Science.gov

Sample records for line widths transition

  1. Experimental Stark widths, shifts, and transition probabilities of several ArII lines

    SciTech Connect

    Aparicio, J. A.; Gigosos, M. A.; Mar, S.; Gonzalez, V. R.

    1997-01-05

    This paper is an extensive experimental contribution to the knowledge of ArII atomic parameters. This specie, which is very important for many astrophysical and industrial plasma diagnostics, has been extensively studied. However, there are still great differences in the experimental Stark widths and shifts coefficients, as well as a great lack of transition probability data, especially for lines coming from the very highly excited energy levels.

  2. Experimental Stark widths, shifts, and transition probabilities of several ArII lines

    SciTech Connect

    Aparicio, J.A.; Gigosos, M.A.; Mar, S.; Gonzalez, V.R.

    1997-01-01

    This paper is an extensive experimental contribution to the knowledge of ArII atomic parameters. This specie, which is very important for many astrophysical and industrial plasma diagnostics, has been extensively studied. However, there are still great differences in the experimental Stark widths and shifts coefficients, as well as a great lack of transition probability data, especially for lines coming from the very highly excited energy levels. {copyright} {ital 1997 American Institute of Physics.}

  3. Narrow-line-width UV Bursts in the Transition Region above Sunspots Observed by IRIS

    NASA Astrophysics Data System (ADS)

    Hou, Zhenyong; Huang, Zhenghua; Xia, Lidong; Li, Bo; Madjarska, Maria S.; Fu, Hui; Mou, Chaozhou; Xie, Haixia

    2016-10-01

    Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions, characterized by strong emissions but extremely narrow Si iv line profiles as found in observations taken with the Interface Region Imaging Spectrograph (IRIS). Tentatively named as narrow-line-width UV bursts (NUBs), these structures are located above sunspots and comprise one or multiple compact bright cores at sub-arcsecond scales. We found six NUBs in two data sets (a raster and a sit-and-stare data set). Among these, four events are short-lived with a duration of ˜10 minutes, while two last for more than 36 minutes. All NUBs have Doppler shifts of 15-18 km s-1, while the NUB found in sit-and-stare data possesses an additional component at ˜50 km s-1 found only in the C ii and Mg ii lines. Given that these events are found to play a role in the local dynamics, it is important to further investigate the physical mechanisms that generate these phenomena and their role in the mass transport in sunspots.

  4. Diatomic predissociation line widths

    NASA Technical Reports Server (NTRS)

    Child, M. S.

    1973-01-01

    Predissociation by rotation and curve crossing in diatomic molecules is discussed. The pattern of predissociation line widths is seen as providing a highly sensitive yardstick for the determination of unknown potential curves. In addition, the computation of such a pattern for given potential curves is considered a matter of routine, unless the predissociation happens to occur from an adiabatic potential curve. Analytic formulas are used to provide physical insight into the details of the predissociation pattern, to the extent that a direct inversion procedure is developed for determination of the repulsive potential curves for Type 1 predissociations.

  5. Stark Widths Of Ionized Xenon UV Lines Of Low Intensity

    SciTech Connect

    Cirisan, M.; Djurovic, S.; Pelaez, R. J.; Aparicio, J. A.; Mar, S.

    2007-04-23

    Stark width measurements of several low intensity Xe II spectral lines (5d - 4f transitions) in UV region, are presented here for the first time. These measurements were obtained from helium - xenon pulsed arc plasma.

  6. Energy level systems and transitions of Ho:LuAG laser resonantly pumped by a narrow line-width Tm fiber laser.

    PubMed

    Chen, Hao; Zhao, Ting; Yang, Hao; Zhang, Le; Zhou, Tianyuan; Tang, Dingyuan; Wong, Chingping; Chen, Yung-Fu; Shen, Deyuan

    2016-11-28

    We presented a Ho:LuAG ceramic laser in-band pumped by a narrow emission line-width Tm fiber laser at 1907 nm. All of potential transitions between 5I7 and 5I8 manifold were discussed to form the Ho's in-band-pump energy level systems, which were not described in details earlier. For the emission band centered at ~2095 nm, both laser absorption and emission transition separately consisted of two groups were first analyzed and observed. Using output couplers (OCs) with different transmittances (T = 6, 10 and 20%), the similar ~0.5 W continuous-wave (CW) output power under an incident pump power of ~4.9 W was obtained, with twin (or triplet) emission bands respectively. The blue shift of center emission wavelengths was observed with the increase of transmittances.

  7. Line shape parameters of PH3 transitions in the Pentad near 4–5 μm: Self-broadened widths, shifts, line mixing and speed dependence

    SciTech Connect

    Malathy Devi, V.; Benner, D. C.; Kleiner, Isabelle; Sams, Robert L.; Fletcher, Leigh N.

    2014-08-01

    Accurate knowledge of spectroscopic line parameters of PH3 is important for remote sensing of the outer planets, especially Jupiter and Saturn. In a recent study, line positions and intensities for the Pentad bands of PH3 have been reported from analysis of high-resolution, high signal-to noise room-temperature spectra recorded with two Fourier transform spectrometers (2014) [1]. The results presented in this study were obtained during the analysis of positions and intensities, but here we focus on the measurements of spectral line shapes (e.g. widths, shifts, line mixing) for the 2ν4, ν2 + ν4, ν1 and ν3 bands. A multispectrum nonlinear least squares curve fitting technique employing a non-Voigt line shape to include line mixing and speed dependence of the Lorentz width was employed to fit the spectra simultaneously. The least squares fittings were performed on five room-temperature spectra recorded at various PH3 pressures (~2–50 Torr) with the Bruker IFS-125HR Fourier transform spectrometer (FTS) located at the Pacific Northwest National Laboratory (PNNL), in Richland, Washington. Over 840 Lorentz self-broadened half-width coefficients, 620 self-shift coefficients and 185 speed dependence parameters were measured. Line mixing was detected for transitions in the 2ν4, ν1 and ν3 bands, and their values were quantified for 10 A+A- pairs of transitions via off-diagonal relaxation matrix element formalism. The dependences of the measured half-width coefficients on the J and K rotational quanta of the transitions are discussed. The self-width coefficients for the ν1 and ν3 bands from this study are compared to the self-width coefficients for transitions with the same rotational quanta (J, K) reported for the Dyad (ν2 and ν4) bands. The measurements from present study should be useful for the

  8. The Variable Line Width of Achernar

    NASA Astrophysics Data System (ADS)

    Rivinius, Th.; Townsend, R. H. D.; Baade, D.; Carciofi, A. C.; Leister, N.; Štefl, S.

    2016-11-01

    Spectroscopic observations of Achernar over the past decades, have shown the photospheric line width, as measured by the rotational parameter v sin i, to vary in correlation with the emission activity. Here we present new observations, covering the most recent activity phase, and further archival data collected from the archives. The v sin i variation is confirmed. On the basis of the available data it cannot be decided with certainty whether the increased line width precedes the emission activity, i.e. is a signature of the ejection mechanism, or postdates it, which would make it a signature of re-accretion of some of the disk-material. However, the observed evidence leans towards the re-accretion hypothesis. Two further stars showing the effect of variable line width in correlation with emission activity, namely 66 Oph and π Aqr, are presented as well.

  9. Calculated Half-widths and Line Shifts of Water Vapor Transitions in the 0.7- Micron Region and a Comparison with Published Data

    NASA Technical Reports Server (NTRS)

    Gamache, Robert R.; Fischer, Jonathan

    2001-01-01

    Pressure-broadened half-widths and pressure-induced line shifts for the two most important bands of water vapor in the 0.7-micron region are determined using the complex Robert-Bonamy (CRB) formalism. The calculations are made with nitrogen and oxygen as the perturbing gas from which values for air as the perturbing gas are determined. The intermolecular potential is taken as a sum of electrostatic contributions and Lennard-Jones (6-12) atom-atom, and isotropic induction and dispersion components. The dynamics of the collision process are correct to second order in time. The calculated values are compared with published measurements and agreement is observed for both half-widths and line shifts. The temperature dependence of the half-width, which is necessary for reduction of remotely sensed data, is determined.

  10. Investigating Starburst Galaxy Emission Line Equivalent Widths

    NASA Astrophysics Data System (ADS)

    Meskhidze, Helen; Richardson, Chris T.

    2016-01-01

    Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent widths. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent widths of varying the metallicity of the cloud, Z = 0.2 Z⊙ to Z = 5.0 Z⊙, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.

  11. Variation in the Width of Transition Region Network Boundaries

    NASA Astrophysics Data System (ADS)

    Raju, K. P.

    2016-12-01

    The transition region network seen in solar extreme ultraviolet (EUV) lines is the extension of the chromospheric network. The network appears as an irregular web-like pattern over the solar surface outside active regions. The average width of transition region network boundaries is obtained from the two-dimensional autocorrelation function of SOlar and Heliospheric Observatory (SOHO)/ Coronal Diagnostic Spectrometer (CDS) synoptic images of the Sun in two emission lines, He i 586 Å and O v 630 Å during 1996 - 2012. The width of the network boundaries is found to be roughly correlated with the solar cycle variation with a lag of about ten months. A comparison of the widths in the two emission lines shows that they are larger for the He i line. The SOHO/CDS data also show large asymmetry in boundary widths in the horizontal (x) and vertical (y) image directions, which is shown to be caused by image distortions that are due to instrumental effects. Since the network boundary widths are related to the magnetic flux concentration along the boundaries, the results are expected to have implications on the flux transport on the solar surface, solar cycle, and the mass and energy budget of network loops and jets.

  12. An Empirical Expression for the Line Widths of Ammonia

    NASA Technical Reports Server (NTRS)

    Brown, Linda R.; Peterson, Dean B.

    1994-01-01

    The hydrogen-broadened line widths of 116 (sup 14)NH(sub 3) ground state transitions have been measured at 0.006 cm(sup -1) resolution using a Bruker spectrometer in the 24 to 210 cm(sup -1) region. The rotational variation of the experimental widths with J(sup '),K(sup ') = 1,0 to 10,10 has been reproduced to 2.4 % using an heuristically derived expression of the form

    gamma = a(sub 0) + a(sub 1) J(sup ') + a (sub 2) K(sup ') + a(sub 3) J(sup ')(sup 2) + a(sub 4) J(sup ') K(sup ')

    where J(sup ') and K(sup ') are the lower state symmetric top quantum numbers. This function has also been applied to the measured widths of the 58 transitions of nu(sub 1) at 3 (micro)m, each broadened by N(sub 2), O(sub 2), Ar, H(sub 2), and He. The rms of the observed minus calculated widths are 5% or better for the five foreign broadeners. The values of the fitted constants suggest that for some broadeners the expression might also be written as

    gamma = a(sub 0) + b(sub 1) J(sup ') + b(sub 2)(J(sup ' )- K(sup ')) + b(sub 3) J(sup ')(J(sup ') - K(sup '))

    .

  13. An Empirical Expression for the Line Widths of Ammonia

    NASA Technical Reports Server (NTRS)

    Brown, Linda R.; Peterson, Dean B.

    1994-01-01

    The hydrogen-broadened line widths of 116 (sup 14)NH(sub 3) ground state transitions have been measured at 0.006 cm(sup -1) resolution using a Bruker spectrometer in the 24 to 210 cm(sup -1) region. The rotational variation of the experimental widths with J(sup '),K(sup ') = 1,0 to 10,10 has been reproduced to 2.4 % using an heuristically derived expression of the form

    gamma = a(sub 0) + a(sub 1) J(sup ') + a (sub 2) K(sup ') + a(sub 3) J(sup ')(sup 2) + a(sub 4) J(sup ') K(sup ')

    where J(sup ') and K(sup ') are the lower state symmetric top quantum numbers. This function has also been applied to the measured widths of the 58 transitions of nu(sub 1) at 3 (micro)m, each broadened by N(sub 2), O(sub 2), Ar, H(sub 2), and He. The rms of the observed minus calculated widths are 5% or better for the five foreign broadeners. The values of the fitted constants suggest that for some broadeners the expression might also be written as

    gamma = a(sub 0) + b(sub 1) J(sup ') + b(sub 2)(J(sup ' )- K(sup ')) + b(sub 3) J(sup ')(J(sup ') - K(sup '))

    .

  14. Line shapes and widths of MAS sidebands for 27Al satellite transitions. multinuclear MAS NMR of tugtupite Na8Al2Be2Si8O24Cl2.

    PubMed

    Skibsted, J; Norby, P; Bildsøe, H; Jakobsen, H J

    1995-12-01

    A multinuclear 9Be, 23Na, 27Al, and 29Si magic-angle spinning (MAS) NMR study has been performed for the mineral tugtupite (Na8Al2Be2Si8O24Cl2). The extremely well-resolved spectra allow observation of separate spinning sidebands (ssb's) from the inner (+/- 1/2, +/- 3/2) and outer (+/- 3/2, +/- 5/2) 27Al satellite transitions, and are utilized in a detailed analysis of the line shapes and widths of the individual ssb's from simulations. The line widths of the ssb's from the inner and outer 27Al satellite transitions are found to decrease systematically with increasing order of the ssb's across the spectrum. Accurate values for the 9Be, 23Na, and 27Al quadrupole coupling parameters and isotropic chemical shifts are obtained from simulations of the manifolds of ssb's from the satellite transitions. MAS NMR of the 9Be satellite transitions for tugtupite, BeO, and beryl(Al2Be3Si6O18) shows that these transitions are particularly useful for determination of 9Be quadrupole couplings because of the small 9Be quadrupole moment. The 29Si shielding anisotropy of delta sigma = 48 ppm in tugtupite is the largest determined so far for a framework SiO4 tetrahedron. Finally, the crystal structure of the tugtupite sample has been refined by single-crystal X-ray diffraction, and correlations between the multinuclear NMR parameters and structural data are reported.

  15. Line Width Recovery after Vectorization of Engineering Drawings

    NASA Astrophysics Data System (ADS)

    Gramblička, Matúš; Vaský, Jozef

    2016-12-01

    Vectorization is the conversion process of a raster image representation into a vector representation. The contemporary commercial vectorization software applications do not provide sufficiently high quality outputs for such images as do mechanical engineering drawings. Line width preservation is one of the problems. There are applications which need to know the line width after vectorization because this line attribute carries the important semantic information for the next 3D model generation. This article describes the algorithm that is able to recover line width of individual lines in the vectorized engineering drawings. Two approaches are proposed, one examines the line width at three points, whereas the second uses a variable number of points depending on the line length. The algorithm is tested on real mechanical engineering drawings.

  16. Line-width temperature dependence of selected R-branch transitions in the nu-3 fundamental of (N-14)2O-16 between 135 and 295 K

    NASA Technical Reports Server (NTRS)

    Loewenstein, Max; Wilson, H. W.

    1992-01-01

    Tunable diode laser spectroscopy has been used to measure the temperature dependence of N2 foreign gas broadening coefficients for eight R-branch transitions in the nu-3 fundamental of (N-14)2O-16 at 135, 176, 210, and 295 K. The exponent n of the relation for quadrupole-quadrupole collisional interactions is found to range from 0.66 to 0.71, in approximate agreement with the theoretically predicted value of 0.75.

  17. Experimental Stark widths and shifts of Ti II spectral lines

    NASA Astrophysics Data System (ADS)

    Manrique, J.; Aguilera, J. A.; Aragón, C.

    2016-10-01

    Stark widths and shifts of Ti II lines with wavelengths in the range 2500-4600 Å have been determined by laser-induced breakdown spectroscopy. The temperature and electron density of the plasma vary in the ranges 11 970-15 520 K and (2.0-7.2) × 1017 cm-3, respectively, for the different measurement instants from 0.6 to 1.8 μs. The samples used are fused glass discs with different titanium concentrations, selected to control the self-absorption of the lines. The Stark widths and shifts are compared with the experimental and theoretical data available in the literature.

  18. Magnetohydrodynamic disc winds and line width distributions - II

    NASA Astrophysics Data System (ADS)

    Chajet, L. S.; Hall, P. B.

    2017-02-01

    We study AGN emission line profiles combining an improved version of the accretion disc-wind model of Murray & Chiang with the magnetohydrodynamic (MHD) model of Emmering et al. Here, we extend our previous work to consider central objects with different masses and/or luminosities. We have compared the dispersions in our model C IV line-width distributions to observational upper limit on that dispersion, considering both smooth and clumpy torus models. Following Fine et al., we transform that scatter in the profile line-widths into a constraint on the torus geometry and show how the half-opening angle of the obscuring structure depends on the mass of the central object and the accretion rate. We find that the results depend only mildly on the dimensionless angular momentum, one of the two integrals of motion that characterize the dynamics of the self-similar ideal MHD outflows.

  19. What sets the line widths in tidal disruption events?

    NASA Astrophysics Data System (ADS)

    Roth, Nathaniel; Kasen, Daniel

    2017-01-01

    The optical and UV spectra of flares from the tidal disruption of stars by massive black holes (TDEs) vary greatly between individual events. In particular, the line widths can differ by at least a factor of five even for events with similar values inferred for the black hole mass. Additionally, the lines narrow over time in some events, and this detail has proven difficult to explain based on hydrodynamical modeling. We present radiative transfer calculations to help understand these aspects of line formation from TDEs, with a focus on the role of electron scattering in both static and outflowing reprocessing envelopes.

  20. Deciduous neonatal line: Width is associated with duration of delivery.

    PubMed

    Hurnanen, Jaana; Visnapuu, Vivian; Sillanpää, Matti; Löyttyniemi, Eliisa; Rautava, Jaana

    2017-02-01

    The delivery-related neonatal line (NNL) appears into the enamel of primary teeth and first permanent molars at birth and is a marker of live birth process. It varies in width and its location, is different in each deciduous tooth type, and is indicative of gestation time. It is unclear which triggers determine NNL at birth. Our objective was to investigate the effect of the duration and mode of delivery on NNL width. NNL of 129 teeth, a collection derived from a long-term, prospectively followed population cohort, was measured under light microscope. Altogether, 54 sections with most optimal plane of sectioning were analysed for the duration and mode of delivery. NNL was detected in 98% of the deciduous teeth with the median width of 9.63μm (min 3.16μm, max 27.58μm). A prolonged duration of vaginal delivery was highly significantly associated with a narrower NNL (r=-0.41, p=0.0097). No significant association was found between the width of NNL and mode of delivery (p=0.36). NNL is demonstrable in virtually all deciduous teeth. The width seems to be inversely proportional to the duration of delivery. Causes of the inverse proportion are speculated to result from altered amelogenesis induced by prolonged and intensified delivery-associated stress. Further research is needed to clarify the underlying mechanisms.

  1. The intrinsic line width of the Fe K α line of AGN

    NASA Astrophysics Data System (ADS)

    Liu, Jiren

    2016-11-01

    X-ray fluorescent lines are unique features of the reflection spectrum of the cold torus when irradiated by the central AGN. Their intrinsic line widths can be used to probe the line-emitting region. The line widths of the Fe K α line measured from the first-order Chandra High Energy Grating (HEG) spectra are 3-5 times larger than those measured with the Si K α line for Circinus, Mrk 3, and NGC 1068. Because the observed Si K α and Fe K α lines are not necessarily coming from the same physical region, it is uncertain whether the line widths of the Fe K α line are overestimated or not. We measured the intrinsic line widths of the Fe K α line of several nearby bright AGN using the second- and third-order Chandra HEG spectra, whose spectral resolutions are better than the first-order data. We found the measured widths are all smaller than those from the first-order data. The results clearly show that the widths of the Fe K α line measured from the first-order HEG data are overestimated. It indicates that the Fe K α lines of the studied sources are originating from regions around the cold dusty torus.

  2. A New Method for Line Width Roughness Mitigation

    NASA Astrophysics Data System (ADS)

    Mayya, K. Subramanya; Yool, Kang; Kim, Hochul; Cho, Han-Ku

    2011-06-01

    Demands of the continuous downscaling of device size impose stringent requirements on the RLS trade-off (R: resolution, L: line width roughness and S: sensitivity). Among the above, line width roughness (LWR) has to be controlled below 10% of critical dimensions (CD). While significant improvement in R&S was achieved, LWR has been relatively high for extreme ultra-violet lithography resists. Herein, we provide a new method for LWR mitigation that overcomes several shortcomings of previously known methods. Our new method is based on a double development method wherein, a polymeric solution in developer is coated on to the patterned surface. The wafer is then subjected to the standard development step during which LWR improvement is affected. In this paper we discuss the hypothesis of our method and provide relevant data to understand the conditions under which LWR improvement is observed. Effect of polymer/developer concentration ratio, solid content and bake temperatures will be discussed. Also, our method will be compared with currently available methods for LWR improvement on pattern transfer.

  3. PCF based high power narrow line width pulsed fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, H.; Yan, P.; Xiao, Q.; Wang, Y.; Gong, M.

    2012-09-01

    Based on semiconductor diode seeded multi-stage cascaded fiber amplifiers, we have obtained 88-W average power of a 1063-nm laser with high repetition rate of up to 1.5 MHz and a constant 2-ns pulse duration. No stimulated Brillouin scattering pulse or optical damage occurred although the maximum pulse peak power has exceeded 112 kW. The output laser exhibits excellent beam quality (M2x = 1.24 and M2y = 1.18), associated with a spectral line width as narrow as 0.065 nm (FWHM). Additionally, we demonstrate high polarization extinction ratio of 18.4 dB and good pulse stabilities superior to 1.6 % (RMS).

  4. Stark widths and shifts for spectral lines of Sn IV

    NASA Astrophysics Data System (ADS)

    de Andrés-García, I.; Alonso-Medina, A.; Colón, C.

    2016-01-01

    In this paper, we present theoretical Stark widths and shifts calculated corresponding to 66 spectral lines of Sn IV. We use the Griem semi-empirical approach and the COWAN computer code. For the intermediate coupling calculations, the standard method of least-squares fitting from experimental energy levels was used. Data are presented for an electron density of 1017 cm-3 and temperatures T = 1.1-5.0 (104 K). The matrix elements used in these calculations have been determined from 34 configurations of Sn IV: 4d10ns(n = 5-10), 4d10nd(n = 5-8), 4d95s2, 4d95p2, 4d95s5d, 4d85s5p2 and 4d105g for even parity and 4d10np(n = 5-8), 4d10nf (n = 4-6), 4d95snp(n = 5-8), 4d85s25p and 4d95snf (n = 4-10) for odd parity. Also, in order to test the matrix elements used in our calculations, we present calculated values of radiative lifetimes of 14 levels of Sn IV. There is good agreement between our calculations and the experimental radiative lifetimes obtained from the bibliography. The spectral lines of Sn IV are observed in UV spectra of HD 149499 B obtained with the Far Ultraviolet Spectroscopic Explorer, the Goddard High Resolution Spectrograph and the International Ultraviolet Explorer. Theoretical trends of the Stark broadening parameter versus the temperature for relevant lines are presented. Also our values of Stark broadening parameters have been compared with the data available in the bibliography.

  5. An OCD perspective of line edge and line width roughness metrology

    NASA Astrophysics Data System (ADS)

    Bonam, Ravi; Muthinti, Raja; Breton, Mary; Liu, Chi-Chun; Sieg, Stuart; Seshadri, Indira; Saulnier, Nicole; Shearer, Jeffrey; Patlolla, Raghuveer; Huang, Huai

    2017-03-01

    Metrology of nanoscale patterns poses multiple challenges that range from measurement noise, metrology errors, probe size etc. Optical Metrology has gained a lot of significance in the semiconductor industry due to its fast turn around and reliable accuracy, particularly to monitor in-line process variations. Apart from monitoring critical dimension, thickness of films, there are multiple parameters that can be extracted from Optical Metrology models3. Sidewall angles, material compositions etc., can also be modeled to acceptable accuracy. Line edge and Line Width roughness are much sought of metrology following critical dimension and its uniformity, although there has not been much development in them with optical metrology. Scanning Electron Microscopy is still used as a standard metrology technique for assessment of Line Edge and Line Width roughness. In this work we present an assessment of Optical Metrology and its ability to model roughness from a set of structures with intentional jogs to simulate both Line edge and Line width roughness at multiple amplitudes and frequencies. We also present multiple models to represent roughness and extract relevant parameters from Optical metrology. Another critical aspect of optical metrology setup is correlation of measurement to a complementary technique to calibrate models. In this work, we also present comparison of roughness parameters extracted and measured with variation of image processing conditions on a commercially available CD-SEM tool.

  6. Catalogue of equivalent widths and line intensities for prominences observed during 1964-1965

    NASA Technical Reports Server (NTRS)

    Rakhubovskiy, A. S.

    1973-01-01

    The method of observation and processing of the prominence spectra are described briefly. The equivalent widths, central intensities, half-widths and Doppler halfwidths are presented of the emission lines of the prominences.

  7. ESR line width and line shape dependence of Overhauser-enhanced magnetic resonance imaging.

    PubMed

    Meenakumari, V; Utsumi, Hideo; Jawahar, A; Milton Franklin Benial, A

    2016-11-01

    Electron spin resonance and Overhauser-enhanced magnetic resonance imaging studies were carried out for various concentrations of (14) N-labeled 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl in pure water. Overhauser-enhancement factor attains maxima in the range of 2.5-3 mm concentration. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameter showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. The electron spin resonance parameters, such as the line width, line shape and g-factor, were determined. The line width analysis confirms that the line broadening is proportional to the agent concentration, and also the agent concentration is optimized in the range of 2.5-3 mm. The line shape analysis shows that the observed electron spin resonance line shape is a Voigt line shape, in which the Lorentzian component is dominant. The contribution of Lorentzian component was estimated using the winsim package. The Lorentzian component of the resonance line attains maxima in the range of 2.5-3 mm concentration. Therefore, this study reveals that the agent concentration, line width and Lorentzian component are the important factors in determining the Overhauser-enhancement factor. Hence, the agent concentration was optimized as 2.5-3 mm for in vivo/in vitro electron spin resonance imaging and Overhauser-enhanced magnetic resonance imaging phantom studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Measurements of air-broadened and nitrogen-broadened half-widths and shifts of ozone lines near 9 microns

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    Air- and nitrogen-broadened half-widths and line shifts at room temperature for more than 60 individual vibration-rotation transitions in the nu1 fundamental band of (O-16)3 and several transitions in the nu3 band were determined from infrared absorption spectra. These spectra were recorded at 0.005/cm resolution with a Fourier-transform spectrometer. A tunable-diode-laser spectrometer operating in the 1090-1150/cm region was also used to record data on oxygen-, nitrogen-, and air-broadened half-widths for selected individual transitions. The nitrogen- and air-broadened half-widths determined by these two different measurement techniques are consistent to within 4 percent. The results are in good agreement with other published measurements and calculations.

  9. Measurements of air-broadened and nitrogen-broadened half-widths and shifts of ozone lines near 9 microns

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    Air- and nitrogen-broadened half-widths and line shifts at room temperature for more than 60 individual vibration-rotation transitions in the nu1 fundamental band of (O-16)3 and several transitions in the nu3 band were determined from infrared absorption spectra. These spectra were recorded at 0.005/cm resolution with a Fourier-transform spectrometer. A tunable-diode-laser spectrometer operating in the 1090-1150/cm region was also used to record data on oxygen-, nitrogen-, and air-broadened half-widths for selected individual transitions. The nitrogen- and air-broadened half-widths determined by these two different measurement techniques are consistent to within 4 percent. The results are in good agreement with other published measurements and calculations.

  10. Study of the OII 7320A spectral line width at Arecibo

    NASA Astrophysics Data System (ADS)

    Santos, P. T.; Noto, J.; Migliozzi, M.; Brum, C. G.; Kerr, R.; Riccobono, J.; Garcia, R.; Robles, E.

    2008-12-01

    This work presents the results for the 7320A line width data acquired from April to October of 2008 at Arecibo (18.35N, 66.75W) using a CCD array detection with a high-spectral resolution Fabry-Perot interferometer. The excited O+(2P) atom is formed by photoionization or electron impact with energy in excess of 18.6EV (< 666Å). With a lifetime of 4.57s in the upper state and no local source in the earth's shadow, the O+(2P) to O+(2D) transition produces a twilight airglow at 7320A and 7330A very near to the solid-earth shadow line. Moreover, this emission has been used in the past to determine the altitude profile of O+ temperature at the terminator, using high-spectral resolution detection. Some of these measurements have been interpreted to imply a population of hot oxygen atoms in the upper thermosphere and lower exosphere. That population remains speculative, but has the potential, if it exists, to confuse ISR ion temperature fits, with hot O+ spectra having similar width to He+ spectra.

  11. Influence of the transition width on the magnetocaloric effect across the magnetostructural transition of Heusler alloys.

    PubMed

    Cugini, F; Porcari, G; Fabbrici, S; Albertini, F; Solzi, M

    2016-08-13

    We report a complete structural and magneto-thermodynamic characterization of four samples of the Heusler alloy Ni-Co-Mn-Ga-In, characterized by similar compositions, critical temperatures and high inverse magnetocaloric effect across their metamagnetic transformation, but different transition widths. The object of this study is precisely the sharpness of the martensitic transformation, which plays a key role in the effective use of materials and which has its origin in both intrinsic and extrinsic effects. The influence of the transition width on the magnetocaloric properties has been evaluated by exploiting a phenomenological model of the transformation built through geometrical considerations on the entropy versus temperature curves. A clear result is that a large temperature span of the transformation is unfavourable to the magnetocaloric performance of a material, reducing both isothermal entropy change and adiabatic temperature change obtainable in a given magnetic field and increasing the value of the maximum field needed to fully induce the transformation. The model, which is based on standard magnetometric and conventional calorimetric measurements, turns out to be a convenient tool for the determination of the optimum values of transformation temperature span in a trade-off between sheer performance and amplitude of the operating range of a material.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'. © 2016 The Author(s).

  12. Photoluminescence line width of self-assembled Ge(Si) islands arranged between strained Si layers

    SciTech Connect

    Shaleev, M. V. Novikov, A. V.; Baydakova, N. A.; Yablonskiy, A. N.; Kuznetsov, O. A.; Lobanov, D. N.; Krasilnik, Z. F.

    2011-02-15

    The effect of variations in the strained Si layer thicknesses, measurement temperature, and optical excitation power on the width of the photoluminescence line produced by self-assembled Ge(Si) nanoislands, which are grown on relaxed SiGe/Si(001) buffer layers and arranged between strained Si layers, is studied. It is shown that the width of the photoluminescence line related to the Ge(Si) islands can be decreased or increased by varying the thickness of strained Si layers lying above and under the islands. A decrease in the width of the photoluminescence line of the Ge(Si) islands to widths comparable with the width of the photoluminescence line of quantum dot (QD) structures based on direct-gap InAs/GaAs semiconductors is attained with consideration of diffusive smearing of the strained Si layer lying above the islands.

  13. Uncertainties Associated with Theoretically Calculated N2-Broadened Half-Widths of H2O Lines

    NASA Technical Reports Server (NTRS)

    Ma, Q.; Tipping, R. H.; Gamache, R. R.

    2010-01-01

    With different choices of the cut-offs used in theoretical calculations, we have carried out extensive numerical calculations of the N2-broadend Lorentzian half-widths of the H2O lines using the modified Robert-Bonamy formalism. Based on these results, we are able to thoroughly check for convergence. We find that, with the low-order cut-offs commonly used in the literature, one is able to obtain converged values only for lines with large half-widths. Conversely, for lines with small half-widths, much higher cut-offs are necessary to guarantee convergence. We also analyse the uncertainties associated with calculated half-widths, and these are correlated as above. In general, the smaller the half-widths, the poorer the convergence and the larger the uncertainty associated with them. For convenience, one can divide all H2O lines into three categories, large, intermediate, and small, according to their half-width values. One can use this division to judge whether the calculated half-widths are converged or not, based on the cut-offs used, and also to estimate how large their uncertainties are. We conclude that with the current Robert- Bonamy formalism, for lines in category lone can achieve the accuracy requirement set by HITRAN, whereas for lines in category 3, it 'is impossible to meet this goal.

  14. On the Stark Widths and Shifts of Ar II 472.68 nm Spectral Line

    SciTech Connect

    Mijatovic, Z.; Gajo, T.; Vujicic, B.; Djurovic, S.; Kobilarov, R.

    2008-10-22

    Stark widths and shifts of Ar II 472.68 nm spectral line were measured from T-tube plasmas. Plasma electron density ranged 1.8-2.210{sup 17} cm{sup -3}, while temperature ranged 20000-43000 K. Obtained results of widths and shifts were compared with measured results of other authors.

  15. Measurement of the room temperture R(1) line width of forty-two rubies.

    PubMed

    Benedict, R A; Nester, J F; Kellington, C M

    1967-03-01

    Accurate measurement of the room temperature R(1) fluorescent line width of forty-two ruby laser crystals has been made using a pressure-scanned Fabry-Perot etalon. In forty-one of these rubies the chromium content was nearly the same, and the R(1) line width for all was 5.0 +/- 0.3 A, in agreement with present theories.

  16. Shift and width measurements of the Stark-broadened ionized helium line at 1215 A

    NASA Technical Reports Server (NTRS)

    Van Zandt, J. R.; Adcock, J. C., Jr.; Griem, H. R.

    1976-01-01

    Time-resolved photoelectric measurements were made of the shifts of helium plasma lines at 1640 A and 1215 A and of the Stark profile of the 1215 A line, using an electromagnetic shock tube as a light source. These red shifts are consistent with a plasma polarization shift, where the interaction energy between the radiating ion and the perturbing plasma electrons corresponds to the Coulomb interaction near the excited state Bohr radius. No significant shifts were observed for the 1640 A line, while the 1215 A line underwent a red shift of about 0.5 A. The measured Stark width of the 1215 A line was 10-45% greater than the calculated width based on the measured width of the 4686 A line.

  17. THE LINE WIDTH DIFFERENCE OF NEUTRALS AND IONS INDUCED BY MHD TURBULENCE

    SciTech Connect

    Xu, Siyao; Lazarian, A.; Yan, Huirong

    2015-09-01

    We address the problem of the different line widths of coexistent neutrals and ions observed in molecular clouds and explore whether this difference can arise from the effects of magnetohydrodynamic (MHD) turbulence acting on partially ionized gas. Among the three fundamental modes of MHD turbulence, we find that fast and slow modes do not contribute to line width differences. We focus on the Alfvénic component, and consider the damping of Alfvén modes by taking into account both neutral-ion collisions and neutral viscosity. We confirm that the line width difference can be explained by the differential damping of the Alfvénic turbulence in ions and the hydrodynamic turbulence in neutrals, and find it strongly depends on the properties of MHD turbulence. We consider various regimes of turbulence corresponding to different media magnetizations and turbulent drivings. In the case of super-Alfvénic turbulence, when the damping scale of Alfvénic turbulence is below the Alfvénic scale l{sub A}, the line width difference does not depend on magnetic field strength. In other turbulence regimes, however, the dependence is present and evaluation of magnetic field from the observed line width difference is possible.

  18. The Importance of Broad Emission Line Widths in Single-epoch Black Hole Mass Estimates

    NASA Astrophysics Data System (ADS)

    Assef, R. J.; Frank, S.; Grier, C. J.; Kochanek, C. S.; Denney, K. D.; Peterson, B. M.

    2012-07-01

    Estimates of the mass of super-massive black holes (BHs) in distant active galactic nuclei (AGNs) can be obtained efficiently only through single-epoch (SE) spectra, using a combination of their broad emission line widths and continuum luminosities. Yet the reliability and accuracy of the method and the resulting mass estimates, M BH, remain uncertain. A recent study by Croom using a sample of Sloan Digital Sky Survey, 2dF QSO Redshift Survey, and 2dF-SDSS LRG and QSO Survey quasars suggests that line widths contribute little information about the BH mass in these SE estimates and can be replaced by a constant value without significant loss of accuracy. In this Letter, we use a sample of nearby reverberation-mapped AGNs to show that this conclusion is not universally applicable. We use the bulge luminosity (L Bulge) of these local objects to test how well the known M BH-L Bulge correlation is recovered when using randomly assigned line widths instead of the measured ones to estimate M BH. We find that line widths provide significant information about M BH, and that for this sample, the line width information is just as significant as that provided by the continuum luminosities. We discuss the effects of observational biases upon the analysis of Croom and suggest that the results can probably be explained as a bias of flux-limited, shallow quasar samples.

  19. N2 pressure - broadened O3 line widths and strengths near 1129.4 cm-1

    NASA Technical Reports Server (NTRS)

    Copeland, G. E.; Majorana, L. N.; Harward, C. N.; Steinkamp, R. J.

    1982-01-01

    A Beer's Law experiment was performed with a tunable diode laser to find the N2 pressure broadening characteristics of a single 03 absorption line at 1129.426 cm for N2 pressures from 10 to 100 torr (O3 pressure = 3.16 torr). SO2 line positions were used for wavelength calibration. Line shapes were interatively fitted to a Lorentz function. Results were delta (HWHM in MHz) = 47.44 (+ or - 5.34) MHz + 1.730 (+ or - 0.088) MHz/torr *p(torr) with sigma = 0.9897. This intercept compares well with the Doppler O3 - O3 broadened (at 3.16 torr) width of 44.52 Hz. This result in a HWHM line width of 0.44 cm atm at 760 torr and 285 K. The line strengths integrated over delta nu = 0.55 cm were found to be N2 pressure dependent.

  20. Variation of Emission Line Width in Mid- and High-Latitude Corona

    NASA Astrophysics Data System (ADS)

    Prasad, S. Krishna; Singh, Jagdev; Banerjee, D.

    2013-02-01

    Spectroscopic studies of the solar corona, using the high spatial and spectral resolution 25-cm coronagraph at the Norikura Solar Observatory for equatorial off-limb observations, indicated that the variation of radiance and line width with height is different for different temperature lines. The line width of the forbidden red emission line [Fe x] 6374 Å was found to increase with height, and that of the green emission line [Fe xiv] 5303 Å decreased with height. This had been interpreted in terms of the interaction between different temperature plasmas but needed to be confirmed. Further observations were made on several days during 2004, in two emission lines simultaneously covering the mid-latitude and polar regions to investigate the existence of the observed variation in other parts of the solar corona. In this study, we have analysed several raster scans that cover mid- and high-latitude regions of the off-limb corona in all four bright emission lines [Fe x] 6374 Å, [Fe xi] 7892 Å, [Fe xiii] 10747 Å, and [Fe xiv] 5303 Å. We find that the FWHM of the red line increases with height and that of the green line decreases with height, similar to the observations in the equatorial regions. The line widths are higher in the polar regions for all of the observed emission lines except the green line. Higher values of FWHM in polar regions may imply higher non-thermal velocities, which could be further linked to a non-thermal source powering the solar-wind acceleration, but the reason for the behaviour of the green emission line remains to be explored.

  1. Line width and line shape analysis in the inductively coupled plasma by high resolution Fourier transform spectrometry

    SciTech Connect

    Faires, L.M.; Palmer, B.A.; Brault, J.W.

    1984-01-01

    High resolution Fourier transform spectrometry has been used to perform line width and line shape analysis of eighty-one iron I emision lines in the spectral range 290 to 390nm originating in the normal analytical zone of an inductively coupled plasma. Computer programs using non-linear least squares fitting techniques for line shape analysis were applied to the fully resolved spectra to determine Gaussian and Lorentzian components of the total observed line width. The effect of noise in the spectrum on the precision of the line fitting technique was assessed, and the importance of signal to noise ratio for line shape analysis is discussed. Translational (Doppler) temperatures were calculated from the Gaussian components of the line width and were found to be on the order of 6300/sup 0/K. The excitation temperature of iron I was also determined from the same spectral data by the spectroscopic slope method based on the Einstein-Boltzmann expression for spectral intensity and was found to be on the order of 4700/sup 0/K. 31 references.

  2. Doppler-width thermodynamic thermometry by means of line-absorbance analysis

    SciTech Connect

    Castrillo, A.; De Vizia, M. D.; Gianfrani, L.; Moretti, L.; Galzerano, G.; Laporta, P.; Merlone, A.

    2011-09-15

    A clean and effective implementation of Doppler-width thermometry is described. Exploiting the relationship between line-center absorbance and integrated absorbance, the Doppler width of a molecular spectral line can be retrieved from a set of profiles resulting from different gas pressures. The method is validated by its application to numerically simulated spectra. Preliminary experiments, in water vapor samples, turn out to be successful, demonstrating Doppler-widths' retrieval in the near-infrared with a precision of 8x10{sup -5}, at the water triple point temperature. The direct link to the Boltzmann constant makes the proposed method very attractive for temperature metrology as a tool for the realization of a new thermodynamic temperature scale.

  3. A simple formula for estimating Stark widths of neutral lines. [of stellar atmospheres

    NASA Technical Reports Server (NTRS)

    Freudenstein, S. A.; Cooper, J.

    1978-01-01

    A simple formula for the prediction of Stark widths of neutral lines similar to the semiempirical method of Griem (1968) for ion lines is presented. This formula is a simplification of the quantum-mechanical classical path impact theory and can be used for complicated atoms for which detailed calculations are not readily available, provided that the effective position of the closest interacting level is known. The expression does not require the use of a computer. The formula has been applied to a limited number of neutral lines of interest, and the width obtained is compared with the much more complete calculations of Bennett and Griem (1971). The agreement generally is well within 50% of the published value for the lines investigated. Comparisons with other formulas are also made. In addition, a simple estimate for the ion-broadening parameter is given.

  4. A simple formula for estimating Stark widths of neutral lines. [of stellar atmospheres

    NASA Technical Reports Server (NTRS)

    Freudenstein, S. A.; Cooper, J.

    1978-01-01

    A simple formula for the prediction of Stark widths of neutral lines similar to the semiempirical method of Griem (1968) for ion lines is presented. This formula is a simplification of the quantum-mechanical classical path impact theory and can be used for complicated atoms for which detailed calculations are not readily available, provided that the effective position of the closest interacting level is known. The expression does not require the use of a computer. The formula has been applied to a limited number of neutral lines of interest, and the width obtained is compared with the much more complete calculations of Bennett and Griem (1971). The agreement generally is well within 50% of the published value for the lines investigated. Comparisons with other formulas are also made. In addition, a simple estimate for the ion-broadening parameter is given.

  5. Shot noise in electron-beam lithography and line-width measurements.

    PubMed

    Kruit, P; Steenbrink, S W H K

    2006-01-01

    Electron-beam lithography is used extensively in nanoscience and technology for making masks for the semiconductor industry and, on a limited scale, for maskless lithography: that is, writing the patterns directly on the chip. We expect the latter application to extend in the years to come. Control of the dimensions of the written structures is essential in the semiconductor industry. For 45 nm generation, which is presently under development and should reach production at the end of the decade, the required control over the line width is between 1.5 and 5 nm, depending on the application. One of the factors of influence on the line-width control is the statistics in the number of electrons illuminating the resist. This effect gives line edge roughness, or in other words a lack of control over the local position of a resist edge. This has long been recognized and often discussed. Recently, we developed an analytic model for the line edge position variation, which we shall illustrate and expand in this paper. The model, supported by Monte Carlo simulations, demonstrates that the line-width variation is inversely proportional to the dose used for the illumination of the resist. This makes it impossible to increase the lithography throughput by developing ultrasensitive resists. For 45 nm features written with a typical resolution of 30 nm, a 30 microC/cm2 resist gives 3 nm line-width variation over line segments of 45 nm long. The line width is usually measured in an adapted critical dimension scanning electron microscope (CD-SEM). This measurement needs to be more precise than the result of the lithography step, so the requirements are typically sub-nm. Apart from all the problems to avoid systematic errors, this measurement also suffers from statistical variations, resulting from the finite number of electrons used for the measurement. In this paper we shall derive an estimate for that variation with a similar model as used for the shot noise effect in the

  6. INFLUENCE OF DOPPLER WIDTH FLUCTUATIONS ON THE SHAPE OF SPECTRAL LINES

    SciTech Connect

    Silant'ev, N. A.; Lekht, E. E.; Alexeeva, G. A.

    2009-05-10

    We investigate the influence of stochastic Doppler width fluctuations on the shape of spectral lines. The photospheres and atmospheres of stars, and the interstellar medium, possess stochastic behavior especially near nonstationary objects such as active galactic nuclei, quasars, flare stars, and regions of star formation. In reality, we observe the mean values of intensities from these objects. In most situations, the spectral line extinction coefficient has a Gaussian shape with the stochastic Doppler width determined by thermal and small-scale turbulent motions of atoms or molecules. For small-scale turbulent motions (short-correlated turbulence) the propagation of radiation is described by the average extinction factor. This coefficient depends on the level of the Doppler width fluctuations {eta}. We show that these fluctuations change both the value of intensity and the shape of spectral lines. We consider distortions of the spectral line shapes for the absorption and emission lines for various values of the parameter {eta}. For a number of H{sub 2}O maser sources we estimate the values of this parameter, the optical depths of the inverted media, and the mean effective Doppler velocities. Maser emission lines with non-Gaussian shape can serve as an additional method for the investigation of the physical parameters in maser 'spots'.

  7. Experimental measurements of Stark widths for Mn I lines in long laser spark

    NASA Astrophysics Data System (ADS)

    Popov, Andrey M.; Akhmetzhanov, Timur F.; Labutin, Timur A.; Zaytsev, Sergey M.; Zorov, Nikita B.; Chekalin, Nikolay V.

    2016-11-01

    We report the experimental Stark widths of Mn I lines belonging to multiplets z6P° → a6S and z6D° → a6D in long spark induced by laser. We have used aluminum alloy containing 80 ppm of manganese as a target to avoid strong self-absorption of Mn I lines. Its absence was proved by the comparison of observed intensities with relative strengths of lines within multiplets. Electron density of plasma estimated by Mg I (5172.68 Å) and Al II (2816.18 Å) lines was within the range of (4-30) × 1016 cm- 3. The shortest possible gate allowed the observation of symmetric atomic and ionic lines. The spatial profiles of plasma temperature and electron density along the axis of long spark demonstrated that both values were lower than for spherical plasma. Measured Stark widths of resonance multiplet z6P° → a6S decrease from 0.075 Å for its first component to 0.055 Å for the last one, while Stark widths of components of multiplet z6D° → a6D increase from 0.095 Å to 0.125 Å. No Stark shifting was observed for the studied multiplets.

  8. Low Loss, Finite Width Ground Plane, Thin Film Microstrip Lines on Si Wafers

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Margomenos, Alexandros; Katehi, Linda P. B.

    1999-01-01

    Si RFICs on standard, 2 Omega-cm. Si wafers require novel transmission lines to reduce the loss caused by the resistive substrate. One such transmission line is commonly called Thin Film Microstrip (TFMS), which is created by depositing a metallic ground plane, thin insulating layers, and the microstrip lines on the Si wafer. Thus, the electric fields are isolated from the Si wafer. In this paper, it is shown through experimental results that the ground plane of TFMS may be finite width and comparable to the strip width in size while still achieving low loss on 2 Omega-cm Si. Measured effective permittivity shows that the field interaction with the Si wafer is small.

  9. High-average-power narrow-line-width sum frequency generation 589 nm laser

    NASA Astrophysics Data System (ADS)

    Lu, Yanhua; Fan, Guobin; Ren, Huaijin; Zhang, Lei; Xu, Xiafei; Zhang, Wei; Wan, Min

    2015-10-01

    An 81 W average-power all-solid-state sodium beacon laser at 589 nm with a repetition rate of 250 Hz is introduced, which is based on a novel sum frequency generation idea between two high-energy, different line widths, different beam quality infrared lasers (a 1064 nm laser and a 1319 nm laser). The 1064 nm laser, which features an external modulated CW single frequency seed source and two stages of amplifiers, can provide average-power of 150 W, beam quality M2 of ~1.8 with ultra-narrow line width (< 100 kHz). The 1319 nm laser can deliver average-power of 100 W, beam quality M2 of ~3.0 with a narrow line width of ~0.3 GHz. By sum frequency mixing in a LBO slab crystal (3 mm x 12 mm x 50 mm), pulse energy of 325 mJ is achieved at 589 nm with a conversion efficiency of 32.5 %. Tuning the center wavelength of 1064 nm laser by a PZT PID controller, the target beam's central wavelength is accurately locked to 589.15910 nm with a line width of ~0.3 GHz, which is dominated mainly by the 1319 nm laser. The beam quality is measured to be M2 < 1.3. The pulse duration is measured to be 150 μs in full-width. To the best of our knowledge, this represents the highest average-power for all-solid-state sodium beacon laser ever reported.

  10. Effect of fluctuations in Doppler width on the center of strong absorption lines

    NASA Astrophysics Data System (ADS)

    Silant'ev, N. A.; Alekseeva, G. A.; Novikov, V. V.

    2011-12-01

    Stochastic temperatures and turbulence are characterized by average velocities u th and < u turb > ≡ u 0 and fluctuations {u'_{th}} and u' (< u' > = 0). Thus, the Doppler width of a line also has a fluctuating component Δ {λ '_D} . Observed spectra correspond to the radiative flux averaged over time and over a star's surface, . Usually, only the average velocities u th and u 0 are taken into account in photospheric models and these yield the Doppler width Δ λ_D^{(0)} of a line in the customary way. The fluctuations Δ {λ '_D} mean that near a line center the average absorption coefficient < αλ > is larger than the usual αλ, which depends only on the average velocities u th and u 0. This enhances the absorption line near the center and is not explained by the photospheric models. This new statistical effect depends on the wavelength of the line. A comparison of observed lines with model profiles yields an estimate for the average level of fluctuations in the Doppler width, η = {{{left< {left| {Δ {{λ '}_D}} right|} rightrangle }} left/ {{Δ λ_D^{(0)}}} right.} , which characterizes the average stochasticity of a photosphere and is important for understanding the physics of photospheres. The depths of lines in synthetic spectra of stars are often greater than the observed values. The observed disagreement between the theoretical and actually observed depths of lines can be corrected by introducing an additional parameter, the fluctuation level η. Then it is possible to obtain estimates of η for a number of stars.

  11. The implications of grading on the emission line width of core–shell nanocrystals

    NASA Astrophysics Data System (ADS)

    Phadnis, Chinmay; Sonawane, Kiran G.; Sudarsan, V.; Mahamuni, Shailaja

    2017-04-01

    An excitonic coupling with phonons leads to broadening of the emission line. The narrow excitonic emission line width observed in CdZnS/ZnS alloy core graded shell nanocrystals (NCs) with varying compositions is studied using temperature-dependent photoluminescence measurements. Contrary to the consensus that a narrow emission line width is observable with a reduction in size (due to the increased exciton–acoustic phonon coupling coefficient σ), an increased value is noted with reduced size. Based on a theoretical approach to graded core–shell NCs, the relationship between the electron–hole wave function overlap and exciton lifetime is invoked to understand this anomaly. Smaller alloy core–shell NCs (CdZnS/ZnS-I) have a longer lifetime than larger NCs (CdZnS/ZnS-II), indicating reduced electron–hole wave function overlap for CdZnS/ZnS-I NCs and hence a larger ‘effective size’ of NCs, even though the actual size is smaller. The experimental findings demonstrate that graded core–shell NCs reveal an additional functionality, facilitating control of the emission line width of NCs via minimal interaction with the solid state environment.

  12. Theoretical Studies of N2-broadened Half-widths of H2O Lines Involving High j States

    NASA Technical Reports Server (NTRS)

    Ma, Q.; Tipping, R. H.; Lavrentieva, N. N.

    2012-01-01

    Based on the properties of the energy levels and wave functions of H2O states, one can categorize H2O lines into individually defined groups such that within the same group, the energy levels and the wave functions associated with two paired lines have an identity property while those associated with different pairs have a similarity property. Meanwhile, by thoroughly analyzing processes used to calculate N2-broadened half-widths, it was found that the 'Fourier series' of W(sup a)(sub L(sub 1))(sub K(sub 1))(sub K(sub 1)) (t; j(sub f) T(sub f) and W(sup a)(sub L(sub 1))(sub K(sub 1))(sub K(sub 1)) (t; j(sub i) T(sub i), and a factor P(sub 222) (j(sub f) T(sub f) j(sub i) T(sub i)) are the key items in the Robert-Bonamy formalism to distinguish contributions to ReS2(r(sub c)) among different transitions of j(sub f) T(sub f) - j(sub i). However, these items are completely determined by the energy levels and the wave functions associated with their initial and final states and they must bear the latter's features as well. Thus, it becomes obvious that for two paired lines in the same group, their calculated half-widths must be almost identical and the values associated with different pairs must vary smoothly as their ji values vary. Thus, the pair identity and the smooth variation rules are established within individual groups of lines. One can use these rules to screen half-width data listed in HITRAN and to improve the data accuracies.

  13. All-electronic line width reduction in a semiconductor diode laser using a crystalline microresonator

    NASA Astrophysics Data System (ADS)

    Rury, Aaron S.; Mansour, Kamjou; Yu, Nan

    2015-07-01

    This study examines the capability to significantly suppress the frequency noise of a semiconductor distributed feedback diode laser using a universally applicable approach: a combination of a high-Q crystalline whispering gallery mode microresonator reference and the Pound-Drever-Hall locking scheme using an all-electronic servo loop. An out-of-loop delayed self-heterodyne measurement system demonstrates the ability of this approach to reduce a test laser's absolute line width by nearly a factor of 100. In addition, in-loop characterization of the laser stabilized using this method demonstrates a 1-kHz residual line width with reference to the resonator frequency. Based on these results, we propose that utilization of an all-electronic loop combined with the use of the wide transparency window of crystalline materials enable this approach to be readily applicable to diode lasers emitting in other regions of the electromagnetic spectrum, especially in the UV and mid-IR.

  14. 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.

  15. Research for different crack width calculation methods of concrete-lined steel pressure pipe

    NASA Astrophysics Data System (ADS)

    Xu, Chuang; Li, Yang

    2017-08-01

    Based on a certain threshold to ensure the durability of structure, the concrete-lined steel pressure pipes used in the structure of large hydropower station widely are allowed to exist in concrete cracking under the action of a certain hydraulic pressure. According to the 1:2 large scale experiment model and the measured data of Three Gorges Hydro-power Station, the existing different methods for calculating crack width were compared and improvements and crack control measures were raised.

  16. Study of the radiation line width and shape from the Bi2212 mesa structure

    NASA Astrophysics Data System (ADS)

    Kashiwagi, Takanari; Yamamoto, Takashi; Ishida, Kazuya; Tsujimoto, Manabu; Delfanazari, Kaveh; Nakayama, Ryo; Kitamura, Takeo; Sawamura, Masashi; Asai, Hidehiro; Minami, Hidetoshi; Kadowaki, Kazuo

    2012-02-01

    Continuous electromagnetic waves in terahertz (THz) range have been observed from mesa structures of Bi2Sr2CaCu2O8+δ(Bi2212) single crystals^1) It has been established that the radiation frequency is determined by both the ac Josephson frequency and the resonance condition of the geometrical cavity^2). In order to understand the mechanism of the radiation from the intrinsic Josephson junctions (IJJs) in Bi2212, we studied the radiation line width and shape. These might depend upon the physical parameters of the Bi2212 single crystal such as the number of IJJs the fluctuations of the quasiparticles and pairs, the non-linearity and non-equilibrium conditions, and the stability of the electrical circuit including the IJJs. However, technical difficulties have been delayed the line width measurements in the THz range. Recently, we succeeded in measuring the radiation line width using a frequency mixer. These results will be compared to those from a single junction 1) L. Ozyuzer et al., Science 318 (2007) 1291., 2) K. Kadowaki et al., J. Phys. Soc. Jpn. 79 (2010) 023703

  17. Comparison of line width calibration using critical dimension atomic force microscopes between PTB and NIST

    NASA Astrophysics Data System (ADS)

    Dai, Gaoliang; Hahm, Kai; Bosse, Harald; Dixson, Ronald G.

    2017-06-01

    International comparisons between National Metrology Institutes are important to verify measurement results and the associated uncertainties. In this paper, we report a comparison of the line width calibration of a crystalline silicon line width standard, referred to as IVPS100-PTB standard, between the Physikalisch-Technische Bundesanstalt in Germany and the National Institute of Standards and Technology in the United States. Critical dimension atomic force microscopy was the measurement method used for this comparison. Both institutes applied generally the same but independently developed traceability pathways: the scaling factor of the atomic force microscope (AFM) scanner was calibrated by a set of step height and lateral standards certified by metrological AFMs, while the effective tip width was ultimately traceable to the lattice parameter of silicon via high resolution transmission electron microscopy. Good agreement has been achieved in the comparison: For two groups of line features with nominal critical dimensions (CDs) of 50 nm, 70 nm, 90 nm, 110 nm and 130 nm that were compared, the observed deviations of CD results were between  -1.5 nm and 0.3 nm. The deviations are well within the associated measurement uncertainty.

  18. Dependence of the width of the glass transition interval on cooling and heating rates.

    PubMed

    Schmelzer, Jürn W P; Tropin, Timur V

    2013-01-21

    In a preceding paper [J. W. P. Schmelzer, J. Chem. Phys. 136, 074512 (2012)], a general kinetic criterion of glass formation has been advanced allowing one to determine theoretically the dependence of the glass transition temperature on cooling and heating rates (or similarly on the rate of change of any appropriate control parameter determining the transition of a stable or metastable equilibrium system into a frozen-in, non-equilibrium state of the system, a glass). In the present paper, this criterion is employed in order to develop analytical expressions for the dependence of the upper and lower boundaries and of the width of the glass transition interval on the rate of change of the external control parameters. It is shown, in addition, that the width of the glass transition range is strongly correlated with the entropy production at the glass transition temperature. The analytical results are supplemented by numerical computations. Analytical results and numerical computations as well as existing experimental data are shown to be in good agreement.

  19. Dependence of the width of the glass transition interval on cooling and heating rates

    NASA Astrophysics Data System (ADS)

    Schmelzer, Jürn W. P.; Tropin, Timur V.

    2013-01-01

    In a preceding paper [J. W. P. Schmelzer, J. Chem. Phys. 136, 074512 (2012), 10.1063/1.3685510], a general kinetic criterion of glass formation has been advanced allowing one to determine theoretically the dependence of the glass transition temperature on cooling and heating rates (or similarly on the rate of change of any appropriate control parameter determining the transition of a stable or metastable equilibrium system into a frozen-in, non-equilibrium state of the system, a glass). In the present paper, this criterion is employed in order to develop analytical expressions for the dependence of the upper and lower boundaries and of the width of the glass transition interval on the rate of change of the external control parameters. It is shown, in addition, that the width of the glass transition range is strongly correlated with the entropy production at the glass transition temperature. The analytical results are supplemented by numerical computations. Analytical results and numerical computations as well as existing experimental data are shown to be in good agreement.

  20. SYNTHESIZED SPECTRA OF OPTICALLY THIN EMISSION LINES PRODUCED BY THE BIFROST STELLAR ATMOSPHERE CODE, INCLUDING NONEQUILIBRIUM IONIZATION EFFECTS: A STUDY OF THE INTENSITY, NONTHERMAL LINE WIDTHS, AND DOPPLER SHIFTS

    SciTech Connect

    Olluri, K.; Gudiksen, B. V.; Hansteen, V. H.; Pontieu, B. De

    2015-03-20

    In recent years realistic 3D numerical models of the solar atmosphere have become available. The models attempt to recreate the solar atmosphere and mimic observations in the best way, in order to make it possible to couple complicated observations with physical properties such as the temperatures, densities, velocities, and magnetic fields. We here present a study of synthetic spectra created using the Bifrost code in order to assess how well they fit with previously taken solar data. A study of the synthetic intensity, nonthermal line widths, Doppler shifts, and correlations between any two of these three components of the spectra first assuming statistical equilibrium is made, followed by a report on some of the effects nonequilibrium ionization will have on the synthesized spectra. We find that the synthetic intensities compare well with the observations. The synthetic observations depend on the assumed resolution and point-spread function (PSF) of the instrument, and we find a large effect on the results, especially for intensity and nonthermal line width. The Doppler shifts produce the reported persistent redshifts for the transition region (TR) lines and blueshifts for the upper TR and corona lines. The nonthermal line widths reproduce the well-known turnoff point around (2–3) × 10{sup 5} K, but with much lower values than those observed. The nonthermal line widths tend to increase with decreasing assumed instrumental resolution, also when nonequilibrium ionization is included. Correlations between the nonthermal line width of any two TR line studies as reported by Chae et al. are reproduced, while the correlations of intensity to line width are reproduced only after applying a PSF to the data. Doppler shift correlations reported by Doschek for the TR lines and correlations of Doppler shift to nonthermal line width of the Fe xii{sub 19.5} line reported by Doschek et al. are reproduced.

  1. Influence of Gridboard Line Width and Spacing on Windscreen Distortion Measurements

    DTIC Science & Technology

    1978-12-01

    photographs. For the 12 x 12-inch flat plate , use one of the grid board lines showing over the top of the plate . For the two F-I I I windscreens, use...thanks are due to TSgt John E. Skuya for preparing the grid board photographs that were used in this study. Thanks are also due to the School of Aerospace...Displacement Used in the Study .............................. 6 3. Grid Board Photograph: 1-inch Grid and 1/16" Line Width taken through the low

  2. Measurement of Stark width of some Ar I transitions and the investigation of local thermodynamic equilibrium (LTE) in an atmospheric d. c. argon plasma jet

    SciTech Connect

    Bakshi, V.

    1988-01-01

    The Stark widths of seven Ar I transitions are reported. Axial line shape data from an atmospheric d.c. argon plasma jet were Abel-inverted to obtain radial line shapes. The electron-density was determined by Stark width measurements of the hydrogen H{sub {beta}} transition. In the electron-density region of {le}6 {times} 10{sup 22} m{sup {minus}3} the experimental Ar I Stark widths are fitted to a linear dependence on the electron-density. Values of Stark width extrapolated to other electron densities are compared to measurements reported in the literature on the 4s-4p array. Experimental values are up to 45% smaller than those predicted by Griem's theory of Stark broadening. Conditions for local thermodynamic equilibrium (LTE) to exist in an atmospheric argon plasma jet were studied. The experiment measures the emission coefficient of seven Ar I transitions and the line shape of the hydrogen H{sub beta} transition. After transforming the side-on data into radial space the excited neutral argon atom-density and the electron-density are determined. It is found LTE does not exist below an electron-density of 6 {times} 10{sup 33} m{sup {minus}3} in the experimental conditions.

  3. A Slippery Slope: Systematic Uncertainties in the Line Width Baryonic Tully-Fisher Relation

    NASA Astrophysics Data System (ADS)

    Bradford, Jeremy D.; Geha, Marla C.; van den Bosch, Frank C.

    2016-11-01

    The baryonic Tully-Fisher relation (BTFR) is both a valuable observational tool and a critical test of galaxy formation theory. We explore the systematic uncertainty in the slope and the scatter of the observed line-width BTFR utilizing homogeneously measured, unresolved H i observations for 930 isolated galaxies. We measure a fiducial relation of {{log}}10 {M}{baryon}=3.24 {{log}}10 {V}{rot} + 3.21 with observed scatter of 0.25 dex over a baryonic mass range of 107.4 to 1011.3 {M}⊙ where {V}{rot} is measured from 20% H i line widths. We then conservatively vary the definitions of {M}{baryon} and {V}{rot}, the sample definition and the linear fitting algorithm. We obtain slopes ranging from 2.64 to 3.53 and scatter measurements ranging from 0.14 to 0.41 dex, indicating a significant systematic uncertainty of 0.25 in the BTFR slope derived from unresolved H i line widths. We next compare our fiducial slope to literature measurements, where reported slopes range from 3.0 to 4.3 and scatter is either unmeasured, immeasurable, or as large as 0.4 dex. Measurements derived from unresolved H i line widths tend to produce slopes of 3.3, while measurements derived strictly from resolved asymptotic rotation velocities tend to produce slopes of 3.9. The single largest factor affecting the BTFR slope is the definition of rotation velocity. The sample definition, the mass range and the linear fitting algorithm also significantly affect the measured BTFR. We find that galaxies in our sample with {V}{rot}\\lt 100 km s-1 are consistent with the line-width BTFR of more massive galaxies, but these galaxies drive most of the observed scatter. It is critical when comparing predictions to an observed BTFR that the rotation velocity definition, the sample selection and the fitting algorithm are similarly defined. We recommend direct statistical comparisons between data sets with commensurable properties as opposed to simply comparing BTFR power-law fits.

  4. Determination of natural line widths of Kα X-ray lines for some elements in the atomic range 50≤Z≤65 at 59.5 keV

    NASA Astrophysics Data System (ADS)

    Kündeyi, Kadriye; Aylıkcı, Nuray Küp; Tıraşoǧlu, Engin; Kahoul, Abdelhalim; Aylıkcı, Volkan

    2017-02-01

    The semi-empirical determination of natural widths of Kα X-ray lines (Kα1 and Kα2) were performed for Sn, Sb, Te, I, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd and Tb. For the semi-empirical determination of the line widths, K shell fluorescence yields of elements were measured. The samples were excited by 59.5 keV γ rays from a 241Am annular radioactive source in order to measure the K shell fluorescence yields. The emitted K X-rays from the samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. The measured K shell fluorescence yields were used for the calculation of K shell level widths. Finally, the natural widths of K X-ray lines were determined as the sums of levels which involved in the transition. The obtained values were compared with earlier studies.

  5. The transmission correlation in the QSO Ly(alpha) forest produced by finite width lines

    NASA Astrophysics Data System (ADS)

    Zuo, Lin; Bond, J. Richard

    1994-03-01

    The transmission of a quasar spectrum (flux divided by the continuum) is correlated because of the finite width of absorption lines. We describe a technique for calculating the transmission correlation function produced by randomly distributed lines. We also introduce straightforward procedure for measuring the pixel-pixel transmission correlation function xipp directly from observed quasar spectra. We apply the method to 12 Sargent, Boksenberg, & Steidel Quasi-Stellar Objects (QSO) spectra and compare these with theoretical transmission correlation functions and with xipp measured from computer-simulated quasar spectra of Ly(alpha) forest models with Poisson-distributed lines. The simulations are designed to mimic the observed spectrum as closely as possible, with the same wavelength sampling, instrumental resolution, continuum and noise properties. The comparisons with line distributions that are power laws in column density and redshift, and Gaussians in line width b reveal an excess in the observed xipp at Delta(v) is approximately or equal to 150 km/s, if we adopt the Carswell et al. (1991) parameters for the Gaussian (mean b0 = 30 km/s, dispersion sigmab = 10 km/s). One possibility is that the Ly(alpha) forest lines are actually clustered at velocity separation scales Delta(v) is approximately or equal to 150 km/s. Another possibility we explore is that the b-distribution has more large b clouds and a larger dispersion. We find the observed xipp is barely consistent with b0 = 40 km/s and sigmab = 25 km/s. We show that the measured xipp is relatively insensitive to the noise level and to errors in the continuum determination, unlike the traditional line counting methods, where the outcome is quite vulnerable to both. It also requires no line deblending and thus offers a powerful tool for extracting information from the crowded Ly(alpha) forest.

  6. [Doppler effect on width of characteristic line in plasma induced by pulsed laser ablating Al].

    PubMed

    Song, Yi-Zhong; He, An-Zhi

    2005-05-01

    Aluminum (Al) plasma was induced with a pulsed Nd: YAG laser beam ablating Al target in Ar. Time-resolved information of the plasma radiation was taken with time-resolved technique, and the spectra of the radiation were recorded with an optical multi-path analyzer (OMA III ), whereupon, time-resolved spectra of the plasma radiation induced by pulsed laser were acquired. Based on the experiment data, Al resonant double lines, Al I 396.15 nm, Al I 394.40 nm, were respectively fitted with Lorentz, Gauss and their linear integrated function (abbr. Integrated function), whereupon, Lorentz and Gauss elements were separated from the experiment data profile curve. By contrasting Lorentz with Gauss curve separated, it was found that the experiment curve mainly consisted of Lorentz element, a with little Gauss. By contrasting Lorentz with Integrated fitting curve for experiment data, a visual picture of the characteristic lines broadened by Doppler effect was exhibited. According to the visual picture, the increase of full half-high width of the characteristic line broadened by Doppler effect was estimated. It was about 2 x 10(-)3 -8 x 10(-3) nm, approximating the theoretical value 6.7 x 10(-)3 nm. As a result, Doppler effect on the width of characteristic lines in the plasma could be reasonably explained by curve fitting analysis and theoretical calculation.

  7. Line width roughness accuracy analysis during pattern transfer in self-aligned quadruple patterning process

    NASA Astrophysics Data System (ADS)

    Lorusso, Gian Francesco; Inoue, Osamu; Ohashi, Takeyoshi; Altamirano Sanchez, Efrain; Constantoudis, Vassilios; Koshihara, Shunsuke

    2016-03-01

    Line edge roughness (LER) and line width roughness (LWR) are analyzed during pattern transfer in a self-aligned quadruple patterning (SAQP) process. This patterning process leads to a final pitch of 22.5nm, relevant for N7/N5 technologies. Measurements performed by CD SEM (Critical Dimension Scanning Electron Microscope) using different settings in terms of averaging, field of view, and pixel size are compared with reference metrology performed by planar TEM and three-Dimensional Atomic Force Microscope (3D AFM) for each patterning process step in order to investigate the optimal condition for an in-line LWR characterization. Pattern wiggling is als0 quantitatively analyzed during LER/LWR transfer in the SAQP process.

  8. Coupling Between Microstrip Lines With Finite Width Ground Plane Embedded in Thin Film Circuits

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Dalton, Edan; Tentzeris, Manos M.; Papapolymerou, John

    2003-01-01

    Three-dimensional (3D) interconnects built upon multiple layers of polyimide are required for constructing 3D circuits on CMOS (low resistivity) Si wafers, GaAs, and ceramic substrates. Thin film microstrip lines (TFMS) with finite width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS lines a r e susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and experimental measurements a r e used to show that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions. Furthermore, it is shown that coupled microstrip lines establish a slotline type mode between the two ground planes and a dielectric waveguide type mode, and that the via holes recommended here eliminate these two modes.

  9. Chromospheric scaling laws, width-luminosity correlations, and the Wilson-Bappu effect. [correlation between stellar magnitude and emission line width

    NASA Technical Reports Server (NTRS)

    Ayres, T. R.

    1979-01-01

    Simple scaling laws for the thickness and mean electron density of stellar chromospheres as functions of surface gravity and chromospheric heating are proposed. These scaling laws are shown to be a consequence of hydrostatic equilibrium, the influence of gas ionization on plasma cooling functions, and the assumption that chromospheric heating is relatively constant with height. It is argued that line width-luminosity correlations similar to those observed in the Ca II K and Mg II k resonance lines are implied by the chromospheric scaling laws if the outer edges of the K and k emission cores are formed in the Lorentzian wings of the absorption profile. The results are compared with the Wilson-Bappu effect, empirical width-luminosity correlations for Ca II K1 minimum features, and solar-plage profiles of the Ca II K and Mg II k resonance lines.

  10. Chromospheric scaling laws, width-luminosity correlations, and the Wilson-Bappu effect. [correlation between stellar magnitude and emission line width

    NASA Technical Reports Server (NTRS)

    Ayres, T. R.

    1979-01-01

    Simple scaling laws for the thickness and mean electron density of stellar chromospheres as functions of surface gravity and chromospheric heating are proposed. These scaling laws are shown to be a consequence of hydrostatic equilibrium, the influence of gas ionization on plasma cooling functions, and the assumption that chromospheric heating is relatively constant with height. It is argued that line width-luminosity correlations similar to those observed in the Ca II K and Mg II k resonance lines are implied by the chromospheric scaling laws if the outer edges of the K and k emission cores are formed in the Lorentzian wings of the absorption profile. The results are compared with the Wilson-Bappu effect, empirical width-luminosity correlations for Ca II K1 minimum features, and solar-plage profiles of the Ca II K and Mg II k resonance lines.

  11. Measurement method for the transition width of precision approach path indicator based on spectral means

    NASA Astrophysics Data System (ADS)

    Shen, Haiping; Zhou, Xiaoli; Zhang, Wanlu; Pan, Jiangen; Liu, Muqing

    2012-10-01

    This paper introduces a new colorimetric measurement method for the transition width of the precision approach path indicator. The measurement system consists of a spectrometer, a fiber probe, a moving means and a ruler. The spectrometer is used to measure the chromaticity coordinates to distinguish the white and red light. The fiber probe is the input of the spectrometer. It is fixed to the moving means, which can move along with the upright rule. The precision approach path indicator certain distance away projects the light to the fiber probe. By moving the fiber probe crossing the transition sector up and down, the chromaticity coordinate of the light moves from the white area to the red area. The intermediate distance of the fiber probe is the width of the transition sector. Use the ruler to measure it and then calculate it to angle. With the measurement distance of 10 meter and the precision of the ruler 1 millimeter, the precision of the system can be 21 seconds of arc. Compared with the traditional measurement methods, the method introduced in this paper is more precise and it strictly accords with the ICAO standard Annex 14.

  12. Continuously current-tunable, narrow line-width miniaturized external cavity diode laser at 633 nm

    NASA Astrophysics Data System (ADS)

    Sumpf, B.; Bawamia, A.; Blume, G.; Eppich, B.; Ginolas, A.; Spießberger, S.; Thomas, M.; Erbert, G.

    2012-03-01

    Red emitting diode lasers with a narrow spectral line-width and continuous tuning are requested as light sources for interferometric measurements with nm-accuracy. Tuning ranges of about 25 GHz together with a spectral line-width smaller than 10 MHz are necessary. A current-tunable miniaturized 633 nm external cavity diode laser (ECDL) will be presented. The resonator is formed without moving parts between the front facet of a semiconductor gain medium and a reflection Bragg grating (RBG). The RBG has a high reflectivity larger than 95% in a small spectral bandwidth, which is approximately equal to the targeted tuning range. Within this bandwidth, the ECDL is tunable by changing the injection current of the gain medium. The length of the resonator is selected so short, that the distance between the laser modes is larger than the tuning range. Herewith, single mode operation should be guaranteed. The device is mounted on an aluminum nitride bench with a footprint of 5 mm x 10 mm. ECDLs using gain media with different front facet reflectivities of 30% and 70% will be compared. Moreover, results for a device encapsulated in a silicon based gel will be presented. For a device with 30% front facet reflectivity in air, a maximal output power of 10 mW was achieved. The tuning range without any mode-hops was 34 pm, i.e. 25 GHz. The line-width was smaller than 10 MHz. The emitted beam was approximately diffraction limited with a M2 ~ 1.1 in both directions.

  13. C IV LINE-WIDTH ANOMALIES: THE PERILS OF LOW SIGNAL-TO-NOISE SPECTRA

    SciTech Connect

    Denney, K. D.; Vestergaard, M.; Pogge, R. W.; Kochanek, C. S.; Peterson, B. M.; Assef, R. J.

    2013-09-20

    Comparison of six high-redshift quasar spectra obtained with the Large Binocular Telescope with previous observations from the Sloan Digital Sky Survey shows that failure to correctly identify absorption and other problems with accurate characterization of the C IV λ1549 emission line profile in low signal-to-noise (S/N) data can severely limit the reliability of single-epoch mass estimates based on the C IV emission line. We combine the analysis of these new high-quality data with a reanalysis of three other samples based on high-S/N spectra of the C IV emission line region. We find that a large scatter between the Hβ- and C IV-based masses remains even for this high-S/N sample when using the FWHM to characterize the broad-line region velocity dispersion and the standard virial assumption to calculate the mass. However, we demonstrate that using high-quality data and the line dispersion to characterize the C IV line width leads to a high level of consistency between C IV- and Hβ-based masses, with <0.3 dex of observed scatter and an estimated ∼0.2 dex intrinsic scatter, in the mass residuals.

  14. 2.5 MHz Line-Width High-energy, 2 Micrometer Coherent Wind Lidar Transmitter

    NASA Technical Reports Server (NTRS)

    Petros, Mulugeta; Yu, Jirong; Trieu, Bo; Bai, Yingxin; Petzar, Paul; Singh, Upendra N.; Reithmaier, Karl

    2007-01-01

    2 micron solid-state lasers are the primary choice for coherent Doppler wind detection. As wind lidars, they are used for wake vortex and clear air turbulence detection providing air transport safety. In addition, 2 micron lasers are one of the candidates for CO2 detection lidars. The rich CO2 absorption line around 2 micron, combined with the long upper state life of time, has made Ho based 2 micron lasers a viable candidate for CO2 sensing DIAL instrument. The design and fabrication of a compact coherent laser radar transmitter for Troposphere wind sensing is under way. This system is hardened for ground as well as airborne applications. As a transmitter for a coherent wind lidar, this laser has stringent spectral line width and beam quality requirements. Although the absolute wavelength does not have to be fixed for wind detection, to maximize return signal, the output wavelength should avoid atmospheric CO2 and H2O absorption lines. The base line laser material is Ho:Tm:LuLF which is an isomorph of Ho:Tm:YLF. LuLF produces 20% more output power than Ho:Tm:YLF. In these materials the Tm absorption cross-section, the Ho emission cross-section, the Tm to Ho energy transfer parameters and the Ho (sup 5) I (sub 7) radiative life time are all identical. However, the improved performance of the LuLF is attributed to the lower thermal population in the (sup 5) I (sub 8) manifold. It also provides higher normal mode to Q-switch conversion than YLF at high pump energy indicating a lower up-conversion. The laser architecture is composed of a seed laser, a ring oscillator, and a double pass amplifier. The seed laser is a single longitudinal mode with a line width of 13 KHz. The 100mJ class oscillator is stretched to 3 meters to accommodate the line-width requirement without compromising the range resolution of the instrument. The amplifier is double passed to produce greater than 300mJ energy.

  15. Stark broadening and shift of neutral iodine lines and regularities for analogous transitions of halogene atoms

    NASA Astrophysics Data System (ADS)

    Djurović, S.; Konjević, N.

    1988-06-01

    We report results of an experimental study of the Stark broadening and shift of fourteen and eight neutral iodine lines, respectively, in a plasma wall stabilized arc. An electron density of about 2 × 1022 m-3 was determined from the width of Hα line, while an electron temperature about 9300 K was derived from plasma composition data. The agreement within 40% of both experimental Stark widths and shifts with results of simple theoretical approach by Dimitrijević and Konjević is found. Results of the investigation of similarities of neutral iodine Stark widths are in agreement with the study of Wiese and Konjević. Comparison of experimental Stark shift shows similar types of regularities. Comparisons of Stark widths along analogous transitions of halogene atoms show an increase of widths from fluorine to iodine. It has been demonstrated also that Stark shifts for the same transitions show similar behaviour.

  16. Narrow line-width phosphors for phosphor-converted white light emitting diodes

    NASA Astrophysics Data System (ADS)

    Khanna, Aloka

    The luminous efficacy of present day phosphor-converted white LEDs is limited by phosphors with broad spectral emission in the long wavelength visible range (600-700 nm). The light output from the cool-white LEDs that do not use a red phosphor is 30-35% higher than the warm white LEDs fabricated with a red phosphor in addition to the yellow phosphor. However, the CRI of cool-white LEDs is significantly lower (~60-70) than the CRI of the warm white LEDs (~80-95) due to lack of the red photons in the emission spectrum. Therefore, a trade-off exists between luminous efficacy and color rendering capability of light generated by phosphor-converted white LEDs. In order to solve this problem, an efficient red phosphor with considerably narrow full width of half maxima (~5-10 nm) and emission in the 600-650 nm wavelength range is required. The narrow spectral line-width can be achieved by introducing trivalent lanthanide ions like Eu3+, Pr3+ and Sm3+ (λpeak- 615 nm, 650 nm, 655 nm) in oxide host lattices although the high energy gaps of these hosts makes these phosphors unsuitable for excitation with near-UV/Blue (380-470 nm) LED sources. Therefore, the goal of this project is two-fold- to develop new material systems which can serve as potential hosts for trivalent lanthanide ions like Eu3+, Pr3+ and Sm3+ (λpeak- 615 nm, 650 nm, 655 nm) with strong excitation bands in the near-UV/blue wavelength region (380-470 nm) and improve the efficiency of the known oxide phosphors doped with trivalent lanthanide ions and the novel phosphors via crystal growth processes. Moreover, phosphors in the green-yellow wavelength region with a narrow emission line-width have the potential of improving the luminous efficacy of the phosphor-converted LEDs as the human eye sensitivity curve peaks at 555 nm. Thus, in parallel with the narrow line-width red phosphor research, new compositions doped with Tb3+ (550 nm), Dy3+ (575 nm), etc. are being explored with strong excitation bands in near

  17. Red-blue-green solid state light sources using a narrow line-width green phosphor.

    PubMed

    Liu, A; Khanna, A; Dutta, P S; Shur, M

    2015-04-06

    We demonstrate that using a narrow line-width green phosphor with the peak wavelength closely aligned with the peak in the human eye sensitivity significantly improves the Luminous Efficacy of Radiation (LER) for Red-Green-Blue (RGB) emitters. Compared to the traditional RGB sources, the improvement in LER of 20 lm/W can be achieved. Combining the narrow band green phosphor with conventional wide band red and blue phosphors allows for trading off these improvements against the deviation from the Planckian locus for even higher LER. The light sources with the narrow line green phosphor are particularly promising for high energy efficiency and high intensity illumination, where somewhat compromises can be made in the color quality such as in automotive, outdoor spaces, industrial ware-houses, public places (train stations, airports) etc..

  18. MEASUREMENTS OF NON-THERMAL LINE WIDTHS IN SOLAR ACTIVE REGIONS

    SciTech Connect

    Brooks, David H.; Warren, Harry P.

    2016-03-20

    Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1–4 MK) often found in the cores of solar active regions. This survey of Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) observations covers 15 non-flaring active regions that span a wide range of solar conditions. We find relatively small non-thermal velocities, with a mean value of 17.6 ± 5.3 km s{sup −1}, and no significant trend with temperature or active region magnetic flux. These measurements appear to be inconsistent with those expected from reconnection jets in the corona, chromospheric evaporation induced by coronal nanoflares, and Alfvén wave turbulence models. Furthermore, because the observed non-thermal widths are generally small, such measurements are difficult and susceptible to systematic effects.

  19. Measurements of Non-thermal Line Widths in Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Brooks, David H.; Warren, Harry P.

    2016-03-01

    Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1-4 MK) often found in the cores of solar active regions. This survey of Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) observations covers 15 non-flaring active regions that span a wide range of solar conditions. We find relatively small non-thermal velocities, with a mean value of 17.6 ± 5.3 km s-1, and no significant trend with temperature or active region magnetic flux. These measurements appear to be inconsistent with those expected from reconnection jets in the corona, chromospheric evaporation induced by coronal nanoflares, and Alfvén wave turbulence models. Furthermore, because the observed non-thermal widths are generally small, such measurements are difficult and susceptible to systematic effects.

  20. Geometric Dependence of the Line Width of Localized Surface Plasmon Resonances.

    PubMed

    Li, Yang; Zhao, Ke; Sobhani, Heidar; Bao, Kui; Nordlander, Peter

    2013-04-18

    For the same number of electrons and plasmon frequencies, longitudinal plasmon resonances in metallic nanorods exhibit narrower line widths than plasmon modes in spherical particles. We show that this property is a general feature of high aspect ratio nanostructures and can be explained very simply by incorporating retardation effects into a harmonic oscillator model. The origin of the effect is dynamic depolarization, which renormalizes the mass of the electrons and the oscillating electron liquid. The scattering spectrum derived from our model agrees very well with FDTD simulations. Because plasmon damping determines many important features and applications of LSPR, such as the Q factor of plasmonics devices and the magnitude of the induced field enhancements, our study will play an important role for the design of nanostructures with narrow plasmon resonances.

  1. Radiative widths and splitting of cyclotron lines in superstrong magnetic fields

    NASA Technical Reports Server (NTRS)

    Pavlov, G. G.; Bezchastnov, V. G.; Meszaros, P.; Alexander, S. G.

    1991-01-01

    The radiative line widths of the Landau levels in a superstrong magnetic field are calculated and simple analytic expressions and fits are given for these which are valid over a wide range of the principal quantum number and the magnetic field strength. If QED corrections are not taken into account, all levels but the first are doubly degenerate, corresponding to the two possible spin projections. However, the interaction with the QED vacuum removes this degeneracy, leading to an energy splitting of each level which exceeds the radiative linewidth for low Landau levels if the magnetic field is not too large (B is less than approximately 10 exp 13 G). Estimations are presented of the splitting in various limits as a function of field strength and Landau number. The possibility of observing this splitting in accreting X-ray pulsars and in gamma-ray bursters is discussed.

  2. Radiative widths and splitting of cyclotron lines in superstrong magnetic fields

    NASA Technical Reports Server (NTRS)

    Pavlov, G. G.; Bezchastnov, V. G.; Meszaros, P.; Alexander, S. G.

    1991-01-01

    The radiative line widths of the Landau levels in a superstrong magnetic field are calculated and simple analytic expressions and fits are given for these which are valid over a wide range of the principal quantum number and the magnetic field strength. If QED corrections are not taken into account, all levels but the first are doubly degenerate, corresponding to the two possible spin projections. However, the interaction with the QED vacuum removes this degeneracy, leading to an energy splitting of each level which exceeds the radiative linewidth for low Landau levels if the magnetic field is not too large (B is less than approximately 10 exp 13 G). Estimations are presented of the splitting in various limits as a function of field strength and Landau number. The possibility of observing this splitting in accreting X-ray pulsars and in gamma-ray bursters is discussed.

  3. Line width roughness control and pattern collapse solutions for EUV patterning

    NASA Astrophysics Data System (ADS)

    Petrillo, Karen; Huang, George; Ashworth, Dominic; Georger, Jacque; Ren, Liping; Cho, K. Y.; Montgomery, Warren; Wurm, Stefan; Kawakami, Shinichiro; Dunn, Shannon; Ko, Akiteryu

    2011-04-01

    Line width roughness (LWR) control is a critical issue in extreme ultraviolet lithography (EUVL). The difficulty of controlling LWR and the need to minimize it have grown as the sensitivity of materials and resolution in the resist patterning process has improved. Another critical feature that has become difficult to control in EUVL and 22nm half-pitch systems is pattern collapse. The increase of aspect ratio that comes from further scaling promotes the onset of pattern collapse. Both pattern collapse and LWR are easily observed in EUVL and leading-edge ArF immersion lithography. This paper will demonstrate recent gains in LWR control in leading EUV films using track-based processes, etch-based improvements, and the results of combined techniques. Also the use of a newly developed EUV-specific FIRM™ rinse chemistry to reduce pattern collapse will be discussed along with future development activities and industry requirements for both LWR and pattern collapse.

  4. Bayesian Redshift Classification of Emission-line Galaxies with Photometric Equivalent Widths

    NASA Astrophysics Data System (ADS)

    Leung, Andrew S.; Acquaviva, Viviana; Gawiser, Eric; Ciardullo, Robin; Komatsu, Eiichiro; Malz, A. I.; Zeimann, Gregory R.; Bridge, Joanna S.; Drory, Niv; Feldmeier, John J.; Finkelstein, Steven L.; Gebhardt, Karl; Gronwall, Caryl; Hagen, Alex; Hill, Gary J.; Schneider, Donald P.

    2017-07-01

    We present a Bayesian approach to the redshift classification of emission-line galaxies when only a single emission line is detected spectroscopically. We consider the case of surveys for high-redshift Lyα-emitting galaxies (LAEs), which have traditionally been classified via an inferred rest-frame equivalent width (EW {W}{Lyα }) greater than 20 Å. Our Bayesian method relies on known prior probabilities in measured emission-line luminosity functions and EW distributions for the galaxy populations, and returns the probability that an object in question is an LAE given the characteristics observed. This approach will be directly relevant for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), which seeks to classify ˜106 emission-line galaxies into LAEs and low-redshift [{{O}} {{II}}] emitters. For a simulated HETDEX catalog with realistic measurement noise, our Bayesian method recovers 86% of LAEs missed by the traditional {W}{Lyα } > 20 Å cutoff over 2 < z < 3, outperforming the EW cut in both contamination and incompleteness. This is due to the method’s ability to trade off between the two types of binary classification error by adjusting the stringency of the probability requirement for classifying an observed object as an LAE. In our simulations of HETDEX, this method reduces the uncertainty in cosmological distance measurements by 14% with respect to the EW cut, equivalent to recovering 29% more cosmological information. Rather than using binary object labels, this method enables the use of classification probabilities in large-scale structure analyses. It can be applied to narrowband emission-line surveys as well as upcoming large spectroscopic surveys including Euclid and WFIRST.

  5. Neonatal line width in deciduous incisors from Neolithic, mediaeval and modern skeletal samples from north-central Poland.

    PubMed

    Kurek, Marta; Żądzińska, Elżbieta; Sitek, Aneta; Borowska-Strugińska, Beata; Rosset, Iwona; Lorkiewicz, Wiesław

    2016-01-01

    The neonatal line is usually the first accentuated incremental line visible on the enamel. The prenatal environment significantly contributes to the width of the neonatal line, influencing the pace of reaching post-delivery homeostasis by the newborn's organism. Studies of the enamel of the earliest developing deciduous teeth can provide an insight into the prenatal development and the perinatal conditions of children of past human populations, thus being an additional source contributing to consideration of the influence of prenatal and perinatal factors modifying growth processes. The aim of this study was to examine whether the neonatal line, reflecting the conditions of the prenatal and perinatal environment, differed between the Neolithic, the mediaeval and the modern populations from the Kujawy region in north-central Poland. The material consisted of longitudinally ground sections of 57 human deciduous incisors obtained from children aged 1.0-7.5 years representing three archaeological series from Brześć Kujawski site. All teeth were sectioned in the labio-linqual plane using a diamond blade (Buechler IsoMet 1000). Final specimens were observed with the microscope Delta Optical Evolution 300 at 10× and 40× magnifications. For each tooth, linear measurements of the neonatal line width were performed on its labial surface at the three levels from the cemento-enamel junction. No significant difference was found in the mean neonatal line width depending on the tooth type and archaeological site, although the thickest neonatal line characterised children from the Neolithic series. In all analysed series, the neonatal line width was diversified depending on the child's age at death. The value of Spearman's rank correlation coefficient calculated for the correlation between the child's age at death and the neonatal line width was statistically significant. A clear increase in the width of the neonatal line was thus observed along with a decrease in the child

  6. Evaluation of a spectral line width for the Phillips spectrum by means of numerical simulation

    NASA Astrophysics Data System (ADS)

    Korotkevich, A. O.; Zakharov, V. E.

    2015-05-01

    The work aims to check one of the assumptions under which the kinetic equation for water waves was derived in order to understand whether it can be applied to the situations described by the Phillips spectrum. We evaluate a spectral line width of the spectrum from the simulations in the framework of primordial dynamical equations at different levels of nonlinearity in the system, corresponding to the weakly turbulent Kolmogorov-Zakharov spectra ω-4, Phillips spectra ω-5, and intermediate cases. The original motivation of the work was to check one of the assumptions under which the kinetic equation for water waves was derived in order to understand whether it can be applied to the Phillips spectrum. It is shown that, even in the case of relatively high average steepness, when the Phillips spectrum is present in the system, the spectral lines are still very narrow, at least in the region of the direct cascade spectrum. It allows us to state that, even in the case of the Phillips spectrum, one of the assumptions used for the derivation of the Hasselmann kinetic equation is still valid, at least in the case of moderate whitecapping.

  7. Single molecule studies of a ladder type conjugated polymer: vibronic spectra, line widths, and energy transfer.

    PubMed

    Zickler, Martin F; Feist, Florian A; Jacob, Josemon; Müllen, Klaus; Basché, Thomas

    2015-06-01

    Confocal fluorescence microscopy and spectroscopy are employed to investigate single poly(ladder-type pentaphenylene) (LPPentP) molecules dispersed in thin poly(methyl methacrylate) (PMMA) films at 1.2 K. Emission spectra of single chains show single as well as multi-chromophore emission indicating variegated communication along the chains. The vibronic structure in the emission spectra resembles the one found for other ladder-type polymers. Purely electronic zero-phonon lines in emission are substantially broadened, most probably due to fast spectral diffusion. By surmounting the limitations of emission spectroscopy, nonemitting donor chromophores, which transfer their excitation energy in a radiationless manner to emitting chromophores, are accessed by excitation spectroscopy. Remarkably, by comparing the data of emitting and nonemitting chromophores a contribution to the zero-phonon excitation line width has to be considered which places a lower limit on the estimated energy transfer time of several picoseconds between adjacent chromophores. Finally, the data indicate qualitatively a restricted flexibility of LPPentP compared to poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV).

  8. Relationships between quencher diffusion constant and exposure dose dependences of line width, line edge roughness, and stochastic defect generation in extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro

    2015-01-01

    Control of the acid catalytic chain reaction is essential in the pattern formation of chemically amplified resists used for the high-volume production of semiconductor devices. In this study, the relationships between the quencher diffusion constant and the exposure dose dependences of the line width, line edge roughness (LER), and stochastic defect generation were investigated assuming extreme ultraviolet (EUV) lithography. The dependence of the latent images of line-and-space patterns with 16 nm half-pitch on the quencher diffusion constant was calculated on the basis of sensitization and reaction mechanisms of chemically amplified EUV resists. The exposure latitude of the line width increased with the quencher diffusion constant. The dependences of LER and stochastic defect (bridges and pinching) generation on the deviation of the exposure dose became weak by increasing the quencher diffusion constant, similarly to the case for the dependence of the line width.

  9. Effects on calculated half-widths and shifts from the line coupling for asymmetric-top molecules

    SciTech Connect

    Ma, Q.; Tipping, R. H.

    2014-06-28

    The refinement of the Robert-Bonamy formalism by considering the line coupling for linear molecules developed in our previous studies [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013); 140, 104304 (2014)] have been extended to asymmetric-top molecules. For H{sub 2}O immersed in N{sub 2} bath, the line coupling selection rules applicable for the pure rotational band to determine whether two specified lines are coupled or not are established. Meanwhile, because the coupling strengths are determined by relative importance of off-diagonal matrix elements versus diagonal elements of the operator −iS{sub 1} − S{sub 2}, quantitative tools are developed with which one is able to remove weakly coupled lines from consideration. By applying these tools, we have found that within reasonable tolerances, most of the H{sub 2}O lines in the pure rotational band are not coupled. This reflects the fact that differences of energy levels of the H{sub 2}O states are pretty large. But, there are several dozen strongly coupled lines and they can be categorized into different groups such that the line couplings occur only within the same groups. In practice, to identify those strongly coupled lines and to confine them into sub-linespaces are crucial steps in considering the line coupling. We have calculated half-widths and shifts for some groups, including the line coupling. Based on these calculations, one can conclude that for most of the H{sub 2}O lines, it is unnecessary to consider the line coupling. However, for several dozens of lines, effects on the calculated half-widths from the line coupling are small, but remain noticeable and reductions of calculated half-widths due to including the line coupling could reach to 5%. Meanwhile, effects on the calculated shifts are very significant and variations of calculated shifts could be as large as 25%.

  10. Effects on Calculated Half-Widths and Shifts from the Line Coupling for Asymmetric-Top Molecules

    NASA Technical Reports Server (NTRS)

    Ma, Q.; Boulet, C.; Tipping, R. H.

    2014-01-01

    The refinement of the Robert-Bonamy formalism by considering the line coupling for linear molecules developed in our previous studies [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013); 140, 104304 (2014)] have been extended to asymmetric-top molecules. For H2O immersed in N2 bath, the line coupling selection rules applicable for the pure rotational band to determine whether two specified lines are coupled or not are established. Meanwhile, because the coupling strengths are determined by relative importance of off-diagonal matrix elements versus diagonal elements of the operator -iS1 -S2, quantitative tools are developed with which one is able to remove weakly coupled lines from consideration. By applying these tools, we have found that within reasonable tolerances, most of the H2O lines in the pure rotational band are not coupled. This reflects the fact that differences of energy levels of the H2O states are pretty large. But, there are several dozen strongly coupled lines and they can be categorized into different groups such that the line couplings occur only within the same groups. In practice, to identify those strongly coupled lines and to confine them into sub-linespaces are crucial steps in considering the line coupling. We have calculated half-widths and shifts for some groups, including the line coupling. Based on these calculations, one can conclude that for most of the H2O lines, it is unnecessary to consider the line coupling. However, for several dozens of lines, effects on the calculated half-widths from the line coupling are small, but remain noticeable and reductions of calculated half-widths due to including the line coupling could reach to 5%. Meanwhile, effects on the calculated shifts are very significant and variations of calculated shifts could be as large as 25%.

  11. Effect of slot width on transition and noise attenuation of a sound shield panel for supersonic wind tunnels

    NASA Technical Reports Server (NTRS)

    Harvey, W. D.; Stainback, P. C.; Srokowski, A. J.

    1976-01-01

    The effect of slot width on transition and noise attenuation of a planar rod wall sound shield has been investigated at Mach 6. Boundary layer laminarization was obtained by induced suction through adjustable slots or gaps between the rods. Transition Reynolds numbers increased significantly with increasing gap width. The local mean flow field above the suction panel rod array was uniform. Important factors for design and performance of a supersonic wind-tunnel sound shield are rod diameter, gap-to-rod diameter ratio, surface finish of the rods, and leading-edge configuration.

  12. Optical Line Width Broadening Mechanisms at the 10 kHz Level in Eu(3+):Y2O3 Nanoparticles.

    PubMed

    Bartholomew, John G; de Oliveira Lima, Karmel; Ferrier, Alban; Goldner, Philippe

    2017-02-08

    We identify the physical mechanisms responsible for the optical homogeneous broadening in Eu(3+):Y2O3 nanoparticles to determine whether rare-earth crystals can be miniaturized to volumes less than λ(3) while preserving their appeal for quantum technology hardware. By studying how the homogeneous line width depends on temperature, applied magnetic field, and measurement time scale, the dominant broadening interactions for various temperature ranges above 3 K were characterized. Below 3 K the homogeneous line width is dominated by an interaction not observed in bulk crystal studies. These measurements demonstrate that broadening due to size-dependent phonon interactions is not a significant contributor to the homogeneous line width, which contrasts previous studies in rare-earth ion nanocrystals. Importantly, the results provide strong evidence that for the 400 nm diameter nanoparticles under study the minimum line width achieved (45 ± 1 kHz at 1.3 K) is not fundamentally limited. In addition, we highlight that the expected broadening caused by electric field fluctuations arising from surface charges is comparable to the observed broadening. Under the assumption that such Stark broadening is a significant contribution to the homogeneous line width, several strategies for reducing this line width to below 10 kHz are discussed. Furthermore, it is demonstrated that the Eu(3+) hyperfine state lifetime is sufficiently long to preserve spectral features for time scales up to 1 s. These results allow integrated rare-earth ion quantum optics to be pursued at a submicron scale and, hence, open up directions for greater scaling of rare-earth quantum technology.

  13. Molecular absorption in transition region spectral lines

    NASA Astrophysics Data System (ADS)

    Schmit, D. J.; Innes, D.; Ayres, T.; Peter, H.; Curdt, W.; Jaeggli, S.

    2014-09-01

    Aims: We present observations from the Interface Region Imaging Spectrograph (IRIS) of absorption features from a multitude of cool atomic and molecular lines within the profiles of Si IV transition region lines. Many of these spectral lines have not previously been detected in solar spectra. Methods: We examined spectra taken from deep exposures of plage on 12 October 2013. We observed unique absorption spectra over a magnetic element which is bright in transition region line emission and the ultraviolet continuum. We compared the absorption spectra with emission spectra that is likely related to fluorescence. Results: The absorption features require a population of sub-5000 K plasma to exist above the transition region. This peculiar stratification is an extreme deviation from the canonical structure of the chromosphere-corona boundary. The cool material is not associated with a filament or discernible coronal rain. This suggests that molecules may form in the upper solar atmosphere on small spatial scales and introduces a new complexity into our understanding of solar thermal structure. It lends credence to previous numerical studies that found evidence for elevated pockets of cool gas in the chromosphere. Movies associated to Figs. 1 and 2 are available in electronic form at http://www.aanda.org

  14. 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.

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

    PubMed

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

    2007-06-01

    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.

  16. Voigt equivalent widths and spectral-bin single-line transmittances: Exact expansions and the MODTRAN®5 implementation

    NASA Astrophysics Data System (ADS)

    Berk, Alexander

    2013-03-01

    Exact expansions for Voigt line-shape total, line-tail and spectral bin equivalent widths and for Voigt finite spectral bin single-line transmittances have been derived in terms of optical depth dependent exponentially-scaled modified Bessel functions of integer order and optical depth independent Fourier integral coefficients. The series are convergent for the full range of Voigt line-shapes, from pure Doppler to pure Lorentzian. In the Lorentz limit, the expansion reduces to the Ladenburg and Reiche function for the total equivalent width. Analytic expressions are derived for the first 8 Fourier coefficients for pure Lorentzian lines, for pure Doppler lines and for Voigt lines with at most moderate Doppler dependence. A strong-line limit sum rule on the Fourier coefficients is enforced to define an additional Fourier coefficient and to optimize convergence of the truncated expansion. The moderate Doppler dependence scenario is applicable to and has been implemented in the MODTRAN5 atmospheric band model radiative transfer software. Finite-bin transmittances computed with the truncated expansions reduce transmittance residuals compared to the former Rodgers-Williams equivalent width based approach by ∼2 orders of magnitude.

  17. Homogeneous line width of the different vibronic bands of retinal absorption in bacteriorhodopsin by the hole-burning technique

    SciTech Connect

    Kamalov, V.F.; Masciangioli, T.M.; El-Sayed, M.A.

    1996-02-22

    Using the hole-burning technique, resolved vibrational structure was observed in the retinal absorption sepctrum of bacteriorhodopsin (bR) in poly(vinyl alcohol) (PVA) film at 10 K with 556 and 632 nm irradiation. The homogeneous line widths of {upsilon}=1 and {upsilon}=2 vibronic bands are estimated from the deconvolution of the observed spectrum. The absorption maximum is found to shift by 100-200 cm{sup -1} by using the two excitation wavelengths; resulting from partial site selection due to the contribution of inhomogeneous broadening. The hole width produced by excitation near the zero-phonon band is found to be nearly 1250 cm{sup -1}, which corresponds to a homogeneous width of nearly 600 cm{sup -1}, and the low limit of dephasing time can be estimated as 20 fs. This width is found to be independent of the vibronic band observed. 26 refs., 4 figs., 1 tab.

  18. Transition region width of nanowire hetero- and pn-junctions grown using vapor-liquid-solid processes

    NASA Astrophysics Data System (ADS)

    Li, Na; Tan, Teh Y.; Gösele, U.

    2008-03-01

    The transition region width of nanowire heterojunctions and pn-junctions grown using vapor-liquid-solid (VLS) processes has been modeled. With two constituents or dopants I and II, the achievable width or abruptness of the junctions is attributed to the residual I atom/molecule stored in the liquid droplet at the onset of introducing II to grow the junction, and the stored I atom/molecule consumption into the subsequently grown crystal layers. The model yields satisfactory quantitative fits to a set of available Si-Ge junction data. Moreover, the model provides a satisfactory explanation to the relative junction width or abruptness differences between elemental and compound semiconductor junction cases, as well as a guideline for achieving the most desirable pn-junction widths.

  19. Landau-Zener-Stueckelberg theory for multiphoton intrashell transitions in Rydberg atoms: Bloch-Siegert shifts and widths

    SciTech Connect

    Foerre, Morten

    2004-07-01

    We derive closed analytic expressions for intrashell transitions in Rydberg atoms exposed to linearly polarized or circularly polarized periodic electromagnetic fields. The resonance energies and transition probabilities are calculated using multichannel Landau-Zener-Stueckelberg theory. The theory provides formulas for the resonance widths and positions for arbitrary field strength and frequency. The formulas are in excellent agreement with numerical solution of the evolution equations.

  20. Relaxation Times and Line Widths of Isotopically-Substituted Nitroxides in Aqueous Solution at X-band

    PubMed Central

    Biller, Joshua R.; Meyer, Virginia; Elajaili, Hanan; Rosen, Gerald M.; Kao, Joseph P.Y.; Eaton, Sandra S.; Eatona, Gareth R.

    2011-01-01

    Optimization of nitroxides as probes for EPR imaging requires detailed understanding of spectral properties. Spin lattice relaxation times, spin packet line widths, nuclear hyperfine splitting, and overall lineshapes were characterized for six low molecular weight nitroxides in dilute deoxygenated aqueous solution at X-band. The nitroxides included 6-member, unsaturated 5-member, or saturated 5-member rings, most of which were isotopically labeled. The spectra are near the fast tumbling limit with T1 ~ T2 in the range of 0.50 to 1.1 μs at ambient temperature. Both spin-lattice relaxation T1 and spin-spin relaxation T2 are longer for 15N- than for 14N-nitroxides. The dominant contributions to T1 are modulation of nitrogen hyperfine anisotropy and spin rotation. Dependence of T1 on nitrogen nuclear spin state mI was observed for both 14N and 15N. Unresolved hydrogen/deuterium hyperfine couplings dominate overall line widths. Lineshapes were simulated by including all nuclear hyperfine couplings and spin packet line widths that agreed with values obtained by electron spin echo. Line widths and relaxation times are predicted to be about the same at 250 MHz as at X-band. PMID:21843961

  1. Scanning electron microscope measurement of width and shape of 10nm patterned lines using a JMONSEL-modeled library.

    PubMed

    Villarrubia, J S; Vladár, A E; Ming, B; Kline, R J; Sunday, D F; Chawla, J S; List, S

    2015-07-01

    The width and shape of 10nm to 12 nm wide lithographically patterned SiO2 lines were measured in the scanning electron microscope by fitting the measured intensity vs. position to a physics-based model in which the lines' widths and shapes are parameters. The approximately 32 nm pitch sample was patterned at Intel using a state-of-the-art pitch quartering process. Their narrow widths and asymmetrical shapes are representative of near-future generation transistor gates. These pose a challenge: the narrowness because electrons landing near one edge may scatter out of the other, so that the intensity profile at each edge becomes width-dependent, and the asymmetry because the shape requires more parameters to describe and measure. Modeling was performed by JMONSEL (Java Monte Carlo Simulation of Secondary Electrons), which produces a predicted yield vs. position for a given sample shape and composition. The simulator produces a library of predicted profiles for varying sample geometry. Shape parameter values are adjusted until interpolation of the library with those values best matches the measured image. Profiles thereby determined agreed with those determined by transmission electron microscopy and critical dimension small-angle x-ray scattering to better than 1 nm. Published by Elsevier B.V.

  2. Air- and Self-Broadened Half Widths, Pressure-Induced Shifts, and Line Mixing in the Nu(sub 2) Band of (12)CH4

    NASA Technical Reports Server (NTRS)

    Smith, M. A. H.; Benner, D. Chris; Pedroi-Cross, A.; Devi, V. Malathy

    2013-01-01

    Lorentz self- and air-broadened half width and pressure-induced shift coefficients and their dependences on temperature have been measured from laboratory absorption spectra for nearly 130 transitions in the nu(sub 2) band of (12)CH4. In addition line mixing coefficients (using the relaxation matrix element formalism) for both self- and airbroadening were experimentally determined for the first time for a small number of transitions in this band. Accurate line positions and absolute line intensities were also determined. These parameters were obtained by analyzing high-resolution (approx. 0.003 to 0.01 per cm) laboratory spectra of high-purity natural CH4 and air-broadened CH4 recorded at temperatures between 226 and 297 K using the McMath-Pierce Fourier transform spectrometer (FTS) located at the National Solar Observatory on Kitt Peak, Arizona. A multispectrum nonlinear least squares technique was used to fit short (5-15 per cm) spectral intervals in 24-29 spectra simultaneously. Parameters were determined for nu(sub 2) transitions up to J" = 16. The variations of the measured broadening and shift parameters with the rotational quantum number index and tetrahedral symmetry species are examined. The present results are also compared with previous measurements available in the literature.

  3. Air- and Self-Broadened Half Widths, Pressure-Induced Shifts, and Line Mixing in the Nu(sub 2) Band of (12)CH4

    NASA Technical Reports Server (NTRS)

    Smith, M. A. H.; Benner, D. Chris; Pedroi-Cross, A.; Devi, V. Malathy

    2013-01-01

    Lorentz self- and air-broadened half width and pressure-induced shift coefficients and their dependences on temperature have been measured from laboratory absorption spectra for nearly 130 transitions in the nu(sub 2) band of (12)CH4. In addition line mixing coefficients (using the relaxation matrix element formalism) for both self- and airbroadening were experimentally determined for the first time for a small number of transitions in this band. Accurate line positions and absolute line intensities were also determined. These parameters were obtained by analyzing high-resolution (approx. 0.003 to 0.01 per cm) laboratory spectra of high-purity natural CH4 and air-broadened CH4 recorded at temperatures between 226 and 297 K using the McMath-Pierce Fourier transform spectrometer (FTS) located at the National Solar Observatory on Kitt Peak, Arizona. A multispectrum nonlinear least squares technique was used to fit short (5-15 per cm) spectral intervals in 24-29 spectra simultaneously. Parameters were determined for nu(sub 2) transitions up to J" = 16. The variations of the measured broadening and shift parameters with the rotational quantum number index and tetrahedral symmetry species are examined. The present results are also compared with previous measurements available in the literature.

  4. Development of stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping

    DOE PAGES

    Liu, Bo; Tong, Xin; Jiang, Chenyang; ...

    2015-06-05

    In this study, we developed a stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping. An optimized external cavity equipped with an off-the-shelf volume holographic grating narrowed the spectral line-width of a 100 W high-power diode laser and stabilized the laser spectrum. The laser spectrum showed a high side mode suppression ratio of >30 dB and good long-term stability (center wavelength drifting within ±0.002 nm during 220 h of operation). Finally, our laser is delivered by a multimode fiber with power ~70 W, center wavelength of 794.77 nm, and spectral bandwidth of ~0.12 nm.

  5. Stark Widths and Shifts Dependence on the Rest Core Charge of the Emitters within ns-np Transition Arrays

    SciTech Connect

    Scepanovic, Mara; Puric, Jagos

    2010-01-21

    Stark width and shift simultaneous dependence on the upper level ionization potential and rest core charge of the emitter has been evaluated and discussed. It has been verified that the found relations, connecting Stark broadening parameters with upper level ionization potential and rest core charge of the emitters for particular electron temperature and density, can be used for prediction of Stark line width and shift data in case of ions for which observed data, or more detailed calculations, are not yet available. Stark widths and shifts published data are used to demonstrate the existence of other kinds of regularities within similar spectra of different elements and their ionization stages. The emphasis is on the Stark parameter dependence on the upper level ionization potential and on the rest core charge for the lines from similar spectra of multiply charged ions. The found relations connecting Stark widths and shift parameters with upper level ionization potential, rest core charge and electron temperature were used for a prediction of new Stark broadening data, thus avoiding much more complicated procedures.

  6. Measurements of argon-, helium-, hydrogen-, and nitrogen-broadened widths of methane lines near 9000 per cm

    NASA Technical Reports Server (NTRS)

    Fox, Kenneth; Jennings, Donald E.; Stern, Elizabeth A.; Hubbard, Rob

    1988-01-01

    Pressure-broadened widths of rotational-vibrational lines in CH4 have been measured at very high spectral resolution in the R-branch of the 3nu3 overtone. The broadening gases were Ar, He, H2, and N2. Results are presented as averages for J-multiplets at ambient temperature. The overall values (per cm per atm) for these R-branch lines are 0.0651 (CH4-Ar), 0.0508 (CH4-He), 0.0728 (CH4-H2), and 0.0715 (CH4-N2).

  7. Measurements of argon-, helium-, hydrogen-, and nitrogen-broadened widths of methane lines near 9000 per cm

    NASA Technical Reports Server (NTRS)

    Fox, Kenneth; Jennings, Donald E.; Stern, Elizabeth A.; Hubbard, Rob

    1988-01-01

    Pressure-broadened widths of rotational-vibrational lines in CH4 have been measured at very high spectral resolution in the R-branch of the 3nu3 overtone. The broadening gases were Ar, He, H2, and N2. Results are presented as averages for J-multiplets at ambient temperature. The overall values (per cm per atm) for these R-branch lines are 0.0651 (CH4-Ar), 0.0508 (CH4-He), 0.0728 (CH4-H2), and 0.0715 (CH4-N2).

  8. Coupling Between Microstrip Lines with Finite Width Ground Plane Embedded in Polyimide Layers for 3D-MMICs on Si

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Dalton, Edan; Tentzeris, Emmanouil M.; Papapolymerou, John; Williams, W. Dan (Technical Monitor)

    2001-01-01

    Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimeter-wave integrated circuits on complementary metal oxide semiconductor (CMOS) (low resistivity) Si wafers. Thin film microstrip lines (TFMS) with finite width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS lines are susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and experimental measurements are used to show that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions.

  9. The Current Sheet Associated with the 2003 November 4 Coronal Mass Ejection: Density, Temperature, Thickness, and Line Width

    NASA Astrophysics Data System (ADS)

    Ciaravella, A.; Raymond, J. C.

    2008-10-01

    In the wake of the 2003 November 4 coronal mass ejection associated with the largest solar flare of the last sunspot cycle, a current sheet (CS) was observed by the Ultraviolet Coronagraph Spectrometer (UVCS) as a narrow bright feature in the [Fe XVIII] (106.8 K) line. This is the first UV observation in which the CS evolution is followed from its onset. UV spectra provide diagnostics of electron temperature, emission measure, Doppler shift, line width, and size of the CS as function of time. Since the UVCS slit was inside the Mark IV K-coronameter (MK4) field of view, the combination of UV spectra and MK4 white light data provides estimates of the electron density and depth along the line of sight of the CS. The thickness of the CS in the [Fe XVIII] line is far larger than classical or anomalous resistivity would predict, and it might indicate an effective resistivity much larger than anomalous resistivity, such as that due to hyperdiffusion. The broad [Fe XVIII] line profiles in the CS cannot be explained as thermal widths. They result from a combination of bulk motions and turbulence. The Petschek reconnection mechanism and turbulent reconnection may be consistent with the observations.

  10. Multispectrum Analysis of 12CH4 in the v4 Band: I. Air-Broadened Half Widths, Pressure-Induced Shifts, Temperature Dependences and Line Mixing

    NASA Technical Reports Server (NTRS)

    Smith, MaryAnn H.; Benner, D. Chris; Predoi-Cross, Adriana; Venkataraman, Malathy Devi

    2009-01-01

    Lorentz air-broadened half widths, pressure-induced shifts and their temperature dependences have been measured for over 430 transitions (allowed and forbidden) in the v4 band of (CH4)-12 over the temperature range 210 to 314 K. A multispectrum non linear least squares fitting technique was used to simultaneously fit a large number of high-resolution (0.006 to 0.01/cm) absorption spectra of pure methane and mixtures of methane diluted with dry air. Line mixing was detected for pairs of A-, E-, and F-species transitions in the P- and R-branch manifolds and quantified using the off-diagonal relaxation matrix elements formalism. The measured parameters are compared to air- and N2-broadened values reported in the literature for the v4 and other bands. The dependence of the various spectral line parameters upon the tetrahedral symmetry species and rotational quantum numbers of the transitions is discussed. All data used in the present work were recorded using the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak.

  11. H{beta} LINE WIDTHS AS AN ORIENTATION INDICATOR FOR LOW-IONIZATION BROAD ABSORPTION LINE QUASARS

    SciTech Connect

    Punsly, Brian; Zhang Shaohua E-mail: brian.punsly@comdev-usa.co

    2010-12-20

    There is evidence from radio-loud quasars to suggest that the distribution of the H{beta} broad emission line (BEL) gas is arranged in a predominantly planar orientation, and this result may well also apply to radio-quiet quasars. This would imply that the observed FWHM of the H{beta} BELs is dependent on the orientation of the line of sight to the gas. If this view is correct then we propose that the FWHM can be used as a surrogate, in large samples, to determine the line of sight to the H{beta} BELs in broad absorption line quasars (BALQSOs). The existence of broad UV absorption lines (BALs) means that the line of sight to BALQSOs must also pass through the BAL out-flowing gas. It is determined that there is a statistically significant excess of narrow-line profiles in the SDSS DR7 archival spectra of low-ionization broad absorption line quasars (LoBALQSOs), indicating that BAL gas flowing close to the equatorial plane does not commonly occur in these sources. We also find that the data is not well represented by random lines of sight to the BAL gas. Our best fit indicates two classes of LoBALQSOs, the majority ({approx}2/3) are polar outflows that are responsible for the enhanced frequency of narrow-line profiles, and the remainder are equatorial outflows. We further motivated the line of sight explanation of the narrow-line excess in LoBALQSOs by considering the notion that the skewed distribution of line profiles is driven by an elevated Eddington ratio in BALQSOs. We constructed a variety of control samples comprised of non-LoBALQSOs matched to a de-reddened LoBALQSO sample in redshift, luminosity, black hole mass, and Eddington ratio. It is demonstrated that the excess of narrow profiles persists within the LoBALQSO sample relative to each of the control samples with no reduction of the statistical significance. Thus, we eliminate the possibility that the excess narrow lines seen in the LoBALQSOs arise from an enhanced Eddington ratio.

  12. Temperature dependences of line widths and peak positions of optical absorption peaks due to localized vibration of hydrogen Si

    NASA Astrophysics Data System (ADS)

    Suezawa, M.; Fukata, N.; Saito, M.; Yamada-Kaneta, H.

    2001-12-01

    We studied the temperature dependences of line widths and peak positions of optical absorptions due to the hydrogen bound to point defects and acceptors in Si. Specimens were prepared from floating-zone-grown Si crystals of high-purity and of p-type, doped with group III acceptors. They were doped with H by heating at 1300°C in H 2 gas followed by quenching. The former specimen was then irradiated with 3 MeV electrons at RT to form complexes of H and point defects and the latter specimens were annealed at 150°C to form H-acceptor pairs. We measured their optical absorption spectra by an FT-IR spectrometer in the temperature range of 6 K and RT. Peaks due to localized vibrational modes of H bound to acceptors and point defects were well fitted with Lorentzian line shapes. The temperature dependences of those line widths and peak positions were analyzed with the dephasing model proposed by Persson and Ryberg.

  13. Investigating the behaviour of neutral hydrogen Lyα spectral line width in polar coronal holes at solar minimum

    NASA Astrophysics Data System (ADS)

    Spadaro, D.; Susino, R.; Dolei, S.; Ventura, R.; Antonucci, E.

    2017-07-01

    We investigate the behaviour of the H I Lyα spectral line widths measured by UVCS/SOHO in polar coronal holes at minimum of solar magnetic activity. The line widths are reported to significantly increase up to 3 R⊙, while above 3 R⊙ there is observational evidence of either nearly constant or slightly decreasing values. We adopt empirical models of polar coronal holes at solar activity minimum reported in the literature and calculate the characteristic timescales relevant to different processes coupling neutral hydrogen atoms and protons, which are heated and accelerated in the outflowing plasma. This analysis leads us to believe that the progressive decoupling of the two sets of particles below 10 R⊙, caused by the decrease of the plasma density due to the rapid expansion of the wind, cannot explain the behaviour of the Lyα line profile observed in polar coronal holes. We also synthesise the intensity and profile of the Lyα line as a function of heliocentric distance from the coronal hole models, adopting H I densities computed in non-equilibrium ionisation with the aim of satisfactorily reproducing the UVCS Lyα observations reported in the literature. Our analysis shows that the coronal Lyα emission decreases with heliocentric distance, down to values below the interplanetary Lyα emission, owing to the decrease of the plasma density and to non-equilibrium ionisation effects in the expanding plasma. This can lead to the predominance of the interplanetary emission, which is characterised by H I velocity distributions corresponding to temperatures about one order of magnitude lower than the coronal temperatures, and to the narrowing of the resulting coronal profile at higher heliocentric distances. This scenario can be a plausible explanation for the behaviour of the Lyα line profile with height observed in polar coronal holes at solar activity minimum.

  14. Doping dependent intrinsic line width of the Cu-O bond-stretching phonon with q=(0.25 0 0) in La2-xSrxCuO4

    NASA Astrophysics Data System (ADS)

    Park, S. R.; Hamann, A.; Pintschovius, L.; Lamago, D.; Khaliullin, G.; Fujita, M.; Yamada, K.; Gu, G. D.; Tranquada, J. M.; Reznik, D.

    2012-02-01

    We have recently found that the charge inhomogeneities provide significant broadening in the Cu-O bond stretching phonon of La2-xSrxCuO4, and the line shape of the phonon at zone boundary is well reproduced by the simple model which takes charge inhomogeneous effect into account [1]. The question is, now, how large intrinsic line width of the phonon at q=(0.25 0 0), where the giant phonon softening and broadening exist [2], is apart from the charge inhomogeneous effect on the line width. In this talk, we will show the doping dependence of the intrinsic line width of the phonon from x=0.05 to x=0.30. Interestingly, the intrinsic line width as a function of doping follows the superconducting transition temperature. We will discuss relationship between the phonon and the superconductivity in La2-xSrxCuO4. [4pt] [1] S. R. Park at al., accepted for publication in PRB (2011).[0pt] [2] D. Reznik et al., Nature 440, 1170 (2006).

  15. Comparison of Trajectory Models in Calculations of N2-broadened Half-widths and N2-induced Line Shifts for the Rotational Band of H2O-16 and Comparison with Measurements

    NASA Technical Reports Server (NTRS)

    Lamouroux, J.; Gamache, R. R.; Laraia, A. L.; Ma, Q.; Tipping, R. H.

    2012-01-01

    In this work, Complex Robert-Bonamy calculations of half-widths and line shifts were done for N2-broadening of water for 1639 transitions in the rotational band using two models for the trajectories. The first is a model correct to second order in time, the Robert-Bonamy parabolic approximation. The second is the solution of Hamilton's equations. Both models use the isotropic part of the atom-atom potential to determine the trajectories. The present calculations used an intermolecular potential expanded to 20th order to assure the convergence of the half-widths and line shifts. The aim of the study is to assess if the difference in the half-widths and line shifts determined from the two trajectory models is greater than the accuracy requirements of the spectroscopic and remote sensing communities. The results of the calculations are compared with measurements of the half-widths and line shifts. It is shown that the effects of the trajectory model greatly exceed the needs of current remote sensing measurements and that line shape parameters calculated using trajectories determined by solving Hamilton's equations agree better with measurement.

  16. A temperature dependence of the width of the atom spectral lines in stellar atmospheres (in Ukrainian)

    NASA Astrophysics Data System (ADS)

    Vakarchuk, I. O.; Rykalyuk, R. E.; Yankiv-Vitkovska, L. M.

    Explicit expressions for the damping constant γ and the frequency shift Δ of Lorentz's profile of absorption coefficient in spectral lines with the consideration of inelastic collisions and post Van der Waals interpretations of the radiating atom with exciting particles have been found. The inelastic collisions are characterized by a constant parameter which equals the relation of an imaginary part of the scattering phase to the real one. For the γ/γ_0 value where γ_0 is a Van der Waals damping constant in approximation of Weisskopt--Lindholm, there were received two types of expansions over the powers of temperature. Considering these effects leads to an increase of the damping constant and is enough for obtaining quantitative results for Fraunhofer's lines profiles without any illegitimate increase of the value of γ (the so called empirical damping constant) ``by the hand" which is used in the analysis of stellar spectra.

  17. Semiclassical calculations of electron impact Stark widths and shifts of singly ionized atom lines revisited

    NASA Astrophysics Data System (ADS)

    Blagojević, Branimir; Konjević, Nikola

    2017-09-01

    The Stark broadening parameters for spectral lines of singly charged Mg II, Al II, Si II, Zn II, Sn II, Hg II, and Pb II ions, calculated in numerically improved semiclassical formalism of Griem are reported and compared with the original results of Griem for Mg, Al and Si ions and the semiclassical calculations in a version of Dimitrijević and Sahal-Bréchot for Mg ions. Detailed comparison with the experimental data is carried out, also.

  18. Scale heights and equivalent widths of the iron K-shell lines in the Galactic diffuse X-ray emission

    NASA Astrophysics Data System (ADS)

    Yamauchi, Shigeo; Nobukawa, Kumiko K.; Nobukawa, Masayoshi; Uchiyama, Hideki; Koyama, Katsuji

    2016-08-01

    This paper reports the analysis of the X-ray spectra of the Galactic diffuse X-ray emission (GDXE) in the Suzaku archive. The fluxes of the Fe I Kα (6.4 keV), Fe XXV Heα (6.7 keV), and Fe XXVI Lyα (6.97 keV) lines are separately determined. From the latitude distributions, we confirm that the GDXE is decomposed into the Galactic center (GCXE), the Galactic bulge (GBXE) and the Galactic ridge (GRXE) X-ray emissions. The scale heights (SHs) of the Fe XXV Heα line of the GCXE, GBXE, and GRXE are determined to be ˜40, ˜310, and ˜140 pc, while those of the Fe I Kα line are ˜30, ˜160, and ˜70 pc, respectively. The mean equivalent widths (EWs) of the sum of the Fe XXV Heα and Fe XXVI Lyα lines are ˜750 eV, ˜600 eV, and ˜550 eV, while those of the Fe I Kα line are ˜150 eV, ˜60 eV, and ˜100 eV for the GCXE, GBXE, and GRXE, respectively. The origin of the GBXE, GRXE, and GCXE is separately discussed based on the new results of the SHs and EWs, in comparison with those of the cataclysmic variables, active binaries and coronal active stars.

  19. All-fiber designed narrow line-width 1.55μm double cladding fiber lasers

    NASA Astrophysics Data System (ADS)

    Su, Hongxin; Wu, Zhiyang; Xu, Lijing

    2014-11-01

    To develop 1.55μm high power lasers with compactness, narrow spectral line-width and high wavelength stability suitable for practical applications, EY-DCFLs built in all-fiber configuration are investigated. The experimental setups are composed of Er3+/Yb3+ co-doped double-clad gain fiber, multimode 976nm pump laser diode, double-clad fiber Bragg gratings (FBGs) and (1+1)x1 side pump couplers. FBGs with different reflectivity are applied as output reflectors, and forward-pump scheme and backward-pump scheme are performed respectively. As the efficiency and the spectral stability are considered simultaneously, EY-DCFL with low reflective FBG mirror and in backward-pump manner is more desirable. In the optimized all-fiber EY-DCFL, the maximum output power with an optical-optical efficiency of more than 17% is up to 1.5 W, and the wavelength is defined at 1550.8nm with a line-width about 0.03nm.

  20. Estimation of Field depolarization and LSPR shift in closely packed metallic Nanoparticles with corrected plasmon line width

    NASA Astrophysics Data System (ADS)

    Arya, Mahima; Ranjan, Mukesh; Nath, Rabinder; Mitra, Anirban

    2017-10-01

    Using modified Yamaguchi model (MYM) along with wavelength dependent plasmon line-width correction, we have developed an analytical model which can calculate effective optical constants of any distribution of ellipsoidal nanoparticles using their morphological parameters. Present approach has been developed using exact expression of electric field outside an ellipsoid and thus the shape dependent interaction of nanoparticle for higher filling fraction has been calculated exactly. Limitations of widely used point dipole approximations and effective medium theories have been discussed and compared with present approach. Previously reported shape dependent expression for plasmon line-width has been incorporated to calculate effective optical constants of the array of nanoparticles system for in-plane and out of plane plasmons. Effect of interparticle distance has been discussed with the direction of polarization for various shapes of nanoparticles. Special case of ripple patterned supported elongated nanoparticles has been discussed and biaxial anisotropic behavior in optical constants of such structures has been understood analytically for the first time.

  1. Effects of dose shift on line width, line edge roughness, and stochastic defect generation in chemically amplified extreme ultraviolet resist with photodecomposable quencher

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro

    2015-01-01

    In chemically amplified resists used for high-volume production of semiconductor devices, the control of acid catalytic reaction is essential for fine patterning. A basic compound, called a quencher, plays an important role in the control of acid catalytic reaction. In particular, the photodecomposable quencher is effective for the enhancement of the chemical gradient. In this study, the effects of photodecomposable quenchers on the dose shift (the deviation from the sizing dose) dependences of line width, line edge roughness (LER), and stochastic defect generation were investigated, assuming line-and-space patterns with 11 nm half-pitch. The exposure latitude of line width in a chemically amplified resist with photodecomposable quenchers was larger than that in a chemically amplified resist with conventional non-photodecomposable quenchers at sizing doses >20 mJ cm-2. By using photodecomposable quenchers, LER and the probability of stochastic defect generation were decreased, while the dose shift dependences of LER and stochastic defect generation did not significantly differ, compared with those observed using conventional non-photodecomposable quenchers.

  2. Raman line width study of rotational motion of cyclohexane in aqueous solution. [CH/sub 3/CN; CH/sub 3/SOCH/sub 3/

    SciTech Connect

    Tanabe, K.

    1982-02-04

    Line widths of isotropic and anisotropic Raman bands of cyclohexane at 802 cm/sup -1/ have been measured in H/sub 2/O, CH/sub 3/OH, CH/sub 3/CN, and CH/sub 3/SOCH/sub 3/ solutions and in the neat liquid. Rotational diffusion constants have been evaluated from the line widths, and the influence of iceberg structures on the rotational motion of cyclohexane molecules in aqueous solution is discussed.

  3. Tunable diode laser measurements of line widths in the nu1-fundamental band of (N-14)2(O-16) at atmospheric temperatures

    NASA Technical Reports Server (NTRS)

    Varanasi, P.; Chudamani, S.

    1989-01-01

    A tunable diode-laser spectrometer and a low-temperature absorption cell have been employed to measure the N2-broadened and O2-broadened half-widths of rotational lines in the nu1 fundamental band of (N-14)2(O-16) at 185, 235, 263, and 295 K. The temperature dependence of the line widths has been observed to be practically identical, thereby leading to the suggestion that air-broadening would exhibit the same dependence.

  4. Spectral analysis of the line-width and line-edge roughness transfer during self-aligned double patterning approach

    NASA Astrophysics Data System (ADS)

    Dupuy, E.; Pargon, E.; Fouchier, M.; Grampeix, H.; Pradelles, J.; Darnon, M.; Pimenta-Barros, P.; Barnola, S.; Joubert, O.

    2015-03-01

    We report a 20 nm half-pitch self-aligned double patterning (SADPP) process based on a resist-core approach. Line/space 20/20 nm features in silicon are successfully obtained with CDvariation, LWR and LER of 0.7 nm, 2.4 nm and 2.3 nm respectively. The LWR and LER are characterized at each technological step of the process using a power spectral density fitting method, which allows a spectral analysis of the roughness and the determination of unbiased roughness values. Although the SADP concept generates two asymmetric populations of lines, the final LLWR and LER are similar. We show that this SADP process allows to decrease significantly the LWR and the LER of about 62% and 48% compared to the initial photoresist patterns. This study also demonstrates that SADP is a very powerful concept to decrease CD uniformity and LWR especially in its low-frequency components to reach sub-20 nm node requirements. However, LER low-frequency components are still high and remain a key issue tot address for an optimized integration.

  5. Distributed seeding for narrow-line width hard x-ray free-electron lasers

    SciTech Connect

    Nguyen, Dinh Cong; Anisimov, Petr Mikhaylovich; Buechler, Cynthia Eileen; Lewellen, IV, John W.; Marksteiner, Quinn R.

    2015-09-09

    We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg crystal monochromators to enhance the spectral brightness of the MaRIE hard X-ray freeelectron laser. DS differs from self-seeding in three important aspects. First, DS relies on spectral filtering of the radiation at multiple locations along the undulator, with a monochromator located every few power gain lengths. Second, DS performs filtering early in the exponential gain region before SASE spikes start to appear in the radiation longitudinal profile. Third, DS provides the option to select a wavelength longer than the peak of the SASE gain curve, which leads to improved spectral contrast of the seeded FEL over the SASE background. Timedependent Genesis simulations show the power-vs-z growth curves for DS exhibit behaviors of a seeded FEL amplifier, such as exponential growth region immediately after the filters. Of the seeding approaches considered, the two-stage DS spectra produce the highest contrast of seeded FEL over the SASE background and that the three-stage DS provides the narrowest linewidth with a relative spectral FWHM of 8 X 10-5 .

  6. Line Shape Parameters of Water Vapor Transitions in the 3645-3975 cm^{-1} Region

    NASA Astrophysics Data System (ADS)

    Devi, V. Malathy; Benner, D. Chris; Gamache, Robert R.; Vispoel, Bastien; Renaud, Candice L.; Smith, Mary Ann H.; Sams, Robert L.; Blake, Thomas A.

    2017-06-01

    A Bruker IFS 120HR Fourier transform spectrometer (FTS) at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington was used to record a series of spectra in the regions of the ν_1 and ν_3 bands of H_2O. The samples included low pressures of pure H_2O as well as H_2O broadened by air at different pressures, temperatures and volume mixing ratios. We fit simultaneously 16 high-resolution (0.008 cm^{-1}), high S/N ratio absorption spectra recorded at 268, 296 and 353 K (L=19.95 cm), employing a multispectrum fitting technique to retrieve accurate line positions, relative intensities, Lorentz air-broadened half-width and pressure-shift coefficients and their temperature dependences for more than 220 H_2O transitions. Self-broadened half-width and self-shift coefficients were measured for over 100 transitions. For select sets of transition pairs for the H_2O-air system we determined collisional line mixing coefficients via the off-diagonal relaxation matrix element formalism, and we also measured speed dependence parameters for 85 transitions. Modified Complex Robert Bonamy (MCRB) calculations of the half-widths, line shifts, and temperature dependences were made for self-, N_2-, O_2-, and air-broadening. The measurements and calculations are compared with each other and with similar parameters reported in the literature. D. C. Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith, D. Atkins, JQSRT 53 (1995) 705-721. A. Levy, N. Lacome, C. Chackerian, Collisional line mixing, in Spectroscopy of the Earth's Atmosphere and Interstellar Medium, Academic Press, Inc., Boston (1992) 261-337.

  7. Variability of spectral lines of extrasolar system HD189733 during a transit

    NASA Astrophysics Data System (ADS)

    Shliakhetska, Y.; Kuznyetsova, Yu.; Vidmachenko, A.; Krushevska, V.

    2014-12-01

    The results of processing and analysis of spectral observations of exoplanet system HD189733 are presented in the paper. The system consists of spectral type K1-K2 star and one extrasolar planet transiting across the star disk. Four object spectra were obtained with spectral resolution R=45 000. High resolution coude-echelle spectrograph locating on the 2-meter mirror telescope Zeiss-2000 at the peak Terskol Observatory was used. It was detected increasing of depth and equivalent width of absorbing lines Hα, Hbeta, Hdelta, Hgamma, H&K CaII, NaI D2&D1 in spectra obtaining during transit and directly after that as compared with spectra obtaining during 30 minutes immediately before transit. Central emissions in H&K CaII lines were detected in all obtaining spectra

  8. Compensation effects and relation between the activation energy of spin transition and the hysteresis loop width for an iron(ii) complex.

    PubMed

    Bushuev, Mark B; Pishchur, Denis P; Nikolaenkova, Elena B; Krivopalov, Viktor P

    2016-06-22

    The enthalpy-entropy compensation was observed for the cooperative → spin transition (the phase is a mononuclear complex [FeL2](BF4)2, L is 4-(3,5-dimethyl-1H-pyrazol-1-yl)-2-(pyridin-2-yl)-6-methylpyrimidine). The physical origin of this effect is the fact that the → spin transition is the first order phase transition accompanied by noticeable variations in the Tonset↑, ΔH and ΔS values. Higher ΔH and ΔS values are correlated with higher Tonset↑ values. The higher the enthalpy and entropy of the spin transition, the wider the hysteresis loop. The kinetic compensation effect, i.e. a linear relationship between ln A and Ea, was observed for the → spin transition. Moreover, an isokinetic relationship was detected in this system: the Arrhenius lines (ln k vs. 1/T) obtained from magnetochemical data for different samples of the phase undergoing the → transition show a common point of intersection (Tiso = 490 ± 2 K, ln kiso = -6.0 ± 0.2). The validity of this conclusion was confirmed by the Exner-Linert statistical method. This means that the isokinetic relationship and the kinetic compensation effect (ln A vs. Ea) in this system are true ones. The existence of a true kinetic compensation effect is supported independently by the fact that the hysteresis loop width for the cooperative spin transition ↔ increases with increasing activation barrier height. Estimating the energy of excitations for the phase with Tiso ∼ 490 K yields wavenumbers of ca. 340 cm(-1) corresponding to the frequencies of the stretching vibrations of the Fe(LS)-N bonds, i.e. the bonds directly involved in the mechanism of the spin transition. This is the first observation of the kinetic compensation effect (ln A vs. Ea) and the isokinetic relationship for a cooperative spin crossover system showing thermal hysteresis. Our results provide the first experimental evidence that the higher the activation barrier for the spin transition, the wider the hysteresis loop for a

  9. Line width roughness reduction by rational design of photoacid generator for sub-millisecond laser post-exposure bake

    NASA Astrophysics Data System (ADS)

    Jiang, Jing; Thompson, Michael O.; Ober, Christopher K.

    2014-03-01

    Sub-millisecond laser post-exposure bake (PEB) is an alternative technology to address the excessive acid diffusion for chemically amplified photoresist systems. By rationally designing the resist, laser post-exposure bake is able to improve the resolution and reduce the line width roughness (LWR) compared to patterns exposed under the same conditions but using conventional hotplate PEB. It was found that only the resist with high deprotection activation energy and low diffusion activation energy showed improved performance using laser PEB. Accordingly, a PAG was designed to have low acid diffusivity by binding the counter ions to a molecular glass core while keeping photophysical properties and processing conditions similar to a conventional PAG. By reducing the diffusivity of the counter ions, the PAG was able to further reduce LWR by 60% using laser PEB.

  10. 140 W high power all-fiber laser at 1940 nm with narrow spectral line-width by MOPA configuration

    NASA Astrophysics Data System (ADS)

    Yang, C.; Ju, Y. L.; Yao, B. Q.; Dai, T. Y.; Duan, X. M.; Zhang, Z. G.; Liu, W.

    2016-08-01

    We report a diode-pumped Tm3+-doped double-clad all-fiber laser operating at 1940 nm with a master oscillator power amplifier configuration; 50 W of seed was generated in master oscillator with 144 W pump power, corresponding to a slope efficiency of 40.1 %. With 212 W pump power, the seed was amplified to 140.9 W in power amplifier, corresponding to a slope efficiency of 47.1 %. The peak wavelength was 1939.57 nm with a narrow spectral line-width of 0.09 nm. The beam quality factor of M 2 was 1.29. Neither amplified spontaneous emission nor parasitic lasing was observed during the amplification process. The output power was only limited by the pump power.

  11. Metal-Substrate-Mediated Plasmon Hybridization in a Nanoparticle Dimer for Photoluminescence Line-Width Shrinking and Intensity Enhancement.

    PubMed

    Li, Guang-Can; Zhang, Yong-Liang; Jiang, Jing; Luo, Yu; Lei, Dang Yuan

    2017-03-28

    Metal-film-coupled nanoparticles with subnanometer particle-film gaps possess an ultrasmall mode volume, responsible for a variety of intriguing phenomena in plasmonic nanophotonics. Due to the large radiative loss associated with dipolar coupling, however, the plasmonic-film-coupled nanocavities usually feature a low-quality factor, setting an ultimate limit of the increased light-matter interaction strength. Here, we demonstrate a plasmonic nanocavity composed of a metal-film-coupled nanoparticle dimer, exhibiting a significantly improved quality factor. Compared to a silica-supported dimer, the spectral line width of the nanocavity plasmon resonance is reduced by a factor of ∼4.6 and is even smaller than its monomer counterpart (∼30% reduction). Comprehensive theoretical analyses reveal that this pronounced resonance narrowing effect can be attributed to intense film-mediated plasmon hybridization between the bonding dipolar and quadrupolar gap modes in the dimer. More importantly, the invoking of the dark quadrupole resonance leads to a giant photoluminescence intensity enhancement (∼200 times) and dramatic emission line-width narrowing (∼4.6 times), compared to the silica-supported dimer. The similar spectral characteristics of the measured plasmonic scattering and photoluminescence emission indicate that the radiative decay of the coupled plasmons in the nanocavity is the origin of the observed photoluminescence, consistent with a proposed phenomenological model. Numerical calculations show that the intensity enhancement is mainly contributed by the dimer-film gap rather than the interparticle gap. These findings not only shed more light on the hybridized interaction between plasmon modes but also deepen the understanding of photoluminescence emission in coupled plasmonic nanostructures.

  12. Effect of slot width on transition and noise attenuation of a flat sound shield in a Mach 6 wind tunnel

    NASA Technical Reports Server (NTRS)

    Stainback, P. C.; Harvey, W. D.; Srokowski, A. J.

    1975-01-01

    An experimental and theoretical study of a sound shield concept to attenuate the noise radiated into the test section from the turbulent boundary layer on the walls of wind tunnels was conducted. The model investigated was planar with a sharp flat plate leading edge faired into an array of rods aligned nearly parallel to the local flow. For a ratio of gap diameter to rod diameter of 0.16, the flow was laminar over the entire model at a maximum local length Reynolds number of 14 million. A 45% reduction in the tunnel free stream root mean square pressure level was measured within the shielded region for this gap width when the boundary layers on the rods were laminar. Smaller ratios of gap diameter to rod diameter resulted in substantial reductions in the transition Reynolds number, and in a 40% pressure reduction.

  13. Behavior of transition-region lines during impulsive solar flares

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E.; Reichmann, E.; Woodgate, B.

    1983-01-01

    The emissions observed in lines originating in the transition-region plasma, particularly during impulsive flares, are investigated using data collected by the Ultraviolet Spectrometer and Polarimeter on the Solar Maximum Mission. Data concerning lines from ions such as Si II, C IV, Si IV, O V, and Fe XXI are analyzed. Topics examined include the transition region away from sunspots, oscillatory motions above sunspots, the shape of the transition region, the transition region during flares, and O V and Fe XXI during flare flash phases.

  14. Non-Maxwellian Analysis of the Transition-region Line Profiles Observed by the Interface Region Imaging Spectrograph

    NASA Astrophysics Data System (ADS)

    Dudík, Jaroslav; Polito, Vanessa; Dzifčáková, Elena; Del Zanna, Giulio; Testa, Paola

    2017-06-01

    We investigate the nature of the spectral line profiles for transition-region (TR) ions observed with the Interface Region Imaging Spectrograph (IRIS). In this context, we analyzed an active-region observation performed by IRIS in its 1400 Å spectral window. The TR lines are found to exhibit significant wings in their spectral profiles, which can be well fitted with a non-Maxwellian κ distribution. The fit with a κ distribution can perform better than a double-Gaussian fit, especially for the strongest line, Si iv 1402.8 Å. Typical values of κ found are about 2, occurring in a majority of spatial pixels where the TR lines are symmetric, i.e., the fit can be performed. Furthermore, all five spectral lines studied (from Si iv, O iv, and S iv) appear to have the same full-width at half-maximum irrespective of whether the line is an allowed or an intercombination transition. A similar value of κ is obtained for the electron distribution by the fitting of the line intensities relative to Si iv 1402.8 Å, if photospheric abundances are assumed. The κ distributions, however, do not remove the presence of non-thermal broadening. Instead, they actually increase the non-thermal width. This is because, for κ distributions, TR ions are formed at lower temperatures. The large observed non-thermal width lowers the opacity of the Si iv line sufficiently enough for this line to become optically thin.

  15. Stark parameters irregularities of Xe II lines obtained by transitions from ({sup 3}P{sub 1})6plevels

    SciTech Connect

    Mar, S.; Pelaez, R. J.; Rodriguez, F.; Aparicio, J. A.

    2008-10-22

    Stark widths and shifts of some Xe II lines belonging to the supermultiplets with upper levels ({sup 3}P{sub 1})6p were measured using a pulsed discharge lamp. Plasma parameters, i.e. electron density and temperature, in this experiment were in the range from 0.2 to 1.4x10{sup 23} m{sup -3} and from 18000 to 23000 K, respectively. Lines obtained by transitions from levels ({sup 3}P{sub 1})6p show some strong intra-supermultiplet irregularities in their Stark widths and shifts. These results and the measurements obtained in previous works were used here to analyse the main irregularities that can appear in the case of Xe II. This study may be very useful for obtaining Stark parameters of non-measured lines, using the known parameters of other lines belonging to similar transitions.

  16. DETECTION OF THE INTERMEDIATE-WIDTH EMISSION LINE REGION IN QUASAR OI 287 WITH THE BROAD EMISSION LINE REGION OBSCURED BY THE DUSTY TORUS

    SciTech Connect

    Li, Zhenzhen; Zhou, Hongyan; Wang, Huiyuan; Liu, Bo; Liu, Wen-Juan; Pan, Xiang; Jiang, Peng; Hao, Lei; Ji, Tuo; Shi, Xiheng; Zhang, Shaohua E-mail: zhouhongyan@pric.org.cn

    2015-10-20

    The existence of intermediate-width emission line regions (IELRs) in active galactic nuclei has been discussed for over two decades. A consensus, however, is yet to be arrived at due to the lack of convincing evidence for their detection. We present a detailed analysis of the broadband spectrophotometry of the partially obscured quasar OI 287. The ultraviolet intermediate-width emission lines (IELs) are very prominent, in high contrast to the corresponding broad emission lines (BELs) which are heavily suppressed by dust reddening. Assuming that the IELR is virialized, we estimated its distance to the central black hole to be ∼2.9 pc, similar to the dust sublimation radius of ∼1.3 pc. Photo-ionization calculations suggest that the IELR has a hydrogen density of ∼10{sup 8.8}–10{sup 9.4} cm{sup −3}, within the range of values quoted for the dusty torus near the sublimation radius. Both its inferred location and physical conditions suggest that the IELR originates from the inner surface of the dusty torus. In the spectrum of this quasar, we identified only one narrow absorption-line system associated with the dusty material. With the aid of photo-ionization model calculations, we found that the obscuring material might originate from an outer region of the dusty torus. We speculate that the dusty torus, which is exposed to the central ionizing source, may produce IELs through photo-ionization processes, as well as obscure BELs as a natural “coronagraph.” Such a “coronagraph” could be found in a large number of partially obscured quasars and may be a useful tool to study IELRs.

  17. On the equivalent widths determination of some lines arising from thea5D term of neutral iron in the solar spectrum.

    NASA Astrophysics Data System (ADS)

    Gasanalizade, A. G.

    Using the absolute oscillator strengths for Fe I lines by the Oxford scale and the absolute curve of growth of iron for two atmospheric models the author determines the equivalent widths of 21 solar lines of Fe I arising from the term a5D.

  18. Phase transitions in two-line ferrihydrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Rani, Chandni; Tiwari, S. D.

    2017-08-01

    Two-line ferrihydrite nanoparticles are synthesized by a chemical method. The sample is characterized with X-ray diffractometer, thermogravimetric analyzer, differential scanning calorimeter, and vibrating sample magnetometer. The system is found to undergo two-phase transitions on heating. Nature of these transitions and magnetic behavior of original and heated samples are reported.

  19. Wetting Transition and Line Tension of Oil on Water

    NASA Astrophysics Data System (ADS)

    Matsubara, H.; Aratono, M.

    Wetting has attracted wide attention in the field of applied chemistry because of its crucial importance in industrial operations such as coating, painting, and lubrication. Here, we summarize our fundamental understandings of surfactant-assisted wetting transitions which we have found and studied for the last ten years. The difference between the surfactant-assisted wetting transitions and existing ones is discussed. Moreover, the relation between wetting transitions and the stability of the three-phase contact line is examined in terms of the line tension of oil lenses.

  20. Natural widths and Coster Kronig transitions of L X-ray spectra in elements between Pd and Sb

    NASA Astrophysics Data System (ADS)

    Sakakura, Shusuke; Oohashi, Hirofumi; Ito, Yoshiaki; Tochio, Tatsunori; Vlaicu, Aurel M.; Yoshikawa, Hideki; Ikenaga, Eiji; Kobayashi, Keisuke

    2006-11-01

    The Lα and Lβ X-ray emission spectra in the elements between Pd ( Z=46) and Sb ( Z=51) were measured using a high-resolution double-crystal vacuum spectrometer. The relative intensities of satellite structures, which originate in L1L3M4,5 Coster-Kronig transitions, were estimated to that of each diagram line, and compared with calculated values. According to the work of Chen et al. [1977a. Theoretical L-shell Coster-Kronig energies 11⩽ Z⩽103. At. Data Nucl. Data Tables 19, 97-151], Salgueiro et al. [1987. J. Phys. (Paris) 48 Colloq. C9, 609] and Vlaicu et al. [1998. Investigation of the 74W L emission spectra and satellites. Phys. Rev. A 58, 3544] L1L3M4 Coster-Kronig transition is forbidden for 50⩽ Z⩽77, and L1L3M5 Coster-Kronig transition is forbidden for 50⩽ Z⩽73. The results suggest that L1L3M4,5 Coster-Kronig transitions may be allowed even for Sn ( Z=50) and Sb ( Z=51).

  1. Erratum: ``CO Line Width Differences in Early Universe Molecular Emission-Line Galaxies: Submillimeter Galaxies versus QSO Hosts'' (AJ, 131, 2763 [2006])

    NASA Astrophysics Data System (ADS)

    Carilli, C. L.; Wang, Ran

    2006-11-01

    It has been pointed out to us that in three dimensions the mean angle of randomly oriented disks with respect to the sky plane is <θ>=30deg, and not the 45° assumed in the original paper. This lower angle for the (assumed) random distribution of submillimeter galaxies, coupled with the factor of 2.3 lower mean CO line width for high-z, far-IR-luminous QSO host galaxies relative to the submillimeter galaxies, implies a mean angle with respect to the sky plane for the QSO host galaxies of <θ>QSO=13deg, as opposed to the 18° quoted in the original paper. We thank Pat Hall for bringing this to our attention.

  2. Multispectrum measurements of spectral line parameters including temperature dependences of N2- and self-broadened half-width coefficients in the region of the v9 band of 12C2H6

    SciTech Connect

    Malathy Devi, V.; Benner, D. C.; Rinsland, C.P.; Smith, M.A.H.; Sams, Robert L.; Blake, Thomas A.; Flaud, Jean Marie; Sung, Keeyoon; Brown, L.R.; Mantz, A. W.

    2010-11-01

    Ethane is a prominent contributor to the spectrum of Titan, particularly in the region of the v9 band at 12μm. A multispectrum nonlinear least squares fitting program was applied to laboratory spectra of ethane to measure accurate positions, absolute intensities, N2- and selfbroadened half- width coefficients and their temperature dependences for a large number transitions. These measurements include several pQ and rQ sub-bands (and other sub-bands such as pP, rR) in the v9 fundamental band of 12C2H6 centered near 822 cm-1. Positions were measured for 2958 transitions and intensities for 3771 transitions. N2- and self-broadened half-width coefficients were determined for over 1700 transitions while temperature dependence exponents were retrieved for over 1350 of those transitions. Of these, many measurements (mostly line positions and intensities) belong to the v9+v4-v4 hot band, v9+2v4-2v4 hot band, 13C12CH6 v9 band and unidentified transitions. Forty-three high resolution (0.0016-0.005 cm-1) infrared laboratory absorption spectra recorded at temperatures between 148 and 298 K were fitted simultaneously to retrieve these parameters. Forty-one of these spectra were obtained in the temperature range of 211-298 K using the Bruker IFS 120HR interferometer located at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington. Two additional spectra at 148 K were recorded using a new temperature stabilized cryogenic cell designed to work inside the sample compartment of the high resolution Bruker IFS 125HR interferometer of the Jet Propulsion Laboratory (JPL) in Pasadena California. The specialized cooling cell developed at Connecticut College and capable of achieving gas sample temperatures down to 70 K with a temperature stability and uniformity of better than ±0.05 K was employed to record the 148 K spectra. Constraints to intensity ratios, doublet separations, half-width coefficients and their temperature dependence exponents were required to

  3. Minimum line width of ion beam-modified polystyrene by negative carbon ions for nerve-cell attachment and neurite extension

    NASA Astrophysics Data System (ADS)

    Sommani, P.; Tsuji, H.; Sato, H.; Kitamura, T.; Hattori, M.; Gotoh, Y.; Ishikawa, J.

    2007-04-01

    The minimum line width of the negative-ion-modified polystyrene (PS) for guidance and immobilizations of nerve-cell body and neurite extension have been investigated. Carbon negative ions were implanted into PS at fluence of 3 × 1015 ions/cm2 and energy of 5-20 keV through the various triangle apertures of the micro-pattern mask. After in vitro culture of the nerve-like cells of rat adrenal pheochromocytoma (PC12h), results showed that the minimum line widths for a single cell attachment and for neurite extension were 5-7 and 3-5 μm, respectively. While the minimum line width for attachment of cell group with long neurite was about 20 μm. The suitable widths for a large number of cells and for neurite extension were 20 and 5 μm, respectively. Therefore, the guidance for a clear separation of the attachment size of cell body and neurite extension could be achieved by the different modified line widths.

  4. Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Hsu, Yung; Hsu, Chin-Wei; Yang, Ling-Gang; Chow, Chi-Wai; Yeh, Chien-Hung; Lai, Yin-Chieh; Tsang, Hon-Ki

    2016-02-01

    In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single sideband (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.

  5. Theoretical study of relationships among resolution, line width roughness, and sensitivity of chemically amplified extreme ultraviolet resists with photodecomposable quenchers

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2016-11-01

    The resolution of chemically amplified extreme ultraviolet (EUV) resists has reached 13-15 nm. However, the line width roughness (LWR) and sensitivity are still inadequate for their application to the high-volume production of semiconductor devices. In this study, the performance of chemically amplified resists with photodecomposable quenchers were investigated by simulation based on the sensitization and reaction mechanisms of chemically amplified EUV resists. The relationships among resolution, LWR, and sensitivity were evaluated in the half-pitch ranges of 12-16 nm. The requirements for 20 mJ cm-2 and 10% critical dimension (CD) LWR are considered to be within the physical limits in the half-pitch range of 12-16 nm when an optical image with a contrast of 1 (normalized image log slope of π) is given. Depending on the given image quality and the required sensitivity, the optimization of sensitizer concentration and the increase in resist absorption coefficient and/or effective reaction radius for deprotection are required to achieve 10% CD LWR.

  6. Revisiting the mechanisms involved in Line Width Roughness smoothing of 193 nm photoresist patterns during HBr plasma treatment

    SciTech Connect

    Brihoum, M.; Ramos, R.; Menguelti, K.; Cunge, G.; Pargon, E.; Joubert, O.

    2013-01-07

    HBr plasma treatments are widely used in nanoscale lithographic technologies to increase the plasma etch resistance of 193 nm photoresist masks as well as to decrease their Line Width Roughness (LWR). VUV irradiation of the photoresist is known to play a major role in this process by inducing polymer chains rearrangement and finally LWR reduction. However, in the plasma environment (i.e., with radical and ion bombardment), the interaction layer formed at the resist surface perturbs this mechanism and a lower LWR reduction is achieved compared to VUV only treatment. So far the nature of the interaction layer, its formation mechanism and its relation with the resist pattern LWR were all unclear. In this paper, we show that a graphite-like layer is formed on the resist patterns by the redeposition of carbon-based species originating from the plasma dissociation of outgassed photo-etched resist moieties. We show that the presence of this layer inhibits the LWR minimization and causes an increase in the LWR when it becomes thick enough (i.e., a few nanometers). We present evidences that the difference in the mechanical properties of the graphite-like top layer which coats the resist patterns and the bulk of the resist patterns is correlated to the LWR after plasma treatment. We can conclude that the optimization of an HBr cure process relies on the minimization of the carbon redeposition while keeping a significant VUV light flux and we show that this can be achieved by using pulsed plasma processes.

  7. Wetting transition for the contact line and Antonov's rule for the line tension

    NASA Astrophysics Data System (ADS)

    Robledo, A.; Varea, C.; Indekeu, J. O.

    1992-02-01

    The standard wetting transition consists of the transformation of a microscopically thin two-dimensional interface into a macroscopically thick structure composed of two interfaces separated by a bulk phase. We consider the one-dimensional analog of this phenomenon, when a contact line among three or more phases decomposes into two contact lines separated by an interface. We uncover a wetting transition for the contact line, which occurs at surface two-phase coexistence, as a function of a line or edge field. This is exemplified by means of a lattice mean-field calculation for an Ising model bounded by two surfaces that meet in an edge.

  8. Temperature-Dependence of Air-Broadened Line Widths and Shifts in the nu3 Band of Ozone

    NASA Technical Reports Server (NTRS)

    Smith, Mary A. H.; Rinsland, Curtis P.; Devi, V. Malathy; Benner, D. Chris; Cox, A. M.

    2006-01-01

    The 9.6-micron bands of O3 are used by many remote-sensing experiments for retrievals of terrestrial atmospheric ozone concentration profiles. Line parameter errors can contribute significantly to the total errors in these retrievals, particularly for nadir-viewing. The McMath-Pierce Fourier transform spectrometer at the National Solar Observatory on Kitt Peak was used to record numerous high-resolution infrared absorption spectra of O3 broadened by various gases at temperatures between 160 and 300 K. Over 30 spectra were analyzed simultaneously using a multispectrum nonlinear least squares fitting technique to determine Lorentz air-broadening and pressure-induced shift coefficients along with their temperature dependences for selected transitions in the 3 fundamental band of (16)O3. We compare the present results with other measurements reported in the literature and with the ozone parameters on the 2000 and 2004 editions of the HITRAN database.

  9. Broadband Uniplanar Microstrip to Slot-Line Transitions

    NASA Technical Reports Server (NTRS)

    Dib, Nihad I.; Simons, Rainee N.; Katehi, Linda P. B.

    1995-01-01

    New in line uniplanar microstrip-to-slotline transitions for MIC/MMIC and phased array slotline antenna applications are described. Such transactions are compact and suitable to be used in an open environment or inside a package or a multichip module. The transitions share the concept of using a balun which consists of two microstrip lines connected to a slotline through a pair of coupled microstrips. The transitions are studied theoretically using the finite difference time domain (FDTD) technique and measured experimentally using an HP8510C Network Analyzer. For a back-to-back configuration, an insertion loss of less than 1.3 dB per transition is achieved over a 40% 3-dB bandwidth with a minimum of 0.6 dB at the design frequency.

  10. Transition Probabilities for Spectral Lines in Co I

    NASA Astrophysics Data System (ADS)

    Nitz, D. E.; Wilson, K. L.; Lentz, L. R.

    1996-05-01

    We are in the process of determining transition probabilities for visible and uv lines in Co I from Fourier transform spectra recorded at Kitt Peak and made available to us by Prof. W. Whaling. Normalization of relative transition probabilities obtained from these spectra is achieved using recently-measured Co I lifetimes.(D. E. Nitz, S. D. Bergeson, and J. E. Lawler, J. Opt. Soc. Am. B 12, 377 (1995).) To date we have obtained preliminary results for 240 lines having branch fractions > 1

  11. On the equivalent width of the Fe Kα line produced by a dusty absorber in active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Gohil, R.; Ballantyne, D. R.

    2015-05-01

    Obscured active galactic nuclei (AGNs) provide an opportunity to study the material surrounding the central engine. Geometric and physical constraints on the absorber can be deduced from the reprocessed AGN emission. In particular, the obscuring gas may reprocess the nuclear X-ray emission producing a narrow Fe Kα line and a Compton reflection hump. In recent years, models of the X-ray reflection from an obscuring torus have been computed; however, although the reflecting gas may be dusty, the models do not yet take into account the effects of dust on the predicted spectrum. We study this problem by analysing two sets of models, with and without the presence of dust, using the one-dimensional photoionization code CLOUDY. The calculations are performed for a range of column densities (22 < log[NH(cm- 2)] < 24.5) and hydrogen densities (6 < log[nH(cm- 3)] < 8). The calculations show the presence of dust can enhance the Fe Kα equivalent width (EW) in the reflected spectrum by factors up to ≈8 for Compton thick (CT) gas and a typical interstellar medium grain size distribution. The enhancement in EW with respect to the reflection continuum is due to the reduction in the reflected continuum intensity caused by the anisotropic scattering behaviour of dust grains. This effect will be most relevant for reflection from distant, predominately neutral gas, and is a possible explanation for AGNs which show a strong Fe Kα EW and a relatively weak reflection continuum. Our results show it is an important to take into account dust while modelling the X-ray reflection spectrum, and that inferring a CT column density from an observed Fe Kα EW may not always be valid. Multidimensional models are needed to fully explore the magnitude of the effect.

  12. Tetralocular ovary and high silique width in yellow sarson lines of Brassica rapa (subspecies trilocularis) are due to a mutation in Bra034340 gene, a homologue of CLAVATA3 in Arabidopsis.

    PubMed

    Yadava, Satish Kumar; Paritosh, Kumar; Panjabi-Massand, Priya; Gupta, Vibha; Chandra, Atika; Sodhi, Y S; Pradhan, Akshay K; Pental, Deepak

    2014-11-01

    Genetic locus for tetralocular ovary (tet-o) in Brassica rapa was identified and it was shown that the number of locules and width of silique are associated. Brassica rapa is a highly polymorphic species containing many vegetables and oleiferous types. An interesting group of oleiferous types is the yellow sarson group (subspecies trilocularis) grown mostly in eastern India. This group contains lines that have bilocular ovaries, a defining trait of Brassicaceae, but also lines that have tetralocular ovaries. Yellow sarson lines commonly have high silique width which is further enhanced in the tetralocular types. We mapped the locus influencing tetralocular ovary in B. rapa using three mapping populations (F2, F6 and F7) derived from a cross between Chiifu (subspecies pekinensis, having bilocular ovary) and Tetralocular (having tetralocular ovary). QTL mapping of silique width was undertaken using the three mapping populations and a F2 population derived from a cross between Chiifu and YSPB-24 (a bilocular line belonging to yellow sarson group). Qualitative mapping of the trait governing locule number (tet-o) in B. rapa mapped the locus to linkage group A4. QTL mapping for silique width detected a major QTL on LG A4, co-mapping with the tet-o locus in bilocular/tetralocular cross. This QTL was not detected in the bilocular/bilocular cross. Saturation mapping of the tet-o region with SNP markers identified Bra034340, a homologue of CLAVATA3 of Arabidopsis thaliana, as the candidate gene for locule number. A C → T transition at position 176 of the coding sequence of Bra034340 revealed co-segregation with the tetralocular phenotype. The study of silique related traits is of interest both for understanding evolution under artificial selection and for breeding of cultivated Brassica species.

  13. Carbon and nitrogen abundances determined from transition layer lines

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika; Mena-Werth, Jose

    1992-01-01

    The possibility of determining relative carbon, nitrogen, and silicon abundances from the emission-line fluxes in the lower transition layers between stellar chromospheres and coronae is explored. Observations for main-sequence and luminosity class IV stars with presumably solar element abundances show that for the lower transition layers Em = BT sup -gamma. For a given carbon abundance the constants gamma and B in this relation can be determined from the C II and C IV emission-line fluxes. From the N V and S IV lines, the abundances of these elements relative to carbon can be determined from their surface emission-line fluxes. Ratios of N/C abundances determined in this way for some giants and supergiants agree within the limits of errors with those determined from molecular bands. For giants, an increase in the ratio of N/C at B-V of about 0.8 is found, as expected theoretically.

  14. INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: Line width of a single longitudinal mode emitted by an AlGaAs heterojunction laser

    NASA Astrophysics Data System (ADS)

    Bogatov, Alexandr P.; Eliseev, P. G.; Luk'yanov, S. A.; Pak, G. T.; Petrakova, T. V.

    1988-11-01

    A nonmonotonic dependence of the emission line width on the power was observed for a single longitudinal mode of an AlGaAs heterojunction laser. This behavior could be due to the dependence of the waveguide coefficient of the amplitude-phase coupling on the nature of operation of the laser.

  15. Phase transitions in tumor growth: II prostate cancer cell lines

    NASA Astrophysics Data System (ADS)

    Llanos-Pérez, J. A.; Betancourt-Mar, A.; De Miguel, M. P.; Izquierdo-Kulich, E.; Royuela-García, M.; Tejera, E.; Nieto-Villar, J. M.

    2015-05-01

    We propose a mechanism for prostate cancer cell lines growth, LNCaP and PC3 based on a Gompertz dynamics. This growth exhibits a multifractal behavior and a "second order" phase transition. Finally, it was found that the cellular line PC3 exhibits a higher value of entropy production rate compared to LNCaP, which is indicative of the robustness of PC3, over to LNCaP and may be a quantitative index of metastatic potential tumors.

  16. Atlas Transmission Line/Transition Design and Fabrication Status

    DTIC Science & Technology

    1999-06-01

    completed for this new generation pulsed-power machine consisting of an azimuthal array of 24, 240-kV Marx modules and transmission lines supplying current...to the center transition section. The cable header interface to the Marx module provides a mechanism to remove the Marx module for maintenance... Marx in the event of a pre-fire condition. The aluminum tri-plate is a low-inductance transmission line that carries radial current flow from the Marx

  17. Localization transition of stiff directed lines in random media.

    PubMed

    Boltz, Horst-Holger; Kierfeld, Jan

    2012-12-01

    We investigate the localization of stiff directed lines with bending energy by a short-range random potential. Using perturbative arguments, Flory arguments, and a replica calculation, we show that a stiff directed line in 1+d dimensions undergoes a localization transition with increasing disorder for d>2/3. We demonstrate that this transition is accessible by numerical transfer matrix calculations in 1+1 dimensions and analyze the properties of the disorder-dominated phase. On the basis of the two-replica problem, we propose a relation between the localization of stiff directed lines in 1+d dimensions and of directed lines under tension in 1+3d dimensions, which is strongly supported by identical free energy distributions. This shows that pair interactions in the replicated Hamiltonian determine the nature of directed line localization transitions with consequences for the critical behavior of the Kardar-Parisi-Zhang (KPZ) equation. Furthermore, we quantify how the persistence length of the stiff directed line is reduced by disorder.

  18. Effect of photoions on the line shape of the Foerster resonance lines and microwave transitions in cold rubidium Rydberg atoms

    SciTech Connect

    Tretyakov, D. B.; Beterov, I. I.; Entin, V. M.; Yakshina, E. A.; Ryabtsev, I. I.; Dyubko, S. F.; Alekseev, E. A.; Pogrebnyak, N. L.; Bezuglov, N. N.; Arimondo, E.

    2012-01-15

    Experiments are carried out on the spectroscopy of the Foerster resonance lines Rb(37P) + Rb(37P) {yields} Rb(37S) + Rb(38S) and microwave transitions nP {yields} n Prime S, n Prime D between Rydberg states of cold rubidium atoms in a magneto-optical trap (MOT). Under ordinary conditions, all spectra exhibit a linewidth of 2-3 MHz irrespective of the interaction time between atoms or between atoms and microwave radiation, although the limit resonance width should be determined by the inverse interaction time. The analysis of experimental conditions has shown that the main source of line broadening is the inhomogeneous electric field of cold photoions that are generated under the excitation of initial nP Rydberg states by broadband pulsed laser radiation. The application of an additional electric-field pulse that rapidly extracts photoions produced by a laser pulse leads to a considerable narrowing of lines of microwave resonances and the Foerster resonance. Various sources of line broadening in cold Rydberg atoms are analyzed.

  19. Fluctuations of a receding contact line near the entrainment transition

    NASA Astrophysics Data System (ADS)

    Bico, Jose; Delon, Giles; Fermigier, Marc

    2004-11-01

    We study experimentally the fluctuations of a contact line receding on a plane solid substrate. The contact line is perturbed by localized defects and we follow the relaxation of perturbations induced by these defects, as a function of the mean contact line speed and wavelengths characteristic of the perturbations. We compare our results with theoretical predictions by Golestanian and Raphael showing a divergence of the relaxation time at the entrainment transition (when the receding velocity exceeds a critical value, the liquid is entrained by the solid).

  20. Width dependent transition of quantized spin-wave modes in Ni{sub 80}Fe{sub 20} square nanorings

    SciTech Connect

    Banerjee, Chandrima; Saha, Susmita; Barman, Saswati; Barman, Anjan; Rousseau, Olivier; Otani, YoshiChika

    2014-10-28

    We investigated optically induced ultrafast magnetization dynamics in square shaped Ni{sub 80}Fe{sub 20} nanorings with varying ring width. Rich spin-wave spectra are observed whose frequencies showed a strong dependence on the ring width. Micromagnetic simulations showed different types of spin-wave modes, which are quantized upto very high quantization number. In the case of widest ring, the spin-wave mode spectrum shows quantized modes along the applied field direction, which is similar to the mode spectrum of an antidot array. As the ring width decreases, additional quantization in the azimuthal direction appears causing mixed modes. In the narrowest ring, the spin-waves exhibit quantization solely in azimuthal direction. The different quantization is attributed to the variation in the internal field distribution for different ring width as obtained from micromagnetic analysis and supported by magnetic force microscopy.

  1. A measurement of the width and shift of the Fe I 3719.94 A line broadened by helium. [for stellar atmosphere studies

    NASA Technical Reports Server (NTRS)

    Driver, R. D.; Lombardi, G.

    1977-01-01

    Results are reported for measurements of the widths and shifts of the overlapping helium-broadened profiles of the Fe I absorption lines at 3719.94 and 3722.56 A, which were performed in a ballistic piston compressor using a saturated solution of FeCl3 in ethanol. It is found that at 4000 K, the 3719.94-A line has a gamma/n (FWHM) value of approximately 5.2 billionths rad/sec per cu cm, the blue shift of this line corresponds to a beta/n value of about 0.49 billionth rad/sec per cu cm, and the 3722.56-A line has the same values. These results are compared with previous experimental determinations and with theoretical calculations of neutral-line broadening for the Fe I lines. The significance of these measurements with respect to the solar spectrum and cool DG white dwarfs is discussed.

  2. DETERMINING INTERSTELLAR CARBON ABUNDANCES FROM STRONG-LINE TRANSITIONS

    SciTech Connect

    Sofia, U. J.; Parvathi, V. S.; Babu, B. R. S.; Murthy, J.

    2011-01-15

    Carbon is arguably the most important element in the interstellar medium, yet its abundance in gas and dust is poorly understood due to a paucity of data. We explore the possibility of substantially increasing our knowledge of interstellar carbon by applying and assessing a new method for determining the column density of the dominant ion of interstellar carbon in diffuse neutral lines of sight. The method relies on profile fitting of the strong transition of C II at 1334 A in spectra continuum normalized with stellar models. We apply our method to six sight lines for which the carbon abundance has previously been determined with a weak intersystem absorption transition. Our strong-line method consistently shows a significantly lower gas-phase C abundance than the measurements from the weak lines. This result implies that more carbon could reside in dust than was previously thought. This has implications for dust models, which often suffer from a lack of sufficient carbon to plausibly explain extinction. There is no immediately clear explanation for the difference found between the strong- and weak-line C II determinations, but there are indications that the results from the method presented here have advantages over the weak-line column densities. If this is the case, then the reported oscillator strength for the C II transition at 2325 A may be too small. Our findings further suggest that damping wings modeled with a single absorption component may not produce accurate abundances. This problem could affect a large number of H I abundances determined through absorption line analysis that are reported in the literature.

  3. Discovery of a transiting planet near the snow-line

    SciTech Connect

    Kipping, D. M.; Torres, G.; Buchhave, L. A.; Kenyon, S. J.; Henze, C.; Bryson, S. T.; Isaacson, H.; Kolbl, R.; Marcy, G. W.; Stassun, K.; Bastien, F.

    2014-11-01

    In most theories of planet formation, the snow-line represents a boundary between the emergence of the interior rocky planets and the exterior ice giants. The wide separation of the snow-line makes the discovery of transiting worlds challenging, yet transits would allow for detailed subsequent characterization. We present the discovery of Kepler-421b, a Uranus-sized exoplanet transiting a G9/K0 dwarf once every 704.2 days in a near-circular orbit. Using public Kepler photometry, we demonstrate that the two observed transits can be uniquely attributed to the 704.2 day period. Detailed light curve analysis with BLENDER validates the planetary nature of Kepler-421b to >4σ confidence. Kepler-421b receives the same insolation as a body at ∼2 AU in the solar system, as well as a Uranian albedo, which would have an effective temperature of ∼180 K. Using a time-dependent model for the protoplanetary disk, we estimate that Kepler-421b's present semi-major axis was beyond the snow-line after ∼3 Myr, indicating that Kepler-421b may have formed at its observed location.

  4. Improved hodograph method to estimate the field-line resonance frequency and the resonance width as a function of latitude: Application to ground magnetometer data

    NASA Astrophysics Data System (ADS)

    Kawano, H.; Pilipenko, V.; Saita, S.; Yumoto, K.; Mann, I. R.

    2011-12-01

    Standing Alfven waves can be excited on field lines in the magnetosphere by the field-line resonance (FLR) mechanism, and thus excited field-line oscillations can be monitored by using ground magnetometers. The frequency of the standing wave (FLR frequency below), observed on the ground, is useful for us to estimate the magnetospheric plasma mass density from the ground, because the FLR frequency decreases with increasing plasma mass along the field line. In the direction of latitude (on the ground) or L (in space), FLR at a specific frequency is active in a finite width, which is called the resonance width. The resonance width is larger if a larger portion of the wave energy in the magnetosphere is absorbed by the ionosphere. FLR frequencies are often difficult to identify in the ground magnetometer data, because different kinds of waves with large amplitudes are often superposed onto the FLR signal and mask the FLR signal. As countermeasures to this problem, methods called the amplitude-ratio method and the cross-phase method have been used; these methods take the difference between the data from two magnetometers that are latitudinally separated by an order of 100km, and provide the FLR frequency at the midpoint between the two magnetometer sites. However, a problem here is that the two methods can yield different values of the FLR frequency from the same dataset. The hodograph method solves this problem, because it merges the amplitude-ratio method and the cross-phase method into one method. Furthermore, it yields the FLR frequency at any latitude from the same dataset (although the estimation error increases with increasing distance from the observation sites). The hodograph method also provides the resonance width, but it is assumed to be a constant of latitude in the method, while in reality the resonance width can be a function of latitude. To solve this problem, we have newly introduced a latitude dependence of the resonance width into the hodograph method

  5. Phase Transitions above the Yrast Line in {sup 154}Dy

    SciTech Connect

    Ma, W. C.; Martin, V.; Khoo, T. L.; Lauritsen, T.; Egido, J. L.; Ahmad, I.; Bhattacharyya, P.; Carpenter, M. P.; Daly, P. J.; Grabowski, Z. W.

    2000-06-26

    Spectra of the E2 quasicontinuum {gamma} rays feeding different spin regions of the {sup 154}Dy yrast line have been extracted. These are compared with corresponding theoretical spectra obtained by numerical simulations based on temperature-dependent Hartree-Fock theory, with thermal shape fluctuations. In this manner, different regions of the spin-energy plane can be examined. The results support the predictions of a smeared-out phase transition at high spin above the yrast line. (c) 2000 The American Physical Society.

  6. Visual search performance on an lcd monitor: effects of color combination of figure and icon background, shape of icon, and line width of icon border.

    PubMed

    Huang, Kuo-Chen; Chiu, Tsai-Lan

    2007-04-01

    This study investigated the effects of color combinations for the figure/icon background, icon shape, and line width of the icon border on visual search performance on a liquid crystal display screen. In a circular stimulus array, subjects had to search for a target item which had a diameter of 20 cm and included one target and 19 distractors. Analysis showed that the icon shape significantly affected search performance. The correct response time was significantly shorter for circular icons than for triangular icons, for icon borders with a line width of 3 pixels than for 1 or 2 pixels, and for 2 pixels than for 1 pixel. The color combination also significantly affected the visual search performance: white/yellow, white/blue, black-red, and black/ yellow color combinations for the figure/icon background had shorter correct response times compared to yellow/blue, red/green, yellow/green, and blue/red. However, no effects were found for the line width of the icon border or the icon shape on the error rate. Results have implications for graphics-based design of interfaces, such as for mobile phones, Web sites, and PDAs, as well as complex industrial processes.

  7. Diode laser measurements of line strengths and widths in the 4.5-micron bands of N2O

    NASA Technical Reports Server (NTRS)

    Lowenstein, M.; Podolske, J. R.; Blackburn, T. E.; Varanasi, P.

    1986-01-01

    Line-strength measurements in the N2O nu3-fundamental region using a tunable diode-laser spectrometer. From these measurements and the Herman-Wallis factor determined by Boissy et al. (1975), the nu-3-fundamental band strength is found to be 1203 + or - 22 per sq cm atm at 297 K. Line-broadening parameters for two nu-3-fundamental lines were determined using nitrogen (N2) as the broadening gas. Measured strengths and N2 line-broadening parameters for several hot-band lines are also presented.

  8. Evaluating Possible Heating Mechanisms Using the Transition Region Line Profiles of Late-Type Stars

    NASA Technical Reports Server (NTRS)

    Wood, Brian E.; Linsky, Jeffrey L.; Ayres, Thomas R.

    1997-01-01

    Our analysis of high-resolution Goddard High-Resolution Spectrograph (GHRS) spectra of late-type stars shows that the Si IV and C IV lines formed near 10(exp 5) K can be decomposed into the sum of two Gaussians, a broad component and a narrow component. We find that the flux contribution of the broad components is correlated with both the C IV and X-ray surface fluxes. For main-sequence stars, the widths of the narrow components suggest subsonic nonthermal velocities, and there appears to be a tight correlation between these nonthermal velocities and stellar surface gravity [xi(sub nc) varies as g(sup (-.68 +/-.07))]. For evolved stars with lower surface gravities, the nonthermal velocities suggested by the narrow components are at or just above the sound speed. Nonthermal velocities computed from the widths of the broad components are always highly supersonic. We propose that the broad components are diagnostics for microflare heating. Turbulent dissipation and Alfven waves are both viable candidates for the narrow component heating mechanism. A solar analog for the broad components might be the 'explosive events' detected by the High-Resolution Telescope and Spectrograph (HRTS) experiment. The broad component we observe for the Si IV lambda 1394 line of alpha Cen A, a star that is nearly identical to the Sun, has a FWHM of 109 +/- 10 km/s and is blueshifted by 9 +/- 3 km/s relative to the narrow component. Both of these properties are consistent with the properties of the solar explosive events. However, the alpha Cen A broad component accounts for 25% +/- 4% of the total Si IV line flux, while solar explosive events are currently thought to account for no more than 5% of the Sun's total transition region emission. This discrepancy must be resolved before the connection between broad components and explosive events can be positively established. In addition to our analysis of the Si IV and C IV lines of many stars, we also provide a more thorough analysis of all

  9. Temperature Dependencies of Linewidths, Positions, and Line Shifts of Spectral Transitions of Trivalent Neodymium Ions in Ceramic Nd3+:Y2O3

    NASA Astrophysics Data System (ADS)

    Pedraza, Francisco; Khachatryan, Edward; Dennis, Robert; Nash, Kelly; Sardar, Dhiraj

    2010-10-01

    Effects of temperature on widths and shifts of the spectral lines of Nd^3+ in Y2O3 polycrystalline ceramic have been investigated. The spectral lines corresponding to the inter-Stark transitions R1 -> Y1 (1074 nm) and R1-> X3 (914 nm) within the ^4F3/2 -> ^4I11/2 and ^4F3/2 -> ^4I9/2 transitions, respectively, have been studied. The widths of these lines and their shifts have been measured as a function of temperature in 10K- 300K range. The spectral linewidths of both transitions are found to increase with increasing temperature. This research was supported by the National Science Foundation Grant No. DMR-0934218.

  10. SunLine Transit Agency Fuel Cell Transit Bus: Fifth Evaluation Report (Report and Appendices)

    SciTech Connect

    Eudy, L.; Chandler, K.

    2009-08-01

    This report describes operations at SunLine Transit Agency for a prototype fuel cell bus and five compressed natural gas (CNG) buses. This is the fifth evaluation report for this site, and it describes results and experiences from October 2008 through June 2009. These results are an addition to those provided in the previous four evaluation reports.

  11. SunLine Transit Agency Fuel Cell Transit Bus: Fourth Evaluation Report (Report and Appendices)

    SciTech Connect

    Chandler, K.; Eudy, L.

    2009-01-01

    This report describes operations at SunLine Transit Agency for a prototype fuel cell bus and five new compressed natural gas (CNG) buses. This is the fourth evaluation report for this site, and it describes results and experiences from April 2008 through October 2008. These results are an addition to those provided in the previous three evaluation reports.

  12. Topological phase transitions in line-nodal superconductors

    NASA Astrophysics Data System (ADS)

    Han, SangEun; Cho, Gil Young; Moon, Eun-Gook

    2017-03-01

    Fathoming interplay between symmetry and topology of many-electron wave functions has deepened our understanding of quantum many-body systems, particularly after the discovery of topological insulators. Topology of electron wave functions often enforces and protects emergent gapless excitation, and symmetry is intrinsically tied to the topological protection of the excitations. Namely, unless the symmetry is broken, the topological nature of the excitations is intact. We show intriguing phenomena of interplay between symmetry and topology in three-dimensional topological phase transitions associated with line-nodal superconductors. More specifically, we discover an exotic universality class out of topological line-nodal superconductors. The order parameter of broken symmetries is strongly correlated with underlying line-nodal fermions, and this gives rise to a large anomalous dimension in sharp contrast to that of the Landau-Ginzburg theory. Remarkably, hyperscaling violation and emergent relativistic scaling appear in spite of the presence of nonrelativistic fermionic excitation. We also propose characteristic experimental signatures around the phase transitions, for example, a linear phase boundary in a temperature-tuning parameter phase diagram, and discuss the implication of recent experiments in pnictides and heavy-fermion systems.

  13. Strong-field cyclotron scattering. I - Scattering amplitudes and natural line width. [in spectra of accretion-powered X-ray pulsars

    NASA Technical Reports Server (NTRS)

    Graziani, Carlo

    1993-01-01

    The introduction of resonance line width into the QED cyclotron scattering amplitudes is considered. It is shown that the width arises from loop corrections to the electron propagator, which also bring about shifts in the Landau energy levels. A formalism is developed that allows the dressed electron propagator to be derived. It is shown that the states of Herold et al. (1982) and of Sokolov and Ternov (1968), which diagonalize the component of the magnetic moment operator parallel to the external magnetic field, are appropriate for calculation of the scattering amplitudes, whereas the states of Johnson and Lippmann (1949) are not. In addition, it is shown that the Breit-Wigner broadening approximation E tends to E - i(Gamma)/2 is consistent with the perturbation-theoretic order of the calculation, if the former basis states are chosen, but not the latter.

  14. Line widths and Doppler velocities according to the Fe X λ6374 and Fe XIV λ5303 observations performed with the Large Coronograph at Sayan Observatory

    NASA Astrophysics Data System (ADS)

    Tyagun, N. F.

    2014-12-01

    Distributions of the Doppler velocities ( V), widths (Δλ), and intensities ( W) have been obtained based on the λ6374 and λ5303 spectra observed with the Large Coronograph at Sayan Observatory above active regions and their surroundings. The average Doppler velocities in both lines are ±5 km/s; a decrease and stabilization of these velocities with increasing W demonstrate the effect of magnetic fields. The dispersion of V for λ6374 in the zones with decreased W is substantially larger than such a dispersion for λ5303, the Δλ values are larger in these zones respectively. This is explained by the fact that the profile shape is affected by the plasma structuring degree along the line of sight controlled by the magnetic field topology in the regions where these lines glow: the field should be open and closed in the red and green coronas, respectively.

  15. Thermodynamic geometry, phase transitions, and the Widom line.

    PubMed

    Ruppeiner, G; Sahay, A; Sarkar, T; Sengupta, G

    2012-11-01

    A microscopic characterization, based on the thermodynamic curvature R, is proposed for first-order liquid-gas phase transitions. Near the critical point, where R is proportional to the correlation volume ξ(3), we propose that R takes the same value in the coexisting phases. This proposal allows a determination of the liquid-gas coexistence curve with no use of the problematic Maxwell equal area construction. Furthermore, |R| ~ ξ(3) allows a direct determination of the Widom line in the supercritical regime. We illustrate with input from the van der Waals model and the National Institute of Standards and Technology Chemistry WebBook.

  16. The role of higher-multipolar and repulsive forces in the calculation of collision-broadened line-widths of linear molecules

    NASA Technical Reports Server (NTRS)

    Varanasi, P.; Sarangi, S.

    1974-01-01

    Collision-broadened line widths in CO-CO2 and CO-O2 collisions have been calculated by incorporating interactions due to octopoles and hexadecapoles and short-range repulsive interactions into Anderson's (1949) theory. It is shown how these higher-order interactions can be manipulated to yield good agreement with experimental data. A critical evaluation of this totally empirical manipulation suggests that a thorough revision of the theory is required for all but simple dipole-dipole interactions. In the process of the evaluation, the values of the multipole moments are discussed.

  17. The role of higher-multipolar and repulsive forces in the calculation of collision-broadened line-widths of linear molecules

    NASA Technical Reports Server (NTRS)

    Varanasi, P.; Sarangi, S.

    1974-01-01

    Collision-broadened line widths in CO-CO2 and CO-O2 collisions have been calculated by incorporating interactions due to octopoles and hexadecapoles and short-range repulsive interactions into Anderson's (1949) theory. It is shown how these higher-order interactions can be manipulated to yield good agreement with experimental data. A critical evaluation of this totally empirical manipulation suggests that a thorough revision of the theory is required for all but simple dipole-dipole interactions. In the process of the evaluation, the values of the multipole moments are discussed.

  18. Effects of an avoided crossing on line widths of resonances in the H2 i 3Π?g state

    NASA Astrophysics Data System (ADS)

    Snoek, L. C.; Siebbeles, L. D. A.; van der Zande, W. J.

    1995-12-01

    We have investigated the influence of nonadiabatic effects on the linewidths of quasi-bound rovibrational levels in the i3Π g state of molecular hydrogen. This state has a potential barrier due to the interaction of the n=33Π g Rydberg series and the Q13Π g valence state. The radial coupling with the higher lying3Π g states has been modelled into a diabatic problem. The widths of the v=4 and 5 levels, a measure for their lifetimes, have been determined both in the adiabatic i3Π g potential, and in the two-state system. The results show small shifts of the i3Π g ( v'=4,5; N'=1) levels of a few wavenumbers, and a significant increase of 49% in the lifetimes of these levels. Both effects are large enough to be important in spectroscopic experiments. The magnitude of the effect is in accordance with observed linewidths obtained in recent experiments. Model calculations for differently shaped potential barriers have been carried out to study the generality of the above conclusions.

  19. The intensities and profiles of XUV transition zone lines in a quiet sun region compared to a polar coronal hole

    NASA Technical Reports Server (NTRS)

    Feldman, U.; Doschek, G. A.; Tousey, R.

    1975-01-01

    The intensities of XUV transition-zone lines from limb spectra of a quiet-sun region and a polar coronal hole are compared. The spectra were obtained with a slit spectrograph on Skylab and cover a region from -12 sec within the limb to 20 sec above it. The lines selected for comparison are formed at temperatures that range from 36,000 to 220,000 K. Lines of the higher-temperature ions, e.g. O v, are significantly less intense in the coronal hole, and lines of lower-temperature ions show little change. Profiles of selected optically thin transition-zone lines from the quiet-sun and coronal-hole spectra are also shown. The lines are broader than expected in ionization equilibrium, and bulk-motion velocities are deduced from the widths of the lines. There appears to be little, if any, statistically significant difference in the velocities obtained from the quiet-sun region and the coronal hole.

  20. Topological Phase Transitions in Line-nodal Superconductors

    NASA Astrophysics Data System (ADS)

    Cho, Gil Young; Han, Sangeun; Moon, Eun-Gook

    Fathoming interplay between symmetry and topology of many-electron wave-functions deepens our understanding in quantum nature of many particle systems. Topology often protects zero-energy excitation, and in a certain class, symmetry is intrinsically tied to the topological protection. Namely, unless symmetry is broken, topological nature is intact. We study one specific case of such class, symmetry-protected line-nodal superconductors in three spatial dimensions (3d). Mismatch between phase spaces of order parameter fluctuation and line-nodal fermion excitation induces an exotic universality class in a drastic contrast to one of the conventional ϕ4 theory in 3d. Hyper-scaling violation and relativistic dynamic scaling with unusually large quantum critical region are main characteristics, and their implication in experiments is discussed. For example, continuous phase transition out of line-nodal superconductors has a linear phase boundary in a temperature-tuning parameter phase-diagram. This work was supported by the Brain Korea 21 PLUS Project of Korea Government and KAIST start-up funding.

  1. Global variations in optical thickness of the atmosphere of Venus. III. Analysis of behavior of equivalent widths of CO2 lines for an inhomogeneous model atmosphere.

    NASA Astrophysics Data System (ADS)

    Fomin, N. N.; Yanovitskij, E. G.

    A two-layer model of Venus atmosphere is considered. The upper layer is a gas-and-aerosol medium with a fixed lower boundary height (h = 50 km) above the planet's surface. The lower layer is a pure CO2 gas. The pressure and temperature in the layers are assumed to satisfy the polytrope equation. The observed variations in the equivalent widths of R(0) lines in the CO2 absorption bands λλ788.3 and 868.9 nm are studied within the context of this model. The observed scatter in the equivalent widths is shown to be explicable in the framework of the model of globally asymmetrical cloud layer on Venus proposed earlier by the authors. The optical thickness of the cloud layer is found in such a case to be τx = 34.4 for one hemisphere, while it is τn = 24.4 for the other hemisphere. The heights of the cloud layer upper boundary in this case are 68.4 and 75.8 km, respectively. The value τx/τn = 1.4 is in complete agreement with independent estimate obtained earlier from measurements of the integral brightness of the planet. Observed variations in the equivalent widths of R(0) lines of the CO2 absorption bands λλ782.0 and 1062.7 nm verify this estimate. Finally, variations in the height of the cloud layer upper boundary are in complete accord with observed scatter in the amount of polarization over the disk of Venus in the UV region. Further feasible observational tests of this effect are discussed.

  2. A sequential assignment procedure for proteins that have intermediate line widths in MAS NMR spectra: amyloid fibrils of human CA150.WW2.

    PubMed

    Becker, Johanna; Ferguson, Neil; Flinders, Jeremy; van Rossum, Barth-Jan; Fersht, Alan R; Oschkinat, Hartmut

    2008-08-11

    The second WW domain (WW2) of CA150, a human transcriptional activator, forms amyloid fibrils in vitro under physiological conditions. Based on experimental constraints from MAS NMR spectroscopy experiments, alanine scanning and electron microscopy, a structural model of CA150.WW2 amyloid fibrils was calculated earlier. Here, the assignment strategy is presented and suggested as a general approach for proteins that show intermediate line width. The (13)C,(13)C correlation experiments were recorded on fully or partially (13)C-labelled fibrils. The earlier (13)C assignment (26 residues) was extended to 34 of the 40 residues by direct (13)C-excitation experiments by using a deuterated sample that showed strongly improved line width. A 3D HNC-TEDOR (transferred-echo double-resonance) experiment with deuterated CA150.WW2 fibrils yielded 14 amide nitrogen and proton resonance assignments. The obtained chemical shifts were compared with the chemical shifts determined with the natively folded WW domain. TALOS (Torsion angle likelihood obtained from shift and sequence similarity) predictions confirmed that, under physiological conditions, the fibrillar form of CA150.WW2 adopts a significantly different beta structure than the native WW-domain fold.

  3. Rise of a Brazil nut: A transition line

    NASA Astrophysics Data System (ADS)

    Godoy, Sergio; Risso, Dino; Soto, Rodrigo; Cordero, Patricio

    2008-09-01

    Using molecular dynamics we study the behavior of a large particle immersed in a bed of smaller ones. The system is bidimensional, consisting of many rough inelastic hard disks of equal size plus a larger one: the intruder. All possible parameters of the system are kept fixed except for two dimensionless parameters determining the frequency and amplitude of the vibrating base. A systematic exploration of this parameter space leads to determining a transition line separating a zone in which the Brazil nut effect is observed and one in which it is not. The results strongly suggest that, in the region of the parameter space in which the study is made, there is a minimum amplitude and a maximum frequency for the Brazil nut effect to take place. These results compare well with isolated results from other authors.

  4. Transition probability measurement of several O II spectral lines

    NASA Astrophysics Data System (ADS)

    del Val, J. A.; Aparicio, J. A.; González, V. R.; Mar, S.

    2001-11-01

    This work reports atomic transition probabilities of 33 spectral lines belonging to 3s-3p, 3p-3d and 3d-4f multiplets of O II, all of them measured in the 405-465 nm spectral region in an emission experiment. Relative intensity measurements have been made on a pulsed discharge lamp and the absolute Aki-values have been obtained taking the NIST database as a reference in temperature diagnosis. The results of this work confirm the other recent available data measured by Veres and Wiese (Veres G and Wiese W L 1996 Phys. Rev. A 54 1999) with a different source and the calculations of Bell et al (Bell K L, Hibbert A, Stafford R P and McLaughlin B M 1994 Phys. Scr. 50 343) with a very satisfactory agreement (usually within 10%).

  5. Measurement of High Ion Temperature using the Doppler Width of the Kr Heb Line (0.8 {angstrom}) from Kr-doped Target Implosions

    SciTech Connect

    Qichang Su

    2000-09-28

    In a recently-published paper, diagnostic methods for laser implosions were proposed, using Krypton K-shell x-ray lines, particularly the He-? line at 15.43 keV (or 0.8 {angstrom}). Strong Kr K-shell lines were indeed observed on Kr-doped implosions on OMEGA and were used to determine the electron temperature. To determine the ion temperature, on the other hand, would require far greater spectral resolution. It was the purpose of this proposal to use a focusing spectrometer (''Rowland circle spectrometer'') to determine the ion temperature, for the first time using the Doppler broadening. In the OMEGA experiment, electron temperatures of 3 - 4 keV were measured and ion temperatures of up to 13 keV were measured, using neutron spectra. For these conditions and the expected density, the total line profile has been calculated1. There are two diagnostic signatures: (a) The ion temperature can be deduced from the line width, and (b) the density can be deduced from the relative intensity of the ''shoulder'' or the forbidden component calculated to appear on the shorter-wavelength wing of the line. To resolve the details of the profile a spectral resolution E/? E much higher than {approx}550 is required. A flat, non-focusing spectrometer has a resolution of E/? E {approx}300, much less than the minimum required. To address this problem we proposed to use a focusing Rowland spectrometer, whose resolution was predicted to be typically E/? E {approx}2000 - 3000. this is sufficient resolution to resolve the profile of the Kr He-? line.

  6. Why Is Non-thermal Line Broadening of Lower Transition Region Lines Independent of Spatial Resolution?

    NASA Astrophysics Data System (ADS)

    De Pontieu, B.; Mcintosh, S. W.; Martínez-Sykora, J.; Peter, H.; Pereira, T. M. D.

    2014-12-01

    Spectral observations of the solar transition region (TR) and corona typically show broadening of the spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant (10-30 km/s), correlated with the intensity, and has been attributed to waves, macro and micro turbulence, nanoflares, etc... Here we study spectra of the low TR Si IV 1403 Angstrom line obtained at high spatial and spectral resolution with the Interface Region Imaging Spectrograph (IRIS). We find that the large improvement in spatial resolution (0.33 arcsec) of IRIS compared to previous spectrographs (2 arcsec) does not resolve the non-thermal line broadening which remains at pre-IRIS levels of 20 km/s. This surprising invariance to spatial resolution indicates that the physical processes behind the non-thermal line broadening either occur along the line-of-sight (LOS) and/or on spatial scales (perpendicular to the LOS) smaller than 250 km. Both effects appear to play a role. Comparison with IRIS chromospheric observations shows that, in regions where the LOS is more parallel to the field, magneto-acoustic shocks driven from below impact the low TR leading to strong non-thermal line broadening from line-of-sight integration across the shock at the time of impact. This scenario is confirmed by advanced MHD simulations. In regions where the LOS is perpendicular to the field, the prevalence of small-scale twist is likely to play a significant role in explaining the invariance and the correlation with intensity.

  7. Investigation of Line Width Narrowing and Spectral Jumps of Single Stable Defect Centers in ZnO at Cryogenic Temperature.

    PubMed

    Neitzke, Oliver; Morfa, Anthony; Wolters, Janik; Schell, Andreas W; Kewes, Günter; Benson, Oliver

    2015-05-13

    Finding new solid state defect centers in novel host materials is crucial for realizing integrated hybrid quantum photonic devices. We present a preparation method for defect centers with photostable bright single photon emission in zinc oxide, a material with promising properties in terms of processability, availability, and applications. A detailed optical study reveals a complex dynamic of intensity fluctuations at room temperature. Measurements at cryogenic temperatures show very sharp (<60 GHz) zero phonon lines (ZPLs) at 580 nm to  620 nm (≈ 2.0 eV) with frozen out fast fluctuations. Remaining discrete jumps of the ZPL, which depend on the excitation power, are observed. The low temperature results will narrow down speculations on the origin of visible-near-infrared (NIR) wavelength defect emission in zinc oxide and provide a basis for improved theoretical models.

  8. Formation of a spiraling line defect and its meandering transition in a period-2 medium.

    PubMed

    Park, Jin-Sung; Lee, Kyoung J

    2002-06-03

    The instability of a period-1 spiral wave resulting in a period-2 spiral wave with a line defect is investigated for the first time in a laboratory system. At the very onset the transition proceeds by an emergence of a spiraling line defect, "breathing" intermittently while retaining its symmetry of a period-1 spiral wave. With a further change in a control parameter, the line defect undergoes a meandering transition producing a compound tip trajectory, following a dynamic shape transition. The observed transitions have a strong analogy to the phase synchronization transition of two coupled nonlinear oscillators and the meandering transition of a period-1 spiral wave.

  9. Evaluation of near-isogenic lines for drought resistance QTL and fine mapping of a locus affecting flag leaf width, spikelet number, and root volume in rice.

    PubMed

    Ding, Xipeng; Li, Xiaokai; Xiong, Lizhong

    2011-09-01

    Drought stress is a major limiting factor for crop production and breeding for drought resistance is very challenging due to the complex nature of this trait. Previous studies in rice suggest that the upland japonica variety IRAT109 shows better drought resistance than the lowland indica variety Zhenshan 97. Numerous quantitative trait loci (QTL) have been previously mapped using a recombinant inbred line population derived from these two genotypes. In this study, near-isogenic lines (NILs) for 17 drought resistance-related QTL were constructed and phenotypic variations of these NILs were investigated under drought and normal conditions. Fourteen of these NILs showed significant phenotypic differences relative to the recurrent parent under at least one of the conditions and nine NILs showed significant differences under both conditions. After eliminating the effect of heading date on drought resistance, only four NILs carrying seven QTL (four for the same grain yield-related traits and three for the same or similar root traits QTL) showed differences consistent with the original QTL mapping results. One of these lines (N19) contains qFSR4, a QTL on chromosome 4 controlling root volume per tiller and co-segregating with flag leaf width and spikelet number per panicle. Using a population derived from N19, qFSR4 was mapped to a 38-kb region containing three open reading frames including the previously characterized NARROW LEAF 1 (NAL1) gene. NAL1, which controls leaf width and also affects vein patterning and polar auxin transport, is the most promising candidate genes for qFSR4. Our results underscore the importance of the development of NILs to confirm the identification of QTL affecting complex traits such as drought resistance.

  10. Passivation process in quasi-continuous laser derusting with intermediate pulse width and line-scanning method.

    PubMed

    Li, Wei; Du, Peng; Zhang, Jun; Shi, Shudong; Liu, Shujing; Chen, Nianjiang; Zhao, Hong; Song, Feng

    2014-02-20

    Floating rust composed of particles and aggregates is the primary product of iron or steel corrosion. Because the floating rust has a porous structure and small thickness, part of the irradiating laser energy can be transmitted through the rust layer and be absorbed by the iron substrate. The adherent force between the floating rust and the metal substrate is weak. In this paper we carried out a series of experiments on this specific rust type to achieve laser derusting and passivating simultaneously. We used a line-scanning method (50% overlapping ratio between adjacent laser spots) to get the nearly average uniform distribution of laser fluence in a large cleaning area. The laser irradiation can directly heat a metal surface to cause thermo-elastic vibration to shake off the rust layer and to cause oxidization to form a protective layer. The most important factor of laser passivating is that the iron surface must be heated to the melting point of iron but not much higher. During this short melting period, on the one hand the iron surface could be oxidized completely; on the other hand the melting of the iron surface could make uniform the oxygen concentration and temperature in the molten iron bath.

  11. Absolute Transition Probabilities of Lines in the Spectra of Astrophysical Atoms, Molecules, and Ions

    NASA Technical Reports Server (NTRS)

    Parkinson, W. H.; Smith, P. L.; Yoshino, K.

    1984-01-01

    Progress in the investigation of absolute transition probabilities (A-values or F values) for ultraviolet lines is reported. A radio frequency ion trap was used for measurement of transition probabilities for intersystem lines seen in astronomical spectra. The intersystem line at 2670 A in Al II, which is seen in pre-main sequence stars and symbiotic stars, was studied.

  12. Measurement of high-energy (10–60 keV) x-ray spectral line widths with eV accuracy

    SciTech Connect

    Seely, J. F. Feldman, U.; Glover, J. L.; Hudson, L. T.; Ralchenko, Y.; Henins, Albert; Pereira, N.; Di Stefano, C. A.; Kuranz, C. C.; Drake, R. P.; Chen, Hui; Williams, G. J.; Park, J.

    2014-11-15

    A high resolution crystal spectrometer utilizing a crystal in transmission geometry has been developed and experimentally optimized to measure the widths of emission lines in the 10–60 keV energy range with eV accuracy. The spectrometer achieves high spectral resolution by utilizing crystal planes with small lattice spacings (down to 2d = 0.099 nm), a large crystal bending radius and Rowland circle diameter (965 mm), and an image plate detector with high spatial resolution (60 μm in the case of the Fuji TR image plate). High resolution W L-shell and K-shell laboratory test spectra in the 10–60 keV range and Ho K-shell spectra near 47 keV recorded at the LLNL Titan laser facility are presented. The Ho K-shell spectra are the highest resolution hard x-ray spectra recorded from a solid target irradiated by a high-intensity laser.

  13. Characterization of Dynamics in Complex Lyophilized Formulations: I. Comparison of Relaxation Times Measured by Isothermal Calorimetry with Data Estimated from the Width of the Glass Transition Temperature Region

    PubMed Central

    Chieng, Norman; Mizuno, Masayasu; Pikal, Michael

    2013-01-01

    The purposes of this study are to characterize the relaxation dynamics in complex freeze dried formulations and to investigate the quantitative relationship between the structural relaxation time as measured by thermal activity monitor (TAM) and that estimated from the width of the glass transition temperature (ΔTg). The latter method has advantages over TAM because it is simple and quick. As part of this objective, we evaluate the accuracy in estimating relaxation time data at higher temperatures (50°C and 60°C) from TAM data at lower temperature (40°C) and glass transition region width (ΔTg) data obtained by differential scanning calorimetry. Formulations studied here were hydroxyethyl starch (HES)-disaccharide, HES-polyol and HES-disaccharide-polyol at various ratios. We also re-examine, using TAM derived relaxation times, the correlation between protein stability (human growth hormone, hGH) and relaxation times explored in a previous report, which employed relaxation time data obtained from ΔTg. Results show that most of the freeze dried formulations exist in single amorphous phase, and structural relaxation times were successfully measured for these systems. We find a reasonably good correlation between TAM measured relaxation times and corresponding data obtained from estimates based on ΔTg, but the agreement is only qualitative. The comparison plot showed that TAM data is directly proportional to the 1/3 power of ΔTg data, after correcting for an offset. Nevertheless, the correlation between hGH stability and relaxation time remained qualitatively the same as found with using ΔTg derived relaxation data, and it was found that the modest extrapolation of TAM data to higher temperatures using ΔTg method and TAM data at 40°C resulted in quantitative agreement with TAM measurements made at 50 °C and 60 °C, provided the TAM experiment temperature is well below the Tg of the sample. PMID:23608636

  14. Experimental and theoretical studies of the npσ1Σu+ and npπ1 Πu+ (n ⩾ 4,N‧ = 1 -6) states of D2: Energies, natural widths, absorption line intensities, and dynamics

    NASA Astrophysics Data System (ADS)

    Glass-Maujean, M.; Jungen, Ch.; Vasserot, A. M.; Schmoranzer, H.; Knie, A.; Kübler, S.; Ehresmann, A.; Ubachs, W.

    2017-08-01

    Over a thousand spectral lines in the photoexcitation spectrum of molecular deuterium (D2) to np1 Σu+ and 1Πu+ Rydberg levels (n ⩾ 4) were measured for rotational levels N‧ = 1 -6 in the 117 000-137 000 cm-1 spectral range by two different types of experiments at two synchrotron radiation sources: a vacuum ultraviolet (VUV) Fourier-transform (FT) spectrometer at SOLEIL, Paris and a 10 m-normal-incidence monochromator (NIM) at BESSY II, Berlin. The experimental energies, the absorption cross sections, Einstein A-coefficients, and line widths are compared with ab initio multi-channel quantum defect (MQDT) calculations for these levels. More than 350 R(0) or P(2) lines were assigned, some 280 R(1) or P(3) lines, some 270 R(2) or P(4) lines, over 100 R(3) or P(5) lines, over 90 R(4) lines, and 24 R(5) lines to extract information on the N‧ = 1 -6 excited levels. Transition energies were determined up to excitation energies of 137 000 cm-1 above the ground state, thereby extending earlier work by various authors and considerably improving the spectral accuracy (< 0.1 cm-1), leading to several reassignments. The absorption and the dissociation, ionization and fluorescence excitation cross sections from the NIM experiment are measured on absolute scale and are used to calibrate intensities in the VUV-FT spectra. The overall agreement between experiment and first principles calculations, without adjustable parameters, is excellent in view of the multi-state interferences treated within the MQDT-framework: For the low N‧ values the averaged deviations between those observed in the FT-SOLEIL spectra and those calculated with MQDT are ∼ 0.1 cm-1 with a spread of ∼ 0.5 cm-1. The line intensities in terms of Einstein coefficients are well represented in the MQDT-framework, as are the level widths representing the lifetimes associated with the sum of the three decay channels. These line intensities follow, in general, the 1 /n3 scaling behavior as characteristic in

  15. Conformational transitions of single polymer adsorption in poor solvent: Wetting transition due to molecular confinement induced line tension.

    PubMed

    Wei, Hsien-Hung; Li, Yen-Ching

    2016-07-01

    We report a theory capable of describing conformational transitions for single polymer adsorption in a poor solvent. We show that an additional molecular confinement effect near the contact line can act exactly like line tension, playing a critical role in the behavior of an absorbed polymer chain. Using this theory, distinct conformational states: desorbed globule (DG), surface attached cap (SAC), and adsorbed lens (AL), can be vividly revealed, resembling the drying-wetting transition of a nanodroplet. But the transitions between these states can behave rather differently from those in the usual wetting transitions. The DG-SAC transition is discrete, occurring at the adsorption threshold when the globule size at the desorbed state is equal to the adsorption blob. The SAC-AL transition is smooth for finite chain lengths, but can change to discontinuous in the infinite chain limit, characterized by the different end-to-end exponent 3/8 and the unique crossover exponent 1/4. Distinctive critical exponents near this transition are also determined, indicating that it is an additional universality class of phase transitions. This work also sheds light on nanodrop spreading, wherein the important role played by line tension might simply be a manifestation of the local molecular confinement near the contact line.

  16. Conformational transitions of single polymer adsorption in poor solvent: Wetting transition due to molecular confinement induced line tension

    NASA Astrophysics Data System (ADS)

    Wei, Hsien-Hung; Li, Yen-Ching

    2016-07-01

    We report a theory capable of describing conformational transitions for single polymer adsorption in a poor solvent. We show that an additional molecular confinement effect near the contact line can act exactly like line tension, playing a critical role in the behavior of an absorbed polymer chain. Using this theory, distinct conformational states: desorbed globule (DG), surface attached cap (SAC), and adsorbed lens (AL), can be vividly revealed, resembling the drying-wetting transition of a nanodroplet. But the transitions between these states can behave rather differently from those in the usual wetting transitions. The DG-SAC transition is discrete, occurring at the adsorption threshold when the globule size at the desorbed state is equal to the adsorption blob. The SAC-AL transition is smooth for finite chain lengths, but can change to discontinuous in the infinite chain limit, characterized by the different end-to-end exponent 3/8 and the unique crossover exponent 1/4. Distinctive critical exponents near this transition are also determined, indicating that it is an additional universality class of phase transitions. This work also sheds light on nanodrop spreading, wherein the important role played by line tension might simply be a manifestation of the local molecular confinement near the contact line.

  17. Analytical solution of microwave transition spectral lines for 87Rb atoms in a Hanle configuration

    NASA Astrophysics Data System (ADS)

    Hu, Zheng-Feng; Deng, Jian-Liao; Ma, Yi-Sheng; He, Hui-Juan; Wang, Yu-Zhu

    2010-07-01

    This paper theoretically investigates the microwave transition spectrum of 87Rb atomic D1 line with specially prepared atomic state in a Hanle configuration. The approximate analytical results have shown that the 0-0 transition spectral line has the highest contrast and can be applied to microwave frequency standards.

  18. Universal phase transition and band structures for spinless nodal-line and Weyl semimetals

    NASA Astrophysics Data System (ADS)

    Okugawa, Ryo; Murakami, Shuichi

    2017-09-01

    We study a general phase transition between spinless topological nodal-line semimetal and Weyl semimetal phases. We classify topological nodal lines into two types based on their positions and shapes, and their phase transitions depend on their types. We show that a topological nodal-line semimetal becomes a Weyl semimetal by breaking time-reversal symmetry when the nodal lines enclose time-reversal-invariant momenta (type-A nodal lines). We also discuss an effect of crystallographic symmetries determining the band structure of the topological nodal-line semimetals. Thanks to protection by the symmetries, the topological nodal-line semimetals can transition into spinless Weyl semimetals or maintain the nodal lines in many crystals after inversion symmetry is broken.

  19. Searching for dielectronic satellite lines associated with 3s → 2p transitions in Fe XVII

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, P.; Brown, G. V.; Laska, A.

    2017-03-01

    Using the electron beam ion trap facility at Livermore we have performed controlled laboratory measurements to search for dielectronic satellite transitions associated with the three strong 3s → 2p transitions in the Fe XVII spectrum. These transitions fall into the 16.5 - 17.1 Å wavelength range. Surprisingly, we find that even the two strong, electric dipole allowed 3s → 2p transitions are not associated with any substantial amount of dielectronic satellite lines. Dielectronic satellite lines are only associated with the two strongest 3d → 2p transitions located near 15 Å.

  20. Full correspondence between asymmetric filling of slits and first-order phase transition lines

    NASA Astrophysics Data System (ADS)

    Szybisz, Leszek; Sartarelli, Salvador A.

    2011-12-01

    Adsorption on single planar walls and filling of slits with identical planar walls are investigated in the frame of the density functional theory. In this sort of slits the external potential is symmetric with respect to its central plane. Calculations were carried out by applying both the canonical and grand canonical ensembles (CE and GCE, respectively). The behavior is analyzed by varying the strength of the adsorbate-substrate attraction, the temperature T, and the coverage Γℓ. Results obtained for physisorption of Xe on alkaline surfaces are reported in the present work. Prewetting (PW) lines and wetting temperatures, Tw, are determined from the analysis of adsorption on single walls. The filling of slits is analyzed for temperatures T > Tw. It is found that whenever for a given Xe-substrate combination the adsorption on a single wall exhibits a first-order wetting transition then asymmetric profiles that break the left-right symmetry of the external potential appear in the filling of an equivalent slit. These spontaneously symmetry breaking (SSB) solutions occur in a restricted range of Γℓ with a T-dependent width. In the case of closed slits analyzed in the CE scheme, the obtained asymmetric profiles exhibit lower Helmholtz free energies than the symmetric species and, therefore, could be stabilized in this geometry. For open slits, the GCE scheme yields all the symmetric and SSB states in the corresponding convex regimes of the free energy. It is shown that both the CE and the GCE frames yield three coexistent states, two symmetric and one asymmetric twofold degenerate. Both a PW line and the related SSB effect terminate at the same temperature. For rather strongly attractive surfaces reentrant SSB states are found at a fixed value of T.

  1. Ring-widths of the above tree-line shrub Rhododendron reveal the change of minimum winter temperature over the past 211 years in Southwestern China

    NASA Astrophysics Data System (ADS)

    Bi, Yingfeng; Xu, Jianchu; Yang, Jinchao; Li, Zongshan; Gebrekirstos, Aster; Liang, Eryuan; Zhang, Shibao; Yang, Yang; Yang, Yongping; Yang, Xuefei

    2016-08-01

    Changes in minimum winter temperature (MWT) and their potential effects on plant growth and development have been gaining increased scientific attention. To better understand these changes across long temporal scales, the present study used dendroclimatological techniques to assess variations in MWT in Southwestern China. Using data from Rhododendron species distributed in areas above the tree-line, a regional composite chronology was generated for a 341-year period. Based on the significant negative correlation between MWT values and ring-width, the most reliable parts of this chronological data were then used to reconstruct MWT values for the past 211 years. This reconstructed MWT series showed decadal to multi-decadal fluctuations. Three distinct cold periods prevailed during 1823-1858, 1882-1891 and 1922-1965, while four warm intervals occurred in 1800-1822, 1858-1881, 1892-1921 and 1966-2011. Our reconstructed MWT reveals a warming trend over the most recent eight decades, which is in agreement with instrumental observations. However, the MWT values and rate of warming over the past seven decades did not exceed those found in the reconstructed temperature data for the past 211 years. Spatial correlations reveal that the MWT in Southwest China is strongly associated with regional temperatures in the Eastern and Central Himalaya, Northern China, and the Indian Peninsula. Larger scale climate oscillations of the Western Pacific and Northern Indian Ocean as well as the North Atlantic Oscillation probably influenced the region's temperature in the past.

  2. Design and performance of broadly tunable, narrow line-width, high repetition rate 1310nm VCSELs for swept source optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Jayaraman, V.; Jiang, J.; Potsaid, B.; Cole, G.; Fujimoto, J.; Cable, A.

    2012-03-01

    MEMS tunable vertical cavity surface emitting laser (MEMS-VCSEL) development, over the past two decades, has primarily focused on communications and spectroscopic applications. Because of the narrow line-width, single-mode operation, monolithic fabrication, and high-speed capability of these devices, MEMS-VCSELs also present an attractive optical source for emerging swept source optical coherence tomography (SSOCT) systems. In this paper, we describe the design and performance of broadly tunable MEMS-VCSELs targeted for SSOCT, emphasizing 1310nm operation for cancer and vascular imaging. We describe the VCSEL structure and fabrication, employing a fully oxidized GaAs/AlxOy mirrors in conjunction with dielectric mirrors and InP-based multi-quantum well active regions. We also describe the optimization of MEMs speed and frequency response for SSOCT. Key results include 1310 nm VCSELs with >120nm dynamic tuning range and imaging rates near 1MHz, representing the widest VCSEL tuning range and some of the fastest swept source imaging rates thus far obtained. We also describe how low-noise semiconductor optical amplification boosts average optical power to the required levels, while maintaining superior OCT imaging quality and state of the art system sensitivity. Finally, we present measured multi-centimeter dynamic coherence length, and discuss the implications of VCSELs for OCT.

  3. Role of re-growth interface preparation process for spectral line-width reduction of single InAs site-controlled quantum dots.

    PubMed

    Herranz, Jesús; Wewior, Lukasz; Alén, Benito; Fuster, David; González, Luisa; González, Yolanda

    2015-05-15

    We present growth and optical characterization measurements of single InAs site-controlled quantum dots (SCQDs) grown by molecular beam epitaxy on GaAs (001) patterned substrates by atomic force microscopy oxidation lithography. InAs SCQDs directly grown on the patterned surface were used as a seed layer and strain template for the nucleation of optically active single InAs SCQDs. The preservation of the initial geometry of the engraved pattern motifs after the re-growth interface preparation process, the lack of buffer layer growth prior to InAs seed layer deposition and the development of suitable growth conditions provide us an improvement of the SCQDs' active layer optical properties while retaining a high ratio of single occupation (89%). In this work a fivefold reduction of the average optical line-width from 870 μeV to 156 μeV for InAs SCQDs located 15 nm from the re-growth interface is obtained by increasing the temperature of the initial thermal treatment step of the re-growth interface from 490 °C to 530 °C.

  4. Ring-widths of the above tree-line shrub Rhododendron reveal the change of minimum winter temperature over the past 211 years in Southwestern China

    NASA Astrophysics Data System (ADS)

    Bi, Yingfeng; Xu, Jianchu; Yang, Jinchao; Li, Zongshan; Gebrekirstos, Aster; Liang, Eryuan; Zhang, Shibao; Yang, Yang; Yang, Yongping; Yang, Xuefei

    2017-06-01

    Changes in minimum winter temperature (MWT) and their potential effects on plant growth and development have been gaining increased scientific attention. To better understand these changes across long temporal scales, the present study used dendroclimatological techniques to assess variations in MWT in Southwestern China. Using data from Rhododendron species distributed in areas above the tree-line, a regional composite chronology was generated for a 341-year period. Based on the significant negative correlation between MWT values and ring-width, the most reliable parts of this chronological data were then used to reconstruct MWT values for the past 211 years. This reconstructed MWT series showed decadal to multi-decadal fluctuations. Three distinct cold periods prevailed during 1823-1858, 1882-1891 and 1922-1965, while four warm intervals occurred in 1800-1822, 1858-1881, 1892-1921 and 1966-2011. Our reconstructed MWT reveals a warming trend over the most recent eight decades, which is in agreement with instrumental observations. However, the MWT values and rate of warming over the past seven decades did not exceed those found in the reconstructed temperature data for the past 211 years. Spatial correlations reveal that the MWT in Southwest China is strongly associated with regional temperatures in the Eastern and Central Himalaya, Northern China, and the Indian Peninsula. Larger scale climate oscillations of the Western Pacific and Northern Indian Ocean as well as the North Atlantic Oscillation probably influenced the region's temperature in the past.

  5. Landau levels and spin splitting in the two-dimensional electron gas of a HgTe quantum well near the critical width for the topological phase transition

    NASA Astrophysics Data System (ADS)

    Pakmehr, M.; Bruene, C.; Buhmann, H.; Molenkamp, L. W.; Stier, A. V.; McCombe, B. D.

    2014-12-01

    We report a detailed low-temperature study of the two-dimensional (2D) electron gas in a 6.1-nm-wide HgTe quantum well with H g0.3C d0.7Te barriers by terahertz magnetophotoconductivity and magnetotransmission combined with magnetotransport measurements (Rx x and Rx y) in magnetic fields up to 10 T. This well width, close to that at the topological phase transition, corresponds to conventional band ordering, and we probe the "bulk" quasi-2D Landau-level (LL) spectrum of the conduction band at high energies (≈135 -160 meV ) above the Dirac point. The calculated separations between adjacent LLs of the same spin based on published parameters for this structure are in fair agreement with the measured cyclotron resonance energies. However, the very large spin splittings observed (Espin>Ecyclotron) require a significantly larger g -parameter ge for electrons. Tilted field coincidence experiments are consistent with the large spin splitting showing coincidences at 3/2 and twice the cyclotron energy. This large value of ge also leads to interesting crossings of the calculated LLs, and we find direct evidence of these crossings in the Rx x measurements at lower electron densities (Fermi energies) produced by negative gate bias.

  6. Chromospheric and Transition region He lines during a flare

    NASA Astrophysics Data System (ADS)

    Falchi, A.; Mauas, P. J. D.; Andretta, V.; Teriaca, L.; Cauzzi, G.; Falciani, R.; Smaldone, L. A.

    An observing campaign (SOHO JOP 139), coordinated between ground based and SOHO instruments, has been planned to obtain simultaneous spectroheliograms of the same area in several spectral lines. The chromospheric lines Ca II K, Hα and Na I D as well as He I 10830, 5876, 584 and 304 Ålines have been observed. These observations allow us to build semi-empirical models of the atmosphere before and during a small flare. With these models, constructed to match the observed line profiles, we can test the He abundance value.

  7. Recent Line-Shape and Doppler Thermometry Studies Involving Transitions in the ν1 +ν3 Band of Acetylene

    NASA Astrophysics Data System (ADS)

    Hashemi, Robab; Rozario, Hoimonti; Povey, Chad; Garber, Jolene; Derksen, Mark; Predoi-Cross, Adriana

    2014-06-01

    The line positions for transitions in the ν1 +ν3 band are often used as a frequency standard by the telecom industry and also needed for planetary atmospheric studies. Four relevant studies have been recently carried out in our group and will be discussed briefly below. (1) N2-broadened line widths and N2-pressure induced line shifts have been measured for transitions in the ν1 +ν3 band of acetylene at seven temperatures in the range 213333K to obtain the temperature dependences of broadening and shift coefficients. The Voigt and hard-collision line profile models were used to retrieve the line parameters. This study has been published in Molecular Physics, 110 Issue 21/22 (2012) 2645-2663. (2) Six nitrogen perturbed transitions of acetylene within the ν1 +ν3 absorption band have been recorded using a 3-channel diode laser spectrometer. We have examined C2H2 spectra using a hard collision (Rautian) profile over a range of five temperatures (213 K-333 K). From these fits we have obtained the N2-broadening and narrowing coefficients of C2H2 and examined their temperature dependence. The experimentally measured narrowing coefficients have been used to estimate the nitrogen diffusion coefficients. The broadening coefficients and corresponding temperature dependence exponents have also been compared to that of calculations completed using a classical impact approach on an ab initio potential energy surface. We have observed a good agreement between our theoretical and experimental results. This study was published in Canadian Journal of Physics 91(11) 896-905 (2013). (3) An extension of the previous study was to analyze the room temperature for the same six transitions using the Voigt, Rautian, Galatry, RautianGalatry and Correlated Rautian profiles. For the entire pressure range, we have tested the applicability of these line-shape models. Except for Voigt profile, Dicke narrowing effect has been considered in all mentioned line-shape models. The experimental

  8. From product line to disease management--easing the transition.

    PubMed

    Stanfill, P

    1997-01-01

    Most facilities have captured the essence of product-line management, but what is the next step? The traditional reasons for product-line management are still more than valid, but forward-thinking organizations are moving to a disease-management focus.

  9. Electric quadrupole transition probabilities and line strengths of Ti{sup 11+}

    SciTech Connect

    Gökçe, Yasin; Çelik, Gültekin; Yıldız, Murat

    2014-07-15

    Electric quadrupole transition probabilities and line strengths have been calculated using the weakest bound electron potential model for sodium-like titanium, considering many transition arrays. We employed numerical Coulomb approximation and non-relativistic Hartree–Fock wavefunctions for the expectation values of radii in determination of parameters of the model. The necessary energy values have been taken from experimental data in the literature. The calculated electric quadrupole line strengths have been compared with available data in the literature and good agreement has been obtained. Moreover, some electric quadrupole transition probability and line strength values not existing in the literature for some highly excited levels have been obtained using this method.

  10. Measurements of argon broadened Lorentz width and pressure-induced line shift coefficients in the nu4 band of (C-12)H4

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    Room temperature argon broadened halfwidth and pressure-induced line shift coefficients have been determined for 118 transitions in the nu4 band of (C-12)H4 from analysis of high resolution laboratory absorption spectra recorded with the McMath Fourier transform spectrometer operated on Kitt Peak by the National Solar Observatory. Transitions up to J-double-prime = 12 have been measured using a nonlinear least-squares spectral fitting procedure. The variation of the measured halfwidth coefficients with symmetry type and rotational quantum number is very similar to that measured previously for N2 and air broadening, but the absolute values of the argon broadening coefficients are all smaller. On average, the ratio of the argon broadened halfwidth coefficient to the corresponding N2 broadened halfwidth coefficient is 0.877 + or - 0.017 (2 Sigma). More than 95 percent of the pressure-induced shifts are negative with values ranging from -0.0081 to +0.0055/cm atm. The pressure shifts in argon are nearly equal to corresponding values measured previously in N2 and air.

  11. Measurements of argon broadened Lorentz width and pressure-induced line shift coefficients in the nu4 band of (C-12)H4

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    Room temperature argon broadened halfwidth and pressure-induced line shift coefficients have been determined for 118 transitions in the nu4 band of (C-12)H4 from analysis of high resolution laboratory absorption spectra recorded with the McMath Fourier transform spectrometer operated on Kitt Peak by the National Solar Observatory. Transitions up to J-double-prime = 12 have been measured using a nonlinear least-squares spectral fitting procedure. The variation of the measured halfwidth coefficients with symmetry type and rotational quantum number is very similar to that measured previously for N2 and air broadening, but the absolute values of the argon broadening coefficients are all smaller. On average, the ratio of the argon broadened halfwidth coefficient to the corresponding N2 broadened halfwidth coefficient is 0.877 + or - 0.017 (2 Sigma). More than 95 percent of the pressure-induced shifts are negative with values ranging from -0.0081 to +0.0055/cm atm. The pressure shifts in argon are nearly equal to corresponding values measured previously in N2 and air.

  12. Accurate transition rates for intercombination lines of singly ionized nitrogen

    NASA Astrophysics Data System (ADS)

    Tayal, S. S.

    2011-01-01

    The transition energies and rates for the 2s22p2 3P1,2-2s2p3 5S2o and 2s22p3s-2s22p3p intercombination transitions have been calculated using term-dependent nonorthogonal orbitals in the multiconfiguration Hartree-Fock approach. Several sets of spectroscopic and correlation nonorthogonal functions have been chosen to describe adequately term dependence of wave functions and various correlation corrections. Special attention has been focused on the accurate representation of strong interactions between the 2s2p3 1,3P1o and 2s22p3s 1,3P1olevels. The relativistic corrections are included through the one-body mass correction, Darwin, and spin-orbit operators and two-body spin-other-orbit and spin-spin operators in the Breit-Pauli Hamiltonian. The importance of core-valence correlation effects has been examined. The accuracy of present transition rates is evaluated by the agreement between the length and velocity formulations combined with the agreement between the calculated and measured transition energies. The present results for transition probabilities, branching fraction, and lifetimes have been compared with previous calculations and experiments.

  13. Accurate transition rates for intercombination lines of singly ionized nitrogen

    SciTech Connect

    Tayal, S. S.

    2011-01-15

    The transition energies and rates for the 2s{sup 2}2p{sup 2} {sup 3}P{sub 1,2}-2s2p{sup 3} {sup 5}S{sub 2}{sup o} and 2s{sup 2}2p3s-2s{sup 2}2p3p intercombination transitions have been calculated using term-dependent nonorthogonal orbitals in the multiconfiguration Hartree-Fock approach. Several sets of spectroscopic and correlation nonorthogonal functions have been chosen to describe adequately term dependence of wave functions and various correlation corrections. Special attention has been focused on the accurate representation of strong interactions between the 2s2p{sup 3} {sup 1,3}P{sub 1}{sup o} and 2s{sup 2}2p3s {sup 1,3}P{sub 1}{sup o}levels. The relativistic corrections are included through the one-body mass correction, Darwin, and spin-orbit operators and two-body spin-other-orbit and spin-spin operators in the Breit-Pauli Hamiltonian. The importance of core-valence correlation effects has been examined. The accuracy of present transition rates is evaluated by the agreement between the length and velocity formulations combined with the agreement between the calculated and measured transition energies. The present results for transition probabilities, branching fraction, and lifetimes have been compared with previous calculations and experiments.

  14. Theoretical study on relationship between exposure pattern width and chemical gradient of 16 nm half-pitch line-and-space patterns in electron beam lithography used for photomask and nanoimprint mold production

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro; Yoshitake, Shusuke

    2017-07-01

    Line edge roughness (LER) is a significant concern for electron beam (EB) lithography used for the production of photomasks and nanoimprint molds owing to the trade-off relationships between resolution, LER, and sensitivity. In this study, the relationship between exposure pattern width and chemical gradient (an indicator of LER) was investigated, assuming the use of a chemically amplified resist consisting of a partially protected polymer, an acid generator, and a photodecomposable quencher. The formation of line-and-space patterns with 16 nm half-pitch was calculated on the basis of the sensitization and reaction mechanisms of chemically amplified EB resists. The effects of exposure pattern width on the chemical gradient were clarified in terms of sensitivity, the concentration of sensitizers, and the diffusion constant of photodecomposable quenchers. The exposure pattern width should be set by taking into account these factors to maximize the chemical gradient for the suppression of LER.

  15. Anomalous optogalvanic line shapes of argon metastable transitions in a hollow cathode lamp

    NASA Technical Reports Server (NTRS)

    Ruyten, W. M.

    1993-01-01

    Anomalous optogalvanic line shapes were observed in a commercial hollow cathode lamp containing argon buffer gas. Deviations from Gaussian line shapes were particularly strong for transitions originating from the 3P2 metastable level of argon. The anomalous line shapes can be described reasonably well by the assumption that two regions in the discharge are excited simultaneously, each giving rise to a purely Gaussian line shape, but with different polarities, amplitudes, and linewidths.

  16. Anomalous optogalvanic line shapes of argon metastable transitions in a hollow cathode lamp

    NASA Technical Reports Server (NTRS)

    Ruyten, W. M.

    1993-01-01

    Anomalous optogalvanic line shapes were observed in a commercial hollow cathode lamp containing argon buffer gas. Deviations from Gaussian line shapes were particularly strong for transitions originating from the 3P2 metastable level of argon. The anomalous line shapes can be described reasonably well by the assumption that two regions in the discharge are excited simultaneously, each giving rise to a purely Gaussian line shape, but with different polarities, amplitudes, and linewidths.

  17. Quantum-mechanical vs. semi-classical spectral-line widths and shifts from the line core in the non-impact region for the Ar-perturbed/ K-radiator system

    NASA Astrophysics Data System (ADS)

    Kreye, W. C.

    2007-09-01

    New quantum-mechanical (QM) and semi-classical (SC) shifts (d's) and widths (HWHM's, w's) were measured from the line core of computed full spectral-line shapes for the Ar-perturbed/K-radiator system (K/Ar). The initial state of our model was based on a 4p2P3/2,1/2 pseudo-potential for the K/Ar system, and the final state on a zero potential. The Fourier transform of the line shape formed the basis for the computations. Excellent agreement was found between the QM and SC values of d and of w in a high-pressure (P) non-impact region, which was characterized by a √P dependence of w and a P dependence of d. These agreements were shown to be another example of a correspondence between classical (SC) quantities and QM quantities in the limit of large quantum numbers. Typically at P=1×106 Torr and T=400 K, wQM=448 cm-1 and wSC=479 cm-1, where the deviation from the mean is ±3.3%. Also, dQM=-3815 cm-1 and dSC=-3716 cm-1, where the deviation from the mean is ±1.3%. A new general method was formulated which yielded a definite pressure P0, which was defined as an upper limit to the low-pressure impact approximation and a lower limit to the non-impact region.

  18. Effects of vacuum ultraviolet photons, ion energy and substrate temperature on line width roughness and RMS surface roughness of patterned 193 nm photoresist

    NASA Astrophysics Data System (ADS)

    Titus, M. J.; Graves, D. B.; Yamaguchi, Y.; Hudson, E. A.

    2011-03-01

    We present a comparison of patterned 193 nm photoresist (PR) line width roughness (LWR) of samples processed in a well characterized argon (Ar) inductively coupled plasma (ICP) system to RMS surface roughness and bulk chemical modification of blanket 193 nm PR samples used as control samples. In the ICP system, patterned and blanket PR samples are irradiated with Ar vacuum ultraviolet photons (VUV) and Ar ions while sample temperature, photon flux, ion flux and ion energy are controlled and measured. The resulting chemical modifications to bulk 193 nm PR (blanket) and surface roughness are analysed with Fourier transform infrared spectroscopy and atomic force microscopy (AFM). LWR of patterned samples are measured with scanning electron microscopy and blanket portions of the patterned PRs are measured with AFM. We demonstrate that with no RF-bias applied to the substrate the LWR of 193 nm PR tends to smooth and correlates with the smoothing of the RMS surface roughness. However, both LWR and RMS surface roughness increases with simultaneous high-energy (>=70 eV) ion bombardment and VUV-irradiation and is a function of exposure time. Both high- and low-frequency LWR correlate well with the RMS surface roughness of the patterned and blanket 193 nm PR samples. LWR, however, does not increase with temperatures ranging from 20 to 80 °C, in contrast to the RMS surface roughness which increases monotonically with temperature. It is unclear why LWR remains independent of temperature over this range. However, the fact that blanket roughness and LWR on patterned samples, both scale similarly with VUV fluence and ion energy suggests a similar mechanism is responsible for both types of surface morphology modifications.

  19. The evolution of the equivalent width of the Hα emission line and specific star formation rate in star-forming galaxies at 1 < z < 5

    NASA Astrophysics Data System (ADS)

    Mármol-Queraltó, E.; McLure, R. J.; Cullen, F.; Dunlop, J. S.; Fontana, A.; McLeod, D. J.

    2016-08-01

    We present the results of a study which uses spectral energy distribution (SED) fitting to investigate the evolution of the equivalent width (EW) of the Hα emission line in star-forming galaxies over the redshift interval 1 < z < 5. After first demonstrating the ability of our SED-fitting technique to recover EW(Hα) using a sample of galaxies at z ≃ 1.3 with EW(Hα) measurements from 3D-HST grism spectroscopy, we proceed to apply our technique to samples of spectroscopically confirmed and photometric-redshift selected star-forming galaxies at z ≥ 1 in the CANDELS (Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey) UDS and GOODS-S fields. Confining our analysis to a constant stellar mass range (9.5 < log (M⋆/M⊙) < 10.5), we find that the median EW(Hα) evolves only modestly with redshift, reaching a rest-frame value of EW(Hα) =301 ± 30 Å by redshift z ≃ 4.5. Furthermore, using estimates of star formation rate (SFR) based on both UV luminosity and Hα line flux, we use our galaxy samples to compare the evolution of EW(Hα) and specific star formation rate (sSFR). Our results indicate that over the redshift range 1 < z < 5, the evolution displayed by EW(Hα) and sSFR is consistent, and can be adequately parametrized as ∝ (1 + z)1.0 ± 0.2. As a consequence, over this redshift range, we find that the sSFR and rest-frame EW(Hα) of star-forming galaxies with stellar masses M⋆ ≃ 10^{10}{ M_{sun;} are related by EW(Hα)/Å = (63 ± 7) × sSFR/Gyr-1. Given the current uncertainties in measuring the SFRs of high-redshift galaxies, we conclude that EW(Hα) provides a useful independent tracer of sSFR for star-forming galaxies out to redshifts of z = 5.

  20. 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.

  1. SOLAR TRANSITION REGION LINES OBSERVED BY THE INTERFACE REGION IMAGING SPECTROGRAPH: DIAGNOSTICS FOR THE O IV AND Si IV LINES

    SciTech Connect

    Dudík, J.; Del Zanna, G.; Mason, H. E.; Dzifčáková, E.; Golub, L.

    2014-01-01

    The formation of the transition region O IV and Si IV lines observable by the Interface Region Imaging Spectrograph (IRIS) is investigated for both Maxwellian and non-Maxwellian conditions characterized by a κ-distribution exhibiting a high-energy tail. The Si IV lines are formed at lower temperatures than the O IV lines for all κ. In non-Maxwellian situations with lower κ, the contribution functions are shifted to lower temperatures. Combined with the slope of the differential emission measure, it is possible for the Si IV lines to be formed at very different regions of the solar transition region than the O IV lines; possibly close to the solar chromosphere. Such situations might be discernible by IRIS. It is found that photoexcitation can be important for the Si IV lines, but is negligible for the O IV lines. The usefulness of the O IV ratios for density diagnostics independently of κ is investigated and it is found that the O IV 1404.78 Å/1399.77 Å ratio provides a good density diagnostics except for very low T combined with extreme non-Maxwellian situations.

  2. Reduced transition probabilities along the yrast line in 166W

    NASA Astrophysics Data System (ADS)

    Sayǧı, B.; Joss, D. T.; Page, R. D.; Grahn, T.; Simpson, J.; O'Donnell, D.; Alharshan, G.; Auranen, K.; Bäck, T.; Boening, S.; Braunroth, T.; Carroll, R. J.; Cederwall, B.; Cullen, D. M.; Dewald, A.; Doncel, M.; Donosa, L.; Drummond, M. C.; Ertuǧral, F.; Ertürk, S.; Fransen, C.; Greenlees, P. T.; Hackstein, M.; Hauschild, K.; Herzan, A.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Konki, J.; Kröll, T.; Labiche, M.; Lopez-Martens, A.; McPeake, C. G.; Moradi, F.; Möller, O.; Mustafa, M.; Nieminen, P.; Pakarinen, J.; Partanen, J.; Peura, P.; Procter, M.; Rahkila, P.; Rother, W.; Ruotsalainen, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Sorri, J.; Stolze, S.; Taylor, M. J.; Thornthwaite, A.; Uusitalo, J.

    2017-08-01

    Lifetimes of excited states in the yrast band of the neutron-deficient nuclide 166W have been measured utilizing the DPUNS plunger device at the target position of the JUROGAM II γ -ray spectrometer in conjunction with the RITU gas-filled separator and the GREAT focal-plane spectrometer. Excited states in 166W were populated in the 92Mo(78Kr,4 p ) reaction at a bombarding energy of 380 MeV. The measurements reveal a low value for the ratio of reduced transitions probabilities for the lowest-lying transitions B (E 2 ;4+→2+) /B (E 2 ;2+→0+) =0.33 (5 ) , compared with the expected ratio for an axially deformed rotor (B4 /2 = 1.43).

  3. Variation in the Pre-transit Balmer Line Signal Around the Hot Jupiter HD 189733b

    NASA Astrophysics Data System (ADS)

    Cauley, P. Wilson; Redfield, Seth; Jensen, Adam G.; Barman, Travis

    2016-07-01

    As followup to our recent detection of a pre-transit signal around HD 189733 b, we obtained full pre-transit phase coverage of a single planetary transit. The pre-transit signal is again detected in the Balmer lines but with variable strength and timing, suggesting that the bow shock geometry reported in our previous work does not describe the signal from the latest transit. We also demonstrate the use of the Ca ii H and K residual core flux as a proxy for the stellar activity level throughout the transit. A moderate trend is found between the pre-transit absorption signal in the 2013 data and the Ca ii H flux. This suggests that some of the 2013 pre-transit hydrogen absorption can be attributed to varying stellar activity levels. A very weak correlation is found between the Ca ii H core flux and the Balmer line absorption in the 2015 transit, hinting at a smaller contribution from stellar activity compared to the 2013 transit. We simulate how varying stellar activity levels can produce changes in the Balmer line transmission spectra. These simulations show that the strength of the 2013 and 2015 pre-transit signals can be reproduced by stellar variability. If the pre-transit signature is attributed to circumplanetary material, its evolution in time can be described by accretion clumps spiraling toward the star, although this interpretation has serious limitations. Further high-cadence monitoring at Hα is necessary to distinguish between true absorption by transiting material and short-term variations in the stellar activity level.

  4. Ultra-dense Hot Low Z Line Transition Opacity Simulations

    NASA Astrophysics Data System (ADS)

    Sauvan, P.; Mínguez, E.; Gil, J. M.; Rodríguez, R.; Rubiano, J. G.; Martel, P.; Angelo, P.; Schott, R.; Philippe, F.; Leboucher-Dalimier, E.; Mancini, R.; Calisti, A.

    2002-12-01

    In this work two atomic physics models (the IDEFIX code using the dicenter model and the code based on parametric potentials ANALOP) have been used to calculate the opacities for bound-bound transitions in hot ultra-dense, low Z plasmas. These simulations are in connection with experiments carried out at LULI during the last two years, focused on bound-bound radiation. In this paper H-like opacities for aluminum and fluorine plasmas have been simulated, using both theoretical models, in a wide range of densities and temperatures higher than 200 eV.

  5. Theoretical and Experimental Study of Microstrip-to-Slot Line Uniplanar Transition

    NASA Technical Reports Server (NTRS)

    Yook, Jong-Gwan; Dib, Nihad I.; Katehi, Linda P. B.; Simons, Rainee N.; Taub, Susan R.

    1994-01-01

    Recent advances in MMCI technology make it possible to construct transitions from CPW-to-microstrip with via hole, microstrip-to-slot line and microshield line-to-CPW all of which have potential applications in the feed network of antennas. In this study we investigate the characteristics of the microstrip-to-slot line uniplanar transition using the finite element methods (FEM) and finite difference time domain (FDTD) techniques, and compared the theoretical results with the measurements. In both cases, the results agree with the measurements within a few percent.

  6. Studies on the P-branch spectral lines of rovibrational transitions of diatomic system.

    PubMed

    Sun, Weiguo; Fan, Qunchao; Li, Huidong; Feng, Hao

    2011-06-01

    An analytical formula is used to predict the accurate P-branch spectral lines of rovibrational transitions for diatomic systems. The formula is derived from elementary expression of molecular total energy by taking multiple spectral differences. It is not only reproduces the known experimental transition lines by using a group of fifteen known experimental transition data, but also predicts the accurate spectral lines that may not be available experimentally. The P-branch emission spectra of the (0,1), (0,2) and (0,3) bands of the B(2)∑(+)→X(2)∑(+) system in the (12)C(17)O(+) molecular ion are studied, and correct values of the unknown spectral lines up to J=80.5 for each band are predicted using the formula.

  7. The Third Transit of Snow-Line Exoplanet Kepler-421b

    NASA Astrophysics Data System (ADS)

    Dalba, Paul A.; Muirhead, Philip Steven

    2016-10-01

    The Kepler Mission has uncovered a handful of long-period transiting exoplanets that orbit from the cold outer reaches of their systems, despite their low transit probabilities. The atmospheres of these cold gas giant exoplanets are amenable to transit transmission spectroscopy enabling tests of planetary formation and evolution theories. Of particular scientific interest is Kepler-421b, a Neptune-sized exoplanet with a 704-day orbital period residing near the snow-line. Since the Kepler Spacecraft only observed two transits of Kepler-421b, the transit ephemeris is relatively uncertain. We observed Kepler-421 during the anticipated third transit of Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Barring significant TTVs, our visible light, time-series observations from the 4.3-meter Discovery Channel Telescope (DCT) were designed to capture pre-transit baseline and the partial transit of Kepler-421b. We find strong evidence in favor of transit models with no TTVs, suggesting that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the combined Kepler and DCT observations, we calculate the timing of future transits and discuss the unique opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy.

  8. No Timing Variations Observed in Third Transit of Snow-line Exoplanet Kepler-421b

    NASA Astrophysics Data System (ADS)

    Dalba, Paul A.; Muirhead, Philip S.

    2016-07-01

    We observed Kepler-421 during the anticipated third transit of the snow-line exoplanet Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Previously, the Kepler spacecraft only observed two transits of Kepler-421b, leaving the planet’s transit ephemeris unconstrained. Our visible light, time-series observations from the 4.3 m Discovery Channel Telescope were designed to capture pre-transit baseline and the partial transit of Kepler-421b, barring significant TTVs. We use the light curves to assess the probabilities of various transit models using both the posterior odds ratio and the Bayesian Information Criterion, and find that a transit model with no TTVs is favored to 3.6σ confidence. These observations suggest that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the Kepler-421b ephemeris constrained, we calculate future transit times and discuss the opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy. Our investigation emphasizes the difficulties associated with observing long-period exoplanet transits and the consequences that arise from failing to refine transit ephemerides.

  9. 100-GHz Phase Switch/Mixer Containing a Slot-Line Transition

    NASA Technical Reports Server (NTRS)

    Gaier, Todd; Wells, Mary; Dawson, Douglas

    2009-01-01

    A circuit that can function as a phase switch, frequency mixer, or frequency multiplier operates over a broad frequency range in the vicinity of 100 GHz. Among the most notable features of this circuit is a grounded uniplanar transition (in effect, a balun) between a slot line and one of two coplanar waveguides (CPWs). The design of this circuit is well suited to integration of the circuit into a microwave monolithic integrated circuit (MMIC) package. One CPW is located at the input end and one at the output end of the top side of a substrate on which the circuit is fabricated (see Figure 1). The input CPW feeds the input signal to antiparallel flip-chip Schottky diodes connected to the edges of the slot line. Phase switching is effected by the combination of (1) the abrupt transition from the input CPW to the slot line and (2) CPW ground tuning effected by switching of the bias on the diodes. Grounding of the slot metal to the bottom metal gives rise to a frequency cutoff in the slot. This cutoff is valuable for separating different frequency components when the circuit is used as a mixer or multiplier. Proceeding along the slot line toward the output end, one encounters the aforementioned transition, which couples the slot line to the output CPW. Impedance tuning of the transition is accomplished by use of a high-impedance section immediately before the transition.

  10. Disappearance of Widom Line for Liquid-Liquid Phase Transition with Horizontal Coexistence Line

    NASA Astrophysics Data System (ADS)

    Luo, Jiayuan; Xu, Limei; Buldyrev, Sergey; Angell, Austen; Stanley, Gene

    2012-02-01

    The study of spherically symmetric two-scale Jagla model with both repulsive and attractive ramps has been very successful in demonstrating the anomalous behavior of liquids (especially water) and its relation with respect to the existence of a liquid-liquid (LL) critical point. However, the co-existence line of Jagla model shows a positive slope, which is opposite to what has been found in the simulations of water. To more convincingly link the result of the study on Jagla model with that of water, we applied discrete molecular dynamics to Gibson and Wilding's modified Jagla model and found that by shrinking both the attractive and repulsive ramps, the slope of the coexistence line can be reduced to zero. However, at these values of the parameters, the LL critical point becomes completely unstable with respect to crystal and glass. We further studied the Widom line, defined as extreme of response functions and also continuation of the coexistence line into one phase region, and found Widom line disappeared in the case of zero slope of the coexistence line, due to the equal enthalpy of low-density liquid (LDL) and high-density liquid (HDL).

  11. On the transition rates of the Fe X and Fe XIV corona lines

    SciTech Connect

    Trabert, E

    2003-11-20

    Despite a considerable scatter of the theoretical predictions of the M1/E2 transition rate of the ''red iron line'' (FeX) in the solar corona, there is disagreement of all the results with the single measurement that used an electrostatic ion trap. Employing a heavy-ion storage ring for measuring the same transition in isoelectronic ions of Co, Ni, and Cu, the situation has been clarified, and a new data point for FeX can be determined by extrapolation. This result agrees with the basic atomic structure prediction for the line strength in combination with the experimental transition energy. For the ''green iron line'' (FeXIV), a recent measurement with an electron beam ion trap has resolved similar discrepancies.

  12. Continuity of states between the cholesteric → line hexatic transition and the condensation transition in DNA solutions

    DOE PAGES

    Yasar, Selcuk; Podgornik, Rudolf; Valle-Orero, Jessica; ...

    2014-11-05

    A new method of finely temperature-tuning osmotic pressure allows one to identify the cholesteric → line hexatic transition of oriented or unoriented long-fragment DNA bundles in monovalent salt solutions as first order, with a small but finite volume discontinuity. This transition is similar to the osmotic pressure-induced expanded → condensed DNA transition in polyvalent salt solutions at small enough polyvalent salt concentrations. Therefore there exists a continuity of states between the two. This finding with the corresponding empirical equation of state, effectively relates the phase diagram of DNA solutions for monovalent salts to that for polyvalent salts and sheds somemore » light on the complicated interactions between DNA molecules at high densities.« less

  13. Continuity of states between the cholesteric → line hexatic transition and the condensation transition in DNA solutions

    SciTech Connect

    Yasar, Selcuk; Podgornik, Rudolf; Valle-Orero, Jessica; Johnson, Mark R.; Parsegian, V. Adrian

    2014-11-05

    A new method of finely temperature-tuning osmotic pressure allows one to identify the cholesteric → line hexatic transition of oriented or unoriented long-fragment DNA bundles in monovalent salt solutions as first order, with a small but finite volume discontinuity. This transition is similar to the osmotic pressure-induced expanded → condensed DNA transition in polyvalent salt solutions at small enough polyvalent salt concentrations. Therefore there exists a continuity of states between the two. This finding with the corresponding empirical equation of state, effectively relates the phase diagram of DNA solutions for monovalent salts to that for polyvalent salts and sheds some light on the complicated interactions between DNA molecules at high densities.

  14. Continuity of states between the cholesteric → line hexatic transition and the condensation transition in DNA solutions

    PubMed Central

    Yasar, Selcuk; Podgornik, Rudolf; Valle-Orero, Jessica; Johnson, Mark R.; Parsegian, V. Adrian

    2014-01-01

    A new method of finely temperature-tuning osmotic pressure allows one to identify the cholesteric → line hexatic transition of oriented or unoriented long-fragment DNA bundles in monovalent salt solutions as first order, with a small but finite volume discontinuity. This transition is similar to the osmotic pressure-induced expanded → condensed DNA transition in polyvalent salt solutions at small enough polyvalent salt concentrations. Therefore there exists a continuity of states between the two. This finding, together with the corresponding empirical equation of state, effectively relates the phase diagram of DNA solutions for monovalent salts to that for polyvalent salts and sheds some light on the complicated interactions between DNA molecules at high densities. PMID:25371012

  15. Continuity of states between the cholesteric → line hexatic transition and the condensation transition in DNA solutions

    NASA Astrophysics Data System (ADS)

    Yasar, Selcuk; Podgornik, Rudolf; Valle-Orero, Jessica; Johnson, Mark R.; Parsegian, V. Adrian

    2014-11-01

    A new method of finely temperature-tuning osmotic pressure allows one to identify the cholesteric --> line hexatic transition of oriented or unoriented long-fragment DNA bundles in monovalent salt solutions as first order, with a small but finite volume discontinuity. This transition is similar to the osmotic pressure-induced expanded --> condensed DNA transition in polyvalent salt solutions at small enough polyvalent salt concentrations. Therefore there exists a continuity of states between the two. This finding, together with the corresponding empirical equation of state, effectively relates the phase diagram of DNA solutions for monovalent salts to that for polyvalent salts and sheds some light on the complicated interactions between DNA molecules at high densities.

  16. The numerical study of first order wetting transition with two defect lines

    NASA Astrophysics Data System (ADS)

    Wu, X. T.

    2016-09-01

    The first order wetting transition with two defect lines, one near a wall and another at a distance N1, in the d = 2 Ising model is studied by the bond propagation algorithm. The numerical calculations are carried out on very large lattices with size up to 1602 × 160. The finite size effects of the first order transition in that model are discussed. The magnetization profile is also calculated. The numerical results agree with the exact results very well.

  17. WAVELENGTH MEASUREMENTS OF K TRANSITIONS OF OXYGEN, NEON, AND MAGNESIUM WITH X-RAY ABSORPTION LINES

    SciTech Connect

    Liao Jinyuan; Zhang Shuangnan; Yao Yangsen

    2013-09-10

    Accurate atomic transition data are important in many astronomical research areas, especially for studies of line spectroscopy. Whereas transition data of He-like and H-like ions (i.e., ions in high-charge states) have been accurately calculated, the corresponding data of K transitions of neutral or low-ionized metal elements are still very uncertain. Spectroscopy of absorption lines produced in the interstellar medium (ISM) has been proven to be an effective way to measure the central wavelengths of these atomic transitions. In this work, we analyze 36 Chandra High Energy Transmission Grating observations to search for and measure the ISM absorption lines along sight lines to 11 low-mass X-ray binaries. We correct the Galactic rotation velocity to the rest frame for every observation and then use two different methods to merge all the corrected spectra to a co-added spectrum. However, the co-added spectra obtained by this method exhibit biases, toward to either observations with high counts or lines with high signal-to-noise ratios. We do a Bayesian analysis of several significantly detected lines to obtain the systematic uncertainty and the bias correction for other lines. Compared to previous studies, our results improve the wavelength accuracy by a factor of two to five and significantly reduce the systematic uncertainties and biases. Several weak transitions (e.g., 1s-2p of Mg IV and Mg V; 1s-3p of Mg III and Mg V) are also detected for the first time, albeit with low significance; future observations with improved accuracy are required to confirm these detections.

  18. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Fourth Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2013-01-01

    SunLine Transit Agency, which provides public transit services to the Coachella Valley area of California, has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technology (AT) fuel cell bus with a hybrid electric propulsion system, fuel cell power system, and lithium-based hybrid batteries. This report describes operations at SunLine for the AT fuel cell bus and five compressed natural gas buses. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate the bus in real-world service to document the results and help determine the progress toward technology readiness. NREL has previously published three reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from February 2012 through November 2012.

  19. Strong optical and UV intermediate-width emission lines in the quasar SDSS J232444.80-094600.3: dust-free and intermediate-density gas at the skin of dusty torus?

    NASA Astrophysics Data System (ADS)

    Li, Zhen-Zhen; Zhou, Hong-Yan; Hao, Lei; Wang, Shu-Fen; Ji, Tuo; Liu, Bo

    2016-09-01

    Emission lines from the broad emission line region (BELR) and the narrow emission line region (NELR) of active galactic nuclei (AGNs) have been extensively studied. However, emission lines are rarely detected between these two regions. We present a detailed analysis of quasar SDSS J232444.80-094600.3 (SDSS J2324-0946), which is remarkable for its strong intermediate-width emission lines (IELs) with FWHM ≈ 1800 km s-1. The IEL component is present in different emission lines, including the permitted lines Lyα λ1216, CIV λ1549, semiforbidden line [CIII] λ1909, and forbidden lines [OIII] λλ4959, 5007. With the aid of photo-ionization models, we found that the IELs are produced by gas with a hydrogen density of nH ˜ 106.2 ˜ 106.3 cm-3, a distance from the central ionizing source of R ˜ 35 - 50 pc, a covering factor of ˜ 6%, and a dust-to-gas ratio of ≤ 4% that of the SMC. We suggest that the strong IELs of this quasar are produced by nearly dust-free and intermediate-density gas located at the skin of the dusty torus. Such strong IELs, which serve as a useful diagnostic, can provide an avenue to study the properties of gas between the BELR and the NELR.

  20. Germ line versus soma in the transition from egg to embryo

    PubMed Central

    Swartz, S. Zachary; Wessel, Gary M.

    2016-01-01

    With few exceptions, all animals acquire the ability to produce eggs or sperm at some point in their lifecycle. Despite this near universal requirement for sexual reproduction, there exists an incredible diversity in germ-line development. For example, animals exhibit a vast range of differences in the timing at which the germ line, which retains reproductive potential, separates from the soma, or terminally differentiated, non-reproductive cells. This separation may occur during embryonic development, after gastrulation, or even in adults, depending on the organism. The molecular mechanisms of germ line segregation are also highly diverse, and intimately intertwined with the overall transition from a fertilized egg to an embryo. The earliest embryonic stages of many species are largely controlled by maternally supplied factors. Later in development, patterning control shifts to the embryonic genome and, concomitantly with this transition, the maternally supplied factors are broadly degraded. This chapter attempts to integrate these processes – germ line segregation, and how the divergence of germ line and soma may utilize the egg to embryo transitions differently. In some embryos, this difference is subtle or maybe lacking altogether, whereas in other embryos, this difference in utilization may be a key step in the divergence of the two lineages. Here we will focus our discussion on the echinoderms, and in particular the sea urchins, in which recent studies have provided mechanistic understanding in germ line determination. We propose that the germ line in sea urchins requires an acquisition of maternal factors from the egg and, when compared to other members of the taxon, this appears to be a derived mechanism. The acquisition is early – at the 32 cell stage – and involves active protection of maternal mRNAs, which are instead degraded in somatic cells with the maternal to embryonic transition. We collectively refer to this model as the Time Capsule method

  1. Germ Line Versus Soma in the Transition from Egg to Embryo.

    PubMed

    Swartz, S Zachary; Wessel, Gary M

    2015-01-01

    With few exceptions, all animals acquire the ability to produce eggs or sperm at some point in their life cycle. Despite this near-universal requirement for sexual reproduction, there exists an incredible diversity in germ line development. For example, animals exhibit a vast range of differences in the timing at which the germ line, which retains reproductive potential, separates from the soma, or terminally differentiated, nonreproductive cells. This separation may occur during embryonic development, after gastrulation, or even in adults, depending on the organism. The molecular mechanisms of germ line segregation are also highly diverse, and intimately intertwined with the overall transition from a fertilized egg to an embryo. The earliest embryonic stages of many species are largely controlled by maternally supplied factors. Later in development, patterning control shifts to the embryonic genome and, concomitantly with this transition, the maternally supplied factors are broadly degraded. This chapter attempts to integrate these processes--germ line segregation, and how the divergence of germ line and soma may utilize the egg to embryo transitions differently. In some embryos, this difference is subtle or maybe lacking altogether, whereas in other embryos, this difference in utilization may be a key step in the divergence of the two lineages. Here, we will focus our discussion on the echinoderms, and in particular the sea urchins, in which recent studies have provided mechanistic understanding in germ line determination. We propose that the germ line in sea urchins requires an acquisition of maternal factors from the egg and, when compared to other members of the taxon, this appears to be a derived mechanism. The acquisition is early--at the 32-cell stage--and involves active protection of maternal mRNAs, which are instead degraded in somatic cells with the maternal-to-embryonic transition. We collectively refer to this model as the Time Capsule method for germ

  2. Line group techniques in description of the structural phase transitions in some superconductors

    NASA Technical Reports Server (NTRS)

    Meszaros, CS.; Balint, A.; Bankuti, J.

    1995-01-01

    The main features of the theory of line groups, and their irreducible representations are briefly discussed, as well as the most important applications of them. A new approach in the general symmetry analysis of the modulated systems is presented. It is shown, that the line group formalism could be a very effective tool in the examination of the structural phase transitions in High Temperature SUperconductors. As an example, the material YBa2Cu3O(7-x) is discussed briefly.

  3. Line tension controls liquid-disordered + liquid-ordered domain size transition in lipid bilayers

    DOE PAGES

    Usery, Rebecca D.; Enoki, Thais A.; Wickramasinghe, Sanjula P.; ...

    2017-04-11

    To better understand animal cell plasma membranes, we studied simplified models, namely four-component lipid bilayer mixtures. Here we describe the domain size transition in the region of coexisting liquid-disordered (Ld) + liquid-ordered (Lo) phases. This transition occurs abruptly in composition space with domains increasing in size by two orders of magnitude, from tens of nanometers to microns. We measured the line tension between coexisting Ld and Lo domains close to the domain size transition for a variety of lipid mixtures, finding that in every case the transition occurs at a line tension of ~0.3 pN. A computational model incorporating linemore » tension and dipole repulsion indicated that even small changes in line tension can result in domains growing in size by several orders of magnitude, consistent with experimental observations. Lastly, we find that other properties of the coexisting Ld and Lo phases do not change significantly in the vicinity of the abrupt domain size transition.« less

  4. Managing the Transition into Higher Education: An On-Line Spiral Induction Programme

    ERIC Educational Resources Information Center

    Laing, Christopher; Robinson, Alan; Johnston, Veronique

    2005-01-01

    In helping students manage the transition into higher education, there must be (i) an understanding of the needs and expectations of the students, and (ii) a process that inducts the students into the needs and expectations of higher education. This premise underpins the on-line Spiral Induction Programme (onSIP) developed at Southampton…

  5. The Broadening of Spectral Lines by Autoionization, Radiative Transitions, and Collisions.

    DTIC Science & Technology

    1980-10-22

    nnounced Justif icai ¢:c Distr -- / Av~a..’ ’ "Co~es fl/-i iii st THE BRAODENING OF SPECTRAL LINES BY AUTOIONIZATION, RADIATIVE TRANSITIONS, AND...of NY Physics Department Stony Brook, New York 11794 Meerut College Meerut, 250001 India Meyerhof, W.E. Department of Physics Stanford University

  6. Effect of temperature on avalanche region width and DC to RF conversion efficiency of the p+nn-n+ 4H-SiC impact avalanche transit time diodes

    NASA Astrophysics Data System (ADS)

    Chen, Qing; Yang, Lin'an; Wang, Shulong; Hao, Yue

    2016-06-01

    The effect of temperature on avalanche region width and DC to RF conversion efficiency of the p+nn-n+ impact ionization avalanche transit time diodes based on 4H-SiC material for 140 GHz design frequency has been investigated by means of the MEDICI simulation platform. It is shown that the avalanche region width of the IMPATT diodes working at the same operating current densities first decreases and then increases with the increasing temperature. The DC to RF conversion efficiency of the IMPATT diodes first increases and then decreases with the increasing temperature. The increase in ionization rate of impurities with increasing temperature and the decrease in the carrier impact ionization rate with increasing temperature are responsible for the results. In addition, the expansion of avalanche region and the degradation of DC to RF conversion efficiency at lower temperature are more pronounced in lower p+ region doping concentration diode than that in higher p+ region doping concentration.

  7. Transition from drift to interchange instabilities in an open magnetic field line configuration

    SciTech Connect

    Poli, F. M.; Ricci, P.; Fasoli, A.; Podesta, M.

    2008-03-15

    The transition from a regime dominated by drift instabilities to a regime dominated by pure interchange instabilities is investigated and characterized in the simple magnetized toroidal device TORPEX [TORoidal Plasma EXperiment, A. Fasoli et al., Phys. of Plasmas 13, 055906 (2006)]. The magnetic field lines are helical, with a dominant toroidal component and a smaller vertical component. Instabilities with a drift character are observed in the favorable curvature region, on the high field side with respect to the maximum of the background density profile. For a limited range of values of the vertical field they coexist with interchange instabilities in the unfavorable curvature region, on the plasma low field side. With increasing vertical magnetic field magnitude, a gradual transition between the two regimes is observed on the low field side, controlled by the value of the field line connection length. The observed transition follows the predictions of a two-fluid linear model.

  8. Superconducting transition width (ΔT c) characteristics of 25 mol% Zr-added (Gd, Y)Ba2Cu3O7-δ superconductor tapes with high in-field critical current density at 30 K

    NASA Astrophysics Data System (ADS)

    Heydari Gharahcheshmeh, M.; Galstyan, E.; Xu, A.; Kukunuru, J.; Katta, R.; Zhang, Y.; Majkic, G.; Li, X.-F.; Selvamanickam, V.

    2017-01-01

    The superconducting transition width (∆T c) characteristics of REBa2Cu3O7-δ (REBCO and RE = Gd, Y) superconductor tapes with Zr content of 25 mol% with high lift factor (ratio of critical current density (J c) at 30 K, 3 T (B||c) to the J c at 77 K, 0 T) has been determined. In this work, heavily doped (Gd, Y)Ba2Cu3O7-δ superconductor tapes with 25 mol% Zr addition were fabricated by metal organic chemical vapor deposition using a reel-to reel process. The optimal chemical composition range of (Gd, Y)Ba2Cu3O7-δ superconductor tapes with Zr content of 25 mol% to achieve critical current densities above 3.5 MA cm-2 at 77 K in zero applied magnetic field has been determined. A superconducting transition width (∆T c) as narrow as 0.4 K and an onset critical transition temperature (T c-onset) as high as 92 K were obtained in the 25 mol% Zr-added (Gd, Y)BaCuO superconductor tapes. Based on the mapped compositional phase diagram of the ∆Tc and lift factor, ∆T c in the range of 0.7-0.9 K is observed in 25 mol% Zr-added (Gd, Y)BaCuO superconductor tapes with a high lift factor.

  9. Excitation rate coefficients and line ratios for the optical and ultraviolet transitions in S II

    NASA Technical Reports Server (NTRS)

    Cai, Wei; Pradhan, Anil K.

    1993-01-01

    New calculations are reported for electron excitation collision strengths, rate coefficients, transition probabilities, and line ratios for the astrophysically important optical and UV lines in S II. The collision strengths are calculated in the close coupling approximation using the R-matrix method. The present calculations are more extensive than previous ones, including all transitions among the 12 lowest LS terms and the corresponding 28 fine-structure levels in the collisional-radiative model for S II. While the present rate coefficients for electron impact excitation are within 10-30 percent of the previous values for the low-lying optical transitions employed as density diagnostics of H II regions and nebulae, the excitation rates for the UV transitions 4S super 0 sub 3/2 - 4Psub 1/2,3/2,5/2 differ significantly from earlier calculations, by up to factor of 2. We describe temperature and density sensitive flux ratios for a number of UV lines. The present UV results are likely to be of interest in a more accurate interpretation of S II emission from the Io plasma torus in the magnetosphere of Jupiter, as well as other UV sources observed from the IUE, ASTRO 1, and the HST.

  10. Study of the transit time of pressure propagation in an acoustic delay line

    NASA Astrophysics Data System (ADS)

    Song, Yunn-Fang; Chen, Ching-Iue; Chang, Chu-Nan; You, Jean-Luh; Hwang, Fu-Kwun; Hsu, Chih-Ying

    1986-12-01

    A fast sensor was used as a vacuum gauge to measure the transit time of a gas pressure through an acoustic delay line (ADL). The results were compared with the predictions of two theoretical models. We found that in the rupture pressure range of 101 to 104 Pa, the predictions of Jean and Rauss' model, based on the assumption that the flow of gas be a gas fluid, set lower boundaries for the observed transit times; while the predictions of our model, based on the molecular motion, set the upper ones.

  11. Electron impact polarization expected in solar EUV lines from flaring chromospheres/transition regions

    NASA Technical Reports Server (NTRS)

    Fineschi, S.; Fontenla, Juan M.; Macneice, P.; Ljepojevic, N. N.

    1991-01-01

    We have evaluated lower bounds on the degree of impact Extreme Ultraviolet/Ultraviolet (EUV/UV) line polarization expected during solar flares. This polarization arises from collisional excitation by energetic electrons with non-Maxwellian velocity distributions. Linear polarization was observed in the S I 1437 A line by the Ultraviolet Spectrometer and Polarimeter/Solar Maximum Mission (UVSP/SMM) during a flare on 15 July 1980. An early interpretation suggested that impact excitation by electrons propagating through the steep temperature gradient of the flaring transition region/high chromosphere produced this polarization. Our calculations show that the observed polarization in this UV line cannot be due to this effect. We find instead that, in some flare models, the energetic electrons can produce an impact polarization of a few percent in EUV neutral helium lines (i.e., lambda lambda 522, 537, and 584 A).

  12. Measurements of solar transition zone velocities and line broadening using the ultraviolet spectrometer and polarimeter on the Solar Maximum Mission

    NASA Technical Reports Server (NTRS)

    Simon, G.; Mein, P.; Vial, J. C.; Shine, R. A.; Woodgate, B. E.

    1982-01-01

    The UVSP instrument on SMM is able to observe solar regions at two wavelengths in the same line with a band-pass of 0.3 A. Intensity and Doppler velocity maps are derived. It is shown that the numerical values are sensitive to the adopted Doppler width and the range of velocities is limited to within 30 km/sec. A method called Double Dopplergram Determination (DDD) is described for deriving both the Doppler width and the velocity (up to 80 km/sec), and the main sources of uncertainties are discussed. To illustrate the method, a set of C IV 1548 A observations is analyzed according to this procedure. The mean C IV Doppler width measured (0.15 A) is comparable to previous determinations. A relation is found between bright regions and down-flows. Large Doppler widths correspond to strong velocity gradients.

  13. Diagnostics of the κ-distribution using Si III lines in the solar transition region

    NASA Astrophysics Data System (ADS)

    Dzifčáková, E.; Kulinová, A.

    2011-07-01

    Aims: The solar transition region satisfies the conditions for appearance of the non-thermal κ-distribution. We aim to prove the occurrence of the non-thermal κ-distribution in the solar transition region and diagnose its parameters. Methods: The intensity ratios of Si iii lines observed by SUMER in 1100-1320 Å region do not correspond to the line ratios computed under the assumption of the Maxwellian electron distribution. We computed a set of synthetic Si iii spectra for the electron κ-distributions with different values of the parameter κ. We had to include the radiation field in our calculations to explain the observed line ratios. We propose diagnostics of the parameter κ and other plasma parameters and analyze the effect of the different gradient of differential emission measures (DEM) on the presented calculations. Results: The used line ratios are sensitive to T, density and the parameter κ. All these parameters were determined from the SUMER observations for the coronal hole (CH), quiet Sun (QS) and active region (AR) using our proposed diagnostics. A strong gradient of DEM influences the diagnosed parameters of plasma. The essential contributions to the total line intensities do not correspond to single T but a wider range of T, and they originate in different atmospheric layers. The amount of the contributions from these atmospheric layers depends on the gradient of DEM and the shape of the electron distribution function. Conclusions: The κ-distribution is able to explain the observed Si iii line spectrum in the transition region. The degree of non-thermality increases with the activity of the solar region, it is lower for CH and higher for the AR. The DEM influences the diagnosed T and Ne but it has only little effect on the diagnostics of the parameter κ.

  14. Recommended Isolated-Line Profile for Representing High-Resolution Spectroscoscopic Transitions

    NASA Astrophysics Data System (ADS)

    Tennyson, J.; Bernath, P. F.; Campargue, A.; Császár, A. G.; Daumont, L.; Gamache, R. R.; Hodges, J. T.; Lisak, D.; Naumenko, O. V.; Rothman, L. S.; Tran, H.; Hartmann, J.-M.; Zobov, N. F.; Buldyreva, J.; Boone, C. D.; De Vizia, M. Domenica; Gianfrani, L.; McPheat, R.; Weidmann, D.; Murray, J.; Ngo, N. H.; Polyansky, O. L.

    2014-06-01

    Recommendations of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules are presented. The well-documented inadequacies of the Voigt profile, used almost universally by databases and radiative-transfer codes to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule, have resulted in the development of a variety of alternative line profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially-Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should be called the Hartmann-Tran profile (HTP). This profile is sophisticated enough to capture the various collisional contributions to the isolated line shape, can be computed in a straightforward and rapid manner, and reduces to simpler profiles, including the Voigt profile, under certain simplifying assumptions. For further details see: J. Tennyson et al, Pure Appl. Chem., 2014, in press.

  15. Line group techniques in description of the structural phase transitions in some superconductors

    SciTech Connect

    Meszaros, C.; Bankuti, J.; Balint, A.

    1994-12-31

    The main features of the theory of line groups, and their irreducible representations are briefly discussed, as well as the most important applications of them. A new approach in the general symmetry analysis of the modulated systems is presented. It is shown, that the line group formalism could be a very effective tool in the examination of the structural phase transitions in High Temperature Superconductors. As an example, the material YBa{sub 2}Cu{sub 3}O{sub 7-x} is discussed briefly.

  16. Effect of Wall Temperature on Roughness Induced Attachment-Line Transition

    NASA Technical Reports Server (NTRS)

    Dietz, Anthony; Coleman, Colin; Laub, Jim; Poll, D. I. A.; Nixon, David (Technical Monitor)

    1999-01-01

    An experiment on a cooled swept cylinder in a low-disturbance Mach 1.6 wind tunnel is described. The flow attachment line is disturbed by trip wires of varying size and the laminar/turbulent state of the downstream boundary layer is determined with a hot wire. The results demonstrate that although cooling the wall increases the stability of the boundary layer, it promotes roughness induced transition. Analysis of the data suggests that the attachment- line Reynolds number can account for the effect of wall cooling if the viscosity is evaluated at a particular reference temperature.

  17. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: First Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-03-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

  18. Measurement of crossflow vortices, attachment-line flow, and transition using microthin hot films

    NASA Technical Reports Server (NTRS)

    Mangalam, S. M.; Agarwal, N. K.; Maddalon, D. V.; Saric, W. S.

    1990-01-01

    A flow diagnostic experiment was conducted on a 45-deg swept-wing model using surface-mounted, multielement, microthin, hot-film sensors. The cross-flow vortex spacing, the attachment-line flow characteristics, and the transition region were all determined using an advanced data acquisition and instrumentation system. In addition to the frequencies of traveling waves predicted by linear stability theory, amplified disturbances at much higher frequencies were observed. Simultaneous measurements from sensors located at a number of chord and span locations highlighted the strong three-dimensionality of the boundary-layer flow in the presence of cross-flow vortices. The state of the attachment-line boundary layer was determined using a multielement sensor wrapped around the wing leading edge. The transition region flow characteristics were also identified.

  19. Prospects for higher spatial resolution quantitative X-ray analysis using transition element L-lines

    NASA Astrophysics Data System (ADS)

    Statham, P.; Holland, J.

    2014-03-01

    Lowering electron beam kV reduces electron scattering and improves spatial resolution of X-ray analysis. However, a previous round robin analysis of steels at 5 - 6 kV using Lα-lines for the first row transition elements gave poor accuracies. Our experiments on SS63 steel using Lα-lines show similar biases in Cr and Ni that cannot be corrected with changes to self-absorption coefficients or carbon coating. The inaccuracy may be caused by different probabilities for emission and anomalous self-absorption for the La-line between specimen and pure element standard. Analysis using Ll(L3-M1)-lines gives more accurate results for SS63 plausibly because the M1-shell is not so vulnerable to the atomic environment as the unfilled M4,5-shell. However, Ll-intensities are very weak and WDS analysis may be impractical for some applications. EDS with large area SDD offers orders of magnitude faster analysis and achieves similar results to WDS analysis with Lα-lines but poorer energy resolution precludes the use of Ll-lines in most situations. EDS analysis of K-lines at low overvoltage is an alternative strategy for improving spatial resolution that could give higher accuracy. The trade-off between low kV versus low overvoltage is explored in terms of sensitivity for element detection for different elements.

  20. Determining tunable diode laser spectrometer performance through measurement of N(2)0 line intensities and widths at 7.8 microm.

    PubMed

    Chen, D W; Niple, E R; Poultney, S K

    1982-08-15

    The N(2)O R(8) doublet of the 11(1)0-01(1)0 band at 7.8 microm was measured by a tunable diode laser spectrometer designed and assembled at Perkin-Elmer. The spectra were digitized and least-squares fitted to Voigt line profiles to yield N(2)O line parameters and a quantitative measure of instrument performance. Scans at various pressures produced consistent spectral line values: S(0) = (0.1746 +/- 0.0043)cm(-2)/atm at 300 K, alpha(L)(N(2)O - N(2)O) = (0.1066 +/- 0.0041)cm(-1)/atm,alpha(D) = (1.194 +/- 0.018) x 10(-3) cm(-1), andalpha(L)(N(2)O - N(2)) = (0.0870 +/- 0.0015)cm(-1)atm. A spectrum with several levels of synthetic noise added was used to verify the fitting algorithm's stability. The spectrometer was shown to possess an excellent SNR (e.g., 900:1) and wave number precision (

  1. Gravure-Offset Printed Metallization of Multi-Crystalline Silicon Solar Cells with Low Metal-Line Width for Mass Production.

    PubMed

    Lee, Jonghwan; Jeong, Chaehwan

    2016-05-01

    The gravure offset method has been developed toward an industrially viable printing technique for electronic circuitry. In this paper, a roller type gravure offset manufacturing process was developed to fabricate fine line for using front electrode for solar cells. In order to obtain the optimum metallization printing lines, thickness of 20 μm which is narrow line is required. The main targets are the reduction of metallized area to reduce the shading loss, and a high conductivity to transport the current as loss free as possible out of the cell. However, it is well known that there is a poor contact resistance between the front Ag electrode and the n(+) emitter. Nickel plating was conducted to prevent the increase of contact resistance and the increase of fill factor (FF). The performance of n-Si/Ag (seed layer)/Ni solar cells were observed in 609 mV of open circuit voltage, 35.54 mA/cm2 of short circuit current density, 75.75% of fill factor, and 16.04% of conversion efficiency.

  2. [Excitation energy and frequency of transition spectral line of electron in an asymmetry quantum dot].

    PubMed

    Xiao, Jing-Lin

    2009-03-01

    In an asymmetry quantum dot, the properties of the electron, which is strongly coupled with phonon, were investigated. The variational relations of the first internal excited state energy, the excitation energy and the frequency of transition spectral line between the first internal excited state and the ground state of the electron which is strongly coupled with phonon in an asymmetry quantum dot with the transverse and longituainal effective confinement length of quantum dot and the electron-phonon coupling strength were studied by using a linear combination operator and the unitary transformation methods. Numerical calculations for the variational relations of the first internal excited state energy, the excitation energy and the frequency of transition spectral line between the first internal excited state and the ground state of the electron which is strongly coupled with phonon in an asymmetry quantum dot with the transverse and longituainal effective confinement length of quantum dot and the electron-phonon coupling strength were performed and the results show that the first internal excited state energy, the excitation energy and the frequency of transition spectral line between the first internal excited state and the ground state of the electron which is strongly coupled with phonon in an asymmetry quantum dot will strongly increase with decreasing the transverse and longitudinal effective confinement length. The first internal excited state energy of the electron which is strongly coupled with phonon in an asymmetry quantum dot will decrease with increasing the electron-phonon coupling strength. The excitation energy and the frequency of transition spectral line between the first internal excited state and the ground state of the electron which is strongly coupled with phonon in an asymmetry quantum dot will increase with increasing the electron-phonon coupling strength.

  3. The accuracy of using the spectral width boundary measured in off-meridional SuperDARN HF radar beams as a proxy for the open-closed field line boundary

    NASA Astrophysics Data System (ADS)

    Chisham, G.; Freeman, M. P.; Sotirelis, T.; Greenwald, R. A.

    2005-10-01

    Determining reliable proxies for the ionospheric signature of the open-closed field line boundary (OCB) is crucial for making accurate measurements of magnetic reconnection. This study compares the latitudes of spectral width boundaries (SWBs) measured by different beams of the Goose Bay radar of the Super Dual Auroral Radar Network (SuperDARN), with the latitudes of OCBs determined using the low-altitude Defense Meteorological Satellite Program (DMSP) spacecraft, in order to determine whether the accuracy of the SWB as a proxy for the ionospheric projection of the OCB depends on the line-of-sight direction of the radar beam. The latitudes of SWBs and OCBs were identified using automated algorithms applied to 5 years (1997 2001) of data measured in the 1000 1400 magnetic local time (MLT) range. Six different Goose Bay radar beams were used, ranging from those aligned in the geomagnetic meridional direction to those aligned in an almost zonal direction. The results show that the SWB is a good proxy for the OCB in near-meridionally-aligned beams but becomes progressively more unreliable for beams greater than 4 beams away from the meridional direction. We propose that SWBs are identified at latitudes lower than the OCB in the off-meridional beams due to the presence of high spectral width values that result from changes in the orientation of the beams with respect to the gradient in the large-scale ionospheric convection pattern. Keywords. Ionosphere (Instruments and techniques; Plasma convection) Magnetospheric physics (Magnetopause, cusp and boundary layers)

  4. Astronomy Behind Enemy Lines in Colonial North America: John Winthrop's Observations of the Transits of Venus

    NASA Astrophysics Data System (ADS)

    Schechner, S. J.

    2005-12-01

    In May 1761, John Winthrop packed up two students, an excellent clock, an octant, and two telescopes, and embarked for Newfoundland to observe the Transit of Venus. Winthrop's departure was hasty. Only days before had the President and Fellows of Harvard College approved Professor Winthrop's request to take the college apparatus behind enemy lines to serve the cause of science, and Winthrop knew he had no time to waste if he were to reach Newfoundland and properly calibrate his equipment before the Transit. Winthrop's expedition to St. John's, Newfoundland was nothing short of remarkable. His goal was to help determine the distance from the Earth to the Sun, and he was the only North American astronomer fit for this project. His expedition was financed by the General Court of Massachusetts, which also secured him safe passage across enemy lines during the French and Indian War. Winthrop's trip to St. John's was a major achievement for colonial astronomy, but he was unhappy with his observations and so looked forward to a second chance to observe a transit in 1769. Benjamin Franklin urged him to go to Lake Superior. Planning for that transit was thwarted, however, by two events: (1) the loss of nearly all of Harvard's apparatus in a fire of 1764; and (2) pre-Revolutionary politics in the American colonies. In the end, Winthrop was forced to content himself with first-class observations with new instruments in Cambridge.

  5. Effects of Sonic Line Transition on Aerothermodynamics of the Mars Pathfinder Probe

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.; Weilmuenster, K. James; Braun, Robert D.; Cruz, Christopher I.

    1995-01-01

    Flow field solutions over the Mars Pathfinder Probe spanning the trajectory through the Martian atmosphere at angles of attack from 0 to 11 degrees are obtained. Aerodynamic coefficients derived from these solutions reveal two regions where the derivative of pitching moment with respect to angle of attack is positive at small angles of attack. The behavior is associated with the transition of the sonic line location between the blunted nose and the windside shoulder of the 70 degree half-angle cone in a gas with a low effective ratio of specific heats. The transition first occurs as the shock layer gas chemistry evolves from highly nonequilibrium to near equilibrium, above approximately 6.5 km/s and 40 km altitude, causing the effective specific heat ratio to decrease. The transition next occurs in an equilibrium flow regime as velocities decrease through 3.5 km/s and the specific heat ratio increases again with decreasing enthalpy. The effects of the expansion over the shoulder into the wake are more strongly felt on the fustrum when the sonic line sits on the shoulder. The transition also produces a counter-intuitive trend in which windside heating levels decrease with increasing angle of attack resulting from an increase in the effective radius of curvature. Six-degree-of-freedom trajectory analyses utilizing the computed aerodynamic coefficients predict a moderate, 3 to 4 degree increase in total angle of attack as the probe, spinning at approximately 2 revolutions per minute, passes through these regions.

  6. Curcumin inhibits invasive capabilities through epithelial mesenchymal transition in breast cancer cell lines.

    PubMed

    Gallardo, Marcela; Calaf, Gloria M

    2016-09-01

    Curcumin (diferuloyl methane) is an antioxidant that exerts antiproliferative and apoptotic effects and has anti-invasive and anti-metastatic properties. Evidence strongly implicates that epithelial-mesenchymal transition (EMT) is involved in malignant progression affecting genes such as Slug, AXL and Twist1. These genes are abnormally expressed in many tumors and favor metastasis. The purpose of this study was to determine the potential effect of curcumin on EMT, migration and invasion. Triple-positive and triple-negative breast cancer cell lines for estrogen receptor (ER), progesterone receptor (PgR) and HER/neu were used: i) MCF-10F, a normal immortalized breast epithelial cell line (negative), ii) Tumor2, a malignant and tumorigenic cell line (positive) derived from Alpha5 cell line injected into the immunologically depressed mice and transformed by 60/60 cGy doses of high LET (linear energy transfer) α particles (150 keV/µm) of radiation and estrogen, and iii) a commercially available MDA-MB‑231 (negative). The effect of curcumin (30 µM for 48 h) was evaluated on expression of EMT-related genes by RT-qPCR. Results showed that curcumin decreased E-cadherin, N-cadherin, β-catenin, Slug, AXL, Twist1, Vimentin and Fibronectin protein expression, independently of the positivity of the markers in the cell lines. Curcumin also decreased migration and invasive capabilities in comparison to their own controls. It can be concluded that curcumin influenced biochemical changes associated with EMT-related genes that seems to promote such transition and are at the core of several signaling pathways that mediate the transition. Thus, it can be suggested that curcumin is able to prevent or delay cancer progression through the interruption of this process.

  7. The Diagnostic Potential of Transition Region Lines Undergoing Transient Ionization in Dynamic Events

    NASA Astrophysics Data System (ADS)

    Doyle, J. G.; Giunta, A.; Singh, A.; Madjarska, M. S.; Summers, H.; Kellett, B. J.; O'Mullane, M.

    2012-09-01

    We discuss the diagnostic potential of high cadence UV spectral data when transient ionization is considered. For this we use high cadence UV spectra taken during the impulsive phase of a solar flare (observed with instruments on-board the Solar Maximum Mission) which showed excellent correspondence with hard X-ray pulses. The ionization fraction of the transition region ion O v and, in particular, the contribution function for the O v 1371 Å line are computed within the Atomic Data and Analysis Structure, which is a collection of fundamental and derived atomic data and codes to manipulate them. Due to transient ionization, the O v 1371 Å line is enhanced in the first fraction of a second with the peak in the line contribution function occurring initially at a higher electron temperature than in ionization equilibrium. The rise time and enhancement factor depend mostly on the electron density. The fractional increase in the O v 1371 Å emissivity due to transient ionization can reach a factor of two-four and can explain the fast response in the line flux of transition regions ions during the impulsive phase of flares solely as a result of transient ionization. This technique can be used to diagnose the electron temperature and density of solar flares observed with the forthcoming Interface Region Imaging Spectrograph.

  8. Doppler wavelength shifts of transition zone lines measured in Skylab solar spectra

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.; Bohlin, J. D.; Feldman, U.

    1976-01-01

    Wavelengths of lines of the transition-zone ions Si IV, C IV, O IV, N V, and O V are observed to be redshifted relative to the wavelengths of chromospheric lines in XUV spectra obtained from the normal-incidence spectrograph on Skylab. The spectra cover the wavelength range from 1200 to 1565 A and were obtained with the slit positioned over chromospheric network and cell regions, on coronal holes, and above the limb. The network-area and coronal-hole spectra were obtained near the disk center. Only some of the spectra show redshifted transition-zone lines. The observed shifts are between 0.03 and 0.08 A, implying velocities of 15 km/s or less. The amount of wavelength shift does not always appear to be the same for lines of different ions. The shifts imply that descending plasma in the solar atmosphere produces more emission than ascending plasma at temperatures between approximately 70,000 and 200,000 K.

  9. Exploring the optical contrast effect in strong atomic lines for exoplanets transiting active stars

    NASA Astrophysics Data System (ADS)

    Cauley, Paul W.; Redfield, Seth

    2017-01-01

    Transmission spectroscopy is a powerful tool for detecting and characterizing planetary atmospheres. Non-photospheric features on the stellar disk, however, can contaminate the planetary signal: during transit the observed spectrum is weighted towards the features not currently being occulted by the planet. This contrast effect can mimic absorption in the planetary atmosphere for strong atomic lines such as Na I, Ca II, and the hydrogen Balmer lines. While the contrast effect is negligible for quiet stars, contributions to the transmission signal from active stellar surfaces can produce ~1% changes in the line core. It is therefore critical that these contrast signals be differentiated from true absorption features in the planetary atmosphere. Here we present our work on simulating the contrast effect for an active stellar surface. We discuss the particular case of HD 189733 b, a well-studied hot Jupiter orbiting an active K-dwarf, due to the plethora of atomic absorption signals reported in its atmosphere.Specifically, we focus on Hα to address recent suggestions that the measured in-transit signals are a result of stellar activity. In the contrast model we include center-to-limb variations and calculate limb darkening parameters as a function of wavelength across the line of interest. The model includes contributions to the spectrum from spots, faculae and plages, filaments, and the bare stellar photosphere. Stellar rotation is also included. We find that it is very difficult to reproduce the measured in-transit Hα signals for reasonable active region parameters. In addition, it is difficult to create an in-transit contrast signature that lasts for the duration of the transit unless the planet is crossing an active latitudinal belt and is always obscuring active regions. This suggests that the Hα measurements arise predominantly in the planetary atmosphere. However, the contrast effect likely contributes to these signals. Furthermore, our results could be

  10. 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.

  11. Transition probabilities of PrII-lines emitted from a ferroelectric plasma source

    NASA Astrophysics Data System (ADS)

    Goly, A.; Kusz, J.; Quang, B. Nguyen; Weniger, S.

    1991-03-01

    An argon-praseodymium plasma was generated under atmospheric pressure between a ceramic ferroelectric plate and a praseodymium plate. The system of plates was connected to an acoustic frequency supply. The plasma radiation was analyzed in the spectral range from 2000 to 7000 A by using a grating spectrograph with a linear dispersion near 1 mm/A, adopted to photoelectric measurements. The emission spectrum of praseodymium was recorded, and the intensities of a few hundred lines were measured. Transition probabilities were determined for 62 PrII-lines, using available lifetime data for excited levels and measured branching ratios of the corresponding lines. Reasonable agreement has been found between the experimental data of Lage and Whaling (1976) and some of the present results.

  12. Critically Evaluated Energy Levels, Spectral Lines, Transition Probabilities, and Intensities of Singly Ionized Vanadium (V ii)

    NASA Astrophysics Data System (ADS)

    Saloman, Edward B.; Kramida, Alexander

    2017-08-01

    The energy levels, observed spectral lines, and transition probabilities of singly ionized vanadium, V ii, have been compiled. The experimentally derived energy levels belong to the configurations 3d 4, 3d 3 ns (n = 4, 5, 6), 3d 3 np, and 3d 3 nd (n = 4, 5), 3d 34f, 3d 24s 2, and 3d 24s4p. Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g-factors and leading percentages for the levels are included when available, as well as Ritz wavelengths calculated from the energy levels. Wavelengths and transition probabilities are reported for 3568 and 1896 transitions, respectively. From the list of observed wavelengths, 407 energy levels are determined. The observed intensities, normalized to a common scale, are provided. From the newly optimized energy levels, a revised value for the ionization energy is derived, 118,030(60) cm-1, corresponding to 14.634(7) eV. This is 130 cm-1 higher than the previously recommended value from Iglesias et al.

  13. Experimental M1 Transition Rates of Coronal Lines from AR X, AR XIV, and AR XV

    NASA Astrophysics Data System (ADS)

    Träbert, E.; Beiersdorfer, P.; Utter, S. B.; Brown, G. V.; Chen, H.; Harris, C. L.; Neill, P. A.; Savin, D. W.; Smith, A. J.

    2000-09-01

    Transition probabilities of three magnetic dipole (M1) transitions in multiply charged ions of Ar have been measured using the Livermore electron-beam ion trap. Two of the transitions are in the ground configurations of Ar XIV (B-like) and Ar IX (F-like), and are associated with the coronal lines at 4412.4 and 5533.4 Å, respectively. The third is in the excited 2s2p configuration of Be-like Ar XV and produces the coronal line at 5943.73 Å. Our results for the three atomic level lifetimes are 9.32+/-0.12 ms for the Ar X 2s22p5 2Po1/2 level, 9.70+/-0.15 ms for the Ar XIV 2s22p 2Po3/2 level, and 15.0+/-0.8 ms for the Ar XV 2s2p 3Po2 level. These results differ significantly from earlier measurements and are the most accurate ones to date.

  14. Electron-impact Excitation Collision Strengths and Theoretical Line Intensities for Transitions in S III

    NASA Astrophysics Data System (ADS)

    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 Te (K) = 3.0-6.0. The calculation incorporates 53 fine-structure levels arising from the six configurations—3s 23p 2, 3s3p 3, 3s 23p3d, 3s 23p4s, 3s 23p4p, and 3s 23p4d—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. 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.

  16. FLUCTUATIONS AND FLARES IN THE ULTRAVIOLET LINE EMISSION OF COOL STARS: IMPLICATIONS FOR EXOPLANET TRANSIT OBSERVATIONS

    SciTech Connect

    Loyd, R. O. Parke; France, Kevin

    2014-03-01

    Variations in stellar flux can potentially overwhelm the photometric signal of a transiting planet. Such variability has not previously been well-characterized in the ultraviolet lines used to probe the inflated atmospheres surrounding hot Jupiters. Therefore, we surveyed 38 F-M stars for intensity variations in four narrow spectroscopic bands: two enclosing strong lines from species known to inhabit hot Jupiter atmospheres, C II λλ1334, 1335 and Si III λ1206; one enclosing Si IV λλ1393, 1402; and 36.5 Å of interspersed continuum. For each star/band combination, we generated 60 s cadence lightcurves from archival Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph time-tagged photon data. Within these lightcurves, we characterized flares and stochastic fluctuations as separate forms of variability. Flares: we used a cross-correlation approach to detect 116 flares. These events occur in the time-series an average of once per 2.5 hr, over 50% last 4 minutes or less, and most produce the strongest response in Si IV. If the flare occurred during a transit measurement integrated for 60 minutes, 90/116 would destroy the signal of an Earth, 27/116 Neptune, and 7/116 Jupiter, with the upward bias in flux ranging from 1% to 109% of quiescent levels. Fluctuations: photon noise and underlying stellar fluctuations produce scatter in the quiescent data. We model the stellar fluctuations as Gaussian white noise with standard deviation σ {sub x}. Maximum likelihood values of σ {sub x} range from 1% to 41% for 60 s measurements. These values suggest that many cool stars will only permit a transit detection to high confidence in ultraviolet resonance lines if the radius of the occulting disk is ≳1 R{sub J} . However, for some M dwarfs this limit can be as low as several R {sub ⊕}.

  17. Fluctuations and Flares in the Ultraviolet Line Emission of Cool Stars: Implications for Exoplanet Transit Observations

    NASA Astrophysics Data System (ADS)

    Loyd, R. O. Parke; France, Kevin

    2014-03-01

    Variations in stellar flux can potentially overwhelm the photometric signal of a transiting planet. Such variability has not previously been well-characterized in the ultraviolet lines used to probe the inflated atmospheres surrounding hot Jupiters. Therefore, we surveyed 38 F-M stars for intensity variations in four narrow spectroscopic bands: two enclosing strong lines from species known to inhabit hot Jupiter atmospheres, C II λλ1334, 1335 and Si III λ1206 one enclosing Si IV λλ1393, 1402; and 36.5 Å of interspersed continuum. For each star/band combination, we generated 60 s cadence lightcurves from archival Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph time-tagged photon data. Within these lightcurves, we characterized flares and stochastic fluctuations as separate forms of variability. Flares: we used a cross-correlation approach to detect 116 flares. These events occur in the time-series an average of once per 2.5 hr, over 50% last 4 minutes or less, and most produce the strongest response in Si IV. If the flare occurred during a transit measurement integrated for 60 minutes, 90/116 would destroy the signal of an Earth, 27/116 Neptune, and 7/116 Jupiter, with the upward bias in flux ranging from 1% to 109% of quiescent levels. Fluctuations: photon noise and underlying stellar fluctuations produce scatter in the quiescent data. We model the stellar fluctuations as Gaussian white noise with standard deviation σ x . Maximum likelihood values of σ x range from 1% to 41% for 60 s measurements. These values suggest that many cool stars will only permit a transit detection to high confidence in ultraviolet resonance lines if the radius of the occulting disk is gsim1 RJ . However, for some M dwarfs this limit can be as low as several R ⊕.

  18. Line shape of a transition between two levels in a three-level {Lambda} configuration

    SciTech Connect

    Han, Hyok Sang; Jeong, Ji Eun; Cho, D.

    2011-09-15

    We report on our study of the line shape of a transition between two levels in a three-level {Lambda} configuration. By using Poisson statistics under the assumption that the atom stays in a two-level steady state before it is optically pumped to the reservoir state, we arrive at a simple analytic expression for the line shape of a three-level atom. This expression reveals a new type of saturation in the time domain, which is conceptually different from that of power-broadening in a two-level atom. It can also be used as a basis for more complicated situations of Doppler-broadened gaseous samples or pump-and-probe spectroscopy. We tested the theory experimentally in an ideal situation of slow pulsed {sup 85}Rb atoms and found excellent agreement. Application to measurements of a branching ratio or a Franck-Condon factor of a diatomic molecule is discussed.

  19. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Second Results Report and Appendices

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-10-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This is the second results report for the AT fuel cell bus since it was placed in service, and it focuses on the newest data analysis and lessons learned since the previous report. The appendices, referenced in the main report, provide the full background for the evaluation. They will be updated as new information is collected but will contain the original background material from the first report.

  20. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Third Results Reports

    SciTech Connect

    Eudy, L.; Chandler, K.

    2012-05-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. NREL has previously published two reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from July 2011 through January 2012.

  1. ON THE TRANSITION RATE OF THE Fe X RED CORONAL LINE

    SciTech Connect

    Brenner, G.; Crespo Lopez-Urrutia, J. R.; Bernitt, S.; Fischer, D.; Ginzel, R.; Kubicek, K.; Maeckel, V.; Mokler, P. H.; Simon, M. C.; Ullrich, J.

    2009-09-20

    We present a lifetime measurement of the 3s {sup 2}3p {sup 52} P{sup o} {sub 1/2} first excited fine-structure level of the ground state configuration in chlorine-like Fe X, which relaxes to the ground state through a magnetic dipole (M1) transition (the so-called red coronal line) with a wavelength accurately determined to 637.454(1) nm. Moreover, the Zeeman splitting of line was observed. The lifetime of 14.2(2) ms is the most precise one measured in the red wavelength region and agrees well with advanced theoretical predictions and an empirically scaled interpolation based on experimental values from the same isoelectronic sequence.

  2. VizieR Online Data Catalog: Transition probabilities for 183 lines of Cr II (Lawler+, 2017)

    NASA Astrophysics Data System (ADS)

    Lawler, J. E.; Sneden, C.; Nave, G.; den Hartog, E. A.; Emrahoglu, N.; Cowan, J. J.

    2017-03-01

    New emission branching fraction (BF) measurements for 183 lines of the second spectrum of chromium (Cr II) and new radiative lifetime measurements from laser-induced fluorescence for 8 levels of Cr+ are reported. The goals of this study are to improve transition probability measurements in Cr II and reconcile solar and stellar Cr abundance values based on Cr I and Cr II lines. Eighteen spectra from three Fourier Transform Spectrometers supplemented with ultraviolet spectra from a high-resolution echelle spectrometer are used in the BF measurements. Radiative lifetimes from this study and earlier publications are used to convert the BFs into absolute transition probabilities. These new laboratory data are applied to determine the Cr abundance log{epsilon} in the Sun and metal-poor star HD 84937. The mean result in the Sun is =5.624+/-0.009 compared to =5.644+/-0.006 on a scale with the hydrogen abundance log{epsilon}(H)=12 and with the uncertainty representing only line-to-line scatter. A Saha (ionization balance) test on the photosphere of HD 84937 is also performed, yielding =3.417+/-0.006 and 0eV)>=3.374+/-0.011 for this dwarf star. We find a correlation of Cr with the iron-peak element Ti, suggesting an associated nucleosynthetic production. Four iron-peak elements (Cr along with Ti, V, and Sc) appear to have a similar (or correlated) production history-other iron-peak elements appear not to be associated with Cr. (1 data file).

  3. EVIDENCE FOR A SNOW LINE BEYOND THE TRANSITIONAL RADIUS IN THE TW Hya PROTOPLANETARY DISK

    SciTech Connect

    Zhang, K.; Pontoppidan, K. M.; Salyk, C.; Blake, G. A.

    2013-04-01

    We present an observational reconstruction of the radial water vapor content near the surface of the TW Hya transitional protoplanetary disk, and report the first localization of the snow line during this phase of disk evolution. The observations are comprised of Spitzer-IRS, Herschel-PACS, and Herschel-HIFI archival spectra. The abundance structure is retrieved by fitting a two-dimensional disk model to the available star+disk photometry and all observed H{sub 2}O lines, using a simple step-function parameterization of the water vapor content near the disk surface. We find that water vapor is abundant ({approx}10{sup -4} per H{sub 2}) in a narrow ring, located at the disk transition radius some 4 AU from the central star, but drops rapidly by several orders of magnitude beyond 4.2 AU over a scale length of no more than 0.5 AU. The inner disk (0.5-4 AU) is also dry, with an upper limit on the vertically averaged water abundance of 10{sup -6} per H{sub 2}. The water vapor peak occurs at a radius significantly more distant than that expected for a passive continuous disk around a 0.6 M{sub Sun} star, representing a volatile distribution in the TW Hya disk that bears strong similarities to that of the solar system. This is observational evidence for a snow line that moves outward with time in passive disks, with a dry inner disk that results either from gas giant formation or gas dissipation and a significant ice reservoir at large radii. The amount of water present near the snow line is sufficient to potentially catalyze the (further) formation of planetesimals and planets at distances beyond a few AU.

  4. Widom line for the liquid-gas transition in Lennard-Jones system.

    PubMed

    Brazhkin, V V; Fomin, Yu D; Lyapin, A G; Ryzhov, V N; Tsiok, E N

    2011-12-08

    The locus of extrema (ridges) for heat capacity, thermal expansion coefficient, compressibility, and density fluctuations for model particle systems with Lennard-Jones (LJ) potential in the supercritical region have been obtained. It was found that the ridges for different thermodynamic values virtually merge into a single Widom line at T < 1.1T(c) and P < 1.5P(c) and become practically completely smeared at T < 2.5T(c) and P < 10P(c), where T(c) and P(c) are the critical temperature and pressure. The ridge for heat capacity approaches close to critical isochore, whereas the lines of extrema for other values correspond to density decrease. The lines corresponding to the supercritical maxima for argon and neon are in good agreement with the computer simulation data for LJ fluid. The behavior of the ridges for LJ fluid, in turn, is close to that for the supercritical van der Waals fluid, which is indicative of a fairly universal behavior of the Widom line for a liquid-gas transition.

  5. VizieR Online Data Catalog: Line lists of transitions for interstellar urea (Remijan+, 2014)

    NASA Astrophysics Data System (ADS)

    Remijan, A. J.; Snyder, L. E.; McGuire, B. A.; Kuo, H.-L.; Looney, L. W.; Friedel, D. N.; Golubiatnikov, G. Y.; Lovas, F. J.; Ilyushin, V. V.; Alekseev, E. A.; Dyubko, S. F.; McCall, B. J.; Hollis, J. M.

    2016-04-01

    The first measurements of the microwave spectra of urea were made from 5GHz to 50GHz using a heated waveguide cell (Brown et al., 1975JMoSp..58..445B). Further measurements were reported by Kasten & Dreizler (1986ZNatA..41.1173K) and Kretschmer et al. (1996MolPh..87.1159K). New spectroscopic measurements were made at NIST over the frequency range from 59GHz to 114GHz. A total of 38 rotational transitions was measured. Later, the Kharkov group carried out higher frequency measurements. Using a heated quartz absorption cell utilizing an automated synthesizer-based spectrometer (Ilyushin et al., 2005JMoSp.231...15I), the Kharkov group provided 75 new measurements between 78GHz and 240GHz. The urea lines for which we searched were calculated using the millimeter-wave data discussed above, as well as the hyperfine-free data from the existing literature cited earlier. As an aid to further interstellar searches for urea transitions, we provide a complete list of predicted rotational lines of urea available in Table6 covering the frequency range of 1GHz to 600GHz. (1 data file).

  6. Transition Probabilities for the 1815 and 3344 Å Forbidden Lines of NE III

    NASA Astrophysics Data System (ADS)

    Daw, Adrian; Parkinson, William H.; Smith, Peter L.; Calamai, Anthony G.

    2000-04-01

    We have measured the radiative lifetime of the 2s22p4 1S0 metastable level of Ne2+ (Ne III) to be 223+/-11 ms at the 90% confidence level by observing the photons emitted at 1815 Å by a decaying population of 1S0 Ne2+ ions produced and stored in a radio-frequency ion trap. This is the first lifetime measurement for an excited term of a ground configuration ion in the second row of the periodic table. The transition probabilities (A-values) for the forbidden transitions in the ground configurations of these ions are required for astrophysical line-ratio diagnostics. Using calculated branching ratios, we estimate that A(λ1815)=1.94+/-0.17 and A(λ3344)=2.55+/-0.19 s-1. Because these numbers have a sum with an experimentally determined uncertainty of 5%, they will provide more accurate results than the calculated A-values for determining electron temperature and density from astrophysical Ne III line ratios.

  7. Transition Probabilities for the 1815 and 3344 Å Forbidden Lines of Ne iii.

    PubMed

    Daw; Parkinson; Smith; Calamai

    2000-04-20

    We have measured the radiative lifetime of the 2s22p4 1S0 metastable level of Ne2+ (Ne iii) to be 223+/-11 ms at the 90% confidence level by observing the photons emitted at 1815 Å by a decaying population of 1S0 Ne2+ ions produced and stored in a radio-frequency ion trap. This is the first lifetime measurement for an excited term of a ground configuration ion in the second row of the periodic table. The transition probabilities (A-values) for the forbidden transitions in the ground configurations of these ions are required for astrophysical line-ratio diagnostics. Using calculated branching ratios, we estimate that A&parl0;lambda1815&parr0;=1.94+/-0.17 and A&parl0;lambda3344&parr0;=2.55+/-0.19 s-1. Because these numbers have a sum with an experimentally determined uncertainty of 5%, they will provide more accurate results than the calculated A-values for determining electron temperature and density from astrophysical Ne iii line ratios.

  8. CO line emission from circumstellar envelopes: towards higher-J transitions

    NASA Astrophysics Data System (ADS)

    Teyssier, D.; Bujarrabal, V.; Yoshida, H.; Phillips, T. G.

    2005-01-01

    We present the results of a multi-transition CO observational program conducted on a sample of AGB and post-AGB stars envelopes. Using new observations of the CO line at 691 GHz at the CSO, we have collected maps and single pointing observations of these envelope in 5 rotational transitions ranging from J=1-0 to J=6-5. Using a simplified version of the model of Bujarrabal et al. (1989), we have conducted a systematic modelling analysis using the whole set of CO data collected on a sample of 12 sources. Our modelling approach simultaneously fits all five transitions, taking into account the spatial information provided by the maps. We show that most AGBs data can be fitted using a single mass-loss rate, at least within the calibration uncertainties associated to the data collected at high frequencies. For some cases though, a change in the mass-loss rate history needs to be invoked to reconcile data at low and high-J respectively.

  9. Complexity in the high latitude HF radar spectral width boundary region

    NASA Astrophysics Data System (ADS)

    Parkinson, M. L.; Hannah, K. M.; Dyson, P. L.

    2008-05-01

    SuperDARN radars are sensitive to the collective Doppler characteristics of decametre-scale irregularities in the high latitude ionosphere. The radars routinely observe a distinct transition from large spectral width (>100 m s-1) located at higher latitudes to low spectral width (<50 m s-1) located at lower latitudes. Because of its equatorward location, the TIGER Tasmanian radar is very sensitive to the detection of the spectral width boundary (SWB) in the nightside auroral ionosphere. An analysis of the line-of-sight velocities and 2-D beam-swinging vectors suggests the meso-scale (~100 km) convection is more erratic in the high spectral width region, but slower and more homogeneous in the low spectral width region. The radar autocorrelation functions are better modelled using Lorentzian Doppler spectra in the high spectral width region, and Gaussian Doppler spectra in the low spectral width region. However, paradoxically, Gaussian Doppler spectra are associated with the largest spectral widths. Application of the Burg maximum entropy method suggests the occurrence of double-peaked Doppler spectra is greater in the high spectral width region, implying the small-scale (~10 km) velocity fluctuations are more intense above the SWB. These observations combined with collective wave scattering theory imply there is a transition from a fast flowing, turbulent plasma with a correlation length of velocity fluctuations less than the scattering wavelength, to a slower moving plasma with a correlation length greater than the scattering wavelength. Peak scaling and structure function analysis of fluctuations in the SWB itself reveals approximately scale-free behaviour across temporal scales of ~10 s to ~34 min. Preliminary scaling exponents for these fluctuations, αGSF=0.18±0.02 and αGSF=0.09±0.01, are even smaller than that expected for MHD turbulence.

  10. Stick-Slip to Sliding Transition of Dynamic Contact Lines under AC Electrowetting.

    PubMed

    't Mannetje, D J C M; Mugele, F; van den Ende, D

    2013-12-03

    We show that at low velocities the dynamics of a contact line of a water drop moving over a Teflon-like surface under ac electrowetting must be described as stick-slip motion, rather than one continuous movement. At high velocities we observe a transition to a slipping regime. In the slipping regime the observed dependence of the contact angle is well described by a linearization of both the hydrodynamic and the molecular-kinetic model for the dynamic contact line behavior. The overall geometry of the drop also has a strong influence on the contact angle: if the drop is confined to a disk-like shape with radius R, much larger than the capillary length, and height h, smaller than the capillary length, the advancing angle increases steeper with velocity as the aspect ratio h/R is smaller. Although influence of the flow field near a contact line on the contact angle behavior has also been observed in other experiments, these observations do not fit either model. Finally, in our ac experiments no sudden increase of the hysteresis beyond a certain voltage and velocity was observed, as reported by other authors for a dc voltage, but instead we find with increasing voltage a steady decrease of the hysteresis.

  11. Magnetic property of transition metal-Si atomic line on silicon Σ3 grain boundary: A theoretical study

    SciTech Connect

    Li, Yong-Hua Guo, Shu-Kuan; Ma, Zhong-Quan; Qu, Guo-Hui; Shi, Ting-Ting; Xia, Qin; Gong, Xin-Gao; Wei, Su-Huai

    2014-06-14

    Using first-principles calculations within density functional theory, we investigate the electronic and magnetic properties of different 3d transition metal-Si atomic lines on silicon Σ3 (112) grain boundary, which can be formed through grain boundary segregation. We find that (i) Fe atoms occupy the substitutional sites at the grain boundary and form an Fe-Si atomic line, but the interaction between the Fe atoms is antiferromagnetic. (ii) The ferromagnetic stability increases with the atomic number of the transition metals and Co-Si atomic line is more stable in the ferromagnetic phase and shows a semimetallic behavior. We suggest that this special TM-Si atomic line formed by thermodynamically favorable transition metal segregation on Si grain boundary could be used in design of spin-dependent quantum devices.

  12. RELATIVISTIC CALCULATION OF TRANSITION PROBABILITIES FOR 557.7 nm AND 297.2 nm EMISSION LINES IN OXYGEN

    SciTech Connect

    Chantler, C. T.; Nguyen, T. V. B.; Lowe, J. A.; Grant, I. P.

    2013-05-20

    The 557.7 nm green line and the 297.2 nm ultraviolet line in oxygen have been studied extensively due to their importance in astrophysics and atmospheric science. Despite the enormous effort devoted to these two prominent transition lines over 30 years, and in fact going back to 1934, the ratio of their transition probabilities remains a subject of major discrepancies amongst various theoretical calculations for many decades. Moreover, theoretical results are inconsistent with available laboratory results, as well as recent spacecraft measurements of Earth's airglow. This work presents new relativistic theoretical calculations of the transition probabilities of these two photoemission lines from neutral oxygen using the multi-configuration Dirac-Hartree-Fock method. Our calculations were performed in both length and velocity gauges in order to check for accuracy and consistency, with agreement to 8%. Whilst remaining a challenging computation, these results directly bear upon interpretations of plasma processes and ionization regimes in the universe.

  13. Alkali metal atoms in strong magnetic fields: "Guiding" atomic transitions foretell the characteristics of all transitions of the D1 line

    NASA Astrophysics Data System (ADS)

    Sargsyan, A.; Hakhumyan, G.; Papoyan, A.; Sarkisyan, D.

    2015-03-01

    It has been shown that the D1 line of atomic vapors of alkali metals excited by π-polarized radiation in a strong transverse magnetic field includes specific "guiding" (indicating) atomic transitions between the magnetic sublevels of the hyperfine structure. The dependence of the frequency shift of the guiding transitions on the magnetic field, as well as on their dipole moments, is asymptotic for all other transitions. An experiment with a nanocell with Rb vapor with a thickness of half the wavelength (λ/2 method) for ensuring a sub-Doppler spectral resolution has completely confirmed the presence of guiding transitions. Two groups of six transitions for 85Rb and two groups of four transitions for 87Rb have been detected in the absorption spectra in magnetic fields above 4 kG. A guiding transition has been identified in each of four groups. Four transitions forbidden at B = 0 have been also detected; with an increase in the magnetic field, their probabilities also approach the probabilities of the guiding transitions.

  14. Determination of nitrogen to carbon abundance ratios from transition layer emission lines

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1992-01-01

    We have finished studying the nitrogen to carbon abundance ratios for stars with different effective temperatures T(sub eff) and luminosities using transition layer emission lines and using spectra available in the IUE archives. The N/C abundance ratio determinations using transition layer emission lines are as accurate as the photospheric abundance determinations as found by comparison of results obtained by both methods for the same stars. Our measurements confirm photospheric abundance determinations in regions of the HR diagram where they can be obtained. Our studies have extended the temperature range to higher temperatures. They have shown the exact positions in the HR diagram where the mixing due to the outer convection zones reaches deep enough to bring nuclear processed material to the surface. This occurs at effective temperatures which are higher by delta log T(sub eff) approximately 0.04 or roughly 400 K than expected theoretically. Since the depth of the convection zone increases rapidly with decreasing T(sub eff) this may indicate considerable overshoot beyond the lower boundary of the convection zone. Our N/C abundance ratio determinations from transition layer emission lines have confirmed that the actual enrichment observed for some cool giants is larger than expected theoretically, again indicating a larger degree of mixing in several stars either from below or from above. For the supergiants it probably indicates overshoot above the convective core in the progenitor main sequence stars. For the more massive giants this may also be the case, though we did not find a correlation between delta log N/C and the absolute magnitudes, but these are rather uncertain. As byproducts of these studies we also found anomalies in Si/C and N/C abundance ratios for F giants which can be understood as the relict of surface abundance changes for their main sequence progenitors due to diffusion. This anomaly disappears for G giants, for which the depths of the

  15. Measurement of the transition probability of the C III 190.9 nanometer intersystem line

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.; Fang, Z.; Gibbons, T. T.; Parkinson, W. H.; Smith, Peter L.

    1993-01-01

    A radio-frequency ion trap has been used to store C(2+) ions created by electron bombardment of CO. The transition probability for the 2s2p 3Po1-2s2 1S0 intersystem line of C m has been measured by recording the radiative decay at 190.9 nm. The measured A-value is 121 +/- 7/s and agrees, within mutual uncertainty limits, with that of Laughlin et al. (1978), but is 20 percent larger than that of Nussbaumer and Storey (1978). The effective collision mixing rate coefficient among the fine structure levels of 3Po and the combined quenching and charge transfer rate coefficients out of the 3Po1 level with the CO source gas have also been measured.

  16. Observed heights of EUV lines formed in the transition zone and corona.

    NASA Technical Reports Server (NTRS)

    Simon, G. W.; Noyes, R. W.

    1972-01-01

    The heights of formation of a number of extreme ultraviolet lines in active regions have been measured from OSO-IV spectroheliograms. Using the Lyman continuum at 2000 km above the white light limb as a reference, we find heights for He I, He II, C III, N III, O IV, O VI, Ne VIII, Mg X, Si XII, Fe XV and Fe XVI that are in approximate agreement with models based on analysis of EUV emission intensities. The height of C II is anomalously high. The accuracy of measurement is typically about 2000 km. The data suggest that the transition zone is less steep than calculated from EUV emission intensities; however, higher resolution observations are necessary to resolve the discrepancy.

  17. Phase transitions in a reaction-diffusion model on a line with boundaries

    SciTech Connect

    Khorrami, Mohammad Aghamohammadi, Amir

    2014-03-15

    A one-dimensional model on a line of length L is investigated, which involves particle diffusion as well as single particle annihilation. There are also creation and annihilation at the boundaries. The static and dynamical behaviors of the system are studied. It is seen that the system could exhibit a dynamical phase transition. For small drift velocities, the relaxation time does not depend on the absorption rates at the boundaries. This is the fast phase. For large velocities, the smaller of the absorption rates at boundaries enter the relaxation rate and makes it longer. This is the slow phase. Finally, the effect of a random particle creation in the bulk is also investigated.

  18. Measurement of the transition probability of the C III 190.9 nanometer intersystem line

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.; Fang, Z.; Gibbons, T. T.; Parkinson, W. H.; Smith, Peter L.

    1993-01-01

    A radio-frequency ion trap has been used to store C(2+) ions created by electron bombardment of CO. The transition probability for the 2s2p 3Po1-2s2 1S0 intersystem line of C m has been measured by recording the radiative decay at 190.9 nm. The measured A-value is 121 +/- 7/s and agrees, within mutual uncertainty limits, with that of Laughlin et al. (1978), but is 20 percent larger than that of Nussbaumer and Storey (1978). The effective collision mixing rate coefficient among the fine structure levels of 3Po and the combined quenching and charge transfer rate coefficients out of the 3Po1 level with the CO source gas have also been measured.

  19. Brazil nut effect: Influence of friction and jamming on the transition line

    NASA Astrophysics Data System (ADS)

    Cordero, P.; Godoy, S.; Risso, D.; Soto, R.

    2009-01-01

    We report a molecular dynamics study of the behavior of a bidimensional system consisting of a large disk (the intruder) immersed in a bed of many small disks. All collisions are instantaneous and inelastic and all possible parameters of the system are kept fixed except for two dimensionless parameters determining the frequency and amplitude of the vibrating base. A systematic exploration of this parameter space leads to determining a transition line separating a zone in which the Brazil nut effect is observed and one in which it is not. It is observed for the BNE to be present it is necessary that the characteristic velocity of the vibrating base is above a certain threshold. This threshold increases as the characteristic acceleration of the base gets larger. The results strongly suggest that, in the region of the parameter space in which the study is made, there is a minimum amplitude and a maximum frequency for the Brazil nut effect to take place. The shape of the transition line is understood in connection with the friction of the system with the lateral walls and with jamming. Friction with the lateral walls produces a net downward force, eventually leading to a convective current that pushes the intruder up. Although the energy injection rate, that helps the development of the convective current, is proportional mainly to the square of the velocity of the base, it is found that the average frictional force decreases when increasing the base acceleration. Therefore, for large base accelerations, higher values of the base velocity are needed to produce a convective current sufficiently strong. But if the system is not excited enough the friction which would produced convective currents are balanced by the reaction forces that result from jamming.

  20. Line nodes, Dirac points, and Lifshitz transition in two-dimensional nonsymmorphic photonic crystals

    NASA Astrophysics Data System (ADS)

    Lin, Jun Yu; Hu, Nai Chao; Chen, You Jian; Lee, Ching Hua; Zhang, Xiao

    2017-08-01

    Topological phase transitions, which have fascinated generations of physicists, are always demarcated by gap closures. In this work, we propose very simple two-dimensional photonic crystal lattices with gap closures, i.e., band degeneracies protected by nonsymmorphic symmetry. Our photonic structures are relatively easy to fabricate, consisting of two inequivalent dielectric cylinders per unit cell. Along high-symmetry directions, they exhibit line degeneracies protected by glide-reflection symmetry and time-reversal symmetry, which we explicitly demonstrate for p g ,p m g ,p g g , and p 4 g nonsymmorphic groups. They also exhibit point degeneracies (Dirac points) protected by a Z2 topological number associated only with crystalline symmetry. Strikingly, the robust protection of p g symmetry allows a Lifshitz transition to a type-II Dirac cone across a wide range of experimentally accessible parameters, thus providing a convenient route for realizing anomalous refraction. Further potential applications include a stoplight device based on electrically induced strain that dynamically switches the lattice symmetry from p g g to the higher p 4 g symmetry. This controls the coalescence of Dirac points and hence the group velocity within the crystal.

  1. EVIDENCE OF POSSIBLE SPIN-ORBIT MISALIGNMENT ALONG THE LINE OF SIGHT IN TRANSITING EXOPLANET SYSTEMS

    SciTech Connect

    Schlaufman, Kevin C.

    2010-08-10

    Of the 26 transiting exoplanet systems with measurements of the Rossiter-McLaughlin (RM) effect, eight have now been found to be significantly spin-orbit misaligned in the plane of the sky (i.e., RM misalignment angle |{lambda}| {approx}> 30{sup 0} and inconsistent with {lambda} = 0{sup 0}). Unfortunately, the RM effect does not constrain the complement misalignment angle between the orbit of the planet and the spin of its host star along the line of sight (LOS). I use a simple model of stellar rotation benchmarked with observational data to statistically identify 10 exoplanet systems from a sample of 75 for which there is likely a significant degree of spin-orbit misalignment along the LOS: HAT-P-7, HAT-P-14, HAT-P-16, HD 17156, Kepler-5, Kepler-7, TrES-4, WASP-1, WASP-12, and WASP-14. All 10 systems have host stellar masses M {sub *} in the range 1.2 M {sub sun} {approx}< M {sub *} {approx}< 1.5 M {sub sun}, and the probability of this occurrence by chance is less than one in ten thousand. In addition, the planets in the candidate-misaligned systems are preferentially massive and eccentric. The coupled distribution of misalignment from the RM effect and from this analysis suggests that transiting exoplanets are more likely to be spin-orbit aligned than expected given predictions for a transiting planet population produced entirely by planet-planet scattering or Kozai cycles and tidal friction. For that reason, there are likely two populations of close-in exoplanet systems: a population of aligned systems and a population of apparently misaligned systems in which the processes that lead to misalignment or to the survival of misaligned systems operate more efficiently in systems with massive stars and planets.

  2. Evidence of Possible Spin-orbit Misalignment Along the Line of Sight in Transiting Exoplanet Systems

    NASA Astrophysics Data System (ADS)

    Schlaufman, Kevin C.

    2010-08-01

    Of the 26 transiting exoplanet systems with measurements of the Rossiter-McLaughlin (RM) effect, eight have now been found to be significantly spin-orbit misaligned in the plane of the sky (i.e., RM misalignment angle |λ| >~ 30° and inconsistent with λ = 0°). Unfortunately, the RM effect does not constrain the complement misalignment angle between the orbit of the planet and the spin of its host star along the line of sight (LOS). I use a simple model of stellar rotation benchmarked with observational data to statistically identify 10 exoplanet systems from a sample of 75 for which there is likely a significant degree of spin-orbit misalignment along the LOS: HAT-P-7, HAT-P-14, HAT-P-16, HD 17156, Kepler-5, Kepler-7, TrES-4, WASP-1, WASP-12, and WASP-14. All 10 systems have host stellar masses M * in the range 1.2 M sun <~ M * <~ 1.5 M sun, and the probability of this occurrence by chance is less than one in ten thousand. In addition, the planets in the candidate-misaligned systems are preferentially massive and eccentric. The coupled distribution of misalignment from the RM effect and from this analysis suggests that transiting exoplanets are more likely to be spin-orbit aligned than expected given predictions for a transiting planet population produced entirely by planet-planet scattering or Kozai cycles and tidal friction. For that reason, there are likely two populations of close-in exoplanet systems: a population of aligned systems and a population of apparently misaligned systems in which the processes that lead to misalignment or to the survival of misaligned systems operate more efficiently in systems with massive stars and planets.

  3. P300 promotes migration, invasion and epithelial-mesenchymal transition in a nasopharyngeal carcinoma cell line

    PubMed Central

    Liao, Zhi-Wei; Zhao, Lei; Cai, Mu-Yan; Xi, Mian; He, Li-Ru; Yu, Fang; Zhou, Tong-Chong; Liu, Meng-Zhong

    2017-01-01

    A previous study demonstrated that p300 is overexpressed in nasopharyngeal carcinoma (NPC), and that its expression is an independent prognostic factor. The aim of the present study is to investigate the role of p300 in human NPC development. A small hairpin (sh) RNA lentiviral expression vector targeting the p300 gene was constructed to suppress the expression of p300 in NPC cells. Knockdown of p300 was verified by reverse transcription-quantitative polymerase chain reaction and western blotting. Wound-healing, invasion, immunofluorescence and immunoprecipitation assays were performed to assess the influence of p300 on nasopharyngeal tumorigenesis and metastasis in vitro. The expression of p300 was upregulated in NPC cell lines. After knockdown of p300, the migration and invasion ability of shp300 cells were significantly inhibited (P<0.05). Furthermore, the depletion of p300 expression in NPC cell lines resulted in the upregulation of epithelial phenotype marker E-cadherin and α-catenin, and downregulation of mesenchymal phenotype markers N-cadherin and vimentin. p300 promotes epithelial-mesenchymal transition (EMT) through the acetylation of Smad2 and Smad3 in the tumor growth factor-β signaling pathway. In conclusion, p300 may be involved in the invasion and metastasis of NPC through the induction of EMT. PMID:28356956

  4. Nonperturbative landscape of the Mott-Hubbard transition: Multiple divergence lines around the critical endpoint

    NASA Astrophysics Data System (ADS)

    Schäfer, T.; Ciuchi, S.; Wallerberger, M.; Thunström, P.; Gunnarsson, O.; Sangiovanni, G.; Rohringer, G.; Toschi, A.

    2016-12-01

    We analyze the highly nonperturbative regime surrounding the Mott-Hubbard metal-to-insulator transition (MIT) by means of dynamical mean field theory (DMFT) calculations at the two-particle level. By extending the results of Schäfer et al. [Phys. Rev. Lett. 110, 246405 (2013), 10.1103/PhysRevLett.110.246405] we show the existence of infinitely many lines in the phase diagram of the Hubbard model where the local Bethe-Salpeter equations, and the related irreducible vertex functions, become singular in the charge as well as the particle-particle channel. By comparing our numerical data for the Hubbard model with analytical calculations for exactly solvable systems of increasing complexity [disordered binary mixture (BM), Falicov-Kimball (FK), and atomic limit (AL)], we have (i) identified two different kinds of divergence lines; (ii) classified them in terms of the frequency structure of the associated singular eigenvectors; and (iii) investigated their relation to the emergence of multiple branches in the Luttinger-Ward functional. In this way, we could distinguish the situations where the multiple divergences simply reflect the emergence of an underlying, single energy scale ν* below which perturbation theory is no longer applicable, from those where the breakdown of perturbation theory affects, not trivially, different energy regimes. Finally, we discuss the implications of our results on the theoretical understanding of the nonperturbative physics around the MIT and for future developments of many-body algorithms applicable in this regime.

  5. Size-Induced Depression of First-Order Transition Lines and Entropy Jump in Extremely Layered Nanocrystalline Vortex Matter

    NASA Astrophysics Data System (ADS)

    Dolz, M. I.; Fasano, Y.; Cejas Bolecek, N. R.; Pastoriza, H.; Mosser, V.; Li, M.; Konczykowski, M.

    2015-09-01

    We detect the persistence of the solidification and order-disorder first-order transition lines in the phase diagram of nanocrystalline Bi2 Sr2 CaCu2 O8 vortex matter down to a system size of less than one hundred vortices. The temperature location of the vortex solidification transition line is not altered by decreasing the sample size although there is a depletion of the entropy jump at the transition with respect to macroscopic vortex matter. The solid order-disorder phase transition field moves upward on decreasing the system size due to the increase of the surface-to-volume ratio of vortices entailing a decrease on the average vortex binding energy.

  6. Size-Induced Depression of First-Order Transition Lines and Entropy Jump in Extremely Layered Nanocrystalline Vortex Matter.

    PubMed

    Dolz, M I; Fasano, Y; Cejas Bolecek, N R; Pastoriza, H; Mosser, V; Li, M; Konczykowski, M

    2015-09-25

    We detect the persistence of the solidification and order-disorder first-order transition lines in the phase diagram of nanocrystalline Bi_{2}Sr_{2}CaCu_{2}O_{8} vortex matter down to a system size of less than one hundred vortices. The temperature location of the vortex solidification transition line is not altered by decreasing the sample size although there is a depletion of the entropy jump at the transition with respect to macroscopic vortex matter. The solid order-disorder phase transition field moves upward on decreasing the system size due to the increase of the surface-to-volume ratio of vortices entailing a decrease on the average vortex binding energy.

  7. Transition of MHD kink-stability properties between line-tied and non-line-tied boundary conditions.

    PubMed

    Sun, X; Intrator, T P; Dorf, L; Furno, I; Lapenta, G

    2008-05-23

    Magnetic flux tubes or flux ropes in plasmas are important in nature and the laboratory. Axial boundary conditions strongly affect flux rope behavior, but this has never been systematically investigated. We experimentally demonstrate for the first time axial boundary conditions that are continuously varied between ideal magnetohydrodynamic (MHD) line-tied (fixed) and non-line-tied (free). In contrast with the usual interpretation that mechanical plasma motion is MHD line-tied to a conducting boundary, we constrain boundary plasma motion to cause the line-tied condition.

  8. The Ion Line Stark Parameters Dependence on the Emitter Rest Core Charge and the Electron Temperature within Ns-Np Transition Arrays

    SciTech Connect

    Scepanovic, Mara; Puric, Jagos

    2007-04-23

    Recently published Stark widths and shifts measured and calculated data and their dependence on the upper level ionization potential {chi} are used here to demonstrate the existence of the other kinds of reularities within similar spectra of different elements and their ionization stage. The emphasis is on the Stark parameter dependence on the rest core charge and the electron temperatures for the lines from similar spectra. The found relations connecting Stark broadening and shift parameters and upper level ionization potential, rest core charge and electron temperature were used for a prediction of new Stark broadening data, avoiding much more comlicated procedures. For opacity calculations and investigation of stellar atmosphere, when a large number of line broadening data was required, present investigation are useful in enlarging the number of required data. This field of research remains largely open to other demonstrations of regularities and similarities, as long as one can relate the same kind of spectroscopic transition. Also, the attained dependencies can be used as an additional criteria for checking accuracy of the particular theoretical and experimental data from diferent sources.

  9. Key contributors for improvement of line width roughness, line edge roughness, and critical dimension uniformity: 15 nm half-pitch patterning with extreme ultraviolet and self-aligned double patterning

    NASA Astrophysics Data System (ADS)

    Xu, Kaidong; Souriau, Laurent; Hellin, David; Versluijs, Janko; Wong, Patrick; Vangoidsenhoven, Diziana; Vandenbroeck, Nadia; Dekkers, Harold; Shi, Xiaoping; Albert, Johan; Tan, Chi Lim; Vertommen, Johan; Coenegrachts, Bart; Orain, Isabelle; Kimura, Yoshie; Wiaux, Vincent; Boullart, Werner

    2013-10-01

    The approach for patterning 15-nm half-pitch (HP) structures using extreme ultraviolet lithography combined with self-aligned double patterning is discussed. A stack composed of a double hard mask, which allows decoupling photoresist transfer and trim, and an α-Si mandrel, which offers better mechanical properties during the mandrel and spacer patterning, is proposed. A break-down study with the patterning steps was performed to investigate the key contributors for improvement of linewidth roughness (LWR), line-edge roughness (LER), and critical dimension uniformity (CDU), targeting integrated solutions with lithography, etch, thin film deposition, and wet cleans for selected applications. Based on the optimization of these key patterning contributors, optimum LWR, LER, and CDU at 15 nm HP are demonstrated.

  10. Photoinduced topological phase transition from a crossing-line nodal semimetal to a multiple-Weyl semimetal

    NASA Astrophysics Data System (ADS)

    Ezawa, Motohiko

    2017-07-01

    We propose a simple scheme to construct a model whose Fermi surface is comprised of crossing-line nodes. The Hamiltonian consists of a normal hopping term and an additional term which is odd under the mirror reflection. The line nodes appear along the mirror-invariant planes, where each line node carries the quantized Berry magnetic flux. We explicitly construct a model with the N -fold rotational symmetry, where the 2 N line nodes merge at the north and south poles. When we apply photoirradiation along the kz axis, there emerge point nodes carrying the monopole charge ±N at these poles, while all the line nodes disappear. In this model, photoirradiation induces a topological phase transition from a crossing-line nodal semimetal to a multiple-Weyl semimetal, where the surface state turns from a drumhead state into a Fermi-arc state.

  11. DISCOVERY OF THE TRANSITION OF A MINI-BROAD ABSORPTION LINE INTO A BROAD ABSORPTION LINE IN THE SDSS QUASAR J115122.14+020426.3

    SciTech Connect

    Hidalgo, Paola Rodriguez; Eracleous, Michael; Charlton, Jane; Hamann, Fred; Murphy, Michael T.; Nestor, Daniel

    2013-09-20

    We present the detection of a rare case of dramatic strengthening in the UV absorption profiles in the spectrum of the quasar J115122.14+020426.3 between observations {approx}2.86 yr apart in the quasar rest frame. A spectrum obtained in 2001 by the Sloan Digital Sky Survey shows a C IV ''mini-broad'' absorption line (FWHM = 1220 km s{sup -1}) with a maximum blueshift velocity of {approx}9520 km s{sup -1}, while a later spectrum from the Very Large Telescope shows a significantly broader and stronger absorption line, with a maximum blueshift velocity of {approx}12, 240 km s{sup -1} that qualifies as a broad absorption line. A similar variability pattern is observed in two additional systems at lower blueshifted velocities and in the Ly{alpha} and N V transitions as well. One of the absorption systems appears to be resolved and shows evidence for partial covering of the quasar continuum source (C{sub f} {approx} 0.65), indicating a transverse absorber size of, at least, {approx}6 Multiplication-Sign 10{sup 16} cm. In contrast, a cluster of narrower C IV lines appears to originate in gas that fully covers the continuum and broad emission line sources. There is no evidence for changes in the centroid velocity of the absorption troughs. This case suggests that at least some of the absorbers that produce ''mini-broad'' and broad absorption lines in quasar spectra do not belong to intrinsically separate classes. Here, the ''mini-broad'' absorption line is most likely interpreted as an intermediate phase before the appearance of a broad absorption line due to their similar velocities. While the current observations do not provide enough constraints to discern among the possible causes for this variability, future monitoring of multiple transitions at high resolution will help achieve this goal.

  12. Transitions.

    ERIC Educational Resources Information Center

    Agnew, Jeanne L.; Choike, James R.

    1987-01-01

    Mathematical observations are made about some continuous curves, called transitions, encountered in well-known experiences. The transition parabola, the transition spiral, and the sidestep maneuver are presented. (MNS)

  13. Synthesized Spectra of Optically Thin Emission Lines

    NASA Astrophysics Data System (ADS)

    Olluri, K.; Gudiksen, B. V.; Hansteen, V. H.; De Pontieu, B.

    2015-03-01

    In recent years realistic 3D numerical models of the solar atmosphere have become available. The models attempt to recreate the solar atmosphere and mimic observations in the best way, in order to make it possible to couple complicated observations with physical properties such as the temperatures, densities, velocities, and magnetic fields. We here present a study of synthetic spectra created using the Bifrost code in order to assess how well they fit with previously taken solar data. A study of the synthetic intensity, nonthermal line widths, Doppler shifts, and correlations between any two of these three components of the spectra first assuming statistical equilibrium is made, followed by a report on some of the effects nonequilibrium ionization will have on the synthesized spectra. We find that the synthetic intensities compare well with the observations. The synthetic observations depend on the assumed resolution and point-spread function (PSF) of the instrument, and we find a large effect on the results, especially for intensity and nonthermal line width. The Doppler shifts produce the reported persistent redshifts for the transition region (TR) lines and blueshifts for the upper TR and corona lines. The nonthermal line widths reproduce the well-known turnoff point around (2-3) × 105 K, but with much lower values than those observed. The nonthermal line widths tend to increase with decreasing assumed instrumental resolution, also when nonequilibrium ionization is included. Correlations between the nonthermal line width of any two TR line studies as reported by Chae et al. are reproduced, while the correlations of intensity to line width are reproduced only after applying a PSF to the data. Doppler shift correlations reported by Doschek for the TR lines and correlations of Doppler shift to nonthermal line width of the Fe xii 19.5 line reported by Doschek et al. are reproduced.

  14. Laser-induced line-narrowing effects in coupled Doppler-broadened transitions. II - Standing-wave features.

    NASA Technical Reports Server (NTRS)

    Feldman, B. J.; Feld, M. S.

    1972-01-01

    Previous theoretical results on the influence of a laser on the line shape of a coupled transition (laser-induced line narrowing) have been restricted to the case where the laser is detuned from the center of its atomic gain profile or is in the form of a traveling wave. The present paper extends these results to the case where the laser is an intense standing-wave field tunable to the center of its atomic gain profile (conditions for Lamb dip). A theoretical solution of the problem is developed, and a detailed discussion of line shapes and physical processes involved is included.

  15. Spectroscopic cell for fast pressure jumps across the glass transition line

    NASA Astrophysics Data System (ADS)

    Di Leonardo, R.; Scopigno, T.; Ruocco, G.; Buontempo, U.

    2004-08-01

    We present an experimental protocol for the spectroscopic study of the dynamics of glasses in the aging regime induced by sudden pressure jumps (crunches) across the glass transition line. The sample, initially in the liquid state, is suddenly brought in the glassy state, and therefore out of equilibrium, in a four-window optical crunch cell which is able to perform pressure jumps of 3 Kbar in a time interval of ≈10 ms. The main advantages of this setup with respect to previous pressure-jump systems is that the pressure jump is induced through a pressure transmitting fluid mechanically coupled to the sample stage through a deformable membrane, thus avoiding any flow of the sample itself in the pressure network and allowing us to deal with highly viscous materials. The dynamics of the sample during the aging regime is investigated by Brillouin light scattering. For this purpose the crunch cell is used in conjunction with a high resolution double monochromator equipped with a charge-coupled device detector. This system is able to record a full spectrum of a typical glass forming material in a single 1 s shot. As an example we present the study of the evolution toward equilibrium of the infinite frequency longitudinal elastic modulus (M∞) of low molecular weight polymer [Poly(bisphenol A-co-epichlorohydrin), glycidyl end capped]. The observed time evolution of M∞, well represented by a single stretched exponential, is interpreted within the framework of the Tool-Narayanaswamy theory.

  16. Mogoltacin enhances vincristine cytotoxicity in human transitional cell carcinoma (TCC) cell line.

    PubMed

    Behnam Rassouli, F; Matin, M M; Iranshahi, M; Bahrami, A R; Neshati, V; Mollazadeh, S; Neshati, Z

    2009-03-01

    Bladder cancer is the second common cancer of the genitourinary system throughout the world and intravesical chemotherapy is usually used to reduce tumour recurrence and progression. Human transitional cell carcinoma (TCC) is an epithelial-like adherent cell line originally established from primary bladder carcinoma. Here we report the effect of mogoltacin, a sesquiterpene coumarin from Ferula badrakema on TCC cells. Mogoltacin was isolated from the fruits of F. badrakema, using silica gel column chromatography and preparative thin layer chromatography. Mogoltacin did not have any significant cytotoxicity effect on neoplastic TCC cells at 16, 32, 64, 128, 200 and 600 microg ml(-1) concentrations. In order to analyse its combination effect, TCC cells were cultured in the presence of various combining concentrations of mogoltacin and vincristine. Cells were then observed for morphological changes (by light microscopy) and cytotoxicity using MTT assay. The effect of mogoltacin on vincristine toxicity was studied after 24, 48 and 72 h of drug administration. The results of MTT assay showed that mogoltacin can significantly enhance the cytotoxicity of vincristine and confirmed the morphological observations. Results revealed that combination of 40 microg ml(-1) vincristine with 16 microg ml(-1) mogoltacin increased the cytotoxicity of vincristine after 48 h by 32.8%.

  17. Second-order quadrupolar line shapes under molecular dynamics: An additional transition in the extremely fast regime.

    PubMed

    Hung, Ivan; Wu, Gang; Gan, Zhehong

    2016-12-10

    NMR spectroscopy is a powerful tool for probing molecular dynamics. For the classic case of two-site exchange, NMR spectra go through the transition from exchange broadening through coalescence and then motional narrowing as the exchange rate increases passing through the difference between the resonance frequencies of the two sites. For central-transition spectra of half-integer quadrupolar nuclei in solids, line shape change due to molecular dynamics occurs in two stages. The first stage occurs when the exchange rate is comparable to the second-order quadrupolar interaction. The second spectral transition comes at a faster exchange rate which approaches the Larmor frequency and generally reduces the isotropic quadrupolar shift. Such a two-stage transition phenomenon is unique to half-integer quadrupolar nuclei. A quantum mechanical formalism in full Liouville space is presented to explain the physical origin of the two-stage phenomenon and for use in spectral simulations. Variable-temperature (17)O NMR of solid NaNO3 in which the NO3(-) ion undergoes 3-fold jumps confirms the two-stage transition process. The spectra of NaNO3 acquired in the temperature range of 173-413K agree well with simulations using the quantum mechanical formalism. The rate constants for the 3-fold NO3(-) ion jumps span eight orders of magnitude (10(2)-10(10)s(-1)) covering both transitions of the dynamic (17)O line shape.

  18. Instability and Transition of Flow at, and Near, an Attachment-line - Including Control by Surface Suction

    NASA Technical Reports Server (NTRS)

    Smith, A.

    1996-01-01

    Advances in aviation during and following the Second World War led to an enormous improvement in the performance of aircraft. The push for enhanced efficiency brought cruise speeds into the transonic range, where the associated drag rise due to the appearance of shock-waves became a limiting factor. Wing sweep was adopted to delay the onset of this drag rise, but with this development came several new and unforeseen problems. Preliminary theoretical work assumed that the boundary layer transition characteristics of a swept wing would be subject to the independence principle, so the chordwise transition position could be predicted from two-dimensional work Gas turbine development has now reached a point where additional increases in efficiency are both difficult and expensive to achieve. Consequently, aircraft manufacturers are looking elsewhere for ways to reduce Direct Operating Costs (DOC's) or increase military performance. The attention of industry is currently focusing on Hybrid Laminar Flow Control (HLFC) as a possible method of reducing DOC's for civil aircraft. Following this study and discussions with NASA Langley and Boeing a different series of questions have been addressed in the present work. There are five areas of interest: Relaminarisation of the attachment-line boundary layer when the value of R exceeds 600. The effects of large suction levels on transition in the attachment-line boundary layer (ie critical oversuction). The transition characteristics of a relaminarised attachment-line flow which encounters a non-porous surface. The effect of attachment-line suction on the spanwise propagation of gross disturbances emanating from the wing-fuselage junction. The attachment-line transition caused by surface blowing.

  19. Transitions.

    ERIC Educational Resources Information Center

    Nathanson, Jeanne H., Ed.

    1993-01-01

    This theme issue on transitions for individuals with disabilities contains nine papers discussing transition programs and issues. "Transition Issues for the 1990s," by Michael J. Ward and William D. Halloran, discusses self-determination, school responsibility for transition, continued educational engagement of at-risk students, and service…

  20. Experimental demonstration of a Ku-band radial-line relativistic klystron oscillator based on transition radiation

    NASA Astrophysics Data System (ADS)

    Dang, Fangchao; Zhang, Xiaoping; Zhang, Jun; Ju, Jinchuan; Zhong, Huihuang

    2017-03-01

    We report on a radial-line relativistic klystron oscillator (RL-RKO), which is physically designed to generate gigawatt-level high power microwaves (HPMs) at Ku-band. The 3π/4 mode of a four-gap buncher is selected to highly modulate the radially propagating intense relativistic electron beam (IREB). A three-gap extractor operating at the π mode is employed to extract the radio-frequency energy efficiently. The Ku-band RL-RKO is investigated experimentally on an intense-current electron beam accelerator. The radially propagating IREB is well focused with an axial-width of 2 mm by a radial magnetic field of 0.4 T. Microwaves with a frequency of 14.86 GHz and a power of 1.5 GW are generated, corresponding to an efficiency of 24%, which indicates a significant advance for the research of radial-line HPM sources.

  1. Equivalent Widths in the Spectrum of Sirius

    NASA Astrophysics Data System (ADS)

    Zhao, G.; Qiu, H. M.; Chen, Y. Q.; Li, Z. W.

    2000-02-01

    The equivalent widths of total 546 lines (26 elements are included) in the spectrum of the bright Am star Sirius from 380 to 930 nm are tabulated. The high-resolution, high signal-to-noise ratio spectrum was obtained with the Coudé Echelle Spectrograph attached to the 2.16 m telescope at Beijing Astronomical Observatory (Xinglong, China). Here we also give the results of the equivalent widths comparison between our measurements and those of Strom et al. and Sadakane & Ueta.

  2. Width of nonlinear resonance

    SciTech Connect

    Ohnuma, S.

    1984-03-01

    Two approximations are made, one essential and the other not so essential but convenient to keep the analytical treatment manageable: (1) Only one nonlinear resonance is considered at a time so that the treatment is best suited when the tune is close to one resonance only. To improve this approximation, one must go to the next order which involves a canonical transformation of dynamical variables. Analytical treatment of more than one resonance is not possible for general cases. (2) In the formalism using the action-angle variables, the Hamiltonian can have terms which are independent of the angle variables. These terms are called phase-independent terms or shear terms. The tune is then a function of the oscillation amplitudes. In the lowest-order treatment, the (4N)-pole components but not the (4N + 2)-pole components contribute to this dependence. In deriving the resonance width analytically, one ignores these terms in the Hamiltonian for the sake of simplicity. If these are retained, one needs at least three extra parameters and the analytical treatment becomes rather unwieldy.

  3. The K x-ray line structures of the 3d-transition metals in warm dense plasma

    NASA Astrophysics Data System (ADS)

    Szymańska, E.; Syrocki, Ł.; Słabkowska, K.; Polasik, M.; Rzadkiewicz, J.

    2016-09-01

    The shapes and positions of the Kα1 and Kα2 x-ray lines for 3d-transition metals can vary substantially as electrons are stripped from the outer-shells. This paper shows the detailed line shapes for nickel and zinc, obtained by calculations with a multiconfiguration Dirac-Fock method that includes Breit interaction and quantum electrodynamics corrections. The line shapes can be useful in interpreting hot, dense plasmas with energetic electrons for which the K x-ray lines are optically thin, as may be produced by pulsed power machines such as the plasma-filled rod pinch diode or the plasma focus, or in short-pulsed high power laser plasmas.

  4. ACCURATE ESTIMATIONS OF STELLAR AND INTERSTELLAR TRANSITION LINES OF TRIPLY IONIZED GERMANIUM

    SciTech Connect

    Dutta, Narendra Nath; Majumder, Sonjoy E-mail: sonjoy@gmail.com

    2011-08-10

    In this paper, we report on weighted oscillator strengths of E1 transitions and transition probabilities of E2 transitions among different low-lying states of triply ionized germanium using highly correlated relativistic coupled cluster (RCC) method. Due to the abundance of Ge IV in the solar system, planetary nebulae, white dwarf stars, etc., the study of such transitions is important from an astrophysical point of view. The weighted oscillator strengths of E1 transitions are presented in length and velocity gauge forms to check the accuracy of the calculations. We find excellent agreement between calculated and experimental excitation energies. Oscillator strengths of few transitions, wherever studied in the literature via other theoretical and experimental approaches, are compared with our RCC calculations.

  5. Transitions.

    ERIC Educational Resources Information Center

    Field, David; And Others

    1992-01-01

    Includes four articles: "Career Aspirations" (Field); "Making the Transition to a New Curriculum" (Baker, Householder); "How about a 'Work to School' Transition?" (Glasberg); and "Technological Improvisation: Bringing CNC to Woodworking" (Charles, McDuffie). (SK)

  6. WHY IS NON-THERMAL LINE BROADENING OF SPECTRAL LINES IN THE LOWER TRANSITION REGION OF THE SUN INDEPENDENT OF SPATIAL RESOLUTION?

    SciTech Connect

    De Pontieu, B.; Martinez-Sykora, J.; McIntosh, S.; Peter, H.; Pereira, T. M. D.

    2015-01-20

    Spectral observations of the solar transition region (TR) and corona show broadening of spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant (5–30 km s{sup −1}) and correlated with intensity. Here we study spectra of the TR Si iv 1403 Å line obtained at high resolution with the Interface Region Imaging Spectrograph (IRIS). We find that the large improvement in spatial resolution (0.″33) of IRIS compared to previous spectrographs (2″) does not resolve the non-thermal line broadening which, in most regions, remains at pre-IRIS levels of about 20 km s{sup −1}. This invariance to spatial resolution indicates that the processes behind the broadening occur along the line-of-sight (LOS) and/or on spatial scales (perpendicular to the LOS) smaller than 250 km. Both effects appear to play a role. Comparison with IRIS chromospheric observations shows that, in regions where the LOS is more parallel to the field, magneto-acoustic shocks driven from below impact the TR and can lead to significant non-thermal line broadening. This scenario is supported by MHD simulations. While these do not show enough non-thermal line broadening, they do reproduce the long-known puzzling correlation between non-thermal line broadening and intensity. This correlation is caused by the shocks, but only if non-equilibrium ionization is taken into account. In regions where the LOS is more perpendicular to the field, the prevalence of small-scale twist is likely to play a significant role in explaining the invariance and correlation with intensity. (letters)

  7. Why is Non-Thermal Line Broadening of Spectral Lines in the Lower Transition Region of the Sun Independent of Spatial Resolution?

    NASA Astrophysics Data System (ADS)

    De Pontieu, B.; McIntosh, S.; Martinez-Sykora, J.; Peter, H.; Pereira, T. M. D.

    2015-01-01

    Spectral observations of the solar transition region (TR) and corona show broadening of spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant (5-30 km s-1) and correlated with intensity. Here we study spectra of the TR Si iv 1403 Å line obtained at high resolution with the Interface Region Imaging Spectrograph (IRIS). We find that the large improvement in spatial resolution (0.″33) of IRIS compared to previous spectrographs (2″) does not resolve the non-thermal line broadening which, in most regions, remains at pre-IRIS levels of about 20 km s-1. This invariance to spatial resolution indicates that the processes behind the broadening occur along the line-of-sight (LOS) and/or on spatial scales (perpendicular to the LOS) smaller than 250 km. Both effects appear to play a role. Comparison with IRIS chromospheric observations shows that, in regions where the LOS is more parallel to the field, magneto-acoustic shocks driven from below impact the TR and can lead to significant non-thermal line broadening. This scenario is supported by MHD simulations. While these do not show enough non-thermal line broadening, they do reproduce the long-known puzzling correlation between non-thermal line broadening and intensity. This correlation is caused by the shocks, but only if non-equilibrium ionization is taken into account. In regions where the LOS is more perpendicular to the field, the prevalence of small-scale twist is likely to play a significant role in explaining the invariance and correlation with intensity.

  8. Identifying and discriminating phase transitions along decaying shocks with line imaging Doppler interferometric velocimetry and streaked optical pyrometry

    SciTech Connect

    Millot, Marius

    2016-01-15

    Ultrafast line-imaging velocity interferometer system for any reflector and streaked optical pyrometry are now commonly used to obtain high precision equation of state and electronic transport data under dynamic compression at major high energy density science facilities. We describe a simple way to improve distinguishing phase transformation signatures from other signals when monitoring decaying shock waves. The line-imaging capability of these optical diagnostics offers additional supporting evidence to the assignment of particular anomalies—such as plateaus or reversals—to the occurrence of a phase transition along the Hugoniot. We illustrate the discussion with two example datasets collected during laser driven shock compression of quartz and stishovite.

  9. Identifying and discriminating phase transitions along decaying shocks with line imaging Doppler interferometric velocimetry and streaked optical pyrometry

    NASA Astrophysics Data System (ADS)

    Millot, Marius

    2016-01-01

    Ultrafast line-imaging velocity interferometer system for any reflector and streaked optical pyrometry are now commonly used to obtain high precision equation of state and electronic transport data under dynamic compression at major high energy density science facilities. We describe a simple way to improve distinguishing phase transformation signatures from other signals when monitoring decaying shock waves. The line-imaging capability of these optical diagnostics offers additional supporting evidence to the assignment of particular anomalies—such as plateaus or reversals—to the occurrence of a phase transition along the Hugoniot. We illustrate the discussion with two example datasets collected during laser driven shock compression of quartz and stishovite.

  10. Transit Rider Body Mass Index Before and After Completion of Street Light-Rail Line in Utah.

    PubMed

    Brown, Barbara B; Smith, Ken R; Jensen, Wyatt A; Tharp, Doug

    2017-09-01

    To determine whether 2012 to 2015 (times 1-3) ridership changes correlated with body mass index (BMI) changes after transit line completion in Salt Lake City, Utah. We used Global Positioning System/accelerometry-measured transit ridership measures in 2012 to 2013 (times 1-2) to compare objective and self-reported ridership. Regression models related changes in objectively measured ridership (times 1-2) and self-reported ridership (times 1-2 and times 1-3) to BMI changes, adjusting for control variables. Objective and self-reported ridership measures were consistent. From time 1 to 2 (P = .021) or to 3 (P = .015), BMI increased among self-reported former riders and decreased among new riders (P = .09 for both times 1-2 and times 1-3), although the latter was nonsignificant. Time 3 attrition adjustment had no effect on results. Adjusting for baseline BMI, the nonsignificant effect for new riders remained nonsignificant, indicating no BMI change; the BMI increase after discontinuing transit remained significant. Observed BMI increases subsequent to stopping transit ridership persisted for more than 2 years (postintervention). These results suggest that transit ridership protects against BMI gains and support the need to provide convenient transit for public health.

  11. THE HANLE EFFECT OF THE HYDROGEN Ly{alpha} LINE FOR PROBING THE MAGNETISM OF THE SOLAR TRANSITION REGION

    SciTech Connect

    Trujillo Bueno, Javier; Stepan, JirI; Casini, Roberto E-mail: stepan@iac.es

    2011-09-01

    We present some theoretical predictions concerning the amplitude and magnetic sensitivity of the linear-polarization signals produced by scattering processes in the hydrogen Ly{alpha} line of the solar transition region. To this end, we have calculated the atomic-level polarization (population imbalances and quantum coherences) induced by anisotropic radiation pumping in semiempirical and hydrodynamical models of the solar atmosphere, taking into account radiative transfer and the Hanle effect caused by the presence of organized and random magnetic fields. The line-center amplitudes of the emergent linear-polarization signals are found to vary typically between 0.1% and 1%, depending on the scattering geometry and the strength and orientation of the magnetic field. The results shown here encourage the development of UV polarimeters for sounding rockets and space telescopes with the aim of opening up a diagnostic window for magnetic field measurements in the upper chromosphere and transition region of the Sun.

  12. Attachment-Line Transition Due to Roughness on a 76 Degree Swept Cylinder at Mach 1.6

    NASA Technical Reports Server (NTRS)

    Coleman, Colin P.; Poll, D. I. A.

    1998-01-01

    Experiments were conducted on a 76 deg. swept cylinder to establish the conditions for the attachment-line transition process with, and without, surface roughness in a low-disturbance ("quiet"), Mach number 1.6 flow. Local flow parameters were estimated from pressure measurements. These were in good agreement with predictions from an Euler code (CFL3D) and a boundary layer code (BL3D). Hot-wires and Schlieren photography were used to determine the state of the boundary layer. It was found that, for a near-adiabatic wall condition and a smooth surface, the attachment-line, boundary-layer remained laminar up to the highest attainable Reynolds number (R-bar of 790). Transition under the influence of trip wires was found to depend on wind-tunnel disturbance levels and the onset conditions have been established. Results suggest that current design practice, which is based upon data from conventional ("noisy") tunnels, may be highly conservative.

  13. Systematic experimental study of the Stark broadening of C II, C III, N II, N III, O II and O III spectral lines

    SciTech Connect

    Blagojevic, B.; Popovic, M. V.; Konjevic, N.

    1999-04-01

    We report the experimental Stark widths of plasma broadened lines belonging to 3s-3p and 3p-3d transitions of singly and doubly ionized C, N and O emitters. The light source was a low pressure pulsed arc. The plasma electron densities were determined from the width of the Hell P{sub {alpha}} line while the electron temperatures were measured from the relative line intensities of five N II spectral lines.

  14. 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.

  15. An Observational Test of Transition Region Lines as a Pressure Gauge

    NASA Technical Reports Server (NTRS)

    Siegmund, Oswald H. W.

    1999-01-01

    The objective of this research project was to use high resolution spectroscopic observations from the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) instrument on SOHO (Solar and Heliospheric Observatory) to study the structure of the solar transition region. Our main focus in this grant was to study the variation in density and emission across the quiet Sun transition region.

  16. A summary of transition probabilities for atomic absorption lines formed in low-density clouds

    NASA Technical Reports Server (NTRS)

    Morton, D. C.; Smith, W. H.

    1973-01-01

    A table of wavelengths, statistical weights, and excitation energies is given for 944 atomic spectral lines in 221 multiplets whose lower energy levels lie below 0.275 eV. Oscillator strengths were adopted for 635 lines in 155 multiplets from the available experimental and theoretical determinations. Radiation damping constants also were derived for most of these lines. This table contains the lines most likely to be observed in absorption in interstellar clouds, circumstellar shells, and the clouds in the direction of quasars where neither the particle density nor the radiation density is high enough to populate the higher levels. All ions of all elements from hydrogen to zinc are included which have resonance lines longward of 912 A, although a number of weaker lines of neutrals and first ions have been omitted.

  17. The effect of nonequilibrium ionization on ultraviolet line shifts in the solar transition region

    NASA Technical Reports Server (NTRS)

    Spadaro, D.; Noci, G.; Zappala, R. A.; Antiochos, S. K.

    1990-01-01

    The line profiles and wavelength positions of all the important emission lines due to carbon were computed for a variety of steady state siphon flow loop models. For the lines from the lower ionization states (C II-C IV) a preponderance of blueshifts was found, contrary to the observations. The lines from the higher ionization states can show either a net red- or blueshift, depending on the position of the loop on the solar disk. Similar results are expected for oxygen. It is concluded that the observed redshifts cannot be explained by the models proposed here.

  18. Line positions, pressure broadening and shift coefficients for the second overtone transitions of carbon monoxide in argon

    NASA Astrophysics Data System (ADS)

    Kowzan, G.; Stec, K.; Zaborowski, M.; Wójtewicz, S.; Cygan, A.; Lisak, D.; Masłowski, P.; Trawiński, R. S.

    2017-04-01

    Absolute positions and spectral line-shape parameters of carbon monoxide 0 → 3 band, P branch transitions are reported. The speed-dependent effects and the influence of velocity-changing collisions were taken into account in the fitted line-shape models. For the first time the values of pressure shift coefficients of CO in argon for this band were determined. The measurements were made with the Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectrometer, with the frequency axis linked through an optical frequency comb to the UTC(AOS) frequency reference based on a hydrogen maser. Achieved uncertainties of line positions are between 70 kHz and 420 kHz.

  19. An evaluation of the accuracy of the Federal Transit Administration approved, groundborne noise and vibration prediction model for rail transit systems; a case study for a new subway line using post construction, transit operation measurements

    NASA Astrophysics Data System (ADS)

    Carman, Richard A.; Reyes, Carlos H.

    2005-09-01

    The groundborne noise and vibration model developed by Nelson and Saurenman in 1984, now recognized by the Federal Transit Administration as the approved model for new transit system facilities, is entering its third decade of use by engineers and consultants in the transit industry. The accuracy of the model has been explored in the past (e.g., Carman and Wolfe). New data obtained for a recently completed extension to a major heavy rail transit system provides an opportunity to evaluate the accuracy of the model once more. During the engineering design phase of the project, noise and vibration predictions were performed for numerous buildings adjacent to the new subway line. The values predicted by the model were used to determine the need for and type of noise and/or vibration control measures. After the start of transit operations on the new line, noise and vibration measurements were made inside several of the buildings to determine whether the criteria were in fact achieved. The measurement results are compared with the values predicted by the model. The predicted and measured, overall noise and vibration levels show very good agreement, whereas the spectral comparisons indicate some differences. Possible reasons for these differences are offered.

  20. SMM/UVSP observations of the distribution of transition region oscillations and other properties in a sunspot

    NASA Technical Reports Server (NTRS)

    Henze, W.; Tandberg-Hanssen, E.; Reichmann, E. J.; Athay, R. G.

    1984-01-01

    Observations of a sunspot in the C IV line at 1548 A formed in the transition region have been analyzed to obtain the time variations and/or mean values of the velocity, intensity, longitudinal magnetic field, and line width. Oscillations with periods between approximately 110 and 200 s are observed only over the umbra where the transition region magnetic field is highest and the line width is smallest. When periodic intensity variations occur at the same frequency as the velocity oscillations, the peak intensities occur slightly before the maximum upward motions. No periodic variations in the transition region magnetic field have been detected. Scatter diagrams are presented which show possible relationships between the flow velocity, emission line intensity, line width, and transition region magnetic field.

  1. The Width of a Proof

    ERIC Educational Resources Information Center

    Hanna, Gila

    2014-01-01

    This paper's aim is to discuss the concept of width of a proof put forward by Timothy Gowers. It explains what this concept means and attempts to show how it relates to other concepts discussed in the existing literature on proof and proving. It also explores how the concept of width of a proof might be used productively in the mathematics…

  2. Phase width reduction project summary

    SciTech Connect

    Clark, D.J.; Xie, Z.Q.; McMahan, M. A.

    1999-11-01

    The purpose of the phase width reduction project, 1993--96, was to reduce the phase width of the 88-Inch Cyclotron beam on target from 5--10 ns to 1--2 ns for certain experiments, such as Gammasphere, which use time-of-flight identification. Since reducing the phase width also reduces beam intensity, tuning should be done to also optimize the transmission. The Multi-turn Collimator slits in the cyclotron center region were used to collimate the early turns radially, thus reducing the phase width from about 5 ns to 1--2 ns FWHM for a Gammasphere beam. The effect of the slits on phase width was verified with a Fast Faraday Cup and with particle and gamma-ray detectors in the external beamline.

  3. Transition.

    ERIC Educational Resources Information Center

    Thompson, Sandy, Ed.; And Others

    1990-01-01

    This "feature issue" focuses on transition from school to adult life for persons with disabilities. Included are "success stories," brief program descriptions, and a list of resources. Individual articles include the following titles and authors: "Transition: An Energizing Concept" (Paul Bates); "Transition…

  4. Frio River line in south Texas - transition from Cordilleran to northern Gulf tectonic regimes

    SciTech Connect

    Ewing, T.E.

    1987-09-01

    A northwest-southeast linear zone, here named the Frio River line, about 60 mi (100 km) southwest of San Antonio, Texas, separates two areas of contrasting structural and stratigraphic history. To the northeast, structures include the uplifted Llano area, the Balcones and Luling zones of normal faulting, and a narrow graben that closely outlines the landward edge of Jurassic salt. To the southwest, northwest-southeast-trending, low-amplitude folds of the Rio Grand foldbelt are present. These folds are similar in orientation and age to Laramide folding in northeastern Mexico. Northeast of the line, Jurassic salt was deposited over broad areas; to the southwest, seismic data suggest an erratic distribution of salt. Early Cretaceous subsidence was marked southwest of the line, and gulfward sliding predominated northeast of the line. Upper Cretaceous alkalic volcanics are restricted to a belt northeast of the line, and are most abundant where that belt intersects the line. Even Tertiary growth-fault styles show distinct differences across this line, probably due to a greater thickness of Upper Cretaceous shale in the south. Fragmentary evidence indicates that the line may have a pre-Late Jurassic origin, possibly as the northeastern boundary of a Mesozoic strike-slip system, or as the southeastward continuation of the Devils River uplift. Oil and gas plays in Cretaceous rocks are different north and south of the Frio River line; the northern Gulf is dominated by traps related to normal-fault systems, whereas southwest Texas contains mostly fold-related and cross-fault traps and stratigraphic traps.

  5. Critical behavior of the three-dimensional Ising model with anisotropic bond randomness at the ferromagnetic-paramagnetic transition line

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, T.; Malakis, A.

    2013-01-01

    We study the ±J three-dimensional (3D) Ising model with a spatially uniaxial anisotropic bond randomness on the simple cubic lattice. The ±J random exchange is applied on the xy planes, whereas, in the z direction, only a ferromagnetic exchange is used. After sketching the phase diagram and comparing it with the corresponding isotropic case, the system is studied at the ferromagnetic-paramagnetic transition line using parallel tempering and a convenient concentration of antiferromagnetic bonds (pz=0;pxy=0.176). The numerical data clearly point out a second-order ferromagnetic-paramagnetic phase transition belonging in the same universality class with the 3D random Ising model. The smooth finite-size behavior of the effective exponents, describing the peaks of the logarithmic derivatives of the order parameter, provides an accurate estimate of the critical exponent 1/ν=1.463(3), and a collapse analysis of magnetization data gives an estimate of β/ν=0.516(7). These results are in agreement with previous papers and, in particular, with those of the isotropic ±J three-dimensional Ising model at the ferromagnetic-paramagnetic transition line, indicating the irrelevance of the introduced anisotropy.

  6. Critical behavior of the three-dimensional Ising model with anisotropic bond randomness at the ferromagnetic-paramagnetic transition line.

    PubMed

    Papakonstantinou, T; Malakis, A

    2013-01-01

    We study the ±J three-dimensional (3D) Ising model with a spatially uniaxial anisotropic bond randomness on the simple cubic lattice. The ±J random exchange is applied on the xy planes, whereas, in the z direction, only a ferromagnetic exchange is used. After sketching the phase diagram and comparing it with the corresponding isotropic case, the system is studied at the ferromagnetic-paramagnetic transition line using parallel tempering and a convenient concentration of antiferromagnetic bonds (p(z)=0;p(xy)=0.176). The numerical data clearly point out a second-order ferromagnetic-paramagnetic phase transition belonging in the same universality class with the 3D random Ising model. The smooth finite-size behavior of the effective exponents, describing the peaks of the logarithmic derivatives of the order parameter, provides an accurate estimate of the critical exponent 1/ν=1.463(3), and a collapse analysis of magnetization data gives an estimate of β/ν=0.516(7). These results are in agreement with previous papers and, in particular, with those of the isotropic ±J three-dimensional Ising model at the ferromagnetic-paramagnetic transition line, indicating the irrelevance of the introduced anisotropy.

  7. 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…

  8. 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…

  9. Comparison of gastrointestinal transit times between chickens from D+ and D- genetic lines selected for divergent digestion efficiency.

    PubMed

    Rougière, N; Carré, B

    2010-11-01

    D+ (high digestion efficiency) and D- (low digestion efficiency) genetic chicken lines selected for divergent digestion efficiency were compared in this experiment. Gizzard functions were tested in terms of digesta mean retention time and reactions to high dilution of a corn diet with 15% coarse sunflower hulls. The corn standard (S) and high fibre (F) experimental diets were given from 9 days of age to chickens from both lines. Besides the measurements of growth efficiencies (9 to 20 days), digestibilities (20 to 23 days) and gut anatomy (0, 9, 29, 42 and 63 days), two digestive transit studies were performed at 9 and 29 days of age. For the transit studies, the S and F diets were labelled with 0.5% TiO2 and 1% Cr-mordanted sunflower hulls. These diets were fed ad libitum during 3 days, and then the birds were euthanized. The digestive contents were analysed for the determination of marker concentrations and mean retention times (MRTs) in digestive compartments (crop + oesophagus, proventriculus + gizzard, duodenum + jejunum, ileum, rectum + cloaca and caeca) were determined. D+ birds were confirmed as better digesters than D- birds during the growth period, in association with larger gizzard and pancreas, and lighter small intestine in D+ than in D-birds. The MRT in the proventriculus-gizzard system, higher in D+ than in D- birds, was a major factor associated with differences between D+ and D- birds regarding digestion efficiencies and gut anatomy. Diet dilution with fibres reduced differences in digestion efficiencies and proventriculus-gizzard MRT between lines. Differences in gut anatomy between lines tended to disappear after 8 weeks of age. In conclusion, this study showed that MRT in the proventriculus-gizzard system was a major factor associated with genotype differences between the D+ and D- genetic chicken lines selected for divergent digestion efficiency, with longer MRT found in D+ than in D- birds.

  10. Characterization of the new bladder cancer cell line HOK-1: expression of transitional, squamous and glandular differentiation patterns.

    PubMed

    Offner, F A; Ott, G; Povey, S; Knuechel, R; Preisler, V; Fuezesi, L; Klosterhalfen, B; Ruebben, H; Hofstaedter, F; Kirkpatrick, C J

    1991-08-19

    The new continuous cell line HOK-1 derived from a grade-III transitional-cell bladder carcinoma with foci of squamous and glandular differentiation was shown to retain this phenotypical heterogeneity for more than 45 passages in vitro. Electron microscopy revealed transitional as well as a considerable proportion of squamous carcinoma and adenocarcinoma cells. PAS-positive mucus was detected in numerous cells. These features were principally maintained when grown as multicellular spheroids and in nude mice. More pronounced signs of differentiation (i.e., expression of cytokeratins 10 and 11, formation of glandular structures) were found in xenograft tumours. Independently, cytokeratins 13, 18 and 19 were detected in vitro and in vivo, reflecting the urothelial origin. The line forms distinct colonies in soft agar, expresses Lewis-x and Lewis-y antigens and reacts with monoclonal antibodies (MAbs) against CEA, beta-HCG and URO-5. Cytogenetic analysis revealed several related clones with a rearrangement at chromosome 1 and loss of one X chromosome as common karyotypic changes in all clones. DNA content, as quantified by image analysis, showed a DNA stemline close to 2c. The new cell line HOK-1 can be used as an in vitro model to study the mechanisms of heterogeneous differentiation patterns in bladder cancer.

  11. Animal model of naturally occurring bladder cancer: Characterization of four new canine transitional cell carcinoma cell lines

    PubMed Central

    2014-01-01

    Background Development and further characterization of animal models for human cancers is important for the improvement of cancer detection and therapy. Canine bladder cancer closely resembles human bladder cancer in many aspects. In this study, we isolated and characterized four primary transitional cell carcinoma (K9TCC) cell lines to be used for future in vitro validation of novel therapeutic agents for bladder cancer. Methods Four K9TCC cell lines were established from naturally-occurring canine bladder cancers obtained from four dogs. Cell proliferation rates of K9TCC cells in vitro were characterized by doubling time. The expression profile of cell-cycle proteins, cytokeratin, E-cadherin, COX-2, PDGFR, VEGFR, and EGFR were evaluated by immunocytochemistry (ICC) and Western blotting (WB) analysis and compared with established human bladder TCC cell lines, T24 and UMUC-3. All tested K9TCC cell lines were assessed for tumorigenic behavior using athymic mice in vivo. Results Four established K9TCC cell lines: K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#4Molly, and K9TCC#5Lilly were confirmed to have an epithelial-cell origin by morphology analysis, cytokeratin, and E-cadherin expressions. The tested K9TCC cells expressed UPIa (a specific marker of the urothelial cells), COX-2, PDGFR, and EGFR; however they lacked the expression of VEGFR. All tested K9TCC cell lines confirmed a tumorigenic behavior in athymic mice with 100% tumor incidence. Conclusions The established K9TCC cell lines (K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#4Molly, and K9TCC#5Lilly) can be further utilized to assist in development of new target-specific imaging and therapeutic agents for canine and human bladder cancer. PMID:24964787

  12. Interface phase transition induced by a driven line in two dimensions.

    PubMed

    Sadhu, Tridib; Shapira, Zvi; Mukamel, David

    2012-09-28

    The effect of a localized drive on the steady state of an interface separating two phases in coexistence is studied. This is done using a spin-conserving kinetic Ising model on a two-dimensional lattice with cylindrical boundary conditions, where a drive is applied along a single ring on which the interface separating the two phases is centered. The drive is found to induce an interface spontaneous symmetry breaking whereby the magnetization of the driven ring becomes nonzero. The width of the interface becomes finite and its fluctuations around the driven ring are nonsymmetric. The dynamical origin of these properties is analyzed in an adiabatic limit, which allows the evaluation of the large deviation function of the magnetization of the driven ring.

  13. Manipulation of a Schlenk Line: Preparation of Tetrahydrofuran Complexes of Transition-Metal Chlorides

    ERIC Educational Resources Information Center

    Davis, Craig M.; Curran, Kelly A.

    2007-01-01

    Before taking an inorganic laboratory course few students have experience handling air-sensitive materials using Schlenk techniques. This exercise introduces them to techniques they will employ in later syntheses. The procedure involves the formation of anhydrous tetrahydrofuran complexes of transition-metal chlorides from metal-chloride hydrates;…

  14. Manipulation of a Schlenk Line: Preparation of Tetrahydrofuran Complexes of Transition-Metal Chlorides

    ERIC Educational Resources Information Center

    Davis, Craig M.; Curran, Kelly A.

    2007-01-01

    Before taking an inorganic laboratory course few students have experience handling air-sensitive materials using Schlenk techniques. This exercise introduces them to techniques they will employ in later syntheses. The procedure involves the formation of anhydrous tetrahydrofuran complexes of transition-metal chlorides from metal-chloride hydrates;…

  15. Size-dependent contact angle and the wetting and drying transition of a droplet adsorbed onto a spherical substrate: Line-tension effect.

    PubMed

    Iwamatsu, Masao

    2016-10-01

    The size-dependent contact angle and the drying and wetting morphological transition are studied with respect to the volume change for a spherical cap-shaped droplet placed on a spherical substrate. The line-tension effect is included using the rigorous formula for the Helmholtz free energy in the droplet capillary model. A morphological drying transition from a cap-shaped to a spherical droplet occurs when the substrate is hydrophobic and the droplet volume is small, similar to the transition predicted on a flat substrate. In addition, a morphological wetting transition from a cap-shaped to a wrapped spherical droplet occurs for a hydrophilic substrate and a large droplet volume. The contact angle depends on the droplet size: it decreases as the droplet volume increases when the line tension is positive, whereas it increases when the line tension is negative. The spherical droplets and wrapped droplets are stable when the line tension is positive and large.

  16. Line Shapes and Intensities of Carbon Monoxide Transitions in the (3→0) and (4→1) Bands

    NASA Astrophysics Data System (ADS)

    Reed, Zachary; Polyansky, Oleg; Hodges, Joseph T.

    2017-06-01

    We have measured several carbon monoxide transitions in the (3→0) and (4→1) band using frequency stabilized cavity ringdown spectroscopy (FS-CRDS). The measured transitions are compared to the line strength values in HITRAN 2012 [1], those determined by Wojtewitz et al [2], and to theoretical calculations. The cavity length is actively locked to an iodine stabilized HeNe laser, providing long term frequency stability of 10 kHz and is linked to a self-referenced, octave-spanning frequency comb. The temperature of the optical cavity is actively regulated at the mK level, and the pressure measurements are SI-traceable. The sample is a NIST calibrated reference mixture of 11.98575(95)% CO in N_{2}. The absorption spectra are modeled using the Hartmann-Tran profile (HTP). The SNR in these spectra may exceed 10,000:1, which necessitates including the effects of speed dependence, collisional narrowing, and correlation between velocity-changing and dephasing collisions. The relative uncertainties of the line strengths calculated in this study are better than 0.1%. There are systematic differences on the 1% level for ^{12}CO against both HITRAN [1] and the previous work by Wojtewitz et al [2]. The measurement uncertainties are nearly an order of magnitude lower than previous results. Additionally, the relative uncertainties in the integrated areas of selected ^{12}CO and ^{13}CO transitions are less than 0.006% and 0.02%, respectively, providing an excellent test case for determination of isotope ratios by direct use of theoretical line intensity calculations. [1] Wojtewicz, S., et al., J Quant Spect and Rad Trans,2013. 130: p.191-200. [2]Rothman, L.S., et al., Journal of Quant Spect and Rad Trans, 2013. 130: p. 4-50.

  17. Small RNA Profiles of the Rice PTGMS Line Wuxiang S Reveal miRNAs Involved in Fertility Transition.

    PubMed

    Zhang, Hongyuan; Hu, Jihong; Qian, Qian; Chen, Hao; Jin, Jing; Ding, Yi

    2016-01-01

    MicroRNAs (miRNAs) play key roles in the regulation of plant growth and developmental processes. In this study, RNA-seq was used to examine the expression profiles of miRNAs in a novel, photo-thermosensitive genic male sterile (PTGMS) rice line, Wuxiang S (WXS), during fertility transition. A total of 497 known miRNAs and 273 novel miRNAs were identified. In a differential expression analysis, 26 miRNAs exhibited significant differential expression between WXS (Sterile, S) and WXS (Fertile, F). Some of these miRNAs were validated by quantitative real-time PCR. Among these miRNAs, 11 showed decreased expression levels, and 15 showed increased expression levels in WXS (S) compared to WXS (F). Some of these miRNAs, such as osa-miR156a-j, osa-miR164d, and osa-miR528, were shown to be negatively correlated with their targets. These targets have previously been reported to be related to pollen development and male sterility, suggesting that these miRNAs may be involved in the regulation of pollen development in the rice PTGMS line WXS. Furthermore, miRNA-mediated editing events were also observed. In this study, a possible model for the control of signaling pathways during the process of fertility transition in the rice PTGMS line WXS by miRNAs was developed. These findings contribute to our understanding of the roles of miRNAs during anther development in PTGMS lines in rice.

  18. Radiosensitivity and capacity for radiation-induced sublethal damage repair of canine transitional cell carcinoma (TCC) cell lines.

    PubMed

    Parfitt, S L; Milner, R J; Salute, M E; Hintenlang, D E; Farese, J P; Bacon, N J; Bova, F J; Rajon, D A; Lurie, D M

    2011-09-01

    Understanding the inherent radiosensitivity and repair capacity of canine transitional cell carcinoma (TCC) can aid in optimizing radiation protocols to treat this disease. The objective of this study was to evaluate the parameters surviving fraction at 2 Gy (SF(2) ), α/β ratio and capacity for sublethal damage repair (SLDR) in response to radiation. Dose-response and split-dose studies were performed using the clonogenic assay. The mean SF(2) for three established TCC cell lines was high at 0.61. All the three cell lines exhibited a low to moderate α/β ratio, with the mean being 3.27. Two cell lines exhibited statistically increased survival at 4 and 24 h in the dose-response assay. Overall, our results indicate that the cell lines are moderately radioresistant, have a high repair capacity and behave similarly to a late-responding normal tissue. These findings indicate that the radiation protocols utilizing higher doses with less fractionation may be more effective for treating TCC.

  19. Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53

    NASA Astrophysics Data System (ADS)

    Doroshenko, Victor; Tsygankov, Sergey S.; Mushtukov, Alexander A.; Lutovinov, Alexander A.; Santangelo, Andrea; Suleimanov, Valery F.; Poutanen, Juri

    2017-04-01

    We report on the analysis of NuSTAR observations of the Be-transient X-ray pulsar V 0332+53 during the giant outburst in 2015 and another minor outburst in 2016. We confirm the cyclotron-line energy-luminosity correlation previously reported in the source and the line energy decrease during the giant outburst. Based on 2016 observations, we find that a year later the line energy has increased again essentially reaching the pre-outburst values. We discuss this behaviour and conclude that it is likely caused by a change of the emission region geometry rather than previously suggested accretion-induced decay of the neutron stars magnetic field. At lower luminosities, we find for the first time a hint of departure from the anticorrelation of line energy with flux, which we interpret as a transition from super- to sub-critical accretion associated with the disappearance of the accretion column. Finally, we confirm and briefly discuss the orbital modulation observed in the outburst light curve of the source.

  20. Roughness-Dominated Transition on Nosetips, Attachment Lines and Lifting-Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Reda, Daniel C.

    2001-01-01

    Modeling of roughness-dominated transition is a critical design issue for both ablating and non-ablating thermal protection systems (TPS). Ablating TPS, used for planetary-entry and earth-return missions, first experience recession under high-altitude, low-Reynolds-number conditions. Such laminar-flow ablation causes the formation of a surface microroughness pattern characteristic of the TPS material composition and fabrication process. For non-ablating TPS, such as the overlapping-tile, metallic heatshields proposed for future reusable launch vehicles, the surface roughness pattern is established a priori by the engineering design and assembly procedure. In both cases, these distributed surface roughness patterns create disturbances within, and alter the mean velocity profile of, the laminar boundary layer flowing over the surface. As altitude decreases, Reynolds number increases, and flow field conditions capable of amplifying these roughness-induced perturbations are eventually achieved, i.e., transition onset occurs. Boundary layer transition to turbulence results in more severe heat-transfer rates. Ablating TPS experience increased recession rates, leading to potential bum-through, while non-ablating TPS experience accelerated temperature rise, leading to potential melting of key components.

  1. Structural transitions in a ring stain created at the contact line of evaporating nanosuspension sessile drops.

    PubMed

    Askounis, Alexandros; Sefiane, Khellil; Koutsos, Vasileios; Shanahan, Martin E R

    2013-01-01

    Monodisperse nanosuspension droplets, placed on a flat surface, evaporated following the stick-slip motion of the three-phase contact line. Unexpectedly, a disordered region formed at the exterior edge of a closely packed nanocolloidal crystalline structure during the "stick" period. In order to assess the role of particle velocity on particle structuring, we did experiments in a reduced pressure environment which allowed the enhancement of particle velocity. These experiments revealed the promotion of hexagonal packing at the very edge of the crystallite with increasing velocity. Quantification of particle velocity and comparison with measured deposit shape for each case allowed us to provide a tentative description of the underlying mechanisms that govern particle deposition of nanoparticles at the triple line of an evaporating droplet. Behavior is governed by an interplay between the fluid, and hence particle, flow velocity (main ordering parameter) and wedge constraints, and consequently disjoining pressure (main disordering parameter). Furthermore, the formation of a second disordered particle region at the interior edge of the deposit (towards bulk fluid) was found and attributed to the rapid motion of the triple line during the "slip" regime. Additionally, the magnitude of the pinning forces acting on the triple line of the same drops was calculated. These findings provide further insight into the mechanisms of the phenomenon and could facilitate its exploitation in various nanotechnological applications.

  2. Structural transitions in a ring stain created at the contact line of evaporating nanosuspension sessile drops

    NASA Astrophysics Data System (ADS)

    Askounis, Alexandros; Sefiane, Khellil; Koutsos, Vasileios; Shanahan, Martin E. R.

    2013-01-01

    Monodisperse nanosuspension droplets, placed on a flat surface, evaporated following the stick-slip motion of the three-phase contact line. Unexpectedly, a disordered region formed at the exterior edge of a closely packed nanocolloidal crystalline structure during the “stick” period. In order to assess the role of particle velocity on particle structuring, we did experiments in a reduced pressure environment which allowed the enhancement of particle velocity. These experiments revealed the promotion of hexagonal packing at the very edge of the crystallite with increasing velocity. Quantification of particle velocity and comparison with measured deposit shape for each case allowed us to provide a tentative description of the underlying mechanisms that govern particle deposition of nanoparticles at the triple line of an evaporating droplet. Behavior is governed by an interplay between the fluid, and hence particle, flow velocity (main ordering parameter) and wedge constraints, and consequently disjoining pressure (main disordering parameter). Furthermore, the formation of a second disordered particle region at the interior edge of the deposit (towards bulk fluid) was found and attributed to the rapid motion of the triple line during the “slip” regime. Additionally, the magnitude of the pinning forces acting on the triple line of the same drops was calculated. These findings provide further insight into the mechanisms of the phenomenon and could facilitate its exploitation in various nanotechnological applications.

  3. Transition to On-Line Information and Reference Retrieval. Experimental Retrieval Systems Studies, Report Number 4.

    ERIC Educational Resources Information Center

    Smith, William A., Jr.; And Others

    An existing experimental document and reference retrieval system operating in batch processing, tape oriented mode was converted to an on-line mode with user interaction. Objectives were faster response time, integration of functions, and system accessibility at user location. Effects on file organization, addressing techniques, file maintenance,…

  4. A multi-transition molecular line study of infrared dark cloud G331.71+00.59

    NASA Astrophysics Data System (ADS)

    Yu, Nai-Ping; Wang, Jun-Jie

    2013-01-01

    Using archive data from the Millimeter Astronomy Legacy Team Survey at 90 GHz (MALT90), carried out using the Mopra 22-m telescope, we made the first multi-transition molecular line study of infrared dark cloud (IRDC) MSXDC G331.71+00.59. Two molecular cores were found embedded in this IRDC. Each of these cores is associated with a known extended green object (EGO), indicating places of massive star formation. The HCO+ (1-0) and HNC (1-0) transitions show prominent blue or red asymmetric structures, suggesting outflow and inflow activities of young stellar objects (YSOs). Other detected molecular lines include H13CO+ (1-0), C2H (1-0), HC3N (10-9), HNCO(40,4-30,3) and SiO (2-1), which are typical of hot cores and outflows. We regard the two EGOs as evolving from the IRDC to hot cores. Using public GLIMPS data, we investigate the spectral energy distribution of EGO G331.71+0.60. Our results support this EGO being a massive YSO driving the outflow. G331.71+0.58 may be at an earlier evolutionary stage.

  5. Relation between the Widom line and the dynamic crossover in systems with a liquid-liquid phase transition.

    PubMed

    Xu, Limei; Kumar, Pradeep; Buldyrev, S V; Chen, S-H; Poole, P H; Sciortino, F; Stanley, H E

    2005-11-15

    We investigate, for two water models displaying a liquid-liquid critical point, the relation between changes in dynamic and thermodynamic anomalies arising from the presence of the liquid-liquid critical point. We find a correlation between the dynamic crossover and the locus of specific heat maxima C(P)(max) ("Widom line") emanating from the critical point. Our findings are consistent with a possible relation between the previously hypothesized liquid-liquid phase transition and the transition in the dynamics recently observed in neutron scattering experiments on confined water. More generally, we argue that this connection between C(P)(max) and dynamic crossover is not limited to the case of water, a hydrogen bond network-forming liquid, but is a more general feature of crossing the Widom line. Specifically, we also study the Jagla potential, a spherically symmetric two-scale potential known to possess a liquid-liquid critical point, in which the competition between two liquid structures is generated by repulsive and attractive ramp interactions.

  6. Near-field-far-field transition of a finite line source using incoherent light: A student laboratory experiment

    NASA Astrophysics Data System (ADS)

    Yan, Xincheng; Yu, Yixin; Shen, Louis; Wanser, Keith H.

    1995-01-01

    A simple experiment employing low cost apparatus is presented which demonstrates the falloff of intensity with distance and the transition from the near field to the far field of a line source filament incandescent light bulb. A derivation of the Poynting vector as a function of the distance away from the filament is presented which shows an exact correspondence to the derivation for the electric field from a finite line charge source in electrostatics. The experimental data of power vs distance from the filament show an inverse first power of the distance falloff in the near field, with a smooth transition to an inverse square law behavior in the far field, in good agreement with the theoretical expression when corrections for the measured angular response of the detector are included. The experiment provides an illustration of the inverse square law falloff of intensity at large distances from the source, experience with simple concepts and techniques of optical radiometry and incoherent light sources, and the analogy between incoherent light sources and electrostatics in an undergraduate laboratory. An additional short experiment provides an illustration of electrical-to-optical power conversion efficiency and temperature dependent resistance associated with electron-phonon scattering in metals. A derivation of isotropic, unpolarized elementary radiators from anisotropic dipole radiation is presented in the Appendix.

  7. Transitions

    NASA Technical Reports Server (NTRS)

    2006-01-01

    26 May 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a variety of textures observed on a dust-covered plain in the Marte Valles region of Mars. Textural variations across the scene include: areas that are littered with small impact craters, a channel-like feature that is dominated by mounds of a variety of sizes, small ripples and/or ridges, and relatively smooth, unremarkable terrain. The contact between the cratered plain and the area dominated by mounds marks one of the banks along the edge of one of the shallow valleys of the Marte Valles system.

    Location near: 17.7oN, 175.0oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

  8. Active control of crossflow-induced transition by means of in-line pneumatic actuator orifices

    NASA Astrophysics Data System (ADS)

    Lohse, J.; Barth, H. P.; Nitsche, W.

    2016-08-01

    The possibility of a pneumatic actuator system for controlling the crossflow vortex-induced laminar breakdown is investigated by means of hot-wire measurements. Steady blowing or suction through a spanwise row of periodically arranged orifices initiates a system of longitudinal vortices which reduces the amplitude of the most amplified stationary crossflow vortices. Thus, the onset of high-frequency secondary instability and the following laminar-turbulent transition was shifted farther downstream. All experiments were conducted at the redesigned DLR swept flat plate experiment in the open test section of the 1 m wind tunnel at the DLR in Göttingen.

  9. Research on conflict detection algorithm in 3D visualization environment of urban rail transit line

    NASA Astrophysics Data System (ADS)

    Wang, Li; Xiong, Jing; You, Kuokuo

    2017-03-01

    In this paper, a method of collision detection is introduced, and the theory of three-dimensional modeling of underground buildings and urban rail lines is realized by rapidly extracting the buildings that are in conflict with the track area in the 3D visualization environment. According to the characteristics of the buildings, CSG and B-rep are used to model the buildings based on CSG and B-rep. On the basis of studying the modeling characteristics, this paper proposes to use the AABB level bounding volume method to detect the first conflict and improve the detection efficiency, and then use the triangular rapid intersection detection algorithm to detect the conflict, and finally determine whether the building collides with the track area. Through the algorithm of this paper, we can quickly extract buildings colliding with the influence area of the track line, so as to help the line design, choose the best route and calculate the cost of land acquisition in the three-dimensional visualization environment.

  10. Resonance and intersystem transition lines of astrophysical importance in neutral sulfur

    NASA Astrophysics Data System (ADS)

    Deb, N. C.; Hibbert, A.

    2006-10-01

    A systematic study of S I levels belonging to 3s23p4, 3s3p5, 3s23p3(4So, 2Do, 2Po)nell, where nell = 4s, 5s, 6s, 4p, 5p, 6p, 3d, 4d, 5d, 4f and 5f configurations and optically allowed and intersystem transitions among them are presented. A very large set of basis functions are generated using up to three electron promotions from the ground configurations for each of the 24 symmetries considered belonging to two parities. Many of the levels are reported for the first time. Relativistic effects are included through the Breit-Pauli Hamiltonian. The resulting fine-structure levels and oscillator strengths for some astrophysically important transitions are then presented and compared with the available measured and calculated values. Excellent agreement between the present lifetimes and the measurement of Berzinsh et al (1997 Phys. Rev. A 55 1836) and Beideck et al (1994 Astrophys. J. 428 393) are achieved for the 3s23p3(4So)ns(3S1o), 4 <= n <= 6, 3s23p3(4So)4p(3P0,1,2o) and 3s23p3(2Po)4s(3P0,1,2o) levels, respectively.

  11. Common raven occurrence in relation to energy transmission line corridors transiting human-altered sagebrush steppe

    USGS Publications Warehouse

    Coates, Peter S.; Howe, Kristy B.; Casazza, Michael L.; Delehanty, David J.

    2014-01-01

    Energy-related infrastructure and other human enterprises within sagebrush steppe of the American West often results in changes that promote common raven (Corvus corax; hereafter, raven) populations. Ravens, a generalist predator capable of behavioral innovation, present a threat to many species of conservation concern. We evaluate the effects of detailed features of an altered landscape on the probability of raven occurrence using extensive raven survey (n= 1045) and mapping data from southern Idaho, USA. We found nonlinear relationships between raven occurrence and distances to transmission lines, roads, and facilities. Most importantly, raven occurrence was greater with presence of transmission lines up to 2.2 km from the corridor.We further explain variation in raven occurrence along anthropogenic features based on the amount of non-native vegetation and cover type edge, such that ravens select fragmented sagebrush stands with patchy, exotic vegetative introgression. Raven occurrence also increased with greater length of edge formed by the contact of big sagebrush (Artemisia tridentate spp.) with non-native vegetation cover types. In consideration of increasing alteration of sagebrush steppe, these findings will be useful for planning energy transmission corridor placement and other management activities where conservation of sagebrush obligate species is a priority.

  12. Time Dependent Nonequilibrium Ionization of Transition Region Lines Observed with IRIS

    NASA Astrophysics Data System (ADS)

    Martínez-Sykora, Juan; De Pontieu, Bart; Hansteen, Viggo H.; Gudiksen, Boris

    2016-01-01

    The properties of nonstatistical equilibrium ionization of silicon and oxygen ions are analyzed in this work. We focus on five solar targets (quiet Sun; coronal hole; plage; quiescent active region, AR; and flaring AR) as observed with the Interface Region Imaging Spectrograph (IRIS). IRIS is best suited for this work owing to the high cadence (up to 0.5 s), high spatial resolution (up to 0.″32), and high signal-to-noise ratios for O iv λ1401 and Si iv λ1402. We find that the observed intensity ratio between lines of three times ionized silicon and oxygen ions depends on their total intensity and that this correlation varies depending on the region observed (quiet Sun, coronal holes, plage, or active regions) and on the specific observational objects present (spicules, dynamic loops, jets, microflares, or umbra). In order to interpret the observations, we compare them with synthetic profiles taken from 2D self-consistent radiative MHD simulations of the solar atmosphere, where the statistical equilibrium or nonequilibrium treatment of silicon and oxygen is applied. These synthetic observations show vaguely similar correlations to those in the observations, i.e., between the intensity ratios and their intensities, but only in the nonequilibrium case do we find that (some of) the observations can be reproduced. We conclude that these lines are formed out of statistical equilibrium. We use our time-dependent nonequilibrium ionization simulations to describe the physical mechanisms behind these observed properties.

  13. TIME DEPENDENT NONEQUILIBRIUM IONIZATION OF TRANSITION REGION LINES OBSERVED WITH IRIS

    SciTech Connect

    Martínez-Sykora, Juan; Pontieu, Bart De; Hansteen, Viggo H.; Gudiksen, Boris

    2016-01-20

    The properties of nonstatistical equilibrium ionization of silicon and oxygen ions are analyzed in this work. We focus on five solar targets (quiet Sun; coronal hole; plage; quiescent active region, AR; and flaring AR) as observed with the Interface Region Imaging Spectrograph (IRIS). IRIS is best suited for this work owing to the high cadence (up to 0.5 s), high spatial resolution (up to 0.″32), and high signal-to-noise ratios for O iv λ1401 and Si iv λ1402. We find that the observed intensity ratio between lines of three times ionized silicon and oxygen ions depends on their total intensity and that this correlation varies depending on the region observed (quiet Sun, coronal holes, plage, or active regions) and on the specific observational objects present (spicules, dynamic loops, jets, microflares, or umbra). In order to interpret the observations, we compare them with synthetic profiles taken from 2D self-consistent radiative MHD simulations of the solar atmosphere, where the statistical equilibrium or nonequilibrium treatment of silicon and oxygen is applied. These synthetic observations show vaguely similar correlations to those in the observations, i.e., between the intensity ratios and their intensities, but only in the nonequilibrium case do we find that (some of) the observations can be reproduced. We conclude that these lines are formed out of statistical equilibrium. We use our time-dependent nonequilibrium ionization simulations to describe the physical mechanisms behind these observed properties.

  14. Inhibition of Epithelial-mesenchymal Transition in Response to Treatment with Metformin and Y27632 in Breast Cancer Cell Lines.

    PubMed

    Leonel, Camila; Ferreira, Lívia Carvalho; Borin, Thaiz Ferraz; Moschetta, Marina Gobbe; Freitas, Gabriela Scavacini; Haddad, Michel Raineri; de Camargos Pinto Robles, João Antonio; Aparecida Pires de Campos Zuccari, Debora

    2017-01-01

    ROCK-1 expression is associated with the malignant character of tumors, while inhibiting this molecule results in a significant suppression of tumor metastasis. Likewise, transforming growth factor beta (TGF-β) is associated with this malignancy by having the ability to induce epithelial-mesenchymal transition (EMT). Metformin, a drug used in the treatment of diabetes, has previously been shown to inhibit EMT in breast cancer cells. The aim of this study is to evaluate the TGF-β1 action model for induction of EMT and the action of metformin and ROCK-1 inhibitor (Y27632) in EMT process in breast cancer cell lines. MCF-7 and MDA-MB-231 cell lines were treated with metformin and Y27632, after induction of EMT by TGF-β1, to examine the effects on cell migration as well as the protein expression of the ROCK-1 markers, vimentin, E-cadherin, CD44 and CD24 by immunocitochemistry. There was a lower protein expression of ROCK-1, vimentin, CD44 and CD24 in both cell lines after treatment with metformin and Y27632. In MDA-MB-231 cells, E-cadherin expression was increased in all treatment groups. Treatment of MDA-MB-231 cell line with metformin and Y27632 significantly reduced the invasion of these cells. This study confirms the benefits of metformin and Y27632 as potential therapeutic agents in mammary tumors, by blocking EMT process and metastatic potential. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Study of the Bus Dynamic Coscheduling Optimization Method under Urban Rail Transit Line Emergency

    PubMed Central

    Yan, Xuedong; Wang, Jiaxi; Chen, Shasha

    2014-01-01

    As one of the most important urban commuter transportation modes, urban rail transit (URT) has been acting as a key solution for supporting mobility needs in high-density urban areas. However, in recent years, high frequency of unexpected events has caused serious service disruptions in URT system, greatly harming passenger safety and resulting in severe traffic delays. Therefore, there is an urgent need to study emergency evacuation problem in URT. In this paper, a method of bus dynamic coscheduling is proposed and two models are built based on different evacuation destinations including URT stations and surrounding bus parking spots. A dynamic coscheduling scheme for buses can be obtained by the models. In the model solution process, a new concept—the equivalent parking spot—is proposed to transform the nonlinear model into an integer linear programming (ILP) problem. A case study is conducted to verify the feasibility of models. Also, sensitivity analysis of two vital factors is carried out to analyze their effects on the total evacuation time. The results reveal that the designed capacity of buses has a negative influence on the total evacuation time, while an increase in the number of passengers has a positive effect. Finally, some significant optimizing strategies are proposed. PMID:25530750

  16. Study of the bus dynamic coscheduling optimization method under urban rail transit line emergency.

    PubMed

    Wang, Yun; Yan, Xuedong; Zhou, Yu; Wang, Jiaxi; Chen, Shasha

    2014-01-01

    As one of the most important urban commuter transportation modes, urban rail transit (URT) has been acting as a key solution for supporting mobility needs in high-density urban areas. However, in recent years, high frequency of unexpected events has caused serious service disruptions in URT system, greatly harming passenger safety and resulting in severe traffic delays. Therefore, there is an urgent need to study emergency evacuation problem in URT. In this paper, a method of bus dynamic coscheduling is proposed and two models are built based on different evacuation destinations including URT stations and surrounding bus parking spots. A dynamic coscheduling scheme for buses can be obtained by the models. In the model solution process, a new concept-the equivalent parking spot-is proposed to transform the nonlinear model into an integer linear programming (ILP) problem. A case study is conducted to verify the feasibility of models. Also, sensitivity analysis of two vital factors is carried out to analyze their effects on the total evacuation time. The results reveal that the designed capacity of buses has a negative influence on the total evacuation time, while an increase in the number of passengers has a positive effect. Finally, some significant optimizing strategies are proposed.

  17. Discrete-line transitions from superdeformed to yrast states in {sup 194}Hg and {sup 192}Hg

    SciTech Connect

    Hackman, G.; Khoo, T.L.; Ackermann, D.

    1996-12-31

    Discrete-line {gamma}-ray decay from superdeformed (SD) to yrast states in {sup 194,192}Hg has been studied with the Gammasphere spectrometer. The previously established decay for the yrast SD band of {sup 194}Hg has been characterized further. In addition, one-step decays have been observed for {sup 194}Hg SD band 3, which fixes the excitation energy and spin of the last observed level of this band at E* = 7.455 MeV, J = 11{Dirac_h}. So far no direct decays from superdeformed to yrast states have been observed in {sup 192}Hg or in {sup 194}Hg band 2, a result which is consistent with fluctuations of the transition strengths.

  18. High efficiency annular magnetically insulated line oscillator-transit time oscillator with three separate frequencies in three bands

    NASA Astrophysics Data System (ADS)

    Xiao, Renzhen; Sun, Jun; Chen, Changhua; Zhang, Yongpeng; Shao, Hao

    2009-08-01

    To increase the efficiency of the magnetically insulated line oscillator (MILO) and expand its frequency band, a coaxial transit time oscillator (TTO) is introduced to use the load currents of an annular MILO, called the annular MILO-TTO, which comprises an inward-emitting MILO, an outward-emitting MILO, and a coaxial TTO. In simulation, when the input power is 78 GW and the diode voltage is 520 kV, three microwaves with powers of 3.2, 9.6, and 7.0 GW are generated, with a total efficiency of 25.4%, in the inward-emitting MILO, the outward-emitting MILO, and the coaxial TTO, and the frequencies are 1.7, 3.3, and 4.2 GHz, corresponding to L, S, and C bands, respectively.

  19. Frequency stabilization of a 1083 nm fiber laser to {sup 4}He transition lines with optical heterodyne saturation spectroscopies

    SciTech Connect

    Gong, W.; Peng, X. Li, W.; Guo, H.

    2014-07-15

    Two kinds of optical heterodyne saturation spectroscopies, namely, frequency modulation spectroscopy (FMS) and modulation transfer spectroscopy (MTS), are demonstrated for locking a fiber laser to the transition lines of metastable {sup 4}He atoms around 1083 nm. The servo-loop error signals of FMS and MTS for stabilizing laser frequency are optimized by studying the dependence of the peak-to-peak amplitude and slope on the optical power of pump and probe beams. A comparison of the stabilization performances of FMS/MTS and polarization spectroscopy (PS) is presented, which shows that MTS exhibits relatively superior performance with the least laser frequency fluctuation due to its flat-background dispersive signal, originated from the four-wave mixing process. The Allan deviation of the stabilized laser frequency is 5.4 × 10{sup −12}@100 s with MTS for data acquired in 1000 s, which is sufficiently applicable for fields like laser cooling, optical pumping, and optical magnetometry.

  20. Frequency stabilization of a 1083 nm fiber laser to 4He transition lines with optical heterodyne saturation spectroscopies

    NASA Astrophysics Data System (ADS)

    Gong, W.; Peng, X.; Li, W.; Guo, H.

    2014-07-01

    Two kinds of optical heterodyne saturation spectroscopies, namely, frequency modulation spectroscopy (FMS) and modulation transfer spectroscopy (MTS), are demonstrated for locking a fiber laser to the transition lines of metastable 4He atoms around 1083 nm. The servo-loop error signals of FMS and MTS for stabilizing laser frequency are optimized by studying the dependence of the peak-to-peak amplitude and slope on the optical power of pump and probe beams. A comparison of the stabilization performances of FMS/MTS and polarization spectroscopy (PS) is presented, which shows that MTS exhibits relatively superior performance with the least laser frequency fluctuation due to its flat-background dispersive signal, originated from the four-wave mixing process. The Allan deviation of the stabilized laser frequency is 5.4 × 10-12@100 s with MTS for data acquired in 1000 s, which is sufficiently applicable for fields like laser cooling, optical pumping, and optical magnetometry.

  1. Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds.

    PubMed

    Bishop, P J; Clemente, C J; Weems, R E; Graham, D F; Lamas, L P; Hutchinson, J R; Rubenson, J; Wilson, R S; Hocknull, S A; Barrett, R S; Lloyd, D G

    2017-07-01

    How extinct, non-avian theropod dinosaurs locomoted is a subject of considerable interest, as is the manner in which it evolved on the line leading to birds. Fossil footprints provide the most direct evidence for answering these questions. In this study, step width-the mediolateral (transverse) distance between successive footfalls-was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age. Comparable kinematic data were also collected for humans and 11 species of ground-dwelling birds. Permutation tests of the slope on a plot of step width against stride length showed that step width decreased continuously with increasing speed in the extinct theropods (p < 0.001), as well as the five tallest bird species studied (p < 0.01). Humans, by contrast, showed an abrupt decrease in step width at the walk-run transition. In the modern bipeds, these patterns reflect the use of either a discontinuous locomotor repertoire, characterized by distinct gaits (humans), or a continuous locomotor repertoire, where walking smoothly transitions into running (birds). The non-avian theropods are consequently inferred to have had a continuous locomotor repertoire, possibly including grounded running. Thus, features that characterize avian terrestrial locomotion had begun to evolve early in theropod history. © 2017 The Author(s).

  2. Masses, widths, and leptonic widths of the higher upsilon resonances

    NASA Astrophysics Data System (ADS)

    Lovelock, D. M.; Horstkotte, J. E.; Klopfenstein, C.; Lee-Franzini, J.; Romero, L.; Schamberger, R. D.; Youssef, S.; Franzini, P.; Son, D.; Tuts, P. M.; Zhao, T.; Herb, S.; Dietl, H.; Eigen, G.; Fonseca, V.; Lorenz, E.; Mageras, G.; Han, K.; Imlay, R.; Metcalf, W.; Sreedhar, V.

    1985-02-01

    The masses, total widths, and leptonic widths of three triplet s-wave bb¯ states Υ(4S), Υ(5S), and Υ(6S) are determined from measurements of the e+e- annihilation cross section into hadrons for 10.55

  3. Relation between index finger width and hand width anthropometric measures.

    PubMed

    Komandur, Sashidharan; Johnson, Peter W; Storch, Richard L; Yost, Michael G

    2009-01-01

    Measures of hand and finger anthropometry are very important for designing many hand held devices as well as understanding anthropometric effects on the operation of such devices. Many historical datasets have measured and recorded gross hand dimensions but do not often record the finer dimensions of the hand such as finger anthropometry. Knowing the size and mass of fingers across genders can be critical to the design and operation of hand held devices. In this paper we compare two empirical linear models that predicts index finger width at the proximal interphalangeal (PIP) joint (a finger anthropometric measure) based on hand-width (hand anthropometric measure). This will be especially useful for deriving population measures of finger anthropometry from large historical data sets where only gross hand dimensions are available.

  4. Relation between the Widom line and the dynamic crossover in systems with a liquid–liquid phase transition

    PubMed Central

    Xu, Limei; Kumar, Pradeep; Buldyrev, S. V.; Chen, S.-H.; Poole, P. H.; Sciortino, F.; Stanley, H. E.

    2005-01-01

    We investigate, for two water models displaying a liquid–liquid critical point, the relation between changes in dynamic and thermodynamic anomalies arising from the presence of the liquid–liquid critical point. We find a correlation between the dynamic crossover and the locus of specific heat maxima \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}C_{P}^{{\\mathrm{max}}}\\end{equation*}\\end{document} (“Widom line”) emanating from the critical point. Our findings are consistent with a possible relation between the previously hypothesized liquid–liquid phase transition and the transition in the dynamics recently observed in neutron scattering experiments on confined water. More generally, we argue that this connection between \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}C_{P}^{{\\mathrm{max}}}\\end{equation*}\\end{document} and dynamic crossover is not limited to the case of water, a hydrogen bond network-forming liquid, but is a more general feature of crossing the Widom line. Specifically, we also study the Jagla potential, a spherically symmetric two-scale potential known to possess a liquid–liquid critical point, in which the competition between two liquid structures is generated by repulsive and attractive ramp interactions. PMID:16267132

  5. Comparative Analysis of a Transition Region Bright Point with a Blinker and Coronal Bright Point Using Multiple EIS Emission Lines

    NASA Astrophysics Data System (ADS)

    Orange, N. Brice; Oluseyi, Hakeem M.; Chesny, David L.; Patel, Maulik; Hesterly, Katie; Preuss, Lauren; Neira, Chantale; Turner, Niescja E.

    2014-05-01

    Since their discovery 20 year ago, transition region bright points have never been observed spectroscopically. Bright point properties have not been compared with similar transition region and coronal structures. In this work we have investigated three transient quiet Sun brightenings including a transition region bright point (TR BP), a coronal bright point (CBP) and a blinker. We use time-series observations of the extreme-ultraviolet emission lines of a wide range of temperature T (log T=5.3 - 6.4) from the EUV Imaging Spectrometer (EIS) onboard the Hinode satellite. We present the EIS temperature maps and Doppler maps, which are compared with magnetograms from the Michelson Doppler Imager (MDI) onboard the SOHO satellite. Doppler velocities of the TR BP and blinker are ≤ 25 km s-1, which is typical of transient TR phenomena. The Doppler velocities of the CBP were found to be ≤ 20 km s-1 with exception of those measured at log T=6.2 where a distinct bi-directional jet is observed. From an EM loci analysis we find evidence of single and double isothermal components in the TR BP and CBP, respectively. TR BP and CBP loci curves are characterized by broad distributions suggesting the existence of unresolved structure. By comparing and contrasting the physical characteristics of the events we find that the BP phenomena are an indication of multi-scaled self-similarity, given the similarities in both their underlying magnetic field configuration and evolution in relation to EUV flux changes. In contrast, the blinker phenomena and the TR BP are sufficiently dissimilar in their observed properties as to constitute different event classes. Our work is an indication that the measurement of similar characteristics across multiple event types holds class-predictive power, and is a significant step towards automated solar atmospheric multi-class classification of unresolved transient EUV sources. Finally, the analysis performed here establishes a connection between solar

  6. Chidamide alleviates TGF-β-induced epithelial-mesenchymal transition in lung cancer cell lines.

    PubMed

    Lin, Sheng-Hao; Wang, Bing-Yen; Lin, Ching-Hsiung; Chien, Peng-Ju; Wu, Yueh-Feng; Ko, Jiunn-Liang; Chen, Jeremy J W

    2016-07-01

    Transforming growth factor-β (TGF-β)-induced epithelial-mesenchymal transition is a critical process in the initiation of metastasis of various types of cancer. Chidamide is a class I histone deacetylase inhibitor with anti-tumor activity. This study investigated the effects of chidamide on TGF-β-mediated suppression of E-cadherin expression in adenocarcinomic lung epithelial cells and the molecular mechanisms involved in these effects. Western blot analysis, confocal microscopy, Quantitative methyl-specific PCR and bisulfite sequencing were used to evaluate the effects of different treatments on chidamide ameliorating TGF-β induced-E-cadherin loss. H3 acetylation binding to the promoter of E-cadherin was detected by chromatin immunoprecipitations (CHIP). We found that chidamide reduced the level of lung cancer cell migration observed using a Boyden chamber assay (as an indicator of metastatic potential). Chidamide inhibited TGF-β-induced SMAD2 phosphorylation and attenuated TGF-β-induced loss of E-cadherin expression in lung cancer cells by Western blotting and confocal microscopy, respectively. Quantitative methyl-specific PCR and bisulfite sequencing revealed that TGF-β-enhanced E-cadherin promoter methylation was ameliorated in cells treated with chidamide. We demonstrated that histone H3 deacetylation within the E-cadherin promoter was required for TGF-β-induced E-cadherin loss; cell treatment with chidamide increased the H3 acetylation detected by CHIP. Taken together, our results demonstrate that TGF-β suppressed E-cadherin expression by regulating promoter methylation and histone H3 acetylation. Chidamide significantly enhanced E-cadherin expression in TGF-β-treated cells and inhibited lung cancer cell migration. These findings indicate that chidamide has a potential therapeutic use due to its capacity to prevent cancer cell metastasis.

  7. Preliminary experimental investigation of a Ku-band radial line oscillator based on transition radiation effect

    SciTech Connect

    Dang, Fangchao Zhang, Xiaoping; Zhong, Huihuang; Li, Yangmei

    2015-09-15

    A Ku-band radial line oscillator (RLO) with low guiding magnetic field was proposed in our previous work. In order to weaken the impedance mismatch between the oscillator and an intense electron accelerator with higher impedance, a transverse electromagnetic reflector is added to improve the RLO, which is favorable to increase the Q-factor and accelerate the device saturation. A preliminary experiment is carried out to investigate the performance of the improved RLO. The radial-radiated electron beam is restrained well under the designed guiding magnetic field of 0.52 T. The preliminary experimental results indicates that high power microwaves with a power of 120 MW and a frequency of 14.12 GHz are generated when the diode voltage is 420 kV and the beam current 14.2 kA. The experimental results suggest the feasibility of the presented RLO generating high power microwaves at a high frequency band. Additionally, more work is needed regarding promotion of the electron beam quality and the impedance match between the electron beam accelerator and the oscillator.

  8. Preliminary experimental investigation of a Ku-band radial line oscillator based on transition radiation effect

    NASA Astrophysics Data System (ADS)

    Dang, Fangchao; Zhang, Xiaoping; Zhong, Huihuang; Li, Yangmei

    2015-09-01

    A Ku-band radial line oscillator (RLO) with low guiding magnetic field was proposed in our previous work. In order to weaken the impedance mismatch between the oscillator and an intense electron accelerator with higher impedance, a transverse electromagnetic reflector is added to improve the RLO, which is favorable to increase the Q-factor and accelerate the device saturation. A preliminary experiment is carried out to investigate the performance of the improved RLO. The radial-radiated electron beam is restrained well under the designed guiding magnetic field of 0.52 T. The preliminary experimental results indicates that high power microwaves with a power of 120 MW and a frequency of 14.12 GHz are generated when the diode voltage is 420 kV and the beam current 14.2 kA. The experimental results suggest the feasibility of the presented RLO generating high power microwaves at a high frequency band. Additionally, more work is needed regarding promotion of the electron beam quality and the impedance match between the electron beam accelerator and the oscillator.

  9. What sets the minimum tokamak scrape-off layer width?

    NASA Astrophysics Data System (ADS)

    Joseph, Ilon

    2016-10-01

    The heat flux width of the tokamak scrape-off layer is on the order of the poloidal ion gyroradius, but the ``heuristic drift'' physics model is still not completely understood. In the absence of anomalous transport, neoclassical transport sets the minimum width. For plateau collisionality, the ion temperature width is set by qρi , while the electron temperature width scales as the geometric mean q(ρeρi) 1 / 2 and is close to qρi in magnitude. The width is enhanced because electrons are confined by the sheath potential and have a much longer time to radially diffuse before escaping to the wall. In the Pfirsch-Schluter regime, collisional diffusion increases the width by the factor (qR / λ) 1 / 2 where qR is the connection length and λ is the mean free path. This qualitatively agrees with the observed transition in the scaling law for detached plasmas. The radial width of the SOL electric field is determined by Spitzer parallel and ``neoclassical'' radial electric conductivity and has a similar scaling to that for thermal transport. Prepared under US DOE contract DE-AC52-07NA27344.

  10. Gamma secretase inhibitor impairs epithelial-to-mesenchymal transition induced by TGF-β in ovarian tumor cell lines.

    PubMed

    Pazos, M C; Abramovich, D; Bechis, A; Accialini, P; Parborell, F; Tesone, M; Irusta, G

    2017-01-15

    Ovarian cancer is characterized by being highly metastatic, a feature that represents the main cause of failure of the treatment. This study investigated the effects of γ-secretase inhibition on the TGF-β-induced epithelial-mesenchymal transition (EMT) process in ovarian cancer cell lines. SKOV3 cells incubated in the presence of TGF-β showed morphological and biochemical changes related to EMT, which were blocked by co-stimulation with TGF-β and the γ-secretase inhibitor DAPT. In SKOV3 and IGROV1 cells, the co-stimulation blocked the cadherin switch and the increase in the transcription factors Snail, Slug, Twist and Zeb1 induced by TGF-β. DAPT impaired the translocation of phospho-β-catenin to the inner cell compartment observed in TGF-β-treated cells, but was not able to block the induction at protein level induced by TGF-β. Moreover, the inhibitor blocked the increased cell migration and invasiveness ability of both cell lines induced by TGF-β. Notch target genes (Hes1 and Hey1) were induced by TGF-β, decreased by DAPT treatment and remained low in the presence of both stimuli. However, DAPT alone caused no effects on most of the parameters analyzed. These results demonstrate that the γ-secretase inhibitor used in this study exerted a blockade on TGF-β-induced EMT in ovarian cancer cells.

  11. Experimental measurements of selenium x-ray laser spectral line profiles

    SciTech Connect

    Koch, J.A.; MacGowan, B.J.; Da Silva, L.B.; Matthews, D.L.; London, R.A.; Lee, R.W.; Mrowka, S.; Underwood, J.H.; Batson, P.J.

    1993-03-01

    The authors discuss their recent measurements of the spectral width of the 206.38 {Angstrom} x-ray laser transition in Ne-like Se. These measurements used a high-resolution grating spectrometer and were performed over a wide range of laser amplifier lengths. The data have enabled them to extrapolate the intrinsic line width and to observe the effects of gain-narrowing and saturation on the line profile. They find an intrinsic width which is 1.4 times the Doppler width, they observe gain-narrowing in intermediate length amplifiers, and they observe no re-broadening in long, saturated amplifiers. These results suggest that collisional line-broadening has a significant effect on the line profile and saturation behavior of this laser.

  12. Mapping variable width riparian buffers

    Treesearch

    Sinan Abood

    2016-01-01

    Riparian buffers are dynamic, transitional ecosystems between aquatic and terrestrial ecosystems with well-defined vegetation and soil characteristics. Previous approaches to riparian buffer delineation have...

  13. Limb-brightening curves of XUV transition zone lines in the quiet sun and in a polar coronal hole observed from Skylab

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.; Tousey, R.; Feldman, U.

    1975-01-01

    Solar limb-brightening curves are discussed for XUV spectral lines formed in the upper chromosphere and transition zone of a quiet region and a polar coronal hole. The spectra were recorded with a slit spectrograph on Skylab. The lines considered are emitted from ions formed within the temperature range from 10,000 to 220,000 K. The limb-brightening curves cover a region from -4 sec within the limb to +20 sec above it. The data from 0 sec to +20 sec are compared with predictions based on both homogeneous and inhomogeneous models of the transition zone. The limb-brightening curve of the O I line at 1355.6 A indicates that O I is formed in spicules. The limb brightening of the He II line at 1640.4 A is consistent with a temperature of formation between about 40,000 and 90,000 K for He II.

  14. Spectroscopic observations of the exoplanet WASP-32b transit

    NASA Astrophysics Data System (ADS)

    Grauzhanina, A. O.; Valyavin, G. G.; Gadelshin, D. R.; Baklanova, D. N.; Plachinda, S. I.; Antonyuk, K. A.; Pit, N. V.; Galazutdinov, G. A.; Valeev, A. F.; Burlakova, T. E.; Kholtygin, A. F.

    2017-01-01

    We present first results of spectroscopic observations of transiting exoplanets in the Special Astrophysical Observatory of the Russian Academy of Sciences with the Main Stellar Spectrograph of the 6-m BTA telescope. For the exoplanetWASP-32b, we detected a significant variation of intensity and equivalent width in the Hα spectral line of the parent star at the time of a transit. The equivalent width of the line during transit is by 8-10% larger than outside the planet passage. Residual intensity in the core of the line reveals the following tendency: the line is by 10-15% deeper inside transit than outside it. Observations with the long-slit spectrograph of the Crimean Astrophysical Observatory at the 2.6-m ZTSh telescope also showed a transit event in the Hα line, although, with a smaller amplitude and shape inverted in relation to the data from the 6-m telescope. While in the observations with the BTA the Hα line becomes deeper during the transit, in the ZTSh observations, the residual intensity of the Hα line decreases during the transit. Reducing and analysis of the archive data of WASP-32b observations with the HARPS spectrograph also confirm the Hα line modulation at the time of the transit. The observed data give evidence of the envelope in WASP-32b filling the Roche lobe and a comet-like tail of changing geometry and orientation relative to the observer. These changes determine different depths and shapes of the Hα spectral line at the time of transits.

  15. Optical waveguide device with an adiabatically-varying width

    DOEpatents

    Watts; Michael R. , Nielson; Gregory N.

    2011-05-10

    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  16. Fixed-Width Confidence Intervals in Linear Regression with Applications to the Johnson-Neyman Technique.

    ERIC Educational Resources Information Center

    Aitkin, Murray A.

    Fixed-width confidence intervals for a population regression line over a finite interval of x have recently been derived by Gafarian. The method is extended to provide fixed-width confidence intervals for the difference between two population regression lines, resulting in a simple procedure analogous to the Johnson-Neyman technique. (Author)

  17. Activation of LINE-1 Retrotransposon Increases the Risk of Epithelial-Mesenchymal Transition and Metastasis in Epithelial Cancer

    PubMed Central

    Rangasamy, D.; Lenka, N.; Ohms, S.; Dahlstrom, J.E.; Blackburn, A.C.; Board, P.G.

    2015-01-01

    Epithelial cancers comprise 80-90% of human cancers. During the process of cancer progression, cells lose their epithelial characteristics and acquire stem-like mesenchymal features that are resistant to chemotherapy. This process, termed the epithelial-mesenchymal transition (EMT), plays a critical role in the development of metastases. Because of the unique migratory and invasive properties of cells undergoing the EMT, therapeutic control of the EMT offers great hope and new opportunities for treating cancer. In recent years, a plethora of genes and noncoding RNAs, including miRNAs, have been linked to the EMT and the acquisition of stem cell-like properties. Despite these advances, questions remain unanswered about the molecular processes underlying such a cellular transition. In this article, we discuss how expression of the normally repressed LINE-1 (or L1) retrotransposons activates the process of EMT and the development of metastases. L1 is rarely expressed in differentiated stem cells or adult somatic tissues. However, its expression is widespread in almost all epithelial cancers and in stem cells in their undifferentiated state, suggesting a link between L1 activity and the proliferative and metastatic behaviour of cancer cells. We present an overview of L1 activity in cancer cells including how genes involved in proliferation, invasive and metastasis are modulated by L1 expression. The role of L1 in the differential expression of the let-7 family of miRNAs (that regulate genes involved in the EMT and metastasis) is also discussed. We also summarize recent novel insights into the role of the L1-encoded reverse transcriptase enzyme in epithelial cell plasticity that suggest it might be a potential therapeutic target that could reverse the EMT and the metastasis-associated stem cell-like properties of cancer cells. PMID:26321759

  18. High-resolution measurements, line identification, and spectral modeling of K{alpha} transitions in Fe XVIII-XXV

    SciTech Connect

    Beiersdorfer, P.; Phillips, T.; Jacobs, V.L.; Hill, K.W.; Bitter, M.; von Goeler, S.; Kahn, S.M.

    1992-11-01

    The iron K{alpha} emission spectrum covering the wavelength region from 1.840 to 1.940 {Angstrom} is analyzed. Measurements are made with a high-resolution Bragg crystal spectrometer on the Princeton Large Torus (PLT) tokamak for plasma conditions which closely resemble those of solar flares. A total of 40 features are identified consisting of either single or multiple lines from eight charge states in iron, Fe XVIII through Fe XXV, and their wavelengths are determined with an accuracy of 0.1--0.4 m{Angstrom}. Many of these features are identified for the first time. In the interpretation of our observations we rely on model calculations that determine the ionic species abundances from electron density and temperature profiles measured independently with non-spectroscopic techniques and that incorporate theoretical collisional excitation and dielectronic recombination rates resulting in the excitation of the 1s2s{sup r}2p{sup s} configurations. The model calculations also include the effect of diffusive ion transport. Good overall agreement between the model calculations and the observations is obtained, which gives us confidence in our line identifications and spectral modeling capabilities. The results are compared with earlier analyses of the K{alpha} emission from the Sun. While many similarities are found, a few differences arise from the somewhat higher electron density in tokamak plasmas (10{sup 13} cm{sup {minus}3}), which affects the fine-structure level populations of the ground states of the initial ion undergoing electron-impact excitation or dielectronic recombination. We also find that several spectral features are comprised of different transitions from those reported in earlier analyses of solar data.

  19. High-resolution measurements, line identification, and spectral modeling of K[alpha] transitions in Fe XVIII-XXV

    SciTech Connect

    Beiersdorfer, P.; Phillips, T. ); Jacobs, V.L. . Condensed Matter and Radiation Sciences Div.); Hill, K.W.; Bitter, M.; von Goeler, S. . Plasma Physics Lab.); Kahn, S.M. )

    1992-11-01

    The iron K[alpha] emission spectrum covering the wavelength region from 1.840 to 1.940 [Angstrom] is analyzed. Measurements are made with a high-resolution Bragg crystal spectrometer on the Princeton Large Torus (PLT) tokamak for plasma conditions which closely resemble those of solar flares. A total of 40 features are identified consisting of either single or multiple lines from eight charge states in iron, Fe XVIII through Fe XXV, and their wavelengths are determined with an accuracy of 0.1--0.4 m[Angstrom]. Many of these features are identified for the first time. In the interpretation of our observations we rely on model calculations that determine the ionic species abundances from electron density and temperature profiles measured independently with non-spectroscopic techniques and that incorporate theoretical collisional excitation and dielectronic recombination rates resulting in the excitation of the 1s2s[sup r]2p[sup s] configurations. The model calculations also include the effect of diffusive ion transport. Good overall agreement between the model calculations and the observations is obtained, which gives us confidence in our line identifications and spectral modeling capabilities. The results are compared with earlier analyses of the K[alpha] emission from the Sun. While many similarities are found, a few differences arise from the somewhat higher electron density in tokamak plasmas (10[sup 13] cm[sup [minus]3]), which affects the fine-structure level populations of the ground states of the initial ion undergoing electron-impact excitation or dielectronic recombination. We also find that several spectral features are comprised of different transitions from those reported in earlier analyses of solar data.

  20. Evidence for structural phase transitions induced by the triple phase line shift in self-catalyzed GaAs nanowires.

    PubMed

    Yu, Xuezhe; Wang, Hailong; Lu, Jun; Zhao, Jianhua; Misuraca, Jennifer; Xiong, Peng; von Molnár, Stephan

    2012-10-10

    Self-catalyzed growth of GaAs nanowires are widely ascribed to the vapor-liquid-solid (VLS) mechanism due to the presence of Ga particles at the nanowire tips. Here we report synthesis of self-catalyzed GaAs nanowires by molecular-beam epitaxy covering a large growth parameter space. By carefully controlling the Ga flux and its ratio with the As flux, GaAs nanowires without Ga particles and exhibiting a flat growth front are produced. Using scanning electron microscopy and high-resolution transmission electron microscopy, we compare the growth rate and structure, especially near the growth front, of the nanowires with and without Ga droplets. We find that regardless of whether Ga droplets are present on top, the nanowires have a short wurtzite section following the zinc-blende bulk structure. The nanowires without Ga droplets are terminated by a thin zinc-blende cap, while the nanowires with Ga droplets do not have such a cap. The bulk zinc-blende phase is attributed to the Ga droplet wetting the sidewall during growth, pinning the triple phase line on the sidewall. The zinc-blend/wurtzite/(zinc-blende) phase transitions at the end of growth are fully consistent with the triple phase line shifting up to the growth front due to the progressive consumption of the Ga in the droplet by crystallization with As. The results imply an identical VLS growth mechanism for both types of GaAs NWs, and their intricate structures provide detailed comparison with and specific experimental verification of the recently proposed growth mechanism for self-catalyzed III-V semiconductor nanowires ( Phy. Rev. Lett. 2011 , 106 , 125505 ). Using this mechanism as a guideline, we successfully demonstrated controllable fabrication of two distinct types of axial superlattice GaAs NWs consisting of zinc-blende/defect-section and wurtzite/defect-section units.

  1. Widths and Shifts of Isolated Lines of Neutral and Ionized Atoms Perturbed by Collisions With Electrons and Ions: An Outline of the Semiclassical Perturbation (SCP) Method and of the Approximations Used for the Calculations

    NASA Astrophysics Data System (ADS)

    Sahal-Bréchot, Sylvie; Dimitrijević, Milan; Nessib, Nabil

    2014-06-01

    "Stark broadening" theory and calculations have been extensively developed for about 50 years. The theory can now be considered as mature for many applications, especially for accurate spectroscopic diagnostics and modeling, in astrophysics, laboratory plasma physics and technological plasmas, as well. This requires the knowledge of numerous collisional line profiles. In order to meet these needs, the "SCP" (semiclassical perturbation) method and numerical code were created and developed. The SCP code is now extensively used for the needs of spectroscopic diagnostics and modeling, and the results of the published calculations are displayed in the STARK-B database. The aim of the present paper is to introduce the main approximations leading to the impact of semiclassical perturbation method and to give formulae entering the numerical SCP code, in order to understand the validity conditions of the method and of the results; and also to understand some regularities and systematic trends. This would also allow one to compare the method and its results to those of other methods and codes.

  2. Tunable RF-excited CO/sub 2/ waveguide laser with variable guide width

    SciTech Connect

    Hill, C.A.; Monk, P.; Hall, D.R.

    1987-11-01

    The resonator mode frequencies and the interline and intraline tuning behavior of CO/sub 2/ waveguide lasers should depend strongly on precise guide dimension. The authors describe a compact grating-tuned RF-excited device with a rectangular Al/Al/sub 2/O/sub 3/ waveguide whose width can be varied during operation. It yields approx. =50 mW with a continuous tuning range of approx. =500 MHz on stronger lines; more interestingly, its line selectivity does seem to depend on guide width, as they predict. In particular, the losses of unwanted lines (and thus the tuning range within a desired line) are very sensitive to waveguide width, because the resonator mode associated with an unwanted line may have significant higher order waveguide mode content. This suggest that variable-width waveguides offer one solution to the problem of line-hopping, without prejudice to the power or transverse mode quality obtainable on the desired line.

  3. Improved Experimental Line Positions for the (1,1) Band of the b 1Σ+ - X 3Σ- Transition of O2 by Intracavity Laser Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    O'Brien, Leah C.; O'Brien, Emily C.; O'Brien, James J.

    2012-06-01

    We report improved experimental line positions for the (1,1) band of the b 1Σ+ - X 3Σ- transition of O2. Results are comparised with previous experimental measurements and predicted values. Additionally, a new method of producing vibrationally hot molecules for use in absorption spectroscopy of stable gas phase molecules is described.

  4. Tables of Relative Strengths of Spectral Lines with Mixed Vector Couplings: Dipole Transitions Between LS and Other Couplings

    NASA Astrophysics Data System (ADS)

    Gongora, T. A.; Escalante, V.

    1991-04-01

    RESUMEN Se presentan tablas de intensidades de oscilador de dipolares del tipo (2SP+1)Lp ni - (2SP+l)Lp ml' para 0 < Sp < 2, 0 < Lp < 2, 1 < 1 <4, para cualquier n y m, en que uno de los estados se describe en el esquema de acoplamiento LS y el otro se describe en el esquema de acoplamiento LK, jK 6 jj. Nuestros resultados son utiles en Ia interpretaci6n e identificaci6n de lfneas espectrales entre estados con ntimeros cuanticos similares. ABSTRACT Tables are presented for the relative strength of dipole transitions of the type (2SP+l)Lp ni - (2SP+l)Lp ml' for 0 < Sp < 2, 0 < Lp < 2, 1 < 1 <4, and for any n and m, in which one of the states is described with the Ls coupling scheme, and the other is described with the LK, jK, or jj coupling scheme. Our results are useful in the interpretation and identification of spectral lines between states with similar quantum numbers. K words: ATOMIC AND MOLECULAR DATA - PROBABILITES

  5. Hydrodynamic study of plasma amplifiers for soft-x-ray lasers: a transition in hydrodynamic behavior for plasma columns with widths ranging from 20 μm to 2 mm.

    PubMed

    Oliva, Eduardo; Zeitoun, Philippe; Velarde, Pedro; Fajardo, Marta; Cassou, Kevin; Ros, David; Sebban, Stephan; Portillo, David; le Pape, Sebastien

    2010-11-01

    Plasma-based seeded soft-x-ray lasers have the potential to generate high energy and highly coherent short pulse beams. Due to their high density, plasmas created by the interaction of an intense laser with a solid target should store the highest amount of energy density among all plasma amplifiers. Our previous numerical work with a two-dimensional (2D) adaptive mesh refinement hydrodynamic code demonstrated that careful tailoring of plasma shapes leads to a dramatic enhancement of both soft-x-ray laser output energy and pumping efficiency. Benchmarking of our 2D hydrodynamic code in previous experiments demonstrated a high level of confidence, allowing us to perform a full study with the aim of the way for 10-100 μJ seeded soft-x-ray lasers. In this paper, we describe in detail the mechanisms that drive the hydrodynamics of plasma columns. We observed transitions between narrow plasmas, where very strong bidimensional flow prevents them from storing energy, to large plasmas that store a high amount of energy. Millimeter-sized plasmas are outstanding amplifiers, but they have the limitation of transverse lasing. In this paper, we provide a preliminary solution to this problem.

  6. Extra sub-Doppler lines in the vicinity of the third-resonance 6S-8P transition of atomic Cs attributed to optically induced Cs dimers

    NASA Astrophysics Data System (ADS)

    Passerat de Silans, Thierry; Maurin, Isabelle; Laliotis, Athanasios; Segundo, Pedro Chaves De Souza; Bloch, Daniel

    2011-04-01

    We report on the observation of additional sub-Doppler lines in a saturated absorption experiment when exploring the vicinity of the 6S1/2-8P3/2 transition of Cs (λ=388 nm). These additional lines are observed only under a relatively strong irradiation of both the pump and the probe beams. Extra narrow lines are also observed in copropagating nonlinear spectroscopy, and around the lines of the V-type three-level system 8P3/2-6S1/2-8P1/2 (λ1=388 nm, λ2=389 nm). We attribute theses additional lines to a probing of high-lying molecular cesium, produced as a result of the optical excitation of Cs atoms, as the low Cs atom density (≤1012cm-3) is unable to populate significantly the dimer states in the condition of thermal equilibrium.

  7. Spectroscopic Transit of Exoplanet WASP-32 b

    NASA Astrophysics Data System (ADS)

    Grauzhanina, A. O.; Gadelshin, D. R.; Baklanova, D. N.; Plachinda, S. I.; Antonyuk, K. A.; Pit, N. V.; Valyavin, G. G.; Galazutdinov, G. A.; Valeev, A. F.; Burlakova, T. E.; Kholtygin, A. F.

    2017-06-01

    Observations of the exoplanet WASP-32 b with the Main Stellar Spectrograph at the 6-m BTA telescope have revealed the presence of a significant change in the intensity and the equivalent width of the Hα spectral line in the spectrum of the parent star of WASP-32 at the time of planet's transit. These observations are discussed in the context of the presence of a hydrogen shell at WASP-32 b filling the Roche lobe of the planet.

  8. Modelling of intense line radiation from laser-produced plasmas

    SciTech Connect

    Lee, Yim T.; Gee, M.

    1990-04-01

    In this paper, we discuss modelling of Lyman-{alpha} (i.e. Ly-{alpha}) radiation emitted from laser-produced plasmas. We are interested in the application of one of these line radiations to pump a transition of an ion in a different plasma spatially separated from the emitting source. The interest is in perturbing the plasma rather than just probing it as in some backlighting experiments. As a result of pumping, the populations of certain excited levels are inverted. The resulting gain coefficients depend strongly on the population inversion density which in turn depends on the brightness of the pump radiation. As a result, we must produce an intense bright radiation source. In addition, to pump a transition effectively, we also need a pump line with a width larger than the mismatch of the resonance since the widths of the pumped transitions are rather narrow

  9. 7 CFR 29.1085 - Width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Width, as an element of quality, does not apply to tobacco in strip form. (See Elements of Quality Chart... Heavy Fleshy Medium Thin Oil Lean Oily Rich Color intensity Pale Weak Moderate Strong Deep. Width... quality...

  10. 7 CFR 29.1085 - Width.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Width, as an element of quality, does not apply to tobacco in strip form. (See Elements of Quality Chart... Heavy Fleshy Medium Thin Oil Lean Oily Rich Color intensity Pale Weak Moderate Strong Deep. Width... quality...

  11. Interatomic Coulombic decay widths of helium trimer: Ab initio calculations

    SciTech Connect

    Kolorenč, Přemysl; Sisourat, Nicolas

    2015-12-14

    We report on an extensive study of interatomic Coulombic decay (ICD) widths in helium trimer computed using a fully ab initio method based on the Fano theory of resonances. Algebraic diagrammatic construction for one-particle Green’s function is utilized for the solution of the many-electron problem. An advanced and universal approach to partitioning of the configuration space into discrete states and continuum subspaces is described and employed. Total decay widths are presented for all ICD-active states of the trimer characterized by one-site ionization and additional excitation of an electron into the second shell. Selected partial decay widths are analyzed in detail, showing how three-body effects can qualitatively change the character of certain relaxation transitions. Previously unreported type of three-electron decay processes is identified in one class of the metastable states.

  12. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  13. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  14. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  15. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  16. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  17. 23 CFR 658.15 - Width.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, WIDTH AND WEIGHT LIMITATIONS § 658.15 Width. (a) No State shall impose a width limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches) on...

  18. [Molecular networks and mechanisms of epithelial-mesenchymal transition regulated by miRNAs in the malignant melanoma cell line].

    PubMed

    Dong, Wang; Yongjun, Li; Nan, Ding; Junyun, Wang; Qiong, Yang; Yaran, Yang; Yanming, Li; Xiangdong, Fang; Hua, Zhao

    2015-07-01

    Melanoma is a malignant cutaneous cancer of high metastasis and lethal rates. Epithelial-mesenchymal transition (EMT) plays an important role in the embryonic developmental process that is often activated during tumorigenesis and metastasis. In this study, we integrated of mRNA and miRNA transcriptome sequencing data of melanocyte and melanoma cell lines to identify genes involved in the process of tumor EMT in the first place, and uncovered 11 miRNAs including miR-130a-3p, miR-130b-3p, miR-125a-5p, miR-30a-3p, miR-195-5p, miR-345-5p, miR-509-3-5p, miR-374a-5p, miR-509-5p, miR-148a-3p and miR-330-3p, negatively related with EMT genes using the Mirsystem software. Bioinformatics analysis with target genes of these miRNAs revealed two networks closely related with cellular development and cell-to-cell interactions, as well as multiple signaling pathways participating in EMT. Validation of the 11 miRNAs with molecular biology experiments demonstrated that four miRNAs regulated oncogenes in melanomas, including miR-195-5p, miR-130a-3p, miR-509-5p, and miR-509-3-5p. Our study integrates two kinds of omics data to screen for EMT-related miRNAs, providing a new research idea in the precision genomics of cancer research.

  19. MEG3 Long Noncoding RNA Contributes to the Epigenetic Regulation of Epithelial-Mesenchymal Transition in Lung Cancer Cell Lines.

    PubMed

    Terashima, Minoru; Tange, Shoichiro; Ishimura, Akihiko; Suzuki, Takeshi

    2017-01-06

    Histone methylation is implicated in a number of biological and pathological processes, including cancer development. In this study, we investigated the molecular mechanism for the recruitment of Polycomb repressive complex-2 (PRC2) and its accessory component, JARID2, to chromatin, which regulates methylation of lysine 27 of histone H3 (H3K27), during epithelial-mesenchymal transition (EMT) of cancer cells. The expression of MEG3 long noncoding RNA (lncRNA), which could interact with JARID2, was clearly increased during transforming growth factor-β (TGF-β)-induced EMT of human lung cancer cell lines. Knockdown of MEG3 inhibited TGF-β-mediated changes in cell morphology and cell motility characteristic of EMT and counteracted TGF-β-dependent changes in the expression of EMT-related genes such as CDH1, ZEB family, and the microRNA-200 family. Overexpression of MEG3 influenced the expression of these genes and enhanced the effects of TGF-β in their expressions. Chromatin immunoprecipitation (ChIP) revealed that MEG3 regulated the recruitment of JARID2 and EZH2 and histone H3 methylation on the regulatory regions of CDH1 and microRNA-200 family genes for transcriptional repression. RNA immunoprecipitation and chromatin isolation by RNA purification assays indicated that MEG3 could associate with JARID2 and the regulatory regions of target genes to recruit the complex. This study demonstrated a crucial role of MEG3 lncRNA in the epigenetic regulation of the EMT process in lung cancer cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Electron impact excitation of Mg VIII . Collision strengths, transition probabilities and theoretical EUV and soft X-ray line intensities for Mg VIII

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    Context. Mg viii emission lines are observed in a range of astronomical objects such as the Sun, other cool stars and in the coronal line region of Seyfert galaxies. Under coronal conditions Mg viii emits strongly in the extreme ultraviolet (EUV) and soft X-ray spectral regions which makes it an ideal ion for plasma diagnostics. Aims: Two theoretical atomic models, consisting of 125 fine structure levels, are developed for the Mg viii ion. The 125 levels arise from the 2s22p, 2s2p2, 2p3, 2s23s, 2s23p, 2s23d, 2s2p3s, 2s2p3p, 2s2p3d, 2p23s, 2p23p and 2p23d configurations. Electron impact excitation collision strengths and radiative transition probabilities are calculated for both Mg viii models, compared with existing data, and the best model selected to generate a set of theoretical emission line intensities. The EUV lines, covering 312-790 Å, are compared with existing solar spectra (SERTS-89 and SUMER), while the soft X-ray transitions (69-97 Å) are examined for potential density diagnostic line ratios and also compared with the limited available solar and stellar observational data. Methods: The R-matrix codes Breit-Pauli RMATRXI and RMATRXII are utilised, along with the PSTGF code, to calculate the collision strengths for two Mg viii models. Collision strengths are averaged over a Maxwellian distribution to produce the corresponding effective collision strengths for use in astrophysical applications. Transition probabilities are also calculated using the CIV3 atomic structure code. The best data are then incorporated into the modelling code CLOUDY and line intensities generated for a range of electron temperatures and densities appropriate to solar and stellar coronal plasmas. Results: The present effective collision strengths are compared with two previous calculations. Good levels of agreement are found with the most recent, but there are large differences with the other for forbidden transitions. The resulting line intensities compare favourably with the

  1. Atomic data from the Iron Project. XLIV. Transition probabilities and line ratios for Fe VI with fluorescent excitation in planetary nebulae

    NASA Astrophysics Data System (ADS)

    Chen, Guo Xin; Pradhan, Anil K.

    2000-11-01

    Relativistic atomic structure calculations for electric dipole (E1), electric quadrupole (E2) and magnetic dipole (M1) transition probabilities among the first 80 fine-structure levels of Fe VI, dominated by configurations 3d3, 3d24s, and 3d24p, are carried out using the Breit-Pauli version of the code SUPERSTRUCTURE. Experimental energies are used to improve the accuracy of these transition probabilities. Employing the 80-level collision-radiative (CR) model with these dipole and forbidden transition probabilities, and Iron Project R-matrix collisional data, we present a number of [Fe VI] line ratios applicable to spectral diagnostics of photoionized H II regions. It is shown that continuum fluorescent excitation needs to be considered in CR models in order to interpret the observed line ratios of optical [Fe VI] lines in planetary nebulae NGC 6741, IC 351, and NGC 7662. The analysis leads to parametrization of line ratios as function of, and as constraints on, the electron density and temperature, as well as the effective radiation temperature of the central source and a geometrical dilution factor. The spectral diagnostics may also help ascertain observational uncertainties. The method may be generally applicable to other objects with intensive background radiation fields, such as novae and active galactic nuclei. The extensive new Iron Project radiative and collisional calculations enable a consistent analysis of many line ratios for the complex iron ions. The complete tables of transition probabilities 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/Abstract.html.

  2. Line-shape study of self-broadened O{sub 2} transitions measured by Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectroscopy

    SciTech Connect

    Wojtewicz, S.; Lisak, D.; Cygan, A.; Domyslawska, J.; Trawinski, R. S.; Ciurylo, R.

    2011-09-15

    We present high-sensitivity and high-spectral-resolution line-shape and line-intensity measurements of self-broadened O{sub 2} b {sup 1}{Sigma}{sub g}{sup +}(v=1)(leftarrow)X {sup 3}{Sigma}{sub g}{sup -}(v=0) band transitions measured using the Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectroscopy technique. We give collisional broadening parameters and take into account the line-narrowing effects described by Dicke narrowing or the speed dependence of collisional broadening. We compare line intensities measured with relative uncertainties below 0.4% to data available in the HITRAN spectroscopic database.

  3. Band width and multiple-angle valence-state mapping of diamond

    SciTech Connect

    Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J.

    1997-04-01

    The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid`s many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of {+-}1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84{degrees} cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space.

  4. Relativistic many-body calculations of lifetimes, rates, and line strengths of multipole transitions between 3l-1 4l' states in Ni-like ions

    SciTech Connect

    Safronova, U I; Safronova, A S; Beiersdorfer, P

    2007-10-08

    Transition rates and line strengths are calculated for electric-multipole (E2 and E3) and magnetic-multipole (M1, M2, and M3) transitions between 3s{sup 2}3p{sup 6}3d{sup 10}, 3s{sup 2}3p{sup 6}3d{sup 9}4l, 3s{sup 2}3p{sup 5}3d{sup 10}4l, and 3s3p{sup 6}3d{sup 10}4l states (with 4l = 4s, 4p, 4d, and 4f) in Ni-like ions with the nuclear charges ranging from Z = 34 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded multipole matrix elements. Transition energies used in the calculation of line strengths and transition rates are from second-order RMBPT. Lifetimes of the 3s{sup 2}3p{sup 6}3d{sup 9}4s levels are given for Z = 34-100. Taking into account that calculations were performed in a very broad range of Z, most of the data are presented in graphs as Z-dependencies. The full set of data is given only for Ni-like W ion. In addition, we also give complete results for the 3d4s{sup 3}D{sub 2}-3d4s {sup 3}D{sub 1} magnetic-dipole transition, as the transition may be observed in future experiments, which measure both transition energies and radiative rates. These atomic data are important in the modeling of radiation spectra from Ni-like multiply-charged ions generated in electron beam ion trap experiments as well as for laboratory plasma diagnostics including fusion research.

  5. Method of averaged energy differences of coupled states and other approaches for calculation line broadening parameters of HD16O transitions

    NASA Astrophysics Data System (ADS)

    Dudaryonok, A. S.; Voronin, B. A.; Lavrentieva, N. N.; Lugovskoy, A. A.; Starikov, V. I.

    2012-11-01

    Air-broadening coefficients of the water isotopologue HD16O up to J = 50 for P, Q and R branches calculated using different methods are presented. For partially labeled lines ("good" quantum numbers: J, symmetry and level number) we combined three methods for calculating half-widths: J-dependence and JJ'-dependence up to J=15 and averaging coefficients calculated using a previously developed semi-empirical method for high J (15-50). For lines with full assignments based on normal modes v1, v2, v3, Ka, Kc we used: (a) an analytical model (approximation) which depends on use of rotational quantum numbers J and Ka for both the upper and lower levels; and (b) a method based on the estimate of the averaged energy differences between coupled states. The comparison of calculated data with broadening coefficients from HITRAN-2008 and available experimental data is presented. The resulting broadening coefficients can be used to calculate spectra of water vapor with hundreds millions of weak lines with reasonable accuracy. The line list VTT [Voronin, Tennyson, Tolchenov, MNRAS, 2010], supporting programs, files for calculations of spectra HD16O and estimation of broadening coefficient are made freely available also in electronic form via http://www.exomol.com.

  6. Semiconductor Laser Line-width Measurements for Space Interferometry Applications

    NASA Technical Reports Server (NTRS)

    Dougherty, D.; Guttierrez, R.; Dubovitsky, S.; Forouhar, S.

    1999-01-01

    This work discusses results using the self-heterodyne delay atechnique to measure 1.3 um InP based DFB lasers. We will also address practical issues concerning detection and elimination of back reflections, choice of fiber length and resolution, and measurement of laser 1/f and current supply noise.

  7. Environmental scanning electron microscopy study of the fine structure of the triple line and cassie-wenzel wetting transition for sessile drops deposited on rough polymer substrates.

    PubMed

    Bormashenko, Edward; Bormashenko, Yelena; Stein, Tamir; Whyman, Gene; Pogreb, Roman; Barkay, Zahava

    2007-04-10

    The wetting of rough honeycomb micrometrically scaled polymer substrates was studied. A very strong dependence of the apparent contact angle on the drop volume has been established experimentally. The environmental scanning electron microscopy study of the fine structure of the triple line is reported first. The triple line is not smooth and prefers grasping the polymer matrix over air holes. The precursor rim surrounding the drop has been observed. The revealed dependence of the apparent contact angle on the drop volume is explained by the transition between the pure Cassie and combined Wenzel-Cassie wetting regimes, which is induced by capillarity penetration of water into the holes of relief.

  8. Explanation of the pressure-induced red shifts of 2E- 4A2 transition line for Cr 3+ ions in the two sites of chrysoberyl

    NASA Astrophysics Data System (ADS)

    Wen-Chen, Zheng

    1996-04-01

    By using the bond length dependence of covalency reduction factor obtained from the high pressure spectroscopy of ruby (Al 2O 3 : Cr 3+), the pressure-induced shifts of 2E- 4A2 transition line for Cr 3+ ions in both sites (mirror site and inverse site) of chrysoberyl BeAl 2O 4 : Cr 3+ are calculated from the distinctive compressibilities of metal-ligand bond for Cr 3+ ions in the two sites. The results are in reasonable agreement with the observed values. It suggests that the large difference of the pressure-induced shifts of 2E- 4A2 transition line between the Cr 3+ ions at the mirror sites and the inverse sites of chrysoberyl is due mainly to the different average bond compressiblity.

  9. The emission-line spectrum above the limb of a solar coronal hole - 1175-1940 A

    NASA Technical Reports Server (NTRS)

    Feldman, U.; Doschek, G. A.; Vanhoosier, M. E.; Purcell, J. D.

    1976-01-01

    Emission-line spectra of a coronal hole that coincided with the north pole of the sun are discussed which were obtained with a slit spectrograph aboard Skylab at positions within and above the solar white-light limb in the wavelength range from 1175 to 1940 A. Relative line intensities, line profiles, and full widths at half-maximum are presented for selected chromospheric and transition-zone lines observed above the present polar coronal hole. Average mass motions in the transition zone are determined as a function of electron temperature from the widths of the optically thin lines by assuming ionization equilibrium. The line intensities and profiles are compared with corresponding results deduced from spectra obtained above a quiet solar region. The coronal-hole spectra are found to imply an angular dependence for the source function as well as a radial dependence such that the source function is the smallest at the south pole and increases with decreasing solar latitude.

  10. Self-, N2-, O2-broadening coefficients and line parameters of HFC-32 for ν7 band and ground state transitions from infrared and microwave spectroscopy

    NASA Astrophysics Data System (ADS)

    Tasinato, Nicola; Turchetto, Arianna; Puzzarini, Cristina; Stoppa, Paolo; Pietropolli Charmet, Andrea; Giorgianni, Santi

    2014-09-01

    Hydrofluorocarbons have been used as replacement gases of chlorofluorocarbons, since the latter have been phased out by the Montreal Protocol due to their environmental hazardous ozone-depleting effects. This is also the case of difluoromethane (CH2F2, HFC-32), which nowadays is widely used in refrigerant mixtures together with CF3CH3, CF3CH2F, and CF3CHF2. Due to its commercial use, in the last years, the atmospheric concentration of HFC-32 has increased significantly. However, this molecule presents strong absorptions within the 8-12 μm atmospheric window, and hence it is a greenhouse gas which contributes to global warming. Although over the years several experimental and theoretical investigations dealt with the spectroscopic properties of CH2F2, up to now pressure broadening coefficients have never been determined. In the present work, the line-by-line parameters of CH2F2 are retrieved for either ground state or ν7 band transitions by means of microwave (MW) and infrared (IR) absorption spectroscopy, respectively. In particular, laboratory experiments are carried out on 9 pure rotational transitions of the ground state and 26 ro-vibrational transitions belonging to the ν7 band lying around 8.2 μm within the atmospheric region. Measurements are carried out at room temperature on self-perturbed CH2F2 as well as on CH2F2 perturbed by N2 and O2. The line shape analysis leads to the first determination of self-, N2-, O2-, and air-broadening coefficients, and also of line intensities (IR). Upon comparison, broadening coefficients of ground state transitions are larger than those of the ν7 band, and no clear dependence on the rotational quantum numbers can be reported. The obtained results represent basic information for the atmospheric modelling of this compound as well as for remote sensing applications.

  11. A Cloudiness Index for Transiting Exoplanets Based on the Sodium and Potassium Lines: Tentative Evidence for Hotter Atmospheres Being Less Cloudy at Visible Wavelengths

    NASA Astrophysics Data System (ADS)

    Heng, Kevin

    2016-07-01

    We present a dimensionless index that quantifies the degree of cloudiness of the atmosphere of a transiting exoplanet. Our cloudiness index is based on measuring the transit radii associated with the line center and wing of the sodium or potassium line. In deriving this index, we revisited the algebraic formulae for inferring the isothermal pressure scale height from transit measurements. We demonstrate that the formulae of Lecavelier et al. and Benneke & Seager are identical: the former is inferring the temperature while assuming a value for the mean molecular mass and the latter is inferring the mean molecular mass while assuming a value for the temperature. More importantly, these formulae cannot be used to distinguish between cloudy and cloud-free atmospheres. We derive values of our cloudiness index for a small sample of seven hot Saturns/Jupiters taken from Sing et al. We show that WASP-17b, WASP-31b, and HAT-P-1b are nearly cloud-free at visible wavelengths. We find the tentative trend that more irradiated atmospheres tend to have fewer clouds consisting of sub-micron-sized particles. We also derive absolute sodium and/or potassium abundances ˜102 cm-3 for WASP-17b, WASP-31b, and HAT-P-1b (and upper limits for the other objects). Higher-resolution measurements of both the sodium and potassium lines, for a larger sample of exoplanetary atmospheres, are needed to confirm or refute this trend.

  12. Analysis and transition probabilities of the A 1Σ+-->X 1Σ+ system of KH excited by the 4880 Å line of the argon ion laser

    NASA Astrophysics Data System (ADS)

    Camacho, J. J.; Poyato, J. M. L.; Pardo, A.; Reyman, D.

    1998-12-01

    The fluorescence spectrum of KH induced by the 4880 Å line of an argon ion laser has been analyzed. This work extends previous observations on potassium hydride in visible region by using this excitation line. Along with the principal fluorescence series for the A 1Σ+→X1Σ+ band system, corresponding to the excitation transition, v'=7, J'=6←v″=0, J″=5, we analyzed a very interesting satellite rotational and vibrational structure induced by collision. The radiative transition probabilities for the A 1Σ+→X1Σ+ band system of KH have been calculated by using hybrid potential energy curves for the X 1Σ+ and A 1Σ+ states and transition dipole moment function from the radiative lifetimes of different vibrational levels (v'=5-22 in the A 1Σ+ state) reported by Giroud and Nedelec. The transition probabilities and lifetimes are in good agreement with the corresponding observed measurements usually within the experimental uncertainty. Collision-induced rotational and vibrational energy transfer in the A 1Σ+ state has been investigated. From the rotational and vibrational satellite structure of some bands, cross sections for rotational and vibrational energy transfer have been determined.

  13. The Nature of High Equivalent Width Lyman-α Galaxies

    NASA Astrophysics Data System (ADS)

    Finkelstein, S. L.; Rhoads, J. E.; Malhotra, S.; Pirzkal, N.; Wang, J.

    2005-12-01

    We present new results on the nature of the high equivalent width Lyα lines seen in high-redshift galaxies. These galaxies were identified on the basis of their large equivalent width Lyα emission, beyond the maximum expected for normal stellar populations. To be produced, this strong Lyα emission requires a strong ionizing continuum. Previous X-ray images and optical spectra show that this emission is not powered by active galactic nuclei. The optical colors of these galaxies provide a diagnostic of the stellar populations. The large equivalent widths seen in the Lyα line in these galaxies could be produced via star formation if the stellar photospheres are hotter than normal, which might be expected for star formation in low metallicity galaxies. They could also result from a top-heavy initial mass function. Both of these scenarios might be expected in primitive galaxies. To investigate these galaxies, we have computed stellar population models using the stellar population synthesis code created by Bruzual and Charlot (2003). We will use these models to predict the equivalent width distribution of the Lyα line in these high-redshift galaxies. We will also be able to derive estimates of stellar masses and stellar population ages, and be able to determine if these systems are indeed young and relatively primitive. Furthermore, we are obtaining new deep broadband imaging data on high-redshift galaxies taken from the Large Area Lyman Alpha (LALA) survey. These observations will yield better equivalent width measurements and continuum colors than previous data has allowed. We will compare these colors with the expectations for hot stars. We will also be able to constrain the star-formation rate using the UV continuum light from these galaxies, which will provide a valuable comparison with star-formation rates derived from the Lyα luminosity alone.

  14. First-order and tricritical wetting transitions in the two-dimensional Ising model caused by interfacial pinning at a defect line

    NASA Astrophysics Data System (ADS)

    Trobo, Marta L.; Albano, Ezequiel V.; Binder, Kurt

    2014-08-01

    We present a study of the critical behavior of the Blume-Capel model with three spin states (S =±1,0) confined between parallel walls separated by a distance L where competitive surface magnetic fields act. By properly choosing the crystal field (D), which regulates the density of nonmagnetic species (S =0), such that those impurities are excluded from the bulk (where D =-∞) except in the middle of the sample [where DM(L/2)≠-∞], we are able to control the presence of a defect line in the middle of the sample and study its influence on the interface between domains of different spin orientations. So essentially we study an Ising model with a defect line but, unlike previous work where defect lines in Ising models were defined via weakened bonds, in the present case the defect line is due to mobile vacancies and hence involves additional entropy. In this way, by drawing phase diagrams, i.e., plots of the wetting critical temperature (Tw) versus the magnitude of the crystal field at the middle of the sample (DM), we observe curves of (first-) second-order wetting transitions for (small) high values of DM. Theses lines meet in tricritical wetting points, i.e., (Twtc,DMtc), which also depend on the magnitude of the surface magnetic fields. It is found that second-order wetting transitions satisfy the scaling theory for short-range interactions, while first-order ones do not exhibit hysteresis, provided that small samples are used, since fluctuations wash out hysteretic effects. Since hysteresis is observed in large samples, we performed extensive thermodynamic integrations in order to accurately locate the first-order transition points, and a rather good agreement is found by comparing such results with those obtained just by observing the jump of the order parameter in small samples.

  15. First-order and tricritical wetting transitions in the two-dimensional Ising model caused by interfacial pinning at a defect line.

    PubMed

    Trobo, Marta L; Albano, Ezequiel V; Binder, Kurt

    2014-08-01

    We present a study of the critical behavior of the Blume-Capel model with three spin states (S=±1,0) confined between parallel walls separated by a distance L where competitive surface magnetic fields act. By properly choosing the crystal field (D), which regulates the density of nonmagnetic species (S=0), such that those impurities are excluded from the bulk (where D=-∞) except in the middle of the sample [where D(M)(L/2)≠-∞], we are able to control the presence of a defect line in the middle of the sample and study its influence on the interface between domains of different spin orientations. So essentially we study an Ising model with a defect line but, unlike previous work where defect lines in Ising models were defined via weakened bonds, in the present case the defect line is due to mobile vacancies and hence involves additional entropy. In this way, by drawing phase diagrams, i.e., plots of the wetting critical temperature (T(w)) versus the magnitude of the crystal field at the middle of the sample (D(M)), we observe curves of (first-) second-order wetting transitions for (small) high values of D(M). Theses lines meet in tricritical wetting points, i.e., (T(w)(tc),D(M)(tc)), which also depend on the magnitude of the surface magnetic fields. It is found that second-order wetting transitions satisfy the scaling theory for short-range interactions, while first-order ones do not exhibit hysteresis, provided that small samples are used, since fluctuations wash out hysteretic effects. Since hysteresis is observed in large samples, we performed extensive thermodynamic integrations in order to accurately locate the first-order transition points, and a rather good agreement is found by comparing such results with those obtained just by observing the jump of the order parameter in small samples.

  16. The role of relative floodplain width in forming anabranching rivers

    NASA Astrophysics Data System (ADS)

    Edmonds, D. A.; Polanco, S. E. M.; Amos, K.

    2015-12-01

    Anabranching rivers (including anastomosing) are a relatively common channel pattern, especially among the world's biggest rivers, and are defined as a system of multiple channels separated by immobile alluvial islands. The origin of anabranching remains poorly understood and is an important topic of research. Previous studies on Australian rivers and a recent empirical compilation show that floodplain width (relative to the size of the channel) might play an important role in the formation of anabranching rivers. To test this idea further we carried out two sets of morphodynamic simulations using Delft3D. In the first set we create a generic channel-floodplain complex with uniform floodplain and channel width, slope, and grain size and allow the system to adjust to passing floodwaves. In successive runs we hold all variables constant, except we increase floodplain width. Results of these simulations show a transition from single channel to braided to anabranching as floodplain width increases. Anabranching arises because as floodplain width increases, alluvial bar growth occurs on the floodplain. The emergence of bars causes flow bifurcation, and subsequent bifurcation instability leads to reduction of channels and the emergence of multiple anabranches. Transition to a stable anabranching pattern is achieved because as anabranches increase their cross-sectional area, Shields stresses on the intervening bars are reduced until they bars stop migrating. To test the idea that alluvial bar growth can be a precursor to anabranching we carried out a second experiment set using boundary conditions from four different field scale anabranching rivers. Results from these simulations show that anabranching can initiate from alluvial bar growth. Compared to field measurements of anabranching rivers our simulations accurately predict number of channels, supporting the idea that relatively wide floodplains might be an important attribute of anabranching rivers.

  17. a Measurement of the Mass, Full Width, and Radiative Width of the Positive B(1237) Meson

    NASA Astrophysics Data System (ADS)

    Collick, Bruce David

    An experiment was performed at Fermi National Accelerator Laboratory to investigate the coherent production of mesons on nuclear targets (lead and copper). The experiment used and 200 GeV/c incident meson beam and a high resolution forward spectrometer consisting of proportional and drift chambers plus a liquid argon photon calorimeter. This thesis reports the results of the process (pi)('+) + A (--->) (pi)('+) (omega) + A. The (pi)('+)(omega) spectrum was found to be dominated by the B('+)(1237) meson. A fit was performed on the line shape of the (pi)('+)(omega) mass spectrum and values of 1.271 (+OR-) 0.011 GeV and 0.232 (+OR-) 0.029 GeV were found for the mass and total width. The helicity zero decay probability of the (omega), (VBAR)F(,0)(VBAR)('2), was measured to be (VBAR)F(,0)(VBAR)('2) = 0.15 (+OR-) 0.035. The t distributions were analyzed allowing the electromagnetic and hadronic production processes to interfer. From these distributions a radiative width of 230 (+OR-) 61 was extracted.

  18. The center-to-limb variation across the Fraunhofer lines of HD 189733. Sampling the stellar spectrum using a transiting planet

    NASA Astrophysics Data System (ADS)

    Czesla, S.; Klocová, T.; Khalafinejad, S.; Wolter, U.; Schmitt, J. H. M. M.

    2015-10-01

    The center-to-limb variation (CLV) describes the brightness of the stellar disk as a function of the limb angle. Across strong absorption lines, the CLV can vary quite significantly. We obtained a densely sampled time series of high-resolution transit spectra of the active planet host star HD 189733 with UVES. Using the passing planetary disk of the hot Jupiter HD 189733 b as a probe, we study the CLV in the wings of the Ca ii H and K and Na i D1 and D2 Fraunhofer lines, which are not strongly affected by activity-induced variability. In agreement with model predictions, our analysis shows that the wings of the studied Fraunhofer lines are limb brightened with respect to the (quasi-)continuum. The strength of the CLV-induced effect can be on the same order as signals found for hot Jupiter atmospheres. Therefore, a careful treatment of the wavelength dependence of the stellar CLV in strong absorption lines is highly relevant in the interpretation of planetary transit spectroscopy. Based on observations made with UVES at the ESO VLT Kueyen telescope under program 089.D-0701(A).

  19. Red cell distribution width and nonalcoholic steatohepatitis

    PubMed Central

    Gulcan Kurt, Yasemin; Cayci, Tuncer; Aydin, Fevzi Nuri; Agilli, Mehmet

    2014-01-01

    Red cell distribution width is a measure of deviation of the volume of red blood cells. It is a marker of anisocytosis and often used to evaluate the possible causes of anemia. Elevated red cell distribution width levels are also associated with acute and chronic inflammatory responses. In nonalcoholic steatohepatitis, inflammation is accompanied with steatosis. For assuming red cell distribution width as a marker of nonalcoholic steatohepatitis, intervening factors such as levels of inflammatory markers should also be evaluated. PMID:25473202

  20. Electron collisional broadening of isolated lines from multiply-ionized atoms.

    NASA Astrophysics Data System (ADS)

    Griem, H. R.; Ralchenko, Yu. V.

    2000-05-01

    Recent experimental and theoretical (both improved semiclassical and fully quantum-mechanical) line broadening calculations for B III and Ne VII Δn = 0 transitions with n = 2 and 3, respectively, are discussed. The disagreements by about a factor of 2 between the fully quantum-mechanically calculated and both measured and semiclassically calculated widths can be explained in terms of violations of validity criteria for the semiclassical calculations and nonthermal Doppler effects. Only the quantum calculations allow a clear separation of elastic and inelastic scattering contributions to the width. For B III, elastic scattering contributes about 30%, for Ne VII inelastic scattering dominates. This allows rather direct comparisons with benchmark electron-ion scattering experiments. Additional independent determinations of line widths for multiply-ionized, nonhydrogenic ions are called for, but meanwhile caution should be exercised in the use of corresponding semiclassically calculated widths, e.g., in opacity calculations or for plasma density diagnostics.

  1. Intersystem transitions of interstellar carbon monoxide toward zeta Ophiuchi

    NASA Technical Reports Server (NTRS)

    Federman, S. R.; Cardelli, Jason A.; Sheffer, Yaron; Lambert, David L.; Morton, D. C.

    1994-01-01

    Absorption from seven intersystem (triplet-singlet) transitions of interstellar (12)CO were detected in ultraviolet spectra of zeta Oph. The observed equivalent widths are approximately consistent with the transitions' predicted f-values and the (12) CO column density derived from the weakest of the observed A-X bands. These unsaturated intersystem transitions provide the opportunity to measure the (12)CO column density for heavily reddened (dense) sight lines. Laboratory measurements of oscillator strengths more precise than available ones will be needed to derive accurate column densities.

  2. 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.

  3. Constraints on the merging of the transition lines at the tricritical point in a wing-structure phase diagram

    DOE PAGES

    Taufour, Valentin; Kaluarachchi, Udhara S.; Kogan, Vladimir G.

    2016-08-19

    Here, we consider the phase diagram of a ferromagnetic system driven to a quantum phase transition with a tuning parameter $p$. Before being suppressed, the transition becomes of the first order at a tricritical point, from which wings emerge under application of the magnetic field H in the T $-$ p $-$ H phase diagram. We show that the edge of the wings merge with tangent slopes at the tricritical point.

  4. A Core Invasiveness Gene Signature Reflects Epithelial-to-Mesenchymal Transition but Not Metastatic Potential in Breast Cancer Cell Lines and Tissue Samples

    PubMed Central

    Marsan, Melike; Van den Eynden, Gert; Limame, Ridha; Neven, Patrick; Hauspy, Jan; Van Dam, Peter A.; Vergote, Ignace; Dirix, Luc Y.; Vermeulen, Peter B.; Van Laere, Steven J.

    2014-01-01

    Introduction Metastases remain the primary cause of cancer-related death. The acquisition of invasive tumour cell behaviour is thought to be a cornerstone of the metastatic cascade. Therefore, gene signatures related to invasiveness could aid in stratifying patients according to their prognostic profile. In the present study we aimed at identifying an invasiveness gene signature and investigated its biological relevance in breast cancer. Methods & Results We collected a set of published gene signatures related to cell motility and invasion. Using this collection, we identified 16 genes that were represented at a higher frequency than observed by coincidence, hereafter named the core invasiveness gene signature. Principal component analysis showed that these overrepresented genes were able to segregate invasive and non-invasive breast cancer cell lines, outperforming sets of 16 randomly selected genes (all P<0.001). When applied onto additional data sets, the expression of the core invasiveness gene signature was significantly elevated in cell lines forced to undergo epithelial-mesenchymal transition. The link between core invasiveness gene expression and epithelial-mesenchymal transition was also confirmed in a dataset consisting of 2420 human breast cancer samples. Univariate and multivariate Cox regression analysis demonstrated that CIG expression is not associated with a shorter distant metastasis free survival interval (HR = 0.956, 95%C.I. = 0.896–1.019, P = 0.186). Discussion These data demonstrate that we have identified a set of core invasiveness genes, the expression of which is associated with epithelial-mesenchymal transition in breast cancer cell lines and in human tissue samples. Despite the connection between epithelial-mesenchymal transition and invasive tumour cell behaviour, we were unable to demonstrate a link between the core invasiveness gene signature and enhanced metastatic potential. PMID:24586640

  5. The Homogeneous Study of Transiting Systems (HoSTS) - II. The influence of the line list on stellar parameters

    NASA Astrophysics Data System (ADS)

    Doyle, Amanda P.; Smalley, Barry; Faedi, Francesca; Pollacco, Don; Gómez Maqueo Chew, Yilen

    2017-08-01

    The use of high-resolution, high signal-to-noise stellar spectra is essential in order to determine the most accurate and precise stellar atmospheric parameters via spectroscopy. This is particularly important for determining the fundamental parameters of exoplanets, which directly depend on the stellar properties. However, different techniques can be implemented when analysing these spectra which will influence the results. These include performing an abundance analysis relative to the solar values in order to negate uncertainties in atomic data, and fixing the surface gravity (log g) to an external value such as those from asteroseismology. The choice of lines used will also influence the results. In this paper, we investigate differential analysis and fixing log g for a set of FGK stars that already have accurate fundamental parameters known from external methods. We find that a differential line list gives slightly more accurate parameters compared to a laboratory line list; however, the laboratory line list still gives robust parameters. We also find that fixing the log g does not improve the spectroscopic parameters. We investigate the effects of line selection on the stellar parameters and find that the choice of lines used can have a significant effect on the parameters. In particular, removal of certain low excitation potential lines can change the Teff by up to 50 K. For future HoSTS papers we will use the differential line list with a solar microturbulence value of 1 km s-1, and we will not fix the log g to an external value.

  6. VizieR Online Data Catalog: Pal1-I elemental equivalent widths and abundances (Monaco+, 2011)

    NASA Astrophysics Data System (ADS)

    Monaco, L.; Saviane, I.; Correnti, M.; Bonifacio, P.; Geisler, D.

    2010-11-01

    Table A1. reports the line list and atomic parameters adopted for the Palomar 1 giant Pal1-I and the Sun. For the Mn and Co lines we adopted the hyperfine structures (HFS) tabulated by Prochaska et al. (2000AJ....120.2513P). The measured equivalent width and the corresponding abundance obtained for each line are also reported. (1 data file).

  7. Assignment of the /Li-7/2 optically pumped laser transitions pumped by Ar/+/ and Kr/+/ laser lines

    NASA Technical Reports Server (NTRS)

    Verma, K. K.; Stwalley, W. C.; Zemke, W. T.

    1981-01-01

    Welling and Wellegehausen (1977) have reported a list of Na2 and Li2 lines (belonging to B-X and A-X systems) which lase when vapors of these dimers are pumped with an Ar(+) or Kr(+) laser. A description is presented of a fluorescence study of the A-X system of the (Li-7)2 molecule excited by a Kr(+) laser (6471 A). The optically pumped laser lines are identified as P and R doublets in two different fluorescence series. The conditions which favor lasing action of these lines are pointed out. All but one of the known optically pumped laser lines of (Li-7)2 along with their assignments are presented in a table. For each pumping line, several additional wavelengths are listed which satisfy the condition for laser oscillations and which might well lase well under slightly improved conditions.

  8. Uncovering Male Fertility Transition Responsive miRNA in a Wheat Photo-Thermosensitive Genic Male Sterile Line by Deep Sequencing and Degradome Analysis.

    PubMed

    Bai, Jian-Fang; Wang, Yu-Kun; Wang, Peng; Duan, Wen-Jing; Yuan, Shao-Hua; Sun, Hui; Yuan, Guo-Liang; Ma, Jing-Xiu; Wang, Na; Zhang, Feng-Ting; Zhang, Li-Ping; Zhao, Chang-Ping

    2017-01-01

    MicroRNAs (miRNAs) are endogenous small RNAs which play important negative regulatory roles at both the transcriptional and post-transcriptional levels in plants. Wheat is the most commonly cultivated plant species worldwide. In this study, RNA-seq analysis was used to examine the expression profiles of miRNA in the spikelets of photo-thermosenisitive genic male sterile (PTGMS) wheat line BS366 during male fertility transition. Through mapping on their corresponding precursors, 917-7,762 novel miRNAs were found in six libraries. Six novel miRNAs were selected for examination of their secondary structures and confirmation by stem-loop RT-PCR. In a differential expression analysis, 20, 22, and 58 known miRNAs exhibited significant differential expression between developmental stages 1 (secondary sporogenous cells had formed), 2 (all cells layers were present and mitosis had ceased), and 3 (meiotic division stage), respectively, of fertile and sterile plants. Some of these differential expressed miRNAs, such as tae-miR156, tae-miR164, tae-miR171, and tae-miR172, were shown to be associated with their targets. These targets were previously reported to be related to pollen development and/or male sterility, indicating that these miRNAs and their targets may be involved in the regulation of male fertility transition in the PTGMS wheat line BS366. Furthermore, target genes of miRNA cleavage sites were validated by degradome sequencing. In this study, a possible signal model for the miRNA-mediated signaling pathway during the process of male fertility transition in the PTGMS wheat line BS366 was developed. This study provides a new perspective for understanding the roles of miRNAs in male fertility in PTGMS lines of wheat.

  9. Shifts and widths of Feshbach resonances in atomic waveguides

    NASA Astrophysics Data System (ADS)

    Saeidian, Shahpoor; Melezhik, Vladimir S.; Schmelcher, Peter

    2012-12-01

    We develop and analyze a theoretical model which yields the shifts and widths of Feshbach resonances in an atomic waveguide. It is based on a multichannel approach for confinement-induced resonances (CIRs) and atomic transitions in the waveguides in the multimode regime. In this scheme we replace the single-channel scalar interatomic interaction by the four-channel tensorial potential modeling resonances of broad, narrow, and overlapping character according to the two-channel parametrization of Lange [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.79.013622 79, 013622 (2009)]. As an input the experimentally known parameters of Feshbach resonances in the absence of the waveguide are used. We calculate the shifts and widths of s-, d-, and g-wave magnetic Feshbach resonances of Cs atoms emerging in harmonic waveguides as CIRs and resonant enhancement of the transmission at zeros of the free space scattering length. We have found the linear dependence of the width of the resonance on the longitudinal atomic momentum and quadratic dependence on the waveguide width. Our model opens possibilities for quantitative studies of the scattering processes in ultracold atomic gases in waveguides beyond the framework of s-wave resonant scattering.

  10. Width Criterion For Weld-Seam-Tracking Data

    NASA Technical Reports Server (NTRS)

    Lincir, Mark R.

    1993-01-01

    Image-processing algorithm in "through-torch-vision" (T3V) system developed to guide gas/tungsten arc welding robot along weld seam modified, according to proposal, reducing incidence of inaccurate tracking of weld seam. Developmental system intended to provide closed-loop control of motion of welding robot along weld seam on basis of lines in T3V image identified by use of image-processing algorithm and assumed to coincide with edges of weld seam. Use of width criterion prevents tracking of many false pairs of lines, with consequent decrease in incidence of inaccurate tracking and increase in confidence in weld-tracking capability of robotic welding system.

  11. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  12. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  13. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  14. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  15. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  16. Instability and Transition of Flow at, and Near, an Attachment-Line: Including Control by Surface Suction

    NASA Technical Reports Server (NTRS)

    Smith, A.; Poll, D. I. A.

    1998-01-01

    Experiments have been performed on an untapered, swept cylinder model in the Cranfield College of Aeronautics 8 ft x 6 ft low-speed wind tunnel to investigate the effect of surface transpiration on the process of relaminarization in the attachment-line boundary layer. Suction coefficients for complete suppression of turbulence were determined as a function of Reynolds number and spanwise distance. The effect of attachment-line suction on the spanwise propagation of gross disturbances emanating from the fuselage-wing junction region was also studied. Finally, the effect of blowing on a laminar attachment-line boundary layer was also considered and excellent agreement was achieved with previous studies.

  17. Extra sub-Doppler lines in the vicinity of the third-resonance 6S-8P transition of atomic Cs attributed to optically induced Cs dimers

    SciTech Connect

    Passerat de Silans, Thierry; Maurin, Isabelle; Laliotis, Athanasios; Segundo, Pedro Chaves de Souza; Bloch, Daniel

    2011-04-15

    We report on the observation of additional sub-Doppler lines in a saturated absorption experiment when exploring the vicinity of the 6S{sub 1/2}-8P{sub 3/2} transition of Cs ({lambda}=388 nm). These additional lines are observed only under a relatively strong irradiation of both the pump and the probe beams. Extra narrow lines are also observed in copropagating nonlinear spectroscopy, and around the lines of the V-type three-level system 8P{sub 3/2}-6S{sub 1/2}-8P{sub 1/2} ({lambda}{sub 1}=388 nm, {lambda}{sub 2}=389 nm). We attribute theses additional lines to a probing of high-lying molecular cesium, produced as a result of the optical excitation of Cs atoms, as the low Cs atom density ({<=}10{sup 12}cm{sup -3}) is unable to populate significantly the dimer states in the condition of thermal equilibrium.

  18. Broad line emission from iron K- and L-shell transitions in the active galaxy 1H 0707-495.

    PubMed

    Fabian, A C; Zoghbi, A; Ross, R R; Uttley, P; Gallo, L C; Brandt, W N; Blustin, A J; Boller, T; Caballero-Garcia, M D; Larsson, J; Miller, J M; Miniutti, G; Ponti, G; Reis, R C; Reynolds, C S; Tanaka, Y; Young, A J

    2009-05-28

    Since the 1995 discovery of the broad iron K-line emission from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K lines have been found in emission from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting neutron stars. The iron K line is prominent in the reflection spectrum created by the hard-X-ray continuum irradiating dense accreting matter. Relativistic distortion of the line makes it sensitive to the strong gravity and spin of the black hole. The accompanying iron L-line emission should be detectable when the iron abundance is high. Here we report the presence of both iron K and iron L emission in the spectrum of the narrow-line Seyfert 1 galaxy 1H 0707-495. The bright iron L emission has enabled us to detect a reverberation lag of about 30 s between the direct X-ray continuum and its reflection from matter falling into the black hole. The observed reverberation timescale is comparable to the light-crossing time of the innermost radii around a supermassive black hole. The combination of spectral and timing data on 1H 0707-495 provides strong evidence that we are witnessing emission from matter within a gravitational radius, or a fraction of a light minute, from the event horizon of a rapidly spinning, massive black hole.

  19. Morphodynamics structures induced by variations of the channel width

    NASA Astrophysics Data System (ADS)

    Duro, Gonzalo; Crosato, Alessandra; Tassi, Pablo

    2014-05-01

    alluvial rivers. References Crosato A. and Mosselman E., 2009. Simple physics-based predictor for the number of river bars and the transition between meandering and braiding. Water Resources Research, 45, W03424, doi: 10.1029/2008WR007242. Crosato A., Mosselman E., Desta F.B. and Uijttewaal W.S.J., 2011. Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels. Water Resources Research, AGU, 47(3), W03511, doi 10.1029/2010WR009714. Frascati A. and Lanzoni S., 2013. A mathematical model for meandering rivers with varying width. J. Geophys. Res.Earth Surf., 118, doi:10.1002/jgrf.20084. Olesen K.W., 1984. Alternate bars in and meandering of alluvial rivers. In: River Meandering, Proc. of the Conf. Rivers '83, 24-26 Oct. 1983, New Orleans, Louisiana, U.S.A., ed. Elliott C.M., pp. 873-884, ASCE, New York. ISBN 0-87262-393-9. Repetto R., Tubino, M. and Paola C., 2002. Planimetric instability of channels with variable width. J. Fluid Mech., 457, 79-109. Struiksma N., Olesen K.W., Flokstra C. and De Vriend H.J., 1985. Bed deformation in curved alluvial channels. J. Hydraul. Res., 23(1), 57- 79. Wu F.-C. and Yeh T.-H., 2005. Forced bars induced by variations of channel width: Implications for incipient bifurcation. J. Geophys. Res., 110, F02009, doi:10.1029/2004JF000160. Zolezzi, G., R. Luchi, and M. Tubino (2012), Modeling morphodynamic processes in meandering rivers with spatial width variations, Rev. Geophys., 50, RG4005, doi:10.1029/2012RG000392.

  20. QED Theory of Radiation Emission and Absorption Lines for Atoms and Ions in a Strong Laser Field

    SciTech Connect

    Glushkov, A. V.

    2008-10-22

    The results of numerical calculating the multi-photon resonance shift and width for transition 6S-6F in the atom of Cs (wavelength 1059nm) in a laser pulse of the Gaussian and soliton-like shapes are presented. QED theory of radiation atomic lines is used.

  1. Critical comparison of Kramers' fission width with the stationary width from the Langevin equation

    SciTech Connect

    Sadhukhan, Jhilam; Pal, Santanu

    2009-06-15

    It is shown that Kramers' fission width, originally derived for a system with constant inertia, can be extended to systems with a deformation-dependent collective inertia, which is the case for nuclear fission. The predictions of Kramers' width for systems with variable inertia are found to be in very good agreement with the stationary fission widths obtained by solving the corresponding Langevin equations.

  2. Power law behavior of the zigzag transition in Yukawa clusters

    SciTech Connect

    Sheridan, T. E.; Magyar, Andrew L.

    2010-11-15

    We provide direct experimental evidence that the width of a Yukawa cluster exhibits power law behavior during the one-dimensional (1D) to two-dimensional (2D) zigzag transition. Configurations of small dusty (complex) plasma clusters confined in a biharmonic potential well are characterized as the well anisotropy is varied. When the anisotropy is large the particles are in a 1D straight-line configuration. As the anisotropy is decreased the cluster undergoes a zigzag transition to a 2D configuration. The measured dependence of cluster width on anisotropy follows a power law. A second transition from the zigzag to an elliptical configuration is also observed. The results are in very good agreement with a model of identical particles interacting through a Yukawa potential.

  3. Field-Lines-Threaded Model for: (1) the Low Solar Corona; (2) Electrons in the Transition Region; and (3) Solar Energetic Particle Acceleration and Transport

    NASA Astrophysics Data System (ADS)

    Sokolov, I.; van der Holst, B.; Jin, M.; Gombosi, T. I.; Taktakishvili, A.; Khazanov, G. V.

    2013-12-01

    In numerical simulations of the solar corona, both for the ambient state and especially for dynamical processes the most computational resources are spent for maintaining the numerical solution in the Low Solar Corona and in the transition region, where the temperature gradients are very sharp and the magnetic field has a complicated topology. The degraded computational efficiency is caused by the need in a highest resolution as well as the use of the fully three-dimensional implicit solver for electron heat conduction. On the other hand, the physical nature of the processes involved is rather simple (which still does not facilitate the numerical methods) as long as the heat fluxes as well as slow plasma motional velocities are aligned with the magnetic field. The Alfven wave turbulence, which is often believed to be the main driver of the solar wind and the main source of the coronal heating, is characterized by the Poynting flux of the waves, which is also aligned with the magnetic field. Therefore, the plasma state in any point of the three-dimensional grid in the Low Solar Corona can be found by solving a set of one-dimensional equations for the magnetic field line ('thread'), which passes through this point and connects it to the chromosphere and to the global Solar Corona. In the present paper we describe an innovative computational technology based upon the use of the magnetic-field-line-threads to find the local solution. We present the development of the AWSoM code of the University of Michigan with the field-lines-threaded Low Solar Corona. In the transition region, where the essentially kinetic description of the electron energy fluxes is required, we solve the Fokker-Plank equation on the system of threads, to achieve the physically consistent description of chromosphere evaporation. The third application for the field-lines-treaded model is the Solar Energetic Particle (SEP) acceleration and transport. Being the natural extension of the Field-Line

  4. Emission line galaxies and active galactic nuclei in WINGS clusters

    NASA Astrophysics Data System (ADS)

    Marziani, P.; D'Onofrio, M.; Bettoni, D.; Poggianti, B. M.; Moretti, A.; Fasano, G.; Fritz, J.; Cava, A.; Varela, J.; Omizzolo, A.

    2017-03-01

    We present the analysis of the emission line galaxies members of 46 low-redshift (0.04 < z < 0.07) clusters observed by WINGS (WIde-field Nearby Galaxy cluster Survey). Emission line galaxies were identified following criteria that are meant to minimize biases against non-star-forming galaxies and classified employing diagnostic diagrams. We examined the emission line properties and frequencies of star-forming galaxies, transition objects, and active galactic nuclei (AGNs: LINERs and Seyferts), unclassified galaxies with emission lines, and quiescent galaxies with no detectable line emission. A deficit of emission line galaxies in the cluster environment is indicated by both a lower frequency, and a systematically lower Balmer emission line equivalent width and luminosity with respect to control samples; this implies a lower amount of ionized gas per unit mass and a lower star formation rate if the source is classified as Hii region. A sizable population of transition objects and of low-luminosity LINERs (≈ 10-20% of all emission line galaxies) are detected among WINGS cluster galaxies. These sources are a factor of ≈1.5 more frequent, or at least as frequent, as in control samples with respect to Hii sources. Transition objects and LINERs in clusters are most affected in terms ofline equivalent width by the environment and appear predominantly consistent with so-called retired galaxies. Shock heating can be a possible gas excitation mechanism that is able to account for observed line ratios. Specific to the cluster environment, we suggest interaction between atomic and molecular gas and the intracluster medium as a possible physical cause of line-emitting shocks. The data whose description is provided in Table B.1, and emission line catalog of the WINGS database are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A83

  5. Terrace width variations in complex lunar craters

    NASA Technical Reports Server (NTRS)

    Pearce, Steven J.; Melosh, H. J.

    1986-01-01

    The widths of terrace structures in complex craters on the moon are compared to existing theoretical models of their origin. Terrace widths in an individual crater increase monotonically outward toward the crater rim. Similarly, the width W of the terraces lying closest to the rim of a crater of diameter D increases monotonically, obeying a least-squares power-law relation WS (km) = 0.09D exp 0.87 km). A simple model of slumping that ignores inertial forces and assumes a constant bedrock yield strength is in good agreement with the observations.

  6. Experimental studies, line-shape analysis and semi-empirical calculations of broadening coefficients for CH335Cl-CO2 submillimeter transitions

    NASA Astrophysics Data System (ADS)

    Dudaryonok, A. S.; Lavrentieva, N. N.; Buldyreva, J.; Margulès, L.; Motiyenko, R. A.; Rohart, F.

    2014-09-01

    Rotational transitions in CH335Cl mixed with CO2 are recorded at 296 K and total pressures up to 0.6 Torr in the frequency interval 186-901 GHz (1.6-0.3 mm) for J=6→7, 10→11, 17→18, 22→23, 31→32, 33→34 and K=0-6, using the frequency-modulation spectrometer of the Laboratory PhLAM (Lille, France). These line-shapes are analyzed with the commonly used Voigt profile as well as with more refined Speed-Dependent Voigt and Galatry models accounting for the line narrowing induced, respectively, by the speed-dependence of the relaxation parameters and by velocity-changing collisions. Due to the high line intensities, the fitting procedure involves the full implementation of the Bee-Lambert law instead of its traditional linear approximation. The experimentally deduced J- and K-dependences of the pressure-broadening coefficients are further used to obtain the model parameters of a semi-empirical approach allowing massive calculations of line-shape parameters for enlarged ranges of rotational quantum numbers requested by spectroscopic databases.

  7. Topological Lifshitz transitions

    NASA Astrophysics Data System (ADS)

    Volovik, G. E.

    2017-01-01

    Different types of Lifshitz transitions are governed by topology in momentum space. They involve the topological transitions with the change of topology of Fermi surfaces, Weyl and Dirac points, nodal lines, and also the transitions between the fully gapped states.

  8. Bipartite Graphs of Large Clique-Width

    NASA Astrophysics Data System (ADS)

    Korpelainen, Nicholas; Lozin, Vadim V.

    Recently, several constructions of bipartite graphs of large clique-width have been discovered in the literature. In the present paper, we propose a general framework for developing such constructions and use it to obtain new results on this topic.

  9. Stark Shift Measurement of Some Xe III Lines

    SciTech Connect

    Djurovic, S.; Cirisaif, M.; Pelaez, R. J.; Aparicio, J. A.; Mar, S.

    2008-10-22

    Examination of ionized xenon spectrum is of a great interest for plasma diagnostic purposes, theory testing and different applications. In this paper, we present Stark shift data for one blue and five UV Xe III lines. One line belongs to the 5d-6p transition, while all other lines belong to 6s-6p transition. Most of the existing papers are devoted to Stark width measurements and only one paper deals with shift data of the lines studied herein. A low-pressure pulsed arc with 95% of helium and 5% of xenon was used as a plasma source. All measurements were performed under following plasma conditions: electron density (0.2-1.4)10{sup 23}m{sup -3} and electron temperature 18000-23000 K.

  10. Critical tests of line broadening theories by precision measurements

    SciTech Connect

    Glenzer, S.H.

    1996-02-22

    The spectral line profiles of ionized emitters in plasmas play an important role in the calculation of opacity, for short-wavelength laser studies, and for the diagnostics of inertial confinement fusion plasmas. Sophisticated theoretical methods and modeling have been advanced and applied in recent years to calculate spectral line profiles in the limits where broadening by electron collisions or by ion microfield dominates. Here, the authors describe recent measurements of spectral line profiles of a z-pinch experiment employing precision plasma diagnostic techniques. In particular, the electron-collisional-broadened 2s--2p transitions in B{sub III} have been investigated because their line profiles provide an excellent test for electron-impact line shape theories and electron collision strength calculations. Although they find good agreement with semiclassical calculations, a factor of two discrepancy with the most elaborate quantum-mechanical five-state close coupling calculations is observed. They discuss the experimental error estimates of the various measured quantities and show that the observed discrepancy can not be explained by experimental shortcomings. They further discuss measurements of non-isolated spectral lines of some {Delta}n = 1 transitions in C{sub IV}--O{sub VI}. For these transitions ion broadening dominates. Excellent agreement for the whole line profile with line broadening calculations is obtained for all cases only when including ion dynamic effects. The latter are calculated using the frequency-fluctuation model and account for about 10--25% of the line width of the considered ions.

  11. Influence of inhomogeneous broadening and deliberately introduced disorder on the width of the lasing spectrum of a quantum dot laser

    SciTech Connect

    Korenev, V. V.; Savelyev, A. V. Zhukov, A. E.; Omelchenko, A. V.; Maximov, M. V.

    2012-05-15

    Analytical expressions for the shape and width of the lasing spectra of a quantum-dot (QD) laser in the case of a small (in comparison with the spectrum width) homogeneous broadening of the QD energy levels have been obtained. It is shown that the dependence of the lasing spectrum width on the output power at room temperature is determined by two dimensionless parameters: the width of QD distribution over the optical-transition energy, normalized to temperature, and the ratio of the optical loss to the maximum gain. The optimal dimensions of the laser active region have been found to obtain a specified width of the emission spectrum at a minimum pump current. The possibility of using multilayer structures with QDs to increase the lasing spectrum's width has been analyzed. It is shown that the use of several arrays of QDs with deliberately variable optical-transition energies leads to broadening of the lasing spectra; some numerical estimates are presented.

  12. Glass transition in ferroic glass K x (ND4)1-x D2PO4: a complete x-ray diffraction line shape analysis

    NASA Astrophysics Data System (ADS)

    Ranjan Choudhury, Rajul; Chitra, R.; Jayakrishnan, V. B.

    2016-03-01

    Quenching of dynamic disorder in glassy systems is termed as the glass transition. Ferroic glasses belong to the class of paracrystalline materials having crystallographic order in-between that of a perfect crystal and amorphous material, a classic example of ferroic glass is the solid solution of ferroelectric deuterated potassium dihydrogen phosphate and antiferroelectric deuterated ammonium dihydrogen phosphate. Lowering temperature of this ferroic glass can lead to a glass transition to a quenched disordered state. The subtle atomic rearrangement that takes place at such a glass transition can be revealed by careful examination of the temperature induced changes occurring in the x-ray powder diffraction (XRD) patterns of these materials. Hence we report here results of a complete diffraction line shape analysis of the XRD patterns recorded at different temperatures from deuterated mixed crystals DK x A1-x DP with mixing concentration x ranging as 0 < x < 1. Changes observed in diffraction peak shapes have been explained on the basis of structural rearrangements induced by changing O-D-O hydrogen bond dynamics in these paracrystals.

  13. Laser gain on 3p-3d and 3s-3p transitions and X-ray line ratios for the nitrogen isoelectronic sequence

    NASA Technical Reports Server (NTRS)

    Feldman, U.; Seely, J. F.; Bhatia, A. K.

    1989-01-01

    Results are presented on calculations of the 72 levels belonging to the 2s(2)2p(3), 2s2p(4), 2p(5), 2s(2)2p(2)3s, 2s(2)2p(2)3p, and 2s(2)2p(2)3d configurations of the N I isoelectronic sequence for the ions Ar XII, Ti XVI, Fe XX, Zn XXIV, and Kr XXX, for electron densities up to 10 to the 24th/cu cm. It was found that large population inversions and gain occur between levels in the 2s(2)2p(2)3p configuration and levels in the 2s(2)2p(2)3d configuration that cannot decay to the ground configuration by an electric dipole transition. For increasing electron densities, the intensities of the X-ray transitions from the 2s(2)2p(2)3p configuration to the ground configuration decrease relative to the transitions from the 2s(2)2p(2)3s and 2s(2)2p(2)3d configurations to the ground configuration. The density dependence of these X-ray line ratios is presented.

  14. A Critical Compilation of Energy Levels, Spectral Lines, and Transition Probabilities of Singly Ionized Silver, Ag II.

    PubMed

    Kramida, Alexander

    2013-01-01

    All available experimental measurements of the spectrum of the Ag(+) ion are critically reviewed. Systematic shifts are removed from the measured wavelengths. The compiled list of critically evaluated wavelengths is used to derive a comprehensive list of energy levels with well-defined uncertainties. Eigenvector compositions and level designations are found in two alternate coupling schemes. Some of the older work is found to be incorrect. A revised value of the ionization energy, 173283(7) cm(-1), equivalent to 21.4844(8) eV, is derived from the new energy levels. A set of critically evaluated transition probabilities is given.

  15. A Critical Compilation of Energy Levels, Spectral Lines, and Transition Probabilities of Singly Ionized Silver, Ag II

    PubMed Central

    Kramida, Alexander

    2013-01-01

    All available experimental measurements of the spectrum of the Ag+ ion are critically reviewed. Systematic shifts are removed from the measured wavelengths. The compiled list of critically evaluated wavelengths is used to derive a comprehensive list of energy levels with well-defined uncertainties. Eigenvector compositions and level designations are found in two alternate coupling schemes. Some of the older work is found to be incorrect. A revised value of the ionization energy, 173283(7) cm−1, equivalent to 21.4844(8) eV, is derived from the new energy levels. A set of critically evaluated transition probabilities is given. PMID:26401429

  16. Computerized analysis of retinal vessel width and tortuosity in premature infants.

    PubMed

    Wilson, Clare M; Cocker, Kenneth D; Moseley, Merrick J; Paterson, Carl; Clay, Simon T; Schulenburg, William E; Mills, Monte D; Ells, Anna L; Parker, Kim H; Quinn, Graham E; Fielder, Alistair R; Ng, Jeffrey

    2008-08-01

    To determine, with novel software, the feasibility of measuring the tortuosity and width of retinal veins and arteries from digital retinal images of infants at risk of retinopathy of prematurity (ROP). The Computer-Aided Image Analysis of the Retina (CAIAR) program was developed to enable semiautomatic detection of retinal vasculature and measurement of vessel tortuosity and width from digital images. CAIAR was tested for accuracy and reproducibility of tortuosity and width measurements by using computer-generated vessel-like lines of known frequency, amplitude, and width. CAIAR was then tested by using clinical digital retinal images for correlation of vessel tortuosity and width readings compared with expert ophthalmologist grading. When applied to 16 computer-generated sinusoidal vessels, the tortuosity measured by CAIAR correlated very well with the known values. Width measures also increased as expected. When the CAIAR readings were compared with five expert ophthalmologists' grading of 75 vessels on 10 retinal images, moderate correlation was found in 10 of the 14 tortuosity output calculations (Spearman rho = 0.618-0.673). Width was less well correlated (rho = 0.415). The measures of tortuosity and width in CAIAR were validated using sequential model vessel analysis. On comparison of CAIAR output with assessments made by expert ophthalmologists, CAIAR correlates moderately with tortuosity grades, but less well with width grades. CAIAR offers the opportunity to develop an automated image analysis system for detecting the vascular changes at the posterior pole, which are becoming increasingly important in diagnosing treatable ROP.

  17. Solid-solid phase transition measurements in iron

    SciTech Connect

    Schwartz, Cynthia Louise

    2010-01-01

    Previously, dynamic experiments on iron have observed a non-zero transition time and width in the solid-solid {alpha}-{var_epsilon} phase transition. Using Proton Radiography at the Los Alamos Neutron Science Center, we have performed plate impact experiments on iron to further study the {alpha}-{var_epsilon} phase transition which occurs at 13GPa. A 40mm bore powder gun was coupled to a proton radiography beam line and imaging system and synchronized to the impact of the projectile on the target sample with the proton beam pattern. A typical experimental configuration for the iron study, as shown below in 3 color-enhanced radiographs, is a 40mm diameter aluminum sabot impacting a 40mm diameter of polycrystalline ARMCO iron. The iron is backed by a sapphire optical window for velocimetry measurements. The aluminum flyer on the left of the iron is barely visible for visual display purposes. Direct density jumps were measured which corresponded to calculations to within 1% using a Wondy mUlti-phase equation of state model. In addition, shock velocities were measured using an edge fitting technique and followed that edge movement from radiograph to radiograph, where radiographs are separated in time by 500 ns. Preliminary measurements give a shock velocity (P1 wave) of 5.251 km/s. The projectile velocity was 0.725 km/s which translate to a peak stress of 17.5 GPa. Assuming the P1 wave is instantaneous, we are able to calibrate the chromatic, motion, object and camera blur by measuring the width of the P1 wave. This approximation works in this case since each of the two density jumps are small compared to the density of the object. Subtracting the measured width of the P1 wave in quadrature from the width of the P2 wave gives a preliminary measurement of the transition length of 265 {mu}m. Therefore, a preliminary measured phase transition relaxation time {tau} = transition length/u{sub s} = 265 {mu}m/5.251 km/s = 50 ns. Both Boettger and Jensen conclude that the

  18. Line parameters measurements and modeling for the ν6 band of CH3F: Generation of a complete line list for atmospheric databases

    NASA Astrophysics Data System (ADS)

    Jacquemart, D.; Guinet, M.

    2016-12-01

    The 8.5 μm-spectral region of methyl fluoride was studied in terms of line positions, intensities and self-broadening coefficients at room temperature. A multispectrum fitting was used to retrieve from 7 high-resolution Fourier transform spectra line parameters for 787 transitions belonging to the ν6 band between 1078 and 1240 cm-1. The accuracy of line intensities and widths measurements were estimated to be around 5% and 5-10% respectively. J- and K-rotational dependences of the transition dipole moment squared and the self-broadening coefficients were observed and modeled from the measurements. A complete line list of almost 1500 transitions was generated for atmospheric or industrial detection of CH3F. Comparisons with previous studies from the literature were also performed.

  19. Interface width effect on the classical Rayleigh-Taylor instability in the weakly nonlinear regime

    SciTech Connect

    Wang, L. F.; Ye, W. H.; Li, Y. J.

    2010-05-15

    In this paper, the interface width effects (i.e., the density gradient effects or the density transition layer effects) on the Rayleigh-Taylor instability (RTI) in the weakly nonlinear (WN) regime are investigated by numerical simulation (NS). It is found that the interface width effects dramatically influence the linear growth rate in the linear growth regime and the mode coupling process in the WN growth regime. First, the interface width effects decrease the linear growth rate of the RTI, particularly for the short perturbation wavelengths. Second, the interface width effects suppress (reduce) the third-order feedback to the fundamental mode, which induces the nonlinear saturation amplitude (NSA) to exceed the classical prediction, 0.1lambda. The wider the density transition layer is, the larger the NSA is. The NSA in our NS can reach a half of its perturbation wavelength. Finally, the interface width effects suppress the generation and the growth of the second and the third harmonics. The ability to suppress the harmonics' growth increases with the interface width but decreases with the perturbation wavelength. On the whole, in the WN regime, the interface width effects stabilize the RTI, except for an enhancement of the NSA, which is expected to improve the understanding of the formation mechanism for the astrophysical jets, and for the jetlike long spikes in the high energy density physics.

  20. Evidence for epithelial-mesenchymal transition in cancer stem-like cells derived from carcinoma cell lines of the cervix uteri.

    PubMed

    Lin, Jiaying; Liu, Xishi; Ding, Ding

    2015-01-01

    The cancer stem cell (CSC) paradigm is one possible way to understand the genesis of cancer, and cervical cancer in particular. We quantified and enriched ALDH1(+) cells within cervical cancer cell lines and subsequently characterized their phenotypical and functional properties like invasion capacity and epithelial-mesenchymal transition (EMT). ALDH1 expression in spheroid-derived cells (SDC) and the parental monolayer-derived cell (MDC) line was compared by flow-cytometry. Invasion capability was evaluated by Matrigel assay and expression of EMT-related genes Twist 1, Twist 2, Snail 1, Snail 2, Vimentin and E-cadherin by real-time PCR. ALDH1 expression was significantly higher in SDC. ALDH1(+) cells showed increased colony-formation. SDC expressed lower levels of E-cadherin and elevated levels of Twist 1, Twist 2, Snail 1, Snail 2 and Vimentin compared to MDC. Cervical cancer cell lines harbor potential CSC, characterized by ALDH1 expression as well as properties like invasiveness, colony-forming ability, and EMT. CSC can be enriched by anchorage-independent culture techniques, which may be important for the investigation of their contribution to therapy resistance, tumor recurrence and metastasis.

  1. Mapping coexistence lines via free-energy extrapolation: application to order-disorder phase transitions of hard-core mixtures.

    PubMed

    Escobedo, Fernando A

    2014-03-07

    In this work, a variant of the Gibbs-Duhem integration (GDI) method is proposed to trace phase coexistence lines that combines some of the advantages of the original GDI methods such as robustness in handling large system sizes, with the ability of histogram-based methods (but without using histograms) to estimate free-energies and hence avoid the need of on-the-fly corrector schemes. This is done by fitting to an appropriate polynomial function not the coexistence curve itself (as in GDI schemes) but the underlying free-energy function of each phase. The availability of a free-energy model allows the post-processing of the simulated data to obtain improved estimates of the coexistence line. The proposed method is used to elucidate the phase behavior for two non-trivial hard-core mixtures: a binary blend of spheres and cubes and a system of size-polydisperse cubes. The relative size of the spheres and cubes in the first mixture is chosen such that the resulting eutectic pressure-composition phase diagram is nearly symmetric in that the maximum solubility of cubes in the sphere-rich solid (∼20%) is comparable to the maximum solubility of spheres in the cube-rich solid. In the polydisperse cube system, the solid-liquid coexistence line is mapped out for an imposed Gaussian activity distribution, which produces near-Gaussian particle-size distributions in each phase. A terminal polydispersity of 11.3% is found, beyond which the cubic solid phase would not be stable, and near which significant size fractionation between the solid and isotropic phases is predicted.

  2. Experimental transition probabilities and Stark-broadening parameters of neutral and single ionized tin

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1979-01-01

    Strengths and Stark-effect widths of the Sn I and Sn II lines prominent between 3200 and 7900 A are measured with a spectroscopic shock tube. Absolute strengths of 17 ionic lines are obtained with estimated (22-50)% accuracy and conform to appropriate quantum-mechanical sum rules. Relative transition probabilities for nine prominent neutral tin lines, normalized to radiative-lifetime data, are compared with other experiments and theoretical predictions. Parameters for Stark-effect broadening are measured over a range of plasma electron densities. Broadening data (with accuracies of 15-35%) for one neutral and ten ionic lines of tin are compared to theoretical predictions.

  3. Direct measurements of collisional Raman line broadening in the S-branch transitions of acetylene (C2H2).

    PubMed

    Hsu, Paul S; Stauffer, Hans U; Jiang, Naibo; Gord, James R; Roy, Sukesh

    2013-10-21

    We report direct measurements of the self- and N2-broadened Raman S-branch linewidths of acetylene (C2H2), obtained by employing time-resolved picosecond rotational coherent anti-Stokes Raman scattering spectroscopy. Using broadband 115-ps pump and Stokes pulses (~135 cm(-1) bandwidth) and a spectrally narrowed 90-ps probe pulse (~0.2 cm(-1) bandwidth), Raman-coherence lifetimes are measured at room temperature for the S-branch (ΔJ = +2) transitions associated with rotational quantum number J = 3-25. These directly measured Raman-coherence lifetimes, when converted to collisional linewidth broadening coefficients, differ from the previously reported broadening coefficients extracted from theoretical calculations by 6%-35% for self-broadening for C2H2 and by up to 60% for N2-broadened C2H2.

  4. High-resolution measurements, line identification, and spectral modeling of K-alpha transitions in Fe XVIII-Fe XXV

    NASA Technical Reports Server (NTRS)

    Beiersdorfer, P.; Phillips, T.; Jacobs, V. L.; Hill, K. W.; Bitter, M.; Von Goeler, S.; Kahn, S. M.

    1993-01-01

    A detailed analysis of the iron K-alpha emission spectrum covering the wavelength region from 1.840 to 1.940 A is presented. Measurements are made with a high-resolution Bragg crystal spectrometer on the Princeton Large Torus (PLT) tokamak for plasma conditions which closely resemble those of solar flares. A total of 40 features are identified, consisting of either single or multiple lines from eight charge states in iron, Fe XVIII - Fe XXV, and their wavelengths are determined with an accuracy of 0.1-0.4 mA. Many of these features are identified for the first time. In the interpretation of our observations we rely on model calculations that determine the ionic species abundances from electron density and temperature profiles measured independently with nonspectroscopic techniques and that incorporate theoretical collisional excitation and dielectronic recombination rates resulting in the excitation of the 1s2sr2ps configurations. The model calculations also include the effect of diffusive ion transport. Good overall agreement between the model calculations and the observations is obtained, which gives us confidence in our line identifications and spectral modeling capabilities. The results are compared with earlier analyses of the K-alpha emission from the Sun.

  5. High-resolution measurements, line identification, and spectral modeling of K-alpha transitions in Fe XVIII-Fe XXV

    NASA Technical Reports Server (NTRS)

    Beiersdorfer, P.; Phillips, T.; Jacobs, V. L.; Hill, K. W.; Bitter, M.; Von Goeler, S.; Kahn, S. M.

    1993-01-01

    A detailed analysis of the iron K-alpha emission spectrum covering the wavelength region from 1.840 to 1.940 A is presented. Measurements are made with a high-resolution Bragg crystal spectrometer on the Princeton Large Torus (PLT) tokamak for plasma conditions which closely resemble those of solar flares. A total of 40 features are identified, consisting of either single or multiple lines from eight charge states in iron, Fe XVIII - Fe XXV, and their wavelengths are determined with an accuracy of 0.1-0.4 mA. Many of these features are identified for the first time. In the interpretation of our observations we rely on model calculations that determine the ionic species abundances from electron density and temperature profiles measured independently with nonspectroscopic techniques and that incorporate theoretical collisional excitation and dielectronic recombination rates resulting in the excitation of the 1s2sr2ps configurations. The model calculations also include the effect of diffusive ion transport. Good overall agreement between the model calculations and the observations is obtained, which gives us confidence in our line identifications and spectral modeling capabilities. The results are compared with earlier analyses of the K-alpha emission from the Sun.

  6. Magnetic local time, substorm, and particle precipitation-related variations in the behaviour of SuperDARN Doppler spectral widths

    NASA Astrophysics Data System (ADS)

    Parkinson, M.; Chisham, G.; Pinnock, M.; Dyson, P.; Devlin, J.

    2004-12-01

    Super Dual Auroral Radar Network (DARN) radars often detect a distinct transition in line-of-sight Doppler velocity spread, or spectral width, from <50ms-1 at lower latitude to >200ms-1 at higher latitude. They also detect a similar boundary, namely the range at which ionospheric scatter with large spectral width suddenly commences (i.e. without preceding scatter with low spectral width). The location and behaviour of the spectral width boundary (SWB) (and scatter boundary) and the open-closed magnetic field line boundary (OCB) are thought to be closely related. The location of the nightside OCB can be inferred from the poleward edge of the auroral oval determined using energy spectra of precipitating particles measured on board Defence Meteorology Satellite Program (DMSP) satellites. Observations made with the Halley SuperDARN radar (75.5° S, 26.6° W, geographic; -62.0°Λ) and the Tasman International Geospace Environment Radar (TIGER) (43.4° S, 147.2° E; -54.5°Λ) are used to compare the location of the SWB with the DMSP-inferred OCB during 08:00 to 22:00 UT on 1 April 2000. This study interval was chosen because it includes several moderate substorms, whilst the Halley radar provided almost continuous high-time resolution measurements of the dayside SWB location and shape, and TIGER provided the same in the nightside ionosphere. The behaviour of the day- and nightside SWB can be understood in terms of the expanding/contracting polar cap model of high-latitude convection change, and the behaviour of the nightside SWB can also be organised according to substorm phase. Previous comparisons with DMSP OCBs have proven that the radar SWB is often a reasonable proxy for the OCB from dusk to just past midnight (Chisham et al., 2004). However, the present case study actually suggests that the nightside SWB is often a better proxy for the poleward edge of Pedersen conductance enhanced by hot particle precipitation in the auroral zone. Simple modeling implies that

  7. Lithologic Heterogeneity and Variable Valley Width in the Buffalo River Watershed, AR

    NASA Astrophysics Data System (ADS)

    Shepherd, S. L.; Keen-Zebert, A.

    2014-12-01

    Lithologic heterogeneity across catchments is thought to be a key control on the style of incision, whether dominated by vertical or lateral processes, but little field evidence is available to support the claims. Map and field observations from the Buffalo National River (BNR) indicate that valley width is related to variation in lithology along the length of the river. The BNR is a gravel-mantled, ingrown meandering, bedrock river that incises through a sequence of Pennsylvanian, Mississippian, and Ordovician carbonate and clastic sedimentary rocks. Using GIS, valley width was measured at 250 m intervals along the entire length of the river through two sequences of limestone and sandstone reaches that represent the dominant lithologies of the catchment. Preliminary results show measurable and statistically significant differences in valley width between limestone and sandstone reaches. Where limestone strata is exposed at river level the mean width is ~ 360 m and is highly variable with a standard deviation of 227 m. The mean width in sandstone strata is ~240 m with a standard deviation of 88 m. At each transition from limestone to sandstone there is a greater than 20% decrease in valley width downstream, with no visible change in channel width at map scales. It is possible the atypical pattern in valley width in the BNR is due to variation in lithologic resistance. These results support the assumption that lithologic heterogeneity exerts control on stream valley evolution.

  8. Relative Width and Height of Handwritten Letter.

    PubMed

    Lizega Rika, Joseba

    2017-02-28

    This is an exploratory study that analyzes the width and the height of letters in two texts written by each of the 21 writers analyzed. After detrending the linear, text, and allograph trends, we proceeded to comparing the sizes obtained in different texts. The different detrended series were compared by means of correlation and t-test. According to the results regarding the width of letters, the texts of 19 of 21 writers correlated strongly, whereas the texts of two writers did not correlate with the limits of the threshold. With regard to the height of letters, texts written by between 18 and 21 writers of 21 writers correlated strongly, whereas texts that did not correlate were within the threshold value. Regarding both the width and the height of letters, of 21 writers, texts written by between 19 and 21 individuals were found to correlate strongly.

  9. Line Transport in Turbulent Atmospheres

    NASA Astrophysics Data System (ADS)

    Nikoghossian, A. G.

    2017-07-01

    The spectral line transfer in turbulent atmospheres with a spatially correlated velocity field is examined. Both the finite and semi-infinite media are treated. In finding the observed intensities we first deal with the problem for determining the mean intensity of radiation emerging from the medium for a fixed value of turbulent velocity at its boundary. A new approach proposed for solving this problem is based on the invariant imbedding technique which yields the solution of the proper problems for a family of media of different optical thicknesses and allows tackling different kinds of inhomogeneous problems. The dependence of the line profile, integral intensity, and the line width on the mean correlation length and the average value of the hydrodynamic velocity is studied. It is shown that the transition from a micro-turbulent regime to a macro-turbulence occurs within a comparatively narrow range of variation in the correlation length . Ambartsumian's principle of invariance is used to solve the problem of diffuse reflection of the line radiation from a one-dimensional semi-infinite turbulent atmosphere. In addition to the observed spectral line profile, statistical averages describing the diffusion process in the atmosphere (mean number of scattering events, average time spent by a diffusing photon in the medium) are determined. The dependence of these quantities on the average hydrodynamic velocity and correlation coefficient is studied.

  10. Line patterning of (Sr,Ba)Nb{sub 2}O{sub 6} crystals in borate glasses by transition metal atom heat processing

    SciTech Connect

    Sato, M.; Honma, T.; Benino, Y.; Komatsu, T.

    2007-09-15

    Some NiO-doped Bi{sub 2}O{sub 3},La{sub 2}O{sub 3}-SrO-BaO-Nb{sub 2}O{sub 5}-B{sub 2}O{sub 3} glasses giving the formation of strontium barium niobate Sr{sub 0.5}Ba{sub 0.5}Nb{sub 2}O{sub 6} (SBN) crystals with a tetragonal tungsten-bronze structure through conventional crystallization in an electric furnace have been developed, and SBN crystal lines have been patterned on the glass surface by heat-assisted (250-300 deg. C) laser irradiation and scanning of continuous-wave Nd:YAG laser (wavelength: 1064 nm). The surface morphology and the quality of SBN crystal lines are examined from measurements of confocal scanning laser micrographs and polarized micro-Raman scattering spectra. The surface morphology of SBN crystal lines changes from periodic bump structures to homogeneous structures, depending on laser scanning conditions. It is suggested that the line patterned at the laser irradiation condition of laser power P=1 W and of laser scanning speed S=1 {mu}m/s in 2NiO-4La{sub 2}O{sub 3}-16SrO-16BaO-32Nb{sub 2}O{sub 5}-30B{sub 2}O{sub 3} glass has a possibility of the orientation of SBN crystals along the laser scanning direction. The present study demonstrates that the transition metal atom heat processing (i.e., a combination of cw Nd:YAG laser and Ni{sup 2+} ions) is a novel technique for spatially selected crystallization of SBN crystals in glass. - Graphical abstract: This figure shows the polarization optical (a) and confocal scanning laser (b) micrographs for the sample obtained by heat-assisted (300 deg. C) Nd:YAG laser irradiation with a laser power of P=1 W and laser scanning speed of S=1 {mu}m/s in Glass C. The figure demonstrates that the transition metal atom heat processing (i.e., a combination of cw Nd:YAG laser and Ni{sup 2+} ions) is a novel technique for spatially selected crystallization of SBN crystals in glass.

  11. Spectral width of laser generation in quantum dot lasers: An analytical approach

    SciTech Connect

    Savelyev, A. V. Maximov, M. V.; Zhukov, A. E.

    2011-02-15

    An analytical approach to description of broad spectra of lasing in quantum-dot lasers has been developed. It is shown that the spectral width of the laser generation is determined by three parameters: the spectral width of the gain spectrum, homogeneous broadening of the line, and the effective parameter of the gain saturation. As a result, the dependence of the spectral width of lasing on the laser output power is shown to be universal and can be described as a function of a single dimensionless parameter.

  12. Effect of Melatonin in Epithelial Mesenchymal Transition Markers and Invasive Properties of Breast Cancer Stem Cells of Canine and Human Cell Lines.

    PubMed

    Gonçalves, Naiane do Nascimento; Colombo, Jucimara; Lopes, Juliana Ramos; Gelaleti, Gabriela Bottaro; Moschetta, Marina Gobbe; Sonehara, Nathália Martins; Hellmén, Eva; Zanon, Caroline de Freitas; Oliani, Sônia Maria; Zuccari, Debora Aparecida Pires de Campos

    2016-01-01

    Cancer stem cells (CSCs) have been associated with metastasis and therapeutic resistance and can be generated via epithelial mesenchymal transition (EMT). Some studies suggest that the hormone melatonin acts in CSCs and may participate in the inhibition of the EMT. The objectives of this study were to evaluate the formation of mammospheres from the canine and human breast cancer cell lines, CMT-U229 and MCF-7, and the effects of melatonin treatment on the modulation of stem cell and EMT molecular markers: OCT4, E-cadherin, N-cadherin and vimentin, as well as on cell viability and invasiveness of the cells from mammospheres. The CMT-U229 and MCF-7 cell lines were subjected to three-dimensional culture in special medium for stem cells. The phenotype of mammospheres was first evaluated by flow cytometry (CD44(+)/CD24(low/-) marking). Cell viability was measured by MTT colorimetric assay and the expression of the proteins OCT4, E-cadherin, N-cadherin and vimentin was evaluated by immunofluorescence and quantified by optical densitometry. The analysis of cell migration and invasion was performed in Boyden Chamber. Flow cytometry proved the stem cell phenotype with CD44(+)/CD24(low/-) positive marking for both cell lines. Cell viability of CMT-U229 and MCF-7 cells was reduced after treatment with 1mM melatonin for 24 h (P<0.05). Immunofluorescence staining showed increased E-cadherin expression (P<0.05) and decreased expression of OCT4, N-cadherin and vimentin (P<0.05) in both cell lines after treatment with 1 mM melatonin for 24 hours. Moreover, treatment with melatonin was able to reduce cell migration and invasion in both cell lines when compared to control group (P<0.05). Our results demonstrate that melatonin shows an inhibitory role in the viability and invasiveness of breast cancer mammospheres as well as in modulating the expression of proteins related to EMT in breast CSCs, suggesting its potential anti-metastatic role in canine and human breast cancer cell

  13. Effect of Melatonin in Epithelial Mesenchymal Transition Markers and Invasive Properties of Breast Cancer Stem Cells of Canine and Human Cell Lines

    PubMed Central

    Gonçalves, Naiane do Nascimento; Colombo, Jucimara; Lopes, Juliana Ramos; Gelaleti, Gabriela Bottaro; Moschetta, Marina Gobbe; Sonehara, Nathália Martins; Hellmén, Eva; Zanon, Caroline de Freitas; Oliani, Sônia Maria; Zuccari, Debora Aparecida Pires de Campos

    2016-01-01

    Cancer stem cells (CSCs) have been associated with metastasis and therapeutic resistance and can be generated via epithelial mesenchymal transition (EMT). Some studies suggest that the hormone melatonin acts in CSCs and may participate in the inhibition of the EMT. The objectives of this study were to evaluate the formation of mammospheres from the canine and human breast cancer cell lines, CMT-U229 and MCF-7, and the effects of melatonin treatment on the modulation of stem cell and EMT molecular markers: OCT4, E-cadherin, N-cadherin and vimentin, as well as on cell viability and invasiveness of the cells from mammospheres. The CMT-U229 and MCF-7 cell lines were subjected to three-dimensional culture in special medium for stem cells. The phenotype of mammospheres was first evaluated by flow cytometry (CD44+/CD24low/- marking). Cell viability was measured by MTT colorimetric assay and the expression of the proteins OCT4, E-cadherin, N-cadherin and vimentin was evaluated by immunofluorescence and quantified by optical densitometry. The analysis of cell migration and invasion was performed in Boyden Chamber. Flow cytometry proved the stem cell phenotype with CD44+/CD24low/- positive marking for both cell lines. Cell viability of CMT-U229 and MCF-7 cells was reduced after treatment with 1mM melatonin for 24 h (P<0.05). Immunofluorescence staining showed increased E-cadherin expression (P<0.05) and decreased expression of OCT4, N-cadherin and vimentin (P<0.05) in both cell lines after treatment with 1 mM melatonin for 24 hours. Moreover, treatment with melatonin was able to reduce cell migration and invasion in both cell lines when compared to control group (P<0.05). Our results demonstrate that melatonin shows an inhibitory role in the viability and invasiveness of breast cancer mammospheres as well as in modulating the expression of proteins related to EMT in breast CSCs, suggesting its potential anti-metastatic role in canine and human breast cancer cell lines. PMID

  14. Energy levels, oscillator strengths, line strengths, and transition probabilities in Si-like ions of La XLIII, Er LIV, Tm LV, and Yb LVI

    NASA Astrophysics Data System (ADS)

    Chen, Zhan-Bin; Ma, Kun; Wang, Hong-Jian; Wang, Kai; Liu, Xiao-Bin; Zeng, Jiao-Long

    2017-01-01

    Detailed calculations using the multi-configuration Dirac-Fock (MCDF) method are carried out for the lowest 64 fine-structure levels of the 3s23p2, 3s23p3d, 3s3p3, 3s3p23d, 3s23d2, and 3p4 configurations in Si-like ions of La XLIII, Er LIV, Tm LV, and Yb LVI. Energies, oscillator strengths, wavelengths, line strengths, and radiative electric dipole transition rates are given for all ions. A parallel calculation using the many-body perturbation theory (MBPT) method is also carried out to assess the present energy levels accuracy. Comparisons are performed between these two sets of energy levels, as well as with other available results, showing that they are in good agreement with each other within 0.5%. These high accuracy results can be used to the modeling and the interpretation of astrophysical objects and fusion plasmas.

  15. Line parameters for CO2 broadening in the ν2 band of HD16O

    NASA Astrophysics Data System (ADS)

    Devi, V. Malathy; Benner, D. Chris; Sung, Keeyoon; Crawford, Timothy J.; Gamache, Robert R.; Renaud, Candice L.; Smith, Mary Ann H.; Mantz, Arlan W.; Villanueva, Geronimo L.

    2017-01-01

    CO2-rich planetary atmospheres such as those of Mars and Venus require accurate knowledge of CO2 broadened HDO half-width coefficients and their temperature dependence exponents for reliable abundance determination. Although a few calculated line lists have recently been published on HDO-CO2 line shapes and their temperature dependences, laboratory measurements of those parameters are thus far non-existent. In this work, we report the first measurements of CO2-broadened half-width and pressure-shift coefficients and their temperature dependences for over 220 transitions in the ν2 band. First measurements of self-broadened half-width and self-shift coefficients at room temperature are also obtained for majority of these transitions. In addition, the first experimental determination of collisional line mixing has been reported for 11 transition pairs for HDO-CO2 and HDO-HDO systems. These results were obtained by analyzing ten high-resolution spectra of HDO and HDO-CO2 mixtures at various sample temperatures and pressures recorded with the Bruker IFS-125HR Fourier transform spectrometer at the Jet Propulsion Laboratory (JPL). Two coolable absorption cells with path lengths of 20.38 cm and 20.941 m were used to record the spectra. The various line parameters were retrieved by fitting all ten spectra simultaneously using a multispectrum nonlinear least squares fitting algorithm. The HDO transitions in the 1100-4100 cm-1 range were extracted from the HITRAN2012 database. For the ν2 and 2ν2 -ν2 bands there were 2245 and 435 transitions, respectively. Modified Complex Robert-Bonamy formalism (MCRB) calculations were made for the half-width coefficients, their temperature dependence and the pressure shift coefficients for the HDO-CO2 and HDO-HDO collision systems. MCRB calculations are compared with the measured values.

  16. Human annoyance, acceptability and concern as responses to vibration from the construction of Light Rapid Transit lines in residential environments.

    PubMed

    Wong-McSweeney, D; Woodcock, J S; Peris, E; Waddington, D C; Moorhouse, A T; Redel-Macías, M D

    2016-10-15

    The aim of this paper is to investigate the use of different self-reported measures for assessing the human response to environmental vibration from the construction of an urban LRT (Light Rapid Transit) system. The human response to environmental stressors such as vibration and noise is often expressed in terms of exposure-response relationships that describe annoyance as a function of the magnitude of the vibration. These relationships are often the basis of noise and vibration policy and the setting of limit values. This paper examines measures other than annoyance by expressing exposure-response relationships for vibration in terms of self-reported concern about property damage and acceptability. The exposure-response relationships for concern about property damage and for acceptability are then compared with those for annoyance. It is shown that concern about property damage occurs at vibration levels well below those where there is any risk of damage. Earlier research indicated that concern for damage is an important moderator of the annoyance induced. Acceptability, on the other hand, might be influenced by both annoyance and concern, as well as by other considerations. It is concluded that exposure-response relationships expressing acceptability as a function of vibration exposure could usefully complement existing relationships for annoyance in future policy decisions regarding environmental vibration. The results presented in this paper are derived from data collected through a socio-vibration survey (N=321) conducted for the construction of an urban LRT in the United Kingdom. Copyright © 2016. Published by Elsevier B.V.

  17. Measurements of Tc (Q,P): Depression of the Superfluid Transition Temperature by a Heat Current Along the Lambda Line

    NASA Technical Reports Server (NTRS)

    Liu, Yuan-Ming; Larson, Melora; Israelsson, Ulf

    1999-01-01

    We report experimental measurements of Tc (Q,P) for heat currents (Q) between I1and 100 micro W/sq cm and pressure (P) between SVP and 15 bar. The measurements were performed in a normal gravity environment, using the low-gravity simulator facility at JPL without the magnet being energized. The sample pressure was controlled to 0.1 micro bar using a hot volume, and a Straty-Adams capacitive pressure gauge. The total volume of helium in the sample cell and the hot volume was held constant using a pneumatic low temperature valve. A melting curve thermometer (MCT) measured the transition temperature (Tc) with a resolution of about 10 nK through a sidewall probe of the thermal conductivity sample cell. We employed the same measurement technique and procedure described by DAS. Preliminary results indicate that Tc (Q,P) depends very little on the pressure in the pressure range between SVP and 15 bar with a variation in the amplitude of Tc(Q,P) of less than about 5% observable in this pressure range. According to the Renormalization-group theory calculation by Haussmann and Dohm, the amplitude of Tc (Q,P) has a leading pressure-dependence term proportional to xi(sub 0) (sup (1/nu)), where xi(sub 0) is the correlation-length amplitude and nu is the correlation-length exponent. Thus, a small pressure dependence of the amplitude of Tc (Q,P) is expected since xi(sub 0) is very weakly dependent on pressure between SVP and 15 bar, consistent with our measurements.

  18. An efficient algorithm for equal width

    NASA Astrophysics Data System (ADS)

    Bakodah, Huda. O.; Banaja, Mona. A.

    2016-10-01

    The new modification of Laplace Adomian decomposition method (ADM) to obtain numerical solution of the equal width equation is presented. The performance of the method illustrated by solving some test examples of the problem. By computing the absolute error the results are found in good agreement with exact solution.

  19. Bounding the Higgs boson width through interferometry.

    PubMed

    Dixon, Lance J; Li, Ye

    2013-09-13

    We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum.

  20. Elucidation of epithelial-mesenchymal transition-related pathways in a triple-negative breast cancer cell line model by multi-omics interactome analysis.

    PubMed

    Pauling, Josch K; Christensen, Anne G; Batra, Richa; Alcaraz, Nicolas; Barbosa, Eudes; Larsen, Martin R; Beck, Hans C; Leth-Larsen, Rikke; Azevedo, Vasco; Ditzel, Henrik J; Baumbach, Jan

    2014-11-01

    In life sciences, and particularly biomedical research, linking aberrant pathways exhibiting phenotype-specific alterations to the underlying physical condition or disease is an ongoing challenge. Computationally, a key approach for pathway identification is data enrichment, combined with generation of biological networks. This allows identification of intrinsic patterns in the data and their linkage to a specific context such as cellular compartments, diseases or functions. Identification of aberrant pathways by traditional approaches is often limited to biological networks based on either gene expression, protein expression or post-translational modifications. To overcome single omics analysis, we developed a set of computational methods that allow a combined analysis of data collections from multiple omics fields utilizing hybrid interactome networks. We apply these methods to data obtained from a triple-negative breast cancer cell line model, combining data sets of gene and protein expression as well as protein phosphorylation. We focus on alterations associated with the phenotypical differences arising from epithelial-mesenchymal transition in two breast cancer cell lines exhibiting epithelial-like and mesenchymal-like morphology, respectively. Here we identified altered protein signaling activity in a complex biologically relevant network, related to focal adhesion and migration of breast cancer cells. We found dysregulated functional network modules revealing altered phosphorylation-dependent activity in concordance with the phenotypic traits and migrating potential of the tested model. In addition, we identified Ser267 on zyxin, a protein coupled to actin filament polymerization, as a potential in vivo phosphorylation target of cyclin-dependent kinase 1.