending on the isotopologue, on the intensity of the line and on the extent of the line overlapping. The observed intensities were used to fit the effective dipole moment parameters for the ΔP=7 series of transitions in 16O12C18O, 16O12C17O, 12C17O2, 17O12C18O, 16O13C17O, 13C17O2 and 17O13C18O isotopologues of carbon dioxide.

  8. Resolving the forbidden band of SF6.

    PubMed

    Boudon, V; Manceron, L; Kwabia Tchana, F; Loëte, M; Lago, L; Roy, P

    2014-01-28

    D and the ν6 integrated intensity to be 0.0035 km mol(-1).

  9. SF_6: the Forbidden Band Unveiled

    NASA Astrophysics Data System (ADS)

    Boudon, V.; Manceron, L.; Kwabia-Tchana, F.; Roy, P.

    2013-06-01

    Sulfur hexafluoride (SF_6) is a greenhouse gas of anthropogenic origin, whose strong infrared absorption in the ν_3 S-F stretching region near 948 cm^{-1} induces a global warming potential 23900 times bigger than CO_2. This heavy species features many hot bands at room temperature (at which the ground state population is only 30 %), especially those originating from the v_6=1 state. Unfortunately, the ν_6 band itself (near 347 cm^{-1}) being, in first approximation, both infrared and Raman inactive, no reliable information could be obtained about it up to now. A long time ago, some authors suggested that this band may be slightly activated through Coriolis interaction and may appear as a very faint band, with an integrated intensity about 2 millionths of that of ν_3. Using a new cryogenic multipass cell with 93 m optical path length and regulated at 165± 2 K temperature, we recorded a spectrum of the ν_6 far-infrared region thanks to the performances of the AILES Beamline at the SOLEIL french synchrotron facility. Low temperature was used to avoid the presence of the 2ν_6-ν_6 hot band and to reduce the neighboring, stronger ν_4-ν_2 difference band. We are thus able to confirm that the small feature in this region, previously viewed at low-resolution is indeed ν_6. We present its fully resolved spectrum. It appears to be activated thanks to unidentified faint interactions resulting in the presence of a first-order dipole moment term that induces unusual selection rules. This spectrum was analyzed thanks to the XTDS software package, leading to accurate molecular spectroscopic parameters that should be useful to model the hot bands of SF_6. W. B. Person, B. J. Krohn, J. Mol. Spectrosc. {98}, 229-257 (1983), C. Chappados, G. Birnbaum, J. Mol. Spectrosc. {105}, 206-214 (1984). Ch. Wenger, V. Boudon, M. Rotger, M. Sanzharov and J.-P. Champion, J. Mol. Spectrosc., {251} 102-113 (2008).

  10. Resolving the forbidden band of SF6.

    PubMed

    Boudon, V; Manceron, L; Kwabia Tchana, F; Loëte, M; Lago, L; Roy, P

    2014-01-28

    D and the ν6 integrated intensity to be 0.0035 km mol(-1). PMID:24297100

  11. Relative coronal abundances derived from X-ray observations 3: The effect of cascades on the relative intensity of Fe (XVII) line fluxes, and a revised iron abundance

    NASA Technical Reports Server (NTRS)

    Walker, A. B. C., Jr.; Rugge, H. R.; Weiss, K.

    1974-01-01

    Permitted lines in the optically thin coronal X-ray spectrum were analyzed to find the distribution of coronal material, as a function of temperature, without special assumptions concerning coronal conditions. The resonance lines of N, O, Ne, Na, Mg, Al, Si, S, and Ar which dominate the quiet coronal spectrum below 25A were observed. Coronal models were constructed and the relative abundances of these elements were determined. The intensity in the lines of the 2p-3d transitions near 15A was used in conjunction with these coronal models, with the assumption of coronal excitation, to determine the Fe XVII abundance. The relative intensities of the 2p-3d Fe XVII lines observed in the corona agreed with theoretical prediction. Using a more complete theoretical model, and higher resolution observations, a revised calculation of iron abundance relative to hydrogen of 0.000026 was made.

  12. Implementing a multifaceted intervention to decrease central line-associated bloodstream infections in SEHA (Abu Dhabi Health Services Company) intensive care units: the Abu Dhabi experience.

    PubMed

    Latif, Asad; Kelly, Bernadette; Edrees, Hanan; Kent, Paula S; Weaver, Sallie J; Jovanovic, Branislava; Attallah, Hadeel; de Grouchy, Kristin K; Al-Obaidli, Ali; Goeschel, Christine A; Berenholtz, Sean M

    2015-07-01

    OBJECTIVE To determine whether implementation of a multifaceted intervention would significantly reduce the incidence of central line-associated bloodstream infections. DESIGN Prospective cohort collaborative. SETTING AND PARTICIPANTS Intensive care units of the Abu Dhabi Health Services Company hospitals in the Emirate of Abu Dhabi. INTERVENTIONS A bundled intervention consisting of 3 components was implemented as part of the program. It consisted of a multifaceted approach that targeted clinician use of evidence-based infection prevention recommendations, tools that supported the identification of local barriers to these practices, and implementation ideas to help ensure patients received the practices. Comprehensive unit-based safety teams were created to improve safety culture and teamwork. Finally, the measurement and feedback of monthly infection rate data to safety teams, senior leaders, and staff in participating intensive care units was encouraged. The main outcome measure was the quarterly rate of central line-associated bloodstream infections. RESULTS Eighteen intensive care units from 7 hospitals in Abu Dhabi implemented the program and achieved an overall 38% reduction in their central line-associated bloodstream infection rate, adjusted at the hospital and unit level. The number of units with a quarterly central line-associated bloodstream infection rate of less than 1 infection per 1,000 catheter-days increased by almost 40% between the baseline and postintervention periods. CONCLUSION A significant reduction in the global morbidity and mortality associated with central line-associated bloodstream infections is possible across intensive care units in disparate settings using a multifaceted intervention.

  13. DISCOVERY OF TIME VARIATION OF THE INTENSITY OF MOLECULAR LINES IN IRC+10216 IN THE SUBMILLIMETER AND FAR-INFRARED DOMAINS

    SciTech Connect

    Cernicharo, J.; Quintana-Lacaci, G.; Agúndez, M.; Velilla-Prieto, L.; Daniel, F.; Decin, L.; Guélin, M.; Encrenaz, P.; De Beck, E.; Barlow, M. J.; Groenewegen, M. A. T.; Neufeld, D.; Pearson, J.

    2014-11-20

    We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species toward the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on board Herschel and with the IRAM30 m telescope. They cover several observing periods spreading over three years. The line intensity variations for molecules produced in the external layers of the envelope most likely result from time variations in the infrared pumping rates. We analyze the main implications this discovery has on the interpretation of molecular line emission in the envelopes of Mira-type stars. Radiative transfer calculations must take into account both the time variability of infrared pumping and the possible variation of the dust and gas temperatures with stellar phase in order to reproduce the observation of molecular lines at different epochs. The effect of gas temperature variations with stellar phase could be particularly important for lines produced in the innermost regions of the envelope. Each layer of the circumstellar envelope sees the stellar light radiation with a different lag time (phase). Our results show that this effect must be included in the models. The submillimeter and far infrared lines of asymptotic giant branch stars can no longer be considered as safe intensity calibrators.

  14. High-resolution characterization of the forbidden Si 200 and Si 222 reflections1

    PubMed Central

    Zaumseil, Peter

    2015-01-01

    The occurrence of the basis-forbidden Si 200 and Si 222 reflections in specular X-ray diffraction ω–2Θ scans is investigated in detail as a function of the in-plane sample orientation Φ. This is done for two different diffractometer types with low and high angular divergence perpendicular to the diffraction plane. It is shown that the reflections appear for well defined conditions as a result of multiple diffraction, and not only do the obtained peaks vary in intensity but additional features like shoulders or even subpeaks may occur within a 2Θ range of about ±2.5°. This has important consequences for the detection and verification of layer peaks in the corresponding angular range. PMID:25844081

  15. Homogeneous and inhomogeneous broadenings and the Voigt line shapes in the phase-resolved and intensity sum-frequency generation vibrational spectroscopy.

    PubMed

    Chen, Shun-Li; Fu, Li; Gan, Wei; Wang, Hong-Fei

    2016-01-21

    In this report, we show that the ability to measure the sub-1 cm(-1) resolution phase-resolved and intensity high-resolution broadband sum frequency generation vibrational spectra of the -CN stretch vibration of the Langmuir-Blodgett (LB) monolayer of the 4-n-octyl-4'-cyanobiphenyl (8CB) on the z-cut α-quartz surface allows the direct comparison and understanding of the homogeneous and inhomogeneous broadenings in the imaginary and intensity SFG vibrational spectral line shapes in detail. The difference of the full width at half maximum (FWHM) of the imaginary and intensity sum-frequency generation vibrational spectroscopy spectra of the same vibrational mode is the signature of the Voigt line shape and it measures the relative contribution to the overall line shape from the homogeneous and inhomogeneous broadenings in SFG vibrational spectra. From the phase-resolved and intensity spectra, we found that the FWHM of the 2238.00 ± 0.02 cm(-1) peak in the phase-resolved imaginary and intensity spectra is 19.2 ± 0.2 cm(-1) and 21.6 ± 0.4 cm(-1), respectively, for the -CN group of the 8CB LB monolayer on the z-cut α-quartz crystal surface. The FWHM width difference of 2.4 cm(-1) agrees quantitatively with a Voigt line shape with a homogeneous broadening half width of Γ = 5.29 ± 0.08 cm(-1) and an inhomogeneous standard derivation width Δω = 5.42 ± 0.07 cm(-1). These results shed new lights on the understanding and interpretation of the line shapes of both the phase-resolved and the intensity SFG vibrational spectra, as well as other incoherent and coherent spectroscopic techniques in general. PMID:26801040

  16. Homogeneous and inhomogeneous broadenings and the Voigt line shapes in the phase-resolved and intensity sum-frequency generation vibrational spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Shun-Li; Fu, Li; Gan, Wei; Wang, Hong-Fei

    2016-01-01

    In this report, we show that the ability to measure the sub-1 cm-1 resolution phase-resolved and intensity high-resolution broadband sum frequency generation vibrational spectra of the -CN stretch vibration of the Langmuir-Blodgett (LB) monolayer of the 4-n-octyl-4'-cyanobiphenyl (8CB) on the z-cut α-quartz surface allows the direct comparison and understanding of the homogeneous and inhomogeneous broadenings in the imaginary and intensity SFG vibrational spectral line shapes in detail. The difference of the full width at half maximum (FWHM) of the imaginary and intensity sum-frequency generation vibrational spectroscopy spectra of the same vibrational mode is the signature of the Voigt line shape and it measures the relative contribution to the overall line shape from the homogeneous and inhomogeneous broadenings in SFG vibrational spectra. From the phase-resolved and intensity spectra, we found that the FWHM of the 2238.00 ± 0.02 cm-1 peak in the phase-resolved imaginary and intensity spectra is 19.2 ± 0.2 cm-1 and 21.6 ± 0.4 cm-1, respectively, for the -CN group of the 8CB LB monolayer on the z-cut α-quartz crystal surface. The FWHM width difference of 2.4 cm-1 agrees quantitatively with a Voigt line shape with a homogeneous broadening half width of Γ = 5.29 ± 0.08 cm-1 and an inhomogeneous standard derivation width Δω = 5.42 ± 0.07 cm-1. These results shed new lights on the understanding and interpretation of the line shapes of both the phase-resolved and the intensity SFG vibrational spectra, as well as other incoherent and coherent spectroscopic techniques in general.

  17. Lines

    ERIC Educational Resources Information Center

    Mires, Peter B.

    2006-01-01

    National Geography Standards for the middle school years generally stress the teaching of latitude and longitude. There are many creative ways to explain the great grid that encircles our planet, but the author has found that students in his college-level geography courses especially enjoy human-interest stories associated with lines of latitude…

  18. Precision half-life measurement of the 4-fold forbidden β decay of V50

    NASA Astrophysics Data System (ADS)

    Dombrowski, H.; Neumaier, S.; Zuber, K.

    2011-05-01

    A sensitive search of the 4-fold forbidden nonunique decay of V50 has been performed. A total mass measuring time product of 186 kg d has been accumulated. A reliable half-life value with the highest precision so far of (2.29±0.25)×1017 years of the electron capture decay of V50 into the first excited state of Ti50 could be obtained. A photon emission line following the β decay into the first excited state of Cr50 could not be observed, resulting in a lower limit on the half-life of the β-decay branch of 1.7×1018 years. This is not in good agreement with a claimed observation of this decay branch published in 1989.

  19. Precision half-life measurement of the 4-fold forbidden {beta} decay of {sup 50}V

    SciTech Connect

    Dombrowski, H.; Neumaier, S.; Zuber, K.

    2011-05-15

    A sensitive search of the 4-fold forbidden nonunique decay of {sup 50}V has been performed. A total mass measuring time product of 186 kg d has been accumulated. A reliable half-life value with the highest precision so far of (2.29{+-}0.25)x10{sup 17} years of the electron capture decay of {sup 50}V into the first excited state of {sup 50}Ti could be obtained. A photon emission line following the {beta} decay into the first excited state of {sup 50}Cr could not be observed, resulting in a lower limit on the half-life of the {beta}-decay branch of 1.7x10{sup 18} years. This is not in good agreement with a claimed observation of this decay branch published in 1989.

  20. Intensities and self-broadening coefficients of the strongest water vapour lines in the 2.7 and 6.25 μm absorption bands

    NASA Astrophysics Data System (ADS)

    Ptashnik, Igor V.; McPheat, Robert; Polyansky, Oleg L.; Shine, Keith P.; Smith, Kevin M.

    2016-07-01

    Intensities and self-broadening coefficients are presented for about 460 of the strongest water vapour lines in the spectral regions 1400-1840 cm-1 and 3440-3970 cm-1 at room temperature, obtained from rather unique measurements using a 5-mm-path-length cell. The retrieved spectral line parameters are compared with those in the HITRAN database ver. 2008 and 2012 and with recent ab-initio calculations. Both the retrieved intensities and half-widths are on average in reasonable agreement with those in HITRAN-2012. Maximum systematic differences do not exceed 4% for intensities (1600 cm-1 band) and 7% for self-broadening coefficients (3600 cm-1 band). For many lines however significant disagreements were detected with the HITRAN-2012 data, exceeding the average uncertainty of the retrieval. In addition, water vapour line parameters for 5300 cm-1 (1.9 μm) band reported by us in 2005 were also compared with HITRAN-2012, and show average differences of 4-5% for both intensities and half-widths.

  1. Investigation of effective line intensities of trans-HONO near 1255 cm-1 using continuous-wave quantum cascade laser spectrometers

    NASA Astrophysics Data System (ADS)

    Cui, Xiaojuan; Dong, Fengzhong; Sigrist, Markus W.; Zhang, Zhirong; Wu, Bian; Xia, Hua; Pang, Tao; Sun, Pengshuai; Fertein, Eric; Chen, Weidong

    2016-10-01

    Effective line intensities of P branch transitions of trans-nitrous acid (HONO) in the ν3 H-O-N bending mode near 1255 cm-1 have been determined by scaling measured HONO absorption intensities by continuous-wave quantum cascade laser absorption spectroscopy to reference values. Gaseous HONO samples were synthetized in the laboratory using the reaction of H2SO4 and NaNO2 solutions and the heterogeneous formation on surfaces in the presence of ambient water vapor and NO2 gas in a sealed gas sampling bag. The quantification of HONO was performed using a denuder associated with a NOx analyzer. Observed absorption line strengths for the trans conformer are found to be by a factor of approximately 1.17 higher than previously reported line strengths.

  2. Radial profile measurement of electron temperature in edge stochastic magnetic field layer of LHD using intensity ratio of extreme ultraviolet line emissions

    SciTech Connect

    Wang Erhui; Morita, Shigeru; Kobayashi, Masahiko; Murakami, Izumi; Goto, Motoshi; Dong Chunfeng

    2012-10-15

    Vertical profile of neon line emissions in 30-650 A wavelength range has been observed in horizontally elongated plasma cross section of Large Helical Device (LHD). Intensity ratio between the neon line emissions is studied to measure the radial profile of electron temperature in the edge stochastic magnetic field layer of LHD. The edge temperature profile successfully obtained from the line ratio of NeVIII 2s-3p to 2p-3s transitions is compared with the simulation based on three-dimensional edge transport code. The result shows a reasonably good agreement with the edge temperature profile analyzed from atomic data and analysis structure code. The electron temperature at last closed flux surface measured from the intensity ratio is also in good agreement with that measured from Thomson scattering.

  3. Radiative rates for forbidden M1 and E2 transitions of astrophysical interest in doubly ionized iron-peak elements

    NASA Astrophysics Data System (ADS)

    Fivet, V.; Quinet, P.; Bautista, M. A.

    2016-01-01

    Aims: Accurate and reliable atomic data for lowly ionized Fe-peak species (Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) are of paramount importance for analyzing the high-resolution astrophysical spectra currently available. The third spectra of several iron group elements have been observed in different galactic sources, such as Herbig-Haro objects in the Orion Nebula and stars like Eta Carinae. However, forbidden M1 and E2 transitions between low-lying metastable levels of doubly charged iron-peak ions have been investigated very little so far, and radiative rates for those lines remain sparse or nonexistent. We attempt to fill that gap and provide transition probabilities for the most important forbidden lines of all doubly ionized iron-peak elements. Methods: We carried out a systematic study of the electronic structure of doubly ionized Fe-peak species. The magnetic dipole (M1) and electric quadrupole (E2) transition probabilities were computed using the pseudo-relativistic Hartree-Fock (HFR) code of Cowan and the central Thomas-Fermi-Dirac-Amaldi potential approximation implemented in AUTOSTRUCTURE. This multiplatform approach allowed for consistency checks and intercomparison and has proven very useful in many previous works for estimating the uncertainties affecting the radiative data. Results: We present transition probabilities for the M1 and E2 forbidden lines depopulating the metastable even levels belonging to the 3dk and 3dk-14s configurations in Sc III (k = 1), Ti III (k = 2), V III (k = 3), Cr III (k = 4), Mn III (k = 5), Fe III (k = 6), Co III (k = 7), and Ni III (k = 8).

  4. Guest-Activated Forbidden Tilts in a Molecular Perovskite Analogue.

    PubMed

    Duyker, Samuel G; Hill, Joshua A; Howard, Christopher J; Goodwin, Andrew L

    2016-09-01

    The manipulation of distortions in perovskite structures is critical to tailoring the properties of these materials for a variety of applications. Here we demonstrate a violation of established octahedral tilt rules in the double perovskite analogue (NH4)2SrFe(CN)6·2H2O. The forbidden tilt pattern we observe arises through coupling to hydration-driven Jahn-Teller-like distortions of the Sr coordination environment. Access to novel distortion mechanisms and the ability to switch these distortions on and off through chemical modification fundamentally expands the toolbox of techniques available for engineering symmetry-breaking processes in solid materials. PMID:27533044

  5. Forbidden transition probabilities for ground terms of ions with p or p5 configurations. [for solar atmosphere

    NASA Technical Reports Server (NTRS)

    Kastner, S. O.

    1976-01-01

    Forbidden transition probabilities are given for ground term transitions of ions in the isoelectronic sequences with outer configurations 2s2 2p (B I), 2p5 (F I), 3s2 3p (Al I), and 3p5 (Cl I). Tables give, for each ion, the ground term interval, the associated wavelength, the quadrupole radial integral, the electric quadrupole transition probability, and the magnetic dipole transition probability. Coronal lines due to some of these ions have been observed, while others are yet to be observed. The tales for the Al I and Cl I sequences include elements up to germanium.

  6. Measurements of Line Positions and Intensities of 14NH_3 in the 1.5 μm Region

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Brown, Linda R.; Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2011-06-01

    In the atmosphere of outer planets, low mass brown dwarfs, and possibly extrasolar planets, ammonia (NH_3) is one of the major opacity sources particularly in the 1.5 μm region (the H-band). However, the spectroscopic information of NH_3 in the region is completely missing in the HITRAN database. NH_3 has four infrared active fundamental modes, with the well-known inversion doubling for {ν_2} band, in addition to the usual vibrational degeneracies. Its strong bands, {ν_1}, {ν_3} and 2{ν_4}, dominate the spectrum at 3 μm, while their corresponding overtone and combination bands (e.g., 2{ν_1}, 2{ν_3}, {ν_1}+{ν_3}, {ν_1}+2{ν_4} and {ν_3}+2{ν_4}) are prominent in the 1.5 μm region. As part of an effort to provide a complete set of NH_3 spectroscopic information in the 1.5 μm region, we are analyzing the laboratory spectra recorded at various temperatures (200 - 299 K) with the McMath-Pierce Fourier transform spectrometer (FTS) on Kitt Peak Observatory in Arizona. Line positions and strengths have been measured from the laboratory spectra, from which lower state energies and quantum assignments are being determined by adopting intensity ratios at two different temperatures and combination differnces. A theoretical IR linelist built upon the recent HSL-2 potential energy surface (nonadiabatic corrections included) is complementarily used for the quantum assignments. Preliminary results are presented for {ν_1}+{ν_3}, 2{ν_3}, {ν_1}+2{ν_4} and {ν_3}+{2ν_4} bands and compared with those from early work available. X. Huang, D.W. Schwenke, and T.J. Lee J. Chem. Phys. 134, (2011) 044320/044321 The research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology and the Ames Research Center under contracts with National Aeronautics and Space Administration.

  7. Far-ultraviolet MAMA detector imagery and emission-line CCD imagery of NGC 6240

    NASA Technical Reports Server (NTRS)

    Smith, Andrew M.; Hill, Robert S.; Vrba, Frederick J.; Timothy, J. G.

    1992-01-01

    An image of the luminous infrared galaxy NGC 6240 at 1480 A was obtained using a multianode microchannel array (MAMA) detector with a rocket-borne telescope. At distances greater than 12 arcsec from the nucleus, the measured ultraviolet luminosity implies intensive star formation activity equal to 2-3 times that of a spiral galaxy such as M83. Optical images in the H-beta and forbidden O III 5007 A emission lines reveal a region of high excitation east of the nucleus between the centers of disks 1 and 2 as described by Bland-Hawthorn et al.

  8. Magnetic field dependence of spin-forbidden electronic excitations reflects the Haldane or paramagnetic ground state

    NASA Astrophysics Data System (ADS)

    Long, V. C.; Montague, J. R.; Kozen, A. C.; Wei, X.; Landry, B. R.; Pearson, K. R.; Turnbull, M. M.; Landee, C. P.

    2007-03-01

    We compare the zero-field and magnetic field-dependent optical spectra of the Haldane chain compound NENB (Ni[en]2NO2BF4; en = C2N2H8) and the paramagnetic compound, Ni(en) 3(ClO4)2,H2O. Due to similar electronic coordination of Ni^2+, the two materials show similar zero-field d-d electronic transitions, including a spin-forbidden (SF) transition at 1.58 eV, overlapping a broad spin-allowed band at 1.45 eV. The relatively greater intensity of the SF band in the Haldane compound suggests activation by a spin exchange mechanism, whereas a spin-orbit coupling origin is likely in the paramagnet. A second narrower SF spin flip transition appears in NENB at 1.66 eV. In both compounds, the SF excitations are sensitive to applied field H. In NENB, the SF intensity is suppressed by H, consistent with behavior of spin exchange-activated bands. In Ni(en)3(ClO4)-2,H2O, the SF field sensitivity appears to combine an energy shift and intensity decrease. Details of the H dependence reflect the magnetic ground state of the material: the field sensitivity commences only above HC 10 T, in the Haldane compound, whereas the field-induced modifications begin immediately at H = 0 T in the paramagnet.

  9. X-ray line ratios from helium-like ions - Updated theory and SMM flare observations

    NASA Technical Reports Server (NTRS)

    Wolfson, C. J.; Leibacher, J. W.; Doyle, J. G.; Phillips, K. J. H.

    1983-01-01

    The potential which the conduction of measurements of the three principal lines emitted from helium-like ions has for the determination of plasma electron density was initially pointed out by Gabriel and Jordan (1969). The diagnostic technique is based on the fact that the ratio, R, of the intensity of a forbidden line to the intensity of an intercombination line decreases as electron density increases due to collisional excitation of levels. In the present investigation a further refinement of this procedure is provided by specifically calculating the effects of cascades from levels with principal quantum numbers up to n=6. Two improved spectrometers recently placed in operation include the SOLEX instrument on the satellite P78-1 and the X-ray Polychromator (XRP) instrument on the NASA Solar Maximum Mission satellite. Measurements obtained with one of the spectrometers making up the XRP are presented, taking into account the emission from Ne IX ions.

  10. What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?

    SciTech Connect

    Niu, Kai; Lee, Soo-Y.

    2015-12-15

    Coherent anti-Stokes Raman spectroscopy (CARS) is conventionally described by just one diagram/term where the three electric field interactions act on the ket side in a Feynman dual time-line diagram in a specific time order of pump, Stokes and probe pulses. In theory, however, any third-order nonlinear spectroscopy with three different electric fields interacting with a molecule can be described by forty eight diagrams/terms. They reduce to just 24 diagrams/terms if we treat the time ordering of the electric field interactions on the ket independently of those on the bra, i.e. the ket and bra wave packets evolve independently. The twenty four polarization terms can be calculated in the multidimensional, separable harmonic oscillator model to obtain the intensities and line-shapes. It is shown that in fs/ps CARS, for the two cases of off-resonance CARS in toluene and resonance CARS in rhodamine 6G, where we use a fs pump pulse, a fs Stokes pulse and a ps probe pulse, we obtain sharp vibrational lines in four of the polarization terms where the pump and Stokes pulses can create a vibrational coherence on the ground electronic state, while the spectral line-shapes of the other twenty terms are broad and featureless. The conventional CARS term with sharp vibrational lines is the dominant term, with intensity at least one order of magnitude larger than the other terms.

  11. What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?

    NASA Astrophysics Data System (ADS)

    Niu, Kai; Lee, Soo-Y.

    2015-12-01

    Coherent anti-Stokes Raman spectroscopy (CARS) is conventionally described by just one diagram/term where the three electric field interactions act on the ket side in a Feynman dual time-line diagram in a specific time order of pump, Stokes and probe pulses. In theory, however, any third-order nonlinear spectroscopy with three different electric fields interacting with a molecule can be described by forty eight diagrams/terms. They reduce to just 24 diagrams/terms if we treat the time ordering of the electric field interactions on the ket independently of those on the bra, i.e. the ket and bra wave packets evolve independently. The twenty four polarization terms can be calculated in the multidimensional, separable harmonic oscillator model to obtain the intensities and line-shapes. It is shown that in fs/ps CARS, for the two cases of off-resonance CARS in toluene and resonance CARS in rhodamine 6G, where we use a fs pump pulse, a fs Stokes pulse and a ps probe pulse, we obtain sharp vibrational lines in four of the polarization terms where the pump and Stokes pulses can create a vibrational coherence on the ground electronic state, while the spectral line-shapes of the other twenty terms are broad and featureless. The conventional CARS term with sharp vibrational lines is the dominant term, with intensity at least one order of magnitude larger than the other terms.

  12. The Role of Velocity Redistribution in Enhancing the Intensity of the He II 304 A Line in the Quiet Sun Spectrum

    NASA Technical Reports Server (NTRS)

    Andretta, Vincenzo; Jordan, Stuart D.; Brosius, Jeffrey W.; Davila, Joseph M.; Thomas, Roger J.; Behring, William E.; Thompson, William T.; Garcia, Adriana

    1999-01-01

    We present observational evidence of the effect of small scale ("microturbulent") velocities in enhancing the intensity of the He II lambda304 line with respect to other transition region emission lines, a process we call "velocity redistribution". We first show results from the 1991 and 1993 flights of SERTS (Solar EUV Rocket Telescope and Spectrograph). The spectral resolution of the SERTS instrument was sufficient to infer that, at the spatial resolution of 5", the line profile is nearly gaussian both in the quiet Sun and in active regions. We were then able to determine, for the quiet Sun, a lower limit for the amplitude of non-thermal motions in the region of formation of the 304 A line of the order of 10 km/s. We estimated that, in the presence of the steep temperature gradients of the solar Transition Region (TR), velocities of this magnitude can significantly enhance the intensity of that line, thus at least helping to bridge the gap between calculated and observed values. We also estimated the functional dependence of such an enhancement on the relevant parameters (non-thermal velocities, temperature gradient, and pressure). We then present results from a coordinated campaign, using SOHO/CDS and H-alpha spectroheliograms from Coimbra Observatory, aimed at determining the relationship between regions of enhanced helium emission and chromospheric velocity fields and transition region emission in the quiescent atmosphere. Using these data, we examined the behavior of the He II lambda304 line in the quiet Sun supergranular network and compared it with other TR lines, in particular with O III lambda600. We also examined the association of 304 A emission with the so-called "coarse dark mottle", chromospheric structures seen in H-alpha red wing images and associated with spicules. We found that all these observations are consistent with the velocity redistribution picture.

  13. The solar XUV He I and He II emission lines. I - Intensities and gross center-to-limb behavior

    NASA Technical Reports Server (NTRS)

    Mango, S. A.; Bohlin, J. D.; Glackin, D. L.; Linsky, J. L.

    1978-01-01

    The center-to-limb variation of the He II 304- and 256-A lines and He I 584- and 537-A lines is derived for different solar features, but averaged over the chromospheric supergranulation structure. The general trend is for limb brightening in quiet-sun regions, limb neutrality in unipolar magnetic regions (UMR), and limb darkening in polar coronal holes. The center-to-limb behavior in these optically thick emission lines indicates collisional excitation and decreasing transition-region temperature gradients with respect to optical depth in the sequence quiet sun to UMR to coronal hole.

  14. Simultaneous analysis of the Ballik-Ramsay and Phillips systems of C{sub 2} and observation of forbidden transitions between singlet and triplet states

    SciTech Connect

    Chen, Wang; Kawaguchi, Kentarou; Tang, Jian; Bernath, Peter F.

    2015-02-14

    6229 lines of the Ballik-Ramsay system (b{sup 3}Σ{sub g}{sup −}–a{sup 3}Π{sub u}) and the Phillips system (A{sup 1}Π{sub u}–X{sup 1}Σ{sub g}{sup +}) of C{sub 2} up to v = 8 and J = 76, which were taken from the literature or assigned in the present work, were analyzed simultaneously by least-squares fitting with 82 Dunham-like molecular parameters and spin-orbit interaction constants between the b{sup 3}Σ{sub g}{sup −} and X{sup 1}Σ{sub g}{sup +} states with a standard deviation of 0.0037 cm{sup −1} for the whole data set. As a result of the deperturbation analysis, the spin-orbit interaction constant A{sub bX} was determined as 6.333(7) cm{sup −1} and the energy difference between the X{sup 1}Σ{sub g}{sup +} and a{sup 3}Π{sub u} states was determined as 720.008(2) cm{sup −1} for the potential minima or 613.650(3) cm{sup −1} for the v = 0 levels with Merer and Brown’s N{sup 2} Hamiltonian for {sup 3}Π states, which is about 3.3 cm{sup −1} larger than the previously determined value. Due to this sizable change, a new energy-level crossing was found at J = 2 for v = 3 (F{sub 1}) of b{sup 3}Σ{sub g}{sup −} state and v = 6 of X{sup 1}Σ{sub g}{sup +} state, where the strong interaction causes a nearly complete mixing of the wave functions of the b{sup 3}Σ{sub g}{sup −} and X{sup 1}Σ{sub g}{sup +} states and the forbidden transitions become observable. Using the predictions of our deperturbation analysis, we were able to identify 16 forbidden transitions between the singlet and triplet states at the predicted frequencies with the expected intensities, which verifies our value for the energy difference between the X{sup 1}Σ{sub g}{sup +} and a{sup 3}Π{sub u} states.

  15. Inorganic-Organic Hybrid Luminescent Binary Probe for DNA Detection Based on Spin-Forbidden Resonance Energy Transfer

    PubMed Central

    Marti, Angel A.; Puckett, Cindy A.; Dyer, Joanne; Stevens, Nathan; Jockusch, Steffen; Ju, Jingyue; Barton, Jacqueline K.; Turro, Nicholas J.

    2009-01-01

    We describe the design of new fluorescent binary probe sensors for DNA detection based on spin-forbidden resonance energy transfer (SF-RET). Binary probes consist of a donor and acceptor fluorophores that are attached to two different oligonucleotides and serve as resonance energy transfer (RET) donor-acceptor pair when hybridized to adjacent sites of a target sequence. In the absence of target, excitation of the donor results in fluorescence only from the donor, but when the probes hybridize to target, the fluorophores are brought into close proximity favoring RET, yielding fluorescence mainly from the acceptor fluorophore. These new binary probes use the metal complex Ru(bpy′)(DIP)22+ as the energy donor and an organic fluorophore (Cy5) as the energy acceptor. Energy transfer from the MLCT state of the Ru complex to singlet Cy5 is spin forbidden and produces a delayed fluorescence of Cy5. This paper demonstrate that fluorescence delay of Cy5 can be used to time resolve the emission of the probe from the intense fluorescence background of a model system for cellular background; this provides the reported system to overcome intense autofluorescence, an important and general advantage over “classical” spin-allowed steady-state probes. PMID:17592843

  16. On the chromatic number of a space with forbidden equilateral triangle

    SciTech Connect

    Zvonarev, A E; Raigorodskii, A M; Kharlamova, A A; Samirov, D V

    2014-09-30

    We improve the Frankl-Rödl estimate for the product of the numbers of edges in uniform hypergraphs with forbidden cardinalities of the intersection of edges. By using this estimate, we obtain explicit bounds for the chromatic number of a space with forbidden monochromatic equilateral triangles. Bibliography: 31 titles.

  17. Transient lasing without inversion via forbidden and virtual transitions

    NASA Astrophysics Data System (ADS)

    Yuan, Luqi; Wang, Dawei; Svidzinsky, Anatoly A.; Xia, Hui; Kocharovskaya, Olga; Sokolov, Alexei; Welch, George R.; Suckewer, Szymon; Scully, Marlan O.

    2014-01-01

    Lasing without inversion (LWI) in the extreme-ultraviolet (XUV) has been the focus of recent research of our Princeton/Texas group. Because of the restriction imposed on the decay rates associated with the usual LWI schemes, it is difficult to transfer the physics gleaned from previous experiments to the XUV. However, with the advent of tunable-ultrashort-high-power laser pulses, we find that the possibility of transient LWI holds promise for a different LWI paradigm in which the lasing is based on forbidden and/or virtual transitions. It is the purpose of the present paper to present simple but (hopefully) convincing arguments and suggest realistic experiments to stimulate interest in this idea.

  18. An optical emission-line phase of the extreme carbon star IRC +30219

    NASA Technical Reports Server (NTRS)

    Cohen, M.

    1980-01-01

    Optical spectroscopic monitoring of the extreme carbon star IRC +30219 has revealed striking changes between 1977 and 1980. The stellar photosphere was barely visible in early 1979. There was an emission line spectrum consisting of H, forbidden O I, forbidden O II, forbidden N I, forbidden N II, forbidden S II, and He I. It is likely that these lines arose in a shocked region where recent stellar mass loss encountered the extensive circumstellar envelope. By late 1979, this emission-line spectrum had vanished, and the photosphere had reappeared. The weakening of the photospheric features in early 1979 was caused by increased attenuation of starlight and overlying thermal emission, both due to recently condensed hot dust grains.

  19. A Solar-pumped Fluorescence Model for Line-by-line Emission Intensities in the B-X, A-X, and X-X Band Systems of 12C14N

    NASA Astrophysics Data System (ADS)

    Paganini, L.; Mumma, M. J.

    2016-09-01

    We present a new quantitative model for detailed solar-pumped fluorescent emission of the main isotopologue of CN. The derived fluorescence efficiencies permit estimation and interpretation of ro-vibrational infrared line intensities of CN in exospheres exposed to solar (or stellar) radiation. Our g-factors are applicable to astronomical observations of CN extending from infrared to optical wavelengths, and we compare them with previous calculations in the literature. The new model enables extraction of rotational temperature, column abundance, and production rate from astronomical observations of CN in the inner coma of comets. Our model accounts for excitation and de-excitation of rotational levels in the ground vibrational state by collisions, solar excitation to the {A}2{{{\\Pi }}}{{i}} and {B}2{{{Σ }}}+ electronically excited states followed by cascade to ro-vibrational levels of {X}2{{{Σ }}}+, and direct solar infrared pumping of ro-vibrational levels in the {X}2{{{Σ }}}+ state. The model uses advanced solar spectra acquired at high spectral resolution at the relevant infrared and optical wavelengths and considers the heliocentric radial velocity of the comet (the Swings effect) when assessing the exciting solar flux for a given transition. We present model predictions for the variation of fluorescence rates with rotational temperature and heliocentric radial velocity. Furthermore, we test our fluorescence model by comparing predicted and measured line-by-line intensities for {X}2{{{Σ }}}+ (1-0) in comet C/2014 Q2 (Lovejoy), thereby identifying multiple emission lines observed at IR wavelengths.

  20. A Solar-pumped Fluorescence Model for Line-by-line Emission Intensities in the B–X, A–X, and X–X Band Systems of 12C14N

    NASA Astrophysics Data System (ADS)

    Paganini, L.; Mumma, M. J.

    2016-09-01

    We present a new quantitative model for detailed solar-pumped fluorescent emission of the main isotopologue of CN. The derived fluorescence efficiencies permit estimation and interpretation of ro-vibrational infrared line intensities of CN in exospheres exposed to solar (or stellar) radiation. Our g-factors are applicable to astronomical observations of CN extending from infrared to optical wavelengths, and we compare them with previous calculations in the literature. The new model enables extraction of rotational temperature, column abundance, and production rate from astronomical observations of CN in the inner coma of comets. Our model accounts for excitation and de-excitation of rotational levels in the ground vibrational state by collisions, solar excitation to the {A}2{{{\\Pi }}}{{i}} and {B}2{{{Σ }}}+ electronically excited states followed by cascade to ro-vibrational levels of {X}2{{{Σ }}}+, and direct solar infrared pumping of ro-vibrational levels in the {X}2{{{Σ }}}+ state. The model uses advanced solar spectra acquired at high spectral resolution at the relevant infrared and optical wavelengths and considers the heliocentric radial velocity of the comet (the Swings effect) when assessing the exciting solar flux for a given transition. We present model predictions for the variation of fluorescence rates with rotational temperature and heliocentric radial velocity. Furthermore, we test our fluorescence model by comparing predicted and measured line-by-line intensities for {X}2{{{Σ }}}+ (1–0) in comet C/2014 Q2 (Lovejoy), thereby identifying multiple emission lines observed at IR wavelengths.

  1. Improving central line infection rates in the neonatal intensive care unit: Effect of hospital location, site of insertion, and implementation of catheter-associated bloodstream infection protocols

    PubMed Central

    Freeman, Jennifer J.; Gadepalli, Samir K.; Siddiqui, Sabina M.; Jarboe, Marcus D.; Hirschl, Ronald B.

    2016-01-01

    Introduction Catheter associated blood stream infections (CABSI) are morbid and expensive for all ages, including neonates. Thus far, the impact of CABSI prevention protocols, such as insertion and maintenance bundles, in the neonatal intensive care unit (NICU) is largely unknown. We hypothesized that lines placed in the operating room (OR) would have a lower infection rate due to established insertion protocols and a more sterile environment. Methods Retrospective chart review of NICU patients who received a percutaneous or tunneled central venous catheter between 2005 and 2012. ECMO cannulas, PICC and umbilical catheters were excluded. Variables of interest included demographics, anatomical site, hospital location, line days, and line infection. Line infection was defined as a positive blood culture drawn through the catheter. Results A total of 368 catheters were placed in 285 NICU patients. Majority of catheters (65.5%) were placed in OR. Saphenous and femoral veins were most common anatomical sites (50.8%). Twenty-eight catheters were infected (7.6%). After adjusting for pre-operative antibiotics, anatomical site, and SNAPPE-II scores, lines placed in OR were three times less likely to become infected (Odds Ratio=0.32, p=0.038). Although implementation of CABSI prevention protocols resulted in statistically significant reductions in infection (Odds Ratio=0.4, p=0.043), lines placed in the OR remained less likely to become infected. Conclusions NICU line infection rates decreased with implementation of CABSI prevention protocols. Despite this implementation, catheters placed in the NICU continued to have higher infection rates. As a result, when patient status allows it, we recommend that central lines in newborns be placed in the operating room. PMID:25783394

  2. Dependence with the oxidation state of X-ray transition energies, intensities and natural line widths of CrKβ spectra

    NASA Astrophysics Data System (ADS)

    Torres Deluigi, M.; Tirao, G.; Stutz, G.; Cusatis, C.; Riveros, J. A.

    2006-06-01

    The Kβ emission spectrum of chromium was experimentally analyzed in different compounds and compared with previous data. Measurements of whole Kβ spectra were performed with a wavelength dispersive commercial XRF equipment. To study possible effects of the chemical state in the width and position of the main Kβ 1,3 line, high resolution measurements were also performed. In the latter measurements, a spectrometer based on a backdiffracting crystal analyzer with spherical focalization and synchrotron radiation monochromatic excitation was used. Kβ 1,3 line shifts in relation to metallic Cr were observed, both to higher energies (≅+1 eV) for Cr III and to lower energies (≅-0.5 eV) for Cr VI. It was also found that the natural width of CrKβ 1,3 line, the ionization energy of the 3p orbital of Cr, and the relative intensities of Kβ″ and Kβ 2,5 lines with respect to the main Kβ 1,3 line increase as the oxidation state increases. The use of these features as an index for chemical state analysis is discussed.

  3. A comparison of H-alpha intensity and radio wave scattering on eight low-latitude lines of sight

    NASA Technical Reports Server (NTRS)

    Spangler, Steven R.; Reynolds, Ronald J.

    1990-01-01

    Radio scattering and H-alpha measurements for eight sources in Cygnus are compared. The diameter of the radio scattering disk at 1 GHz is found to be correlated with emission measure as determined from the H-alpha measurements, and that strong radio scattering characterized by a diameter of about 30 milliarcsec is produced in regions with emission measures of about 100/cm exp 6 pc or less. The slope of diameter-emission measure correlation is steeper than would be the case if all lines of sight were characterized by the same turbulent outer scale and modulation index. It is suggested that the lines of sight to unscattered or lightly scattered sources traverse only a diffuse medium which is revealed by H-alpha observations at high latitudes. Heavily scattered sources are viewed through an additional component of interstellar H II which has turbulence with different properties.

  4. Line Positions and Intensities in the 2nu2/nu4 Vibrational System of 14NH3 near 5-7 micron

    NASA Astrophysics Data System (ADS)

    Cottaz, C.; Kleiner, I.; Tarrago, G.; Brown, L. R.; Margolis, J. S.; Poynter, R. L.; Pickett, H. M.; Fouchet, T.; Drossart, P.; Lellouch, E.

    2000-10-01

    Line positions and intensities belonging to the vibrational system 2nu2/nu4 of ammonia 14NH3 are measured and analyzed between 1200 and 2200 cm-1 in order to improve the molecular database. For this, laboratory spectra are obtained at 0.006 and 0.011 cm-1 unapodized resolution and with 4% precisions for the intensities using Fourier transform spectrometers located at the Kitt Peak National Observatory and the Jet Propulsion Laboratory. The observed data contain transitions of the nu4 fundamental band near 1626.276(1) and 1627.375(2) cm-1 (for s and a inversion upper states, respectively) and the 2nu2 overtone band near 1597.470(3) and 1882.179(5) cm-1 (for s and a inversion states, respectively). A total of 2345 lines with J'<=15 is assigned from which 2114 line positions with J'<=15 are fitted using an effective rotation-inversion-rotation Hamiltonian to achieve an rms of 0.003 cm-1 with 57 molecular parameters. Over 1200 intensity measurements are modeled to +/-4.7% using 16 terms of the dipole moment expansion. A dyad model is used in order to model all the interactions expected within the 2nu2/nu4 system. The bandstrength of 2nu2 (s <- a), 2nu2 (a <- s) and nu4 (s <- s and a <- a) are estimated to be 6.68(24), 0.201(5) and 116(3) cm-1 atm-1, respectively, at 296 K. The prediction generated by this study is available for planetary studies.

  5. Optimizing TaOx memristor performance and consistency within the reactive sputtering "forbidden region"

    NASA Astrophysics Data System (ADS)

    Lohn, Andrew J.; Stevens, James E.; Mickel, Patrick R.; Marinella, Matthew J.

    2013-08-01

    Standard deposition processes for depositing ReRAM oxides utilize mass flow of reactive gas to control stoichiometry and have difficulty depositing a precisely defined sub-stoichiometry within a "forbidden region" where film properties are discontinuous with mass flow. We show that by maintaining partial pressure within this discontinuous "forbidden region," instead of by maintaining mass flow, we can optimize tantalum oxide device properties and reduce or eliminate the electroforming step. We also show that defining the partial pressure set point as a fraction of the "forbidden region" instead of as an absolute value can be used to improve wafer-to-wafer consistency with minimal recalibration efforts.

  6. Communication: Proper treatment of classically forbidden electronic transitions significantly improves detailed balance in surface hopping.

    PubMed

    Sifain, Andrew E; Wang, Linjun; Prezhdo, Oleg V

    2016-06-01

    Surface hopping is the most popular method for nonadiabatic molecular dynamics. Many have reported that it does not rigorously attain detailed balance at thermal equilibrium, but does so approximately. We show that convergence to the Boltzmann populations is significantly improved when the nuclear velocity is reversed after a classically forbidden hop. The proposed prescription significantly reduces the total number of classically forbidden hops encountered along a trajectory, suggesting that some randomization in nuclear velocity is needed when classically forbidden hops constitute a large fraction of attempted hops. Our results are verified computationally using two- and three-level quantum subsystems, coupled to a classical bath undergoing Langevin dynamics. PMID:27276938

  7. Asymmetric conduction in biological nanopores created by high-intensity, nanosecond pulsing: Inference on internal charge lining the membrane based on a model study

    NASA Astrophysics Data System (ADS)

    Joshi, R. P.; Qiu, H.

    2015-09-01

    Nanosecond, high-intensity electric pulses have been reported to open rectifying pores in biological cell membranes. The present goal is to qualitatively understand and analyze the experimental current-voltage (I-V) data. Here, nanopore transport is probed using a numerical method and on the basis of an analytical model. Our results show that geometric asymmetry in the nanopore would not yield asymmetry in the I-V characteristics. However, positive surface charge lining the pore could produce characteristics that compare well with data from patch-clamp measurements, and a value of ˜0.02 C/m2 is predicted from the numerical calculations.

  8. Dynamic Stark effect and forbidden-transition spectrallineshapes

    SciTech Connect

    Stalnaker, Jason E.; Budker, D.; Freedman, S.J.; Guzman, J.S.; Rochester, S.M.; Yashchuk, V.V.

    2005-12-15

    We report on an experimental and theoretical study of thedynamic (ac) Stark effect on a for bidden transition. A general frameworkfor parameterizing and describing off-resonant ac-Stark shifts ispresented. A model is developed to calculate spectral line shapesresulting from resonant excitation of atoms in an intense standinglight-wave in the presence of off-resonant ac-Stark shifts. The model isused in the analysis and interpretation of a measurement of the ac-Starkshifts of the static-electric-field-induced 6s2 1S0 -->5d6s 3D1transition at 408 nm in atomic Yb. The results are in agreement withestimates of the ac-Stark shift of the transition under the assumptionthat the shift is dominated by that of the 6s2 1S0 ground state. Adetailed description of the experiment and analysis is presented. Abi-product of this work is an ind ependent determination (from thesaturation behavior of the 408-nm transition) of the Stark transitionpolarizability, which is found to be in agreement with our earliermeasurement. This work is part of the ongoing effort aimed at a precisionmeasurement of atomic parity-violation effects in Yb.

  9. Implementation of central venous catheter bundle in an intensive care unit in Kuwait: Effect on central line-associated bloodstream infections.

    PubMed

    Salama, Mona F; Jamal, Wafaa; Al Mousa, Haifa; Rotimi, Vincent

    2016-01-01

    Central line-associated bloodstream infection (CLABSIs) is an important healthcare-associated infection in the critical care units. It causes substantial morbidity, mortality and incurs high costs. The use of central venous line (CVL) insertion bundle has been shown to decrease the incidence of CLABSIs. Our aim was to study the impact of CVL insertion bundle on incidence of CLABSI and study the causative microbial agents in an intensive care unit in Kuwait. Surveillance for CLABSI was conducted by trained infection control team using National Health Safety Network (NHSN) case definitions and device days measurement methods. During the intervention period, nursing staff used central line care bundle consisting of (1) hand hygiene by inserter (2) maximal barrier precautions upon insertion by the physician inserting the catheter and sterile drape from head to toe to the patient (3) use of a 2% chlorohexidine gluconate (CHG) in 70% ethanol scrub for the insertion site (4) optimum catheter site selection. (5) Examination of the daily necessity of the central line. During the pre-intervention period, there were 5367 documented catheter-days and 80 CLABSIs, for an incidence density of 14.9 CLABSIs per 1000 catheter-days. After implementation of the interventions, there were 5052 catheter-days and 56 CLABSIs, for an incidence density of 11.08 per 1000 catheter-days. The reduction in the CLABSI/1000 catheter days was not statistically significant (P=0.0859). This study demonstrates that implementation of a central venous catheter post-insertion care bundle was associated with a reduction in CLABSI in an intensive care area setting.

  10. Ratio of forbidden transition rates in the ground-state configuration of O ii

    NASA Astrophysics Data System (ADS)

    Han, Xiao-Ying; Gao, Xiang; Zeng, De-Ling; Yan, Jun; Li, Jia-Ming

    2012-06-01

    Based on a set of “quasicomplete bases,” using the large-scale multiconfiguration Dirac-Fock (MCDF) method, we calculate the forbidden electric quadrupole (E2) and magnetic dipole (M1) transition rates of the transitions 2D5/2,3/2o→4S3/2o of the O ii ground state considering the quantum electrodynamics (QED) corrections. Our calculations demonstrate that the Breit interactions are most important among all the QED corrections. The calculated E2 and M1 transition rates converge in a systematical and uniform manner with the extending orbital basis and the calculation uncertainty of 2.5% is achieved by considering the valence- and core-excitation correlations totally. With the converged transition rates, a value of the intensity ratio between the two transitions in high-electron-density limit in planetary nebulas is given, that is, r(∞)=0.363±0.009, which is within the overlap of the different observations and with the least uncertainty up to now. In addition, the E2 and M1 transition rates of two transitions 2P3/2,1/2o→4S3/2o of O ii ground state and the ratio between the two transition rates in high-electron-density limit are calculated and compared with the previous results.

  11. Intramolecular vibrational relaxation and forbidden transitions in the SEP spectrum of acetylene

    SciTech Connect

    Jonas, D.M.; Solina, S.A.B.; Rajaram, B.; Silbey, R.J.; Field, R.W. ); Yamanouchi, K.; Tsuchiya, S. )

    1992-08-15

    {ital {tilde A}} {sup 1}{ital A}{sub {ital u}}{r arrow}{ital {tilde X}} {sup 1{Sigma}}{sub {ital g}}{sup +} SEP spectra of acetylene near {ital E}{sub VIB}=7000 cm{sup {minus}1} show that Darling--Dennison resonance between the {ital cis}- and {ital trans}-bending vibrations is the {ital first} {ital step} in a series of anharmonic resonances which can transfer nearly all the vibrational energy out of the Franck--Condon bright states at higher energy. In addition to allowed {vert bar}{Delta}{ital K}{vert bar}{equivalent to}{vert bar}{ital K}{prime}{minus}l{double prime}{vert bar}=1 rotational transitions, nominally forbidden {vert bar}{Delta}{ital K}{vert bar}=0,2,3 rotational transitions have also been observed due to axis-switching and rotational-l-resonance. Although the range of detectable fluorescence dips is only about 30, the range of detectable SEP intensities in these spectra is probably about 500.

  12. Searches for Rare or Forbidden Semileptonic Charm Decays

    SciTech Connect

    Lees, J.P.

    2011-08-15

    We present searches for rare or forbidden charm decays of the form X{sub c}{sup +} {yields} h{sup {+-}}{ell}{sup {-+}}{ell}{sup ({prime})+}, where X{sub c}{sup +} is a charm hardron (D{sup +}, D{sub s}{sup +}, or {Lambda}{sub c}{sup +}), h{sup {+-}} is a pion, kaon, or proton, and {ell}{sup ({prime}){+-}} is an electron or muon. The analysis is based on 384 fb{sup -1} of e{sup +}e{sup -} annihilation data collected at or close to the {Upsilon}(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the 35 decay modes that are investigated. We establish 90% confidence-level upper limits on the branching fractions between 1 x 10{sup -6} and 44 x 10{sup -6} depending on the channel. In most cases, these results represent either the first limits or significant improvements on existing limits for the decay modes studied.

  13. Shrinking light to allow forbidden transitions on the atomic scale

    NASA Astrophysics Data System (ADS)

    Rivera, Nicholas; Kaminer, Ido; Zhen, Bo; Joannopoulos, John D.; Soljačić, Marin

    2016-07-01

    The diversity of light-matter interactions accessible to a system is limited by the small size of an atom relative to the wavelength of the light it emits, as well as by the small value of the fine-structure constant. We developed a general theory of light-matter interactions with two-dimensional systems supporting plasmons. These plasmons effectively make the fine-structure constant larger and bridge the size gap between atom and light. This theory reveals that conventionally forbidden light-matter interactions—such as extremely high-order multipolar transitions, two-plasmon spontaneous emission, and singlet-triplet phosphorescence processes—can occur on very short time scales comparable to those of conventionally fast transitions. Our findings may lead to new platforms for spectroscopy, sensing, and broadband light generation, a potential testing ground for quantum electrodynamics (QED) in the ultrastrong coupling regime, and the ability to take advantage of the full electronic spectrum of an emitter.

  14. Shrinking light to allow forbidden transitions on the atomic scale.

    PubMed

    Rivera, Nicholas; Kaminer, Ido; Zhen, Bo; Joannopoulos, John D; Soljačić, Marin

    2016-07-15

    The diversity of light-matter interactions accessible to a system is limited by the small size of an atom relative to the wavelength of the light it emits, as well as by the small value of the fine-structure constant. We developed a general theory of light-matter interactions with two-dimensional systems supporting plasmons. These plasmons effectively make the fine-structure constant larger and bridge the size gap between atom and light. This theory reveals that conventionally forbidden light-matter interactions--such as extremely high-order multipolar transitions, two-plasmon spontaneous emission, and singlet-triplet phosphorescence processes--can occur on very short time scales comparable to those of conventionally fast transitions. Our findings may lead to new platforms for spectroscopy, sensing, and broadband light generation, a potential testing ground for quantum electrodynamics (QED) in the ultrastrong coupling regime, and the ability to take advantage of the full electronic spectrum of an emitter. PMID:27418505

  15. Forbidden unique beta-decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2013-12-30

    The measurement of the electron spectrum in beta-decays provides a robust direct determination of the values of neutrino masses. The planned rhenium beta-decay experiment, called the “Microcalorimeter Arrays for a Rhenium Experiment” (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which is expected to collect data in a near future. In this contribution we discuss the spectrum of emitted electrons close to the end point in the case of the first unique forbidden beta-decay of {sup 79}Se, {sup 107}Pd and {sup 187}Re. It is found that the p{sub 3/2}-wave emission dominates over the s{sub 1/2}-wave. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed beta-decay of {sup 3}H.

  16. The oxygen red OI 630.0 nm line nightglow intensity as an indicator of atmospheric waves propagation in the mid-latitude ionosphere F2 region

    NASA Astrophysics Data System (ADS)

    Javakhishvili, Giorgi; Didebulidze, Goderdzi; Gudadze, Nikoloz; Toriashvili, Lexo

    2016-04-01

    The behavior of the oxygen red OI 630.0 nm line nightglow intensity under influence of atmospheric gravity waves (AGWs) is considered, taking into account nightly changes of the thermosphere meridional wind by observations from Abastumani (41.75 N; 42.82 E). The vortical type perturbations, which can be in situ excited, are also considered. On the basis of theoretical model, the 630.0 nm line integral intensity variations are estimated taking into account thermosphere wind field changes and atmospheric waves propagation influence on the nighttime ionosphere F2 layer. A possibility of identification of waves propagation from polar and equatorial regions during various helio-geophysical conditions is noted. The cases of detected large scale traveling ionosphere disturbances -TIDs (mostly generated in the polar regions) and traveling atmospheric disturbances -TADs (which can be generated both in polar and equatorial regions) are demonstrated. Acknowledgements: This work has been supported by Shota Rustaveli National Science Foundation Grant no. 31/56.

  17. Anti-screening optically allowed and forbidden collisional excitations in nonthermal astrophysical plasmas

    SciTech Connect

    Hong, Woo-Pyo; Jung, Young-Dae

    2014-08-01

    The influence of nonthermal shielding on the optically allowed and forbidden anti-screening channels for ion-ion collisional excitations is investigated in astrophysical Lorentzian plasmas. The semiclassical trajectory method and effective interaction Hamiltonian are employed to obtain the transition amplitudes, differential cross-sections, and momentum transfer-dependent effective projectile charges for the optically allowed and forbidden excitation channels as functions of the impact parameter, collision energy, Debye radius, and spectral index of nonthermal astrophysical plasmas. It is found that the nonthermal effect suppresses the ion-ion collisional excitation probability in astrophysical Lorentzian plasmas. Additionally, the influence of nonthermal shielding on the optically allowed transition is found to be more significant than that on the optically forbidden transition. The variations of the nonthermal shielding effects on the optically allowed and forbidden anti-screening channels in astrophysical nonthermal plasmas are also discussed.

  18. Permitted and forbidden sets in discrete-time linear threshold recurrent neural networks.

    PubMed

    Yi, Zhang; Zhang, Lei; Yu, Jiali; Tan, Kok Kiong

    2009-06-01

    The concepts of permitted and forbidden sets enable a new perspective of the memory in neural networks. Such concepts exhibit interesting dynamics in recurrent neural networks. This paper studies the basic theories of permitted and forbidden sets of the linear threshold discrete-time recurrent neural networks. The linear threshold transfer function has been regarded as an adequate transfer function for recurrent neural networks. Networks with this transfer function form a class of hybrid analog and digital networks which are especially useful for perceptual computations. Networks in discrete time can directly provide algorithms for efficient implementation in digital hardware. The main contribution of this paper is to establish foundations of permitted and forbidden sets. Necessary and sufficient conditions for the linear threshold discrete-time recurrent neural networks are obtained for complete convergence, existence of permitted and forbidden sets, as well as conditionally multiattractivity, respectively. Simulation studies explore some possible interesting practical applications.

  19. A novel method to determine the electron temperature and density from the absolute intensity of line and continuum emission: application to atmospheric microwave induced Ar plasmas

    NASA Astrophysics Data System (ADS)

    Iordanova, E.; Palomares, J. M.; Gamero, A.; Sola, A.; van der Mullen, J. J. A. M.

    2009-08-01

    An absolute intensity measurement (AIM) technique is presented that combines the absolute measurements of the line and the continuum emitted by strongly ionizing argon plasmas. AIM is an iterative combination of the absolute line intensity-collisional radiative model (ALI-CRM) and the absolute continuum intensity (ACI) method. The basis of ALI-CRM is that the excitation temperature T13 determined by the method of ALI is transformed into the electron temperature Te using a CRM. This gives Te as a weak function of electron density ne. The ACI method is based on the absolute value of the continuum radiation and determines the electron density in a way that depends on Te. The iterative combination gives ne and Te. As a case study the AIM method is applied to plasmas created by torche à injection axiale (TIA) at atmospheric pressure and fixed frequency at 2.45 GHz. The standard operating settings are a gas flow of 1 slm and a power of 800 W; the measurements have been performed at a position of 1 mm above the nozzle. With AIM we found an electron temperature of 1.2 eV and electron density values around 1021 m-3. There is not much dependence of these values on the plasma control parameters (power and gas flow). From the error analysis we can conclude that the determination of Te is within 7% and thus rather accurate but comparison with other studies shows strong deviations. The ne determination comes with an error of 40% but is in reasonable agreement with other experimental results.

  20. Relationship between Fluorescence Intensity of GFP and the Expression Level of Prestin in a Prestin-Expressing Chinese Hamster Ovary Cell Line

    NASA Astrophysics Data System (ADS)

    Iida, Koji; Nagaoka, Tomoyuki; Tsumoto, Kouhei; Ikeda, Katsuhisa; Kumagai, Izumi; Kobayashi, Toshimitsu; Wada, Hiroshi

    Outer hair cells (OHCs) in mammals can elongate and contract at frequencies up to 100kHz in response to changes in their membrane potential. The origin of this unique motility is the motor protein prestin, which is densely packed in the lateral membrane of the OHCs. In a previous work, we constructed a prestin-expressing cell line using Chinese hamster ovary (CHO) cells to obtain a stable supply of prestin. When we research prestin using constructed cells, it is necessary to estimate the expression level of prestin in the cells easily and non-invasively. As the prestin gene and a green fluorescent protein (GFP) gene were introduced into constructed cells using the same vector, the expression level of prestin and fluorescence intensity of GFP are possibly correlated. Since this correlation is not clear, however, in this study, we therefore investigated whether the expression level of prestin evaluated by patch-clamp recording and the fluorescence intensity of GFP obtained from fluorescence images are correlated or not. As a result, it was demonstrated that they were correlated. The expression level of prestin can therefore be evaluated by measuring the fluorescence intensity of GFP.

  1. Noise-benefit forbidden-interval theorems for threshold signal detectors based on cross correlations.

    PubMed

    Mitaim, Sanya; Kosko, Bart

    2014-11-01

    We show that the main forbidden interval theorems of stochastic resonance hold for a correlation performance measure. Earlier theorems held only for performance measures based on mutual information or the probability of error detection. Forbidden interval theorems ensure that a threshold signal detector benefits from deliberately added noise if the average noise does not lie in an interval that depends on the threshold value. We first show that this result holds for correlation for all finite-variance noise and for all forms of infinite-variance stable noise. A second forbidden-interval theorem gives necessary and sufficient conditions for a local noise benefit in a bipolar signal system when the noise comes from a location-scale family. A third theorem gives a general condition for a local noise benefit for arbitrary signals with finite second moments and for location-scale noise. This result also extends forbidden intervals to forbidden bands of parameters. A fourth theorem gives necessary and sufficient conditions for a local noise benefit when both the independent signal and noise are normal. A final theorem derives necessary and sufficient conditions for forbidden bands when using arrays of threshold detectors for arbitrary signals and location-scale noise. PMID:25493756

  2. Forbidden Food Survey: measure of bulimic's anticipated emotional reactions to specific foods.

    PubMed

    Ruggiero, L; Williamson, D; Davis, C J; Schlundt, D G; Carey, M P

    1988-01-01

    The Forbidden Food Survey is an instrument that was designed for use with eating disordered individuals. The first experiment in this study includes a description of the Forbidden Food Survey and the reliability and internal consistency of its scales. The second investigation examined the discriminant validity of the Forbidden Food Survey by comparing the responses of three groups: bulimic binge-purgers, bulimic binge-eaters, and normals. The Forbidden Food Survey was found to differentiate the two bulimic groups on two scales, high caloric foods, medium calorie foods, and milk. As predicted from the anxiety model of bulimia, binge-purgers consistently reported stronger negative emotional responses to these foods than did the other groups. In the third experiment, bulimic binge-purgers were compared on Forbidden Food Survey responses to obese and normal subjects. Again, binge purgers were found to respond with stronger negative responses than obese and normals. These studies support the reliability and discriminant validity of the Forbidden Food Survey with eating disordered individuals.

  3. Compliance with Prevention Practices and their Association with Central Line-Associated Blood Stream Infections in Neonatal Intensive Care Units

    PubMed Central

    Zachariah, Philip; Furuya, E. Yoko; Edwards, Jeffrey; Dick, Andrew; Liu, Hangsheng; Herzig, Carolyn; Pogorzelska-Maziarz, Monika; Stone, Patricia W.; Saiman, Lisa

    2014-01-01

    Background Bundles and checklists have been shown to decrease CLABSIs, but implementation of these practices and association with CLABSI rates have not been described nationally. We describe implementation and levels of compliance with prevention practices in a sample of US Neonatal ICUs and assess their association with CLABSI rates. Methods An online survey assessing infection prevention practices was sent to hospitals participating in National Healthcare Safety Network CLABSI surveillance in October 2011. Participating hospitals permitted access to their NICU CLABSI rates. Multivariable regressions were used to test the association between compliance with NICU specific CLABSI prevention practices and corresponding CLABSI rates. Results Overall, 190 Level II/III and Level III NICUs participated. The majority of NICUs had written policies (84%-93%) and monitored compliance with bundles and checklists (88% - 91%). Reporting ≥ 95% compliance for any of the practices ranged from 50%- 63%. Reporting ≥ 95% compliance with insertion checklist and assessment of daily line necessity were significantly associated with lower CLABSI rates (p<0.05). Conclusions Most NICUs in this national sample have instituted CLABSI prevention policies and monitor compliance, although reporting compliance ≥ 95% was suboptimal. Reporting ≥ 95% compliance with select CLABSI prevention practices was associated with lower CLABSI rates. Further studies should focus on identifying and improving compliance with effective CLABSI prevention practices in neonates. PMID:25087136

  4. Fast electron heating in ultra-intense laser-solid interaction by shifted Kα line fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Martinolli, E.; Koenig, M.; Santos, J. J.; Amiranoff, F.; Baton, S. D.; Batani, D.; Perelli, E.; Scianitti, F.; Gremillet, L.; Rabec, M.; Rousseaux, C.; Hall, T. A.; Key, M. H.; MacKinnon, A. J.; Koch, J. A.; Freeman, R. R.; Snavely, R. A.; King, J. A.; Andersen, C.; Hill, J. M.; Stephens, R. B.; Cowan, T. E.; Ng, A.; Ao, T.

    2002-11-01

    In the context of the fast ignition studies[1], the heating of the dense fuel by fast electrons appears to be one of the most relevant aspects currently investigated [2]. In order to estimate the energy deposition and the efficiency of the fast electron transport in solid targets, we have performed experiments on LULI and RAL high power lasers, at irradiances up to a few 10^19 W/cm^2. Shifted Kα lines from an aluminum fluorescer layer buried at different depths in multilayered targets were detected using a Bragg conical-crystal spectrograph. The results were used to infer the ionization stage of the Al layer. Monte Carlo and hybrid transport codes[3] were used to study fast electron energy release by collisions and ohmic effect. The energy coupling to the target is described within an ionization model for dense matter[4] and compared to the experimental data. Despite some uncertainties of the modeling, the results give an indication of a deep heating of the target up to 30 eV after propagation in 100 μm Al. [1] M Tabak et al., Phys. of Plasmas 1, 1626 (1994) [2] E Martinolli et al., submitted to PRL, may 2002 [3] L Gremillet et al. Phys. of Plasmas 9, 941, (2002) [4] G Chiu and A Ng, PRE 59, 1024, (1999)

  5. Physical processes in an electron current layer causing intense plasma heating and formation of x-lines

    NASA Astrophysics Data System (ADS)

    Singh, Nagendra; Khazanov, Igor; Wells, B. E.

    2015-05-01

    We study the evolution of an electron current layer (ECL) through its several stages by means of three-dimensional particle-in-cell (PIC) simulations with ion to electron mass ratio M/me = 400. An ECL evolves through the following stages: (i) Electrostatic (ES) current-driven instability (CDI) soon after its formation with half width w about 2 electron skin depth (de), (ii) current disruption in the central part of the ECL by trapping of electrons and generation of anomalous resistivity, (iii) electron tearing instability (ETI) with significantly large growth rates in the lower end of the whistler frequency range, (iv) widening of the ECL and modulation of its width by the ETI, (v) gradual heating of electrons by the CDI-driven ES ion modes create the condition that the electrons become hotter than the ions, (vi) despite the reduced electron drift associated with the current disruption by the CDI, the enhanced electron temperature continues to favor a slow growth of the ion waves reaching nonlinear amplitudes, (vii) the nonlinear ion waves undergo modulation and collapse into localized density cavities containing spiky electric fields like in double layers (DLs), (viii) such spiky electric fields are very effective in further rapid heating of both electrons and ions. As predicted by the electron magnetohydrodynamic (EMHD) theories, the ETI growth rate maximizes at wave numbers in the range 0.4 < kxW < 0.8 where kx is the wave number parallel to the ECL magnetic field and w is the evolving half width of the ECL. The developing ETI generates in-plane currents that support out-of-plane magnetic fields around the emerging x-lines. The ETI and the spiky electrostatic structures are accompanied by fluctuations in the magnetic fields near and above the lower-hybrid (ion plasma) frequency, including the whistler frequency range. We compare our results with experimental results and satellite observation.

  6. High sensitivity cavity ring down spectroscopy of N2O near 1.22 μm: (II) 14N216O line intensity modeling and global fit of 14N218O line positions

    NASA Astrophysics Data System (ADS)

    Tashkun, S. A.; Perevalov, V. I.; Karlovets, E. V.; Kassi, S.; Campargue, A.

    2016-06-01

    In a recent work (Karlovets et al., 2016 [1]), we reported the measurement and rovibrational assignments of more than 3300 transitions belonging to 64 bands of five nitrous oxide isotopologues (14N216O, 14N15N16O, 15N14N16O, 14N218O and 14N217O) in the high sensitivity CRDS spectrum recorded in the 7915-8334 cm-1 spectral range. The assignments were performed by comparison with predictions of the effective Hamiltonian models developed for each isotopologue. In the present paper, the large amount of measurements from our previous work mentioned above and literature are gathered to refine the modeling of the nitrous oxide spectrum in two ways: (i) improvement of the intensity modeling for the principal isotopologue, 14N216O, near 8000 cm-1 from a new fit of the relevant effective dipole moment parameters, (ii) global modeling of 14N218O line positions from a new fit of the parameters of the global effective Hamiltonian using an exhaustive input dataset collected in the literature in the 12-8231 cm-1 region. The fitted set of 81 parameters allowed reproducing near 5800 measured line positions with an RMS deviation of 0.0016 cm-1. The dimensionless weighted standard deviation of the fit is 1.22. As an illustration of the improvement of the predictive capabilities of the obtained effective Hamiltonian, two new 14N218O bands could be assigned in the CRDS spectrum in the 7915-8334 cm-1 spectral range. A line list at 296 K has been generated in the 0-10,700 cm-1 range for 14N218O in natural abundance with a 10-30 cm/molecule intensity cutoff.

  7. Physical processes in an electron current layer causing intense plasma heating and formation of x-lines

    SciTech Connect

    Singh, Nagendra; Wells, B. E.; Khazanov, Igor

    2015-05-15

    We study the evolution of an electron current layer (ECL) through its several stages by means of three-dimensional particle-in-cell (PIC) simulations with ion to electron mass ratio M/m{sub e} = 400. An ECL evolves through the following stages: (i) Electrostatic (ES) current-driven instability (CDI) soon after its formation with half width w about 2 electron skin depth (d{sub e}), (ii) current disruption in the central part of the ECL by trapping of electrons and generation of anomalous resistivity, (iii) electron tearing instability (ETI) with significantly large growth rates in the lower end of the whistler frequency range, (iv) widening of the ECL and modulation of its width by the ETI, (v) gradual heating of electrons by the CDI-driven ES ion modes create the condition that the electrons become hotter than the ions, (vi) despite the reduced electron drift associated with the current disruption by the CDI, the enhanced electron temperature continues to favor a slow growth of the ion waves reaching nonlinear amplitudes, (vii) the nonlinear ion waves undergo modulation and collapse into localized density cavities containing spiky electric fields like in double layers (DLs), (viii) such spiky electric fields are very effective in further rapid heating of both electrons and ions. As predicted by the electron magnetohydrodynamic (EMHD) theories, the ETI growth rate maximizes at wave numbers in the range 0.4 < k{sub x}W < 0.8 where k{sub x} is the wave number parallel to the ECL magnetic field and w is the evolving half width of the ECL. The developing ETI generates in-plane currents that support out-of-plane magnetic fields around the emerging x-lines. The ETI and the spiky electrostatic structures are accompanied by fluctuations in the magnetic fields near and above the lower-hybrid (ion plasma) frequency, including the whistler frequency range. We compare our results with experimental results and satellite observation.

  8. Status of the "ARC", a Quad of High-Intensity Beam Lines at the National Ignition Facility

    SciTech Connect

    Crane, J K; Arnold, P; Beach, R J; Betts, S; Boley, C; Chang, M; Chrisp, M; Clark, W; Dawson, J W; Erlandson, A; Henesian, M; Hernandez, J E; Jovanovic, I; Kanz, V; Key, M; Lucianetti, A; Messerly, M J; Page, R; Rushford, M; Semenov, V; Seppala, L; Siders, C; Stolz, C; Trummer, D J; Williams, W; Wong, J N; Tiebohl, G; Barty, C J

    2006-06-21

    We present the status of plans to commission a short-pulse, quad of beams on the National Ignition Facility (NIF), capable of generating > 10 kJ of energy in 10 ps. These beams will initially provide an advanced radiographic capability (ARC) to generate brilliant, x-ray back-lighters for diagnosing fuel density and symmetry during ignition experiments. A fiber, mode-locked oscillator generates the seed pulse for the ARC beam line in the NIF master oscillator room (MOR). The 200 fs, 1053 nm oscillator pulse is amplified and stretched in time using a chirped-fiber-Bragg grating. The stretched pulse is split to follow two separate beam paths through the chain. Each pulse goes to separate pulse tweakers where the dispersion can be adjusted to generate a range of pulse widths and delays at the compressor output. After further fiber amplification the two pulses are transported to the NIF preamplifier area and spatially combined using shaping masks to form a split-spatial-beam profile that fits in a single NIF aperture. This split beam propagates through a typical NIF chain where the energy is amplified to several kilojoules. A series of mirrors directs the amplified, split beam to a folded grating compressor that is located near the equator of the NIF target chamber. Figure 1 shows a layout of the beam transport and folded compressor, showing the split beam spatial profile. The folder compressor contains four pairs of large, multi-layer-dielectric gratings; each grating in a pair accepts half of the split beam. The compressed output pulse can be 0.7-50 ps in duration, depending on the setting of the pulse tweaker in the MOR. The compressor output is directed to target chamber center using four additional mirrors that include a 9 meter, off-axis parabola. The final optic, immediately following the parabola, is a pair of independently adjustable mirrors that can direct the pair of ARC beams to individual x-ray backlighter targets. The first mirror after the compressor

  9. Overview spectra and axial distribution of spectral line intensities in a high-current vacuum arc with CuCr electrodes

    SciTech Connect

    Lisnyak, M.; Pipa, A. V.; Gorchakov, S. E-mail: weltmann@inp-greifswald.de; Iseni, S.; Franke, St.; Khapour, A.; Methling, R.; Weltmann, K.-D. E-mail: weltmann@inp-greifswald.de

    2015-09-28

    Spectroscopic investigations of free-burning vacuum arcs in diffuse mode with CuCr electrodes are presented. The experimental conditions of the investigated arc correspond to the typical system for vacuum circuit breakers. Spectra of six species Cu I, Cu II, Cu III, Cr I, Cr II, and Cr III have been analyzed in the wavelength range 350–810 nm. The axial intensity distributions were found to be strongly dependent on the ionization stage of radiating species. Emission distributions of Cr II and Cu II can be distinguished as well as the distributions of Cr III and Cu III. Information on the axial distribution was used to identify the spectra and for identification of overlapping spectral lines. The overview spectra and some spectral windows recorded with high resolution are presented. Analysis of axial distributions of emitted light, which originates from different ionization states, is presented and discussed.

  10. Strong excitation intensity dependence of the photoluminescence line shape in GaAs{sub 1-x}Bi{sub x} single quantum well samples

    SciTech Connect

    Mazur, Yu. I.; Dorogan, V. G.; Ware, M. E.; Salamo, G. J.; Schmidbauer, M.; Tarasov, G. G.; Johnson, S. R.; Lu, X.; Yu, S.-Q.; Tiedje, T.

    2013-04-14

    A set of high quality single quantum well samples of GaAs{sub 1-x}Bi{sub x} with bismuth concentrations not exceeding 6% and well widths ranging from 7.5 to 13 nm grown by molecular beam epitaxy on a GaAs substrate at low temperature is studied by means of photoluminescence (PL). It is shown that the PL line shape changes when the exciton reduced mass behavior changes from an anomalous increase (x < 5%) to a conventional decrease (x > 5%). Strongly non-monotonous PL bandwidth dependence on the excitation intensity is revealed and interpreted in terms of optically unresolved contributions from the saturable emission of bound free excitons.

  11. Emission intensity of the λ = 1.54 μm line in ZnO films grown by magnetron sputtering, diffusion doped with Ce, Yb, Er

    SciTech Connect

    Mezdrogina, M. M. Eremenko, M. V.; Smirnov, A. N.; Petrov, V. N.; Terukov, E. I.

    2015-08-15

    The effect of the Er{sup 3+}-ion excitation type on the photoluminescence spectra of crystalline ZnO(ZnO〈Ce, Yb, Er〉) films is determined in the cases of resonant (λ = 532 nm, Er{sup 3+}-ion transition from {sup 4}S{sub 3/2}, {sup 2}H{sub 11/2} levels to {sup 4}I{sub 15/2}) and non-resonant (λ = 325 nm, in the region near the ZnO band-edge emission) excitation. It is shown that resonant excitation gives rise to lines with various emission intensities, characteristic of the Er{sup 3+}-ion intracenter 4f transition with λ = 1535 nm when doping crystalline ZnO films with three rare-earth ions (REIs, Ce, Yb, Er) or with two impurities (Ce, Er) or (Er, Yb), independently of the measurement temperature (T = 83 and 300 K). The doping of crystalline ZnO films with rare-earth impurities (Ce, Yb, Er) leads to the efficient transfer of energy to REIs, a consequence of which is the intense emission of an Er{sup 3+} ion in the IR spectral region at λ{sub max} = 1535 nm. The kick-out diffusion mechanism is used upon the sequential introduction of impurities into semiconductor matrices and during the postgrowth annealing of the ZnO films under study. The crystalline ZnO films doped with Ce, Yb, Er also exhibit intense emission in the visible spectral region at room temperature, which makes them promising materials for optoelectronics.

  12. Design of the axial beam line for the injection of high intensity beams into the Laboratorio Nazionale del Sud superconducting cyclotron

    NASA Astrophysics Data System (ADS)

    Gammino, S.; Ciavola, G.

    1996-03-01

    At Laboratorio Nazionale del Sud the superconducting electron cyclotron resonance source SERSE will be used as injector for the K-800 Superconducting Cyclotron which in the future will provide the intense light ion beams to be used as primary beams for the radioactive beam project EXCYT. The goal is to inject and accelerate a few pμA of fully stripped carbon and oxygen into the cyclotron with an emittance as close as possible to the typical acceptance of the cyclotron, which should be in the order of 50π mm mrad. The study of the beam line has been carried out by taking into account both the phase space growth due to space charge and the aberrations inside the magnets. The design has been based on the results of different codes (TRANSPORT, GIOSP, PARMILA). A few details on the diagnostics will also be given. The assembly of the beam line is scheduled for the summer of 1996, just before the transfer of the source SERSE from Grenoble to Catania.

  13. Mesosphere-thermosphere regions coupling with the lower atmosphere through the inter-annual variations of the hydroxyl OH(8-3) bands, the oxygen 557.7 nm and 630.0 nm lines nightglow intensities

    NASA Astrophysics Data System (ADS)

    Didebulidze, Goderdzi; Javakhishvili, Giorgi; Todua, Maya; Toriashvili, Lekso

    2016-04-01

    The characteristics of the inter-annual/seasonal distributions of the mid-latitude nightglow intensities of the mesopause hydroxyl OH(8-3) bands (maximum luminous layer about 87 km), the thermosphere oxygen green 557.7 nm (main maximum of luminous layer in the lower thermosphere at about 95 km) and the red 630.0 nm line (emitted from the ionosphere F2 region with maximum luminous layer about 230-280 km) intensities are considered by observations from Abastumani (41.75 E; 42.82 E). The observed inter-annual variations of the OH bands and green line, along with the maximal values at spring (March-April) and fall (September-October) equinoxial periods which are noticed also from other regions, exhibit maxima in June as well. The red line intensity mainly tends to decrease at equinoxial months, while it is maximal in summer and is accompanied by relatively small increase in June (compared to May and July). Maximal values of OH band and green line intensities in June are observed both in maximum and minimum phases of solar activity. This is considered as a manifestation of the features of upper and lower atmosphere dynamical coupling of this region of the South Caucasus. Such dynamical coupling can involve the ionosphere F2 region and can be accompanied by relative decrease of the red line intensity in June. It is observed that the increase of OH band and green line intensities is accompanied by the red line intensity decrease at the end of March and beginning of April, which also is considered as a manifestation of lower and upper atmosphere dynamical coupling. Acknowledgements: This work has been supported by Shota Rustaveli National Science Foundation Grants no. 31/56 and 31/81.

  14. The epidemiology of tick-borne haemoparasites as determined by the reverse line blot hybridization assay in an intensively studied cohort of calves in western Kenya

    PubMed Central

    Njiiri, Nyawira E.; Bronsvoort, B. Mark deC.; Collins, Nicola E.; Steyn, Helena C.; Troskie, Milana; Vorster, Ilse; Thumbi, S.M.; Sibeko, Kgomotso P.; Jennings, Amy; van Wyk, Ilana Conradie; Mbole-Kariuki, Mary; Kiara, Henry; Poole, E. Jane; Hanotte, Olivier; Coetzer, Koos; Oosthuizen, Marinda C.; Woolhouse, Mark; Toye, Philip

    2015-01-01

    The development of sensitive surveillance technologies using PCR-based detection of microbial DNA, such as the reverse line blot assay, can facilitate the gathering of epidemiological information on tick-borne diseases, which continue to hamper the productivity of livestock in many parts of Africa and elsewhere. We have employed a reverse line blot assay to detect the prevalence of tick-borne parasites in an intensively studied cohort of indigenous calves in western Kenya. The calves were recruited close to birth and monitored for the presence of infectious disease for up to 51 weeks. The final visit samples from 453 calves which survived for the study period were analyzed by RLB. The results indicated high prevalences of Theileria mutans (71.6%), T. velifera (62.8%), Anaplasma sp. Omatjenne (42.7%), A. bovis (39.9%), Theileria sp. (sable) (32.7%), T. parva (12.9%) and T. taurotragi (8.5%), with minor occurrences of eight other haemoparasites. The unexpectedly low prevalence of the pathogenic species Ehrlichia ruminantium was confirmed by a species-specific PCR targeting the pCS20 gene region. Coinfection analyses of the seven most prevalent haemoparasites indicated that they were present as coinfections in over 90% of the cases. The analyses revealed significant associations between several of the Theileria parasites, in particular T. velifera with Theileria sp. sable and T. mutans, and T. parva with T. taurotragi. There was very little coinfection of the two most common Anaplasma species, although they were commonly detected as coinfections with the Theileria parasites. The comparison of reverse line blot and serological results for four haemoparasites (T. parva, T. mutans, A. marginale and B. bigemina) indicated that, except for the mostly benign T. mutans, indigenous cattle seem capable of clearing infections of the three other, pathogenic parasites to below detectable levels. Although the study site was located across four agroecological zones, there was

  15. Using forbidden ordinal patterns to detect determinism in irregularly sampled time series

    NASA Astrophysics Data System (ADS)

    Kulp, C. W.; Chobot, J. M.; Niskala, B. J.; Needhammer, C. J.

    2016-02-01

    It is known that when symbolizing a time series into ordinal patterns using the Bandt-Pompe (BP) methodology, there will be ordinal patterns called forbidden patterns that do not occur in a deterministic series. The existence of forbidden patterns can be used to identify deterministic dynamics. In this paper, the ability to use forbidden patterns to detect determinism in irregularly sampled time series is tested on data generated from a continuous model system. The study is done in three parts. First, the effects of sampling time on the number of forbidden patterns are studied on regularly sampled time series. The next two parts focus on two types of irregular-sampling, missing data and timing jitter. It is shown that forbidden patterns can be used to detect determinism in irregularly sampled time series for low degrees of sampling irregularity (as defined in the paper). In addition, comments are made about the appropriateness of using the BP methodology to symbolize irregularly sampled time series.

  16. Using forbidden ordinal patterns to detect determinism in irregularly sampled time series.

    PubMed

    Kulp, C W; Chobot, J M; Niskala, B J; Needhammer, C J

    2016-02-01

    It is known that when symbolizing a time series into ordinal patterns using the Bandt-Pompe (BP) methodology, there will be ordinal patterns called forbidden patterns that do not occur in a deterministic series. The existence of forbidden patterns can be used to identify deterministic dynamics. In this paper, the ability to use forbidden patterns to detect determinism in irregularly sampled time series is tested on data generated from a continuous model system. The study is done in three parts. First, the effects of sampling time on the number of forbidden patterns are studied on regularly sampled time series. The next two parts focus on two types of irregular-sampling, missing data and timing jitter. It is shown that forbidden patterns can be used to detect determinism in irregularly sampled time series for low degrees of sampling irregularity (as defined in the paper). In addition, comments are made about the appropriateness of using the BP methodology to symbolize irregularly sampled time series.

  17. Using forbidden ordinal patterns to detect determinism in irregularly sampled time series.

    PubMed

    Kulp, C W; Chobot, J M; Niskala, B J; Needhammer, C J

    2016-02-01

    It is known that when symbolizing a time series into ordinal patterns using the Bandt-Pompe (BP) methodology, there will be ordinal patterns called forbidden patterns that do not occur in a deterministic series. The existence of forbidden patterns can be used to identify deterministic dynamics. In this paper, the ability to use forbidden patterns to detect determinism in irregularly sampled time series is tested on data generated from a continuous model system. The study is done in three parts. First, the effects of sampling time on the number of forbidden patterns are studied on regularly sampled time series. The next two parts focus on two types of irregular-sampling, missing data and timing jitter. It is shown that forbidden patterns can be used to detect determinism in irregularly sampled time series for low degrees of sampling irregularity (as defined in the paper). In addition, comments are made about the appropriateness of using the BP methodology to symbolize irregularly sampled time series. PMID:26931588

  18. Neutral Atomic Hydrogen Gas at Forbidden Velocities in the Galactic Plane

    NASA Astrophysics Data System (ADS)

    Kang, Ji-hyun

    2009-01-01

    In large-scale (l,v) diagrams from surveys of HI 21-cm emission lines, there are many faint wing-like features protruding beyond the velocity boundaries of Galactic rotation (Forbidden-Velocity Wings, FVWs). These are confined within small areas (< 2 deg). Their sizes and high velocities imply that they are associated with violent events. One of the strongest candidates for their origin are the rapidly expanding HI shells of previously unrecognized, old, Galactic SNRs. We have made high-resolution HI observations toward 22 FVWs using the Arecibo 305-m and the Green Bank 100-m telescopes. Some of the Arecibo observations were part of the GALFA (Galactic Arecibo L-band Feed Array) project. Results show that 50-60% of the observed FVWs are likely to be partial expanding shells. Five of these show the clear features of an expanding shell in both individual channel images and position-velocity diagrams. We have investigated a simple model to demonstrate that an expanding shell can generate the various features of the FVWs as seen in position-velocity diagrams. About half of the shell-type FVWs do not have spatially associated early-type stars, and most do not have associated radio continuum features. This suggests that a significant fraction of the FVW population could indeed be the HI shells of old Galactic SNRs that are too faint to be detected in the radio continuum. The other 40-50% of FVWs seem to have cloud-related origins, such as high/intermediate-velocity clouds or halo clouds.

  19. Radiative Rates for Forbidden Transitions in Doubly-Ionized Fe-Peak Elements

    NASA Astrophysics Data System (ADS)

    Fivet, Vanessa; Quinet, P.; Bautista, M.

    2012-05-01

    Accurate and reliable atomic data for lowly-ionized Fe-peak species (Sc, Ti, V, Cr, Mn, Fe, Co, Ni and Cu) are of paramount importance for the analysis of the high resolution astrophysical spectra currently available. The third spectra of several iron group elements have been observed in different galactic sources like Herbig-Haro objects in the Orion Nebula [1] and stars like Eta Carinae [2]. However, forbidden transitions between low-lying metastable levels of doubly-ionized iron-peak ions have been very little investigated so far and radiative rates for those lines remain sparse or inexistent. We are carrying out a systematic study of the electronic structure of doubly-ionized iron-peak elements. The magnetic dipole (M1) and electric quadrupole (E2) transition probabilities are computed using the pseudo-relativistic Hartree-Fock (HFR) code of Cowan [3] and the central Thomas-Fermi-Dirac potential approximation implemented in AUTOSTRUCTURE [4]. This multi-platform approach allows for consistency checks and intercomparison and has proven very successful in the study of the complex Fe-peak species where many different effects contribute [5]. References [1] A. Mesa-Delgado et al., MNRAS 395 (2009) 855 [2] S. Johansson et al., A&A 361 (2000) 977 [3] R.D. Cowan, The Theory of Atomic Structure and Spectra, Berkeley: Univ. California Press (1981) [4] N.R. Badnell, J. Phys. B: At. Mol. Opt. Phys. 30 (1997) 1 [5] M. Bautista et al., ApJ 718 (2010) L189

  20. Forbidden pitches: causes, source optimization, and their role in design rules

    NASA Astrophysics Data System (ADS)

    Apostol, Štefan; Hurley, Paul

    2015-03-01

    Forbidden pitches are the result of unwanted, non-linear effects that limit yield and not always well understood. Yet, as approximations, they are implicitly deployed through design rules. Many believe they result as a consequence of more complicated light sources. We develop an analytical model of aerial image quality as a function of light source. We show the effect is most pronounced for a point light source, the simplest of all. We develop a method to improve print image quality by illumination source optimization, and show promising first results. Additionally, it is shown how design rules capture forbidden pitches unsatisfactorily.

  1. Identification of forbidden vibration-rotation transitions in 15NH3

    NASA Astrophysics Data System (ADS)

    Urban, Š.; D'Cunha, Romola; Narahari Rao, K.

    1984-07-01

    Forbidden Δk - l = 3 vibration-rotation transitions have been observed in the ν4 band of 15NH3. The analysis of these transitions, together with previously published data on the allowed transitions, has made it possible to determine a set of molecular parameters, including for the first time the rotational constant C as well as the centrifugal distortion constants DK and HKKK, which are necessary for the calculation of energy levels. Some weak forbidden transitions in the ν2 band have also been observed.

  2. Low intensity pulsed ultrasound (LIPUS) influences the multilineage differentiation of mesenchymal stem and progenitor cell lines through ROCK-Cot/Tpl2-MEK-ERK signaling pathway.

    PubMed

    Kusuyama, Joji; Bandow, Kenjiro; Shamoto, Mitsuo; Kakimoto, Kyoko; Ohnishi, Tomokazu; Matsuguchi, Tetsuya

    2014-04-11

    Mesenchymal stem cells (MSCs) are pluripotent cells that can differentiate into multilineage cell types, including adipocytes and osteoblasts. Mechanical stimulus is one of the crucial factors in regulating MSC differentiation. However, it remains unknown how mechanical stimulus affects the balance between adipogenesis and osteogenesis. Low intensity pulsed ultrasound (LIPUS) therapy is a clinical application of mechanical stimulus and facilitates bone fracture healing. Here, we applied LIPUS to adipogenic progenitor cell and MSC lines to analyze how multilineage cell differentiation was affected. We found that LIPUS suppressed adipogenic differentiation of both cell types, represented by impaired lipid droplet appearance and decreased gene expression of peroxisome proliferator-activated receptor γ2 (Pparg2) and fatty acid-binding protein 4 (Fabp4). LIPUS also down-regulated the phosphorylation level of peroxisome proliferator-activated receptor γ2 protein, inhibiting its transcriptional activity. In contrast, LIPUS promoted osteogenic differentiation of the MSC line, characterized by increased cell calcification as well as inductions of runt-related transcription factor 2 (Runx2) and Osteocalcin mRNAs. LIPUS induced phosphorylation of cancer Osaka thyroid oncogene/tumor progression locus 2 (Cot/Tpl2) kinase, which was essential for the phosphorylation of mitogen-activated kinase kinase 1 (MEK1) and p44/p42 extracellular signal-regulated kinases (ERKs). Notably, effects of LIPUS on both adipogenesis and osteogenesis were prevented by a Cot/Tpl2-specific inhibitor. Furthermore, effects of LIPUS on MSC differentiation as well as Cot/Tpl2 phosphorylation were attenuated by the inhibition of Rho-associated kinase. Taken together, these results indicate that mechanical stimulus with LIPUS suppresses adipogenesis and promotes osteogenesis of MSCs through Rho-associated kinase-Cot/Tpl2-MEK-ERK signaling pathway. PMID:24550383

  3. Hospital costs of central line-associated bloodstream infections and cost-effectiveness of closed vs. open infusion containers. The case of Intensive Care Units in Italy

    PubMed Central

    2010-01-01

    Objectives The aim was to evaluate direct health care costs of central line-associated bloodstream infections (CLABSI) and to calculate the cost-effectiveness ratio of closed fully collapsible plastic intravenous infusion containers vs. open (glass) infusion containers. Methods A two-year, prospective case-control study was undertaken in four intensive care units in an Italian teaching hospital. Patients with CLABSI (cases) and patients without CLABSI (controls) were matched for admission departments, gender, age, and average severity of illness score. Costs were estimated according to micro-costing approach. In the cost effectiveness analysis, the cost component was assessed as the difference between production costs while effectiveness was measured by CLABSI rate (number of CLABSI per 1000 central line days) associated with the two infusion containers. Results A total of 43 cases of CLABSI were compared with 97 matched controls. The mean age of cases and controls was 62.1 and 66.6 years, respectively (p = 0.143); 56% of the cases and 57% of the controls were females (p = 0.922). The mean length of stay of cases and controls was 17.41 and 8.55 days, respectively (p < 0.001). Overall, the mean total costs of patients with and without CLABSI were € 18,241 and € 9,087, respectively (p < 0.001). On average, the extra cost for drugs was € 843 (p < 0.001), for supplies € 133 (p = 0.116), for lab tests € 171 (p < 0.001), and for specialist visits € 15 (p = 0.019). The mean extra cost for hospital stay (overhead) was € 7,180 (p < 0.001). The closed infusion container was a dominant strategy. It resulted in lower CLABSI rates (3.5 vs. 8.2 CLABSIs per 1000 central line days for closed vs. open infusion container) without any significant difference in total production costs. The higher acquisition cost of the closed infusion container was offset by savings incurred in other phases of production, especially waste management. Conclusions CLABSI results in

  4. The [NeIV] Lines in High Excitation Gaseous Nebulae.

    PubMed

    Aller, L H

    1970-04-01

    The "forbidden" lines of three times ionized neon are among the most precious indicators of electron temperature and excitation. They are also predicted to be among the strongest lines observed in the far ultraviolet spectra of high excitation nebulae. PMID:16591822

  5. Absolute intensities and self-, N2-, and air-broadened Lorentz halfwidths for selected lines in the nu3 band of (C-12)H3D from measurements with a tunable diode laser spectrometer

    NASA Technical Reports Server (NTRS)

    Malathy Devi, V.; Benner, D. C.; Rinsland, C. P.; Smith, M. A. H.; Thakur, K. B.

    1986-01-01

    Absolute intensities and self-, air- and N2-broadened half-widths have been determined for the first time for individual lines in the nu3(A1) band of (C-12)H3D near 7.6 microns from measurements of individual vibration-rotation lines using a tunable diode laser spectrometer. The intensity measurements are believed to be accurate to within three percent. Within experimental uncertainties, equal broadening efficiencies are found for both air and nitrogen. Self-broadened half-widths determined for three transitions yield an average half-width value of 0.803 + or -0.0010/cm/atm at 296 K.

  6. Nitroxyl free radical enhancement of the forbidden singlet oxygen luminescent transition

    SciTech Connect

    Belford, R.E.

    1993-01-01

    Utilizing transient near IR luminescence spectroscopy, nitroxyl free radicals like TEMPO, (2,2,6,6-tetramethyl piperidine-N-oxyl), have been shown to increase the rate of quantum mechanically forbidden O[sub 2]([sup 3][Sigma][sub g][sup [minus

  7. The response of the inductively coupled argon plasma to solvent plasma load: spatially resolved maps of electron density obtained from the intensity of one argon line

    NASA Astrophysics Data System (ADS)

    Weir, D. G. J.; Blades, M. W.

    1994-12-01

    A survey of spatially resolved electron number density ( ne) in the tail cone of the inductively coupled argon plasma (ICAP) is presented: all of the results of the survey have been radially inverted by numerical, asymmetric Abel inversion. The survey extends over the entire volume of the plasma beyond the exit of the ICAP torch; It extends over distances of z = 5-25 mm downstream from the induction coil, and over radial distances of ± 8 mm from the discharge axis. The survey also explores a range of inner argon flow rates ( QIN), solvent plasma load ( Qspl) and r.f. power: moreover, it explores loading by water, methanol and chloroform. Throughout the survey, ne was determined from the intensity of one, optically thin argon line, by a method which assumes that the atomic state distribution function (ASDF) for argon lies close to local thermal equilibrium (LTE). The validity of this assumption is reviewed. Also examined are the discrepancies between ne from this method and ne from Stark broadening measurements. With the error taken into account, the results of the survey reveal how time averaged values of ne in the ICAP respond over an extensive, previously unexplored range of experimental parameters. Moreover, the spatial information lends insight into how the thermal conditions and the transport of energy respond. Overall, the response may be described in terms of energy consumption along the axial channel and thermal pinch within the induction region. The predominating effect depends on the solvent plasma load, the solvent composition, the robustness of the discharge, and the distribution of solvent material over the argon stream.

  8. The Association of State Legal Mandates for Data Submission of Central Line-associated Blood Stream Infections in Neonatal Intensive Care Units with Process and Outcome Measures

    PubMed Central

    Zachariah, Philip; Reagan, Julie; Furuya, E. Yoko; Dick, Andrew; Liu, Hangsheng; Herzig, Carolyn T.A; Pogorzelska-Maziarz, Monika; Stone, Patricia W.; Saiman, Lisa

    2014-01-01

    Objective To determine the association between state legal mandates for data submission of central line-associated blood stream infections (CLABSIs) in neonatal intensive care units (NICUs) with process/outcome measures. Design Cross-sectional study. Participants National sample of level II/III and III NICUs participating in National Healthcare Safety Network (NHSN) surveillance. Methods State mandates for data submission of CLABSIs in NICUs in place by 2011 were compiled and verified with state healthcare-associated infection coordinators. A web-based survey of infection control departments in October 2011 assessed CLABSI prevention practices i.e. compliance with checklist and bundle components (process measures) in ICUs including NICUs. Corresponding 2011 NHSN NICU CLABSI rates (outcome measures) were used to calculate Standardized Infection Ratios (SIR). The association between mandates and process/outcome measures was assessed by multivariable logistic regression. Results Among 190 study NICUs, 107 (56.3%) NICUs were located in states with mandates, with mandates in place for 3 or more years for half. More NICUs in states with mandates reported ≥95% compliance to at least one CLABSI prevention practice (52.3% – 66.4%) than NICUs in states without mandates (28.9% – 48.2%). Mandates were predictors of ≥95% compliance with all practices (OR 2.8; 95% CI 1.4–6.1). NICUs in states with mandates reported lower mean CLABSI rates in the <750gm birth-weight group (2.4 vs. 5.7 CLABSIs/1000 CL-days) but not in others. Mandates were not associated with SIR <1. Conclusions State mandates for NICU CLABSI data submission were significantly associated with ≥95% compliance with CLABSI prevention practices but not with lower CLABSI rates. PMID:25111921

  9. Tracing outflows in the AGN forbidden region with SINFONI

    NASA Astrophysics Data System (ADS)

    Kakkad, D.; Mainieri, V.; Padovani, P.; Cresci, G.; Husemann, B.; Carniani, S.; Brusa, M.; Lamastra, A.; Lanzuisi, G.; Piconcelli, E.; Schramm, M.

    2016-08-01

    Context. Active galactic nucleus (AGN) driven outflows are invoked in numerical simulations to reproduce several observed properties of local galaxies. The z > 1 epoch is of particular interest as it was during this time that the volume averaged star formation and the accretion rate of black holes were at their maximum. Radiatively driven outflows are therefore believed to be common during this epoch. Aims: We aim to trace and characterize outflows in AGN hosts with high mass accretion rates at z > 1 using integral field spectroscopy. We obtain spatially resolved kinematics of the [O iii] λ5007 line in two targets which reveal the morphology and spatial extension of the outflows. Methods: We present SINFONI observations in the J band and the H + K band of five AGNs at 1.2 < z < 2.2. To maximize the chance of observing radiatively driven outflows, our sample was pre-selected based on peculiar values of the Eddington ratio and the hydrogen column density of the surrounding interstellar medium. We observe high velocity (~600-1900 km s-1) and kiloparsec scale extended ionized outflows in at least three of our targets, using [O iii] λ5007 line kinematics tracing the AGN narrow line region. We estimate the total mass of the outflow, the mass outflow rate, and the kinetic power of the outflows based on theoretical models and report on the uncertainties associated with them. Results: We find mass outflow rates of ~1-10 M⊙/yr for the sample presented in this paper. Based on the high star formation rates of the host galaxies, the observed outflow kinetic power, and the expected power due to the AGN, we infer that both star formation and AGN radiation could be the dominant source for the outflows. The outflow models suffer from large uncertainties, hence we call for further detailed observations for an accurate determination of the outflow properties to confirm the exact source of these outflows.

  10. Absolute Rovibrational Intensities of C-12O2-16 Absorption Bands in the 3090-3850/ CM Spectral Region

    NASA Technical Reports Server (NTRS)

    Devi, V. Malathy; Benner, D. Chris; Rinsland, Curtis P.; Smith, Mary Ann H.

    1998-01-01

    A multispectrum nonlinear least-squares fitting technique has been used to determine the absolute intensities for approximately 1500 spectral lines in 36 vibration - rotation bands Of C-12O2-16 between 3090 and 3850/ cm. A total of six absorption spectra of a high- purity (99.995% minimum) natural sample of carbon dioxide were used in the analysis. The spectral data (0.01/cm resolution) were recorded at room temperature and low pressure (1 to 10 Torr) using the McMath-Pierce Fourier transform spectrometer of the National Solar Observatory (NSO) on Kitt Peak. The absorption path lengths for these spectra varied between 24.86 and 385.76 m. The first experimental determination of the intensity of the theoretically predicted 2(nu)(sub 2, sup 2) + nu(sub 3) "forbidden" band has been made. The measured line intensities obtained for each band have been analyzed to determine the vibrational band intensity, S(sub nu), in /cm/( molecule/sq cm) at 296 K, square of the rotationless transition dipole moment |R|(exp 2) in Debye, as well as the nonrigid rotor coefficients. The results are compared to the values listed in the 1996 HITRAN database which are obtained using the direct numerical diagonalization (DND) technique as well as to other published values where available.

  11. Highly Forbidden Transitions in Alkalis: Preparations for a Parity Violation Experiment

    NASA Astrophysics Data System (ADS)

    Oliveira, Claudia

    Preparatory steps for the experimental investigation of the highly forbidden 5s → 6s transition in rubidium using an atom trap and laser cooling are reported. A magneto-optical trap (MOT) has been assembled including saturation spectroscopy and a dichroic vapor laser lock. A frequency-doubled diode laser system has been installed to perform the spectroscopy of the forbidden transition with cold Rb atoms in the trap. The properties of the ns → n's transition in the presence of an external electric field have been investigated theoretically. A first measurement will be exploring the Stark-induced transition amplitude and the very faint magnetic dipole amplitude. The rubidium experiment is a precursor study for a long-term project at TRIUMF, Canada's National Laboratory for nuclear and particle physics, to measure atomic parity violation in the equivalent 7s → 8s transition in francium, the heaviest alkali atom which has no stable isotopes.

  12. Contribution of forbidden orbits in the photoabsorption spectra of atoms and molecules in a magnetic field

    NASA Astrophysics Data System (ADS)

    Matzkin, A.; Dando, P. A.; Monteiro, T. S.

    2003-02-01

    In a previous work [Phys. Rev. A 66, 013410 (2002)], we noted a partial disagreement between quantum R matrix and semiclassical calculations of photoabsorption spectra of molecules in a magnetic field. We show that this disagreement is due to a nonvanishing contribution of processes, which are forbidden according to the usual semiclassical formalism. Formulas to include these processes are obtained by using a refined stationary phase approximation. The resulting higher order in ħ contributions also account for previously unexplained “recurrences without closed orbits.” Quantum and semiclassical photoabsorption spectra for Rydberg atoms and molecules in a magnetic field are calculated and compared to assess the validity of the first-order forbidden orbit contributions.

  13. Probing the Extended Atmosphere and Wind of Betelgeuse with SOFIA-EXES: Exploiting the Forbidden Fe II Ladder

    NASA Astrophysics Data System (ADS)

    Harper, Graham M.; Richter, Matthew; O'Gorman, Eamon; DeWitt, Curtis; Guinan, Edward F.; EXES Instrument Team

    2016-01-01

    Betelgeuse is a proving ground for theories of mass loss from cool massive stars: it has little circumstellar dust and low molecular abundances, but it is still able to drive a massive outflow just like its dusty cousins of later spectral-types. To constrain the physical processes causing mass loss we need to examine the conditions in the wind acceleration zone where most of the required energy is deposited. To study the dynamics and thermodynamics in this zone requires spectrally-resolved line profiles from diagnostics with different excitation energies.Forbidden mid-IR Fe II transitions from within the first three terms, with Texc=540 K, 3,400 K, and 11,700 K, provide just such diagnostics. NASA-DLR SOFIA with the Echelon-Cross-Echelle Spectrograph (EXES) provide the required low water vapor (42,000~ft) and spectral resolution (R=50,000) for two of the transitions, while the 17.94 μm line can be observed with TEXES on NASA's IRTF.We present key spectra from our Cycle 2 SOFIA program, which also enabled us to explore the mid-IR signature of the two cm-radio hot-spots that had recently been reported from eMERLIN interferometry. Our high S/N spectra place tight constraints on the amount of warm chromospheric plasma, and we have resolved the 25.99 μm ground-state line for the first time, showing blue-shifted emission from the outflow. Please note that the nature of the puzzling radio-hot spots are now understood.

  14. Contribution of a pure NCG forbidden process to the Z associated Higgs production

    SciTech Connect

    Bradji, O.; Mebarki, N.

    2012-06-27

    The contribution of the pure NCG forbidden subprocess gg{yields}ZHis calculated. It is shown that the cross section becomes important at the LHC energies and depends strongly on the choice of the noncommutativity parameter. Because of the gluons luminosity inside the proton, it becomes comparable to that of the commutative standard model subprocess qq(bar sign)ZH for reasonable values of the NCG parameter.

  15. Energy transfer enhancement by oxygen perturbation of spin-forbidden electronic transitions in aromatic systems

    NASA Astrophysics Data System (ADS)

    Monguzzi, A.; Tubino, R.; Salamone, M. M.; Meinardi, F.

    2010-09-01

    Triplet-triplet energy transfer in multicomponent organic systems is usually entirely ascribed to a Dexter-type mechanism involving only short-range donor/acceptor interactions. We demonstrate that the presence of molecular oxygen introduces a perturbation to the electronic structure of one of the involved moieties which can induce a large increase in the spin-forbidden transition oscillator strength so that the otherwise negligible Förster contribution dominates the overall energy transfer rate.

  16. A systematic and detailed investigation of radiative rates for forbidden transitions of astrophysical interest in doubly ionized iron peak elements

    NASA Astrophysics Data System (ADS)

    Quinet, Pascal; Fivet, Vanessa; Bautista, Manuel

    2015-08-01

    The knowledge of accurate and reliable atomic data for lowly ionized iron peak elements, from scandium to copper, is of paramount importance for the analysis of the high resolution spectra currently available. The third spectra of several iron group elements have been observed in different galactic sources like Herbig-Haro objects in the Orion Nebula [1] and stars like Eta Carinae [2]. However, forbidden transitions between low-lying metastable levels of doubly ionized species have been little investigated so far and radiative rates for those lines remain sparse or inexistent.In the present contribution, we report on the recent study we have performed concerning the determination of magnetic dipole (M1) and electric quadrupole (E2) transition probabilities in those ions. For the calculations, we have extensively used the pseudo-relativistic Hartree-Fock (HFR) code of Cowan [3] and the central Thomas-Fermi-Dirac potential approximation implemented in AUTOSTRUCTURE [4]. This multi-platform approach allowed us to check the consistency and to assess the accuracy of the results obtained.[1] Mesa-Delgado A. et al., MNRAS 395, 855 (2009)[2] Johansson S. et al., A&A 361, 977 (2000)[3] Cowan R.D., The Theory of Atomic Structure and Spectra, Univ. California Press, Berkeley (1981)[4] Badnell N.R., J. Phys. B: At. Mol. Opt. Phys. 30, 1 (1997)

  17. Ab-Initio Based Computation of Rate Constants for Spin Forbidden Metalloprotein-Substrate Reactions

    NASA Astrophysics Data System (ADS)

    Ozkanlar, Abdullah; Rodriguez, Jorge H.

    2007-03-01

    Some chemical and biochemical reactions are non-adiabatic processes whereby the total spin angular momentum, before and after the reaction, is not conserved. These are named spin- forbidden reactions. The application of ab-initio methods, such as spin density functional theory (SDFT), to the prediction of rate constants is a challenging task of fundamental and practical importance. We apply non-adiabatic transition state theory (NA-TST) in conjuntion with SDFT to predict the rate constant of the spin- forbidden recombination of carbon monoxide with iron tetracarbonyl. To model the surface hopping probability between singlet and triplet states, the Landau-Zener formalism is used. The lowest energy point for singlet-triplet crossing, known as minimum energy crossing point (MECP), was located and used to compute, in a semi-quantum approach, reaction rate constants at 300 K. The predicted rates are in very good agreement with experiment. In addition, we present results for the spin- forbidden ligand binding reactions of iron-containing heme proteins such as myoglobin.

  18. Theoretical studies of spin-forbidden processes within the Breit-Pauli approximation

    NASA Astrophysics Data System (ADS)

    Yarkony, David R.

    1990-01-01

    This program considered the electronic structure aspects of radiative and radiationless decay processes related to the stability and formation of high energy density materials. To accomplish this goal a unique system of electronic structure algorithms, the BROOKLYN programs, was developed. These programs provide advanced capabilities for the study of the electronic structure aspects of spin-forbidden and electronically nonadiabatic processes. The methodology is based exclusively on large scale configuration state function expansions (100000 to 1000000 terms). These methods permit significant contributions to the understanding of radiative and radiationless decay processes. Problems of particular relevance to the high energy density materials program include: (1) a study of the possible stability of the energetic maximum ionicity state (HeH)+ to H-; (2) a study of the spin-forbidden decay mechanism of the model azide system N3H(1A') yields N2(1 Sigma (+) sub g) + NH(X 3Sigma(-)) and finally a study of the decay pathways for the metastable excited state of the helium atom, He(23S), resulting from collisions with other (ground state) helium atoms. Finally a new phase of program development has been initiated focusing on the efficient determination of regions of allowed and avoided crossings of potential energy surfaces using analytic gradient techniques. This program development will provide powerful new tools for the study of spin-forbidden and electronically nonadiabatic processes.

  19. Ultraviolet observations of cool stars. IV - Intensities of Lyman-alpha and Mg II in epsilon Pegasi and epsilon Eridani, and line width-luminosity correlations

    NASA Technical Reports Server (NTRS)

    Mcclintock, W.; Linsky, J. L.; Henry, R. C.; Moos, H. W.

    1975-01-01

    A spectrometer on the Copernicus satellite has been used to confirm the existence of a line width-luminosity relation for the Ly-alpha and Mg II 2800-A chromospheric emission lines in K-type stars by observation of a K2 dwarf (epsilon Eri) and a K2 supergiant (epsilon Peg). Combined with previously reported observations of lines in three K giants (alpha Boo, alpha Tau, and beta Gem), the data are consistent with an identical dependence of line width on absolute visual magnitude for the Ca II K, Ly-alpha, and Mg II 2795-A lines. Surface fluxes of Ly-alpha, Mg II 2800-A, and O V 1218-A (upper limit) for epsilon Eri, and of Mg II 2800-A for epsilon Peg are also compared with values reported previously for the three giant stars.

  20. Speeding up the r-PROCESS. Investigation of First Forbidden β Decays in N>50 Isotopes Near 78Ni

    NASA Astrophysics Data System (ADS)

    Padgett, S.; Grzywacz, R.; Liddick, S. N.; Batchelder, J. C.; Bingham, C.; Darby, I.; Gross, C. J.; Korgul, A.; Królas, W.; Mazzocchi, C.; Piechaczek, A.; Rajabali, M.; Rykaczewski, K.; Winger, J. A.; Zganjar, E.; Unirib Collaboration

    2008-08-01

    The calculation of β decay properties often only includes the Gamow-Teller allowed decays. Theory indicates that nuclei above Z=28, N=50 may need to include first forbidden decays as well in the calculations of β decay properties. An experiment will be conducted at the HRIBF of ORNL to investigate branching ratios of first forbidden decays in 86,88,90,92Br to Kr isotopes since nearly pure Br beams are available at the HRIBF.

  1. Some features of the radial-velocity variations of lines of different intensity in the spectrum of HD 93521. Variability of the stellar wind

    NASA Astrophysics Data System (ADS)

    Rzaev, A. Kh.

    2007-12-01

    CCD spectra taken with the PFES echelle spectrograph of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences are used to perform a detailed study of the variability of the profiles of Hell, H β, and H α lines in the spectrum of HD 93521. The pattern and nature of the variability of the Hell lines are similar to those of weak HeI lines and are due to nonradial pulsations. The period and amplitude of the radial-velocity variations are the same for the blue and red halves of the absorption profile but their phases are opposite. The behavior of the variations of H β and H α hydrogen lines relative to their mean profiles is the same as that of strong HeI line and is due to nonradial pulsations. The period and phase of the radial-velocity oscillations are the same for the blue and red halves of the absorption profile but their amplitude are different. The behavior of the radial-velocity variations of the absorption and emission components of the H α line indicates that the latter also are caused by nonradial pulsations. All this is indicative of the complex structure of the stellar wind in the region of its origin. The behavior of variability and wind kinematics differ in different directions and for different regions of the atmosphere and/or envelope.

  2. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. IV - Intensity variations of the optical emission lines of NGC 5548

    NASA Technical Reports Server (NTRS)

    Dietrich, M.; Kollatschny, W.; Peterson, B. M.; Bechtold, J.; Bertram, R.; Bochkarev, N. G.; Boroson, T. A.; Carone, T. E.; Elvis, M.; Filippenko, A. V.

    1993-01-01

    Measurements of optical emission-line flux variations based on spectra of the Seyfert galaxy NGC 5548 obtained between December 1988 and October 1989 are reported. All of the measured optical emission lines, H-alpha, H-beta, H-gamma, He I 5876, and He II 4686, exhibit the same qualitative behavior as the UV and optical continua, but with short time delays, or lags, which are different for the various lines. Cross-correlation analysis is applied to measure the lags between the various lines and the continuum. Similar lags are found with respect to the UV continuum for H-alpha and H-beta, 17 and 19 d, respectively. The lag for H-gamma is shorter (13 d), only somewhat larger than the lag measured for Ly-alpha (about 10 d). The helium lines respond to continuum variations more rapidly than the hydrogen lines, with lags of about 7 d for He II 4686 and 11 d for He I 5876.

  3. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. II - An intensive study of NGC 5548 at optical wavelengths

    NASA Technical Reports Server (NTRS)

    Peterson, B. M.; Balonek, T. J.; Barker, E. S.; Bechtold, J.; Bertram, R.

    1991-01-01

    A large, international program of ground-based optical spectroscopy and photometry of the variable Seyfert 1 galaxy NGC 5548 undertaken in support of an IUE monitoring campaign is described. This contribution presents the data base and describes the methods used to correct for systematic differences between spectra from different sources. Optical continuum and H-beta emission-line light curves are derived from the spectra. The behavior of the optical continuum is qualitatively the same as the behavior of the ultraviolet continuum. Cross-correlation of the ultraviolet and optical continuum measurements does not reveal any significant lag between them. The h-beta emission-line variations show the same basic pattern as seen in the continuum and ultraviolet emission lines, with H-beta lagging behind the continuum by about 20 days. This is significantly larger than the about 10 day lag deduced for Ly-alpha.

  4. Intensity Frontier Instrumentation

    SciTech Connect

    Kettell S.; Rameika, R.; Tshirhart, B.

    2013-09-24

    The fundamental origin of flavor in the Standard Model (SM) remains a mystery. Despite the roughly eighty years since Rabi asked “Who ordered that?” upon learning of the discovery of the muon, we have not understood the reason that there are three generations or, more recently, why the quark and neutrino mixing matrices and masses are so different. The solution to the flavor problem would give profound insights into physics beyond the Standard Model (BSM) and tell us about the couplings and the mass scale at which the next level of insight can be found. The SM fails to explain all observed phenomena: new interactions and yet unseen particles must exist. They may manifest themselves by causing SM reactions to differ from often very precise predictions. The Intensity Frontier (1) explores these fundamental questions by searching for new physics in extremely rare processes or those forbidden in the SM. This often requires massive and/or extremely finely tuned detectors.

  5. Electron diffraction patterns with thermal diffuse scattering maxima around Kikuchi lines

    NASA Astrophysics Data System (ADS)

    Karakhanyan, R. K.; Karakhanyan, K. R.

    2011-01-01

    Transmission electron diffraction patterns of silicon with thermal diffuse maxima around Kikuchi lines, which are analogs of the maxima of thermal diffuse electron scattering around point reflections, have been recorded. Diffuse maxima are observed only around Kikuchi lines with indices that are forbidden for the silicon structure. The diffraction conditions for forming these maxima are discussed.

  6. Local-field effects and forbidden transitions in C60 solid thin films

    NASA Astrophysics Data System (ADS)

    Li, Dongmei; Velasquez, Steven; Schnatterly, S. E.

    1994-01-01

    We have measured the momentum-dependent inelastic-electron-scattering spectra of C60 solid thin films. These data allow the oscillator strength of dipole-forbidden transitions and the dispersion coefficient of the volume plasmon to be evaluated. In addition, we evaluate the complex molecular polarizability from the dielectric function using a point-dipole model for the local-field effects. The results are consistent with the presence and calculated energies of both dipolar and quadrupolar collective molecular excitations in molecular C60.

  7. Theoretical investigation on dye sensitizer solar cell: Spin-forbidden transition

    SciTech Connect

    Imamura, Yutaka

    2015-12-31

    We studied spin-forbidden transitions of metal polypyridyl sensitizers by two-component relativistic time-dependent density functional theory with the spin-orbit interaction based on Tamm-Dancoff approximation. The singlet-to-triplet transition, which is assigned to a metal-to-ligand charge-transfer type excitation, appears for a phosphine-coordinated Ru(II), DX1. Absorption spectra of the modified DX1 molecules, whose Ru is replaced with Fe and Os, were also calculated for examining the effects of metals on the spin-orbit interaction.

  8. Theoretical investigation on dye sensitizer solar cell: Spin-forbidden transition

    NASA Astrophysics Data System (ADS)

    Imamura, Yutaka

    2015-12-01

    We studied spin-forbidden transitions of metal polypyridyl sensitizers by two-component relativistic time-dependent density functional theory with the spin-orbit interaction based on Tamm-Dancoff approximation. The singlet-to-triplet transition, which is assigned to a metal-to-ligand charge-transfer type excitation, appears for a phosphine-coordinated Ru(II), DX1. Absorption spectra of the modified DX1 molecules, whose Ru is replaced with Fe and Os, were also calculated for examining the effects of metals on the spin-orbit interaction.

  9. Effect of a dimer of nanoparticles on the linewidth of forbidden E2 transitions

    NASA Astrophysics Data System (ADS)

    Guzatov, D. V.; Klimov, V. V.

    2016-07-01

    In the framework of classical electrodynamics we have obtained and investigated analytical expressions for the radiation linewidth of forbidden E2 transitions in an atom located near a dimer of spherical particles. It is shown that the material of particles, their location and size have a significant effect on the linewidth of the E2 transition in the atom. It is found that in the gap between metal spherical nanoparticles, the linewidth of E2 transitions in the atom can take on substantially larger values than in the case of an atom near a single metal nanoparticle.

  10. Prediction of Forbidden Ultraviolet and Visible Emissions in Comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Raghuram, Susarla; Bhardwaj, Anil; Galand, Marina

    2016-02-01

    Remote observation of spectroscopic emissions is a potential tool for the identification and quantification of various species in comets. The CO Cameron band (to trace CO2) and atomic oxygen emissions (to trace H2O and/or CO2, CO) have been used to probe neutral composition in the cometary coma. Using a coupled-chemistry-emission model, various excitation processes controlling the CO Cameron band and different atomic oxygen and atomic carbon emissions have been modeled in comet 67P/Churyumov-Gerasimenko at 1.29 AU (perihelion) and at 3 AU heliocentric distances, which is being explored by ESA's Rosetta mission. The intensities of the CO Cameron band, atomic oxygen, and atomic carbon emission lines as a function of projected distance are calculated for different CO and CO2 volume mixing ratios relative to water. Contributions of different excitation processes controlling these emissions are quantified. We assess how CO2 and/or CO volume mixing ratios with respect to H2O can be derived based on the observed intensities of the CO Cameron band, atomic oxygen, and atomic carbon emission lines. The results presented in this work serve as baseline calculations to understand the behavior of low out-gassing cometary coma and compare them with the higher gas production rate cases (e.g., comet Halley). Quantitative analysis of different excitation processes governing the spectroscopic emissions is essential to study the chemistry of inner coma and to derive neutral gas composition.

  11. Resonance Scattering of Fe XVII X-ray and EUV Lines

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Saba, J. L. R.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Over the years a number of calculations have been carried out to derive intensities of various X-ray and EUV lines in Fe XVII to compare with observed spectra. The predicted intensities have not agreed with solar observations, particularly for the line at 1.5.02 Angstroms; resonance scattering has been suggested as the source for much of the disagreement. The atomic data calculated earlier used seven configurations having n=3 orbitals and the scattering calculations were carried out only for incident energies above the threshold of the highest fine-structure level. These calculations have now been extended to thirteen configurations having n=4 orbitals and the scattering calculations are carried out below as well as above the threshold of the highest fine structure level. These improved calculations of Fe XVII change the intensity ratios compared to those obtained earlier, bringing the optically thin F(15.02)/F(16.78) ratio and several other ratios closer to the observed values. However, some disagreement with the solar observations still persists, even thought the agreement of the presently calculated optically thin F(15.02)/F(15.26) ratio with the experimental results of Brown et al. (1998) and Laming et al. (2000) has improved. Some of the remaining discrepancy is still thought to be the effect of opacity, which is consistent with expected physical conditions for solar sources. EUV intensity ratios are also calculated and compared with observations. Level populations and intensity ratios are calculated, as a function of column density of Fe XVII, in the slab and cylindrical geometries. As found previously, the predicted intensities for the resonance lines at 15.02 and 15.26 Angstroms exhibit initial increases in flux relative to the forbidden line at 17.10 Angstroms and the resonance line at 16.78 Angstroms as optical thickness increases. The same behavior is predicted for the lines at 12.262 and 12.122 Angstroms. Predicted intensities for some of the allowed

  12. Improved visualization of tubes and lines in portable intensive care unit radiographs: a study comparing a new approach to the standard approach.

    PubMed

    Foos, David H; Yankelevitz, David F; Wang, Xiaohui; Berlin, David; Zappetti, Dana; Cham, Matthew; Sanders, Abraham; Parker, Katherine Novak; Henschke, Claudia I

    2011-01-01

    Tube and line interpretation in portable chest radiographs was assessed using a new visualization method. When using the new method, radiologists' interpretation time was reduced by 30% vs. standard modality processing and window and level (23 vs. 33 s). For pulmonary ICU physicians, reading time was essentially unchanged. There was more than a 50% reduction in the use of inferential language in the dictation for both reader groups when using the new method, suggesting greater interpretation confidence.

  13. FT-IR measurements of NH3 in the 1.5 μm region: line positions, intensities and their quantum assignments

    NASA Astrophysics Data System (ADS)

    Sung, K.; Brown, L. R.; Huang, X.; Schwenke, D. W.; Lee, T. J.

    2011-12-01

    As part of an effort to provide a complete set of spectroscopic line parameters of NH3 in the 1.5 μm region, we have analyzed the laboratory spectra recorded at various temperatures (200 - 299 K) with the McMath-Pierce Fourier transform spectrometer (FTS) on Kitt Peak Observatory in Arizona. The integrated sum of observed line strengths is measured to be 4.7×10-19 cm/molecule in the 6300 - 7000 cm-1 region. In this poster, we present line positions and strengths for the lines from four strong bands (2v1, 2v3, v1+v3, v1+2v4 and v3+2v4), which contribute more than 65% of opacity in the region. Lower state energies and quantum assignments determined by constructing combination differences are also presented. A theoretical IR linelist (X. Huang, D. W. Schwenke, and T. J. Lee. J. Chem. Phys., 134, 044320/044321, 2011) built upon the recent HSL-2 potential energy surface (nonadiabatic corrections included) is complementarily used for the quantum assignments. This work will support spectroscopic studies of atmospheres of outer planets, low mass brown dwarfs, and possibly extrasolar planets, in the 1.5 μm region (the H-band), where ammonia is one of significant opacity sources. (Research described in this talk was performed at Jet Propulsion Laboratory, California Institute of Technology, and was supported by the Planetary Atmospheric Research Program under the National Aeronautics and Space Administration. The AMES group acknowledges support from the NASA APRA & Herschel GO Program, and X.H. acknowledges the support by NASA/SETI Institute Co-operative Agreement.)

  14. Dual-wavelength in-line phase-shifting interferometry based on two dc-term-suppressed intensities with a special phase shift for quantitative phase extraction.

    PubMed

    Xu, Xiaoqing; Wang, Yawei; Xu, Yuanyuan; Jin, Weifeng

    2016-06-01

    To efficiently promote the phase retrieval in quantitative phase imaging, a new approach of quantitative phase extraction is proposed based on two intensities with dual wavelength after filtering the corresponding dc terms for each wavelength, in which a special phase shift is used. In this approach, only the combination of the phase-shifting technique and subtraction procedures is needed, and no additional algorithms are required. The thickness of the phase object can be achieved from the phase image, which is related to the synthetic beat wavelength. The feasibility of this method is verified by the simulated experiments of the optically transparent objects. PMID:27244381

  15. Forbidden phonon: Dynamical signature of bond symmetry breaking in the iron chalcogenides

    NASA Astrophysics Data System (ADS)

    Fobes, David M.; Zaliznyak, Igor A.; Tranquada, John M.; Xu, Zhijun; Gu, Genda; He, Xu-Gang; Ku, Wei; Zhao, Yang; Matsuda, Masaaki; Garlea, V. Ovidiu; Winn, Barry

    2016-09-01

    Investigation of the inelastic neutron scattering spectra in Fe1 +yTe1 -xSex near a signature wave vector Q =(1 ,0 ,0 ) for the bond-order wave (BOW) formation of parent compound Fe1 +yTe [D. Fobes et al., Phys. Rev. Lett. 112, 187202 (2014), 10.1103/PhysRevLett.112.187202] reveals an acoustic-phonon-like dispersion present in all structural phases. While a structural Bragg peak accompanies the mode in the low-temperature phase of Fe1 +yTe , it is absent in the high-temperature tetragonal phase, where Bragg scattering at this Q is forbidden by symmetry. Notably, this mode is also observed in superconducting FeTe0.55Se0.45 , where structural and magnetic transitions are suppressed, and no BOW has been observed. The presence of this "forbidden" phonon indicates that the lattice symmetry is dynamically or locally broken by magneto-orbital BOW fluctuations, which are strongly coupled to lattice in these materials.

  16. Plant species forbidden in health food and their toxic constituents, toxicology and detoxification.

    PubMed

    Xu, Xi-Lin; Shang, Yu; Jiang, Jian-Guo

    2016-02-01

    Many plants with pharmacological efficacies are widely used as ingredients in so-called "health foods", but many of them are toxic. In order to ensure the safety of "health food", the Chinese Ministry of Health has listed 59 materials that are forbidden from being used in health food and are called health food forbidden species (HFFS). This review focuses on 47 plants among the HFFS to discuss research regarding their pharmacology, toxicology, and detoxification methods. According to the literature published in the last 2 decades, the main constituents and the pharmacology of such plants are described here, especially their toxic constituents and toxicology. The toxicity mechanisms of several typical toxic components from the 47 plants are outlined and some effective detoxification methods are introduced. Although all HFFS are poisonous, they are considered to be useful in the treatment of many diseases. How to keep their pharmacological effects and at the same time decrease their toxicity is a great challenge. In the future, more attention should be paid to the application of modern science and technology in the exploration of the toxicology and detoxification of HFFS.

  17. Absolute number density calibration of the absorption by ground-state lead atoms of the 283. 3-nm resonance line from a high-intensity lead hollow cathode lamp and the calculated effect of argon pressures

    SciTech Connect

    Simons, J.W.; McClean, R.E. ); Oldenborg, R.C. )

    1991-03-21

    The absolute number density calibration for the absorption by ground-state lead atoms of the 283.3-nm resonance line from a high-intensity lead hollow cathode lamp (Photron superlamp) is determined and found to be the same as that of a standard hollow cathode lamp. Comparisons of the calibrations to theoretical calculations are found to be quite satisfactory. The effects of argon pressures in the absorption cell on the calibration are examined theoretically by using a simple Lorentzian broadening and shifting model. These calculations show the expected reduction in sensitivity and increasing linearity of Beer-Lambert plots with increasing argon pressure.

  18. Optimizing TaO{sub x} memristor performance and consistency within the reactive sputtering “forbidden region”

    SciTech Connect

    Lohn, Andrew J.; Stevens, James E.; Mickel, Patrick R.; Marinella, Matthew J.

    2013-08-05

    Standard deposition processes for depositing ReRAM oxides utilize mass flow of reactive gas to control stoichiometry and have difficulty depositing a precisely defined sub-stoichiometry within a “forbidden region” where film properties are discontinuous with mass flow. We show that by maintaining partial pressure within this discontinuous “forbidden region,” instead of by maintaining mass flow, we can optimize tantalum oxide device properties and reduce or eliminate the electroforming step. We also show that defining the partial pressure set point as a fraction of the “forbidden region” instead of as an absolute value can be used to improve wafer-to-wafer consistency with minimal recalibration efforts.

  19. Electron-impact excitation of Ni II. Collision strengths and effective collision strengths for low-lying fine-structure forbidden transitions

    NASA Astrophysics Data System (ADS)

    Cassidy, C. M.; Ramsbottom, C. A.; Scott, M. P.; Burke, P. G.

    2010-04-01

    Context. Considerable demand exists for electron excitation data for ion{Ni}{ii}, since lines from this abundant ion are observed in a wide variety of laboratory and astrophysical spectra. The accurate theoretical determination of these data can present a significant challenge however, due to complications arising from the presence of an open 3d-shell in the description of the target ion. Aims: In this work we present collision strengths and Maxwellian averaged effective collision strengths for the electron-impact excitation of ion{Ni}{ii}. Attention is concentrated on the 153 forbidden fine-structure transitions between the energetically lowest 18 levels of ion{Ni}{ii}. Effective collision strengths have been evaluated at 27 individual electron temperatures ranging from 30-100 000 K. To our knowledge this is the most extensive theoretical collisional study carried out on this ion to date. Methods: The parallel R-matrix package RMATRX II has recently been extended to allow for the inclusion of relativistic effects. This suite of codes has been utilised in the present work in conjunction with PSTGF to evaluate collision strengths and effective collision strengths for all of the low-lying forbidden fine-structure transitions. The following basis configurations were included in the target model - 3d9, 3d84s, 3d84p, 3d74s2 and 3d74s4p - giving rise to a sophisticated 295 jj-level, 1930 coupled channel scattering problem. Results: Comprehensive comparisons are made between the present collisional data and those obtained from earlier theoretical evaluations. While the effective collision strengths agree well for some transitions, significant discrepancies exist for others. Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/513/A55

  20. Evanescent waves in high numerical aperture aplanatic solid immersion microscopy: effects of forbidden light on subsurface imaging.

    PubMed

    Yurt, Abdulkadir; Uyar, Aydan; Cilingiroglu, T Berkin; Goldberg, Bennett B; Ünlü, M Selim

    2014-04-01

    The collection of light at very high numerical aperture allows detection of evanescent waves above the critical angle of total internal reflection in solid immersion lens microscopy. We investigate the effect of such evanescent modes, so-called forbidden light, on the far-field imaging properties of an aplanatic solid immersion microscope by developing a dyadic Green's function formalism in the context of subsurface semiconductor integrated circuit imaging. We demonstrate that the collection of forbidden light allows for sub-diffraction spatial resolution and substantial enhancement of photon collection efficiency albeit inducing wave-front discontinuities and aberrations.

  1. A spatially encoded dose difference maximal intensity projection map for patient dose evaluation: A new first line patient quality assurance tool

    SciTech Connect

    Hu Weigang; Graff, Pierre; Boettger, Thomas; Pouliot, Jean; and others

    2011-04-15

    Purpose: To develop a spatially encoded dose difference maximal intensity projection (DD-MIP) as an online patient dose evaluation tool for visualizing the dose differences between the planning dose and dose on the treatment day. Methods: Megavoltage cone-beam CT (MVCBCT) images acquired on the treatment day are used for generating the dose difference index. Each index is represented by different colors for underdose, acceptable, and overdose regions. A maximal intensity projection (MIP) algorithm is developed to compress all the information of an arbitrary 3D dose difference index into a 2D DD-MIP image. In such an algorithm, a distance transformation is generated based on the planning CT. Then, two new volumes representing the overdose and underdose regions of the dose difference index are encoded with the distance transformation map. The distance-encoded indices of each volume are normalized using the skin distance obtained on the planning CT. After that, two MIPs are generated based on the underdose and overdose volumes with green-to-blue and green-to-red lookup tables, respectively. Finally, the two MIPs are merged with an appropriate transparency level and rendered in planning CT images. Results: The spatially encoded DD-MIP was implemented in a dose-guided radiotherapy prototype and tested on 33 MVCBCT images from six patients. The user can easily establish the threshold for the overdose and underdose. A 3% difference between the treatment and planning dose was used as the threshold in the study; hence, the DD-MIP shows red or blue color for the dose difference >3% or {<=}3%, respectively. With such a method, the overdose and underdose regions can be visualized and distinguished without being overshadowed by superficial dose differences. Conclusions: A DD-MIP algorithm was developed that compresses information from 3D into a single or two orthogonal projections while hinting the user whether the dose difference is on the skin surface or deeper.

  2. Favorable outcome in infants with AML after intensive first- and second-line treatment: an AML-BFM study group report.

    PubMed

    Creutzig, U; Zimmermann, M; Bourquin, J-P; Dworzak, M N; Kremens, B; Lehrnbecher, T; von Neuhoff, C; Sander, A; von Stackelberg, A; Schmid, I; Starý, J; Steinbach, D; Vormoor, J; Reinhardt, D

    2012-04-01

    Infants <1 year of age have a high prevalence of prognostically unfavorable leukemias and a presumed susceptibility to treatment-related toxicities. A total of 125 infants with acute myeloid leukemia (AML) were treated in studies AML-BFM-98 (n = 59) and -2004 (n = 66). Treatment regimens of both studies were comparable, consisting of intensive induction followed by four courses (mainly high-dose cytarabine and anthracyclines). Allogeneic-hematopoietic stem-cell-transplantation (allo-HSCT) in 1st remission was optional for high-risk (HR) patients. Most infants (120/125=96%) were HR patients according to morphological, cytogenetic/molecular genetic and response criteria. Five-year overall survival was 66 ± 4%, and improved from 61 ± 6% in study-98 to 75 ± 6% in study-2004 (P(logrank) 0.14) and event-free survival rates were 44 ± 6% and 51 ± 6% (P(logrank) 0.66), respectively. Results in HR infants were similar to those of older HR children (1-<2- or 2-<10-year olds, P(logrank) 0.90 for survival). Survival rates of HSCT in 1st remission, initial partial response and after relapse were high (13/14, 2/8 and 20/30 patients, respectively). The latter contributes to excellent 5-year survival after relapse (50±8%). Despite more severe infections and pulmonary toxicities in infants, treatment-related death rate was identical to that of older children (3%). Our data indicate that intensive frontline and relapse AML treatment is feasible in infants, toxicities are manageable, and outcome is favorable. PMID:21968880

  3. Ionization structure of the Orion Nebula - infrared line observations and models

    SciTech Connect

    Simpson, J.P.; Rubin, R.H.; Erickson, E.F.; Haas, M.R.

    1986-12-01

    Observations of the forbidden O III 52 and 88 microns lines and the forbidden N III 57 microns line have been made at six positions and the forbidden Ne III 36 microns line at four positions in the Orion Nebula to probe its ionization structure. The wavelength of the forbidden Ne III line was measured to be 36.009-36.017 microns. Electron densities and abundance ratios of N(++)/O(++) have been calculated and compared to other radio and optical observations. Detailed one-component and two-component (bar plus halo) spherical models were calculated for exciting stars with effective temperatures of 37,000-40,000 K and log g = 4.0 and 4.5. Both the new IR observations and the visible line measurements of oxygen and nitrogen require Teff of no more than 37,000 K. However, the doubly ionized neon requires a model with Teff of at least 39,000 K, which is more consistent with that inferred from the radio flux or spectral type. These differences in Teff are not due to effects of dust on the stellar radiation field but are probably due to inaccuracies in the assumed stellar spectrum. Neon and nitrogen are approximately solar, but oxygen is half-solar in abundance. From the IR O(++) lines, it is concluded that the ionization bar results from an increase in column depth rather than from a local density enhancement. 54 references.

  4. The ionization structure of the Orion Nebula - Infrared line observations and models

    NASA Technical Reports Server (NTRS)

    Simpson, J. P.; Rubin, R. H.; Erickson, E. F.; Haas, M. R.

    1986-01-01

    Observations of the forbidden O III 52 and 88 microns lines and the forbidden N III 57 microns line have been made at six positions and the forbidden Ne III 36 microns line at four positions in the Orion Nebula to probe its ionization structure. The wavelength of the forbidden Ne III line was measured to be 36.009-36.017 microns. Electron densities and abundance ratios of N(++)/O(++) have been calculated and compared to other radio and optical observations. Detailed one-component and two-component (bar plus halo) spherical models were calculated for exciting stars with effective temperatures of 37,000-40,000 K and log g = 4.0 and 4.5. Both the new IR observations and the visible line measurements of oxygen and nitrogen require Teff of no more than 37,000 K. However, the doubly ionized neon requires a model with Teff of at least 39,000 K, which is more consistent with that inferred from the radio flux or spectral type. These differences in Teff are not due to effects of dust on the stellar radiation field but are probably due to inaccuracies in the assumed stellar spectrum. Neon and nitrogen are approximately solar, but oxygen is half-solar in abundance. From the IR O(++) lines, it is concluded that the ionization bar results from an increase in column depth rather than from a local density enhancement.

  5. Influence of the Light Intensity on the layers electrophotographic intensity based on As and Sb chalkogenides

    NASA Astrophysics Data System (ADS)

    Andriesh, A. M.; Buzdugan, A. I.; Shutov, S. D.

    1988-10-01

    Based on dependence of the electrographic sensitivity from the intensity of illumination by an integral and monochromatic light one show that the law of intercompatibility in thin layers based on glasses As_2S_3, alloys of As_2S_3 and Sb_2S_3 and heterostructures Sb_2S_3 and As_2S_3 is not more valid. Underlinear dependences of the lux-ampere characteristics are interpreted based on the Rose model which supposes a great density of localized states of the quasicontinuous and an exponential distribution by energy in a forbidden zone of a semiconductor. Tables 1, Bibliography 5, Illustr. 2

  6. Analysis of the competition between forbidden and hyperfine-induced transitions in Ne-like ions

    NASA Astrophysics Data System (ADS)

    Andersson, Martin; Grumer, Jon; Brage, Tomas; Zou, Yaming; Hutton, Roger

    2016-03-01

    In this work we investigate the decay of the |2 p53 s P30> state in neon-like ions along the isoelectronic sequence ranging from Z =10 to Z =35 . In the absence of a nuclear spin, the magnetic dipole transition to |2 p53 s P31> is the dominating decay channel. However, for isotopes with a nuclear spin, the interaction between the nuclear magnetic dipole moment and the electronic field introduces a mixing of |2 p53 s P31> and |P11> into the |P30> state, which in turn opens up a competing hyperfine-induced electric dipole decay channel to the ground state. This hyperfine-induced transition channel clearly dominates over the magnetic dipole channel for the neutral end of the isoelectronic sequence, when present. We give values for the rates of both these competing channels and discuss how the introduction of the hyperfine-induced transition channel could have a dramatic influence on the spectrum, not only because it introduces a new line, but also since it can substantially decrease the intensity of the magnetic dipole 2 p53 s P30→2 p53 s P31 line and affect the predicted ionization balance in different plasmas.

  7. Is it Possible to Use the Green Coronal Line Instead of X rays to Cancel an Effect of the Coronal Emissivity Deficit in Estimation of the Prominence Total Mass from Decrease of the EUV-corona Intensities?

    NASA Astrophysics Data System (ADS)

    Schwartz, P.; Heinzel, P.; Jejčič, S.; Rybák, J.; Kotrč, P.; Fárník, F.; Kupryakov, Yu. A.; Deluca, E. E.; Golub, L.; Jibben, P. R.; Anzer, U.; Tlatov, A. G..; Guseva, S. A.

    2016-04-01

    Total masses of six quiescent prominences observed from April through June 2011 were estimated using multi-spectral observations (in EUV, X-rays, Hα, and Ca II H). The method for the total mass estimation is based on the fact that the intensity of the EUV solar corona at wavelengths below 912 Å is reduced at a prominence by the absorption in resonance continua (photoionisation) of hydrogen and possibly by helium and subsequently an amount of absorbed radiation is proportional to the column density of hydrogen and helium plasma. Moreover, the deficit of the coronal emissivity in volume occupied by the cool prominence plasma also contributes to the intensity decrease. The observations in X-rays which are not absorbed by the prominence plasma, allow us to separate these two mechanisms from each other. The X-ray observations of XRT onboard the Hinode satellite made with the Al-mesh focal filter were used because the X-ray coronal radiation formed in plasma of temperatures of the order of 106 K was registered and EUV spectral lines occurring in the 193, 211 and 335 Å channels of the Atmospheric Imaging Assembly of the Solar Dynamics Observatory satellite are also formed at such temperatures. Unfortunately, the Al-mesh filter has a secondary peak of the transmittance at around 171 Å which causes a contribution from the EUV corona to the measured data of up to 11 % in the quiet corona. Thus, absorption in prominence plasma influences XRT X-ray data when using the Al-mesh filter. On the other hand, other X-ray XRT filters are more sensitive to plasma of much higher temperatures (log T of the order of 7), thus observations using these filters cannot be used together with the AIA observations in the method for mass estimations. This problem could be solved using observations in the green coronal line instead of X-rays. Absorption of the green coronal line by a prominence plasma is negligible and this line is formed at temperatures of the order of 106 K. We

  8. Photopolymer material sensitized by xanthene dyes for holographic recording using forbidden singlet–triplet electronic transitions

    NASA Astrophysics Data System (ADS)

    Shelkovnikov, Vladimir; Vasiljev, Evgeny; Russkih, Vladimlen; Berezhnaya, Viktoria

    2016-07-01

    A new holographic photopolymer material is developed. The photopolymer material is sensitized by dyes of xanthene and thioxanthene series which contain iodine and bromine heavy atoms. Holographic recording was carried out during excitation of forbidden singlet–triplet electron transitions of dyes. Thioerythrosin triethylammonium was identified as the most effective sensitizer among a number of tested dyes. The spectral absorption area of the singlet–triplet electronic transition of the dye is conveyed in the red spectral range from 600 to 700 nm. The sensitivity of the photopolymer material to radiation with 633 nm wavelength is 180 mJ cm‑2. Optimization of concentration of the main components of the photopolymer compositions was carried out in order to achieve maximum efficiency of holographic recording.

  9. The Amigó paradigm of forbidden/missing patterns: a detailed analysis

    NASA Astrophysics Data System (ADS)

    Rosso, O. A.; Carpi, L. C.; Saco, P. M.; Ravetti, M. G.; Larrondo, H. A.; Plastino, A.

    2012-12-01

    We deal here with the issue of determinism versus randomness in time series (TS), with the goal of identifying their relative importance in a given TS. To this end we extend (i) the use of ordinal patterns based probability distribution functions associated to a TS [C. Bandt and B. Pompe, Phys. Rev. Lett. 88, 174102 (2002)] and (ii) the so-called Amigó paradigm of forbidden/missing patterns [J.M. Amigó et al., Europhys. Lett. 79, 50001 (2007)], to analyze deterministic finite TS contaminated with strong additive noises of different correlation-degree. Useful information on the deterministic component of the original time series is obtained with the help of the so-called causal entropy-complexity plane [O.A. Rosso et al., Phys. Rev. Lett. 99, 154102 (2007)].

  10. Precise determination of the 113Cd fourth-forbidden non-unique β -decay Q value

    NASA Astrophysics Data System (ADS)

    Gamage, N. D.; Bollen, G.; Eibach, M.; Gulyuz, K.; Izzo, C.; Kandegedara, R. M. E. B.; Redshaw, M.; Ringle, R.; Sandler, R.; Valverde, A. A.

    2016-08-01

    Using Penning trap mass spectrometry, we have performed a precise determination of the Q value for the highly forbidden β decay of 113Cd. An independent measurement of the Q value fixes the end-point energy in a fit to the 113Cdβ -decay spectrum. This provides a strong test of systematics for detectors that have observed this decay, such as those developed for β β -decay searches in cadmium and other isotopes. It will also aid in the theoretical description of the β -decay spectrum. The result, Qβ=323.89 (27 ) keV , agrees at the 1.3 σ level with the value obtained from the 2012 Atomic Mass Evaluation [Chin. Phys. C 36, 1603 (2012), 10.1088/1674-1137/36/12/003], but is a factor of almost four more precise. We also report improved values for the atomic masses of 113Cd,113In, and 112Cd.

  11. Generalized laws of refraction that can lead to wave-optically forbidden light-ray fields.

    PubMed

    Courtial, Johannes; Tyc, Tomáš

    2012-07-01

    The recent demonstration of a metamaterial phase hologram so thin that it can be classified as an interface in the effective-medium approximation [Science 334, 333 (2011)] has dramatically increased interest in generalized laws of refraction. Based on the fact that scalar wave optics allows only certain light-ray fields, we divide generalized laws of refraction into two categories. When applied to a planar cross section through any allowed light-ray field, the laws in the first category always result in a cross section through an allowed light-ray field again, whereas the laws in the second category can result in a cross section through a forbidden light-ray field.

  12. Resisting temptation: effects of exposure to a forbidden food on eating behaviour.

    PubMed

    Soetens, Barbara; Braet, Caroline; Van Vlierberghe, Leen; Roets, Arne

    2008-07-01

    The study tests existing evidence on the paradoxical effects of exposure to a forbidden snack. Sixty-eight females were assigned randomly to one of two conditions: a temptation group, who were given the instruction to abstain from a favourite snack for 24h while being exposed to it, or a control group, who were given no specific instructions. A further distinction was made between high-restraint/high-disinhibition (n=21), high-restraint/low-disinhibition (n=20) and low-restraint participants (n=27) based on DEBQ subscale scores. After exposure to the foods, all participants were given free access to the food. Participants ate more of the snack after abstinence with exposure. The high-restraint/high-disinhibition group in particular displayed a substantial disinhibition effect. Results indicate that prohibition with exposure may backfire and increase the risk of loss of control over eating behaviour, particularly in at-risk groups of disinhibited restrained eaters.

  13. Multiplex PCR assay for the detection of five meat species forbidden in Islamic foods.

    PubMed

    Ali, Md Eaqub; Razzak, Md Abdur; Hamid, Sharifah Bee Abd; Rahman, Md Mahfujur; Amin, Md Al; Rashid, Nur Raifana Abd; Asing

    2015-06-15

    Food falsification has direct impact on public health, religious faith, fair-trades and wildlife. For the first time, here we described a multiplex polymerase chain reaction assay for the accurate identification of five meat species forbidden in Islamic foods in a single assay platform. Five pairs of species-specific primers were designed targeting mitochondrial ND5, ATPase 6, and cytochrome b genes to amplify 172, 163, 141, 129 and 108 bp DNA fragments from cat, dog, pig, monkey and rat meats, respectively. All PCR products were identified in gel-images and electrochromatograms obtained from Experion Bioanalyzer. Species-specificity checking against 15 important meat and fish and 5 plant species detected no cross-species amplification. Screening of target species in model and commercial meatballs reflected its application to detect target species in process foods. The assay was tested to detect 0.01-0.02 ng DNA under raw states and 1% suspected meats in meatball formulation.

  14. Absolute mass of neutrinos and the first unique forbidden {beta} decay of {sup 187}Re

    SciTech Connect

    Dvornicky, Rastislav; Simkovic, Fedor; Muto, Kazuo; Faessler, Amand

    2011-04-15

    The planned rhenium {beta}-decay experiment, called the ''Microcalorimeter Arrays for a Rhenium Experiment'' (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which will take commissioning data in 2011 and will proceed for 5 years. We present the energy distribution of emitted electrons for the first unique forbidden {beta} decay of {sup 187}Re. It is found that the p-wave emission of electron dominates over the s wave. By assuming mixing of three neutrinos, the Kurie function for the rhenium {beta} decay is derived. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed {beta} decay of {sup 3}H.

  15. Composition determination of quaternary GaAsPN layers from single X-ray diffraction measurement of quasi-forbidden (002) reflection

    SciTech Connect

    Tilli, J.-M. Jussila, H.; Huhtio, T.; Sopanen, M.; Yu, K. M.

    2014-05-28

    GaAsPN layers with a thickness of 30 nm were grown on GaP substrates with metalorganic vapor phase epitaxy to study the feasibility of a single X-ray diffraction (XRD) measurement for full composition determination of quaternary layer material. The method is based on the peak intensity of a quasi-forbidden (002) reflection, which is shown to vary with changing arsenic content for GaAsPN. The method works for thin films with a wide range of arsenic contents and shows a clear variation in the reflection intensity as a function of changing layer composition. The obtained thicknesses and compositions of the grown layers are compared with accurate reference values obtained by Rutherford backscattering spectroscopy combined with nuclear reaction analysis measurements. Based on the comparison, the error in the XRD defined material composition becomes larger with increasing nitrogen content and layer thickness. This suggests that the dominating error source is the deteriorated crystal quality due to the nonsubstitutional incorporation of nitrogen into the crystal lattice and strain relaxation. The results reveal that the method overestimates the arsenic and nitrogen content within error margins of about 0.12 and about 0.025, respectively.

  16. Parity- and spin-forbidden optical transitions of Cr{sup +3} in GdAlO{sub 3}

    SciTech Connect

    Basso, H.C.

    1997-10-01

    In this paper, the electric-dipole transition induced by exchange is used to explain the strong dependence of spin- and parity-forbidden transitions of Cr{sup +3} on the sublattice magnetization of an antiferromagnet host. {copyright} {ital 1997} {ital The American Physical Society}

  17. Devaluation of Forbidden Toys Among Lower Socioeconomic Children as a Function of Severity and Specificity of Threat.

    ERIC Educational Resources Information Center

    Dembroski, Theodore M.; And Others

    A prediction derived from cognitive dissonance theory is that children devalue an attractive but forbidden toy when mild rather than severe threat deters them from playing with it. One study found the opposite effect for lower socioeconomic class children, i.e., a harsh verbal threat produced more devaluation than a mild threat. Since the latter…

  18. Oxygen isotope fractionation during spin-forbidden photolysis of CO2: Relevance to the atmosphere of Mars

    NASA Astrophysics Data System (ADS)

    Lyons, J. R.; Stark, G.; Pack, A.; de Oliveira, N.; Nahon, L.

    2015-12-01

    The oxygen isotope composition of the Martian atmosphere is of interest for comparison with recent MSL SAM results, and to understand the origin of oxygen isotope anomalies (i.e., mass-independent fractionation or MIF) in secondary minerals in SNC meteorites. Our focus here is on spin-forbidden photolysis of CO2, CO2 + hv (>167 nm) → CO(X1S) + O(3P). The spin-forbidden photolysis of CO2 is unusual in the Martian atmosphere because of its high reaction rate from the upper atmosphere (80 km) all the way to the ground. This range of altitudes spans 4 orders of magnitude in atmospheric pressure, and occurs because of the gradual decrease in the CO2 cross sections from 167 to ~200 nm. Previous laboratory photolysis experiments on CO2 in the spin-allowed and spin-forbidden regions have yielded a remarkably large MIF signature (17O excess ~ 100 permil) in O2 product for photolysis at 185 nm. Recent theoretical cross sections for CO2 isotopologues argue for a much smaller MIF signature from spin-forbidden photolysis. Here, we report the results of photolysis experiments on CO2 at the Soleil synchrotron DESIRS beamline. High purity, natural isotope abundance CO2 was placed in a 20 cm photocell with MgF2 windows. Experiments were performed at 3 wavelengths (7% FWHM): 160 nm (spin-allowed), and at 175 nm and 185 nm (spin-forbidden). After VUV exposure, aliquots of the photolyzed CO2 were sent to the Department of Isotope Geology at the University of Goettingen for O isotope analysis. The isotope results show that the spin-allowed photolysis yields normal, mass-dependent fractionation in agreement with earlier work. Photolysis at 175 nm, which is mostly spin-forbidden, yields a small positive (or zero) MIF signature. Photolysis at 185 nm, which is entirely spin-forbidden, yields O2 with a negative MIF signature (D17O ~ -8 to -10 permil). The results at 185 nm disagree in magnitude and sign with the very large positive MIF signature previously reported, and provides support

  19. VizieR Online Data Catalog: Collision Strengths for [Co III] Forbidden Lines - SS5 (Storey+, 2016)

    NASA Astrophysics Data System (ADS)

    Storey, P. J.; Sochi, T.

    2016-04-01

    The data set consists of 105 files which are labeled as 'OMEGAmn_CoIII.dat' where m=1,2,...,14 and n=2,3,...,15 with m

  20. VizieR Online Data Catalog: Collision Strengths for [Co II] Forbidden Lines - SS4 (Storey+, 2016)

    NASA Astrophysics Data System (ADS)

    Storey, P. J.; Zeippen, C. J.; Sochi, T.

    2016-02-01

    The data set consists of 105 files which are labeled as 'OMEGAmn_CoII.dat' where m=1,2,...,14 and n=2,3,...,15 with m

  1. VizieR Online Data Catalog: 3D model for fitting forbidden OI 6300 line (Socas-Navarro, 2015)

    NASA Astrophysics Data System (ADS)

    Socas-Navarro, H.

    2015-04-01

    modelin.mod and modelout.mod contain three-dimensional cubes each column represents the physical stratification of each pixel, with the in and the out suffix referring to the two atmospheric components coexisting with the filling factor. The code manual has details on the file format and the variables stored. (3 data files).

  2. Quantum Cascade Laser Measurements of Line Intensities, N2-, O2- and Ar- Collisional Broadening Coefficients of N2O in the ν3 Band Near 4.5 µm.

    PubMed

    Es-Sebbar, Et-Touhami; Deli, Meriem; Farooq, Aamir

    2016-06-01

    This study deals with precise measurements of absolute line intensities, N2-, O2- and Ar- collisional broadening coefficients of N2O in the P-branch of the ν3 vibrational band near 4.5 µm. Collisional broadening coefficients of N2O-air are derived from the N2- and O2- broadening contributions by considering an ideal atmospheric composition. Studies are performed at room temperature for 10 rotational transitions over 2190-2202 cm(-1) spectral range using a distributed-feedback quantum cascade laser. To retrieve spectroscopic parameters for each individual transition, measured absorption line shape is simulated within Voigt and Galatry profiles. The obtained results compare well with previous experimental data available in the literature: the discrepancies being less than 4% for most of the probed transitions. The spectroscopic data reported here are very useful for the design of sensors used to monitor the abundance of N2O in earth's atmosphere.

  3. Mechanism of biological effects observed in honey bees (Apis mellifera, L. ) hived under extra-high-voltage transmission lines: implications derived from bee exposure to simulated intense electric fields and shocks

    SciTech Connect

    Bindokas, V.P.; Gauger, J.R.; Greenberg, B.

    1988-01-01

    This work explores mechanisms for disturbance of honey bee colonies under a 765 kV, 60-Hz transmission line (electric (E) field = 7 kV/m) observed in previous studies. Proposed mechanisms fell into two categories: direct bee perception of enhanced in-hive E fields and perception of shock from induced currents. The adverse biological effects could be reproduced in simulations where only the worker bees were exposed to shock or to E field in elongated hive entranceways (= tunnels). We now report the results of full-scale experiments using the tunnel exposure scheme, which assesses the contribution of shock and intense E field to colony disturbance. Exposure of worker bees (1400 h) to 60-Hz E fields including 100 kV/m under moisture-free conditions within a nonconductive tunnel causes no deleterious affect on colony behavior. Exposure of bees in conductive (e.g., wet) tunnels produces bee disturbance, increased mortality, abnormal propolization, and possible impairment of colony growth. We propose that this substrate dependence of bee disturbance is the result of perception of shock from coupled body currents and enhanced current densities postulated to exist in the legs and thorax of bees on conductors. Similarly, disturbance occurs when bees are exposed to step-potential-induced currents. At 275-350 nA single bees are disturbed; at 600 nA bees begin abnormal propolization behavior; and stinging occurs at 900 nA. We conclude that biological effects seen in bee colonies under a transmission line are primarily the result of electric shock from induced hive currents. This evaluation is based on the limited effects of E-field exposure in tunnels, the observed disturbance thresholds caused by shocks in tunnels, and the ability of hives exposed under a transmission line to source currents 100-1,000 times the shock thresholds.

  4. Theoretical study on spin-forbidden transitions of osmium complexes by two-component relativistic time-dependent density functional theory

    NASA Astrophysics Data System (ADS)

    Imamura, Yutaka; Kamiya, Muneaki; Nakajima, Takahito

    2016-03-01

    We study spin-forbidden transitions of Os polypyridyl sensitizers by two-component relativistic time-dependent density functional theory with the spin-orbit interaction based on Tamm-Dancoff approximation. The absorption spectra, including spin-forbidden-transition peaks, for the Os complexes are reasonably reproduced in comparison with the experimental ones. The extension of the conjugated lengths in the Os complexes is investigated and found to be effective to enhance photo absorption for spin-allowed transitions as well as spin-forbidden ones. This study provides fruitful information for a design of new dyes in terms of conjugation lengths.

  5. Gufa, a unique cultural ritual--a tale of forbidden sun and a girl

    NASA Astrophysics Data System (ADS)

    Shrestha, Pritisha

    2015-08-01

    Gufa, one of the traditional rituals has been performed in Nepal since time immemorial by an especial indigenous Newar people. Gufa, in its literal translation means cave. Just like in the cave where darkness seeps deep within its wall as the sun’s ray cannot penetrate, in the ritual of Gufa, a young girl who just had her first period is hidden in a dark room for twelve consecutive days. The girl, by strict custom and ritual performance stays in the room, protected from the sun’s light. From her female elders, she also receives informal education on family and societal values and norms.Sun, the reason behind our existence, is forbidden for the girl to observe. This very aspect of purely shunning away from the sun has become the crucial aspect for delving into the explanations offered by cultural astronomy. The present paper would argue that astronomy and astronomy education should not only focus on looking into the future, but also should go back to the ancient civilization to comprehend ritual performance our forefathers had learned from gazing the sky.After twelve days, the girl is carefully brought out to an open space where she sees the forbidden sun and symbolically marries the star via ritual. The logic behind the union after a pure restriction is to protect her sensitive young body and to ward off any harm to her reproductive parts from the sun’s harsh rays.From astronomical point, this logic behind protecting the girl from the effects of then deemed harmful rays should be studied. In ancient times, who with which instruments could have possibly fathom the life-giving sun could harness harmful solar rays. Although it looks like a primitive custom of hiding the girl immediately during her first period, there are logical social, cultural and scientific reasons for doing it even today in modern, urban and among the educated Newar households of Nepal and abroad.The paper would expound the importance of traditional ritual performance and its nexus with

  6. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 8: An intensive HST, IUE, and ground-based study of NGC 5548

    NASA Technical Reports Server (NTRS)

    Korista, K.; Alloin, D.; Barr, P.; Clavel, J.; Cohen, R. D.; Crenshaw, D. M.; Evans, I. N.; Horne, K.; Koratkar, A. P.; Kriss, G. A.

    1994-01-01

    We present the data and initial results from a combined HST/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-89. IUE spectra were obtained once every two days for a period of 74 days beginning on 14 March 1993. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October to 1993 September, although much of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution, we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies. During the HST portion of the monitoring campaign, the 1350 A continuum flux is found to have varied by nearly a factor of two. In other wavebands, the continuum shows nearly identical behavior, except that the amplitude of variability is larger at shorter wavelengths, and the continuum light curves appear to show more short time-scale variability at shorter wavelengths. The broad emission lines also vary in flux, with amplitudes that are slightly smaller than the UV continuum variations and with a small time delay relative to the UV continuum. On the basis of simple time-series analysis of the UV and optical continuum and emission line light curves, we find (1) that the ultraviolet and optical continuum variations are virtually simultaneous

  7. Processes entangling interactions in communities: forbidden links are more important than abundance in a hummingbird–plant network

    PubMed Central

    Vizentin-Bugoni, Jeferson; Maruyama, Pietro Kiyoshi; Sazima, Marlies

    2014-01-01

    Understanding the relative importance of multiple processes on structuring species interactions within communities is one of the major challenges in ecology. Here, we evaluated the relative importance of species abundance and forbidden links in structuring a hummingbird–plant interaction network from the Atlantic rainforest in Brazil. Our results show that models incorporating phenological overlapping and morphological matches were more accurate in predicting the observed interactions than models considering species abundance. This means that forbidden links, by imposing constraints on species interactions, play a greater role than species abundance in structuring the ecological network. We also show that using the frequency of interaction as a proxy for species abundance and network metrics to describe the detailed network structure might lead to biased conclusions regarding mechanisms generating network structure. Together, our findings suggest that species abundance can be a less important driver of species interactions in communities than previously thought. PMID:24552835

  8. Processes entangling interactions in communities: forbidden links are more important than abundance in a hummingbird-plant network.

    PubMed

    Vizentin-Bugoni, Jeferson; Maruyama, Pietro Kiyoshi; Sazima, Marlies

    2014-04-01

    Understanding the relative importance of multiple processes on structuring species interactions within communities is one of the major challenges in ecology. Here, we evaluated the relative importance of species abundance and forbidden links in structuring a hummingbird-plant interaction network from the Atlantic rainforest in Brazil. Our results show that models incorporating phenological overlapping and morphological matches were more accurate in predicting the observed interactions than models considering species abundance. This means that forbidden links, by imposing constraints on species interactions, play a greater role than species abundance in structuring the ecological network. We also show that using the frequency of interaction as a proxy for species abundance and network metrics to describe the detailed network structure might lead to biased conclusions regarding mechanisms generating network structure. Together, our findings suggest that species abundance can be a less important driver of species interactions in communities than previously thought.

  9. Twilight airglow. I - Photoelectrons and forbidden O I 5577-angstrom radiation.

    NASA Technical Reports Server (NTRS)

    Hays, P. B.; Sharp, W. E.

    1973-01-01

    A payload consisting of a number of experiments to study the earth's atmosphere was launched from White Sands on Feb. 8, 1971. The differential photoelectron flux spectrum was measured as a function of altitude. The energy distribution revealed the N2 vibrational structure appearing at 2.8 V, rising to a maximum at 4 eV, decreasing to an 8-volt-wide plateau at 20 V, and then further decreasing. The ion and electron density distributions were measured simultaneously. An optical measurement of forbidden O I 5577-A radiation was made. Both electron impact on atomic oxygen and dissociative recombination of O2(+) were found to produce this emission above 150 km. The recombination rate for the O(1 S) found from a reported nightglow profile is 2.5 plus or minus 1.5 x 10 to the minus 9th cu cm/sec. Between 140 and 120 km, photodissociation is a source of 5577 radiation. Chapman three-body recombination is dominant below 120 km.

  10. A B cell explanation for autoimmune disease: the forbidden clone returns.

    PubMed

    McQueen, Fiona

    2012-04-01

    More than 60 years ago, Burnet first proposed the 'forbidden clone' hypothesis postulating that autoimmune disease arises as a result of persistence of self-reactive clones of lymphocytes that should have been deleted via immune tolerance. These autoreactive clones could effect immune-mediated end-organ damage via peripheral self-antigen recognition. Recent evidence that stretches across the boundaries of many medical specialties supports this proposal, implicating a B cell precursor as the culprit. The success of B cell depleting therapy in rheumatoid arthritis, anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis, polymyositis, lupus and autoimmune diseases as diverse as multiple sclerosis and idiopathic thrombocytopenic purpura supports this proposal. Clonality of B cells and plasma cells has been described in a number of autoimmune disorders and the presence of autoantibodies, which may arise years before the onset of clinical disease, supports the notion of autoreactivity within the B cell lineage. T cell activation within the end-organ would be predicted by cognate B-T cell interactions and resultant tissue inflammation and destruction could produce diverse clinical manifestations dictated by the original specificity of the autoimmune B cell.

  11. Explicit magnification control of self-organizing maps for "forbidden" data.

    PubMed

    Merényi, Erzsébet; Jain, Abha; Villmann, Thomas

    2007-05-01

    In this paper, we examine the scope of validity of the explicit self-organizing map (SOM) magnification control scheme of Bauer et al. (1996) on data for which the theory does not guarantee success, namely data that are n-dimensional, n > or =2, and whose components in the different dimensions are not statistically independent. The Bauer et al. algorithm is very attractive for the possibility of faithful representation of the probability density function (pdf) of a data manifold, or for discovery of rare events, among other properties. Since theoretically unsupported data of higher dimensionality and higher complexity would benefit most from the power of explicit magnification control, we conduct systematic simulations on "forbidden" data. For the unsupported n=2 cases that we investigate, the simulations show that even though the magnification exponent alpha achieved achieved by magnification control is not the same as the desired alpha desired, alpha achieved systematically follows alpha desired with a slowly increasing positive offset. We show that for simple synthetic higher dimensional data information, theoretically optimum pdf matching (alpha achieved = 1) can be achieved, and that negative magnification has the desired effect of improving the detectability of rare classes. In addition, we further study theoretically unsupported cases with real data. PMID:17526344

  12. Vervet monkeys solve a multiplayer "forbidden circle game" by queuing to learn restraint.

    PubMed

    Fruteau, Cécile; van Damme, Eric; Noë, Ronald

    2013-04-22

    In social dilemmas, the ability of individuals to coordinate their actions is crucial to reach group optima. Unless exacted by power or force, coordination in humans relies on a common understanding of the problem, which is greatly facilitated by communication. The lack of means of consultation about the nature of the problem and how to solve it may explain why multiagent coordination in nonhuman vertebrates has commonly been observed only when multiple individuals react instantaneously to a single stimulus, either natural or experimentally simulated, for example a predator, a prey, or a neighboring group. Here we report how vervet monkeys solved an experimentally induced coordination problem. In each of three groups, we trained a low-ranking female, the "provider," to open a container holding a large amount of food, which the providers only opened when all individuals dominant to them ("dominants") stayed outside an imaginary "forbidden circle" around it. Without any human guidance, the dominants learned restraint one by one, in hierarchical order from high to low. Once all dominants showed restraint immediately at the start of the trial, the providers opened the container almost instantly, saving all individuals opportunity costs due to lost foraging time. Solving this game required trial-and-error learning based on individual feedback from the provider to each dominant, and all dominants being patient enough to wait outside the circle while others learned restraint. Communication, social learning, and policing by high-ranking animals played no perceptible role.

  13. Second unique forbidden {beta} decay of {sup 115}In and neutrino mass

    SciTech Connect

    Dvornicky, R.; Simkovic, F.

    2011-12-16

    The measurement of the electron spectrum in {beta} decays close to the end point provides a robust direct determination of the values of neutrino masses. The most sensitive experiments use tritium and rhenium {beta} decays because these transitions have low Q value. Recent measurement with Penning traps established that the {beta} decay of {sup 115}In(9/2{sup +}) to the first excited state of {sup 115}Sn(3/2{sup +}) is a transition with the smallest Q value among {beta} decays. The decay is associated with a change of spin and parity {Delta}J{sup {pi}} = 3{sup +} ({Delta}L = 2, {Delta}S = 1) of nucleus, i.e., classified as unique second forbidden {beta} decay. Our investigation shows that in this transition electrons are predominantly emitted in d{sub 5/2} partial waves. In addition, it is found that the Kurie function associated with this transition near the end point within a good accuracy reflects a behavior the Kurie function of superallowed {beta} transitions.

  14. Gamow-Teller and first-forbidden decays near the r-process paths at N=50, 82, and 126

    NASA Astrophysics Data System (ADS)

    Borzov, I. N.

    2003-02-01

    The β-decay rates of neutron-rich nuclei relevant to the r-process nucleosynthesis are mostly beyond experimental reach. Their predictions demand a self-consistent extrapolation of various nuclear properties away from the experimentally known regions. The allowed transitions approximation commonly used in large-scale microscopic calculations also needs to be revised in different mass regions. The density functional+continuum QRPA approximation to self-consistent calculations of the ground state properties, Gamow-Teller and first-forbidden β-decay transitions of nuclei far from stability is developed. Systematic calculations are performed of the allowed and first-forbidden β-decay rates for the r-process relevant nuclides near the closed neutron shells at N=50,82,126. The importance of first-forbidden decays near Z⩾50, N≈82 and near N=126 is shown. The total β-decay half-lives in the region “east” of the 208Pb are estimated. A comparison with recent experimental data, global calculations, and self-consistent microscopic predictions is presented.

  15. Measurement of Oxygen A Band Line Parameters by Using Modulation Spectroscopy with Higher Harmonic Detection

    NASA Technical Reports Server (NTRS)

    Dharamsi, Amin

    1999-01-01

    Wavelength modulation spectroscopy is used to demonstrate that extremely weak absorption lines can be measured even when these lines suffer from interference from the wings of adjacent stronger lines. It is shown that the use of detection at several harmonics allows such interference to be examined clearly and conveniently. The results of experimental measurements on a weak magnetic dipole driven, spin-forbidden line in the oxygen A band, which experiences interference from the wings of a pair of adjacent lines towards the blue and red regions of line center, are presented. A comparison of the experimental results to theory is given.

  16. Discovery of a narrow line quasar

    NASA Technical Reports Server (NTRS)

    Stocke, J.; Liebert, J.; Maccacaro, T.; Griffiths, R. E.; Steiner, J. E.

    1982-01-01

    A stellar object is reported which, while having X-ray and optical luminosities typical of quasars, has narrow permitted and forbidden emission lines over the observed spectral range. The narrow-line spectrum is high-excitation, the Balmer lines seem to be recombinational, and a redder optical spectrum than that of most quasars is exhibited, despite detection as a weak radio source. The object does not conform to the relationships between H-beta parameters and X-ray flux previously claimed for a large sample of the active galactic nuclei. Because reddish quasars with narrow lines, such as the object identified, may not be found by the standard techniques for the discovery of quasars, the object may be a prototype of a new class of quasars analogous to high-luminosity Seyfert type 2 galaxies. It is suggested that these objects cannot comprise more than 10% of all quasars.

  17. Identification of emission lines in the low-ionization strontium filament near Eta Carinae

    NASA Astrophysics Data System (ADS)

    Hartman, H.; Gull, T.; Johansson, S.; Smith, N.; HST Eta Carinae Treasury Project Team

    2004-05-01

    We have obtained deep spectra from 1640 to 10 100 Å with the Space Telescope Imaging Spectrograph (STIS) of the strontium filament, a largely neutral emission nebulosity lying close to the very luminous star Eta Carinae and showing an uncommon spectrum. Over 600 emission lines, both permitted and forbidden, have been identified. The majority originates from neutral or singly-ionized iron group elements (Sc, Ti, V, Cr, Mn, Fe, Co, Ni). Sr is the only neutron capture element detected. The presence of Sr II, numerous strong Ti II and V II lines and the dominance of Fe I over Fe II are notable discoveries. While emission lines of hydrogen, helium, and nitrogen are associable with other spatial structures at other velocities within the Homunculus, no emission lines from these elements correspond to the spatial structure or velocity of the \\ion{Sr} filament. Moreover, no identified \\ion{Sr} filament emission line requires an ionization or excitation energy above approximately 8 eV. Ionized gas extends spatially along the aperture, oriented along the polar axis of the Homunculus, and in velocity around the strontium filament. We suggest that the strontium filament is shielded from ultraviolet radiation at energies above 8 eV, but is intensely irradiated by the central star at wavelengths longward of 1500 Å. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/419/215

  18. Intense accretion and mass loss of a very low mass young stellar object

    NASA Astrophysics Data System (ADS)

    Fernández, M.; Comerón, F.

    2001-12-01

    We present visible and near-infrared photometry and spectroscopy of LS-RCrA 1, a faint, very late-type object (M 6.5-M 7) seen in the direction of the R Coronae Australis star forming complex. While its emission spectrum shows prominent features of accretion and mass loss typical of young stellar objects, its underlying continuum and photometric properties are puzzling when trying to derive a mass and age based on pre-main sequence evolutionary tracks: the object appears to be far too faint for a young member of the R Coronae Australis complex of its spectral type. We speculate that this may be due to either its evolution along pre-main sequence tracks being substantially altered by the intense accretion, or to a combination of partial blocking and scattering of the light of the object by a nearly edge-on circumstellar disk. The rich emission line spectrum superimposed on the stellar continuum is well explained by an intense accretion process: the Halpha , CaII infrared triplet, and HeI 6678 lines show equivalent widths typical of very active classical T Tauri stars. The near-infrared observations show anomalously weak spectral features and no significant excess emission in the K band, which we tentatively interpret as indicating line filling due to emission in a magnetic accretion funnel flow. At the same time, numerous, strong forbidden optical lines ([OI], [NII] and [SII]) and H2 emission at 2.12 mu m suggest that the object is simultaneously undergoing mass loss, providing another example that shows that mass loss and accretion are closely related processes. Such an intense accretion and mass loss activity is observed for the first time in a young stellar object in the transition region between low mass stars and brown dwarfs, and provides a valuable observational test on the effects of accretion on the evolution of objects with such low masses. Based on observations collected at the European Southern Observatory in La Silla and Cerro Paranal (Chile), in

  19. Spin-forbidden ligand binding to the ferrous-heme group: ab initio and DFT studies.

    PubMed

    Strickland, Nikki; Harvey, Jeremy N

    2007-02-01

    The potential energy surfaces (PESs) and associated energy barriers that characterize the spin-forbidden recombination reactions of the gas-phase ferrous deoxy-heme group with CO, NO, and H2O ligands have been calculated using density functional theory (DFT). The bond energy for binding of O2 has also been calculated. Extensive large basis set CCSD(T) calculations on two small models of the heme group have been used to calibrate the accuracy of different DFT functionals for treating these systems. Pure functionals are shown to overestimate the stability of the low-spin forms of the deoxy-heme model, and to overestimate the binding energy of H2O and CO, whereas hybrid functionals such as B3PW91 and B3LYP yield accurate results. Accordingly, the latter functionals have been used to explore the PESs for binding. CO binding is found to involve a significant barrier of ca. 3 kcal mol-1 due to the need to change from the deoxy-heme quintet ground state to the bound singlet state. Binding of water does not involve a barrier, but the resulting bond is weak and may be further weakened in the protein environment, which should explain why water binding is not usually observed in heme proteins such as myoglobin. NO binding involves a low barrier, which is consistent with observed rapid geminate recombination. The calculated bond energies are in good agreement with previous reported values and in fair agreement with experiment for CO and O2. The value for NO is significantly lower than the experimentally derived bond energy, suggesting that B3LYP is less accurate in this case.

  20. NEUTRON FLUX INTENSITY DETECTION

    DOEpatents

    Russell, J.T.

    1964-04-21

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

  1. Signatures of the non-Maxwellian κ-distributions in optically thin line spectra. I. Theory and synthetic Fe IX-XIII spectra

    NASA Astrophysics Data System (ADS)

    Dudík, J.; Del Zanna, G.; Mason, H. E.; Dzifčáková, E.

    2014-10-01

    Aims: We investigate the possibility of diagnosing the degree of departure from the Maxwellian distribution using single-ion spectra originating in astrophysical plasmas in collisional ionization equilibrium. Methods: New atomic data for excitation of Fe ix - Fe xiii are integrated under the assumption of a κ-distribution of electron energies. Diagnostic methods using lines of a single ion formed at any wavelength are explored. Such methods minimize uncertainties from the ionization and recombination rates, as well as the possible presence of non-equilibrium ionization. Approximations to the collision strengths are also investigated. Results: The calculated intensities of most of the Fe ix - Fe xiii EUV lines show consistent behaviour with κ at constant temperature. Intensities of these lines decrease with κ, with the vast majority of ratios of strong lines showing little or no sensitivity to κ. Several of the line ratios, especially involving temperature-sensitive lines, show a sensitivity to κ that is of the order of several tens of per cent, or, in the case of Fe ix, up to a factor of two. Forbidden lines in the near-ultraviolet, visible, or infrared parts of the spectrum are an exception, with smaller intensity changes or even a reverse behaviour with κ. The most conspicuous example is the Fe x 6378.26 Å red line, whose intensity incerases with κ. This line is a potentially strong indicator of departures from the Maxwellian distribution. We find that it is possible to perform density diagnostics independently of κ, with many Fe xi, Fe xii, and Fe xiii line ratios showing strong density-sensitivity and negligible sensitivity to κ and temperature. We also tested different averaging of the collision strengths. It is found that averaging over 0.01 interval in log(E [ Ryd ]) is sufficient to produce accurate distribution-averaged collision strengths Υ(T,κ) at temperatures of the ion formation in ionization equilibrium. Appendices are available in

  2. Luminescence spectroscopy of matrix-isolated atomic manganese: Excitation of the ``forbidden'' a6DJ<-->a6S transitions

    NASA Astrophysics Data System (ADS)

    Collier, Martin A.; Ryan, Maryanne C.; McCaffrey, John G.

    2005-07-01

    Laser-induced excitation spectra recorded for the electric-quadrupole 3d64saDJ6←3d54s2aS5/26 transitions of atomic Mn, allow assignment of the red emission features, previously observed in Mn/RG (RG =Ar, Kr and Xe) matrices with resonance 3d54s4pzP5/26←3d54s2aS5/26 excitation, to the metastable aD9/26 state. Narrow excitation bands recorded for the red site in the Mn /Kr system allow identification of all five spin-orbit levels (J =1/2, 3/2, 5/2, 7/2 and 9/2) in the aD6 state. The coincidence of the lowest energy excitation band and the observed 585.75nm (17072cm-1) emission band of atomic Mn in Kr matrices, yielded a definitive assignment of this emission to a transition from the J =9/2 spin-orbit level. Temperature dependent emission scans lead to the identification of the zero phonon line for the aD9/26→aS5/26 transition at 585.75nm. The identified matrix-shift of +20cm-1 allows an assessment of the extent of the ground state stabilization in the red (2°) site of atomic Mn isolation in solid Kr. Emission produced with direct aD6 state excitation yielded both the 585.75 and 626nm features. The former band arises for Mn atoms occupying the red site—the latter from blue site occupancy in solid Kr. The excitation linewidths recorded for these two sites differ greatly, with the blue site yielding a broad featureless profile, in contrast to the narrow, structured features of the red site. The corresponding red site aDJ6↔aS5/26 transitions in Ar and Xe matrices are broader than in Kr—a difference considered to originate from the site sizes available in these hosts and the interatomic Mn •RG potentials. The millisecond decay times recorded for the red emission bands in the Mn/RG systems are all much shorter than the 3s value predicted for the gas phase aD9/26→aS5/26 transition. This enhancement allows optical pumping of the forbidden aDJ6↔aS6 transitions with low laser powers when atomic manganese is isolated in the solid state. However all the

  3. EC Transmission Line Materials

    SciTech Connect

    Bigelow, Tim S

    2012-05-01

    The purpose of this document is to identify materials acceptable for use in the US ITER Project Office (USIPO)-supplied components for the ITER Electron cyclotron Heating and Current Drive (ECH&CD) transmission lines (TL), PBS-52. The source of material property information for design analysis shall be either the applicable structural code or the ITER Material Properties Handbook. In the case of conflict, the ITER Material Properties Handbook shall take precedence. Materials selection, and use, shall follow the guidelines established in the Materials Assessment Report (MAR). Materials exposed to vacuum shall conform to the ITER Vacuum Handbook. [Ref. 2] Commercial materials shall conform to the applicable standard (e.g., ASTM, JIS, DIN) for the definition of their grade, physical, chemical and electrical properties and related testing. All materials for which a suitable certification from the supplier is not available shall be tested to determine the relevant properties, as part of the procurement. A complete traceability of all the materials including welding materials shall be provided. Halogenated materials (example: insulating materials) shall be forbidden in areas served by the detritiation systems. Exceptions must be approved by the Tritium System and Safety Section Responsible Officers.

  4. Infrared Dual-line Hanle diagnostic of the Coronal Vector Magnetic Field

    NASA Astrophysics Data System (ADS)

    Dima, Gabriel; Kuhn, Jeffrey; Berdyugina, Svetlana

    2016-04-01

    Measuring the coronal vector magnetic field is still a major challenge in solar physics. This is due to the intrinsic weakness of the field (e.g. ~4G at a height of 0.1Rsun above an active region) and the large thermal broadening of coronal emission lines. We propose using concurrent linear polarization measurements of near-infrared forbidden and permitted lines together with Hanle effect models to calculate the coronal vector magnetic field. In the unsaturated Hanle regime both the direction and strength of the magnetic field affect the linear polarization, while in the saturated regime the polarization is insensitive to the strength of the field. The relatively long radiative lifetimes of coronal forbidden atomic transitions implies that the emission lines are formed in the saturated Hanle regime and the linear polarization is insensitive to the strength of the field. By combining measurements of both forbidden and permitted lines, the direction and strength of the field can be obtained. For example, the SiX 1.4301 um line shows strong linear polarization and has been observed in emission over a large field-of-view (out to elongations of 0.5 Rsun. Here we describe an algorithm that combines linear polarization measurements of the SiX 1.4301 um forbidden line with linear polarization observations of the HeI 1.0830 um permitted coronal line to obtain the vector magnetic field. To illustrate the concept we assume the emitting gas for both atomic transitions is located in the plane of the sky. The further development of this method and associated tools will be a critical step towards interpreting the high spectral, spatial and temporal infrared spectro-polarimetric measurements that will be possible when the Daniel K. Inouye Solar Telescope (DKIST) is completed in 2019.

  5. Multidimensional effects in nonadiabatic statistical theories of spin- forbidden kinetics. A case study of 3O + CO → CO2

    DOE PAGESBeta

    Jasper, Ahren

    2015-04-14

    The appropriateness of treating crossing seams of electronic states of different spins as nonadiabatic transition states in statistical calculations of spin-forbidden reaction rates is considered. We show that the spin-forbidden reaction coordinate, the nuclear coordinate perpendicular to the crossing seam, is coupled to the remaining nuclear degrees of freedom. We found that this coupling gives rise to multidimensional effects that are not typically included in statistical treatments of spin-forbidden kinetics. Three qualitative categories of multidimensional effects may be identified: static multidimensional effects due to the geometry-dependence of the local shape of the crossing seam and of the spin–orbit coupling, dynamicalmore » multidimensional effects due to energy exchange with the reaction coordinate during the seam crossing, and nonlocal(history-dependent) multidimensional effects due to interference of the electronic variables at second, third, and later seam crossings. Nonlocal multidimensional effects are intimately related to electronic decoherence, where electronic dephasing acts to erase the history of the system. A semiclassical model based on short-time full-dimensional trajectories that includes all three multidimensional effects as well as a model for electronic decoherence is presented. The results of this multidimensional nonadiabatic statistical theory (MNST) for the 3O + CO → CO2 reaction are compared with the results of statistical theories employing one-dimensional (Landau–Zener and weak coupling) models for the transition probability and with those calculated previously using multistate trajectories. The MNST method is shown to accurately reproduce the multistate decay-of-mixing trajectory results, so long as consistent thresholds are used. Furthermore, the MNST approach has several advantages over multistate trajectory approaches and is more suitable in chemical kinetics calculations at low temperatures and for complex systems

  6. Reduction of central line-associated bloodstream infection rates in a neonatal intensive care unit after implementation of a multidisciplinary evidence-based quality improvement collaborative: A four-year surveillance

    PubMed Central

    Ting, Joseph Y; Goh, Vicki SK; Osiovich, Horacio

    2013-01-01

    BACKGROUND: The use of central venous catheters has permitted lifesaving treatment for critically ill neonates; however, the attributable mortality rate for central line-associated bloodstream infections (CLABSIs) has been estimated to be between 4% and 20%. In 2006/2007, the authors’ neonatal intensive care unit (NICU) had a CLABSI rate that was nearly twofold higher than that reported by other Canadian NICUs. OBJECTIVE: To implement a quality improvement collaborative to reduce the incidence of neonatal CLABSI. METHODS: A retrospective observational study was performed to compare CLABSI in neonates admitted to the authors’ level III NICU between August 2007 and March 2011. The entire study period was divided into four time periods to evaluate secular trends. A comprehensive catheter-related bloodstream infection prevention initiative was implemented in August 2007. The initiatives included staff education, standardization of skin preparation protocol, introduction of new antiseptic agents, implementation of central catheter insertion and maintenance checklists, reinforcement of the use of maximal sterile barrier precautions, and revision of the central catheter configuration and maintenance protocols. RESULTS: The median CLABSI rate of 7.9 per 1000 catheter days at the beginning of the study (period 1 [August 2007 to June 2008]) gradually decreased over the entire study period (P=0.034): period 2 (July 2008 to May 2009), 3.3 per 1000 catheter days; period 3 (June 2009 to April 2010), 2.6 per 1000 catheter days; and period 4 (May 2010 to March 2011), 2.2 per 1000 catheter days. CONCLUSION: A multidisciplinary evidence-based quality improvement collaborative resulted in a significant reduction in the CLABSI rate. Continuous quality improvement measures are required to reduce catheter-related bloodstream infections among low-birth-weight infants. PMID:24489559

  7. Large-scale evaluation of β -decay rates of r -process nuclei with the inclusion of first-forbidden transitions

    NASA Astrophysics Data System (ADS)

    Marketin, T.; Huther, L.; Martínez-Pinedo, G.

    2016-02-01

    Background: r -process nucleosynthesis models rely, by necessity, on nuclear structure models for input. Particularly important are β -decay half-lives of neutron-rich nuclei. At present only a single systematic calculation exists that provides values for all relevant nuclei making it difficult to test the sensitivity of nucleosynthesis models to this input. Additionally, even though there are indications that their contribution may be significant, the impact of first-forbidden transitions on decay rates has not been systematically studied within a consistent model. Purpose: Our goal is to provide a table of β -decay half-lives and β -delayed neutron emission probabilities, including first-forbidden transitions, calculated within a fully self-consistent microscopic theoretical framework. The results are used in an r -process nucleosynthesis calculation to asses the sensitivity of heavy element nucleosynthesis to weak interaction reaction rates. Method: We use a fully self-consistent covariant density functional theory (CDFT) framework. The ground state of all nuclei is calculated with the relativistic Hartree-Bogoliubov (RHB) model, and excited states are obtained within the proton-neutron relativistic quasiparticle random phase approximation (p n -RQRPA). Results: The β -decay half-lives, β -delayed neutron emission probabilities, and the average number of emitted neutrons have been calculated for 5409 nuclei in the neutron-rich region of the nuclear chart. We observe a significant contribution of the first-forbidden transitions to the total decay rate in nuclei far from the valley of stability. The experimental half-lives are in general well reproduced for even-even, odd-A , and odd-odd nuclei, in particular for short-lived nuclei. The resulting data table is included with the article as Supplemental Material. Conclusions: In certain regions of the nuclear chart, first-forbidden transitions constitute a large fraction of the total decay rate and must be

  8. Spectroscopic survey of emission-line stars - I. B[e] stars

    NASA Astrophysics Data System (ADS)

    Aret, A.; Kraus, M.; Šlechta, M.

    2016-02-01

    Emission-line stars are typically surrounded by dense circumstellar material, often in form of rings or disc-like structures. Line emission from forbidden transitions trace a diversity of density and temperature regimes. Of particular interest are the forbidden lines of [O I] λλ6300, 6364 and [Ca II] λλ7291, 7324. They arise in complementary, high-density environments, such as the inner-disc regions around B[e] supergiants. To study physical conditions traced by these lines and to investigate how common they are, we initiated a survey of emission-line stars. Here, we focus on a sample of nine B[e] stars in different evolutionary phases. Emission of the [O I] lines is one of the characteristics of B[e] stars. We find that four of the objects display [Ca II] line emission: for the B[e] supergiants V1478 Cyg and 3 Pup, the kinematics obtained from the [O I] and [Ca II] line profiles agrees with a Keplerian rotating disc scenario; the forbidden lines of the compact planetary nebula OY Gem display no kinematical broadening beyond spectral resolution; the luminous blue variable candidate V1429 Aql shows no [O I] lines, but the profile of its [Ca II] lines suggests that the emission originates in its hot, ionized circumbinary disc. As none of the B[e] stars of lower mass displays [Ca II] line emission, we conclude that these lines are more likely observable in massive stars with dense discs, supporting and strengthening the suggestion that their appearance requires high-density environments.

  9. Non-Born-Oppenheimer molecular dynamics of the spin-forbidden reaction O(3P) + CO(X 1Σ+) → CO2(tilde X{}^1Σ _g^ +)

    NASA Astrophysics Data System (ADS)

    Jasper, Ahren W.; Dawes, Richard

    2013-10-01

    The lowest-energy singlet (1 1A') and two lowest-energy triplet (1 3A' and 1 3A″) electronic states of CO2 are characterized using dynamically weighted multireference configuration interaction (dw-MRCI+Q) electronic structure theory calculations extrapolated to the complete basis set (CBS) limit. Global analytic representations of the dw-MRCI+Q/CBS singlet and triplet surfaces and of their CASSCF/aug-cc-pVQZ spin-orbit coupling surfaces are obtained via the interpolated moving least squares (IMLS) semiautomated surface fitting method. The spin-forbidden kinetics of the title reaction is calculated using the coupled IMLS surfaces and coherent switches with decay of mixing non-Born-Oppenheimer molecular dynamics. The calculated spin-forbidden association rate coefficient (corresponding to the high pressure limit of the rate coefficient) is 7-35 times larger at 1000-5000 K than the rate coefficient used in many detailed chemical models of combustion. A dynamical analysis of the multistate trajectories is presented. The trajectory calculations reveal direct (nonstatistical) and indirect (statistical) spin-forbidden reaction mechanisms and may be used to test the suitability of transition-state-theory-like statistical methods for spin-forbidden kinetics. Specifically, we consider the appropriateness of the "double passage" approximation, of assuming statistical distributions of seam crossings, and of applications of the unified statistical model for spin-forbidden reactions.

  10. Non-Born-Oppenheimer molecular dynamics of the spin-forbidden reaction O(3P) + CO(X(1)Σ+) → CO2(X̃(1)Σg(+)).

    PubMed

    Jasper, Ahren W; Dawes, Richard

    2013-10-21

    The lowest-energy singlet (1 (1)A') and two lowest-energy triplet (1 (3)A' and 1 (3)A") electronic states of CO2 are characterized using dynamically weighted multireference configuration interaction (dw-MRCI+Q) electronic structure theory calculations extrapolated to the complete basis set (CBS) limit. Global analytic representations of the dw-MRCI+Q∕CBS singlet and triplet surfaces and of their CASSCF∕aug-cc-pVQZ spin-orbit coupling surfaces are obtained via the interpolated moving least squares (IMLS) semiautomated surface fitting method. The spin-forbidden kinetics of the title reaction is calculated using the coupled IMLS surfaces and coherent switches with decay of mixing non-Born-Oppenheimer molecular dynamics. The calculated spin-forbidden association rate coefficient (corresponding to the high pressure limit of the rate coefficient) is 7-35 times larger at 1000-5000 K than the rate coefficient used in many detailed chemical models of combustion. A dynamical analysis of the multistate trajectories is presented. The trajectory calculations reveal direct (nonstatistical) and indirect (statistical) spin-forbidden reaction mechanisms and may be used to test the suitability of transition-state-theory-like statistical methods for spin-forbidden kinetics. Specifically, we consider the appropriateness of the "double passage" approximation, of assuming statistical distributions of seam crossings, and of applications of the unified statistical model for spin-forbidden reactions.

  11. Resonance Scattering of Fe XVII X-Ray and EUV Lines

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Saba, J. L. R.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    still persists, even though the agreement of the presently calculated optically thin F(15.02)/F(15.26) ratio with the experimental results of Brown et al. and Laming et al. has improved. Some of the remaining discrepancy is still thought to be the effect of opacity, which is consistent with expected physical conditions for solar sources. EUV intensity ratios are also calculated and compared with observations. Level populations and intensity ratios are calculated, as a function of column density of Fe XVII, in the slab and cylindrical geometries. As found previously, the predicted intensities for the resonance lines at 15.02 and 15.26 Angstroms exhibit initial increases in flux relative to the forbidden line at 17.10 Angstroms and the resonance line at 16.78 Angstroms as optical thickness increases. The same behavior is predicted for the lines at 12.262 and 12.122 Angstroms. Predicted intensities for some of the allowed EUV lines are also affected by opacity.

  12. The HST quasar absorption line key project. 9: An emission-line study of PG 2251+113

    NASA Technical Reports Server (NTRS)

    Espey, Brian R.; Turnshek, David A.; Lee, Lincoln; Bergeron, Jacqueline; Boksenberg, Alec; Hartig, George F.; Jannuzi, Buell T.; Sargent, W. L. W.; Savage, Blair D.; Schneider, Donald P.

    1994-01-01

    We present Hubble Space Telescope (HST) and quasi-simultaneous ground-based observations of the z = 0.3252 QSO PG 2251+113. We find a correlation between line widths and the critical density for de-excitation of the forbidden emission lines observed in this object. We can show that this correlation also applies to the semiforbidden and possibly also the permitted lines which arise in the broad emission-line region. While this result was predicted from statistical studies, it has never previously been shown to hold in detail in any individual object. This relationship between the narrow and broad emission-line regions may help constrain dynamical models of both regions. We examine the implications of this result for a simple radial infall model of the emitting gas developed to explain the origin of narrow-line profiles.

  13. Ice lubrication for moving heavy stones to the Forbidden City in 15th- and 16th-century China.

    PubMed

    Li, Jiang; Chen, Haosheng; Stone, Howard A

    2013-12-10

    Lubrication plays a crucial role in reducing friction for transporting heavy objects, from moving a 60-ton statue in ancient Egypt to relocating a 15,000-ton building in modern society. Although in China spoked wheels appeared ca. 1500 B.C., in the 15th and 16th centuries sliding sledges were still used in transporting huge stones to the Forbidden City in Beijing. We show that an ice lubrication technique of water-lubricated wood-on-ice sliding was used instead of the common ancient approaches, such as wood-on-wood sliding or the use of log rollers. The technique took full advantage of the natural properties of ice, such as sufficient hardness, flatness, and low friction with a water film. This ice-assisted movement is more efficient for such heavy-load and low-speed transportation necessary for the stones of the Forbidden City. The transportation of the huge stones provides an early example of ice lubrication and complements current studies of the high-speed regime relevant to competitive ice sports.

  14. Ice lubrication for moving heavy stones to the Forbidden City in 15th- and 16th-century China

    PubMed Central

    Li, Jiang; Chen, Haosheng; Stone, Howard A.

    2013-01-01

    Lubrication plays a crucial role in reducing friction for transporting heavy objects, from moving a 60-ton statue in ancient Egypt to relocating a 15,000-ton building in modern society. Although in China spoked wheels appeared ca. 1500 B.C., in the 15th and 16th centuries sliding sledges were still used in transporting huge stones to the Forbidden City in Beijing. We show that an ice lubrication technique of water-lubricated wood-on-ice sliding was used instead of the common ancient approaches, such as wood-on-wood sliding or the use of log rollers. The technique took full advantage of the natural properties of ice, such as sufficient hardness, flatness, and low friction with a water film. This ice-assisted movement is more efficient for such heavy-load and low-speed transportation necessary for the stones of the Forbidden City. The transportation of the huge stones provides an early example of ice lubrication and complements current studies of the high-speed regime relevant to competitive ice sports. PMID:24191029

  15. Optical Dark-Field and Electron Energy Loss Imaging and Spectroscopy of Symmetry-Forbidden Modes in Loaded Nanogap Antennas.

    PubMed

    Brintlinger, Todd; Herzing, Andrew A; Long, James P; Vurgaftman, Igor; Stroud, Rhonda; Simpkins, B S

    2015-06-23

    We have produced large numbers of hybrid metal-semiconductor nanogap antennas using a scalable electrochemical approach and systematically characterized the spectral and spatial character of their plasmonic modes with optical dark-field scattering, electron energy loss spectroscopy with principal component analysis, and full wave simulations. The coordination of these techniques reveal that these nanostructures support degenerate transverse modes which split due to substrate interactions, a longitudinal mode which scales with antenna length, and a symmetry-forbidden gap-localized transverse mode. This gap-localized transverse mode arises from mode splitting of transverse resonances supported on both antenna arms and is confined to the gap load enabling (i) delivery of substantial energy to the gap material and (ii) the possibility of tuning the antenna resonance via active modulation of the gap material's optical properties. The resonant position of this symmetry-forbidden mode is sensitive to gap size, dielectric strength of the gap material, and is highly suppressed in air-gapped structures which may explain its absence from the literature to date. Understanding the complex modal structure supported on hybrid nanosystems is necessary to enable the multifunctional components many seek.

  16. A study of diagnostic x-ray lines in heliumlike neon using an electron beam ion trap

    SciTech Connect

    Wargelin, B.J.

    1993-10-01

    Heliumlike ions play an extremely important role in X-ray astrophysics because of their emissivity and because the relative intensities of their emission lines can be used to infer physical characteristics of X-ray emitting plasmas, including temperature, electron density, and ionization balance. In order to properly apply these diagnostics, accurate atomic data are required, including cross sections for collisional excitation and ionization, radiative rates, and the wavelengths and strengths of satellite lines. Although theoretical atomic models have been created to estimate many of the rates and cross sections involved, very few experimental results are available for comparison with theoretical predictions. This thesis describes an experimental study of heliumlike neon using an electron beam ion trap, a device specifically designed to study X-ray emission from highly charged ions. Using a low-energy X-ray spectrometer designed and built for this experiment, electron impact excitation cross sections and dielectronic satellite strengths were measured for all significant n = 2{yields}1 emission lines in He-like and Li-like Ne over a range of energy extending from well below the direct excitation threshold of the lines to over fourteen times the threshold energy. The cross section for innershell ionization of Li-like Ne, which excites the He-like forbidden line, was also measured. In addition, the radiative and collisional depopulation rates of the metastable ls2s {sup 3}S{sub 1}, state, which form the basis of the He-like Ne density diagnostic, were determined. Experimental results were generally in agreement with theoretical predictions, although some significant differences were noted, particularly for the wavelengths and resonance strengths of dielectronic satellites.

  17. Relative intensity calculations for nitrous oxide.

    NASA Technical Reports Server (NTRS)

    Young, L. D. G.

    1972-01-01

    A tabulation of calculated rotational line intensities, relative to the integrated intensity of a vibration-rotation band, is given for Sigma-Sigma, Pi-Sigma, Sigma-Pi, Pi-Pi, and Delta-Pi transitions of nitrous oxide. These calculations were made for temperatures of 250 K and 300 K. A summary of band-intensity measurements is also presented.

  18. Design of spin-forbidden transitions for polypyridyl metal complexes by time-dependent density functional theory including spin-orbit interaction.

    PubMed

    Kanno, Shohei; Imamura, Yutaka; Hada, Masahiko

    2016-05-25

    We explore spin-forbidden transitions for a Ru dye with an N3 skeleton and an Fe dye with a DX1 skeleton by time-dependent density functional theory with spin-orbit interaction. The modified N3-based Ru dye with iodine anions has an absorption edge in the long wavelength region which is not observed in the original N3 dye. The long wavelength absorption edge originates from the spin-orbit interaction with iodine. Although the Fe dye has a small spin-orbit interaction, because of less spin-orbit interaction from the light metal, spin-forbidden transitions also occur for DX1-based Fe dye systems with iodine anions. This result indicates that the introduction of iodine can strengthen the spin-orbit interaction for a dye sensitizer and offers a new approach for designing spin-forbidden transitions.

  19. Bottom Line, Bottom Line

    ERIC Educational Resources Information Center

    Trachtenberg, Stephen Joel

    2008-01-01

    Unlike most businesses, universities are both capital-and labor-intensive; yet contrary to standard business practice, they wring the most use and value out of their plants and payrolls for fewer than seven months a year. University presidents may appear to be very much like chief executive officers, but their powers to change course--or even a…

  20. Line and continuum variability in active galaxies

    NASA Astrophysics Data System (ADS)

    Rashed, Y. E.; Eckart, A.; Valencia-S., M.; García-Marín, M.; Busch, G.; Zuther, J.; Horrobin, M.; Zhou, H.

    2015-12-01

    We compared optical spectroscopic and photometric data for 18 active galactic nuclei (AGN) galaxies over two to three epochs, with time intervals of typically 5 to 10 yr. We used the multi-object double spectrograph (MODS) at the Large Binocular Telescope (LBT) and compared the spectra with data taken from the SDSS data base and the literature. We found variations in the forbidden oxygen lines as well as in the hydrogen recombination lines of these sources. For four of the sources we found that, within the calibration uncertainties, the variations in continuum and line spectra of the sources are very small. We argue that it is mainly the difference in black hole mass between the samples that is responsible for the different degree of continuum variability. In addition, we found that for an otherwise constant accretion rate the total line variability (dominated by the narrow line contributions) reverberates in a similar way to the continuum variability with a dependence ΔLline ∝ (ΔLcont)3/2. Because this dependence is predominantly expressed in the narrow line emission, the implication is that the part of the source that dominates the luminosity in the narrow line region must be very compact, with a diameter of the order of at least 10 light-years. A comparison with data from the literature shows that these findings describe the variability characteristics of a total of 61 broad and narrow line sources.

  1. Spectroscopically Accurate Line Lists for Application in Sulphur Chemistry

    NASA Astrophysics Data System (ADS)

    Underwood, D. S.; Azzam, A. A. A.; Yurchenko, S. N.; Tennyson, J.

    2013-09-01

    Monitoring sulphur chemistry is thought to be of great importance for exoplanets. Doing this requires detailed knowledge of the spectroscopic properties of sulphur containing molecules such as hydrogen sulphide (H2S) [1], sulphur dioxide (SO2), and sulphur trioxide (SO3). Each of these molecules can be found in terrestrial environments, produced in volcano emissions on Earth, and analysis of their spectroscopic data can prove useful to the characterisation of exoplanets, as well as the study of planets in our own solar system, with both having a possible presence on Venus. A complete, high temperature list of line positions and intensities for H32 2 S is presented. The DVR3D program suite is used to calculate the bound ro-vibration energy levels, wavefunctions, and dipole transition intensities using Radau coordinates. The calculations are based on a newly determined, spectroscopically refined potential energy surface (PES) and a new, high accuracy, ab initio dipole moment surface (DMS). Tests show that the PES enables us to calculate the line positions accurately and the DMS gives satisfactory results for line intensities. Comparisons with experiment as well as with previous theoretical spectra will be presented. The results of this study will form an important addition to the databases which are considered as sources of information for space applications; especially, in analysing the spectra of extrasolar planets, and remote sensing studies for Venus and Earth, as well as laboratory investigations and pollution studies. An ab initio line list for SO3 was previously computed using the variational nuclear motion program TROVE [2], and was suitable for modelling room temperature SO3 spectra. The calculations considered transitions in the region of 0-4000 cm-1 with rotational states up to J = 85, and includes 174,674,257 transitions. A list of 10,878 experimental transitions had relative intensities placed on an absolute scale, and were provided in a form suitable

  2. CORONAL EMISSION LINES AS THERMOMETERS

    SciTech Connect

    Judge, Philip G.

    2010-01-10

    Coronal emission-line intensities are commonly used to measure electron temperatures using emission measure and/or line ratio methods. In the presence of systematic errors in atomic excitation calculations and data noise, the information on underlying temperature distributions is fundamentally limited. Increasing the number of emission lines used does not necessarily improve the ability to discriminate between different kinds of temperature distributions.

  3. Characterization of solar cells for space applications. Volume 12: Electrical characteristics of Solarex BSF, 2-ohm-cm, 50-micron solar cells (1978 pilot line) as a function of intensity, temperature, and irradiation

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.; Beckert, D. M.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1980-01-01

    Electrical characteristics of Solarex back-surface-field, 2-ohm-cm, 50-micron N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity, temperature, and irradiation.

  4. Shell-model study of the 4th- and 6th-forbidden β-decay branches of Ca48

    NASA Astrophysics Data System (ADS)

    Haaranen, M.; Horoi, M.; Suhonen, J.

    2014-03-01

    The highly forbidden β- decay of Ca48 is reexamined by performing shell-model calculations with the GXPF1A effective interaction. We examine the three available decay branches to the lowest 6+, 5+, and 4+ states of 48Sc, and extract a theoretical half-life of T1/2β=5.2-1.3+1.7×1020gA-2 yr for the β- decay, where gA is the value of the axial-vector coupling constant. The current half-life estimate suggests stronger competition between the single-β-decay and double-β-decay branches of Ca48 than previously expected on theoretical grounds.

  5. Magnetic field-induced spectroscopy of forbidden optical transitions with application to lattice-based optical atomic clocks.

    PubMed

    Taichenachev, A V; Yudin, V I; Oates, C W; Hoyt, C W; Barber, Z W; Hollberg, L

    2006-03-01

    We develop a method of spectroscopy that uses a weak static magnetic field to enable direct optical excitation of forbidden electric-dipole transitions that are otherwise prohibitively weak. The power of this scheme is demonstrated using the important application of optical atomic clocks based on neutral atoms confined to an optical lattice. The simple experimental implementation of this method--a single clock laser combined with a dc magnetic field--relaxes stringent requirements in current lattice-based clocks (e.g., magnetic field shielding and light polarization), and could therefore expedite the realization of the extraordinary performance level predicted for these clocks. We estimate that a clock using alkaline-earth-like atoms such as Yb could achieve a fractional frequency uncertainty of well below 10(-17) for the metrologically preferred even isotopes.

  6. Forbidden band gaps in the spin-wave spectrum of a two-dimensional bicomponent magnonic crystal.

    PubMed

    Tacchi, S; Duerr, G; Klos, J W; Madami, M; Neusser, S; Gubbiotti, G; Carlotti, G; Krawczyk, M; Grundler, D

    2012-09-28

    The spin-wave band structure of a two-dimensional bicomponent magnonic crystal, consisting of Co nanodisks partially embedded in a Permalloy thin film, is experimentally investigated along a high-symmetry direction by Brillouin light scattering. The eigenfrequencies and scattering cross sections are interpreted using plane wave method calculations and micromagnetic simulations. At the boundary of both the first and the second Brillouin zones, we measure a forbidden frequency gap whose width depends on the magnetic contrast between the constituent materials. The modes above and below the gap exhibit resonant spin-precession amplitudes in the complementary regions of periodically varying magnetic parameters. Our findings are key to advance both the physics and the technology of band gap engineering in magnonics.

  7. Forbidden Band Gaps in the Spin-Wave Spectrum of a Two-Dimensional Bicomponent Magnonic Crystal

    NASA Astrophysics Data System (ADS)

    Tacchi, S.; Duerr, G.; Klos, J. W.; Madami, M.; Neusser, S.; Gubbiotti, G.; Carlotti, G.; Krawczyk, M.; Grundler, D.

    2012-09-01

    The spin-wave band structure of a two-dimensional bicomponent magnonic crystal, consisting of Co nanodisks partially embedded in a Permalloy thin film, is experimentally investigated along a high-symmetry direction by Brillouin light scattering. The eigenfrequencies and scattering cross sections are interpreted using plane wave method calculations and micromagnetic simulations. At the boundary of both the first and the second Brillouin zones, we measure a forbidden frequency gap whose width depends on the magnetic contrast between the constituent materials. The modes above and below the gap exhibit resonant spin-precession amplitudes in the complementary regions of periodically varying magnetic parameters. Our findings are key to advance both the physics and the technology of band gap engineering in magnonics.

  8. Intramolecular [2 + 2] photocycloaddition/thermal fragmentation: formally "allowed" and "forbidden"pathways toward 5-8-5 ring systems.

    PubMed

    Bader, Scott J; Snapper, Marc L

    2005-02-01

    The thermal fragmentation of highly functionalized, linear polycyclobutanes with a cis,syn,cis-relative stereochemistry is shown to offer a rapid entry into the dicyclopenta[a,d]cyclooctenyl (5-8-5) ring system. The thermolysis of polyfused cyclobutanes with a cis,syn,cis- or a cis,anti,cis-relationship proceeds in a formally "symmetry-allowed" manner through the intermediacy of a cis,trans-cyclooctadiene. When a bridging tether used to establish the cis,syn,cis-stereochemistry in the intramolecular [2 + 2] photocyclization is present in the thermolysis step, however, the result of a formally "symmetry-forbidden" fragmentation is observed yielding cis,cis-cyclooctadiene-containing 5-8-5 products. In general, the stereochemical observations noted in these fragmentations offer new opportunities for accessing a variety of stereochemical relationships in these 5-8-5 ring systems.

  9. Impact of the first-forbidden β decay on the production of A ∼ 195 r-process peak

    NASA Astrophysics Data System (ADS)

    Nishimura, Nobuya; Podolyák, Zsolt; Fang, Dong-Liang; Suzuki, Toshio

    2016-05-01

    We investigated the effects of first-forbidden transitions in β decays on the production of the r-process A ∼ 195 peak. The theoretical calculated β-decay rates with β-delayed neutron emission were examined using several astrophysical conditions. As the FF decay is dominant in N ∼ 126 neutron-rich nuclei, their inclusion shortens β-decay lifetimes and shifts the abundance peak towards higher masses. Additionally, the inclusion of the β-delayed neutron emission results in a wider abundance peak, and smoothens the mass distribution by removing the odd-even mass staggering. The effects are commonly seen in the results of all adopted astrophysical models. Nevertheless there are quantitative differences, indicating that remaining uncertainty in the determination of half-lives for N = 126 nuclei is still significant in order to determine the production of the r-process peak.

  10. Recent results at the N = Z line with GASP and EUROBALL

    SciTech Connect

    Farnea, E.

    2004-02-27

    Valuable information on the validity of the isospin symmetry was obtained by studying nuclei close to the N = Z line with the GASP and EUROBALL {gamma}-ray spectrometres coupled to ancillary devices. Here a few selected results on the study of mirror nuclei are presented, together with an estimate of the isospin mixing probability through the measurement of a forbidden E1 transition in 64Ge.

  11. Kbeta satellite and forbidden transitions in elements with 12 <=<= Z <=<= 30 induced by electron impact

    SciTech Connect

    Limandri, Silvina P.; Trincavelli, Jorge C.; Carreras, Alejo C.; Bonetto, Rita D.

    2010-01-15

    The emission of x rays in the Kbeta region of Mg, Al, Si, Sc, Ti, Cr, Fe, Ni, and Zn induced by electron bombardment was studied by means of wavelength dispersive spectroscopy. The lines studied were: the Kbeta{sup III} and Kbeta{sup IV} spectator hole transitions, the 1s->3s quadrupole decay, the Kbeta{sub 2} and Kbeta{sub 5} diagram transitions, the structures related to radiative Auger processes, and the Kbeta{sup '} and Kbeta{sup ''} lines. Relative energies and probabilities were determined through a careful spectral processing based on a parameter refinement method. The results obtained were compared with other experimental and theoretical determinations when available.

  12. Collision strengths for nebular [O III] optical and infrared lines

    NASA Astrophysics Data System (ADS)

    Storey, P. J.; Sochi, Taha; Badnell, N. R.

    2014-07-01

    We present electron collision strengths and their thermally averaged values for the nebular forbidden lines of the astronomically abundant doubly ionized oxygen ion, O2+, in an intermediate coupling scheme using the Breit-Pauli relativistic terms as implemented in an R-matrix atomic scattering code. We use several atomic targets for the R-matrix scattering calculations including one with 72 atomic terms. We also compare with new results obtained using the intermediate coupling frame transformation method. We find spectroscopically significant differences against a recent Breit-Pauli calculation for the excitation of the [O III] λ4363 transition but confirm the results of earlier calculations.

  13. Excitation of knotted vortex lines in matter waves

    NASA Astrophysics Data System (ADS)

    Maucher, F.; Gardiner, S. A.; Hughes, I. G.

    2016-06-01

    We study the creation of knotted ultracold matter waves in Bose–Einstein condensates via coherent two-photon Raman transitions with a Λ level configuration. The Raman transition allows an indirect transfer of atoms from the internal state | a> to the target state | b> via an excited state | e> , that would be otherwise dipole-forbidden. This setup enables us to imprint three-dimensional knotted vortex lines embedded in the probe field to the density in the target state. We elaborate on experimental feasibility as well as on subsequent dynamics of the matter wave.

  14. Microwave spectral line listing

    NASA Technical Reports Server (NTRS)

    White, W. F., Jr.

    1975-01-01

    The frequency, intensity, and identification of 9615 spectral lines belonging to 75 molecules are tabulated in order of increasing frequency. Measurements for all 75 molecules were made in the frequency range from 26500 to 40000 MHz by a computer controlled spectrometer. Measurements were also made in the 18000 to 26500 MHz range for some of the molecules.

  15. Dipole-forbidden atomic transitions induced by superintense x-ray laser fields

    NASA Astrophysics Data System (ADS)

    Simonsen, Aleksander Skjerlie; Førre, Morten

    2016-06-01

    A hydrogen atom, initially prepared in the 2 s and/or 2 p (m =±1 ) states, is assumed irradiated by 0.8 keV (1.5 nm) photons in pulses of 1 -250 fs duration and intensities in the range 1020 to 1023W /cm2 . Solving the corresponding time-dependent Schrödinger equation from first principles, we show that the ionization and excitation dynamics of the laser-atom system is strongly influenced by interactions beyond the electric dipole approximation. A beyond-dipole two-photon Raman-like transition between the 2 s and 2 p (m =±1 ) states is found to completely dominate the underlying laser-matter interaction. It turns out that the large difference in the ionization rates of the 2 s and 2 p (m =±1 ) states is important in this context, effectively leading to a symmetry breaking in the corresponding (beyond-dipole) bound-bound dynamics with the result that a net population transfer between the states occurs throughout the laser-matter interaction period. Varying the x-ray exposure time as well as the laser intensity, we probe the phenomenon as the bound wave packet oscillates between having 2 s and 2 p (m =±1 ) character, eventually giving rise to a Rabi-like oscillation pattern in the populations.

  16. Analysis of the variability of the luminous emission line star MWC 314

    NASA Astrophysics Data System (ADS)

    Muratorio, G.; Rossi, C.; Friedjung, M.

    2008-08-01

    Context: We investigated the surroundings of MWC 314 in the framework of the study of hot emission line star environments using the SAC method. This star is either a B[e] supergiant or a luminous blue variable and appears to be extremely luminous and massive. Aims: We determine the structure and physical conditions of the emitting region and study the possible variations. Methods: We measured the absorption and emission line radial velocities and the emission line fluxes on high-resolution spectra obtained with Aurelie at the 1.52 m OHP telescope in July 1998, with Elodie at the 1.93 m OHP telescope at various epochs, and with echelle spectrographs of the Asiago and Loiano observatories (Italy) in 2006. We used the statistical approach of the self-absorption curve method (SAC) to derive physical parameters of the line-emitting region. Results: We detected drastic variations of the photospheric absorption line radial velocities with time, while the emission line velocities appear to be stable. The Cr II, Ti II, and Fe II emission lines have a complex structure. They are double-peaked, and each of these two 60 km s-1 separated components, is composed of a narrow and a broad component, while the [Fe II] line components are narrower. The fit of the various components of the Fe II lines to a SAC curve indicates that their intensities are affected by some self absorption. We obtained a Boltzmann-type population law whose mean excitation temperature is 6500-1000+1500 K for the narrow component lower and upper levels. We obtained a higher Boltzmann-type population law of 10 500-2000+3000 K for the forbidden transition upper levels. Conclusions: From the absorption lines we confirm the binarity for MWC 314. The periodicity has nevertheless to be improved with a higher sampling frequency. Our results from the emission lines are consistent with line formation in a rotating disk around a star. The typical minimum radius of the line emitting region obtained from the SAC study

  17. Submillimeter and far-infrared line observations of M17 SW - A clumpy molecular cloud penetrated by ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Stutzki, J.; Genzel, R.; Harris, A. I.; Stacey, G. J.; Jaffe, D. T.

    1988-01-01

    Millimeter, submillimeter, and far-IR spectroscopic observations of the M17 SW star formation region are reported. Strong forbidden C II 158 micron and CO J = 7 - 6 line emission arises in an H II region/molecular cloud interface of several pc thickness. Weaker forbidden C II emission appears to be extended over 15 pc throughout the molecular cloud. CO J = 14 - 13 and forbidden O I 145 micron spectra indicate high temperatures and densities for both molecular and atomic gas in the interface. The results require the molecular cloud near the interface to be clumpy or filamentary. The extended forbidden C II emission throughout the molecular cloud has a level around 20 times higher than expected from a single molecular cloud interface exposed to an ultraviolet radiation field typical of the solar neighborhood. The high gas temperature of molecular material in the UV-illuminated interface region suggests that CO self-shielding and heating of CO by photoelectrons are important.

  18. Forbidden games: the construction of sexuality and sexual pleasure by BDSM 'players'.

    PubMed

    Faccio, Elena; Casini, Claudia; Cipolletta, Sabrina

    2014-01-01

    This study aims to explore personal meanings related to the constructs 'sexuality' and 'sexual pleasure' in people who choose to write in forums and blogs about their own experience with Bondage and Discipline, dominance and submission, and Sadism and Masochism (BDSM). We carried out semi-structured online interviews with 343 people, of whom 50 (24 women and 26 men) claimed to practise or to have practised BDSM, in order to investigate participants' definitions of their sexual experiences and the construction of sexuality and sexual pleasure from their personal point of view and from the perspective of the opposite sex. Data were analysed according to Grounded Theory methodology. Questions concerning the 'normality' or the 'deviance' of participants' sexual practices were reflected in the answers of the majority of BDSM practitioners. Sexuality was construed as a 'game' with specific rules, and 'pleasure' was associated with extremely intense experiences. The relationship between the partners was considered fundamental, as it gave meaning to the sexual practice. Both dominant and dominated roles were found to be tightly linked to the possession and management of power between partners, which either confirms or reverses the social construction of traditional male and female roles. PMID:24828811

  19. Forbidden games: the construction of sexuality and sexual pleasure by BDSM 'players'.

    PubMed

    Faccio, Elena; Casini, Claudia; Cipolletta, Sabrina

    2014-01-01

    This study aims to explore personal meanings related to the constructs 'sexuality' and 'sexual pleasure' in people who choose to write in forums and blogs about their own experience with Bondage and Discipline, dominance and submission, and Sadism and Masochism (BDSM). We carried out semi-structured online interviews with 343 people, of whom 50 (24 women and 26 men) claimed to practise or to have practised BDSM, in order to investigate participants' definitions of their sexual experiences and the construction of sexuality and sexual pleasure from their personal point of view and from the perspective of the opposite sex. Data were analysed according to Grounded Theory methodology. Questions concerning the 'normality' or the 'deviance' of participants' sexual practices were reflected in the answers of the majority of BDSM practitioners. Sexuality was construed as a 'game' with specific rules, and 'pleasure' was associated with extremely intense experiences. The relationship between the partners was considered fundamental, as it gave meaning to the sexual practice. Both dominant and dominated roles were found to be tightly linked to the possession and management of power between partners, which either confirms or reverses the social construction of traditional male and female roles.

  20. Measure Lines

    ERIC Educational Resources Information Center

    Crissman, Sally

    2011-01-01

    One tool for enhancing students' work with data in the science classroom is the measure line. As a coteacher and curriculum developer for The Inquiry Project, the author has seen how measure lines--a number line in which the numbers refer to units of measure--help students not only represent data but also analyze it in ways that generate…

  1. Momentum-Transfer-Resolved Electron Energy Loss Spectroscopy of BaBiO3: Anisotropic Dispersion of Threshold Excitation and Optically Forbidden Transition

    NASA Astrophysics Data System (ADS)

    Wang, Y. Y.; Dravid, V. P.; Bulut, N.; Han, P. D.; Klein, M. V.; Schnatterly, S. E.; Zhang, F. C.

    1995-09-01

    Momentum-transfer-resolved electron energy loss spectroscopy of the valence band transitions in BaBiO3 has revealed for the first time that dispersion of the excitation at the optical gap \\(~2 eV\\) and an optically forbidden transition at 4.5 eV are all anisotropic along [100] and [110]. The anisotropic dispersion of the threshold excitation cannot be described by a simple charge density wave picture but can be explained by a small exciton model proposed in this paper. The optically forbidden transition is found to agree well with a proposed molecular orbital model, where the transition is assigned as the excitation from the O 2pσ nonbonding states to the empty Bi 6s state.

  2. Half-life systematics across the N=126 shell closure: role of first-forbidden transitions in the β decay of heavy neutron-rich nuclei.

    PubMed

    Morales, A I; Benlliure, J; Kurtukián-Nieto, T; Schmidt, K-H; Verma, S; Regan, P H; Podolyák, Z; Górska, M; Pietri, S; Kumar, R; Casarejos, E; Al-Dahan, N; Algora, A; Alkhomashi, N; Álvarez-Pol, H; Benzoni, G; Blazhev, A; Boutachkov, P; Bruce, A M; Cáceres, L S; Cullen, I J; Denis Bacelar, A M; Doornenbal, P; Estévez-Aguado, M E; Farrelly, G; Fujita, Y; Garnsworthy, A B; Gelletly, W; Gerl, J; Grebosz, J; Hoischen, R; Kojouharov, I; Kurz, N; Lalkovski, S; Liu, Z; Mihai, C; Molina, F; Mücher, D; Rubio, B; Shaffner, H; Steer, S J; Tamii, A; Tashenov, S; Valiente-Dobón, J J; Walker, P M; Wollersheim, H J; Woods, P J

    2014-07-11

    This Letter reports on a systematic study of β-decay half-lives of neutron-rich nuclei around doubly magic (208)Pb. The lifetimes of the 126-neutron shell isotone (204)Pt and the neighboring (200-202)Ir, (203)Pt, (204)Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden β strength reveal significant deviations for most of the nuclei with N<126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during β decay back to stability. PMID:25062171

  3. Characterization of a chiral phase in an achiral bent-core liquid crystal by polarization studies of resonant x-ray forbidden reflections

    SciTech Connect

    Ponsinet, V.; Pindak, R.; Barois, P.; Pan, L.; Wang, S.; Huang, C.C.; Wang, S.T.; Baumeister, U. and Weissflog, W.

    2011-07-15

    The chiral antiferroelectric structure of an achiral bent-core liquid crystal is characterized by resonant x-ray scattering at chlorine K edge. The 'forbidden' reflections resulting from the glide or screw symmetry elements are restored by the anisotropy of the tensor structure factor, which we calculate for two possible structural models. A careful analysis of the polarization states of the restored 'forbidden' reflections enables an unambiguous identification of a chiral structure (i.e., the so-called anticlinic, antiferroelectric smectic-C or Sm-C{sub A}P{sub A}) coexisting with the achiral synclinic antiferroelectric smectic-C or Sm-C{sub S}P{sub A}. The method proves to be quite powerful as it identifies the chiral structure within coexisting phases despite an imperfect orientation of the sample. The volume fraction of the chiral phase and the distribution of alignment are extracted from the data.

  4. Spectroscopy of the forbidden 1S0 -->3P0 transition on ultra-cold ytterbium atoms

    NASA Astrophysics Data System (ADS)

    Dareau, Alexandre; Scholl, Matthias; Beaufils, Quentin; Döring, Daniel; Beugnon, Jérôme; Gerbier, Fabrice

    2015-05-01

    Cold atoms in optical lattices are often considered a rich playground for emulating condensed matter systems, since they make it possible to engineer many-body Hamiltonians with tunable parameters. However, one missing feature is the ability to emulate orbital magnetism. Recent proposals for simulating orbital magnetism with neutral atoms rely on a state-dependent optical lattice with laser-driven hopping. Ytterbium, with its long lived metastable state (3P0), is a well-suited candidate for the implementation of such schemes. Addressing the forbidden transition between ytterbium ground (1S0) and meta-stable (3P0) states is experimentally challenging, and requires the use of a laser with stability close to the standards of atomic clocks. I will report on the building of a ultra-narrow laser locked on a high-finesse low-expansion cavity. I will then show how the absolute frequency of the cavity modes can be calibrated by performing high-resolution spectroscopy on molecular iodine, allowing us perform Doppler spectroscopy on the 1S0 -->3P0 transition of an ytterbium BEC.

  5. Biologically inspired band-edge laser action from semiconductor with dipole-forbidden band-gap transition

    PubMed Central

    Wang, Cih-Su; Liau, Chi-Shung; Sun, Tzu-Ming; Chen, Yu-Chia; Lin, Tai-Yuan; Chen, Yang-Fang

    2015-01-01

    A new approach is proposed to light up band-edge stimulated emission arising from a semiconductor with dipole-forbidden band-gap transition. To illustrate our working principle, here we demonstrate the feasibility on the composite of SnO2 nanowires (NWs) and chicken albumen. SnO2 NWs, which merely emit visible defect emission, are observed to generate a strong ultraviolet fluorescence centered at 387 nm assisted by chicken albumen at room temperature. In addition, a stunning laser action is further discovered in the albumen/SnO2 NWs composite system. The underlying mechanism is interpreted in terms of the fluorescence resonance energy transfer (FRET) from the chicken albumen protein to SnO2 NWs. More importantly, the giant oscillator strength of shallow defect states, which is served orders of magnitude larger than that of the free exciton, plays a decisive role. Our approach therefore shows that bio-materials exhibit a great potential in applications for novel light emitters, which may open up a new avenue for the development of bio-inspired optoelectronic devices. PMID:25758749

  6. Biologically inspired band-edge laser action from semiconductor with dipole-forbidden band-gap transition

    NASA Astrophysics Data System (ADS)

    Wang, Cih-Su; Liau, Chi-Shung; Sun, Tzu-Ming; Chen, Yu-Chia; Lin, Tai-Yuan; Chen, Yang-Fang

    2015-03-01

    A new approach is proposed to light up band-edge stimulated emission arising from a semiconductor with dipole-forbidden band-gap transition. To illustrate our working principle, here we demonstrate the feasibility on the composite of SnO2 nanowires (NWs) and chicken albumen. SnO2 NWs, which merely emit visible defect emission, are observed to generate a strong ultraviolet fluorescence centered at 387 nm assisted by chicken albumen at room temperature. In addition, a stunning laser action is further discovered in the albumen/SnO2 NWs composite system. The underlying mechanism is interpreted in terms of the fluorescence resonance energy transfer (FRET) from the chicken albumen protein to SnO2 NWs. More importantly, the giant oscillator strength of shallow defect states, which is served orders of magnitude larger than that of the free exciton, plays a decisive role. Our approach therefore shows that bio-materials exhibit a great potential in applications for novel light emitters, which may open up a new avenue for the development of bio-inspired optoelectronic devices.

  7. Direct Excitation of the Forbidden Clock Transition in Neutral {sup 174}Yb Atoms Confined to an Optical Lattice

    SciTech Connect

    Barber, Z.W.; Hoyt, C.W.; Oates, C.W.; Hollberg, L.; Taichenachev, A.V.; Yudin, V.I.

    2006-03-03

    We report direct single-laser excitation of the strictly forbidden (6s{sup 2}){sup 1}S{sub 0}{r_reversible}(6s6p){sup 3}P{sub 0} clock transition in {sup 174}Yb atoms confined to a 1D optical lattice. A small ({approx}1.2 mT) static magnetic field was used to induce a nonzero electric dipole transition probability between the clock states at 578.42 nm. Narrow resonance linewidths of 20 Hz (FWHM) with high contrast were observed, demonstrating a resonance quality factor of 2.6x10{sup 13}. The previously unknown ac Stark shift-canceling (magic) wavelength was determined to be 759.35{+-}0.02 nm. This method for using the metrologically superior even isotope can be easily implemented in current Yb and Sr lattice clocks and can create new clock possibilities in other alkaline-earth-like atoms such as Mg and Ca.

  8. Biologically inspired band-edge laser action from semiconductor with dipole-forbidden band-gap transition.

    PubMed

    Wang, Cih-Su; Liau, Chi-Shung; Sun, Tzu-Ming; Chen, Yu-Chia; Lin, Tai-Yuan; Chen, Yang-Fang

    2015-01-01

    A new approach is proposed to light up band-edge stimulated emission arising from a semiconductor with dipole-forbidden band-gap transition. To illustrate our working principle, here we demonstrate the feasibility on the composite of SnO2 nanowires (NWs) and chicken albumen. SnO2 NWs, which merely emit visible defect emission, are observed to generate a strong ultraviolet fluorescence centered at 387 nm assisted by chicken albumen at room temperature. In addition, a stunning laser action is further discovered in the albumen/SnO2 NWs composite system. The underlying mechanism is interpreted in terms of the fluorescence resonance energy transfer (FRET) from the chicken albumen protein to SnO2 NWs. More importantly, the giant oscillator strength of shallow defect states, which is served orders of magnitude larger than that of the free exciton, plays a decisive role. Our approach therefore shows that bio-materials exhibit a great potential in applications for novel light emitters, which may open up a new avenue for the development of bio-inspired optoelectronic devices.

  9. Theoretical studies of nonadiabatic and spin-forbidden processes: Investigations of the reactions and spectroscopy of radical species relevant to combustion reactions and diagnostics

    SciTech Connect

    Yarkony, D.R.

    1993-12-01

    This research program focusses on studies of spin-forbidden and electronically nonadiabatic processes involving radical species relevant to combustion reactions and combustion diagnostics. To study the electronic structure aspects of these processes a unique and powerful system of electronic structure programs, developed over the past nine years, the BROOKLYN codes, is employed. These programs enable the authors to address questions basic to the understanding of elementary combustion processes not tractable using more standard quantum chemistry codes.

  10. A theoretical study of cyclohexyne addition to carbonyl-Cα bonds: allowed and forbidden electrocyclic and nonpericyclic ring-openings of strained cyclobutenes.

    PubMed

    Sader, C Avery; Houk, K N

    2012-06-01

    The mechanism of cyclohexyne insertion into a C(O)-C(α) bond of cyclic ketones, explored experimentally by the Carreira group, has been investigated using density functional theory. B3LYP and M06-2X calculations were performed in both gas phase and THF (CPCM, UAKS radii). The reaction proceeds through a stepwise [2 + 2] cycloaddition of cyclohexyne to the enolate, followed by three disparate ring-opening possibilities of the cyclobutene alkoxide to give the product: (1) thermally allowed conrotatory electrocyclic ring-opening, (2) thermally forbidden disrotatory electrocyclic ring-opening, or (3) nonpericyclic C-C bond cleavage. Our computational results for the model alkoxide and potassium alkoxide systems show that the thermally allowed electrocyclic ring-opening pathway is favored by less than 1 kcal/mol. In more complex systems containing a potassium alkoxide (e-f), the barrier of the allowed conrotatory ring-opening is disfavored by 4-8 kcal/mol. This suggests that the thermodynamically more stable disrotatory product can be formed directly through a "forbidden" pathway. Analysis of geometrical parameters and atomic charges throughout the ring-opening pathways provides evidence for a nonpericyclic C-C bond cleavage, rather than a thermally forbidden disrotatory ring-opening. A true forbidden disrotatory ring-opening transition structure was computed for the cyclobutene alcohol; however, it was 19 kcal/mol higher in energy than the allowed conrotatory transition structure. An alternate mechanism in which the disrotatory product forms via isomerization of the conrotatory product was also explored for the alkoxide and potassium alkoxide systems. PMID:22537557

  11. Quantum theory of IR spectroscopy of dipole-forbidden vibrational modes of adsorbed molecules on the surface of a metal in the frequency range of the anomalous skin effect

    SciTech Connect

    Volokitin, A.I.; Persson, B.N.J.

    1995-09-01

    A completely quantum-mechanical calculation of the IR spectrum for the dipole-forbidden vibrational modes of adsorbed molecules on a metal surface is performed. IT is shown for broad-band metals with a simple band structure that the asymmetry of the line shape is determined by nonlocal effects, while the nonadiabaticity makes a small contribution. In the region of the limiting anomalous skin effect ({omega}/{omega}{sub 1}{much_lt} 1, where {omega} is the frequency of the IR radiation, {omega}{sub 1}={upsilon}{sub F}/{delta}, {upsilon}{sub F} is the Fermi velocity, {delta}=c/{omega}{sub p} is the depth of the skin layer, and {omega}{sub p} is the plasma frequency) the broad-band absorption spectrum caused by the adsorbed molecules has an asymptotic limit {omega}{sup O}. The theory is compared with new absolute measurements of the IR spectrum of the CO/Cu(100) system. 20 refs., 2 figs.

  12. Effect of tin ions on enhancing the intensity of narrow luminescence line at 311 nm of Gd3+ ions in Li2Osbnd PbOsbnd P2O5 glass system

    NASA Astrophysics Data System (ADS)

    Gandhi, Y.; Rajanikanth, P.; Sundara Rao, M.; Ravi Kumar, V.; Veeraiah, N.; Piasecki, M.

    2016-07-01

    This study is mainly focused on enriching the UVB 311 narrow emission band of Gd3+ ions in Li2Osbnd PbOsbnd P2O5 glasses doped with 1.0 mol% of Gd2O3 and mixed with different concentrations of SnO2 (0-7.0 mol%). The emission spectra SnO2 free glasses exhibited intense narrow UVB band at 311 nm due to 6P7/2 → 8S7/2 transition of Gd3+ ions when excited at 273 nm. The intensity of this band is found to be enhanced nearly four times when the glasses are mixed with 3.0 mol% of SnO2. The reasons for this enhancement have been explored in the light of energy transfer from Sn4+ to Gd3+ ions with the help of rate equations. The declustering of Gd3+ ions (that reduce cross relaxation losses) by tin ions is also found to the other reason for such enrichment. The 311 nm radiation is an efficient in the treatment of various skin diseases and currently it is one of the most desirable and commonly utilised UVB in the construction of phototherapy devices.

  13. Effect of tin ions on enhancing the intensity of narrow luminescence line at 311 nm of Gd3+ ions in Li2Osbnd PbOsbnd P2O5 glass system

    NASA Astrophysics Data System (ADS)

    Gandhi, Y.; Rajanikanth, P.; Sundara Rao, M.; Ravi Kumar, V.; Veeraiah, N.; Piasecki, M.

    2016-07-01

    This study is mainly focused on enriching the UVB 311 narrow emission band of Gd3+ ions in Li2Osbnd PbOsbnd P2O5 glasses doped with 1.0 mol% of Gd2O3 and mixed with different concentrations of SnO2 (0-7.0 mol%). The emission spectra SnO2 free glasses exhibited intense narrow UVB band at 311 nm due to 6P7/2 → 8S7/2 transition of Gd3+ ions when excited at 273 nm. The intensity of this band is found to be enhanced nearly four times when the glasses are mixed with 3.0 mol% of SnO2. The reasons for this enhancement have been explored in the light of energy transfer from Sn4+ to Gd3+ ions with the help of rate equations. The declustering of Gd3+ ions (that reduce cross relaxation losses) by tin ions is also found to the other reason for such enrichment. The 311 nm radiation is an efficient in the treatment of various skin diseases and currently it is one of the most desirable and commonly utilised UVB in the construction of phototherapy devices.

  14. Studying the Variation of the Fine-Structure Constant Using Emission-Line Multiplets

    NASA Astrophysics Data System (ADS)

    Grupe, Dirk; Pradhan, Anil K.; Frank, Stephan

    2005-08-01

    As an extension of the method by Bahcall and coworkers to investigate the time dependence of the fine-structure constant, we describe an approach based on new observations of forbidden-line multiplets from different ionic species. We obtain optical spectra of fine-structure transitions in [Ne III], [Ne V], [O III], [O I], and [S II] multiplets from a sample of 14 Seyfert 1.5 galaxies in the low-z range 0.035line studies of the time variation of the fine-structure constant. The approach can be further extended and generalized to a ``many-multiplet emission-line method'' analogous in principle to the corresponding method using absorption lines. With that aim, we note that the theoretical limits on emission-line ratios of selected ions are precisely known and provide well-constrained selection criteria. We also discuss several other forbidden and allowed lines that may constitute the basis for a more rigorous study using high-resolution instruments on the next generation of 8 m class telescopes. Based on observations obtained at MDM Observatory, Arizona.

  15. Band gap control in a line-defect magnonic crystal waveguide

    SciTech Connect

    Morozova, M. A. Grishin, S. V.; Sadovnikov, A. V.; Romanenko, D. V.; Sharaevskii, Yu. P.; Nikitov, S. A.

    2015-12-14

    We report on the experimental observation of the spin wave spectrum control in a line-defect magnonic crystal (MC) waveguide. We demonstrate the possibility to control the forbidden frequency band (band gap) for spin waves tuning the line-defect width. In particular, this frequency may be greater or lower than the one of 1D MC waveguide without line-defect. By means of space-resolved Brillouin light scattering technique, we study the localization of magnetization amplitude in the line-defect area. We show that the length of this localization region depends on the line-defect width. These results agree well with theoretical calculations of spin wave spectrum using the proposed model of two coupled magnonic crystal waveguides. The proposed simple geometry of MC with line-defect can be used as a logic and multiplexing block for application in the novel field of magnonic devices.

  16. Effects of ion-neutral collisions on Alfven waves: The presence of forbidden zone and heavy damping zone

    SciTech Connect

    Weng, C. J.; Lee, L. C.; Kuo, C. L.; Wang, C. B.

    2013-03-15

    Alfven waves are low-frequency transverse waves propagating in a magnetized plasma. We define the Alfven frequency {omega}{sub 0} as {omega}{sub 0}=kV{sub A}cos{theta}, where k is the wave number, V{sub A} is the Alfven speed, and {theta} is the angle between the wave vector and the ambient magnetic field. There are partially ionized plasmas in laboratory, space, and astrophysical plasma systems, such as in the solar chromosphere, interstellar clouds, and the earth ionosphere. The presence of neutral particles may modify the wave frequency and cause damping of Alfven waves. The effects on Alfven waves depend on two parameters: (1) {alpha}=n{sub n}/n{sub i}, the ratio of neutral density (n{sub n}), and ion density (n{sub i}); (2) {beta}={nu}{sub ni}/{omega}{sub 0}, the ratio of neutral collisional frequency by ions {nu}{sub ni} to the Alfven frequency {omega}{sub 0}. Most of the previous studies examined only the limiting case with a relatively large neutral collisional frequency or {beta} Much-Greater-Than 1. In the present paper, the dispersion relation for Alfven waves is solved for all values of {alpha} and {beta}. Approximate solutions in the limit {beta} Much-Greater-Than 1 as well as {beta} Much-Less-Than 1 are obtained. It is found for the first time that there is a 'forbidden zone (FZ)' in the {alpha}-{beta} parameter space, where the real frequency of Alfven waves becomes zero. We also solve the wavenumber k from the dispersion equation for a fixed frequency and find the existence of a 'heavy damping zone (HDZ).' We then examine the presence of FZ and HDZ for Alfven waves in the ionosphere and in the solar chromosphere.

  17. Gaia-ESO Survey: Gas dynamics in the Carina nebula through optical emission lines

    NASA Astrophysics Data System (ADS)

    Damiani, F.; Bonito, R.; Magrini, L.; Prisinzano, L.; Mapelli, M.; Micela, G.; Kalari, V.; Maíz Apellániz, J.; Gilmore, G.; Randich, S.; Alfaro, E.; Flaccomio, E.; Koposov, S.; Klutsch, A.; Lanzafame, A. C.; Pancino, E.; Sacco, G. G.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Worley, C.; Zaggia, S.; Zwitter, T.; Dorda, R.

    2016-06-01

    Aims: We present observations from the Gaia-ESO Survey in the lines of Hα, [N II], [S II], and He I of nebular emission in the central part of the Carina nebula. Methods: We investigate the properties of the two already known kinematic components (approaching and receding), which account for the bulk of emission. Moreover, we investigate the features of the much less known low-intensity high-velocity (absolute RV >50 km s-1) gas emission. Results: We show that gas giving rise to Hα and He I emission is dynamically well correlated with but not identical to gas seen through forbidden-line emission. Gas temperatures are derived from line-width ratios, and densities from [S II] doublet ratios. The spatial variation of N ionization is also studied, and found to differ between the approaching and receding components. The main result is that the bulk of the emission lines in the central part of Carina arise from several distinct shell-like expanding regions, the most evident found around η Car, the Trumpler 14 core, and the star WR25. These "shells" are non-spherical and show distortions probably caused by collisions with other shells or colder, higher-density gas. Some of them are also partially obscured by foreground dust lanes, while very little dust is found in their interior. Preferential directions, parallel to the dark dust lanes, are found in the shell geometries and physical properties, probably related to strong density gradients in the studied region. We also find evidence that the ionizing flux emerging from η Car and the surrounding Homunculus nebula varies with polar angle. The high-velocity components in the wings of Hα are found to arise from expanding dust reflecting the η Car spectrum. Based on observations collected with the FLAMES spectrograph at VLT/UT2 telescope (Paranal Observatory, ESO, Chile), for the Gaia-ESO Large Public Survey (program 188.B-3002).Full Tables 1-3 are only available at the CDS via anonymous ftp to http

  18. Steps toward determination of the size and structure of the broad-line region in active galatic nuclei. 8: An intensive HST, IUE, and ground-based study of NGC 5548

    NASA Technical Reports Server (NTRS)

    Korista, K. T.; Alloin, D.; Barr, P.; Clavel, J.; Cohen, R. D.; Crenshaw, D. M.; Evans, I. N.; Horne, K.; Koratkar, A. P.; Kriss, G. A.

    1995-01-01

    We present the data and initial results from a combined Hubble Space Telescope (HST)/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-1989. IUE spectra were obtained once every 2 days for a period of 74 days beginning on 1993 March 14. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October-1993 September, although many of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies.

  19. The Birkland Currents, the Electrojets, Auroral Precipitation, Intense Electric Field Channels, and the Open-Closed Field Line Boundary: A Synthesis of Quiet Time Auroral Current Structure Near the Harang Discontinuity.

    NASA Astrophysics Data System (ADS)

    Archer, W. E.; Knudsen, D. J.; Burchill, J. K.; Jackel, B. J.; Donovan, E.; Spanswick, E.; Connors, M. G.

    2015-12-01

    The European Space Agency Swarm satellite mission began with all three Swarm satellites in similar, noon-to-midnight polar orbits. We present electric field, magnetic field, electron density, electron temperature, and ion temperature measurements from early in the Swarm mission (December 2013). This data set is of particular interest as the pearls-on-a-string orientation of the satellites provide multiple measurements of similar volumes of space taken minutes apart, providing confidence in measurement integrity and reducing the spatio-temporal ambiguity inherent to in-situ measurements. Furthermore, the measurement period is characterized by low geomagnetic activity which results in consistent measurement conditions orbit to orbit. The December 2013 ionospheric Swarm measurements combined with ground-based optical and magnetic measurements provide a consistent picture of ionospheric and field-aligned currents near midnight during quiet geomagnetic conditions. Relationships between large-scale field aligned currents, auroral precipitation, narrow regions of enhanced electric fields, the electrojets, and the open-closed field line boundary have all been studied pairwise previously. We present a synthesis interpretation of the set of measurements to arrive at a consistent picture of the auroral current structure near midnight. This work is supported by a grant from the Canadian Space Agency.

  20. Gamma-ray lines and one-loop continuum from s-channel dark matter annihilations

    SciTech Connect

    Jackson, C.B.; Servant, Géraldine; Shaughnessy, Gabe; Tait, Tim M.P.; Taoso, Marco E-mail: chris@uta.edu E-mail: ttait@uci.edu

    2013-07-01

    The era of indirect detection searches for dark matter has begun, with the sensitivities of gamma-ray detectors now approaching the parameter space relevant for weakly interacting massive particles. In particular, gamma ray lines would be smoking gun signatures of dark matter annihilation, although they are typically suppressed compared to the continuum. In this paper, we pay particular attention to the 1-loop continuum generated together with the gamma-ray lines and investigate under which conditions a dark matter model can naturally lead to a line signal that is relatively enhanced. We study generic classes of models in which DM is a fermion that annihilates through an s-channel mediator which is either a vector or scalar and identify the coupling and mass conditions under which large line signals occur. We focus on the ''forbidden channel mechanism'' advocated a few years ago in the ''Higgs in space'' scenario for which tree level annihilation is kinematically forbidden today. Detailed calculations of all 1-loop annihilation channels are provided. We single out very simple models with a large line over continuum ratio and present general predictions for a large range of WIMP masses that are relevant not only for Fermi and Hess II but also for the next generation of telescopes such as CTA and Gamma-400. Constraints from the relic abundance, direct detection and collider bounds are also discussed.

  1. Resolution of an intense sweetener mixture by use of a flow injection sensor with on-line solid-phase extraction. Application to saccharin and aspartame in sweets and drinks.

    PubMed

    Capitán-Vallvey, L F; Valencia, M C; Arana Nicolás, E; García-Jiménez, J F

    2006-05-01

    An integrated solid-phase spectrophotometry-FIA method is proposed for simultaneous determination of the mixture of saccharin (1,2-benzisothiazol-3(2H)-one-1,1-dioxide; E-954) (SA) and aspartame (N-L-alpha-aspartyl-L-phenylalanine-1-methyl ester; E-951) (AS). The procedure is based on on-line preconcentration of AS on a C18 silica gel minicolumn and separation from SA, followed by measurement, at lambda = 210 nm, of the absorbance of SA which is transiently retained on the adsorbent Sephadex G-25 placed in the flow-through cell of a monochannel FIA setup using pH 3.0 orthophosphoric acid-dihydrogen phosphate buffer, 3.75x10(-3) mol L(-1), as carrier. Subsequent desorption of AS with methanol enables its determination at lambda = 205 nm. With a sampling frequency of 10 h(-1), the applicable concentration range, the detection limit, and the relative standard deviation were from 1.0 to 200.0 microg mL(-1), 0.30 microg mL(-1), and 1.0% (80 microg mL(-1), n = 10), respectively, for SA and from 10.0 to 200.0 microg mL(-1), 1.4 microg mL(-1), and 1.6% (100 microg mL(-1), n = 10) for AS. The method was used to determine the amounts of aspartame and saccharin in sweets and drinks. Recovery was always between 99 and 101%. The method enabled satisfactory determination of blends of SA and AS in low-calorie and dietary products and the results were compared with those from an HPLC reference method.

  2. Prospects for a narrow line MOT in YO

    NASA Astrophysics Data System (ADS)

    Collopy, Alejandra L.; Hummon, Matthew T.; Yeo, Mark; Yan, Bo; Ye, Jun

    2015-05-01

    In addition to being suitable for laser cooling and trapping in a magneto-optical trap (MOT) using a relatively broad (∼ 5 MHz) transition, the molecule YO possesses a narrow-line transition. This forbidden transition between the {{X}2}Σ and A{{\\prime }2}{{Δ }3/2} states has linewidth ∼ 2π × 160 kHz. After cooling in a MOT on the 614 nm {{X}2}Σ to {{A}2}{{\\Pi }1/2} (orange) transition, the narrow 690 nm (red) transition can be used to further cool the sample, requiring only minimal additions to the first stage system. We estimate that the narrow line cooling stage will bring the temperature from ∼1 mK to ∼10 μK, significantly advancing the frontier on direct cooling achievable for molecules.

  3. The discrepant kinematics of recombination and collisionally excited lines in NGC 7009 as a function of ionization structure

    NASA Astrophysics Data System (ADS)

    Torres-Peimbert, S.; Richer, M. R.; Georgiev, L.; Arrieta, A.

    2014-10-01

    We have analyzed the kinematics of emission of the planetary nebula NGC 7009 from long slit spectroscopy from the UVES spectrograph at the VLT of ESO. In particular we are interested in comparing lines excited by recombination and collisions with electrons to determine whether similarities or differences could be useful in elucidating the well-known abundance discrepancy derived from them. We construct position-velocity maps for recombination, fluorescence, charge transfer, and collisionally excited lines.We find a plasma component emitting in the C II, N II, O II, and Ne II recombination lines whose kinematics are discrepant: they are incompatible with the ionization structure derived from all other evidence and the kinematics derived from all of these lines are unexpectedly very similar. We found direct evidence for a recombination contribution to [N II] λ5755. Once taken into account, the electron temperatures from [N II], [O III], and [Ne III] agree at a given position and velocity. The electron densities derived from [O II] and [Ar IV] are consistent with direct imaging and the distribution of hydrogen emission. The kinematics of the C II, N II, O II, and Ne II lines does not coincide with the kinematics of the [O III] and [Ne III] forbidden emission, indicating that there is an additional plasma component to the recombination emission that arises from a different volume from that giving rise to the forbidden emission from the parent ions within NGC 7009. Thus, the chemical abundances derived from either type of line are correct only for the plasma component from which they arise. Apart from [N II] λ5755, we find no anomaly with the forbidden lines usually used to determine chemical abundances in ionized nebulae, so the abundances derived from them should be reliable for the medium from which they arise.

  4. Chimpanzees share forbidden fruit.

    PubMed

    Hockings, Kimberley J; Humle, Tatyana; Anderson, James R; Biro, Dora; Sousa, Claudia; Ohashi, Gaku; Matsuzawa, Tetsuro

    2007-01-01

    The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a 'social tool' for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa) very rarely transferred wild plant foods. In contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events). Sharing primarily consists of adult males allowing reproductively cycling females to take food that they possess. We propose that hypotheses focussing on 'food-for-sex and -grooming' and 'showing-off' strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observations suggest that crop-raiding provides adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies.

  5. Multidimensional effects in nonadiabatic statistical theories of spin- forbidden kinetics. A case study of 3O + CO → CO2

    SciTech Connect

    Jasper, Ahren

    2015-04-14

    The appropriateness of treating crossing seams of electronic states of different spins as nonadiabatic transition states in statistical calculations of spin-forbidden reaction rates is considered. We show that the spin-forbidden reaction coordinate, the nuclear coordinate perpendicular to the crossing seam, is coupled to the remaining nuclear degrees of freedom. We found that this coupling gives rise to multidimensional effects that are not typically included in statistical treatments of spin-forbidden kinetics. Three qualitative categories of multidimensional effects may be identified: static multidimensional effects due to the geometry-dependence of the local shape of the crossing seam and of the spin–orbit coupling, dynamical multidimensional effects due to energy exchange with the reaction coordinate during the seam crossing, and nonlocal(history-dependent) multidimensional effects due to interference of the electronic variables at second, third, and later seam crossings. Nonlocal multidimensional effects are intimately related to electronic decoherence, where electronic dephasing acts to erase the history of the system. A semiclassical model based on short-time full-dimensional trajectories that includes all three multidimensional effects as well as a model for electronic decoherence is presented. The results of this multidimensional nonadiabatic statistical theory (MNST) for the 3O + CO → CO2 reaction are compared with the results of statistical theories employing one-dimensional (Landau–Zener and weak coupling) models for the transition probability and with those calculated previously using multistate trajectories. The MNST method is shown to accurately reproduce the multistate decay-of-mixing trajectory results, so long as consistent thresholds are used. Furthermore, the MNST approach has several advantages over multistate trajectory approaches and is more suitable in chemical kinetics calculations at low temperatures and for

  6. Multidimensional Effects in Nonadiabatic Statistical Theories of Spin-Forbidden Kinetics: A Case Study of (3)O + CO → CO2.

    PubMed

    Jasper, Ahren W

    2015-07-16

    The appropriateness of treating crossing seams of electronic states of different spins as nonadiabatic transition states in statistical calculations of spin-forbidden reaction rates is considered. We show that the spin-forbidden reaction coordinate, the nuclear coordinate perpendicular to the crossing seam, is coupled to the remaining nuclear degrees of freedom. This coupling gives rise to multidimensional effects that are not typically included in statistical treatments of spin-forbidden kinetics. Three qualitative categories of multidimensional effects may be identified: static multidimensional effects due to the geometry-dependence of the local shape of the crossing seam and of the spin-orbit coupling, dynamical multidimensional effects due to energy exchange with the reaction coordinate during the seam crossing, and nonlocal (history-dependent) multidimensional effects due to interference of the electronic variables at second, third, and later seam crossings. Nonlocal multidimensional effects are intimately related to electronic decoherence, where electronic dephasing acts to erase the history of the system. A semiclassical model based on short-time full-dimensional trajectories that includes all three multidimensional effects as well as a model for electronic decoherence is presented. The results of this multidimensional nonadiabatic statistical theory (MNST) for the (3)O + CO → CO2 reaction are compared with the results of statistical theories employing one-dimensional (Landau-Zener and weak coupling) models for the transition probability and with those calculated previously using multistate trajectories. The MNST method is shown to accurately reproduce the multistate decay-of-mixing trajectory results, so long as consistent thresholds are used. The MNST approach has several advantages over multistate trajectory approaches and is more suitable in chemical kinetics calculations at low temperatures and for complex systems. The error in statistical

  7. Multidimensional Effects in Nonadiabatic Statistical Theories of Spin-Forbidden Kinetics: A Case Study of (3)O + CO → CO2.

    PubMed

    Jasper, Ahren W

    2015-07-16

    The appropriateness of treating crossing seams of electronic states of different spins as nonadiabatic transition states in statistical calculations of spin-forbidden reaction rates is considered. We show that the spin-forbidden reaction coordinate, the nuclear coordinate perpendicular to the crossing seam, is coupled to the remaining nuclear degrees of freedom. This coupling gives rise to multidimensional effects that are not typically included in statistical treatments of spin-forbidden kinetics. Three qualitative categories of multidimensional effects may be identified: static multidimensional effects due to the geometry-dependence of the local shape of the crossing seam and of the spin-orbit coupling, dynamical multidimensional effects due to energy exchange with the reaction coordinate during the seam crossing, and nonlocal (history-dependent) multidimensional effects due to interference of the electronic variables at second, third, and later seam crossings. Nonlocal multidimensional effects are intimately related to electronic decoherence, where electronic dephasing acts to erase the history of the system. A semiclassical model based on short-time full-dimensional trajectories that includes all three multidimensional effects as well as a model for electronic decoherence is presented. The results of this multidimensional nonadiabatic statistical theory (MNST) for the (3)O + CO → CO2 reaction are compared with the results of statistical theories employing one-dimensional (Landau-Zener and weak coupling) models for the transition probability and with those calculated previously using multistate trajectories. The MNST method is shown to accurately reproduce the multistate decay-of-mixing trajectory results, so long as consistent thresholds are used. The MNST approach has several advantages over multistate trajectory approaches and is more suitable in chemical kinetics calculations at low temperatures and for complex systems. The error in statistical

  8. Enhancement of Near-IR Photoelectric Conversion in Dye-Sensitized Solar Cells Using an Osmium Sensitizer with Strong Spin-Forbidden Transition.

    PubMed

    Kinoshita, Takumi; Fujisawa, Jun-Ichi; Nakazaki, Jotaro; Uchida, Satoshi; Kubo, Takaya; Segawa, Hiroshi

    2012-02-01

    A new osmium (Os) complex of the [Os(tcterpy)-(4,4'-bis(p-butoxystyryl)-2,2'-bipyridine)Cl]PF6 (Os-stbpy) has been synthesized and characterized for dye-sensitized solar cells (DSSCs). The Os-stbpy dye shows enhanced spin-forbidden absorptions around 900 nm. The DSSCs with Os-stbpy show a wide-band spectral response up to 1100 nm with high overall conversion efficiency of 6.1% under standard solar illumination.

  9. Inspecting an ethylene pipe line

    SciTech Connect

    Ramsvig, D.M. ); Duncan, J.; Zillinger, L. )

    1991-07-01

    This paper reports on the Alberta Gas Ethylene Co. (AGEC), completion of intensive internal cleaning and inspection program on their 112-mi ethylene pipe line. AGEC operates two ethylene manufacturing facilities in central Alberta, Canada. The ethylene plants are located 12.4 mi east of Red Deer, Alta., at Joffre, and supply two customers in Joffre. The remaining ethylene is shipped by the 112-mi, 12-in. line to a storage cavern near Edmonton.

  10. Observation of strong anisotropic forbidden transitions in (001) InGaAs/GaAs single-quantum well by reflectance-difference spectroscopy and its behavior under uniaxial strain.

    PubMed

    Yu, Jin-Ling; Chen, Yong-Hai; Tang, Chen-Guang; Jiang, Chongyun; Ye, Xiao-Ling

    2011-01-01

    The strong anisotropic forbidden transition has been observed in a series of InGaAs/GaAs single-quantum well with well width ranging between 3 nm and 7 nm at 80 K. Numerical calculations within the envelope function framework have been performed to analyze the origin of the optical anisotropic forbidden transition. It is found that the optical anisotropy of this transition can be mainly attributed to indium segregation effect. The effect of uniaxial strain on in-plane optical anisotropy (IPOA) is also investigated. The IPOA of the forbidden transition changes little with strain, while that of the allowed transition shows a linear dependence on strain.PACS 78.66.Fd, 78.20.Bh, 78.20.Fm. PMID:21711728

  11. Intensive Versus Non-Intensive Arabic.

    ERIC Educational Resources Information Center

    Hanna, Sami A.

    This paper investigates the difference in achievement among 20 University of Utah students of modern standard Arabic. One group of 11 students followed an intensive eight-week summer course, and a second group of nine students studied the same course during a regular academic year. Also reported on is the correlation between achievement and…

  12. Physical conditions derived from O II recombination lines in planetary nebulae and their implications

    NASA Astrophysics Data System (ADS)

    Peimbert, A.; Peimbert, M.; Delgado-Inglada, G.; García-Rojas, J.; Peña, M.

    2014-10-01

    Based on high quality observations of multiplet V1 of O II and the NLTE atomic computations for O II we study the density and temperature of a sample of PNe. We find that, in general, the densities derived from recombination lines of O II are similar to the densities derived from forbidden lines. This implies that the signature for oxygen rich clumps of high density and low temperature is absent in most of the objects of our sample. Electron pressures derived from the hotter zones are similar or slightly larger than those derived from the colder zones, suggesting the presence of shock waves. The average temperatures and t^{2} values derived from H, He and O lines are similar and consistent with chemical homogeneity. These results suggest that the abundances of these objects are the ones derived from recombination lines.

  13. On systematic errors in spectral line parameters retrieved with the Voigt line profile

    NASA Astrophysics Data System (ADS)

    Kochanov, V. P.

    2012-08-01

    Systematic errors inherent in the Voigt line profile are analyzed. Molecular spectrum processing with the Voigt profile is shown to underestimate line intensities by 1-4%, with the errors in line positions being 0.0005 cm-1 and the decrease in pressure broadening coefficients varying from 5% to 55%.

  14. Rethinking Intensive Quantities via Guided Mediated Abduction

    ERIC Educational Resources Information Center

    Abrahamson, Dor

    2012-01-01

    Some intensive quantities, such as slope, velocity, or likelihood, are perceptually privileged in the sense that they are experienced as holistic, irreducible sensations. However, the formal expression of these quantities uses "a/b" analytic metrics; for example, the slope of a line is the quotient of its rise and run. Thus, whereas students'…

  15. Intensive Care, Intense Conflict: A Balanced Approach.

    PubMed

    Paquette, Erin Talati; Kolaitis, Irini N

    2015-01-01

    Caring for a child in a pediatric intensive care unit is emotionally and physically challenging and often leads to conflict. Skilled mediators may not always be available to aid in conflict resolution. Careproviders at all levels of training are responsible for managing difficult conversations with families and can often prevent escalation of conflict. Bioethics mediators have acknowledged the important contribution of mediation training in improving clinicians' skills in conflict management. Familiarizing careproviders with basic mediation techniques is an important step towards preventing escalation of conflict. While training in effective communication is crucial, a sense of fairness and justice that may only come with the introduction of a skilled, neutral third party is equally important. For intense conflict, we advocate for early recognition, comfort, and preparedness through training of clinicians in de-escalation and optimal communication, along with the use of more formally trained third-party mediators, as required.

  16. Light intensity compressor

    DOEpatents

    Rushford, Michael C.

    1990-01-01

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  17. Light intensity compressor

    DOEpatents

    Rushford, Michael C.

    1990-02-06

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  18. IONIS: Approximate atomic photoionization intensities

    NASA Astrophysics Data System (ADS)

    Heinäsmäki, Sami

    2012-02-01

    A program to compute relative atomic photoionization cross sections is presented. The code applies the output of the multiconfiguration Dirac-Fock method for atoms in the single active electron scheme, by computing the overlap of the bound electron states in the initial and final states. The contribution from the single-particle ionization matrix elements is assumed to be the same for each final state. This method gives rather accurate relative ionization probabilities provided the single-electron ionization matrix elements do not depend strongly on energy in the region considered. The method is especially suited for open shell atoms where electronic correlation in the ionic states is large. Program summaryProgram title: IONIS Catalogue identifier: AEKK_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKK_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1149 No. of bytes in distributed program, including test data, etc.: 12 877 Distribution format: tar.gz Programming language: Fortran 95 Computer: Workstations Operating system: GNU/Linux, Unix Classification: 2.2, 2.5 Nature of problem: Photoionization intensities for atoms. Solution method: The code applies the output of the multiconfiguration Dirac-Fock codes Grasp92 [1] or Grasp2K [2], to compute approximate photoionization intensities. The intensity is computed within the one-electron transition approximation and by assuming that the sum of the single-particle ionization probabilities is the same for all final ionic states. Restrictions: The program gives nonzero intensities for those transitions where only one electron is removed from the initial configuration(s). Shake-type many-electron transitions are not computed. The ionized shell must be closed in the initial state. Running time: Few seconds for a

  19. Quadrupolar susceptibility of LiTmF4 crystal and the nature of forbidden 3H6(Γ2)-3F2(Γ2) transition

    NASA Astrophysics Data System (ADS)

    Altshuler, N. S.; Larionov, Alexander L.; Rodionova, M. P.; Stolov, A. L.

    2002-07-01

    The narrow low intensity line with maximum at (lambda) -1 equals 15104 cm-1 and width (delta) equals 0.7 cm-1 at T equals 4.2 K have been detected in absorption spectrum of regular LiTmF4 crystal. The observed line belongs to transition form ground state 3H6((Gamma) 2) to lowest level (Gamma) 2 of 3F2 term of Tm3+(4f12) ion. The perturbation, which induces (Gamma) 2 - (Gamma) 2 transition, does not break S4 symmetry of Tm3+ sites. The perturbation of this kind is the interaction of Tm3+ 4f-electrons with electric field, created by quadrupolar moments of lattice ions, which are induced, int urn, by incident electromagnetic wave. To calculate the components of the quadrupolar moment tensors for ions in LiTmF4 single crystal, we have formulated and solved the system of self-consistent linear equations. We take into account interactions between all induced dipolar and quadrupolar moments and their interactions with electric fields of incident wave. The calculated transition probailities per second are in qualitative accordance with experimental data.

  20. Intensity Biased PSP Measurement

    NASA Technical Reports Server (NTRS)

    Subramanian, Chelakara S.; Amer, Tahani R.; Oglesby, Donald M.; Burkett, Cecil G., Jr.

    2000-01-01

    The current pressure sensitive paint (PSP) technique assumes a linear relationship (Stern-Volmer Equation) between intensity ratio (I(sub o)/I) and pressure ratio (P/P(sub o)) over a wide range of pressures (vacuum to ambient or higher). Although this may be valid for some PSPs, in most PSPs the relationship is nonlinear, particularly at low pressures (less than 0.2 psia when the oxygen level is low). This non-linearity can be attributed to variations in the oxygen quenching (de-activation) rates (which otherwise is assumed constant) at these pressures. Other studies suggest that some paints also have non-linear calibrations at high pressures; because of heterogeneous (non-uniform) oxygen diffusion and quenching. Moreover, pressure sensitive paints require correction for the output intensity due to light intensity variation, paint coating variation, model dynamics, wind-off reference pressure variation, and temperature sensitivity. Therefore to minimize the measurement uncertainties due to these causes, an insitu intensity correction method was developed. A non-oxygen quenched paint (which provides a constant intensity at all pressures, called non-pressure sensitive paint, NPSP) was used for the reference intensity (I(sub NPSP) with respect to which all the PSP intensities (I) were measured. The results of this study show that in order to fully reap the benefits of this technique, a totally oxygen impermeable NPSP must be available.

  1. Intensity Biased PSP Measurement

    NASA Technical Reports Server (NTRS)

    Subramanian, Chelakara S.; Amer, Tahani R.; Oglesby, Donald M.; Burkett, Cecil G., Jr.

    2000-01-01

    The current pressure sensitive paint (PSP) technique assumes a linear relationship (Stern-Volmer Equation) between intensity ratio (I(sub 0)/I) and pressure ratio (P/P(sub 0)) over a wide range of pressures (vacuum to ambient or higher). Although this may be valid for some PSPs, in most PSPs the relationship is nonlinear, particularly at low pressures (less than 0.2 psia when the oxygen level is low). This non-linearity can be attributed to variations in the oxygen quenching (de-activation) rates (which otherwise is assumed constant) at these pressures. Other studies suggest that some paints also have non-linear calibrations at high pressures; because of heterogeneous (non-uniform) oxygen diffusion and c quenching. Moreover, pressure sensitive paints require correction for the output intensity due to light intensity variation, paint coating variation, model dynamics, wind-off reference pressure variation, and temperature sensitivity. Therefore to minimize the measurement uncertainties due to these causes, an in- situ intensity correction method was developed. A non-oxygen quenched paint (which provides a constant intensity at all pressures, called non-pressure sensitive paint, NPSP) was used for the reference intensity (I(sub NPSP)) with respect to which all the PSP intensities (I) were measured. The results of this study show that in order to fully reap the benefits of this technique, a totally oxygen impermeable NPSP must be available.

  2. Lepton mixing under the lepton charge nonconservation, neutrino masses and oscillations and the 'forbidden' decay Micro-Sign {sup -} {yields} e{sup -} + {gamma}

    SciTech Connect

    Lyuboshitz, V. L.; Lyuboshitz, V. V.

    2013-08-15

    The lepton-charge (L{sub e}, L{sub {mu}}, L{sub {tau}}) nonconserving interaction leads to the mixing of the electron, muon, and tau neutrinos, which manifests itself in spatial oscillations of a neutrino beam, and also to the mixing of the electron, negative muon, and tau lepton, which, in particular, may be the cause of the 'forbidden' radiative decay of the negative muon into the electron and {gamma} quantum. Under the assumption that the nondiagonal elements of the mass matrices for neutrinos and ordinary leptons, connected with the lepton charge nonconservation, are the same, and by performing the joint analysis of the experimental data on neutrino oscillations and experimental restriction for the probability of the decay Micro-Sign {sup -} {yields} e{sup -} + {gamma} per unit time, the following estimate for the lower bound of neutrino mass has been obtained: m{sup ({nu})} > 1.5 eV/c{sup 2}.

  3. New insights on frequency combinations and ‘forbidden frequencies’ in the de Haas-van Alphen spectrum of κ-(ET)2Cu(SCN)2

    NASA Astrophysics Data System (ADS)

    Audouard, Alain; Fortin, Jean-Yves; Vignolles, David; Laukhin, Vladimir N.; Kushch, Nataliya D.; Yagubskii, Eduard B.

    2016-07-01

    de Haas-van Alphen oscillations of the organic metal κ-(ET)2Cu(SCN)2 have been measured up to 55 T at liquid helium temperatures. The Fermi surface of this charge transfer salt is a textbook example of a linear chain of orbits coupled by magnetic breakdown. Accordingly, the oscillation spectrum is composed of linear combinations of the frequencies linked to the α and magnetic breakdown-induced β orbits. The field and temperature dependence of all the observed Fourier components, in particular the ‘forbidden frequency’ β -α which cannot correspond to a classical orbit, are quantitatively accounted for by analytical calculations based on a second order development of the free energy, i.e. beyond the first order Lifshitz-Kosevich formula.

  4. Detection of singly ionized oxygen around Jupiter

    NASA Technical Reports Server (NTRS)

    Pilcher, C. B.; Morgan, J. S.

    1979-01-01

    Forbidden emission from singly ionized oxygen at wavelengths of 3726 and 3729 angstroms has been detected in the inner Jovian magnetosphere. The emission is present between approximately 4 and 7 to 8 Jovian radii from the planet and appears concentrated in the magnetic equator. The line intensity ratio indicates the same plasma characteristics as those derived from observations of forbidden sulfur emission.

  5. Carbon lines at limitedly low frequencies

    NASA Technical Reports Server (NTRS)

    Valtts, I. Y.

    1983-01-01

    Detection of several absorption recombination radio lines of carbon at 26 MHz in Cas A direction resulted in an attempt to select similar situations (a gas cloud projection on the intense source of the nonthermal radio emission) that are promising for detecting lines of such a kind. Recommendations are given for observations to be made.

  6. New Strong-line Abundance Diagnostics for H II Regions: Effects of κ-distributed Electron Energies and New Atomic Data

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Sutherland, Ralph S.; Nicholls, David C.; Kewley, Lisa J.; Vogt, Frédéric P. A.

    2013-09-01

    Recently, Nicholls et al., inspired by in situ observations of solar system astrophysical plasmas, suggested that the electrons in H II regions are characterized by a κ-distribution of energies rather than a simple Maxwell-Boltzmann distribution. Here, we have collected together new atomic data within a modified photoionization code to explore the effects of both the new atomic data and the κ-distribution on the strong-line techniques used to determine chemical abundances in H II regions. By comparing the recombination temperatures (T rec) with the forbidden line temperatures (T FL), we conclude that κ ~ 20. While representing only a mild deviation from equilibrium, this result is sufficient to strongly influence abundances determined using methods that depend on measurements of the electron temperature from forbidden lines. We present a number of new emission line ratio diagnostics that cleanly separate the two parameters determining the optical spectrum of H II regions—the ionization parameter q or \\cal {U} and the chemical abundance, 12+log(O/H). An automated code to extract these parameters is presented. Using the homogeneous data set from van Zee et al., we find self-consistent results between all of these different diagnostics. The systematic errors between different line ratio diagnostics are much smaller than those found in the earlier strong-line work. Overall, the effect of the κ-distribution on the strong-line abundances derived solely on the basis of theoretical models is rather small.

  7. Spin-forbidden and spin-allowed cyclopropenone (c-H{sub 2}C{sub 3}O) formation in interstellar medium

    SciTech Connect

    Ahmadvand, Seyedsaeid; Zaari, Ryan R.; Varganov, Sergey A.

    2014-11-10

    Three proposed mechanisms of cyclopropenone (c-H{sub 2}C{sub 3}O) formation from neutral species are studied using high-level electronic structure methods in combination with nonadiabatic transition state and collision theories to deduce the likelihood of each reaction mechanism under interstellar conditions. The spin-forbidden reaction involving the singlet electronic state of cyclopenylidene (c-C{sub 3}H{sub 2}) and the triplet state of atomic oxygen is studied using nonadiabatic transition state theory to predict the rate constant for c-H{sub 2}C{sub 3}O formation. The spin-allowed reactions of c-C{sub 3}H{sub 2} with molecular oxygen and acetylene with carbon monoxide were also investigated. The reaction involving the ground electronic states of acetylene and carbon monoxide has a very large reaction barrier and is unlikely to contribute to c-H{sub 2}C{sub 3}O formation in interstellar medium. The spin-forbidden reaction of c-C{sub 3}H{sub 2} with atomic oxygen, despite the high probability of nonadiabatic transition between the triplet and singlet states, was found to have a very small rate constant due to the presence of a small (3.8 kcal mol{sup –1}) reaction barrier. In contrast, the spin-allowed reaction between c-C{sub 3}H{sub 2} and molecular oxygen is found to be barrierless, and therefore can be an important path to the formation of c-H{sub 2}C{sub 3}O molecule in interstellar environment.

  8. Imaging spectrophotometry of ionized gas in NGC 1068. I - Kinematics of the narrow-line region

    NASA Technical Reports Server (NTRS)

    Cecil, Gerald; Bland, Jonathan; Tully, R. Brent

    1990-01-01

    The kinematics of collisionally excited forbidden N II 6548, 6583 across the inner 1 arcmin diameter of the nearby Seyfert galaxy NGC 1068 is mapped using an imaging Fabry-Perot interferometer and low-noise CCD. The stack of monochromatic images, which spatially resolved the high-velocity gas, was analyzed for kinematic and photometric content. Profiles agree well with previous long-slit work, and their complete spatial coverage makes it possible to constrain the gas volume distribution. It is found that the narrow-line region is distributed in a thick center-darkened, line-emitting cylinder that envelopes the collimated radio jet. Three distinct kinematic subsystems, of which the cylinder is composed, are discussed in detail. Detailed behavior of the emission-line profiles, at the few points in the NE quadrant with simple kinematics, argues that the ionized gas develops a significant component of motion perpendicular to the jet axis.

  9. Near-infrared line identification in type Ia supernovae during the transitional phase

    SciTech Connect

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R.; Parrent, Jerod T.; Thomas, R. C.; Marion, G. H.

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  10. High intensity neutrino beams

    SciTech Connect

    Ichikawa, A. K.

    2015-07-15

    High-intensity proton accelerator complex enabled long baseline neutrino oscillation experiments with a precisely controlled neutrino beam. The beam power so far achieved is a few hundred kW with enourmorous efforts of accelerator physicists and engineers. However, to fully understand the lepton mixing structure, MW-class accelerators are desired. We describe the current intensity-frontier high-energy proton accelerators, their plans to go beyond and technical challenges in the neutrino beamline facilities.

  11. The ultraviolet continuum and the fluorescent H2 lines in low-excitation Herbig-Haro objects

    NASA Technical Reports Server (NTRS)

    Boehm, K. H.; Scott, D. M.; Solf, J.

    1991-01-01

    Long-exposure IUE observations are used here to determine the spatial distribution of the fluorescent H2 line emission in the low-excitation objects HH 43 and HH 47. In HH 43, the spatial distribution of the fluorescent H2 line emission has a width equal to or smaller than the width of the point-spread function of IUE, while both the short-wavelength UV continuum and the optical forbidden S II lines show distributions which are wider by more than a factor of two. In HH 47, the results are qualitatively analogous, but the differences between the fluorescent HH 23 emission distribution on the one hand, and the UV continuum and optical forbidden S II distribution on the other, are smaller. These distributions indicate that the appropriate conditions for the formation of fluorscent H2 lines are fulfilled only in rather narrow regions for these low-excitation objects. A continuous energy distribution in HH 43 and HH 47 is found which differs only slightly from that in the high-excitation objects HH 1 and HH 2.

  12. Auroral resonance line radiative transfer

    SciTech Connect

    Gladstone, G.R. )

    1992-02-01

    A model is developed for simulating the two-dimensional radiative transfer of resonance line emissions in auroras. The method of solution utilizes Fourier decomposition of the horizontal dependence in the intensity field so that the two-dimensional problem becomes a set of one-dimensional problems having different horizontal wavenumbers. The individual one-dimensional problems are solved for using a Feautrier-type solution of the differential-integral form of the radiative transfer equation. In the limit as the horizontal wavenumber becomes much larger than the local line-center extinction coefficient, the scattering integral becomes considerably simplified, and the final source function is evaluated in closed form. The two-dimensional aspects of the model are tested against results for nonresonance radiative transfer studies, and the resonance line part of the model is tested against results of existing plane-parallel resonance line radiative transfer codes. Finally, the model is used to simulate the intensity field of O{sub I} 1,304{angstrom} for hard and soft auroras of various Gaussian horizontal widths. The results demonstrate the importance of considering the effects of two-dimensional radiative transfer when analyzing auroral resonance line data.

  13. Texas Intense Positron Source (TIPS)

    NASA Astrophysics Data System (ADS)

    O'Kelly, D.

    2003-03-01

    The Texas Intense Positron Source (TIPS) is a state of the art variable energy positron beam under construction at the Nuclear Engineering Teaching Laboratory (NETL). Projected intensities on the order of the order of 10^7 e+/second using ^64Cu as the positron source are expected. Owing to is short half-life (t1/2 12.8 hrs), plans are to produce the ^64Cu isotope on-site using beam port 1 of NETL TRIGA Mark II reactor. Following tungsten moderation, the positrons will be electrostatically focused and accelerated from few 10's of eV up to 30 keV. This intensity and energy range should allow routine performance of several analytical techniques of interest to surface scientists (PALS, PADB and perhaps PAES and LEPD.) The TIPS project is being developed in parallel phases. Phase I of the project entails construction of the vacuum system, source chamber, main beam line, electrostatic/magnetic focusing and transport system as well as moderator design. Initial construction, testing and characterization of moderator and beam transport elements are underway and will use a commercially available 10 mCi ^22Na radioisotope as a source of positrons. Phase II of the project is concerned primarily with the Cu source geometry and thermal properties as well as production and physical handling of the radioisotope. Additional instrument optimizing based upon experience gained during Phase I will be incorporated in the final design. Current progress of both phases will be presented along with motivations and future directions.

  14. Observation of strongly forbidden solid effect dynamic nuclear polarization transitions via electron-electron double resonance detected NMR

    SciTech Connect

    Smith, Albert A.; Corzilius, Björn; Haze, Olesya; Swager, Timothy M.; Griffin, Robert G.

    2013-12-07

    We present electron paramagnetic resonance experiments for which solid effect dynamic nuclear polarization transitions were observed indirectly via polarization loss on the electron. This use of indirect observation allows characterization of the dynamic nuclear polarization (DNP) process close to the electron. Frequency profiles of the electron-detected solid effect obtained using trityl radical showed intense saturation of the electron at the usual solid effect condition, which involves a single electron and nucleus. However, higher order solid effect transitions involving two, three, or four nuclei were also observed with surprising intensity, although these transitions did not lead to bulk nuclear polarization—suggesting that higher order transitions are important primarily in the transfer of polarization to nuclei nearby the electron. Similar results were obtained for the SA-BDPA radical where strong electron-nuclear couplings produced splittings in the spectrum of the indirectly observed solid effect conditions. Observation of high order solid effect transitions supports recent studies of the solid effect, and suggests that a multi-spin solid effect mechanism may play a major role in polarization transfer via DNP.

  15. Ultraviolet and optical spectra of high-ionization Seyfert galaxies with narrow lines

    NASA Technical Reports Server (NTRS)

    Crenshaw, D. Michael; Peterson, Bradley M.; Korista, Kirk T.; Wagner, R. Mark; Aufdenberg, Jason P.

    1991-01-01

    Ultraviolet and optical spectra are presented for three unusual Seyfert galaxies (Mrk 1239, Mrk 42, and Mrk 493) that resemble Seyfert 1 galaxies in that they have strong high-ionization lines and strong nonstellar continua, but resemble Seyfert 2 galaxies in that the widths of their permitted lines are as narrow as the widths of their forbidden lines. The He II lambda 1640 and He II lambda 4686 lines are used to determine an upper limit to the reddening experienced by the emission lines. Published optical data show that these particular high-ionization narrow-line (HINL) Seyferts have low lambda 5007 H beta ratios and strong Fe II emission, which suggest the presence of high-density regions. The low Lalpha/H-beta ratios in these objects indicate that high-density clouds are indeed present, and, like the broad-line region clouds in Seyfert 1 galaxies, these clouds have large optical depths with partially ionized zones. Overall, the line ratios and continuum fluxes of these particular HINL Seyferts are indistinguishable from those of broad-lined Seyfert 1 galaxies.

  16. X-Ray Spectrum of a Narrow Line Quasi-Stellar Object

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.

    1996-01-01

    This AO-3 observation of a new narrow-line QSO was motivated by our extensive study of the unclassified X-ray sources from the ROSAT/IRAS survey of Boller et al. IRAS 2018.1-2244 was observed to have Balmer lines and forbidden lines of roughly equal width. There are possibly weak broad wings on the H-alpha line. One of the questions to be addressed by hard X-ray spectroscopy is whether or not these wings are to be interpreted as scattered or weakly transmitted flux from a hidden broad-line region. The optical spectrum of this QSO also has very weak permitted Fe II lines, possibly indicative of a hidden broad line region. A new wrinkle on the concept of the narrow-line QSO is the gradual realization that luminous objects with very strong but narrow Fe II lines are showing up preferentially in soft X-ray surveys. The AO-1 objective was to detect the Geminga Pulsar and to interpret its 2-10 keV spectrum and pulse profile in terms of its X-ray emission spectra. Also, the AO-1 observed the Seyfert galaxy NGC 3516 to obtain a high signal-to-noise ratio spectrum. We expected NGC 3516 to be one of the best candidates for a successful demonstration of the details of the warm-absorber model.

  17. Central line infections - hospitals

    MedlinePlus

    ... infection; CVC - infection; Central venous device - infection; Infection control - central line infection; Nosocomial infection - central line infection; Hospital acquired infection - central line infection; Patient safety - central ...

  18. EUV and infra-red lines of Fe 13

    NASA Technical Reports Server (NTRS)

    Young, P. R.; Mason, Helen E.; Thomas, R. J.

    1994-01-01

    New level population calculations for Fe-XIII are presented, and line intensities predicted. The extreme ultraviolet (EUV) lines are compared with the recent observations of the solar extreme ultraviolet rocket telescope and spectrograph (SERTS), and density estimates for the active region are given. Uses of the Fe-XIII lines are suggested, both for the sun and other stars, and the possibility of coordinating SOHO studies of EUV lines with ground based observations of Fe-XIII infrared lines is discussed.

  19. Strongly intensive quantities

    SciTech Connect

    Gorenstein, M. I.; Gazdzicki, M.

    2011-07-15

    Analysis of fluctuations of hadron production properties in collisions of relativistic particles profits from use of measurable intensive quantities which are independent of system size variations. The first family of such quantities was proposed in 1992; another is introduced in this paper. Furthermore we present a proof of independence of volume fluctuations for quantities from both families within the framework of the grand canonical ensemble. These quantities are referred to as strongly intensive ones. Influence of conservation laws and resonance decays is also discussed.

  20. Zeeman effect induced by intense laser light.

    PubMed

    Stambulchik, E; Maron, Y

    2014-08-22

    We analyze spectral line shapes of hydrogenlike species subjected to fields of electromagnetic waves. It is shown that the magnetic component of an electromagnetic wave may significantly influence the spectra. In particular, the Zeeman effect induced by a visible or infrared light can be experimentally observed using present-day powerful lasers. In addition, the effect may be used for diagnostics of focused beam intensities achieved at existing and newly built laser facilities. PMID:25192094

  1. Zeeman effect induced by intense laser light.

    PubMed

    Stambulchik, E; Maron, Y

    2014-08-22

    We analyze spectral line shapes of hydrogenlike species subjected to fields of electromagnetic waves. It is shown that the magnetic component of an electromagnetic wave may significantly influence the spectra. In particular, the Zeeman effect induced by a visible or infrared light can be experimentally observed using present-day powerful lasers. In addition, the effect may be used for diagnostics of focused beam intensities achieved at existing and newly built laser facilities.

  2. Field and intensity correlation in random media

    PubMed

    Sebbah; Pnini; Genack

    2000-11-01

    We have obtained the spectral and spatial field correlation functions, C(E)(Deltaomega) and C(E)(Deltax), respectively, from measurement of the microwave field spectrum at a series of points along a line on the output of a random dielectric medium. C(E)(Deltaomega) and C(E)(Deltax) are shown to be the Fourier transforms, respectively, of the time of flight distribution, obtained from pulsed measurements, and of the specific intensity. Unlike C(E)(Deltaomega), the imaginary part of C(E)(Deltax) is shown to vanish as a result of the isotropy of the correlation function in the output plane. The complex square of the field correlation function gives the short-range or C1 contribution to the intensity correlation function C. Longer-range contributions to the intensity correlation function are obtained directly by subtracting C1 from C and are in good agreement with theory.

  3. An integrated-intensity method for emission spectrographic computer analysis

    USGS Publications Warehouse

    Thomas, Catharine P.

    1975-01-01

    An integrated-intensity method has been devised to improve the computer analysis of data by emission spectrography. The area of the intensity profile of a spectral line is approximated by a rectangle whose height is related to the intensity difference between the peak and background of the line and whose width is measured at a fixed transmittance below the apex of the line. The method is illustrated by the determination of strontium in the presence of greater than 10 percent calcium. The Sr 3380.711-A line, which is unaffected by calcium and which has a linear analytical curve extending from 100-3,000 ppm, has been used to determine strontium in 18 standard reference rocks covering a wide range of geologic materials. Both the accuracy and the precision of the determinations were well within the accepted range for a semiquantitative procedure.

  4. Binge Drinking Intensity

    PubMed Central

    Esser, Marissa B.; Kanny, Dafna; Brewer, Robert D.; Naimi, Timothy S.

    2015-01-01

    Background Binge drinking (≥4 drinks for women; ≥5 drinks for men, per occasion) is responsible for more than half of the estimated 80,000 U.S. deaths annually and three-quarters of the $223.5 billion in costs in 2006. Binge drinking prevalence is assessed more commonly than binge drinking intensity (i.e., number of drinks consumed per binge episode). Risk of binge drinking–related harm increases with intensity, and thus it is important to monitor. The largest number of drinks consumed is assessed in health surveys, but its usefulness for assessing binge intensity is unknown. Purpose To assess the agreement between two potential measures of binge drinking intensity: the largest number of drinks consumed by binge drinkers (maximum-drinks) and the total number of drinks consumed during their most recent binge episode (drinks-per-binge). Methods Data were analyzed from 7909 adult binge drinkers from 14 states responding to the 2008 Behavioral Risk Factor Surveillance System (BRFSS) binge drinking module. Mean and median drinks-per-binge from that module were compared to mean and median maximum-drinks. Analyses were conducted in 2010–2011. Results Mean (8.2) and median (5.9) maximum-drinks were strongly correlated with mean (7.4) and median (5.4) drinks-per-binge (r=0.57). These measures were also strongly correlated across most sociodemographic and drinking categories overall and within states. Conclusions The maximum-drinks consumed by binge drinkers is a practical method for assessing binge drinking intensity and thus can be used to plan and evaluate Community Guide–recommended strategies for preventing binge drinking (e.g., increasing the price of alcoholic beverages and regulating alcohol outlet density). PMID:22608381

  5. Cosmic gamma-ray lines - Theory

    NASA Technical Reports Server (NTRS)

    Lingenfelter, R. E.; Ramaty, R.

    1980-01-01

    The various processes that lead to gamma-ray line emission and the possible astrophysical sources of such emission are reviewed. The processes of nuclear excitation, radiative capture, positron annihilation, and cyclotron radiation, which may produce gamma-ray line emission from such diverse sources as the interstellar medium, novas, supernovas, pulsars, accreting compact objects, the galactic nucleus and the nuclei of active galaxies are considered. The significance of the relative intensities, widths, and frequency shifts of the lines are also discussed. Particular emphasis is placed on understanding those gamma-ray lines that have already been observed from astrophysical sources.

  6. Submillimeter, millimeter, and microwave spectral line catalogue

    NASA Technical Reports Server (NTRS)

    Poynter, R. L.; Pickett, H. M.

    1980-01-01

    A computer accessible catalogue of submillimeter, millimeter, and microwave spectral lines in the frequency range between O and 3000 GHz (such as; wavelengths longer than 100 m) is discussed. The catalogue was used as a planning guide and as an aid in the identification and analysis of observed spectral lines. The information listed for each spectral line includes the frequency and its estimated error, the intensity, lower state energy, and quantum number assignment. The catalogue was constructed by using theoretical least squares fits of published spectral lines to accepted molecular models. The associated predictions and their estimated errors are based upon the resultant fitted parameters and their covariances.

  7. The 2001 June 21 Eclipse Polarimetric Observations of the Fe XIII 1074.7 nm Emission Line

    NASA Astrophysics Data System (ADS)

    Habbal, S. R.; Arndt, M. B.; Nayfeh, M. H.; Arnaud, J.; Johnson, J.; Hegwer, S.; Ene, A.

    2003-05-01

    Polarimetric measurements of the coronal forbidden lines have been recognized for quite some time as a diagnostic tool for inferring the direction of the coronal magnetic field. Following the first successful measurements by Eddy et al. (1973) during the total solar eclipse of 1966, an observing campaign using the coronagraph at Sacramento Peak Observatory was pursued between 1977-1980 (Arnaud and Newkirk, 1987). All these measurements yielded the surprising result that the direction of polarization implied a predominantly radial coronal magnetic field. We report on the polarization measurements of the Fe XIII 1074.7nm line, the strongest of the coronal forbidden lines, which were obtained during the total solar eclipse of 2001 June 21 from Zambia. In addition to confirming the earlier results of a predominantly radial field, the signature of nano-size interplanetary dust in the inner corona, most likely in the form of silicon nanoparticles, appeared for the first time in these measurements. The signature of these particles also coincides with the radial expansion of coronal holes outwards from the Sun, a signature that has never appeared in any measurement before. Support for this work was provided by NSF grant ATM-0003661 and NASA grant NAG5-10873

  8. Radiative lifetimes of spin forbidden a1Δ → X 3Σ- and spin allowed A3Π → X 3Σ- transitions and complete basis set extrapolated ab initio potential energy curves for the ground and excited states of CH-

    NASA Astrophysics Data System (ADS)

    Srivastava, Saurabh; Sathyamurthy, N.

    2012-12-01

    The spin forbidden transition a1Δ → X3Σ- in CH- has been studied using the Breit-Pauli Hamiltonian for a large number of geometries. This transition acquires intensity through spin-orbit coupling with singlet and triplet Π states. The transition moment matrix including more than one singlet and triplet Π states was calculated at the multi-reference configuration interaction/aug-cc-pV6Z level of theory. The computed radiative lifetime of 5.63 s is in good agreement with the experimental (5.9 s) and other theoretical (6.14 s) results. Transition moment values of the spin allowed A3Π → X3Σ- transition have also been calculated at the same level of theory. Calculations show that the corresponding radiative lifetime is considerably low, 2.4 × 10-7 s. Complete basis set extrapolated potential energy curves for the ground state of CH and the ground state and six low lying excited states (a1Δ, b1Σ+, two 3Π, and two 1Π) of CH- are reported. These curves are then used to calculate the vibrational bound states for CH and CH-. The computed electron affinity of CH supports the electron affinity bounds reported by Okumura et al. [J. Chem. Phys. 85, 1971 (1986), 10.1063/1.451140].

  9. Line-by-line spectroscopic simulations on graphics processing units

    NASA Astrophysics Data System (ADS)

    Collange, Sylvain; Daumas, Marc; Defour, David

    2008-01-01

    We report here on software that performs line-by-line spectroscopic simulations on gases. Elaborate models (such as narrow band and correlated-K) are accurate and efficient for bands where various components are not simultaneously and significantly active. Line-by-line is probably the most accurate model in the infrared for blends of gases that contain high proportions of H 2O and CO 2 as this was the case for our prototype simulation. Our implementation on graphics processing units sustains a speedup close to 330 on computation-intensive tasks and 12 on memory intensive tasks compared to implementations on one core of high-end processors. This speedup is due to data parallelism, efficient memory access for specific patterns and some dedicated hardware operators only available in graphics processing units. It is obtained leaving most of processor resources available and it would scale linearly with the number of graphics processing units in parallel machines. Line-by-line simulation coupled with simulation of fluid dynamics was long believed to be economically intractable but our work shows that it could be done with some affordable additional resources compared to what is necessary to perform simulations on fluid dynamics alone. Program summaryProgram title: GPU4RE Catalogue identifier: ADZY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 62 776 No. of bytes in distributed program, including test data, etc.: 1 513 247 Distribution format: tar.gz Programming language: C++ Computer: x86 PC Operating system: Linux, Microsoft Windows. Compilation requires either gcc/g++ under Linux or Visual C++ 2003/2005 and Cygwin under Windows. It has been tested using gcc 4.1.2 under Ubuntu Linux 7.04 and using Visual C

  10. Vortex-based line beam optical tweezers

    NASA Astrophysics Data System (ADS)

    Cheng, Shubo; Tao, Shaohua

    2016-10-01

    A vortex-based line beam, which has a straight-line shape of intensity and possesses phase gradient along the line trajectory is developed and applied for optical manipulation in this paper. The intensity and phase distributions of the beam in the imaging plane of the Fourier transform are analytically studied. Simulation results show that the length of the line and phase gradient possessed by a vortex-based line beam are dependent on the topological charge and the azimuthal proportional constant. A superposition of multiple phase-only holograms with elliptical azimuthal phases can be used to generate an array of vortex-based line beams. Optical trapping with the vortex-based line beams has been implemented. Furthermore, the automatic transportation of microparticles along the line trajectory perpendicular to the optical axis is realized with an array of the beams. The generation method for the vortex-based line beam is simple. The beam would have potential applications in fields such as optical trapping, laser machining, and so on.

  11. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  12. Intense ion beam generator

    DOEpatents

    Humphries, Jr., Stanley; Sudan, Ravindra N.

    1977-08-30

    Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation.

  13. Water intensity of transportation.

    PubMed

    King, Carey W; Webber, Michael E

    2008-11-01

    As the need for alternative transportation fuels increases, it is important to understand the many effects of introducing fuels based upon feedstocks other than petroleum. Water intensity in "gallons of water per mile traveled" is one method to measure these effects on the consumer level. In this paper we investigate the water intensity for light duty vehicle (LDV) travel using selected fuels based upon petroleum, natural gas, unconventional fossil fuels, hydrogen, electricity, and two biofuels (ethanol from corn and biodiesel from soy). Fuels more directly derived from fossil fuels are less water intensive than those derived either indirectly from fossil fuels (e.g., through electricity generation) or directly from biomass. The lowest water consumptive (<0.15 gal H20/mile) and withdrawal (<1 gal H2O/mile) rates are for LDVs using conventional petroleum-based gasoline and diesel, nonirrigated biofuels, hydrogen derived from methane or electrolysis via nonthermal renewable electricity, and electricity derived from nonthermal renewable sources. LDVs running on electricity and hydrogen derived from the aggregate U.S. grid (heavily based upon fossil fuel and nuclear steam-electric power generation) withdraw 5-20 times and consume nearly 2-5 times more water than by using petroleum gasoline. The water intensities (gal H20/mile) of LDVs operating on biofuels derived from crops irrigated in the United States at average rates is 28 and 36 for corn ethanol (E85) for consumption and withdrawal, respectively. For soy-derived biodiesel the average consumption and withdrawal rates are 8 and 10 gal H2O/mile. PMID:19031873

  14. Measurement of Itch Intensity.

    PubMed

    Reich, Adam; Szepietowski, Jacek C

    2016-01-01

    Measurement of itch intensity is essential to properly evaluate pruritic disease severity, to understand the patients' needs and burden, and especially to assess treatment efficacy, particularly in clinical trials. However, measurement of itch remains a challenge, as, per definition, it is a subjective sensation and assessment of this symptom represents significant difficulty. Intensity of itch must be considered in relation to its duration, localization, course of symptoms, presence and type of scratch lesions, response to antipruritic treatment, and quality of life impairment. Importantly, perception of itch may also be confounded by different cofactors including but not limited to patient general condition and other coexisting ailments. In the current chapter we characterize the major methods of itch assessments that are used in daily clinical life and as research tools. Different methods of itch assessment have been developed; however, so far none is without limitations and any data on itch intensity should always be interpreted with caution. Despite these limitations, it is strongly recommended to implement itch measurement tools in routine daily practice, as it would help in proper assessment of patient clinical status. In order to improve evaluation of itch in research studies, it is recommended to use at least two independent methods, as such an approach should increase the validity of achieved results. PMID:27578068

  15. Variations in the Strength of the Infrared Forbidden 2328.2 cm-1 Fundamental of Solid N2 in Binary Mixtures

    NASA Technical Reports Server (NTRS)

    Bernstein, Max P.; Sandford, Scott A.; Mead, Susan (Technical Monitor)

    2002-01-01

    We present the 2335-2325 cm(exp -1) infrared spectra and band positions, profiles, and strengths (A values) of solid nitrogen and binary mixtures of N2 with other molecules at 12 K. The data demonstrate that the strength of the infrared forbidden N2 fundamental near 2328 cm(exp -1) is moderately enhanced in the presence of NH3, strongly enhanced in the presence of H2O and very strongly enhanced in the presence of CO2, but is not significantly affected by CO, CH4, or O2. The mechanisms for the enhancements in N2-NH3 and N2-H2O mixtures are fundamentally different from those proposed for N2-CO2 mixtures. In the first case, interactions involving hydrogen-bonding are likely the cause. In the latter, a resonant exchange between the N2 stretching fundamental and the O-18=C-12 asymmetric stretch of O-18C-12O-16 is indicated. The implications of these results for several astrophysical issues are briefly discussed.

  16. Precise ro-vibrational analysis of molecular bands forbidden in absorption: The ν8 +ν10 band of 13C2H4

    NASA Astrophysics Data System (ADS)

    Ulenikov, O. N.; Gromova, O. V.; Bekhtereva, E. S.; Kashirina, N. V.; Maul, C.; Bauerecker, S.

    2015-10-01

    The high resolution spectra of the 13C2H4 molecule was recorded with a Bruker IFS 120 Fourier transform spectrometer and theoretically analyzed in the 1650 - 1800cm-1 region of the ν8 +ν10 band which is forbidden in absorption. About 1200 experimental transitions with the maximum values of quantum numbers Jmax. = 34 and Kamax. = 17 were assigned to the ν8 +ν10 band. On that basis the 516 high accuracy ro-vibrational energies of the (v8=v10=1) vibrational state, as well as energy levels with J ≤ 2 of the (v4 =v8 = 1) and (v7 =v8 = 1) vibrational states, were determined which then were used as input data in the weighted fit of spectroscopic parameters of the Hamiltonian (strong local resonance interactions of the ν8 +ν10 band with the bands ν4 +ν8 and ν7 +ν8 have been taken into account). A set of 34 vibrational, rotational, centrifugal distortion, and resonance interaction parameters was obtained from the fit. These parameters reproduce positions of about 1200 experimentally recorded and assigned transitions with the rms error drms = 0.00018cm-1 (blended and very weak transitions are not taken into account in that case).

  17. Associating a prototypical forbidden food item with guilt or celebration: relationships with indicators of (un)healthy eating and the moderating role of stress and depressive symptoms.

    PubMed

    Kuijer, Roeline G; Boyce, Jessica A; Marshall, Emma M

    2015-01-01

    The increase in obesity and the many educational messages prompting us to eat a healthy diet have heightened people's concerns about the effects of food choice on health and weight. An unintended side effect may be that such awareness fuels feelings of guilt and worry about food. Although guilt has the potential to motivate behaviour change, it may also lead to feelings of helplessness and loss of control. The current study examined the relationship between a default association of either 'guilt' or 'celebration' with a prototypical forbidden food item (chocolate cake), indicators of healthy eating and choosing food for mood regulation reasons. Following a 'diathesis-stress' perspective, the moderating roles of depressive symptoms and stress were examined. Although a default association of guilt was found to be harmless under some circumstances (i.e. under low stress), those who associated chocolate cake with guilt (vs. celebration) reported unhealthier eating habits and lower levels of perceived behavioural control over healthy eating when under stress, rated mood regulation reasons for food choice as important irrespective of their current affective state, and did not have more positive attitudes towards healthy eating. Implications for public health messages and interventions will be discussed. PMID:25186250

  18. Variations in the strength of the infrared forbidden 2328.2 cm-1 fundamental of solid N2 in binary mixtures.

    PubMed

    Bernstein, M P; Sandford, S A

    1999-10-01

    We present the 2335-2325 cm-1 infrared spectra and band positions, profiles and strengths (A values) of solid nitrogen and binary mixtures of N2 with other molecules at 12 K. The data demonstrate that the strength of the infrared forbidden N2 fundamental near 2328 cm-1 is moderately enhanced in the presence of NH3, strongly enhanced in the presence of H2O and very strongly enhanced (by over a factor of 1000) in the presence of CO2, but is not significantly affected by CO, CH4, or O2. The mechanisms for the enhancements in N2-NH3 and N2-H2O mixtures are fundamentally different from those proposed for N2-CO2 mixtures. In the first case, interactions involving hydrogen-bonding are likely the cause. In the latter, a resonant exchange between the N2 stretching fundamental and the 18O = 12C asymmetric stretch of 18O12C16O is indicated. The implications of these results for several astrophysical issues are briefly discussed. PMID:11543545

  19. Observation of the Forbidden Magnetic Dipole Transition 6{sup 2}P{sub ½} --> 7{sup 2}P{sub ½} in Atomic Thallium

    DOE R&D Accomplishments Database

    Chu, S.

    1976-10-01

    A measurement of the 6{sup 2}P{sub ½} --> 7{sup 2}P{sub ½} forbidden magnetic dipole matrix element in atomic thallium is described. A pulsed, linearly polarized dye laser tuned to the transition frequency is used to excite the thallium vapor from the 6{sup 2}P{sub ½} ground state to the 7{sup 2}P{sub ½} excited state. Interference between the magnetic dipole M1 amplitude and a static electric field induced E1 amplitude results in an atomic polarization of the 7{sup 2}P{sub ½} state, and the subsequent circular polarization of 535 nm fluorescence. The circular polarization is seen to be proportional to / as expected, and measured for several transitions between hyperfine levels of the 6{sup 2}P{sub ½} and 7{sup 2}P{sub ½} states. The result is = -(2.11 +- 0.30) x 10{sup -5} parallel bar e parallel bar dirac constant/2mc, in agreement with theory.

  20. Effect of cooler electrons on a compressive ion acoustic solitary wave in a warm ion plasma — Forbidden regions, double layers, and supersolitons

    SciTech Connect

    Ghosh, S. S.; Sekar Iyengar, A. N.

    2014-08-15

    It is observed that the presence of a minority component of cooler electrons in a three component plasma plays a deterministic role in the evolution of solitary waves, double layers, or the newly discovered structures called supersolitons. The inclusion of the cooler component of electrons in a single electron plasma produces sharp increase in nonlinearity in spite of a decrease in the overall energy of the system. The effect maximizes at certain critical value of the number density of the cooler component (typically 15%–20%) giving rise to a hump in the amplitude variation profile. For larger amplitudes, the hump leads to a forbidden region in the ambient cooler electron concentration which dissociates the overall existence domain of solitary wave solutions in two distinct parameter regime. It is observed that an inclusion of the cooler component of electrons as low as < 1% affects the plasma system significantly resulting in compressive double layers. The solution is further affected by the cold to hot electron temperature ratio. In an adequately hotter bulk plasma (i.e., moderately low cold to hot electron temperature ratio), the parameter domain of compressive double layers is bounded by a sharp discontinuity in the corresponding amplitude variation profile which may lead to supersolitons.

  1. Screening of preservatives by HPLC-PDA-ESI/MS: A focus on both allowed and recently forbidden compounds in the new EU cosmetics regulation.

    PubMed

    Lecce, Raffaele; Regazzoni, Luca; Mustazza, Carlo; Incarnato, Giampaolo; Porrà, Rita; Panusa, Alessia

    2016-06-01

    Commission regulation (EU) No 358/2014 amending the new regulation (EC) No 1223/2009 on cosmetics has prohibited the use of isopropyl-, isobutyl-, phenyl-, benzyl- and pentylparaben. Furthermore, Commission regulation (EU) No 1004/2014 has lowered the maximum permitted concentration of butyl- and propylparaben in cosmetics and it has also banned them in leave-on products designed for application on the nappy area of children under three years of age. A HPLC-PDA-ESI/MS method has been developed herein for the detection of seventeen preservatives, both the most utilised and the recently forbidden by the new EU regulations. The separation of these compounds, including benzoic acid and its derivatives in a 1.10 - 3.04 log Pow range, has been performed with a gradient elution on a Symmetry(®) C18 column (250×4.6mm i.d., particle size 5μm) with water and acetonitrile (0.1% formic acid) as mobile phase. Quantification has been carried out by HPLC-PDA. The method has been validated and successfully applied to the analysis of a large number of cosmetics with different functions like rinse-off and leave-on, or composition like skin, hair, face and oral products. PMID:27055177

  2. [Screening method for 29 forbidden or limited synthetic pigments in cheese by liquid chromatography/quadrupole time-of-flight mass spectrometry].

    PubMed

    Zhao, Yansheng; Yang, Minli; Zhang, Feng; Feng, Feng; Chu, Xiaogang; Dong, Ying

    2011-07-01

    A screening method for 29 forbidden or limited synthetic pigments in cheese samples was established by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF MS). The pigments were extracted by n-hexane/water (3:1, v/v). After extraction, the n-hexane extract, water extract and residue, were obtained. The n-hexane extract was then cleaned-up by gel permeation chromatography (GPC). The water extract was extracted by acetonitrile, and the residue by ammonia water/methanol (1:99, v/v). The results showed that the 29 synthetic pigments with a wide range of polarities were extracted effectively with the recoveries between 70% and 95%, and matched well by Q-TOF MS precision mass searching to the mass spectral library with matching scores between 59. 66 and 99. 47. The quantitative analysis of the 29 pigments was carried out by Target MS/MS. The limits of detection (LODs) for 8 Sudan dyes were 0.4-2.5 micro/kg while for 21 water-soluble synthetic pigments were 20-80 microg/kg. The screening method is suitable for a wide range of synthetic pigments, and can be applied to food samples with proteins and fat in matrix.

  3. Formation of a Spin-Forbidden Product, (1)[MnO4](-), from Gas-Phase Decomposition of (6)[Mn(NO3)3](.).

    PubMed

    Lightcap, Johnny; Hester, Thomas H; Patterson, Daniel; Butler, Joseph T; Goebbert, Daniel J

    2016-09-15

    The manganese nitrate complex, [Mn(NO3)3](-), was generated via electrospray ionization and studied by tandem quadrupole mass spectrometry. The complex is assumed to decompose into [MnO(NO3)2](-) by elimination of NO2(•). The [MnO(NO3)2](-) product undergoes elimination of NO2(•) to yield [MnO2(NO3)](-), or elimination of NO(•) to yield [MnO3(NO3)](-). Both [MnO2(NO3)](-) and [MnO3(NO3)](-) yield [MnO4](-) via the transfer of oxygen atoms from the remaining nitrate ligand. The mechanism of permanganate formation is interesting because it can be generated through two competing pathways, and because the singlet ground state is spin-forbidden from the high-spin sextet [Mn(NO3)3](-) precursor. Theory and experiment suggest [MnO2(NO3)](-) is the major intermediate leading to formation of [MnO4](-). Theoretical studies show crossing from the high-spin to low-spin surface upon neutral oxygen atom transfer from the nitrate ligand in [MnO2(NO3)](-) allows formation of (1)[MnO4](-). Relative energy differences for the formation of (1)[MnO4](-) and (1)[MnO3](-) predicted by theory agree with experiment. PMID:27585373

  4. First-forbidden β-decay rates, energy rates of β-delayed neutrons and probability of β-delayed neutron emissions for neutron-rich nickel isotopes

    NASA Astrophysics Data System (ADS)

    Nabi, Jameel-Un; Çakmak, Necla; Iftikhar, Zafar

    2016-01-01

    First-forbidden (FF) transitions can play an important role in decreasing the calculated half-lives specially in environments where allowed Gamow-Teller (GT) transitions are unfavored. Of special mention is the case of neutron-rich nuclei where, due to phase-space amplification, FF transitions are much favored. We calculate the allowed GT transitions in various pn-QRPA models for even-even neutron-rich isotopes of nickel. Here we also study the effect of deformation on the calculated GT strengths. The FF transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. Later we take into account deformation of nuclei and calculate GT + unique FF transitions, stellar β-decay rates, energy rate of β-delayed neutrons and probability of β-delayed neutron emissions. The calculated half-lives are in excellent agreement with measured ones and might contribute in speeding-up of the r-matter flow.

  5. Associating a prototypical forbidden food item with guilt or celebration: relationships with indicators of (un)healthy eating and the moderating role of stress and depressive symptoms.

    PubMed

    Kuijer, Roeline G; Boyce, Jessica A; Marshall, Emma M

    2015-01-01

    The increase in obesity and the many educational messages prompting us to eat a healthy diet have heightened people's concerns about the effects of food choice on health and weight. An unintended side effect may be that such awareness fuels feelings of guilt and worry about food. Although guilt has the potential to motivate behaviour change, it may also lead to feelings of helplessness and loss of control. The current study examined the relationship between a default association of either 'guilt' or 'celebration' with a prototypical forbidden food item (chocolate cake), indicators of healthy eating and choosing food for mood regulation reasons. Following a 'diathesis-stress' perspective, the moderating roles of depressive symptoms and stress were examined. Although a default association of guilt was found to be harmless under some circumstances (i.e. under low stress), those who associated chocolate cake with guilt (vs. celebration) reported unhealthier eating habits and lower levels of perceived behavioural control over healthy eating when under stress, rated mood regulation reasons for food choice as important irrespective of their current affective state, and did not have more positive attitudes towards healthy eating. Implications for public health messages and interventions will be discussed.

  6. Nanoscale shift of the intensity distribution of dipole radiation.

    PubMed

    Shu, Jie; Li, Xin; Arnoldus, Henk F

    2009-02-01

    The energy flow lines (field lines of the Poynting vector) for radiation emitted by a dipole are in general curves, rather than straight lines. For a linear dipole the field lines are straight, but when the dipole moment of a source rotates, the field lines wind numerous times around an axis, which is perpendicular to the plane of rotation, before asymptotically approaching a straight line. We consider an elliptical dipole moment, representing the most general state of oscillation, and this includes the linear dipole as a special case. Due to the spiraling near the source, for the case of a rotating dipole moment, the field lines in the far field are displaced with respect to the outward radial direction, and this leads to a shift of the intensity distribution of the radiation in the far field. This shift is shown to be independent of the distance to the source and, although of nanoscale dimension, should be experimentally observable.

  7. Characteristics of spectral lines with crater development during laser-induced breakdown spectroscopy.

    PubMed

    Li, Kuohu; Guo, Lianbo; Li, Xiangyou; Hao, Zhongqi; Li, Jiaming; Yang, Xinyan; Shen, Meng; Zeng, Qingdong; Lu, Yongfeng; Zeng, Xiaoyan

    2016-09-10

    To study the characteristics of spectral lines with crater development during laser-induced breakdown spectroscopy, the changes in the spectral line intensities of iron (Fe) and chromium (Cr) during the development of craters were investigated. Images of the plasmas formed during crater development were captured, and the temperatures and electron densities of the plasmas were calculated. The results showed that when a crater developed, the intensities of the ion lines decreased and the intensities of the atomic lines increased. This is because the plasmas generated in the crater have a higher initial emission intensity and experience more rapid cooling as the crater develops. These two effects lead to changes in the rates of decrease of ion and atomic line intensities over time. Therefore, the changes in intensities of ion lines caused by crater development differ from which of atomic lines.

  8. Characteristics of spectral lines with crater development during laser-induced breakdown spectroscopy.

    PubMed

    Li, Kuohu; Guo, Lianbo; Li, Xiangyou; Hao, Zhongqi; Li, Jiaming; Yang, Xinyan; Shen, Meng; Zeng, Qingdong; Lu, Yongfeng; Zeng, Xiaoyan

    2016-09-10

    To study the characteristics of spectral lines with crater development during laser-induced breakdown spectroscopy, the changes in the spectral line intensities of iron (Fe) and chromium (Cr) during the development of craters were investigated. Images of the plasmas formed during crater development were captured, and the temperatures and electron densities of the plasmas were calculated. The results showed that when a crater developed, the intensities of the ion lines decreased and the intensities of the atomic lines increased. This is because the plasmas generated in the crater have a higher initial emission intensity and experience more rapid cooling as the crater develops. These two effects lead to changes in the rates of decrease of ion and atomic line intensities over time. Therefore, the changes in intensities of ion lines caused by crater development differ from which of atomic lines. PMID:27661384

  9. Characteristics of gamma-ray line flares

    NASA Technical Reports Server (NTRS)

    Bai, T.; Dennis, B.

    1983-01-01

    Observations of solar gamma rays by the Solar Maximum Mission (SMM) demonstrate that energetic protons and ions are rapidly accelerated during the impulsive phase. To understand the acceleration mechanisms for these particles, the characteristics of the gamma ray line flares observed by SMM were studied. Some very intense hard X-ray flares without detectable gamma ray lines were also investigated. Gamma ray line flares are distinguished from other flares by: (1) intense hard X-ray and microwave emissions; (2) delay of high energy hard X-rays; (3) emission of type 2 and/or type 4 radio bursts; and (4) flat hard X-ray spectra (average power law index: 3.1). The majority of the gamma ray line flares shared all these characteristics, and the remainder shared at least three of them. Positive correlations were found between durations of spike bursts and spatial sizes of flare loops as well as between delay times and durations of spike bursts.

  10. Cryopreservation of Xenopus transgenic lines.

    PubMed

    Buchholz, Daniel R; Fu, Liezhen; Shi, Yun-Bo

    2004-01-01

    Xenopus laevis has been widely used for molecular, cellular, and developmental studies. With the development of the sperm-mediated transgenic method, it is now possible to study gene function during vertebrate development by using this popular model. On the other hand, like other animal species, it is labor intensive, and the maintenance of transgenic lines is expensive. In this article, we investigated the possibility of using sperm-cryopreservation as a means to preserve transgenic frog lines. We demonstrated that cryopreserved sperms are viable but not fertile under our in vitro fertilization (IVF) conditions. However, by microinjecting cryopreserved sperm nuclei, we successfully regenerated a transgenic line carrying a double promoter transgene construct, where the marker gene encoding the green fluorescent protein (GFP) is driven by the gamma-crystallin gene promoter and a gene of interest, encoding a fusion protein of GFP with the matrix metalloproteinase stromelysin-3 (ST3-GFP), is driven by a heat shock-inducible promoter. We demonstrated the functional transmission of the ST3-GFP transgene by analyzing the phenotype of the F1 animals after heat-shock to induce its expression. Our method thus provides an inexpensive means to preserve transgenic frog lines and a convenient way for distribution of transgenic lines. Furthermore, the ease with which to microinject nuclei compared to the technically demanding transgenesis procedure with variable outcome should facilitate more laboratories to use transgenic Xenopus laevis for functional studies in vivo. Mol. Reprod. Dev. 67: 65-69, 2004.

  11. Intensity modulated proton therapy.

    PubMed

    Kooy, H M; Grassberger, C

    2015-07-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed "pencil beams" of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak-the characteristic peak of dose at the end of range-combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radiotherapy or volumetric modulated arc therapy) with dose modulation along the beam axis as well as lateral, in-field, dose modulation. The clinical practice of IMPT further improves the healthy tissue vs target dose differential in comparison with X-rays and thus allows increased target dose with dose reduction elsewhere. In addition, heavy-charged-particle beams allow for the modulation of biological effects, which is of active interest in combination with dose "painting" within a target. The clinical utilization of IMPT is actively pursued but technical, physical and clinical questions remain. Technical questions pertain to control processes for manipulating pencil beams from the creation of the proton beam to delivery within the patient within the accuracy requirement. Physical questions pertain to the interplay between the proton penetration and variations between planned and actual patient anatomical representation and the intrinsic uncertainty in tissue stopping powers (the measure of energy loss per unit distance). Clinical questions remain concerning the impact and management of the technical and physical questions within the context of the daily treatment delivery, the clinical benefit of IMPT and the biological response differential compared with X-rays against which clinical benefit will be judged. It is expected that IMPT will replace other modes of proton field delivery. Proton radiotherapy, since its first practice 50 years ago, always required the highest level of

  12. High intensity ultrasound.

    PubMed

    ter Haar, G

    2001-03-01

    High-intensity focused ultrasound (HIFU) is a technique that was first investigated in the 1940s as a method of destroying selective regions within the brain in neuro-surgical An ultrasound beam can be brought to a tight focus at a distance from its source, and if sufficient energy is concentrated within the focus, the cells lying within this focal volume are killed, whereas those lying elsewhere are spared. This is a noninvasive method of producing selective and trackless tissue destruction in deep seated targets in the body, without damage to overlying tissues. This field, known both as HIFU and focused ultrasound surgery (FUS), is reviewed in this article.

  13. Intensive Care Unit Psychosis

    PubMed Central

    Monks, Richard C.

    1984-01-01

    Patients who become psychotic in intensive care units are usually suffering from delirium. Underlying causes of delirium such as anxiety, sleep deprivation, sensory deprivation and overload, immobilization, an unfamiliar environment and pain, are often preventable or correctable. Early detection, investigation and treatment may prevent significant mortality and morbidity. The patient/physician relationship is one of the keystones of therapy. More severe cases may require psychopharmacological measures. The psychotic episode is quite distressing to the patient and family; an educative and supportive approach by the family physician may be quite helpful in patient rehabilitation. PMID:21279016

  14. Intensity modulated proton therapy

    PubMed Central

    Grassberger, C

    2015-01-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed “pencil beams” of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak—the characteristic peak of dose at the end of range—combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radiotherapy or volumetric modulated arc therapy) with dose modulation along the beam axis as well as lateral, in-field, dose modulation. The clinical practice of IMPT further improves the healthy tissue vs target dose differential in comparison with X-rays and thus allows increased target dose with dose reduction elsewhere. In addition, heavy-charged-particle beams allow for the modulation of biological effects, which is of active interest in combination with dose “painting” within a target. The clinical utilization of IMPT is actively pursued but technical, physical and clinical questions remain. Technical questions pertain to control processes for manipulating pencil beams from the creation of the proton beam to delivery within the patient within the accuracy requirement. Physical questions pertain to the interplay between the proton penetration and variations between planned and actual patient anatomical representation and the intrinsic uncertainty in tissue stopping powers (the measure of energy loss per unit distance). Clinical questions remain concerning the impact and management of the technical and physical questions within the context of the daily treatment delivery, the clinical benefit of IMPT and the biological response differential compared with X-rays against which clinical benefit will be judged. It is expected that IMPT will replace other modes of proton field delivery. Proton radiotherapy, since its first practice 50 years ago, always required the

  15. Signal-to-noise enhancement in ground-based intensity observations of solar p modes

    NASA Technical Reports Server (NTRS)

    Germain, Marvin E.

    1995-01-01

    Intensity observations of solar p modes are needed to form a complete picture of wave propagation in the photosphere. Ground-based intensity observations are severely hampered by terrestrial atmospheric noise. Partial cancellation of the noise power can be achieved if two spectra having disparate signal-to- noise ratios, and based on time series acquired simultaneously at the same site, are combined. A method of combining the spectra is suggested in which one amplitude is scaled and subtracted from the other. The result is squared yielding a positive-definite power density. To test the method, the intensity of light scattered by the Earth's atmnosphere was recorded at fifteen- second intervals in two narrow bands centered on 0.5 microns and 1.6 microns. When the two resulting spectra were combined, the noise power was attenuated by a factor of 2.7. The scale factor was varied about its optimum value, revealing that noise peaks have a different siganture than signal peaks, and opening up the possibility of a new tool in discrimination against noise peaks. Maxima at symmetry-allowed frequencies and minima at symmetry- forbidden frequencies indicate that the possibility that these results are obtained by chance is only 6.1 x 10(exp -4). The positions of these maxima and minima also support the solar-cycle dependent frequency shifts found by Palle, Regulo, and Roca Cortes.

  16. [Safety of intensive sweeteners].

    PubMed

    Lugasi, Andrea

    2016-04-01

    Nowadays low calorie or intesive sweeteners are getting more and more popular. These sweeteners can be placed to the market and used as food additives according to the recent EU legislation. In the meantime news are coming out one after the other stating that many of these artificial intensive sweeteners can cause cancer - the highest risk has been attributed to aspartam. Low calorie sweeteners, just like all the other additives can be authorized after strickt risk assessment procedure according to the recent food law. Only after the additive has gone through these procedure can be placed to the list of food additives, which contains not only the range of food these additives can be used, but also the recommended highest amount of daily consumption. European Food Safety Authority considering the latest scientific examination results, evaluates regularly the safety of sweeteners authorized earlier. Until now there is no evidence found to question the safety of the authorized intensive sweeteners. Orv. Hetil., 2016, 157(Suppl. 1), 14-28. PMID:27088715

  17. French intensive truck garden

    SciTech Connect

    Edwards, T D

    1983-01-01

    The French Intensive approach to truck gardening has the potential to provide substantially higher yields and lower per acre costs than do conventional farming techniques. It was the intent of this grant to show that there is the potential to accomplish the gains that the French Intensive method has to offer. It is obvious that locally grown food can greatly reduce transportation energy costs but when there is the consideration of higher efficiencies there will also be energy cost reductions due to lower fertilizer and pesticide useage. As with any farming technique, there is a substantial time interval for complete soil recovery after there have been made substantial soil modifications. There were major crop improvements even though there was such a short time since the soil had been greatly disturbed. It was also the intent of this grant to accomplish two other major objectives: first, the garden was managed under organic techniques which meant that there were no chemical fertilizers or synthetic pesticides to be used. Second, the garden was constructed so that a handicapped person in a wheelchair could manage and have a higher degree of self sufficiency with the garden. As an overall result, I would say that the garden has taken the first step of success and each year should become better.

  18. High intensity proton synchrotrons

    NASA Astrophysics Data System (ADS)

    Craddock, M. K.

    1986-10-01

    Strong initiatives are being pursued in a number of countries for the construction of ``kaon factory'' synchrotrons capable of producing 100 times more intense proton beams than those available now from machines such as the Brookhaven AGS and CERN PS. Such machines would yield equivalent increases in the fluxes of secondary particles (kaons, pions, muons, antiprotons, hyperons and neutrinos of all varieties)—or cleaner beams for a smaller increase in flux—opening new avenues to various fundamental questions in both particle and nuclear physics. Major areas of investigation would be rare decay modes, CP violation, meson and hadron spectroscopy, antinucleon interactions, neutrino scattering and oscillations, and hypernuclear properties. Experience with the pion factories has already shown how high beam intensities make it possible to explore the ``precision frontier'' with results complementary to those achievable at the ``energy frontier''. This paper will describe proposals for upgrading and AGS and for building kaon factories in Canada, Europe, Japan and the United States, emphasizing the novel aspects of accelerator design required to achieve the desired performance (typically 100 μA at 30 GeV).

  19. Observations of the infrared fine-structure lines of S III at 18.71 and 33.47 microns in four H II regions

    NASA Technical Reports Server (NTRS)

    Herter, T.; Briotta, D. A., Jr.; Gull, G. E.; Shure, M. A.; Houck, J. R.

    1982-01-01

    Infrared fine-structure lines provide a particularly useful probe of ionized nebulae. The present investigation is concerned with measurements of the forbidden S III lines at 18.71 and 33.47 micrometers for four H II regions, S158A, S158G, G75.84+0.4, and W3 IRS 1. These lines are used to estimate densities, and comparisons are made with rms densities determined from radio observations to evaluate the importance of clumping. For the case of the optical H II region S158A, comparisons are made with both optical and forbidden O III line determinations of the density. The reported observations were made using a dual-grating, liquid-helium-cooled spectrometer containing a three-element Si:Sb detector array and a three-element Ge:Ga detector array. It is found that clumping is important in the cases of G75.84+0.4, W3 IRS 1, and M42. These three H II regions have filling factors of 0.024, 0.09, and 0.03, respectively.

  20. Peripheral intravenous line - infants

    MedlinePlus

    PIV - infants; Peripheral IV - infants; Peripheral line - infants; Peripheral line - neonatal ... A peripheral intravenous line (PIV) is a small, short, plastic tube, called a catheter. A health care provider puts ...