Science.gov

Sample records for broadened super continuum

  1. 0.4-1.4 {mu}m Visible to Near-Infrared Widely Broadened Super Continuum Generation with Er-doped Ultrashort Pulse Fiber Laser System

    SciTech Connect

    Nishizawa, Norihiko; Sumimura, Kazuhiko; Mitsuzawa, Hideyuki

    2009-03-17

    Visible to near-infrared widely broadened super continuum generation is demonstrated using ultrashort-pulse fiber laser system. Er-doped fiber chirped-pulse amplification system operated at 1550 nm in wavelength is used for the amplifier system, which generated ultrashort-pulse of 112 fs in FWHM with output power of 160 mW, on average. Almost pedestal free 200 fs second harmonic generation pulse is generated at 780 nm region using periodically poled LiNbO{sub 3} and conversion efficiency is as high as 37%. 0.45-1.40 {mu}m widely broadened super continuum is generated in highly nonlinear photonic crystal fiber and spectrum flatness is within {+-}6 dB. All of the fiber devices are fusion spliced so that this system shows a good stability.

  2. Mid-IR super-continuum generation

    NASA Astrophysics Data System (ADS)

    Islam, Mohammed N.; Xia, Chenan; Freeman, Mike J.; Mauricio, Jeremiah; Zakel, Andy; Ke, Kevin; Xu, Zhao; Terry, Fred L., Jr.

    2009-02-01

    A Mid-InfraRed FIber Laser (MIRFIL) has been developed that generates super-continuum covering the spectral range from 0.8 to 4.5 microns with a time-averaged power as high as 10.5W. The MIRFIL is an all-fiber integrated laser with no moving parts and no mode-locked lasers that uses commercial off-the-shelf parts and leverages the mature telecom/fiber optics platform. The MIRFIL power can be easily scaled by changing the repetition rate and modifying the erbium-doped fiber amplifier. Some of the applications using the super-continuum laser will be described in defense, homeland security and healthcare. For example, the MIRFIL is being applied to a catheter-based medical diagnostic system to detect vulnerable plaque, which is responsible for most heart attacks resulting from hardening-of-the-arteries or atherosclerosis. More generally, the MIRFIL can be a platform for selective ablation of lipids without damaging normal protein or smooth muscle tissue.

  3. Broadening of white-light continuum by filamentation in BK7 glass at its zero-dispersion point

    NASA Astrophysics Data System (ADS)

    Jiang, Jiaming; Zhong, Yue; Zheng, Yinghui; Zeng, Zhinan; Ge, Xiaochun; Li, Ruxin

    2015-09-01

    Broadening of white-light continuum is observed by filamentation of near-infrared femtosecond laser pulses with peak power exceeding the megawatt level in BK7 glass with the presence of the zero-dispersion point. The simulated results show that, due to the low dispersion at the zero-dispersion point, the broadening of white-light continuum can be wider and the filament can persist in propagating stably longer distance.

  4. SUPERSONIC LINE BROADENING WITHIN YOUNG AND MASSIVE SUPER STAR CLUSTERS

    SciTech Connect

    Tenorio-Tagle, Guillermo; Silich, Sergiy; Wuensch, Richard; Munoz-Tunon, Casiana; Palous, Jan E-mail: richard@wunsch.c E-mail: cmt@ll.iac.e

    2010-01-10

    The origin of supersonic infrared and radio recombination nebular lines often detected in young and massive superstar clusters is discussed. We suggest that these arise from a collection of repressurizing shocks (RSs), acting effectively to re-establish pressure balance within the cluster volume and from the cluster wind which leads to an even broader although much weaker component. The supersonic lines here are shown to occur in clusters that undergo a bimodal hydrodynamic solution, that is within clusters that are above the threshold line in the mechanical luminosity or cluster mass versus the size of the cluster plane. A plethora of RSs is due to frequent and recurrent thermal instabilities that take place within the matter reinserted by stellar winds and supernovae. We show that the maximum speed of the RSs and of the cluster wind are both functions of the temperature reached at the stagnation radius. This temperature depends only on the cluster heating efficiency (eta). Based on our two-dimensional simulations we calculate the line profiles that result from several models and confirm our analytical predictions. From a comparison between the predicted and observed values of the half-width zero intensity of the two line components, we conclude that the thermalization efficiency in young super star clusters above the threshold line must be lower than 20%.

  5. Optical stealth transmission based on super-continuum generation in highly nonlinear fiber over WDM network.

    PubMed

    Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Chen, Dalei

    2015-06-01

    In this Letter, the optical stealth transmission carried by super-continuum spectrum optical pulses generated in highly nonlinear fiber is proposed and experimentally demonstrated. In the proposed transmission scheme, super-continuum signals are reshaped in the spectral domain through a wavelength-selective switch and are temporally spread by a chromatic dispersion device to achieve the same noise-like characteristic as the noise in optical networks, so that in both the time domain and the spectral domain, the stealth signals are hidden in public channel. Our experimental results show that compared with existing schemes where stealth channels are carried by amplified spontaneous emission noise, super-continuum signal can increase the transmission performance and robustness.

  6. Optical stealth transmission based on super-continuum generation in highly nonlinear fiber over WDM network.

    PubMed

    Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Chen, Dalei

    2015-06-01

    In this Letter, the optical stealth transmission carried by super-continuum spectrum optical pulses generated in highly nonlinear fiber is proposed and experimentally demonstrated. In the proposed transmission scheme, super-continuum signals are reshaped in the spectral domain through a wavelength-selective switch and are temporally spread by a chromatic dispersion device to achieve the same noise-like characteristic as the noise in optical networks, so that in both the time domain and the spectral domain, the stealth signals are hidden in public channel. Our experimental results show that compared with existing schemes where stealth channels are carried by amplified spontaneous emission noise, super-continuum signal can increase the transmission performance and robustness. PMID:26030557

  7. RHESSI LINE AND CONTINUUM OBSERVATIONS OF SUPER-HOT FLARE PLASMA

    SciTech Connect

    Caspi, A.; Lin, R. P.

    2010-12-20

    We use RHESSI high-resolution imaging and spectroscopy observations from {approx}5 to 100 keV to characterize the hot thermal plasma during the 2002 July 23 X4.8 flare. These measurements of the steeply falling thermal X-ray continuum are well fit throughout the flare by two distinct isothermal components: a super-hot (T{sub e} > 30 MK) component that peaks at {approx}44 MK and a lower-altitude hot (T{sub e} {approx}< 25 MK) component whose temperature and emission measure closely track those derived from GOES measurements. The two components appear to be spatially distinct, and their evolution suggests that the super-hot plasma originates in the corona, while the GOES plasma results from chromospheric evaporation. Throughout the flare, the measured fluxes and ratio of the Fe and Fe-Ni excitation line complexes at {approx}6.7 and {approx}8 keV show a close dependence on the super-hot continuum temperature. During the pre-impulsive phase, when the coronal thermal and non-thermal continua overlap both spectrally and spatially, we use this relationship to obtain limits on the thermal and non-thermal emission.

  8. Broadband master-slave interferometry using a super-continuum source

    NASA Astrophysics Data System (ADS)

    Maria, M.; Marques, M. J. M.; Costa, C.; Bradu, A.; Feuchter, T.; Leick, L.; Podoleanu, A. G.

    2016-03-01

    In this report we applied the principle of Master-Slave Interferometry (MSI) to an Optical Coherence Tomography (OCT) employing a Super-Continuum (SC) light source. A-scans and B-scan images of biological and non-biological sample are presented in order to demonstrate similar performance with the images obtained with the resampled Fourier Transform (FT) based OCT technique. Dispersion tolerance of MSI method is demonstrated as a constant axial resolution over the depth range even though dispersion is left uncompenstaed in the system.

  9. Radiative effects of CH4, N2O, halocarbons and the foreign-broadened H2O continuum: A GCM experiment

    NASA Astrophysics Data System (ADS)

    Schwarzkopf, M. Daniel; Ramaswamy, V.

    1999-04-01

    The simplified exchange approximation (SEA) method for calculation of infrared radiative transfer, used for general circulation model (GCM) climate simulations at the Geophysical Fluid Dynamics Laboratory (GFDL) and other institutions, has been updated to permit inclusion of the effects of methane (CH4), nitrous oxide (N2O), halocarbons, and water-vapor-air molecular broadening (foreign broadening). The effects of CH4 and N2O are incorporated by interpolation of line-by-line (LBL) transmissivity calculations evaluated at standard species concentrations; halocarbon effects are calculated from transmissivities computed using recently measured frequency-dependent absorption coefficients. The effects of foreign broadening are included by adoption of the "CKD" formalism for the water vapor continuum [Clough et al., 1989]. For a standard midlatitude summer profile, the change in the net infrared flux at the model tropopause due to the inclusion of present-day concentrations of CH4 and N2O is evaluated to within ˜5% of corresponding LBL results; the change in net flux at the tropopause upon inclusion of 1 ppbv of CFC-11, CFC-12, CFC-113, and HCFC-22 is within ˜10% of the LBL results. Tropospheric heating rate changes resulting from the introduction of trace species (CH4, N2O, and halocarbons) are calculated to within ˜0.03 K/d of the LBL results. Introduction of the CKD water vapor continuum causes LBL-computed heating rates to decrease by up to ˜0.4 K/d in the upper troposphere and to increase by up to ˜0.25 K/d in the midtroposphere; the SEA method gives changes within ˜0.05 K/d of the LBL values. The revised SEA formulation has been incorporated into the GFDL "SKYHI" GCM. Two simulations (using fixed sea surface temperatures and prescribed clouds) have been performed to determine the changes to the model climate from that of a control calculation upon inclusion of (1) the trace species and (2) the foreign-broadened water vapor continuum. When the trace species

  10. Surface roughness measurement of flat and curved machined metal parts using a near infrared super-continuum laser

    NASA Astrophysics Data System (ADS)

    Alexander, Vinay V.; Deng, Huaqiu; Islam, Mohammed N.; Terry, Fred L.; Pittman, Raymond B.; Valen, Thomas

    2011-11-01

    We describe a system for performing high-accuracy, noncontact rms roughness measurements of flat and curved machined parts in the industrially relevant range of ~0.05 to 0.35 μm. The system uses a near infrared (NIR) super-continuum laser to measure the intensity of specular reflection versus wavelength, at relatively long (~1 m) stand-off distances and has the potential to be used in high speed, in-line manufacturing applications. The surface roughness value is extracted from the slope of the normalized specular intensity using the Beckmann-Kirchhoff (BK) model. According to the BK model, the normalized specular intensity in the NIR mostly depends on the surface roughness parameter alone and is independent of the absolute reflectance due to the normalization process. We discuss the benefits of performing the reflectance measurements in the NIR versus the commonly used visible spectrum. These include measurements at lower angles of incidence and the lack of need for a reference of the same metal composition. The roughness measurements performed by this system are in very good agreement with comparative data from a stylus profilometer and a white light interferometer. A potential industrial application is also demonstrated where the system is used to detect polishing defects in automotive engine crankshaft journals.

  11. Mid infra-red hyper-spectral imaging with bright super continuum source and fast acousto-optic tuneable filter for cytological applications.

    NASA Astrophysics Data System (ADS)

    Farries, Mark; Ward, Jon; Valle, Stefano; Stephens, Gary; Moselund, Peter; van der Zanden, Koen; Napier, Bruce

    2015-06-01

    Mid-IR imaging spectroscopy has the potential to offer an effective tool for early cancer diagnosis. Current development of bright super-continuum sources, narrow band acousto-optic tunable filters and fast cameras have made feasible a system that can be used for fast diagnosis of cancer in vivo at point of care. The performance of a proto system that has been developed under the Minerva project is described.

  12. Continuum absorption spectra in the far wings of the Hg 1S0-->3P1 resonance line broadened by Ar

    NASA Astrophysics Data System (ADS)

    Sato, Y.; Nakamura, T.; Okunishi, M.; Ohmori, K.; Chiba, H.; Ueda, K.

    1996-02-01

    Absolute reduced absorption coefficients for the Hg resonance line at 253.7 nm broadened by Ar were determined between 390 and 430 K in the spectral range from 20 to 1000 cm-1 on the red wing and from 20 to 400 cm-1 on the blue wing. The resultant reduced absorption coefficients are in fair agreement with those obtained by Petzold and Behmenburg [Z. Naturtorsch. Teil A 33, 1461 (1978)]. The observed A 30+<--X 10+ spectrum in the spectral range from 80 to 800 cm-1 on the red wing agrees remarkably well both in shape and magnitude with the quasistatic line shape calculated using the potential-energy curves of the HgAr van der Waals molecule given by Fuke, Saito, and Kaya [J. Chem. Phys. 81, 2591 (1984)], and Yamanouchi et al. [J. Chem. Phys. 88, 205 (1988)]. The blue-wing spectrum is interpreted as the B 31<--X 10+ free-free transition of HgAr by a simulation of the spectrum using uniform semiclassical treatment for the free-free Franck-Condon factor. The source of the satellites on the blue wing is attributed to the phase-interference effect arising from a stationary phase-shift difference between the B- and X-state translational wave functions. The stationary phase-shift difference arises owing to the existence of a maximum in the difference potential between the B and X states. The repulsive branches of the potential-energy curves of HgAr for the X and B states have been revised to give excellent agreement between the observed and calculated spectra, both in shape and magnitude.

  13. High dynamic range measurement of spectral responsivity and linearity of a radiation thermometer using a super-continuum laser and LEDs

    SciTech Connect

    Yoo, Y. S.; Lee, D. H.; Park, C. W.; Park, S. N.

    2013-09-11

    To realize the temperature scale above the freezing point of silver according to the definition of ITS-90, the dynamic range of the spectral responsivity is one of the most important factors which limit its uncertainty. When the residual spectral response at both side bands of a spectral band is not negligible, a significant uncertainty can be caused by a low dynamic range of the spectral responsivity measurement. In general, incandescent lamps are used to measure the spectral responsivity and the linearity. The dynamic range of the spectral responsivity measurement is often limited by a trade-off with the desired spectral resolution, which is less than 6 decades. Nonlinearity is another limiting fact of uncertainties of the temperature scale. Tungsten lamps have disadvantage in the nonlinearity measurements in terms of adjustability of radiance level and spectral selectivity. We report spectral responsivity measurements of which the measurable dynamic range is enhanced 50 times after replacing a QTH lamp with a super continuum laser. We also present a spectrally selected linearity measurement over a wide dynamic range using high-brightness light emitting diode arrays to observe a slight saturation of linearity.

  14. Spectral broadening induced by intense ultra-short pulse in 4H-SiC crystals

    NASA Astrophysics Data System (ADS)

    Chun-hua, Xu; Teng-fei, Yan; Gang, Wang; Wen-jun, Wang; Jing-kui, Liang; Xiao-long, Chen

    2016-06-01

    We report the observation of spectral broadening induced by 200 femtosecond laser pulses with the repetition rate of 1 kHz at the wavelength of 532 nm in semi-insulating 4H-SiC single crystals. It is demonstrated that the full width at half maximum of output spectrum increases linearly with the light propagation length and the peak power density, reaching a maximum 870 cm-1 on a crystal of 19 mm long under an incident laser with a peak power density of 60.1 GW/cm2. Such spectral broadening can be well explained by the self-phase modulation model which correlates time-dependent phase change of pulses to intensity-dependent refractive index. The nonlinear refractive index n 2 is estimated to be 1.88×10-15 cm2/W. The intensity-dependent refractive index is probably due to both the nonlinear optical polarizability of the bound electrons and the increase of free electrons induced by the two-photon absorption process. Super continuum spectra could arise as crystals are long enough to induce the self-focusing effect. The results show that SiC crystals may find applications in spectral broadening of high power lasers. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA041402) and the National Natural Science Foundation of China (Grant Nos. 51272276 and 51322211).

  15. Spectral broadening induced by intense ultra-short pulse in 4H–SiC crystals

    NASA Astrophysics Data System (ADS)

    Chun-hua, Xu; Teng-fei, Yan; Gang, Wang; Wen-jun, Wang; Jing-kui, Liang; Xiao-long, Chen

    2016-06-01

    We report the observation of spectral broadening induced by 200 femtosecond laser pulses with the repetition rate of 1 kHz at the wavelength of 532 nm in semi-insulating 4H–SiC single crystals. It is demonstrated that the full width at half maximum of output spectrum increases linearly with the light propagation length and the peak power density, reaching a maximum 870 cm‑1 on a crystal of 19 mm long under an incident laser with a peak power density of 60.1 GW/cm2. Such spectral broadening can be well explained by the self-phase modulation model which correlates time-dependent phase change of pulses to intensity-dependent refractive index. The nonlinear refractive index n 2 is estimated to be 1.88×10‑15 cm2/W. The intensity-dependent refractive index is probably due to both the nonlinear optical polarizability of the bound electrons and the increase of free electrons induced by the two-photon absorption process. Super continuum spectra could arise as crystals are long enough to induce the self-focusing effect. The results show that SiC crystals may find applications in spectral broadening of high power lasers. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA041402) and the National Natural Science Foundation of China (Grant Nos. 51272276 and 51322211).

  16. Broaden Students' Music Preferences.

    ERIC Educational Resources Information Center

    Le Blanc, Albert

    1983-01-01

    A model of music preference theory suggests ways that teachers can broaden their students' musical preferences. Teachers can change preferences by changing something in the listener, the social environment, the music, or the ways that the listener processes information. (AM)

  17. Continuum mechanics

    NASA Astrophysics Data System (ADS)

    Khristianovich, S. A.

    The volume contains a collection of papers dealing with various problems of continuum mechanics which were written by the author at different times during the period 1936-1974. Topics covered include supersonic gas flow, design of Laval nozzles, physical foundations of transonic aerodynamics, theory of short waves, cohesion modulus in the theory of cracks, and deformation of strain-hardening plastic materials.

  18. Collision Broadening Of Line Spectrum In Sonoluminescence

    SciTech Connect

    Li Chaohui; An Yu

    2008-06-24

    The direct measurement of temperature inside a sonoluminescing bubble as it is at its flashing phase is almost impossible due to the smallness of the bubble and the short duration of the flashing. One may estimate the temperature through fitting the continuum spectrum of sonoluminescence by the black body radiation formula, or fitting the shape of atomic or molecular line spectrum (the different temperature, density and pressure result in the different shape of the line spectrum due to the effect of collision broadening). However, the temperature changes in a huge range at short duration as the bubble flashes, therefore, the observed spectra are some kind of average one, so are those fitted results. To evaluate the instantaneous temperature more accurately, we simulate the processes of the bubble motion and the thermodynamics inside the bubble, in which atomic or molecular line spectra with the collision broadening effect and the continuum spectra contributed from the processes of electron-atom bremsstrahlung, electron-ion bremsstrahlung and recombination radiation and radiative attachment of electrons to atoms and molecules are taken into account in calculating the light emission. If both the calculated continuum spectra and the shape of line spectra can well represent the experimental data, we may deduce that the calculation of the temperature, density and pressure is reliable and we indirectly evaluate those quantities inside the bubble. In the present calculation, the line spectra of OH radical at about 310 nm mixing the electron transition with the vibration and rotational bands are considered. The calculation qualitatively consists with the observation, and we expect that with the more precise bubble dynamics model instead of the uniform model employed in the present calculation we may improve the quantitative result.

  19. Overview of plasma line broadening

    NASA Astrophysics Data System (ADS)

    Alexiou, S.

    2009-12-01

    We review the basics of line broadening, its relation to fluctuations and disorder, what causes broadening, the memory loss mechanism and the Standard Theory of line broadening developed by H.R. Griem and others from a modern viewpoint. This modern view benefits from many years of progress and includes a coherent theoretical perspective without the need for a conceptually different view of electrons and ions. Both electrons and ions are described in terms of their random fields. This modern and unified view allows, among other things, extending the range of validity of line profile calculations to complex situations.

  20. Broadening nanotechnology's impact on development

    NASA Astrophysics Data System (ADS)

    Beumer, Koen

    2016-05-01

    Discussions about nanotechnology and development focus on applications that directly address the needs of the world's poor. Nanotechnology can certainly make an impact in the fight against global poverty, but we need to broaden our imagination.

  1. Optical continuum generation on a silicon chip

    NASA Astrophysics Data System (ADS)

    Jalali, Bahram; Boyraz, Ozdal; Koonath, Prakash; Raghunathan, Varun; Indukuri, Tejaswi; Dimitropoulos, Dimitri

    2005-08-01

    Although the Raman effect is nearly two orders of magnitude stronger than the electronic Kerr nonlinearity in silicon, under pulsed operation regime where the pulse width is shorter than the phonon response time, Raman effect is suppressed and Kerr nonlinearity dominates. Continuum generation, made possible by the non-resonant Kerr nonlinearity, offers a technologically and economically appealing path to WDM communication at the inter-chip or intra-chip levels. We have studied this phenomenon experimentally and theoretically. Experimentally, a 2 fold spectral broadening is obtained by launching ~4ps optical pulses with 2.2GW/cm2 peak power into a conventional silicon waveguide. Theoretical calculations, that include the effect of two-photon-absorption, free carrier absorption and refractive index change indicate that up to >30 times spectral broadening is achievable in an optimized device. The broadening is due to self phase modulation and saturates due to two photon absorption. Additionally, we find that free carrier dynamics also contributes to the spectral broadening and cause the overall spectrum to be asymmetric with respect to the pump wavelength.

  2. Super Ears.

    ERIC Educational Resources Information Center

    Thompson, Stan

    1995-01-01

    Presents an activity in which students design, construct, and test "super ears" to investigate sound and hearing. Students work in groups of three and explore how the outer ear funnels sound waves to the inner ear and how human hearing compares to that of other animals. (NB)

  3. Continuum radiation at Uranus

    SciTech Connect

    Kurth, W.S.; Gurnett, D.A. ); Desch, M.D. )

    1990-02-01

    Uranus has proven to be a radio source of remarkable complexity with as many as six distinctly different types of emission. One Uranian radio emission which has thus far escaped attention is an analog of continuum radiation at Earth, Jupiter, and Saturn. The emission is found to be propagating in the ordinary mode in the range of one to a few kHz on the inbound leg of the Voyager 2 encounter, shortly after the magnetopause crossing. The continuum radiation spectrum at Uranus also includes bands with frequencies as high as 12 kHz or greater on both the inbound and outbound legs. The Uranian continuum radiation is notably weak, making it more like that detected at Saturn than the extremely intense Jovian continuum radiation. The Uranian emission shows some evidence for narrow-band components lying in the same frequency regime as the continuum, completing the analogy with the other planets, which also show narrow-band components superimposed on the continuum spectrum. The authors argue that the low intensity of the Uranian continuum is most likely related to the lack of a density cavity within the Uranian magnetosphere that is deep relative to the solar wind plasma density.

  4. Understanding Doppler Broadening of Gamma Rays

    SciTech Connect

    Rawool-Sullivan, Mohini; Sullivan, John P.

    2014-07-03

    Doppler-broadened gamma ray peaks are observed routinely in the collection and analysis of gamma-ray spectra. If not recognized and understood, the appearance of Doppler broadening can complicate the interpretation of a spectrum and the correct identification of the gamma ray-emitting material. We have conducted a study using a simulation code to demonstrate how Doppler broadening arises and provide a real-world example in which Doppler broadening is found. This report describes that study and its results.

  5. The Aquatic Systems Continuum

    NASA Astrophysics Data System (ADS)

    Winter, T. C.

    2004-12-01

    The Aquatic Systems Continuum is a proposed framework for interrelating the physical, chemical, and biological characteristics of aquatic ecosystems. The continuum can be represented by a three-dimensional matrix that relates aquatic ecosystems to their position within hydrologic flow paths (x-axis, a spatial dimension) and their response to climate variability (y-axis). The z-axis describes the structure of biological communities as they relate to the hydrological conditions defined by the x and y axes. The concept is an extension of the Wetland Continuum that was derived from field studies of a prairie pothole wetland complex in North Dakota. At that site, the hydrologic continuum in space is defined by ground-water flow systems. The wetlands are surface-water expressions of larger ground-water watersheds, in which wetlands serve recharge, flow-through, and discharge functions with respect to ground water. The water balance of the wetlands is dominated by precipitation and evaporation. However, the interaction of the wetlands with ground water, although a small part of their water budget, provides the primary control on delivery of major solutes to and from the wetlands. Having monitored these wetlands for more than 25 years, during which time the site had a complete range of climate conditions from drought to deluge, the response of the aquatic communities to a wide variety of climate conditions has been well documented. The Aquatic Systems Continuum extends the model provided by the Wetland Continuum to include rivers and their interaction with ground water. As a result, both ground water and surface water are used to describe terrestrial water flows for all types of aquatic ecosystems. By using the Aquatic Systems Continuum to describe the hydrologic flow paths in all types of terrain, including exchange with atmospheric water, it is possible to design studies, monitoring programs, and management plans for nearly any type of aquatic ecosystem.

  6. Spectral broadening in a microdroplet dye laser

    NASA Astrophysics Data System (ADS)

    Knospe, Anders G.; Kwok, Alfred S.

    2004-05-01

    We have observed broadening of the lasing spectrum of 60-μm diameter micrdroplet dye lasers. The spectral width of microdroplet dye lasers consisting of Rhodamine 6G or Pyrromethene 597 is essentially constant when water is used as a solvent but broaden by >30% at high input-laser intensities when ethanol is used as solvent. Spectral broadening is preceded by stimulated Raman scattering of ethanol in the microdroplets as the input-laser intensity increases.

  7. Teacher Education: A Continuum.

    ERIC Educational Resources Information Center

    Momentum, 1990

    1990-01-01

    This document is a theme issue of the journal "Momentum", devoted to the topic "Teacher Education: A Continuum." It contains 15 articles in the central section and 7 articles in a special section subtitled "The Multicultural Challenge." The following articles on the central theme are presented: (1) "Closing the Gap" concerns fusing the college and…

  8. Extragalactic continuum sources.

    NASA Astrophysics Data System (ADS)

    Valtaoja, E.

    1989-09-01

    As with most other high-frequency radio telescopes, continuum work occupies only a small fraction - currently about 5% - of SEST's total time. The importance of these observations in increasing our understanding of quasars and other extragalactic sources is, however, large.

  9. The Continuum of Listening

    ERIC Educational Resources Information Center

    Rud, A. G.; Garrison, Jim

    2007-01-01

    The distinction between "apophatic" and "cataphatic" listening is defined and analyzed. "Apophatic" listening is more or less devoid of cognitivist claims, whereas "cataphatic" listening involves cognition and questioning. Many of the papers in this volume are discussed along the continuum determined by these two types of listening.…

  10. Stark broadening of B IV spectral lines

    NASA Astrophysics Data System (ADS)

    Dimitrijević, Milan S.; Christova, Magdalena; Simić, Zoran; Kovačević, Andjelka; Sahal-Bréchot, Sylvie

    2016-08-01

    Stark broadening parameters for 157 multiplets of helium-like boron (B IV) have been calculated using the impact semiclassical perturbation formalism. Obtained results have been used to investigate the regularities within spectral series. An example of the influence of Stark broadening on B IV lines in DO white dwarfs is given.

  11. Stark broadening data for stellar plasma research.

    NASA Astrophysics Data System (ADS)

    Dimitrijević, M. S.

    Results of an effort to provide to astrophysicists and physicists an as much as possible complete set of Stark broadening parameters needed for stellar opacity calculations, stellar atmosphere modelling, abundance determinations and diagnostics of different plasmas in astrophysics, physics and plasma technology, are presented. Stark broadening has been considered within the semiclassical perturbation, and the modified semiempirical approaches.

  12. Solar radio continuum storms

    NASA Technical Reports Server (NTRS)

    Sakurai, K.

    1976-01-01

    The paper reviews the current status of research on solar radio continuum emissions from metric to hectometric wave frequencies, emphasizing the role of energetic electrons in the 10-100 keV range in these emissions. It is seen that keV-energy electrons generated in active sunspot groups must be the sources of radio continuum storm emissions for wide frequency bands. These electrons excite plasma oscillations in the medium, which in turn are converted to electromagnetic radiation. The radio noise continuum sources are usually associated with type III burst activity observed above these sources. Although the mechanism for the release of the energetic electrons is not known, it seems they are ejected from storm source regions in association with rapid variation of associated sunspot magnetic fields due to their growth into complex types. To explain some of the observed characteristics, the importance of two-stream instability and the scattering of ambient plasma ions on energetic electron streams is pointed out.

  13. Multifrequency super-thin cloaks

    NASA Astrophysics Data System (ADS)

    Wang, Jiafu; Qu, Shaobo; Xu, Zhuo; Zhang, Anxue; Ma, Hua; Zhang, Jieqiu; Chen, Hongya; Feng, Mingde

    2014-04-01

    Bandwidth and thickness have become the most troublesome problems for EM cloaks. In this paper, we propose to solve the two problems using connected patches based on the microwave network model. By covering an obstacle with combined connected patches, cloaking effect can be achieved at multiple frequencies so as to expand the operating band. As an explicit example, a dual-band super-thin cloak using two different connected patch unit cells is demonstrated. Cloaking effect can be achieved at 3.50 GHz and 4.14 GHz simultaneously with an 8 dB transmission enhancement. The cloak design method provides a new route to broadening the bandwidth of thin EM cloaks.

  14. Charge Correlations in Plasma Line Broadening

    SciTech Connect

    Wrighton, Jeffrey M.; Dufty, James W.

    2008-10-22

    The traditional theory of plasma line broadening is re-examined to correct for phenom-enological assumptions regarding charge correlations. Conditions for static ions are assumed, and the ion microfield distribution is introduced without neglecting ion-electron correlations, and with a precise definition for the ion field at the radiator. Radiator and plasma subsystems are defined so as to make a second order calculation of electron broadening valid for the case of high Z radiators. The electron broadening operator is identified in terms of the fluctuation of the electron density at the radiator, averaged over the entire plasma constrained by a given value for the ion microfield.

  15. Thermally induced microstrain broadening in hexagonal zinc

    SciTech Connect

    Lawson, Andrew C; Valdez, James A; Roberts, Joyce A; Leineweber, Andreas; Mittemeijer, E J; Kreher, W

    2008-01-01

    Neutron powder-diffraction experiments on polycrystalline hexagonal zinc show considerable temperature-dependent line broadening. Whereas as-received zinc at 300 K exhibits narrow reflections, during cooling to a minimum temperature of 10K considerable line-broadening appears, which largely disappears again during reheating. The line broadening may be ascribed to microstrains induced by thermal microstresses due to the anisotropy of the thermal expansion (shrinkage) of hexagonal zinc. Differences between the thermal microstrains and theoretical predictions considering elastic deformation of the grains can be explained by plastic deformation and surface effects.

  16. The Response Continuum

    SciTech Connect

    Caltagirone, Sergio; Frincke, Deborah A.

    2005-06-17

    Active response is a sequence of actions per- formed speci¯cally to mitigate a detected threat. Response decisions always follow detection: a decision to take `no ac- tion' remains a response decision. However, active response is a complex subject that has received insu±cient formal attention. To facilitate discussion, this paper provides a framework that proposes a common de¯nition, describes the role of response and the major issues surrounding response choices, and ¯nally, provides a model for the process of re- sponse. This provides a common starting point for discus- sion of the full response continuum as an integral part of contemporary computer security.

  17. Kilometric Continuum Radiation

    NASA Technical Reports Server (NTRS)

    Green, James L.; Boardsen, Scott

    2006-01-01

    Kilometric continuum (KC) is the high frequency component (approximately 100 kHz to approximately 800 kHz) of nonthermal continuum (NTC). Unlike the lower frequency portion of NTC (approximately 5 kHz to approximately 100 kHz) whose source is around the dawn sector, the source of KC occurs at all magnetic local times. The latitudinal beaming of KC as observed by GEOTAIL is, for most events, restricted to plus or minus 15 degrees magnetic latitude. KC has been observed during periods of both low and strong geomagnetic activity, with no significant correlation of wave intensity with K(sub p), index. However statistically the maximum observed frequency of KC emission tends to increase with K(sub p) index, the effect is more pronounced around solar maximum, but is also detected near solar minimum. There is strong evidence that the source region of KC is from the equatorial plasmapause during periods when a portion of the plasmapause moves significantly inwards from its nominal position. Case studies have shown that KC emissions are nearly always associated with plasmaspheric notches, shoulders, and tails. There is a recent focus on trying to understand the banded frequency structure of this emission and its relationship to plasmaspheric density ducts and irregularities in the source region.

  18. Foreign-gas broadening of nitrous oxide absorption lines.

    NASA Technical Reports Server (NTRS)

    Tubbs, L. D.; Williams, D.

    1972-01-01

    We have measured the foreign-gas broadening coefficients for collisional broadening of lines in the nu-3 fundamental of N2O by He, Ne, Ar, Kr, Xe, H2, D2, and CH4. These coefficients, which give the ratio of the line-broadening ability of these gases to the line-broadening ability of N2, can be used with recent measurements and calculations of N2 broadening to obtain optical collision cross sections.

  19. Broadening Our View of Linguistic Diversity

    ERIC Educational Resources Information Center

    O'Neal, Debra; Ringler, Marjorie

    2010-01-01

    The definition of English language learners needs to be broadened to include the marginalized dialects of English. Not all native speakers speak Standard English, and even those who do need to learn Academic English to succeed in school. By using strategies developed for ELLs, teachers can help all students become fluent in the language of school.

  20. Unified classical path theories of pressure broadening.

    NASA Technical Reports Server (NTRS)

    Bottcher, C.

    1971-01-01

    Derivation of a unified classical path theory of pressure broadening, using only elementary concepts. It is shown that the theory of Smith, Cooper and Vidal (1969) is only correct at all frequencies to first order in the number density of perturbers.

  1. Relativistic Continuum Shell Model

    NASA Astrophysics Data System (ADS)

    Grineviciute, Janina; Halderson, Dean

    2011-04-01

    The R-matrix formalism of Lane and Thomas has been extended to the relativistic case so that the many-coupled channels problem may be solved for systems in which binary breakup channels satisfy a relative Dirac equation. The formalism was previously applied to the relativistic impulse approximation RIA and now we applied it to Quantum Hadrodynamics QHD in the continuum Tamm-Dancoff approximation TDA with the classical meson fields replaced by one-meson exchange potentials. None of the published QHD parameters provide a decent fit to the 15 N + p elastic cross section. The deficiency is also evident in inability of the QHD parameters with the one meson exchange potentials to reproduce the QHD single particle energies. Results with alternate parameters sets are presented. A. M. Lane and R. G. Thomas, R-Matrix Theory of Nuclear Reactions, Reviews of Modern Physics, 30 (1958) 257

  2. Supermanifolds and super Riemann surfaces

    SciTech Connect

    Rabin, J.M.

    1986-09-01

    The theory of super Riemann surfaces is rigorously developed using Rogers' theory of supermanifolds. The global structures of super Teichmueller space and super moduli space are determined. The super modular group is shown to be precisely the ordinary modular group. Super moduli space is shown to be the gauge-fixing slice for the fermionic string path integral.

  3. The Paranoid-Depressive Continuum

    ERIC Educational Resources Information Center

    Johnson, Betty J.

    1977-01-01

    Few investigators have attempted to lay a conceptual base for comparative studies of paranoia and depression within a single general framework. The paranoid-depressive continuum is an attempt to develop such a framework. (Author)

  4. SuperPILOT.

    ERIC Educational Resources Information Center

    Weissmann, Stephen M.

    1983-01-01

    SuperPILOT is Apple Computer's new computer assisted instruction authoring language. Provided is a review of SuperPILOT, indicated to be ideally suited for the development of interactive tutorials for the classroom. Includes comments on the language's strengths/weaknesses as well as comments on system requirements and special program features. (JN)

  5. The Intraprofessional Continuum and Cleft.

    PubMed

    Jensen, Clyde B

    2016-08-01

    The continuum cleft is a costly and precarious gap that divides professions on the health professions' continuum. It is an interprofessional phenomenon that is encouraged because health care professions protect their members in professional silos and isolate competing professions in professional cysts. This article uses case studies of the allopathic, osteopathic, naturopathic, and chiropractic professions to contemplate the existence, consequences, and possible mitigation of intraprofessional silos, cysts, and clefts. PMID:27574493

  6. Spectral line broadening in magnetized black holes

    SciTech Connect

    Frolov, Valeri P.; Shoom, Andrey A.; Tzounis, Christos E-mail: ashoom@ualberta.ca

    2014-07-01

    We consider weakly magnetized non-rotating black holes. In the presence of a regular magnetic field the motion of charged particles in the vicinity of a black hole is modified. As a result, the position of the innermost stable circular orbit (ISCO) becomes closer to the horizon. When the Lorentz force is repulsive (directed from the black hole) the ISCO radius can reach the gravitational radius. In the process of accretion charged particles (ions) of the accreting matter can be accumulated near their ISCO, while neutral particles fall down to the black hole after they reach 6M radius. The sharp spectral line Fe α, emitted by iron ions at such orbits, is broadened when the emission is registered by a distant observer. In this paper we study this broadening effect and discuss how one can extract information concerning the strength of the magnetic field from the observed spectrum.

  7. Symmetry-dependent broadening parameters for methane

    NASA Technical Reports Server (NTRS)

    Fox, K.

    1984-01-01

    Experimental results for the pressure-broadened linewidths gamma of methane are presented and compared with theoretical results. A solar Fourier transform spectrometer with spectral resolving power of about one million was used together with a 6-m base length multitraversal absorption cell. Pressures were determined to an accuracy of + or - 0.2 Torr by means of a capacitance manometer. The pressuring gases were N2, H2, and He. Results are presented for numerical averages of all linewidths corresponding to a given tetrahedral symmetry for J = 0-6. For all cases studied, gamma(E) is found to be substantially less than gamma(A), and gamma(A) is found to be near to, but significantly smaller than, gamma(F). Relative inelastic cross sections calculated for argon scattering from methane are compared with relative pressure-broadened linewidths measured in several experiments involving methane and other gases.

  8. The X-ray eclipse geometry of the super-soft X-ray source CAL 87

    SciTech Connect

    Ribeiro, T.; Lopes de Oliveira, R.

    2014-09-01

    We explore XMM-Newton observations of the eclipsing super-soft X-ray source CAL 87 in order to map the accretion structures of the system. Indirect imaging techniques were applied in X-ray light curves to provide eclipse maps. The surface brightness distribution exhibits an extended and symmetric emission, and a feature is revealed from the hardest X-rays that is likely due to a bright spot. A rate of P-dot =(+6±2)×10{sup −10} for changes in the orbital period of the system was derived from the eclipses. There is no significant variation of the emission lines even during eclipses, arguing that the lines are formed in an extended region. The continuum emission dominates the decrease in flux that is observed during eclipses. The O VIII Lyα line reveals a broadening velocity that is estimated to be 365{sub −69}{sup +65} km s{sup –1} (at 1σ), marginal evidence for asymmetry in its profile, and sometimes shows evidence of double-peaked emission. Together, the results support that the wind-driven mass transfer scenario is running in CAL 87.

  9. Broadening and Simplifying the First SETI Protocol

    NASA Astrophysics Data System (ADS)

    Michaud, M. A. G.

    The Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence, known informally as the First SETI Protocol, is the primary existing international guidance on this subject. During the fifteen years since the document was issued, several people have suggested revisions or additional protocols. This article proposes a broadened and simplified text that would apply to the detection of alien technology in our solar system as well as to electromagnetic signals from more remote sources.

  10. Line Broadening and the Solar Opacity Problem

    NASA Astrophysics Data System (ADS)

    Krief, M.; Feigel, A.; Gazit, D.

    2016-06-01

    The calculation of line widths constitutes theoretical and computational challenges in the calculation of opacities of hot, dense plasmas. Opacity models use line broadening approximations that are untested at stellar interior conditions. Moreover, calculations of atomic spectra of the Sun indicate a large discrepancy in the K-shell line widths between several atomic codes and the Opacity-Project (OP). In this work, the atomic code STAR is used to study the sensitivity of solar opacities to line broadening. Variations in the solar opacity profile due to an increase of the Stark widths resulting from discrepancies with OP, are compared, in light of the solar opacity problem, with the required opacity variations of the present day Sun, as imposed by helioseismic and neutrino observations. The resulting variation profile is much larger than the discrepancy between different atomic codes, agrees qualitatively with the missing opacity profile, recovers about half of the missing opacity nearby the convection boundary, and has a little effect in the internal regions. Since it is hard to estimate quantitatively the uncertainty in the Stark widths, we show that an increase of all line widths by a factor of about ˜100 recovers quantitatively the missing opacity. These results emphasize the possibility that photoexcitation processes are not modeled properly, and more specifically, highlight the need for a better theoretical characterization of the line broadening phenomena at stellar interior conditions, and of the uncertainty due to the way it is implemented by atomic codes.

  11. Broadening the frequency band of microstrip antennas

    NASA Astrophysics Data System (ADS)

    Belenko, V. Iu.; Efremov, Iu. G.

    1989-07-01

    Three techniques for broadening the band of microstrip antennas are examined: (1) the introduction of additional resonators; (2) the use of an additional stub galvanically connected to the main resonator; and (3) the use of an electrically variable diode capacitor. It is shown that the third method (i.e., the electrical tuning of the resonant frequencies) has the greatest potential for multichannel systems; an antenna is proposed which can operate with a tuning speed of 4 microsec at an output power of 1 kW.

  12. Process dependent nuclear k⊥ broadening effect

    NASA Astrophysics Data System (ADS)

    Schäfer, Andreas; Zhou, Jian

    2013-10-01

    We study the process dependent nuclear k⊥ broadening effect by employing the transverse momentum dependent (TMD) factorization approach in combination with the Mclerran-Venugopalan model. More specifically, we investigate how the parton transverse momentum distributions are affected by the process dependent gauge links in cold nuclear matter. In particular, our analysis also applies to the polarized cases including the nuclear quark Boer-Mulders function and the linearly polarized gluon distribution. Our main focus is on the nuclear TMDs at intermediate or large x.

  13. Super Ball Bot

    NASA Video Gallery

    Tensegrity Robot: Child's Play or Space Tech? Super Ball Bot is an all-in-one landing and mobility platform based on tensegrity structures, allowing for lower-cost, and more reliable planetary miss...

  14. Super Thin Ceramic Coatings

    NASA Video Gallery

    New technology being developed at NASA's Glenn Research Center creates super thin ceramic coatings on engine components. The Plasma Spray – Physical Vapor Deposition (PS-PVD) rig uses a powerful ...

  15. Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Magro, Lluís Martí

    2016-06-01

    The Super-Kamiokande experiment performs a large variety of studies, many of them in the neutrino sector. The archetypes are atmospheric neutrino (recently awarded with the Nobel prize for Mr. T. Kajita) and the solar neutrinos analyses. In these proceedings we report our latest results and present updates to indirect dark matter searches, our solar neutrino analysis and discuss the future upgrade of Super-Kamiokande by loading gadolinium into our ultra-pure water.

  16. Submillimeter Continuum Observations of Comets

    NASA Technical Reports Server (NTRS)

    Jewitt, David

    1998-01-01

    The aim of this proposal was to study the submillimeter continuum emission from comets. The study was based mainly on the exploitation of the world's leading submillimeter telescope, the JCMT (James Clerk Maxwell Telescope) on Mauna Kea. Submillimeter wavelengths provide a unique view of cometary physics for one main reason. The cometary size distribution is such that the scattering cross-section is dominated by small dust grains, while the mass is dominated by the largest particles. Submillimeter continuum radiation samples cometary particles much larger than those sampled by more common observations at shorter (optical and infrared) wavelengths and therefore provides a nearly direct measure of the cometary dust mass.

  17. Lagrangian continuum dynamics in ALEGRA.

    SciTech Connect

    Wong, Michael K. W.; Love, Edward

    2007-12-01

    Alegra is an ALE (Arbitrary Lagrangian-Eulerian) multi-material finite element code that emphasizes large deformations and strong shock physics. The Lagrangian continuum dynamics package in Alegra uses a Galerkin finite element spatial discretization and an explicit central-difference stepping method in time. The goal of this report is to describe in detail the characteristics of this algorithm, including the conservation and stability properties. The details provided should help both researchers and analysts understand the underlying theory and numerical implementation of the Alegra continuum hydrodynamics algorithm.

  18. Additive manufacturing of patient-specific tubular continuum manipulators

    NASA Astrophysics Data System (ADS)

    Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

    2015-03-01

    Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

  19. Commitment to Broadening Participation at NOAO

    NASA Astrophysics Data System (ADS)

    Garmany, Catharine D.; Norman, D.

    2011-01-01

    AURA and NOAO take seriously the importance of Broadening Participation in Astronomy. At the request of the AURA President, each of the AURA centers (NOAO, NSO, STSCI, Gemini) appointed a Diversity Advocates (DA). At NOAO this job is shared by Dara Norman and Katy Garmany, who were appointed by Dave Silva in Jan 2009. The DA's are members of the AURA Committee on Workforce and Diversity (WDC), a designated subcommittee of the AURA Board of Directors. The role of this committee includes reviewing activities and plans on an AURA wide basis aimed at broadening the participation within AURA, and reviewing AURA wide policies on the workforce. At NOAO, the role of the DAs spans a number of departments and activities. They serve on observatory search committees, and offer suggestions on how NOAO job searches can reach the most diverse audience. The DA's job is to insure that NOAO actively pursues every opportunity to increase diversity: to this end they are involved in outreach and educational activities that focus on workplace development and encourage inclusion of woman, minorities and persons with disabilities.

  20. Action potential broadening in a presynaptic channelopathy

    NASA Astrophysics Data System (ADS)

    Begum, Rahima; Bakiri, Yamina; Volynski, Kirill E.; Kullmann, Dimitri M.

    2016-07-01

    Brain development and interictal function are unaffected in many paroxysmal neurological channelopathies, possibly explained by homoeostatic plasticity of synaptic transmission. Episodic ataxia type 1 is caused by missense mutations of the potassium channel Kv1.1, which is abundantly expressed in the terminals of cerebellar basket cells. Presynaptic action potentials of small inhibitory terminals have not been characterized, and it is not known whether developmental plasticity compensates for the effects of Kv1.1 dysfunction. Here we use visually targeted patch-clamp recordings from basket cell terminals of mice harbouring an ataxia-associated mutation and their wild-type littermates. Presynaptic spikes are followed by a pronounced afterdepolarization, and are broadened by pharmacological blockade of Kv1.1 or by a dominant ataxia-associated mutation. Somatic recordings fail to detect such changes. Spike broadening leads to increased Ca2+ influx and GABA release, and decreased spontaneous Purkinje cell firing. We find no evidence for developmental compensation for inherited Kv1.1 dysfunction.

  1. Action potential broadening in a presynaptic channelopathy

    PubMed Central

    Begum, Rahima; Bakiri, Yamina; Volynski, Kirill E.; Kullmann, Dimitri M.

    2016-01-01

    Brain development and interictal function are unaffected in many paroxysmal neurological channelopathies, possibly explained by homoeostatic plasticity of synaptic transmission. Episodic ataxia type 1 is caused by missense mutations of the potassium channel Kv1.1, which is abundantly expressed in the terminals of cerebellar basket cells. Presynaptic action potentials of small inhibitory terminals have not been characterized, and it is not known whether developmental plasticity compensates for the effects of Kv1.1 dysfunction. Here we use visually targeted patch-clamp recordings from basket cell terminals of mice harbouring an ataxia-associated mutation and their wild-type littermates. Presynaptic spikes are followed by a pronounced afterdepolarization, and are broadened by pharmacological blockade of Kv1.1 or by a dominant ataxia-associated mutation. Somatic recordings fail to detect such changes. Spike broadening leads to increased Ca2+ influx and GABA release, and decreased spontaneous Purkinje cell firing. We find no evidence for developmental compensation for inherited Kv1.1 dysfunction. PMID:27381274

  2. Windowed multipole for cross section Doppler broadening

    NASA Astrophysics Data System (ADS)

    Josey, C.; Ducru, P.; Forget, B.; Smith, K.

    2016-02-01

    This paper presents an in-depth analysis on the accuracy and performance of the windowed multipole Doppler broadening method. The basic theory behind cross section data is described, along with the basic multipole formalism followed by the approximations leading to windowed multipole method and the algorithm used to efficiently evaluate Doppler broadened cross sections. The method is tested by simulating the BEAVRS benchmark with a windowed multipole library composed of 70 nuclides. Accuracy of the method is demonstrated on a single assembly case where total neutron production rates and 238U capture rates compare within 0.1% to ACE format files at the same temperature. With regards to performance, clock cycle counts and cache misses were measured for single temperature ACE table lookup and for windowed multipole. The windowed multipole method was found to require 39.6% more clock cycles to evaluate, translating to a 7.9% performance loss overall. However, the algorithm has significantly better last-level cache performance, with 3 fewer misses per evaluation, or a 65% reduction in last-level misses. This is due to the small memory footprint of the windowed multipole method and better memory access pattern of the algorithm.

  3. Action potential broadening in a presynaptic channelopathy.

    PubMed

    Begum, Rahima; Bakiri, Yamina; Volynski, Kirill E; Kullmann, Dimitri M

    2016-01-01

    Brain development and interictal function are unaffected in many paroxysmal neurological channelopathies, possibly explained by homoeostatic plasticity of synaptic transmission. Episodic ataxia type 1 is caused by missense mutations of the potassium channel Kv1.1, which is abundantly expressed in the terminals of cerebellar basket cells. Presynaptic action potentials of small inhibitory terminals have not been characterized, and it is not known whether developmental plasticity compensates for the effects of Kv1.1 dysfunction. Here we use visually targeted patch-clamp recordings from basket cell terminals of mice harbouring an ataxia-associated mutation and their wild-type littermates. Presynaptic spikes are followed by a pronounced afterdepolarization, and are broadened by pharmacological blockade of Kv1.1 or by a dominant ataxia-associated mutation. Somatic recordings fail to detect such changes. Spike broadening leads to increased Ca(2+) influx and GABA release, and decreased spontaneous Purkinje cell firing. We find no evidence for developmental compensation for inherited Kv1.1 dysfunction. PMID:27381274

  4. Population transfer through the continuum

    SciTech Connect

    Nakajima, T.; Elk, M.; Zhang, J.; Lambropoulos, P. Foundation of Research and Technology Hellas, Institute of Electronic Structure and Laser and Department of Physics, University of Crete, P.O. Box 1527, Heraklion 711 10, Crete Department of Physics, University of Southern California, Los Angeles, California 90089-0484 )

    1994-08-01

    We show that complete population transfer is not in general possible through continuum intermediate states. We present a formal theoretical argument and supporting numerical results. In addition, the behavior of the system is compared with the well-known [Lambda] system.

  5. Parameter identification in continuum models

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Crowley, J. M.

    1983-01-01

    Approximation techniques for use in numerical schemes for estimating spatially varying coefficients in continuum models such as those for Euler-Bernoulli beams are discussed. The techniques are based on quintic spline state approximations and cubic spline parameter approximations. Both theoretical and numerical results are presented. Previously announced in STAR as N83-28934

  6. Parameter identification in continuum models

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Crowley, J. M.

    1983-01-01

    Approximation techniques for use in numerical schemes for estimating spatially varying coefficients in continuum models such as those for Euler-Bernoulli beams are discussed. The techniques are based on quintic spline state approximations and cubic spline parameter approximations. Both theoretical and numerical results are presented.

  7. A continuum of care model.

    PubMed

    Godchaux, C W; Travioli, J; Hughes, L A

    1997-11-01

    An interdisciplinary documentation tool provides a composite of all of the planning activities that occur relative to each individual patient and his/her family before discharge. In response to the Joint Commission on Accreditation of Healthcare Organization's mandate, this tool evolved into a "Continuum of Care" model. Now, all disciplines maintain a patient's continuity of care. PMID:9385163

  8. Recent results from the super EBIT

    SciTech Connect

    Marrs, R.E.

    1995-09-15

    The Super EBIT device at LLNL can produce and trap any highly charged ion at rest in the laboratory, including bare U{sup 92+} ions. Recently, the ionization cross sections for high-Z hydrogenlike ions have been measured for the first time, and measurements of the L-shell ionization cross sections for uranium ions are in progress. The two-electron contributions to the ground state energies of heliumlike ions have been directly measured using a novel technique, and spectra of 2s-2p transitions in highly ionized thorium and uranium have been used to test QED corrections to the energy levels of few electron high-Z ions. A new capability for the study of rare isotopes has been demonstrated. Ion cooling has been used to reduce the thermal broadening of x-ray emission lines to the point where natural line widths can be observed in some cases.

  9. Inhomogeneous Broadening in Perturbed Angular Correlation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bunker, Austin; Adams, Mike; Hodges, Jeffery; Park, Tyler; Stufflebeam, Michael; Evenson, William; Matheson, Phil; Zacate, Matthew

    2009-10-01

    Our research concerns the effect of a static distribution of defects on the net electric field gradient (EFG) within crystal structures. Defects and vacancies perturb the distribution of gamma rays emitted from radioactive probe nuclei within the crystal. These defects and vacancies produce a net EFG at the site of the probe which causes the magnetic quadrupole moment of the nucleus of the probe to precess about the EFG. The net EFG, which is strongly dependent upon the defect concentration, perturbs the angular correlation (PAC) of the gamma rays, and is seen in the damping of the perturbation function, G2(t), in time and broadening of the spectral peaks in the Fourier transform. We have used computer simulations to study the probability distribution of EFG tensor components in order to uncover the concentration dependence of G2(t). This in turn can be used to analyze experimental PAC data and quantitatively describe properties of the crystal.

  10. Coherent Forward Broadening in Cold Atom Clouds

    NASA Astrophysics Data System (ADS)

    Sutherland, R. T.; Robicheaux, Francis

    2016-05-01

    It is shown that homogeneous line-broadening in a diffuse cold atom cloud is proportional to the resonant optical depth of the cloud. Further, it is demonstrated how the strong directionality of the coherent interactions causes the cloud's spectra to depend strongly on its shape, even when the cloud is held at constant densities. These two numerical observations can be predicted analytically by extending the single photon wavefunction model. Lastly, elongating a cloud along the line of laser propagation causes the excitation probability distribution to deviate from the exponential decay predicted by the Beer-Lambert law to the extent where the atoms in the back of the cloud are more excited than the atoms in the front. These calculations are conducted at low densities relevant to recent experiments. This work was supported by the National Science Foundation under Grant No. 1404419-PHY.

  11. Coherent forward broadening in cold atom clouds

    NASA Astrophysics Data System (ADS)

    Sutherland, R. T.; Robicheaux, F.

    2016-02-01

    It is shown that homogeneous line-broadening in a diffuse cold atom cloud is proportional to the resonant optical depth of the cloud. Furthermore, it is demonstrated how the strong directionality of the coherent interactions causes the cloud's spectra to depend strongly on its shape, even when the cloud is held at constant densities. These two numerical observations can be predicted analytically by extending the single-photon wave-function model. Lastly, elongating a cloud along the line of laser propagation causes the excitation probability distribution to deviate from the exponential decay predicted by the Beer-Lambert law to the extent where the atoms at the back of the cloud are more excited than the atoms at the front. These calculations are conducted at the low densities relevant to recent experiments.

  12. The Super HMS

    SciTech Connect

    Chen Yan

    1998-06-01

    As a part of physics instrumentation development for TJNAF long range institution upgrade plan, a 12 GeV/c Super High Momentum Spectrometer (the Super HMS) has been proposed for high luminosity and high q2 physics in endstation Hall C. The fundamental configuration of Super HMS is QQDD. Two identical quadrupoles are the superconducting HMS Q1s with maximum gradient 8 Tesla/m. Two identical SLAC B202/B203 dipole magnets are considered for the use of dispersive elements with accumulative bending power 18.7 degree at 12 GeV/c while the central field is set to 2.05 Tesla. A sliding mechanism could guide the whole system, including the magnetic elements and detector house, moving forwards and backwards by +/- 100 cm. Under an assumed magnetic structure, the Super HMS optics performance has been studied by using TRANSPORT, TURTLE, and RAYTRACE codes and related reconstruction methods. The applicable solid angle can be adjusted between 1 msr and 2.3 msr. The maximum central momentum is 12 GeV/c. The reconstructed momentum resolution within full momentum range 20% is better than 10-3. The in-plane angle reconstruction accuracy is about 0.5 mr, mainly determined by the local multiple scattering from detector materials. This report also points out the strategy of super HMS optics adapting low rigidity quadrupoles for the use of high momentum operation, and the potential capability of very forward angle operations.

  13. Differential Complexes in Continuum Mechanics

    NASA Astrophysics Data System (ADS)

    Angoshtari, Arzhang; Yavari, Arash

    2015-04-01

    We study some differential complexes in continuum mechanics that involve both symmetric and non-symmetric second-order tensors. In particular, we show that the tensorial analogue of the standard grad-curl-div complex can simultaneously describe the kinematics and the kinetics of motion of a continuum. The relation between this complex and the de Rham complex allows one to readily derive the necessary and sufficient conditions for the compatibility of displacement gradient and the existence of stress functions on non-contractible bodies.We also derive the local compatibility equations in terms of the Green deformation tensor for motions of 2D and 3D bodies, and shells in curved ambient spaces with constant curvatures.

  14. A continuum of misidentification symptoms.

    PubMed

    Sno, H N

    1994-01-01

    A case study of a schizophrenic patient with differing forms of experiences of inappropriate familiarity is described. Reduplicative paramnesia is redefined as a delusion of familiarity related to a reduplication of time, place or person. The author proposes the concept of a continuum of positive and negative misidentification symptoms. The positive pole of the continuum ranges from the minor form of déjà vu experience to reduplicative paramnesia. The negative pole ranges from depersonalisation to nihilistic delusions. Differentiation is based on the severity of the disturbance of reality testing. The argumentation is based on the fact that both déjà vu experiences and depersonalisation occurring in pathological as well as non-pathological conditions are phenomenologically uniform.

  15. Super Guppy in Flight

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Super Guppy, bigger sister of the aptly named Pregnant Guppy, was the only airplane in the world capable of carrying a complete S-IVB stage. This aircraft was built by John M. Conroy of Aero Spaceliners, Incorporated, who started with the fuselages of a surplus Boeing C-97 Stratocruiser, ballooned out the upper decks enormously, and hinged the front sections so that they could be folded back 110 degrees. The Super Guppy flew smoothly at a 250-mph cruising speed, and its cargo deck provided a 25-foot clear diameter.

  16. Super resolution fluorescence microscopy

    PubMed Central

    Huang, Bo; Bates, Mark; Zhuang, Xiaowei

    2010-01-01

    Achieving a spatial resolution that is not limited by the diffraction of light, recent developments of super-resolution fluorescence microscopy techniques allow the observation of many biological structures not resolvable in conventional fluorescence microscopy. New advances in these techniques now give them the ability to image three-dimensional (3D) structures, measure interactions by multicolor colocalization, and record dynamic processes in living cells at the nanometer scale. It is anticipated that super-resolution fluorescence microscopy will become a widely used tool for cell and tissue imaging to provide previously unobserved details of biological structures and processes. PMID:19489737

  17. Stark Broadening in Compact Stars: Xe VI Lines

    NASA Astrophysics Data System (ADS)

    Dimitrijević, Milan S.; Simić, Zoran; Kovačević, Andjelka; Valjarević, Aleksandar; Sahal-Bréchot, Sylvie

    2015-12-01

    We will consider Stark broadening of non hydrogenic spectral lines in the impact approximation in compact stars: pre-white dwarf and white dwarf atmospheres. In order to show an example, Stark broadening parameters have been calculated, using the impact semiclassical perturbation approach for four Xe VI spectral lines. Obtained results have been used to demonstrate the influence of Stark broadening in DA and DB white dwarf atmospheres.

  18. Continuum representations of cellular solids

    SciTech Connect

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  19. Continuum modelling of granular flows

    NASA Astrophysics Data System (ADS)

    Staron, L.; Lagrée, P.-Y.

    2011-10-01

    The continuum modelling of transient granular flows is of primary importance in the context of predicting the behaviour of many natural systems involving granular matter. In this perspective, the granular column collapse experiment provides an interesting benchmark due to its challenging complexity (Lajeunesse et al 2004, Lube et al 2004), and form a trying test for candidate rheological models. In this contribution, we present 2D continuum simulations of granular column collapse using Navier-Stokes solver Gerris (Popinet 2003). The rheology implemented to model the granular media is the so-called μ(I)-rheology, relating the frictional properties and the viscosity of the material to the pressure and shear rate. In addition, discrete simulations using the Contact Dynamics method are performed for systematic comparison between the granular flow dynamics and its continuum counterpart (Staron & Hinch 2005). We find a good agreement, recovering the shape of the flow in the course of time as well as experimental scaling laws for the run-out. A systematic underestimation of the latter is nevertheless observed, and discussed in terms of physical and numerical modeling.

  20. Continuum radiation in planetary magnetospheres

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.

    1991-01-01

    With the completion of the Voyager tour of the outer planets, radio and plasma wave instruments have executed the first survey of the wave spectra of Earth, Jupiter, Saturn, Uranus, and Neptune. One of the most notable conclusions of this survey is that there is a great deal of qualitative similarity in both the plasma wave and radio wave spectra from one magnetosphere to the next. In particular, in spite of detailed differences, most of the radio emissions at each of the planets have been tentatively classified into two primary categories. First, the most intense emissions are generally associated with the cyclotron maser instability. Second, a class of weaker emissions can be found at each of the magnetospheres which appears to be the result of conversion from intense electrostatic emissions at the upper hybrid resonance frequency into (primarily) ordinary mode radio emission. It is this second category, often referred to as nonthermal continuum radiation, which we will discuss in this review. We review the characteristics of the continuum spectrum at each of the planets, discuss the source region and direct observations of the generation of the emissions where available, and briefly describe the theories for the generation of the emissions. Over the past few years evidence has increased that the linear mode conversion of electrostatic waves into the ordinary mode can account for at least some of the continuum radiation observed. There is no definitive evidence which precludes the possibility that a nonlinear mechanism may also be important.

  1. 77 FR 45367 - Continuum of Care Homeless Assistance Grant Application; Continuum of Care Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-31

    ... URBAN DEVELOPMENT Continuum of Care Homeless Assistance Grant Application; Continuum of Care Application... subject proposal. Pre-established communities, called Continuums of Care (CoC), will complete the Exhibit 1 of the Continuum of Care Homeless Assistance application which collects data about the...

  2. Scalar generalized nonlinear Schrödinger equation-quantified continuum generation in an all-normal dispersion photonic crystal fiber for broadband coherent optical sources

    PubMed Central

    Tu, Haohua; Liu, Yuan; Lægsgaard, Jesper; Sharma, Utkarsh; Siegel, Martin; Kopf, Daniel; Boppart, Stephen A.

    2010-01-01

    We quantitatively predict the observed continuum-like spectral broadening in a 90-mm weakly birefringent all-normal dispersion-flattened photonic crystal fiber pumped by 1041-nm 229-fs 76-MHz pulses from a solid-state Yb:KYW laser. The well-characterized continuum pulses span a bandwidth of up to 300 nm around the laser wavelength, allowing high spectral power density pulse shaping useful for various coherent control applications. We also identify the nonlinear polarization effect that limits the bandwidth of these continuum pulses, and therefore report the path toward a series of attractive alternative broadband coherent optical sources. PMID:21197060

  3. Handbook of Super 8 Production.

    ERIC Educational Resources Information Center

    Telzer, Ronnie, Ed.

    This handbook is designed for anyone interested in producing super 8 films at any level of complexity and cost. Separate chapters present detailed discussions of the following topics: super 8 production systems and super 8 shooting and editing systems; budgeting; cinematography and sound recording; preparing to edit; editing; mixing sound tracks;…

  4. Anomalous broadening in driven dissipative Rydberg systems

    NASA Astrophysics Data System (ADS)

    Boulier, Thomas; Goldschmidt, Elizabeth; Brown, Roger; Koller, Silvio; Young, Jeremy; Gorshkov, Alexey; Rolston, Steven; Porto, James

    2016-05-01

    Due to their strong, long-range, coherently-controllable interactions, Rydberg atoms have been proposed as a basis for quantum information processing and simulation of many-body physics. Using the coherent dynamics of such highly excited atomic states, however, requires addressing challenges posed by the dense spectrum of Rydberg levels, the detrimental effects of spontaneous emission, and strong interactions. We report the observation of interaction-induced broadening of the two-photon 5s-18s Rydberg transition in ultra-cold 87Rb atoms, trapped in a 3D optical lattice. The measured linewidth increases by nearly two orders of magnitude with increasing atomic density and excitation strength, with corresponding suppression of resonant scattering and enhancement of off-resonant scattering. We attribute the increased linewidth to resonant dipole-dipole interactions of 18s atoms with spontaneously created populations of nearby Rydberg p-states. This dephasing mechanism implies that the timescales available for the coherent addressing of such systems are dramatically shortened, hampering many recent proposals to use Rydberg-dressed atoms for quantum simulation. Now at Physikalisch-Technische Bundesanstalt.

  5. Broadening the Mission of an RNA Enzyme

    PubMed Central

    Marvin, Michael C.; Engelke, David R.

    2009-01-01

    The “RNA World” hypothesis suggests that life developed from RNA enzymes termed ribozymes, which carry out reactions without assistance from proteins. Ribonuclease (RNase) P is one ribozyme that appears to have adapted these origins to modern cellular life by adding protein to the RNA core in order to broaden the potential functions. This RNA-protein complex plays diverse roles in processing RNA, but its best-understood reaction is pre-tRNA maturation, resulting in mature 5’ ends of tRNAs. The core catalytic activity resides in the RNA subunit of almost all RNase P enzymes but broader substrate tolerance is required for recognizing not only the diverse sequences of tRNAs, but also additional cellular RNA substrates. This broader substrate tolerance is provided by the addition of protein to the RNA core and allows RNase P to selectively recognize different RNAs, and possibly ribonucleoprotein (RNP) substrates. Thus, increased protein content correlated with evolution from bacteria to eukaryotes has further enhanced substrate potential enabling the enzyme to function in a complex cellular environment. PMID:19844921

  6. Broadening the mission of an RNA enzyme.

    PubMed

    Marvin, Michael C; Engelke, David R

    2009-12-15

    The "RNA World" hypothesis suggests that life developed from RNA enzymes termed ribozymes, which carry out reactions without assistance from proteins. Ribonuclease (RNase) P is one ribozyme that appears to have adapted these origins to modern cellular life by adding protein to the RNA core in order to broaden the potential functions. This RNA-protein complex plays diverse roles in processing RNA, but its best-understood reaction is pre-tRNA maturation, resulting in mature 5' ends of tRNAs. The core catalytic activity resides in the RNA subunit of almost all RNase P enzymes but broader substrate tolerance is required for recognizing not only the diverse sequences of tRNAs, but also additional cellular RNA substrates. This broader substrate tolerance is provided by the addition of protein to the RNA core and allows RNase P to selectively recognize different RNAs, and possibly ribonucleoprotein (RNP) substrates. Thus, increased protein content correlated with evolution from bacteria to eukaryotes has further enhanced substrate potential enabling the enzyme to function in a complex cellular environment. PMID:19844921

  7. Continuum Theory of Retroviral Capsids

    NASA Astrophysics Data System (ADS)

    Nguyen, T. T.; Bruinsma, R. F.; Gelbart, W. M.

    2006-02-01

    We present a self-assembly phase diagram for the shape of retroviral capsids, based on continuum elasticity theory. The spontaneous curvature of the capsid proteins drives a weakly first-order transition from spherical to spherocylindrical shapes. The conical capsid shape which characterizes the HIV-1 retrovirus is never stable under unconstrained energy minimization. Only under conditions of fixed volume and/or fixed spanning length can the conical shape be a minimum energy structure. Our results indicate that, unlike the capsids of small viruses, retrovirus capsids are not uniquely determined by the molecular structure of the constituent proteins but depend in an essential way on physical constraints present during assembly.

  8. Continuum theory of contractile fibres

    NASA Astrophysics Data System (ADS)

    Kruse, K.; Zumdieck, A.; Jülicher, F.

    2003-12-01

    The generation of contractile forces by living cells often involves linear arrangements of actively interacting polar filaments. We develop a physical description of the dynamics of active fibers based on a general expression for the tension in terms of the filament density and the bundle polarisation. We discuss the long-time behaviour of oriented and of nonpolar fibres, discuss effects of polymerization and depolymerization, and relate this continuum theory to nonlocal descriptions of filament-motor systems. We show that a nonpolar arrangement of filaments suppresses oscillatory instabilities which could be relevant for muscle fibers.

  9. Concentration dependence of inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Moreno, Carlos; Hodges, Jeffery A.; Park, Tyler; Stufflebeam, Michael; Evenson, W.; Matheson, P.; Zacate, M. O.

    2008-10-01

    Since real crystals always include defects, the effect of the defects on crystal properties depends on how many defects are present, i.e. on defect concentration. In perturbed angular correlation (PAC), these defects produce damping of the correlation signal in time and broadening of the frequency spectrum. This ``inhomogeneous broadening'' depends quantitatively on defect concentration, so the size of the broadening in a PAC spectrum can be a measure of the concentration of defects. Using simulated PAC spectra and independent component analysis to obtain the probability distribution function for electric field gradient (EFG) components, we have found defect concentration-dependent parameters for the probability functions. This allows us to calculate broadened PAC spectra for any selected defect concentration. It also allows us to fit defect concentration from an experimental PAC spectrum. This work will be applied initially to broadened PAC data from β-Mn, Al-doped β-Mn, and Sr2RuO4.

  10. Super loop groups, Hamiltonian actions and super Virasoro algebras

    NASA Astrophysics Data System (ADS)

    Harnad, J.; Kupershmidt, B. A.

    1990-09-01

    The quotient{{widetilde{LG}} G} of a super loop groupwidetilde{LG} by the subgroup of constant loops is given a supersymplectic structure and identified through a moment map embedding MediaObjects/220_2005_BF02096652_f1.jpg with a coadjoint orbit of the centrally extended super loop algebra. The algebra widetilde{diff}^c S^1 of super-conformal vector fields on the circle is shown to have a natural representation as Hamiltonian vector fields on{{widetilde{LG}} G} generated by an equivariant moment map. This map is obtained by composition of 315-8 with a super Poisson map defining a supersymmetric extension of the classical Sugawara formula. Upon quantization, this yields the corresponding formula of Kac and Todorov on unitary highest weight representations. For any homomorphism ρ: u(1)→ G, an associated "twisted" moment map is also derived, generating a super Poisson bracket realization of a super Virasoro subalgebra widetilde{Vir} of the semi-direct sum. The corresponding super Poisson map is interpreted as a nonabelian generalization of the super Miura map and applied to two super KdV hierarchies to derive corresponding integrable generalized super MKdV hierarchies in Figure 8.

  11. Nuclear rotation in the continuum

    NASA Astrophysics Data System (ADS)

    Fossez, K.; Nazarewicz, W.; Jaganathen, Y.; Michel, N.; Płoszajczak, M.

    2016-01-01

    Background: Atomic nuclei often exhibit collective rotational-like behavior in highly excited states, well above the particle emission threshold. What determines the existence of collective motion in the continuum region is not fully understood. Purpose: In this work, by studying the collective rotation of the positive-parity deformed configurations of the one-neutron halo nucleus 11Be, we assess different mechanisms that stabilize collective behavior beyond the limits of particle stability. Method: To solve a particle-plus-core problem, we employ a nonadiabatic coupled-channel formalism and the Berggren single-particle ensemble, which explicitly contains bound states, narrow resonances, and the scattering continuum. We study the valence-neutron density in the intrinsic rotor frame to assess the validity of the adiabatic approach as the excitation energy increases. Results: We demonstrate that collective rotation of the ground band of 11Be is stabilized by (i) the fact that the ℓ =0 one-neutron decay channel is closed, and (ii) the angular momentum alignment, which increases the parentage of high-ℓ components at high spins; both effects act in concert to decrease decay widths of ground-state band members. This is not the case for higher-lying states of 11Be, where the ℓ =0 neutron-decay channel is open and often dominates. Conclusion: We demonstrate that long-lived collective states can exist at high excitation energy in weakly bound neutron drip-line nuclei such as 11Be.

  12. OPE for super loops

    NASA Astrophysics Data System (ADS)

    Sever, Amit; Vieira, Pedro; Wang, Tianheng

    2011-11-01

    We extend the Operator Product Expansion for Null Polygon Wilson loops to the Mason-Skinner-Caron-Huot super loop dual to non MHV gluon amplitudes. We explain how the known tree level amplitudes can be promoted into an infinite amount of data at any loop order in the OPE picture. As an application, we re-derive all one loop NMHV six gluon amplitudes by promoting their tree level expressions. We also present some new all loops predictions for these amplitudes.

  13. Super-quantum curves from super-eigenvalue models

    NASA Astrophysics Data System (ADS)

    Ciosmak, Paweł; Hadasz, Leszek; Manabe, Masahide; Sułkowski, Piotr

    2016-10-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/ β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  14. Super Star Cluster Nebula in the Starburst Galaxy NGC 660

    NASA Astrophysics Data System (ADS)

    Naiman, J. P.; Turner, J. L.; Tsai, C.-W.; Beck, S. C.; Ho, P. T. P.

    2004-12-01

    We have mapped the starburst galaxy NGC 660 at 100mas resolution at K band (1.3 cm) with the NRAO Very Large Array. A peculiar galaxy at a distance of 13 Mpc, NGC 660 contains concentrated central star formation of power ˜ 2 x 1010 Lsun. Our 1.3 cm continuum image reveals a bright, compact source of less than 10 pc extent with a rising spectral index. We infer that this is optically thick free-free emission from a super star cluster nebula. The nebula is less than 10 pc in size, comparable in luminosity to the ``supernebula" in the dwarf galaxy, NGC 5253. We estimate that there are a few thousand O stars contained in this single young cluster. There are a number of other weaker continuum sources, either slightly smaller or more evolved clusters of similar size within the central 300 parsecs of the galaxy. This work is supported in part by the National Science Foundation.

  15. Swift detection of the super-swift switch-on of the super-soft phase in nova V745 Sco (2014)

    NASA Astrophysics Data System (ADS)

    Page, K. L.; Osborne, J. P.; Kuin, N. P. M.; Henze, M.; Walter, F. M.; Beardmore, A. P.; Bode, M. F.; Darnley, M. J.; Delgado, L.; Drake, J. J.; Hernanz, M.; Mukai, K.; Nelson, T.; Ness, J.-U.; Schwarz, G. J.; Shore, S. N.; Starrfield, S.; Woodward, C. E.

    2015-12-01

    V745 Sco is a recurrent nova, with the most recent eruption occurring in February 2014. V745 Sco was first observed by Swift a mere 3.7 h after the announcement of the optical discovery, with the super-soft X-ray emission being detected around 4 d later and lasting for only ˜2 d, making it both the fastest follow-up of a nova by Swift and the earliest switch-on of super-soft emission yet detected. Such an early switch-on time suggests a combination of a very high velocity outflow and low ejected mass and, together with the high effective temperature reached by the super-soft emission, a high mass white dwarf (>1.3 M⊙). The X-ray spectral evolution was followed from an early epoch where shocked emission was evident, through the entirety of the super-soft phase, showing evolving column density, emission lines, absorption edges, and thermal continuum temperature. UV grism data were also obtained throughout the super-soft interval, with the spectra showing mainly emission lines from lower ionization transitions and the Balmer continuum in emission. V745 Sco is compared with both V2491 Cyg (another nova with a very short super-soft phase) and M31N 2008-12a (the most rapidly recurring nova yet discovered). The longer recurrence time compared to M31N 2008-12a could be due to a lower mass accretion rate, although inclination of the system may also play a part. Nova V745 Sco (2014) revealed the fastest evolving super-soft source phase yet discovered, providing a detailed and informative data set for study.

  16. NASA broadened-specification fuels combustion technology program

    NASA Technical Reports Server (NTRS)

    Fear, J. S.

    1980-01-01

    The broadened-Specification Fuels Combustion Technology program's purpose is to evolve and demonstrate the technology required to enable current and next generation high-thrust, high-bypass-ratio turbofan engines to use fuels with broadened properties and to verify the evolved technology in full scale engine tests. The three phases of the program are combustor concept screening, combustor optimization testing, and engine verification testing. Constraints for designing combustion systems are outlined and problems to be expected in the use of broadened properties fuels are listed.

  17. Relativistic formulation for the Doppler-broadened line profile

    SciTech Connect

    Huang, Young-Sea; Chiue, Juang-Han; Huang, Yi-Chi; Hsiung, Te-Chih

    2010-07-15

    Profiles of spectral lines due to the thermal motion of light-emitting particles are formulated based on the classical and the relativistic Doppler effects, respectively. For the classical case, the well-known Doppler-broadened line profile is reproduced. For the relativistic case, the line profile obtained is asymmetrically broadened with increasing temperature. However, the peak frequency remains unshifted, in contrast to blueshifted, as has been predicted in the current literature. Reasoning is given as to why the relativistic Doppler-broadened line profile currently accepted is probably invalid.

  18. Continuum Fitting HST QSO Spectra

    NASA Technical Reports Server (NTRS)

    Tytler, David; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    The Principal Component Analysis (PCA) method which we are using to fit and describe QSO spectra relies upon the fact that QSO continuum are generally very smooth and simple except for emission and absorption lines. To see this we need high signal-to-noise (S/N) spectra of QSOs at low redshift which have relatively few absorption lines in the Lyman-a forest. We need a large number of such spectra to use as the basis set for the PCA analysis which will find the set of principal component spectra which describe the QSO family as a whole. We have found that too few HST spectra have the required S/N and hence we need to supplement them with ground based spectra of QSOs at higher redshift. We have many such spectra and we have been working to make them suitable for this analysis. We have concentrated on this topic since 12/15/01.

  19. Bound states in the continuum

    NASA Astrophysics Data System (ADS)

    Hsu, Chia Wei; Zhen, Bo; Stone, A. Douglas; Joannopoulos, John D.; Soljačić, Marin

    2016-09-01

    Bound states in the continuum (BICs) are waves that remain localized even though they coexist with a continuous spectrum of radiating waves that can carry energy away. Their very existence defies conventional wisdom. Although BICs were first proposed in quantum mechanics, they are a general wave phenomenon and have since been identified in electromagnetic waves, acoustic waves in air, water waves and elastic waves in solids. These states have been studied in a wide range of material systems, such as piezoelectric materials, dielectric photonic crystals, optical waveguides and fibres, quantum dots, graphene and topological insulators. In this Review, we describe recent developments in this field with an emphasis on the physical mechanisms that lead to BICs across seemingly very different materials and types of waves. We also discuss experimental realizations, existing applications and directions for future work.

  20. Dementia: Continuum or Distinct Entity?

    PubMed Central

    Walters, Glenn D.

    2009-01-01

    The latent structure of dementia was examined in a group of 10,775 older adults with indicators derived from a neuropsychological test battery. Subjecting these data to taxometric analysis using mean above minus below a cut (MAMBAC), maximum covariance (MAXCOV), and latent mode factor analysis (L-Mode) produced results more consistent with dementia as a dimensional (lying along a continuum) than categorical (representing a distinct entity) construct. A second study conducted on a group of 2375 21-to-64-year olds produced similar results. These findings denote that dementia, as measured by deficits in episodic memory, attention/concentration, executive function, and language, differs quantitatively rather than qualitatively from the cognitive status of non-demented adults. The implications of these results for classification, assessment, etiology, and prevention are discussed. PMID:20677881

  1. Micropolar continuum in spatial description

    NASA Astrophysics Data System (ADS)

    Ivanova, Elena A.; Vilchevskaya, Elena N.

    2016-11-01

    Within the spatial description, it is customary to refer thermodynamic state quantities to an elementary volume fixed in space containing an ensemble of particles. During its evolution, the elementary volume is occupied by different particles, each having its own mass, tensor of inertia, angular and linear velocities. The aim of the present paper is to answer the question of how to determine the inertial and kinematic characteristics of the elementary volume. In order to model structural transformations due to the consolidation or defragmentation of particles or anisotropic changes, one should consider the fact that the tensor of inertia of the elementary volume may change. This means that an additional constitutive equation must be formulated. The paper suggests kinetic equations for the tensor of inertia of the elementary volume. It also discusses the specificity of the inelastic polar continuum description within the framework of the spatial description.

  2. Solar Wind Strahl Broadening by Self-Generated Plasma Waves

    NASA Technical Reports Server (NTRS)

    Pavan, J.; Vinas, A. F.; Yoon, P. H.; Ziebell, L. F.; Gaelzer, R.

    2013-01-01

    This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to kinetic quasi-linear wave-particle interaction. Making use of static analytical electron distribution in an inhomogeneous field, it is found that self-generated electrostatic waves at the plasma frequency, i.e., Langmuir waves, are capable of scattering the strahl component, resulting in energy and pitch-angle diffusion that broadens its velocity distribution significantly. The present theoretical results provide an alternative or complementary explanation to the usual whistler diffusion scenario, suggesting that self-induced electrostatic waves at the plasma frequency might play a key role in broadening the solar wind strahl during quiet solar conditions.

  3. SOLAR WIND STRAHL BROADENING BY SELF-GENERATED PLASMA WAVES

    SciTech Connect

    Pavan, J.; Gaelzer, R.; Vinas, A. F.; Yoon, P. H.; Ziebell, L. F. E-mail: rudi@ufpel.edu.br E-mail: yoonp@umd.edu

    2013-06-01

    This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to kinetic quasi-linear wave-particle interaction. Making use of static analytical electron distribution in an inhomogeneous field, it is found that self-generated electrostatic waves at the plasma frequency, i.e., Langmuir waves, are capable of scattering the strahl component, resulting in energy and pitch-angle diffusion that broadens its velocity distribution significantly. The present theoretical results provide an alternative or complementary explanation to the usual whistler diffusion scenario, suggesting that self-induced electrostatic waves at the plasma frequency might play a key role in broadening the solar wind strahl during quiet solar conditions.

  4. Meta-Research: Broadening the Scope of PLOS Biology.

    PubMed

    Kousta, Stavroula; Ferguson, Christine; Ganley, Emma

    2016-01-01

    In growing recognition of the importance of how scientific research is designed, performed, communicated, and evaluated, PLOS Biology announces a broadening of its scope to cover meta-research articles.

  5. Frequency band broadening of magnetospheric VLF emissions near the equator

    NASA Technical Reports Server (NTRS)

    Maeda, K.; Lin, C. S.

    1981-01-01

    The broadening of the whistler mode VLF emission band has frequently been observed by the equatorially orbiting S3-A (Explorer 45) satellite outside the midnight sector of the plasmasphere, during periods of geomagnetic disturbance. Prior to the broadening, the band of this emission is narrow with a sharp gap at the half electron gyrofrequency. The gradual broadening of the emission band on the low-frequency side is associated with the simultaneously observed spreading of the anisotropy of the ring current electrons to higher and wider energy ranges. Using the modeled distribution function, the linear growth rates of the cyclotron instability are calculated numerically. The results suggest that broadening of the VLF emission band near the plasmasphere can be caused by spreading of the ring current electron anisotropy toward higher energies.

  6. Spectral broadening measurements of the ionospheres of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Woo, R.; Armstrong, J. W.

    1980-01-01

    Using data obtained from radio occultation experiments of Pioneer 10 and 11, the theory for spectral broadening is compared with the theory of weak intensity scintillation. This comparison is possible because Pioneer's observed spectral broadening occurred when the intensity scintillations were weak. Good agreement is found, and the inferred characteristics of the electron density irregularities for the ionospheres of both Jupiter and Saturn are presented.

  7. Self-phase-modulation induced spectral broadening in silicon waveguides

    NASA Astrophysics Data System (ADS)

    Boyraz, Ozdal; Indukuri, Tejaswi; Jalali, Bahram

    2004-03-01

    The prospect for generating supercontinuum pulses on a silicon chip is studied. Using ~4ps optical pulses with 2.2GW/cm2 peak power, a 2 fold spectral broadening is obtained. Theoretical calculations, that include the effect of two-photon-absorption, indicate up to 5 times spectral broadening is achievable at 10x higher peak powers. Representing a nonlinear loss mechanism at high intensities, TPA limits the maximum optical bandwidth that can be generated.

  8. Self-phase-modulation induced spectral broadening in silicon waveguides.

    PubMed

    Boyraz, Ozdal; Indukuri, Tejaswi; Jalali, Bahram

    2004-03-01

    The prospect for generating supercontinuum pulses on a silicon chip is studied. Using ~4ps optical pulses with 2.2GW/cm(2) peak power, a 2 fold spectral broadening is obtained. Theoretical calculations, that include the effect of two-photon-absorption, indicate up to 5 times spectral broadening is achievable at 10x higher peak powers. Representing a nonlinear loss mechanism at high intensities, TPA limits the maximum optical bandwidth that can be generated.

  9. The super collider revisited

    SciTech Connect

    Hussein, M.S.; Pato, M.P. )

    1992-05-20

    In this paper, the authors suggest a revised version of the Superconducting Super Collider (SSC) that employs the planned SSC first stage machine as an injector of 0.5 TeV protons into a power laser accelerator. The recently developed Non-linear Amplification of Inverse Bremsstrahlung Acceleration (NAIBA) concept dictates the scenario of the next stage of acceleration. Post Star Wars lasers, available at several laboratories, can be used for the purpose. The 40 TeV CM energy, a target of the SSC, can be obtained with a new machine which can be 20 times smaller than the planned SSC.

  10. Super-heptazethrene.

    PubMed

    Zeng, Wangdong; Sun, Zhe; Herng, Tun Seng; Gonçalves, Théo P; Gopalakrishna, Tullimilli Y; Huang, Kuo-Wei; Ding, Jun; Wu, Jishan

    2016-07-18

    The challenging synthesis of a laterally extended heptazethrene molecule, the super-heptazethrene derivative SHZ-CF3, is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel-Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ-CF3 exhibits an open-shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo-terrylene SHZ-2H was also obtained during the synthesis. This study provides a new synthetic method to access large-size quinoidal polycyclic hydrocarbons with unique physical properties. PMID:27240255

  11. Turbulent fluid motion 3: Basic continuum equations

    NASA Technical Reports Server (NTRS)

    Deissler, Robert G.

    1991-01-01

    A derivation of the continuum equations used for the analysis of turbulence is given. These equations include the continuity equation, the Navier-Stokes equations, and the heat transfer or energy equation. An experimental justification for using a continuum approach for the study of turbulence is given.

  12. Research on Fast-Doppler-Broadening of neutron cross sections

    SciTech Connect

    Li, S.; Wang, K.; Yu, G.

    2012-07-01

    A Fast-Doppler-Broadening method is developed in this work to broaden Continuous Energy neutron cross-sections for Monte Carlo calculations. Gauss integration algorithm and parallel computing are implemented in this method, which is unprecedented in the history of cross section processing. Compared to the traditional code (NJOY, SIGMA1, etc.), the new Fast-Doppler-Broadening method shows a remarkable speedup with keeping accuracy. The purpose of using Gauss integration is to avoid complex derivation of traditional broadening formula and heavy load of computing complementary error function that slows down the Doppler broadening process. The OpenMP environment is utilized in parallel computing which can take full advantage of modern multi-processor computers. Combination of the two can reduce processing time of main actinides (such as {sup 238}U, {sup 235}U) to an order of magnitude of 1{approx}2 seconds. This new method is fast enough to be applied to Online Doppler broadening. It can be combined or coupled with Monte Carlo transport code to solve temperature dependent problems and neutronics-thermal hydraulics coupled scheme which is a big challenge for the conventional NJOY-MCNP system. Examples are shown to determine the efficiency and relative errors compared with the NJOY results. A Godiva Benchmark is also used in order to test the ACE libraries produced by the new method. (authors)

  13. Electron-ion continuum-continuum mixing in dissociative recombination

    NASA Technical Reports Server (NTRS)

    Guberman, Steven L.

    1993-01-01

    In recent calculations on the dissociative recombination (DR) of the v=1 vibrational level of the ground state of N2(+), N2(+)(v=1) + e(-) yields N + N, we have observed an important continuun-continuum mixing process involving the open channels on both sides of N2(+)(v=1) + e(-) yields N2(+)(v=0) + e(-). In vibrational relaxation by electron impact (immediately above) the magnitude of the cross section depends upon the strength of the interaction between these continua. In DR of the v=1 ion level, these continua can also interact in the entrance channel, and the mixing can have a profound effect upon the DR cross section from v=1, as we illustrate in this paper. In our theoretical calculations of N2(+) DR using multichannel quantum defect theory (MQDT), the reactants and products in the two above equations are described simultaneously. This allows us to calculate vibrational relaxation and excitation cross sections as well as DR cross sections. In order to understand the mixing described above, we first present a brief review of the prior results for DR of the v=0 level of N2(+).

  14. Continuum lowering - A new perspective

    NASA Astrophysics Data System (ADS)

    Crowley, B. J. B.

    2014-12-01

    What is meant by continuum lowering and ionization potential depression (IPD) in a Coulomb system depends very much upon precisely what question is being asked. It is shown that equilibrium (equation of state) phenomena and non-equilibrium dynamical processes like photoionization are characterized by different values of the IPD. In the former, the ionization potential of an atom embedded in matter is the difference in the free energy of the many-body system between states of thermodynamic equilibrium differing by the ionization state of just one atom. Typically, this energy is less than that required to ionize the same atom in vacuo. Probably, the best known example of this is the IPD given by Stewart and Pyatt (SP). However, it is a common misconception that this formula should apply directly to the energy of a photon causing photoionization, since this is a local adiabatic process that occurs in the absence of a response from the surrounding plasma. To achieve the prescribed final equilibrium state, in general, additional energy, in the form of heat and work, is transferred between the atom and its surroundings. This additional relaxation energy is sufficient to explain the discrepancy between recent spectroscopic measurements of IPD in dense plasmas and the predictions of the SP formula. This paper provides a detailed account of an analytical approach, based on SP, to calculating thermodynamic and spectroscopic (adiabatic) IPDs in multicomponent Coulomb systems of arbitrary coupling strength with Te ≠ Ti. The ramifications for equilibrium Coulomb systems are examined in order to elucidate the roles of the various forms of the IPD and any possible connection with the plasma microfield. The formulation embodies an analytical equation of state (EoS) that is thermodynamically self-consistent, provided that the bound and free electrons are dynamically separable, meaning that the system is not undergoing pressure ionization. Apart from this restriction, the model is

  15. Melting in super-earths.

    PubMed

    Stixrude, Lars

    2014-04-28

    We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures characteristic of super-earths. We find that the efficiency of kinetic energy deposition during accretion increases with planetary mass; considering the likely role of giant impacts and core formation, we find that super-earths probably complete their accretionary phase in an entirely molten state. Considerations of thermal regulation lead us to propose model temperature profiles of super-earths that are controlled by silicate melting. We estimate melting curves of iron and rock components up to the extreme pressures characteristic of super-earth interiors based on existing experimental and ab initio results and scaling laws. We construct super-earth thermal models by solving the equations of mass conservation and hydrostatic equilibrium, together with equations of state of rock and iron components. We set the potential temperature at the core-mantle boundary and at the surface to the local silicate melting temperature. We find that ancient (∼4 Gyr) super-earths may be partially molten at the top and bottom of their mantles, and that mantle convection is sufficiently vigorous to sustain dynamo action over the whole range of super-earth masses.

  16. Lattice continuum and diffusional creep

    NASA Astrophysics Data System (ADS)

    Mesarovic, Sinisa Dj.

    2016-04-01

    Diffusional creep is characterized by growth/disappearance of lattice planes at the crystal boundaries that serve as sources/sinks of vacancies, and by diffusion of vacancies. The lattice continuum theory developed here represents a natural and intuitive framework for the analysis of diffusion in crystals and lattice growth/loss at the boundaries. The formulation includes the definition of the Lagrangian reference configuration for the newly created lattice, the transport theorem and the definition of the creep rate tensor for a polycrystal as a piecewise uniform, discontinuous field. The values associated with each crystalline grain are related to the normal diffusional flux at grain boundaries. The governing equations for Nabarro-Herring creep are derived with coupled diffusion and elasticity with compositional eigenstrain. Both, bulk diffusional dissipation and boundary dissipation accompanying vacancy nucleation and absorption, are considered, but the latter is found to be negligible. For periodic arrangements of grains, diffusion formally decouples from elasticity but at the cost of a complicated boundary condition. The equilibrium of deviatorically stressed polycrystals is impossible without inclusion of interface energies. The secondary creep rate estimates correspond to the standard Nabarro-Herring model, and the volumetric creep is small. The initial (primary) creep rate is estimated to be much larger than the secondary creep rate.

  17. Continuum methods in lattice perturbation theory

    SciTech Connect

    Becher, Thomas G

    2002-11-15

    We show how methods of continuum perturbation theory can be used to simplify perturbative lattice calculations. We use the technique of asymptotic expansions to expand lattice loop integrals around the continuum limit. After the expansion, all nontrivial dependence on momenta and masses is encoded in continuum loop integrals and the only genuine lattice integrals left are tadpole integrals. Using integration-by-parts relations all of these can be expressed in terms of a small number of master integrals. Four master integrals are needed for bosonic one loop integrals, sixteen in QCD with Wilson or staggered fermions.

  18. A nonperturbative definition of N = 4 Super Yang-Mills by the plane wave matrix model

    SciTech Connect

    Shimasaki, Shinji

    2008-11-23

    We propose a nonperturbative definition of N = 4 Super Yang-Mills(SYM). We realize N = 4 SYM on RxS{sup 3} as the theory around a vacuum of the plane wave matrix model. Our regularization preserves 16 supersymmetries and the gauge symmetry. We perform the one-loop calculation to give evidence that in the continuum limit the superconformal symmetry is restored.

  19. Simulated models of inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Hodges, Jeffery A.; Park, Tyler; Stufflebeam, Michael; Evenson, W.; Matheson, P.; Zacate, M. O.

    2008-10-01

    All real crystals have defects such as impurities and vacancies which affect their properties. In perturbed angular correlation (PAC), these defects produce damping of the correlation signal in time and broadening of the frequency spectrum. This broadening is termed ``inhomogeneous broadening'' since it is due to the inhomogeneities (i.e. defects) in the crystal. We have simulated PAC spectra for various concentrations (0.1% to 15%) of randomly distributed defects with a near-neighbor vacancy in simple cubic and face-centered cubic crystal structures. For every particular set of defects, the randomly distributed defects and the near-neighbor vacancy together produce a net electric field gradient (EFG), from which we obtain the PAC spectrum. We then average PAC spectra to study the effects of defect concentration and crystal structure on inhomogeneous broadening as an aid to analyzing experimental data. This work will be applied initially to broadened PAC data from β-Mn, Al-doped β-Mn, and Sr2RuO4.

  20. Plasma motions and non-thermal line broadening in flaring twisted coronal loops

    NASA Astrophysics Data System (ADS)

    Gordovskyy, M.; Kontar, E. P.; Browning, P. K.

    2016-05-01

    Context. Observation of coronal extreme ultra-violet (EUV) spectral lines sensitive to different temperatures offers an opportunity to evaluate the thermal structure and flows in flaring atmospheres. This, in turn, can be used to estimate the partitioning between the thermal and kinetic energies released in flares. Aims: Our aim is to forward-model large-scale (50-10 000 km) velocity distributions to interpret non-thermal broadening of different spectral EUV lines observed in flares. The developed models allow us to understand the origin of the observed spectral line shifts and broadening, and link these features to particular physical phenomena in flaring atmospheres. Methods: We use ideal magnetohydrodynamics (MHD) to derive unstable twisted magnetic fluxtube configurations in a gravitationally stratified atmosphere. The evolution of these twisted fluxtubes is followed using resistive MHD with anomalous resistivity depending on the local density and temperature. The model also takes thermal conduction and radiative losses in the continuum into account. The model allows us to evaluate average velocities and velocity dispersions, which would be interpreted as non-thermal velocities in observations, at different temperatures for different parts of the models. Results: Our models show qualitative and quantitative agreement with observations. Thus, the line-of-sight (LOS) velocity dispersions demonstrate substantial correlation with the temperature, increasing from about 20-30 km s-1 around 1 MK to about 200-400 km s-1 near 10-20 MK. The average LOS velocities also correlate with velocity dispersions, although they demonstrate a very strong scattering compared to the observations. We also note that near footpoints the velocity dispersions across the magnetic field are systematically lower than those along the field. We conclude that the correlation between the flow velocities, velocity dispersions, and temperatures are likely to indicate that the same heating

  1. Periodic amplitude variations in Jovian continuum radiation

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.; Gurnett, D. A.; Scarf, F. L.

    1986-01-01

    An analysis of periodic variations in the amplitude of continuum radiation near 3 kHz trapped in the Jovian magnetosphere shows structure with periods near both five and ten hours. Contrary to a plausible initial idea, the continuum amplitudes are not organized by position of the observer relative to the dense plasma sheet. Instead, there seem to be preferred orientations of system III longitude with respect to the direction to the sun which account for the peaks. This implies a clock-like modulation of the continuum radiation intensity as opposed to a searchlight effect. The importance of the dipole longitude-solar wind alignment to the amplitude of the continuum radiation implies the source region of the radiation is near the magnetopause and may indirectly tie the generation of the radio waves to the clocklike modulation of energetic electron fluxes from Jupiter.

  2. Characterization of Continuum Coma features in Comets

    NASA Astrophysics Data System (ADS)

    Mueller, Beatrice E. A.; Samarasinha, Nalin H.; Hergenrother, Carl W.

    2016-10-01

    We will present the results of an analysis of continuum coma features of comets belonging to different dynamical classes at geocentric distances less than 1.5 AU. Our analysis focusses on groundbased visible observations of over a dozen comets. The position angles of the continuum features close to the nucleus, the curvatures, and extents of radial features will be determined, and the dynamics of dust grains will be investigated. We will also use the change in position angles (if relevant) to place constraints on the periodicity of the repeatability of the features. The prevalence of the features in the sunward direction compared to other orientations will be investigated. We will further compare continuum features with CN features when available. This investigation will eventually lead to the discrimination between hemispherical and localized outgassing for the sunward continuum features seen in comets.We acknowledge support from the NASA SSW and PAST programs.

  3. Geometric continuum regularization of quantum field theory

    SciTech Connect

    Halpern, M.B. . Dept. of Physics)

    1989-11-08

    An overview of the continuum regularization program is given. The program is traced from its roots in stochastic quantization, with emphasis on the examples of regularized gauge theory, the regularized general nonlinear sigma model and regularized quantum gravity. In its coordinate-invariant form, the regularization is seen as entirely geometric: only the supermetric on field deformations is regularized, and the prescription provides universal nonperturbative invariant continuum regularization across all quantum field theory. 54 refs.

  4. SuperB Progress Report: Detector

    SciTech Connect

    Grauges, E.; Donvito, G.; Spinoso, V.; Manghisoni, M.; Re, V.; Traversi, G.; Eigen, G.; Fehlker, D.; Helleve, L.; Carbone, A.; Di Sipio, R.; Gabrielli, A.; Galli, D.; Giorgi, F.; Marconi, U.; Perazzini, S.; Sbarra, C.; Vagnoni, V.; Valentinetti, S.; Villa, M.; Zoccoli, A.; /INFN, Bologna /Bologna U. /Caltech /Carleton U. /Cincinnati U. /INFN, CNAF /INFN, Ferrara /Ferrara U. /UC, Irvine /Taras Shevchenko U. /Orsay, LAL /LBL, Berkeley /UC, Berkeley /Frascati /INFN, Legnaro /Orsay, IPN /Maryland U. /McGill U. /INFN, Milan /Milan U. /INFN, Naples /Naples U. /Novosibirsk, IYF /INFN, Padua /Padua U. /INFN, Pavia /Pavia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Caltech /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /PNL, Richland /Queen Mary, U. of London /Rutherford /INFN, Rome /Rome U. /INFN, Rome2 /Rome U.,Tor Vergata /INFN, Rome3 /Rome III U. /SLAC /Tel Aviv U. /INFN, Turin /Turin U. /INFN, Padua /Trento U. /INFN, Trieste /Trieste U. /TRIUMF /British Columbia U. /Montreal U. /Victoria U.

    2012-02-14

    This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  5. Multigroup Free-atom Doppler-broadening Approximation. Experiment

    SciTech Connect

    Gray, Mark Girard

    2015-11-06

    The multigroup energy Doppler-broadening approximation agrees with continuous energy Dopplerbroadening generally to within ten percent for the total cross sections of 1H, 56Fe, and 235U at 250 lanl. Although this is probably not good enough for broadening from room temperature through the entire temperature range in production use, it is better than any interpolation scheme between temperatures proposed to date, and may be good enough for extrapolation from high temperatures. The method deserves further study since additional improvements are possible.

  6. Multigroup Free-atom Doppler-broadening Approximation. Theory

    SciTech Connect

    Gray, Mark Girard

    2015-11-06

    Multigroup cross sections at a one target temperature can be Doppler-broadened to multigroup cross sections at a higher target temperature by matrix multiplication if the group structure suf- ficiently resolves the original temperature continuous energy cross section. Matrix elements are the higher temperature group weighted averages of the integral over the lower temperature group boundaries of the free-atom Doppler-broadening kernel. The results match theory for constant and 1/v multigroup cross sections at 618 lanl group structure resolution.

  7. Trace Isotope Detection Enhanced by Coherent Elimination of Power Broadening

    SciTech Connect

    Conde, Alvaro Peralta; Brandt, Lukas; Halfmann, Thomas

    2006-12-15

    The selectivity and spectral resolution of traditional laser-based trace isotope analysis, i.e., resonance ionization mass spectrometry (RIMS), is limited by power broadening of the radiative transition. We use the fact that power broadening does not occur in coherently driven quantum systems when the probing and excitation processes are temporally separated to demonstrate significant improvement of trace element detection, even under conditions of strong signals. Specifically, we apply a coherent variant of RIMS to the detection of traces of molecular nitric oxide (NO) isobars. For large laser intensities, the detected isotope signal can be increased by almost 1 order of magnitude without any loss in spectral resolution.

  8. Super continuum generation for real time ultrahigh resolution optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Nishizawa, Norihiko; Aguirre, Aaron D.; Fujimoto, James G.

    2006-02-01

    Optical coherence tomography (OCT) is an emerging technology for micrometer-scale, cross-sectional imaging of biological tissue and materials. One of the key limitations to achieving ultrahigh-resolution OCT imaging outside the laboratory setting has been the lack of compact, high-performance broadband light sources with sufficient power and stability to allow practical real-time imaging. The broad-bandwidth supercontinuum (SC) sources were recently demonstrated with femtosecond lasers in combination with nonlinear fibers. Using SC, we can demonstrate ultrahigh resolution OCT. However, wideband SC generally has large excess noise and significant fine structure. Low noise and smooth spectral shape are desired in the ideal supercontinnum source. In this paper, we describe recent studies on practical SC generation for ultrahigh-resolution OCT. SC generation is first analyzed both numerically and experimentally in terms of OCT imaging requirements and optimized conditions for generation are discussed. Supercontinua generated by use of highly nonlinear fiber which have a zero-dispersion wavelength near the pump wavelength, generally result in severe spectral modulation and fluctuating fine structure in the spectra. This spectral modulation produces sidelobes and reduced contrast in the interferometric point-spread function. In contrast, normally dispersive, highly nonlinear fibers (ND-HNFs) can generate smooth and Gaussian shaped supercontinua by the combination of self-phase modulation and normal dispersion. Low noise and wideband SC generation is demonstrated using ND-HNFs. Two colored SC generation is also demonstrated using a photonic crystal fiber which has two close zero dispersion wavelengths. The numerical results are almost in agreement with the experimental ones. Finally, low noise SC generation is demonstrated in an all fiber system based on an ultrashort pulse fiber laser. Wideband, low noise, near Gaussian shaped, high power SC is generated in the 1.55 μm wavelength region. In vivo, high-speed OCT imaging of human skin with ~5.5 μm resolution and 99 dB sensitivity is demonstrated.

  9. Super-sample signal

    NASA Astrophysics Data System (ADS)

    Li, Yin; Hu, Wayne; Takada, Masahiro

    2014-11-01

    When extracting cosmological information from power spectrum measurements, we must consider the impact of super-sample density fluctuations whose wavelengths are larger than the survey scale. These modes contribute to the mean density fluctuation δb in the survey and change the power spectrum in the same way as a change in the cosmological background. They can be simply included in cosmological parameter estimation and forecasts by treating δb as an additional cosmological parameter enabling efficient exploration of its impact. To test this approach, we consider here an idealized measurement of the matter power spectrum itself in the Λ CDM cosmology though our techniques can readily be extended to more observationally relevant statistics or other parameter spaces. Using subvolumes of large-volume N -body simulations for power spectra measured with respect to either the global or local mean density, we verify that the minimum variance estimator of δb is both unbiased and has the predicted variance. Parameter degeneracies arise since the response of the matter power spectrum to δb and cosmological parameters share similar properties in changing the growth of structure and dilating the scale of features especially in the local case. For matter power spectrum measurements, these degeneracies can lead in certain cases to substantial error degradation and motivates future studies of specific cosmological observables such as galaxy clustering and weak lensing statistics with these techniques.

  10. Evaluating super resolution algorithms

    NASA Astrophysics Data System (ADS)

    Kim, Youn Jin; Park, Jong Hyun; Shin, Gun Shik; Lee, Hyun-Seung; Kim, Dong-Hyun; Park, Se Hyeok; Kim, Jaehyun

    2011-01-01

    This study intends to establish a sound testing and evaluation methodology based upon the human visual characteristics for appreciating the image restoration accuracy; in addition to comparing the subjective results with predictions by some objective evaluation methods. In total, six different super resolution (SR) algorithms - such as iterative back-projection (IBP), robust SR, maximum a posteriori (MAP), projections onto convex sets (POCS), a non-uniform interpolation, and frequency domain approach - were selected. The performance comparison between the SR algorithms in terms of their restoration accuracy was carried out through both subjectively and objectively. The former methodology relies upon the paired comparison method that involves the simultaneous scaling of two stimuli with respect to image restoration accuracy. For the latter, both conventional image quality metrics and color difference methods are implemented. Consequently, POCS and a non-uniform interpolation outperformed the others for an ideal situation, while restoration based methods appear more accurate to the HR image in a real world case where any prior information about the blur kernel is remained unknown. However, the noise-added-image could not be restored successfully by any of those methods. The latest International Commission on Illumination (CIE) standard color difference equation CIEDE2000 was found to predict the subjective results accurately and outperformed conventional methods for evaluating the restoration accuracy of those SR algorithms.

  11. Holography based super resolution

    NASA Astrophysics Data System (ADS)

    Hussain, Anwar; Mudassar, Asloob A.

    2012-05-01

    This paper describes the simulation of a simple technique of superresolution based on holographic imaging in spectral domain. The input beam assembly containing 25 optical fibers with different orientations and positions is placed to illuminate the object in the 4f optical system. The position and orientation of each fiber is calculated with respect to the central fiber in the array. The positions and orientations of the fibers are related to the shift of object spectrum at aperture plane. During the imaging process each fiber is operated once in the whole procedure to illuminate the input object transparency which gives shift to the object spectrum in the spectral domain. This shift of the spectrum is equal to the integral multiple of the pass band aperture width. During the operation of single fiber (ON-state) all other fibers are in OFF-state at that time. The hologram recorded by each fiber at the CCD plane is stored in computer memory. At the end of illumination process total 25 holograms are recorded by the whole fiber array and by applying some post processing and specific algorithm single super resolved image is obtained. The superresolved image is five times better than the band-limited image. The work is demonstrated using computer simulation only.

  12. Effect of nuclear hyperfine structure on microwave spectral pressure broadening

    NASA Astrophysics Data System (ADS)

    Green, Sheldon

    1988-06-01

    The spectral pressure broadening formalism of Ben-Reuven [Phys. Rev. 145, 7 (1966)] is applied to rotational transitions of a closed-shell linear molecule with nuclear quadrupole hyperfine structure (hfs) due to a nucleus of spin I. If, as expected, nuclear spin does not affect molecular collision dynamics, generalized pressure broadening cross sections can be expressed in terms of the spin-free collisional S matrices. For the three hfs components of the lowest j=0-1 rotational transition, the line shape is a simple sum of three noninterfering Lorentzians each of which has the same width and shift as would be expected in the absence of nuclear spin. For higher rotational transitions, however, the line shape is no longer so simple; in general, each hfs component is described by a different width and shift, and collisions transfer intensity among them. Numerical results for HCN broadened by He atoms are presented using both the accurate close coupling (CC) collision formalism and also the infinite order sudden (IOS) approximation. For the case that broadening is very large compared with the hfs splittings it is shown (numerically, within the IOS approximation) that the line shape is nearly (but not exactly, except for j=0-1 as noted above) a Lorentzian with the same width as would be expected in the absence of nuclear spin.

  13. Community Colleges Broadening Horizons through Service Learning, 2006-2009

    ERIC Educational Resources Information Center

    Robinson, Gail

    2007-01-01

    This brief introduces "Community Colleges Broadening Horizons through Service Learning," the American Association of Community Colleges' (AACC's) fifth national Learn and Serve America grant project and describes its grantee college programs. The goals of this grant project are to build on established foundations to integrate service learning…

  14. Quality's Higher Education Dividends: Broadened Custodianship and Global Public Scholarship

    ERIC Educational Resources Information Center

    Jacobs, Gerrie J.

    2010-01-01

    This paper speculates on the possible contribution of the quality movement to higher education and the perceived dividends received from this, in general, over the past two decades but also, more specifically, with reference to the author's institution in South Africa. The first major quality contribution is a gradual broadening of higher…

  15. Extending, Broadening and Rethinking Existing Research on Transfer of Training

    ERIC Educational Resources Information Center

    Volet, Simone

    2013-01-01

    The aim of this Special Issue was to generate a new integrated agenda for research on transfer of training. It brought together scholars from diverse perspectives and invited them to strive toward synergy. This article examines how this collection of articles, as well as other bodies of literature, can help extend, broaden and rethink current…

  16. Rayleigh-backscattering doppler broadening correction for differential absorption lidar

    NASA Astrophysics Data System (ADS)

    Fan, Lanlan; Zhang, Yinchao; Chen, Siying; Guo, Pan; Chen, He

    2015-11-01

    The spectral broadening by Rayleigh backscattering can cause large changes in water vapor echo signals, causing errors when the water vapor concentration is inversed by differential absorption lidar (DIAL). A correction algorithm is proposed to revise the errors due to the effect of laser spectral broadening. The relative errors of water vapor are calculated in cases of different aerosol distribution and temperature changes before and after correction. The results show that measurement errors due to the Doppler broadening are more than 5% before correction and a 2% measurement error after corrected for the case of a smooth, background aerosol distribution. However, due to the high aerosol gradients and strong temperature inversion, errors can be up to 40% and 10% with no corrections for this effect, respectively. The relative errors can reduce to less than 2% after correction. Hence, the correction algorithm for Rayleigh Doppler broadening can improve detection accuracy in H2O DIAL measurements especially when it is applied to high aerosol concentration or strong temperature inversion.

  17. The STARS Alliance: Viable Strategies for Broadening Participation in Computing

    ERIC Educational Resources Information Center

    Dahlberg, Teresa; Barnes, Tiffany; Buch, Kim; Rorrer, Audrey

    2011-01-01

    The Students and Technology in Academia, Research, and Service (STARS) Alliance is a nationally-connected system of regional partnerships among higher education, K-12 schools, industry and the community with a mission to broaden the participation of women, under-represented minorities and persons with disabilities in computing (BPC). Each regional…

  18. Relational Themes in Counseling Supervision: Broadening and Narrowing Processes

    ERIC Educational Resources Information Center

    Gazzola, Nicola; Theriault, Anne

    2007-01-01

    This study investigated the experiences of broadening (i.e., thinking and acting creatively and being open to exploring new ways of being) and narrowing (i.e., the experience of perceiving one's choices as limited) in the supervisory process with the aim of identifying key relational themes from the perspective of supervisees. We interviewed 10…

  19. Robust Algorithm for Computing Statistical Stark Broadening of Spectral Lines

    SciTech Connect

    Iglesias, C A; Sonnad, V

    2010-02-10

    A method previously developed to solve large-scale linear systems is applied to statistical Stark broadened line shape calculations. The method is formally exact, numerically stable, and allows optimization of the integration over the quasi-static field to assure numerical accuracy. Furthermore, the method does not increase the computational effort and often can decrease it compared to the conventional approach.

  20. 34 CFR 300.115 - Continuum of alternative placements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Continuum of alternative placements. 300.115 Section... Continuum of alternative placements. (a) Each public agency must ensure that a continuum of alternative... services. (b) The continuum required in paragraph (a) of this section must— (1) Include the...

  1. 34 CFR 300.115 - Continuum of alternative placements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Continuum of alternative placements. 300.115 Section... Continuum of alternative placements. (a) Each public agency must ensure that a continuum of alternative... services. (b) The continuum required in paragraph (a) of this section must— (1) Include the...

  2. Observation of Doppler broadening in β -delayed proton- γ decay

    DOE PAGES

    Schwartz, S. B.; Wrede, C.; Bennett, M. B.; Liddick, S. N.; Pérez-Loureiro, D.; Bowe, A.; Chen, A. A.; Chipps, K. A.; Cooper, N.; Irvine, D.; et al

    2015-09-14

    Background: The Doppler broadening of gamma-ray peaks is due to nuclear recoil from beta-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using beta-delayed proton emission or applied to a recoil heavier than A = 10. Purpose: To test and apply this Doppler broadening method using gamma-ray peaks from the P-26(beta p gamma)Al-25 decay sequence. Methods: A fast beam of P-26 was implanted into a planar Ge detector, which was used as a P-26 beta-decay trigger. The SeGA array of high-purity Ge detectors was used to detect gamma rays frommore » the P-26(beta p gamma)Al-25 decay sequence. Results: Radiative Doppler broadening in beta-delayed proton-gamma decay was observed for the first time. Moreover, the Doppler broadening analysis method was verified using the 1613-keV gamma-ray line for which the proton energies were previously known. The 1776-keV gamma ray de-exciting the 2720 keV Al-25 level was observed in P-26(beta p gamma)Al-25 decay for the first time and used to determine that the center-of-mass energy of the proton emission feeding the 2720-keV level is 5.1 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV, corresponding to a Si-26 excitation energy of 13.3 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV for the proton-emitting level. Conclusions: Finally, the Doppler broadening method has been demonstrated to provide practical measurements of the energies for beta-delayed nucleon emissions populating excited states of nuclear recoils at least as heavy as A = 25.« less

  3. Solvation dynamics of a radical ion pair in micro-heterogeneous binary solvents: a semi-quantitative study utilizing MARY line-broadening experiments.

    PubMed

    Pal, Kunal; Grampp, Günter; Kattnig, Daniel R

    2013-10-01

    This work aims at elucidating the mechanism of solvation of a radical ion pair (RIP) in a micro-heterogeneous binary solvent mixture using magnetically affected reaction yield (MARY) spectroscopy. For the exciplex-forming 9,10-dimethylanthracene/N,N-dimethylaniline system a comparative, composition-dependent MARY line-broadening study is undertaken in a heterogeneous (toluene/dimethylsulfoxide) and a quasi-homogenous (propyl acetate/butyronitrile) solvent mixture. The half-saturation field extrapolated to zero-quencher concentration, B(1/2), and the self-exchange rate constants are analyzed in the light of solvent dynamical properties of the mixtures and a dielectric continuum solvation model. The dependence of B(1/2) on the solvent composition is explained by cluster formation giving rise to shortened RIP lifetimes. The results are in qualitative agreement with the continuum solvation model suggesting that it could serve as a theoretical basis for quantitative modeling.

  4. Phonon characteristics of high {Tc} superconductors from neutron Doppler broadening measurements

    SciTech Connect

    Trela, W.J.; Kwei, G.H.; Lynn, J.E.; Meggers, K.

    1994-12-01

    Statistical information on the phonon frequency spectrum of materials can be measured by neutron transmission techniques if they contain nuclei with low energy resonances, narrow enough to be Doppler-broadened, in their neutron cross sections. The authors have carried out some measurements using this technique for materials of the lanthanum barium cuprate class, La{sub 2{minus}x}Ba{sub x}CuO{sub 4}. Two samples with slightly different concentrations of oxygen, one being superconductive, the other not, were examined. Pure lanthanum cuprate was also measured. Lanthanum, barium and copper all have relatively low energy narrow resonances. Thus it should be possible to detect differences in the phonons carried by different kinds of atom in the lattice. Neutron cross section measurements have been made with high energy resolution and statistical precision on the 59m flight path of LANSCE, the pulsed spallation neutron source at Los Alamos National Laboratory. Measurements on all three materials were made over a range of temperatures from 15K to 300K, with small steps through the critical temperature region near 27K. No significant changes in the mean phonon energy of the lanthanum atoms were observed near the critical temperature of the super-conducting material. It appears however that the mean phonon energy of lanthanum in the superconductor is considerably higher than that in the non-superconductors. The samples used in this series of experiments were too thin in barium and copper to determine anything significant about their phonon spectra.

  5. Recent advances in measurement of the water vapour continuum in the far-infrared spectral region.

    PubMed

    Green, Paul D; Newman, Stuart M; Beeby, Ralph J; Murray, Jonathan E; Pickering, Juliet C; Harries, John E

    2012-06-13

    We present a new derivation of the foreign-broadened water vapour continuum in the far-infrared (far-IR) pure rotation band between 24 μm and 120 μm (85-420 cm(-1)) from field data collected in flight campaigns of the Continuum Absorption by Visible and IR radiation and Atmospheric Relevance (CAVIAR) project with Imperial College's Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) far-IR spectro-radiometer instrument onboard the Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft; and compare this new derivation with those recently published in the literature in this spectral band. This new dataset validates the current Mlawer-Tobin-Clough-Kneizys-Davies (MT-CKD) 2.5 model parametrization above 300 cm(-1), but indicates the need to strengthen the parametrization below 300 cm(-1), by up to 50 per cent at 100 cm(-1). Data recorded at a number of flight altitudes have allowed measurements within a wide range of column water vapour environments, greatly increasing the sensitivity of this analysis to the continuum strength.

  6. Continuum Absorption Coefficient of Atoms and Ions

    NASA Technical Reports Server (NTRS)

    Armaly, B. F.

    1979-01-01

    The rate of heat transfer to the heat shield of a Jupiter probe has been estimated to be one order of magnitude higher than any previously experienced in an outer space exploration program. More than one-third of this heat load is due to an emission of continuum radiation from atoms and ions. The existing computer code for calculating the continuum contribution to the total load utilizes a modified version of Biberman's approximate method. The continuum radiation absorption cross sections of a C - H - O - N ablation system were examined in detail. The present computer code was evaluated and updated by being compared with available exact and approximate calculations and correlations of experimental data. A detailed calculation procedure, which can be applied to other atomic species, is presented. The approximate correlations can be made to agree with the available exact and experimental data.

  7. OPACITY BROADENING OF {sup 13}CO LINEWIDTHS AND ITS EFFECT ON THE VARIANCE-SONIC MACH NUMBER RELATION

    SciTech Connect

    Correia, C.; De Medeiros, J. R.; Burkhart, B.; Lazarian, A.; Ossenkopf, V.; Stutzki, J.; Kainulainen, J.; Kowal, G.

    2014-04-10

    We study how the estimation of the sonic Mach number (M{sub s} ) from {sup 13}CO linewidths relates to the actual three-dimensional sonic Mach number. For this purpose we analyze MHD simulations that include post-processing to take radiative transfer effects into account. As expected, we find very good agreement between the linewidth estimated sonic Mach number and the actual sonic Mach number of the simulations for optically thin tracers. However, we find that opacity broadening causes M{sub s} to be overestimated by a factor of ≈1.16-1.3 when calculated from optically thick {sup 13}CO lines. We also find that there is a dependence on the magnetic field: super-Alfvénic turbulence shows increased line broadening compared with sub-Alfvénic turbulence for all values of optical depth for supersonic turbulence. Our results have implications for the observationally derived sonic Mach number-density standard deviation (σ{sub ρ/(ρ)}) relationship, σ{sub ρ/〈ρ〉}{sup 2}=b{sup 2}M{sub s}{sup 2}, and the related column density standard deviation (σ {sub N/(N)}) sonic Mach number relationship. In particular, we find that the parameter b, as an indicator of solenoidal versus compressive driving, will be underestimated as a result of opacity broadening. We compare the σ {sub N/(N)}-M{sub s} relation derived from synthetic dust extinction maps and {sup 13}CO linewidths with recent observational studies and find that solenoidally driven MHD turbulence simulations have values of σ {sub N/(N)}which are lower than real molecular clouds. This may be due to the influence of self-gravity which should be included in simulations of molecular cloud dynamics.

  8. Disentangling vibronic and solvent broadening effects in the absorption spectra of coumarin derivatives for dye sensitized solar cells.

    PubMed

    Cerezo, Javier; Avila Ferrer, Francisco J; Santoro, Fabrizio

    2015-05-01

    We simulate from first-principles the absorption spectra of five structure-related coumarin derivatives utilized in dye sensitized solar cells (DSSCs), investigating the vibronic and solvent contributions to the position and width of the spectra in ethanol. Ground and excited state potential energy surfaces (PESs) are modeled by Density Functional Theory (DFT) and its time-dependent (TD) expression for the excited state (TD-DFT). The solute vibronic structure associated with the spectrum is calculated by a TD formalism, accounting for both Duschinsky and temperature effects, while solvent inhomogeneous broadening is evaluated according to Marcus' theory, computing the solvent reorganization energy by the state-specific implementation of the polarizable continuum model (PCM) within TD-DFT. We adopted both the standard hybrid PBE0 and the range separated CAM-B3LYP functionals showing that the latter performs better both concerning the vibronic and solvent-induced contributions to the absorption lineshape. The different predictions of the two functionals are then rationalized in terms of the charge transfer (CT) character of the transitions showing that, in this class of compounds, it is strongly dependent on the nuclear structure. Such a dependence introduces a bias in the PBE0 PES that has a drastic impact on the vibronic spectra. We show that both the intrinsic vibronic structure and the solvent broadening play a relevant role in differentiating the absorption width of the five dyes. In this sense, our results provide a guide to understand the sources of spectral broadening of this family of dyes, a valuable help for a rational design of new molecules to improve DSSC devices.

  9. Fundamental edge broadening effects during focused electron beam induced nanosynthesis

    SciTech Connect

    Schmied, Roland; Fowlkes, Jason Davidson; Winkler, Robert; Rack, Phillip D.; Plank, Harald

    2015-02-16

    In this study, we explore lateral broadening effects of 3D structures fabricated through focused electron beam induced deposition using MeCpPt(IV)Me3 precursor. In particular, the scaling behavior of proximity effects as a function of the primary electron energy and the deposit height is investigated through experiments and validated through simulations. Correlated Kelvin force microscopy and conductive atomic force microscopy measurements identified conductive and non-conductive proximity regions. It was determined that the highest primary electron energies enable the highest edge sharpness while lower energies contain a complex convolution of broadening effects. In addition, it is demonstrated that intermediate energies lead to even more complex proximity effects that significantly reduce lateral edge sharpness and thus should be avoided if desiring high lateral resolution.

  10. Fundamental edge broadening effects during focused electron beam induced nanosynthesis

    DOE PAGES

    Schmied, Roland; Fowlkes, Jason Davidson; Winkler, Robert; Rack, Phillip D.; Plank, Harald

    2015-02-16

    In this study, we explore lateral broadening effects of 3D structures fabricated through focused electron beam induced deposition using MeCpPt(IV)Me3 precursor. In particular, the scaling behavior of proximity effects as a function of the primary electron energy and the deposit height is investigated through experiments and validated through simulations. Correlated Kelvin force microscopy and conductive atomic force microscopy measurements identified conductive and non-conductive proximity regions. It was determined that the highest primary electron energies enable the highest edge sharpness while lower energies contain a complex convolution of broadening effects. In addition, it is demonstrated that intermediate energies lead to evenmore » more complex proximity effects that significantly reduce lateral edge sharpness and thus should be avoided if desiring high lateral resolution.« less

  11. Positive emotions and the social broadening effects of Barack Obama.

    PubMed

    Ong, Anthony D; Burrow, Anthony L; Fuller-Rowell, Thomas E

    2012-10-01

    Past experiments have demonstrated that the cognitive broadening produced by positive emotions may extend to social contexts. Building on this evidence, we hypothesized that positive emotions triggered by thinking about Barack Obama may broaden and expand people's sense of self to include others. Results from an expressive-writing study demonstrated that African American college students prompted to write about Obama immediately prior to and after the 2008 presidential election used more plural self-references, fewer other-references, and more social references. Mediation analyses revealed that writing about Obama increased positive emotions, which in turn increased the likelihood that people thought in terms of more-inclusive superordinate categories (we and us rather than they and them). Implications of these findings for the role of positive emotions in perspective-taking and intergroup relations are considered.

  12. Positive emotions and the social broadening effects of Barack Obama.

    PubMed

    Ong, Anthony D; Burrow, Anthony L; Fuller-Rowell, Thomas E

    2012-10-01

    Past experiments have demonstrated that the cognitive broadening produced by positive emotions may extend to social contexts. Building on this evidence, we hypothesized that positive emotions triggered by thinking about Barack Obama may broaden and expand people's sense of self to include others. Results from an expressive-writing study demonstrated that African American college students prompted to write about Obama immediately prior to and after the 2008 presidential election used more plural self-references, fewer other-references, and more social references. Mediation analyses revealed that writing about Obama increased positive emotions, which in turn increased the likelihood that people thought in terms of more-inclusive superordinate categories (we and us rather than they and them). Implications of these findings for the role of positive emotions in perspective-taking and intergroup relations are considered. PMID:22905966

  13. Fundamental edge broadening effects during focused electron beam induced nanosynthesis

    PubMed Central

    Schmied, Roland; Fowlkes, Jason D; Winkler, Robert; Rack, Phillip D

    2015-01-01

    Summary The present study explores lateral broadening effects of 3D structures fabricated through focused electron beam induced deposition using MeCpPt(IV)Me3 precursor. In particular, the scaling behavior of proximity effects as a function of the primary electron energy and the deposit height is investigated through experiments and validated through simulations. Correlated Kelvin force microscopy and conductive atomic force microscopy measurements identified conductive and non-conductive proximity regions. It was determined that the highest primary electron energies enable the highest edge sharpness while lower energies contain a complex convolution of broadening effects. Moreover, it is demonstrated that intermediate energies lead to even more complex proximity effects that significantly reduce lateral edge sharpness and thus should be avoided if desiring high lateral resolution. PMID:25821687

  14. SUPER ESP: Ultimate electrostatic precipitation

    SciTech Connect

    Plaks, N.

    1991-01-01

    The paper discusses SUPER ESP, a new electrostatic precipitator (ESP) concept, enabling high collection efficiencies with considerably smaller collection areas than has previously been possible. The new concept allows a major reduction in ESP size by using an alternating sequence of prechargers and short collector sections. The length of the collection section in each precharger/collector pair (module) dominates the optimization. The size reduction is greater for ESPs operating with high resistivity particulate matter than with low resistivity particulate matter. The relationship in number of modules, collector section size, and overall ESP collection is presented and discussed. Comparisons are given of ESP size for both conventional and SUPER ESP technology operating with either high or low resistivity particulate matter. Because of the size reduction, the cost of the SUPER ESP is projected to be lower than that of a conventional ESP of comparable efficiencY. The paper is based on an ESP model, ESPVI 4.0.

  15. SOWFA + Super Controller User's Manual

    SciTech Connect

    Fleming, P.; Gebraad, P.; Churchfield, M.; Lee, S.; Johnson, K.; Michalakes, J.; van Wingerden, J. W.; Moriarty, P.

    2013-08-01

    SOWFA + Super Controller is a modification of the NREL's SOWFA tool which allows for a user to apply multiturbine or centralized wind plant control algorithms within the high-fidelity SOWFA simulation environment. The tool is currently a branch of the main SOWFA program, but will one day will be merged into a single version. This manual introduces the tool and provides examples such that a user can implement their own super controller and set up and run simulations. The manual only discusses enough about SOWFA itself to allow for the customization of controllers and running of simulations, and details of SOWFA itself are reported elsewhere Churchfield and Lee (2013); Churchfield et al. (2012). SOWFA + Super Controller, and this manual, are in alpha mode.

  16. Hydrogen Stark broadening by different kinds of model microfields

    NASA Astrophysics Data System (ADS)

    Seidel, J.

    1980-07-01

    A new model microfield is defined (the theta process) which in conjunction with the kangaroo process, is used to demonstrate the effects of different model microfields on hydrogen line profiles. The differences in the statistical features of the models give an estimate of the uncertainties associated with the method of model microfields. Stark broadening of hydrogen Lyman lines by either electrons or ions is investigated specifically.

  17. Line broadening estimate from averaged energy differences of coupled states

    NASA Astrophysics Data System (ADS)

    Lavrentieva, Nina N.; Dudaryonok, Anna S.; Ma, Qiancheng

    2014-11-01

    The method to the calculation of rotation-vibrational line half-width of asymmetric top molecules is proposed. The influence of the buffer gas on the internal state of the absorbing molecule is emphasized in this method. The basic expressions of present approach are given. The averaged energy differences method was used for the calculation of H2O and HDO lines broadening. Comparisons of the calculated line shape parameters with the experimental values in different absorption bands are made.

  18. Line broadening in the neutral and ionized mercury spectra

    NASA Astrophysics Data System (ADS)

    Gavrilov, M.; Skočić, M.; Burger, M.; Bukvić, S.; Djeniže, S.

    2012-10-01

    The neutral, singly, doubly and triply ionized mercury (Hg I-IV, respectively) spectral line shapes and line center positions have been investigated in the laboratory helium plasma at electron densities ranging between 9.3 × 1022 m-3 and 1.93 × 1023 m-3 and electron temperatures around 19,500 K, both interesting for astrophysics. The mercury (natural isotope composition) atoms were sputtered from the cylindrical amalgamated gold plates located in the homogenous part of the pulsed helium discharge operating at a pressure of 665 Pa in a flowing regime. The mercury spectral line profiles were recorded using the McPherson model 209 spectrograph and the Andor ICCD camera as the detection system. This research presents Stark broadening parameters, the width (W) and the shift (d), of one Hg I, 19 Hg II, 6 Hg III and 4 Hg IV lines, not investigated so far. Our experimental W values were compared with the data calculated applying various approaches. The shape and intensity of astrophysically important 398.4 nm Hg II spectral line was discussed taking into account the isotope shift, hyperfine structure and Penning effects. At the mentioned plasma parameters the Stark broadening is found to be a main line broadening mechanism of the lines (λ > 200 nm) in the Hg I-IV spectra.

  19. Jet broadening in unstable non-Abelian plasmas

    SciTech Connect

    Dumitru, Adrian; Schenke, Bjoern; Strickland, Michael; Nara, Yasushi

    2008-08-15

    We perform numerical simulations of the SU(2) Boltzmann-Vlasov equation including both hard elastic particle collisions and soft interactions mediated by classical Yang-Mills fields. Using this technique we calculate the momentum-space broadening of high-energy jets in real time for both locally isotropic and anisotropic plasmas. In both cases we introduce a separation scale that separates hard and soft interactions and demonstrate that our results for jet broadening are independent of the precise separation scale chosen. For an isotropic plasma this allows us to calculate the jet transport coefficient q-circumflex including hard and soft nonequilibrium dynamics. For an anisotropic plasma the jet transport coefficient becomes a tensor with q-circumflex{sub L}{ne}q-circumflex{sub perpendicular}. We find that for weakly coupled anisotropic plasmas the fields develop unstable modes, forming configurations where B{sub perpendicular}>E{sub perpendicular} and E{sub z}>B{sub z}, which lead to q-circumflex{sub L}>q-circumflex{sub perpendicular}. We study whether the effect is strong enough to explain the experimental observation that high-energy jets traversing the plasma perpendicular to the beam axis experience much stronger broadening in rapidity, {delta}{eta}, than in azimuth, {delta}{phi}.

  20. Soft X-ray continuum radiation from low-energy pinch discharges of hydrogen

    NASA Astrophysics Data System (ADS)

    Mills, R.; Booker, R.; Lu, Y.; Lu

    2013-10-01

    Under a study contracted by GEN3 Partners, spectra of high current pinch discharges in pure hydrogen and helium were recorded in the extreme ultraviolet radiation region at the Harvard Smithsonian Center for Astrophysics (CfA) in an attempt to reproduce experimental results published by BlackLight Power, Inc. (BLP) showing predicted continuum radiation due to hydrogen in the 10-30 nm region (Mills, R. L. and Lu, Y. 2010 Hydrino continuum transitions with cutoffs at 22.8 nm and 10.1 nm. Int. J. Hydrog. Energy 35, 8446-8456, doi:10.1016?j.ijhydene.2010.05.098). Alternative explanations were considered to the claimed interpretation of the continuum radiation as being that emitted during transitions of H to lower-energy states (hydrinos). Continuum radiation was observed at CfA in the 10-30 nm region that matched BLP's results. Considering the low energy of 5.2 J per pulse, the observed radiation in the energy range of about 120-40 eV, reference experiments and analysis of plasma gases, cryofiltration to remove contaminants, and spectra of the electrode metal, no conventional explanation was found in the prior or present work to be plausible including contaminants, electrode metal emission, and Bremsstrahlung, ion recombination, molecular or molecular ion band radiation, and instrument artifacts involving radicals and energetic ions reacting at the charge-coupled device and H2 re-radiation at the detector chamber. Moreover, predicted selective extraordinarily high-kinetic energy H was observed by the corresponding Doppler broadening of the Balmer α line.

  1. Modal kinematics for multisection continuum arms.

    PubMed

    Godage, Isuru S; Medrano-Cerda, Gustavo A; Branson, David T; Guglielmino, Emanuele; Caldwell, Darwin G

    2015-05-13

    This paper presents a novel spatial kinematic model for multisection continuum arms based on mode shape functions (MSF). Modal methods have been used in many disciplines from finite element methods to structural analysis to approximate complex and nonlinear parametric variations with simple mathematical functions. Given certain constraints and required accuracy, this helps to simplify complex phenomena with numerically efficient implementations leading to fast computations. A successful application of the modal approximation techniques to develop a new modal kinematic model for general variable length multisection continuum arms is discussed. The proposed method solves the limitations associated with previous models and introduces a new approach for readily deriving exact, singularity-free and unique MSF's that simplifies the approach and avoids mode switching. The model is able to simulate spatial bending as well as straight arm motions (i.e., pure elongation/contraction), and introduces inverse position and orientation kinematics for multisection continuum arms. A kinematic decoupling feature, splitting position and orientation inverse kinematics is introduced. This type of decoupling has not been presented for these types of robotic arms before. The model also carefully accounts for physical constraints in the joint space to provide enhanced insight into practical mechanics and impose actuator mechanical limitations onto the kinematics thus generating fully realizable results. The proposed method is easily applicable to a broad spectrum of continuum arm designs.

  2. Modal kinematics for multisection continuum arms.

    PubMed

    Godage, Isuru S; Medrano-Cerda, Gustavo A; Branson, David T; Guglielmino, Emanuele; Caldwell, Darwin G

    2015-06-01

    This paper presents a novel spatial kinematic model for multisection continuum arms based on mode shape functions (MSF). Modal methods have been used in many disciplines from finite element methods to structural analysis to approximate complex and nonlinear parametric variations with simple mathematical functions. Given certain constraints and required accuracy, this helps to simplify complex phenomena with numerically efficient implementations leading to fast computations. A successful application of the modal approximation techniques to develop a new modal kinematic model for general variable length multisection continuum arms is discussed. The proposed method solves the limitations associated with previous models and introduces a new approach for readily deriving exact, singularity-free and unique MSF's that simplifies the approach and avoids mode switching. The model is able to simulate spatial bending as well as straight arm motions (i.e., pure elongation/contraction), and introduces inverse position and orientation kinematics for multisection continuum arms. A kinematic decoupling feature, splitting position and orientation inverse kinematics is introduced. This type of decoupling has not been presented for these types of robotic arms before. The model also carefully accounts for physical constraints in the joint space to provide enhanced insight into practical mechanics and impose actuator mechanical limitations onto the kinematics thus generating fully realizable results. The proposed method is easily applicable to a broad spectrum of continuum arm designs. PMID:25969947

  3. Aims, Modes, and the Continuum of Discourse.

    ERIC Educational Resources Information Center

    Beale, Walter H.

    A framework for the study of discourse, based on the analysis of three superordinate features of discourse (asymmetry, hierarchy, and continuum), is proposed in this paper. The paper begins by noting the confusion in terminology that exists in the world of composition pedagogy and theory; pointing to the need for a framework for testing,…

  4. Radio continuum from FU Orionis stars

    SciTech Connect

    Rodriguez, L.F.; Hartmann, L.W.; Chavira, E. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA Instituto Nacional de Astrofisica, Optica y Electronica, Puebla )

    1990-12-01

    Using the very large array a sensitive search is conducted for 3.6-cm continuum emission toward four FU Orionis objects: FU Ori, V1515 Cyg, V1057 Cyg, and Elias 1-12. V1057 Cyg and Elias 1-12 at the level of about 0.1 mJy is detected. The association of radio continuum emission with these FU Ori objects strengthens a possible relation between FU Ori stars and objects like L 1551 IRS 5 and Z CMa that are also sources of radio continuum emission and have been proposed as post-FU Ori objects. Whether the radio continuum emission is caused by free-free emission from ionized ejecta or if it is optically thin emission from a dusty disk is discussed. It was determined that, in the archives of the Tonantzintla Observatory, a plate taken in 1957 does not show Elias 1-12. This result significantly narrows the time range for the epoch of the outburst of this source to between 1957 and 1965. 38 refs.

  5. Parental Involvement to Parental Engagement: A Continuum

    ERIC Educational Resources Information Center

    Goodall, Janet; Montgomery, Caroline

    2014-01-01

    Based on the literature of the field, this article traces a continuum between parental involvement with schools, and parental engagement with children's learning. The article seeks to shed light on an area of confusion; previous research has shown that different stakeholder groups understand "parental engagement" in different ways.…

  6. 3D holography: from discretum to continuum

    NASA Astrophysics Data System (ADS)

    Bonzom, Valentin; Dittrich, Bianca

    2016-03-01

    We study the one-loop partition function of 3D gravity without cosmological constant on the solid torus with arbitrary metric fluctuations on the boundary. To this end we employ the discrete approach of (quantum) Regge calculus. In contrast with similar calculations performed directly in the continuum, we work with a boundary at finite distance from the torus axis. We show that after taking the continuum limit on the boundary — but still keeping finite distance from the torus axis — the one-loop correction is the same as the one recently found in the continuum in Barnich et al. for an asymptotically flat boundary. The discrete approach taken here allows to identify the boundary degrees of freedom which are responsible for the non-trivial structure of the one-loop correction. We therefore calculate also the Hamilton-Jacobi function to quadratic order in the boundary fluctuations both in the discrete set-up and directly in the continuum theory. We identify a dual boundary field theory with a Liouville type coupling to the boundary metric. The discrete set-up allows again to identify the dual field with degrees of freedom associated to radial bulk edges attached to the boundary. Integrating out this dual field reproduces the (boundary diffeomorphism invariant part of the) quadratic order of the Hamilton-Jacobi functional. The considerations here show that bulk boundary dualities might also emerge at finite boundaries and moreover that discrete approaches are helpful in identifying such dualities.

  7. Clinical Integration Managing across the care continuum.

    PubMed

    Karash, Julius A; Larson, Laurie

    2016-06-01

    In the changing world of health care, the traditional boundaries are vanishing and hospitals and others must integrate care within their own organizations, as well as externally, across the care continuum. Here are three approaches to accomplishing just that. PMID:27468454

  8. Continuum modeling of large lattice structures: Status and projections

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Mikulas, Martin M., Jr.

    1988-01-01

    The status and some recent developments of continuum modeling for large repetitive lattice structures are summarized. Discussion focuses on a number of aspects including definition of an effective substitute continuum; characterization of the continuum model; and the different approaches for generating the properties of the continuum, namely, the constitutive matrix, the matrix of mass densities, and the matrix of thermal coefficients. Also, a simple approach is presented for generating the continuum properties. The approach can be used to generate analytic and/or numerical values of the continuum properties.

  9. Temperature Effect on the Optical Emission Intensity in Laser Induced Breakdown Spectroscopy of Super Alloys

    NASA Astrophysics Data System (ADS)

    Darbani, S. M. R.; Ghezelbash, M.; Majd, A. E.; Soltanolkotabi, M.; Saghafifar, H.

    2014-12-01

    In this paper, the influence of heating and cooling samples on the optical emission spectra and plasma parameters of laser-induced breakdown spectroscopy for Titanium 64, Inconel 718 super alloys, and Aluminum 6061 alloy is investigated. Samples are uniformly heated up to approximately 200°C and cooled down to -78°C by an external heater and liquid nitrogen, respectively. Variations of plasma parameters like electron temperature and electron density with sample temperature are determined by using Boltzmann plot and Stark broadening methods, respectively. Heating the samples improves LIBS signal strength and broadens the width of the spectrum. On the other hand, cooling alloys causes fluctuations in the LIBS signal and decrease it to some extent, and some of the spectral peaks diminish. In addition, our results show that electron temperature and electron density depend on the sample temperature variations.

  10. Super 8: The Modest Medium.

    ERIC Educational Resources Information Center

    Gunter, Jonathan F.

    This state of the art review gives an overview of the history of the development of Super 8 film, and describes a range of hardware associated with it, covering such areas as camera, sound synchronization, double system recording, lighting, film processing, sound transfer, editing, sound mixing, display, and methods of distribution. It examines…

  11. Review: SuperCalc3.

    ERIC Educational Resources Information Center

    Jadrnicek, Rik

    1984-01-01

    Reviews the latest version of the SuperCalc spreadsheet, indicating that it now provides color graphics, two-key sorting, and database management functions (including Internal Rate of Return). Also indicates that the program is not copy protected, useful in trying to integrate a variety of programs. (JN)

  12. The SuperB project

    SciTech Connect

    Lesiak, Tadeusz

    2011-05-23

    This paper presents a very short review of the SuperB project which aims to construct a new generation flavour factory with a designed luminosity of at least 10{sup 36} cm{sup -2} s{sup -1}. The main issues related to the physics programme, together with the description of the conceptual design of the accelerator and detector are briefly discussed.

  13. The rotational broadening of V395 Carinae. Implications on the compact object's mass

    NASA Astrophysics Data System (ADS)

    Shahbaz, T.; Watson, C. A.

    2007-11-01

    Context: The masses previously obtained for the X-ray binary 2S 0921-630 inferred a compact object that was either a high-mass neutron star or low-mass black-hole, but used a previously published value for the rotational broadening (v sin i) with large uncertainties. Aims: We aim to determine an accurate mass for the compact object through an improved measurement of the secondary star's projected equatorial rotational velocity. Methods: We have used UVES echelle spectroscopy to determine the v sin i of the secondary star (V395 Car) in the low-mass X-ray binary 2S 0921-630 by comparison to an artificially broadened spectral-type template star. In addition, we have also measured v sin i from a single high signal-to-noise ratio absorption line profile calculated using the method of Least-Squares Deconvolution (LSD). Results: We determine v sin i to lie between 31.3±0.5 km s-1 to 34.7±0.5 km s-1 (assuming zero and continuum limb darkening, respectively) in disagreement with previous results based on intermediate resolution spectroscopy obtained with the 3.6 m NTT. Using our revised v sin i value in combination with the secondary star's radial velocity gives a binary mass ratio of 0.281±0.034. Furthermore, assuming a binary inclination angle of 75° gives a compact object mass of 1.37±0.13 M_⊙. Conclusions: We find that using relatively low-resolution spectroscopy can result in systemic uncertainties in the measured v sin i values obtained using standard methods. We suggest the use of LSD as a secondary, reliable check of the results as LSD allows one to directly discern the shape of the absorption line profile. In the light of the new v sin i measurement, we have revised down the compact object's mass, such that it is now compatible with a canonical neutron star mass. Based on observations collected at the European Southern Observatory, Chile, under the programme 077.D-0579A.

  14. A marching method for calculating line and continuum radiation in high energy flow fields

    NASA Technical Reports Server (NTRS)

    Bolz, C. W., Jr.

    1979-01-01

    A method is presented for calculating nongrey radiative fluxes and intensities in a highly ionized, low temperature plasma with extreme line broadening. The method was developed to study radiative heating phenomena in the mass-injected hypersonic shock-layer environments characteristic of outer planet atmospheric entry, although it is not limited to such studies. The radiative properties model assumed local thermodynamic equilibrium and used standard continuum and molecular band models. The atomic line model, however, used a frequency-marching method for the frequency integration, which not only accounted completely for line overlapping (reabsorption) effects, but compared favorably in economy with the best equivalent-width methods. An assessment of hydrogen line-far-wing treatments, with recommendations for engineering models, is also presented.

  15. Line-Shape Transition of Collision Broadened Lines

    NASA Astrophysics Data System (ADS)

    Harde, H.; Katzenellenbogen, N.; Grischkowsky, D.

    1995-02-01

    Using the newly developed technique of THz time-domain spectroscopy, we have measured the far-wing absorption line profile of the ensemble of collision broadened ground state rotational lines of methylchloride vapor out to more than 200 linewidths from resonance, corresponding to frequency offsets as much as 5× the resonant frequency. On these far wings the measured absorption is approximately an order of magnitude less than that predicted by the van Vleck-Weisskopf theory. Our observations show that at higher frequencies a transition occurs from the regime of the van Vleck-Weisskopf theory to the regime of the Lorentz theory.

  16. Strategies for broadening public involvement in space developments

    NASA Technical Reports Server (NTRS)

    Harris, Philip R.

    1992-01-01

    There is widespread public interest in and goodwill toward the space program. For NASA's plans for the next 25 years to be achieved, this public reservoir of support needs to be tapped and channeled. NASA endeavors have to reach out beyond the scientific, technological, and aerospace communities to foster wider participation in space exploration and exploitation. To broaden NASA support and spread out the financing of space activities, recommendations for consideration are offered in the area of economics, political, institutional, international, and managerial areas.

  17. Curves of growth for van der Waals broadened spectral lines

    NASA Technical Reports Server (NTRS)

    Park, C.

    1980-01-01

    Curves of growth are evaluated for a spectral line broadened by the van der Waals interactions during collisions. The growth of the equivalent widths of such lines is shown to be dependent on the product of the perturber density and the 6/10 power of the van der Waals potential coefficient. When the parameter is small, the widths grow as the 1/2 power of the optical depth as they do for the Voigt profile: but when the parameter is large, they grow as 2/3 power and, hence, faster than the Voigt profile. An approximate analytical expression for the computed growth characteristics is given.

  18. Broadening sources of Diginity and Affirmation in Work and Relationship

    PubMed Central

    Byars-Winston, Angela

    2012-01-01

    This article builds on assertions in Richardson’s (2012, this issue) Major Contribution on counseling for work and relationship. In this reaction, I expand on the relevance and potential of the counseling for work and relationship perspective to enrich the field of counseling psychology. My comments focus on three considerations to further extend the cultural relevance of Richardson’s work and relationship perspective: (1) broadening sources of dignity, (2) centering knowledge of marginalized communities, and (3) promoting psychologists’ critical consciousness. Richardson’s perspective holds great promise for being a guiding heuristic to inform counseling psychology research, theory, and practice. PMID:22563131

  19. Numerical computation of doppler-broadening in the resonance domain

    SciTech Connect

    Sanchez, R.

    2013-07-01

    We have implemented an accurate and fast calculation of the Doppler-broadened kernel PT(E {yields} E') for neutron elastic scattering based on a gas model. An exponential cutoff which accounts for the asymptotic behavior of the error function helps limit the range of integration while eliminating difference effects. This allows for calculating a kernel library for {sup 238}U over a very fine energy grid covering the resonance range in only a few hours in a laptop. We give an example showing the impact of {sup 238}U elastic up-scattering on the values of self shielded cross sections. (authors)

  20. Selective optical pumping process in Doppler-broadened atoms

    SciTech Connect

    Liu Shuangqiang; Zhang Yundong; Fan Daikun; Wu Hao; Yuan Ping

    2011-04-10

    By solving the optical Bloch equations with the rate-equation approximation, we calculate the time dependence of the magnetic sublevel populations of Doppler-broadened atoms. With an increase of the left-circularly polarized pump intensity, the population fraction of a certain sublevel of the excited state almost reaches 0.3, resulting in anisotropy in the excited state, which is important to the optical filter based on circular birefringence and dichroism. Furthermore, numerical results show that the real saturation pump intensity for the moving atoms is much larger than that for the resting atoms.

  1. Commercial observation satellites: broadening the sources of geospatial data

    NASA Astrophysics Data System (ADS)

    Baker, John C.; O'Connell, Kevin M.; Venzor, Jose A.

    2002-09-01

    Commercial observation satellites promise to broaden substantially the sources of imagery data available to potential users of geospatial data and related information products. We examine the new trend toward private firms acquiring and operating high-resolution imagery satellites. These commercial observation satellites build on the substantial experience in Earth observation operations provided by government-owned imaging satellites for civilian and military purposes. However, commercial satellites will require governments and companies to reconcile public and private interests in allowing broad public access to high-resolution satellite imagery data without creating national security risks or placing the private firms at a disadvantage compared with other providers of geospatial data.

  2. Spectral properties of acoustic black hole radiation: Broadening the horizon

    SciTech Connect

    Finazzi, Stefano; Parentani, Renaud

    2011-04-15

    The sensitivity of the black hole spectrum when introducing short distance dispersion is studied in the context of atomic Bose condensates. By considering flows characterized by several length scales, we show that, while the spectrum remains remarkably Planckian, the temperature is no longer fixed by the surface gravity. Rather it is determined by the average of the flow gradient across the horizon over an interval fixed by the healing length and the surface gravity, as if the horizon were broadened. This remains valid as long as the flow does not induce nonadiabatic effects that produce oscillations or some parametric amplification of the flux.

  3. Focusing super resolution on the cytoskeleton

    PubMed Central

    Shelden, Eric A.; Colburn, Zachary T.; Jones, Jonathan C.R.

    2016-01-01

    Super resolution imaging is becoming an increasingly important tool in the arsenal of methods available to cell biologists. In recognition of its potential, the Nobel Prize for chemistry was awarded to three investigators involved in the development of super resolution imaging methods in 2014. The availability of commercial instruments for super resolution imaging has further spurred the development of new methods and reagents designed to take advantage of super resolution techniques. Super resolution offers the advantages traditionally associated with light microscopy, including the use of gentle fixation and specimen preparation methods, the ability to visualize multiple elements within a single specimen, and the potential to visualize dynamic changes in living specimens over time. However, imaging of living cells over time is difficult and super resolution imaging is computationally demanding. In this review, we discuss the advantages/disadvantages of different super resolution systems for imaging fixed live specimens, with particular regard to cytoskeleton structures. PMID:27303635

  4. 34 CFR 300.115 - Continuum of alternative placements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Continuum of alternative placements. 300.115 Section 300... alternative placements. (a) Each public agency must ensure that a continuum of alternative placements is...) The continuum required in paragraph (a) of this section must— (1) Include the alternative...

  5. Continuum of Collaboration: Little Steps for Little Feet

    ERIC Educational Resources Information Center

    Powell, Gwynn M.

    2013-01-01

    This mini-article outlines a continuum of collaboration for faculty within a department of the same discipline. The goal of illustrating this continuum is showcase different stages of collaboration so that faculty members can assess where they are as a collective and consider steps to collaborate more. The separate points along a continuum of…

  6. Continuum Statistics of the Airy2 Process

    NASA Astrophysics Data System (ADS)

    Corwin, Ivan; Quastel, Jeremy; Remenik, Daniel

    2013-01-01

    We develop an exact determinantal formula for the probability that the Airy_2 process is bounded by a function g on a finite interval. As an application, we provide a direct proof that {sup({A}2(x)-x^2)} is distributed as a GOE random variable. Both the continuum formula and the GOE result have applications in the study of the end point of an unconstrained directed polymer in a disordered environment. We explain Johansson's (Commun. Math. Phys. 242(1-2):277-329, 2003) observation that the GOE result follows from this polymer interpretation and exact results within that field. In a companion paper (Moreno Flores et al. in Commun. Math. Phys. 2012) these continuum statistics are used to compute the distribution of the endpoint of directed polymers.

  7. A continuum model of transcriptional bursting

    PubMed Central

    Corrigan, Adam M; Tunnacliffe, Edward; Cannon, Danielle; Chubb, Jonathan R

    2016-01-01

    Transcription occurs in stochastic bursts. Early models based upon RNA hybridisation studies suggest bursting dynamics arise from alternating inactive and permissive states. Here we investigate bursting mechanism in live cells by quantitative imaging of actin gene transcription, combined with molecular genetics, stochastic simulation and probabilistic modelling. In contrast to early models, our data indicate a continuum of transcriptional states, with a slowly fluctuating initiation rate converting the gene between different levels of activity, interspersed with extended periods of inactivity. We place an upper limit of 40 s on the lifetime of fluctuations in elongation rate, with initiation rate variations persisting an order of magnitude longer. TATA mutations reduce the accessibility of high activity states, leaving the lifetime of on- and off-states unchanged. A continuum or spectrum of gene states potentially enables a wide dynamic range for cell responses to stimuli. DOI: http://dx.doi.org/10.7554/eLife.13051.001 PMID:26896676

  8. Models of Uranium continuum radio emission

    NASA Technical Reports Server (NTRS)

    Romig, Joseph H.; Evans, David R.; Sawyer, Constance B.; Schweitzer, Andrea E.; Warwick, James W.

    1987-01-01

    Uranium continuum radio emission detected by the Voyager 2 Planetary Radio Astronomy experiment during the January 1986 encounter is considered. The continuum emissions comprised four components (equatorial emissions, anomaly emissions, strong nightside emissions, and weak nightside emissions) associated with different sources. The equatorial emissions appeared most prominently during the days before closest approach and extended from 40 kHz or below to about 120 kHz. The anomaly emissions were seen about 12 hours before closest approach and extended to about 250 kHz. The agreement found between Miranda's phase and strong radio emission at 20.4 kHz, just after closest approach, suggests intense dynamic activity on the Miranda L shell.

  9. Spatiotemporal dynamics of continuum neural fields

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.

    2012-01-01

    We survey recent analytical approaches to studying the spatiotemporal dynamics of continuum neural fields. Neural fields model the large-scale dynamics of spatially structured biological neural networks in terms of nonlinear integrodifferential equations whose associated integral kernels represent the spatial distribution of neuronal synaptic connections. They provide an important example of spatially extended excitable systems with nonlocal interactions and exhibit a wide range of spatially coherent dynamics including traveling waves oscillations and Turing-like patterns.

  10. MODIFICATION OF THE MOOG SPECTRAL SYNTHESIS CODES TO ACCOUNT FOR ZEEMAN BROADENING OF SPECTRAL LINES

    SciTech Connect

    Deen, Casey P.

    2013-09-15

    In an attempt to widen access to the study of magnetic fields in stellar astronomy, I present MOOGStokes, a version of the MOOG one-dimensional local thermodynamic equilibrium radiative transfer code, overhauled to incorporate a Stokes vector treatment of polarized radiation through a magnetic medium. MOOGStokes is a suite of three complementary programs, which together can synthesize the disk-averaged emergent spectrum of a star with a magnetic field. The first element (a pre-processing script called CounterPoint) calculates for a given magnetic field strength, wavelength shifts, and polarizations for the components of Zeeman-sensitive lines. The second element (a MOOG driver called SynStokes derived from the existing MOOG driver Synth) uses the list of Zeeman-shifted absorption lines together with the existing machinery of MOOG to synthesize the emergent spectrum at numerous locations across the stellar disk, accounting for stellar and magnetic field geometry. The third and final element (a post-processing script called DiskoBall) calculates the disk-averaged spectrum by weighting the individual emergent spectra by limb darkening and projected area, and applying the effects of Doppler broadening. All together, the MOOGStokes package allows users to synthesize emergent spectra of stars with magnetic fields in a familiar computational framework. MOOGStokes produces disk-averaged spectra for all Stokes vectors ( I, Q, U, V ), normalized by the continuum. MOOGStokes agrees well with the predictions of INVERS10 a polarized radiative transfer code with a long history of use in the study of stellar magnetic fields. In the non-magnetic limit, MOOGStokes also agrees with the predictions of the scalar version of MOOG.

  11. Bipotential continuum models for granular mechanics

    NASA Astrophysics Data System (ADS)

    Goddard, Joe

    2014-03-01

    Most currently popular continuum models for granular media are special cases of a generalized Maxwell fluid model, which describes the evolution of stress and internal variables such as granular particle fraction and fabric,in terms of imposed strain rate. It is shown how such models can be obtained from two scalar potentials, a standard elastic free energy and a ``dissipation potential'' given rigorously by the mathematical theory of Edelen. This allows for a relatively easy derivation of properly invariant continuum models for granular media and fluid-particle suspensions within a thermodynamically consistent framework. The resulting continuum models encompass all the prominent regimes of granular flow, ranging from the quasi-static to rapidly sheared, and are readily extended to include higher-gradient or Cosserat effects. Models involving stress diffusion, such as that proposed recently by Kamrin and Koval (PRL 108 178301), provide an alternative approach that is mentioned in passing. This paper provides a brief overview of a forthcoming review articles by the speaker (The Princeton Companion to Applied Mathematics, and Appl. Mech. Rev.,in the press, 2013).

  12. A Continuum Theory of Thermal Transpiration

    NASA Astrophysics Data System (ADS)

    Bielenberg, James; Brenner, Howard

    2003-11-01

    A rational, continuum mechanical description is given for the pressure drop that develops in a closed capillary tube subject to an imposed temperature gradient. This phenomenon, termed thermal transpiration, has been experimentally demonstrated in systems at vanishing Knudsen numbers, yet no purely continuum mechanical description has, until now, been given. Previous hybrid solutions (dating back to Maxwell in 1879) have utilized the classical, incompressible flow equations along with molecularly derived slip boundary conditions. This solution approach will be briefly discussed and shown to be dynamically consistent yet energetically flawed. Subsequently, we will apply a novel reformulation of continuum-mechanics and -thermodynamics, which clearly distinguishes between the Lagrangian (tracer) and the barycentric velocities, to generate a solution for the thermal pressure drop developed in a closed system. Explicitly, the phenomena at hand will be shown to be entirely analogous to Poiseuille flow in tube, albeit with the tacit recognition that the ``flow'' we are speaking of is defined in a dynamic sense rather than in the more traditional, kinematic mass-flux based sense. This solution will be show to be free of ad hoc parameters, consistent with experimental results, and in accordance with classical macroscopic thermodynamics. Beyond its purely scientific importance, this phenomenon may find applications in the emerging area of micro-fluidic pumping.

  13. Polymer Fluid Dynamics: Continuum and Molecular Approaches.

    PubMed

    Bird, R B; Giacomin, A J

    2016-06-01

    To solve problems in polymer fluid dynamics, one needs the equations of continuity, motion, and energy. The last two equations contain the stress tensor and the heat-flux vector for the material. There are two ways to formulate the stress tensor: (a) One can write a continuum expression for the stress tensor in terms of kinematic tensors, or (b) one can select a molecular model that represents the polymer molecule and then develop an expression for the stress tensor from kinetic theory. The advantage of the kinetic theory approach is that one gets information about the relation between the molecular structure of the polymers and the rheological properties. We restrict the discussion primarily to the simplest stress tensor expressions or constitutive equations containing from two to four adjustable parameters, although we do indicate how these formulations may be extended to give more complicated expressions. We also explore how these simplest expressions are recovered as special cases of a more general framework, the Oldroyd 8-constant model. Studying the simplest models allows us to discover which types of empiricisms or molecular models seem to be worth investigating further. We also explore equivalences between continuum and molecular approaches. We restrict the discussion to several types of simple flows, such as shearing flows and extensional flows, which are of greatest importance in industrial operations. Furthermore, if these simple flows cannot be well described by continuum or molecular models, then it is not necessary to lavish time and energy to apply them to more complex flow problems. PMID:27276553

  14. Line and continuum variability in active galaxies

    NASA Astrophysics Data System (ADS)

    Rashed, Y. E.; Eckart, A.; Valencia-S., M.; García-Marín, M.; Busch, G.; Zuther, J.; Horrobin, M.; Zhou, H.

    2015-12-01

    We compared optical spectroscopic and photometric data for 18 active galactic nuclei (AGN) galaxies over two to three epochs, with time intervals of typically 5 to 10 yr. We used the multi-object double spectrograph (MODS) at the Large Binocular Telescope (LBT) and compared the spectra with data taken from the SDSS data base and the literature. We found variations in the forbidden oxygen lines as well as in the hydrogen recombination lines of these sources. For four of the sources we found that, within the calibration uncertainties, the variations in continuum and line spectra of the sources are very small. We argue that it is mainly the difference in black hole mass between the samples that is responsible for the different degree of continuum variability. In addition, we found that for an otherwise constant accretion rate the total line variability (dominated by the narrow line contributions) reverberates in a similar way to the continuum variability with a dependence ΔLline ∝ (ΔLcont)3/2. Because this dependence is predominantly expressed in the narrow line emission, the implication is that the part of the source that dominates the luminosity in the narrow line region must be very compact, with a diameter of the order of at least 10 light-years. A comparison with data from the literature shows that these findings describe the variability characteristics of a total of 61 broad and narrow line sources.

  15. Improving Program Design and Assessment with Broadening Participation Resources

    NASA Astrophysics Data System (ADS)

    Siegfried, D.; Johnson, A.; Thomas, S. H.; Fauver, A.; Detrick, L.

    2012-12-01

    Many theoretical and research-based approaches suggest how to best use mentoring to enhance an undergraduate research program. The Institute for Broadening Participation's Pathways to Engineering and Pathways to Ocean Sciences projects synthesized a set of mentoring studies, theoretical sources, and other texts pertinent to undergraduate research program design into a suite of practical tools that includes an online mentoring manual, an online reference library of mentoring and diversity literature, and practical guides such as Using Social Media to Build Diversity in Your REU. The overall goal is to provide easy-to-access resources that can assist faculty and program directors in implementing or honing the mentoring elements in their research programs for undergraduates. IBP's Online Mentoring Manual addresses common themes, such as modeling, student self-efficacy, career development, retention and evaluation. The Online Diversity Reference Library provides a comprehensive, annotated selection of key policy documents, research studies, intervention studies, and other texts on broadening participation in science, technology, engineering and mathematics. IBP's suite of tools provides the theoretical underpinnings and research findings that can help leaders in education integrate site-appropriate mentoring elements into their educational programs. Program directors and faculty from a variety of program types and disciplines have benefitted from using the Manual and other resources. IBP continues the work of translating and synthesizing theory to practice and welcomes your participation and partnership in that effort.

  16. Broadening the diagnosis of bipolar disorder: benefits vs. risks

    PubMed Central

    STRAKOWSKI, STEPHEN M.; FLECK, DAVID E.; MAJ, MARIO

    2011-01-01

    There is considerable debate over whether bipolar and related disorders that share common signs and symptoms, but are currently defined as distinct clinical entities in DSM-IV and ICD-10, may be better characterized as falling within a more broadly defined “bipolar spectrum”. With a spectrum view in mind, the possibility of broadening the diagnosis of bipolar disorder has been proposed. This paper discusses some of the rationale for an expanded diagnostic scheme from both clinical and research perspectives in light of potential drawbacks. The ultimate goal of broadening the diagnosis of bipolar disorder is to help identify a common etiopathogenesis for these conditions to better guide treatment. To help achieve this goal, bipolar researchers have increasingly expanded their patient populations to identify objective biological or endophenotypic markers that transcend phenomenological observation. Although this approach has and will likely continue to produce beneficial results, the upcoming DSM-IV and ICD-10 revisions will place increasing scrutiny on psychiatry’s diagnostic classification systems and pressure to re-evaluate our conceptions of bipolar disorder. However, until research findings can provide consistent and converging evidence as to the validity of a broader diagnostic conception, clinical expansion to a dimensional bipolar spectrum should be considered with caution. PMID:21991268

  17. Non-thermal line-broadening in solar prominences

    NASA Astrophysics Data System (ADS)

    Stellmacher, G.; Wiehr, E.

    2015-09-01

    Aims: We show that the line broadening in quiescent solar prominences is mainly due to non-thermal velocities. Methods: We have simultaneously observed a wide range of optically thin lines in quiescent prominences, selected for bright and narrow Mg b emission without line satellites from macro-shifts. Results: We find a ratio of reduced widths, ΔλD/λ0, of Hγ and Hδ of 1.05 ± 0.03, which can hardly be attributed to saturation, since both are optically thin for the prominences observed: τγ ≤ 0.3, τδ ≤ 0.15. We confirm the ratio of reduced widths of He 4772 (triplet) and He 5015 (singlet) of 1.1 ± 0.05 at higher significance and detect a width ratio of Mg b2 and Mg 4571 (both from the triplet system) of 1.3 ± 0.1. Conclusions: The discrepant widths of lines from different atoms, and even from the same atom, cannot be represented by a unique pair [Tkin; Vnth]. Values of Tkin deduced from observed line radiances using models indicate low temperatures down to Tkin ≈ 5000 K. Non-thermal velocities, related to different physical states of the respective emitting prominence region, seem to be the most important line broadening mechanism.

  18. Expansion and broadening of coronal loop transients - A theoretical explanation

    NASA Technical Reports Server (NTRS)

    Mouschovias, T. CH.; Poland, A. I.

    1978-01-01

    Consequences are examined of the assumption that an observed coronal loop transient is a twisted rope of magnetic-field lines expanding and broadening in the background coronal plasma and magnetic field. It is shown that the expansion can be accounted for by the azimuthal component of the field; the observed broadening of the loop as it moves outward can be accounted for by the longitudinal component of the field. In order to have a net outward force and at the same time avoid a classical pinch (sausage) instability, the two components of the field must satisfy a certain inequality. It is predicted that, as the loop rises, the width (h) of its top portion should vary proportionally with distance (R) from the sun's center. This is in good agreement with measurements that show h is proportional to the 0.8 power of R. The prediction that the radius of curvature of the top portion of the loop should be proportional to R differs from the measured variation. The difference could be accounted for by a drag due to the background coronal field that flattens the loop's top.

  19. Positive mood broadens visual attention to positive stimuli

    PubMed Central

    Wadlinger, Heather A.; Isaacowitz, Derek M.

    2010-01-01

    In an attempt to investigate the impact of positive emotions on visual attention within the context of Fredrickson's (1998) broaden-and-build model, eye tracking was used in two studies to measure visual attentional preferences of college students (n=58, n=26) to emotional pictures. Half of each sample experienced induced positive mood immediately before viewing slides of three similarly-valenced images, in varying central-peripheral arrays. Attentional breadth was determined by measuring the percentage viewing time to peripheral images as well as by the number of visual saccades participants made per slide. Consistent with Fredrickson's theory, the first study showed that individuals induced into positive mood fixated more on peripheral stimuli than did control participants; however, this only held true for highly-valenced positive stimuli. Participants under induced positive mood also made more frequent saccades for slides of neutral and positive valence. A second study showed that these effects were not simply due to differences in emotional arousal between stimuli. Selective attentional broadening to positive stimuli may act both to facilitate later building of resources as well as to maintain current positive affective states. PMID:20431711

  20. Super-stable Poissonian structures

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2012-10-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics.

  1. Super-heavy element research

    NASA Astrophysics Data System (ADS)

    Oganessian, Yu Ts; Utyonkov, V. K.

    2015-02-01

    A review of the discovery and investigation of the ‘island of stability’ of super-heavy nuclei at the separator DGFRS (FLNR, JINR) in the fusion reactions of 48Ca projectiles with target nuclei 238U-249Cf is presented. The synthesis of the heaviest nuclei, their decay properties, and methods of identification are discussed. The role of shell effects in the stability of super-heavy nuclei is demonstrated by comparison of the experimental data and results of theoretical calculations. The radioactive properties of the new nuclei, the isotopes of elements 112-118 as well as of their decay products, give evidence of the significant increase of the stability of the heavy nuclei with rise of their neutron number and approaching magic number N = 184.

  2. Super VGA Primitives Graphics System.

    1992-05-14

    Version 00 These primitives are the lowest level routines needed to perform super VGA graphics on a PC. A sample main program is included that exercises the primitives. Both Lahey and Microsoft FORTRAN's have graphics libraries. However, the libraries do not support 256 color graphics at resolutions greater than 320x200. The primitives bypass these libraries while still conforming to standard usage of BIOS. The supported graphics modes depend upon the PC graphics card and itsmore » memory. Super VGA resolutions of 640x480 and 800x600 have been tested on an ATI VGA Wonder card with 512K memory and on several 80486 PC's (unknown manufacturers) at retail stores.« less

  3. Super Resolution Image of Yogi

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Yogi is a meter-size rock about 5 meters northwest of the Mars Pathfinder lander and was the second rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument. This mosaic shows super resolution techniques applied to the second APXS target rock, which was poorly illuminated in the rover's forward camera view taken before the instrument was deployed. Super resolution was applied to help to address questions about the texture of this rock and what it might tell us about its mode of origin.

    This mosaic of Yogi was produced by combining four 'Super Pan' frames taken with the IMP camera. This composite color mosaic consists of 7 frames from the right eye, taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. This panchromatic frame was then colorized with the red, green, and blue filtered images from the same sequence. The color balance was adjusted to approximate the true color of Mars. Shadows were processed separately from the rest of the rock and combined with the rest of the scene to bring out details in the shadow of Yogi that would be too dark to view at the same time as the sunlit surfaces.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  4. Polarimetery for SuperB

    SciTech Connect

    Sullivan, Michael; Field, R.; Moffeit, Kenneth; Nosochkov, Yuri; Wienands, Ulrich; Wittmer, Walter; Woods, Mike; /SLAC

    2012-07-06

    We provide an overview description of a Compton polarimeter for measuring electron beam polarization near the IR in the Low Energy Ring of SuperB. The polarimeter is designed to achieve 1.0% accuracy. A scheme for measuring the electron beam polarization at SuperB near the IR has been described. The Compton polarimeter has been designed to fit into the existing lattice of the SuperB ring and results in a Compton IP measuring the polarization located where the beam is almost longitudinal with opposite helicity to that at the IR. The polarization at the IR is expected to be determined with an accuracy of {approx}1% from the measurement at the Compton IP provided the beam direction at the electron-positron interaction region and the Compton IP are well known and the beam energy is measured to better than 20 MeV. Detailed detector studies are needed to study resolution and acceptance effects on detector analyzing powers, and to determine sensitivity to beam and machine parameters.

  5. SUPER-ECCENTRIC MIGRATING JUPITERS

    SciTech Connect

    Socrates, Aristotle; Katz, Boaz; Dong Subo; Tremaine, Scott

    2012-05-10

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e = 0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e > 0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is a-dot {proportional_to}a{sup 1/2} and consequently the number distribution satisfies dN/d log a{proportional_to}a{sup 1/2}. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  6. A robust, coupled approach for atomistic-continuum simulation.

    SciTech Connect

    Aubry, Sylvie; Webb, Edmund Blackburn, III; Wagner, Gregory John; Klein, Patrick A.; Jones, Reese E.; Zimmerman, Jonathan A.; Bammann, Douglas J.; Hoyt, Jeffrey John; Kimmer, Christopher J.

    2004-09-01

    This report is a collection of documents written by the group members of the Engineering Sciences Research Foundation (ESRF), Laboratory Directed Research and Development (LDRD) project titled 'A Robust, Coupled Approach to Atomistic-Continuum Simulation'. Presented in this document is the development of a formulation for performing quasistatic, coupled, atomistic-continuum simulation that includes cross terms in the equilibrium equations that arise due to kinematic coupling and corrections used for the calculation of system potential energy to account for continuum elements that overlap regions containing atomic bonds, evaluations of thermo-mechanical continuum quantities calculated within atomistic simulations including measures of stress, temperature and heat flux, calculation used to determine the appropriate spatial and time averaging necessary to enable these atomistically-defined expressions to have the same physical meaning as their continuum counterparts, and a formulation to quantify a continuum 'temperature field', the first step towards constructing a coupled atomistic-continuum approach capable of finite temperature and dynamic analyses.

  7. Comparing the line broadened quasilinear model to Vlasov code

    SciTech Connect

    Ghantous, K.; Berk, H. L.; Gorelenkov, N. N.

    2014-03-15

    The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations.

  8. Calculation of pressure-broadened linewidths for CO in Ar

    NASA Technical Reports Server (NTRS)

    Green, S.

    1985-01-01

    Calculations of the pressure-broadening cross sections of CO in Ar have been made within the infinite-order sudden (IOS) and coupled states (CS) quantum scattering approximations. Two intermolecular potentials were used, a pairwise additive atom-atom potential which has been employed previously in semiclassical (modified Anderson theory) studies of this system and one calculated ab initio within an electron gas formalism. Predictions from the two potentials generally agree within about 25 percent and bracket experimental values (except for some recent high temperature data obtained in shock tube experiments). The CS approximation appears to be quite accurate although computationally expensive. The much cheaper IOS approximation is accurate for the J = 0-1 line but does not properly predict the dependence on line number. The quantum results are also compared with earlier semiclassical values.

  9. Comparing the line broadened quasilinear model to Vlasov code

    NASA Astrophysics Data System (ADS)

    Ghantous, K.; Berk, H. L.; Gorelenkov, N. N.

    2014-03-01

    The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations.

  10. Interface contributions to peak broadening in CE-ESI-MS

    SciTech Connect

    Udseth, H.R.; Barinaga, C.J.; Smith, R.D. ); Whitted, W.H. )

    1991-06-01

    The applications of capillary electrophoresis (CE) are expanding, and a number of commercial CE instruments are now available. Combining CE with mass spectroscopy (MS), first done with an electrospray ionization (ESI) interface, yields additional advantages. Other interfaces have been proposed, but CE-ESI-MS offers better sensitivity, reduced background, applicability to higher molecular weight (MW) compounds and a better interface design. Our aim has been to exploit the advantages of automated CE coupled to MS for separation of biological materials. Details of our instrument design are provided. Samples used for these studies were a mixture of myoglobin proteins (MW {approximately}17 kilodaltons) and a tryptic digest of tuna cytochrome c. The results show the ESI-MS interface does not broaden bands, and ion dissociation in the mass spectrometer permits the unambiguous identification of fragments in cases where mass alone is insufficient. 2 refs., 2 figs. (MHB)

  11. Broadening the interface bandwidth in simulation based training

    NASA Technical Reports Server (NTRS)

    Somers, Larry E.

    1989-01-01

    Currently most computer based simulations rely exclusively on computer generated graphics to create the simulation. When training is involved, the method almost exclusively used to display information to the learner is text displayed on the cathode ray tube. MICROEXPERT Systems is concentrating on broadening the communications bandwidth between the computer and user by employing a novel approach to video image storage combined with sound and voice output. An expert system is used to combine and control the presentation of analog video, sound, and voice output with computer based graphics and text. Researchers are currently involved in the development of several graphics based user interfaces for NASA, the U.S. Army, and the U.S. Navy. Here, the focus is on the human factors considerations, software modules, and hardware components being used to develop these interfaces.

  12. Standard line broadening impact theory for hydrogen including penetrating collisions.

    PubMed

    Alexiou, S; Poquérusse, A

    2005-10-01

    In recent years there has been significant interest in the emission spectra from high-density plasmas, as manifested by a number of experiments. At these high densities short range (small impact parameter) interactions become important and these cannot be adequately handled by the standard theory, whose predictions depend on some cutoffs, necessary to preserve unitarity, the long range approximation, and to ensure the validity of a semiclassical picture. Very recently, as a result of a debate concerning the broadening of isolated ion lines, the importance of penetration of bound electron wave functions by plasma electrons has been realized. By softening the interaction, penetration makes perturbative treatments more valid. The penetration effect has now been included analytically into the standard theory. It turns out that the integrations may be done in closed form in terms of the modified Bessel functions K0 and K1. This work develops the new theory and applies it to experimental measurements. PMID:16383542

  13. Workshops Without Walls: broadening access to science around the world.

    PubMed

    Arslan, Betül K; Boyd, Eric S; Dolci, Wendy W; Dodson, K Estelle; Boldt, Marco S; Pilcher, Carl B

    2011-08-01

    The National Aeronautics and Space Administration (NASA) Astrobiology Institute (NAI) conducted two "Workshops Without Walls" during 2010 that enabled global scientific exchange--with no travel required. The second of these was on the topic "Molecular Paleontology and Resurrection: Rewinding the Tape of Life." Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel.

  14. Interpreting angina: symptoms along a gender continuum

    PubMed Central

    Crea-Arsenio, Mary; Shannon, Harry S; Velianou, James L; Giacomini, Mita

    2016-01-01

    Background ‘Typical’ angina is often used to describe symptoms common among men, while ‘atypical’ angina is used to describe symptoms common among women, despite a higher prevalence of angina among women. This discrepancy is a source of controversy in cardiac care among women. Objectives To redefine angina by (1) qualitatively comparing angina symptoms and experiences in women and men and (2) to propose a more meaningful construct of angina that integrates a more gender-centred approach. Methods Patients were recruited between July and December 2010 from a tertiary cardiac care centre and interviewed immediately prior to their first angiogram. Symptoms were explored through in-depth semi-structured interviews, transcribed verbatim and analysed concurrently using a modified grounded theory approach. Angiographically significant disease was assessed at ≥70% stenosis of a major epicardial vessel. Results Among 31 total patients, 13 men and 14 women had angiograpically significant CAD. Patients describe angina symptoms according to 6 symptomatic subthemes that array along a ‘gender continuum’. Gender-specific symptoms are anchored at each end of the continuum. At the centre of the continuum, are a remarkably large number of symptoms commonly expressed by both men and women. Conclusions The ‘gender continuum’ offers new insights into angina experiences of angiography candidates. Notably, there is more overlap of shared experiences between men and women than conventionally thought. The gender continuum can help researchers and clinicians contextualise patient symptom reports, avoiding the conventional ‘typical’ versus ‘atypical’ distinction that can misrepresent gendered angina experiences. PMID:27158523

  15. Implementation of on-the-fly doppler broadening in MCNP

    SciTech Connect

    Martin, W. R.; Wilderman, S.; Brown, F. B.; Yesilyurt, G.

    2013-07-01

    A new method to obtain Doppler broadened cross sections has been implemented into MCNP, removing the need to generate cross sections for isotopes at problem temperatures. When a neutron of energy E enters a material region that is at some temperature T, the cross sections for that material at temperature T are immediately obtained 'on-the-fly' (OTF) by interpolation using a high order functional expansion for the temperature dependence of the Doppler-broadened cross section for that isotope at the neutron energy E. The OTF cross sections agree with the NJOY-based cross sections for all neutron energies and all temperatures in the range specified by the user, e.g., 250 K - 3200 K. The OTF methodology has been successfully implemented into the MCNP Monte Carlo code and has been tested on several test problems by comparing MCNP with conventional ACE cross sections versus MCNP with OTF cross sections. The test problems include the Doppler defect reactivity benchmark suite and two full-core VHTR configurations, including one with multiphysics coupling using RELAP5-3D/ATHENA for the thermal-hydraulic analysis. The comparison has been excellent, verifying that the OTF libraries can be used in place of the conventional ACE libraries generated at problem temperatures. In addition, it has been found that the OTF methodology greatly reduces the complexity of the input for MCNP, resulting in an order of magnitude decrease in the number of input lines for full-core configurations. Finally, for full-core problems with multiphysics feedback, the memory required to store the cross section data is considerably reduced with OTF cross sections and the additional computational effort with OTF is modest, on the order of 10-15%. (authors)

  16. Continuum elastic modeling of graphene resonators.

    PubMed

    Atalaya, Juan; Isacsson, Andreas; Kinaret, Jari M

    2008-12-01

    Starting from an atomistic approach, we have derived a hierarchy of successively more simplified continuum elasticity descriptions for modeling the mechanical properties of suspended graphene sheets. We find that already for deflections of the order of 0.5 A a theory that correctly accounts for nonlinearities is necessary and that for many purposes a set of coupled Duffing-type equations may be used to accurately describe the dynamics of graphene membranes. The descriptions are validated by applying them to square graphene-based resonators with clamped edges and studying numerically their mechanical responses. Both static and dynamic responses are treated, and we find good agreement with recent experimental findings. PMID:19367927

  17. Continuum regularization of gauge theory with fermions

    SciTech Connect

    Chan, H.S.

    1987-03-01

    The continuum regularization program is discussed in the case of d-dimensional gauge theory coupled to fermions in an arbitrary representation. Two physically equivalent formulations are given. First, a Grassmann formulation is presented, which is based on the two-noise Langevin equations of Sakita, Ishikawa and Alfaro and Gavela. Second, a non-Grassmann formulation is obtained by regularized integration of the matter fields within the regularized Grassmann system. Explicit perturbation expansions are studied in both formulations, and considerable simplification is found in the integrated non-Grassmann formalism.

  18. Continuum description of avalanches in granular media.

    SciTech Connect

    Aranson, I. S.; Tsimring, L. S.

    2000-12-05

    A continuum theory of partially fluidized granular flows is proposed. The theory is based on a combination of the mass and momentum conservation equations with the order parameter equation which describes the transition between flowing and static components of the granular system. We apply this model to the dynamics of avalanches in chutes. The theory provides a quantitative description of recent observations of granular flows on rough inclined planes (Daerr and Douady 1999): layer bistability, and the transition from triangular avalanches propagating downhill at small inclination angles to balloon-shaped avalanches also propagating uphill for larger angles.

  19. Continuum modeling of clustering of myxobacteria

    PubMed Central

    Harvey, Cameron W.; Alber, Mark; Tsimring, Lev S.; Aranson, Igor S.

    2013-01-01

    In this paper we develop a continuum theory of clustering in ensembles of self-propelled inelastically colliding rods with applications to collective dynamics of common gliding bacteria Myxococcus Xanthus. A multiphase hydrodynamic model that couples densities of oriented and isotropic phases is described. This model is used for the analysis of an instability that leads to spontaneous formation of directionally moving dense clusters within initially dilute isotropic “gas” of myxobacteria. Numerical simulations of this model confirm the existence of stationary dense moving clusters and also elucidate the properties of their collisions. The results are shown to be in a qualitative agreement with experiments. PMID:23712128

  20. Continuum eigenmodes in some linear stellar models

    NASA Astrophysics Data System (ADS)

    Winfield, Christopher J.

    2016-10-01

    We apply parallel approaches in the study of continuous spectra to adiabatic stellar models. We seek continuum eigenmodes for the LAWE formulated as both finite difference and linear differential equations. In particular, we apply methods of Jacobi matrices and methods of subordinancy theory in these respective formulations. We find certain pressure-density conditions which admit positive-measured sets of continuous oscillation spectra under plausible conditions on density and pressure. We arrive at results of unbounded oscillations and computational or, perhaps, dynamic instability.

  1. Radiation from charges in the continuum limit

    SciTech Connect

    Ianconescu, Reuven

    2013-06-15

    It is known that an accelerating charge radiates according to Larmor formula. On the other hand, any DC current following a curvilinear path, consists of accelerating charges, but in such case the radiated power is 0. The scope of this paper is to analyze and quantify how a system of charges goes from a radiating state to a non radiating state when the charges distribution goes to the continuum limit. Understanding this is important from the theoretical point of view and the results of this work are applicable to particle accelerator, cyclotron and other high energy devices.

  2. Status of the Super B Factory Projects

    SciTech Connect

    Sangro, Riccardo de

    2010-08-05

    Two proposals have been presented for the construction of super high luminosity B factories, the SuperB in Italy and SuperKEKB in Japan. We review the physics case for the construction of such facilities in the LHC era and highlight several topics of hadronic physics that can benefit from the high luminosity they will integrate. The present status of the accelerator and detector work toward the Technical Design Reports is also presented.

  3. A CONTINUUM OF PLANET FORMATION BETWEEN 1 AND 4 EARTH RADII

    SciTech Connect

    Schlaufman, Kevin C.

    2015-02-01

    It has long been known that stars with high metallicity are more likely to host giant planets than stars with low metallicity. Yet the connection between host star metallicity and the properties of small planets is only just beginning to be investigated. It has recently been argued that the metallicity distribution of stars with exoplanet candidates identified by Kepler provides evidence for three distinct clusters of exoplanets, distinguished by planet radius boundaries at 1.7 R{sub ⨁} and 3.9 R{sub ⨁}. This would suggest that there are three distinct planet formation pathways for super-Earths, mini-Neptunes, and giant planets. However, as I show through three independent analyses, there is actually no evidence for the proposed radius boundary at 1.7 R{sub ⨁}. On the other hand, a more rigorous calculation demonstrates that a single, continuous relationship between planet radius and metallicity is a better fit to the data. The planet radius and metallicity data therefore provides no evidence for distinct categories of small planets. This suggests that the planet formation process in a typical protoplanetary disk produces a continuum of planet sizes between 1 R{sub ⨁} and 4 R{sub ⨁}. As a result, the currently available planet radius and metallicity data for solar-metallicity F and G stars give no reason to expect that the amount of solid material in a protoplanetary disk determines whether super-Earths or mini-Neptunes are formed.

  4. The continuum limit of aN-1(2) spin chains

    NASA Astrophysics Data System (ADS)

    Vernier, Eric; Jacobsen, Jesper Lykke; Saleur, Hubert

    2016-10-01

    Building on our previous work for a2(2) and a3(2) we explore systematically the continuum limit of gapless aN-1(2) vertex models and spin chains. We find the existence of three possible regimes. Regimes I and II for a2n-1(2) are related with a2n-1(2) Toda, and described by n compact bosons. Regime I for a2n(2) is related with a2n(2) Toda and involves n compact bosons, while regime II is related instead with B (1) (0 , n) super Toda, and involves in addition a single Majorana fermion. The most interesting is regime III, where non-compact degrees of freedom appear, generalising the emergence of the Euclidean black hole CFT in the a2(2) case. For a2n(2) we find a continuum limit made of n compact and n non-compact bosons, while for a2n-1(2) we find n compact and n - 1 non-compact bosons. We also find deep relations between aN-1(2) in regime III and the gauged WZW models SO (N) / SO (N - 1).

  5. Wall-collision line broadening of molecular oxygen within nanoporous materials

    SciTech Connect

    Xu, Can T.; Lewander, Maerta; Andersson-Engels, Stefan; Svensson, Tomas; Svanberg, Sune; Adolfsson, Erik

    2011-10-15

    Wall-collision broadening of near-infrared absorption lines of molecular oxygen confined in nanoporous zirconia is studied by employing high-resolution diode-laser spectroscopy. The broadening is studied for pores of different sizes under a range of pressures, providing new insights on how wall collisions and intermolecular collisions influence the total spectroscopic line profile. The pressure series show that wall-collision broadening is relatively more prominent under reduced pressures, enabling sensitive means to probe pore sizes of porous materials. In addition, we show that the total wall-collision-broadened profile strongly deviates from a Voigt profile and that wall-collision broadening exhibits an additive-like behavior to the pressure and Doppler broadening.

  6. Continuum robot arms inspired by cephalopods

    NASA Astrophysics Data System (ADS)

    Walker, Ian D.; Dawson, Darren M.; Flash, Tamar; Grasso, Frank W.; Hanlon, Roger T.; Hochner, Binyamin; Kier, William M.; Pagano, Christopher C.; Rahn, Christopher D.; Zhang, Qiming M.

    2005-05-01

    In this paper, we describe our recent results in the development of a new class of soft, continuous backbone ("continuum") robot manipulators. Our work is strongly motivated by the dexterous appendages found in cephalopods, particularly the arms and suckers of octopus, and the arms and tentacles of squid. Our ongoing investigation of these animals reveals interesting and unexpected functional aspects of their structure and behavior. The arrangement and dynamic operation of muscles and connective tissue observed in the arms of a variety of octopus species motivate the underlying design approach for our soft manipulators. These artificial manipulators feature biomimetic actuators, including artificial muscles based on both electro-active polymers (EAP) and pneumatic (McKibben) muscles. They feature a "clean" continuous backbone design, redundant degrees of freedom, and exhibit significant compliance that provides novel operational capacities during environmental interaction and object manipulation. The unusual compliance and redundant degrees of freedom provide strong potential for application to delicate tasks in cluttered and/or unstructured environments. Our aim is to endow these compliant robotic mechanisms with the diverse and dexterous grasping behavior observed in octopuses. To this end, we are conducting fundamental research into the manipulation tactics, sensory biology, and neural control of octopuses. This work in turn leads to novel approaches to motion planning and operator interfaces for the robots. The paper describes the above efforts, along with the results of our development of a series of continuum tentacle-like robots, demonstrating the unique abilities of biologically-inspired design.

  7. Measurements of Continuum Flux in Solar Flares

    NASA Astrophysics Data System (ADS)

    Kotrč, P.; Heinzel, P.; Procházka, O.

    2016-04-01

    A broad-band diagnostics of chromospheric flare plasma needs to analyze spectra covering many spectral lines and various continuum features. The flare spectra are well detected on the background of the solar disk, but the detection of flare line emission from the Sun-as-a-star in optical is much more difficult due to a strong background radiation. When the flare/background radiation contrast is strong enough to be detected, we need a device for measuring the flux from a selected part of the flaring region. Here we present technical demands for such an instrument and its brief description. This device denoted as Image Selector is a post-focus instrument installed at the horizontal solar telescope HSFA2 of the Ondřejov observatory, described by Kotrč (2009). Its core consists of a system of diaphragms, imaging Hα telescope and a fast spectrometer with dispersion of 3 px per Å but with cadency reaching up to 50 frames per second. The first solar flares observed recently by this novel technique provide quite interesting results. Our analysis of the data proves that the described device is sufficiently sensitive to detect variations in the Balmer continuum during solar flares.

  8. Atomistic to continuum modeling of solidification microstructures

    SciTech Connect

    Karma, Alain; Tourret, Damien

    2015-09-26

    We summarize recent advances in modeling of solidification microstructures using computational methods that bridge atomistic to continuum scales. We first discuss progress in atomistic modeling of equilibrium and non-equilibrium solid–liquid interface properties influencing microstructure formation, as well as interface coalescence phenomena influencing the late stages of solidification. The latter is relevant in the context of hot tearing reviewed in the article by M. Rappaz in this issue. We then discuss progress to model microstructures on a continuum scale using phase-field methods. We focus on selected examples in which modeling of 3D cellular and dendritic microstructures has been directly linked to experimental observations. Finally, we discuss a recently introduced coarse-grained dendritic needle network approach to simulate the formation of well-developed dendritic microstructures. The approach reliably bridges the well-separated scales traditionally simulated by phase-field and grain structure models, hence opening new avenues for quantitative modeling of complex intra- and inter-grain dynamical interactions on a grain scale.

  9. Accurate Molecular Polarizabilities Based on Continuum Electrostatics

    PubMed Central

    Truchon, Jean-François; Nicholls, Anthony; Iftimie, Radu I.; Roux, Benoît; Bayly, Christopher I.

    2013-01-01

    A novel approach for representing the intramolecular polarizability as a continuum dielectric is introduced to account for molecular electronic polarization. It is shown, using a finite-difference solution to the Poisson equation, that the Electronic Polarization from Internal Continuum (EPIC) model yields accurate gas-phase molecular polarizability tensors for a test set of 98 challenging molecules composed of heteroaromatics, alkanes and diatomics. The electronic polarization originates from a high intramolecular dielectric that produces polarizabilities consistent with B3LYP/aug-cc-pVTZ and experimental values when surrounded by vacuum dielectric. In contrast to other approaches to model electronic polarization, this simple model avoids the polarizability catastrophe and accurately calculates molecular anisotropy with the use of very few fitted parameters and without resorting to auxiliary sites or anisotropic atomic centers. On average, the unsigned error in the average polarizability and anisotropy compared to B3LYP are 2% and 5%, respectively. The correlation between the polarizability components from B3LYP and this approach lead to a R2 of 0.990 and a slope of 0.999. Even the F2 anisotropy, shown to be a difficult case for existing polarizability models, can be reproduced within 2% error. In addition to providing new parameters for a rapid method directly applicable to the calculation of polarizabilities, this work extends the widely used Poisson equation to areas where accurate molecular polarizabilities matter. PMID:23646034

  10. Atomistic to continuum modeling of solidification microstructures

    DOE PAGES

    Karma, Alain; Tourret, Damien

    2015-09-26

    We summarize recent advances in modeling of solidification microstructures using computational methods that bridge atomistic to continuum scales. We first discuss progress in atomistic modeling of equilibrium and non-equilibrium solid–liquid interface properties influencing microstructure formation, as well as interface coalescence phenomena influencing the late stages of solidification. The latter is relevant in the context of hot tearing reviewed in the article by M. Rappaz in this issue. We then discuss progress to model microstructures on a continuum scale using phase-field methods. We focus on selected examples in which modeling of 3D cellular and dendritic microstructures has been directly linked tomore » experimental observations. Finally, we discuss a recently introduced coarse-grained dendritic needle network approach to simulate the formation of well-developed dendritic microstructures. The approach reliably bridges the well-separated scales traditionally simulated by phase-field and grain structure models, hence opening new avenues for quantitative modeling of complex intra- and inter-grain dynamical interactions on a grain scale.« less

  11. Polarized Continuum Radiation from Stellar Atmospheres

    NASA Astrophysics Data System (ADS)

    Harrington, J. Patrick

    2015-10-01

    Continuum scattering by free electrons can be significant in early type stars, while in late type stars Rayleigh scattering by hydrogen atoms or molecules may be important. Computer programs used to construct models of stellar atmospheres generally treat the scattering of the continuum radiation as isotropic and unpolarized, but this scattering has a dipole angular dependence and will produce polarization. We review an accurate method for evaluating the polarization and limb darkening of the radiation from model stellar atmospheres. We use this method to obtain results for: (i) Late type stars, based on the MARCS code models (Gustafsson et al. 2008), and (ii) Early type stars, based on the NLTE code TLUSTY (Lanz and Hubeny 2003). These results are tabulated at http://www.astro.umd.edu/~jph/Stellar_Polarization.html. While the net polarization vanishes for an unresolved spherical star, this symmetry is broken by rapid rotation or by the masking of part of the star by a binary companion or during the transit of an exoplanet. We give some numerical results for these last cases.

  12. The Urban Watershed Continuum: Biogeochemistry of Carbon

    NASA Astrophysics Data System (ADS)

    Kaushal, S.; Belt, K.; Smith, C.; Newcomb, K.; Newcomer, T. A.; Smith, R.; Duan, S.; Findlay, S.; Groffman, P. M.; Mayer, P. M.

    2012-12-01

    Urban ecosystems are constantly evolving, and they are expected to change in both space and time. We explore the relationship between infrastructure and ecosystem function relevant to the inorganic and organic carbon cycle along urban watersheds across spatial and temporal dimensions. We provide examples from watersheds of the Baltimore Ecosystem Study Long-Term Ecological (LTER) and Washington D.C. Urban Long-Term Research Area (ULTRA EX) sites with varying land use and contrasting sanitary sewer systems. At a stream and river network scale, there are distinct longitudinal patterns in dissolved inorganic carbon, dissolved organic carbon, and particulate carbon concentrations from suburban headwaters to progressively urbanized receiving waters. There are also distinct changes in stable isotopic signatures of organic carbon and inorganic carbon suggesting shifts in carbon sources and processing throughout urban stream and river networks. Longitudinal patterns appear to be related to in-stream transformations, as suggested by high frequency sensor measurements, mass balances, and diurnal sampling. We suggest that stream and river networks act as "transformers" of watershed nitrogen and phosphorus pollution to increasingly generate carbon throughout the urban watershed continuum via biological processes. Additionally, sources and quality of carbon may vary with watershed inputs from suburban headwaters to progressively urbanized downstream reaches. The role of the urban watershed continuum as a "transporter" and "transformer" of organic matter has important implications for anticipating changes in the forms and reactivity of carbon delivered to receiving waters and coastal zones.

  13. Ash Dispersal in Planetary Atmospheres: Continuum vs. Non-continuum Effects

    NASA Astrophysics Data System (ADS)

    Fagents, S. A.; Baloga, S. M.; Glaze, L. S.

    2013-12-01

    The dispersal of ash from a volcanic vent on any given planet is dictated by particle properties (density, shape, and size distribution), the intensity of the eruptive source, and the characteristics of the planetary environment (atmospheric structure, wind field, and gravity) into which the ash is erupted. Relating observations of potential pyroclastic deposits to source locations and eruption conditions requires a detailed quantitative understanding of the settling rates of individual particles under changing ambient conditions. For atmospheres that are well described by continuum mechanics, the conventional Newtonian description of particle motion allows particle settling velocities to be related to particle characteristics via a drag coefficient. However, under rarefied atmospheric conditions (i.e., on Mars and at high altitude on Earth), non-continuum effects become important for ash-sized particles, and an equation of motion based on statistical mechanics is required for calculating particle motion. We have developed a rigorous new treatment of particle settling under variable atmospheric conditions and applied it to Earth and Mars. When non-continuum effects are important (as dictated by the mean free path of atmospheric gas relative to the particle size), fall velocities are greater than those calculated by continuum mechanics. When continuum conditions (i.e., higher atmospheric densities) are reached during descent, our model switches to a conventional formulation that determines the appropriate drag coefficient as the particle transits varying atmospheric properties. The variation of settling velocity with altitude allows computation of particle trajectories, fall durations and downwind dispersal. Our theoretical and numerical analyses show that several key, competing factors strongly influence the downwind trajectories of ash particles and the extents of the resulting deposits. These factors include: the shape of the particles (non-spherical particles

  14. Notes on super Killing tensors

    NASA Astrophysics Data System (ADS)

    Howe, P. S.; Lindström, U.

    2016-03-01

    The notion of a Killing tensor is generalised to a superspace setting. Conserved quantities associated with these are defined for superparticles and Poisson brackets are used to define a supersymmetric version of the even Schouten-Nijenhuis bracket. Superconformal Killing tensors in flat superspaces are studied for spacetime dimensions 3,4,5,6 and 10. These tensors are also presented in analytic superspaces and super-twistor spaces for 3,4 and 6 dimensions. Algebraic structures associated with superconformal Killing tensors are also briefly discussed.

  15. SuperLU users' guide

    SciTech Connect

    Demmel, James W.; Gilbert, John R.; Li, Xiaoye S.

    1999-11-01

    This document describes a collection of three related ANSI C subroutine libraries for solving sparse linear systems of equations AX = B: Here A is a square, nonsingular, n x n sparse matrix, and X and B are dense n x nrhs matrices, where nrhs is the number of right-hand sides and solution vectors. Matrix A need not be symmetric or definite; indeed, SuperLU is particularly appropriate for matrices with very unsymmetric structure. All three libraries use variations of Gaussian elimination optimized to take advantage both of sparsity and the computer architecture, in particular memory hierarchies (caches) and parallelism.

  16. Super B Factory at KEK

    SciTech Connect

    Cheon, Byung Gu

    2008-11-23

    A Super--KEKB factory, an asymmetric--energy e{sup +}e{sup -} lepton collider at KEK in Japan, has been proposed with the design peak luminosity of 8x10{sup 35} cm{sup -2} s{sup -1}, which is about 50 times higher than that of the current operation of the KEKB collider. The physics goal of this project is mainly to measure extremely rare heavy flavor weak decays and CP violation phenomena, which are very sensitive on physics beyond the Standard Model. Hot physics topics and the status of experimental design are briefly described.

  17. Non-coherent continuum scattering as a line polarization mechanism

    SciTech Connect

    Del Pino Alemán, T.; Manso Sainz, R.; Trujillo Bueno, J. E-mail: rsainz@iac.es

    2014-03-20

    Line scattering polarization can be strongly affected by Rayleigh scattering at neutral hydrogen and Thomson scattering at free electrons. Often a depolarization of the continuum results, but the Doppler redistribution produced by the continuum scatterers, which are light (hence, fast), induces more complex interactions between the polarization in spectral lines and in the continuum. Here we formulate and solve the radiative transfer problem of scattering line polarization with non-coherent continuum scattering consistently. The problem is formulated within the spherical tensor representation of atomic and light polarization. The numerical method of solution is a generalization of the Accelerated Lambda Iteration that is applied to both the atomic system and the radiation field. We show that the redistribution of the spectral line radiation due to the non-coherence of the continuum scattering may modify the shape of the emergent fractional linear polarization patterns significantly, even yielding polarization signals above the continuum level in intrinsically unpolarizable lines.

  18. Air broadening coefficients for the ν3 band of hydroperoxyl radicals

    NASA Astrophysics Data System (ADS)

    Minamida, Maya; Tonokura, Kenichi

    2014-11-01

    Using mid-infrared laser absorption spectroscopy, we investigated the room-temperature pressure broadening coefficients for hydroperoxyl radicals (HO2) in nitrogen and oxygen over the 1060.0-1065.5 cm-1 range of the ν3 band. The HO2 radicals were produced by flash photolysis of a chlorine/1,4-cyclohexadiene/oxygen mixture. The 20 measured absorption profiles were analyzed with Voigt functions. Air broadening coefficients were estimated from the nitrogen- and oxygen-broadening results and compared with previous results. We discuss the dependence of air broadening on rotational states.

  19. Continuum capture in the three-body problem

    SciTech Connect

    Sellin, I A

    1980-01-01

    The three-body problem, especially the problem of electron capture to the continuum in heavy particle collisions is reviewed. Major topics covered include: second born-induced asymmetry in electron capture to the continuum; historical context, links to other tests of atomic scattering theory; experiments characterizing the velocity distribution of ECC electrons; other atomic physics tests of high velocity Born expansions; atom capture; capture by positrons; and pion capture to the continuum. (GHT)

  20. Angled Layers in Super Resolution

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Researchers used a special imaging technique with the panoramic camera on NASA's Mars Exploration Rover Opportunity to get as detailed a look as possible at a target region near eastern foot of 'Burns Cliff.' The intervening terrain was too difficult for driving the rover closer. The target is the boundary between two sections of layered rock. The layers in lower section (left) run at a marked angle to the layers in next higher section (right).

    This view is the product of a technique called super resolution. It was generated from data acquired on sol 288 of Opportunity's mission (Nov. 14, 2004) from a position along the southeast wall of 'Endurance Crater.' Resolution slightly higher than normal for the panoramic camera was synthesized for this view by combining 17 separate images of this scene, each one 'dithered' or pointed slightly differently from the previous one. Computer manipulation of the individual images was then used to generate a new synthetic view of the scene in a process known mathematically as iterative deconvolution, but referred to informally as super resolution. Similar methods have been used to enhance the resolution of images from the Mars Pathfinder mission and the Hubble Space Telescope.

  1. Broadening the Participation of Native Americans in Earth Science

    NASA Astrophysics Data System (ADS)

    Bueno Watts, Nievita

    Climate change is not a thing of the future. Indigenous people are being affected by climate changes now. Native American Earth scientists could help Native communities deal with both climate change and environmental pollution issues, but are noticeably lacking in Earth Science degree programs. The Earth Sciences produce the lowest percentage of minority scientists when compared with other science and engineering fields. Twenty semi-structured interviews were gathered from American Indian/ Alaska Native Earth Scientists and program directors who work directly with Native students to broaden participation in the field. Data was analyzed using qualitative methods and constant comparison analysis. Barriers Native students faced in this field are discussed, as well as supports which go the furthest in assisting achievement of higher education goals. Program directors give insight into building pathways and programs to encourage Native student participation and success in Earth Science degree programs. Factors which impede obtaining a college degree include financial barriers, pressures from familial obligations, and health issues. Factors which impede the decision to study Earth Science include unfamiliarity with geoscience as a field of study and career choice, the uninviting nature of Earth Science as a profession, and curriculum that is irrelevant to the practical needs of Native communities or courses which are inaccessible geographically. Factors which impede progress that are embedded in Earth Science programs include educational preparation, academic information and counseling and the prevalence of a Western scientific perspective to the exclusion of all other perspectives. Intradepartmental relationships also pose barriers to the success of some students, particularly those who are non-traditional students (53%) or women (80%). Factors which support degree completion include financial assistance, mentors and mentoring, and research experiences. Earth scientists

  2. N2-broadening coefficients of methyl chloride at room temperature

    NASA Astrophysics Data System (ADS)

    Bray, C.; Jacquemart, D.; Buldyreva, J.; Lacome, N.; Perrin, A.

    2012-07-01

    Methyl chloride is of interest for atmospheric applications, since this molecule is directly involved in the catalytic destruction of ozone in the lower stratosphere. In a previous work [Bray et al. JQSRT 2011;112:2446], lines positions and intensities of self-perturbed 12CH335Cl and 12CH337Cl have been studied into details for the 3.4 μm spectral region. The present work is focused on measurement and calculation of N2-broadening coefficients of the 12CH335Cl and 12CH337Cl isotopologues. High-resolution Fourier Transform spectra of CH3Cl-N2 mixtures at room-temperature have been recorded between 2800 and 3200 cm-1 at LADIR (using a classical source) and between 47 and 59 cm-1 at SOLEIL (using the synchrotron source on the AILES beamline). 612 mid-infrared transitions of the ν1 band and 86 far-infrared transitions of the pure rotational band have been analyzed using a multispectrum fitting procedure. Average accuracy on the deduced N2-broadening coefficients has been estimated to 5% and 10% in the mid- and far-infrared spectral regions, respectively. The J- and K-rotational dependences of these coefficients have been observed in the mid-infrared region and then a simulation has been performed using an empirical model for 0≤J≤50, K≤9. The 12CH335Cl-N2 line widths for 0≤J≤50 and K≤10 of the ν1 band and for 55≤J≤67 and K≤15 of the pure rotational band have been computed using a semi-classical approach involving exact trajectories and a real symmetric-top geometry of the active molecule. Finally, a global comparison with the experimental and theoretical data existing in the literature has been performed. Similar J- and K-rotational dependences have been appeared while no clear evidence for any vibrational or isotopic dependences have been pointed out.

  3. Continuum and line emission in Cygnus A

    NASA Astrophysics Data System (ADS)

    Stockton, Alan; Ridgway, Susan E.; Lilly, Simon J.

    1994-08-01

    We present the results from (1) imaging observations of Cygnus A in five essentially line-free continuum bands with central wavelengths ranging from 0.34 to 2.1 microns. (2) imaging observations in five narrowband filters centered on the emission lines H beta(O III) lambda5007, H alpha(N II) lambda6583, and (S II) lambda lambda6716, 6731, and (3) deep spectroscopy covering the entire central region of Cyg A. We confirm that the featureless spectrum component is to be identified with the prominent double morphology at the center of Cyg A, but uncertainties in the distribution of the dust in this region tend to limit the accuracy with which we can determine its morphology and spectral-energy distribution (SED). From regions that appear to be least affected by obscuration, we find fv is approximately v-0.1 for this component. This SED could be consistent with free-free emission, a population of young stars, or a quasar continuum scattered by electrons, but probably not with a quasar continuum scattered by dust, which would be bluer. Our spectroscopy places an upper limit on the equivalent width of broad H beta that is well below that of typical quasars, showing that this flat-spectrum component (FSC) is almost certainly not dominated by scattered quasar radiation. Appeals to scattering by hot electrons to smear the scattered broad lines into invisibility appear to fail because the large density scale height of the electrons and the inefficiency of electron scattering should result in smoother and more extensive structure than we observe. Although the relative SED is consistent with free-free emission, the required amount of hot gas violates other observational constraints. At high angular resolution, the apparent morphology of the FSC is spiral-like. Although this impression may be partly due to obscuration, the distribution of the dust itself only serves to reinforce the spiral-like nature of the material with which it is associated. We conclude that the FSC is most

  4. SuperPILOT: Between Student and Teacher.

    ERIC Educational Resources Information Center

    Pattison, Linda J.

    1984-01-01

    Apple's SuperPILOT is an authoring language that allows teachers to easily and quickly create effective programs for classroom use. SuperPILOT features (such as turtle graphics routines) and commands are described. Several sample program listings (including one for a tutorial on the periodic table) are presented. (JN)

  5. The quest for ultimate super resolution

    NASA Astrophysics Data System (ADS)

    Hemmer, Philip; Ben-Benjamin, Jonathan Samuel

    2016-09-01

    With the wealth of super-resolution techniques available in the literature it is useful to provide a succinct review of the general concepts involved in the different schemes. In this paper we group super-resolution schemes into several broad categories to simplify comparison, and to elucidate the factors limiting their respective resolutions.

  6. Contributions from the SuperKamiokande Collaboration

    SciTech Connect

    Wilkes, R.J.; Fukuda, Y.; Inoue, K.

    1995-09-01

    This document consists of two reports contributed to the XXIV International Cosmic Ray Conference (Rome, Italy, August 28--September 8, 1995) from the SuperKamiokande Collaboration: one on the SuperKamiokande outer data acquisition system, and one on preliminary results from muon/electron identification tests at KEK of IMB3-detector phototubes and electronics.

  7. Broadly continuously tunable slot waveguide quantum cascade lasers based on a continuum-to-continuum active region design

    SciTech Connect

    Meng, Bo; Zeng, Yong Quan; Liang, Guozhen; Hu, Xiao Nan; Rodriguez, Etienne; Wang, Qi Jie

    2015-09-14

    We report our progress in the development of broadly tunable single-mode slot waveguide quantum cascade lasers based on a continuum-to-continuum active region design. The electroluminescence spectrum of the continuum-to-continuum active region design has a full width at half maximum of 440 cm{sup −1} at center wavelength ∼10 μm at room temperature (300 K). Devices using the optimized slot waveguide structure and the continuum-to-continuum design can be tuned continuously with a lasing emission over 42 cm{sup −1}, from 9.74 to 10.16 μm, at room temperature by using only current tuning scheme, together with a side mode suppression ratio of above 15 dB within the whole tuning range.

  8. Ending Aging in Super Glassy Polymer Membranes

    SciTech Connect

    Lau, CH; Nguyen, PT; Hill, MR; Thornton, AW; Konstas, K; Doherty, CM; Mulder, RJ; Bourgeois, L; Liu, ACY; Sprouster, DJ; Sullivan, JP; Bastow, TJ; Hill, AJ; Gin, DL; Noble, RD

    2014-04-16

    Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N-2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.

  9. Kuiper belt structure around nearby super-Earth host stars

    NASA Astrophysics Data System (ADS)

    Kennedy, Grant M.; Matrà, Luca; Marmier, Maxime; Greaves, Jane S.; Wyatt, Mark C.; Bryden, Geoffrey; Holland, Wayne; Lovis, Christophe; Matthews, Brenda C.; Pepe, Francesco; Sibthorpe, Bruce; Udry, Stéphane

    2015-05-01

    We present new observations of the Kuiper belt analogues around HD 38858 and HD 20794, hosts of super-Earth mass planets within 1 au. As two of the four nearby G-type stars (with HD 69830 and 61 Vir) that form the basis of a possible correlation between low-mass planets and debris disc brightness, these systems are of particular interest. The disc around HD 38858 is well resolved with Herschel and we constrain the disc geometry and radial structure. We also present a probable James Clerk Maxwell Telescope sub-mm continuum detection of the disc and a CO J = 2-1 upper limit. The disc around HD 20794 is much fainter and appears marginally resolved with Herschel, and is constrained to be less extended than the discs around 61 Vir and HD 38858. We also set limits on the radial location of hot dust recently detected around HD 20794 with near-IR interferometry. We present High Accuracy Radial velocity Planet Searcher upper limits on unseen planets in these four systems, ruling out additional super-Earths within a few au, and Saturn-mass planets within 10 au. We consider the disc structure in the three systems with Kuiper belt analogues (HD 69830 has only a warm dust detection), concluding that 61 Vir and HD 38858 have greater radial disc extent than HD 20794. We speculate that the greater width is related to the greater minimum planet masses (10-20 M⊕ versus 3-5 M⊕), arising from an eccentric planetesimal population analogous to the Solar system's scattered disc. We discuss alternative scenarios and possible means to distinguish among them.

  10. The hurricane-flood-landslide continuum

    USGS Publications Warehouse

    Negri, A.J.; Burkardt, N.; Golden, J.H.; Halverson, J.B.; Huffman, G.J.; Larsen, M.C.; McGinley, J.A.; Updike, R.G.; Verdin, J.P.; Wieczorek, G.F.

    2005-01-01

    In August 2004, representatives from NOAA, NASA, the US Geological Survey (USGS), as well as other government agencies and academic institutions convened in San Juan, Puerto Rico, at a workshop to discuss a proposed research project called the Hurricane-Flood-Landslide Continuum (HFLC). The purpose of the HFLC is to develop and integrate the multidisciplinary tools needed to issue regional guidance products for floods and landslide associated with major tropical rain systems with sufficient lead time that local emergency managers can notify vulnerable populations and protect infrastructure. The workshop sought to initiate discussion among these agencies about their highly complementary capabilities, and to establish a framework to leverage the strengths of each agency. Once a prototype system is developed, it could be adapted for use in regions that have a high frequency of tropical disturbances.

  11. Human Mobility in a Continuum Approach

    PubMed Central

    Simini, Filippo; Maritan, Amos; Néda, Zoltán

    2013-01-01

    Human mobility is investigated using a continuum approach that allows to calculate the probability to observe a trip to any arbitrary region, and the fluxes between any two regions. The considered description offers a general and unified framework, in which previously proposed mobility models like the gravity model, the intervening opportunities model, and the recently introduced radiation model are naturally resulting as special cases. A new form of radiation model is derived and its validity is investigated using observational data offered by commuting trips obtained from the United States census data set, and the mobility fluxes extracted from mobile phone data collected in a western European country. The new modeling paradigm offered by this description suggests that the complex topological features observed in large mobility and transportation networks may be the result of a simple stochastic process taking place on an inhomogeneous landscape. PMID:23555885

  12. Continuum dynamics of elastocapillary coalescence and arrest

    NASA Astrophysics Data System (ADS)

    Wei, Z.; Mahadevan, L.

    2014-04-01

    The surface-tension-driven coalescence of wet hair, nano-pillars and supported lamellae immersed in an evaporating liquid is eventually arrested elastically. To characterize this at a continuum level, we start from a discrete microscopic model of the process and derive a mesoscopic theory that couples the inhomogeneous dynamics of drying to the capillary forcing and elastic bending of the lamellae. Numerical simulations of the resulting partial differential equation capture the primary unstable mode seen in experiments, and the dynamic coalescence of the lamellae into dimers and quadrimers. Our theory also predicts the elastic arrest of the pattern or the separation of lamellar bundles into their constituents as a function of the amount of liquid left at the end of the process.

  13. Continuum mechanics, stresses, currents and electrodynamics.

    PubMed

    Segev, Reuven

    2016-04-28

    The Eulerian approach to continuum mechanics does not make use of a body manifold. Rather, all fields considered are defined on the space, or the space-time, manifolds. Sections of some vector bundle represent generalized velocities which need not be associated with the motion of material points. Using the theories of de Rham currents and generalized sections of vector bundles, we formulate a weak theory of forces and stresses represented by vector-valued currents. Considering generalized velocities represented by differential forms and interpreting such a form as a generalized potential field, we present a weak formulation of pre-metric, p-form electrodynamics as a natural example of the foregoing theory. Finally, it is shown that the assumptions leading to p-form electrodynamics may be replaced by the condition that the force functional is continuous with respect to the flat topology of forms.

  14. The evolution of the quasar continuum

    NASA Technical Reports Server (NTRS)

    Elvis, M.

    1992-01-01

    We now have in hand a large data base of Roentgen Satellite (ROSAT), optical, and IR complementary data. We are in the process of obtaining a large amount of the International Ultraviolet Explorer (IUE) data for the same quasar sample. For our complementary sample at high redshifts, where the UV was redshifted into the optical, we have just had approved large amounts of observing time to cover the quasar continuum in the near-IR using the new Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) array spectrographs. Ten micron, optical, and VLA radio, data also have approved time. An ISO US key program was approved to extend this work into the far-IR, and the launch of ASTRO-D (early in 1993) promises to extend it to higher energy X-rays.

  15. Floquet bound states in the continuum

    NASA Astrophysics Data System (ADS)

    Longhi, Stefano; Della Valle, Giuseppe

    2013-07-01

    Quantum mechanics predicts that certain stationary potentials can sustain bound states with an energy buried in the continuous spectrum of scattered states, the so-called bound states in the continuum (BIC). Originally regarded as mathematical curiosities, BIC have found an increasing interest in recent years, particularly in quantum and classical transport of matter and optical waves in mesoscopic and photonic systems where the underlying potential can be judiciously tailored. Most of our knowledge of BIC is so far restricted to static potentials. Here we introduce a new kind of BIC, referred to as Floquet BIC, which corresponds to a normalizable Floquet state of a time-periodic Hamiltonian with a quasienergy embedded into the spectrum of Floquet scattered states. We discuss the appearance of Floquet BIC states in a tight-binding lattice model driven by an ac field in the proximity of the dynamic localization regime.

  16. Polymer quantum mechanics and its continuum limit

    SciTech Connect

    Corichi, Alejandro; Vukasinac, Tatjana; Zapata, Jose A.

    2007-08-15

    A rather nonstandard quantum representation of the canonical commutation relations of quantum mechanics systems, known as the polymer representation, has gained some attention in recent years, due to its possible relation with Planck scale physics. In particular, this approach has been followed in a symmetric sector of loop quantum gravity known as loop quantum cosmology. Here we explore different aspects of the relation between the ordinary Schroedinger theory and the polymer description. The paper has two parts. In the first one, we derive the polymer quantum mechanics starting from the ordinary Schroedinger theory and show that the polymer description arises as an appropriate limit. In the second part we consider the continuum limit of this theory, namely, the reverse process in which one starts from the discrete theory and tries to recover back the ordinary Schroedinger quantum mechanics. We consider several examples of interest, including the harmonic oscillator, the free particle, and a simple cosmological model.

  17. Floquet bound states in the continuum

    PubMed Central

    Longhi, Stefano; Valle, Giuseppe Della

    2013-01-01

    Quantum mechanics predicts that certain stationary potentials can sustain bound states with an energy buried in the continuous spectrum of scattered states, the so-called bound states in the continuum (BIC). Originally regarded as mathematical curiosities, BIC have found an increasing interest in recent years, particularly in quantum and classical transport of matter and optical waves in mesoscopic and photonic systems where the underlying potential can be judiciously tailored. Most of our knowledge of BIC is so far restricted to static potentials. Here we introduce a new kind of BIC, referred to as Floquet BIC, which corresponds to a normalizable Floquet state of a time-periodic Hamiltonian with a quasienergy embedded into the spectrum of Floquet scattered states. We discuss the appearance of Floquet BIC states in a tight-binding lattice model driven by an ac field in the proximity of the dynamic localization regime. PMID:23860625

  18. Developments and trends in continuum plasticity

    NASA Astrophysics Data System (ADS)

    Becker, Richard

    2002-05-01

    Multiscale modeling applied to meso and macro scale continuum calculations is a broad field with a long history. It encompasses hardening relations based on dislocation density, porosity related ductile failure models, crystal plasticity, composite media and numerous other general topics dating back more than half a century. There are also a myriad of more recent activities that can be grouped under this subject heading. Emphasis will be placed on efforts described at the Bodega Bay workshop aimed at bridging length scales rather than focusing on model developments at any particular length scale. Also, areas will be highlighted where additional connections should be possible with available tools; methods exist but need to be exercised; and critical experiments are needed for validation.

  19. A nonlocal continuum model for biological aggregation.

    PubMed

    Topaz, Chad M; Bertozzi, Andrea L; Lewis, Mark A

    2006-10-01

    We construct a continuum model for biological aggregations in which individuals experience long-range social attraction and short-range dispersal. For the case of one spatial dimension, we study the steady states analytically and numerically. There exist strongly nonlinear states with compact support and steep edges that correspond to localized biological aggregations, or clumps. These steady-state clumps are reached through a dynamic coarsening process. In the limit of large population size, the clumps approach a constant density swarm with abrupt edges. We use energy arguments to understand the nonlinear selection of clump solutions, and to predict the internal density in the large population limit. The energy result holds in higher dimensions as well, and is demonstrated via numerical simulations in two dimensions.

  20. Continuum mechanics, stresses, currents and electrodynamics.

    PubMed

    Segev, Reuven

    2016-04-28

    The Eulerian approach to continuum mechanics does not make use of a body manifold. Rather, all fields considered are defined on the space, or the space-time, manifolds. Sections of some vector bundle represent generalized velocities which need not be associated with the motion of material points. Using the theories of de Rham currents and generalized sections of vector bundles, we formulate a weak theory of forces and stresses represented by vector-valued currents. Considering generalized velocities represented by differential forms and interpreting such a form as a generalized potential field, we present a weak formulation of pre-metric, p-form electrodynamics as a natural example of the foregoing theory. Finally, it is shown that the assumptions leading to p-form electrodynamics may be replaced by the condition that the force functional is continuous with respect to the flat topology of forms. PMID:27002071

  1. Space-time as a deformable continuum

    NASA Astrophysics Data System (ADS)

    Tartaglia, A.; Radicella, N.

    2010-04-01

    Space-time may be thought of as a physical continuum endowed with properties similar to the ones of material threedimensional continua. In this view a non-trivial metric tensor can be considered to be the sum of the Minkowski metric plus an appropriate strain tensor. The global symmetry of the universe can be seen as the effect of a spontaneous strained state due to the presence of a texture defect. Consistently with this approach the Lagrangian of space time is obtained adding to the scalar curvature, acting as a kinetic term, a potential term depending on the strain and modeled on the one of the elasticity theory, extended to four dimensions. The theory is applied to the fit of the luminosity dependence of type Ia supernovae on the redshift. A result is obtained slightly better than the one of the ΛCDM theory.

  2. Assessing and broadening genetic diversity of a rapeseed germplasm collection.

    PubMed

    Wu, Jinfeng; Li, Feng; Xu, Kun; Gao, Guizhen; Chen, Biyun; Yan, Guixin; Wang, Nian; Qiao, Jiangwei; Li, Jun; Li, Hao; Zhang, Tianyao; Song, Weiling; Wu, Xiaoming

    2014-12-01

    Assessing the level of genetic diversity within a germplasm collection contributes to evaluating the potential for its utilization as a gene pool to improve the performance of cultivars. In this study, 45 high-quality simple sequence repeat (SSR) markers were screened and used to estimate the genetic base of a world-wide collection of 248 rapeseed (Brassica napus) inbred lines. For the whole collection, the genetic diversity of A genome was higher than that of C genome. The genetic diversity of C genome for the semi-winter type was the lowest among the different germplasm types. Because B. oleracea is usually used to broaden the genetic diversity of C genome in rapeseed, we evaluated the potential of 25 wild B. oleracea lines. More allelic variations and a higher genetic diversity were observed in B. oleracea than in rapeseed. One B. oleracea line and one oilseed B. rapa line were used to generate a resynthesized Brassica napus line, which was then crossed with six semi-winter rapeseed cultivars to produce 7 F1 hybrids. Not only the allele introgression but also mutations were observed in the hybrids, resulting in significant improvement of the genetic base.

  3. Workshops without Walls: Broadening Access to Science around the World

    PubMed Central

    Arslan, Betül K.; Boyd, Eric S.; Dolci, Wendy W.; Dodson, K. Estelle; Boldt, Marco S.; Pilcher, Carl B.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Astrobiology Institute (NAI) conducted two “Workshops Without Walls” during 2010 that enabled global scientific exchange—with no travel required. The second of these was on the topic “Molecular Paleontology and Resurrection: Rewinding the Tape of Life.” Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel. PMID:21829326

  4. EFG Component Distribution Functions in Inhomogeneous Broadening in PAC Spectroscopy

    NASA Astrophysics Data System (ADS)

    Adams, Mike; Matheson, P.; Evenson, W. E.; Zacate, M. O.

    2010-10-01

    Perturbed Angular Correlation (PAC) spectroscopy is used to study the distribution and mobility of defects within crystals. The angular correlation of multiple gamma rays emitted from probe nuclei, affected by the net electric field gradient (EFG) in a probe's vicinity, are used to produce the PAC spectrum, G2(t). The distribution of EFGs from many random defects in a crystal, results in inhomogeneous broadening (IHB) of G2(t). Our EFG component probability distribution functions are found by summing 20,000 net EFGs, each found from taking a random distribution of vacancies of a particular concentration, combined with a single trapped vacancy in a near neighbor position to a probe nucleus. The derived EFG component distributions allow us to reconstruct the G2(t) as a function of defection concentration. The EFG component distribution functions are characterized by weighted sums of either Gamma, Lorenztian or Gaussian distributions. A systematic change in the type and number of distribution functions required to model IHB is apparent as defect concentration increases. In particular, the EFG distributions become increasingly skewed with increasing defect concentration. Results for the EFG components in simple cubic (SC), face-centered cubic (FCC) and body-centered cubic (BCC) lattices are presented.

  5. Mass transfer kinetics, band broadening and column efficiency.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2012-01-20

    Important progress was recently made in our understanding of the physico-chemical aspects of mass transfer kinetics in chromatographic columns, in methods used for accurate determination of the different contributions to the height equivalent to a theoretical plate (HETP), and in the application of these advances to the elucidation of mass transfer mechanisms in columns packed with recent chromatographic supports (sub-2 μm fully porous particles, sub-3 μm core-shell particles, and monoliths). The independent contributions to the HETP are longitudinal diffusion, eddy dispersion, liquid-solid mass transfer (including trans-particle or trans-skeleton mass transfer and external film mass transfer), and the contributions caused by the thermal heterogeneity of the column. The origin and importance of these contributions are investigated in depth. This work underlines the areas in which improvements are needed, an understanding of the contribution of the external film mass transfer term, a better design of HPLC instruments providing a decrease of the extra-column band broadening contributions to the apparent HETP, the development of better packing procedures giving more radially homogeneous column beds, and new packing materials having a higher thermal conductivity to eliminate the nefarious impact of heat effects in very high pressure liquid chromatography (vHPLC) and supercritical fluid chromatography (SFC).

  6. Magnetic field measurements of ɛ Eridani from Zeeman broadening

    NASA Astrophysics Data System (ADS)

    Lehmann, L. T.; Künstler, A.; Carroll, T. A.

    2015-04-01

    We present new magnetic field measurements of the K2 main-sequence star ɛ Eri based on principal components analysis (PCA) line-profile reconstructions. The aim of this paper is to quantify the surface-averaged magnetic field and search for possible variations. A total of 338 optical échelle spectra from our robotic telescope facility STELLA with a spectral resolution of 55 000 were available for analysis. This time-series was used to search for the small line-profile variations due to a surface magnetic field with the help of a PCA. Evidence for a spatial and temporal inhomogeneous magnetic field distribution is presented. The mean, surface averaged, magnetic field strength was found to be < B > = 186 ± 47 G in good agreement with previous Zeeman-broadening measurements. Clear short-term variations of the surface averaged magnetic field of up to few tens Gauss were detected together with evidence for a three-year cycle in the surface-averaged magnetic field of ɛ Eri. Based on data obtained with the STELLA robotic telescopes in Tenerife, an AIP facility jointly operated with IAC.

  7. Broadening Participation: Mentoring Community College Students in a Geoscience REU

    NASA Astrophysics Data System (ADS)

    Smith, M.; Osborn, J.

    2015-12-01

    Increasingly, REUs are recruiting from community colleges as a means of broadening participation of underrepresented minorities, women, and low-income students in STEM. As inclusion of community college students becomes normalized, defining the role of science faculty and preparing them to serve as mentors to community college students is a key component of well-designed programs. This session will present empirical research regarding faculty mentoring in the first two years of an NSF-REU grant to support community college students in a university's earth and environmental science labs. Given the documented benefits of undergraduate research on students' integration into the scientific community and their career trajectory in STEM, the focus of the investigation has been on the processes and impact of mentoring community college STEM researchers at a university serving a more traditionally privileged population; the degree to which the mentoring relationships have addressed community college students needs including their emotional, cultural and resource needs; and gaps in mentor training and the mentoring relationship identified by mentors and students.

  8. Multimode instabilities in a homogeneously broadened ring laser

    SciTech Connect

    Lugiato, L.A.; Narducci, L.M.; Eschenazi, E.V.; Bandy, D.K.; Abraham, N.B.

    1985-09-01

    This paper contains a description of the behavior of a multimode unidirectional ring laser with a homogeneously broadened active medium. Our formulation is based on the conventional Maxwell-Bloch (MB) equations, but is distinguished from other treatments by the inclusion of a finite mirror reflectivity and an arbitrary value of the gain parameter. We review the steady-state behavior of the system and analyze the longitudinal profile of the field and of the atomic variables. With an appropriate transformation of variables, we transform the boundary conditions of the ring cavity into standard periodicity type, even in the presence of a finite reflectivity, and derive an infinite hierarchy of coupled mode equations. We analyze exactly the linear stability of the system, and investigate the dependence of the instability domain on the reflectivity and gain parameters. A numerical study of the full MB equations for a parameter range of the type explored in the recent experiments by Hillman et al. (Phys. Rev. Lett. 52, 1605 (1984)) reveals similarities, but also considerable differences between the results of the theory and the main experimental signatures of their instability. However, the injection of numerical noise shows the presence of numerous coexisting basins of attraction which are likely to play a significant role in the dynamics of a noisy laser.

  9. A Survey For Broadened CO Lines Toward Galactic Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Charles; Bieging, John H.; Rieke, George

    2016-01-01

    We performed molecular spectroscopy in 12CO J=2-1 with the Heinrich Hertz Submillimeter Telescope toward 50 Galactic supernova remnants as part of a systematic survey for broad molecular line regions indicative of interactions with molecular clouds. These observations revealed broad molecular lines toward nineteen remnants, including nine newly identified associations between molecular clouds and remnants. Morphology of the molecular emission suggests molecular shocks can arise at large separations from the remnants, consistent with a scenario where high-velocity ejecta from bipolar outflows or fast-moving knots shocks nearby molecular clouds. Also, broadened 12CO J=2-1 line emission should be detectable toward virtually all supernova remnant/molecular cloud interactions and, therefore, the total number of observed interactions is low. This result favors predictions that SN feedback plays little or no role in star formation over short timescales. In addition, we find no significant association between TeV gamma-ray sources and molecular cloud interactions, contrary to predictions that supernova remnant/molecular cloud interfaces are the primary venues for cosmic ray acceleration.

  10. Water Vapor Self-Continuum by Cavity Ring Down Spectroscopy in the 1.6 Micron Transparency Window

    NASA Astrophysics Data System (ADS)

    Campargue, Alain; Kassi, Samir; Mondelain, Didier

    2014-06-01

    Since its discovery one century ago, a deep and unresolved controversy remains on the nature of the water vapor continuum. Several interpretations are proposed: accumulated effect of the distant wings of many individual spectral lines, metastable or true bound water dimers, collision-induced absorption. The atmospheric science community has largely sidestepped this controversy, and has adopted a pragmatic approach: most radiative transfer codes used in climate modelling, numerical weather prediction and remote sensing use the MT_CKD model which is a semi-empirical formulation of the continuum The MT_CKD cross-sections were tuned to available observations in the mid-infrared but in the absence of experimental constraints, the extrapolated near infrared (NIR) values are much more hazardous. Due to the weakness of the broadband absorption signal to be measured, very few measurements of the water vapor continuum are available in the NIR windows especially for temperature conditions relevant for our atmosphere. This is in particular the case for the 1.6 μm window where the very few available measurements show a large disagreement. Here we present the first measurements of the water vapor self-continuum cross-sections in the 1.6 μm window by cavity ring down spectroscopy (CRDS). The pressure dependence of the absorption continuum was investigated during pressure cycles up to 12 Torr for selected wavenumber values. The continuum level is observed to deviate from the expected quadratic dependence with pressure. This deviation is interpreted as due to a significant contribution of water adsorbed on the super mirrors to the cavity loss rate. The pressure dependence is well reproduced by a second order polynomial. We interpret the linear and quadratic terms as the adsorbed water and vapour water contribution, respectively. The derived self-continuum cross sections, measured between 5875 and 6450 wn, shows a minimum value around 6300 wn. These cross sections will be compared

  11. A Threshold Continuum for Aeolian Sand Transport

    NASA Astrophysics Data System (ADS)

    Swann, C.; Ewing, R. C.; Sherman, D. J.

    2015-12-01

    The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

  12. Continuum beliefs about psychotic symptoms are a valid, unidimensional construct: Construction and validation of a revised continuum beliefs questionnaire.

    PubMed

    Schlier, Björn; Scheunemann, Jakob; Lincoln, Tania M

    2016-07-30

    Growing evidence supports a continuum model of psychosis, with mild psychotic symptoms being frequently experienced by the general population. Moreover, believing in the continuum model correlates with less stigmatization of schizophrenia. This study explores whether continuum beliefs are a valid construct and develops a continuum beliefs scale. First, expert-generated items were reduced to a candidate scale (study 1, n=95). One-dimensionality was tested using confirmatory factor analysis (study 2, n=363). Convergent validity was tested with a previous continuum beliefs scale, essentialist beliefs, and stigmatization (study 2), while self-reported psychotic experiences (i.e. frequency and conviction) served to test discriminant validity (study 3, n=229). A nine item questionnaire that assesses continuum beliefs about schizophrenia symptoms showed acceptable to good psychometric values, high correlations with a previous continuum beliefs scale and small correlations with essentialist beliefs, stereotypes, and desired social distance. No correlations with psychotic experiences were found. Thus, continuum beliefs can be considered a valid construct. The construed CBQ-R asks about symptoms rather than the abstract category "schizophrenia", which may increase understandability of the scale. Validation confirms previous studies and highlights the difference between continuum beliefs and personal psychotic experiences. PMID:27175910

  13. Gas Temperature Determination in Argon-Helium Plasma at Atmospheric Pressure using van der Waals Broadening

    SciTech Connect

    Munoz, Jose; Yubero, Cristina; Calzada, Maria Dolores; Dimitrijevic, Milan S.

    2008-10-22

    The use of the van der Waals broadening of Ar atomic lines to determine the gas temperature in Ar-He plasmas, taking into account both argon and helium atoms as perturbers, has been analyzed. The values of the gas temperature inferred from this broadening have been compared with those obtained from the spectra of the OH molecular species in the discharge.

  14. The SuperCDMS Experiment

    SciTech Connect

    Schnee, Richard W.; Akerib, D.S.; Attisha, M.J.; Bailey, C.N.; Baudis, L.; Bauer, Daniel A.; Brink, P.L.; Brusov, P.P.; Bunker, R.; Cabrera, B.; Caldwell, D.O.; Chang, C.L.; Cooley, J.; Crisler, M.B.; Cushman, P.; Denes, P.; Dragowsky, M.R.; Duong, L.; Filippini, J.; Gaitskell, R.J.; Golwala, S.R.; /Case Western Reserve U. /Brown U. /Florida U. /Fermilab /Stanford U., Phys. Dept. /UC, Santa Barbara /Minnesota U. /LBL, Berkeley /UC, Berkeley /Caltech /Colorado U., Denver /NIST, Boulder /Santa Clara U.

    2005-02-01

    Modest improvements in the level and/or discrimination of backgrounds are needed to keep backgrounds negligible during the three phases of SuperCDMS. By developing production designs that require only modest testing, detector production rates may be improved sufficiently to allow an exposure of 500 ton d within a reasonable time and budget. Overall, the improvement estimates described above are conservative. Previous development efforts have shown that some areas prove easier and provide larger factors while others prove more difficult. The conservative estimates together with the broad approach reduce the risk and give us confidence that we will succeed, providing the surest way to probe to WIMP-nucleon cross sections of 10{sup -46} cm{sup 2}.

  15. Continuum Thinking and the Contexts of Personal Information Management

    ERIC Educational Resources Information Center

    Huvila, Isto; Eriksen, Jon; Häusner, Eva-Maria; Jansson, Ina-Maria

    2014-01-01

    Introduction: Recent personal information management literature has underlined the significance of the contextuality of personal information and its use. The present article discusses the applicability of the records continuum model and its generalisation, continuum thinking, as a theoretical framework for explicating the overlap and evolution of…

  16. PATHWAYS: A Continuum of Reading and Writing Skills.

    ERIC Educational Resources Information Center

    Lovett, Ollie M.

    Developed for use with the PATHWAYS ABE (Adult Basic Education) and Pre-GED (General Educational Development) Curriculum, a scope and sequence of reading and writing skills, or continuum, was designed with tasks of both educator and Indian Adult learner in mind. The continuum introduces individual skills at students' entry proficiency levels and…

  17. Teaching Continuum Mechanics in a Mechanical Engineering Program

    ERIC Educational Resources Information Center

    Liu, Yucheng

    2011-01-01

    This paper introduces a graduate course, continuum mechanics, which is designed for and taught to graduate students in a Mechanical Engineering (ME) program. The significance of continuum mechanics in engineering education is demonstrated and the course structure is described. Methods used in teaching this course such as topics, class…

  18. Curriculum Building for the Continuum in Social Welfare Education.

    ERIC Educational Resources Information Center

    Austin, Michael J., Ed.; And Others

    During 1970 Florida's University and Community College Systems held a workshop to discuss the idea of a curriculum continuum that would begin at the community college level and extend through the upper levels of graduate work. It was acknowledged that any continuum involving more than 1 level of education should include flexible opportunities for…

  19. Continuum of Counseling Goals: A Framework for Differentiating Counseling Strategies.

    ERIC Educational Resources Information Center

    Bruce, Paul

    1984-01-01

    Presents counseling goals in a developmental continuum similar in concept to Maslow's hierarchy of needs. Discusses ego development goals, socialization goals, developmental goals, self-esteem goals, and self-realization goals and describes characteristics and implications of the continuum. (JAC)

  20. A Behavioral Continuum: A Look at Personality Disorders.

    ERIC Educational Resources Information Center

    Harris, George; Kirk, Nancy A.

    1985-01-01

    Suggests that narcissistic, borderline, and antisocial personality disorders are not discrete diagnostic categories, but that they lie along a continuum and have in common the dimensions of degree of self-centeredness and degree of differentiation. Presents evidence supporting existence of continuum of behavior rather than discrete diagnostic…

  1. Finding probability distributions for electric field gradient components with inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Park, Tyler; Adams, Mike; Bunker, Austin; Hodges, Jeffery; Stufflebeam, Michael; Evenson, William; Matheson, Phil; Zacate, Matthew

    2009-10-01

    Materials contain defects, which affect crystal properties such as damping of the correlation signal,G2(t), in time and broadening of the frequency spectrum in perturbed angular correlation (PAC) experiments. We attribute this inhomogeneous broadening (IHB) to the random static defects that produce a distribution of electric field gradients (EFGs). Our goal is to find a relationship between the amount of broadening and the concentration of defects. After simulating the EFGs from random configurations of defects, we map our results from the Vzz-Vxx plane to a coordinate system optimized for the EFG distribution through a Czjzek transformation, followed by a conformal mapping. From histograms in this space, we can define probability distribution functions with parameters that vary according to defect concentration. This allows us to calculate the broadened G2(t) spectrum for any concentration, and, in reverse, identify concentrations given a broadened G2(t) spectrum.

  2. Correction of Doppler-broadened Rayleigh backscattering effects in H2O dial measurements

    NASA Technical Reports Server (NTRS)

    Ansmann, A.; Bosenberg, J.

    1986-01-01

    A general method of solutions for treating effects of Doppler-broadened Rayleigh backscattering in H2O Differential Absorption Lidar (DIAL) measurements are described and discussed. Errors in vertical DIAL measuremtns caused by this laser line broadening effect can be very large and, therfore, this effect has to be accounted for accurately. To analyze and correct effects of Doppler-broadened Rayleigh backscattering in DIAL experiments, a generalized DIAL approximation was derived starting from a lidar equation, which includes Doppler broadening. To evaluate the accuracy of H2O DIAL measurements, computer simulations were performed. It was concluded that correction of Doppler broadened Rayleigh backscattering is possible with good accuracy in most cases of tropospheric H2O DIAL measurements, but great care has to be taken when layers with steep gradients of Mie backscattering like clouds or inversion layers are present.

  3. Dipole-dipole broadening of Rb ns-np microwave transitions

    SciTech Connect

    Park, Hyunwook; Tanner, P. J.; Claessens, B. J.; Shuman, E. S.; Gallagher, T. F.

    2011-08-15

    The dipole-dipole broadening of ns-np microwave transitions of cold Rb Rydberg atoms in a magneto-optical trap has been recorded for 28{<=}n{<=}51. Since the electric dipole transition matrix elements scale as n{sup 2}, a broadening rate scaling as n{sup 4} is expected and a broadening rate of 8.2x10{sup -15}n{sup 4} MHz cm{sup 3} is observed. The observed broadening is smaller than expected from a classical picture due to the spin-orbit interaction in the np atoms. The broadened resonances are asymmetric and cusp shaped, and their line shapes can be reproduced by a diatomic model which takes into account the dipole-dipole interaction, including the spin-orbit interaction, the strengths of the allowed microwave transitions, and the distribution of the atomic spacings in the trap.

  4. Simultaneous Ultraviolet Line and Continuum Variability Studies in Seyfert 1 Galaxies and Quasars

    NASA Astrophysics Data System (ADS)

    Honnappa, Vijayakumar; Prabhakar, Vedavvathi

    Simultaneous Ultraviolet Line and Continuum Variability Studies in Seyfert 1 Galaxies and Quasars Vijayakumar H. Doddamani*and P. Vedavathi Department of Physics, Bangalore University, Bangalore-560056, *Corresponding author:drvkdmani@gmail.com, Abstract The line and continuum flux variability is a hallmark phenomenon of Seyfert 1 galaxies and quasars. Large amplitude luminosity variability is observed in AGNs from x-rays through radio waves over a wide-ranging timescales from minutes to years. The combinations of high luminosity and short variability time scales suggests, that the power of AGN is produced by a phenomena more efficient in terms of energy release per unit mass than ordinary stellar processes. The basic structure of AGNs thus developed based on the variability studies consists of a central super massive black hole surrounded by an accretion disk or more generally optically thick plasma radiating brightly at UV and soft X-ray wavelengths. The variability studies have been important tools of understanding the physics of the central regions of AGNs, which in general cannot be resolved with the existing or planned ground and space telescopes. Therefore, we have undertaken a study of the simultaneous ultraviolet line and continuum flux variability studies in MRK501, ESOB113-IG45 (also called as Fairall 9), MRK1506, MRK1095 V*GQCOM, PG1211+143, MRK205, PG1226+023 (also known as 3C273), PG1351+640, MRK 1383, MRK876 and QSO2251-178 as these objects have been repeatedly observed by IUE satellite over several years.. It is observed that Fairall 9, MRK 1095 and 3C273 exhibit the large amplitude variability (» 30 times) over the observed timescale, which spans several years. The remaining nine objects exhibit small amplitude (» 5 times) variability over the long time scale of observations. The highest amplitude variability is observed in Lya with a least in the MgII line. The amplitude of variability decreases in the order of Lya, CIV and Mg II, lines. These

  5. Doppler Broadening Thermometry Based on Cavity Ring-Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Sun, Yu Robert; Cheng, Cunfeng; Tao, Lei-Gang; Tan, Yan; Kang, Peng; Liu, An-Wen; Hu, Shui-Ming

    2016-06-01

    A Doppler broadening thermometry (DBT) instrument is implemented based on a laser-locked cavity ring-down spectrometer. [1,2] It can be used to determine the Boltzmann constant by measuring the Doppler width of a molecular ro-vibrational transition in the near infrared. Compared with conventional direct absorption methods, the high-sensitivity of CRDS allows to reach satisfied precision at lower sample pressures, which reduces the influence due to collisions. By measuring the ro-vibrational transition of C_2H_2 at 787 nm, we demonstrate a statistical uncertainty of 6 ppm (part per million) in the determined linewidth by several hours' measurement at a sample pressure of 1.5 Pa. [3] However, the complicity in the spectrum of a polyatomic molecule induces potential systematic influence on the line profile due to nearby ``hidden'' lines from weak bands or minor isotopologues. Recently, the instrument has been upgraded in both sensitivity and frequency accuracy. A narrow-band fiber laser frequency-locked to a frequency comb is applied, and overtone transitions at 1.56 μm of the 12C16O molecule are used in the CRDS-DBT measurements. The simplicity of the spectrum of the diatomic CO molecule eliminates the potential influence from ``hidden'' lines. Our preliminary measurements and analysis show that it is feasible to pursue a DBT measurement toward the 1 ppm precision. H. Pan, et al., Rev. Sci. Instrum. 82, 103110 (2011) Y. R. Sun, et al., Opt. Expr., 19, 19993 (2011) C.-F. Cheng, et al., Metrologia, 52, S385 (2015)

  6. Doppler Broadening Thermometry Based on Cavity Ring-Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hu, Shui-Ming; Cheng, Cunfeng; Wang, Jin; Tan, Yan; Sun, Yu Robert; Liu, An-Wen; Zhang, Jin-Tao

    2014-06-01

    A Doppler broadening thermometry is implemented using a laser-locked cavity ring-down spectrometer [1,2] combined with a temperature-stabilized sample cell. The temperature fluctuation of the gas sample cell is kept below 1 mK for hours. The probing laser is frequency locked at a longitudinal mode of a Fabry-Pérot interferometer made of ultra-low-expansion glass, and the spectral scan is implemented by scanning the sideband produced by an electro-optic modulator. As a result, a kHz precision has been maintained during the measurement of the spectrum of 10 GHz wide. A ro-vibrational line of C_2H_2 is measured at sample pressures of a few Pa. Using a pair of mirrors with a reflectivity of 0.99997 at 787 nm, we are able to detect absorption line profiles with a signal-to-noise ratio of 10^5. Fitting of the recorded spectra allows us to determine the Doppler width with a statistical uncertainty of 10 ppm. Further improvements on the experimental reproducibility and investigations on the collision effects will probably lead to an optical determination of the Boltzmann constant with an uncertainty of a few ppm. H. Pan, C.-F. Cheng, Y. R. Sun, B. Gao, A.-W. Liu, S.-M. Hu, ``Laser-locked, continuously tunable high resolution cavity ring-down spectrometer," Rev. Sci. Instrum. 82, 103110 (2011) Y. R. Sun, H. Pan, C.-F. Cheng, A.-W. Liu, J.-T. Zhang, S.-M. Hu, ``Application of cavity ring-down spectroscopy to the Boltzmann constant determination," Opt. Express, 19, 19993 (2011)

  7. HOW MIGHT INDUSTRY GOVERNANCE BE BROADENED TO INCLUDE NONPROLIFERATION

    SciTech Connect

    Hund, Gretchen; Seward, Amy M.

    2009-10-06

    Broadening industry governance to support nonproliferation could provide significant new leverage in preventing the spread/diversion of nuclear, radiological, or dual-use material or technology that could be used in making a nuclear or radiological weapon. Industry is defined broadly to include 1) the nuclear industry, 2) dual-use industries, and 3) radioactive source manufacturers and selected radioactive source-user industries worldwide. This paper describes how industry can be an important first line of defense in detecting and thwarting proliferation, such as an illicit trade network or an insider theft case, by complementing and strengthening existing governmental efforts. For example, the dual-use industry can play a critical role by providing export, import, or security control information that would allow a government or the International Atomic Energy Agency (IAEA) to integrate this information with safeguards, export, import, and physical protection information it has to create a more complete picture of the potential for proliferation. Because industry is closest to users of the goods and technology that could be illicitly diverted throughout the supply chain, industry information can potentially be more timely and accurate than other sources of information. Industry is in an ideal position to help ensure that such illicit activities are detected. This role could be performed more effectively if companies worked together within a particular industry to promote nonproliferation by implementing an industry-wide self-regulation program. Performance measures could be used to ensure their materials and technologies are secure throughout the supply chain and that customers are legitimately using and/or maintaining oversight of these items. Nonproliferation is the overarching driver that industry needs to consider in adopting and implementing a self-regulation approach. A few foreign companies have begun such an approach to date; it is believed that, ultimately

  8. Some Strategies From SOARS for Broadening Participation in the Geosciences

    NASA Astrophysics Data System (ADS)

    Haacker-Santos, R.; Pandya, R.; Calhoun, A.

    2006-12-01

    The mission of SOARS® is to broaden participation in the geosciences by increasing the number of Black or African-American, American Indian or Alaska Native, Hispanic or Latino, female, and first-generation college students who enroll and succeed in graduate school in the atmospheric and related sciences. This mission contributes to national goals of developing a diverse, internationally competitive, and globally engaged workforce of scientists and engineers. SOARS is a multiyear undergraduate-to-graduate bridge program that uses three strategies: a strong learning community, a multidimensional mentoring program, and experience in research. Our presentation will describe SOARS' strategies in more detail, with an eye toward how such strategies might be adapted for other programs. To do this, we will draw upon recent research that documents how these strategies can be successfully implemented, including: - A survey of over 124 higher-education based STEM programs - A workshop report from the American Chemical Society emphasizing cooperation between industry and academia - An independent ethnographic study of the Significant Opportunities in Atmospheric and Related Science (SOARS®) program, administered by the University Corporation for Atmospheric Research (UCAR) In the 11 years since SOARS' founding, 104 students have participated in the program. Of those participants, 16 are still enrolled as undergraduates, and 60 have gone on to purse graduate school in STEM. Overall, this represents a success rate 91%. Of the 35 SOARS participants who have entered the workforce, 26 are in STEM related disciplines. Four SOARS participants have already earned their PhD, and additional 17 are in PhD programs. Seventeen protégés have earned Master's and entered the workforce, and 17 more protégés are enrolled in Master's programs.

  9. Self-broadening of the hydrogen Balmer α line

    NASA Astrophysics Data System (ADS)

    Allard, N. F.; Kielkopf, J. F.; Cayrel, R.; van't Veer-Menneret, C.

    2008-03-01

    Context: Profiles of hydrogen lines in stellar spectra are determined by the properties of the hydrogen atom and the structure of the star's atmosphere. Hydrogen line profiles are therefore a very important diagnostic tool in stellar modeling. In particular they are widely used as effective temperature criterion for stellar atmospheres in the range T_eff 5500-7000 K. Aims: In cool stars such as the Sun hydrogen is largely neutral and the electron density is low. The line center width at half maximum and the spectral energy distribution in the wings are determined primarily by collisions with hydrogen atoms due to their high relative density. This work aims to provide benchmark calculations of Balmer α based on recent H2 potentials. Methods: For the first time an accurate determination of the broadening of Balmer α by atomic hydrogen is made in a unified theory of collisional line profiles using ab initio calculations of molecular hydrogen potential energies and transition matrix elements among singlet and triplet electronic states. Results: We computed the shape, width and shift of the Balmer α line perturbed by neutral hydrogen and studied their dependence on temperature. We present results over the full range of temperatures from 3000 to 12 000 K needed for stellar spectra models. Conclusions: Our calculations lead to larger values than those obtained with the commonly used Ali & Griem (1966, Phys. Rev. A, 144, 366) theory and are closer to the recent calculations of Barklem et al. (2000a, A&A, 355, L5; 2000b, A&A, 363, 1091). We conclude that the line parameters are dependent on the sum of many contributing molecular transitions, each with a different temperature dependence, and we provide tables for Balmer α. The unified line shape theory with complete molecular potentials also predicts additional opacity in the far non-Lorentzian wing.

  10. Detection of nonthermal continuum radiation in Saturn's magnetosphere

    SciTech Connect

    Kuth, W.S.; Scarf, F.L.; Sullivan, J.D.; Gurnett, D.A.

    1982-08-01

    A detailed analysis of high resolution wideband data from the Voyager 1 and 2 plasma wave receivers has revealed the presence of heretofore undiscovered nonthermal continuum radiation trapped within the Saturnian magnetosphere. The discovery of Saturnian trapped continuum radiation fills a disturbing void in the Saturnian radio spectrum. On the basis of observations at both the Earth and Jupiter it was expected that continuum radiation should be a pervasive signature of planetary magnetospheres in general. Special processing of the Voyager 1 plasma wave data at Saturn has now confirmed the existence of weak emissions that have a spectrum characteristic of trapped continuum radiation. Similar radiation was also detected by Voyager 2; however, in this case it is not certain that Saturn was the only source. Considerable evidence exists which suggests that Saturn may have been immersed in the Jovian tail during the Voyager 2 encounter, so that Jupiter may provide an additional source of the continuum radiation detected by Voyager 2.

  11. An Optimization-based Atomistic-to-Continuum Coupling Method

    SciTech Connect

    Olson, Derek; Bochev, Pavel B.; Luskin, Mitchell; Shapeev, Alexander V.

    2014-08-21

    In this paper, we present a new optimization-based method for atomistic-to-continuum (AtC) coupling. The main idea is to cast the latter as a constrained optimization problem with virtual Dirichlet controls on the interfaces between the atomistic and continuum subdomains. The optimization objective is to minimize the error between the atomistic and continuum solutions on the overlap between the two subdomains, while the atomistic and continuum force balance equations provide the constraints. Separation, rather then blending of the atomistic and continuum problems, and their subsequent use as constraints in the optimization problem distinguishes our approach from the existing AtC formulations. Finally, we present and analyze the method in the context of a one-dimensional chain of atoms modeled using a linearized two-body potential with next-nearest neighbor interactions.

  12. An Optimization-based Atomistic-to-Continuum Coupling Method

    DOE PAGES

    Olson, Derek; Bochev, Pavel B.; Luskin, Mitchell; Shapeev, Alexander V.

    2014-08-21

    In this paper, we present a new optimization-based method for atomistic-to-continuum (AtC) coupling. The main idea is to cast the latter as a constrained optimization problem with virtual Dirichlet controls on the interfaces between the atomistic and continuum subdomains. The optimization objective is to minimize the error between the atomistic and continuum solutions on the overlap between the two subdomains, while the atomistic and continuum force balance equations provide the constraints. Separation, rather then blending of the atomistic and continuum problems, and their subsequent use as constraints in the optimization problem distinguishes our approach from the existing AtC formulations. Finally,more » we present and analyze the method in the context of a one-dimensional chain of atoms modeled using a linearized two-body potential with next-nearest neighbor interactions.« less

  13. Communication: Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach

    SciTech Connect

    Liu, Zhen-Fei; Neaton, Jeffrey B.

    2014-10-07

    The electronic structure of organic-inorganic interfaces often features resonances originating from discrete molecular orbitals coupled to continuum lead states. An example is molecular junction, individual molecules bridging electrodes, where the shape and peak energy of such resonances dictate junction conductance, thermopower, I-V characteristics, and related transport properties. In molecular junctions where off-resonance coherent tunneling dominates transport, resonance peaks in the transmission function are often assumed to be Lorentzian functions with an energy-independent broadening parameter Γ. Here we define a new energy-dependent resonance broadening function, Γ(E), based on diagonalization of non-Hermitian matrices, which can describe resonances of a more complex, non-Lorentzian nature and can be decomposed into components associated with the left and right leads, respectively. We compute this quantity via an ab initio non-equilibrium Green's function (NEGF) approach based on density functional theory (DFT) for both symmetric and asymmetric molecular junctions, and show that our definition of Γ(E), when combined with Breit-Wigner formula, reproduces the transmission calculated from DFT-NEGF. Through a series of examples, we illustrate how this approach can shed new light on experiments and understanding of junction transport properties in terms of molecular orbitals.

  14. Communication: Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach

    NASA Astrophysics Data System (ADS)

    Liu, Zhen-Fei; Neaton, Jeffrey B.

    2014-10-01

    The electronic structure of organic-inorganic interfaces often features resonances originating from discrete molecular orbitals coupled to continuum lead states. An example is molecular junction, individual molecules bridging electrodes, where the shape and peak energy of such resonances dictate junction conductance, thermopower, I-V characteristics, and related transport properties. In molecular junctions where off-resonance coherent tunneling dominates transport, resonance peaks in the transmission function are often assumed to be Lorentzian functions with an energy-independent broadening parameter Γ. Here we define a new energy-dependent resonance broadening function, Γ(E), based on diagonalization of non-Hermitian matrices, which can describe resonances of a more complex, non-Lorentzian nature and can be decomposed into components associated with the left and right leads, respectively. We compute this quantity via an ab initio non-equilibrium Green's function (NEGF) approach based on density functional theory (DFT) for both symmetric and asymmetric molecular junctions, and show that our definition of Γ(E), when combined with Breit-Wigner formula, reproduces the transmission calculated from DFT-NEGF. Through a series of examples, we illustrate how this approach can shed new light on experiments and understanding of junction transport properties in terms of molecular orbitals.

  15. Continuum and molecular-dynamics simulation of nanodroplet collisions

    NASA Astrophysics Data System (ADS)

    Bardia, Raunak; Liang, Zhi; Keblinski, Pawel; Trujillo, Mario F.

    2016-05-01

    The extent to which the continuum treatment holds in binary droplet collisions is examined in the present work by using a continuum-based implicit surface capturing strategy (volume-of-fluid coupled to Navier-Stokes) and a molecular dynamics methodology. The droplet pairs are arranged in a head-on-collision configuration with an initial separation distance of 5.3 nm and a velocity of 3 ms-1. The size of droplets ranges from 10-50 nm. Inspecting the results, the collision process can be described as consisting of two periods: a preimpact phase that ends with the initial contact of both droplets, and a postimpact phase characterized by the merging, deformation, and coalescence of the droplets. The largest difference between the continuum and molecular dynamics (MD) predictions is observed in the preimpact period, where the continuum-based viscous and pressure drag forces significantly overestimate the MD predictions. Due to large value of Knudsen number in the gas (Kngas=1.972 ), this behavior is expected. Besides the differences between continuum and MD, it is also observed that the continuum simulations do not converge for the set of grid sizes considered. This is shown to be directly related to the initial velocity profile and the minute size of the nanodroplets. For instance, for micrometer-size droplets, this numerical sensitivity is not an issue. During the postimpact period, both MD and continuum-based simulations are strikingly similar, with only a moderate difference in the peak kinetic energy recorded during the collision process. With values for the Knudsen number in the liquid (Knliquid=0.01 for D =36 nm ) much closer to the continuum regime, this behavior is expected. The 50 nm droplet case is sufficiently large to be predicted reasonably well with the continuum treatment. However, for droplets smaller than approximately 36 nm, the departure from continuum behavior becomes noticeably pronounced, and becomes drastically different for the 10 nm droplets.

  16. SuperB Progress Report for Physics

    SciTech Connect

    O'Leary, B.; Matias, J.; Ramon, M.; Pous, E.; De Fazio, F.; Palano, A.; Eigen, G.; Asgeirsson, D.; Cheng, C.H.; Chivukula, A.; Echenard, B.; Hitlin, D.G.; Porter, F.; Rakitin, A.; Heinemeyer, S.; McElrath, B.; Andreassen, R.; Meadows, B.; Sokoloff, M.; Blanke, M.; Lesiak, T.; /Cracow, INP /DESY /Zurich, ETH /INFN, Ferrara /Frascati /INFN, Genoa /Glasgow U. /Indiana U. /Mainz U., Inst. Phys. /Karlsruhe, Inst. Technol. /KEK, Tsukuba /LBL, Berkeley /UC, Berkeley /Lisbon, IST /Ljubljana U. /Madrid, Autonoma U. /Maryland U. /MIT /INFN, Milan /McGill U. /Munich, Tech. U. /Notre Dame U. /PNL, Richland /INFN, Padua /Paris U., VI-VII /Orsay, LAL /Orsay, LPT /INFN, Pavia /INFN, Perugia /INFN, Pisa /Queen Mary, U. of London /Regensburg U. /Republica U., Montevideo /Frascati /INFN, Rome /INFN, Rome /INFN, Rome /Rutherford /Sassari U. /Siegen U. /SLAC /Southern Methodist U. /Tel Aviv U. /Tohoku U. /INFN, Turin /INFN, Trieste /Uppsala U. /Valencia U., IFIC /Victoria U. /Wayne State U. /Wisconsin U., Madison

    2012-02-14

    SuperB is a high luminosity e{sup +}e{sup -} collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B{sub u,d,s}, D and {tau} decays, SuperB has a broad physics programme that includes spectroscopy both in terms of the Standard Model and exotica, and precision measurements of sin{sup 2} {theta}{sub W}. In addition to performing CP violation measurements at the {Upsilon}(4S) and {phi}(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model. In terms of other precision tests of the Standard Model, this experiment will be able to perform precision over

  17. MIRO Continuum Calibration for Asteroid Mode

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon

    2011-01-01

    MIRO (Microwave Instrument for the Rosetta Orbiter) is a lightweight, uncooled, dual-frequency heterodyne radiometer. The MIRO encountered asteroid Steins in 2008, and during the flyby, MIRO used the Asteroid Mode to measure the emission spectrum of Steins. The Asteroid Mode is one of the seven modes of the MIRO operation, and is designed to increase the length of time that a spectral line is in the MIRO pass-band during a flyby of an object. This software is used to calibrate the continuum measurement of Steins emission power during the asteroid flyby. The MIRO raw measurement data need to be calibrated in order to obtain physically meaningful data. This software calibrates the MIRO raw measurements in digital units to the brightness temperature in Kelvin. The software uses two calibration sequences that are included in the Asteroid Mode. One sequence is at the beginning of the mode, and the other at the end. The first six frames contain the measurement of a cold calibration target, while the last six frames measure a warm calibration target. The targets have known temperatures and are used to provide reference power and gain, which can be used to convert MIRO measurements into brightness temperature. The software was developed to calibrate MIRO continuum measurements from Asteroid Mode. The software determines the relationship between the raw digital unit measured by MIRO and the equivalent brightness temperature by analyzing data from calibration frames. The found relationship is applied to non-calibration frames, which are the measurements of an object of interest such as asteroids and other planetary objects that MIRO encounters during its operation. This software characterizes the gain fluctuations statistically and determines which method to estimate gain between calibration frames. For example, if the fluctuation is lower than a statistically significant level, the averaging method is used to estimate the gain between the calibration frames. If the

  18. Super-Memorizers Are Not Super-Recognizers.

    PubMed

    Ramon, Meike; Miellet, Sebastien; Dzieciol, Anna M; Konrad, Boris Nikolai; Dresler, Martin; Caldara, Roberto

    2016-01-01

    Humans have a natural expertise in recognizing faces. However, the nature of the interaction between this critical visual biological skill and memory is yet unclear. Here, we had the unique opportunity to test two individuals who have had exceptional success in the World Memory Championships, including several world records in face-name association memory. We designed a range of face processing tasks to determine whether superior/expert face memory skills are associated with distinctive perceptual strategies for processing faces. Superior memorizers excelled at tasks involving associative face-name learning. Nevertheless, they were as impaired as controls in tasks probing the efficiency of the face system: face inversion and the other-race effect. Super memorizers did not show increased hippocampal volumes, and exhibited optimal generic eye movement strategies when they performed complex multi-item face-name associations. Our data show that the visual computations of the face system are not malleable and are robust to acquired expertise involving extensive training of associative memory. PMID:27008627

  19. Super-Memorizers Are Not Super-Recognizers

    PubMed Central

    Ramon, Meike; Miellet, Sebastien; Dzieciol, Anna M.; Konrad, Boris Nikolai

    2016-01-01

    Humans have a natural expertise in recognizing faces. However, the nature of the interaction between this critical visual biological skill and memory is yet unclear. Here, we had the unique opportunity to test two individuals who have had exceptional success in the World Memory Championships, including several world records in face-name association memory. We designed a range of face processing tasks to determine whether superior/expert face memory skills are associated with distinctive perceptual strategies for processing faces. Superior memorizers excelled at tasks involving associative face-name learning. Nevertheless, they were as impaired as controls in tasks probing the efficiency of the face system: face inversion and the other-race effect. Super memorizers did not show increased hippocampal volumes, and exhibited optimal generic eye movement strategies when they performed complex multi-item face-name associations. Our data show that the visual computations of the face system are not malleable and are robust to acquired expertise involving extensive training of associative memory. PMID:27008627

  20. Continuum Thermodynamics - Part II: Applications and Examples

    NASA Astrophysics Data System (ADS)

    Albers, Bettina; Wilmanski, Krzysztof

    The intention by writing Part II of the book on continuum thermodynamics was the deepening of some issues covered in Part I as well as a development of certain skills in dealing with practical problems of oscopic processes. However, the main motivation for this part is the presentation of main facets of thermodynamics which appear when interdisciplinary problems are considered. There are many monographs on the subjects of solid mechanics and thermomechanics, on fluid mechanics and on coupled fields but most of them cover only special problems in great details which are characteristic for the chosen field. It is rather seldom that relations between these fields are discussed. This concerns, for instance, large deformations of the skeleton of porous materials with diffusion (e.g. lungs), couplings of deformable particles with the fluid motion in suspensions, couplings of adsorption processes and chemical reactions in immiscible mixtures with diffusion, various multi-component aspects of the motion, e.g. of avalanches, such as segregation processes, etc...

  1. Modeling continuum of epithelial mesenchymal transition plasticity.

    PubMed

    Mandal, Mousumi; Ghosh, Biswajoy; Anura, Anji; Mitra, Pabitra; Pathak, Tanmaya; Chatterjee, Jyotirmoy

    2016-02-01

    Living systems respond to ambient pathophysiological changes by altering their phenotype, a phenomenon called 'phenotypic plasticity'. This program contains information about adaptive biological dynamism. Epithelial-mesenchymal transition (EMT) is one such process found to be crucial in development, wound healing, and cancer wherein the epithelial cells with restricted migratory potential develop motile functions by acquiring mesenchymal characteristics. In the present study, phase contrast microscopy images of EMT induced HaCaT cells were acquired at 24 h intervals for 96 h. The expression study of relevant pivotal molecules viz. F-actin, vimentin, fibronectin and N-cadherin was carried out to confirm the EMT process. Cells were intuitively categorized into five distinct morphological phenotypes. A population of 500 cells for each temporal point was selected to quantify their frequency of occurrence. The plastic interplay of cell phenotypes from the observations was described as a Markovian process. A model was formulated empirically using simple linear algebra, to depict the possible mechanisms of cellular transformation among the five phenotypes. This work employed qualitative, semi-quantitative and quantitative tools towards illustration and establishment of the EMT continuum. Thus, it provides a newer perspective to understand the embedded plasticity across the EMT spectrum. PMID:26762753

  2. A continuum model of retinal electrical stimulation

    NASA Astrophysics Data System (ADS)

    Joarder, Saiful A.; Abramian, Miganoosh; Suaning, Gregg J.; Lovell, Nigel H.; Dokos, Socrates

    2011-10-01

    A continuum mathematical model of retinal electrical stimulation is described. The model is represented by a passive vitreous domain, a thin layer of active retinal ganglion cell (RGC) tissue adjacent to deeper passive neural layers of the retina, the retinal pigmented epithelium (RPE) and choroid thus ending at the sclera. To validate the model, in vitro epiretinal responses to stimuli from 50 µm disk electrodes, arranged in a hexagonal mosaic, were recorded from rabbit retinas. 100 µs/phase anodic-first biphasic current pulses were delivered to the retinal surface in both the mathematical model and experiments. RGC responses were simulated and recorded using extracellular microelectrodes. The model's epiretinal thresholds compared favorably with the in vitro data. In addition, simulations showed that single-return bipolar electrodes recruited a larger area of the retina than twin-return or six-return electrodes arranged in a hexagonal layout in which a central stimulating electrode is surrounded by six, eqi-spaced returns. Simulations were also undertaken to investigate the patterns of RGC activation in an anatomically-accurate model of the retina, as well as RGC activation patterns for subretinal and suprachoroidal bipolar stimulation. This paper was originally submitted for the special issue containing contributions from the Sixth Biennial Research Congress of The Eye and the Chip.

  3. Compact continuum brain model for human electroencephalogram

    NASA Astrophysics Data System (ADS)

    Kim, J. W.; Shin, H.-B.; Robinson, P. A.

    2007-12-01

    A low-dimensional, compact brain model has recently been developed based on physiologically based mean-field continuum formulation of electric activity of the brain. The essential feature of the new compact model is a second order time-delayed differential equation that has physiologically plausible terms, such as rapid corticocortical feedback and delayed feedback via extracortical pathways. Due to its compact form, the model facilitates insight into complex brain dynamics via standard linear and nonlinear techniques. The model successfully reproduces many features of previous models and experiments. For example, experimentally observed typical rhythms of electroencephalogram (EEG) signals are reproduced in a physiologically plausible parameter region. In the nonlinear regime, onsets of seizures, which often develop into limit cycles, are illustrated by modulating model parameters. It is also shown that a hysteresis can occur when the system has multiple attractors. As a further illustration of this approach, power spectra of the model are fitted to those of sleep EEGs of two subjects (one with apnea, the other with narcolepsy). The model parameters obtained from the fittings show good matches with previous literature. Our results suggest that the compact model can provide a theoretical basis for analyzing complex EEG signals.

  4. Continuum regularization of quantum field theory

    SciTech Connect

    Bern, Z.

    1986-04-01

    Possible nonperturbative continuum regularization schemes for quantum field theory are discussed which are based upon the Langevin equation of Parisi and Wu. Breit, Gupta and Zaks made the first proposal for new gauge invariant nonperturbative regularization. The scheme is based on smearing in the ''fifth-time'' of the Langevin equation. An analysis of their stochastic regularization scheme for the case of scalar electrodynamics with the standard covariant gauge fixing is given. Their scheme is shown to preserve the masslessness of the photon and the tensor structure of the photon vacuum polarization at the one-loop level. Although stochastic regularization is viable in one-loop electrodynamics, two difficulties arise which, in general, ruins the scheme. One problem is that the superficial quadratic divergences force a bottomless action for the noise. Another difficulty is that stochastic regularization by fifth-time smearing is incompatible with Zwanziger's gauge fixing, which is the only known nonperturbaive covariant gauge fixing for nonabelian gauge theories. Finally, a successful covariant derivative scheme is discussed which avoids the difficulties encountered with the earlier stochastic regularization by fifth-time smearing. For QCD the regularized formulation is manifestly Lorentz invariant, gauge invariant, ghost free and finite to all orders. A vanishing gluon mass is explicitly verified at one loop. The method is designed to respect relevant symmetries, and is expected to provide suitable regularization for any theory of interest. Hopefully, the scheme will lend itself to nonperturbative analysis. 44 refs., 16 figs.

  5. Continuum percolation of congruent overlapping spherocylinders

    NASA Astrophysics Data System (ADS)

    Xu, Wenxiang; Su, Xianglong; Jiao, Yang

    2016-09-01

    Continuum percolation of randomly orientated congruent overlapping spherocylinders (composed of cylinder of height H with semispheres of diameter D at the ends) with aspect ratio α =H /D in [0 ,∞ ) is studied. The percolation threshold ϕc, percolation transition width Δ, and correlation-length critical exponent ν for spherocylinders with α in [0, 200] are determined with a high degree of accuracy via extensive finite-size scaling analysis. A generalized excluded-volume approximation for percolation threshold with an exponent explicitly depending on both aspect ratio and excluded volume for arbitrary α values in [0 ,∞ ) is proposed and shown to yield accurate predictions of ϕc for an extremely wide range of α in [0, 2000] based on available numerical and experimental data. We find ϕc is a universal monotonic decreasing function of α and is independent of the effective particle size. Our study has implications in percolation theory for nonspherical particles and composite material design.

  6. Second law violations, continuum mechanics, and permeability

    NASA Astrophysics Data System (ADS)

    Ostoja-Starzewski, Martin

    2016-03-01

    The violations of the second law are relevant as the length and/or time scales become very small. The second law then needs to be replaced by the fluctuation theorem and mathematically, the irreversible entropy is a submartingale. First, we discuss the consequences of these results for the axioms of continuum mechanics, arguing in favor of a framework relying on stochastic functionals of energy and entropy. We next determine a Lyapunov function for diffusion-type problems governed by stochastic rather than deterministic functionals of internal energy and entropy, where the random field coefficients of diffusion are not required to satisfy the positive definiteness everywhere. Next, a formulation of micropolar fluid mechanics is developed, accounting for the lack of symmetry of stress tensor on molecular scales. This framework is then applied to employed to show that spontaneous random fluctuations of the microrotation field will arise in Couette—and Poiseuille-type flows in the absence of random (turbulence-like) fluctuations of the classical velocity field. Finally, while the permeability is classically modeled by the Darcy law or its modifications, besides considering the violations of the second law, one also needs to account for the spatial randomness of the channel network, implying a modification of the hierarchy of scale-dependent bounds on the macroscopic property of the network.

  7. Radio continuum properties of young planetary nebulae

    NASA Astrophysics Data System (ADS)

    Cerrigone, L.; Umana, G.; Trigilio, C.; Leto, P.; Buemi, C. S.; Hora, J. L.

    2008-10-01

    We have selected a small sample of post-AGB (Asymptotic Giant Branch) stars in transition towards the planetary nebula and present new Very Large Array multi-frequency high-angular resolution radio observations of them. The multi-frequency data are used to create and model the targets' radio continuum spectra, proving that these stars started their evolution as very young planetary nebulae. In the optically thin range, the slopes are compatible with the expected spectral index (-0.1). Two targets (IRAS 18062+2410 and 17423-1755) seem to be optically thick even at high frequency, as observed in a handful of other post-AGB stars in the literature, while a third one (IRAS 20462+3416) shows a possible contribution from cold dust. In IRAS 18062+2410, where we have three observations spanning a period of four years, we detect an increase in its flux density, similar to that observed in CRL 618. High-angular resolution imaging shows bipolar structures that may be due to circumstellar tori, although a different hypothesis (i.e. jets) could also explain the observations. Further observations and monitoring of these sources will enable us to test the current evolutionary models of planetary nebulae.

  8. Continuum Edge Gyrokinetic Theory and Simulations

    SciTech Connect

    Xu, X Q; Xiong, Z; Dorr, M R; Hittinger, J A; Bodi, K; Candy, J; Cohen, B I; Cohen, R H; Colella, P; Kerbel, G D; Krasheninnikov, S; Nevins, W M; Qin, H; Rognlien, T D; Snyder, P B; Umansky, M V

    2007-01-09

    The following results are presented from the development and application of TEMPEST, a fully nonlinear (full-f) five dimensional (3d2v) gyrokinetic continuum edge-plasma code. (1) As a test of the interaction of collisions and parallel streaming, TEMPEST is compared with published analytic and numerical results for endloss of particles confined by combined electrostatic and magnetic wells. Good agreement is found over a wide range of collisionality, confining potential, and mirror ratio; and the required velocity space resolution is modest. (2) In a large-aspect-ratio circular geometry, excellent agreement is found for a neoclassical equilibrium with parallel ion flow in the banana regime with zero temperature gradient and radial electric field. (3) The four-dimensional (2d2v) version of the code produces the first self-consistent simulation results of collisionless damping of geodesic acoustic modes and zonal flow (Rosenbluth-Hinton residual) with Boltzmann electrons using a full-f code. The electric field is also found to agree with the standard neoclassical expression for steep density and ion temperature gradients in the banana regime. In divertor geometry, it is found that the endloss of particles and energy induces parallel flow stronger than the core neoclassical predictions in the SOL. (5) Our 5D gyrokinetic formulation yields a set of nonlinear electrostatic gyrokinetic equations that are for both neoclassical and turbulence simulations.

  9. Edge gyrokinetic theory and continuum simulations

    NASA Astrophysics Data System (ADS)

    Xu, X. Q.; Xiong, Z.; Dorr, M. R.; Hittinger, J. A.; Bodi, K.; Candy, J.; Cohen, B. I.; Cohen, R. H.; Colella, P.; Kerbel, G. D.; Krasheninnikov, S.; Nevins, W. M.; Qin, H.; Rognlien, T. D.; Snyder, P. B.; Umansky, M. V.

    2007-08-01

    The following results are presented from the development and application of TEMPEST, a fully nonlinear (full-f) five-dimensional (3d2v) gyrokinetic continuum edge-plasma code. (1) As a test of the interaction of collisions and parallel streaming, TEMPEST is compared with published analytic and numerical results for endloss of particles confined by combined electrostatic and magnetic wells. Good agreement is found over a wide range of collisionality, confining potential and mirror ratio, and the required velocity space resolution is modest. (2) In a large-aspect-ratio circular geometry, excellent agreement is found for a neoclassical equilibrium with parallel ion flow in the banana regime with zero temperature gradient and radial electric field. (3) The four-dimensional (2d2v) version of the code produces the first self-consistent simulation results of collisionless damping of geodesic acoustic modes and zonal flow (Rosenbluth-Hinton residual) with Boltzmann electrons using a full-f code. The electric field is also found to agree with the standard neoclassical expression for steep density and ion temperature gradients in the plateau regime. In divertor geometry, it is found that the endloss of particles and energy induces parallel flow stronger than the core neoclassical predictions in the SOL.

  10. Continuum elastic theory of adsorbate vibrational relaxation

    NASA Astrophysics Data System (ADS)

    Lewis, Steven P.; Pykhtin, M. V.; Mele, E. J.; Rappe, Andrew M.

    1998-01-01

    An analytical theory is presented for the damping of low-frequency adsorbate vibrations via resonant coupling to the substrate phonons. The system is treated classically, with the substrate modeled as a semi-infinite elastic continuum and the adsorbate overlayer modeled as an array of point masses connected to the surface by harmonic springs. The theory provides a simple expression for the relaxation rate in terms of fundamental parameters of the system: γ=mω¯02/AcρcT, where m is the adsorbate mass, ω¯0 is the measured frequency, Ac is the overlayer unit-cell area, and ρ and cT are the substrate mass density and transverse speed of sound, respectively. This expression is strongly coverage dependent, and predicts relaxation rates in excellent quantitative agreement with available experiments. For a half-monolayer of carbon monoxide on the copper (100) surface, the predicted damping rate of in-plane frustrated translations is 0.50×1012s-1, as compared to the experimental value of (0.43±0.07)×1012s-1. Furthermore it is shown that, for all coverages presently accessible to experiment, adsorbate motions exhibit collective effects which cannot be treated as stemming from isolated oscillators.

  11. Heterosexuality/homosexuality: dichotomy or continuum.

    PubMed

    McConaghy, N

    1987-10-01

    A recent reanalysis of Kinsey's data rejected his conclusion that heterosexuality and homosexuality were a continuum. A number of studies have been published over the past decade reporting that 5% or less of adolescents were aware of homosexual feelings, a finding also inconsistent with Kinsey's data. These studies have rejected prenatal hormones and rearing by homosexual parents as influencing sexual orientation. If Kinsey's data are correct and 40% or more of adolescents are aware of homosexual feeling the findings of these studies are invalid. Two replications of an initial study with representative samples of medical students found over 40% of both males and females currently aware of some homosexual feelings, consistent with Kinsey's conclusion. The ratio of reported homosexual to heterosexual feelings correlated with opposite sex-linked behaviors in the male, supporting the validity of the subjects' reports. If subjects representative of other subgroups of the population are investigated with this easily implemented method and report similar data, this theoretically and sociologically significant divergence of belief concerning the incidence of the heterosexual/homosexual balance would be resolved.

  12. Fluorescence and Lasing in Fe II lines Driven by Diluted Continuum of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Messenger, Stephen J.; Strelnitski, V.

    2009-01-01

    We are analyzing the pumping mechanism that may be responsible for the production of two bright UV lines of Fe II at λ=250.75nm and λ=250.91nm in the B and D Weigelt blobs of Eta Carinae, as well as for the production of two bright 1.7 μm lines (whose localization in the expanding envelope of the star is not certain). The current explanation [e.g. Johansson & Letokhov, 2007] is based on the hypothesis that the Ly-α photons produced by ionization and cascade recombination of hydrogen and trapped in the blobs drive the pumping cycles due to the "accidental resonance” of these photons with the UV transitions of Fe II that start the cycles. A strong broadening of the Ly-α line due to the multiple scatterings of the photons is crucial to this model because the "resonance” is not precise. Here, we consider an alternative model based on direct pumping by the diluted continuum of the star. We show that the number of the UV photons from the star driving the fluorescence cycles directly is sufficient for providing the observed intensities of the two bright UV lines. We also demonstrate that the diluted black body continuum of the star can create an inversion of populations in the 1.7 μm transitions for the observed projected distances of the blobs from the star. However, possible laser amplification is strongly limited by the insufficient optical depth and/or by saturation. Observations of the two IR lines with higher spatial resolution are needed to discriminate between the possible lasing and the thermal or fluorescent radiation. This project was supported by the NSF/REU grant AST-0354056 and the Nantucket Maria Mitchell Association.

  13. Spatiotemporal stick-slip phenomena in a coupled continuum-granular system

    NASA Astrophysics Data System (ADS)

    Ecke, Robert

    In sheared granular media, stick-slip behavior is ubiquitous, especially at very small shear rates and weak drive coupling. The resulting slips are characteristic of natural phenomena such as earthquakes and well as being a delicate probe of the collective dynamics of the granular system. In that spirit, we developed a laboratory experiment consisting of sheared elastic plates separated by a narrow gap filled with quasi-two-dimensional granular material (bi-dispersed nylon rods) . We directly determine the spatial and temporal distributions of strain displacements of the elastic continuum over 200 spatial points located adjacent to the gap. Slip events can be divided into large system-spanning events and spatially distributed smaller events. The small events have a probability distribution of event moment consistent with an M - 3 / 2 power law scaling and a Poisson distributed recurrence time distribution. Large events have a broad, log-normal moment distribution and a mean repetition time. As the applied normal force increases, there are fractionally more (less) large (small) events, and the large-event moment distribution broadens. The magnitude of the slip motion of the plates is well correlated with the root-mean-square displacements of the granular matter. Our results are consistent with mean field descriptions of statistical models of earthquakes and avalanches. We further explore the high-speed dynamics of system events and also discuss the effective granular friction of the sheared layer. We find that large events result from stored elastic energy in the plates in this coupled granular-continuum system.

  14. Super Resolution Read Only Memory Disc Using Super-Resolution Near-Field Structure Technology

    NASA Astrophysics Data System (ADS)

    Yoon, Duseop; Kim, Jooho; Kim, Hyunki; Hwang, Inoh; Park, Insik; Shin, Dongho; Park, Yunchang; Tominaga, Junji

    2004-07-01

    Super resolution near-field structure (super-RENS) technology is one of the promising technologies for a sub-terabyte optical storage of around 200 GB capacity. We confirmed the possibility of super-RENS read only memory (ROM) media with multilayer structure using the combination of the PtOx, AgInSbTe, ZnS-SiO2 films. The carrier to noise ratio (CNR) and readout cyclability was measured for the super-RENS ROM disc in both the red laser and the blue laser systems.

  15. A Global Fitting Approach For Doppler Broadening Thermometry

    NASA Astrophysics Data System (ADS)

    Amodio, Pasquale; Moretti, Luigi; De Vizia, Maria Domenica; Gianfrani, Livio

    2014-06-01

    Very recently, a spectroscopic determination of the Boltzmann constant, kB, has been performed at the Second University of Naples by means of a rather sophisticated implementation of Doppler Broadening Thermometry (DBT)1. Performed on a 18O-enriched water sample, at a wavelength of 1.39 µm, the experiment has provided a value for kB with a combined uncertainty of 24 parts over 106, which is the best result obtained so far, by using an optical method. In the spectral analysis procedure, the partially correlated speed-dependent hard-collision (pC-SDHC) model was adopted. The uncertainty budget has clearly revealed that the major contributions come from the statistical uncertainty (type A) and from the uncertainty associated to the line-shape model (type B)2. In the present work, we present the first results of a theoretical and numerical work aimed at reducing these uncertainty components. It is well known that molecular line shapes exhibit clear deviations from the time honoured Voigt profile. Even in the case of a well isolated spectral line, under the influence of binary collisions, in the Doppler regime, the shape can be quite complicated by the joint occurrence of velocity-change collisions and speed-dependent effects. The partially correlated speed-dependent Keilson-Storer profile (pC-SDKS) has been recently proposed as a very realistic model, capable of reproducing very accurately the absorption spectra for self-colliding water molecules, in the near infrared3. Unfortunately, the model is so complex that it cannot be implemented into a fitting routine for the analysis of experimental spectra. Therefore, we have developed a MATLAB code to simulate a variety of H218O spectra in thermodynamic conditions identical to the one of our DBT experiment, using the pC-SDKS model. The numerical calculations to determine such a profile have a very large computational cost, resulting from a very sophisticated iterative procedure. Hence, the numerically simulated spectra

  16. Super Bubble and For Fingers Only.

    ERIC Educational Resources Information Center

    Barrow, Lloyd H.; And Others

    1997-01-01

    Presents two activities, the "Super Bubble" that challenges students and parents to blow the biggest bubbles and "For Fingers Only" that asks them to duplicate a pattern of blocks using only the sense of touch. (JRH)

  17. Pressure Broadening of Several Terahertz Transitions of Water from 20K to 200K

    NASA Astrophysics Data System (ADS)

    Dick, Michael J.; Drouin, Brian J.; Pearson, John C.

    2009-06-01

    The pressure broadening of the 0_{00} to 1_{11}, 1_{11} to 2_{02}, 3_{03} to 3_{12}, 2_{21} to 3_{12} and 3_{12} to 3_{21} transitions of water by hydrogen and helium has been investigated using the collisional cooling technique. This technique has allowed the broadening to be examined over the temperature range of 20K to 200K, far below the freezing point of water. The results of the investigation show a general trend of two distinct regions of broadening for each rotational line. Above 50K, the temperature dependence of the broadening follows the expected power law behavior. Below 50K, the broadening decreases very rapidly with temperature. This behavior is similar to that observed in a recent study of the pressure broadening of the 556 GHz line of water completed in our lab. However, this behavior is in sharp contrast to that predicted by previous theoretical calculations. We will present the results of our current investigation. This will include a discussion comparing the current study with the results of the previous experimental and theoretical work. The pressure broadening is a window into the collisional excitation and the implications of our results for the interpretation of water spectra in the interstellar medium will be discussed.

  18. Hybrid continuum-atomistic approach to model electrokinetics in nanofluidics.

    PubMed

    Amani, Ehsan; Movahed, Saeid

    2016-06-01

    In this study, for the first time, a hybrid continuum-atomistic based model is proposed for electrokinetics, electroosmosis and electrophoresis, through nanochannels. Although continuum based methods are accurate enough to model fluid flow and electric potential in nanofluidics (in dimensions larger than 4 nm), ionic concentration is too low in nanochannels for the continuum assumption to be valid. On the other hand, the non-continuum based approaches are too time-consuming and therefore is limited to simple geometries, in practice. Here, to propose an efficient hybrid continuum-atomistic method of modelling the electrokinetics in nanochannels; the fluid flow and electric potential are computed based on continuum hypothesis coupled with an atomistic Lagrangian approach for the ionic transport. The results of the model are compared to and validated by the results of the molecular dynamics technique for a couple of case studies. Then, the influences of bulk ionic concentration, external electric field, size of nanochannel, and surface electric charge on the electrokinetic flow and ionic mass transfer are investigated, carefully. The hybrid continuum-atomistic method is a promising approach to model more complicated geometries and investigate more details of the electrokinetics in nanofluidics. PMID:27155300

  19. Equivalent-Continuum Modeling With Application to Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Odegard, Gregory M.; Gates, Thomas S.; Nicholson, Lee M.; Wise, Kristopher E.

    2002-01-01

    A method has been proposed for developing structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with equivalent-continuum models. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As important examples with direct application to the development and characterization of single-walled carbon nanotubes and the design of nanotube-based devices, the modeling technique has been applied to determine the effective-continuum geometry and bending rigidity of a graphene sheet. A representative volume element of the chemical structure of graphene has been substituted with equivalent-truss and equivalent continuum models. As a result, an effective thickness of the continuum model has been determined. This effective thickness has been shown to be significantly larger than the interatomic spacing of graphite. The effective thickness has been shown to be significantly larger than the inter-planar spacing of graphite. The effective bending rigidity of the equivalent-continuum model of a graphene sheet was determined by equating the vibrational potential energy of the molecular model of a graphene sheet subjected to cylindrical bending with the strain energy of an equivalent continuum plate subjected to cylindrical bending.

  20. 77 FR 44653 - Continuum of Care Homeless Assistance Grant Application-Technical Submission

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... URBAN DEVELOPMENT Continuum of Care Homeless Assistance Grant Application-- Technical Submission AGENCY... the original Continuum of Care Homeless Assistance Grant Application. DATES: Comments Due Date: August... lists the following information: Title of Proposal: Continuum of Care Homeless Assistance...

  1. 77 FR 23491 - Notice of Submission of Proposed Information Collection to OMB; Continuum of Care Homeless...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... URBAN DEVELOPMENT Notice of Submission of Proposed Information Collection to OMB; Continuum of Care Homeless Assistance Grant Application--Continuum of Care Registration AGENCY: Office of the Chief... reporting burden associated with registration requirements that Continuum of Care Homeless Assistance...

  2. Super Capacitor Development At NASA MSFC

    NASA Technical Reports Server (NTRS)

    Hall, David K.

    2000-01-01

    A viewgraph presentation outlines super capacitor development at NASA Marshall Space Flight Center. The concept, proof of concept testing and the test set-ups are described. An overview of super capacitor classification is shown and several types of capacitors are detailed: Ni-C chemical double layer (CDL), Ru-Oxide pseudo-cap, and a Ru-Oxide 2 F 30 V capacitor.

  3. On Bayesian adaptive video super resolution.

    PubMed

    Liu, Ce; Sun, Deqing

    2014-02-01

    Although multiframe super resolution has been extensively studied in past decades, super resolving real-world video sequences still remains challenging. In existing systems, either the motion models are oversimplified or important factors such as blur kernel and noise level are assumed to be known. Such models cannot capture the intrinsic characteristics that may differ from one sequence to another. In this paper, we propose a Bayesian approach to adaptive video super resolution via simultaneously estimating underlying motion, blur kernel, and noise level while reconstructing the original high-resolution frames. As a result, our system not only produces very promising super resolution results outperforming the state of the art, but also adapts to a variety of noise levels and blur kernels. To further analyze the effect of noise and blur kernel, we perform a two-step analysis using the Cramer-Rao bounds. We study how blur kernel and noise influence motion estimation with aliasing signals, how noise affects super resolution with perfect motion, and finally how blur kernel and noise influence super resolution with unknown motion. Our analysis results confirm empirical observations, in particular that an intermediate size blur kernel achieves the optimal image reconstruction results.

  4. Far-infrared self-broadening in methylcyanide - Absorber-perturber resonance

    NASA Technical Reports Server (NTRS)

    Buffa, G.; Tarrini, O.; De Natale, P.; Inguscio, M.; Pavone, F. S.; Prevedelli, M.; Evenson, K. M.; Zink, L. R.; Schwaab, G. W.

    1992-01-01

    Using tunable far-infrared spectrometers with high-frequency stability and accuracy, the self-pressure broadening and shift of CH3CN are measured. Evidence of absorber-perturber resonance effects on the collisional line shape are obtained. This tests the theoretical model and its possible improvements and also allows predictions of broadening and shift for a large class of molecules. Moreover, the resonance effect produces a theoretical temperature dependence of self-broadening that is different from what is commonly assumed.

  5. Solar background rejection by a pressure-broadened atomic resonance filter operating at a Fraunhofer wavelength.

    PubMed

    Gelbwachs, J A; Tabat, M D

    1989-02-15

    We have calculated the solar background rejection of the Mg atomic resonance filter operating at the b(1) Fraunhofer wavelength (518.4 nm) as a function of the pressure-broadened filter linewidth. For pressure broadening induced by the noble gases the solar background rejection decreases from 93% at a 0.002-nm bandwidth to 82-84% at a 0.02-nm bandwidth. Solar background rejection was insensitive to buffer gas and was optimum for the noble gas with the smallest shift-to-broadening ratio.

  6. Gain and Raman line-broadening with graphene coated diamond-shape nano-antennas.

    PubMed

    Paraskevaidis, Charilaos; Kuykendall, Tevye; Melli, Mauro; Weber-Bargioni, Alexander; Schuck, P James; Schwartzberg, Adam; Dhuey, Scott; Cabrini, Stefano; Grebel, Haim

    2015-10-01

    Using Surface Enhanced Raman Scattering (SERS), we report on intensity-dependent broadening in graphene-deposited broad-band antennas. The antenna gain curve includes both the incident frequency and some of the scattered mode frequencies. By comparing antennas with various gaps and types (bow-tie vs. diamond-shape antennas) we make the case that the line broadening did not originate from strain, thermal or surface potential. Strain, if present, further shifts and broadens those Raman lines that are included within the antenna gain curve.

  7. Role of collisional broadening in Monte Carlo simulations of terahertz quantum cascade lasers

    SciTech Connect

    Matyas, Alpar; Lugli, Paolo; Jirauschek, Christian

    2013-01-07

    Using a generalized version of Fermi's golden rule, collisional broadening is self-consistently implemented into ensemble Monte Carlo carrier transport simulations, and its effect on the transport and optical properties of terahertz quantum cascade lasers is investigated. The inclusion of broadening yields improved agreement with the experiment, without a significant increase of the numerical load. Specifically, this effect is crucial for a correct modeling at low biases. In the lasing regime, broadening can lead to significantly reduced optical gain and output power, affecting the obtained current-voltage characteristics.

  8. Computing the inhomogeneous broadening of electronic transitions in solution: a first-principle quantum mechanical approach.

    PubMed

    Avila Ferrer, Francisco José; Improta, Roberto; Santoro, Fabrizio; Barone, Vincenzo

    2011-10-14

    Starting from Marcus's relationship connecting the inhomogeneous broadening with the solvent reorganization energy and exploiting recent state-specific developments in PCM/TD-DFT calculations, we propose a procedure to estimate the polar broadening of optical transitions. When applied to two representative molecular probes, coumarin C153 and 4-aminophthalimide, in different solvents, our approach provides for the polar broadening values fully consistent with the experimental ones. Thanks to these achievements, for the first time fully ab initio vibrationally resolved absorption spectra in solution are computed, obtaining spectra for coumarin C153 in remarkable agreement with experiments.

  9. SEACAS Theory Manuals: Part II. Nonlinear Continuum Mechanics

    SciTech Connect

    Attaway, S.W.; Laursen, T.A.; Zadoks, R.I.

    1998-09-01

    This report summarizes the key continuum mechanics concepts required for the systematic prescription and numerical solution of finite deformation solid mechanics problems. Topics surveyed include measures of deformation appropriate for media undergoing large deformations, stress measures appropriate for such problems, balance laws and their role in nonlinear continuum mechanics, the role of frame indifference in description of large deformation response, and the extension of these theories to encompass two dimensional idealizations, structural idealizations, and rigid body behavior. There are three companion reports that describe the problem formulation, constitutive modeling, and finite element technology for nonlinear continuum mechanics systems.

  10. The submillimeter radio continuum of Comet P/Brorsen-Metcalf

    SciTech Connect

    Jewitt, D.; Luu, J. MIT, Cambridge, MA )

    1990-12-01

    Observations of Comet P/Brorsen-Metcalf in the submillimeter radio continuum are presented. The observations were taken using the James Clerk Maxwell Telescope on Mauna Kea, and include the first truly submillimeter detection of a comet, and the first submillimeter continuum spectrum. The submillimeter radiation is attributed to thermal emission from a transient population of large grains with a total mass of (1-10) x 10 to the 9th kg. The large grains may be produced by catastrophic failure of part of the refractory mantle on the surface of the cometary nucleus. Models of the submillimeter continuum are discussed. 49 refs.

  11. Super Typhoon Halong off Taiwan

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On July 14, 2002, Super Typhoon Halong was east of Taiwan (left edge) in the western Pacific Ocean. At the time this image was taken the storm was a Category 4 hurricane, with maximum sustained winds of 115 knots (132 miles per hour), but as recently as July 12, winds were at 135 knots (155 miles per hour). Halong has moved northwards and pounded Okinawa, Japan, with heavy rain and high winds, just days after tropical Storm Chataan hit the country, creating flooding and killing several people. The storm is expected to be a continuing threat on Monday and Tuesday. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on July 14, 2002. Please note that the high-resolution scene provided here is 500 meters per pixel. For a copy of the scene at the sensor's fullest resolution, visit the MODIS Rapid Response Image Gallery. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  12. SUPER-B LATTICE STUDIES

    SciTech Connect

    Biagini, M.E.; Raimondi, P.; Piminov, P.; Sinyatkin, S.; Nosochkov, Y.; Wittmer, W.; /SLAC

    2010-08-25

    The SuperB asymmetric e{sup +}e{sup -} collider is designed for 10{sup 36} cm{sup -2} s{sup -1} luminosity and beam energies of 6.7 and 4.18 GeV for e{sup +} and e{sup -} respectively. The High and Low Energy Rings (HER and LER) have one Interaction Point (IP) with 66 mrad crossing angle. The 1258 m rings fit to the INFN-LNF site at Frascati. The ring emittance is minimized for the high luminosity. The Final Focus (FF) chromaticity correction is optimized for maximum transverse acceptance and energy bandwidth. Included Crab Waist sextupoles suppress betatron resonances induced in the collisions with a large Piwinski angle. The LER Spin Rotator sections provide longitudinally polarized electron beam at the IP. The lattice is flexible for tuning the machine parameters and compatible with reusing the PEP-II magnets, RF cavities and other components. Details of the lattice design are presented.

  13. Super-B Project Overview

    SciTech Connect

    Biagini, M.E.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Guiducci, S.; Raimondi, P.; Tomassini, S.; Zobov, M.; Bertsche, K.; Donald, M.; Nosochkov, Y.; Novokhatski, A.; Seeman, J.; Sullivan, M.; Yocky, G.; Wienands, U.; Wittmer, W.; Koop, I.; Levichev, E.; Nikitin, S.; /Novosibirsk, IYF /KEK, Tsukuba /Pisa U. /CERN

    2010-08-26

    The SuperB project aims at the construction of an asymmetric very high luminosity B-Factory on the Frascati/Tor Vergata (Italy) area, providing a uniquely sensitive probe of New Physics in the flavour sector of the Standard Model. The luminosity goal of 10{sup 36} cm{sup -2} s{sup -1} can be reached with a new collision scheme with 'large Piwinski angle' (LPA) and the use of 'crab waist sextupoles' (CW). A LPA&CW Interaction Region (IR) has been successfully tested at the DA{Phi}NE {Phi}-Factory at LNF-Frascati in 2008. The LPA&CW scheme, together with very low {beta}*, will allow for operation with relatively low beam currents and reasonable bunch length, comparable to those of PEP-II and KEKB. In the High Energy Ring (HER), two spin rotators will bring longitudinally polarized beams into collision at the IP. The lattice has been designed with a very low intrinsic emittance and is quite compact, less than 2 km long. The tight focusing requires the final doublet quadrupoles to be very close to the IP and very compact. A Conceptual Design Report was published in March 2007, and beam dynamics and collective effects R&D studies are in progress in order to publish a Technical Design Report by the end of 2010.

  14. Microstructural and continuum evolution modeling of sintering.

    SciTech Connect

    Braginsky, Michael V.; Olevsky, Eugene A.; Johnson, D. Lynn; Tikare, Veena; Garino, Terry J.; Arguello, Jose Guadalupe, Jr.

    2003-12-01

    All ceramics and powder metals, including the ceramics components that Sandia uses in critical weapons components such as PZT voltage bars and current stacks, multi-layer ceramic MET's, ahmindmolybdenum & alumina cermets, and ZnO varistors, are manufactured by sintering. Sintering is a critical, possibly the most important, processing step during manufacturing of ceramics. The microstructural evolution, the macroscopic shrinkage, and shape distortions during sintering will control the engineering performance of the resulting ceramic component. Yet, modeling and prediction of sintering behavior is in its infancy, lagging far behind the other manufacturing models, such as powder synthesis and powder compaction models, and behind models that predict engineering properties and reliability. In this project, we developed a model that was capable of simulating microstructural evolution during sintering, providing constitutive equations for macroscale simulation of shrinkage and distortion during sintering. And we developed macroscale sintering simulation capability in JAS3D. The mesoscale model can simulate microstructural evolution in a complex powder compact of hundreds or even thousands of particles of arbitrary shape and size by 1. curvature-driven grain growth, 2. pore migration and coalescence by surface diffusion, 3. vacancy formation, grain boundary diffusion and annihilation. This model was validated by comparing predictions of the simulation to analytical predictions for simple geometries. The model was then used to simulate sintering in complex powder compacts. Sintering stress and materials viscous module were obtained from the simulations. These constitutive equations were then used by macroscopic simulations for simulating shrinkage and shape changes in FEM simulations. The continuum theory of sintering embodied in the constitutive description of Skorohod and Olevsky was combined with results from microstructure evolution simulations to model shrinkage and

  15. dbSUPER: a database of super-enhancers in mouse and human genome

    PubMed Central

    Khan, Aziz; Zhang, Xuegong

    2016-01-01

    Super-enhancers are clusters of transcriptional enhancers that drive cell-type-specific gene expression and are crucial to cell identity. Many disease-associated sequence variations are enriched in super-enhancer regions of disease-relevant cell types. Thus, super-enhancers can be used as potential biomarkers for disease diagnosis and therapeutics. Current studies have identified super-enhancers in more than 100 cell types and demonstrated their functional importance. However, a centralized resource to integrate all these findings is not currently available. We developed dbSUPER (http://bioinfo.au.tsinghua.edu.cn/dbsuper/), the first integrated and interactive database of super-enhancers, with the primary goal of providing a resource for assistance in further studies related to transcriptional control of cell identity and disease. dbSUPER provides a responsive and user-friendly web interface to facilitate efficient and comprehensive search and browsing. The data can be easily sent to Galaxy instances, GREAT and Cistrome web-servers for downstream analysis, and can also be visualized in the UCSC genome browser where custom tracks can be added automatically. The data can be downloaded and exported in variety of formats. Furthermore, dbSUPER lists genes associated with super-enhancers and also links to external databases such as GeneCards, UniProt and Entrez. dbSUPER also provides an overlap analysis tool to annotate user-defined regions. We believe dbSUPER is a valuable resource for the biology and genetic research communities. PMID:26438538

  16. The Hurricane-Flood-Landslide Continuum

    NASA Technical Reports Server (NTRS)

    Negri, Andrew J.; Burkardt, Nina; Golden, Joseph H.; Halverson, Jeffrey B.; Huffman, George J.; Larsen, Matthew C.; McGinley, John A.; Updike, Randall G.; Verdin, James P.; Wieczorek, Gerald F.

    2005-01-01

    In August 2004, representatives from NOAA, NASA, the USGS, and other government agencies convened in San Juan, Puerto Rim for a workshop to discuss a proposed research project called the Hurricane-Flood-Landslide Continuum (HFLC). The essence of the HFLC is to develop and integrate tools across disciplines to enable the issuance of regional guidance products for floods and landslides associated with major tropical rain systems, with sufficient lead time that local emergency managers can protect vulnerable populations and infrastructure. All three lead agencies are independently developing precipitation-flood-debris flow forecasting technologies, and all have a history of work on natural hazards both domestically and overseas. NOM has the capability to provide tracking and prediction of storm rainfall, trajectory and landfall and is developing flood probability and magnTtude capabilities. The USGS has the capability to evaluate the ambient stability of natural and man-made landforms, to assess landslide susceptibilities for those landforms, and to establish probabilities for initiation of landslides and debris flows. Additionally, the USGS has well-developed operational capacity for real-time monitoring and reporting of streamflow across distributed networks of automated gaging stations (http://water.usgs.gov/waterwatch/). NASA has the capability to provide sophisticated algorithms for satellite remote sensing of precipitation, land use, and in the future, soil moisture. The Workshop sought to initiate discussion among three agencies regarding their specific and highly complimentary capabilities. The fundamental goal of the Workshop was to establish a framework that will leverage the strengths of each agency. Once a prototype system is developed for example, in relatively data-rich Puerto Rim, it could be adapted for use in data-poor, low-infrastructure regions such as the Dominican Republic or Haiti. This paper provides an overview of the Workshop s goals

  17. On the Continuum Representation of Fracture Networks

    NASA Astrophysics Data System (ADS)

    Hassan, A.; Botros, F.; Reeves, D. M.; Pohll, G.

    2006-12-01

    Discrete Fracture Network (DFN) and Stochastic Continuum (SC) are the two dominant modeling approaches used for simulating of fluid flow and solute transport in fractured media. While the SC approach has several variants, we focus on two methods introduced by Svensson [2001] and McKenna and Reeves [2002] where discrete fracture networks are directly mapped onto a finite-difference grid as grid cell conductivities. These methods combine the merits of each approach; a computationally efficient grid is utilized for the solution of fluid flow, and details of the fracture network are preserved by assigning a permeability contrast between the grid cells representing the rock matrix and fracture cells. In this paper, we focus on several outstanding issues that are associated with SC models: enhanced connectivity between fractures that would otherwise not be in connection in a DFN simulation, the formulation of grid cell conductivity for cells containing multiple fractures, and the influence of grid size. To addresses these issues, both DFN and SC models are used to solve for fluid flow through two-dimensional, randomly generated fracture networks. To minimize connectivity between fractures in the SC model, a percolation algorithm is used to define the hydraulic backbone before fractures are mapped onto a model grid. The effect of grid size is studied by using two different regularly-spaced grids with cell lengths of 1m and 10m. The resultant DFN flow solutions are used as a metric to evaluate different approaches used to assign grid cell conductivity. Results from this study are presented as guidelines for representing fracture networks as grid cell conductivities.

  18. Continuum physics: Correlation and fluctuation analysis

    SciTech Connect

    Herskind, B.

    1993-10-01

    It is well known that the main flow of the {gamma}-decay from high spin states passes through the regions of high level density several MeV above the yrast line. Nevertheless, only very limited information about the nuclear structure in this region is available, due to the extremely high complexity of the decay patterns. The new highly efficient {gamma}-spectrometer arrays, GASP, EUROGAM and GAMMASPHERE coming into operation these years, with several orders of magnitude higher selectivity for studying weakly populated states, offers new exiting possibilities also for a much more detailed study of the high spin quasi-continuum. It is of special interest to study the phase transition from the region of discrete regular rotational band structures found close to the yrast line, into the region of damped rotational motion at higher excitation energies and investigate the interactions responsible for the damping phenomena. Some of the first large data-sets to be analyzed are made on residues around e.g. {sup 152}Dy and {sup 168}Yb produced with EUROGAM in Daresbury, UK, in addition to {sup 143}Eu and {sup 182}Pt produced with GASP in Legnaro, Italy. These data-sets will for the first time contain enough counts to allow for a fluctuation analysis of 3-fold coincidence matrixes. The high spatial resolution in a cube of triples make it possible to select transitions from specific configurations using 2 of the detectors and measure the fluctuations caused by the simplicity of feeding the selected configuration by the 3. detector. Thus, weakly mixed structures in the damped region as e.g. superdeformed- or high-K bands are expected to show large fluctuations. Results from these experiments will be discussed.

  19. Continuum and computational modeling of flexoelectricity

    NASA Astrophysics Data System (ADS)

    Mao, Sheng

    , stationary cracks, as well as structures with periodic structures, can be studied consistently with the continuum theory. We also generate predictions of experimental merit and reveal interesting flexoelectric phenomena with potential for application.

  20. Cosmological measurements with forthcoming radio continuum surveys

    NASA Astrophysics Data System (ADS)

    Raccanelli, Alvise; Zhao, Gong-Bo; Bacon, David J.; Jarvis, Matt J.; Percival, Will J.; Norris, Ray P.; Röttgering, Huub; Abdalla, Filipe B.; Cress, Catherine M.; Kubwimana, Jean-Claude; Lindsay, Sam; Nichol, Robert C.; Santos, Mario G.; Schwarz, Dominik J.

    2012-08-01

    We present forecasts for constraints on cosmological models that can be obtained using the forthcoming radio continuum surveys: the wide surveys with the Low Frequency Array (LOFAR) for radio astronomy, the Australian Square Kilometre Array Pathfinder (ASKAP) and the Westerbork Observations of the Deep Apertif Northern Sky (WODAN). We use simulated catalogues that are appropriate to the planned surveys in order to predict measurements obtained with the source autocorrelation, the cross-correlation between radio sources and cosmic microwave background (CMB) maps (the integrated Sachs-Wolfe effect), the cross-correlation of radio sources with foreground objects resulting from cosmic magnification, and a joint analysis together with the CMB power spectrum and supernovae (SNe). We show that near-future radio surveys will bring complementary measurements to other experiments, probing different cosmological volumes and having different systematics. Our results show that the unprecedented sky coverage of these surveys combined should provide the most significant measurement yet of the integrated Sachs-Wolfe effect. In addition, we show that the use of the integrated Sachs-Wolfe effect will significantly tighten the constraints on modified gravity parameters, while the best measurements of dark energy models will come from galaxy autocorrelation function analyses. Using a combination of the Evolutionary Map of the Universe (EMU) and WODAN to provide a full-sky survey, it will be possible to measure the dark energy parameters with an uncertainty of {σ(w0) = 0.05, σ(wa) = 0.12} and the modified gravity parameters {σ(η0) = 0.10, σ(μ0) = 0.05}, assuming Planck CMB+SN (current data) priors. Finally, we show that radio surveys would detect a primordial non-Gaussianity of fNL= 8 at 1σ, and we briefly discuss other promising probes.

  1. Mentorship: The Education-Research Continuum

    SciTech Connect

    Correll, D

    2008-05-29

    Mentoring of science students stems naturally from the intertwined link between science education and science research. In fact, the mentoring relationship between a student and a scientist may be thought of analogically as a type of double helix forming the 'DNA' that defines the blueprint for the next generation of scientists. Although this analogy would not meet the rigorous tests commonly used for exploring the natural laws of the universe, the image depicted does capture how creating and sustaining the future science workforce benefits greatly from the continuum between education and research. The path science students pursue from their education careers to their research careers often involves training under an experienced and trusted advisor, i.e., a mentor. For many undergraduate science students, a summer research internship at a DOE National Laboratory is one of the many steps they will take in their Education-Research Continuum. Scientists who choose to be mentors share a commitment for both science education and science research. This commitment is especially evident within the research staff found throughout the Department of Energy's National Laboratories. Research-based internship opportunities within science, technology, engineering and mathematics (STEM) exist at most, if not all, of the Laboratories. Such opportunities for students are helping to create the next generation of highly trained professionals devoted to the task of keeping America at the forefront of scientific innovation. 'The Journal of Undergraduate Research' (JUR) provides undergraduate interns the opportunity to publish their scientific innovation and to share their passion for education and research with fellow students and scientists. The theme of this issue of the JUR (Vol. 8, 2008) is 'Science for All'. Almost 20 years have passed since the American Association for the Advancement of Science published its 1989 report, 'Science for All Americans-Project 2061'. The first

  2. OBSERVATIONAL EVIDENCE FOR A CORRELATION BETWEEN MACROTURBULENT BROADENING AND LINE-PROFILE VARIATIONS IN OB SUPERGIANTS

    SciTech Connect

    Simon-Diaz, S.; Herrero, A.; Castro, N.; Uytterhoeven, K.; Puls, J.

    2010-09-10

    The spectra of O and B supergiants (Sgs) are known to be affected by a significant form of extra line broadening (usually referred to as macroturbulence) in addition to that produced by stellar rotation. Recent analyses of high-resolution spectra have shown that the interpretation of this line broadening as a consequence of large-scale turbulent motions would imply highly supersonic velocity fields in photospheric regions, making this scenario quite improbable. Stellar oscillations have been proposed as a likely alternative explanation. As part of a long-term observational project, we are investigating the macroturbulent broadening in O and B Sgs and its possible connection with spectroscopic variability phenomena and stellar oscillations. In this Letter, we present the first encouraging results of our project, namely, firm observational evidence for a strong correlation between the extra broadening and photospheric line-profile variations in a sample of 13 Sgs with spectral types ranging from O9.5 to B8.

  3. Simulated models of inhomogeneous broadening in perturbed angular correlation spectroscopy (PAC)

    NASA Astrophysics Data System (ADS)

    Stufflebeam, Michael A.; Hodges, Jeffery A.; Evenson, William E.; Matheson, P.; Zacate, M. O.

    2007-10-01

    All real crystals have defects: missing atoms (vacancies), impurities, atoms out of place, etc. In perturbed angular correlation (PAC), these defects produce damping of the correlation signal in time and broadening of the frequency spectrum. This broadening is termed ``inhomogeneous broadening'' since it is due to the inhomogeneities (i.e. defects) in the crystal. We have simulated PAC spectra for various concentrations (0.1% to 5%) of distant randomly distributed defects plus a near-neighbor vacancy in simple cubic and face-centered cubic crystal structures. For every particular set of defects, the randomly distributed defects and the near-neighbor vacancy together produce a net electric field gradient (EFG), from which we obtain the PAC spectrum. We fit average PAC spectra to study the effects of defect concentration and crystal structure on inhomogeneous broadening as an aid to analyzing experimental data.

  4. Measurements of H2O-broadening coefficients of O2 A-band lines

    NASA Astrophysics Data System (ADS)

    Delahaye, T.; Landsheere, X.; Pangui, E.; Huet, F.; Hartmann, J.-M.; Tran, H.

    2016-11-01

    We report laboratory measurements of H2O-broadening coefficients of O2 absorption lines in the A-band near 13,000 cm-1. For this, four spectra of oxygen gas mixed with water vapor were recorded with a high resolution Fourier transform spectrometer for total pressures ranging from 125 to 175 Torr at 323 K, and a fifth at 175 Torr and 365 K. Broadening coefficients of 39 transitions (up to J″ = 21) were retrieved from the measured spectra through fits using Galatry line profiles. Values at room temperature (296 K) were then extrapolated and compared with previous determinations in the A-band and millimeter waves region. This enables to resolve some controversial issues related to the inconsistencies between these studies. Finally, comparing our results with the line broadening coefficients by dry air confirms that H2O-broadenings of oxygen lines are, on average, 10% larger than those by dry air.

  5. Progress with On-The-Fly Neutron Doppler Broadening in MCNP

    SciTech Connect

    Brown, Forrest B.; Martin, William R.; Yesilyurt, Gokhan; Wilderman, Scott

    2012-06-18

    The University of Michigan, ANL, and LANL have been collaborating on a US-DOE-NE University Programs project 'Implementation of On-the-Fly Doppler Broadening in MCNP5 for Multiphysics Simulation of Nuclear Reactors.' This talk describes the project and provides results from the initial implementation of On-The-Fly Doppler broadening (OTF) in MCNP and testing. The OTF methodology involves high precision fitting of Doppler broadened cross-sections over a wide temperature range (the target for reactor calculations is 250-3200K). The temperature dependent fits are then used within MCNP during the neutron transport, for OTF broadening based on cell temperatures. It is straightforward to extend this capability to cover any temperature range of interest, allowing the Monte Carlo simulation to account for a continuous distribution of temperature ranges throughout the problem geometry.

  6. Smile to see the forest: Facially expressed positive emotions broaden cognition

    PubMed Central

    Johnson, Kareem J.; Waugh, Christian E.; Fredrickson, Barbara L.

    2011-01-01

    The broaden hypothesis, part of Fredrickson’s (1998, 2001) broaden-and-build theory, proposes that positive emotions lead to broadened cognitive states. Here, we present evidence that cognitive broadening can be produced by frequent facial expressions of positive emotion. Additionally, we present a novel method of using facial electromyography (EMG) to discriminate between Duchenne (genuine) and non-Duchenne (non-genuine) smiles. Across experiments, Duchenne smiles occurred more frequently during positive emotion inductions than neutral or negative inductions. Across experiments, Duchenne smiles correlated with self-reports of specific positive emotions. In Experiment 1, high frequencies of Duchenne smiles predicted increased attentional breadth on a global–local visual processing task. In Experiment 2, high frequencies of Duchenne smiles predicted increased attentional flexibility on a covert attentional orienting task. These data underscore the value of using multiple methods to measure emotional experience in studies of emotion and cognition. PMID:23275681

  7. Experimental and Theoretical Studies of Pressure Broadened Alkali-Metal Atom Resonance Lines

    NASA Technical Reports Server (NTRS)

    Shindo, F.; Zhu, C.; Kirby, K.; Babb, J. F.

    2006-01-01

    We are carrying out a joint theoretical and experimental research program to study the broadening of alkali atom resonance lines due to collisions with helium and molecular hydrogen for applications to spectroscopic studies of brown dwarfs and extrasolar giant planets.

  8. A universal equation for computing the beam broadening of incident electrons in thin films.

    PubMed

    Gauvin, Raynald; Rudinsky, Samantha

    2016-08-01

    A universal equation for computing the beam broadening of incident electrons in thin films is presented. This equation is based on the concepts of anomalous diffusion with the Hurst exponent H. When the thickness to elastic mean free path ratio, t/λ, is greater than 1, the Hurst exponent goes to 0.5 and this random walk behavior leads to the Goldstein et al. [1] beam broadening equation when non-relativistic screened Rutherford elastic cross-sections are used. When t/λ≪1, the lack of elastic collisions for the electron trajectories gives an H exponent of 1 and a different beam broadening equation is obtained. A general equation to compute the beam broadening that takes into account the variation of H with t/λ is presented and this equation was fitted and validated with Monte Carlo simulations of electron trajectories in thin films. PMID:27161415

  9. Vasculopathy of Aging and the Revised Cardiovascular Continuum

    PubMed Central

    Kim, Su-A; Park, Jeong Bae; O'Rourke, Michael F.

    2015-01-01

    There have been attempts to explain the process of developments in overt cardiovascular disease, resulting in the presentation of the classic cardiovascular disease continuum and the aging cardiovascular continuum. Although the starting points of these two continua are different, they meet in the midstream of the cycle and reach a consensus at the end of the process. The announcement of the aging cardiovascular continuum made both continua complete, explaining the cardiovascular events in patients without atherosclerotic cardiovascular disease with aging. Impairment of the vascular structure by pulse wave and reflected wave is considered the cause of aortic damage, which influences the development of ischemic heart disease and the development of overt renal disease or cerebrovascular disease. The pathophysiology of vascular aging through pulse wave and its effect on other organs was discussed with Prof. Michael F. O'Rourke who devised the aging cardiovascular continuum. PMID:26587463

  10. Four-body continuum-discretized coupled-channels calculations

    SciTech Connect

    Rodriguez-Gallardo, M.; Arias, J. M.; Moro, A. M.; Gomez-Camacho, J.; Thompson, I. J.; Tostevin, J. A.

    2009-11-15

    The development of a continuum-bin scheme of discretization for three-body projectiles is necessary for studies of reactions of Borromean nuclei such as {sup 6}He within the continuum-discretized coupled-channels approach. Such a procedure, for constructing bin states on selected continuum energy intervals, is formulated and applied for the first time to reactions of a three-body projectile. The continuum representation uses the eigenchannel expansion of the three-body S matrix. The method is applied to the challenging case of the {sup 6}He+{sup 208}Pb reaction at 22 MeV, where an accurate treatment of both the Coulomb and the nuclear interactions with the target is necessary.

  11. Continuum discretised BCS approach for weakly bound nuclei

    NASA Astrophysics Data System (ADS)

    Lay, J. A.; Alonso, C. E.; Fortunato, L.; Vitturi, A.

    2016-08-01

    The Bardeen-Cooper-Schrieffer (BCS) formalism is extended by including the single-particle continuum in order to analyse the evolution of pairing in an isotopic chain from stability up to the drip-line. We propose a continuum discretised generalised BCS based on single-particle pseudostates (PS). These PS are generated from the diagonalisation of the single-particle Hamiltonian within a transformed harmonic oscillator basis. The consistency of the results versus the size of the basis is studied. The method is applied to neutron rich oxygen and carbon isotopes and compared with similar previous works and available experimental data. We make use of the flexibility of the proposed model in order to study the evolution of the occupation of the low-energy continuum when the system becomes weakly bound. We find an increasing influence of the non-resonant continuum as long as the Fermi level approaches the neutron separation threshold.

  12. Equivalent-Continuum Modeling of Nano-Structured Materials

    NASA Technical Reports Server (NTRS)

    Odegard, Gregory M.; Gates, Thomas S.; Nicholson, Lee M.; Wise, Kristopher E.

    2001-01-01

    A method has been developed for modeling structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with an equivalent-continuum model. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As an important example with direct application to the development and characterization of single-walled carbon nanotubes, the model has been applied to determine the effective continuum geometry of a graphene sheet. A representative volume element of the equivalent-continuum model has been developed with an effective thickness. This effective thickness has been shown to be similar to, but slightly smaller than, the interatomic spacing of graphite.

  13. N2- and (H2+He)-broadened cross sections of benzene (C6H6) in the 7-15 μm region for the Titan and jovian atmospheres

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Toon, Geoffrey C.; Crawford, Timothy J.

    2016-06-01

    In support of atmospheric remote sensing of Titan and jovian planets, we measured absorption cross sections of benzene (C6H6) in the 7-15 μm region at temperatures between 235 K and 297 K. For this, high-resolution laboratory spectra of C6H6 were obtained using two cold cells (80 cm and 2.07 cm path length) configured to a high resolution Fourier-transform infrared (FT-IR) spectrometer, Bruker IFS-125HR, at the Jet Propulsion Laboratory (JPL). The spectrum sets include 15 pure and 15 N2-broadened benzene spectra in the 630-1534 cm-1 region, along with four additional spectra broadened by an H2(85%) and He(15%) gas mixture for the 630-740 cm-1 region. From these spectra, temperature dependent benzene cross sections were obtained for gas phase benzene in the presence of N2 and (H2+He) at ambient pressures and temperatures down to 235 K. In addition, we generated two independent sets of pseudolines: one of N2-broadened benzene for Titan and the other of (H2+He)-broadened benzene for jovian planets. It is shown that the benzene pseudolines can reproduce the observed features to ˜ 5% in transmittance, including the continuum-like absorption formed by numerous overlapping weak and hot band transitions. Based on the pseudoline parameters, the integrated band intensities at 296 K for the three strongest bands in the region were measured to be 177.0(73), 14.0(10), 27.2(9)×10-17 cm-1/(molecule·cm-2) in the region of v4 at 674 cm-1, v14 at 1038.267, and v13 at 1483.985 cm-1, respectively, from the combined set of pure and N2-broadened benzene spectra. For the (H2+He) mixture-broadened benzene spectra, the integrated band intensity for v4 band in the 630-735 cm-1 region was measured to be 168.8(17)×10-17 cm-1/(molecule·cm-2) at 296 K, which is in agreement with the intensity derived from the N2-broadened benzene spectra within the combined measurement uncertainties. The results from this work show an excellent agreement (2%) with one of the latest experimental studies by

  14. Searching for New Physics at SuperB - The Super Flavor Factory

    ScienceCinema

    Hiltin, David [Caltech, Pasadena, California, United States

    2016-07-12

    SuperB – a Super Flavor Factory, an electron-positron collider with a luminosity of 1036 cm-2 s-1, can conduct conduct unique sensitive searches for New Physics effects such as lepton flavor violation and new sources of CP violation in the quark and lepton sectors.

  15. A hybrid particle/continuum approach for nonequilibrium hypersonic flows

    NASA Astrophysics Data System (ADS)

    Wang, Wen-Lan

    A hybrid particle-continuum computational framework is developed and presented for simulating nonequilibrium hypersonic flows, aimed to be more accurate than conventional continuum methods and faster than particle methods. The frame work consists of the direct simulation Monte Carlo-Information Preservation (DSMC-IP) method coupled with a Navier-Stokes solver. Since the DSMC-IP method provides the macroscopic information at each time step, determination of the continuum fluxes across the interface between the particle and continuum domains becomes straightforward. Buffer and reservoir calls are introduced in the continuum domain and work as an extension of the particle domain. At the end of the particle movement phase, particles in either particle or buffer cells are retained. All simulated particles in the reservoir cells are first deleted for each time, step and re-generated based on the local cell values. The microscopic velocities for the newly generated particles are initialized to the Chapman-Enskog distribution using an acceptance-rejection scheme. Continuum breakdown in a flow is defined as when the continuum solution departs from the particle solution to at least 5%. Numerical investigations show that a Knudsen-number-like parameter can best predict the continuum breakdown in the flows of interest. Numerical experiments of hypersonic flows over a simple blunted cone and a much more complex hollow cylinder/flare are conducted. The solutions for the two geometries considered from the hybrid framework are compared with experimental data and pure particle solutions. Generally speaking, it is concluded that the hybrid approach works quite well. In the blunted cone flow, numerical accuracy is improved when 10 layers of buffer cells are employed and the continuum breakdown cut-off value is set to be 0.03. In the hollow cylinder/flare hybrid simulation, the size of the separation zone near the conjunction of the cylinder and flare is improved from the initial

  16. An extended Coleman-Noll procedure for generalized continuum theories

    NASA Astrophysics Data System (ADS)

    Hütter, Geralf

    2016-11-01

    Within rational continuum mechanics, the Coleman-Noll procedure is established to derive requirements to constitutive equations. Aiming in particular at generalized continuum theories, the present contribution demonstrates how this procedure can be extended to yield additionally the underlying balance equations of stress-type quantities. This is demonstrated for micromorphic and strain gradient media as well as for the microforce theory. The relation between the extended Coleman-Noll procedure and the method of virtual powers is pointed out.

  17. Uses of continuum radiation in the AXAF calibration

    NASA Technical Reports Server (NTRS)

    Kolodziejczak, J. J.; Austin, R. A.; Elsner, R. F.; O'Dell, S. L.; Sulkanen, M. E.; Swartz, D. A.; Tennant, A. F.; Weisskopf, M. C.; Zirnstein, G.; McDermott, W. C.

    1997-01-01

    X-ray calibration of the Advanced X-ray Astrophysics Facility (AXAF) observatory at the MSFC X-Ray Calibration Facility (XRCF) made novel use of the x-ray continuum from a conventional electron-impact source. Taking advantage of the good spectral resolution of solid-state detectors, continuum measurements proved advantageous in calibrating the effective area of AXAF's High-Resolution Mirror Assembly (HRMA) and in verifying its alignment to the XRCF's optical axis.

  18. High-energy continuum emission from solar flares

    NASA Technical Reports Server (NTRS)

    Vestrand, W. Thomas

    1988-01-01

    The properties of solar flare continuum emission at energies of greater than 300 keV have been determined from observations obtained during the 21st solar maximum by gamma-ray detectors aboard the SMM and Hinotori satellites. The temporal structure of the high-energy continuum is modeled by two-step acceleration and particle trapping. The results suggest that the very high-energy emission noted must be a mixture of pion-decay radiation and primary electron bremsstrahlung.

  19. Variable temperature pressure broadening of HNO3 in the millimeter wave spectral region

    NASA Technical Reports Server (NTRS)

    Goyette, Thomas M.; Guo, Wei; Delucia, Frank C.; Helminger, Paul

    1991-01-01

    Measurements were performed for both O2 and N2 broadening in the 100-380 K temperature range by using a heated equilibrium cell for elevated temperatures and the utilization of a collisionally cooled cell at the lower temperatures where HNO3 has a small vapor pressure. Observed pressure-broadening data can be fit to the normal empirical law, giving n values between 0.62 and 0.84.

  20. Global α -decay study based on the mass table of the relativistic continuum Hartree-Bogoliubov theory

    NASA Astrophysics Data System (ADS)

    Zhang, Lin-Feng; Xia, Xue-Wei

    2016-05-01

    The α-decay energies (Q α ) are systematically investigated with the nuclear masses for 10 ⩽ Z ⩽ 120 isotopes obtained by the relativistic continuum Hartree-Bogoliubov (RCHB) theory with the covariant density functional PC-PK1, and compared with available experimental values. It is found that the α-decay energies deduced from the RCHB results present a similar pattern to those from available experiments. Owing to the large predicted Q α values (⩾ 4 MeV), many undiscovered heavy nuclei in the proton-rich side and super-heavy nuclei may have large possibilities for α-decay. The influence of nuclear shell structure on α-decay energies is also analysed. Supported by Major State 973 Program of China (2013CB834400), National Natural Science Foundation of China (11175002, 11335002, 11375015, 11461141002), Research Fund for the Doctoral Program of Higher Education (20110001110087) and National Undergraduate Innovation Training Programs of Peking University.

  1. Broadening the Study of Participation in the Life Sciences: How Critical Theoretical and Mixed-Methodological Approaches Can Enhance Efforts to Broaden Participation

    ERIC Educational Resources Information Center

    Metcalf, Heather

    2016-01-01

    This research methods Essay details the usefulness of critical theoretical frameworks and critical mixed-methodological approaches for life sciences education research on broadening participation in the life sciences. First, I draw on multidisciplinary research to discuss critical theory and methodologies. Then, I demonstrate the benefits of these…

  2. Caring Across the Continuum: A Call to Nurse Leaders to Manifest Values Through Action With Community Outreach.

    PubMed

    Dyess, Susan MacLeod; Opalinski, Andra; Saiswick, Kim; Fox, Valerie

    2016-01-01

    As health reform continues to advance, there is a need for nurse leaders to broaden their perspective related to possible nursing practice models and potential community partners in order to successfully address caring, accomplish the triple aim mandate, and achieve suitable metrics for maximum reimbursement. Intentional efforts must be made by nurse leaders to maximize caring and ensure that professional nurses are responding to the key drivers shifting health care delivery in the 21st century. Academic-practice collaboration (APC) and community-based participatory action research (CBPAR) align well. Together, they provide an ideal mechanism to pursue endeavors that extend evidence for caring services across the health care continuum. One APC/CBPAR model for community outreach that can maximize individual and population health outcomes is highlighted in this article. Furthermore, useful action steps are offered that could be taken by a nurse leader to develop and maintain any form of APC/CBPAR in order to manifest values through caring action across the health care continuum. PMID:26938186

  3. Airglow continuum emission in the visible wavelength regime

    NASA Astrophysics Data System (ADS)

    Unterguggenberger, S.; Noll, S.; Kausch, W.; Proxauf, B.; Kimeswenger, S.

    2015-03-01

    To probe dynamics and chemistry of the atmosphere at high altitudes ( 80-100 km), we need to understand airglow line and continuum emission. Accounting for the continuum emission is harder than for the emission lines. Gaining knowledge of the upper atmospheric continuum emission needs e.g. a proper subtraction of the other continuum components, and a very good subtraction of the other emission lines which requires a high spectral resolution. In this study, we want to focus on FeO continuum emission. FeO emits in the wavelength range from 0.5 to 0.72 m and probes an altitude of about 89 km. The altitude of the emission peak lies between those of OH (87 km) and NaD (92 km). Fe and Na are linked by their source, meteors, and their common reactant O3, which holds also for OH emission. Lidar and limb sounding studies provide measurements about the continuum contribution of the FeO and Fe density in the upper atmosphere, but for a more detailed analysis in terms of emission structure and variability a ground-based high resolution and high signal-to-noise spectrum would be preferable.

  4. Relativistic corrections and non-Gaussianity in radio continuum surveys

    SciTech Connect

    Maartens, Roy; Zhao, Gong-Bo; Bacon, David; Koyama, Kazuya; Raccanelli, Alvise E-mail: Gong-bo.Zhao@port.ac.uk E-mail: Kazuya.Koyama@port.ac.uk

    2013-02-01

    Forthcoming radio continuum surveys will cover large volumes of the observable Universe and will reach to high redshifts, making them potentially powerful probes of dark energy, modified gravity and non-Gaussianity. We consider the continuum surveys with LOFAR, WSRT and ASKAP, and examples of continuum surveys with the SKA. We extend recent work on these surveys by including redshift space distortions and lensing convergence in the radio source auto-correlation. In addition we compute the general relativistic (GR) corrections to the angular power spectrum. These GR corrections to the standard Newtonian analysis of the power spectrum become significant on scales near and beyond the Hubble scale at each redshift. We find that the GR corrections are at most percent-level in LOFAR, WODAN and EMU surveys, but they can produce O(10%) changes for high enough sensitivity SKA continuum surveys. The signal is however dominated by cosmic variance, and multiple-tracer techniques will be needed to overcome this problem. The GR corrections are suppressed in continuum surveys because of the integration over redshift — we expect that GR corrections will be enhanced for future SKA HI surveys in which the source redshifts will be known. We also provide predictions for the angular power spectra in the case where the primordial perturbations have local non-Gaussianity. We find that non-Gaussianity dominates over GR corrections, and rises above cosmic variance when f{sub NL}∼>5 for SKA continuum surveys.

  5. Relativistic corrections and non-Gaussianity in radio continuum surveys

    NASA Astrophysics Data System (ADS)

    Maartens, Roy; Zhao, Gong-Bo; Bacon, David; Koyama, Kazuya; Raccanelli, Alvise

    2013-02-01

    Forthcoming radio continuum surveys will cover large volumes of the observable Universe and will reach to high redshifts, making them potentially powerful probes of dark energy, modified gravity and non-Gaussianity. We consider the continuum surveys with LOFAR, WSRT and ASKAP, and examples of continuum surveys with the SKA. We extend recent work on these surveys by including redshift space distortions and lensing convergence in the radio source auto-correlation. In addition we compute the general relativistic (GR) corrections to the angular power spectrum. These GR corrections to the standard Newtonian analysis of the power spectrum become significant on scales near and beyond the Hubble scale at each redshift. We find that the GR corrections are at most percent-level in LOFAR, WODAN and EMU surveys, but they can produce O(10%) changes for high enough sensitivity SKA continuum surveys. The signal is however dominated by cosmic variance, and multiple-tracer techniques will be needed to overcome this problem. The GR corrections are suppressed in continuum surveys because of the integration over redshift — we expect that GR corrections will be enhanced for future SKA HI surveys in which the source redshifts will be known. We also provide predictions for the angular power spectra in the case where the primordial perturbations have local non-Gaussianity. We find that non-Gaussianity dominates over GR corrections, and rises above cosmic variance when fNLgtrsim5 for SKA continuum surveys.

  6. Temperature-Dependent Line Shift and Broadening of CO Infrared Transitions.

    PubMed

    Drascher; Giesen; Wang; Schmücker; Schieder; Winnewisser; Joubert; Bonamy

    1998-12-01

    The temperature dependence of lineshift and broadening of the rovibrational transitions R(18) and R(20) of the CO fundamental band, perturbed by Ar, N2, O2, and H2, have been measured with high frequency accuracy and at temperatures between 160 and 270 K in steps of 20 K. A wavelength stabilized tunable diode laser spectrometer has been combined with a low temperature long path cell of 134 m absorption length and 1 m basis length. For all measurements the CO pressure was below 0.1 mbar to avoid self-shift and self-broadening. In case of line broadening the temperature dependence is quite well reproduced by an exponential relation, b(T) = b(T0)(T/T0)-n. For all foreign gases, the exponent n has been obtained (0.53 broadening and shift for CO with Ar and the broadening of CO by N2 and O2 have been compared to calculations from the semi-classical theory of Robert and Bonamy. Sufficient agreement has been achieved for the line broadening, while the calculated shifts are for all temperatures larger than the measured values. Copyright 1998 Academic Press.

  7. Non-symmetric broadening of the reflection notch in polymer stabilized cholesteric liquid crystals

    NASA Astrophysics Data System (ADS)

    Natarajan, Lalgudi V.; Voss, Jimmy R.; Tondiglia, Vincent P.; Yang, Deng-Ke; White, Timothy J.; Bunning, Timothy J.

    2010-08-01

    Non-symmetric broadening (to the blue side) of a cholesteric reflection notch was observed when a cell containing diacrylate and monoacrylate nematic LC monomers, a chiral dopant, nematic LC and a photoinitiator was exposed to very low intensity (microwatts) of 335 nm UV light. At very low intensity, the polymerization rate is very slow and takes a long time to complete as observed by real-time monitoring experiments. The polymerized scaffold templates the original liquid crystal helical structure. The 335 nm light is highly absorbed by the system which generates an intensity gradient throughout the thickness of the cell. This gradient produces a free radical density gradient in the later stage of the polymerization when diffusion is slowed by the growing polymer network. Since more monomer is consumed at the front half of the cell, a counter diffusion of chiral dopant towards the cell backside is observed. This leads to a local increase in the HTP causing a local blue shift of the notch wavelength. The net result observed in transmission is a broadening of the reflection bandwidth from 70 nm to 200 nm where the broadening occurs only to the blue side of the original notch. By varying the intensity of the UV source on one side of the substrate, the broadening magnitude could be controlled. Simultaneous UV illumination from both sides of the cell reduced the broadening considerably. The broadened notch was switchable at high electrical field (20V/μm).

  8. Integrated radio continuum spectra of galaxies

    SciTech Connect

    Marvil, Joshua; Owen, Frazer; Eilek, Jean

    2015-01-01

    We investigate the spectral shape of the total continuum radiation, between 74 MHz and 5 GHz (400-6 cm in wavelength), for a large sample of bright galaxies. We take advantage of the overlapping survey coverage of the VLA Low-Frequency Sky Survey, the Westerbork Northern Sky Survey, the NRAO VLA Sky Survey, and the Green Bank 6 cm Survey to achieve significantly better resolution, sensitivity, and sample size compared to prior efforts of this nature. For our sample of 250 bright galaxies we measure a mean spectral index, α, of –0.69 between 1.4 and 4.85 GHz, –0.55 between 325 MHz and 1.4 GHz, and –0.45 between 74 and 325 MHz, which amounts to a detection of curvature in the mean spectrum. The magnitude of this curvature is approximately Δα = –0.2 per logarithmic frequency decade when fit with a generalized function having constant curvature. No trend in low-frequency spectral flattening versus galaxy inclination is evident in our data, suggesting that free-free absorption is not a satisfying explanation for the observed curvature. The ratio of thermal to non-thermal emission is estimated through two independent methods: (1) using the IRAS far-IR fluxes and (2) with the value of the total spectral index. Method (1) results in a distribution of 1.4 GHz thermal fractions of 9% ± 3%, which is consistent with previous studies, while method (2) produces a mean 1.4 GHz thermal fraction of 51% with dispersion 26%. The highly implausible values produced by method (2) indicate that the sum of typical power-law thermal and non-thermal components is not a viable model for the total spectral index between 325 and 1.4 GHz. An investigation into relationships between spectral index, infrared-derived quantities, and additional source properties reveals that galaxies with high radio luminosity in our sample are found to have, on average, a flatter radio spectral index, and early types tend to have excess radio emission when compared to the radio-infrared ratio of later

  9. Integrated Radio Continuum Spectra of Galaxies

    NASA Astrophysics Data System (ADS)

    Marvil, Joshua; Owen, Frazer; Eilek, Jean

    2015-01-01

    We investigate the spectral shape of the total continuum radiation, between 74 MHz and 5 GHz (400-6 cm in wavelength), for a large sample of bright galaxies. We take advantage of the overlapping survey coverage of the VLA Low-Frequency Sky Survey, the Westerbork Northern Sky Survey, the NRAO VLA Sky Survey, and the Green Bank 6 cm Survey to achieve significantly better resolution, sensitivity, and sample size compared to prior efforts of this nature. For our sample of 250 bright galaxies we measure a mean spectral index, α, of -0.69 between 1.4 and 4.85 GHz, -0.55 between 325 MHz and 1.4 GHz, and -0.45 between 74 and 325 MHz, which amounts to a detection of curvature in the mean spectrum. The magnitude of this curvature is approximately Δα = -0.2 per logarithmic frequency decade when fit with a generalized function having constant curvature. No trend in low-frequency spectral flattening versus galaxy inclination is evident in our data, suggesting that free-free absorption is not a satisfying explanation for the observed curvature. The ratio of thermal to non-thermal emission is estimated through two independent methods: (1) using the IRAS far-IR fluxes and (2) with the value of the total spectral index. Method (1) results in a distribution of 1.4 GHz thermal fractions of 9% ± 3%, which is consistent with previous studies, while method (2) produces a mean 1.4 GHz thermal fraction of 51% with dispersion 26%. The highly implausible values produced by method (2) indicate that the sum of typical power-law thermal and non-thermal components is not a viable model for the total spectral index between 325 and 1.4 GHz. An investigation into relationships between spectral index, infrared-derived quantities, and additional source properties reveals that galaxies with high radio luminosity in our sample are found to have, on average, a flatter radio spectral index, and early types tend to have excess radio emission when compared to the radio-infrared ratio of later types

  10. Breeding Super-Earths and Birthing Super-Puffs in Transitional Disks

    NASA Astrophysics Data System (ADS)

    Lee, Eve J.; Chiang, Eugene

    2015-12-01

    The riddle posed by super-Earths (1--4 Earth radii, 2--20 Earth masses) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earthsformed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many orders of magnitude, and super-Earths can robustly emerge with percent-by-weight atmospheres after ~0.1--1 Myr. We propose that 1) close-in super-Earths form in situ, because their cores necessarily coagulate in gas-poor environments—gas dynamical friction must be weakened sufficiently to allow constituent protocores to cross orbits and merge; 2) super- Earths acquire their atmospheres from ambient wisps of gas that are supplied from a diffusing outer disk. The formation environment is reminiscent of the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also 3) address the inverse problem presented by super-puffs: an uncommon class of short- period planets seemingly too voluminous for their small masses (4--10 Earth radii, 2--6 Earth masses). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ~1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content.

  11. Super-resolution benefit for face recognition

    NASA Astrophysics Data System (ADS)

    Hu, Shuowen; Maschal, Robert; Young, S. Susan; Hong, Tsai Hong; Phillips, Jonathon P.

    2011-06-01

    Vast amounts of video footage are being continuously acquired by surveillance systems on private premises, commercial properties, government compounds, and military installations. Facial recognition systems have the potential to identify suspicious individuals on law enforcement watchlists, but accuracy is severely hampered by the low resolution of typical surveillance footage and the far distance of suspects from the cameras. To improve accuracy, super-resolution can enhance suspect details by utilizing a sequence of low resolution frames from the surveillance footage to reconstruct a higher resolution image for input into the facial recognition system. This work measures the improvement of face recognition with super-resolution in a realistic surveillance scenario. Low resolution and super-resolved query sets are generated using a video database at different eye-to-eye distances corresponding to different distances of subjects from the camera. Performance of a face recognition algorithm using the super-resolved and baseline query sets was calculated by matching against galleries consisting of frontal mug shots. The results show that super-resolution improves performance significantly at the examined mid and close ranges.

  12. Continuum and molecular-dynamics simulation of nanodroplet collisions.

    PubMed

    Bardia, Raunak; Liang, Zhi; Keblinski, Pawel; Trujillo, Mario F

    2016-05-01

    The extent to which the continuum treatment holds in binary droplet collisions is examined in the present work by using a continuum-based implicit surface capturing strategy (volume-of-fluid coupled to Navier-Stokes) and a molecular dynamics methodology. The droplet pairs are arranged in a head-on-collision configuration with an initial separation distance of 5.3 nm and a velocity of 3 ms^{-1}. The size of droplets ranges from 10-50 nm. Inspecting the results, the collision process can be described as consisting of two periods: a preimpact phase that ends with the initial contact of both droplets, and a postimpact phase characterized by the merging, deformation, and coalescence of the droplets. The largest difference between the continuum and molecular dynamics (MD) predictions is observed in the preimpact period, where the continuum-based viscous and pressure drag forces significantly overestimate the MD predictions. Due to large value of Knudsen number in the gas (Kn_{gas}=1.972), this behavior is expected. Besides the differences between continuum and MD, it is also observed that the continuum simulations do not converge for the set of grid sizes considered. This is shown to be directly related to the initial velocity profile and the minute size of the nanodroplets. For instance, for micrometer-size droplets, this numerical sensitivity is not an issue. During the postimpact period, both MD and continuum-based simulations are strikingly similar, with only a moderate difference in the peak kinetic energy recorded during the collision process. With values for the Knudsen number in the liquid (Kn_{liquid}=0.01 for D=36nm) much closer to the continuum regime, this behavior is expected. The 50 nm droplet case is sufficiently large to be predicted reasonably well with the continuum treatment. However, for droplets smaller than approximately 36 nm, the departure from continuum behavior becomes noticeably pronounced, and becomes drastically different for the 10 nm

  13. Assessing resolution in super-resolution imaging.

    PubMed

    Demmerle, Justin; Wegel, Eva; Schermelleh, Lothar; Dobbie, Ian M

    2015-10-15

    Resolution is a central concept in all imaging fields, and particularly in optical microscopy, but it can be easily misinterpreted. The mathematical definition of optical resolution was codified by Abbe, and practically defined by the Rayleigh Criterion in the late 19th century. The limit of conventional resolution was also achieved in this period, and it was thought that fundamental constraints of physics prevented further increases in resolution. With the recent development of a range of super-resolution techniques, it is necessary to revisit the concept of optical resolution. Fundamental differences in super-resolution modalities mean that resolution is not a directly transferrable metric between techniques. This article considers the issues in resolution raised by these new technologies, and presents approaches for comparing resolution between different super-resolution methods.

  14. Earths, Super-Earths, and Jupiters

    NASA Astrophysics Data System (ADS)

    Chiang, Eugene; Lee, Eve J.

    2015-12-01

    We review and add to the theory of how planets acquire atmospheres from parent circumstellar disks. We derive (in real time) a simple and general analytic expression for how a planet's atmosphere grows with time, as a function of the underlying core mass and nebular conditions, including the gas metallicity. Planets accrete as much gas as can cool: an atmosphere's doubling time is given by its Kelvin-Helmholtz time. The theory can be applied in any number of settings --- gas-rich vs. gas-poor nebulae; dusty vs. dust-free atmospheres; close-in vs. far-out distances --- and is confirmed against detailed numerical models for objects ranging in mass from Mars (0.1 Mearth) to the most extreme super Earths (10--20 Mearth). We explain why heating from planetesimal accretion, commonly invoked in models of core accretion, is irrelevant. This talk sets the stage for another presentation, "Breeding Super-Earths and Birthing Super-Puffs".

  15. Genomic Study of Cardiovascular Continuum Comorbidity

    PubMed Central

    Makeeva, O. A.; Sleptsov, A. A.; Kulish, E. V.; Barbarash, O. L.; Mazur, A. M.; Prokhorchuk, E. B.; Chekanov, N. N.; Stepanov, V. A.; Puzyrev, V. P.

    2015-01-01

    Comorbidity or a combination of several diseases in the same individual is a common and widely investigated phenomenon. However, the genetic background for non–random disease combinations is not fully understood. Modern technologies and approaches to genomic data analysis enable the investigation of the genetic profile of patients burdened with several diseases (polypathia, disease conglomerates) and its comparison with the profiles of patients with single diseases. An association study featuring three groups of patients with various combinations of cardiovascular disorders and a control group of relatively healthy individuals was conducted. Patients were selected as follows: presence of only one disease, ischemic heart disease (IHD); a combination of two diseases, IHD and arterial hypertension (AH); and a combination of several diseases, including IHD, AH, type 2 diabetes mellitus (T2DM), and hypercholesterolemia (HC). Genotyping was performed using the “My Gene” genomic service (www.i–gene.ru). An analysis of 1,400 polymorphic genetic variants and their associations with the studied phenotypes are presented. A total of 14 polymorphic variants were associated with the phenotype “IHD only,” including those in the APOB, CD226, NKX2–5, TLR2, DPP6, KLRB1, VDR, SCARB1, NEDD4L, and SREBF2 genes, and intragenic variants rs12487066, rs7807268, rs10896449, and rs944289. A total of 13 genetic markers were associated with the “IHD and AH” phenotype, including variants in the BTNL2, EGFR, CNTNAP2, SCARB1, and HNF1A genes, and intragenic polymorphisms rs801114, rs10499194, rs13207033, rs2398162, rs6501455, and rs1160312. A total of 14 genetic variants were associated with a combination of several diseases of cardiovascular continuum (CVC), including those in the TAS2R38, SEZ6L, APOA2, KLF7, CETP, ITGA4, RAD54B, LDLR, and MTAP genes, along with intragenic variants rs1333048, rs1333049, and rs6501455. One common genetic marker was identified for the

  16. A Description of the Continuum of Eating Disorders: Implications for Intervention and Research.

    ERIC Educational Resources Information Center

    Scarano, Gina M.; Kalodner-Martin, Cynthia R.

    1994-01-01

    Presents an eating disorders continuum. Describes groups on the continuum by highlighting behavioral, cognitive-attitudinal, and self-esteem differences. Discusses relationship between continuum and developmental course of eating disorders. Presents prevention, early intervention, and treatment programs for various continuum groups. Offers…

  17. Super-sampling SART with ordered subsets.

    PubMed

    Kunz, Michael; Frangakis, Achilleas S

    2014-11-01

    In tomography, the quality of the reconstruction is essential because the complete cascade of the subsequent analysis is based on it. To date, weighted back-projection (WBP) has been the most commonly used technique due to its versatility and performance in sub-tomogram averaging. Here we present super-sampling SART that is based on the simultaneous algebraic reconstruction technique. While algebraic reconstruction techniques typically produce better contrast and lately showed a significant improvement in terms of processing speed, sub-tomogram averages derived from those reconstructions were inferior in resolution compared to those derived from WBP data. Super-sampling SART, however, outperforms both in term of contrast and the resolution achieved in sub-tomogram averaging several other tested methods and in particular WBP. The main feature of super-sampling SART, as the name implies, is the super-sampling option - by which parameter-based up-sampling and down-sampling are used to reduce artifacts. In particular, the aliasing that is omnipresent in the reconstruction can be practically eliminated without a significant increase in the computational time. Furthermore, super-sampling SART reaches convergence within a single iteration, making the processing time comparable to WBP, and eliminating the ambiguity of parameter-controlled convergence times. We find that grouping of projections increases the contrast, while when projections are used individually the resolution can be maximized. Using sub-tomogram averaging of ribosomes as a test case, we show that super-sampling SART achieves equal or better sub-tomogram averaging results than WBP, which is of particular importance in cryo-electron tomography.

  18. Effect of pressure broadening on molecular absorption cross sections in exoplanetary atmospheres

    NASA Astrophysics Data System (ADS)

    Hedges, Christina; Madhusudhan, Nikku

    2016-05-01

    Spectroscopic observations of exoplanets are leading to unprecedented constraints on their atmospheric compositions. However, molecular abundances derived from spectra are degenerate with the absorption cross-sections which form critical input data in atmospheric models. Therefore, it is important to quantify the uncertainties in molecular cross-sections to reliably estimate the uncertainties in derived molecular abundances. However, converting line lists into cross-sections via line broadening involves a series of prescriptions for which the uncertainties are not well understood. We investigate and quantify the effects of various factors involved in line broadening in exoplanetary atmospheres - the profile evaluation width, pressure versus thermal broadening, broadening agent, spectral resolution and completeness of broadening parameters - on molecular absorption cross-sections. We use H2O as a case study as it has the most complete absorption line data. For low-resolution spectra (R ≲ 100) for representative temperatures and pressures (T ˜ 500-3000 K, P ≲ 1 atm) of H2-rich exoplanetary atmospheres, we find the median difference in cross-sections (δ) introduced by various aspects of pressure broadening to be ≲1 per cent. For medium resolutions (R ≲ 5000), including those attainable with James Webb Space Telescope, we find that δ can be up to 40 per cent. For high resolutions (R ˜ 105), δ can be ≳100 per cent, reaching ≳1000 per cent for low temperatures (T ≲ 500 K) and high pressures (P ≳ 1 atm). The effect is higher still for self-broadening. We generate a homogeneous data base of absorption cross-sections of molecules of relevance to exoplanetary atmospheres for which high-temperature line lists are available, particularly H2O, CO, CH4, CO2, HCN, and NH3.

  19. A broad-standard technique for correcting for band broadening in size-exclusion chromatography.

    PubMed

    Zhang, Peng; Mazoyer, Paul; Gilbert, Robert G

    2016-04-22

    Band broadening in size-exclusion chromatography (SEC) is always present to some extent. Broadening effects on averages such as the weight- and number average molecular weights (MW and Mn respectively) are minimal with modern SEC systems. However, broadening distorts the shape of the true molecular weight distribution (MWD), which causes problems if one wants to compare the detailed form of the MWD to a model. An addition to current methods for overcoming this problem is presented. One starts with a sufficiently wide range of samples whose exact values of Mn and MW have been measured by non-SEC methods (e.g. by fluorimetry and light scattering, respectively, of the sample without size separation). A true (unbroadened) molecular weight distribution for a sample can be obtained by deconvolution (here using a maximum-entropy algorithm) by fitting SEC data for these samples to these exact Mn and MW values to find the values of the parameters in a sufficiently flexible assumed broadening function. This was modelled using simulated band broadening and subsequent deconvolution, with the broadening parameters least-squares fitted to the "exact" sets of values of Mn and MW. The results show that if these Mn and MW values are for a series of broad (not narrow) standards covering a sufficient range of molecular weight, then after deconvolution, a good representation of the original molecular weight distribution used in the simulation is obtained. The method should prove useful for water-soluble polymers, for which it is often difficult to obtain narrow standards of a wide range of molecular weight, as required in a number of well-established methods for correcting for band broadening. PMID:27016112

  20. Rotational relaxation in ozone and its relation to atmospheric pressure broadening

    SciTech Connect

    Flannery, C.C.

    1993-01-01

    The relationship between rotational relaxation rates and pressure broadening of the ozone infrared spectrum has been investigated through a complementary set of time and frequency domain experiments and calculations. Rotational relaxation rates were measured by time-resolved infrared double resonance experiments. A pulsed CO[sub 2] laser was used to pump ozone molecules into selected rotational states of the [nu][sub 3] = 1 manifold. Total depopulation and hole-filling rates were measured by observation of time-resolved transient absorption signals originating in the upper or lower level of the pump transition. The temperature and collision partner dependence of these rates was investigated. Additional double resonance signals were recorded for [nu][sub 3] rotational levels not pumped directly by the laser, but receiving population through inelastic relaxation channels. Pressure-broadening coefficients were determined for ozone [nu][sub 3] rovibrational transitions. Room temperature self-broadening measurements were the first in the [nu][sub 3] band. The temperature dependence of nitrogen and oxygen broadening of ozone [nu][sub 3] lines was studied over the 200-3009 K range. Comparisons of broadening coefficients and total inelastic rates showed that average nitrogen and oxygen coefficients could be predicted from measured total inelastic rates but elastic processes contribute to ozone self-broadening. State-to-state relaxation rates were calculated by decomposing line-broadening calculations and also through the use of approximate energy transfer scaling laws. These sets of state-to-state inelastic rates were used in a kinetic model of relaxation in the [nu][sub 3] manifold to simulate transient infrared absorption signals. Model simulations were used to evaluate rate calculations and rotational energy transfer propensity rules. Comparisons of kinetic model simulations and double resonance signals confirmed a propensity for first order dipolar transitions.

  1. A broad-standard technique for correcting for band broadening in size-exclusion chromatography.

    PubMed

    Zhang, Peng; Mazoyer, Paul; Gilbert, Robert G

    2016-04-22

    Band broadening in size-exclusion chromatography (SEC) is always present to some extent. Broadening effects on averages such as the weight- and number average molecular weights (MW and Mn respectively) are minimal with modern SEC systems. However, broadening distorts the shape of the true molecular weight distribution (MWD), which causes problems if one wants to compare the detailed form of the MWD to a model. An addition to current methods for overcoming this problem is presented. One starts with a sufficiently wide range of samples whose exact values of Mn and MW have been measured by non-SEC methods (e.g. by fluorimetry and light scattering, respectively, of the sample without size separation). A true (unbroadened) molecular weight distribution for a sample can be obtained by deconvolution (here using a maximum-entropy algorithm) by fitting SEC data for these samples to these exact Mn and MW values to find the values of the parameters in a sufficiently flexible assumed broadening function. This was modelled using simulated band broadening and subsequent deconvolution, with the broadening parameters least-squares fitted to the "exact" sets of values of Mn and MW. The results show that if these Mn and MW values are for a series of broad (not narrow) standards covering a sufficient range of molecular weight, then after deconvolution, a good representation of the original molecular weight distribution used in the simulation is obtained. The method should prove useful for water-soluble polymers, for which it is often difficult to obtain narrow standards of a wide range of molecular weight, as required in a number of well-established methods for correcting for band broadening.

  2. VLA Radio Continuum Imaging of Radio-Infrared Supernebulae in Starburst Galaxies at 1.3 cm

    NASA Astrophysics Data System (ADS)

    Tsai, C.-W.; Turner, J. L.; Beck, S. C.

    2005-12-01

    We present 1''-resolution VLA K-band images of 14 nearby starburst galaxies in which we have detected compact (sub-arcsecond) and luminous mid-IR sources with LWS imaging spectrograph on Keck Observatory. Of the galaxies observed, 11 are detected with strong continuum emission at 1.3 cm. In the VLA K-band where synchrotron emission is weak and dust emission has not yet kicked in, therefore the radio continuum emission should be dominated by thermal free-free emission. The strong extended free-free emission indicates the existence of ˜ 104 - 105 O stars living in active regions of these starburst galaxies. Our K-band maps also reveal many compact sources which are presumbly ''radio-infrared supernebulae", or RISN. These nebulae are dense, young (< 1 Myr), and require the immediate presence of thousands of young O stars within regions only a few parsecs in extent. RISN in these galaxies are excited by massive (105 - 106 MSun) super star clusters (SSCs) which may be the precursors to globular clusters.

  3. Single-Molecule Spectroscopy, Imaging, and Photocontrol: Foundations for Super-Resolution Microscopy (Nobel Lecture).

    PubMed

    Moerner, W E William E

    2015-07-01

    The initial steps toward optical detection and spectroscopy of single molecules in condensed matter arose out of the study of inhomogeneously broadened optical absorption profiles of molecular impurities in solids at low temperatures. Spectral signatures relating to the fluctuations of the number of molecules in resonance led to the attainment of the single-molecule limit in 1989 using frequency-modulation laser spectroscopy. In the early 90s, many fascinating physical effects were observed for individual molecules, and the imaging of single molecules as well as observations of spectral diffusion, optical switching and the ability to select different single molecules in the same focal volume simply by tuning the pumping laser frequency provided important forerunners of the later super-resolution microscopy with single molecules. In the room temperature regime, imaging of single copies of the green fluorescent protein also uncovered surprises, especially the blinking and photoinduced recovery of emitters, which stimulated further development of photoswitchable fluorescent protein labels. Because each single fluorophore acts a light source roughly 1 nm in size, microscopic observation and localization of individual fluorophores is a key ingredient to imaging beyond the optical diffraction limit. Combining this with active control of the number of emitting molecules in the pumped volume led to the super-resolution imaging of Eric Betzig and others, a new frontier for optical microscopy beyond the diffraction limit. The background leading up to these observations is described and current developments are summarized.

  4. Nobel Lecture: Single-molecule spectroscopy, imaging, and photocontrol: Foundations for super-resolution microscopy*

    NASA Astrophysics Data System (ADS)

    Moerner, W. E. William E.

    2015-10-01

    The initial steps toward optical detection and spectroscopy of single molecules in condensed matter arose out of the study of inhomogeneously broadened optical absorption profiles of molecular impurities in solids at low temperatures. Spectral signatures relating to the fluctuations of the number of molecules in resonance led to the attainment of the single-molecule limit in 1989 using frequency-modulation laser spectroscopy. In the early 1990s, many fascinating physical effects were observed for individual molecules, and the imaging of single molecules as well as observations of spectral diffusion, optical switching and the ability to select different single molecules in the same focal volume simply by tuning the pumping laser frequency provided important forerunners of the later super-resolution microscopy with single molecules. In the room-temperature regime, imaging of single copies of the green fluorescent protein also uncovered surprises, especially the blinking and photoinduced recovery of emitters, which stimulated further development of photoswitchable fluorescent protein labels. Because each single fluorophore acts as a light source roughly 1 nm in size, microscopic observation and localization of individual fluorophores is a key ingredient to imaging beyond the optical diffraction limit. Combining this with active control of the number of emitting molecules in the pumped volume led to the super-resolution imaging of Eric Betzig and others, a new frontier for optical microscopy beyond the diffraction limit. The background leading up to these observations is described and selected current developments are summarized.

  5. KML Super Overlay to WMS Translator

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian

    2007-01-01

    This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

  6. Super-resolution optical microscopy: multiple choices.

    PubMed

    Huang, Bo

    2010-02-01

    The recent invention of super-resolution optical microscopy enables the visualization of fine features in biological samples with unprecedented clarity. It creates numerous opportunities in biology because vast amount of previously obscured subcellular processes now can be directly observed. Rapid development in this field in the past two years offers many imaging modalities that address different needs but they also complicates the choice of the 'perfect' method for answering a specific question. Here I will briefly describe the principles of super-resolution optical microscopy techniques and then focus on comparing their characteristics in various aspects of practical applications. PMID:19897404

  7. The current status of super computers

    NASA Technical Reports Server (NTRS)

    Knight, J. C.

    1978-01-01

    In this paper, commercially available super computers are surveyed. Computer performance in general is limited by circuit speeds and physical size. Assuming the use of the fastest technology, super computers typically use parallelism in the form of either vector processing or array processing to obtain performance. The Burroughs Scientific Processor is an array computer with 16 separate processors, the Cray-1 and CDC STAR-100 are vector processors, the Goodyear Aerospace STARAN is an array processor with up to 8192 single bit processors, and the Systems Development Corporation PEPE is a collection of up to 288 separate processors.

  8. Background considerations for SuperCDMS

    SciTech Connect

    Cooley, J.; Collaboration: SuperCDMS Collaboration

    2013-08-08

    Rejection and protection from background is a key issue for the next generation SuperCDMS SNOLAB experiment that will have a cross-section sensitivity of better than 8 × 10{sup −46} cm{sup 2} for spin-independent WIMP-nucleon interactions. This paper presents the details of the methods used to reject electromagnetic backgrounds using the new iZIP detectors that are currently operated in the Soudan Underground Laboratory, MN and the methods the collaboration is investigating to protect against neutron background in the next generation SuperCDMS experiment.

  9. Super-collimation by axisymmetric photonic crystals

    SciTech Connect

    Purlys, V.; Gailevičius, D.; Peckus, M.; Gadonas, R.; Maigyte, L.; Staliunas, K.

    2014-06-02

    We propose and experimentally show the mechanism of beam super-collimation by axisymmetric photonic crystals, specifically by periodic (in propagation direction) structure of layers of concentric rings. The physical mechanism behind the effect is an inverse scattering cascade of diffracted wave components back into on- and near-axis angular field components, resulting in substantial enhancement of intensity of these components. We explore the super-collimation by numerical calculations and prove it experimentally. We demonstrate experimentally the axial field enhancement up to 7 times in terms of field intensity.

  10. The SuperCDMS SNOLAB Detector Tower

    NASA Astrophysics Data System (ADS)

    Aramaki, Tsuguo

    2016-08-01

    The SuperCDMS collaboration is moving forward with the design and construction of SuperCDMS SNOLAB, where the initial deployment will include ˜ 30 kg of Ge and ˜ 5 kg of Si detectors. Here, we will discuss the associated cryogenic cold hardware required for the detector readout. The phonon signals will be read out with superconducting quantum interference device arrays and the ionization signals will use high electron mobility transistor amplifiers operating at 4 K. A number of design challenges exist regarding the required wiring complex impedance, noise pickup, vibration, and thermal isolation. Our progress to date will be presented.

  11. Femtosecond continuum interferometer for transient phase and transmission spectroscopy

    NASA Astrophysics Data System (ADS)

    Tokunaga, E.; Terasaki, A.; Kobayashi, T.

    1996-03-01

    We measure difference phase spectra (DPS) over the whole visible spectrum by frequency-domain interferometry (FDI), using chirped femtosecond continuum pulses. The effects of the probe-pulse chirp on time-resolved dispersion relations are studied. Because of the correspondence between time and frequency in the chirp, temporal evolution of the optical Kerr response in CS2 is projected into DPS. In addition, it is found that the chirped continuum shows unexpected frequency shifts owing to induced phase modulation even when the continuum has a flat spectrum. The chirp character can be readily obtained from the projected traces, and the potential application to the single-shot pulse-shape measurement by FDI is discussed. It is shown that the delay-time-corrected spectra satisfy the Kramers-Kronig relations if the continuum has a flat spectrum and does not have higher chirp than the linear chirp but that the distortion caused by the induced modulation of the continuum remains unremoved in the corrected spectra.

  12. Measuring the continuum polarization with ESPaDOnS

    NASA Astrophysics Data System (ADS)

    Pereyra, A.; Rodrigues, C. V.; Martioli, E.

    2015-01-01

    Aims: Our goal is to test the feasibility of obtaining accurate measurements of the continuum polarization from high-resolution spectra using the spectropolarimetric mode of ESPaDOnS. Methods: We used the new pipeline OPERA to reduce recent and archived ESPaDOnS data. Several polarization standard stars and science objects were tested for the linear mode. In addition, the circular mode was tested using several objects from the archive with expected null polarization. Synthetic broad-band polarization was computed from the ESPaDOnS continuum polarization spectra and compared with published values (when available) to quantify the accuracy of the instrument. Results: The continuum linear polarization measured by ESPaDOnS is consistent with broad-band polarimetry measurements available in the literature. The accuracy in the degree of linear polarization is around 0.2-0.3% considering the full sample. The accuracy in polarization position angle using the most polarized objects is better than 5°. Consistent with this, the instrumental polarization computed for the circular continuum polarization is also between 0.2-0.3%. Our results suggest that measurements of the continuum polarization using ESPaDOnS are viable and can be used to study many astrophysical objects. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientique of France, and the University of Hawaii.

  13. Do subglacial bedforms comprise a size and shape continuum?

    NASA Astrophysics Data System (ADS)

    Ely, Jeremy C.; Clark, Chris D.; Spagnolo, Matteo; Stokes, Chris R.; Greenwood, Sarah L.; Hughes, Anna L. C.; Dunlop, Paul; Hess, Dale

    2016-03-01

    Understanding the evolution of the ice-bed interface is fundamentally important for gaining insight into the dynamics of ice masses and how subglacial landforms are created. However, the formation of the suite of landforms generated at this boundary - subglacial bedforms - is a contentious issue that is yet to be fully resolved. Bedforms formed in aeolian, fluvial, and marine environments either belong to separate morphological populations or are thought to represent a continuum of forms generated by the same governing processes. For subglacial bedforms, a size and shape continuum has been hypothesised, yet it has not been fully tested. Here we analyse the largest data set of subglacial bedform size and shape measurements ever collated (96,900 bedforms). Our results show that flutes form a distinct population of narrow bedforms. However, no clear distinction was found between drumlins and megascale glacial lineations (MSGLs), which form a continuum of subglacial lineations. A continuum of subglacial ribs also exists, with no clear size or shape distinctions indicating separate populations. Furthermore, an underreported class of bedform with no clear orientation to ice flow (quasi-circular bedforms) overlaps with the ribbed and lineation continua and typically occurs in spatial transition zones between the two, potentially merging these three bedform types into a larger continuum.

  14. Suicide and the continuum of self-destructive behavior.

    PubMed

    Firestone, R W; Seiden, R H

    1990-03-01

    Suicide and self-destructive behavior are strongly influenced by a negative thought process, referred to here as the "voice." The voice process represents a well-integrated pattern of thoughts, attitudes, and beliefs, antithetical to self and hostile toward others, that is at the core of a patient's self-limitations and self-defeating actions. The voice varies along a continuum of intensity ranging from mild self-criticism to angry self-attacks and even suicidal thoughts. Self-destructive behavior similarly exists on a continuum ranging from self-denial to accident proneness, drug abuse, alcoholism, and other self-defeating behaviors, culminating in actual bodily harm. The two processes, cognitive and behavioral, parallel each other, and suicide represents the acting out of the extreme end of the continuum. The authors provide a chart depicting the levels of increasing suicidal intent along the continuum. The chart identifies specific negative thoughts and injunctions typically reported by persons who attempt suicide, neurotic patients, and "normal" subjects. Understanding where an individual can be placed on the continuum of self-destructive thoughts and actions can assist clinicians in their diagnoses and help pinpoint those students who are more at risk for suicide.

  15. Explosive Super-eruptions: Problems and Prejudices

    NASA Astrophysics Data System (ADS)

    Self, S.

    2010-12-01

    A super-eruption is defined as one with a magma yield > 10^15 kg (magnitude (M) 8). The term has mainly been applied to large-scale, caldera and ignimbrite-forming explosive eruptions, but it can be applied to all eruptions that released > 10^15 kg of magma. For effusive volcanism, evidence suggests that individual eruptions of this size ( > ~ 370 km^3 of typical basalt or > 450 km^3 of rhyolite flood lava) arise only during periods of LIP formation. The super-eruption concept raises interesting questions about genesis and storage of magmas that feed these vast events. Deposits of major explosive eruptions are Plinian fallout, ignimbrite sheets, and co-ignimbrite ash fall. Based on earlier suggestions and evidence, widespread outflow ignimbrite (O), co-ignimbrite ash (A), and inter-caldera ignimbrite (I) are all major components of the total super-eruption deposit and may tend towards being subequal. In super-eruption deposits, the reported volume of vent-derived Plinian eruption column fallout is often a minor component of the total volume, yet in several cases (Oruanui, Taupo, 26 ka ago, M 8.1; Bishop Tuff, 760 ka, M 8.2; Bandelier (Otowi) Tuff, 1.6 Ma, M8) it is now recognized that vent-derived columns persisted for most of the eruption. Thus, distally, the ash-fall derived from co-ignimbrite ash clouds may be mixed with contemporaneous fallout from a vertical column. Some major ignimbrites have no reported associated Plinian deposit; the huge Young Toba Tuff (YTT, 74 ka, M 8.8) is a significant example. However, the very widespread Toba ash-fall deposit constitutes ~ 40 % of the total mass of magma erupted and is presumed to be co-ignimbrite. Timing of the onset of column collapse probably controls whether a recognizable Plinian deposit is laid down. All super-eruptions probably produce extensive fallout deposits, and this is generally of vent-derived and pyroclastic-flow-derived origin. Establishing the relationships between large-scale ignimbrites and their

  16. The Weighted Super Bergman Kernels Over the Supermatrix Spaces

    NASA Astrophysics Data System (ADS)

    Feng, Zhiming

    2015-12-01

    The purpose of this paper is threefold. Firstly, using Howe duality for , we obtain integral formulas of the super Schur functions with respect to the super standard Gaussian distributions. Secondly, we give explicit expressions of the super Szegö kernels and the weighted super Bergman kernels for the Cartan superdomains of type I. Thirdly, combining these results, we obtain duality relations of integrals over the unitary groups and the Cartan superdomains, and the marginal distributions of the weighted measure.

  17. Phase Change Super Resolution near Field Structure ROM

    NASA Astrophysics Data System (ADS)

    Kim, Hyunki; Hwang, Inoh; Kim, Jooho; Park, Changmin; Ro, Myongdo; Lee, Jinkyung; Jung, Moonil; Park, Insik

    2005-05-01

    We confirmed a super resolution phenomenon and a typical super resolution near field structure threshold phenomenon in a read only memory (ROM)-type sample disk. We found that this super resolution phenomenon originates from a phase-change layer and is closely related to the thermal properties of the super resolution layer. We also improved the readout stability using a co-sputtered layer with phase change (GST) and dielectric materials (ZnS-SiO2).

  18. Happy heart, smiling eyes: A systematic review of positive mood effects on broadening of visuospatial attention.

    PubMed

    Vanlessen, Naomi; De Raedt, Rudi; Koster, Ernst H W; Pourtois, Gilles

    2016-09-01

    Positive mood contributes to mental and physical wellbeing. The broaden-and-build theory (Fredrickson, 2001) proposed that the beneficial effects of positive mood on life quality result from attentional broadening. In this article, we systematically review (following PRISMA guidelines; Moher et al., 2009), a host of studies investigating the nature and extent of attentional changes triggered by the experience of positive mood, with a focus on vision. While several studies reported a broadening of attention, others found that positive mood led to a more diffuse information processing style. Positive mood appears to lessen attention selectivity in a way that is context-specific and bound to limitations. We propose a new framework in which we postulate that positive mood impacts the balance between internally and externally directed attention, through modulations of cognitive control processes, instead of broadening attention per se. This novel model is able to accommodate discrepant findings, seeks to translate the phenomenon of the so-called broadening of attention with positive mood into functional terms, and provides plausible neurobiological mechanisms underlying this effect, suggesting a crucial role of the anterior and posterior cingulate cortex in this interaction. PMID:27395341

  19. Physical limits to broadening compensation in a linear slow light system.

    PubMed

    Gonzalez-Herraez, Miguel; Thévenaz, Luc

    2009-03-16

    The dispersion experienced by a signal in a slow light system leads to a significant pulse broadening and sets a limit to the maximum delay actually achievable by the system. To overcome this limitation, a substantial research effort is currently being carried out, and successful strategies to reduce distortion in linear slow light systems have already been demonstrated. Recent theoretical and experimental works have even claimed the achievement of zero-broadening of pulses in these systems. In this work we obtain some physical limits to broadening compensation in linear slow light systems based on simple Fourier analysis. We show that gain and dispersion broadening can never compensate in such a system. Additionally, it is simply proven that all the linear slow light systems that introduce a low-pass filtering of the signal (a reduction in the signal root-mean- square spectral width), will always cause pulse broadening. These demonstrations are done using a rigorous shape-independent definition of pulse width (the root-mean-square temporal width) and arguments borrowed from time-frequency analysis. PMID:19293903

  20. BROAD IRON LINES IN NEUTRONS STARS: DYNAMICAL BROADENING OR WIND SCATTERING?

    SciTech Connect

    Cackett, Edward M.; Miller, Jon M.

    2013-11-01

    Broad iron emission lines are observed in many accreting systems from black holes in active galactic nuclei and X-ray binaries to neutron star low-mass X-ray binaries. The origin of the line broadening is often interpreted as due to dynamical broadening and relativistic effects. However, alternative interpretations have been proposed, included broadening due to Compton scattering in a wind or accretion disk atmosphere. Here we explore the observational signatures expected from broadening in a wind, in particular that the iron line width should increase with an increase in the column density of the absorber (due to an increase in the number of scatterings). We study the data from three neutron star low-mass X-ray binaries where both a broad iron emission line and absorption lines are seen simultaneously, and show that there is no significant correlation between line width and column density. This favors an inner disk origin for the line broadening rather than scattering in a wind.

  1. Stark broadening of impurity absorption lines by inhomogeneous electric fields in highly compensated germanium

    NASA Astrophysics Data System (ADS)

    Harada, Y.; Fujii, K.; Ohyama, T.; Itoh, K. M.; Haller, E. E.

    1996-06-01

    Stark broadening of Zeeman absorption lines caused by inhomogeneous electric fields in highly compensated Ge has been studied by means of far-infrared magneto-optical absorption spectroscopy measurements. A number of transmutation-doped Ge single crystals with a systematically varying compensation ratio were employed. The broadening of the full width at half maximum (FWHM) of an absorption line of the Ga acceptor is studied as a function of excitation light intensity with above-band-gap energy. The FWHM increases with decreasing intensity of the band-edge light excitation. Observation of the theoretically predicted 4/3-power law of Stark broadening, due to ionized impurities, is reported. The line broadening originates in the Stark effect, due to inhomogeneous electric fields caused by the random distribution of ionized impurities. In order to understand the mechanism for the line broadening in detail, a numerical approach based on a Monte Carlo simulation has been performed. The results of this simulation show that the inhomogeneity of the field distribution becomes larger with increasing concentration of ionized impurities. The simulation based on a perfectly random distribution for an initial impurity arrangement gives a fairly good agreement with the experimental results. We conclude that the distribution of impurities in transmutation-doped Ge samples is close to random.

  2. Super ready: how a regional approach to Super Bowl EMS paid off.

    PubMed

    Clancy, Terry; Cortacans, Henry P

    2014-07-01

    The Super Bowl and its associated activities represent one of the largest special events in the world. Super Bowl XLVIII was geographically unique because the NFL's and Super Bowl Host Committee's activities, venues and events encompassed two states and fell across numerous jurisdictions within six counties (Bergen, Hudson, Morris, Essex, Middlesex, and Manhattan).This Super Bowl was the first to do this. EMS was one of the largest operational components during this event. Last and most important, it is the people and relationships that make any planning initiative and event a success. Sit down and have a cup a coffee with your colleagues, partners and neighbors in and out of state to discuss your planning initiatives. Do it early-it will make your efforts less painful should an event of this magnitude come to a city near you! PMID:25181868

  3. Super ready: how a regional approach to Super Bowl EMS paid off.

    PubMed

    Clancy, Terry; Cortacans, Henry P

    2014-07-01

    The Super Bowl and its associated activities represent one of the largest special events in the world. Super Bowl XLVIII was geographically unique because the NFL's and Super Bowl Host Committee's activities, venues and events encompassed two states and fell across numerous jurisdictions within six counties (Bergen, Hudson, Morris, Essex, Middlesex, and Manhattan).This Super Bowl was the first to do this. EMS was one of the largest operational components during this event. Last and most important, it is the people and relationships that make any planning initiative and event a success. Sit down and have a cup a coffee with your colleagues, partners and neighbors in and out of state to discuss your planning initiatives. Do it early-it will make your efforts less painful should an event of this magnitude come to a city near you!

  4. Quantum state transfer by time reversal in the continuum

    NASA Astrophysics Data System (ADS)

    Longhi, S.

    2016-03-01

    A method for high-fidelity quantum state transfer in a quantum network coupled to a continuum, based on time reversal in the continuum after decay, is theoretically suggested. Provided that the energy spectrum of the network is symmetric around a reference energy and symmetric energy states are coupled the same way to the common continuum, ideal perfect state transfer can be obtained after time reversal. In particular, it is shown that in a linear tight-binding chain a quantum state can be transformed into its mirror image with respect to the center of the chain after a controllable time. As compared to a quantum mirror image based on coherent transport in a static chain with properly tailored inhomogeneous hopping rates, our method does not require hopping rate engineering and is less sensitive to disorder for long transfer times.

  5. Unusually strong attraction in the presence of continuum bound state

    SciTech Connect

    Delfino, A.; Adhikari, S.K.; Tomio, L.; Frederico, T. Departamento de Fisica, Universidade Federal Fluminense, 24210 Niteroi, Rio de Janeiro Instituto de Fisica Teorica, Universidade Estadual Paulista, 01405 Sao Paulo, SP School of Physical Sciences, The Flinders University of South Australia, Bedford Park, SA 5042 Instituto de Estudos Avancados, Centro Tecnico Aeroespacial, 12231 Sao Jose dos Campos, SP )

    1992-11-01

    The result of few-particle ground-state calculation employing a two-particle nonlocal potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unusually strong attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of {pi} as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states.

  6. A polarizable continuum model for molecules at spherical diffuse interfaces

    NASA Astrophysics Data System (ADS)

    Di Remigio, Roberto; Mozgawa, Krzysztof; Cao, Hui; Weijo, Ville; Frediani, Luca

    2016-03-01

    We present an extension of the Polarizable Continuum Model (PCM) to simulate solvent effects at diffuse interfaces with spherical symmetry, such as nanodroplets and micelles. We derive the form of the Green's function for a spatially varying dielectric permittivity with spherical symmetry and exploit the integral equation formalism of the PCM for general dielectric environments to recast the solvation problem into a continuum solvation framework. This allows the investigation of the solvation of ions and molecules in nonuniform dielectric environments, such as liquid droplets, micelles or membranes, while maintaining the computationally appealing characteristics of continuum solvation models. We describe in detail our implementation, both for the calculation of the Green's function and for its subsequent use in the PCM electrostatic problem. The model is then applied on a few test systems, mainly to analyze the effect of interface curvature on solvation energetics.

  7. Continuum model of tendon pathology – where are we now?

    PubMed Central

    McCreesh, Karen; Lewis, Jeremy

    2013-01-01

    Chronic tendon pathology is a common and often disabling condition, the causes of which remain poorly understood. The continuum model of tendon pathology was proposed to provide a model for the staging of tendon pathology and to assist clinicians in managing this often complex condition (Br. J. Sports Med., 43, 2009, 409). The model presents clinical, histological and imaging evidence for the progression of tendon pathology as a three-stage continuum: reactive tendinopathy, tendon disrepair and degenerative tendinopathy. It also provides clinical information to assist in identifying the stage of pathology, in addition to proposed treatment approaches for each stage. The usefulness of such a model is determined by its ability to incorporate and inform new and emerging research. This review examines the degree to which recent research supports or refutes the continuum model and proposes future directions for clinical and research application of the model. PMID:23837792

  8. Quasiparticle-continuum level repulsion in a quantum magnet

    DOE PAGES

    Plumb, K. W.; Hwang, Kyusung; Qiu, Y.; Harriger, Leland W.; Granroth, G.  E.; Kolesnikov, Alexander I.; Shu, G. J.; Chou, F. C.; Rüegg, Ch.; Kim, Yong Baek; et al

    2015-11-30

    When the energy eigenvalues of two coupled quantum states approach each other in a certain parameter space, their energy levels repel each other and level crossing is avoided. Such level repulsion, or avoided level crossing, is commonly used to describe the dispersion relation of quasiparticles in solids. But, little is known about the level repulsion when more than two quasiparticles are present; for example, in a strongly interacting quantum system where a quasiparticle can spontaneously decay into a many-particle continuum. Here we show that even in this case level repulsion exists between a long-lived quasiparticle state and a continuum. Here,more » we observe a renormalization of the quasiparticle dispersion relation due to the presence of the continuum of multi-quasiparticle states, in our fine-resolution neutron spectroscopy study of magnetic quasiparticles in the frustrated quantum magnet BiCu2PO6.« less

  9. Quasiparticle-continuum level repulsion in a quantum magnet

    SciTech Connect

    Plumb, K. W.; Hwang, Kyusung; Qiu, Y.; Harriger, Leland W.; Granroth, G.  E.; Kolesnikov, Alexander I.; Shu, G. J.; Chou, F. C.; Rüegg, Ch.; Kim, Yong Baek; Kim, Young-June

    2015-11-30

    When the energy eigenvalues of two coupled quantum states approach each other in a certain parameter space, their energy levels repel each other and level crossing is avoided. Such level repulsion, or avoided level crossing, is commonly used to describe the dispersion relation of quasiparticles in solids. But, little is known about the level repulsion when more than two quasiparticles are present; for example, in a strongly interacting quantum system where a quasiparticle can spontaneously decay into a many-particle continuum. Here we show that even in this case level repulsion exists between a long-lived quasiparticle state and a continuum. Here, we observe a renormalization of the quasiparticle dispersion relation due to the presence of the continuum of multi-quasiparticle states, in our fine-resolution neutron spectroscopy study of magnetic quasiparticles in the frustrated quantum magnet BiCu2PO6.

  10. Quasiparticle-continuum level repulsion in a quantum magnet

    NASA Astrophysics Data System (ADS)

    Plumb, K. W.; Hwang, Kyusung; Qiu, Y.; Harriger, Leland W.; Granroth, G. E.; Kolesnikov, Alexander I.; Shu, G. J.; Chou, F. C.; Rüegg, Ch.; Kim, Yong Baek; Kim, Young-June

    2016-03-01

    When the energy eigenvalues of two coupled quantum states approach each other in a certain parameter space, their energy levels repel each other and level crossing is avoided. Such level repulsion, or avoided level crossing, is commonly used to describe the dispersion relation of quasiparticles in solids. However, little is known about the level repulsion when more than two quasiparticles are present; for example, in a strongly interacting quantum system where a quasiparticle can spontaneously decay into a many-particle continuum. Here we show that even in this case level repulsion exists between a long-lived quasiparticle state and a continuum. In our fine-resolution neutron spectroscopy study of magnetic quasiparticles in the frustrated quantum magnet BiCu2PO6, we observe a renormalization of the quasiparticle dispersion relation due to the presence of the continuum of multi-quasiparticle states.

  11. A polarizable continuum model for molecules at spherical diffuse interfaces.

    PubMed

    Di Remigio, Roberto; Mozgawa, Krzysztof; Cao, Hui; Weijo, Ville; Frediani, Luca

    2016-03-28

    We present an extension of the Polarizable Continuum Model (PCM) to simulate solvent effects at diffuse interfaces with spherical symmetry, such as nanodroplets and micelles. We derive the form of the Green's function for a spatially varying dielectric permittivity with spherical symmetry and exploit the integral equation formalism of the PCM for general dielectric environments to recast the solvation problem into a continuum solvation framework. This allows the investigation of the solvation of ions and molecules in nonuniform dielectric environments, such as liquid droplets, micelles or membranes, while maintaining the computationally appealing characteristics of continuum solvation models. We describe in detail our implementation, both for the calculation of the Green's function and for its subsequent use in the PCM electrostatic problem. The model is then applied on a few test systems, mainly to analyze the effect of interface curvature on solvation energetics. PMID:27036423

  12. Energy Conversion over Super-hydrophobic Surfaces

    NASA Astrophysics Data System (ADS)

    Zhao, Hui; Zhai, Shengjie

    2015-11-01

    The streaming potential generated by a pressure-driven flow over a charged slip-stick surface with an arbitrary double layer thickness is both theoretically and experimentally studied. To understand the impact of the slip, the streaming potential is compared against that over a homogenously charged smooth surface. Our results indicate that the streaming potential over a super-hydrophobic surface only can be enhanced under certain conditions. In addition, the Onsager relation which directly relates the magnitude of electro-osmotic effect to that of the streaming current effect has been explicitly proved to be valid for thin and thick double layers and homogeneously charged super-hydrophobic surfaces. Comparisons between the streaming current and electro-osmotic mobility for an arbitrary electric double layer thickness under various conditions indicate that the Onsager relation seems applicable for arbitrary weakly charged super-hydrophobic surfaces though there is no general proof. Knowledge of the streaming potential over a slip-stick surface can provide guidance for designing novel and efficient microfluidic energy-conversion devices using super-hydrophobic surfaces. The work was supported by the NSF Grant No. ECCS-1509866.

  13. Typhoon effects on super-tall buildings

    NASA Astrophysics Data System (ADS)

    Li, Q. S.; Xiao, Y. Q.; Wu, J. R.; Fu, J. Y.; Li, Z. N.

    2008-06-01

    Full-scale measurement is considered to be the most reliable method for evaluating wind effects on buildings and structures. This paper presents selected results of wind characteristics and structural responses measured from four super-tall buildings, The Center (350 m high, 79 floors) in Hong Kong, Di Wang Tower (384 m high, 78 floors) in Shenzhen, CITIC Plaza Tower (391 m high, 80 floors) in Guangzhou and Jin Mao Building (421 m high, 88 floors) in Shanghai, during the passages of three typhoons. The field data such as wind speed, wind direction and acceleration responses, etc., were continuously measured from the super-tall buildings during the typhoons. Detailed analysis of the field data was conducted to investigate the characteristics of typhoon-generated wind and wind-induced vibrations of these super-tall buildings under typhoon conditions. The dynamic characteristics of the tall buildings were determined from the field measurements and comparisons with those calculated from the finite element (FE) models of the structures were made. Furthermore, the full-scale measurements were compared with wind tunnel results to evaluate the accuracy of the model test results and the adequacy of the techniques used in the wind tunnel tests. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing super-tall buildings.

  14. Towards an Educational SuperInterface.

    ERIC Educational Resources Information Center

    De Diana, Italo P. F.; White, T. N.

    1994-01-01

    Describes an educational computer network, SuperInterface, that could be used for telestudy for university education. Topics discussed include computer-supported collaborative work; computer-based learning; multimedia databases, or electronic books; human-machine interfaces; hardware, software, and groupware; learners; teachers; organizations and…

  15. Super-sensing through industrial process tomography

    PubMed Central

    2016-01-01

    In this introduction article, we present a brief overview of industrial process tomography. This will start by linking between the concept of industrial process tomography and super-sensing. This will follow with a brief introduction to various process tomography systems and in particular electrical tomography methods. This article is part of the themed issue ‘Supersensing through industrial process tomography’. PMID:27185965

  16. Research Program of a Super Fast Reactor

    SciTech Connect

    Oka, Yoshiaki; Ishiwatari, Yuki; Liu, Jie; Terai, Takayuki; Nagasaki, Shinya; Muroya, Yusa; Abe, Hiroaki; Akiba, Masato; Akimoto, Hajime; Okumura, Keisuke; Akasaka, Naoaki; GOTO, Shoji

    2006-07-01

    Research program of a supercritical-pressure light water cooled fast reactor (Super Fast Reactor) is funded by MEXT (Ministry of Education, Culture, Sports, Science and Technology) in December 2005 as one of the research programs of Japanese NERI (Nuclear Energy Research Initiative). It consists of three programs. (1) development of Super Fast Reactor concept; (2) thermal-hydraulic experiments; (3) material developments. The purpose of the concept development is to pursue the advantage of high power density of fast reactor over thermal reactors to achieve economic competitiveness of fast reactor for its deployment without waiting for exhausting uranium resources. Design goal is not breeding, but maximizing reactor power by using plutonium from spent LWR fuel. MOX will be the fuel of the Super Fast Reactor. Thermal-hydraulic experiments will be conducted with HCFC22 (Hydro chlorofluorocarbons) heat transfer loop of Kyushu University and supercritical water loop at JAEA. Heat transfer data including effect of grid spacers will be taken. The critical flow and condensation of supercritical fluid will be studied. The materials research includes the development and testing of austenitic stainless steel cladding from the experience of PNC1520 for LMFBR. Material for thermal insulation will be tested. SCWR (Supercritical-Water Cooled Reactor) of GIF (Generation-4 International Forum) includes both thermal and fast reactors. The research of the Super Fast Reactor will enhance SCWR research and the data base. The research period will be until March 2010. (authors)

  17. Super-Higgs mechanism in string theory

    SciTech Connect

    Bagger, Jonathan; Giannakis, Ioannis

    2006-05-15

    We exhibit the super-Higgs effect in heterotic string theory by turning on a background antisymmetric tensor B field and deforming the Becchi-Rouet-Stora-Tyutin operator consistent with superconformal invariance. The B field spontaneously breaks spacetime supersymmetry. We show how the gravitini and the physical dilatini gain mass by eating the would-be Goldstone fermions.

  18. Searching for Frozen Super Earth via Microlensing

    NASA Astrophysics Data System (ADS)

    Batista, V.; Beaulieu, J. P.; Cassan, A.; Coutures, C.; Donatowicz, J.; Fouqué, P.; Kubas, D.; Marquette, J. B.

    2009-04-01

    Microlensing planet hunt is a unique method to probe efficiently for frozen Super Earth orbiting the most common stars of our galaxy. It is nicely complementing the parameter space probed by very high accuracy radial velocity measurements and future space based detections of low mass transiting planets. In order to maximize the planet catch, the microlensing community is engaged in a total cooperation among the different groups (OGLE, MicroFUN, MOA, PLANET/RoboNET) by making the real time data available, and mutual informing/reporting about modeling efforts. Eight planets have been published so far by combinations of the different groups, 4 Jovian analogues, one Neptune and two Super Earth. Given the microlensing detection efficiency, it suggests that these Neptunes/Super Earths may be quite common. Using networks of dedicated 1-2m class telescopes, the microlensing community has entered a new phase of planet discoveries, and will be able to provide constraints on the abundance of frozen Super-Earths in the near future. Statistics about Mars to Earth mass planets, extending to the habitable zone will be achieved with space based wide field imagers (EUCLID) at the horizon 2017.

  19. Facile preparation of super durable superhydrophobic materials.

    PubMed

    Wu, Lei; Zhang, Junping; Li, Bucheng; Fan, Ling; Li, Lingxiao; Wang, Aiqin

    2014-10-15

    The low stability, complicated and expensive fabrication procedures seriously hinder practical applications of superhydrophobic materials. Here we report an extremely simple method for preparing super durable superhydrophobic materials, e.g., textiles and sponges, by dip coating in fluoropolymers (FPs). The morphology, surface chemical composition, mechanical, chemical and environmental stabilities of the superhydrophobic textiles were investigated. The results show how simple the preparation of super durable superhydrophobic textiles can be! The superhydrophobic textiles outperform their natural counterparts and most of the state-of-the-art synthetic superhydrophobic materials in stability. The intensive mechanical abrasion, long time immersion in various liquids and repeated washing have no obvious influence on the superhydrophobicity. Water drops are spherical in shape on the samples and could easily roll off after these harsh stability tests. In addition, this simple dip coating approach is applicable to various synthetic and natural textiles and can be easily scaled up. Furthermore, the results prove that a two-tier roughness is helpful but not essential with regard to the creation of super durable superhydrophobic textiles. The combination of microscale roughness of textiles and materials with very low surface tension is enough to form super durable superhydrophobic textiles. According to the same procedure, superhydrophobic polyurethane sponges can be prepared, which show high oil absorbency, oil/water separation efficiency and stability. PMID:25069050

  20. Diffusion of Super-Gaussian Profiles

    ERIC Educational Resources Information Center

    Rosenberg, C.-J.; Anderson, D.; Desaix, M.; Johannisson, P.; Lisak, M.

    2007-01-01

    The present analysis describes an analytically simple and systematic approximation procedure for modelling the free diffusive spreading of initially super-Gaussian profiles. The approach is based on a self-similar ansatz for the evolution of the diffusion profile, and the parameter functions involved in the modelling are determined by suitable…

  1. Difficult Decisions: The Superconducting Super Collider.

    ERIC Educational Resources Information Center

    Newton, David E.; Slesnick, Irwin L.

    1990-01-01

    The fundamental principles of the superconducting super collider are presented. Arguments for the construction of this apparatus and policy issues surrounding its construction are discussed. Charts of the fundamental atomic particles and forces and the history of particle accelerators are provided. An activity for discussing this controversial…

  2. Breeding Super-Earths and Birthing Super-puffs in Transitional Disks

    NASA Astrophysics Data System (ADS)

    Lee, Eve J.; Chiang, Eugene

    2016-02-01

    The riddle posed by super-Earths (1-4R⊕, 2-20M⊕) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ˜0.1-1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4-10R⊕, 2-6M⊕). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ˜1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

  3. Dielectric spectra broadening as the signature of dipole-matrix interaction. I. Water in nonionic solutions.

    PubMed

    Levy, Evgeniya; Puzenko, Alexander; Kaatze, Udo; Ishai, Paul Ben; Feldman, Yuri

    2012-03-21

    Whenever water interacts with another dipolar entity, a broadening of its dielectric relaxation occurs. Often this broadening can be described by the Cole-Cole (CC) spectral function. A new phenomenological approach has been recently presented [A. Puzenko, P. Ben Ishai, and Y. Feldman, Phys. Rev. Lett. 105, 037601 (2010)] that illustrates a physical mechanism of the dipole-matrix interaction underlying the CC behavior in complex systems. By considering the relaxation amplitude Δε, the relaxation time τ, and the broadening parameter α, one can construct a set of 3D trajectories, representing the dynamic behavior of different systems under diverse conditions. Our hypothesis is that these trajectories will contribute to a deeper understanding of the dielectric properties of complex systems. The paper demonstrates how the model describes the state of water in aqueous solutions of non-ionic solutes. For this purpose complex dielectric spectra for aqueous solutions of D-glucose and D-fructose are analyzed.

  4. Positron lifetime and Doppler broadening techniques applied to irradiation-damaged silver

    SciTech Connect

    Howell, R.H.

    1981-07-27

    Positron lifetime and Doppler broadening measurements have been used to study defect production resulting from room temperature irradiation of pure silver by D-T fusion neutrons or energetic protons. Use of the positron annihilation analysis has established that the surviving defects from both irradiations have the same dose dependence and that defect concentration can be quantitatively measured and compared to damage models. The relative merit of the lifetime and Doppler broadening measurements in arriving at these conclusions is discussed in this report along with some practical aspects of the measurements. In the proton damaged samples the trapping rate approaches saturation, a circumstance which could be misinterpreted if a less extensive data set containing only Doppler broadening data were available. Some remarks about the analysis of positron data and general conclusions about the defect structure are given. 3 figures.

  5. Line broadening interference for high-resolution nuclear magnetic resonance spectra under inhomogeneous magnetic fields

    SciTech Connect

    Wei, Zhiliang; Yang, Jian; Lin, Yanqin E-mail: chenz@xmu.edu.cn; Chen, Zhong E-mail: chenz@xmu.edu.cn; Chen, Youhe

    2015-04-07

    Nuclear magnetic resonance spectroscopy serves as an important tool for analyzing chemicals and biological metabolites. However, its performance is subject to the magnetic-field homogeneity. Under inhomogeneous fields, peaks are broadened to overlap each other, introducing difficulties for assignments. Here, we propose a method termed as line broadening interference (LBI) to provide high-resolution information under inhomogeneous magnetic fields by employing certain gradients in the indirect dimension to interfere the magnetic-field inhomogeneity. The conventional spectral-line broadening is thus interfered to be non-diagonal, avoiding the overlapping among adjacent resonances. Furthermore, an inhomogeneity correction algorithm is developed based on pattern recognition to recover the high-resolution information from LBI spectra. Theoretical deductions are performed to offer systematic and detailed analyses on the proposed method. Moreover, experiments are conducted to prove the feasibility of the proposed method for yielding high-resolution spectra in inhomogeneous magnetic fields.

  6. Line broadening interference for high-resolution nuclear magnetic resonance spectra under inhomogeneous magnetic fields.

    PubMed

    Wei, Zhiliang; Yang, Jian; Chen, Youhe; Lin, Yanqin; Chen, Zhong

    2015-04-01

    Nuclear magnetic resonance spectroscopy serves as an important tool for analyzing chemicals and biological metabolites. However, its performance is subject to the magnetic-field homogeneity. Under inhomogeneous fields, peaks are broadened to overlap each other, introducing difficulties for assignments. Here, we propose a method termed as line broadening interference (LBI) to provide high-resolution information under inhomogeneous magnetic fields by employing certain gradients in the indirect dimension to interfere the magnetic-field inhomogeneity. The conventional spectral-line broadening is thus interfered to be non-diagonal, avoiding the overlapping among adjacent resonances. Furthermore, an inhomogeneity correction algorithm is developed based on pattern recognition to recover the high-resolution information from LBI spectra. Theoretical deductions are performed to offer systematic and detailed analyses on the proposed method. Moreover, experiments are conducted to prove the feasibility of the proposed method for yielding high-resolution spectra in inhomogeneous magnetic fields.

  7. Positive emotions broaden the scope of attention and thought-action repertoires

    PubMed Central

    Fredrickson, Barbara L.; Branigan, Christine

    2011-01-01

    The broaden-and-build theory (Fredrickson, 1998, 2001) hypothesises that positive emotions broaden the scope of attention and thought-action repertoires. Two experiments with 104 college students tested these hypotheses. In each, participants viewed a film that elicited (a) amusement, (b) contentment, (c) neutrality, (d) anger, or (e) anxiety. Scope of attention was assessed using a global-local visual processing task (Experiment 1) and thought-action repertoires were assessed using a Twenty Statements Test (Experiment 2). Compared to a neutral state, positive emotions broadened the scope of attention in Experiment 1 and thought-action repertoires in Experiment 2. In Experiment 2, negative emotions, relative to a neutral state, narrowed thought-action repertoires. Implications for promoting emotional well-being and physical health are discussed. PMID:21852891

  8. Effectiveness and Toxicity of Several DTPA Broadening Agents for Biological ESR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zaplatin, A. N.; Baker, Kent A.; Kleinhans, F. W.

    1996-03-01

    The effectiveness of a standard ESR broadening agent, potassium trioxalatochromiate (CrOx), for use with the spin-label tempone, was compared to that of diethylenetriaminepentaacetic acid (DTPA) containing an ion (Gd, Cr, Mn, Fe) with a large magnetic moment. Signal attenuation, line broadening, toxicity, and cell membrane permeability were compared. As a broadening agent, CrOx was most effective, followed by Fe-DTPA. CrOx proved mildly toxic while Gd-DTPA and Fe-DTPA were virtually nontoxic. The human red blood cell membrane was tested for permeability to Fe- and Gd-DTPA and found to be impermeable to both. In situations where toxicity to cells is critical, the DTPA chelates, particularly Fe-DTPA, may prove an acceptable substitute for CrOx.

  9. Influence of Rayleigh-Doppler broadening on the selection of H2O dial system parameters

    NASA Technical Reports Server (NTRS)

    Ismail, S.; Browell, E. V.

    1986-01-01

    Computer simulations have enabled the performance of a H2O Differential Absorption Lidar (DIAL) system to be studied by spectrally analyzing the forward propagating and backscattered laser energy. The simulations were done for a high altitude (21 km) DIAL system operating in a nadir-viewing mode. The influence of Rayleigh Doppler broadening on DIAL measurement accuracies were evaluated and show that the Rayleigh broadening influence, which can be corrected to first order in regions free of large aerosol gradients, reduces the sensitivity of DIAL H2O measurement errors in the upper tropospheric region. The ability to correct the Rayleigh broadening and the selection of H2O DIAL parameters when all the systematic effects are combined, were discussed.

  10. Extraction of inhomogeneous broadening and nonradiative losses in InAs quantum-dot lasers

    SciTech Connect

    Chow, Weng W.; Liu, Alan Y.; Gossard, Arthur C.; Bowers, John E.

    2015-10-26

    We present a method to quantify inhomogeneous broadening and nonradiative losses in quantum dot lasers by comparing the gain and spontaneous emission results of a microscopic laser theory with measurements made on 1.3 μm InAs quantum-dot lasers. Calculated spontaneous-emission spectra are first matched to those measured experimentally to determine the inhomogeneous broadening in the experimental samples. This is possible because treatment of carrier scattering at the level of quantum kinetic equations provides the homogeneously broadened spectra without use of free parameters, such as the dephasing rate. We then extract the nonradiative recombination current associated with the quantum-dot active region from a comparison of measured and calculated gain versus current relations.

  11. Collisional broadening of rotational lines in the stimulated Raman pentad Q-branch of CD4

    NASA Technical Reports Server (NTRS)

    Millot, G.; Lavorel, B.; Steinfeld, J. I.

    1992-01-01

    Self- and argon-broadening coefficients are reported for a number of Raman Q-branch transitions in the nu(1) and nu(2) + nu(4) bands of (C-12)D4 at room temperature (296 K). The coefficients display a variation with j and with C exp n (symmetry species A, E, F) that is essentially independent of collision partner and which is similar to the j- and C exp n-dependence found in previous measurements of the IR line-broadening coefficients. The rotationally inelastic collision rates previously measured by Foy et al. (1988) for (C-13)D4 (V4 = 0, 1) in collision with (C-13)D4 or Ar account for only a part of the Raman broadening rate, suggesting possibly significant contributions to the linewidths from efficient V-V transfer or elastic dephasing collisions.

  12. Manipulability, force, and compliance analysis for planar continuum manipulators

    NASA Technical Reports Server (NTRS)

    Gravagne, Ian A.; Walker, Ian D.

    2002-01-01

    Continuum manipulators, inspired by the natural capabilities of elephant trunks and octopus tentacles, may find niche applications in areas like human-robot interaction, multiarm manipulation, and unknown environment exploration. However, their true capabilities will remain largely inaccessible without proper analytical tools to evaluate their unique properties. Ellipsoids have long served as one of the foremost analytical tools available to the robotics researcher, and the purpose of this paper is to first formulate, and then to examine, three types of ellipsoids for continuum robots: manipulability, force, and compliance.

  13. FUV Continuum in Flare Kernels Observed by IRIS

    NASA Astrophysics Data System (ADS)

    Daw, Adrian N.; Kowalski, Adam; Allred, Joel C.; Cauzzi, Gianna

    2016-05-01

    Fits to Interface Region Imaging Spectrograph (IRIS) spectra observed from bright kernels during the impulsive phase of solar flares are providing long-sought constraints on the UV/white-light continuum emission. Results of fits of continua plus numerous atomic and molecular emission lines to IRIS far ultraviolet (FUV) spectra of bright kernels are presented. Constraints on beam energy and cross sectional area are provided by cotemporaneous RHESSI, FERMI, ROSA/DST, IRIS slit-jaw and SDO/AIA observations, allowing for comparison of the observed IRIS continuum to calculations of non-thermal electron beam heating using the RADYN radiative-hydrodynamic loop model.

  14. Diffuse Galactic low energy gamma ray continuum emission

    NASA Technical Reports Server (NTRS)

    Skibo, J. G.; Ramaty, R.

    1993-01-01

    We investigate the origin of diffuse low-energy Galactic gamma-ray continuum down to about 30 keV. We calculate gamma-ray emission via bremsstrahlung and inverse Compton scattering by propagating an unbroken electron power law injection spectrum and employing a Galactic emmissivity model derived from COSB observations. To maintain the low energy electron population capable of producing the observed continuum via bremsstrahlung, a total power input of 4 x 10 exp 41 erg/s is required. This exceeds the total power supplied to the nuclear cosmic rays by about an order of magnitude.

  15. Improving the Capabilities of a Continuum Laser Plasma Interaction Code

    SciTech Connect

    Hittinger, J F; Dorr, M R

    2006-06-15

    The numerical simulation of plasmas is a critical tool for inertial confinement fusion (ICF). We have been working to improve the predictive capability of a continuum laser plasma interaction code pF3d, which couples a continuum hydrodynamic model of an unmagnetized plasma to paraxial wave equations modeling the laser light. Advanced numerical techniques such as local mesh refinement, multigrid, and multifluid Godunov methods have been adapted and applied to nonlinear heat conduction and to multifluid plasma models. We describe these algorithms and briefly demonstrate their capabilities.

  16. Resonance continuum coupling in high-permittivity dielectric metamaterials

    NASA Astrophysics Data System (ADS)

    Lepetit, Thomas; Akmansoy, Eric; Ganne, Jean-Pierre; Lourtioz, Jean-Michel

    2010-11-01

    A detailed investigation of resonance-continuum coupling is carried out both experimentally and theoretically in metamaterials based on high-permittivity dielectric subwavelength resonators. An original experimental scheme is designed at microwave frequencies, which mimics a periodic array of resonators. Fano resonances are discussed in the framework of temporal coupled mode theory for the cases where one or two resonator modes couples to the continuum. Fano lineshapes are unambiguously demonstrated experimentally for the single-mode case in agreement with theoretical modeling. Numerical evidence of resonance trapping is shown in the two-mode case when modes with the same symmetry coincide in frequency.

  17. Super-Eddington accreting massive black holes as long-lived cosmological standards.

    PubMed

    Wang, Jian-Min; Du, Pu; Valls-Gabaud, David; Hu, Chen; Netzer, Hagai

    2013-02-22

    Super-Eddington accreting massive black holes (SEAMBHs) reach saturated luminosities above a certain accretion rate due to photon trapping and advection in slim accretion disks. We show that these SEAMBHs could provide a new tool for estimating cosmological distances if they are properly identified by hard x-ray observations, in particular by the slope of their 2-10 keV continuum. To verify this idea we obtained black hole mass estimates and x-ray data for a sample of 60 narrow line Seyfert 1 galaxies that we consider to be the most promising SEAMBH candidates. We demonstrate that the distances derived by the new method for the objects in the sample get closer to the standard luminosity distances as the hard x-ray continuum gets steeper. The results allow us to analyze the requirements for using the method in future samples of active black holes and to demonstrate that the expected uncertainty, given large enough samples, can make them into a useful, new cosmological ruler.

  18. Super-Eddington Accreting Massive Black Holes as Long-Lived Cosmological Standards

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Min; Du, Pu; Valls-Gabaud, David; Hu, Chen; Netzer, Hagai

    2013-02-01

    Super-Eddington accreting massive black holes (SEAMBHs) reach saturated luminosities above a certain accretion rate due to photon trapping and advection in slim accretion disks. We show that these SEAMBHs could provide a new tool for estimating cosmological distances if they are properly identified by hard x-ray observations, in particular by the slope of their 2-10 keV continuum. To verify this idea we obtained black hole mass estimates and x-ray data for a sample of 60 narrow line Seyfert 1 galaxies that we consider to be the most promising SEAMBH candidates. We demonstrate that the distances derived by the new method for the objects in the sample get closer to the standard luminosity distances as the hard x-ray continuum gets steeper. The results allow us to analyze the requirements for using the method in future samples of active black holes and to demonstrate that the expected uncertainty, given large enough samples, can make them into a useful, new cosmological ruler.

  19. A very small and super strong zebra pattern burst at the beginning of a solar flare

    SciTech Connect

    Tan, Baolin; Tan, Chengming; Zhang, Yin; Huang, Jing; Yan, Yihua; Mészárosová, Hana; Karlický, Marian

    2014-08-01

    Microwave emission with spectral zebra pattern structures (ZPs) is frequently observed in solar flares and the Crab pulsar. The previous observations show that ZP is a structure only overlapped on the underlying broadband continuum with slight increments and decrements. This work reports an unusually strong ZP burst occurring at the beginning of a solar flare observed simultaneously by two radio telescopes located in China and the Czech Republic and by the EUV telescope on board NASA's satellite Solar Dynamics Observatory on 2013 April 11. It is a very short and super strong explosion whose intensity exceeds several times that of the underlying flaring broadband continuum emission, lasting for just 18 s. EUV images show that the flare starts from several small flare bursting points (FBPs). There is a sudden EUV flash with extra enhancement in one of these FBPs during the ZP burst. Analysis indicates that the ZP burst accompanying an EUV flash is an unusual explosion revealing a strong coherent process with rapid particle acceleration, violent energy release, and fast plasma heating simultaneously in a small region with a short duration just at the beginning of the flare.

  20. A Super-Eddington, Compton-thick Wind in GRO J1655–40?

    NASA Astrophysics Data System (ADS)

    Neilsen, J.; Rahoui, F.; Homan, J.; Buxton, M.

    2016-05-01

    During its 2005 outburst, GRO J1655–40 was observed at high spectral resolution with the Chandra High-Energy Transmission Grating Spectrometer, revealing a spectrum rich with blueshifted absorption lines indicative of an accretion disk wind—apparently too hot, too dense, and too close to the black hole to be driven by radiation pressure or thermal pressure (Miller et al.). However, this exotic wind represents just one piece of the puzzle in this outburst, as its presence coincides with an extremely soft and curved X-ray continuum spectrum, remarkable X-ray variability (Uttley & Klein-Wolt), and a bright, unexpected optical/infrared blackbody component that varies on the orbital period. Focusing on the X-ray continuum and the optical/infrared/UV spectral energy distribution, we argue that the unusual features of this “hypersoft state” are natural consequences of a super-Eddington Compton-thick wind from the disk: the optical/infrared blackbody represents the cool photosphere of a dense, extended outflow, while the X-ray emission is explained as Compton scattering by the relatively cool, optically thick wind. This wind obscures the intrinsic luminosity of the inner disk, which we suggest may have been at or above the Eddington limit.

  1. The 2015 super-resolution microscopy roadmap

    NASA Astrophysics Data System (ADS)

    Hell, Stefan W.; Sahl, Steffen J.; Bates, Mark; Zhuang, Xiaowei; Heintzmann, Rainer; Booth, Martin J.; Bewersdorf, Joerg; Shtengel, Gleb; Hess, Harald; Tinnefeld, Philip; Honigmann, Alf; Jakobs, Stefan; Testa, Ilaria; Cognet, Laurent; Lounis, Brahim; Ewers, Helge; Davis, Simon J.; Eggeling, Christian; Klenerman, David; Willig, Katrin I.; Vicidomini, Giuseppe; Castello, Marco; Diaspro, Alberto; Cordes, Thorben

    2015-11-01

    Far-field optical microscopy using focused light is an important tool in a number of scientific disciplines including chemical, (bio)physical and biomedical research, particularly with respect to the study of living cells and organisms. Unfortunately, the applicability of the optical microscope is limited, since the diffraction of light imposes limitations on the spatial resolution of the image. Consequently the details of, for example, cellular protein distributions, can be visualized only to a certain extent. Fortunately, recent years have witnessed the development of ‘super-resolution’ far-field optical microscopy (nanoscopy) techniques such as stimulated emission depletion (STED), ground state depletion (GSD), reversible saturated optical (fluorescence) transitions (RESOLFT), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), structured illumination microscopy (SIM) or saturated structured illumination microscopy (SSIM), all in one way or another addressing the problem of the limited spatial resolution of far-field optical microscopy. While SIM achieves a two-fold improvement in spatial resolution compared to conventional optical microscopy, STED, RESOLFT, PALM/STORM, or SSIM have all gone beyond, pushing the limits of optical image resolution to the nanometer scale. Consequently, all super-resolution techniques open new avenues of biomedical research. Because the field is so young, the potential capabilities of different super-resolution microscopy approaches have yet to be fully explored, and uncertainties remain when considering the best choice of methodology. Thus, even for experts, the road to the future is sometimes shrouded in mist. The super-resolution optical microscopy roadmap of Journal of Physics D: Applied Physics addresses this need for clarity. It provides guidance to the outstanding questions through a collection of short review articles from experts in the field, giving a thorough

  2. The SuperMAG data processing technique

    NASA Astrophysics Data System (ADS)

    Gjerloev, J. W.

    2012-09-01

    In this paper I outline the data processing technique which is used in the SuperMAG initiative. SuperMAG is a worldwide collaboration of organizations and national agencies that currently operate more than 300 ground based magnetometers. SuperMAG provides easy access to validated ground magnetic field perturbations in the same coordinate system, identical time resolution and with a common baseline removal approach. The purpose of SuperMAG is to provide scientists, teachers, students and the general public easy access to measurements of the magnetic field at the surface of the Earth. Easy access to data, plots and derived products maximizes the utilization of this unique data set. It is outlined how SuperMAG processes the observations obtained by the individual data provider. Data are rotated into a local magnetic coordinate system by determining a time dependent declination angle. This angle displays a slow gradual change and a yearly periodic variation attributed to changes in the Earth main field and season temperature variations. The baseline is determined from the data itself in a three step process: (1) a daily baseline, (2) a yearly trend, and (3) a residual offset. This technique does not require so-called quiet days and thus it avoids all the well-known problems associated with their identification. The residual offset for the N- and Z-components shows a distinct latitudinal dependence while the E-component is independent of the latitude. This result is interpreted as being due to a weak ring current (likely asymmetric) which is present even during official quiet days. For the purpose of M-I research using 1-min data I find no difference between observatories and variometers. I finally argue that there is no correct baseline determination technique since we do not have a set of ground-truth observations required to make an objective evaluation. Instead, the user must keep in mind the assumptions on which the baseline was determined and draw conclusions

  3. Nitrogen-broadened lineshapes in the oxygen A-band: Experimental results and theoretical calculations

    NASA Astrophysics Data System (ADS)

    Predoi-Cross, Adriana; Holladay, Christopher; Heung, Henry; Bouanich, Jean-Pierre; Mellau, Georg Ch.; Keller, Reimund; Hurtmans, Daniel R.

    2008-09-01

    We report measurements for N 2-broadening, pressure-shift and line mixing coefficients for 55 oxygen transitions in the A-band retrieved using a multispectrum fitting technique. Nineteen laboratory absorption spectra were recorded at 0.02 cm -1 resolution using a multi-pass absorption cell with path length of 1636.9 cm and the IFS 120 Fourier transform spectrometer located at Justus-Liebig-University in Giessen, Germany. The total sample pressures ranged from 8.8 to 3004.5 Torr with oxygen volume mixing ratios in nitrogen ranging between 0.057 and 0.62. An Exponential Power Gap (EPG) scaling law was used to calculate the N 2-broadening and N 2-line mixing coefficients. The line broadening and shift coefficients for the A-band of oxygen self-perturbed and perturbed by N 2 are modeled using semiclassical calculations based on the Robert-Bonamy formalism and two intermolecular potentials. These potentials involve electrostatic contributions including the hexadecapole moment of the molecules and (a) a simple dispersion contribution with one adjustable parameter to fit the broadening coefficients or (b) the atom-atom Lennard-Jones model without such adjustable parameters. The first potential leads to very weak broadening coefficients for high J transitions whereas the second potential gives much more improved results at medium and large J values, in reasonable agreement with the experimental data. For the line shifts which mainly arise in our calculation from the electronic state dependence of the isotropic potential, their general trends with increasing J values can be well predicted, especially from the first potential. From the theoretical results, we have derived air-broadening and air-induced shift coefficients with an agreement comparable to that obtained for O 2-O 2 and O 2-N 2.

  4. Collisional Shift and Broadening of Iodine Spectral Lines in Air Near 543 nm

    NASA Technical Reports Server (NTRS)

    Fletcher, D. G.; McDaniel, J. C.

    1995-01-01

    The collisional processes that influence the absorption of monochromatic light by iodine in air have been investigated. Measurements were made in both a static cell and an underexpanded jet flow over the range of properties encountered in typical compressible-flow aerodynamic applications. Experimentally measured values of the collisional shift and broadening coefficients were 0.058 +/- 0.004 and 0.53 +/- 0.010 GHz K(exp 0.7)/torr, respectively. The measured shift value showed reasonable agreement with theoretical calculations based on Lindholm-Foley collisional theory for a simple dispersive potential. The measured collisional broadening showed less favorable agreement with the calculated value.

  5. Atom localization in a Doppler broadened medium via two standing-wave fields

    NASA Astrophysics Data System (ADS)

    Abd-Elnabi, Somia; Osman, Kariman I.

    2016-01-01

    The atom localization has been achieved in a four-level V-type atomic system interacting with two classical unidirectional standing-wave fields and weak probe field in a Doppler broadened medium under several conditions at very low temperature. The precision of the atom localization is compared with the system in the presence and absence of the Doppler broadened medium. The influence of some parameters such as the amplitude, wave vectors and the phase shift of the standing-wave fields on the atom localization is studied and has been found to obtain various atom localization patterns with symmetric shape.

  6. Pressure broadening of vibrational Raman lines in N2 at temperatures below 300 K

    NASA Technical Reports Server (NTRS)

    Herring, G. C.; South, B. W.

    1994-01-01

    Using quasi-cw stimulated Raman gain spectroscopy, the pressure broadening coefficients for the N2 vibrational Q-branch transitions have been measured over the temperature range 113-297 K for the rotational components J = 4, 6, 8, 10, and 12. The experimental results are fit to a simple power law to give an empirical formula for the temperature dependence of the pressure broadening over the 100-300 K range. These results are also compared to previously published scaling laws that are based on collision induced rotational transition rates.

  7. Enhancement of self-phase modulation induced spectral broadening in silicon suspended membrane waveguides

    NASA Astrophysics Data System (ADS)

    Zhang, Yaojing; Cheng, Zhenzhou; Liu, Linghai; Zhu, Bingqing; Wang, Jiaqi; Zhou, Wen; Wu, Xinru; Tsang, Hon Ki

    2016-05-01

    We experimentally observed a possibly enhanced self-phase modulation (SPM) in silicon suspended membrane waveguides (SMWs) by measuring the spectral broadening of optical pulses. The nonlinear coefficient n 2 and the two-photon absorption coefficient β 2 of silicon SMWs were measured to be (4.6 ± 0.9) × 10-18 m2 W-1 and 0.46 cm GW-1 at 1555 nm wavelength. We also proposed a method of using SPM-induced spectral broadening to obtain the coupling loss of a single grating coupler and experimentally compared the spectra of two grating couplers in silicon SMWs and in silicon-on-insulator waveguides.

  8. Effect of Viewing Angle on Super-Soft-Source X-Ray Spectra

    NASA Astrophysics Data System (ADS)

    Ness, Jan-Uwe

    2012-09-01

    The advent of the X-ray grating spectrometers has given new momentum to the studies of Super-Soft-Source (SSS) X-ray spectra in high resolution. Earlier CCD-type spectra only allow determinations of effective temperatures while in the grating spectra, lines and continuum can be resolved. I have studied the X-ray grating spectra of eight classical novae during their SSS phase, two of them candidates for recurrent novae, two established recurrent novae, and four permanent SSSs including the prototypes Cal 83 and Cal 87. I discovered two categories of SSSs: those dominated by emission lines (SSSe) and by absorption line (SSSa). All spectra contain photospheric continuum emission, indicated by the shape of a blackbody. For the majority of SSSe, the inclination angle is known, which are all greater than 75 degrees. I argue that the SSSe are high-inclination systems in which photospheric X-ray emission from the central source is partially blocked and scattered via Thompson scattering, which preserves the spectral shape of the continuum. Since the electrons in the scattering medium move at high velocities, photospheric absorption lines are smeared out and are therefore not seen. Additional emission lines are produced by resonant line scattering. The fact that only high inclination systems show these effects of scattering, the scattering material must be concentrated to the ecliptic plane. While in permanent SSSs, the accretion disk can explain this behavior, this result implies that in novae, the reformation of the accretion disk has already progressed to an advanced stage during their SSS phase. I argue that also the novae in low-inclination angle systems possess a reformed accretion disk. The viewing angle dependence requires non-symmetrical modeling approaches. Early disk reformation can also explain high-amplitude variations that have frequently been observed during the early SSS phase.

  9. THE 3-5 {mu}m SPECTRUM OF NGC 1068 AT HIGH ANGULAR RESOLUTION: DISTRIBUTION OF EMISSION AND ABSORPTION FEATURES ACROSS THE NUCLEAR CONTINUUM SOURCE

    SciTech Connect

    Geballe, T. R.; Mason, R. E.; Rodriguez-Ardila, A.; Axon, D. J.

    2009-08-20

    We report moderate resolution 3-5 {mu}m spectroscopy of the nucleus of NGC 1068 obtained at 0.''3 (20 pc) resolution with the spectrograph slit aligned approximately along the ionization cones of the active galactic nucleus. The deconvolved full width at half-maximum of the nuclear continuum source in this direction is 0.''3. Four coronal lines of widely different excitations were detected; the intensity of each peaks near radio knot C, approximately 0.''3 north of the infrared continuum peak, where the radio jet changes direction. Together with the broadened line profiles observed near that location, this suggests that shock ionization is the dominant excitation mechanism of the coronal lines. The depth of the 3.4 {mu}m hydrocarbon absorption is maximum at and just south of the continuum peak, similar to the 10 {mu}m silicate absorption. That and the similar and rapid variations of the optical depths of both features across the nucleus suggest that substantial portions of both arise in a dusty environment just in front of the continuum source(s). A new and tighter limit is set on the column density of CO. Although clumpy models of the dust screen might explain the shallowness of the silicate feature, the presence of the 3.4 {mu}m feature and the absence of CO are strongly reminiscent of Galactic diffuse cloud environments and a consistent explanation for them and the observed silicate feature is found if all three phenomena occur in such an environment, existing as close as 10 pc to the central engine.

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

    NASA Technical Reports Server (NTRS)

    May, Randy D.

    1992-01-01

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

  11. Problem Drinking Continuum: A Tool for Treatment, Training and Education.

    ERIC Educational Resources Information Center

    Worden, Mark; Rosellini, Gayle

    1980-01-01

    The problem drinking continuum was devised to illustrate different kinds of alcohol-related problems, without implying irreversibility, progression, or the presence of a unitary disease. It is one way of conceptualizing alcohol dependencies that has been fruitful in outpatient counseling, residential care, alcohol education, and training programs.…

  12. Isospin Mixing and the Continuum Coupling in Weakly Bound Nuclei

    SciTech Connect

    Michel, N.; Nazarewicz, Witold; Ploszajczak, M.

    2010-01-01

    We investigate the near-threshold behavior of one-nucleon spectroscopic factors in mirror nuclei using the Gamow Shell Model, which simultaneously takes into account many-body correlations and continuum effects. We demonstrate that for weakly bound or unbound systems, the mirror symmetry-breaking effects are appreciable, and they manifest in large differences of spectroscopic factors in a mirror pair.

  13. The Continuum and Current Controversies in the USA.

    ERIC Educational Resources Information Center

    Taylor, Steven J.

    2001-01-01

    This article reviews policy developments in deinstitutionalization and community inclusion in North America, specifically the United States. It begins with a critique of the continuum concept and the associated principle of the least restrictive environment. Past and current controversies surrounding deinstitutionalization are then examined.…

  14. The Eating Disorders Continuum, Self-Esteem, and Perfectionism

    ERIC Educational Resources Information Center

    Peck, Lisa D.; Lightsey, Owen Richard

    2008-01-01

    Among 261 undergraduate women, increased severity of eating disorders along a continuum was associated with decreased self-esteem, increased perfectionism, and increased scores on 7 subscales of the Eating Disorders Inventory-2. Women with eating disorders differed from both symptomatic women and asymptomatic women on all variables, whereas…

  15. Characterizing the radio continuum emission from intense starburst galaxies

    NASA Astrophysics Data System (ADS)

    Galvin, T. J.; Seymour, N.; Filipović, M. D.; Tothill, N. F. H.; Marvil, J.; Drouart, G.; Symeonidis, M.; Huynh, M. T.

    2016-09-01

    The intrinsic thermal (free-free) and non-thermal (synchrotron) emission components that comprise the radio continuum of galaxies represent unique, dust-free measures of star formation rates (SFR). Such high SFR galaxies will dominate the deepest current and future radio surveys. We disentangle the thermal and non-thermal emission components of the radio continuum of six ultraluminous infrared galaxies (LFIR > 1012.5 L⊙) at redshifts of 0.2 ≤ z ≤ 0.5 and 22 IR selected galaxies. Radio data over a wide frequency range (0.8 < ν < 10 GHz) are fitted with a star-forming galaxy model comprising of thermal and non-thermal components. The luminosities of both radio continuum components are strongly correlated to the 60 μm luminosity across many orders of magnitude (consistent with the far-IR to radio correlation). We demonstrate that the spectral index of the radio continuum spectral energy distribution is a useful proxy for the thermal fraction. We also find that there is an increase in mean and scatter of the thermal fraction with FIR to radio luminosity ratio which could be influenced by different time-scales of the thermal and non-thermal emission mechanisms.

  16. Space shuttle Ram glow: Implication of NO2 recombination continuum

    NASA Astrophysics Data System (ADS)

    Swenson, G. R.; Mende, S. B.; Clifton, S.

    1985-09-01

    The ram glow data gathered to data from imaging experiments on space shuttle suggest the glow is a continuum (within 34 angstrom resolution); the continuum shape is such that the peak is near 7000 angstroms decreasing to the blue and red, and the average molecular travel leading to emission after leaving the surface is 20 cm (assuming isotropic scattering from the surface). Emission continuum is rare in molecular systems but the measured spectrum does resemble the laboratory spectrum of NO2 (B) recombination continuum. The thickness of the observed emission is consistent with the NO2 hypothesis given an exit velocity of approx. 2.5 km/sec (1.3 eV) which leaves approx. 3.7 eV of ramming OI energy available for unbonding the recombined NO2 from the surface. The NO2 is formed in a 3-body recombination of OI + NO + m = NO2 + m where OI originates from the atmosphere and NO is chemically formed on the surface from atmospheric NI and OI. The spacecraft surface then acts as the n for the reaction: Evidence exists from orbital mass spectrometer data that the NO and NO2 chemistry described in this process does occur on surfaces of spectrometer orifices in orbit. Surface temperature effects are likely a factor in the NO sticking efficiency and, therefore, glow intensities.

  17. Optical lattices with exceptional points in the continuum

    NASA Astrophysics Data System (ADS)

    Longhi, Stefano; Della Valle, Giuseppe

    2014-05-01

    The spectral, dynamical, and topological properties of physical systems described by non-Hermitian (including PT-symmetric) Hamiltonians are deeply modified by the appearance of exceptional points and spectral singularities. Here we show that exceptional points in the continuum can arise in non-Hermitian (yet admitting an entirely real-valued energy spectrum) optical lattices with engineered defects. At an exceptional point, the lattice sustains a bound state with an energy embedded in the spectrum of scattered states, similar to the von Neumann-Wigner bound states in the continuum of Hermitian lattices. However, the dynamical and scattering properties of the bound state at an exceptional point are deeply different from those of ordinary von Neumann-Wigner bound states in a Hermitian system. In particular, the bound state in the continuum at an exceptional point is an unstable state that can secularly grow by an infinitesimal perturbation. Such properties are discussed in details for transport of discretized light in a PT-symmetric array of coupled optical waveguides, which could provide an experimentally accessible system to observe exceptional points in the continuum.

  18. Written Language Developmental Continuum: Preschool-Second Grade.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh.

    The purpose of this "Written Language Developmental Continuum" brochure for preschool-second grade is to provide helpful information for parents, teachers, and other adults as they work with young children to advance and refine written language (writing) competence. The brochure is intended to be a useful tool for assessing children's development…

  19. Continuum modeling of dense granular flow down heaps

    NASA Astrophysics Data System (ADS)

    Henann, David; Liu, Daren

    Dense, dry granular flows display many manifestations of grain-size dependence, or nonlocality, in which the finite-size of grains has an observable impact on flow phenomenology. Such behaviors make the formulation of an accurate continuum model for dense granular flow particularly difficult, since local continuum models are not equipped to describe size-effects. One example of grain-size dependence is seen when avalanches occur on a granular heap - a situation which is frequently encountered in industry, as in rotating drums, as well as in nature, such as in landslides. In this case, flow separates into a thin, quickly flowing surface layer and a slowly creeping bulk. While existing local granular flow models are capable of capturing aspects of the flowing surface layer, they fail to even predict the existence of creeping flow beneath, much less being able to quantitatively describe the flow fields. Recently, we have proposed a new, scale-dependent continuum model - the nonlocal granular fluidity (NGF) model - that successfully predicted steady, slow granular flow fields, including grain-size-dependent shear-band widths in a variety of flow configurations. In this talk, we extend our model to the rapid flow regime and show that the model is capable of quantitatively predicting all aspects of gravity-driven heap flow. In particular, the model predicts the coexistence of a rapidly flowing, rate-dependent top surface layer and a rate-independent, slowly creeping bulk - a feature which is beyond local continuum approaches.

  20. Rape nitrogen nutrition diagnosis using continuum-removed hyperspectral reflectance

    NASA Astrophysics Data System (ADS)

    Zhang, Xuehong; Tian, Qingjiu

    2008-12-01

    The hyperspectral reflectance for rape fresh leaves and data of chlorophyll and total nitrogen content were acquired in primary growth stages under different nitrogen levels in order to monitor rape status and diagnose nitrogen using remote sensing method. A new method was developed for estimating the nitrogen nutrition of rape using continuum-removed method, which generally used in spectral analysis on rock and mineral. Based on the continuum-removed treatment and the correlation between absorption feature parameters and total nitrogen content of fresh leaves, results show that reflectance at the visible region decreased with increasing in the nitrogen fertilization, and continuum-removed operation can magnify the subtle difference in spectral absorption characteristics arose from the nitrogen stress on rape. During the seeding stage, bud-emerging stage and flowering stage of rape, total area of absorption peak, area left of the absorption peak and area right of the absorption peak in 550-750 nm region increased with increasing in the nitrogen fertilization, but it was opposite for the area-normalized maximal absorption depth. The correlation analysis indicated that it is at seeding stage that the relation between absorption characteristics parameters and leaf total nitrogen was best close. The research demonstrated that continuum-removed method is a feasible method for quantificational evaluation of rape nitrogen nutrition, and the seeding stage of rape is the best stage for assessment of rape nitrogen nutrition based on absorption characteristics of fresh leaves.

  1. Levels of Mental Health Continuum and Personality Traits

    ERIC Educational Resources Information Center

    Joshanloo, Mohsen; Nosratabadi, Masoud

    2009-01-01

    Empirically, mental health and mental illness are not opposite ends of a single measurement continuum. In view of this fact, Keyes ("J Health Soc Behav," 43:207-202, 2002) operationalizes mental health as a syndrome of symptoms of both positive feelings (emotional well-being) and positive functioning (psychological and social well-being) in life.…

  2. Pidgin and English in Melanesia: Is There a Continuum?

    ERIC Educational Resources Information Center

    Siegel, Jeff

    1997-01-01

    Examines the linguistic features of Tok Pisin (the Papua New Guinea variety of Melanesian Pidgin) resulting from decreolization and the linguistic features of Papua New Guinea English. Discusses code-switching and transference between Tok Pisin and English and concludes that an English-to-pidgin continuum does not exist in Papua New Guinea or in…

  3. Evaluation as a Process: The Formative-Summative Continuum.

    ERIC Educational Resources Information Center

    Caudle, Sharon L.

    Rather than automatically presuming explicit conditions exist when designing an evaluation to fit the summative or formative mold, evaluators should think of an evaluation design as fitting between endpoints on an evaluation process continuum. Evaluators can blend techniques from both the formative and summative evaluation, matching actual program…

  4. Continuum of Medical Education in Obstetrics and Gynecology.

    ERIC Educational Resources Information Center

    Dohner, Charles W.; Hunter, Charles A., Jr.

    1980-01-01

    Over the past eight years the obstetric and gynecology specialty has applied a system model of instructional planning to the continuum of medical education. The systems model of needs identification, preassessment, instructional objectives, instructional materials, learning experiences; and evaluation techniques directly related to objectives was…

  5. Online Learning Interaction Continuum (OLIC): A Qualitative Case Study

    ERIC Educational Resources Information Center

    Hashim, Mohamad Hisyam Mohd.; Hashim, Yusup; Esa, Ahmad

    2011-01-01

    The purpose of this research project is to explore the use of Blackboard Learning System (BLS) in enhancing interaction in online teaching and learning enviornment. This paper discusses the conceptual framework of Online Learning Interaction Continuum (OLIC) which explains the five levels of interactions. The OLIC was conceptualized as a result of…

  6. Scaffolding the Inquiry Continuum and the Constitution of Identity

    ERIC Educational Resources Information Center

    Melville, Wayne; Bartley, Anthony; Fazio, Xavier

    2013-01-01

    This article considers the impact of scaffolding on pre-service science teachers' constitution of identities as teachers of inquiry. This scaffolding has consisted of 2 major components, a unit on current electricity which encompasses the inquiry continuum and an open inquiry which is situated in context of classroom practice. Our analysis…

  7. 24 CFR 578.39 - Continuum of Care planning activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 3 2013-04-01 2013-04-01 false Continuum of Care planning activities. 578.39 Section 578.39 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  8. 24 CFR 578.39 - Continuum of Care planning activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Continuum of Care planning activities. 578.39 Section 578.39 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  9. Single attosecond pulse generation via continuum wave packet interference

    NASA Astrophysics Data System (ADS)

    Zhou, Shengpeng; Yang, Yujun; Ding, Dajun

    2016-07-01

    A single attosecond pulse generation via continuum-continuum interference is investigated theoretically by exposing a single-electron atom in a femtosecond laser field with the intensity in over-the-barrier ionization regime. We show that the ground state of the atom is depleted in such intense laser field and the high-order harmonics (HHG) via continuum to continuum coherence are generated. In a few-cycle monochromatic laser field (5 fs/800 nm, 1.2×1016 W cm-2), a single attosecond pulse with duration of 49 as is obtained from the HHG. With a two-color laser field combined by 1200 nm (8 fs/7.5×1015 W cm-2) and 800 nm (5 fs/1.0×1016 W cm-2), a shorter single pulse with duration of 29 as can further be produced by changing the relative carrier envelope phase of two laser pulses as a result of controlling the electronic quantum path in the intense electric field. Our results also show that a short single attosecond pulse can be generated in a wide range of the relative carrier envelope phase of the two laser pulses.

  10. Stimulated Raman scattering seeded by a fibre continuum

    NASA Technical Reports Server (NTRS)

    Selker, M. D.; Lawandy, N. M.

    1990-01-01

    A broadband continuum generated in a germanosilicate optical fiber has been used as a coherent seed to initiate stimulated Raman scattering in gases. The technique used is described. The results show a fivefold increase in conversion efficiency and a similar reduction in the requisite pump power.

  11. Searching for the Center on the Mathematics-Science Continuum.

    ERIC Educational Resources Information Center

    Roebuck, Kay I.; Warden, Melissa A.

    1998-01-01

    The history of mathematics and science integration in American schools is a continuum which runs from math for math's sake to science for science's sake. While examples of the integration of process skills are common, integration of content is not. Presents two lessons developed around radioactive decay and efficiency. Suggests that changes in…

  12. The Continuum: A Teaching Strategy for Science and Society Issues.

    ERIC Educational Resources Information Center

    Hendrix, Jon R.

    1993-01-01

    Describes a decision-making lesson where students rank genetic defects and syndromes from least to most severe. Students are then asked to draw a line in the continuum where they would not feel obligated to support the life, or in the case of an in utero life, maintain the pregnancy. (PR)

  13. JCMT COADD: UKT14 continuum and photometry data reduction

    NASA Astrophysics Data System (ADS)

    Hughes, David; Oliveira, Firmin J.; Tilanus, Remo P. J.; Jenness, Tim

    2014-11-01

    COADD was used to reduce photometry and continuum data from the UKT14 instrument on the James Clerk Maxwell Telescope in the 1990s. The software can co-add multiple observations and perform sigma clipping and Kolmogorov-Smirnov statistical analysis. Additional information on the software is available in the JCMT Spring 1993 newsletter (large PDF).

  14. JCMTDR: Applications for reducing JCMT continuum data in GSD format

    NASA Astrophysics Data System (ADS)

    Lightfoot, John F.; Harrison, Paul A.; Meyerdierks, Horst; Jenness, Tim

    2014-06-01

    JCMTDR reduces continuum on-the-fly mapping data obtained with UKT14 or the heterodyne instruments using the IFD on the James Clerk Maxwell Telescope. This program reduces archive data and heterodyne beam maps and was distributed as part of the Starlink software collection (ascl:1110.012).

  15. Space shuttle ram glow: Implication of NO2 recombination continuum

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.; Mende, S. B.; Clifton, S.

    1985-01-01

    The ram glow data gathered to data from imaging experiments on space shuttle suggest the glow is a continuum (within 34 angstrom resolution); the continuum shape is such that the peak is near 7000 angstroms decreasing to the blue and red, and the average molecular travel leading to emission after leaving the surface is 20 cm (assuming isotropic scattering from the surface). Emission continuum is rare in molecular systems but the measured spectrum does resemble the laboratory spectrum of NO2 (B) recombination continuum. The thickness of the observed emission is consistent with the NO2 hypothesis given an exit velocity of approx. 2.5 km/sec (1.3 eV) which leaves approx. 3.7 eV of ramming OI energy available for unbonding the recombined NO2 from the surface. The NO2 is formed in a 3-body recombination of OI + NO + m = NO2 + m where OI originates from the atmosphere and NO is chemically formed on the surface from atmospheric NI and OI. The spacecraft surface then acts as the n for the reaction: Evidence exists from orbital mass spectrometer data that the NO and NO2 chemistry described in this process does occur on surfaces of spectrometer orifices in orbit. Surface temperature effects are likely a factor in the NO sticking efficiency and, therefore, glow intensities.

  16. Comparison of Mesomechanical and Continuum Granular Flow Models for Ceramics

    SciTech Connect

    Curran, D. R.

    2006-07-28

    Constitutive models for the shear strength of ceramics undergoing fracture are needed for modeling long rod and shaped-charge jet penetration events in ceramic armor. The ceramic material ahead of the penetrator has been observed to be finely comminuted material that flows around the nose of the eroding penetrator (Shockey et al.). The most-used continuum models are of the Drucker-Prager type with an upper cutoff, or of the Mohr-Coulomb type with strain rate dependence and strain softening. A disadvantage of such models is that they have an unclear connection to the actual microscopic processes of granular flow and comminution. An alternate approach is to use mesomechanical models that describe the dynamics of the granular flow, as well as containing a description of the granular comminution and resultant material softening. However, a disadvantage of the mesomechanical models is that they are computationally more burdensome to apply. In the present paper, we compare the behaviors of a mesomechanical model, FRAGBED2, with the Walker and Johnson-Holmquist continuum models, where the granular material is subjected to simple strain histories under various confining pressures and strain rates. We conclude that the mesomechanical model can provide valuable input to the continuum models, both in interpretation of the continuum models' parameters and in suggesting their range of applicability.

  17. Predicting Eating Disorder Continuum Groups: Hardiness and College Adjustment.

    ERIC Educational Resources Information Center

    Simon-Boyd, Gail D.; Bieschke, Kathleen J.

    This study examined relationships between hardiness, college adjustment (academic adjustment, social adjustment, personal-emotional adjustment, institutional attachment) and eating disorder (ED) continuum categories in 122 female and 20 male college students. Students who exhibited a higher level of personal-emotional adjustment (PEA) to college…

  18. Continuum Response and Reaction in Neutron-Rich Be Nuclei

    SciTech Connect

    Nakatsukasa, Takashi; Ueda, Manabu; Yabana, Kazuhiro

    2004-02-27

    We study E1 resonances, breakup and fusion reactions for weakly bound Be nuclei. The absorbing-boundary condition (ABC) is used to describe both the outgoing and incoming boundary conditions. The neutron continuum plays important roles in response and reaction of neutron drip-line nuclei.

  19. cSELF (Computer Science Education from Life): Broadening Participation through Design Agency

    ERIC Educational Resources Information Center

    Bennett, Audrey; Eglash, Ron

    2013-01-01

    The phrase "broadening participation" is often used to describe efforts to decrease the race and gender gap in science and engineering education, and in this paper the authors describe an educational program focused on addressing the lower achievement rates and career interests of underrepresented ethnic groups (African American, Native…

  20. Improved electron collisional line broadening for low-temperature ions and neutrals in plasma modeling

    SciTech Connect

    Johns, H. M.; Kilcrease, D. P.; Colgan, J.; Judge, E. J.; Barefield II, J. E.; Wiens, R. C.; Clegg, S. M.

    2015-09-29

    In this study, electron collisional broadening of observed spectral lines depends on plasma electron temperature and density. Including this effect in models of measured spectra is necessary to determine plasma conditions; however, computational limits make accurate line broadening treatments difficult to implement in large-scale plasma modeling efforts. In this paper, we report on improvements to the treatment of electron collisional line broadening and illustrate this with calculations using the Los Alamos ATOMIC code. We implement the Dimitrijevic and Konjevic modified semi-empirical model Dimitrijevic and Konjevic (1986 Astron. and Astrophy. 163 297 and 1987 Astron. Astrophys. 172 345), which we amend by employing oscillator strengths from Hartree–Fock calculations. This line broadening model applies to near-neutral plasmas with electron temperatures of Te ~ 1 eV and electron densities of Ne ~1017 cm-3. We evaluate the D.K.-inspired model against the previous hydrogenic approach in ATOMIC through comparison to NIST-rated measurements for selected neutral and singly-ionized Ca, O, Fe, and Sn lines using both fine-structure and configuration-averaged oscillator strengths. The new D.K.-inspired model is significantly more accurate than the previous hydrogenic model and we find the use of configuration-averaged oscillator strengths a good approximation for applications such as LIBS (laser induced breakdown spectroscopy), for which we demonstrate the use of the D.K.-inspired model.

  1. PULSE BROADENING MEASUREMENTS FROM THE GALACTIC CENTER PULSAR J1745-2900

    SciTech Connect

    Spitler, L. G.; Lee, K. J.; Eatough, R. P.; Kramer, M.; Karuppusamy, R.; Desvignes, G.; Champion, D. J.; Falcke, H.; Bassa, C. G.; Lyne, A. G.; Stappers, B. W.; Cognard, I.; Cordes, J. M.

    2014-01-01

    We present temporal scattering measurements of single pulses and average profiles of PSR J1745-2900, a magnetar recently discovered only 3 arcsec away from Sagittarius A* (Sgr A*), from 1.2 to 18.95 GHz using the Effelsberg 100 m Radio Telescope, the Nançay Decimetric Radio Telescope, and the Jodrell Bank Lovell Telescope. Single pulse analysis shows that the integrated pulse profile above 2 GHz is dominated by pulse jitter, while below 2 GHz the pulse profile shape is dominated by scattering. This is the first object in the Galactic center (GC) with both pulse broadening and angular broadening measurements. We measure a pulse broadening time scale at 1 GHz of τ{sub 1GHz} = 1.3 ± 0.2 and pulse broadening spectral index of α = –3.8 ± 0.2, which is several orders of magnitude lower than predicted by the NE2001 model (Cordes and Lazio 2002). If this scattering time scale is representative of the GC as a whole, then previous surveys should have detected many pulsars. The lack of detections implies either our understanding of scattering in the GC is incomplete or there are fewer pulsars in the GC than previously predicted. Given that magnetars are a rare class of radio pulsar, there are likely many canonical and millisecond pulsars in the GC, and not surprisingly, scattering in the GC is spatially complex.

  2. Pulse Broadening Measurements from the Galactic Center Pulsar J1745-2900

    NASA Astrophysics Data System (ADS)

    Spitler, L. G.; Lee, K. J.; Eatough, R. P.; Kramer, M.; Karuppusamy, R.; Bassa, C. G.; Cognard, I.; Desvignes, G.; Lyne, A. G.; Stappers, B. W.; Bower, G. C.; Cordes, J. M.; Champion, D. J.; Falcke, H.

    2014-01-01

    We present temporal scattering measurements of single pulses and average profiles of PSR J1745-2900, a magnetar recently discovered only 3 arcsec away from Sagittarius A* (Sgr A*), from 1.2 to 18.95 GHz using the Effelsberg 100 m Radio Telescope, the Nançay Decimetric Radio Telescope, and the Jodrell Bank Lovell Telescope. Single pulse analysis shows that the integrated pulse profile above 2 GHz is dominated by pulse jitter, while below 2 GHz the pulse profile shape is dominated by scattering. This is the first object in the Galactic center (GC) with both pulse broadening and angular broadening measurements. We measure a pulse broadening time scale at 1 GHz of τ1GHz = 1.3 ± 0.2 and pulse broadening spectral index of α = -3.8 ± 0.2, which is several orders of magnitude lower than predicted by the NE2001 model (Cordes & Lazio 2002). If this scattering time scale is representative of the GC as a whole, then previous surveys should have detected many pulsars. The lack of detections implies either our understanding of scattering in the GC is incomplete or there are fewer pulsars in the GC than previously predicted. Given that magnetars are a rare class of radio pulsar, there are likely many canonical and millisecond pulsars in the GC, and not surprisingly, scattering in the GC is spatially complex.

  3. Independent component analysis of inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Stufflebeam, Michael; Hodges, Jeffery A.; Park, Tyler; Evenson, W.; Matheson, P.; Zacate, M. O.

    2008-10-01

    Independent component analysis (ICA) of electric field gradient (EFG) tensor components has proven useful in analysis of inhomogeneous broadening in perturbed angular correlation (PAC). We have simulated PAC spectra for various concentrations (0.1% to 15%) of randomly distributed defects with a near- neighbor vacancy in simple cubic and face-centered cubic crystal structures. In analyzing this simulation, we used ICA to transform the Vxx and Vzz EFG components to find a joint probability distribution function for the EFGs. ICA allowed us to separate the components and develop the joint probability function as a product of the probability distributions for two independent coordinates. Then we found the broadened G2(t) by integration over the joint probability distribution function. We have compared these results to simulated G2(t) functions, allowing us to analyze the concentration dependence of the broadened PAC spectrum. This work will be applied initially to broadened PAC data from β-Mn, Al-doped β-Mn, and Sr2RuO4.

  4. Improved electron collisional line broadening for low-temperature ions and neutrals in plasma modeling

    DOE PAGES

    Johns, H. M.; Kilcrease, D. P.; Colgan, J.; Judge, E. J.; Barefield II, J. E.; Wiens, R. C.; Clegg, S. M.

    2015-09-29

    In this study, electron collisional broadening of observed spectral lines depends on plasma electron temperature and density. Including this effect in models of measured spectra is necessary to determine plasma conditions; however, computational limits make accurate line broadening treatments difficult to implement in large-scale plasma modeling efforts. In this paper, we report on improvements to the treatment of electron collisional line broadening and illustrate this with calculations using the Los Alamos ATOMIC code. We implement the Dimitrijevic and Konjevic modified semi-empirical model Dimitrijevic and Konjevic (1986 Astron. and Astrophy. 163 297 and 1987 Astron. Astrophys. 172 345), which we amendmore » by employing oscillator strengths from Hartree–Fock calculations. This line broadening model applies to near-neutral plasmas with electron temperatures of Te ~ 1 eV and electron densities of Ne ~1017 cm-3. We evaluate the D.K.-inspired model against the previous hydrogenic approach in ATOMIC through comparison to NIST-rated measurements for selected neutral and singly-ionized Ca, O, Fe, and Sn lines using both fine-structure and configuration-averaged oscillator strengths. The new D.K.-inspired model is significantly more accurate than the previous hydrogenic model and we find the use of configuration-averaged oscillator strengths a good approximation for applications such as LIBS (laser induced breakdown spectroscopy), for which we demonstrate the use of the D.K.-inspired model.« less

  5. Improved electron collisional line broadening for low-temperature ions and neutrals in plasma modeling

    NASA Astrophysics Data System (ADS)

    Johns, H. M.; Kilcrease, D. P.; Colgan, J.; Judge, E. J.; Barefield, J. E., II; Wiens, R. C.; Clegg, S. M.

    2014-11-01

    Electron collisional broadening of observed spectral lines depends on plasma electron temperature and density. Including this effect in models of measured spectra is necessary to determine plasma conditions; however, computational limits make accurate line broadening treatments difficult to implement in large-scale plasma modeling efforts. In this paper, we report on improvements to the treatment of electron collisional line broadening and illustrate this with calculations using the Los Alamos ATOMIC code. We implement the Dimitrijevic and Konjevic modified semi-empirical model Dimitrijevic and Konjevic (1986 Astron. and Astrophy. 163 297 and 1987 Astron. Astrophys. 172 345), which we amend by employing oscillator strengths from Hartree-Fock calculations. This line broadening model applies to near-neutral plasmas with electron temperatures of Te ˜ 1 eV and electron densities of Ne ˜ 1017 cm-3. We evaluate the D K-inspired model against the previous hydrogenic approach in ATOMIC through comparison to NIST-rated measurements for selected neutral and singly-ionized Ca, O, Fe, and Sn lines using both fine-structure and configuration-averaged oscillator strengths. The new D K-inspired model is significantly more accurate than the previous hydrogenic model and we find the use of configuration-averaged oscillator strengths a good approximation for applications such as LIBS (laser induced breakdown spectroscopy), for which we demonstrate the use of the D K-inspired model.

  6. An Experiment to Demonstrate the Energy Broadening of Annihilation Gamma Rays

    ERIC Educational Resources Information Center

    Ouseph, P. J.; DuBard, James L.

    1978-01-01

    Shows that when positions annihilate in solid materials the energy distribution of the annihilation gamma rays is much broader than that of a 0.511-Mev gamma peak. This broadening is caused by the momentum distribution of the electrons in the material. (Author/GA)

  7. The origins of quantum interference and uncertainty broadening. A linear ribbon model approach

    SciTech Connect

    Tang, J.

    1996-02-01

    As an alternative to the orthodox Schroedinger wave mechanics or Heisenberg matrix mechanics approach, a simple linear ribbon model for quantum theory is presented. A different perspective and better physical insights into the origins of quantum interference and the mechanisms for uncertainty broadening are offered. Quantum interference in the atomic scale and superconducting behaviour in the macroscopic scale are compared.

  8. Broadening the definition of resilience and "reappraising" the use of appetitive motivation.

    PubMed

    Soenke, Melissa; O'Connor, Mary-Frances; Greenberg, Jeff

    2015-01-01

    Kalisch et al.'s PASTOR model synthesizes current knowledge of resilience, focusing on mechanisms as a common pathway to outcomes and highlighting neuroscience as a method for exploring this. We propose the model broaden its definition of resiliency to include positive indices of recovery, include positive affect as a mechanism, and approach motivation as distinct from overcoming aversive motivation. PMID:26785906

  9. Broadening the definition of resilience and "reappraising" the use of appetitive motivation.

    PubMed

    Soenke, Melissa; O'Connor, Mary-Frances; Greenberg, Jeff

    2015-01-01

    Kalisch et al.'s PASTOR model synthesizes current knowledge of resilience, focusing on mechanisms as a common pathway to outcomes and highlighting neuroscience as a method for exploring this. We propose the model broaden its definition of resiliency to include positive indices of recovery, include positive affect as a mechanism, and approach motivation as distinct from overcoming aversive motivation.

  10. LBQ2D, Extending the Line Broadened Quasilinear Model to TAE-EP Interaction

    NASA Astrophysics Data System (ADS)

    Ghantous, Katy; Gorelenkov, Nikolai; Berk, Herbert

    2012-10-01

    The line broadened quasilinear model was proposed and tested on the one dimensional electrostatic case of the bump on tailfootnotetextH.L Berk, B. Breizman and J. Fitzpatrick, Nucl. Fusion, 35:1661, 1995 to study the wave particle interaction. In conventional quasilinear theory, the sea of overlapping modes evolve with time as the particle distribution function self consistently undergo diffusion in phase space. The line broadened quasilinear model is an extension to the conventional theory in a way that allows treatment of isolated modes as well as overlapping modes by broadening the resonant line in phase space. This makes it possible to treat the evolution of modes self consistently from onset to saturation in either case. We describe here the model denoted by LBQ2D which is an extension of the proposed one dimensional line broadened quasilinear model to the case of TAEs interacting with energetic particles in two dimensional phase space, energy as well as canonical angular momentum. We study the saturation of isolated modes in various regimes and present the analytical derivation and numerical results. Finally, we present, using ITER parameters, the case where multiple modes overlap and describe the techniques used for the numerical treatment.

  11. Wideband nonlinear spectral broadening in ultra-short ultra - silicon rich nitride waveguides

    PubMed Central

    Choi, Ju Won; Chen, George F. R.; Ng, D. K. T.; Ooi, Kelvin J. A.; Tan, Dawn T. H.

    2016-01-01

    CMOS-compatible nonlinear optics platforms with high Kerr nonlinearity facilitate the generation of broadband spectra based on self-phase modulation. Our ultra – silicon rich nitride (USRN) platform is designed to have a large nonlinear refractive index and low nonlinear losses at 1.55 μm for the facilitation of wideband spectral broadening. We investigate the ultrafast spectral characteristics of USRN waveguides with 1-mm-length, which have high nonlinear parameters (γ ∼ 550 W−1/m) and anomalous dispersion at 1.55 μm wavelength of input light. USRN add-drop ring resonators broaden output spectra by a factor of 2 compared with the bandwidth of input fs laser with the highest quality factors of 11000 and 15000. Two – fold self phase modulation induced spectral broadening is observed using waveguides only 430 μm in length, whereas a quadrupling of the output bandwidth is observed with USRN waveguides with a 1-mm-length. A broadening factor of around 3 per 1 mm length is achieved in the USRN waveguides, a value which is comparatively larger than many other CMOS-compatible platforms. PMID:27272558

  12. Attitudes and Motivation of Poor and Good Spellers: Broadening Planned Behavior Theory

    ERIC Educational Resources Information Center

    Sideridis, Georgios D.

    2005-01-01

    The purpose of the present study was to broaden planned behavior theory and examine its applicability to predict the academic achievement of students of low and high spelling ability. Two hundred fifty seven students, 54 low spellers and 203 high spellers from thirty elementary schools in northern Greece, participated in the study. Between groups…

  13. Measurements of ion-ion collisional broadening of ion acoustic modes

    NASA Astrophysics Data System (ADS)

    Tierney, T. E.; Benage, J. F.; Montgomery, D. S.; Murillo, M. S.; Wysocki, F. J.; Rostoker, N.

    2002-10-01

    Although collisional plasmas are often encountered in inertial confinement fusion, dense plasma experiments and astrophysics, very few experiments have looked at the effects produced by the presence of these collisions. Ion-acoustic modes are predicted to broaden due to ion-ion collisions when the ion-ion mean free path, λ_ii, becomes comparable to the ion-acoustic wavelength, λ_iaw. This paper presents the first quantitative data of ion-acoustic wave broadening in moderately ion-ion collisional (0.05broadening of ion-acoustic modes was observed using collective Thomson scattering and analyzed using a collisional model that includes, ion and electron Landau, inhomogeneity and instrumental broadening. The results indicate that standard collisional models do not adequately predict the degree of ion-acoustic damping when 0.1

  14. Broaden Engineering Technology students' knowledge through hands-on with motion robotics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The skills and knowledge that employers value most are not always well-aligned with undergraduate engineering technology programs. With the support of a federal grant, we identify and propose to broaden the undergraduate student experience to include training in transferable skills with agricultura...

  15. Second harmonic generation of spectrally broadened femtosecond ytterbium laser radiation in a gas-filled capillary

    SciTech Connect

    Didenko, N V; Konyashchenko, Aleksandr V; Kostryukov, P V; Losev, Leonid L; Tenyakov, S Yu

    2011-09-30

    A 300-fs radiation pulse of an ytterbium laser with a wavelength of 1030 nm and energy of 150 {mu}J were converted to a 15-fs pulse with a wavelength of 515 nm by broadening the emission spectrum in a capillary filled with xenon and by generating the second harmonic in a KDP crystal. The energy efficiency of the conversion was 30 %.

  16. PROBLEM DEPENDENT DOPPLER BROADENING OF CONTINUOUS ENERGY CROSS SECTIONS IN THE KENO MONTE CARLO COMPUTER CODE

    SciTech Connect

    Hart, S. W. D.; Maldonado, G. Ivan; Celik, Cihangir; Leal, Luiz C

    2014-01-01

    For many Monte Carlo codes cross sections are generally only created at a set of predetermined temperatures. This causes an increase in error as one moves further and further away from these temperatures in the Monte Carlo model. This paper discusses recent progress in the Scale Monte Carlo module KENO to create problem dependent, Doppler broadened, cross sections. Currently only broadening the 1D cross sections and probability tables is addressed. The approach uses a finite difference method to calculate the temperature dependent cross-sections for the 1D data, and a simple linear-logarithmic interpolation in the square root of temperature for the probability tables. Work is also ongoing to address broadening theS (alpha , beta) tables. With the current approach the temperature dependent cross sections are Doppler broadened before transport starts, and, for all but a few isotopes, the impact on cross section loading is negligible. Results can be compared with those obtained by using multigroup libraries, as KENO currently does interpolation on the multigroup cross sections to determine temperature dependent cross-sections. Current results compare favorably with these expected results.

  17. Transverse flow measurement using photoacoustic Doppler bandwidth broadening: phantom and in vivo studies

    NASA Astrophysics Data System (ADS)

    Yao, Junjie; Maslov, Konstantin I.; Wang, Lihong V.

    2010-02-01

    In photoacoustic (PA) imaging of microvascular networks, the transverse component of the blood flow that is perpendicular to the acoustic probing beam is usually dominant. We propose a new method to measure the transverse flow, based on the Doppler bandwidth broadening. The bandwidth broadening is inversely proportional to the transit time spent by the absorbers passing through the focus. Because the photoacoustic signal in one A-scan has a wide band, multiple successive A-scans are used to estimate the relatively small signal variance. Then the bandwidth broadening can be calculated from the standard derivation of the Doppler spectrum. By exploiting the pulse excitation and bidirectional raster motor scanning, threedimensional structural and flow information can be obtained simultaneously. From a flow of a suspension of carbon particles (diameter: 6 μm), transverse flow speeds from 0 to 2.5 mm/s were measured using optical-resolution photoacoustic microscopy. The bandwidth broadening at each speed was in good agreement with the theoretical prediction. The blood flow in a mouse brain was also imaged.

  18. Improving Enzyme Activity and Broadening Selectivity for Biological Desulfurization and Upgrading of Petroleum Feedstocks

    SciTech Connect

    Abhijeet P. Borole; Choo Y. Hamilton; Karen Miller; Brian Davison; Matthew Grossman; Robert Shong

    2003-05-12

    The objective of this project was to develop improved biocatalysts for desulfurization and upgrading of petroleum feedstocks. The goal was to improve the activity and broaden the selectivity of desulfurization enzymes using directed evolution as a tool as well as to explore the impact of ring-opening on biological desulfurization

  19. Broadening Educational Outcomes: Social Relations, Skills Development, and Employability for Youth

    ERIC Educational Resources Information Center

    Dejaeghere, Joan; Wiger, Nancy Pellowski; Willemsen, Laura Wangsness

    2016-01-01

    This article argues that, if a global development aim is to address educational inequalities, the post-2015 agenda needs to conceptually and practically broaden the focus of learning to include social relations as important processes and outcomes for achieving educational equity. We draw on Sen's capability approach and Bourdieu's forms of capital…

  20. Super-resolution imaging in live cells.

    PubMed

    Cox, Susan

    2015-05-01

    Over the last twenty years super-resolution fluorescence microscopy has gone from proof-of-concept experiments to commercial systems being available in many labs, improving the resolution achievable by up to a factor of 10 or more. There are three major approaches to super-resolution, stimulated emission depletion microscopy, structured illumination microscopy, and localisation microscopy, which have all produced stunning images of cellular structures. A major current challenge is optimising performance of each technique so that the same sort of data can be routinely taken in live cells. There are several major challenges, particularly phototoxicity and the speed with which images of whole cells, or groups of cells, can be acquired. In this review we discuss the various approaches which can be successfully used in live cells, the tradeoffs in resolution, speed, and ease of implementation which one must make for each approach, and the quality of results that one might expect from each technique.