Science.gov

Sample records for albeit ultraviolet bright

  1. DUST-SCATTERED ULTRAVIOLET HALOS AROUND BRIGHT STARS

    SciTech Connect

    Murthy, Jayant; Henry, Richard Conn

    2011-06-10

    We have discovered ultraviolet (UV) halos extending as far as 5 deg. around four (of six) bright UV stars using data from the Galaxy Evolution Explorer satellite. These halos are due to scattering of the starlight from nearby thin, foreground dust clouds. We have placed limits of 0.58 {+-} 0.12 and 0.72 {+-} 0.06 on the phase function asymmetry factor (g) in the FUV (1521 A) and NUV (2320 A) bands, respectively. We suggest that these halos are a common feature around bright stars and may be used to explore the scattering function of interstellar grains at small angles.

  2. Ultraviolet brightness of celestial targets for Apollo 17

    NASA Technical Reports Server (NTRS)

    Fastie, W. G.

    1972-01-01

    An evaluation of the ultraviolet flux from the stars expected in the various inertial-hold pointing directions and PTC scans during the Apollo 17 mission is presented. These directions and PTC scan poles for the nominal mission are listed. The methodology used in evaluating the flux, and the individual targets themselves is explained.

  3. Observations of ultraviolet-bright stars in globular clusters with the Hopkins Ultraviolet Telescope

    NASA Technical Reports Server (NTRS)

    Van Dyke Dixon, W.; Davidsen, Arthur F.; Ferguson, Henry C.

    1994-01-01

    Two UV-bright stars in globular clusters, UV5 in NGC 1851 and vZ 1128 in M3, were observed with the Hopkins Ultraviolet Telescope (HUT) during the Astro-1 space shuttle mission in 1990 December. The stars' spectra show weak absorption features and no significant emission features other than well known geocoronal lines. Detailed fitting of Kurucz (1991) stellar atmosphere models using a chi(sup 2) minimization technique indicates T(sub eff) = 16 000 K, log g = 2.5, and abundance (-1.0) (logarithm of abundance of elements heavier than helium relative to solar) for UV5, and T(sub eff) = 35 000 K, log g = 4.0, and abundance (-3.5) for vZ 1128. The Kurucz model which best fits vZ 1128 overpredicts the flux in the region below approximately 1000 A, an effect seen in previous models of O-type stars. Our results are robust (to within approximately 1000 K) with respect to uncertainties in interstellar reddening and atomic and molecular hydrogen column densities. We do not see significant molecular hydrogen absorption, which might have indicated material in a circumstellar shell, in either star's spectrum. We estimate the stellar luminosities to be log L/solar luminosity = 3.33 +/- 0.15 for UV5 and log L/solar luminosity = 3.21 +/- 0.12 for vZ 1128. These atmospheric parameters place both stars on the Schoenberner (post-AGB) tracks, though the stellar masses derived from the best-fitting Kurucz models are somewhat less than those predicted by the Schoenberner models. Examination of individual absorption line strengths reveals no significant abundance anomalies in either star.

  4. Numerical evaluation of a 13.5-nm high-brightness microplasma extreme ultraviolet source

    SciTech Connect

    Hara, Hiroyuki Arai, Goki; Dinh, Thanh-Hung; Higashiguchi, Takeshi; Jiang, Weihua; Miura, Taisuke; Endo, Akira; Ejima, Takeo; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sunahara, Atsushi

    2015-11-21

    The extreme ultraviolet (EUV) emission and its spatial distribution as well as plasma parameters in a microplasma high-brightness light source are characterized by the use of a two-dimensional radiation hydrodynamic simulation. The expected EUV source size, which is determined by the expansion of the microplasma due to hydrodynamic motion, was evaluated to be 16 μm (full width) and was almost reproduced by the experimental result which showed an emission source diameter of 18–20 μm at a laser pulse duration of 150 ps [full width at half-maximum]. The numerical simulation suggests that high brightness EUV sources should be produced by use of a dot target based microplasma with a source diameter of about 20 μm.

  5. Evolution of laser-produced Sn extreme ultraviolet source diameter for high-brightness source

    SciTech Connect

    Roy, Amitava E-mail: aroy@barc.gov.in; Arai, Goki; Hara, Hiroyuki; Higashiguchi, Takeshi; Ohashi, Hayato; Sunahara, Atsushi; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Miura, Taisuke; Mocek, Tomas; Endo, Akira

    2014-08-18

    We have investigated the effect of irradiation of solid Sn targets with laser pulses of sub-ns duration and sub-mJ energy on the diameter of the extreme ultraviolet (EUV) emitting region and source conversion efficiency. It was found that an in-band EUV source diameter as low as 18 μm was produced due to the short scale length of a plasma produced by a sub-ns laser. Most of the EUV emission occurs in a narrow region with a plasma density close to the critical density value. Such EUV sources are suitable for high brightness and high repetition rate metrology applications.

  6. Generation of bright phase-matched circularly-polarized extreme ultraviolet high harmonics

    NASA Astrophysics Data System (ADS)

    Kfir, Ofer; Grychtol, Patrik; Turgut, Emrah; Knut, Ronny; Zusin, Dmitriy; Popmintchev, Dimitar; Popmintchev, Tenio; Nembach, Hans; Shaw, Justin M.; Fleischer, Avner; Kapteyn, Henry; Murnane, Margaret; Cohen, Oren

    2015-02-01

    Circularly-polarized extreme ultraviolet and X-ray radiation is useful for analysing the structural, electronic and magnetic properties of materials. To date, such radiation has only been available at large-scale X-ray facilities such as synchrotrons. Here, we demonstrate the first bright, phase-matched, extreme ultraviolet circularly-polarized high harmonics source. The harmonics are emitted when bi-chromatic counter-rotating circularly-polarized laser pulses field-ionize a gas in a hollow-core waveguide. We use this new light source for magnetic circular dichroism measurements at the M-shell absorption edges of Co. We show that phase-matching of circularly-polarized harmonics is unique and robust, producing a photon flux comparable to linearly polarized high harmonic sources. This work represents a critical advance towards the development of table-top systems for element-specific imaging and spectroscopy of multiple elements simultaneously in magnetic and other chiral media with very high spatial and temporal resolution.

  7. EXTENDED ULTRAVIOLET DISKS AND ULTRAVIOLET-BRIGHT DISKS IN LOW-MASS E/S0 GALAXIES

    SciTech Connect

    Moffett, Amanda J.; Kannappan, Sheila J.; Baker, Andrew J.; Laine, Seppo

    2012-01-20

    We have identified 15 extended ultraviolet (XUV) disks in a largely field sample of 38 E/S0 galaxies that have stellar masses primarily below {approx}4 Multiplication-Sign 10{sup 10} M{sub Sun} and comparable numbers on the red and blue sequences. We use a new purely quantitative XUV-disk definition designed with reference to the 'Type 1' XUV-disk definition found in the literature, requiring UV extension relative to a UV-defined star formation threshold radius. The 39% {+-} 9% XUV-disk frequency for these E/S0s is roughly twice the {approx}20% reported for late-type galaxies (although differences in XUV-disk criteria complicate the comparison), possibly indicating that XUV disks are preferentially associated with galaxies experiencing weak or inefficient star formation. Consistent with this interpretation, we find that the XUV disks in our sample do not correlate with enhanced outer-disk star formation as traced by blue optical outer-disk colors. However, UV-Bright (UV-B) disk galaxies with blue UV colors outside their optical 50% light radii do display enhanced optical outer-disk star formation as well as enhanced atomic gas content. UV-B disks occur in our E/S0s with a 42{sup +9}{sub -8}% frequency and need not coincide with XUV disks; thus their combined frequency is 61% {+-} 9%. For both XUV and UV-B disks, UV colors typically imply <1 Gyr ages, and most such disks extend beyond the optical R{sub 25} radius. XUV disks occur over the full sample mass range and on both the red and blue sequences, suggesting an association with galaxy interactions or another similarly general evolutionary process. In contrast, UV-B disks favor the blue sequence and may also prefer low masses, perhaps reflecting the onset of cold-mode gas accretion or another mass-dependent evolutionary process. Virtually all blue E/S0s in the gas-rich regime below stellar mass M{sub t} {approx} 5 Multiplication-Sign 10{sup 9} M{sub Sun} (the 'gas-richness threshold mass') display UV-B disks

  8. Note: Development of a volume-limited dot target for a high brightness extreme ultraviolet microplasma source

    SciTech Connect

    Dinh, Thanh Hung Suzuki, Yuhei; Hara, Hiroyuki; Higashiguchi, Takeshi; Hirose, Ryoichi; Ohashi, Hayato; Li, Bowen; Dunne, Padraig; O’Sullivan, Gerry; Sunahara, Atsushi

    2014-11-15

    We report on production of volume-limited dot targets based on electron beam lithographic and sputtering technologies for use in efficient high brightness extreme ultraviolet microplasma sources. We successfully produced cylindrical tin (Sn) targets with diameters of 10, 15, and 20 μm and a height of 150 nm. The calculated spectrum around 13.5 nm was in good agreement with that obtained experimentally.

  9. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    SciTech Connect

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. In this article, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s-1 is generated at 22.3 eV, with 5 × 10-5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Finally, spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  10. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    PubMed Central

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

    2015-01-01

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s−1 is generated at 22.3 eV, with 5 × 10−5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications. PMID:26067922

  11. Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars

    NASA Astrophysics Data System (ADS)

    Placco, Vinicius M.; Beers, Timothy C.; Ivans, Inese I.; Filler, Dan; Imig, Julie A.; Roederer, Ian U.; Abate, Carlo; Hansen, Terese; Cowan, John J.; Frebel, Anna; Lawler, James E.; Schatz, Hendrik; Sneden, Christopher; Sobeck, Jennifer S.; Aoki, Wako; Smith, Verne V.; Bolte, Michael

    2015-10-01

    We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the bright carbon-enhanced metal-poor (CEMP) stars HD 196944 (V=8.40, [Fe/H] = -2.41) and HD 201626 (V=8.16, [Fe/H] = -1.51), based on data acquired with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope. Both of these stars belong to the sub-class CEMP-s, and exhibit clear over-abundances of heavy elements associated with production by the slow neutron-capture process. HD 196944 has been well-studied in the optical region, but we add abundance results for six species (Ge, Nb, Mo, Lu, Pt, and Au) that are only accessible in the NUV. In addition, we provide the first determination of its orbital period, P = 1325 days. HD 201626 has only a limited number of abundance results based on previous optical work—here we add five new species from the NUV, including Pb. We compare these results with models of binary-system evolution and s-process element production in stars on the asymptotic giant branch, with the goal of explaining their origin and evolution. Our best-fitting models for HD 196944 ({M}1,i=0.9{M}⊙ , {M}2,i=0.86{M}⊙ , for [Fe/H] = -2.2), and HD 201626 ({M}1,i=0.9{M}⊙ , {M}2,i=0.76{M}⊙ , for [Fe/H] = -2.2; {M}1,i=1.6{M}⊙ , {M}2,i=0.59{M}⊙ , for [Fe/H] = -1.5) are consistent with the current accepted scenario for the formation of CEMP-s stars. The data presented herein were obtained with the (i) NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. (These observations are associated with program GO-12554, data sets OBQ601010-30 and OBQ602010-30.); and (ii) W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. (The Observatory was made

  12. BRIGHT RAY-LIKE FEATURES IN THE AFTERMATH OF CORONAL MASS EJECTIONS: WHITE LIGHT VERSUS ULTRAVIOLET SPECTRA

    SciTech Connect

    Ciaravella, A.; Webb, D. F.; Giordano, S.; Raymond, J. C.

    2013-03-20

    Current sheets (CSs) are important signatures of magnetic reconnection in the eruption of confined solar magnetic structures. Models of coronal mass ejections (CMEs) involve formation of a CS connecting the ejected flux rope with the post-eruption magnetic loops. CSs have been identified in white light (WL) images of CMEs as narrow rays trailing the outward moving CME core, and in ultraviolet spectra as narrow bright features emitting the [Fe XVIII] line. In this work, samples of rays detected in WL images or in ultraviolet spectra have been analyzed. Temperatures, widths, and line intensities of the rays have been measured, and their correlation to the CME properties has been studied. The samples show a wide range of temperatures with hot, coronal, and cool rays. In some cases, the UV spectra support the identification of rays as CSs, but they show that some WL rays are cool material from the CME core. In many cases, both hot and cool material are present, but offset from each other along the Ultraviolet Coronagraph Spectrometer slit. We find that about 18% of the WL rays show very hot gas consistent with the CS interpretation, while about 23% show cold gas that we attribute to cool prominence material draining back from the CME core. The remaining events have ordinary coronal temperatures, perhaps because they have relaxed back to a quiescent state.

  13. EFFECTS OF MAGNETIC FIELD AND FAR-ULTRAVIOLET RADIATION ON THE STRUCTURES OF BRIGHT-RIMMED CLOUDS

    SciTech Connect

    Motoyama, Kazutaka; Umemoto, Tomofumi; Shang, Hsien; Hasegawa, Tatsuhiko

    2013-03-20

    The bright-rimmed cloud SFO 22 was observed with the 45 m telescope of Nobeyama Radio Observatory in the {sup 12}CO (J = 1-0), {sup 13}CO (J = 1-0), and C{sup 18}O (J = 1-0) lines, where well-developed head-tail structure and small line widths were found. Such features were predicted by radiation-driven implosion models, suggesting that SFO 22 may be in a quasi-stationary equilibrium state. We compare the observed properties with those from numerical models of a photoevaporating cloud, which include effects of magnetic pressure and heating due to strong far-ultraviolet (FUV) radiation from an exciting star. The magnetic pressure may play a more important role in the density structures of bright-rimmed clouds than the thermal pressure that is enhanced by the FUV radiation. The FUV radiation can heat the cloud surface to near 30 K; however, its effect is not enough to reproduce the observed density structure of SFO 22. An initial magnetic field of 5 {mu}G in our numerical models produces the best agreement with the observations, and its direction can affect the structures of bright-rimmed clouds.

  14. Visual and ultraviolet flux variability of the bright CP star θ Aurigae

    NASA Astrophysics Data System (ADS)

    Krtička, J.; Mikulášek, Z.; Lüftinger, T.; Jagelka, M.

    2015-04-01

    Context. Chemically peculiar stars of the upper part of the main sequence show periodical variability in line intensities and continua, modulated by the stellar rotation, which is attributed to the existence of chemical spots on the surface of these stars. The flux variability is caused by the changing redistribution rate of the radiative flux predominantly from the short-wavelength part of the spectra to the long-wavelength part, which is a result of abundance anomalies. Many details of this process are still unknown. Aims: We study the nature of the multi-spectral variability of one of the brightest chemically peculiar stars, θ Aur. Methods: We predict the flux variability of θ Aur from the emerging intensities calculated for individual surface elements of the star taking into account horizontal variation of chemical composition. The surface chemical composition was derived from Doppler abundance maps. Results: The simulated optical variability in the Strömgren photometric system and the ultraviolet flux variability agree well with observations. The IUE flux distribution is reproduced in great detail by our models in the near ultraviolet region. A minor disagreement remains between the observed and predicted fluxes in the far ultraviolet region. The resonance lines of magnesium and possibly also some lines of silicon are relatively weak in the ultraviolet domain, which indicates non-negligible vertical abundance gradients in the atmosphere. We also derive a new period of the star, P = 3.618 664(10) d, from all available photometric and magnetic measurements and show that the observed rotational period is constant over decades. Conclusions: The ultraviolet and visual variability of θ Aur is mostly caused by silicon bound-free absorption and chromium and iron line absorption. Manganese also contributes to the variability, but to a lesser extent. These elements redistribute the flux mainly from the far-ultraviolet region to the near-ultraviolet and optical

  15. The ultraviolet-bright stars of Omega Centauri, M3, and M13

    NASA Technical Reports Server (NTRS)

    Landsman, Wayne B.; O'Connell, Robert W.; Whitney, Jonathan H.; Bohlin, Ralph C.; Hill, Robert S.; Maran, Stephen P.; Parise, Ronald A.; Roberts, Morton S.; Smith, Andrew A.; Stecher, Theodore P.

    1992-01-01

    Two new UV-bright stars detected within 2 arcmin of the center of Omega Cen are spectroscopically investigated with the short-wavelength spectrograph of the IUE. The IUE spectra of the UV-bright stars UIT-1 and UIT-2 in the core of Omega Cen superficially resemble those of Population I mid-B stars. The absorption lines of the core UV-bright stars are significantly weaker than in Population I stars, consistent with their membership in the cluster. Synthetic spectra calculated from low-metallicity Kurucz model stellar atmospheres are compared with the spectra. These objects are insufficiently luminous to be classical hydrogen-burning post-AGB stars. They may be evolved hot horizontal branch stars which have been brightened by more than 3 mag since leaving the zero-age horizontal branch. It is inferred from the spectra and luminosity of the core UV-bright stars that similar objects could provide the source of the UV light in elliptical galaxies.

  16. SUPERNOVA 2009kf: AN ULTRAVIOLET BRIGHT TYPE IIP SUPERNOVA DISCOVERED WITH PAN-STARRS 1 AND GALEX

    SciTech Connect

    Botticella, M. T.; Trundle, C.; Pastorello, A.; Smartt, S. J.; Young, D.; Smith, K.; Valenti, S.; Kotak, R.; Rodney, S.; Gezari, S.; Huber, M. E.; Rest, A.; Narayan, G.; Tonry, J. L.; Bresolin, F.; Mattila, S.; Kankare, E.; Wood-Vasey, W. M.; Riess, A.; Neill, J. D.

    2010-07-01

    We present photometric and spectroscopic observations of a luminous Type IIP Supernova (SN) 2009kf discovered by the Pan-STARRS 1 (PS1) survey and also detected by the Galaxy Evolution Explorer. The SN shows a plateau in its optical and bolometric light curves, lasting approximately 70 days in the rest frame, with an absolute magnitude of M{sub V} = -18.4 mag. The P-Cygni profiles of hydrogen indicate expansion velocities of 9000 km s{sup -1} at 61 days after discovery which is extremely high for a Type IIP SN. SN 2009kf is also remarkably bright in the near-ultraviolet (NUV) and shows a slow evolution 10-20 days after optical discovery. The NUV and optical luminosity at these epochs can be modeled with a blackbody with a hot effective temperature (T {approx} 16,000 K) and a large radius (R {approx} 1 x 10{sup 15} cm). The bright bolometric and NUV luminosity, the light curve peak and plateau duration, the high velocities, and temperatures suggest that 2009kf is a Type IIP SN powered by a larger than normal explosion energy. Recently discovered high-z SNe (0.7 < z < 2.3) have been assumed to be IIn SNe, with the bright UV luminosities due to the interaction of SN ejecta with a dense circumstellar medium. UV-bright SNe similar to SN 2009kf could also account for these high-z events, and its absolute magnitude M{sub NUV} = -21.5 {+-} 0.5 mag suggests such SNe could be discovered out to z {approx} 2.5 in the PS1 survey.

  17. Bright subcycle extreme ultraviolet bursts from a single dense relativistic electron sheet.

    PubMed

    Ma, W J; Bin, J H; Wang, H Y; Yeung, M; Kreuzer, C; Streeter, M; Foster, P S; Cousens, S; Kiefer, D; Dromey, B; Yan, X Q; Meyer-ter-Vehn, J; Zepf, M; Schreiber, J

    2014-12-01

    Double-foil targets separated by a low density plasma and irradiated by a petawatt-class laser are shown to be a copious source of coherent broadband radiation. Simulations show that a dense sheet of relativistic electrons is formed during the interaction of the laser with the tenuous plasma between the two foils. The coherent motion of the electron sheet as it transits the second foil results in strong broadband emission in the extreme ultraviolet, consistent with our experimental observations. PMID:25526132

  18. The far-ultraviolet main auroral emission at Jupiter - Part 1: Dawn-dusk brightness asymmetries

    NASA Astrophysics Data System (ADS)

    Bonfond, B.; Gustin, J.; Gérard, J.-C.; Grodent, D.; Radioti, A.; Palmaerts, B.; Badman, S. V.; Khurana, K. K.; Tao, C.

    2015-10-01

    The main auroral emission at Jupiter generally appears as a quasi-closed curtain centered around the magnetic pole. This auroral feature, which accounts for approximately half of the total power emitted by the aurorae in the ultraviolet range, is related to corotation enforcement currents in the middle magnetosphere. Early models for these currents assumed axisymmetry, but significant local time variability is obvious on any image of the Jovian aurorae. Here we use far-UV images from the Hubble Space Telescope to further characterize these variations on a statistical basis. We show that the dusk side sector is ~ 3 times brighter than the dawn side in the southern hemisphere and ~ 1.1 brighter in the northern hemisphere, where the magnetic anomaly complicates the interpretation of the measurements. We suggest that such an asymmetry between the dawn and the dusk sectors could be the result of a partial ring current in the nightside magnetosphere.

  19. BRIGHT ULTRAVIOLET REGIONS AND STAR FORMATION CHARACTERISTICS IN NEARBY DWARF GALAXIES

    SciTech Connect

    Melena, Nicholas W.; Hunter, Deidre A.; Zernow, Lea; Elmegreen, Bruce G. E-mail: dah@lowell.edu E-mail: bge@us.ibm.com

    2009-11-15

    We compare star formation in the inner and outer disks of 11 dwarf irregular galaxies (dIm) within 3.6 Mpc. The regions are identified on Galaxy Evolution Explorer near-UV images, and modeled with UV, optical, and near-IR colors to determine masses and ages. A few galaxies have made 10{sup 5}-10{sup 6} M {sub sun} complexes in a starburst phase, while others have not formed clusters in the last 50 Myr. The maximum region mass correlates with the number of regions as expected from the size-of-sample effect. We find no radial gradients in region masses and ages, even beyond the realm of H{alpha} emission, although there is an exponential decrease in the luminosity density and number density of the regions with radius. H{alpha} is apparently lacking in the outer parts only because nebular emission around massive stars is too faint to see. The outermost regions for the five galaxies with H I data formed at average gas surface densities of 1.9-5.9 M {sub sun} pc{sup -2}. These densities are at the low end of commonly considered thresholds for star formation and imply either that local gas densities are higher before star formation begins or subthreshold star formation is possible. The first case could be explained by supernovae triggering and other local processes, while the second case could be explained by gravitational instabilities with angular momentum loss in growing condensations. The distribution of regions on a log(mass) - log(age) plot is examined. The distribution is usually uniform along log(age) for equal intervals of log(mass) and this implies a region count that varies as 1/age. This variation results from either an individual region mass that varies as 1/age or a region disruption probability that varies as 1/age. A correlation between fading-corrected surface brightness and age suggests the former. The implied loss of mass is from fading of region envelopes below the surface brightness limit.

  20. Young, Ultraviolet-bright Stars Dominate Dust Heating in Star-forming Galaxies

    NASA Astrophysics Data System (ADS)

    Law, Ka-Hei; Gordon, Karl D.; Misselt, K. A.

    2011-09-01

    In star-forming galaxies, dust plays a significant role in shaping the ultraviolet (UV) through infrared (IR) spectrum. Dust attenuates the radiation from stars, and re-radiates the energy through equilibrium and non-equilibrium emission. Polycyclic aromatic hydrocarbons (PAHs), graphite, and silicates contribute to different features in the spectral energy distribution; however, they are all highly opaque in the same spectral region—the UV. Compared to old stellar populations, young populations release a higher fraction of their total luminosity in the UV, making them a good source of the energetic UV photons that can power dust emission. However, given their relative abundance, the question of whether young or old stellar populations provide most of these photons that power the IR emission is an interesting question. Using three samples of galaxies observed with the Spitzer Space Telescope and our dusty radiative transfer model, we find that young stellar populations (on the order of 100 million years old) dominate the dust heating in star-forming galaxies, and old stellar populations (13 billion years old) generally contribute less than 20% of the far-IR luminosity.

  1. YOUNG, ULTRAVIOLET-BRIGHT STARS DOMINATE DUST HEATING IN STAR-FORMING GALAXIES

    SciTech Connect

    Law, Ka-Hei; Gordon, Karl D.; Misselt, K. A. E-mail: kgordon@stsci.edu

    2011-09-10

    In star-forming galaxies, dust plays a significant role in shaping the ultraviolet (UV) through infrared (IR) spectrum. Dust attenuates the radiation from stars, and re-radiates the energy through equilibrium and non-equilibrium emission. Polycyclic aromatic hydrocarbons (PAHs), graphite, and silicates contribute to different features in the spectral energy distribution; however, they are all highly opaque in the same spectral region-the UV. Compared to old stellar populations, young populations release a higher fraction of their total luminosity in the UV, making them a good source of the energetic UV photons that can power dust emission. However, given their relative abundance, the question of whether young or old stellar populations provide most of these photons that power the IR emission is an interesting question. Using three samples of galaxies observed with the Spitzer Space Telescope and our dusty radiative transfer model, we find that young stellar populations (on the order of 100 million years old) dominate the dust heating in star-forming galaxies, and old stellar populations (13 billion years old) generally contribute less than 20% of the far-IR luminosity.

  2. Observations of the bright novalike variable IX Velorum with the Hopkins Ultraviolet Telescope

    NASA Technical Reports Server (NTRS)

    Long, Knox S.; Wade, Richard A.; Blair, William P.; Davidsen, Arthur F.; Hubeny, Ivan

    1994-01-01

    The Hopkins Ultraviolet Telescope, an experiment flown on the Space Shuttle as part of the Astro-1 mission, was used to obtain a spectrum of the novalike variable IX Vel (= CPD -48 deg 1577) in the wavelength range 830-1860 A. The observation revealed a rich absorption-line and continuum spectrum that peaks near 1050 A at a flux of 1.6 x 10(exp -11) ergs/sq cm/s/A. In the sub-Lyman-alpha region, some of the more prominent absorption lines are S VI lambda lambda-933, 945, C III lambda-977, Lyman-beta, O VI lambda lambda-1032, 1038, P V lambda lambda-1118, 1128, and C III lambda-1176. No emission was detected below the Lyman limit. The overall continuum shape of IX Vel in the FUV can be approximated using models of an optically thick accretion disk in which the integrated spectrum has been constructed by summing model stellar atmospheres or proper disk model spectra. However, if the distance to IX Vel is approximately 95 pc, standard disk models without reddening cannot simultaneously reproduce the color and flux in the UV. While interstellar reddening can reconcile this difference, the amount of reddening appears inconsistent with the absence of a 2200 A bump in the spectrum and the very low H I column density measured along the line of sight. Improved fits to the data can be obtained by modifying the accretion disk stucture within three white dwarf radii. None of the models reproduces the profiles of the Li- and Na-like ions, which are observed as strong but relatively narrow absorption lines, and which are almost surely due to a wind above the disk.

  3. Sparkling extreme-ultraviolet bright dots observed with Hi-C

    SciTech Connect

    Régnier, S.; Alexander, C. E.; Walsh, R. W.; Winebarger, A. R.; Cirtain, J.; Golub, L.; Korreck, K. E.; Weber, M.; Mitchell, N.; Platt, S.; De Pontieu, B.; Title, A.; Kobayashi, K.; Kuzin, S.; DeForest, C. E.

    2014-04-01

    Observing the Sun at high time and spatial scales is a step toward understanding the finest and fundamental scales of heating events in the solar corona. The high-resolution coronal (Hi-C) instrument has provided the highest spatial and temporal resolution images of the solar corona in the EUV wavelength range to date. Hi-C observed an active region on 2012 July 11 that exhibits several interesting features in the EUV line at 193 Å. One of them is the existence of short, small brightenings 'sparkling' at the edge of the active region; we call these EUV bright dots (EBDs). Individual EBDs have a characteristic duration of 25 s with a characteristic length of 680 km. These brightenings are not fully resolved by the SDO/AIA instrument at the same wavelength; however, they can be identified with respect to the Hi-C location of the EBDs. In addition, EBDs are seen in other chromospheric/coronal channels of SDO/AIA, which suggests a temperature between 0.5 and 1.5 MK. Based on their frequency in the Hi-C time series, we define four different categories of EBDs: single peak, double peak, long duration, and bursty. Based on a potential field extrapolation from an SDO/HMI magnetogram, the EBDs appear at the footpoints of large-scale, trans-equatorial coronal loops. The Hi-C observations provide the first evidence of small-scale EUV heating events at the base of these coronal loops, which have a free magnetic energy of the order of 10{sup 26} erg.

  4. STEREOSCOPIC DETERMINATION OF HEIGHTS OF EXTREME ULTRAVIOLET BRIGHT POINTS USING DATA TAKEN BY SECCHI/EUVI ABOARD STEREO

    SciTech Connect

    Kwon, Ryun-Young; Chae, Jongchul; Zhang Jie

    2010-05-01

    We measure the heights of EUV bright points (BPs) above the solar surface by applying a stereoscopic method to the data taken by the Solar TErrestrial RElations Observatory/SECCHI/Extreme UltraViolet Imager (EUVI). We have developed a three-dimensional reconstruction method for point-like features such as BPs using the simple principle that the position of a point in the three-dimensional space is specified as the intersection of two lines of sight. From a set of data consisting of EUVI 171 A, 195 A, 284 A, and 304 A images taken on 11 days arbitrarily selected during a period of 14 months, we have identified and analyzed 210 individual BPs that were visible on all four passband images and smaller than 30 Mm. The BPs seen in the 304 A images have an average height of 4.4 Mm, and are often associated with the legs of coronal loops. In the 171 A, 195 A, and 284 A images the BPs appear loop-shaped, and have average heights of 5.1, 6.7, and 6.1 Mm, respectively. Moreover, there is a tendency that overlying loops are filled with hotter plasmas. The average heights of BPs in 171 A, 195 A, and 284 A passbands are roughly twice the corresponding average lengths. Our results support the notion that an EUV BP represents a system of small loops with temperature stratification like flaring loops, being consistent with the magnetic reconnection origin.

  5. Differential responses to high- and low-dose ultraviolet-B stress in tobacco Bright Yellow-2 cells

    PubMed Central

    Takahashi, Shinya; Kojo, Kei H.; Kutsuna, Natsumaro; Endo, Masaki; Toki, Seiichi; Isoda, Hiroko; Hasezawa, Seiichiro

    2015-01-01

    Ultraviolet (UV)-B irradiation leads to DNA damage, cell cycle arrest, growth inhibition, and cell death. To evaluate the UV-B stress–induced changes in plant cells, we developed a model system based on tobacco Bright Yellow-2 (BY-2) cells. Both low-dose UV-B (low UV-B: 740 J m−2) and high-dose UV-B (high UV-B: 2960 J m−2) inhibited cell proliferation and induced cell death; these effects were more pronounced at high UV-B. Flow cytometry showed cell cycle arrest within 1 day after UV-B irradiation; neither low- nor high-UV-B–irradiated cells entered mitosis within 12 h. Cell cycle progression was gradually restored in low-UV-B–irradiated cells but not in high-UV-B–irradiated cells. UV-A irradiation, which activates cyclobutane pyrimidine dimer (CPD) photolyase, reduced inhibition of cell proliferation by low but not high UV-B and suppressed high-UV-B–induced cell death. UV-B induced CPD formation in a dose-dependent manner. The amounts of CPDs decreased gradually within 3 days in low-UV-B–irradiated cells, but remained elevated after 3 days in high-UV-B–irradiated cells. Low UV-B slightly increased the number of DNA single-strand breaks detected by the comet assay at 1 day after irradiation, and then decreased at 2 and 3 days after irradiation. High UV-B increased DNA fragmentation detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay 1 and 3 days after irradiation. Caffeine, an inhibitor of ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) checkpoint kinases, reduced the rate of cell death in high-UV-B–irradiated cells. Our data suggest that low-UV-B–induced CPDs and/or DNA strand-breaks inhibit DNA replication and proliferation of BY-2 cells, whereas larger contents of high-UV-B–induced CPDs and/or DNA strand-breaks lead to cell death. PMID:25954287

  6. THREE-DIMENSIONAL STRUCTURE AND EVOLUTION OF EXTREME-ULTRAVIOLET BRIGHT POINTS OBSERVED BY STEREO/SECCHI/EUVI

    SciTech Connect

    Kwon, Ryun-Young; Poomvises, Watanachak; Chae, Jongchul; Davila, Joseph M.; Jones, Shaela I.; Zhang Jie; Moon, Yong-Jae

    2012-10-01

    We unveil the three-dimensional structure of quiet-Sun EUV bright points and their temporal evolution by applying a triangulation method to time series of images taken by SECCHI/EUVI on board the STEREO twin spacecraft. For this study we examine the heights and lengths as the components of the three-dimensional structure of EUV bright points and their temporal evolutions. Among them we present three bright points which show three distinct changes in the height and length: decreasing, increasing, and steady. We show that the three distinct changes are consistent with the motions (converging, diverging, and shearing, respectively) of their photospheric magnetic flux concentrations. Both growth and shrinkage of the magnetic fluxes occur during their lifetimes and they are dominant in the initial and later phases, respectively. They are all multi-temperature loop systems which have hot loops ({approx}10{sup 6.2} K) overlying cooler ones ({approx}10{sup 6.0} K) with cool legs ({approx}10{sup 4.9} K) during their whole evolutionary histories. Our results imply that the multi-thermal loop system is a general character of EUV bright points. We conclude that EUV bright points are flaring loops formed by magnetic reconnection and their geometry may represent the reconnected magnetic field lines rather than the separator field lines.

  7. Three-Dimensional Structure and Evolution of Extreme-Ultraviolet Bright Points Observed by STEREO/SECCHI/EUVI

    NASA Technical Reports Server (NTRS)

    Kwon, Ryun Young; Chae, Jongchul; Davila, Joseph M.; Zhang, Jie; Moon, Yong-Jae; Poomvises, Watanachak; Jones, Shaela I.

    2012-01-01

    We unveil the three-dimensional structure of quiet-Sun EUV bright points and their temporal evolution by applying a triangulation method to time series of images taken by SECCHI/EUVI on board the STEREO twin spacecraft. For this study we examine the heights and lengths as the components of the three-dimensional structure of EUV bright points and their temporal evolutions. Among them we present three bright points which show three distinct changes in the height and length: decreasing, increasing, and steady. We show that the three distinct changes are consistent with the motions (converging, diverging, and shearing, respectively) of their photospheric magnetic flux concentrations. Both growth and shrinkage of the magnetic fluxes occur during their lifetimes and they are dominant in the initial and later phases, respectively. They are all multi-temperature loop systems which have hot loops (approx. 10(exp 6.2) K) overlying cooler ones (approx 10(exp 6.0) K) with cool legs (approx 10(exp 4.9) K) during their whole evolutionary histories. Our results imply that the multi-thermal loop system is a general character of EUV bright points. We conclude that EUV bright points are flaring loops formed by magnetic reconnection and their geometry may represent the reconnected magnetic field lines rather than the separator field lines.

  8. Resonances in the Photoionization Cross Sections of Atomic Nitrogen Shape the Far-ultraviolet Spectrum of the Bright Star in 47 Tucanae

    NASA Astrophysics Data System (ADS)

    Dixon, William V.; Chayer, Pierre

    2013-08-01

    The far-ultraviolet spectrum of the Bright Star (B8 III) in 47 Tuc (NGC 104) shows a remarkable pattern: it is well fit by local thermodynamic equilibrium models at wavelengths longer than Lyβ, but at shorter wavelengths it is fainter than the models by a factor of two. A spectrum of this star obtained with the Far Ultraviolet Spectroscopic Explorer shows broad absorption troughs with sharp edges at 995 and 1010 Å and a deep absorption feature at 1072 Å none of which are predicted by the models. We find that these features are caused by resonances in the photoionization cross sections of the first and second excited states of atomic nitrogen (2s 2 2p 3 2 D 0 and 2 P 0). Using cross sections from the Opacity Project, we can reproduce these features, but only if we use the cross sections at their full resolution, rather than the resonance-averaged cross sections usually employed to model stellar atmospheres. These resonances are strongest in stellar atmospheres with enhanced nitrogen and depleted carbon abundances, a pattern typical of post-asymptotic giant branch stars.

  9. RESONANCES IN THE PHOTOIONIZATION CROSS SECTIONS OF ATOMIC NITROGEN SHAPE THE FAR-ULTRAVIOLET SPECTRUM OF THE BRIGHT STAR IN 47 TUCANAE

    SciTech Connect

    Dixon, William V.; Chayer, Pierre E-mail: chayer@stsci.edu

    2013-08-10

    The far-ultraviolet spectrum of the Bright Star (B8 III) in 47 Tuc (NGC 104) shows a remarkable pattern: it is well fit by local thermodynamic equilibrium models at wavelengths longer than Ly{beta}, but at shorter wavelengths it is fainter than the models by a factor of two. A spectrum of this star obtained with the Far Ultraviolet Spectroscopic Explorer shows broad absorption troughs with sharp edges at 995 and 1010 A and a deep absorption feature at 1072 A; none of which are predicted by the models. We find that these features are caused by resonances in the photoionization cross sections of the first and second excited states of atomic nitrogen (2s {sup 2} 2p {sup 3} {sup 2} D {sup 0} and {sup 2} P {sup 0}). Using cross sections from the Opacity Project, we can reproduce these features, but only if we use the cross sections at their full resolution, rather than the resonance-averaged cross sections usually employed to model stellar atmospheres. These resonances are strongest in stellar atmospheres with enhanced nitrogen and depleted carbon abundances, a pattern typical of post-asymptotic giant branch stars.

  10. ULTRAVIOLET-BRIGHT STELLAR POPULATIONS AND THEIR EVOLUTIONARY IMPLICATIONS IN THE COLLAPSED-CORE CLUSTER M15

    SciTech Connect

    Haurberg, Nathalie C.; Lubell, Gabriel M. G.; Cohn, Haldan N.; Lugger, Phyllis M.; Anderson, Jay; Cool, Adrienne M.; Serenelli, Aldo M. E-mail: glubell@astro.indiana.ed E-mail: lugger@astro.indiana.ed E-mail: cool@stars.sfsu.ed

    2010-10-10

    We performed deep photometry of the central region of the Galactic globular cluster M15 from archival Hubble Space Telescope data taken on the High Resolution Channel and Solar Blind Channel of the Advanced Camera for Surveys. Our data set consists of images in far-UV (FUV{sub 140}; F140LP), near-UV (NUV{sub 220}; F220W), and blue (B{sub 435}; F435W) filters. The addition of an optical filter complements previous UV work on M15 by providing an additional constraint on the UV-bright stellar populations. Using color-magnitude diagrams (CMDs), we identified several populations that arise from non-canonical evolution including candidate blue stragglers, extreme horizontal branch (HB) stars, blue hook (BHk) stars, cataclysmic variables (CVs), and helium-core white dwarfs (He WDs). Due to preliminary identification of several He WD and BHk candidates, we add M15 as a cluster containing an He WD sequence and suggest it be included among clusters with a BHk population. We also investigated a subset of CV candidates that appear in the gap between the main sequence (MS) and WDs in FUV{sub 140}-NUV{sub 220} but lie securely on the MS in NUV{sub 220}-B{sub 435}. These stars may represent a magnetic CV or detached WD-MS binary population. Additionally, we analyze our candidate He WDs using model cooling sequences to estimate their masses and ages and investigate the plausibility of thin versus thick hydrogen envelopes. Finally, we identify a class of UV-bright stars that lie between the HB and WD cooling sequences, a location not usually populated on cluster CMDs. We conclude these stars may be young, low-mass He WDs.

  11. Hubble space telescope near-ultraviolet spectroscopy of the bright cemp-no star BD+44°493

    SciTech Connect

    Placco, Vinicius M.; Beers, Timothy C.; Smith, Verne V.; Roederer, Ian U.; Cowan, John J.; Frebel, Anna; Filler, Dan; Ivans, Inese I.; Lawler, James E.; Schatz, Hendrik; Sneden, Christopher; Sobeck, Jennifer S.; Aoki, Wako

    2014-07-20

    We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the extremely metal-poor star BD+44°493 a ninth magnitude subgiant with [Fe/H] =–3.8 and enhanced carbon, based on data acquired with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This star is the brightest example of a class of objects that, unlike the great majority of carbon-enhanced metal-poor (CEMP) stars, does not exhibit over-abundances of heavy neutron-capture elements (CEMP-no). In this paper, we validate the abundance determinations for a number of species that were previously studied in the optical region, and obtain strong upper limits for beryllium and boron, as well as for neutron-capture elements from zirconium to platinum, many of which are not accessible from ground-based spectra. The boron upper limit we obtain for BD+44°493, log ε (B) <–0.70, the first such measurement for a CEMP star, is the lowest yet found for very and extremely metal-poor stars. In addition, we obtain even lower upper limits on the abundances of beryllium, log ε (Be) <–2.3, and lead, log ε (Pb) <–0.23 ([Pb/Fe] <+1.90), than those reported by previous analyses in the optical range. Taken together with the previously measured low abundance of lithium, the very low upper limits on Be and B suggest that BD+44°493 was formed at a very early time, and that it could well be a bona-fide second-generation star. Finally, the Pb upper limit strengthens the argument for non-s-process production of the heavy-element abundance patterns in CEMP-no stars.

  12. The ultraviolet-bright, slowly declining transient PS1-11af as a partial tidal disruption event

    SciTech Connect

    Chornock, R.; Berger, E.; Zauderer, B. A.; Kamble, A.; Soderberg, A. M.; Czekala, I.; Dittmann, J.; Drout, M.; Foley, R. J.; Fong, W.; Kirshner, R. P.; Lunnan, R.; Marion, G. H.; Narayan, G.; Gezari, S.; Rest, A.; Riess, A. G.; Chomiuk, L.; Huber, M. E.; Lawrence, A.; and others

    2014-01-01

    We present the Pan-STARRS1 discovery of the long-lived and blue transient PS1-11af, which was also detected by Galaxy Evolution Explorer with coordinated observations in the near-ultraviolet (NUV) band. PS1-11af is associated with the nucleus of an early type galaxy at redshift z = 0.4046 that exhibits no evidence for star formation or active galactic nucleus activity. Four epochs of spectroscopy reveal a pair of transient broad absorption features in the UV on otherwise featureless spectra. Despite the superficial similarity of these features to P-Cygni absorptions of supernovae (SNe), we conclude that PS1-11af is not consistent with the properties of known types of SNe. Blackbody fits to the spectral energy distribution are inconsistent with the cooling, expanding ejecta of a SN, and the velocities of the absorption features are too high to represent material in homologous expansion near a SN photosphere. However, the constant blue colors and slow evolution of the luminosity are similar to previous optically selected tidal disruption events (TDEs). The shape of the optical light curve is consistent with models for TDEs, but the minimum accreted mass necessary to power the observed luminosity is only ∼0.002 M {sub ☉}, which points to a partial disruption model. A full disruption model predicts higher bolometric luminosities, which would require most of the radiation to be emitted in a separate component at high energies where we lack observations. In addition, the observed temperature is lower than that predicted by pure accretion disk models for TDEs and requires reprocessing to a constant, lower temperature. Three deep non-detections in the radio with the Very Large Array over the first two years after the event set strict limits on the production of any relativistic outflow comparable to Swift J1644+57, even if off-axis.

  13. Hubble Space Telescope Near-ultraviolet Spectroscopy of the Bright CEMP-no Star BD+44°493

    NASA Astrophysics Data System (ADS)

    Placco, Vinicius M.; Beers, Timothy C.; Roederer, Ian U.; Cowan, John J.; Frebel, Anna; Filler, Dan; Ivans, Inese I.; Lawler, James E.; Schatz, Hendrik; Sneden, Christopher; Sobeck, Jennifer S.; Aoki, Wako; Smith, Verne V.

    2014-07-01

    We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the extremely metal-poor star BD+44°493 a ninth magnitude subgiant with [Fe/H] =-3.8 and enhanced carbon, based on data acquired with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This star is the brightest example of a class of objects that, unlike the great majority of carbon-enhanced metal-poor (CEMP) stars, does not exhibit over-abundances of heavy neutron-capture elements (CEMP-no). In this paper, we validate the abundance determinations for a number of species that were previously studied in the optical region, and obtain strong upper limits for beryllium and boron, as well as for neutron-capture elements from zirconium to platinum, many of which are not accessible from ground-based spectra. The boron upper limit we obtain for BD+44°493, log epsilon (B) <-0.70, the first such measurement for a CEMP star, is the lowest yet found for very and extremely metal-poor stars. In addition, we obtain even lower upper limits on the abundances of beryllium, log epsilon (Be) <-2.3, and lead, log epsilon (Pb) <-0.23 ([Pb/Fe] <+1.90), than those reported by previous analyses in the optical range. Taken together with the previously measured low abundance of lithium, the very low upper limits on Be and B suggest that BD+44°493 was formed at a very early time, and that it could well be a bona-fide second-generation star. Finally, the Pb upper limit strengthens the argument for non-s-process production of the heavy-element abundance patterns in CEMP-no stars. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-12554, and we also make use of data taken in program GO-12268.

  14. Heavy element abundances in Ap stars from ultraviolet data. I - The bright reference stars Alpha Lyrae and Alpha Canis Majoris A

    NASA Technical Reports Server (NTRS)

    Boiarchuk, A. A.; Snow, T. P., Jr.

    1978-01-01

    Curve-of-growth analysis is used to derive chemical abundances in Alpha Lyr and Alpha CMa, based on ultraviolet spectra obtained with Copernicus. This analysis is part of a program to study the abundances of the heavy elements mercury and platinum and the short-lived element technetium in the atmospheres of Ap and Am stars. Ultraviolet Fe II lines are used to establish the curves of growth for Alpha Lyr and Alpha CMa A; abundances of a variety of elements, along with upper limits on Hg, Pt, and Tc, are derived. In cases where previous studies based on visual spectra have included elements in common with the present analysis, the agreement is good within the known uncertainties. One new element, cadmium, is observed for these two stars. The upper limits on Pt and Hg, as well as Tc, show that these elements are probably not enhanced in Alpha CMa A by more than about one order of magnitude.

  15. THE BRIGHT END OF THE ULTRAVIOLET LUMINOSITY FUNCTION AT z {approx} 8: NEW CONSTRAINTS FROM CANDELS DATA IN GOODS-SOUTH

    SciTech Connect

    Oesch, P. A.; Illingworth, G. D.; Gonzalez, V.; Magee, D.; Trenti, M.; Van Dokkum, P. G.; Carollo, C. M.

    2012-11-10

    We present new z {approx} 8 galaxy candidates from a search over {approx}95 arcmin{sup 2} of WFC3/IR data, tripling the previous search area for bright z {approx} 8 galaxies. Our analysis uses newly acquired WFC3/IR imaging data from the CANDELS Multi-Cycle Treasury program over the GOODS-South field. These new data are combined with existing deep optical Advanced Camera for Surveys (ACS) imaging to search for relatively bright (M {sub UV} < -19.5 mag) z {approx} 8 galaxy candidates using the Lyman break technique. These new candidates are used to determine the bright end of the UV luminosity function (LF) of star-forming galaxies at z {approx} 7.2-8.7, i.e., a cosmic age of 600 {+-} 80 Myr. To minimize contamination from lower redshift galaxies, we make full use of all optical ACS data and impose strict non-detection criteria based on an optical {chi}{sup 2} {sub opt} flux measurement. In the whole search area, we identify 16 candidate z {approx} 8 galaxies, spanning a magnitude range H {sub 160,AB} = 25.7-27.9 mag. The new data show that the UV LF is a factor {approx}1.7 lower at M {sub UV} < -19.5 mag than determined from the HUDF09 and Early Release Science (ERS) data alone. Combining this new sample with the previous candidates from the HUDF09 and ERS data allows us to perform the most accurate measurement of the z {approx} 8 UV LF yet. Schechter function fits to the combined data result in a best-fit characteristic magnitude of M {sub *}(z = 8) = -20.04 {+-} 0.46 mag. The faint-end slope is very steep, though quite uncertain, with {alpha} = -2.06 {+-} 0.32. A combination of wide-area data with additional ultra-deep imaging will be required to significantly reduce the uncertainties on these parameters in the future.

  16. UV-bright stars in globular clusters

    NASA Technical Reports Server (NTRS)

    Landsman, Wayne B.

    1994-01-01

    This paper highlights globular cluster studies with Ultraviolet Imaging Telescope (UIT) in three areas: the discrepancy between observed ultraviolet HB magnitudes and predictions of theoretical HB models; the discovery of two hot subdwarfs in NGC 1851, a globular not previously known to contain such stars; and spectroscopic follow up of newly identified UV-bright stars in M79 and w Cen. I also present results of a recent observation of NGC 6397 with the Voyager ultraviolet spectrometer.

  17. The EUVE bright source list

    NASA Technical Reports Server (NTRS)

    Stroozas, B.; Mcdonald, K.; Antia, B.; Mcdonald, J.; Wiercigroch, A.

    1993-01-01

    Initial results for bright extreme ultraviolet sources discovered during the EUVE all-sky and deep ecliptic surveys have been published as a Bright Source List (BSL) and released to the astronomical community with a recent NASA research announcement (NRA 93-OSS-02, Appendix F). This paper describes the data processing software, the EUVE survey data set, and the production of the BSL at the Center for EUV Astrophysics. The contents, format, and selection criteria for sources, the data processing strategy, some problems encountered, and a summary of the BSL results are presented.

  18. Bright stars observed by FIMS/SPEAR

    NASA Astrophysics Data System (ADS)

    Jo, Young-Soo; Seon, Kwang-Il; Min, Kyoung-Wook; Choi, Yeon-Ju; Lim, Tae-Ho; Lim, Yeo-Myeong; Edelstein, Jerry; Han, Wonyong

    2016-02-01

    In this paper, we present a catalogue of the spectra of bright stars observed during the sky survey using the Far-Ultraviolet Imaging Spectrograph (FIMS), which was designed primarily to observe diffuse emissions. By carefully eliminating the contamination from the diffuse background, we obtain the spectra of 70 bright stars observed for the first time with a spectral resolution of 2-3 Å over the wavelength of 1370-1710 Å. The far-ultraviolet spectra of an additional 139 stars are also extracted with a better spectral resolution and/or higher reliability than those of the previous observations. The stellar spectral type of the stars presented in the catalogue spans from O9 to A3. The method of spectral extraction of the bright stars is validated by comparing the spectra of 323 stars with those of the International Ultraviolet Explorer (IUE) observations.

  19. Rainbow brightness.

    PubMed

    Gedzelman, S D

    1982-08-15

    A theory for the brightness of rainbows is presented. The light reaching the observer consists of a beam of singly scattered sunlight, originating from the directly illuminated portion of a rainswath, which, in turn, has suffered depletion by scattering or absorption in its path through the atmosphere. The model incorporates the relevant features of cloud geometry and solar position in relation to the observer appropriate to rainbows. The model helps explain why the bottom (or near-horizon portion) of the rainbow tends to be both brighter and redder than the top (or horizontal portion furthest above the ground) when the sun is near the horizon. The greater brightness of the bottom of the bow derives principally from the greater length of the directly illuminated part of the rainswath near the horizon, while the increased redness of the bow's bottom is due to the severe depletion of the short-wavelength contribution to the rainbow beam in its passage through the atmosphere. PMID:20396168

  20. Ultraviolet Waves

    ERIC Educational Resources Information Center

    Molde, Trevor

    1973-01-01

    Outlines the discovery and nature of ultraviolet light, discusses some applications for these wavelengths, and describes a number of experiments with ultraviolet radiation suitable for secondary school science classes. (JR)

  1. Ultraviolet observations of comets

    NASA Technical Reports Server (NTRS)

    Code, A. D.; Houck, T. E.; Lillie, C. F.

    1972-01-01

    The first observations of a comet in the vacuum ultraviolet were obtained on January 14, 1970, when OAO-2 recorded the spectrum of the bright comet Tago-Sato-Kosaka (1969g). The observations revealed, among other things, the predicted extensive hydrogen Lyman alpha halo. OAO-2 continued to collect spectrophotometric measurements of this comet throughout January of that year; a photograph of the nucleus in Lyman alpha revealed finer scale structures. In February of 1970, the bright comet Bennet (1969i) became favorable for space observations. On the basis of the OAO discovery, OGO-V made several measurements of comet Bennet with low spatial resolution photometers. Comet Enke was detected by OGO in January of 1971 at a large heliocentric distance from its Lyman alpha emission.

  2. Compact, passively Q-switched, all-solid-state master oscillator-power amplifier-optical parametric oscillator (MOPA-OPO) system pumped by a fiber-coupled diode laser generating high-brightness, tunable, ultraviolet radiation.

    PubMed

    Peuser, Peter; Platz, Willi; Fix, Andreas; Ehret, Gerhard; Meister, Alexander; Haag, Matthias; Zolichowski, Paul

    2009-07-01

    We report on a compact, tunable ultraviolet laser system that consists of an optical parametric oscillator (OPO) and a longitudinally diode-pumped Nd:YAG master oscillator-power amplifier (MOPA). The pump energy for the whole laser system is supplied via a single delivery fiber. Nanosecond pulses are produced by an oscillator that is passively Q-switched by a Cr(4+):YAG crystal. The OPO is pumped by the second harmonic of the Nd:YAG MOPA. Continuously tunable radiation is generated by an intracavity sum-frequency mixing process within the OPO in the range of 245-260 nm with high beam quality. Maximum pulse energies of 1.2 mJ were achieved, which correspond to an optical efficiency of 3.75%, relating to the pulse energy of the MOPA at 1064 nm. PMID:19571944

  3. THE LBT BOOeTES FIELD SURVEY. I. THE REST-FRAME ULTRAVIOLET AND NEAR-INFRARED LUMINOSITY FUNCTIONS AND CLUSTERING OF BRIGHT LYMAN BREAK GALAXIES AT Z {approx} 3

    SciTech Connect

    Bian Fuyan; Fan Xiaohui; Jiang Linhua; McGreer, Ian; Dave, Romeel; Dey, Arjun; Green, Richard F.; Maiolino, Roberto; Walter, Fabian; Lee, Kyoung-Soo

    2013-09-01

    We present a deep LBT/LBC U{sub spec}-band imaging survey (9 deg{sup 2}) covering the NOAO Booetes field. A total of 14,485 Lyman break galaxies (LBGs) at z {approx} 3 are selected, which are used to measure the rest-frame UV luminosity function (LF). The large sample size and survey area reduce the LF uncertainties due to Poisson statistics and cosmic variance by {>=}3 compared to previous studies. At the bright end, the LF shows excess power compared to the best-fit Schechter function, which can be attributed to the contribution of z {approx} 3 quasars. We compute the rest-frame near-infrared LF and stellar mass function (SMF) of z {approx} 3 LBGs based on the R-band and [4.5 {mu}m]-band flux relation. We investigate the evolution of the UV LFs and SMFs between z {approx} 7 and z {approx} 3, which supports a rising star formation history in the LBGs. We study the spatial correlation function of two bright LBG samples and estimate their average host halo mass. We find a tight relation between the host halo mass and the galaxy star formation rate (SFR), which follows the trend predicted by the baryonic accretion rate onto the halo, suggesting that the star formation in LBGs is fueled by baryonic accretion through the cosmic web. By comparing the SFRs with the total baryonic accretion rates, we find that cosmic star formation efficiency is about 5%-20% and it does not evolve significantly with redshift, halo mass, or galaxy luminosity.

  4. Ultraviolet Extensions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Side-by-Side Comparison Click on image for larger view

    This ultraviolet image from NASA's Galaxy Evolution Explorer shows the Southern Pinwheel galaxy, also know as Messier 83 or M83. It is located 15 million light-years away in the southern constellation Hydra.

    Ultraviolet light traces young populations of stars; in this image, young stars can be seen way beyond the main spiral disk of M83 up to 140,000 light-years from its center. Could life exist around one of these far-flung stars? Scientists say it's unlikely because the outlying regions of a galaxy are lacking in the metals required for planets to form.

    The image was taken at scheduled intervals between March 15 and May 20, 2007. It is one of the longest-exposure, or deepest, images ever taken of a nearby galaxy in ultraviolet light. Near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow, and far-ultraviolet light is blue.

    What Lies Beyond the Edge of a Galaxy The side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy's long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms.

    The ultraviolet image was taken by NASA's Galaxy Evolution Explorer between March 15 and May 20, 2007, at scheduled intervals. Back in 2005, the telescope first photographed M83 over a shorter period of time. That picture was the first to reveal far-flung baby stars forming up to 63,000 light-years from the edge of the main spiral disk. This came as a surprise to astronomers because a galaxy's outer territory typically lacks high densities of star-forming materials.

    The newest picture of M83 from the Galaxy Evolution Explorer is shown at the right, and was taken over a longer period of

  5. Auroral bright spots on the dayside oval

    SciTech Connect

    Lui, A.T.Y. ); Venkatesan, D.; Murphree, J.S. )

    1989-05-01

    Global auroral images from the ultraviolet imager on the Viking spacecraft are used to investigate spatially periodic bright spots on the dayside auroral oval that resemble beads on a string. The newly achieved temporal resolution of 1 min. or less in monitoring worldwide auroral distributions by the Viking imager contributes significant to the capability of observing this phenomenon. It is found that these are frequently seen in the 1,400-1,600 MLT sector. The series of bright spots are not, however, limited to this unique local time sector, since they are seen to extend into the prenoon sector on some occasions. They occur often during substorm intervals but are also seen unaccompanied by substorm activities in the nightside. There is neither a consistent north-south nor east-west direction of motion for all the dayside bright spots observed so far. The observation of the time scales for the transient intensifications of bright spots and the lack of consistent directions of their motion are consistent with the characteristics expected from the suggestion that these bright spots are related to the Kelvin-Helmholtz instability occurring within the magnetosphere.

  6. Brightness of Moonlight.

    ERIC Educational Resources Information Center

    Garstang, R. H.

    1985-01-01

    Measurement of the brightness of moonlight by comparison with lamp-light from a low wattage light bulb is an elementary project in astronomy which illustrates scientific principles for the freshman level. Two methods used for the comparison (shadow brightness method and grease spot method) are explained, with suggestions and expected answers. (DH)

  7. Observations of the Ultraviolet Spectra of Carbon White Dwarfs

    NASA Technical Reports Server (NTRS)

    Wagner, G. A.

    1982-01-01

    Strong ultraviolet carbon lines were detected in additional white DC (continuous visual spectra) dwarfs using the IUE. These lines are not seen in the ultraviolet spectrum of the cool DC star Stein 2051 B. The bright DA white dwarf LB 3303 has a strong unidentified absorption near lambda 1400.

  8. Bright superior mirages

    NASA Astrophysics Data System (ADS)

    Lehn, Waldemar H.

    2003-01-01

    Superior mirages of unusual brightness are occasionally observed. Two such cases, photographed over the frozen surface of Lake Winnipeg, Canada, are documented. Visually, these mirages appear as featureless bright barriers far out on the lake. They are just images of the lake ice, yet the luminance in one case was 2.5 times (in the other, 1.7 times) the luminance of the ice surface in front of the mirage. The mirage itself can be modeled by means of a conduction inversion, but a proper explanation of the brightness is not yet available.

  9. Star Light, Star Bright.

    ERIC Educational Resources Information Center

    Iadevaia, David G.

    1984-01-01

    Presents a technique for obtaining a rough measure of the brightness among different stars. Materials needed include a standard 35-mm camera, a plastic ruler, and a photo enlarger. Although a telescope can be used, it is not essential. (JN)

  10. Compact ultraviolet laser

    NASA Astrophysics Data System (ADS)

    Baird, Brian Walter

    1997-09-01

    wavelength are presented. This work includes results for the highest cw output powers reported for NUV SHG output from a laser-pumped KTP PSW. In an important step towards demonstration of an URSL- pumped KTP PSW laser, fabrication methods and test results ate reported for half-symmetric, low magnification SQW AlGaAs URSLs emitting at 770 nm and designed for use as diode pump sources for hydrothermal KTP PSWs. These devices utilize a 200 /mu m × 500 /mu m active region profile and were focused-ion- beam micromachined to achieve a total resonator magnification of 2.9. The first demonstration of high brightness, single-longitudinal mode operation from a core grating URSL is reported. This dissertation concludes with results for the first demonstration of an URSL-pumped KTP waveguide laser. This compact ultraviolet laser represents a pioneering effort to take advantage of the high cw output powers available from high brightness URSLs to increase the SH output powers obtainable from diode-pumped nonlinear waveguide lasers and to extend the useful spectral range from these sources into the near ultraviolet.

  11. Bright patches on Ariel

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Distinct bright patches are visible on Ariel, the brightest of Uranus' five largest satellites. Voyager 2 obtained this image Jan. 22, 1986, from a distance of 2.52 million kilometers (1.56 million miles). The clear-filter image, obtained with the narrow-angle camera, shows a resolution of 47 km (29 miles). Ariel is about 1,300 km (800 mi) in diameter. This image shows several distinct bright areas that reflect nearly 45 percent of the incident sunlight; on average, the satellite displays a reflectivity of about 25-30 percent. The bright areas are probably fresh water ice, perhaps excavated by impacts. The south pole of Ariel is slightly off center of the disk in this view. Voyager 2 will obtain its best views of the satellite on Jan. 24, at a closest-approach distance of 127,000 km (79,000 mi). The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  12. High Brightness Test Stand

    SciTech Connect

    Birx, D.L.; Caporaso, G.J.; Boyd, J.K.; Hawkins, S.A.; Poor, S.E.; Reginato, L.L.; Rogers, D. Jr.; Smith, M.W.

    1985-08-07

    The High Brightness Test Stand is a 2 MeV, less than or equal to 10 kA electron accelerator module. This accelerator module, designed as an upgrade prototype for the Advanced Test Accelerator (ATA), combines solid state nonlinear magnetic drives with state-of-the-art induction linac technology. The facility serves a dual role, as it not only provides a test bed for this new technology, but is used to develop high brightness electron optics. We will both further describe the accelerator, as well as present some of the preliminary electron optics measurements.

  13. Bright Fireball Over Georgia

    NASA Video Gallery

    A camera in Cartersville, Ga., captured this view of a bright fireball over Georgia on the night of Mar. 7, 2012, at approx. 10:19:11 EST. The meteor was first recorded at an altitude of 51.5 miles...

  14. Brightness predictions for comets

    NASA Astrophysics Data System (ADS)

    Green, Daniel W. E.; Marsden, Brian G.; Morris, Charles S.

    2001-02-01

    Daniel W E Green, Brian G Marsden and Charles S Morris write with the aim of illuminating the issue of cometary light curves and brightness predictions, following the publication in this journal last October of the letter by John McFarland (2000).

  15. A Bright Shining Lesson

    ERIC Educational Resources Information Center

    Hurowitz, Amanda

    2010-01-01

    Sometimes students come up with crazy ideas. When this author first started teaching at Thomas Jefferson High School for Science and Technology in Virginia five years ago, she had a sophomore share such an idea with her. He wanted to put solar panels on the school's roof as a way to reduce the school's carbon footprint and set a bright clean…

  16. Bright Streak on Amalthea

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These two images of Jupiter's small, irregularly shaped moon Amalthea, obtained by the camera onboard NASA's Galileo spacecraft in August 1999(left) and November 1999 (right), form a 'stereo pair' that helps scientists determine this moon's shape and the topography of its surface features. Features as small as 3.8 kilometers (2.4 miles) across can be resolved in these images, making them among the highest-resolution images ever taken of Amalthea.

    The large impact crater visible in both images, near the right-hand edge of Amalthea's disk, is about 40 kilometers (about 29 miles) across; two ridges, tall enough to cast shadows, extend from the top of the crater in a V-shape reminiscent of a 'rabbit ears' television antenna. To the left of these ridges, in the top center portion of Amalthea's disk, is a second large impact crater similar in size to the first crater. To the left of this second crater is a linear 'streak' of relatively bright material about 50 kilometers (31 miles) long. In previous spacecraft images of Amalthea taken from other viewing directions, this bright feature was thought to be a small, round, bright 'spot' and was given the name Ida. These new images reveal for the first time that Ida is actually a long, linear 'streak.' This bright streak may represent material ejected during the formation of the adjacent impact crater, or it may just mark the crest of a local ridge. Other patches of relatively bright material can be seen elsewhere on Amalthea's disk, although none of these other bright spots has Ida's linear shape.

    In both images, sunlight is coming from the left and north is approximately up. Note that the north pole of Amalthea is missing in the right-hand image (it was cut off by the edge of the camera frame). The bright streak, Ida, is on the side of the moon that faces permanently away from Jupiter, and the crater near the right-hand edge of the disk is in the center of Amalthea's leading side (the side of the moon that 'leads

  17. Low-Dispersion Observations of Bright Stars

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Edward L.

    Seven US2 observing shifts are being requested to obtain low-dispersion SWP and LWP spectra of approximately 15 bright, nearby early-type stars. The targets are taken from the 10-year old effective temperature and bolometric correction study of Code, Davis, Bless, and Hanbury Brown (CDBB). The CDBB stars represent the only sample of stars for which angular diameter measurements are available. The stars which we plan to observe have been unobservable with the low-dispersion mode of IUE in the past because of their extreme brightness; however, the recent refinements in the fast-trailing technique now allow optimally exposed spectra to be obtained. With the new spectra and with Archival spectra which are available for some of the less bright CDBB stars, we plan to repeat the earlier effective temperature and bolometric correction determinations, taking advantage of the higher photometric stability and higher resolution of IUE over previous ultraviolet missions and utilizing improvements in the ground-based optical/lR data and calibrations. This study will tie the large IUE database into a system of fundamental stellar effective temperature and bolometric correction determinations.

  18. Bright field illumination system

    NASA Technical Reports Server (NTRS)

    Huber, Edward D. (Inventor)

    1998-01-01

    A Bright Field Illumination system for inspecting a range of characteristically different kinds of defects, depressions, and ridges in a selected material surface. The system has an illumination source placed near a first focus of an elliptical reflector. In addition, a camera facing the inspected area is placed near the illumination source and the first focus. The second focus of the elliptical reflector is located at a distance approximately twice the elliptical reflector's distance above the inspected surface. The elliptical reflector directs the light from the source onto the inspected surface. Due to the shape of the elliptical reflector, light that is specularly reflected from the inspected surface is directed into the camera is which located at the position of the reflected second focus of the ellipse. This system creates a brightly lighted background field against which damage sites appear as high contrast dark objects which can be easily detected by a person or an automated inspection system. In addition, the Bright Field Illumination system and method can be used in combination with a vision inspection system providing for multiplexed illumination and data handling of multiple kinds of surface characteristics including abrupt and gradual surface variations and differences between measured characteristics of different kinds and prior instruments.

  19. MEASURED PROPERTIES OF THE DUVFEL HIGH BRIGHTNESS, ULTRASHORT ELECTRON BEAM.

    SciTech Connect

    GRAVES, W.S.; CARR, G.L.; DIMAURO, L.F.; DOYURAN, A.; HEESE, R.; JOHNSON, E.D.; KRINSKY, S.; NEUMAN, C.; RAKOWSKY, G.; ROSE, J.; ROTHMAN, J.; RUDATI, J.; SHAFTAN, T.; SHEEHY, B.; SKARITKA, J.; YU, L.H.; DOWELL, D.H.; EMMA, P.

    2001-06-18

    The DUVFEL electron linac is designed to produce sub-picosecond, high brightness electron bunches to drive an ultraviolet FEL. The accelerator consists of a 1.6 cell S-band photoinjector, variable pulse length Ti:Sapp laser, 4 SLAC-type S-band accelerating sections, and 4-dipole chicane bunch compressor. In preparation for FEL operation, the compressed electron beam has been fully characterized. Measurement of the beam parameters and simulation of the beam are presented.

  20. Large, Bright Wind Ripples

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-397, 20 June 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows large, relatively bright ripples of windblown sediment in the Sinus Sabaeus region south of Schiaparelli Basin. The surrounding substrate is thickly mantled by very dark material, possibly windblown silt that settled out of the atmosphere. The picture is located near 7.1oS, 343.7oW. Sunlight illuminates the scene from the left.

  1. Large Bright Ripples

    NASA Technical Reports Server (NTRS)

    2004-01-01

    3 February 2004 Wind is the chief agent of change on Mars today. Wind blows dust and it can move coarser sediment such as sand and silt. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows bright ripples or small dunes on the floors of troughs northeast of Isidis Planitia near 31.1oN, 244.6oW. The picture covers an area 3 km (1.9 mi) wide; sunlight illuminates the scene from the lower left.

  2. Lightness, brightness, and anchoring.

    PubMed

    Anderson, Barton L; Whitbread, Michael; de Silva, Chamila

    2014-01-01

    The majority of work in lightness perception has evaluated the perception of lightness using flat, matte, two-dimensional surfaces. In such contexts, the amount of light reaching the eye contains a conflated mixture of the illuminant and surface lightness. A fundamental puzzle of lightness perception is understanding how it is possible to experience achromatic surfaces as specific achromatic shades in the face of this ambiguity. It has been argued that the perception of lightness in such contexts implies that the visual system imposes an "anchoring rule" whereby a specific relative luminance (the highest) serves as a fixed point in the mapping of image luminance onto the lightness scale ("white"). We conducted a series of experiments to explicitly test this assertion in contexts where this mapping seemed most unlikely-namely, low-contrast images viewed in dim illumination. Our results provide evidence that the computational ambiguity in mapping luminance onto lightness is reflected in perceptual experience. The perception of the highest luminance in a two-dimensional Mondrian display varied monotonically with its brightness, ranging from midgray to white. Similar scaling occurred for the lowest luminance and, by implication, all other luminance values. We conclude that the conflation between brightness and lightness in two-dimensional Mondrian displays is reflected in perception and find no support for the claim that any specific relative luminance value acts as a fixed anchor point in this mapping function. PMID:25104828

  3. Direct ultraviolet imaging and spectroscopy of betelgeuse

    NASA Astrophysics Data System (ADS)

    Dupree, A. K.; Stefanik, R. P.

    2013-05-01

    Direct images of Betelgeuse were obtained over a span of 4 years with the Faint Object Camera on the Hubble Space Telescope. These images reveal the extended ultraviolet continuum emission (~2 times the optical diameter), the varying overall ultraviolet flux levels and a pattern of bright surface continuum features that change in position and appearance over several months or less. Concurrent photometry and radial velocity measures support the model of a pulsating star, first discovered in the ultraviolet from IUE. Spatially resolved HST spectroscopy reveals a larger extention in chromospheric emissions of Mg II as well as the rotation of the supergiant. Changing localized subsonic flows occur in the low chromosphere that can cover a substantial fraction of the stellar disk and may initiate the mass outflow.

  4. High brightness electron accelerator

    DOEpatents

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  5. High brightness electron sources

    SciTech Connect

    Sheffield, R.L.

    1995-07-01

    High energy physics accelerators and free electron lasers put increased demands on the electron beam sources. This paper describes the present research on attaining intense bright electron beams using photoinjectors. Recent results from the experimental programs will be given. The performance advantages and difficulties presently faced by researchers will be discussed, and the following topics will be covered. Progress has been made in photocathode materials, both in lifetime and quantum efficiency. Cesium telluride has demonstrated significantly longer lifetimes than cesium antimonide at 10{sup {minus}8} torr. However, the laser system is more difficult because cesium telluride requires quadrupled YLF instead of the doubled YLF required for cesium antimonide. The difficulty in using photoinjectors is primarily the drive laser, in particular the amplitude stability. Finally, emittance measurements of photoinjector systems can be complicated by the non-thermal nature of the electron beam. An example of the difficulty in measuring beam emittance is given.

  6. Bright Dust Devil Tracks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    9 June 2004 Martian dust devils sometimes disrupt thin coatings of surface dust to create dark streak patterns on the surface. However, not all dust devils make streaks, and not all dust devil streaks are dark. In Syria Planum, the streaks are lighter than the surrounding plains. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows an example from Syria near 8.8oS, 103.6oW. The thin coating of surface dust in this region is darker than the substrate beneath it. This is fairly unusual for Mars, because most dust is bright. This image covers an area about 3 km (1.9 mi) across and is illuminated by sunlight from the left/lower left.

  7. Maximizing Brightness in Photoinjectors

    SciTech Connect

    Limborg-Deprey, C.; Tomizawa, H.; /JAERI-RIKEN, Hyogo

    2011-11-30

    If the laser pulse driving photoinjectors could be arbitrarily shaped, the emittance growth induced by space charge effects could be totally compensated for. In particular, for RF guns the photo-electron distribution leaving the cathode should have a 3D-ellipsoidal shape. The emittance at the end of the injector could be as small as the cathode emittance. We explore how the emittance and the brightness can be optimized for photoinjector based on RF gun depending on the peak current requirements. Techniques available to produce those ideal laser pulse shapes are also discussed. If the laser pulse driving photoinjectors could be arbitrarily shaped, the emittance growth induced by space charge effects could be totally compensated for. In particular, for RF guns, the photo-electron distribution leaving the cathode should be close to a uniform distribution contained in a 3D-ellipsoid contour. For photo-cathodes which have very fast emission times, and assuming a perfectly uniform emitting surface, this could be achieved by shaping the laser in a pulse of constant fluence and limited in space by a 3D-ellipsoid contour. Simulations show that in such conditions, with the standard linear emittance compensation, the emittance at the end of the photo-injector beamline approaches the minimum value imposed by the cathode emittance. Brightness, which is expressed as the ratio of peak current over the product of the two transverse emittance, seems to be maximized for small charges. Numerical simulations also show that for very high charge per bunch (10nC), emittances as small as 2 mm-mrad could be reached by using 3D-ellipsoidal laser pulses in an S-Band gun. The production of 3D-ellipsoidal pulses is very challenging, but seems worthwhile the effort. We briefly discuss some of the present ideas and difficulties of achieving such pulses.

  8. Inverse relationship between surface brightness and polarization

    NASA Astrophysics Data System (ADS)

    Egan, Walter G.

    1999-10-01

    There is an inverse relationship between surface brightness and polarization in the wavelength range from the ultraviolet to the near infrared. This relationship was first observed by the French astronomers B. Lyot and A. Dollfus in the early 20th century for planetary surfaces and laboratory models. The relationship was later confirmed principally by Egan and his coworkers in the Grumman Research Department in lunar simulation experiments prior to the Lunar Module landing. The observations indicate that the percent polarization (The percent polarization is the ratio of the difference between two orthogonal polarized measurements ratioed to the sum multiplied by 100) is an inverse function of the surface brightness (albedo). The Grumman instrument was a unique large scale polarimeter/photometer that allowed measurements not only of coated surfaces, but of particulates or structural surfaces up to 10 centimeters in diameter. It was found that, for instance, a diffuse surface having a reflectance of 2% could have a percent polarization of nearly 100%. The polarization was found to be a function of the optical complex index of refraction of the surface and the surface structure, and the relationship was found to be true for farm soils, agricultural and forested areas and was useful to characterize them. Astronomical and recent laboratory data will be presented to illustrate the relationship. More recent polarimeters will be discussed that permit polarization measurements accurate to plus or minus 0.1% from 0 to 100%.

  9. A high brightness photoinjector

    NASA Astrophysics Data System (ADS)

    Le Sage, Gregory Peter

    Linear colliders, future electron acceleration schemes, and short pulse, ultrawideband millimeter-wave sources require very bright electron beams. Conventional electron injectors including thermionic cathodes and RF bunchers or DC guns have intrinsic limitations which preclude their usage for many of these applications. RF photoinjectors have shown their ability to produce relativistic electron beams with low emittance and energy spread. However, previously developed RF photoinjectors are also subject to significant limitations. These include extreme sensitivity to timing between the RF in the accelerator structure and the drive laser, low efficiency with respect to the number and charge of the electron bunches produced by the injector, and high cost associated with both the RF drive and laser systems. The presently described system has addressed these issues by combining state-of-the-art capabilities in the laser and RF systems, photocathode materials, and new concepts for synchronization. Phase jitter generated by sources including Klystron modulator voltage fluctuation has been measured in detail, and schemes for alleviating this problem have undergone initial proof-of-principle testing. New concepts for the drive laser system have been tested which will lead to further improvements in performance, simplicity, cost-effectiveness, and compactness. The analytical and experimental work associated with the development of a high brightness, high gradient electron accelerator is presented. The presentation emphasizes the systematic progress toward the original design goals of the project, as well as the state-of-the-art innovations characterizing the system. The linear electron accelerator system is based on a 1 1/2 cell side-wall coupled, π-mode standing wave accelerator structure, driven by a 20 MW SLAC Klystron operating at 8.548 GHz, a Ti:Sapphire laser oscillator, and an 8-pass, chirped pulse Ti:Sapphire laser amplifier. Simulations show an rms transverse

  10. How Bright Is the Sun?

    ERIC Educational Resources Information Center

    Berr, Stephen

    1991-01-01

    Presents a sequence of activities designed to allow eighth grade students to deal with one of the fundamental relationships that govern energy distribution. Activities guide students to measure light bulb brightness, discover the inverse square law, compare light bulb light to candle light, and measure sun brightness. (two references) (MCO)

  11. The Ultraviolet Albedo of Ganymede

    NASA Technical Reports Server (NTRS)

    McGrath, Melissa; Hendrix, Amanda

    2013-01-01

    A large set of ultraviolet images of Ganymede have been acquired with the Hubble Space Telescope over the last 15 years. These images have been used almost exclusively to study Ganymede's stunning auroral emissions (Feldman et al. 2000; Eviatar et al. 2001; McGrath et al. 2004; Saur et al. 2011; McGrath et al. 2013), and even the most basic information about Ganymede's UV albedo has yet to be gleaned from these data. We will present a first-cut analysis of both disk-averaged and spatially-resolved UV albedos of Ganymede, with focus on the spatially-resolved Lyman-alpha albedo, which has never been considered previously for this satellite. Ganymede's visibly bright regions are known to be rich in water ice, while the visibly dark regions seem to be more carbonaceous (Carlson et al., 1996). At Lyman-alpha, these two species should also have very different albedo values.

  12. Ultraviolet Spectroscopy of Narrow CMEs

    NASA Astrophysics Data System (ADS)

    Dobrzycka, D.; Raymond, J. C.; Biesecker, D. A.; Li, J.; Ciaravella, A.

    2002-12-01

    Coronal mass ejections (CMEs) are commonly described as new, discrete, bright features appearing in the field of view of a white light coronagraph and moving outward over a period of minutes to hours. Apparent angular widths of the CMEs cover a wide range, from few to 360°. The very narrow structures (narrower than ~15-20°) form only a small subset of all the observed CMEs and are usually referred to as rays, spikes, fans, etc. Recently, Gilbert et al. (2001, ApJ, 550, 1093) reported LASCO white light observations of 15 selected narrow CMEs. We extended the study and analyzed ultraviolet spectroscopy of narrow ejections, including several events listed by Gilbert et al. The data were obtained by the Ultraviolet Coronagraph Spectrometer (UVCS/SOHO). We present comparison of narrow and large CMEs and discuss the relation of the narrow CMEs to coronal jets and/or other narrow transient events. This work is supported by NASA under Grant NAG5-11420 to the Smithsonian Astrophysical Observatory, by the Italian Space Agency and by PRODEX (Swiss contribution).

  13. Brightness measurements on the Livermore high brightness test stand

    SciTech Connect

    Caporaso, G.J.; Birx, D.L.

    1985-05-09

    Several techniques using small radius collimating pipes with and without axial magnetic fields to measure the brightness of an extracted 1 - 2 kA, 1 - 1.5 MeV electron beam will be described. The output beam of the High Brightness Test Stand as measured by one of these techniques is in excess of 2 x 10/sup 5/ amp/cm/sup 2//steradian. 5 refs., 4 figs.

  14. Statistical Properties of Solar Coronal Bright Points

    NASA Astrophysics Data System (ADS)

    Alipour, N.; Safari, H.

    2015-07-01

    Here, we aim to study the statistical properties (i.e., spatial, temporal, and magnetic structures) of extreme ultraviolet coronal bright points (CBPs) observed by SDO during a 4.4 yr period (2010 June 1 to 2014 October 31). We developed the automatic detection method for CBPs based on the machine-learning technique and Zernike image moments. The average number and the mean density of CBPs are estimated to be about 572 (per full disk image taken at 193 Å) and 1.9× {10}-4 Mm-2, respectively. There is a negative correlation (-0.7) between the number of CBPs and the number of sunspots. The size and lifetime frequency distribution of CBPs show the lognormal and power-law (exponent equal to -1.6) behaviors, respectively. The relationship between the lifetime and size of CBPs is clearly treated by a power-law function with an exponent equal to 0.13. Around 1.3% of the solar surface is covered by the bright cores of CBPs and 2.6% of that is covered by their total area. About 52% of CBPs have lifetimes of less than 20 minutes and the remaining 48% have mean lifetimes of 6 hr. More than 95% of CBPs with lifetimes of less than 20 hr and nine CBPs with lifetimes of more than 72 hr are detected. The average number of the new CBPs emerging every 45 s in the whole of the Sun is about 27 ± 3. The temporal self-affinity of the time series of CBPs that emerged, indexed by the Hurst exponent determined using both detrended fluctuation analysis and R/S analysis, is 0.78. This long-temporal correlation suggests that CBPs form a system of self-organized criticality.

  15. Space station contamination study: Assessment of contaminant spectral brightness

    NASA Technical Reports Server (NTRS)

    Torr, D. G.

    1988-01-01

    The assessment of spectral brightness resulting from the ambient-contaminant interaction requires a knowledge of the details of cross sections and excitation mechanisms. The approach adopted was to utilize the spectral brightness measurements made on Spacelab 1 and on the S3-4 spacecraft to identify source mechanisms, key cross sections and hence, the abundance of contaminant species. These inferred abundances were then used to update the composition comprising the total column concentrations predicted by the Science and Engineering Associates' configuration contamination model for the Space Station and to scale the irradiances to four altitudes: 300, 350, 400, and 463 km. The concentration irradiances are compared with zodiacal natural background levels. The results demonstrate that emissive contamination is significantly more severe than anticipated. It is shown that spectral emissions can become competitive with the zodiacal background up to altitudes as high as 400 km for the vacuum ultraviolet and visible emissions.

  16. Lyman Alpha Mapping Project (LAMP) Brightness Maps

    NASA Astrophysics Data System (ADS)

    Retherford, Kurt D.; Gladstone, G.; Stern, S.; Egan, A. F.; Miles, P. F.; Parker, J. W.; Greathouse, T. K.; Davis, M. W.; Slater, D. C.; Kaufmann, D. E.; Versteeg, M. H.; Feldman, P. D.; Hurley, D. M.; Pryor, W. R.; Hendrix, A. R.

    2010-10-01

    The Lyman Alpha Mapping Project (LAMP) is an ultraviolet (UV) spectrograph on the Lunar Reconnaissance Orbiter (LRO) that is designed to map the lunar albedo at far-UV wavelengths. LAMP primarily measures interplanetary Hydrogen Lyman-alpha sky-glow and far-UV starlight reflected from the night-side lunar surface, including permanently shadowed regions (PSRs) near the poles. Dayside observations are also obtained. Brightness maps sorted by wavelength (including the Lyman-alpha wavelength of 121.6 nm) are reported for the polar regions, with a few regions of interest reported in more detail. LAMP's spectral range of 58 nm to 196 nm includes a water ice spectral feature near 160 nm, which provides a diagnostic tool for detecting water on the lunar surface that is complementary to recent discoveries using infrared and radio frequency techniques. Progress towards producing far-UV albedo maps and searching for water ice signatures will be reported. We'll discuss how LAMP data may address questions regarding how water is formed on the moon, transported through the lunar atmosphere, and deposited in the PSRs.

  17. Atmospheric ultraviolet remote sensing

    NASA Astrophysics Data System (ADS)

    Huffman, Robert E.

    Techniques and applications of the ultraviolet wavelength region are examined. The topics addressed include: radiometry, sensors, space operations, the earth's atmosphere, solar photoabsorption, photon cross sections, airglow, aurora, scattering and fluorescence, atmospheric ultraviolet backgrounds, radiance and transmission codes, ozone and lower atmospheric composition, upper atmospheric composition and density, global auroral imaging, and ionospheric electron density.

  18. Orientation of migratory birds under ultraviolet light.

    PubMed

    Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2014-05-01

    In view of the finding that cryptochrome 1a, the putative receptor molecule for the avian magnetic compass, is restricted to the ultraviolet single cones in European Robins, we studied the orientation behaviour of robins and Australian Silvereyes under monochromatic ultraviolet (UV) light. At low intensity UV light of 0.3 mW/m(2), birds showed normal migratory orientation by their inclination compass, with the directional information originating in radical pair processes in the eye. At 2.8 mW/m(2), robins showed an axial preference in the east-west axis, whereas silvereyes preferred an easterly direction. At 5.7 mW/m(2), robins changed direction to a north-south axis. When UV light was combined with yellow light, robins showed easterly 'fixed direction' responses, which changed to disorientation when their upper beak was locally anaesthetised with xylocaine, indicating that they were controlled by the magnetite-based receptors in the beak. Orientation under UV light thus appears to be similar to that observed under blue, turquoise and green light, albeit the UV responses occur at lower light levels, probably because of the greater light sensitivity of the UV cones. The orientation under UV light and green light suggests that at least at the level of the retina, magnetoreception and vision are largely independent of each other. PMID:24718656

  19. In Situ Mosaic Brightness Correction

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Lorre, Jean J.

    2012-01-01

    In situ missions typically have pointable, mast-mounted cameras, which are capable of taking panoramic mosaics comprised of many individual frames. These frames are mosaicked together. While the mosaic software applies radiometric correction to the images, in many cases brightness/contrast seams still exist between frames. This is largely due to errors in the radiometric correction, and the absence of correction for photometric effects in the mosaic processing chain. The software analyzes the overlaps between adjacent frames in the mosaic and determines correction factors for each image in an attempt to reduce or eliminate these brightness seams.

  20. A Far-Ultraviolet Study of the Cygnus Loop Using the VOYAGER Ultraviolet Spectrometers

    NASA Technical Reports Server (NTRS)

    Vancura, Olaf; Blair, William P.; Long, Knox S.; Raymond, John C.; Holberg, J. B.

    1993-01-01

    We have used the Voyager 1 and 2 Ultraviolet Spectrometers to study the far-ultraviolet emissions from different types of shock waves in the Cygnus Loop. In the southeast and northern parts of the supernova remnant (SNR), we have measured the O(VI) lambda1035 surface brightness from the main blast wave. This value is several times below the average and more than one order of magnitude below the peak O(VI) brightness in the SNR as measured with Voyager. A simple blast wave model appears able to reproduce the observations in the southeast and the northern parts of the Cygnus Loop but can only account for 10%-15% of the total O(VI) emission from the Cygnus Loop. The brightest O(VI) and C(III) lambda977 emission is found coincident with optical filamentation and X-ray enhancements in the northeast. We interpret the observations in the northeast in terms of nonradiative and incomplete shocks whose surface area rises in the optical filamentary regions. We conclude that the bulk of the O(VI) emission from the Cygnus Loop arises from optically bright clouds within which intermediate-velocity (200 + 50 km/s) nonradiative and incomplete shocks are widespread.

  1. The Surface Compositon of Enceladus: Clues from the Ultraviolet

    NASA Technical Reports Server (NTRS)

    Hendrix, Amanda R.; Hansen, Candice J.

    2009-01-01

    The reflectance of Saturn's moon Enceladus has been measured at far ultraviolet (FUV) wavelengths (115-190 nm) by Cassini's UltraViolet Imaging Spectrograph (UVIS). At visible and near infrared (VNIR) wavelengths Enceladus' reflectance spectrum is very bright, consistent with a surface composed primarily of H2O ice. At FUV wavelengths, however, Enceladus is surprisingly dark - darker than would be expected for pure water ice. We find that the low FUV reflectance of Enceladus can be explained by the presence of a small amount of NH3 and a small amount of a tholin in addition to H?O ice on the surface.

  2. Far-ultraviolet imagery of the Orion Nebula

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.; Opal, C. B.

    1977-01-01

    Two electrographic cameras carried on a sounding rocket have yielded useful-resolution far-ultraviolet (1000-2000 A) imagery of the Orion Nebula. The brightness distribution in the images is consistent with a primary source which is due to scattering of starlight by dust grains, although an emission-line contribution, particularly in the fainter outer regions, is not ruled out. The results are consistent with an albedo of the dust grains that is high in the far-ultraviolet and which increases toward shorter wavelengths below 1230 A.

  3. StarBright Learning Exchange

    ERIC Educational Resources Information Center

    Kalinowski, Michael

    2007-01-01

    This article features StarBright Learning Exchange, a program that provides a cross-cultural exchange between Australian and South African early childhood educators. The program was originated when its president, Carol Allen, and her colleague, Karen Williams, decided that they could no longer sit by and watch the unfolding social catastrophe that…

  4. Bright Transients discovered by PSST

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Young, D. R.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-08-01

    Six bright transients have been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  5. Bright Transients discovered by PSST

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-04-01

    Seven bright transients have been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  6. Teradiode's high brightness semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz

    2016-03-01

    TeraDiode is manufacturing multi-kW-class ultra-high brightness fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, <0.08 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. Our TeraBlade industrial platform achieves world-record brightness levels for direct diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high brightness Mid-Infrared Lasers.

  7. Network based sky Brightness Monitor

    NASA Astrophysics Data System (ADS)

    McKenna, Dan; Pulvermacher, R.; Davis, D. R.

    2009-01-01

    We have developed and are currently testing an autonomous 2 channel photometer designed to measure the night sky brightness in the visual wavelengths over a multi-year campaign. The photometer uses a robust silicon sensor filtered with Hoya CM500 glass. The Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The Sky Brightness monitor consists of two units, the remote photometer and a network interface. Currently these devices use 2.4 Ghz transceivers with a free space range of 100 meters. The remote unit is battery powered with day time recharging using a solar panel. Data received by the network interface transmits data via standard POP Email protocol. A second version is under development for radio sensitive areas using an optical fiber for data transmission. We will present the current comparison with the National Park Service sky monitoring camera. We will also discuss the calibration methods used for standardization and temperature compensation. This system is expected to be deployed in the next year and be operated by the International Dark Sky Association SKYMONITOR project.

  8. Ultraviolet absorption hygrometer

    DOEpatents

    Gersh, M.E.; Bien, F.; Bernstein, L.S.

    1986-12-09

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined. 5 figs.

  9. Ultraviolet absorption hygrometer

    DOEpatents

    Gersh, Michael E.; Bien, Fritz; Bernstein, Lawrence S.

    1986-01-01

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.

  10. The Ultraviolet Albedo of Ganymede

    NASA Astrophysics Data System (ADS)

    McGrath, Melissa; Hendrix, A.

    2013-10-01

    A large set of ultraviolet images of Ganymede have been acquired with the Hubble Space Telescope over the last 15 years. These images have been used almost exclusively to study Ganymede’s stunning auroral emissions (Feldman et al. 2000; Eviatar et al. 2001; McGrath et al. 2004; Saur et al. 2011; McGrath et al. 2013), and even the most basic information about Ganymede’s UV albedo has yet to be gleaned from these data. We will present a first-cut analysis of both disk-averaged and spatially-resolved UV albedos of Ganymede, with focus on the spatially-resolved Lyman-alpha albedo, which has never been considered previously for this satellite. Ganymede's visibly bright regions are known to be rich in water ice, while the visibly dark regions seem to be more carbonaceous (Carlson et al., 1996). At Lyman-alpha, these two species should also have very different albedo values. References Carlson, R. and 39 co-authors, Near-infrared spectroscopy and spectral mapping of Jupiter and the Galilean satellites: Results from Galileo’s initial orbit, Science, 274, 385-388, 1996. Eviatar, A., D. F. Strobel, B. C. Wolven, P. D. Feldman, M. A. McGrath, and D. J. Williams, Excitation of the Ganymede ultraviolet aurora, Astrophys. J, 555, 1013-1019, 2001. Feldman, P. D., M. A. McGrath, D. F. Strobel, H. W. Moos, K. D. Retherford, and B. C. Wolven, HST/STIS imaging of ultraviolet aurora on Ganymede, Astrophys. J, 535, 1085-1090, 2000. McGrath M. A., Lellouch E., Strobel D. F., Feldman P. D., Johnson R. E., Satellite Atmospheres, Chapter 19 in Jupiter: The Planet, Satellites and Magnetosphere, ed. F. Bagenal, T. Dowling, W. McKinnon, Cambridge University Press, 2004. McGrath M. A., Jia, Xianzhe; Retherford, Kurt; Feldman, Paul D.; Strobel, Darrell F.; Saur, Joachim, Aurora on Ganymede, J. Geophys. Res., doi: 10.1002/jgra.50122, 2013. Saur, J., S. Duling, S., L. Roth, P. D. Feldman, D. F. Strobel, K. D. Retherford, M. A. McGrath, A. Wennmacher, American Geophysical Union, Fall Meeting

  11. Investigation of the diffuse ultraviolet background using satellite data: Dynamics explorer guest investigator program

    NASA Technical Reports Server (NTRS)

    Fix, J. D.

    1986-01-01

    The imaging instrumentation for the Dynamics Explorer Mission was designed primarily to obtain global auroral images. The instrument, however, was also used successfully to study marine bioluminescence, the geocorona, and the global distribution of atmospheric ozone. The imager has considerable potential for the study of astronomical sources of ultraviolet radiation as well. The data produced by the imager is used to study the brightness and isotrophy of the diffuse ultraviolet background.

  12. Low-brightness quantum radar

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco

    2015-05-01

    One of the major scientific thrusts from recent years has been to try to harness quantum phenomena to dramatically increase the performance of a wide variety of classical information processing devices. These advances in quantum information science have had a considerable impact on the development of standoff sensors such as quantum radar. In this paper we analyze the theoretical performance of low-brightness quantum radar that uses entangled photon states. We use the detection error probability as a measure of sensing performance and the interception error probability as a measure of stealthiness. We compare the performance of quantum radar against a coherent light sensor (such as lidar) and classical radar. In particular, we restrict our analysis to the performance of low-brightness standoff sensors operating in a noisy environment. We show that, compared to the two classical standoff sensing devices, quantum radar is stealthier, more resilient to jamming, and more accurate for the detection of low reflectivity targets.

  13. Brightness-equalized quantum dots

    NASA Astrophysics Data System (ADS)

    Lim, Sung Jun; Zahid, Mohammad U.; Le, Phuong; Ma, Liang; Entenberg, David; Harney, Allison S.; Condeelis, John; Smith, Andrew M.

    2015-10-01

    As molecular labels for cells and tissues, fluorescent probes have shaped our understanding of biological structures and processes. However, their capacity for quantitative analysis is limited because photon emission rates from multicolour fluorophores are dissimilar, unstable and often unpredictable, which obscures correlations between measured fluorescence and molecular concentration. Here we introduce a new class of light-emitting quantum dots with tunable and equalized fluorescence brightness across a broad range of colours. The key feature is independent tunability of emission wavelength, extinction coefficient and quantum yield through distinct structural domains in the nanocrystal. Precise tuning eliminates a 100-fold red-to-green brightness mismatch of size-tuned quantum dots at the ensemble and single-particle levels, which substantially improves quantitative imaging accuracy in biological tissue. We anticipate that these materials engineering principles will vastly expand the optical engineering landscape of fluorescent probes, facilitate quantitative multicolour imaging in living tissue and improve colour tuning in light-emitting devices.

  14. A New Sky Brightness Monitor

    NASA Astrophysics Data System (ADS)

    Crawford, David L.; McKenna, D.

    2006-12-01

    A good estimate of sky brightness and its variations throughout the night, the months, and even the years is an essential bit of knowledge both for good observing and especially as a tool in efforts to minimize sky brightness through local action. Hence a stable and accurate monitor can be a valuable and necessary tool. We have developed such a monitor, with the financial help of Vatican Observatory and Walker Management. The device is now undergoing its Beta test in preparation for production. It is simple, accurate, well calibrated, and automatic, sending its data directly to IDA over the internet via E-mail . Approximately 50 such monitors will be ready soon for deployment worldwide including most major observatories. Those interested in having one should enquire of IDA about details.

  15. Brightness-equalized quantum dots

    PubMed Central

    Lim, Sung Jun; Zahid, Mohammad U.; Le, Phuong; Ma, Liang; Entenberg, David; Harney, Allison S.; Condeelis, John; Smith, Andrew M.

    2015-01-01

    As molecular labels for cells and tissues, fluorescent probes have shaped our understanding of biological structures and processes. However, their capacity for quantitative analysis is limited because photon emission rates from multicolour fluorophores are dissimilar, unstable and often unpredictable, which obscures correlations between measured fluorescence and molecular concentration. Here we introduce a new class of light-emitting quantum dots with tunable and equalized fluorescence brightness across a broad range of colours. The key feature is independent tunability of emission wavelength, extinction coefficient and quantum yield through distinct structural domains in the nanocrystal. Precise tuning eliminates a 100-fold red-to-green brightness mismatch of size-tuned quantum dots at the ensemble and single-particle levels, which substantially improves quantitative imaging accuracy in biological tissue. We anticipate that these materials engineering principles will vastly expand the optical engineering landscape of fluorescent probes, facilitate quantitative multicolour imaging in living tissue and improve colour tuning in light-emitting devices. PMID:26437175

  16. Iapetus Bright and Dark Terrains

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Saturn's outermost large moon, Iapetus, has a bright, heavily cratered icy terrain and a dark terrain, as shown in this Voyager 2 image taken on August 22, 1981. Amazingly, the dark material covers precisely the side of Iapetus that leads in the direction of orbital motion around Saturn (except for the poles), whereas the bright material occurs on the trailing hemisphere and at the poles. The bright terrain is made of dirty ice, and the dark terrain is surfaced by carbonaceous molecules, according to measurements made with Earth-based telescopes. Iapetus' dark hemisphere has been likened to tar or asphalt and is so dark that no details within this terrain were visible to Voyager 2. The bright icy hemisphere, likened to dirty snow, shows many large impact craters. The closest approach by Voyager 2 to Iapetus was a relatively distant 600,000 miles, so that our best images, such as this, have a resolution of about 12 miles. The dark material is made of organic substances, probably including poisonous cyano compounds such as frozen hydrogen cyanide polymers. Though we know a little about the dark terrain's chemical nature, we do not understand its origin. Two theories have been developed, but neither is fully satisfactory--(1) the dark material may be organic dust knocked off the small neighboring satellite Phoebe and 'painted' onto the leading side of Iapetus as the dust spirals toward Saturn and Iapetus hurtles through the tenuous dust cloud, or (2) the dark material may be made of icy-cold carbonaceous 'cryovolcanic' lavas that were erupted from Iapetus' interior and then blackened by solar radiation, charged particles, and cosmic rays. A determination of the actual cause, as well as discovery of any other geologic features smaller than 12 miles across, awaits the Cassini Saturn orbiter to arrive in 2004.

  17. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

    SciTech Connect

    Brown, Peter J.

    2014-11-20

    We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the Type Ia supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observed—more than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 × 10{sup 13} cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia.

  18. LSST Site: Sky Brightness Data

    NASA Astrophysics Data System (ADS)

    Burke, Jamison; Claver, Charles

    2015-01-01

    The Large Synoptic Survey Telescope (LSST) is an upcoming robotic survey telescope. At the telescope site on Cerro Pachon in Chile there are currently three photodiodes and a Canon camera with a fisheye lens, and both the photodiodes and Canon monitor the night sky continuously. The NIST-calibrated photodiodes directly measure the flux from the sky, and the sky brightness can also be obtained from the Canon images via digital aperture photometry. Organizing and combining the two data sets gives nightly information of the development of sky brightness across a swath of the electromagnetic spectrum, from blue to near infrared light, and this is useful for accurately predicting the performance of the LSST. It also provides data for models of moonlight and twilight sky brightness. Code to accomplish this organization and combination was successfully written in Python, but due to the backlog of data not all of the nights were processed by the end of the summer.Burke was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

  19. High-brightness multilaser source

    NASA Astrophysics Data System (ADS)

    Goodman, Douglas S.; Gordon, Wayne L.; Jollay, Richard A.; Roblee, Jeffrey W.; Gavrilovic, Paul; Kuksenkov, Dmitri V.; Goyal, Anish K.; Zu, Qinxin

    1999-04-01

    This paper discusses a high-brightness multi-laser source developed at Polaroid for such applications as coupling light to fibers, pumping fiber lasers, pumping solid state lasers, material processing, and medical procedures. The power and brightness are obtained by imaging the nearfields of up to eight separate multi-mode lasers side by side on a multi-faceted mirror that makes the beams parallel. The lasers are microlensed to equalize the divergences in the two principal meridians. Each laser is aligned in a field- replaceable illuminator module whose output beam, focused at infinity, is bore-sighted in a mechanical cylinder. The illuminators are arranged roughly radially and the nearfields are reimaged on the mirror, which is produced by diamond machining. The array of nearfields is linearly polarized. A customizable afocal relay forms a telecentric image of the juxtaposed nearfields, as required by the application. The lasers can be of differing powers and wavelengths, and they can be independently switched. Light from other sources can be combined. The output can be utilized in free space or it can be coupled into a fiber for transport or a fiber laser for pumping. A linearly polarized free space output can be obtained, which allows two units to be polarization combined to double the power and brightness.

  20. International Ultraviolet Explorer (IUE)

    NASA Technical Reports Server (NTRS)

    Boehm, Karl-Heinz

    1992-01-01

    The observation, data reduction, and interpretation of ultraviolet spectra (obtained with the International Ultraviolet Explorer) of Herbig-Haro objects, stellar jets, and (in a few cases) reflection nebulae in star-forming regions is discussed. Intermediate results have been reported in the required semi-annual reports. The observations for this research were obtained in 23 (US1) IUE shifts. The spectra were taken in the low resolution mode with the large aperture. The following topics were investigated: (1) detection of UV spectra of high excitation Herbig-Haro (HH) objects, identification of emission lines, and a preliminary study of the energy distribution of the ultraviolet continuum; (2) details of the continuum energy distribution of these spectra and their possible interpretation; (3) the properties of the reddening (extinction) of HH objects; (4) the possible time variation of strong emission lines in high excitation HH objects; (5) the ultraviolet emission of low excitation HH objects, especially in the fluorescent lines of the H2 molecule; (6) the ultraviolet emission in the peculiar object HH24; (7) the spatial emission distribution of different lines and different parts of the continuum in different HH objects; and (8) some properties of reflection nebula, in the environment of Herbig-Haro objects. Each topic is discussed.

  1. High brightness beams and applications

    SciTech Connect

    Sheffield, R.L.

    1995-09-01

    This paper describes the present research on attaining intense bright electron beams. Thermionic systems are briefly covered. Recent and past results from the photoinjector programs are given. The performance advantages and difficulties presently faced by researchers using photoinjectors is discussed. The progress that has been made in photocathode materials, both in lifetime and quantum efficiency, is covered. Finally, a discussion of emittance measurements of photoinjector systems and how the measurement is complicated by the non-thermal nature of the electron beam is presented.

  2. ASASSN-15lh: A Superluminous Ultraviolet Rebrightening Observed by Swift and Hubble

    NASA Astrophysics Data System (ADS)

    Brown, Peter J.; Yang, Yi; Cooke, Jeff; Olaes, Melanie; Quimby, Robert M.; Baade, Dietrich; Gehrels, Neil; Hoeflich, Peter; Maund, Justyn; Mould, Jeremy; Wang, Lifan; Wheeler, J. Craig

    2016-09-01

    We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope, all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Lyα absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs. Based on observations with the NASA/ESA Hubble Space Telescope (HST) obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.

  3. ASASSN-15lh: A Superluminous Ultraviolet Rebrightening Observed by Swift and Hubble

    NASA Astrophysics Data System (ADS)

    Brown, Peter J.; Yang, Yi; Cooke, Jeff; Olaes, Melanie; Quimby, Robert M.; Baade, Dietrich; Gehrels, Neil; Hoeflich, Peter; Maund, Justyn; Mould, Jeremy; Wang, Lifan; Wheeler, J. Craig

    2016-09-01

    We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope, all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ˜4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ˜20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Lyα absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs. Based on observations with the NASA/ESA Hubble Space Telescope (HST) obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.

  4. Jupiter in blue, ultraviolet and near infrared

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These three images of Jupiter, taken through the narrow angle camera of NASA's Cassini spacecraft from a distance of 77.6 million kilometers (48.2 million miles) on October 8, reveal more than is apparent to the naked eye through a telescope.

    The image on the left was taken through the blue filter. The one in the middle was taken in the ultraviolet. The one on the right was taken in the near infrared.

    The blue-light filter is within the part of the electromagnetic spectrum detectable by the human eye. The appearance of Jupiter in this image is, consequently, very familiar. The Great Red Spot (below and to the right of center) and the planet's well-known banded cloud lanes are obvious. The brighter bands of clouds are called zones and are probably composed of ammonia ice particles. The darker bands are called belts and are made dark by particles of unknown composition intermixed with the ammonia ice.

    Jupiter's appearance changes dramatically in the ultraviolet and near infrared images. These images are near negatives of each other and illustrate the way in which observations in different wavelength regions can reveal different physical regimes on the planet.

    All gases scatter sunlight efficiently at short wavelengths; this is why the sky appears blue on Earth. The effect is even more pronounced in the ultraviolet. The gases in Jupiter's atmosphere, above the clouds, are no different. They scatter strongly in the ultraviolet, making the deep banded cloud layers invisible in the middle image. Only the very high altitude haze appears dark against the bright background. The contrast is reversed in the near infrared, where methane gas, abundant on Jupiter but not on Earth, is strongly absorbing and therefore appears dark. Again the deep clouds are invisible, but now the high altitude haze appears relatively bright against the dark background. High altitude haze is seen over the poles and the equator.

    The Great Red Spot, prominent in all images, is

  5. Very high brightness diode laser

    NASA Astrophysics Data System (ADS)

    Heinemann, Stefan; Lewis, Ben; Michaelis, Karsten; Schmidt, Torsten

    2012-03-01

    Multiple Single Emitter (MSE) modules allow highest power and highest brightness diode lasers based on standard broad area diodes. 12 single emitters, each rated at 11 W, are stacked in fast axis and with polarization multiplexing 200W are achieved in a fully collimated beam with a beam quality of 7mm*mrad in both axes. Volume Bragg Gratings (VBG) stabilize the wavelength and narrow the linewidth to less than 2nm. Dichroic mirrors are used for dense wavelength multiplexing of 4 channels within 12 nm. 400W are measured from a 0.2 mm fiber, 0.1 NA. Control and drive electronics are integrated into the 200 W platform and represent a basic building block for a variety of applications, such as a flexible turn key system comprising 12 MSE modules. An integrated beam switch directs the light in six 100 μm, or in one 0.2 mm and one 0.1 mm fiber. 800W are measured from the six 0.1 mm fibers and 700W from the 0.2 mm fiber. The technologies can be transferred to other wavelengths to include 793 nm and 1530 nm. Narrow line gratings and optimized spectral combining enable further improvements in spectral brightness and power.

  6. The UV Brightness of Quiescent Black Holes and Neutron Stars

    NASA Astrophysics Data System (ADS)

    Hynes, Robert I.; Robinson, E. L.; McClintock, J. E.; Haswell, C. A.

    2006-06-01

    HST/STIS observations of quiescent black hole and neutron star soft X-ray transients have suggested that the two may exhibit dramatically different ultraviolet spectra, with neutron stars being more UV bright. We describe new HST/ACS observations providing near-UV detections of another neutron star system, Aql X-1, and three more black hole systems, X-ray Nova Mus 1991, GRO J0422+32, and X-ray Nova Vel 1993, together with upper limits for the neutron star system XTE J2123-058. These more than double the sample available. We will discuss models for the spectral energy distributions of quiescent soft X-ray transients, and the evidence that they are systematically different in the light of this larger and more significant sample.This work was supported by a grant from the Space Telescope Science Institute.

  7. New Standards for Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Sliney, D. H.

    1971-01-01

    Guidelines covering safe levels for exposure to ultraviolet radiation in an occupational environment are reported. The guidelines clarify the spectral radiant exposure doses and relative spectral effectiveness of ultraviolet radiation required to elicit adverse biologic effects.

  8. Line Tunable Ultraviolet Laser

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.; Barnes, Norman P.

    2004-01-01

    An ultraviolet laser is demonstrated using a dual wavelength Nd:YAG oscillator, sum frequency and second harmonic process. Synchronous pulses at 1.052 and 1.319 micrometers are amplified, mixed and subsequently doubled, producing pulses at 0.293 micrometers.

  9. Vacuum ultraviolet holography

    NASA Technical Reports Server (NTRS)

    Bjorklund, G. C.; Harris, S. E.; Young, J. F.

    1974-01-01

    We report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182-A radiation. The holograms were recorded in polymethyl methacrylate and examined with an electron microscope. A holographic grating with a fringe spacing of 386 A was produced and far-field Fraunhofer holograms of submicron particles were recorded.

  10. International Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This report is the November 6, 1996 - October 9, 1997, IUE Final Report for the International Ultraviolet Explorer Final Archive contract. The ultimate objective of this contract is the completion of the archival reprocessing of all IUE data obtained at GSFC between 1978 and 1995.

  11. Vacuum ultraviolet holography

    NASA Technical Reports Server (NTRS)

    Bjorklund, G. C.; Harris, S. E.; Young, J. F.

    1974-01-01

    The authors report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182 A radiation. The holograms were recorded in polymethyl methacrylate and read out with an electron microscope. A holographic grating with a fringe spacing of 836 A was produced and far-field Fraunhofer holograms of sub-micron particles were recorded.

  12. Ultraviolet radiation changes

    NASA Technical Reports Server (NTRS)

    Mckenzie, Richard L.; Frederick, John E.; Ilyas, Mohammad; Filyushkin, V.; Wahner, Andreas; Stamnes, K.; Muthusubramanian, P.; Blumthaler, M.; Roy, Colin E.; Madronich, Sasha

    1991-01-01

    A major consequence of ozone depletion is an increase in solar ultraviolet (UV) radiation received at the Earth's surface. This chapter discusses advances that were made since the previous assessment (World Meteorological Organization (WMO)) to our understanding of UV radiation. The impacts of these changes in UV on the biosphere are not included, because they are discussed in the effects assessment.

  13. Psoriasis and ultraviolet radiation

    SciTech Connect

    Farber, E.M.; Nall, L. )

    1993-09-01

    Prevention and detection screening programs as a public health service in curtailing the ever-increasing incidence of all forms of skin cancer are reviewed. The effect of solar and artificial ultraviolet radiation on the general population and persons with psoriasis is examined. 54 refs.

  14. International Ultraviolet Explorer (IUE) ultraviolet spectral atlas of selected astronomical objects

    NASA Technical Reports Server (NTRS)

    Wu, Chi-Chao; Reichert, Gail A.; Ake, Thomas B.; Boggess, Albert; Holm, Albert V.; Imhoff, Catherine L.; Kondo, Yoji; Mead, Jaylee M.; Shore, Steven N.

    1992-01-01

    The IUE Ultraviolet Spectral Atlas of Selected Astronomical Objects (or 'the Atlas'), is based on the data that were available in the IUE archive in 1986, and is intended to be a quick reference for the ultraviolet spectra of many categories of astronomical objects. It shows reflected sunlight from the Moon, planets, and asteroids, and also shows emission from comets. Comprehensive compilations of UV spectra for main sequence, subgiant, giant, bright giant, and supergiant stars are published elsewhere. This Atlas contains the spectra for objects occupying other areas of the Hertzsprung-Russell diagram: pre-main sequence stars, chemically peculiar stars, pulsating variables, subluminous stars, and Wolf-Rayet stars. This Atlas also presents phenomena such as the chromospheric and transition region emissions from late-type stars; composite spectra of stars, gas streams, accretion disks and gas envelopes of binary systems; the behavior of gas ejecta shortly after the outburst of novac and supernovac; and the H II regions, planetary nebulae, and supernova remnants. Population 2 stars, globular clusters, and luminous stars in the Magellanic Clouds, M31, and M33, are also included in this publication. Finally, the Atlas gives the ultraviolet spectra of galaxies of different Hubble types and of active galaxies.

  15. How Bright Can Supernovae Get?

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-04-01

    Supernovae enormous explosions associated with the end of a stars life come in a variety of types with different origins. A new study has examined how the brightest supernovae in the Universe are produced, and what limits might be set on their brightness.Ultra-Luminous ObservationsRecent observations have revealed many ultra-luminous supernovae, which haveenergies that challenge our abilities to explain them usingcurrent supernova models. An especially extreme example is the 2015 discovery of the supernova ASASSN-15lh, which shone with a peak luminosity of ~2*1045 erg/s, nearly a trillion times brighter than the Sun. ASASSN-15lh radiated a whopping ~2*1052 erg in the first four months after its detection.How could a supernova that bright be produced? To explore the answer to that question, Tuguldur Sukhbold and Stan Woosley at University of California, Santa Cruz, have examined the different sources that could produce supernovae and calculated upper limits on the potential luminosities ofeach of these supernova varieties.Explosive ModelsSukhbold and Woosley explore multiple different models for core-collapse supernova explosions, including:Prompt explosionA stars core collapses and immediately explodes.Pair instabilityElectron/positron pair production at a massive stars center leads to core collapse. For high masses, radioactivity can contribute to delayed energy output.Colliding shellsPreviously expelled shells of material around a star collide after the initial explosion, providing additional energy release.MagnetarThe collapsing star forms a magnetar a rapidly rotating neutron star with an incredibly strong magnetic field at its core, which then dumps energy into the supernova ejecta, further brightening the explosion.They then apply these models to different types of stars.Setting the LimitThe authors show that the light curve of ASASSN-15lh (plotted in orange) can be described by a model (black curve) in which a magnetar with an initial spin period of 0.7 ms

  16. [Bright light therapy for elderly].

    PubMed

    Okawa, Masako

    2015-06-01

    Bright light therapy (BLT) holds considerable promise for sleep problems in the elderly. BLT for community-dwelling patients with Alzheimer's disease showed significant improvement in sleep parameters. In the institutional setting, BLT was effective in reducing daytime nap duration. Morning BLT was found to advance the peak circadian rhythm and increase activity level in daytime and melatonin level at night. Light therapy could be used in combination with other nonpharmacological methods such as social activities, outside walking, physical exercises, which showed greater effects than independent BLT on sleep and cognitive function. BLT treatment strategy was proposed in the present paper. We should pay more attentions to BLT in community setting for mental and physical well-being. PMID:26065132

  17. Quantum communication with macroscopically bright nonclassical states.

    PubMed

    Usenko, Vladyslav C; Ruppert, Laszlo; Filip, Radim

    2015-11-30

    We analyze homodyne detection of macroscopically bright multimode nonclassical states of light and propose their application in quantum communication. We observe that the homodyne detection is sensitive to a mode-matching of the bright light to the highly intense local oscillator. Unmatched bright modes of light result in additional noise which technically limits detection of Gaussian entanglement at macroscopic level. When the mode-matching is sufficient, we show that multimode quantum key distribution with bright beams is feasible. It finally merges the quantum communication with classical optical technology of visible beams of light. PMID:26698776

  18. Properties of Photospheric Bright Points outside Sunspots

    NASA Astrophysics Data System (ADS)

    Qu, H. X.; Yang, Y. F.; Feng, S.; Wang, F.; Deng, H.; Ji, K. F.

    2015-09-01

    Photospheric bright points are tiny bright features located in intergranular lanes. They are widely believed as the foot points of magnetic flux tubes. In this paper, various properties of bright points outside NOAA 11598 sunspots are analyzed using the TiO-band data detected by the 1-m New Vacuum Solar Telescope of Yunnan Observatories, which is located at the Fuxian Solar Physics Observing Station, Yunnan Province. We divide the periphery of the sunspot into four annular regions based on the dilation technology of image morphology. Then, a Laplacian and morphological dilation algorithm is used to identify bright points, and a three-dimensional segment algorithm is applied to track the evolution of bright points. Finally, we detect the parameters of the bright points in the four annular regions, including the density, intensity, size, shape, and velocity. Statistical results show that the density, size, and velocity of photospheric bright points are obviously affected by the strong magnetic fields of sunspots, and their peak values are in the second region instead of the closest region of the sunspot. The bright points decrease their densities and sizes, but increase their velocities with the distance away from the sunspot center. Additionally, the maximum intensity contrast presents the decreasing trend. However, the bright point shapes are basically invariant, and independent of this distance.

  19. On the Origin of Io's Ultraviolet Aurora

    NASA Astrophysics Data System (ADS)

    Shaposhnikov, V. E.; Zaitsev, V. V.; Rucker, H. O.

    A model involving an additional contribution to Io's ultraviolet (UV) aurora is presented. A mechanism for heating of electrons of Io's ionospheric plasma up to sufficient energies for the excitation of Io's atmospheric oxygen and emitting of observed UV emission is proposed. The mechanism operates by the effect of the different magnetization of the electrons and ions in Io's ionosphere which in the course of Io's motion through the Jovian magnetic field causes the creation of a charge-separation electric field in the upstream part of the ionosphere. This field has a component parallel to the magnetic and shifts the electron distribution function relative to the ion distribution function by a value exceeding the thermal velocity of electrons. In this case, a Bunemann instability with a very large growth rate develops. This results in the excitation of turbulent pulsations at frequency close to the ion-sound frequency and the occurrence of anomalous resistance to the electric current. The latter causes heating of Io's ionospheric electrons up to a temperature of about 25 eV. Atmospheric oxygen molecules excited by collisions with the heated electrons of Io's ionosphere, whose density is about 6 × 10^4 cm^(-3), can contribute to the observed UV brightness. The proposed model permits one to explain the correlation of UV brightness with Io's magnetic longitude and the discrepancy between the anti-Jovian equatorial UV spots and sub-Jovian spots as well.

  20. Ultraviolet phototherapy for pruritus.

    PubMed

    Rivard, Jennifer; Lim, Henry W

    2005-01-01

    Ultraviolet-based therapy has been used to treat various pruritic conditions including pruritus in chronic renal failure, atopic dermatitis, HIV, aquagenic pruritus and urticaria, solar, chronic, and idiopathic urticaria, urticaria pigmentosa, polycythemia vera, pruritic folliculitis of pregnancy, breast carcinoma skin infiltration, Hodgkin's lymphoma, chronic liver disease, and acquired perforating dermatosis, among others. Various mechanisms of action for phototherapy have been posited. Treatment limitations, side effects, and common dosing protocols are reviewed. PMID:16297008

  1. Spatial Brightness Perception of Trichromatic Stimuli

    SciTech Connect

    Royer, Michael P.; Houser, Kevin W.

    2012-11-16

    An experiment was conducted to examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. The results indicate that light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, V(λ)-based photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. The results suggest further development of metrics to predict brightness perception is warranted, and that including age as a variable in predictive models may be valuable.

  2. Incoherently coupled dark-bright photorefractive solitons

    NASA Astrophysics Data System (ADS)

    Chen, Zhigang; Segev, Mordechai; Coskun, Tamer H.; Christodoulides, Demetrios N.; Kivshar, Yuri S.; Afanasjev, Vsevolod V.

    1996-11-01

    We report the observation of incoherently coupled dark-bright spatial soliton pairs in a biased bulk photorefractive crystal. When such a pair is decoupled, the dark component evolves into a triplet structure, whereas the bright one decays into a self-defocusing beam.

  3. Bright Star Astrometry with URAT

    NASA Astrophysics Data System (ADS)

    Zacharias, N.

    2015-10-01

    The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) is observing the northern sky since April 2012 for an astrometric survey. Multiple overlaps per year are performed in a single bandpass (680-750 nm) using the "redlens" 20 cm aperture astrograph and a mosaic of large CCDs. Besides the regular, deep survey to magnitude 18.5, short exposures with an objective grating are taken to access stars as bright as 3rd magnitude. A brief overview of the program, observing and reductions is given. Positions on the 8 to 20 mas level are obtained of 66,202 Hipparcos stars at current epochs. These are compared to the Hipparcos Catalog to investigate its accuracy. About 20% of the observed Hipparcos stars are found to have inconsistent positions with the Hipparcos Catalog prediction on the 3 sigma level or over (about 75 mas or more discrepant position offsets). Some stars are now seen at an arcsec (or 25 sigma) off their Hipparcos Catalog predicted position.

  4. Brightness alteration with interweaving contours

    PubMed Central

    Roncato, Sergio

    2012-01-01

    Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation) or when lines of different colours are collinear (neon effect) or adjacent (watercolour) to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread). The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975) and Kanizsa (1979) in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed. PMID:23483806

  5. Cortical processing of a brightness illusion

    PubMed Central

    Roe, Anna Wang; Lu, Haidong D.; Hung, Chou P.

    2005-01-01

    Several brightness illusions indicate that borders can affect the perception of surfaces dramatically. In the Cornsweet illusion, two equiluminant surfaces appear to be different in brightness because of the contrast border between them. Here, we report the existence of cells in monkey visual cortex that respond to such an “illusory” brightness. We find that luminance responsive cells are located in color-activated regions (cytochrome oxidase blobs and bridges) of primary visual cortex (V1), whereas Cornsweet responsive cells are found preferentially in the color-activated regions (thin stripes) of second visual area (V2). This colocalization of brightness and color processing within V1 and V2 suggests a segregation of contour and surface processing in early visual pathways and a hierarchy of brightness information processing from V1 to V2 in monkeys. PMID:15738406

  6. Research in extreme ultraviolet and far ultraviolet astronomy

    NASA Technical Reports Server (NTRS)

    Labov, S. E.

    1985-01-01

    Instruments designed to explore different aspects of far and extreme ultraviolet cosmic radiation were studied. The far ultraviolet imager (FUVI) was flown on the Aries sounding rocket. Its unique large format 75mm detector mapped out the far ultraviolet background radiation with a resolution of only a few arc minutes. Analysis of this data indicates to what extent the FUVI background is extra galactic in origin. A power spectrum of the spatial fluctuations will have direct consequences for galactic evolution.

  7. Bright Streaks and Dark Fans

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The south polar region of Mars is covered every year by a layer of carbon dioxide ice. In a region called the 'cryptic terrain,' the ice is translucent and sunlight can penetrate through the ice to warm the surface below.

    The ice layer sublimates (evaporates) from the bottom. The dark fans of dust seen in this image come from the surface below the layer of ice, carried to the top by gas venting from below. The translucent ice is 'visible' by virtue of the effect it has on the tone of the surface below, which would otherwise have the same color and reflectivity as the fans.

    Bright streaks in this image are fresh frost. The CRISM team has identified the composition of these streaks to be carbon dioxide.

    Observation Geometry Image PSP_003113_0940 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 26-Mar-2007. The complete image is centered at -85.8 degrees latitude, 106.0 degrees East longitude. The range to the target site was 244.9 km (153.0 miles). At this distance the image scale is 49.0 cm/pixel (with 2 x 2 binning) so objects 147 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 06:20 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 207.6 degrees, the season on Mars is Northern Autumn.

  8. Bright Sparks of Our Future!

    NASA Astrophysics Data System (ADS)

    Riordan, Naoimh

    2016-04-01

    My name is Naoimh Riordan and I am the Vice Principal of Rockboro Primary School in Cork City, South of Ireland. I am a full time class primary teacher and I teach 4th class, my students are aged between 9-10 years. My passion for education has developed over the years and grown towards STEM (Science, Technology, Engineering and Mathematics) subjects. I believe these subjects are the way forward for our future. My passion and beliefs are driven by the unique after school programme that I have developed. It is titled "Sparks" coming from the term Bright Sparks. "Sparks" is an after school programme with a difference where the STEM subjects are concentrated on through lessons such as Science, Veterinary Science Computer Animation /Coding, Eco engineering, Robotics, Magical Maths, Chess and Creative Writing. All these subjects are taught through activity based learning and are one-hour long each week for a ten-week term. "Sparks" is fully inclusive and non-selective which gives all students of any level of ability an opportunity to engage into these subjects. "Sparks" is open to all primary students in County Cork. The "Sparks" after school programme is taught by tutors from the different Universities and Colleges in Cork City. It works very well because the tutor brings their knowledge, skills and specialised equipment from their respective universities and in turn the tutor gains invaluable teaching practise, can trial a pilot programme in a chosen STEM subject and gain an insight into what works in the physical classroom.

  9. Vehicle/Atmosphere Interaction Glows: Far Ultraviolet, Visible, and Infrared

    NASA Astrophysics Data System (ADS)

    Swenson, G.

    1999-10-01

    Spacecraft glow information has been gathered from a number of spacecraft including Atmospheric and Dynamic satellites, and Space Shuttles (numerous flights) with dedicated pallet flow observations on STS-39 (DOD) and STS-62 (NASA). In addition, a larger number of laboratory experiments with low energy oxygen beam studies have made important contributions to glow understanding. The following report provides information on three engineering models developed for spacecraft glow including the far ultraviolet to ultraviolet (1400-4000 A), and infrared (0.9-40 microns) spectral regions. The models include effects resulting from atmospheric density/altitude, spacecraft temperature, spacecraft material, and ram angle. Glow brightness would be predicted as a function of distance from surfaces for all wavelengths.

  10. Vehicle/Atmosphere Interaction Glows: Far Ultraviolet, Visible, and Infrared

    NASA Technical Reports Server (NTRS)

    Swenson, G.

    1999-01-01

    Spacecraft glow information has been gathered from a number of spacecraft including Atmospheric and Dynamic satellites, and Space Shuttles (numerous flights) with dedicated pallet flow observations on STS-39 (DOD) and STS-62 (NASA). In addition, a larger number of laboratory experiments with low energy oxygen beam studies have made important contributions to glow understanding. The following report provides information on three engineering models developed for spacecraft glow including the far ultraviolet to ultraviolet (1400-4000 A), and infrared (0.9-40 microns) spectral regions. The models include effects resulting from atmospheric density/altitude, spacecraft temperature, spacecraft material, and ram angle. Glow brightness would be predicted as a function of distance from surfaces for all wavelengths.

  11. Observing SN 1987A with the International Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Kirshner, Robert P.

    1991-01-01

    The International Ultraviolet Explorer (IUE) satellite played a leading role in elucidating the nature of SN 1987A, providing a unique ultraviolet perspective on the brightest supernova since 1604. IUE observations of SN 1987A began promptly after discovery and were frequent through 1988 and 1989, using the FES (Fine Error Sensor) for photometry, low dispersion spectra for the supernova spectrum, high dispersion observations for the interstellar medium when the supernova was bright, and for circumstellar gas surrounding the supernova as the initial event faded. The UV data were especially useful in determining which star exploded, assessing the ionizing pulse produced as the shock hit the surface of the star, and in constraining the stellar evolution that preceded the explosion through observation of a circumstellar shell.

  12. The Lunar Phase Curve in the Near Ultraviolet

    NASA Technical Reports Server (NTRS)

    Hendrix, A. R.

    2002-01-01

    We present results from an ongoing program to perform UV measurements (215.0 and 237.0 nm) of the Moon at varying solar phase angles to understand the lunar phase curve at ultraviolet wavelengths. We use new observations from the Ultraviolet Spectrometer (UVS) aboard the Student Nitric Oxide Explorer (SNOE) combined with existing observations from the Galileo UVS. The lunar UV phase curve can be used to further understand the scattering properties of the lunar surface. The Moon's scattering properties at visible wavelengths are well understood; studying scattering properties at shorter wavelengths may provide insight into the roles of volume scattering vs. surface scattering and how weathering processes may affect scattering properties. The UV lunar phase curve can also be helpful for UV observers, as the Moon is often used as a UV calibration source, but the UV brightness variation with phase angle has not been well understood.

  13. Detecting contaminants by ultraviolet photography

    NASA Technical Reports Server (NTRS)

    Neiswander, D. W.

    1980-01-01

    Relatively high ultraviolet absorptivity of most organics as compared to metal is suggested as basis for detecting traces of contamination. By photographing metal surface in ultraviolet light, contaminants that might otherwise interfere with adhesion of surface coatings, or with welding or brazing, could be detected and removed. Real time monitoring of cleaning process is also possible if ultraviolet sensitive television camera is used instead of photographic film.

  14. Far-ultraviolet studies. II - Galactic-latitude dependence of the 1530 A interstellar radiation field

    NASA Technical Reports Server (NTRS)

    Henry, R. C.; Swandic, J. R.; Shulman, S. D.; Fritz, G.

    1977-01-01

    A 0.62-sq cm Geiger counter, sensitive between 1425 and 1640 A, was used to map the far-ultraviolet brightness of about half the sky, providing an experimental measurement of the far-ultraviolet interstellar radiation field. At 1530 A, the energy density is approximately 7.4 by 10 to the -17th power erg/cu cm per A. Comparison with integrations of star catalogs calibrated to the ultraviolet shows, as expected, that the bulk of the radiation comes directly from B- and A-type stars. The galactic-latitude dependence of the radiation is analyzed in an unsuccessful attempt to set limits on the absorbing and scattering properties of the interstellar grains in the far-ultraviolet. Excess radiation observed at the galactic pole is probably residual airglow from above the rocket altitude.

  15. Telescope baffle performance for Lyman Far Ultraviolet Spectrographic Explorer

    NASA Astrophysics Data System (ADS)

    Morbey, Christopher; Hutchings, J. B.

    1993-07-01

    The Lyman Far Ultraviolet Spectrographic Explorer telescope is a Wolter type II glancing incidence design with an aperture of 64 cm. Because the spacecraft is required to guide on stars fainter than m(v) = 16, a visible light baffle is necessary to protect the FOV from the stray light that results from out-of-field bright sources. Such a baffle system is described here. Total point-source transmittances are computed for incident beams in the range 0-70 deg. Estimates for background brightness on the detector are made for the contribution from direct sunlight and earthshine. Scattering from the black surfaces of the baffle, the vanes, and diffraction at the structure's edges are taken into consideration.

  16. Ultraviolet-renormalon calculus

    SciTech Connect

    Vainshtein, A.I. Budker Institute of Nuclear Physics, 630090 Novosibirsk ); Zakharov, V.I. )

    1994-08-29

    We consider the status of the so-called ultraviolet (UV) renormalon which contributes to large order divergences of perturbative expansions in quantum chromodynamics. We argue that although the renormalon is associated with short distance dynamics, the class of renormalon graphs is not well defined and its overall weight is not controlled by theory. From this point of view there is not much difference from the case of Borel nonsummable singularities. Phenomenologically the UV renormalon is related to an effective four-fermion interaction originating within fundamental QCD.

  17. Ultraviolet atomic emission detector

    NASA Technical Reports Server (NTRS)

    Braun, W.; Peterson, N. C.; Bass, A. M.; Kurylo, M. J., III (Inventor)

    1972-01-01

    A device and method are provided for performing qualitative and quantitative elemental analysis through the utilization of a vacuum UV chromatographic detector. The method involves the use of a carrier gas at low pressure. The gas carries a sample to a gas chromatograph column; the column output is directed to a microwave cavity. In this cavity, a low pressure microwave discharge produces fragmentation of the compounds present and generates intense atomic emissions in the vacuum ultraviolet. These emissions are isolated by a monochromator and measured by photometer to establish absolute concentration for the elements.

  18. Transparent ultraviolet photovoltaic cells.

    PubMed

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future. PMID:26872163

  19. The influence of depicted illumination on brightness

    PubMed Central

    Williams, S. Mark; McCoy, Allison N.; Purves, Dale

    1998-01-01

    The striking illusions produced by simultaneous brightness contrast generally are attributed to the center-surround receptive field organization of lower order neurons in the primary visual pathway. Here we show that the apparent brightness of test objects can be either increased or decreased in a predictable manner depending on how light and shadow are portrayed in the scene. This evidence suggests that perceptions of brightness are generated empirically by experience with luminance relationships, an idea whose implications we pursue in the accompanying paper. PMID:9789082

  20. The solar brightness temperature at millimeter wavelengths

    NASA Technical Reports Server (NTRS)

    Kuseski, R. A.; Swanson, P. N.

    1976-01-01

    Measurements of the brightness temperature of the sun near 36 GHz and 93 GHz were made using the new moon as a calibration source. Provided the brightness temperature of the moon is known and all measurements are reduced to the same zenith angle, a simple expression can be used for the sun-to-new moon ratio which is independent of antenna gain, atmospheric absorption and reemission, and radiometer calibration constants. This ratio was measured near 36 GHz and at two frequencies near 93 GHz with a Dicke switched superheterodyne radiometer system and a 2.4 m Cassegrain antenna. The slopes of the solar brightness temperature spectrum based on these ratios were measured. The absolute solar brightness spectrum derived from all current available measurements supplemented by the present ones is also plotted and discussed.

  1. Just How Bright Is a Laser?

    ERIC Educational Resources Information Center

    Van Baak, David A.

    1995-01-01

    Attempts to quantify the subjective sensation of brightness of the spot projected by a helium-neon laser and compares this with conventional sources of light. Provides an exercise in using the blackbody radiation formulas. (JRH)

  2. New Observations of Subarcsecond Photospheric Bright Points

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.

    1995-01-01

    We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 15-20 Sept. 1993 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on 20 Sept. A total of 1804 bright points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured FWHM distribution of the bright points in the image is lognormal with a modal value of 220 km (0.30 sec) and an average value of 250 km (0.35 sec). The smallest measured bright point diameter is 120 km (0.17 sec) and the largest is 600 km (O.69 sec). Approximately 60% of the measured bright points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured bright points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic bright-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane brightness in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band bright points is constant across the entire measured size range. The measured area of the bright points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this area fraction measurement in the context of

  3. New Observations of Subarcsecond Photospheric Bright Points

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.

    1995-01-01

    We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 1993 September 15-20 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on September 20. A total of 1804 bright points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured Full Width at Half Maximum (FWHM) distribution of the bright points in the image is lognormal with a modal value of 220 km (0 sec .30) and an average value of 250 km (0 sec .35). The smallest measured bright point diameter is 120 km (0 sec .17) and the largest is 600 km (O sec .69). Approximately 60% of the measured bright points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured bright points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic bright-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane brightness in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band bright points is constant across the entire measured size range. The measured area of the bright points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this

  4. Observations and diagnostics in high brightness beams

    NASA Astrophysics Data System (ADS)

    Cianchi, A.; Anania, M. P.; Bisesto, F.; Castellano, M.; Chiadroni, E.; Pompili, R.; Shpakov, V.

    2016-09-01

    The brightness is a figure of merit largely used in the light sources, like FEL (Free Electron Lasers), but it is also fundamental in several other applications, as for instance Compton backscattering sources, beam driven plasma accelerators and THz sources. Advanced diagnostics are essential tools in the development of high brightness beams. 6D electron beam diagnostics will be reviewed with emphasis on emittance measurement.

  5. Several evolutionary channels for bright planetary nebulae

    NASA Astrophysics Data System (ADS)

    Richer, Michael G.; McCall, Marshall L.

    2016-08-01

    The populations of bright planetary nebulae in the discs of spirals appear to differ in their spectral properties from those in ellipticals and the bulges of spirals. The bright planetary nebulae from the bulge of the Milky Way are entirely compatible with those observed in the discs of spiral galaxies. The similarity might be explained if the bulge of the Milky Way evolved secularly from the disc, in which case the bulge should be regarded as a pseudo-bulge.

  6. HUBBLE IDENTIFIES SOURCE OF ULTRAVIOLET LIGHT IN AN OLD GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hubble Space Telescope's exquisite resolution has allowed astronomers to resolve, for the first time, hot blue stars deep inside an elliptical galaxy. The swarm of nearly 8,000 blue stars resembles a blizzard of snowflakes near the core (lower right) of the neighboring galaxy M32, located 2.5 million light-years away in the constellation Andromeda. Hubble confirms that the ultraviolet light comes from a population of extremely hot helium-burning stars at a late stage in their lives. Unlike the Sun, which burns hydrogen into helium, these old stars exhausted their central hydrogen long ago, and now burn helium into heavier elements. The observations, taken in October 1998, were made with the camera mode of the Space Telescope Imaging Spectrograph (STIS) in ultraviolet light. The STIS field of view is only a small portion of the entire galaxy, which is 20 times wider on the sky. For reference, the full moon is 70 times wider than the STIS field-of-view. The bright center of the galaxy was placed on the right side of the image, allowing fainter stars to be seen on the left side of the image. These results are to be published in the March 1, 2000 issue of The Astrophysical Journal. Thirty years ago, the first ultraviolet observations of elliptical galaxies showed that they were surprisingly bright when viewed in ultraviolet light. Before those pioneering UV observations, old groups of stars were assumed to be relatively cool and thus extremely faint in the ultraviolet. Over the years since the initial discovery of this unexpected ultraviolet light, indirect evidence has accumulated that it originates in a population of old, but hot, helium-burning stars. Now Hubble provides the first direct visual evidence. Nearby elliptical galaxies are thought to be relatively simple galaxies comprised of old stars. Because they are among the brightest objects in the Universe, this simplicity makes them useful for tracing the evolution of stars and galaxies. Credits: NASA and Thomas

  7. Differential Rotation via Tracking of Coronal Bright Points.

    NASA Astrophysics Data System (ADS)

    McAteer, James; Boucheron, Laura E.; Osorno, Marcy

    2016-05-01

    The accurate computation of solar differential rotation is important both as a constraint for, and evidence towards, support of models of the solar dynamo. As such, the use of Xray and Extreme Ultraviolet bright points to elucidate differential rotation has been studied in recent years. In this work, we propose the automated detection and tracking of coronal bright points (CBPs) in a large set of SDO data for re-evaluation of solar differential rotation and comparison to other results. The big data aspects, and high cadence, of SDO data mitigate a few issues common to detection and tracking of objects in image sequences and allow us to focus on the use of CBPs to determine differential rotation. The high cadence of the data allows to disambiguate individual CBPs between subsequent images by allowing for significant spatial overlap, i.e., by the fact that the CBPs will rotate a short distance relative to their size. The significant spatial overlap minimizes the effects of incorrectly detected CBPs by reducing the occurrence of outlier values of differential rotation. The big data aspects of the data allows to be more conservative in our detection of CBPs (i.e., to err on the side of missing CBPs rather than detecting extraneous CBPs) while still maintaining statistically larger populations over which to study characteristics. The ability to compute solar differential rotation through the automated detection and tracking of a large population of CBPs will allow for further analyses such as the N-S asymmetry of differential rotation, variation of differential rotation over the solar cycle, and a detailed study of the magnetic flux underlying the CBPs.

  8. Bright high-order harmonic generation with controllable polarization from a relativistic plasma mirror.

    PubMed

    Chen, Zi-Yu; Pukhov, Alexander

    2016-01-01

    Ultrafast extreme ultraviolet (XUV) sources with a controllable polarization state are powerful tools for investigating the structural and electronic as well as the magnetic properties of materials. However, such light sources are still limited to only a few free-electron laser facilities and, very recently, to high-order harmonic generation from noble gases. Here we propose and numerically demonstrate a laser-plasma scheme to generate bright XUV pulses with fully controlled polarization. In this scheme, an elliptically polarized laser pulse is obliquely incident on a plasma surface, and the reflected radiation contains pulse trains and isolated circularly or highly elliptically polarized attosecond XUV pulses. The harmonic polarization state is fully controlled by the laser-plasma parameters. The mechanism can be explained within the relativistically oscillating mirror model. This scheme opens a practical and promising route to generate bright attosecond XUV pulses with desirable ellipticities in a straightforward and efficient way for a number of applications. PMID:27531047

  9. Bright high-order harmonic generation with controllable polarization from a relativistic plasma mirror

    PubMed Central

    Chen, Zi-Yu; Pukhov, Alexander

    2016-01-01

    Ultrafast extreme ultraviolet (XUV) sources with a controllable polarization state are powerful tools for investigating the structural and electronic as well as the magnetic properties of materials. However, such light sources are still limited to only a few free-electron laser facilities and, very recently, to high-order harmonic generation from noble gases. Here we propose and numerically demonstrate a laser–plasma scheme to generate bright XUV pulses with fully controlled polarization. In this scheme, an elliptically polarized laser pulse is obliquely incident on a plasma surface, and the reflected radiation contains pulse trains and isolated circularly or highly elliptically polarized attosecond XUV pulses. The harmonic polarization state is fully controlled by the laser–plasma parameters. The mechanism can be explained within the relativistically oscillating mirror model. This scheme opens a practical and promising route to generate bright attosecond XUV pulses with desirable ellipticities in a straightforward and efficient way for a number of applications. PMID:27531047

  10. Investigation of ultraviolet interstellar extinction

    NASA Technical Reports Server (NTRS)

    Payne, C.; Haramundanis, K. L.

    1973-01-01

    Results concerning interstellar extinction in the ultraviolet are reported. These results were initially obtained by using data from main-sequence stars and were extended to include supergiants and emission stars. The principal finding of the analysis of ultraviolet extinction is not only that it is wavelength dependent, but that if changes with galactic longitude in the U3 passband (lambda sub eff = 1621 A); it does not change significantly in the U2 passband (lambda sub eff = 2308 A). Where data are available in the U4 passband (lambda sub eff = 1537 A), they confirm the rapid rise of extinction in the ultraviolet found by other investigators. However, in all cases, emission stars must be used with great caution. It is important to realize that while extinction continues to rise toward shorter wavelengths in the ultraviolet, including the shortest ultraviolet wavelengths measured (1100 A), it no longer plays an important role in the X-ray region (50 A).

  11. Influence of interplanetary magnetic field and solar wind on auroral brightness in different regions

    NASA Astrophysics Data System (ADS)

    Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.

    2013-01-01

    Abstract<p label="1">By integrating and averaging the auroral <span class="hlt">brightness</span> from Polar <span class="hlt">Ultraviolet</span> Imager auroral images, which have the whole auroral ovals, and combining the observation data of interplanetary magnetic field (IMF) and solar wind from NASA Operating Missions as a Node on the Internet (OMNI), we investigate the influence of IMF and solar wind on auroral activities, and analyze the separate roles of the solar wind dynamic pressure, density, and velocity on aurora, respectively. We statistically analyze the relations between the interplanetary conditions and the auroral <span class="hlt">brightness</span> in dawnside, dayside, duskside, and nightside. It is found that the three components of the IMF have different effects on the auroral <span class="hlt">brightness</span> in the different regions. Different from the nightside auroral <span class="hlt">brightness</span>, the dawnside, dayside, and duskside auroral <span class="hlt">brightness</span> are affected by the IMF Bx, and By components more significantly. The IMF Bx and By components have different effects on these three regional auroral <span class="hlt">brightness</span> under the opposite polarities of the IMF Bz. As expected, the nightside aurora is mainly affected by the IMF Bz, and under southward IMF, the larger the |Bz|, the brighter the nightside aurora. The IMF Bx and By components have no visible effects. On the other hand, it is also found that the aurora is not intensified singly with the increase of the solar wind dynamic pressure: when only the dynamic pressure is high, but the solar wind velocity is not very fast, the aurora will not necessarily be intensified significantly. These results can be used to qualitatively predict the auroral activities in different regions for various interplanetary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26764780','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26764780"><span id="translatedtitle">Energy-exchange collisions of dark-<span class="hlt">bright-bright</span> vector solitons.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Radhakrishnan, R; Manikandan, N; Aravinthan, K</p> <p>2015-12-01</p> <p>We find a dark component guiding the practically interesting <span class="hlt">bright-bright</span> vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-<span class="hlt">bright-bright</span> mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-<span class="hlt">bright-bright</span> vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the <span class="hlt">bright-bright</span> vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-<span class="hlt">bright-bright</span> vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-<span class="hlt">bright-bright</span> vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices. PMID:26764780</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..92f2913R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..92f2913R"><span id="translatedtitle">Energy-exchange collisions of dark-<span class="hlt">bright-bright</span> vector solitons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radhakrishnan, R.; Manikandan, N.; Aravinthan, K.</p> <p>2015-12-01</p> <p>We find a dark component guiding the practically interesting <span class="hlt">bright-bright</span> vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-<span class="hlt">bright-bright</span> mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-<span class="hlt">bright-bright</span> vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the <span class="hlt">bright-bright</span> vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-<span class="hlt">bright-bright</span> vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-<span class="hlt">bright-bright</span> vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950048182&hterms=1080&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D1080','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950048182&hterms=1080&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D1080"><span id="translatedtitle">Observations of the far <span class="hlt">ultraviolet</span> airflow by the <span class="hlt">Ultraviolet</span> Limb Imaging experiment on STS-39</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Budzien, S. A.; Feldman, P. D.; Conway, R. R.</p> <p>1994-01-01</p> <p>The <span class="hlt">Ultraviolet</span> Limb Imaging (UVLIM) experiment flew on STS-39 in the spring of 1991 to observe the Earth's thermospheric airglow and included a far <span class="hlt">ultraviolet</span> (1080-1800 A) spectrometer. We present first results from this spectrometer, including a spectroscopic analysis at 6-A resolution of H, O, N, and N2 dayglow emissions and modeling of the observed limb-scan profiles of dayglow emissions. The observed N2 Lyman-Birge-Hopfield (LBH) emission reflects a vibrational population distribution in the a(1 Pi)(sub g) state that differs significantly from those predicted for direct electron excitation and excitation with cascade from the a('1 Sigma)(sub u)(-) and w(1 Delta)(sub u) states. The vibrational population distribution and LBH <span class="hlt">brightness</span> suggest a total cascade rate 45% that of direct excitation, in contrast to laboratory measurements. For the first time, pronounced limb brightening is observed in both the N I lambda 1200 limb emission profiles, as expected for emissions excited by N2 dissociation which produces kinetically fast N fragments; however, optically thick components of these features are also observed. Preliminary modeling of the OI lambda 1356, HI lambda 1216, and OI lambda 1304 and OI lambda 1641 emissions agrees to within roughly 10% of the observed limb-scan profiles, but the models underestimate the N2 LBH profiles by a factor of 1.4-1.6, consistent with the inferred cascade effect. Other findings include: an OI lambda 1152/lambda 1356 intensity ratio that is inconsistent with the large cascade contribution to OI lambda 1356 from np 5P states required by laboratory and nightglow observations; nightglow observations of the tropical <span class="hlt">ultraviolet</span> arcs exhibit a wide range of OI lambda 1356/lambda 1304 intensity ratios and illustrate the complicated observing geometry and radiative transfer effects that must be modeled; and we find a 3-sigma upper limit of 8.5 R to the total LBH vehicle glow emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770011045','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770011045"><span id="translatedtitle">Skylab experiment SO73: Gegenschein/zodiacal light. [electrophotometry of surface <span class="hlt">brightness</span> and polarization</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weinberg, J. L.</p> <p>1976-01-01</p> <p>A 10 color photoelectric polarimeter was used to measure the surface <span class="hlt">brightness</span> and polarization associated with zodiacal light, background starlight, and spacecraft corona during each of the Skylab missions. Fixed position and sky scanning observations were obtained during Skylab missions SL-2 and SL-3 at 10 wavelenghts between 4000A and 8200A. Initial results from the fixed-position data are presented on the spacecraft corona and on the polarized <span class="hlt">brightness</span> of the zodiacal light. Included among the fixed position regions that were observed are the north celestial pole, south ecliptic pole, two regions near the north galactic pole, and 90 deg from the sun in the ecliptic. The polarized <span class="hlt">brightness</span> of the zodiacal light was found to have the color of the sun at each of these positions. Because previous observations found the total <span class="hlt">brightness</span> to have the color of the sun from the near <span class="hlt">ultraviolet</span> out to 2.4 micrometers, the degree of polarization of the zodiacal light is independent of wavelength from 4000A to 8200A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890014180','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890014180"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> radiation effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slemp, Wayne S.</p> <p>1989-01-01</p> <p>Solar <span class="hlt">ultraviolet</span> testing was not developed which will provide highly accelerated (20 to 50X) exposures that correlate to flight test data. Additional studies are required to develop an exposure methodology which will assure that accelerated testing can be used for qualification of materials and coatings for long duration space flight. Some conclusions are listed: Solar UV radiation is present in all orbital environments; Solar UV does not change in flux with orbital altitude; UV radiation can degrade most coatings and polymeric films; Laboratory UV simulation methodology is needed for accelerated testing to 20 UV solar constants; Simulation of extreme UV (below 200 nm) is needed to evaluate requirements for EUV in solar simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016MNRAS.461.1308F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016MNRAS.461.1308F&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> diversity of Type Ia Supernovae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foley, Ryan J.; Pan, Yen-Chen; Brown, P.; Filippenko, A. V.; Fox, O. D.; Hillebrandt, W.; Kirshner, R. P.; Marion, G. H.; Milne, P. A.; Parrent, J. T.; Pignata, G.; Stritzinger, M. D.</p> <p>2016-09-01</p> <p><span class="hlt">Ultraviolet</span> (UV) observations of Type Ia supernovae (SNe Ia) probe the outermost layers of the explosion, and UV spectra of SNe Ia are expected to be extremely sensitive to differences in progenitor composition and the details of the explosion. Here, we present the first study of a sample of high signal-to-noise ratio SN Ia spectra that extend blueward of 2900 Å. We focus on spectra taken within 5 d of maximum <span class="hlt">brightness</span>. Our sample of 10 SNe Ia spans, the majority of the parameter space of SN Ia optical diversity. We find that SNe Ia have significantly more diversity in the UV than in the optical, with the spectral variance continuing to increase with decreasing wavelengths until at least 1800 Å (the limit of our data). The majority of the UV variance correlates with optical light-curve shape, while there are no obvious and unique correlations between spectral shape and either ejecta velocity or host-galaxy morphology. Using light-curve shape as the primary variable, we create a UV spectral model for SNe Ia at peak <span class="hlt">brightness</span>. With the model, we can examine how individual SNe vary relative to expectations based on only their light-curve shape. Doing this, we confirm an excess of flux for SN 2011fe at short wavelengths, consistent with its progenitor having a subsolar metallicity. While most other SNe Ia do not show large deviations from the model, ASASSN-14lp has a deficit of flux at short wavelengths, suggesting that its progenitor was relatively metal rich.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SASS...30...45C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SASS...30...45C"><span id="translatedtitle">The Sky <span class="hlt">Brightness</span> Data Archive (SBDA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Craine, Eric R.; Craine, Erin M.; Craine, Brian L.</p> <p>2011-05-01</p> <p>Although many astronomers have long been sensitive to issues of light pollution and deteriorating sky quality it is only in recent years that such interest has extended to other groups including, among others, ecologists, health professionals, and urban planners. Issues of light pollution and loss of dark skies are starting to appear in the scientific literature in the context of health and behavior impacts on both human and animal life. Nonetheless, a common deficiency in most such studies is the absence of historical or baseline data against which to compare sky <span class="hlt">brightness</span> trends and temporal changes. To address this deficiency we have begun to collect a variety of types of quantitative sky <span class="hlt">brightness</span> data for insertion in an international sky <span class="hlt">brightness</span> archive that can be accessed for research projects which are dependent upon an understanding of the nature of local light pollution issues. To aid this process we have developed a mobile sky <span class="hlt">brightness</span> meter which automatically logs sky <span class="hlt">brightness</span> and observation location. The device can be stationary for long periods of time or can be easily transported for continuous sky <span class="hlt">brightness</span> measurement from ground vehicles, boats, or aircraft. The sampling rate is typically about 0.25Hz. We present here examples of different modes of sky <span class="hlt">brightness</span> measurement, various means of displaying and analyzing such data, ways to interpret natural astronomical phenomena apparent in the data, and suggest a number of complementary scientific projects that may capture the interest of both professional and amateur scientists. Finally, we discuss the status of the archive and ways that potential contributors may submit their observations for publication in the archive.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990023305','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990023305"><span id="translatedtitle">Microwave <span class="hlt">Brightness</span> Temperatures of Tilted Convective Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hong, Ye; Haferman, Jeffrey L.; Olson, William S.; Kummerow, Christian D.</p> <p>1998-01-01</p> <p>Aircraft and ground-based radar data from the Tropical Ocean and Global Atmosphere Coupled-Ocean Atmosphere Response Experiment (TOGA COARE) show that convective systems are not always vertical. Instead, many are tilted from vertical. Satellite passive microwave radiometers observe the atmosphere at a viewing angle. For example, the Special Sensor Microwave/Imager (SSM/I) on Defense Meteorological Satellite Program (DMSP) satellites and the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) on the TRMM satellite have an incident angle of about 50deg. Thus, the <span class="hlt">brightness</span> temperature measured from one direction of tilt may be different than that viewed from the opposite direction due to the different optical depth. This paper presents the investigation of passive microwave <span class="hlt">brightness</span> temperatures of tilted convective systems. To account for the effect of tilt, a 3-D backward Monte Carlo radiative transfer model has been applied to a simple tilted cloud model and a dynamically evolving cloud model to derive the <span class="hlt">brightness</span> temperature. The radiative transfer results indicate that <span class="hlt">brightness</span> temperature varies when the viewing angle changes because of the different optical depth. The tilt increases the displacements between high 19 GHz <span class="hlt">brightness</span> temperature (Tb(sub 19)) due to liquid emission from lower level of cloud and the low 85 GHz <span class="hlt">brightness</span> temperature (Tb(sub 85)) due to ice scattering from upper level of cloud. As the resolution degrades, the difference of <span class="hlt">brightness</span> temperature due to the change of viewing angle decreases dramatically. The dislocation between Tb(sub 19) and Tb(sub 85), however, remains prominent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21582814','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21582814"><span id="translatedtitle">AN ALL-SKY CATALOG OF <span class="hlt">BRIGHT</span> M DWARFS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lepine, Sebastien; Gaidos, Eric</p> <p>2011-10-15</p> <p>We present an all-sky catalog of M dwarf stars with apparent infrared magnitude J < 10. The 8889 stars are selected from the ongoing SUPERBLINK survey of stars with proper motion {mu} > 40 mas yr{sup -1}, supplemented on the <span class="hlt">bright</span> end with the Tycho-2 catalog. Completeness tests which account for kinematic (proper motion) bias suggest that our catalog represents {approx}75% of the estimated {approx}11, 900 M dwarfs with J < 10 expected to populate the entire sky. Our catalog is, however, significantly more complete for the northern sky ({approx}90%) than it is for the south ({approx}60%). Stars are identified as cool, red M dwarfs from a combination of optical and infrared color cuts, and are distinguished from background M giants and highly reddened stars using either existing parallax measurements or, if such measurements are lacking, using their location in an optical-to-infrared reduced proper motion diagram. These <span class="hlt">bright</span> M dwarfs are all prime targets for exoplanet surveys using the Doppler radial velocity or transit methods; the combination of low-mass and <span class="hlt">bright</span> apparent magnitude should make possible the detection of Earth-size planets on short-period orbits using currently available techniques. Parallax measurements, when available, and photometric distance estimates are provided for all stars, and these place most systems within 60 pc of the Sun. Spectral type estimated from V - J color shows that most of the stars range from K7 to M4, with only a few late M dwarfs, all within 20 pc. Proximity to the Sun also makes these stars good targets for high-resolution exoplanet imaging searches, especially if younger objects can be identified on the basis of X-ray or UV excess. For that purpose, we include X-ray flux from ROSAT and FUV/NUV <span class="hlt">ultraviolet</span> magnitudes from GALEX for all stars for which a counterpart can be identified in those catalogs. Additional photometric data include optical magnitudes from Digitized Sky Survey plates and infrared magnitudes from</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950034059&hterms=torus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtorus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950034059&hterms=torus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtorus"><span id="translatedtitle">Extreme <span class="hlt">ultraviolet</span> explorer satellite observation of Jupiter's Io plasma torus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hall, D. T; Gladstone, G. R.; Moos, H. W.; Bagenal, F.; Clarke, J. T.; Feldman, P. D.; Mcgrath, M. A.; Schneider, N. M.; Shemansky, D. E.; Strobel, D. F.</p> <p>1994-01-01</p> <p>We present the first Extreme <span class="hlt">Ultraviolet</span> Explorer (EUVE) satellite observation of the Jupiter system, obtained during the 2 day period 1993 March 30 through April 1, which shows a rich emission-line spectrum from the Io plasma torus spanning wavelengths 370 to 735 A. The emission features correspond primarily to known multiplets of oxygen and sulfur ions, but a blended feature near 372 A is a plausible Na II transition. The summed detected energy flux of (7.2 +/- 0.2) x 10(exp -11) ergs/sq cm(s) corresponds to a radiated power of approximately equal to 4 x 10(exp 11) W in this spectral range. All ansa emissions show a distinct dawn-dusk <span class="hlt">brightness</span> asymmetry and the measured dusk/dawn ratio of the <span class="hlt">bright</span> S III lambda-680 feature is 2.3 +/- 0.3, significantly larger than the ratio measured by the Voyager spacecraft <span class="hlt">ultraviolet</span> (UV) instruments. A preliminary estimate of ion partitioning indicates that the oxygen/sulfur ion ratio is approximately equal to 2, compared to the value approximately equal to 1.3 measured by Voyager, and that (Na(+))/(e) greater than 0.01.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=60139&keyword=carotenoids&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64813026&CFTOKEN=92375617','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=60139&keyword=carotenoids&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64813026&CFTOKEN=92375617"><span id="translatedtitle"><span class="hlt">ULTRAVIOLET</span> PROTECTIVE COMPOUNDS AS A RESPONSE TO <span class="hlt">ULTRAVIOLET</span> RADIATION EXPOSURE</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Life on Earth has evolved adaptations to many environmental stresses over the epochs. One consistent stress has been exposure to <span class="hlt">ultraviolet</span> radiation. In response to UVR organisms have adapted myriad responses; behavioral, morphological and physiological. Behaviorally, some orga...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863021','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863021"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> radiation induced discharge laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gilson, Verle A.; Schriever, Richard L.; Shearer, James W.</p> <p>1978-01-01</p> <p>An <span class="hlt">ultraviolet</span> radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between <span class="hlt">ultraviolet</span> radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The <span class="hlt">ultraviolet</span> radiation is produced by a light source or by a spark discharge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AJ....136.1810A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AJ....136.1810A&link_type=ABSTRACT"><span id="translatedtitle">Chandra's Darkest <span class="hlt">Bright</span> Star: not so Dark after All?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ayres, Thomas R.</p> <p>2008-11-01</p> <p>The Chandra High Resolution camera (HRC) has obtained numerous short exposures of the <span class="hlt">ultraviolet</span> (UV)-<span class="hlt">bright</span> star Vega (α Lyrae; HD 172167: A0 V), to calibrate the response of the detector to out-of-band (non-X-ray) radiation. A new analysis uncovered a stronger "blue leak" in the imaging section (HRC-I) than reported in an earlier study of Vega based on a subset of the pointings. The higher count rate—a factor of nearly 2 above prelaunch estimates—raised the possibility that genuine coronal X-rays might lurk among the out-of-band events. Exploiting the broader point-spread function of the UV leak compared with soft X-rays identified an excess of counts centered on the target, technically at 3σ significance. A number of uncertainties, however, prevent a clear declaration of a Vegan corona. A more secure result would be within reach of a deep uninterrupted HRC-I pointing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AAS...21113505S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AAS...21113505S&link_type=ABSTRACT"><span id="translatedtitle">COS Target Acquisition Guidelines and <span class="hlt">Bright</span> Object Protection Rules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shaw, Brittany L.; Friedman, S.; Keyes, T.; Soderblom, D.</p> <p>2007-12-01</p> <p>The Cosmic Origins Spectrograph will provide unparalleled high sensitivity spectroscopy of faint <span class="hlt">ultraviolet</span> sources. To effectively utilize the unique capabilities of COS, target selection and acquisitions should be carefully planned. Acquisitions of faint objects with COS will typically use the NUV imaging mode. For brighter sources, spiral search and peakup acquisition modes are available for both FUV and NUV. We highlight guidelines and strategies for observers to craft target acquisitions with all modes and how to choose between them. Based upon COS Exposure Time Calculator (ETC) modeling, we illustrate the time requirements for different target acquisition scenarios. To preserve the health and safety of COS detectors, separate <span class="hlt">bright</span> object protection rules have been created for each detector. We explain these rules and their implications for potential COS targets and users. Most science observations will be performed in TIME-TAG mode in which individual photon arrival times and locations are recorded. This mode is preferred because it allows for optimized data reduction. Brighter objects that produce high count rates must be handled by using ACCUM mode that collects photons only by location on the detector. We discuss the count rate limits and specific data quality considerations of each mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AAS...212.2505G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AAS...212.2505G&link_type=ABSTRACT"><span id="translatedtitle">COS Target Acquisition Guidelines and <span class="hlt">Bright</span> Object Protection Rules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghavamian, Parviz; Keyes, T.; Shaw, B.; Soderblom, D.; Friedman, S.; COS/STIS STScI Team; COS IDT Team</p> <p>2008-05-01</p> <p>The Cosmic Origins Spectrograph will provide spectroscopy of faint <span class="hlt">ultraviolet</span> sources with unparalleled sensitivity. However, careful planning is required to effectively utilize the unique capabilities of COS. Faint object acquisition with COS will typically utilize the Near-UV (NUV) imaging mode. For brighter sources, spiral search and peakup acquisition modes are available for both the NUV and Far-UV (FUV). Here we highlight guidelines and strategies for observers to craft target acquisitions in all modes and describe how to choose between them. Based upon COS Exposure Time Calculator (ETC) modeling, we illustrate the time requirements for different target acquisition scenarios. To preserve the health and safety of COS detectors, separate <span class="hlt">bright</span> object protection rules have been created for each detector. We explain these rules and their implications for potential COS targets and users. Most science observations will be performed in time-tag (TTAG) mode in which individual photon arrival times and locations are recorded. This mode is preferred because it allows for optimized data reduction. Brighter objects that produce high count rates must be handled by using accumulation (ACCUM) mode that collects photons according to their location on the detector. For each observation mode we discuss the count rate limits and specific data quality considerations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850011592','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850011592"><span id="translatedtitle">Research in extreme <span class="hlt">ultraviolet</span> and far <span class="hlt">ultraviolet</span> astronomy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bowyer, C. S.</p> <p>1985-01-01</p> <p>The Far <span class="hlt">Ultraviolet</span> imager (FUVI) was flown on the Aries class sounding rocket 24.015, producing outstanding results. The diffuse extreme <span class="hlt">ultraviolet</span> (EUV) background spectrometer which is under construction is described. It will be launched on the Black Brant sounding rocket flight number 27.086. Ongoing design studies of a high resolution spectrometer are discussed. This instrument incorporates a one meter normal incidence mirror and will be suitable for an advanced Spartan mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ASPC..497..491M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ASPC..497..491M"><span id="translatedtitle">Spectroscopic Surface <span class="hlt">Brightness</span> Fluctuations: Amplifying <span class="hlt">Bright</span> Stars in Unresolved Stellar Populations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitzkus, M.; Dreizler, S.; Roth, M. M.</p> <p>2015-08-01</p> <p>We report on our early-stage efforts to resolve the Surface <span class="hlt">Brightness</span> Fluctuations (SBFs) in the spectral dimension. Combining the diagnostic power of SBFs with the physical information content of spectra seems a tempting possibility to gain new insights into the <span class="hlt">bright</span> stars in unresolved stellar populations. The new VLT integral field spectrograph MUSE is the first instrument that enables spectroscopic SBFs observationally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23349946','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23349946"><span id="translatedtitle"><span class="hlt">Brightness</span> discrimination in budgerigars (Melopsittacus undulatus).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lind, Olle; Karlsson, Sandra; Kelber, Almut</p> <p>2013-01-01</p> <p>Birds have excellent spatial acuity and colour vision compared to other vertebrates while spatial contrast sensitivity is relatively poor for unknown reasons. Contrast sensitivity describes the detection of gratings of varying spatial frequency. It is unclear whether bird <span class="hlt">brightness</span> discrimination between large uniform fields is poor as well. Here we show that budgerigars (Melopsittacus undulatus) need a Michelson contrast of 0.09 to discriminate between large spatially separated achromatic fields in <span class="hlt">bright</span> light conditions. This is similar to the peak contrast sensitivity of 10.2 (0.098 Michelson contrast) for achromatic grating stimuli established in earlier studies. The <span class="hlt">brightness</span> discrimination threshold described in Weber fractions is 0.18, which is modest compared to other vertebrates. PMID:23349946</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IAUS..282..163S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IAUS..282..163S"><span id="translatedtitle">Observing Faint Companions Close to <span class="hlt">Bright</span> Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serabyn, Eugene</p> <p>2012-04-01</p> <p>Progress in a number of technical areas is enabling imaging and interferometric observations at both smaller angular separations from <span class="hlt">bright</span> stars and at deeper relative contrast levels. Here we discuss recent progress in several ongoing projects at the Jet Propulsion Laboratory. First, extreme adaptive optics wavefront correction has recently enabled the use of very short (i.e., blue) wavelengths to resolve close binaries. Second, phase-based coronagraphy has recently allowed observations of faint companions to within nearly one diffraction beam width of <span class="hlt">bright</span> stars. Finally, rotating interferometers that can observe inside the diffraction beam of single aperture telescopes are being developed to detect close-in companions and <span class="hlt">bright</span> exozodiacal dust. This paper presents a very brief summary of the techniques involved, along with some illustrative results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title21-vol8/pdf/CFR-2013-title21-vol8-sec872-6350.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title21-vol8/pdf/CFR-2013-title21-vol8-sec872-6350.pdf"><span id="translatedtitle">21 CFR 872.6350 - <span class="hlt">Ultraviolet</span> detector.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-04-01</p> <p>... 21 Food and Drugs 8 2013-04-01 2013-04-01 false <span class="hlt">Ultraviolet</span> detector. 872.6350 Section 872.6350...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6350 <span class="hlt">Ultraviolet</span> detector. (a) Identification. An <span class="hlt">ultraviolet</span> detector is a device intended to provide a source of <span class="hlt">ultraviolet</span> light which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title21-vol8/pdf/CFR-2010-title21-vol8-sec872-6350.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title21-vol8/pdf/CFR-2010-title21-vol8-sec872-6350.pdf"><span id="translatedtitle">21 CFR 872.6350 - <span class="hlt">Ultraviolet</span> detector.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-04-01</p> <p>... 21 Food and Drugs 8 2010-04-01 2010-04-01 false <span class="hlt">Ultraviolet</span> detector. 872.6350 Section 872.6350...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6350 <span class="hlt">Ultraviolet</span> detector. (a) Identification. An <span class="hlt">ultraviolet</span> detector is a device intended to provide a source of <span class="hlt">ultraviolet</span> light which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol8/pdf/CFR-2012-title21-vol8-sec872-6350.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol8/pdf/CFR-2012-title21-vol8-sec872-6350.pdf"><span id="translatedtitle">21 CFR 872.6350 - <span class="hlt">Ultraviolet</span> detector.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-04-01</p> <p>... 21 Food and Drugs 8 2012-04-01 2012-04-01 false <span class="hlt">Ultraviolet</span> detector. 872.6350 Section 872.6350...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6350 <span class="hlt">Ultraviolet</span> detector. (a) Identification. An <span class="hlt">ultraviolet</span> detector is a device intended to provide a source of <span class="hlt">ultraviolet</span> light which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720024182','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720024182"><span id="translatedtitle">The Celescope catalog of <span class="hlt">ultraviolet</span> observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, R. J.</p> <p>1972-01-01</p> <p>Data obtained from approximately 7500 <span class="hlt">ultraviolet</span> television pictures are used to compile a celescope catalog of <span class="hlt">ultraviolet</span> observations. This catalog lists the magnitude as observed in each of celescope's four <span class="hlt">ultraviolet</span> color bands, the standard deviations of the observed <span class="hlt">ultraviolet</span> magnitudes, positions, identifications, and ground based magnitudes, colors, and spectral types for approximately 5000 stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02356&hterms=sand+dune+formed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsand%2Bdune%2Bformed','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02356&hterms=sand+dune+formed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsand%2Bdune%2Bformed"><span id="translatedtitle">Dark Dunes Over-riding <span class="hlt">Bright</span> Dunes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p><p/>Some martian sand dunes may be more active than others. In this picture, wind has caused the dark and somewhat crescent-shaped dunes to advance toward the lower left. While their movement cannot actually be seen in this April 1998snapshot, the location of their steepest slopes--their slip faces--on their southwestern sides indicates the direction of movement. Oddly, these dark dunes have moved across and partly cover sets of smaller, <span class="hlt">bright</span> ridges that also formed by wind action.<p/>This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image illustrates an intriguing martian 'find.' Strangely, the two dune types have different shapes and a different relative <span class="hlt">brightness</span>. There are two explanations for the relationship seen here, and neither can be distinguished as 'the answer'--(1) it is possible that the brighter dunes are old and cemented, and represent some ancient wind activity, whereas the dark dunes are modern and are marching across the older, 'fossilized' dune forms, or (2) the <span class="hlt">bright</span> dunes are composed of grains that are much larger or more dense than those that compose the dark dunes. In the latter scenario, the <span class="hlt">bright</span> dunes move more slowly and are over-taken by the dark dunes because their grains are harder to transport. An interpretation involving larger or denser grains is consistent with the small size and even-spacing of the <span class="hlt">bright</span> dunes, as well, but usually on Earth such features occur on the surfaces of larger, finer-grained dunes, not under them. The actual composition of either the <span class="hlt">bright</span> or dark materials are unknown. This example is located on the floor of an impact crater in western Arabia Terra at 10.7oN, 351.0oW. The picture is illuminated from the right.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780053253&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2528ultraviolet%2Bradiation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780053253&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2528ultraviolet%2Bradiation%2529"><span id="translatedtitle">Laser-induced two-photon blackbody radiation in the vacuum <span class="hlt">ultraviolet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zych, L. J.; Young, J. F.; Harris, S. E.; Lukasik, J.</p> <p>1978-01-01</p> <p>Experimental measurements of a new type of vacuum-<span class="hlt">ultraviolet</span> radiation source are reported. It is shown that the maximum source <span class="hlt">brightness</span>, within its narrow linewidth, is that of a blackbody at the temperature of a metastable storage level. The laser-induced emission at 569 A from a He glow discharge corresponded to a metastable temperature of 22,700 K and was over 100 times brighter than the 584-A He resonance line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890037413&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528ultraviolet%2Bradiation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890037413&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528ultraviolet%2Bradiation%2529"><span id="translatedtitle">The diffuse far-<span class="hlt">ultraviolet</span> cosmic background radiation field observed from the Space Shuttle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Murthy, J.; Henry, R. C.; Feldman, P. D.; Tennyson, P. D.</p> <p>1989-01-01</p> <p>The paper presents 17-A resolution spectra of the diffuse far-<span class="hlt">ultraviolet</span> (1200-1700 A) cosmic background in eight regions of the sky obtained from the Johns Hopkins University UVX experiment aboard the Space Shuttle Columbia (STS-61C) in January 1986. A spectrally flat background is found with <span class="hlt">brightnesses</span> between 100 and 700 + or - 200 photons/sq cm s sr A, with some evidence for spatial variations, but not for the high-intensity regions found by other experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JAHH....1..123H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JAHH....1..123H"><span id="translatedtitle">The historical investigation of cometary <span class="hlt">brightness</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, David W.</p> <p>1998-12-01</p> <p>The interpretation of the way in which the <span class="hlt">brightness</span> of a comet varied as a function of both its heliocentric and geocentric distance was essentially started by Isaac Newton in his book Philosophiae Naturalis Principia Mathematica, published in 1687. Astronomers have argued about the form of this variability ever since, and for many years it was regarded as an important clue as to the physical nature of the cometary nucleus and its decay process. This paper reviews our understanding of the causes of cometary <span class="hlt">brightness</span> variability between about 1680 and the 1950s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6515680','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6515680"><span id="translatedtitle">Diagnostics for high-<span class="hlt">brightness</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shafer, R.E.</p> <p>1990-01-01</p> <p>Special techniques are required for beam diagnostics on high-<span class="hlt">brightness</span> particle beams. Examples of high-<span class="hlt">brightness</span> beams include low-emittance proton linacs (either pulsed or CW), electron linacs suitable for free-electron-laser applications, and future linear colliders. Non-interceptive and minimally-interceptive techniques for measuring beam current, position, profile, and transverse and longitudinal emittance will be reviewed. Included will be stripline, wire scanner, laser neutralization, beam-beam scattering, interceptive microgratings, spontaneous emission, optical transition radiation, and other techniques. 24 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760013983','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760013983"><span id="translatedtitle">Comet <span class="hlt">brightness</span> parameters: Definition, determination, and correlations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meisel, D. D.; Morris, C. S.</p> <p>1976-01-01</p> <p>The power-law definition of comet <span class="hlt">brightness</span> is reviewed and possible systematic influences are discussed that can affect the derivation of m sub o and n values from visual magnitude estimates. A rationale for the Bobrovnikoff aperture correction method is given and it is demonstrated that the Beyer extrafocal method leads to large systematic effects which if uncorrected by an instrumental relationship result in values significantly higher than those derived according to the Bobrovnikoff guidelines. A series of visual <span class="hlt">brightness</span> parameter sets are presented which have been reduced to the same photometric system. Recommendations are given to insure that future observations are reduced to the same system.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA07251&hterms=ultraviolet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dultraviolet','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA07251&hterms=ultraviolet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dultraviolet"><span id="translatedtitle">Surprise <span class="hlt">Ultraviolet</span> Party in the Sky</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2005-01-01</p> <p><p/> Galaxies aren't the only objects filling up the view of NASA's Galaxy Evolution Explorer. Since its launch in 2003, the space telescope -- originally designed to observe galaxies across the universe in <span class="hlt">ultraviolet</span> light -- has discovered a festive sky blinking with flaring and erupting stars, as well as streaking asteroids, satellites and space debris. A group of six streaking objects -- the identities of which remain unknown -- can be seen here flying across the telescope's sight in this sped-up movie. <p/> The two brightest objects appear to perform a sharp turn then travel in the reverse direction. This illusion is most likely the result of the Galaxy Evolution Explorer overtaking the objects as it orbits around Earth. <p/> Careful inspection reveals four additional faint objects with the same timing and behavior. These faint objects are easiest to see during the retrograde portion of their paths. Three appear between the two <span class="hlt">bright</span> sources, and one is above them, near the edge of the field of view. <p/> These bonus objects are being collected in to public catalogues for other astronomers to study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810000171&hterms=hasegawa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhasegawa','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810000171&hterms=hasegawa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhasegawa"><span id="translatedtitle"><span class="hlt">Ultraviolet</span>-Induced Mirror Degradation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bouquet, F. L.; Hasegawa, T. T.; Cleland, E. L.</p> <p>1982-01-01</p> <p>Recent tests of second-surface mirrors show that <span class="hlt">ultraviolet</span> radiation penetrates glass and metalized zone and impinges upon backing paint. According to report, many backing materials are degraded by <span class="hlt">ultraviolet</span> radiation. Mirror corrosion is a serious problem in solar-energy collection systems. Effects of UV on polymeric materials have been studied, and in general, all are degraded by UV. Polymers most resistant to UV radiation are polyimides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930001885','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930001885"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> studies of Cepheids</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boehm-Vitense, Erika</p> <p>1992-01-01</p> <p>We discuss whether with new evolutionary tracks we still have a problem fitting the Cepheids and their evolved companions on the appropriate evolutionary tracks. We find that with the Bertelli et al. tracks with convective overshoot by one pressure scale height the problem is essentially removed, though somewhat more mixing would give a better fit. By using the results of recent nonlinear hydrodynamic calculations, we find that we also have no problem matching the observed pulsation periods of the Cepheids with those expected from their new evolutionary masses, provided that Cepheids with periods less than 9 days are overtone pulsators. We investigate possible mass loss of Cepheids from UV studies of the companion spectrum of S Mus and from the <span class="hlt">ultraviolet</span> spectra of the long period Cepheid l Carinae. For S Mus with a period of 9.6 days we derive an upper limit for the mass loss of M less than 10(exp -9) solar mass, if a standard velocity law is assumed for the wind. For l Carinae with a period of 35.5 days we find a probable mass loss of M is approximately 10(exp -5+/-2) solar mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JHEP...12..004B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JHEP...12..004B"><span id="translatedtitle">Higgs <span class="hlt">ultraviolet</span> softening</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brivio, I.; Éboli, O. J. P.; Gavela, M. B.; Gonzalez-García, M. C.; Merlo, L.; Rigolin, S.</p> <p>2014-12-01</p> <p>We analyze the leading effective operators which induce a quartic momentum dependence in the Higgs propagator, for a linear and for a non-linear realization of electroweak symmetry breaking. Their specific study is relevant for the understanding of the <span class="hlt">ultraviolet</span> sensitivity to new physics. Two methods of analysis are applied, trading the Lagrangian coupling by: i) a "ghost" scalar, after the Lee-Wick procedure; ii) other effective operators via the equations of motion. The two paths are shown to lead to the same effective Lagrangian at first order in the operator coefficients. It follows a modification of the Higgs potential and of the fermionic couplings in the linear realization, while in the non-linear one anomalous quartic gauge couplings, Higgs-gauge couplings and gauge-fermion interactions are induced in addition. Finally, all LHC Higgs and other data presently available are used to constrain the operator coefficients; the future impact of pp → 4 leptons data via off-shell Higgs exchange and of vector boson fusion data is considered as well. For completeness, a summary of pure-gauge and gauge-Higgs signals exclusive to non-linear dynamics at leading-order is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/872884','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/872884"><span id="translatedtitle">Extreme <span class="hlt">ultraviolet</span> lithography machine</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Tichenor, Daniel A.; Kubiak, Glenn D.; Haney, Steven J.; Sweeney, Donald W.</p> <p>2000-01-01</p> <p>An extreme <span class="hlt">ultraviolet</span> lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/481480','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/481480"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> fluorescence monitor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hargis, P.J. Jr.; Preppernau, B.L.; Aragon, B.P.</p> <p>1997-05-01</p> <p>A multispectral <span class="hlt">ultraviolet</span> (UV) fluorescence imaging fluorometer and a pulsed molecular beam laser fluorometer were developed to detect volatile organic compounds of interest in environmental monitoring and drug interdiction applications. The UV fluorescence imaging fluorometer is a relatively simple instrument which uses multiple excitation wavelengths to measure the excitation/emission matrix for irradiated samples. Detection limits in the high part-per-million to low part-per-million range were measured for a number of volatile organic vapors in the atmosphere. Detection limits in the low part-per-million range were obtained using cryogenic cooling to pre-concentrate unknown samples before introducing them into the imaging fluorometer. A multivariate analysis algorithm was developed to analyze the excitation/emission matrix and used to determine the relative concentrations of species in computer synthesized mixtures containing up to five organic compounds. Analysis results demonstrated the utility of multispectral UV fluorescence in analytical measurements. A transportable UV fluorescence imaging fluorometer was used in two field tests. Field test results demonstrated that detection limits in the part-per-billion range were needed to reliably identify volatile organic compounds in realistic field test measurements. The molecular beam laser fluorometer, a more complex instrument with detection limits in the part-per-billion to part-per-trillion range, was therefore developed to satisfy detection sensitivity requirements for field test measurements. High-resolution spectroscopic measurements made with the molecular beam laser fluorometer demonstrated its utility in identifying volatile organic compounds in the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25463663','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25463663"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> radiation and cyanobacteria.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Häder, Donat-Peter; Han, Taejun</p> <p>2014-12-01</p> <p>Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar <span class="hlt">ultraviolet</span> radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. PMID:25463663</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992AAS...180.5202G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992AAS...180.5202G"><span id="translatedtitle">The SPARTAN <span class="hlt">Ultraviolet</span> Coronagraph</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gardner, L. D.; Esser, R.; Habbal, S. R.; Hassler, D. M.; Raymond, J. C.; Strachan, L.; van Ballegooijen, A. A.; Kohl, J. L.; Fineschi, S.</p> <p>1992-05-01</p> <p>An <span class="hlt">ultraviolet</span> coronagraph (UVC) is being prepared for a series of orbital flights on NASA's Spartan 201 which is deployed and retrieved by Shuttle. The Spartan 201 payload consists of the UVC and a white light coronagraph developed by the High Altitude Observatory. Spartan is expected to provide 26 orbits of solar observations per flight. The first flight is scheduled for May 1993 and subsequent flights are planned to occur at each polar passage of Ulysses (1994 and 1995). The UVC measures the intensity and spectral line profile of resonantly scattered H I Ly-alpha and the intensities of O VI lambda 1032 and lambda 1037 at heliocentric heights between 1.3 and 3.5 solar radii. A description of the UVC instrument, its characteristics, and the observing program for the first flight will be presented. The initial scientific objective is to determine the random velocity distribution and bulk outflow velocity of coronal protons and the density and outflow velocity of O(5+) in polar coronal holes and adjoining high latitude streamers. This work is supported by NASA under Grant No. NAG5-613 to the Smithsonian Astrophysical Observatory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2835849','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2835849"><span id="translatedtitle">Light, Including <span class="hlt">Ultraviolet</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Maverakis, Emanual; Miyamura, Yoshinori; Bowen, Michael P.; Correa, Genevieve; Ono, Yoko; Goodarzi, Heidi</p> <p>2009-01-01</p> <p><span class="hlt">Ultraviolet</span> (UV) light is intricately linked to the functional status of the cutaneous immune system. In susceptible individuals, UV radiation can ignite pathogenic inflammatory pathways leading to allergy or autoimmunity. In others, this same UV radiation can be used as a phototherapy to suppress pathogenic cutaneous immune responses. These vastly different properties are a direct result of UV light’s ability to ionize molecules in the skin and thereby chemically alter them. Sometimes these UV-induced chemical reactions are essential, the formation of pre-vitamin D3 from 7-dehydrocholesterol, for example. In other instances they can be potentially detrimental. UV radiation can ionize a cell’s DNA causing adjacent pyrimidine bases to chemically bond to each other. To prevent malignant transformation, a cell may respond to this UV-induced DNA damage by undergoing apoptosis. Although this pathway prevents skin cancer it also has the potential of inducing or exacerbating autoreactive immune responses by exposing the cell’s nuclear antigens. Ultaviolet-induced chemical reactions can activate the immune system by a variety of other mechanisms as well. In response to UV irradiation keratinocytes secrete cytokines and chemokines, which activate and recruit leukocytes to the skin. In some individuals UV-induced chemical reactions can synthesize novel antigens resulting in a photoallergy. Alternatively, photosensitizing molecules can damage cells by initiating sunburn-like phototoxic reactions. Herein we review all types of UV-induced skin reactions, especially those involving the immune system. PMID:20018479</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930009803','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930009803"><span id="translatedtitle">Extreme <span class="hlt">Ultraviolet</span> Explorer. Long look at the next window</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maran, Stephen P.</p> <p>1991-01-01</p> <p>The Extreme <span class="hlt">Ultraviolet</span> Explorer (EUVE) will map the entire sky to determine the existence, direction, <span class="hlt">brightness</span>, and temperature of thousands of objects that are sources of so-called extreme <span class="hlt">ultraviolet</span> (EUV) radiation. The EUV spectral region is located between the x-ray and <span class="hlt">ultraviolet</span> regions of the electromagnetic spectrum. From the sky survey by EUVE, astronomers will determine the nature of sources of EUV light in our galaxy, and infer the distribution of interstellar gas for hundreds of light years around the solar system. It is from this gas and the accompanying dust in space that new stars and solar systems are born and to which evolving and dying stars return much of their material in an endless cosmic cycle of birth, death, and rebirth. Besides surveying the sky, astronomers will make detailed studies of selected objects with EUVE to determine their physical properties and chemical compositions. Also, they will learn about the conditions that prevail and the processes at work in stars, planets, and other sources of EUV radiation, maybe even quasars. The EUVE mission and instruments are described. The objects that EUVE will likely find are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006Ap%26SS.303...85G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006Ap%26SS.303...85G"><span id="translatedtitle">Starbursts at space <span class="hlt">ultraviolet</span> wavelengths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González Delgado, Rosa M.</p> <p>2006-06-01</p> <p>Starbursts are systems with very high star formation rate per unit area. They are the preferred place where massive stars form; the main source of thermal and mechanical heating in the interstellar medium, and the factory where the heavy elements form. Thus, starbursts play an important role in the origin and evolution of galaxies. The similarities between the physical properties of local starbursts and high-z star-forming galaxies, highlight the cosmological relevance of starbursts. On the other hand, nearby starbursts are laboratories where to study violent star formation processes and their interaction with the interstellar and intergalactic media, in detail and deeply. Starbursts are <span class="hlt">bright</span> at <span class="hlt">ultraviolet</span> (UV) wavelengths, as they are in the far-infrared, due to the ‘picket-fence’ interstellar dust distribution. After the pioneering IUE program, high spatial and spectral resolution UV observations of local starburst galaxies, mainly taken with HST and FUSE, have made relevant contributions to the following issues: <UnorderedList Mark="Dash"> <ItemContent> <Para> The determination of the initial mass function (IMF) in violent star forming systems in low and high metallicity environments, and in dense (e.g. in stellar clusters) and diffuse environments: A Salpeter IMF with high-mass stars constrains well the UV properties.</Para> </ItemContent> <ItemContent> <Para> The modes of star formation: Starburst clusters are an important mode of star formation. Super-stellar clusters have properties similar to globular clusters.</Para> </ItemContent> <ItemContent> <Para> The role of starbursts in AGN: Nuclear starbursts can dominate the UV light in Seyfert 2 galaxies, having bolometric luminosities similar to the estimated bolometric luminosities of the obscured AGN.</Para> </ItemContent> <ItemContent> <Para> The interaction between massive stars and the interstellar and intergalactic media: Outflows in cold, warm and coronal phases leave their imprints on the UV</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70112257','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70112257"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> investigations for lunar missions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hemphill, William R.; Fischer, William A.; Dornbach, J.E.</p> <p>1966-01-01</p> <p>Preliminary field tests of an active <span class="hlt">ultraviolet</span> imaging system have shown that it is possible to produce linages of the terrain from distances as great as 75 feet by means of reflected <span class="hlt">ultraviolet</span> light at wavelengths longer than 3300 A. Minerals that luminesce when exposed to <span class="hlt">ultraviolet</span> energy have been detected from distances as great as 200 feet. With appropriate design modifications, it may be possible to utilize a similar system in detecting luminescing minerals from greater distances. Also, with a similar system and appropriate auxiliary equipment such as image intensifiers, it may be possible to discriminate between naturally occurring materials on the basis of reflected <span class="hlt">ultraviolet</span> energy at wavelengths shorter than 3000 A. In this part of the spectrum image contrast for some rock types may exceed that from visible light. Information from these and related <span class="hlt">ultraviolet</span> spectralanalysis studies may be useful in evaluating data obtained from passive <span class="hlt">ultraviolet</span> systems in lunar orbit as well as from active systems on the lunar surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840061584&hterms=flare+up&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dflare%2Bup','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840061584&hterms=flare+up&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dflare%2Bup"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> flare on Lambda Andromedae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baliunas, S. L.; Guinan, E. F.; Dupree, A. K.</p> <p>1984-01-01</p> <p>On November 5, 6, 1982, a luminous, flarelike brightening of the <span class="hlt">ultraviolet</span> emissions was observed with IUE from the active RS CVn type star Lambda And during the phase of rotation period corresponding to maximum area coverage of the visible hemisphere by starspots and active regions. Enhancements during the flare in the <span class="hlt">ultraviolet</span> emission lines as large as factors of several and in the <span class="hlt">ultraviolet</span> continuum up to 80 percent persisted for over 5 hours. The bulk of the radiative output of the flare occurred in Mg II h and k and H I Ly-alpha. Because of the long duration and extreme luminosity of the event, the energy radiated by the flare alone is in excess of 10 to the 35th ergs just in the <span class="hlt">ultraviolet</span> region. This is the most energetic stellar flare ever recorded in the <span class="hlt">ultraviolet</span>. In addition, it is the first <span class="hlt">ultraviolet</span> flare observed from a giant star. In comparison to the largest solar flares, the flare on Lambda And is at least three orders of magnitude more energetic in similar emission lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJS..220....6B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJS..220....6B"><span id="translatedtitle">An Updated <span class="hlt">Ultraviolet</span> Catalog of GALEX Nearby Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bai, Yu; Zou, Hu; Liu, JiFeng; Wang, Song</p> <p>2015-09-01</p> <p>The <span class="hlt">ultraviolet</span> (UV) catalog of nearby galaxies compiled by Gil de Paz et al. presents the integrated photometry and surface <span class="hlt">brightness</span> profiles for 1034 nearby galaxies observed by GALEX. We provide an updated catalog of 4138 nearby galaxies based on the latest Genral Release (GR6/GR7) of GALEX. These galaxies are selected from HyperLeda with apparent diameters larger than 1‧. From the surface <span class="hlt">brightness</span> profiles accurately measured using the deep NUV and FUV images, we have calculated the asymptotic magnitudes, aperture (D25) magnitudes, colors, structural parameters (effective radii and concentration indices), luminosities, and effective surface <span class="hlt">brightness</span> for these galaxies. Archival optical and infrared photometry from HyperLeda, 2MASS, and IRAS are also integrated into the catalog. Our parameter measurements and some analyses are consistent with those of Paz et al. The (FUV - K) color provides a good criterion to distinguish between early- and late-type galaxies, which can be improved further using the concentration indices. The IRX-β relation is reformulated with our UV-selected nearby galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NatCh...6..955S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NatCh...6..955S&link_type=ABSTRACT"><span id="translatedtitle">Photochemistry: A <span class="hlt">bright</span> future for sunscreens</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stavros, Vasilios G.</p> <p>2014-11-01</p> <p>Understanding the intrinsic properties of molecules that protect our skin from the harmful rays of the Sun is critical to developing more efficacious sunscreen products. Now, gas-phase spectroscopy and microsolvation studies of model <span class="hlt">ultraviolet</span>-filter molecules have shown that they may provide a route to developing improved sunscreens.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NIMPA.807...13G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NIMPA.807...13G"><span id="translatedtitle"><span class="hlt">Brightness</span> of synchrotron radiation from wigglers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni</p> <p>2016-01-01</p> <p>According to the literature, while calculating the <span class="hlt">brightness</span> of synchrotron radiation from wigglers, one needs to account for the so-called 'depth-of-field' effects. In fact, the particle beam cross-section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the <span class="hlt">brightness</span> is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler <span class="hlt">brightness</span> turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the <span class="hlt">brightness</span> from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. We exemplify this formalism in simple limiting cases. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810058932&hterms=shorthill&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dshorthill','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810058932&hterms=shorthill&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dshorthill"><span id="translatedtitle">Lunar craters with radar <span class="hlt">bright</span> ejecta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, T. W.; Zisk, S. H.; Schultz, P. H.; Cutts, J. A.; Shorthill, R. W.</p> <p>1981-01-01</p> <p>The properties of the 3.8-cm radar-<span class="hlt">bright</span> halos observed around certain lunar impact craters are compiled and compared with 70-cm radar, thermal infrared and photogeological data in order to address the nature of the halos. Diameters, positions, and radar and IR signal strengths are presented for 120 radar-<span class="hlt">bright</span> ejecta regions of size greater than 20 km and twice the diameter of the crater. The 3.8-cm halos are noted to range in size up to 30 times that of the crater itself, although the strength of the signal from the crater and rim lies in a narrow range, while the IR halos are smaller in extent and variable in signal strength. The radar-<span class="hlt">bright</span> ejecta are found to have a range of optical properties, and to be associated with fresh primary impact craters. Data are thus consistent with craters having radar-<span class="hlt">bright</span> ejecta deposits having ages of less than 10 million to 1 billion years, with the radar and infrared signatures of the ejecta deposits produced by combinations of enhanced blockiness and roughness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5770716','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5770716"><span id="translatedtitle">Polyvinylpyrrolidone dewaxing aid for <span class="hlt">bright</span> stocks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Achia, B.U.; Shaw, D.H.</p> <p>1980-05-20</p> <p>Polyvinylpyrrolidone having a number average molecular weight ranging from about 150,000 to 400,000 has been found to be an effective dewaxing aid for <span class="hlt">bright</span> stock in ketone dewaxing processes. Using as little as 100 ppm based on the waxy oil can result in almost a 50% increase in the filter rate of the dewaxed oils from the wax.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7941364','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7941364"><span id="translatedtitle">Illusory <span class="hlt">brightness</span> step in the Chevreul illusion.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morrone, M C; Burr, D C; Ross, J</p> <p>1994-06-01</p> <p>It is well known that a staircase luminance profile is not seen veridically, but appears as the scallopy-like Chevreul illusion. We have shown that adding thin lines (either light or dark) to the centre of each step creates an illusory <span class="hlt">brightness</span> change at the point of the line. The regions between the added lines and the edges seem to be uniform, with a clear change in <span class="hlt">brightness</span> at the point where the line was added. The conditions under which the illusion occurred were measured systematically, both by contrast matching and by annulment. One model that can readily account for the illusion is the local-energy model of feature detection (Morrone & Burr, 1988 Proceedings of the Royal Society of London B, 235, 221-245). Adding the bar to the step creates a peak in local energy at all scales. At the higher scales, the phase of the energy is near zero, the signal for a line; but at the lower scales the phase is near pi/2, the signal for an edge. We propose that the edge signal of the lower scales causes the <span class="hlt">brightness</span> illusion and that this <span class="hlt">brightness</span> difference is structured by the feature defined sharply by the higher scales (even though that feature is not an edge). As well as predicting the existence of the illusion, simulations with the energy model predicted quantitatively the apparent contrast of the illusion as a function of stimulus contrast, bar-position and high-pass filter frequency. PMID:7941364</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.youtube.com/watch?v=vaTZVcL0yWw','SCIGOVIMAGE-NASA'); return false;" href="http://www.youtube.com/watch?v=vaTZVcL0yWw"><span id="translatedtitle"><span class="hlt">Bright</span> Meteor Lights Up Atlanta Skies</span></a></p> <p><a target="_blank" href="http://www.nasa.gov/multimedia/videogallery/index.html">NASA Video Gallery</a></p> <p></p> <p></p> <p>This video shows a very <span class="hlt">bright</span> meteor that streaked over the skies of Atlanta, Ga., on the night of Aug. 28, 2011. The view is from an all sky camera in Cartersville, Ga., operated by NASA’s Mars...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=nonprofit+AND+websites&pg=4&id=ED409692','ERIC'); return false;" href="http://eric.ed.gov/?q=nonprofit+AND+websites&pg=4&id=ED409692"><span id="translatedtitle">Alberta Associations for <span class="hlt">Bright</span> Children Members' Handbook.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Alberta Association for Bright Children, Edmonton.</p> <p></p> <p>This handbook is designed to provide information to parents of gifted children in Alberta, Canada. The handbook outlines the mission and objectives of the Alberta Associations for <span class="hlt">Bright</span> Children and describes the structure of the non-profit organization. The booklet then addresses: (1) the characteristics of gifted children; (2) the rights of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3311899','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3311899"><span id="translatedtitle">Simultaneous <span class="hlt">brightness</span> contrast of foraging Papilio butterflies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro</p> <p>2012-01-01</p> <p>This study focuses on the sense of <span class="hlt">brightness</span> in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive <span class="hlt">brightness</span> in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn <span class="hlt">brightness</span> and darkness of targets independent of colour, and that they have the so-called simultaneous <span class="hlt">brightness</span> contrast. PMID:22179808</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20155120','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20155120"><span id="translatedtitle">Sky <span class="hlt">brightness</span> during eclipses: a review.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Silverman, S M; Mullen, E G</p> <p>1975-12-01</p> <p>This paper is abstracted from the introductory section of "Sky <span class="hlt">Brightness</span> During Eclipses: A Compendium from the Literature," AFCRL-TR-74-0363, Special Reports 180, Air Force Cambridge Research Laboratories, Hanscom AFB, Massachusetts 01731. This report should be consulted for fuller details and tables. PMID:20155120</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17775626','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17775626"><span id="translatedtitle">A remarkable auroral event on jupiter observed in the <span class="hlt">ultraviolet</span> with the hubble space telescope.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gérard, J C; Grodent, D; Dols, V; Prangé, R; Waite, J H; Gladstone, G R; Franke, K A; Paresce, F; Storrs, A; Jaffel, L B</p> <p>1994-12-01</p> <p>Two sets of <span class="hlt">ultraviolet</span> images of the Jovian north aurora were obtained with the Faint Object Camera on board the Hubble Space Telescope. The first series shows an intense discrete arc in near corotation with the planet. The maximum apparent molecular hydrogen emission rate corresponds to an electron precipitation of approximately 1 watt per square meter, which is about 30,000 times larger than the solar heating by extreme <span class="hlt">ultraviolet</span> radiation. Such a particle heating rate of the auroral upper atmosphere of Jupiter should cause a large transient temperature increase and generate strong thermospheric winds. Twenty hours after initial observation, the discrete arc had decreased in <span class="hlt">brightness</span> by more than one order of magnitude. The time scale and magnitude of the change in the <span class="hlt">ultraviolet</span> aurora leads us to suggest that the discrete Jovian auroral precipitation is related to large-scale variations in the current system, as is the case for Earth's discrete aurorae. PMID:17775626</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770040309&hterms=Bless+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBless%2Byou','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770040309&hterms=Bless+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBless%2Byou"><span id="translatedtitle">Apollo-16 far-<span class="hlt">ultraviolet</span> spectra in the Large Magellanic Cloud</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carruthers, G. R.; Page, T.</p> <p>1977-01-01</p> <p>Spectra in the wavelength ranges from 900 to 1600 A and 1050 to 1600 A of some OB associations in the Large Magellanic Cloud were obtained from the lunar surface by the Apollo-16 far-<span class="hlt">ultraviolet</span> camera/spectrograph on April 22, 1972. The observed spectral distributions appear consistent with a stellar model having an effective temperature of 30,000 K, reddened by E(B-V) = 0.3, and characterized by the average far-<span class="hlt">ultraviolet</span> extinction curve of Bless and Savage (1972). However, the absolute intensity of the far-<span class="hlt">ultraviolet</span> spectrum of the associations NGC 2050 and 2055 seems somewhat too <span class="hlt">bright</span> in comparison with ground-based photometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020081264&hterms=ultraviolet+astronomy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020081264&hterms=ultraviolet+astronomy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">Far <span class="hlt">Ultraviolet</span> Astronomy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sonneborn, George; Rabin, Douglas M. (Technical Monitor)</p> <p>2002-01-01</p> <p>The Far <span class="hlt">Ultraviolet</span> Spectroscopic Explorer (FUSE) is studying a wide range of astronomical problems in the 905-1187 Angstrom wavelength region through the use of high resolution spectroscopy. The FUSE bandpass forms a nearly optimal complement to the spectral coverage provided by the Hubble Space Telescope (HST), which extends down to approximately 1170 Angstroms. The photoionization threshold of atomic hydrogen (911 Angstroms) sets a natural short-wavelength limit for the FUV. FUSE was launched in June 1999 from Cape Canaveral, Florida, on a Delta II rocket into a 768 km circular orbit. Scientific observations started later that year. This spectral region is extremely rich in spectral diagnostics of astrophysical gases over a wide range of temperatures (100 K to over 10 million K). Important strong spectral lines in this wavelength range include those of neutral hydrogen, deuterium, nitrogen, oxygen, and argon (H I, D I, N I, O I, and Ar I), molecular hydrogen (H2), five-times ionized oxygen (O VI), and several ionization states of sulfur (S III - S VI). These elements are essential for understanding the origin and evolution of the chemical elements, the formation of stars and our Solar System, and the structure of galaxies, including our Milky Way. FUSE is one of NASA's Explorer missions and a cooperative project of NASA and the space agencies of Canada and France. These missions are smaller, more scientifically focused missions than the larger observatories, like Hubble and Chandra. FUSE was designed, built and operated for NASA by the Department of Physics and Astronomy at Johns Hopkins University. Hundreds of astronomers world-wide are using FUSE for a wide range of scientific research. Some of the important scientific discoveries from the first two years of the mission are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004ApJ...615L.109O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004ApJ...615L.109O"><span id="translatedtitle">Properties of Molecular Gas in Massive Low Surface <span class="hlt">Brightness</span> Galaxies, Including New 12CO Observations of Three Malin 1 ``Cousins''</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Neil, K.; Schinnerer, E.</p> <p>2004-11-01</p> <p>To date, the only low surface <span class="hlt">brightness</span> (LSB) galaxies that have been detected in CO are the massive LSB (MLSB) galaxies. In 2003, O'Neil, Schinnerer, & Hofner hypothesized that it is the prominent bulge component in MLSB galaxies, not present in less massive LSB galaxies, that gives rise to the detectable quantities of CO gas. To test this hypothesis, we have used the IRAM 30 m telescope to obtain three new, deep CO J(1-0) and J(2-1) observations of MLSB galaxies. Two of the three galaxies observed were detected in CO-one in the J(1-0) line and the other in both the J(1-0) and J(2-1) lines-bringing the total number of MLSB galaxies with CO detections to five, out of a total of nine MLSB galaxies observed at CO to date. The third object had no detection to 2 mK at CO J(1-0). Comparing all MLSB galaxy CO results with surveys of high surface <span class="hlt">brightness</span> galaxies, we find that the MLSB galaxies' MH2 and MH2/MHI values fall within the ranges typically found for high surface <span class="hlt">brightness</span> objects, <span class="hlt">albeit</span> at the low end of the distribution, with the two MLSB galaxies detected at CO in this survey having the highest MH2/MHI values yet measured for any LSB system, by factors of 2-3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24398523','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24398523"><span id="translatedtitle">Cortical <span class="hlt">brightness</span> adaptation when darkness and <span class="hlt">brightness</span> produce different dynamical states in the visual cortex.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xing, Dajun; Yeh, Chun-I; Gordon, James; Shapley, Robert M</p> <p>2014-01-21</p> <p>Darkness and <span class="hlt">brightness</span> are very different perceptually. To understand the neural basis for the visual difference, we studied the dynamical states of populations of neurons in macaque primary visual cortex when a spatially uniform area (8° × 8°) of the visual field alternated between black and white. Darkness evoked sustained nerve-impulse spiking in primary visual cortex neurons, but <span class="hlt">bright</span> stimuli evoked only a transient response. A peak in the local field potential (LFP) γ band (30-80 Hz) occurred during darkness; white-induced LFP fluctuations were of lower amplitude, peaking at 25 Hz. However, the sustained response to white in the evoked LFP was larger than for black. Together with the results on spiking, the LFP results imply that, throughout the stimulus period, <span class="hlt">bright</span> fields evoked strong net sustained inhibition. Such cortical <span class="hlt">brightness</span> adaptation can explain many perceptual phenomena: interocular speeding up of dark adaptation, tonic interocular suppression, and interocular masking. PMID:24398523</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20090017530&hterms=ultraviolet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dultraviolet','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20090017530&hterms=ultraviolet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dultraviolet"><span id="translatedtitle">Future Directions in <span class="hlt">Ultraviolet</span> Spectroscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael</p> <p>2009-01-01</p> <p>The 'Future Directions in <span class="hlt">Ultraviolet</span> Spectroscopy' conference was inspired by the accomplishments of the Far <span class="hlt">Ultraviolet</span> Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-<span class="hlt">ultraviolet</span> universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the <span class="hlt">ultraviolet</span> capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other <span class="hlt">ultraviolet</span> instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7067878','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7067878"><span id="translatedtitle">Harmful effects of <span class="hlt">ultraviolet</span> radiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1989-07-21</p> <p>Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to <span class="hlt">ultraviolet</span> radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, <span class="hlt">ultraviolet</span> radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by <span class="hlt">ultraviolet</span> radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to <span class="hlt">ultraviolet</span> radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to <span class="hlt">ultraviolet</span> radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4216005','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4216005"><span id="translatedtitle">Intermittent Episodes of <span class="hlt">Bright</span> Light Suppress Myopia in the Chicken More than Continuous <span class="hlt">Bright</span> Light</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank</p> <p>2014-01-01</p> <p>Purpose <span class="hlt">Bright</span> light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of <span class="hlt">bright</span> light are the most potent in suppressing deprivation myopia in chickens. Methods Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10∶14 light∶dark cycle. Episodes of <span class="hlt">bright</span> light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant <span class="hlt">bright</span> light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of <span class="hlt">bright</span> light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Results Compared with the reference group, exposure to continuous <span class="hlt">bright</span> light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of <span class="hlt">bright</span> light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1∶1 or 7∶7 minutes of <span class="hlt">bright</span> light enhanced the protective effect against myopia and could fully suppress its development. Conclusions The protective effect of <span class="hlt">bright</span> light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous <span class="hlt">bright</span> light, low frequency cycles of <span class="hlt">bright</span> light (1∶1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27103935','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27103935"><span id="translatedtitle">Circadian Phase-Shifting Effects of <span class="hlt">Bright</span> Light, Exercise, and <span class="hlt">Bright</span> Light + Exercise.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A</p> <p>2016-01-01</p> <p>Limited research has compared the circadian phase-shifting effects of <span class="hlt">bright</span> light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night <span class="hlt">bright</span> light, late night exercise, and late evening <span class="hlt">bright</span> light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) <span class="hlt">bright</span> light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) <span class="hlt">bright</span> light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of <span class="hlt">bright</span> light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following <span class="hlt">bright</span> light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night <span class="hlt">bright</span> light followed by early morning exercise can have an additive circadian phase-shifting effect. PMID:27103935</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4834751','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4834751"><span id="translatedtitle">Circadian Phase-Shifting Effects of <span class="hlt">Bright</span> Light, Exercise, and <span class="hlt">Bright</span> Light + Exercise</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kline, Christopher E.; Elliott, Jeffrey A.; Zielinski, Mark R.; Devlin, Tina M.; Moore, Teresa A.</p> <p>2016-01-01</p> <p>Limited research has compared the circadian phase-shifting effects of <span class="hlt">bright</span> light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night <span class="hlt">bright</span> light, late night exercise, and late evening <span class="hlt">bright</span> light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) <span class="hlt">bright</span> light alone (5,000 lux) from 2210–2340 h, (2) treadmill exercise alone from 2210–2340 h, or (3) <span class="hlt">bright</span> light (2210–2340 h) followed by exercise from 0410–0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of <span class="hlt">bright</span> light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following <span class="hlt">bright</span> light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night <span class="hlt">bright</span> light followed by early morning exercise can have an additive circadian phase-shifting effect. PMID:27103935</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5342501','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5342501"><span id="translatedtitle"><span class="hlt">Ultraviolet</span>-radiation-curable paints</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grosset, A M; Su, W F.A.; Vanderglas, E</p> <p>1981-09-30</p> <p>In product finishing lines, <span class="hlt">ultraviolet</span> radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse <span class="hlt">ultraviolet</span> light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by <span class="hlt">ultraviolet</span> light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860055326&hterms=spectrophotometry+UV&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dspectrophotometry%2BUV','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860055326&hterms=spectrophotometry+UV&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dspectrophotometry%2BUV"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> spectrophotometry of three LINERs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goodrich, R. W.; Keel, W. C.</p> <p>1986-01-01</p> <p>Three galaxies known to be LINERs were observed spectroscopically in the <span class="hlt">ultraviolet</span> in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended <span class="hlt">ultraviolet</span> light profile. Comparison with the optical light profile of NGC 5005 indicates that the <span class="hlt">ultraviolet</span> source is distributed spatially in the same manner as the optical starlight, probably indicating that the <span class="hlt">ultraviolet</span> excess is due to a component of hot stars in the nucleus. These stars contribute detectable absorption features longward of 2500 A; together with optical data, the IUE spectra suggest a burst of star formation about 1 billion yr ago, with a lower rate continuing to produce a few OB stars. In NGC 4579, a point source contributing most of the <span class="hlt">ultraviolet</span> excess is found that is much different than the optical light distribution. Furthermore, the <span class="hlt">ultraviolet</span> to X-ray spectral index in NGC 4579 is 1.4, compatible with the UV to X-ray indices found for samples of Seyfert galaxies. This provides compelling evidence for the detection of the photoionizing continuum in NGC 4579 and draws the research fields of normal galaxies and active galactic nuclei closer together. The emission-line spectrum of NGC 4579 is compared with calculations from a photoionization code, CLOUDY, and several shock models. The photoionization code is found to give superior results, adding to the increasing weight of evidence that the LINER phenomenon is essentially a scaled-down version of the Seyfert phenomenon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006A%26A...454L.119J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006A%26A...454L.119J"><span id="translatedtitle">The <span class="hlt">bright</span> optical flash from GRB 060117</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jelínek, M.; Prouza, M.; Kubánek, P.; Hudec, R.; Nekola, M.; Řídký, J.; Grygar, J.; Boháčová, M.; Castro-Tirado, A. J.; Gorosabel, J.; Hrabovský, M.; Mandát, D.; Nosek, D.; Nožka, L.; Palatka, M.; Pandey, S. B.; Pech, M.; Schovánek, P.; Šmída, R.; Trávníček, P.; de Ugarte Postigo, A.; Vítek, S.</p> <p>2006-08-01</p> <p>We present a discovery and observation of an extraordinarily <span class="hlt">bright</span> prompt optical emission of the GRB 060117 obtained by a wide-field camera atop the robotic telescope FRAM of the Pierre Auger Observatory from 2 to 10 min after the GRB. We found rapid average temporal flux decay of α = -1.7 ± 0.1 and a peak <span class="hlt">brightness</span> R = 10.1 mag. Later observations by other instruments set a strong limit on the optical and radio transient fluxes, unveiling an unexpectedly rapid further decay. We present an interpretation featuring a relatively steep electron-distribution parameter p ≃ 3.0 and providing a straightforward solution for the overall fast decay of this optical transient as a transition between reverse and forward shock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AcPPA.116..772S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AcPPA.116..772S"><span id="translatedtitle">Quantum <span class="hlt">Bright</span> Soliton in a Disorder Potential</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sacha, K.; Delande, D.; Zakrzewski, J.</p> <p>2009-11-01</p> <p>At very low temperature, a quasi-one-dimensional ensemble of atoms with attractive interactions tend to form a <span class="hlt">bright</span> soliton. When exposed to a sufficiently weak external potential, the shape of the soliton is not modified, but its external motion is affected. We develop in detail the Bogoliubov approach for the problem, treating, in a non-perturbative way, the motion of the center of mass of the soliton. Quantization of this motion allows us to discuss its long time properties. In particular, in the presence of a disordered potential, the quantum motion of the center of mass of a <span class="hlt">bright</span> soliton may exhibit Anderson localization, on a localization length which may be much larger than the soliton size and could be observed experimentally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016CNSNS..36..366V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016CNSNS..36..366V&link_type=ABSTRACT"><span id="translatedtitle">N-<span class="hlt">bright-bright</span> and N-dark-dark solitons of the coupled generalized nonlinear Schrödinger equations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vishnu Priya, N.; Senthilvelan, M.</p> <p>2016-07-01</p> <p>We construct N-<span class="hlt">bright-bright</span> and N-dark-dark soliton solutions of an integrable two coupled generalized nonlinear Schrödinger (CGNLS) equation for arbitrary values of system parameters. These solutions are more general than the reported one. While the <span class="hlt">bright-bright</span> solitons are captured in the focusing regime of CGNLS equation, the dark-dark soliton solutions are identified in the defocusing regime. We present N-<span class="hlt">bright-bright</span> solitons in the Gram determinant forms and prove that these determinant forms satisfy the Hirota bilinear equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002804','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002804"><span id="translatedtitle">Spectral Characterization of <span class="hlt">Bright</span> Materials on Vesta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Capaccioni, Fabrizio; DeSanctis, M. C.; Ammannito, E.; Li, Jian-Yang; Longobardo, A.; Mittlefehldt, David W.; Palomba, E.; Pieters, C. M.; Schroeder, S. E.; Tosi, F.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.</p> <p>2012-01-01</p> <p>The surface of Vesta, as observed by the camera and imaging spectrometer onboard the Dawn spacecraft, displays large surface diversity in terms of its geology and mineralogy with noticeably dark and <span class="hlt">bright</span> areas on the surface often associated with various geological features and showing remarkably different forms. Here we report our initial attempt to spectrally characterize the areas that are distinctively brighter than their surroundings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890000820','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890000820"><span id="translatedtitle">Australia 31-GHz <span class="hlt">brightness</span> temperature exceedance statistics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gary, B. L.</p> <p>1988-01-01</p> <p>Water vapor radiometer measurements were made at DSS 43 during an 18 month period. <span class="hlt">Brightness</span> temperatures at 31 GHz were subjected to a statistical analysis which included correction for the effects of occasional water on the radiometer radome. An exceedance plot was constructed, and the 1 percent exceedance statistics occurs at 120 K. The 5 percent exceedance statistics occurs at 70 K, compared with 75 K in Spain. These values are valid for all of the three month groupings that were studied.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1240069-nonlinear-brightness-optimization-compton-scattering','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1240069-nonlinear-brightness-optimization-compton-scattering"><span id="translatedtitle">Nonlinear <span class="hlt">Brightness</span> Optimization in Compton Scattering</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Hartemann, Fred V.; Wu, Sheldon S. Q.</p> <p>2013-07-26</p> <p>In Compton scattering light sources, a laser pulse is scattered by a relativistic electron beam to generate tunable x and gamma rays. Because of the inhomogeneous nature of the incident radiation, the relativistic Lorentz boost of the electrons is modulated by the ponderomotive force during the interaction, leading to intrinsic spectral broadening and <span class="hlt">brightness</span> limitations. We discuss these effects, along with an optimization strategy to properly balance the laser bandwidth, diffraction, and nonlinear ponderomotive force.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23931374','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23931374"><span id="translatedtitle">Nonlinear <span class="hlt">brightness</span> optimization in compton scattering.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hartemann, Fred V; Wu, Sheldon S Q</p> <p>2013-07-26</p> <p>In Compton scattering light sources, a laser pulse is scattered by a relativistic electron beam to generate tunable x and gamma rays. Because of the inhomogeneous nature of the incident radiation, the relativistic Lorentz boost of the electrons is modulated by the ponderomotive force during the interaction, leading to intrinsic spectral broadening and <span class="hlt">brightness</span> limitations. These effects are discussed, along with an optimization strategy to properly balance the laser bandwidth, diffraction, and nonlinear ponderomotive force. PMID:23931374</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760019131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760019131"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> corona detection sensor study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schmitt, R. J.; MATHERN</p> <p>1976-01-01</p> <p>The feasibility of detecting electrical corona discharge phenomena in a space simulation chamber via emission of <span class="hlt">ultraviolet</span> light was evaluated. A corona simulator, with a hemispherically capped point to plane electrode geometry, was used to generate corona glows over a wide range of pressure, voltage, current, electrode gap length and electrode point radius. Several <span class="hlt">ultraviolet</span> detectors, including a copper cathode gas discharge tube and a UV enhanced silicon photodiode detector, were evaluated in the course of the spectral intensity measurements. The performance of both silicon target vidicons and silicon intensified target vidicons was evaluated analytically using the data generated by the spectroradiometer scans and the performance data supplied by the manufacturers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22722206A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22722206A"><span id="translatedtitle">The <span class="hlt">Ultraviolet</span> Spectroscopic Legacy of HST</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ayres, Thomas R.</p> <p>2016-01-01</p> <p>Hubble Space Telescope has been a spectacularly successful platform for spectroscopy in the diagnostic-rich far-<span class="hlt">ultraviolet</span> (FUV: 120-170 nm) and near-<span class="hlt">ultraviolet</span> (NUV: 170-310 nm) regions. HST has hosted four generations of UV instruments, beginning with Faint Object Spectrograph (FOS) and Goddard High-Resolution Spectrograph (GHRS) in the original 1990 payload, followed by Space Telescope Imaging Spectrograph (STIS) in 1997, and more recently Cosmic Origins Spectrograph (COS) as part of Servicing Mission 4 in 2009. The latter two instruments have contributed by far the lion's share of HST's spectroscopic archive: STIS, because of its longevity (thirteen years in operation so far, although with a hiatus between 2004-2009); and COS because of its high sensitivity, which allows efficient observations, and thus many more targets in a typical GO program. STIS benefits from a compact echelle design, and the sharp stable imaging of HST, to provide high-resolution (3-7 km s-1) spectra of <span class="hlt">bright</span> objects, including stars, nebulae, quasars, novae, and so forth. COS achieves astounding sensitivity in the FUV by a sophisticated design that compensates for the spherical abberation of HST's primary mirror, disperses the target's light, and focuses the spectral image all with just a single optical element. While the spectral resolution of COS (about 18 km s-1) is not as high as that of STIS, it is adequate for diverse investigations, including faint broad-lined AGN at the edge of the Universe, hot stars in nearby galaxies, and magnetically active planet-hosting red dwarfs in the solar neighborhood. Thanks in part to the "UV Initiative" in recent HST proposal cycles, there have been several large efforts involving both STIS and COS, to assemble important spectral collections, including full UV atlases of representative hot and cool stars at high resolution with STIS; long time series of archetype AGN ("reverberation mapping") with COS; and hundreds of sightlines to distant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26881944','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26881944"><span id="translatedtitle"><span class="hlt">Brightness</span> illusion in the guppy (Poecilia reticulata).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Agrillo, Christian; Miletto Petrazzini, Maria Elena; Bisazza, Angelo</p> <p>2016-02-01</p> <p>A long-standing debate surrounds the issue of whether human and nonhuman species share similar perceptual mechanisms. One experimental strategy to compare visual perception of vertebrates consists in assessing how animals react in the presence of visual illusions. To date, this methodological approach has been widely used with mammals and birds, while few studies have been reported in distantly related species, such as fish. In the present study we investigated whether fish perceive the <span class="hlt">brightness</span> illusion, a well-known illusion occurring when 2 objects, identical in physical features, appear to be different in <span class="hlt">brightness</span>. Twelve guppies (Poecilia reticulata) were initially trained to discriminate which rectangle was darker or lighter between 2 otherwise identical rectangles. Three different conditions were set up: neutral condition between rectangle and background (same background used for both darker and lighter rectangle); congruent condition (darker rectangle in a darker background and lighter rectangle in a lighter background); and incongruent condition (darker rectangle in a lighter background and lighter rectangle in a darker background). After reaching the learning criterion, guppies were presented with the illusory pattern: 2 identical rectangles inserted in 2 different backgrounds. Guppies previously trained to select the darker rectangle showed a significant choice of the rectangle that appears to be darker by human observers (and vice versa). The human-like performance exhibited in the presence of the illusory pattern suggests the existence of similar perceptual mechanisms between humans and fish to elaborate the <span class="hlt">brightness</span> of objects. PMID:26881944</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22265992','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22265992"><span id="translatedtitle">Search for <span class="hlt">bright</span> stars with infrared excess</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Raharto, Moedji</p> <p>2014-03-24</p> <p><span class="hlt">Bright</span> stars, stars with visual magnitude smaller than 6.5, can be studied using small telescope. In general, if stars are assumed as black body radiator, then the color in infrared (IR) region is usually equal to zero. Infrared data from IRAS observations at 12 and 25μm (micron) with good flux quality are used to search for <span class="hlt">bright</span> stars (from <span class="hlt">Bright</span> Stars Catalogues) with infrared excess. In magnitude scale, stars with IR excess is defined as stars with IR color m{sub 12}−m{sub 25}>0; where m{sub 12}−m{sub 25} = −2.5log(F{sub 12}/F{sub 25})+1.56, where F{sub 12} and F{sub 25} are flux density in Jansky at 12 and 25μm, respectively. Stars with similar spectral type are expected to have similar color. The existence of infrared excess in the same spectral type indicates the existence of circum-stellar dust, the origin of which is probably due to the remnant of pre main-sequence evolution during star formation or post AGB evolution or due to physical process such as the rotation of those stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998taas....2..889H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998taas....2..889H"><span id="translatedtitle"><span class="hlt">Brightness</span> Changes in Sun-like Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henry, Stephen M.; Henry, Gregory W.</p> <p>1998-02-01</p> <p>Does the Sun's energy output vary with time? Are observable climatic changes on the earth caused by changes in the Sun? Can we gain greater insight into this relation-ship by studying other stars with properties similar to the Sun's? In recent years, satellite observations have shown that the solar irradiance varies in phase with the 1 l-year sunspot cycle. The Sun is brighter by about O.l% at the peak of the sunspot cycle when solar magnetic activity is at its maximum. Over longer intervals, changes in the cart h's climate and solar magnetic activity seem to be correlated. We are using automatic photoelectric telescopes to measure <span class="hlt">brightness</span> changes in a sample of 150 Sun-like stars. Lowell Observatory astronomers have also observed about 30 of these same stars with a manual telescope in a program that began 10 years before ours. Since these two data sets were acquired with different instruments and so have significant systematic differences, we developed software to combine them accurately and, therefore, extend our observational time coverage. We show sample results of <span class="hlt">brightness</span> variations over 14 years in several Sun-like stars with different ages. Longitudinal studies like these, combined with cross-sectional studies of the larger sample of stars, may eventually allow us to infer with confidence the Sun's long-term <span class="hlt">brightness</span> history and its impact on the earth's climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA01515&hterms=Gardening&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGardening','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA01515&hterms=Gardening&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGardening"><span id="translatedtitle"><span class="hlt">Bright</span> Ray Craters in Ganymede's Northern Hemisphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1979-01-01</p> <p>GANYMEDE COLOR PHOTOS: This color picture as acquired by Voyager 1 during its approach to Ganymede on Monday afternoon (the 5th of March). At ranges between about 230 to 250 thousand km. The images show detail on the surface with a resolution of four and a half km. This picture is of a region in the northern hemisphere near the terminator. It shows a variety of impact structures, including both razed and unrazed craters, and the odd, groove-like structures discovered by Voyager in the lighter regions. The most striking features are the <span class="hlt">bright</span> ray craters which have a distinctly 'bluer' color appearing white against the redder background. Ganymede's surface is known to contain large amounts of surface ice and it appears that these relatively young craters have spread <span class="hlt">bright</span> fresh ice materials over the surface. Likewise, the lighter color and reflectivity of the grooved areas suggests that here, too, there is cleaner ice. We see ray craters with all sizes of ray patterns, ranging from extensive systems of the crater in the southern part of this picture, which has rays at least 300-500 kilometers long, down to craters which have only faint remnants of <span class="hlt">bright</span> ejects patterns (such as several of the craters in the southern half of PIA01516; P21262). This variation suggests that, as on the Moon, there are processes which act to darken ray material, probably 'gardening' by micrometeoroid impact. JPL manages and controls the Voyager project for NASA's Office of Space Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2860692','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2860692"><span id="translatedtitle"><span class="hlt">Bright</span> light activates a trigeminal nociceptive pathway</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Okamoto, Keiichiro; Tashiro, Akimasa; Chang, Zheng; Bereiter, David A.</p> <p>2010-01-01</p> <p><span class="hlt">Bright</span> light can cause ocular discomfort and/or pain; however, the mechanism linking luminance to trigeminal nerve activity is not known. In this study we identify a novel reflex circuit necessary for <span class="hlt">bright</span> light to excite nociceptive neurons in superficial laminae of trigeminal subnucleus caudalis (Vc/C1). Vc/C1 neurons encoded light intensity and displayed a long delay (>10 s) for activation. Microinjection of lidocaine into the eye or trigeminal root ganglion (TRG) inhibited light responses completely, whereas topical application onto the ocular surface had no effect. These findings indicated that light-evoked Vc/C1 activity was mediated by an intraocular mechanism and transmission through the TRG. Disrupting local vasomotor activity by intraocular microinjection of the vasoconstrictive agents, norepinephrine or phenylephrine, blocked light-evoked neural activity, whereas ocular surface or intra-TRG microinjection of norepinephrine had no effect. Pupillary muscle activity did not contribute since light-evoked responses were not altered by atropine. Microinjection of lidocaine into the superior salivatory nucleus diminished light-evoked Vc/C1 activity and lacrimation suggesting that increased parasympathetic outflow was critical for light-evoked responses. The reflex circuit also required input through accessory visual pathways since both Vc/C1 activity and lacrimation were prevented by local blockade of the olivary pretectal nucleus. These findings support the hypothesis that <span class="hlt">bright</span> light activates trigeminal nerve activity through an intraocular mechanism driven by a luminance-responsive circuit and increased parasympathetic outflow to the eye. PMID:20206444</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA01058&hterms=Dark+web&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDark%2Bweb','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA01058&hterms=Dark+web&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDark%2Bweb"><span id="translatedtitle"><span class="hlt">Bright</span> and Dark Slopes on Ganymede</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>Ridges on the edge of Ganymede's north polar cap show <span class="hlt">bright</span> east-facing slopes and dark west-facing slopes with troughs of darker material below the larger ridges. North is to the top. The <span class="hlt">bright</span> slopes may be due to grain size differences, differences in composition between the original surface and the underlying material, frost deposition, or illumination effects. The large 2.4 kilometer (1.5 mile) diameter crater in this image shows frost deposits located on the north-facing rim slope, away from the sun. A smaller 675 meter (2200 foot) diameter crater in the center of the image is surrounded by a <span class="hlt">bright</span> deposit which may be ejecta from the impact. Ejecta deposits such as this are uncommon for small craters on Ganymede. This image measures 18 by 19 kilometers (11 by 12 miles) and has a resolution of 45 meters (148 feet) per pixel. NASA's Galileo spacecraft obtained this image on September 6, 1996 during its second orbit around Jupiter.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).<p/>This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/800059','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/800059"><span id="translatedtitle">Measured Properties of the DUVFEL High <span class="hlt">Brightness</span>, Ultrashort Electron Beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Emma, Paul J</p> <p>2002-08-20</p> <p>The DUVFEL electron linac is designed to produce sub-picosecond, high <span class="hlt">brightness</span> electron bunches to drive an <span class="hlt">ultraviolet</span> FEL. The accelerator consists of a 1.6 cell S-band photoinjector, variable pulse length Ti:Sapp laser, 4 SLAC-type S-band accelerating sections, and 4-dipole chicane bunch compressor. In preparation for FEL operation, the compressed electron beam has been fully characterized. Measurement of the beam parameters and simulation of the beam are presented. The properties of the laser and photoinjector are summarized in Table 1. In typical running, 10 mJ of IR light is produced by the Spectraphyics Tsunami Ti:Sapphire oscillator and TSA50 amplifier, which is frequency tripled to produce 450 uJ of UV light. After spatial filtering and aperturing of the gaussian mode to produce a nearly uniform laser spot, about 200-300 uJ is delivered to the cathode. This produces 300 pC of charge at the accelerating phase of 30 degrees. The RF cavity is a Gun IV [1] with copper cathode that has been modified for better performance [2]. In principle, the laser pulse length may be adjusted from 100 fs to 10 ps, however there are practical limitations on the range of adjustment due to dispersion characteristics and efficiency of the BBO crystals. The thickness of the harmonic crystals is optimized for pulse lengths from 1-5 ps. Within this range of pulse lengths there is evidence [3] of variations in the time profile of the UV light that are sensitive to the phase-matching angle of the crystal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PASA...29..489F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PASA...29..489F"><span id="translatedtitle">Distance Measurements and Stellar Population Properties via Surface <span class="hlt">Brightness</span> Fluctuations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fritz, Alexander</p> <p>2012-05-01</p> <p>Surface <span class="hlt">Brightness</span> Fluctuations (SBFs) are one of the most powerful techniques to measure the distance and to constrain the unresolved stellar content of extragalactic systems. For a given bandpass, the absolute SBF magnitude AS11076_IE1.gif depends on the properties of the underlying stellar population. Multi-band SBFs allow scientists to probe different stages of the stellar evolution: <span class="hlt">ultraviolet</span> and blue wavelength band SBFs are sensitive to the evolution of stars within the hot horizontal branch and post-asymptotic giant branch phases, whereas optical SBF magnitudes explore the stars within the red giant branch and horizontal branch regimes. Near- and far-infrared SBF luminosities probe the important stellar evolution stage within the asymptotic giant branch and thermally pulsating asymptotic giant branch phases. Since the first successful application by Tonry and Schneider, a multiplicity of works have used this method to expand the distance scale up to 150Mpc and beyond. This article gives a historical background of distance measurements, reviews the basic concepts of the SBF technique, presents a broad sample of investigations and discusses possible selection effects, biases, and limitations of the method. In particular, exciting new developments and improvements in the field of stellar population synthesis are discussed that are essential to understand the physics and properties of the populations in unresolved stellar systems. Further, promising future directions of the SBF technique are presented. With new upcoming space-based satellites such as Gaia, the SBF method will remain as one of the most important tools to derive distances to galaxies with unprecedented accuracy and to give detailed insights into the stellar content of globular clusters and galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA10140&hterms=PSP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DPSP','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA10140&hterms=PSP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DPSP"><span id="translatedtitle">Active Processes: <span class="hlt">Bright</span> Streaks and Dark Fans</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p><p/> [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2 <p/> In a region of the south pole known informally as 'Ithaca' numerous fans of dark frost form every spring. HiRISE collected a time lapse series of these images, starting at L<sub>s</sub> = 185 and culminating at L<sub>s</sub> = 294. 'L<sub>s</sub>' is the way we measure time on Mars: at L<sub>s</sub> = 180 the sun passes the equator on its way south; at L<sub>s</sub> = 270 it reaches its maximum subsolar latitude and summer begins. <p/> In the earliest image (figure 1) fans are dark, but small narrow <span class="hlt">bright</span> streaks can be detected. In the next image (figure 2), acquired at L<sub>s</sub> = 187, just 106 hours later, dramatic differences are apparent. The dark fans are larger and the <span class="hlt">bright</span> fans are more pronounced and easily detectable. The third image in the sequence shows no <span class="hlt">bright</span> fans at all. <p/> We believe that the <span class="hlt">bright</span> streaks are fine frost condensed from the gas exiting the vent. The conditions must be just right for the <span class="hlt">bright</span> frost to condense. <p/> Observation Geometry Image PSP_002622_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 16-Feb-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 246.9 km (154.3 miles). At this distance the image scale is 49.4 cm/pixel (with 2 x 2 binning) so objects 148 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 05:46 PM and the scene is illuminated from the west with a solar incidence angle of 88 degrees, thus the sun was about 2 degrees above the horizon. At a solar longitude of 185.1 degrees, the season on Mars is Northern Autumn.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014BaltA..23..245L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014BaltA..23..245L"><span id="translatedtitle">Catalogue of <span class="hlt">bright</span> IDS stars with extensive cross-identifications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lipaeva, N. A.; Sementsov, V. N.; Malkov, O. Yu.</p> <p></p> <p>A new catalogue of <span class="hlt">bright</span> binary stars is presented. The catalogue1 includes <span class="hlt">bright</span> IDS systems and <span class="hlt">bright</span> spectroscopic binaries. Besides IDS data (coordinates, relative positions, magnitudes and spectral classification), the catalogue contains extensive cross-identification and comments for 27452 systems. The catalogue is complete to the 9th mag, but also contains stars down to about 16th mag.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...814...95F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...814...95F"><span id="translatedtitle">An Increasing Stellar Baryon Fraction in <span class="hlt">Bright</span> Galaxies at High Redshift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finkelstein, Steven L.; Song, Mimi; Behroozi, Peter; Somerville, Rachel S.; Papovich, Casey; Milosavljević, Miloš; Dekel, Avishai; Narayanan, Desika; Ashby, Matthew L. N.; Cooray, Asantha; Fazio, Giovanni G.; Ferguson, Henry C.; Koekemoer, Anton M.; Salmon, Brett; Willner, S. P.</p> <p>2015-12-01</p> <p>Recent observations have shown that the characteristic luminosity of the rest-frame <span class="hlt">ultraviolet</span> (UV) luminosity function does not significantly evolve at 4 < z < 7 and is approximately {M}{UV}*˜ -21. We investigate this apparent non-evolution by examining a sample of 173 <span class="hlt">bright</span>, MUV < -21 galaxies at z = 4-7, analyzing their stellar populations and host halo masses. Including deep Spitzer/IRAC imaging to constrain the rest-frame optical light, we find that {M}{UV}* galaxies at z = 4-7 have similar stellar masses of log(M/M⊙) = 9.6-9.9 and are thus relatively massive for these high redshifts. However, <span class="hlt">bright</span> galaxies at z = 4-7 are less massive and have younger inferred ages than similarly <span class="hlt">bright</span> galaxies at z = 2-3, even though the two populations have similar star formation rates and levels of dust attenuation for a fixed dust-attenuation curve. Matching the abundances of these <span class="hlt">bright</span> z = 4-7 galaxies to halo mass functions from the Bolshoi ΛCDM simulation implies that the typical halo masses in ˜ {M}{{UV}}* galaxies decrease from log(Mh/M⊙) = 11.9 at z = 4 to log(Mh/M⊙) = 11.4 at z = 7. Thus, although we are studying galaxies at a similar stellar mass across multiple redshifts, these galaxies live in lower mass halos at higher redshift. The stellar baryon fraction in ˜ {M}{{UV}}* galaxies in units of the cosmic mean Ωb/Ωm rises from 5.1% at z = 4 to 11.7% at z = 7; this evolution is significant at the ˜3σ level. This rise does not agree with simple expectations of how galaxies grow, and implies that some effect, perhaps a diminishing efficiency of feedback, is allowing a higher fraction of available baryons to be converted into stars at high redshifts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ultraviolet&pg=7&id=EJ300481','ERIC'); return false;" href="http://eric.ed.gov/?q=ultraviolet&pg=7&id=EJ300481"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> and Light Absorption Spectrometry.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hargis, L. G.; Howell, J. A.</p> <p>1984-01-01</p> <p>Reviews developments in <span class="hlt">ultraviolet</span> and light absorption spectrometry from December 1981 through November 1983, focusing on the chemistry involved in developing suitable reagents, absorbing systems, and methods of determination, and on physical aspects of the procedures. Includes lists of spectrophotometric methods for metals, non-metals, and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810059463&hterms=intercombination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dintercombination','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810059463&hterms=intercombination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dintercombination"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> observations of the Io torus from the IUE observatory</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moos, H. W.; Clarke, J. T.</p> <p>1981-01-01</p> <p>The short wavelength spectrograph on the International <span class="hlt">Ultraviolet</span> Explorer (IUE) has been used to obtain 11 A resolution spectra of the Io torus from 1175-1950 A. The four spectra, obtained in the springs of 1979 and 1980, show emissions (about 40R) of S II A1256A and S III A1199A. An unidentified feature is also present at 1729 A; a tentative identification as an intercombination line of S III is proposed. Weak features, probably due to O III A1664A and S IV A1406A, appear in some of the spectra. Abundances of the ions are determined from the <span class="hlt">brightnesses</span> of the observed features. Upper limits are also set for the abundances of a number of ionic and neutral species. An observation of Io itself does not show any additional or enhanced spectral features, permitting upper limits to be set on the injection rate for a number of species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780021057','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780021057"><span id="translatedtitle">Unusual satellite data: A black hole?. [International <span class="hlt">Ultraviolet</span> Explorer observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1978-01-01</p> <p>Data obtained by the NASA-launched European Space Agency's International <span class="hlt">Ultraviolet</span> Explorer satellite suggests the possibility of a massive black hole at the center of some globular clusters (star groups) in our galaxy. Six of these clusters, three of them X-ray sources, were closely examined. Onboard short wavelength UV instrumentation penetrated the background denseness of the clusters 15,000 light years away where radiation, probably from a group of 10 to 20 <span class="hlt">bright</span> blue stars orbiting the core, was observed. The stars may well be orbiting a massive black hole the size of 1,000 solar systems. The existence of the black hole is uncertain. The dynamics of the stars must be studied first to determine how they rotate in relation to the center of the million-star cluster. This may better indicate what provides the necessary gravitational pull that holds them in orbit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title21-vol8/pdf/CFR-2011-title21-vol8-sec872-6350.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title21-vol8/pdf/CFR-2011-title21-vol8-sec872-6350.pdf"><span id="translatedtitle">21 CFR 872.6350 - <span class="hlt">Ultraviolet</span> detector.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-04-01</p> <p>... 21 Food and Drugs 8 2011-04-01 2011-04-01 false <span class="hlt">Ultraviolet</span> detector. 872.6350 Section 872.6350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... An <span class="hlt">ultraviolet</span> detector is a device intended to provide a source of <span class="hlt">ultraviolet</span> light which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title21-vol8/pdf/CFR-2014-title21-vol8-sec872-6350.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title21-vol8/pdf/CFR-2014-title21-vol8-sec872-6350.pdf"><span id="translatedtitle">21 CFR 872.6350 - <span class="hlt">Ultraviolet</span> detector.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-04-01</p> <p>... 21 Food and Drugs 8 2014-04-01 2014-04-01 false <span class="hlt">Ultraviolet</span> detector. 872.6350 Section 872.6350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... An <span class="hlt">ultraviolet</span> detector is a device intended to provide a source of <span class="hlt">ultraviolet</span> light which is...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=GL-2002-001248&hterms=light+color&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlight%2Bcolor','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=GL-2002-001248&hterms=light+color&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlight%2Bcolor"><span id="translatedtitle">Saturn's E Ring in <span class="hlt">Ultraviolet</span> Light</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>Visible from Earth only at times of ring plane crossing, Saturn's tenuous E Ring was discovered during the 1966 crossings and imaged again in 1980. From these observations, its color is known to be distinctively blue. The E Ring was captured in <span class="hlt">ultraviolet</span> light for the first time in this image taken with HST's Wide Field and Planetary Camera on 9 August 1995. Five individual images taken with a broadband 3000 A filter were combined, amounting to a total exposure time of 2200 sec. Shorter exposure images were also obtained with blue, red and infrared filters in order to characterize the ring's color. The peak <span class="hlt">brightness</span> of the E Ring occurs at 3.9 Saturn radii (235,000 km), coinciding with the orbit of Enceladus. In the HST images it can be traced out to a maximum distance of approximately 8 Rs (480,000 km). The vertical thickness of the ring, on the other hand, is smallest at Enceladus' orbit, with the ring puffing up noticeably at larger distances to 15,000 km or more thick. Also visible in this image, between the E Ring and the overexposed outermost part of the main rings near the lower edge of the frame, is the tenuous, thin, 6000 km-wide G Ring at 2.8 Rs (170,000 km). This is among the first earth-based observations of the G Ring, which was discovered by the Pioneer 11 spacecraft in 1979. Noticeably thinner than the E Ring and more neutral in color, the G Ring is thought to be composed of larger, macroscopic particles, and to pose a significant hazard to spacecraft. The faint diagonal band in the lower right part of the image is due to diffracted light from the heavily-overexposed planet. Credit: Phil Nicholson (Cornell University), Mark Showalter (NASA-Ames/Stanford) and NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11886503','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11886503"><span id="translatedtitle">Regulation of keratin expression by <span class="hlt">ultraviolet</span> radiation: differential and specific effects of <span class="hlt">ultraviolet</span> B and <span class="hlt">ultraviolet</span> a exposure.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bernerd, F; Del Bino, S; Asselineau, D</p> <p>2001-12-01</p> <p>Skin, the most superficial tissue of our body, is the first target of environmental stimuli, among which is solar <span class="hlt">ultraviolet</span> radiation. Very little is known about the regulation of keratin gene expression by <span class="hlt">ultraviolet</span> radiation, however, although (i) it is well established that <span class="hlt">ultraviolet</span> exposure is involved in skin cancers and photoaging and (ii) keratins represent the major epidermal proteins. The aim of this study was to analyze the regulation of human keratin gene expression under <span class="hlt">ultraviolet</span> B (290-320 nm) or <span class="hlt">ultraviolet</span> A (320-400 nm) irradiation using a panel of constructs comprising different human keratin promoters cloned upstream of a chloramphenicol acetyl transferase reporter gene and transfected into normal epidermal keratinocytes. By this approach, we demonstrated that <span class="hlt">ultraviolet</span> B upregulated the transcription of keratin 19 gene and to a lesser extent the keratin 6, keratin 5, and keratin 14 genes. The DNA sequence responsible for keratin 19 induction was localized between -130 and +1. In contrast to <span class="hlt">ultraviolet</span> B, <span class="hlt">ultraviolet</span> A irradiation induced only an increase in keratin 17, showing a differential gene regulation between these two <span class="hlt">ultraviolet</span> ranges. The induction of keratin 19 was confirmed by studying the endogenous protein in keratinocytes in classical cultures as well as in skin reconstructed in vitro and normal human skin. These data show for the first time that keratin gene expression is regulated by <span class="hlt">ultraviolet</span> radiation at the transcriptional level with a specificity regarding the <span class="hlt">ultraviolet</span> domain of solar light. PMID:11886503</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810015449','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810015449"><span id="translatedtitle">Documentation for the machine-readable version of an atlas of <span class="hlt">ultraviolet</span> stellar spectra and a second atlas of <span class="hlt">ultraviolet</span> stellar spectra from OAO 2 observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Warren, W. H., Jr.; Sheridan, W. T.</p> <p>1980-01-01</p> <p>The magnetic tape version of the Orbiting Astronomical Observatory 2 atlases of <span class="hlt">ultraviolet</span> stellar spectra is described. The first file of the tape contains <span class="hlt">ultraviolet</span> stellar fluxes for 164 <span class="hlt">bright</span> stars in lambda the spectral region 1200 to 1300 A with resolutions of 22 A in the region from 3600 to 1850 A and 12 A in the region from 1850 to 1160 A. Files two and three contain spectra for 132 stars in the region lamba 1200 to 1850 A and 34 stars in the lambda region 1800 to 3600 A, respectively, with resolutions as stated above. The monochromatic flux is given in units of ergs cm(-2)s(-1) (-1) for all data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.9401B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.9401B"><span id="translatedtitle">How <span class="hlt">bright</span> is the Io UV footprint?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bonfond, Bertrand; Grodent, Denis; Gérard, Jean-Claude; Radioti, Aikaterini; Hess, Sébastien</p> <p>2010-05-01</p> <p>The electro-magnetic interaction between Io and the Jovian magnetosphere generates a perturbation in the magnetospheric plasma which propagates along the magnetic field lines and creates auroral footprint emissions in both hemispheres. Recent results showed that this footprint is formed of several spots and an extended tail. Each feature is suggested to correspond to a different step in the propagation of the perturbation and in the electron energization processes. The present study focuses on the variations of the spots' <span class="hlt">brightness</span> at different timescales from minutes to years through the rotation period of Jupiter. It relies on FUV images acquired with the STIS and ACS instruments onboard the Hubble Space Telescope. Since the footprint is composed of several localized features, a good understanding of the emission region geometry is critical to derive the actual vertical <span class="hlt">brightness</span> and thus the precipitated energy flux. We developed a 3D emission model in order to assess as precisely as possible the respective contribution of each individual feature and to correctly estimate the precipitating energy flux. As far as the <span class="hlt">brightness</span> variations on timescales of minutes are concerned, we will present results from the high time resolution campaign executed during summer 2009. On timescale of several hours, we will show that the variation of the emitted power as a function of the location of Io in the plasma torus suggests that the Jovian surface magnetic field strength is an important controlling parameter. Finally, the measured precipitated power and particle fluxes will be discussed in comparison with recent simulations considering both Alfvén waves filamentation and electron acceleration when the Alfvén waves become inertial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA01179&hterms=Dark+web&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDark%2Bweb','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA01179&hterms=Dark+web&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDark%2Bweb"><span id="translatedtitle">Dark and <span class="hlt">Bright</span> Ridges on Europa</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1998-01-01</p> <p>This high-resolution image of Jupiter's moon Europa, taken by NASA's Galileo spacecraft camera, shows dark, relatively smooth region at the lower right hand corner of the image which may be a place where warm ice has welled up from below. The region is approximately 30 square kilometers in area. An isolated <span class="hlt">bright</span> hill stands within it. The image also shows two prominent ridges which have different characteristics; youngest ridge runs from left to top right and is about 5 kilometers in width (about 3.1 miles). The ridge has two <span class="hlt">bright</span>, raised rims and a central valley. The rims of the ridge are rough in texture. The inner and outer walls show <span class="hlt">bright</span> and dark debris streaming downslope, some of it forming broad fans. This ridge overlies and therefore must be younger than a second ridge running from top to bottom on the left side of the image. This dark 2 km wide ridge is relatively flat, and has smaller-scale ridges and troughs along its length.<p/>North is to the top of the picture, and the sun illuminates the surface from the upper left. This image, centered at approximately 14 degrees south latitude and 194 degrees west longitude, covers an area approximately 15 kilometers by 20 kilometers (9 miles by 12 miles). The resolution is 26 meters (85 feet) per picture element. This image was taken on December 16, 1997 at a range of 1300 kilometers (800 miles) by Galileo's solid state imaging system.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).<p/>This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6531354','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6531354"><span id="translatedtitle"><span class="hlt">Bright</span> emission lines in new Seyfert galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Afanasev, V.L.; Denisiuk, E.K.; Lipovetskii, V.A.; Shapovalova, A.I.</p> <p>1983-01-01</p> <p>Observational data are given on <span class="hlt">bright</span> emission lines (H-alpha, H-beta, and forbidden N II, S II, and O III) for 14 recently discovered Seyfert galaxies. The investigated objects can be divided into three groups, which correspond approximately to the first (5 objects), the intermediate (4 objects), and the second (4 objects) Seyfert types. Attention is drawn to the properties of the galaxy Markaryan 1018, which has features of both the first and the second type and is distinguished by the weakness of its emission lines, which is probably due to a gas deficit. 7 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6696813','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6696813"><span id="translatedtitle">Rotation and macroturbulence in <span class="hlt">bright</span> giants</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gray, D.F.; Toner, C.G.</p> <p>1986-11-01</p> <p>Spectral line profiles of 35 F, G, and K <span class="hlt">bright</span> giants were analyzed to obtain rotation rates, v sin i, and macroturbulence dispersion. This sample indicates that rotation rates of cool class II giants is less than 11 km/s, in contrast with some recent periodicity measurements. Macroturbulence dispersion generally increases with effective temperature, but the range of values at a given effective temperature is much larger than seen for lower luminosity classes; this is interpreted in terms of red-giant and blue-loop evolution. No evidence is found for angular momentum dissipation on the first crossing of the H-R diagram. 57 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1224423','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1224423"><span id="translatedtitle">Raman beam combining for laser <span class="hlt">brightness</span> enhancement</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.</p> <p>2015-10-27</p> <p>An optical source capable of enhanced scaling of pulse energy and <span class="hlt">brightness</span> utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910069763&hterms=calculator&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dcalculator','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910069763&hterms=calculator&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dcalculator"><span id="translatedtitle">A model of the <span class="hlt">brightness</span> of moonlight</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krisciunas, Kevin; Schaefer, Bradley E.</p> <p>1991-01-01</p> <p>In this paper, measurements of the sky <span class="hlt">brightness</span> from the 2800-m level of Mauna Kea are reported. In addition, a model is presented for predicting the moonlight as a function of the moon's phase, the zenith distance of the moon, the zenith distance of the sky position, the angular separation of the moon and sky position, and the local extinction coefficient. The model equations can be quickly calculated on a pocket calculator. A comparison of the model with lunar data and with some Russian solar data shows the accuracy of the predictions to range from 8 percent to 23 percent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012MNRAS.426.2819S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MNRAS.426.2819S"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> variability of the helium-peculiar star a Centauri</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sokolov, N. A.</p> <p>2012-11-01</p> <p>The spectrophotometric variability of the classical magnetic chemically peculiar star a Cen in the <span class="hlt">ultraviolet</span> spectral region from 1150 to 3100 Å is investigated. This study is based on archival International <span class="hlt">Ultraviolet</span> Explorer data obtained at various phases of the rotational cycle. The light variations in wavelengths shorter than λ1616 Å are mainly in antiphase to the light variations in the longer-wavelength region. The <span class="hlt">brightness</span> of the star in the spectral region λλ1616-1640 Å is constant over the period of rotation, which means that a so-called 'null wavelength region' exists over these wavelengths. There is also a second 'null wavelength region' in the spectrum of a Cen. According to our investigation, the semi-amplitude of the light variations is practically zero over the period of rotation in the spectral region λλ1244-1343 Å. The exception is the light variation in the depressions at λλ1265 and 1300 Å, which are formed by resonance lines of silicon. However, the fluxes are constant at the cores of some features and in small depressions. An explanation for the light variations of a Cen is flux redistribution through bound-free and bound-bound silicon transitions combined with an inhomogeneous surface distribution of silicon on the stellar surface. The influence of other elements on the flux redistribution is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=387953','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=387953"><span id="translatedtitle">Indirect <span class="hlt">Ultraviolet</span>-Reactivation of Phage λ</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>George, Jacqueline; Devoret, Raymond; Radman, Miroslav</p> <p>1974-01-01</p> <p>When an F- recipient Escherichia coli K12 bacterium receives Hfr or F-lac+ DNA from an <span class="hlt">ultraviolet</span>-irradiated donor, its capacity to promote DNA repair and mutagenesis of <span class="hlt">ultraviolet</span>-damaged phage λ is substantially increased. We call this phenomenon indirect <span class="hlt">ultraviolet</span>-reactivation, since its features are essentially the same as those of <span class="hlt">ultraviolet</span>-reactivation; this repair process occurs in pyrimidine dimer excision-deficient strains and produces clear plaque mutations of the restored phage. Moreover, this process is similar to indirect <span class="hlt">ultraviolet</span>-induction of prophage λ, since it is promoted by conjugation. However, contrarily to indirect induction, it is produced by Hfr donors and occurs in recipients restricting the incoming <span class="hlt">ultraviolet</span>-damaged donor DNA. The occurrence of indirect <span class="hlt">ultraviolet</span>-reactivation provides evidence for the existence in E. coli of an inducible error-prone mechanism for the repair of DNA. PMID:4589889</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Natur.528..237N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Natur.528..237N"><span id="translatedtitle">Sublimation in <span class="hlt">bright</span> spots on (1) Ceres</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nathues, A.; Hoffmann, M.; Schaefer, M.; Le Corre, L.; Reddy, V.; Platz, T.; Cloutis, E. A.; Christensen, U.; Kneissl, T.; Li, J.-Y.; Mengel, K.; Schmedemann, N.; Schaefer, T.; Russell, C. T.; Applin, D. M.; Buczkowski, D. L.; Izawa, M. R. M.; Keller, H. U.; O'Brien, D. P.; Pieters, C. M.; Raymond, C. A.; Ripken, J.; Schenk, P. M.; Schmidt, B. E.; Sierks, H.; Sykes, M. V.; Thangjam, G. S.; Vincent, J.-B.</p> <p>2015-12-01</p> <p>The dwarf planet (1) Ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5, 6, 7) have raised interest in the possible presence of surface ice. Here we report the presence of localized <span class="hlt">bright</span> areas on Ceres from an orbiting imager. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a <span class="hlt">bright</span> pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles may explain this haze. We conclude that Ceres must have accreted material from beyond the ‘snow line’, which is the distance from the Sun at which water molecules condense.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26659183','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26659183"><span id="translatedtitle">Sublimation in <span class="hlt">bright</span> spots on (1) Ceres.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nathues, A; Hoffmann, M; Schaefer, M; Le Corre, L; Reddy, V; Platz, T; Cloutis, E A; Christensen, U; Kneissl, T; Li, J-Y; Mengel, K; Schmedemann, N; Schaefer, T; Russell, C T; Applin, D M; Buczkowski, D L; Izawa, M R M; Keller, H U; O'Brien, D P; Pieters, C M; Raymond, C A; Ripken, J; Schenk, P M; Schmidt, B E; Sierks, H; Sykes, M V; Thangjam, G S; Vincent, J-B</p> <p>2015-12-10</p> <p>The dwarf planet (1) Ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5-7) have raised interest in the possible presence of surface ice. Here we report the presence of localized <span class="hlt">bright</span> areas on Ceres from an orbiting imager. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a <span class="hlt">bright</span> pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles may explain this haze. We conclude that Ceres must have accreted material from beyond the 'snow line', which is the distance from the Sun at which water molecules condense. PMID:26659183</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24350673','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24350673"><span id="translatedtitle">Small <span class="hlt">bright</span> charged colloidal quantum dots.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qin, Wei; Liu, Heng; Guyot-Sionnest, Philippe</p> <p>2014-01-28</p> <p>Using electrochemical charge injection, the fluorescence lifetimes of negatively charged core/shell CdTe/CdSe QDs are measured as a function of core size and shell thickness. It is found that the ensemble negative trion lifetimes reach a maximum (∼4.5 ns) for an intermediate shell thickness. This leads to the smallest particles (∼4.5 nm) with the brightest trion to date. Single dot measurements show that the negative charge suppresses blinking and that the trion can be as <span class="hlt">bright</span> as the exciton at room temperature. In contrast, the biexciton lifetimes remain short and exhibit only a monotonous increase with shell thickness, showing no correlation with the negative trion decays. The suppression of the Auger process in small negatively charged CdTe/CdSe quantum dots is unprecedented and a significant departure from prior results with ultrathick CdSe/CdS core/shell or dot-in-rod structures. The proposed reason for the optimum shell thickness is that the electron-hole overlap is restricted to the CdTe core while the electron is tuned to have zero kinetic energy in the core for that optimum shell thickness. The different trend of the biexciton lifetime is not explained but tentatively attributed to shorter-lived positive trions at smaller sizes. These results improve our understanding of multiexciton recombination in colloidal quantum dots and may lead to the design of <span class="hlt">bright</span> charged QDs for more efficient light-emitting devices. PMID:24350673</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22370183','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22370183"><span id="translatedtitle">Coronal <span class="hlt">bright</span> points associated with minifilament eruptions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Li, Haidong; Yang, Bo; Yang, Dan</p> <p>2014-12-01</p> <p>Coronal <span class="hlt">bright</span> points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite polarity. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the <span class="hlt">brightness</span> maxima of CBPs and possibly result from the convergence and cancellation of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 10{sup 9} cm{sup –3}. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA10006&hterms=duck&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dduck','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA10006&hterms=duck&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dduck"><span id="translatedtitle">At <span class="hlt">Bright</span> Band Inside Victoria Crater</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p><p/> A layer of light-toned rock exposed inside Victoria Crater in the Meridiani Planum region of Mars appears to mark where the surface was at the time, many millions of years ago, when an impact excavated the crater. NASA's Mars Exploration Rover Opportunity drove to this <span class="hlt">bright</span> band as the science team's first destination for the rover during investigations inside the crater. <p/> Opportunity's left front hazard-identification camera took this image just after the rover finished a drive of 2.25 meters (7 feet, 5 inches) during the rover's 1,305th Martian day, or sol, (Sept. 25, 2007). The rocks beneath the rover and its extended robotic arm are part of the <span class="hlt">bright</span> band. <p/> Victoria Crater has a scalloped shape of alternating alcoves and promontories around the crater's circumference. Opportunity descended into the crater two weeks earlier, within an alcove called 'Duck Bay.' Counterclockwise around the rim, just to the right of the arm in this image, is a promontory called 'Cabo Frio.'</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015IAUGA..2257516C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015IAUGA..2257516C&link_type=ABSTRACT"><span id="translatedtitle">Globe at Night - Sky <span class="hlt">Brightness</span> Monitoring Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheung, Sze Leung; Pun, Jason Chun Shing; SO, Chu-wing; Shibata, Yukiko; Walker, Constance Elaine; Agata, Hidehiko</p> <p>2015-08-01</p> <p>The Global at Night - Sky <span class="hlt">Brightness</span> Monitoring Network (GaN-MN) is an international project for long-term monitoring of night sky conditions around the world. The GaN-MN consists of fixed monitoring stations each equipped with a Sky Quality Meter - Lensed Ethernet (SQM-LE), which is a specialized light sensor for night sky <span class="hlt">brightness</span> (NSB) measurement. NSB data are continuously collected at high sampling frequency throughout the night, and these data will be instantly made available to the general public to provide a real-time snapshot of the global light pollution condition. A single data collection methodology, including data sampling frequency, data selection criteria, device design and calibration, and schemes for data quality control, was adopted to ensure uniformity in the data collected. This is essential for a systematic and global study of the level of light pollution. The data collected will also provide the scientific backbone in our efforts to contribute to dark sky conservation through education to the general public and policy makers. The GaN-MN project is endorsed by the IAU IYL Executive Committee Working Group as a major Cosmic Light program in the International Year of Light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/449464','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/449464"><span id="translatedtitle">A high <span class="hlt">brightness</span> field emission display</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Palevsky, A.</p> <p>1996-12-31</p> <p>The military requirement for avionics display performance requires that displays be legible with 10,000 foot-candles (fc) <span class="hlt">bright</span> light shining into the pilot`s eyes, or 10,000 fc shining directly on the display. The contrast ratio under these conditions must be at least 4.66:1. In addition, instant-on operation is sought for temperatures as low as {minus}54 C. Currently these specifications can barely be met by monochrome CRTs whose use is counter-indicated by other factors. No color display can achieve optimum performance in the areas mentioned, nor do any current contenders, primarily AMLCD`s, have any prospects of achieving full compliance. The FED being developed by Raytheon shows strong promise of being able to achieve the <span class="hlt">brightness</span> and contrast ratios desired. The FED is also inherently able to provide instant-on functionality at any terrestrial temperature and does not require any heating at low temperatures. The technical objective of the Raytheon development program is to develop a high performance, full color, FED Panel that meets the performance and environmental operating condition requirements specified for military and other high performance display applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ASAJ..118.2656P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ASAJ..118.2656P"><span id="translatedtitle">Study of the <span class="hlt">brightness</span> of trumpet tones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poirson, Emilie; Petiot, Jean-François; Gilbert, Joël</p> <p>2005-10-01</p> <p>This study focuses on a particular attribute of trumpet tones, the <span class="hlt">brightness</span>, and on the physical characteristics of the instrument thought to govern its magnitude. On the one hand, an objective study was carried out with input impedance measurements, and, on the other hand, a subjective study with hearing tests and a panel of subjects. To create a set of different trumpets a variable depth mouthpiece was developed whose depth can be easily and continuously adjusted from ``deep'' to ``shallow.'' Using this mouthpiece and the same trumpet, several instruments were generated which may be played in three ways: (i) by a musician, (ii) by an artificial mouth, and (iii) using physical modeling simulations. The influence of the depth of the mouthpiece on the perception of the trumpet's tones was investigated, and the ability of a musician, the artificial mouth, or physical modeling simulations to demonstrate perceptively noticeable differences was assessed. Physical characteristics extracted from the impedance curves are finally proposed to explain the <span class="hlt">brightness</span> of trumpet tones. As a result, the physical modeling simulations now seem to be mature enough to exhibit coherent and subtle perceptual differences between tones. This opens the door to virtual acoustics for instrument makers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810018493','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810018493"><span id="translatedtitle">Synchrotron <span class="hlt">brightness</span> distribution of turbulent radio jets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Henriksen, R. N.; Bridle, A. H.; Chan, K. L.</p> <p>1981-01-01</p> <p>Radio jets are considered as turbulent mixing regions and it is proposed that the essential small scale viscous dissipation in these jets is by emission of MHD waves and by their subsequent strong damping due, at least partly, to gyro-resonant acceleration of supra-thermal particles. A formula relating the synchrotron surface <span class="hlt">brightness</span> of a radio jet to the turbulent power input is deduced from physical postulates, and is tested against the data for NGC315 and 3C31 (NGC383). The predicted <span class="hlt">brightness</span> depends essentially on the collimation behavior of the jet, and, to a lesser extent, on the CH picture of a 'high' nozzle with accelerating flow. The conditions for forming a large scale jet at a high nozzle from a much smaller scale jet are discussed. The effect of entrainment on the prediction is discussed with the use of similarity solutions. Although entrainment is inevitably associated with the turbulent jet, it may or may not be a dominant factor depending on the ambient density profile.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930005117','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930005117"><span id="translatedtitle"><span class="hlt">Bright</span> crater outflows: Possible emplacement mechanisms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chadwick, D. John; Schaber, Gerald G.; Strom, Robert G.; Duval, Darla M.</p> <p>1992-01-01</p> <p>Lobate features with a strong backscatter are associated with 43 percent of the impact craters cataloged in Magellan's cycle 1. Their apparent thinness and great lengths are consistent with a low-viscosity material. The longest outflow yet identified is about 600 km in length and flows from the 90-km-diameter crater Addams. There is strong evidence that the outflows are largely composed of impact melt, although the mechanisms of their emplacement are not clearly understood. High temperatures and pressures of target rocks on Venus allow for more melt to be produced than on other terrestrial planets because lower shock pressures are required for melting. The percentage of impact craters with outflows increases with increasing crater diameter. The mean diameter of craters without outflows is 14.4 km, compared with 27.8 km for craters with outflows. No craters smaller than 3 km, 43 percent of craters in the 10- to 30-km-diameter range, and 90 percent in the 80- to 100-km-diameter range have associated <span class="hlt">bright</span> outflows. More melt is produced in the more energetic impact events that produce larger craters. However, three of the four largest craters have no outflows. We present four possible mechanisms for the emplacement of <span class="hlt">bright</span> outflows. We believe this 'shotgun' approach is justified because all four mechanisms may indeed have operated to some degree.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950034185&hterms=Lanzetta&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DLanzetta','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950034185&hterms=Lanzetta&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DLanzetta"><span id="translatedtitle">Hubble Space Telescope faint object spectrograph Quasar Absorption System Snapshot Survey (AbSnap). 1: Astrometric optical positions and finding charts of 269 <span class="hlt">bright</span> QSO</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bowen, David V.; Osmer, Samantha J.; Blades, J. Chris; Tytler, David; Cottrell, Lance; Fan, Xiao-Ming; Lanzetta, Kenneth M.</p> <p>1994-01-01</p> <p>We present finding charts and optical positions accurate to less than 1 arcsec for 269 <span class="hlt">bright</span> (V less than or = 18.5) Quasi-Stellar Objects (QSOs). These objects were selected as candidates for the Hubble Space Telescope (HST) Quasar Absorption System Snapshot Survey (AbSnap), a program designed to use the Faint Object Spectrograph (FOS) to obtain short exposure <span class="hlt">ultraviolet</span> (UV) spectra of <span class="hlt">bright</span> QSOs. Many quasars were included because of their proximity to <span class="hlt">bright</span>, low redshift galaxies and positions of these QSOs are measured accurately for the first time. Data were obtained using the digitized sky survey produced by the Space Telescope Science Institute's Guide Stars Selection System Astrometric Support Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2856J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2856J"><span id="translatedtitle">Relation between the Sunrise photospheric magnetic field and the Ca II H <span class="hlt">bright</span> features</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jafarzadeh, Shahin; Hirzberger, J.; Feller, A.; Lagg, A.; Solanki, S. K.; Pietarila, A.; Danilovic, S.; Riethmueller, T.; Barthol, P.; Berkefeld, T.; Gandorfer, A.; Knülker, M.; Martínez Pillet, V.; Schmidt, W.; Schüssler, M.; Title, A.</p> <p></p> <p>Recent observations from the Sunrise balloon-borne solar telescope have enabled us to reach an unprecedented high spatial resolution on the solar surface with the near-<span class="hlt">ultraviolet</span> photo-spheric and chromospheric images as well as the magnetograms. We use these high resolution observations to investigate the structure of the solar upper photosphere and lower chromosphere as well as their temporal evolutions. We study the relation between the inter-granular Ca II 397 nm <span class="hlt">bright</span> structures in images obtained by the Sunrise Filter Imager (SuFI) and their corresponding photospheric vector magnetic field computed from the Imaging Magnetogram eXperiment (IMaX) observations. The targets under study are in a quiet Sun region and close to disc-centre.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22373343','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22373343"><span id="translatedtitle">EUV light source with high <span class="hlt">brightness</span> at 13.5 nm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Borisov, V M; Prokof'ev, A V; Khristoforov, O B; Koshelev, K N; Khadzhiyskiy, F Yu</p> <p>2014-11-30</p> <p>The results of the studies on the development of a highbrightness radiation source in the extreme <span class="hlt">ultraviolet</span> (EUV) range are presented. The source is intended for using in projection EUV lithography, EUV mask inspection, for the EUV metrology, etc. Novel approaches to creating a light source on the basis of Z-pinch in xenon allowed the maximal <span class="hlt">brightness</span> [130 W(mm{sup 2} sr){sup -1}] to be achieved in the vicinity of plasma for this type of radiation sources within the 2% spectral band centred at the wavelength of 13.5 nm that corresponds to the maximal reflection of multilayer Mo/Si mirrors. In this spectral band the radiation power achieves 190 W in the solid angle of 2π at a pulse repetition rate of 1.9 kHz and an electric power of 20 kW, injected into the discharge. (laser applications and other topics in quantum electronics)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873452','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873452"><span id="translatedtitle">Method for extreme <span class="hlt">ultraviolet</span> lithography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Felter, T. E.; Kubiak, G. D.</p> <p>2000-01-01</p> <p>A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme <span class="hlt">ultraviolet</span> (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme <span class="hlt">ultraviolet</span> radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/872784','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/872784"><span id="translatedtitle">Method for extreme <span class="hlt">ultraviolet</span> lithography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Felter, T. E.; Kubiak, Glenn D.</p> <p>1999-01-01</p> <p>A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme <span class="hlt">ultraviolet</span> (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme <span class="hlt">ultraviolet</span> radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720024174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720024174"><span id="translatedtitle">Interstellar extinction in the <span class="hlt">ultraviolet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bless, R. C.; Savage, B. D.</p> <p>1972-01-01</p> <p>Interstellar extinction curves over the region 3600-1100 A for 17 stars are presented. The observations were made by the two Wisconsin spectrometers onboard the OAO-2 with spectral resolutions of 10 A and 20 A. The extinction curves generally show a pronounced maximum at 2175 plus or minus 25 A, a broad minimum in the region 1800-1350 A, and finally a rapid rise to the far <span class="hlt">ultraviolet</span>. Large extinction variations from star to star are found, especially in the far <span class="hlt">ultraviolet</span>; however, with only two possible exceptions in this sample, the wavelength at the maximum of the extinction bump is essentially constant. These data are combined with visual and infrared observations to display the extinction behavior over a range in wavelength of about a factor of 20.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860016875','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860016875"><span id="translatedtitle">International <span class="hlt">Ultraviolet</span> Explorer Observatory operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1985-01-01</p> <p>This volume contains the final report for the International <span class="hlt">Ultraviolet</span> Explorer IUE Observatory Operations contract. The fundamental operational objective of the International <span class="hlt">Ultraviolet</span> Explorer (IUE) program is to translate competitively selected observing programs into IUE observations, to reduce these observations into meaningful scientific data, and then to present these data to the Guest Observer in a form amenable to the pursuit of scientific research. The IUE Observatory is the key to this objective since it is the central control and support facility for all science operations functions within the IUE Project. In carrying out the operation of this facility, a number of complex functions were provided beginning with telescope scheduling and operation, proceeding to data processing, and ending with data distribution and scientific data analysis. In support of these critical-path functions, a number of other significant activities were also provided, including scientific instrument calibration, systems analysis, and software support. Routine activities have been summarized briefly whenever possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...788L...9B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...788L...9B"><span id="translatedtitle">Larger Planet Radii Inferred from Stellar "Flicker" <span class="hlt">Brightness</span> Variations of <span class="hlt">Bright</span> Planet-host Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua</p> <p>2014-06-01</p> <p>Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in <span class="hlt">brightness</span> as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale <span class="hlt">brightness</span> variations ("flicker") of stars can be used to measure log g to a high accuracy of ~0.1-0.2 dex. Here, we use flicker measurements of 289 <span class="hlt">bright</span> (Kepmag < 13) candidate planet-hosting stars with T eff = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the <span class="hlt">bright</span> planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22365802','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22365802"><span id="translatedtitle">LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' <span class="hlt">BRIGHTNESS</span> VARIATIONS OF <span class="hlt">BRIGHT</span> PLANET-HOST STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua</p> <p>2014-06-10</p> <p>Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in <span class="hlt">brightness</span> as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale <span class="hlt">brightness</span> variations ({sup f}licker{sup )} of stars can be used to measure log g to a high accuracy of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 <span class="hlt">bright</span> (Kepmag < 13) candidate planet-hosting stars with T {sub eff} = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the <span class="hlt">bright</span> planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=magnitude&pg=4&id=EJ838375','ERIC'); return false;" href="http://eric.ed.gov/?q=magnitude&pg=4&id=EJ838375"><span id="translatedtitle">Does Stevens's Power Law for <span class="hlt">Brightness</span> Extend to Perceptual <span class="hlt">Brightness</span> Averaging?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bauer, Ben</p> <p>2009-01-01</p> <p>Stevens's power law ([Psi][infinity][Phi][beta]) captures the relationship between physical ([Phi]) and perceived ([Psi]) magnitude for many stimulus continua (e.g., luminance and <span class="hlt">brightness</span>, weight and heaviness, area and size). The exponent ([beta]) indicates whether perceptual magnitude grows more slowly than physical magnitude ([beta] less…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920034468&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920034468&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">The Extreme <span class="hlt">Ultraviolet</span> Explorer mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Welsh, Barry Y.</p> <p>1991-01-01</p> <p>The Extreme <span class="hlt">Ultraviolet</span> Explorer (EUVE) is a NASA astronomy mission which will operate in the 70-760A spectral band. The science payload consists of three grazing incidence scanning telescopes and an EUV spectrometer/deep survey instrument. An overview of the planned mission profile is given, and the instrumentation which comprises the science payload is discussed. The EUVE is scheduled for launch in late August 1991.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880032700&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880032700&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">Search for <span class="hlt">ultraviolet</span> Shuttle glow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tennyson, P. D.; Feldman, P. D.; Henry, R. C.</p> <p>1987-01-01</p> <p>In January 1986, the Space Shuttle Columbia carried two <span class="hlt">ultraviolet</span> experiments (UVX) in an attempt to observe very weak diffuse emission from various astronomical sources at wavelengths below 3200 A with moderate spectral resolution. The experiment attested to the feasibility of low cost astronomy from the Space Shuttle using Get Away Special canisters. Emissions from O2, O, and NO were detected and shown to be consistent with an atmospheric origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993AAS...183.1702S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993AAS...183.1702S&link_type=ABSTRACT"><span id="translatedtitle">Far-<span class="hlt">Ultraviolet</span> Stellar Photometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, E. G.; Carruthers, G. R.</p> <p>1993-12-01</p> <p>During a shuttle flight in May, 1991, wide field images were obtained for 12 star fields with the NRL far-<span class="hlt">ultraviolet</span> cameras. These cameras provide sensitivity bands with effective wavelengths of lambda eff = 1367 Angstroms and lambda eff = 1702 Angstroms. The properties of the resulting magnitude system will be described and compared with previous photometry from the OAO2, ANS and TD1 satellites. Results from several fields in the vicinity of the galactic center will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100010950','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100010950"><span id="translatedtitle"><span class="hlt">Ultraviolet</span>-Resistant Bacterial Spores</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Venkateswaran, Kasthuri; Newcombe, David; LaDuc, Myron T.; Osman, Shariff R.</p> <p>2007-01-01</p> <p>A document summarizes a study in which it was found that spores of the SAFR-032 strain of Bacillus pumilus can survive doses of <span class="hlt">ultraviolet</span> (UV) radiation, radiation, and hydrogen peroxide in proportions much greater than those of other bacteria. The study was part of a continuing effort to understand the survivability of bacteria under harsh conditions and develop means of sterilizing spacecraft to prevent biocontamination of Mars that could interfere with the search for life there.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...800..109B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...800..109B"><span id="translatedtitle">No Time for Dead Time: Timing Analysis of <span class="hlt">Bright</span> Black Hole Binaries with NuSTAR</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bachetti, Matteo; Harrison, Fiona A.; Cook, Rick; Tomsick, John; Schmid, Christian; Grefenstette, Brian W.; Barret, Didier; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Fabian, Andrew C.; Fürst, Felix; Gandhi, Poshak; Hailey, Charles J.; Kara, Erin; Maccarone, Thomas J.; Miller, Jon M.; Pottschmidt, Katja; Stern, Daniel; Uttley, Phil; Walton, Dominic J.; Wilms, Jörn; Zhang, William W.</p> <p>2015-02-01</p> <p>Timing of high-count-rate sources with the NuSTAR Small Explorer Mission requires specialized analysis techniques. NuSTAR was primarily designed for spectroscopic observations of sources with relatively low count rates rather than for timing analysis of <span class="hlt">bright</span> objects. The instrumental dead time per event is relatively long (~2.5 msec) and varies event-to-event by a few percent. The most obvious effect is a distortion of the white noise level in the power density spectrum (PDS) that cannot be easily modeled with standard techniques due to the variable nature of the dead time. In this paper, we show that it is possible to exploit the presence of two completely independent focal planes and use the cospectrum, the real part of the cross PDS, to obtain a good proxy of the white-noise-subtracted PDS. Thereafter, one can use a Monte Carlo approach to estimate the remaining effects of dead time, namely, a frequency-dependent modulation of the variance and a frequency-independent drop of the sensitivity to variability. In this way, most of the standard timing analysis can be performed, <span class="hlt">albeit</span> with a sacrifice in signal-to-noise ratio relative to what would be achieved using more standard techniques. We apply this technique to NuSTAR observations of the black hole binaries GX 339-4, Cyg X-1, and GRS 1915+105.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940021731','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940021731"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> observations of astronomical sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eaton, Joel A.</p> <p>1994-01-01</p> <p>The final report on '<span class="hlt">Ultraviolet</span> Observations of Astronomical Sources,' which ran for a total of three years, roughly between 1 July 1988 and 14 Feb. 1993 is presented. During the first year, I worked at Indiana University; since October, 1989, I have been at Tennessee State University. This grant has supported my studies of archival International <span class="hlt">Ultraviolet</span> Explorer (IUE) observations of zeta Aur binaries, cool stars that are paired with hot stars in binary systems. Such systems are important as a source of detailed knowledge about the structures of chromospheres and winds in cool giant and supergiant stars, since the hot star serves as a probe of many lines of sight through the cool supergiant star's outer atmosphere. By determining the physical conditions along many such lines of sight, a detailed two-dimensional map of the chromosphere and wind may be constructed. The grant grew out of my analysis of archival IUE observations of 31 Cyg in which I analyzed five epochs of an atmospheric eclipse that occurred in 1982. I fit the attenuation spectra of atmospheric eclipse throughout the <span class="hlt">ultraviolet</span> (lambda(lambda)1175-1950 and lambda(lambda)2500-3100) with theoretically calculated spectra, thereby determining the physical properties of gas (mass column density of absorbers, temperature, and velocity spread) along each observed line of sight. A similar analysis for other such zeta Aur binaries was accomplished and theoretical models for the chromospheres of these stars based on my observations were constructed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.459.1415B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.459.1415B"><span id="translatedtitle">Remnant planetary systems around <span class="hlt">bright</span> white dwarfs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barber, Sara D.; Belardi, Claudia; Kilic, Mukremin; Gianninas, A.</p> <p>2016-06-01</p> <p>We cross-correlate several sources of archival photometry for 1265 <span class="hlt">bright</span> (V ˜ 16 mag) white dwarfs (WDs) with available high signal-to-noise spectroscopy. We find 381 WDs with archival Spitzer+IRAC data and investigate this subsample for infrared excesses due to circumstellar dust. This large data set reveals 15 dusty WDs, including three new debris discs and the hottest WD known to host dust (WD 0010+280). We study the frequency of debris discs at WDs as function of mass. The frequency peaks at 12.5 per cent for 0.7-0.75 M⊙ WDs (with 3 M⊙ main-sequence star progenitors) and falls off for stars more massive than this, which mirrors predicted planet occurrence rates for stars of different masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19547121','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19547121"><span id="translatedtitle">High purity <span class="hlt">bright</span> single photon source.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neergaard-Nielsen, J S; Nielsen, B M; Takahashi, H; Vistnes, A I; Polzik, E S</p> <p>2007-06-25</p> <p>Using cavity-enhanced non-degenerate parametric down-conversion, we have built a frequency tunable source of heralded single photons with a narrow bandwidth of 8 MHz, making it compatible with atomic quantum memories. The photon state is 70% pure single photon as characterized by a tomographic measurement and reconstruction of the quantum state, revealing a clearly negative Wigner function. Furthermore, it has a spectral <span class="hlt">brightness</span> of ~1,500 photons/s per MHz bandwidth, making it one of the brightest single photon sources available. We also investigate the correlation function of the down-converted fields using a combination of two very distinct detection methods; photon counting and homodyne measurement. PMID:19547121</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ApPhL.106i1105H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ApPhL.106i1105H&link_type=ABSTRACT"><span id="translatedtitle">High <span class="hlt">brightness</span> angled cavity quantum cascade lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.</p> <p>2015-03-01</p> <p>A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh <span class="hlt">brightness</span> value of 156 MW cm-2 sr-1 is obtained, which marks the brightest QCL to date.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22412740','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22412740"><span id="translatedtitle">High <span class="hlt">brightness</span> angled cavity quantum cascade lasers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.</p> <p>2015-03-02</p> <p>A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh <span class="hlt">brightness</span> value of 156 MW cm{sup −2 }sr{sup −1} is obtained, which marks the brightest QCL to date.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ASPC..504..273Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ASPC..504..273Y&link_type=ABSTRACT"><span id="translatedtitle">Modelling Solar and Stellar <span class="hlt">Brightness</span> Variabilities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yeo, K. L.; Shapiro, A. I.; Krivova, N. A.; Solanki, S. K.</p> <p>2016-04-01</p> <p>Total and spectral solar irradiance, TSI and SSI, have been measured from space since 1978. This is accompanied by the development of models aimed at replicating the observed variability by relating it to solar surface magnetism. Despite significant progress, there remains persisting controversy over the secular change and the wavelength-dependence of the variation with impact on our understanding of the Sun's influence on the Earth's climate. We highlight the recent progress in TSI and SSI modelling with SATIRE. <span class="hlt">Brightness</span> variations have also been observed for Sun-like stars. Their analysis can profit from knowledge of the solar case and provide additional constraints for solar modelling. We discuss the recent effort to extend SATIRE to Sun-like stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22706523','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22706523"><span id="translatedtitle"><span class="hlt">Bright</span> photoluminescent hybrid mesostructured silica nanoparticles.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miletto, Ivana; Bottinelli, Emanuela; Caputo, Giuseppe; Coluccia, Salvatore; Gianotti, Enrica</p> <p>2012-07-28</p> <p><span class="hlt">Bright</span> photoluminescent mesostructured silica nanoparticles were synthesized by the incorporation of fluorescent cyanine dyes into the channels of MCM-41 mesoporous silica. Cyanine molecules were introduced into MCM-41 nanoparticles by physical adsorption and covalent grafting. Several photoluminescent nanoparticles with different organic loadings have been synthesized and characterized by X-ray powder diffraction, high resolution transmission electron microscopy and nitrogen physisorption porosimetry. A detailed photoluminescence study with the analysis of fluorescence lifetimes was carried out to elucidate the cyanine molecules distribution within the pores of MCM-41 nanoparticles and the influence of the encapsulation on the photoemission properties of the guests. The results show that highly stable photoluminescent hybrid materials with interesting potential applications as photoluminescent probes for diagnostics and imaging can be prepared by both methods. PMID:22706523</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ApJ...715L..26S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApJ...715L..26S"><span id="translatedtitle">Magnetic <span class="hlt">Bright</span> Points in the Quiet Sun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez Almeida, J.; Bonet, J. A.; Viticchié, B.; Del Moro, D.</p> <p>2010-05-01</p> <p>We present a visual determination of the number of <span class="hlt">bright</span> points (BPs) existing in the quiet Sun, which are structures though to trace intense kG magnetic concentrations. The measurement is based on a 0farcs1 angular resolution G-band movie obtained with the Swedish Solar Telescope at the solar disk center. We find 0.97 BPs Mm-2, which is a factor 3 larger than any previous estimate. It corresponds to 1.2 BPs per solar granule. Depending on the details of the segmentation, the BPs cover between 0.9% and 2.2% of the solar surface. Assuming their field strength to be 1.5 kG, the detected BPs contribute to the solar magnetic flux with an unsigned flux density between 13 G and 33 G. If network and inter-network regions are counted separately, they contain 2.2 BPs Mm-2 and 0.85 BPs Mm-2, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22724807B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22724807B"><span id="translatedtitle">Dark Skies, <span class="hlt">Bright</span> Kids Year 7</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bittle, Lauren E.; Johnson, Kelsey E.; Borish, H. Jacob; Burkhardt, Andrew; Firebaugh, Ariel; Hancock, Danielle; Rochford Hayes, Christian; Linden, Sean; Liss, Sandra; Matthews, Allison; Prager, Brian; Pryal, Matthew; Sokal, Kimberly R.; Troup, Nicholas William; Wenger, Trey</p> <p>2016-01-01</p> <p>We present updates from our seventh year of operation including new club content, continued assessments, and our fifth annual Star Party. Dark Skies, <span class="hlt">Bright</span> Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Central Virginia through fun, hands-on activities that introduce basic Astronomy concepts. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25032924','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25032924"><span id="translatedtitle"><span class="hlt">Bright</span> solitonic matter-wave interferometer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McDonald, G D; Kuhn, C C N; Hardman, K S; Bennetts, S; Everitt, P J; Altin, P A; Debs, J E; Close, J D; Robins, N P</p> <p>2014-07-01</p> <p>We present the first realization of a solitonic atom interferometer. A Bose-Einstein condensate of 1×10(4) atoms of rubidium-85 is loaded into a horizontal optical waveguide. Through the use of a Feshbach resonance, the s-wave scattering length of the 85Rb atoms is tuned to a small negative value. This attractive atomic interaction then balances the inherent matter-wave dispersion, creating a <span class="hlt">bright</span> solitonic matter wave. A Mach-Zehnder interferometer is constructed by driving Bragg transitions with the use of an optical lattice colinear with the waveguide. Matter-wave propagation and interferometric fringe visibility are compared across a range of s-wave scattering values including repulsive, attractive and noninteracting values. The solitonic matter wave is found to significantly increase fringe visibility even compared with a noninteracting cloud. PMID:25032924</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000A%26A...353.1083B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000A%26A...353.1083B"><span id="translatedtitle">EUV <span class="hlt">brightness</span> variations in the quiet Sun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brković, A.; Rüedi, I.; Solanki, S. K.; Fludra, A.; Harrison, R. A.; Huber, M. C. E.; Stenflo, J. O.; Stucki, K.</p> <p>2000-01-01</p> <p>The Coronal Diagnostic Spectrometer (CDS) onboard the SOHO satellite has been used to obtain movies of quiet Sun regions at disc centre. These movies were used to study <span class="hlt">brightness</span> variations of solar features at three different temperatures sampled simultaneously in the chromospheric He I 584.3 Ä (2 * 104 K), the transition region O V 629.7 Ä (2.5 * 105 K) and coronal Mg IX 368.1 Ä (106 K) lines. In all parts of the quiet Sun, from darkest intranetwork to brightest network, we find significant variability in the He I and O V line, while the variability in the Mg IX line is more marginal. The relative variability, defined by rms of intensity normalised to the local intensity, is independent of <span class="hlt">brightness</span> and strongest in the transition region line. Thus the relative variability is the same in the network and the intranetwork. More than half of the points on the solar surface show a relative variability, determined over a period of 4 hours, greater than 15.5% for the O V line, but only 5% of the points exhibit a variability above 25%. Most of the variability appears to take place on time-scales between 5 and 80 minutes for the He I and O V lines. Clear signs of ``high variability'' events are found. For these events the variability as a function of time seen in the different lines shows a good correlation. The correlation is higher for more variable events. These events coincide with the (time averaged) brightest points on the solar surface, i.e. they occur in the network. The spatial positions of the most variable points are identical in all the lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA08039&hterms=salt+water+salty&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsalt%2Bwater%2Bsalty','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA08039&hterms=salt+water+salty&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsalt%2Bwater%2Bsalty"><span id="translatedtitle"><span class="hlt">Bright</span> Soil Near 'McCool'</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2006-01-01</p> <p><p/> While driving eastward toward the northwestern flank of 'McCool Hill,' the wheels of NASA's Mars Exploration Rover Spirit churned up the largest amount of <span class="hlt">bright</span> soil discovered so far in the mission. This image from Spirit's panoramic camera (Pancam), taken on the rover's 788th Martian day, or sol, of exploration (March 22, 2006), shows the strikingly <span class="hlt">bright</span> tone and large extent of the materials uncovered. <p/> Several days earlier, Spirit's wheels unearthed a small patch of light-toned material informally named 'Tyrone.' In images from Spirit's panoramic camera, 'Tyrone' strongly resembled both 'Arad' and 'Paso Robles,' two patches of light-toned soils discovered earlier in the mission. Spirit found 'Paso Robles' in 2005 while climbing 'Cumberland Ridge' on the western slope of 'Husband Hill.' In early January 2006, the rover discovered 'Arad' on the basin floor just south of 'Husband Hill.' Spirit's instruments confirmed that those soils had a salty chemistry dominated by iron-bearing sulfates. Spirit's Pancam and miniature thermal emission spectrometer examined this most recent discovery, and researchers will compare its properties with the properties of those other deposits. <p/> These discoveries indicate that salty, light-toned soil deposits might be widely distributed on the flanks and valley floors of the 'Columbia Hills' region in Gusev Crater on Mars. The salts, which are easily mobilized and concentrated in liquid solution, may record the past presence of water. So far, these enigmatic materials have generated more questions than answers, however, and as Spirit continues to drive across this region in search of a safe winter haven, the team continues to formulate and test hypotheses to explain the rover's most fascinating recent discovery. <p/> This view is an approximately true-color rendering that combines separate images taken through the Pancam's 753-nanometer, 535-nanometer, and 432-nanometer filters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20050156651&hterms=Product+concept&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DProduct%2Bconcept','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20050156651&hterms=Product+concept&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DProduct%2Bconcept"><span id="translatedtitle">The GPM Common Calibrated <span class="hlt">Brightness</span> Temperature Product</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stout, John; Berg, Wesley; Huffman, George; Kummerow, Chris; Stocker, Erich</p> <p>2005-01-01</p> <p>The Global Precipitation Measurement (GPM) project will provide a core satellite carrying the GPM Microwave Imager (GMI) and will use microwave observations from a constellation of other satellites. Each partner with a satellite in the constellation will have a calibration that meets their own requirements and will decide on the format to archive their <span class="hlt">brightness</span> temperature (Tb) record in GPM. However, GPM multi-sensor precipitation algorithms need to input intercalibrated Tb's in order to avoid differences among sensors introducing artifacts into the longer term climate record of precipitation. The GPM Common Calibrated <span class="hlt">Brightness</span> Temperature Product is intended to address this problem by providing intercalibrated Tb data, called "Tc" data, where the "c" stands for common. The precipitation algorithms require a Tc file format that is both generic and flexible enough to accommodate the different passive microwave instruments. The format will provide detailed information on the processing history in order to allow future researchers to have a record of what was done. The format will be simple, including the main items of scan time, latitude, longitude, and Tc. It will also provide spacecraft orientation, spacecraft location, orbit, and instrument scan type (cross-track or conical). Another simplification is to store data in real numbers, avoiding the ambiguity of scaled data. Finally, units and descriptions will be provided in the product. The format is built on the concept of a swath, which is a series of scans that have common geolocation and common scan geometry. Scan geometry includes pixels per scan, sensor orientation, scan type, and incidence angles. The Tc algorithm and data format are being tested using the pre-GPM Precipitation Processing System (PPS) software to generate formats and 1/0 routines. In the test, data from SSM/I, TMI, AMSR-E, and WindSat are being processed and written as Tc products.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AAS...196.2913H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AAS...196.2913H"><span id="translatedtitle">Star Bursts in the UV <span class="hlt">Bright</span> Interacting Galaxies NGC 3395 & 3396</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hancock, M.; Weistrop, D.; Nelson, C. H.</p> <p>2000-05-01</p> <p>We have obtained <span class="hlt">ultraviolet</span> and visible wavelength images for the interacting galaxies, NGC 3395 and 3396, using the Space Telescope Imaging Spectrograph on Hubble Space Telescope. IUE observations (Kinney et al. 1993) indicate that both of these galaxies have strong UV emission. Ground based spectra display evidence of extensive star formation. The visible images were obtained using the CCD detector and filter F28X50LP (central wavelength ~ 7230 Angstroms , FWHM ~ 1998 Angstroms). The <span class="hlt">ultraviolet</span> images were obtained using the F25QTZ filter with the far-UV MAMA detector (central wavelength ~ 1595 Angstroms , FWHM ~ 206 Angstroms), and the F25CN182 filter with the near-UV MAMA detector (central wavelength ~ 2010 Angstroms, FWHM ~ 681 Angstroms). The data were reduced and analyzed using standard IRAF and STSDAS packages and customized software routines. This work has been supported in part by NASA, under contract NAS5-31231. We will present luminosities, luminosity functions, sizes and colors for the UV <span class="hlt">bright</span> star forming regions. Stellar populations and ages of these knots will be constrained by comparison with star burst models (Leitherer et al. 1999). We will discuss the dependence of the characteristics of the knots on position in the galaxies and the possible relationship to the tidal interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840056759&hterms=electric+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528electric%2Bcurrent%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840056759&hterms=electric+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528electric%2Bcurrent%2529"><span id="translatedtitle">Photospheric electric current and transition region <span class="hlt">brightness</span> within an active region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deloach, A. C.; Hagyard, M. J.; Rabin, D.; Moore, R. L.; Smith, B. J., Jr.; West, E. A.; Tandberg-Hanssen, E.</p> <p>1984-01-01</p> <p>Distributions of vertical electrical current density J(z) calculated from vector measurements of the photospheric magnetic field are compared with <span class="hlt">ultraviolet</span> spectroheliograms to investigate whether resistive heating is an important source of enhanced emission in the transition region. The photospheric magnetic fields in Active Region 2372 were measured on April 6 and 7, 1980 with the Marshall Space Flight Center vector magnetograph; <span class="hlt">ultraviolet</span> wavelength spectroheliograms (L-alpha and N V 1239 A) were obtained with the UV Spectrometer and Polarimeter experiment aboard the Solar Maximum Mission satellite. Spatial registration of the J(z) (5 arcsec resolution) and UV (3 arcsec resolution) maps indicates that the maximum current density is cospatial with a minor but persistent UV enhancement, but there is little detected current associated with other nearby <span class="hlt">bright</span> areas. It is concluded that, although resistive heating may be important in the transition region, the currents responsible for the heating are largely unresolved in the present measurements and have no simple correlation with the residual current measured on 5-arcsec scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PASP..126..496G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PASP..126..496G"><span id="translatedtitle">Sky <span class="hlt">Brightness</span> at Weihai Observatory of Shandong University</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Di-Fu; Hu, Shao-Ming; Chen, Xu; Gao, Dong-Yang; Du, Jun-Ju</p> <p>2014-05-01</p> <p>In this paper, a total of about 28000 images in V and R band obtained over 161 nights using the one-meter optical telescope at Weihai Observatory (WHO) of Shandong University from 2008 to 2012 have been processed to measure the sky <span class="hlt">brightness</span>. They provide us with an unprecedented database, which can be used to study the variation of the sky <span class="hlt">brightness</span> with the sky position, the moonlight contribution, and the twilight sky <span class="hlt">brightness</span>. The darkest sky <span class="hlt">brightness</span> is about 19.0 and 18.6 mag arcsec-2 in V and R band, respectively. An obvious darkening trend is found at the first half of the night at WHO, and the variation rate is much larger in summer than in other seasons. The sky <span class="hlt">brightness</span> variation depends more on the azimuth than on the altitude of the telescope pointing for WHO. Our results indicate that the sky <span class="hlt">brightness</span> at WHO is seriously influenced by urban light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995eso..pres...10.&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995eso..pres...10.&link_type=ABSTRACT"><span id="translatedtitle">New Distant Comet Headed for <span class="hlt">Bright</span> Encounter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>1995-08-01</p> <p>How Impressive Will Comet Hale-Bopp Become in 1997 ? A very unusual comet was discovered last month, on its way from the outer reaches of the solar system towards the Sun. Although it is still situated beyond the orbit of Jupiter, it is so <span class="hlt">bright</span> that it can be observed in even small telescopes. It has been named `Hale-Bopp' after the discoverers and is already of great interest to cometary astronomers. No less than seven telescopes have been used at the ESO La Silla observatory for the first observations of the new object. Together with data gathered at other sites, their aim is to elucidate the nature of this comet and also to determine whether there is reason to hope that it will become a <span class="hlt">bright</span> and beautiful object in the sky from late 1996 and well into 1997. Further observations are now being planned at ESO and elsewhere to monitor closely the behaviour of this celestial visitor during the coming months. Discovery circumstances The comet was discovered on 23 July 1995, nearly simultaneously by two American amateur astronomers, Alan Hale of Cloudcroft (New Mexico) and Thomas Bopp of Glendale (Arizona). Although the chronology is slightly uncertain, it appears that Hale first saw it some 10 - 20 minutes before Bopp, at 06:10 - 06:15 UT on that day. In any case, he informed the IAU Central Bureau for Astronomical Telegrams (CBAT) in Cambridge (Massachussetts) about his discovery by email already at 06:50 UT, while Bopp's message was filed more than 2 hours later, after he had driven back to his home, 140 km from where he had been observing. Upon receipt of these messages, Brian Marsden at the CBAT assigned the designation `1995 O1' (indicating that it is the first comet found in the second half of July 1995). After further sightings had been made by other observers, and according to the venerable astronomical tradition, the new object was named after the discoverers. The magnitude, reported as 10.5 by Hale, is not unusual for a comet that is discovered within</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820010375&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820010375&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">Far <span class="hlt">ultraviolet</span> astronomy using the FAUST telescope</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bowyer, C. S.</p> <p>1981-01-01</p> <p>The Far <span class="hlt">Ultraviolet</span> Space Telescope (FAUST) a compact, wide field-of-view, far <span class="hlt">ultraviolet</span> instrument designed for astronomical observations of extended and point sources is discussed. The design and application of the instrument are described. The prime objective is to observe faint astronomical sources with sensitivities higher than previously available. Scientific programs will include: (1) a search for <span class="hlt">ultraviolet</span> stars which are predicted to exist at the stage of evolution prior to the final death of a star; (2) observations of galaxies and quasars; and (3) joint programs with other Spacelab 1 experiments. The secondary objective is to verify the suitability of the Spacelab as a platform for far <span class="hlt">ultraviolet</span> astronomy: data will be provided on the <span class="hlt">ultraviolet</span> background levels due to astronomical, terrestrial, and spacecraft generated sources; the levels of contaminants which affect <span class="hlt">ultraviolet</span> instruments; and the capability of the Orbiter for stable pointing at celestial sources for useful periods of time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Icar..233..106F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Icar..233..106F"><span id="translatedtitle">Upper limits for a lunar dust exosphere from far-<span class="hlt">ultraviolet</span> spectroscopy by LRO/LAMP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feldman, Paul D.; Glenar, David A.; Stubbs, Timothy J.; Retherford, Kurt D.; Randall Gladstone, G.; Miles, Paul F.; Greathouse, Thomas K.; Kaufmann, David E.; Parker, Joel Wm.; Alan Stern, S.</p> <p>2014-05-01</p> <p>Since early 2012, the Lyman-Alpha Mapping Project (LAMP) far-<span class="hlt">ultraviolet</span> spectrograph on the Lunar Reconnaissance Orbiter (LRO) spacecraft has carried out a series of limb observations from within lunar shadow to search for the presence of a high altitude dust exosphere via forward-scattering of sunlight from dust grains. <span class="hlt">Bright</span> “horizon-glow” was observed from orbit during several Apollo missions and interpreted in terms of dust at altitudes of several km and higher. However, no confirmation of such an exosphere has been made since that time. This raises basic questions about the source(s) of excess <span class="hlt">brightness</span> in the early measurements and also the conditions for producing observable dust concentrations at km altitudes and higher. Far-<span class="hlt">ultraviolet</span> measurements between 170 and 190 nm, near the LAMP long wavelength cutoff, are especially sensitive to scattering by small (0.1-0.2 μm radius) dust grains, since the scattering cross-section is near-maximum, and the solar flux is rising rapidly with wavelength. An additional advantage of <span class="hlt">ultraviolet</span> measurements is the lack of interference by background zodiacal light which must be taken into account at longer wavelengths. As of July 2013, LAMP has completed several limb-observing sequences dedicated to the search for horizon glow, but no clear evidence of dust scattering has yet been obtained. Upper limits for vertical dust column abundance have been estimated at less than 10 grains cm-2 (0.1 μm grain radius), by comparing the measured noise-equivalent <span class="hlt">brightness</span> with the results of Mie scattering simulations for the same observing geometries. These results indicate that Lunar Atmosphere Dust Environment Explorer (LADEE) UVS lunar dust observations will be considerably more challenging than planned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OptCo.324...34G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OptCo.324...34G"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> continuous-wave laser source at 205 nm for hydrogen spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galtier, Sandrine; Nez, François; Julien, Lucile; Biraben, François</p> <p></p> <p>This paper reports on the generation of 15 mW of continuous narrow-band laser source at 205 nm. The infra-red light source provided by a Titanium-Sapphire (TiSa) laser is mixed with the fourth harmonic of a Nd:YVO4 laser by the use of a β-barium borate (BBO) non-linear crystal. This highly reliable and powerful <span class="hlt">ultraviolet</span> (UV) source is an ideal tool for the 1S-3S hydrogen spectroscopy. Moreover, the wide tunability of the TiSa laser combined with this experimental set up makes the generation of <span class="hlt">bright</span> deep <span class="hlt">ultra-violet</span> (D-UV) sources possible. In particular, we plan to produce a 194 nm continuous light beam which is necessary to perform the 1S-4S transition in hydrogen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002669','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002669"><span id="translatedtitle">Development and testing of the <span class="hlt">ultraviolet</span> spectrometer for the Mariner Mars 1971 spacecraft</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farrar, J. W.</p> <p>1972-01-01</p> <p>The Mariner Mars 1971 <span class="hlt">ultraviolet</span> spectrometer is an Ebert-Fastie type of the same basic design as the Mariner Mars 1969 instrument. Light enters the instrument and is split into component wavelengths by a scanning reflection diffraction grating. Two monochrometer exit slits allow the use of two independent photomultiplier tube sensors. Channel 1 has a spectral range of 1100 to 1692 A with a fixed gain, while Channel 2 has a spectral range of 1450 to 3528 A with an automatic step gain control, providing a dynamic range over the expected atmosphere and surface <span class="hlt">brightness</span> of Mars. The scientific objectives, basic operation, design, testing, and calibration for the Mariner Mars 1971 <span class="hlt">ultraviolet</span> spectrometer are described. The design discussion includes those modifications that were necessary to extend the lifetime of the instrument in order to accomplish the Mariner Mars 1971 mission objectives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780055507&hterms=xxx&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dxxx','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780055507&hterms=xxx&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dxxx"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> photometry from the orbiting astronomical observatory. XXX - The Orion reflection nebulosity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Witt, A. N.; Lillie, C. F.</p> <p>1978-01-01</p> <p>Surface-<span class="hlt">brightness</span> measurements are presented that cover the region of Orion in nine intermediate-width bandpasses ranging from 4250 to 1550 A. The existence of an extended <span class="hlt">ultraviolet</span> reflection nebulosity in this area is confirmed, and the characteristics of its spectrum and spatial distribution are derived. The observations are consistent with a model in which the dense molecular cloud complex in Orion is illuminated by the foreground Orion aggregate of early-type stars. The interpretation is complicated by the fact that foreground dust may contribute to the observed scattered light. The scattering particles in the cloud appear to exhibit a wavelength-dependent albedo similar to that found for interstellar grains in general, with a strong indication that the phase function changes to a less forward-scattering form in the <span class="hlt">ultraviolet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..154W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..154W"><span id="translatedtitle">Data preprocessing and preliminary results of the moon-based <span class="hlt">ultraviolet</span> telescope on CE-3 lander</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, f.</p> <p>2015-10-01</p> <p>The moon-based <span class="hlt">ultraviolet</span> telescope (MUVT) is one of the payloads on the Chang'e-3(CE-3)lunar lander. Because of the advantages of having no atmospheric disturbances and the slow rotation of the Moon, we can make longterm continuous observations of a series of important remote celestial objects in the near <span class="hlt">ultraviolet</span> band, and perform a sky survey of selected areas. We can find characteristic changes incelestial <span class="hlt">brightness</span> with time by analyzing image data from the MUVT ,and deduce the radiation mechanism and physical properties of these celestial objects after comparing with a physical model. In order to explain the scientific purposes of MUVT, this article analyzes the preprocessing of MUVT image data and makes a preliminary evaluation of data quality. The results demonstrate that the methods used for data collection and preprocessing are effective, and the Level 2A and 2B image data satisfy the requirements of follow-up scientific researches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22370436','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22370436"><span id="translatedtitle">Investigation of the moving structures in a coronal <span class="hlt">bright</span> point</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ning, Zongjun; Guo, Yang</p> <p>2014-10-10</p> <p>We have explored the moving structures in a coronal <span class="hlt">bright</span> point (CBP) observed by the Solar Dynamic Observatory Atmospheric Imaging Assembly (AIA) on 2011 March 5. This CBP event has a lifetime of ∼20 minutes and is <span class="hlt">bright</span> with a curved shape along a magnetic loop connecting a pair of negative and positive fields. AIA imaging observations show that a lot of <span class="hlt">bright</span> structures are moving intermittently along the loop legs toward the two footpoints from the CBP <span class="hlt">brightness</span> core. Such moving <span class="hlt">bright</span> structures are clearly seen at AIA 304 Å. In order to analyze their features, the CBP is cut along the motion direction with a curved slit which is wide enough to cover the bulk of the CBP. After integrating the flux along the slit width, we get the spacetime slices at nine AIA wavelengths. The oblique streaks starting from the edge of the CBP <span class="hlt">brightness</span> core are identified as moving <span class="hlt">bright</span> structures, especially on the derivative images of the <span class="hlt">brightness</span> spacetime slices. They seem to originate from the same position near the loop top. We find that these oblique streaks are bi-directional, simultaneous, symmetrical, and periodic. The average speed is about 380 km s{sup –1}, and the period is typically between 80 and 100 s. Nonlinear force-free field extrapolation shows the possibility that magnetic reconnection takes place during the CBP, and our findings indicate that these moving <span class="hlt">bright</span> structures could be the observational outflows after magnetic reconnection in the CBP.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830010947','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830010947"><span id="translatedtitle">Polymerizable <span class="hlt">ultraviolet</span> stabilizers for outdoor use</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vogl, O.</p> <p>1982-01-01</p> <p>Polymeric materials that are stable enough to use outdoors without changes in excess of 20 years are investigated. <span class="hlt">Ultraviolet</span> stabilizers or plastic materials were synthesized, polymerizable <span class="hlt">ultraviolet</span> stabilizers, particularly of the 2(2-hydroxyphenyl)2H-benzotriazole family were prepared their polymerization, copolymerization and grafting onto other polymers were demonstrated, and <span class="hlt">ultraviolet</span> stabilizing systems were devised. These materials were evaluated from the photophysical point of view.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5021950','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5021950"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> light and hyperpigmentation in healing wounds</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wiemer, D.R.; Spira, M.</p> <p>1983-10-01</p> <p>The concept of permanent hyperpigmentation in wounds following <span class="hlt">ultraviolet</span> light exposure during the postoperative period has found a place in plastic surgical literature but has not been documented. This study evaluates the effect of <span class="hlt">ultraviolet</span> light on healing wounds in paraplegics. It failed to confirm permanent alteration in pigmentation response to <span class="hlt">ultraviolet</span> exposure and suggests that other factors are of greater importance in the development of hyperpigmentation in the healing wound.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/93460','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/93460"><span id="translatedtitle">Large-solid-angle illuminators for extreme <span class="hlt">ultraviolet</span> lithography with laser plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kubiak, G.D.; Tichenor, D.A.; Sweatt, W.C.; Chow, W.W.</p> <p>1995-06-01</p> <p>Laser Plasma Sources (LPSS) of extreme <span class="hlt">ultraviolet</span> radiation are an attractive alternative to synchrotron radiation sources for extreme <span class="hlt">ultraviolet</span> lithography (EUVL) due to their modularity, <span class="hlt">brightness</span>, and modest size and cost. To fully exploit the extreme <span class="hlt">ultraviolet</span> power emitted by such sources, it is necessary to capture the largest possible fraction of the source emission half-sphere while simultaneously optimizing the illumination stationarity and uniformity on the object mask. In this LDRD project, laser plasma source illumination systems for EUVL have been designed and then theoretically and experimentally characterized. Ellipsoidal condensers have been found to be simple yet extremely efficient condensers for small-field EUVL imaging systems. The effects of aberrations in such condensers on extreme <span class="hlt">ultraviolet</span> (EUV) imaging have been studied with physical optics modeling. Lastly, the design of an efficient large-solid-angle condenser has been completed. It collects 50% of the available laser plasma source power at 14 nm and delivers it properly to the object mask in a wide-arc-field camera.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850010601','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850010601"><span id="translatedtitle">Combined <span class="hlt">ultraviolet</span> studies of astronomical sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dupree, A. K.; Baliunas, S. L.; Blair, W. P.; Hartmann, L. W.; Huchra, J. P.; Raymond, J. C.; Smith, G. H.; Sonderblom, D. R.</p> <p>1985-01-01</p> <p><span class="hlt">Ultraviolet</span> studies of various astronomical entities are reported. Among the specific phenomena examined were supernova remnants, dwarf novae, red giant stars, stellar winds, binary stars, and galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720000708','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720000708"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> and thermally stable polymer compositions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adamson, M. J.; Gloria, H. R.; Goldsberry, R. E.; Reinisch, R. F.</p> <p>1972-01-01</p> <p>Copolymers, produced from aromatic substituted aromatic azine-siloxane compositions, are thermally stable, solar <span class="hlt">ultraviolet</span> light non-degradable by wavelengths shorter than those reaching earth surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/2133336','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/2133336"><span id="translatedtitle">Dynamic <span class="hlt">ultraviolet</span> sterilization of different implant types.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Delgado, A A; Schaaf, N G</p> <p>1990-01-01</p> <p>This paper investigates the use of the dynamic <span class="hlt">ultraviolet</span> sterilization process with various dental implants, stainless steel orthopedic cortical bone screws, and polysulfone polymer healing caps. These biomaterials were inoculated with the spores of Bacillus subtilis and Bacillus stearothermophilus. They were then exposed to dynamic <span class="hlt">ultraviolet</span> radiation in the chamber of a BUD <span class="hlt">Ultraviolet</span> Device. Samples were incubated in trypticase soy broth at 37 degrees C and 56 degrees C, and they were subcultured onto an enriched agar medium. Results indicate that 16 seconds of dynamic <span class="hlt">ultraviolet</span> radiation is effective in sterilizing these materials. This is significantly less time than other sterilization techniques presently used. PMID:2133336</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040074999&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528ultraviolet%2Bradiation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040074999&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528ultraviolet%2Bradiation%2529"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Radiation and Stratospheric Ozone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stolarski, R.</p> <p>2003-01-01</p> <p><span class="hlt">Ultraviolet</span> radiation from the sun produces ozone in the stratosphere and it participates in the destruction of ozone. Absorption of solar <span class="hlt">ultraviolet</span> radiation by ozone is the primary heating mechanism leading to the maximum in temperature at the stratopause. Variations of solar <span class="hlt">ultraviolet</span> radiation on both the 27-day solar rotation period and the 11-year solar cycle affect ozone by several mechanisms. The temperature and ozone in the upper stratosphere respond to solar uv variations as a coupled system. An increase in uv leads to an increase in the production of ozone through the photolysis of molecular oxygen. An increase in uv leads to an increase in temperature through the heating by ozone photolysis. The increase in temperature leads to a partially-offsetting decrease in ozone through temperature-dependent reaction rate coefficients. The ozone variation modulates the heating by ozone photolysis. The increase in ozone at solar maximum enhances the uv heating. The processes are understood and supported by long-term data sets. Variation in the upper stratospheric temperatures will lead to a change in the behavior of waves propagating upward from the troposphere. Changes in the pattern of wave dissipation will lead to acceleration or deceleration of the mean flow and changes in the residual or transport circulation. This mechanism could lead to the propagation of the solar cycle uv variation from the upper stratosphere downward to the lower stratosphere. This process is not well-understood and has been the subject of an increasing number of model studies. I will review the data analyses for solar cycle and their comparison to model results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6303997','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6303997"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> divergences and supersymmetric theories</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sagnotti, A.</p> <p>1984-09-01</p> <p>This article is closely related to the one by Ferrara in these same Proceedings. It deals with what is perhaps the most fascinating property of supersymmetric theories, their improved <span class="hlt">ultraviolet</span> behavior. My aim here is to present a survey of the state of the art as of August, 1984, and a somewhat more detailed discussion of the breakdown of the superspace power-counting beyond N = 2 superfields. A method is also described for simplifying divergence calculations that uses the locality of subtracted Feynman integrals. 74 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869509','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869509"><span id="translatedtitle">Microgap <span class="hlt">ultra-violet</span> detector</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wuest, Craig R.; Bionta, Richard M.</p> <p>1994-01-01</p> <p>A microgap <span class="hlt">ultra-violet</span> detector of photons with wavelengths less than 400 run (4000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap. Either the anode or the cathode is semi-transparent to UV light. Upon a UV photon striking the cathode an electron is expelled and accelerated across the gap by the electric field causing interactions with other electrons to create an electron avalanche which contacts the anode. The electron avalanche is detected and converted to an output pulse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6980724','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6980724"><span id="translatedtitle">Microgap <span class="hlt">ultra-violet</span> detector</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wuest, C.R.; Bionta, R.M.</p> <p>1994-09-20</p> <p>A microgap <span class="hlt">ultra-violet</span> detector of photons with wavelengths less than 400 run (4,000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap is disclosed. Either the anode or the cathode is semi-transparent to UV light. Upon a UV photon striking the cathode an electron is expelled and accelerated across the gap by the electric field causing interactions with other electrons to create an electron avalanche which contacts the anode. The electron avalanche is detected and converted to an output pulse. 2 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940024090&hterms=fourier+transform+spectrometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfourier%2Btransform%2Bspectrometer','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940024090&hterms=fourier+transform+spectrometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfourier%2Btransform%2Bspectrometer"><span id="translatedtitle">JPL Fourier transform <span class="hlt">ultraviolet</span> spectrometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cageao, R. P.; Friedl, R. R.; Sander, Stanley P.; Yung, Y. L.</p> <p>1994-01-01</p> <p>The Fourier Transform <span class="hlt">Ultraviolet</span> Spectrometer (FTUVS) is a new high resolution interferometric spectrometer for multiple-species detection in the UV, visible and near-IR. As an OH sensor, measurements can be carried out by remote sensing (limb emission and column absorption), or in-situ sensing (long-path absorption or laser-induced fluorescence). As a high resolution detector in a high repetition rate (greater than 10 kHz) LIF system, OH fluorescence can be discriminated against non-resonant background emission and laser scatter, permitting (0, 0) excitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820023341&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820023341&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">The far <span class="hlt">ultraviolet</span> spectroscopic explorer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boggess, A.</p> <p>1982-01-01</p> <p>The scientific objectives and performance characteristics of a new astronomy mission referred to as the far <span class="hlt">ultraviolet</span> spectroscopic explorer, or FUSE are being defined by a team involving people experienced instrumental requirements that best meet the scientific needs. The team is intended to have a lifetime of about one year, ending with the submission of a report to NASA which could be used as the basis for an engineering design study. The principal objective of FUSE is to obtain astronomical spectra at wavelengths shorter than is possible with the Space Telescope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890037976&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890037976&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">LYMAN - The far <span class="hlt">ultraviolet</span> explorer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moos, Warren; Osantowski, John F.</p> <p>1989-01-01</p> <p>The LYMAN FUSE mission concept for far <span class="hlt">ultraviolet</span> astronomy is presented. The wavelength window from 100 to 1200 A provides access to a wide range of important scientific problems in cosmology, galactic structure, stellar evolution, and planetary magnetospheres, which cannot be studied in any other way. The LYMAN FUSE Phase A study is examining in detail mission operations, instrumentation technology, the construction of the instrument module, and the interfaces between the Instrument Module and the Explorer Platform Mission. Most of the mission observing time will be allotted through a competitive Guest Observer program analogous to that in operation for the IUE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JaJAP..55iSD03T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JaJAP..55iSD03T&link_type=ABSTRACT"><span id="translatedtitle">Plasmonic lens for <span class="hlt">ultraviolet</span> wavelength</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeda, Minoru; Tanimoto, Takuya; Inoue, Tsutomu; Aizawa, Kento</p> <p>2016-09-01</p> <p>A plasmonic lens (PL) is one of the promising photonic devices utilizing the surface plasmon wave. In this study, we have newly developed a PL with a 3.5 µm diameter for a wavelength of 375 nm (<span class="hlt">ultraviolet</span> region). It is composed of multiple circular slit apertures milled in aluminum (Al) thin film. We have simulated the electric field distribution of the PL, and confirmed that a tightly focused beam spot of subwavelength size in the far-field region was attained. We have also measured the focusing characteristics of the PL using a near-field scanning optical microscope (NSOM) and compared them with the calculated results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730041432&hterms=wanner&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwanner','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730041432&hterms=wanner&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwanner"><span id="translatedtitle">A standard for <span class="hlt">ultraviolet</span> radiation.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fisher, G. B.; Spicer, W. E.; Mckernan, P. C.; Pereskok, V. F.; Wanner, S. J.</p> <p>1973-01-01</p> <p>Photoemission diode standards for accurately measuring monochromatic <span class="hlt">ultraviolet</span> light intensity (3000 A-1100 A) are described that are also blind to visible light. The standard uses an opaque photocathode of Cs2Te and is unique because of its combination of thinness (19 mm), high sensitivity, time stability, and uniformity of response. Design criteria, construction methods, and difficulties overcome in obtaining a stable, uniform, high yield photocathode responses are discussed. Cs2Te is discussed in terms of a model for high yield photoemitters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790050226&hterms=spectrophotometry+UV&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dspectrophotometry%2BUV','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790050226&hterms=spectrophotometry+UV&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dspectrophotometry%2BUV"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> spectrophotometry of degenerate stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Greenstein, J. L.; Oke, J. B.</p> <p>1979-01-01</p> <p>Observations of one helium- and three hydrogen-atmosphere degenerates made with the International <span class="hlt">Ultraviolet</span> Explorer are discussed. Fluxes in the UV give temperatures in good accordance with those determined from the ground and from the ANS satellite data. Profiles of the strong L-alpha absorption in two DA's fit predictions for the expected temperatures. Gravity determination is vitiated by their steep temperature dependence. If one accepts that theoretical predictions should be correct, corrections to the absolute IUE calibration derived are an upward shift of 3-5%, with irregular residuals attaining + or - 7%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720024178','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720024178"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> photometry of planetary nebulae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Holm, A. V.</p> <p>1972-01-01</p> <p>Nine of the planetary nebulae observed by the Wisconsin filter photometers are compared with 15 Monocerotis in the spectral region 1430-4250 A. The data are corrected for the degradation of the filters of stellar photometer number four with time. Comparisons with simple models indicate that most of the observed nebulae are subject to some interstellar extinction in the far <span class="hlt">ultraviolet</span>. However, NGC 246 and NGC 1360 appear to be nearly unreddened. Thus far no unexpected features have been found in the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983rbit.rept.....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983rbit.rept.....K"><span id="translatedtitle">The relation between isolated tree <span class="hlt">brightness</span> temperature and grass background <span class="hlt">brightness</span> temperature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krusinger, A. E.</p> <p>1983-08-01</p> <p>This study involves thermal infrared measurement for the determination of the diurnal and seasonal aspects of the relations between isolated evergreen tress and a cut grass background and between a large truck <span class="hlt">brightness</span> temperature and cut grass, uncut grass, and bare soil backgrounds. Seasonal changes in the tree <span class="hlt">brightness</span> temperature-background <span class="hlt">brightness</span> temperature contrast ranged from 4 to 5 C in February and March to 1 to 2 C in July. At night, the thermal contrast between trees and background was found to vary inversely with long wave incoming radiation, which is a measure of cloudiness. A study of the change in the thermal contrast during the night showed that, during clear weather, the contrast was at a peak a few hours after sundown and decreased the rest of the night. In overcast conditions, a reduced contrast peak occurred at sundown and very gradually diminished through the night. Isothermal conditions were found to occur in the early mornings, and the time of these occurrences changed seasonally, in a systematic manner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960016737','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960016737"><span id="translatedtitle">The <span class="hlt">Ultraviolet</span> Spectrum of the Jovian Dayglow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liu, Weihong; Dalgarno, A.</p> <p>1995-01-01</p> <p>The <span class="hlt">ultraviolet</span> spectra of molecular hydrogen H2 and HD due to solar fluorescence and photoelectron excitation are calculated and compared with the Jovian equatorial dayglow spectrum measured at 3 A resolution at solar maximum. The dayglow emission is accounted for in both <span class="hlt">brightness</span> and spectral shape by the solar fluorescence and photoelectron excitation and requires no additional energy source. The emission is characterized by an atmospheric temperature of 530 K and an H2 column density of 10(exp 20) cm(exp -2). The dayglow spectrum contains a cascade contribution to the Lyman band emission from high-lying E and F states. Its relative weakness at short wavelengths is due to both self-absorption by H2 and absorption by CH4. Strong wavelength coincidences of solar emission lines and absorption lines of H2 and HD produce unique line spectra which can be identified in the dayglow spectrum. The strongest fluorescence is due to absorption of the solar Lyman-beta line at 1025.72 A by the P(1) line of the (6, 0) Lyman band of H2 at 1025.93 A. The fluorescence lines due to absorption of the solar O 6 line at 1031.91 A by vibrationally excited H2 via the Q(3) line of the (1, 1) Werner band at 1031.86 A are identified. The fluorescence lines provide a sensitive measure of the atmospheric temperature. There occurs an exact coincidence of the solar O 6 line at 1031.91 A and the R(0) line of the (6, 0) Lyman band of HD at 1031-91 A, but HD on Jupiter is difficult to detect due to the dominance of the H2 emission where the HD emission is particularly strong. Higher spectral resolution and higher sensitivity may make possible such a detection. The high resolution (0.3 A) spectra of H2 and HD are presented to stimulate search for the HD on Jupiter with the Hubble Space Telescope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AAS...200.2802F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AAS...200.2802F"><span id="translatedtitle">A Comparison of Variable Total and <span class="hlt">Ultraviolet</span> Solar Irradiance Inputs to 20 th Century Global Warming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foukal, P. V.</p> <p>2002-05-01</p> <p>Analysis of spaceborne radiometry has shown that the total solar irradiance variation over the past two activity cycles was approximately proportional to the weighted difference between areas of dark spots and <span class="hlt">bright</span> faculae and enhanced network. Empirical models of <span class="hlt">ultraviolet</span> irradiance variation indicate that its behavior is dominated by changes in area of the <span class="hlt">bright</span> component alone, whose photometric contrast increases at shorter wavelength.This difference in time behavior of total and UV irradiances could help to discriminate between their relative importance in forcing of global warming. Our recent digitization of archival Ca K images from Mt Wilson and NSO provides the first direct measurement of variations in area of the <span class="hlt">bright</span> component, extending between 1915 and 1999 (previous models have relied on the sunspot number or other proxies to estimate the <span class="hlt">bright</span> - component contribution). We use these more direct measurements to derive the time behavior of solar total and UV irradiance variation, over this period .We find that they are significantly different;the total irradiance variation accounts for over 80 percent of the variance in global temperature during this period, while the <span class="hlt">ultraviolet</span> irradiance variation accounts for only about 20 percent. The amplitude of total irradiance variation in our model is smaller than required to influence global warming,in current climate models.Also, the impact of sulfate aerosol variations on the extended cooling between the 1940's and 1970's must be better understood before the significance of correlations between 20 th century global warming, and any solar activity index can be properly assessed. Despite these caveats, the lower correlation we find between global temperature and UV,compared to total, irradiance requires consideration in the search for physical mechanisms linking solar activity and climate. This work was supported in part under NASA grant NAG5-7607 to CRI, Inc., and NAG5-10998 to the Applied Physics</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920012738','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920012738"><span id="translatedtitle">Dust near luminous <span class="hlt">ultraviolet</span> stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Henry, Richard C.</p> <p>1992-01-01</p> <p>More than 700 luminous stars in the infrared astronomical satellite (IRAS) Skyflux plates were examined for the presence of dust heated by a nearby star. This dust may be distinguished from the ubiquitous cool cirrus by its higher temperature and thus enhanced 60 micron emission. More than 120 dust clouds were found around only 106 of the stars with a volume filling factor of 0.006 and an intercloud separation of 46 pc. A region of dust smoothly distributed through the volume of space heated by the star could not be found and hence an upper limit of 0.05 cm(exp -3) is placed on the equivalent gas density in the intercloud regions. The clouds have an average density of 0.22 cm(exp -3) and a radius of 1.9 pc, <span class="hlt">albeit</span> with wide variations in their properties. Two different scale heights of 140 and 540 pc were found. This was interpreted as evidence for different distributions of dust in and out of the galactic disk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/943506','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/943506"><span id="translatedtitle">High <span class="hlt">Brightness</span> Neutron Source for Radiography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cremer, J. T.; Piestrup, Melvin, A.; Gary, Charles, K.; Harris, Jack, L. Williams, David, J.; Jones, Glenn, E.; Vainionpaa, J. , H.; Fuller, Michael, J.; Rothbart, George, H.; Kwan, J., W.; Ludewigt, B., A.; Gough, R.., A..; Reijonen, Jani; Leung, Ka-Ngo</p> <p>2008-12-08</p> <p>This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and <span class="hlt">brightness</span> was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high <span class="hlt">brightness</span> thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure for the generator and effectively mimics a nuclear reactor. In addition to the new prototype generators, an entirely new plasma ion source for neutron production was developed. First developed by LBNL, this source uses a spiral antenna to more efficiently couple the RF radiation into the plasma, reducing the required gas pressure so that the generator head can be completely sealed, permitting the possible use of tritium gas. This also permits the generator to use the deuterium-tritium reaction to produce 14-MeV neutrons with increases</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Nanos...612635F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Nanos...612635F"><span id="translatedtitle">Ultra-<span class="hlt">bright</span> alkylated graphene quantum dots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, Lan; Tang, Xing-Yan; Zhong, Yun-Xin; Liu, Yue-Wen; Song, Xue-Huan; Deng, Shun-Liu; Xie, Su-Yuan; Yan, Jia-Wei; Zheng, Lan-Sun</p> <p>2014-10-01</p> <p>Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-<span class="hlt">bright</span> PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The photocatalytic rate is ca. 5.9 times higher than that of pure P25, indicating that AGQDs could harness the visible spectrum of sunlight for energy conversion or environmental therapy.Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-<span class="hlt">bright</span> PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22098572','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22098572"><span id="translatedtitle">Reflection modeling in <span class="hlt">ultraviolet</span> phototherapy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grimes, David Robert; Robbins, Chris; Martin, Colin J.; Phanco, Graeme; Hare, Neil John O'</p> <p>2011-07-15</p> <p>Purpose: <span class="hlt">Ultraviolet</span> phototherapy is a widely used treatment which has exceptional success with a variety of skin conditions. Over-exposure to <span class="hlt">ultraviolet</span> radiation (UVR) can however be detrimental and cause side effects such as erythema, photokeratisis, and even skin cancer. Quantifying patient dose is therefore imperative to ensure biologically effective treatment while minimizing negative repercussions. A dose model for treatment would be valuable in achieving these ends. Methods: Prior work by the authors concentrated on modeling the output of the lamps used in treatment and it was found a line source model described the output from the sources to a high degree. In practice, these lamps are surrounded by reflective anodized aluminum in patient treatment cabins and this work extends the model to quantify specular reflections from these planes on patient dose. Results: The extension of the model to allow for reflected images in addition to tube output shows a remarkably good fit to the actual data measured. Conclusions: The reflection model yields impressive accuracy and is a good basis for full UVR cabin modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990ASSL..166...35K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990ASSL..166...35K"><span id="translatedtitle">The International <span class="hlt">Ultraviolet</span> Explorer (IUE)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kondo, Yoji</p> <p></p> <p>The International <span class="hlt">Ultraviolet</span> Explorer (IUE) was launched into a geosynchronous orbit on 26 January 1978. It is equipped with a 45-cm mirror and spectrographs operating in the far-<span class="hlt">ultraviolet</span> (1150-2000 A) and the midultraviolet (1900-3200 A) wavelength regions. In a low-dispersion mode, the spectral resolution is some 6-7 A. In a high-dispersion echelle mode, the resolution is about 0.1 Aat the shortest wavelength and about 0.3 A at the longest. It is a collaborative program among NASA, ESA, and the British SERC. The IUE is operated in real time 16 hours a day from NASA Goddard Space Flight Center near Washington, D.C. and 8 hours daily from ESA's Villafranca ground station near Madrid, Spain. By the end of 1989, 1870 papers, using IUE observations, have been published in referred journals. During the same period, over 1700 different astronomers from all over the world used the IUE for their research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARW27002W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARW27002W"><span id="translatedtitle">Rhodium Nanoparticles for <span class="hlt">Ultraviolet</span> Plasmonics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watson, Anne; Zhang, Xiao; Alcaraz de La Osa, Rodrigo; Sanz, Juan; Fernandez, Francisco; Moreno, Fernando; Finkelstein, Gleb; Liu, Jie; Everitt, Henry</p> <p></p> <p>We introduce the non-oxidizing catalytic noble metal rhodium for <span class="hlt">ultraviolet</span> (UV) plasmonics. 8 nm tripod-shaped planar Rh nanoparticles (NPs) were synthesized by a modified polyol reduction chemistry. They have a calculated local surface plasmon resonance (LSPR) near 330 nm. To illustrate the UV plasmonic performance of Rh, p-aminothiophenol (PATP) was attached to the Rh NPs and enhanced Raman and fluorescence were observed upon UV illumination. The PATP Raman spectra produced by UV and visible excitation were respectively in and out of resonance with the Rh NP LSPR. This clearly revealed resonant spectral enhancement in the UV and accelerated photo-damage produced by intense local fields concentrated near the plasmonic Rh NPs. Simultaneously, surface enhanced fluorescence increased during 13 minutes of resonant UV illumination, providing direct evidence of charge transfer from the Rh NPs. The combined local field enhancement and charge transfer demonstrate essential steps toward plasmonically-enhanced <span class="hlt">ultraviolet</span> photocatalysis. Due to its high chemical stability and strong plasmonic effect, Rh nanoparticles could find wide applications in UV plasmonics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22096784','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22096784"><span id="translatedtitle">Dose modeling in <span class="hlt">ultraviolet</span> phototherapy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grimes, David Robert; Robbins, Chris; O'Hare, Neil John</p> <p>2010-10-15</p> <p>Purpose: <span class="hlt">Ultraviolet</span> phototherapy is widely used in the treatment of numerous skin conditions. This treatment is well established and largely beneficial to patients on both physical and psychological levels; however, overexposure to <span class="hlt">ultraviolet</span> radiation (UVR) can have detrimental effects, such as erythemal responses and ocular damage in addition to the potentially carcinogenic nature of UVR. For these reasons, it is essential to control and quantify the radiation dose incident upon the patient to ensure that it is both biologically effective and has the minimal possible impact on the surrounding unaffected tissue. Methods: To date, there has been little work on dose modeling, and the output of artificial UVR sources is an area where research has been recommended. This work characterizes these sources by formalizing an approach from first principles and experimentally examining this model. Results: An implementation of a line source model is found to give impressive accuracy and quantifies the output radiation well. Conclusions: This method could potentially serve as a basis for a full computational dose model for quantifying patient dose.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23722672','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23722672"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> light and ocular diseases.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yam, Jason C S; Kwok, Alvin K H</p> <p>2014-04-01</p> <p>The objective of this study is to review the association between <span class="hlt">ultraviolet</span> (UV) light and ocular diseases. The data are sourced from the literature search of Medline up to Nov 2012, and the extracted data from original articles, review papers, and book chapters were reviewed. There is a strong evidence that <span class="hlt">ultraviolet</span> radiation (UVR) exposure is associated with the formation of eyelid malignancies [basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)], photokeratitis, climatic droplet keratopathy (CDK), pterygium, and cortical cataract. However, the evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, ocular surface squamous neoplasia (OSSN), and ocular melanoma remained limited. There is insufficient evidence to determine whether age-related macular degeneration (AMD) is related to UV exposure. It is now suggested that AMD is probably related to visible radiation especially blue light, rather than UV exposure. From the results, it was concluded that eyelid malignancies (BCC and SCC), photokeratitis, CDK, pterygium, and cortical cataract are strongly associated with UVR exposure. Evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, OSSN, and ocular melanoma remained limited. There is insufficient evidence to determine whether AMD is related to UV exposure. Simple behaviural changes, appropriate clothing, wearing hats, and UV blocking spectacles, sunglasses or contact lens are effective measures for UV protection. PMID:23722672</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930039408&hterms=aat&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daat','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930039408&hterms=aat&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daat"><span id="translatedtitle">The International <span class="hlt">Ultraviolet</span> Explorer (IUE)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kondo, Yoji</p> <p>1990-01-01</p> <p>The International <span class="hlt">Ultraviolet</span> Explorer (IUE) was launched into a geosynchronous orbit on 26 January 1978. It is equipped with a 45-cm mirror and spectrographs operating in the far-<span class="hlt">ultraviolet</span> (1150-2000 A) and the midultraviolet (1900-3200 A) wavelength regions. In a low-dispersion mode, the spectral resolution is some 6-7 A. In a high-dispersion echelle mode, the resolution is about 0.1 Aat the shortest wavelength and about 0.3 A at the longest. It is a collaborative program among NASA, ESA, and the British SERC. The IUE is operated in real time 16 hours a day from NASA Goddard Space Flight Center near Washington, D.C. and 8 hours daily from ESA's Villafranca groundstation near Madrid, Spain. By the end of 1989, 1870 papers, using IUE observations, have been published in referred journals. During the same period, over 1700 different astronomers from all over the world used the IUE for their research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9202447','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9202447"><span id="translatedtitle"><span class="hlt">Brightness</span> discrimination ability in the West Indian manatee (Trichechus manatus).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Griebel, U; Schmid, A</p> <p>1997-06-01</p> <p>Two manatees were tested on their ability to discriminate <span class="hlt">brightness</span> using a series of 30 shades of grey varying from white to black. The animals were trained to discriminate between different shades of grey in a twofold simultaneous-choice situation. Their ability to discern <span class="hlt">brightness</span> differences correlates with Werber's law, and the calculated Werber fraction is 0.35. PMID:9202447</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1215320','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1215320"><span id="translatedtitle">Analysis of <span class="hlt">Bright</span> Harvest Remote Analysis for Residential Solar Installations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nangle, John; Simon, Joseph</p> <p>2015-06-17</p> <p><span class="hlt">Bright</span> Harvest provides remote shading analysis and design products for residential PV system installers. The National Renewable Energy Laboratory (NREL) through the NREL Commercialization Assistance Program, completed comparative assessments between on-site measurements and remotely calculated values to validate the accuracy of <span class="hlt">Bright</span> Harvest’s remote shading and power generation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890000819','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890000819"><span id="translatedtitle">Spain 31-GHz observations of sky <span class="hlt">brightness</span> temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gary, B. L.</p> <p>1988-01-01</p> <p>A water vapor radiometer was deployed at DSS 63 for 3 months of sky <span class="hlt">brightness</span> temperature measurements at 31 GHz. An exceedance plot was derived from this data showing the fraction of time that 31 GHz 30 degree elevation angle <span class="hlt">brightness</span> temperature exceeds specified values. The 5 percent exceedance statistics occurs at 75 K, compared with 70 K in Australia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Social-Emotional+AND+Development+AND+children&pg=7&id=ED564302','ERIC'); return false;" href="http://eric.ed.gov/?q=Social-Emotional+AND+Development+AND+children&pg=7&id=ED564302"><span id="translatedtitle">Challenging Exceptionally <span class="hlt">Bright</span> Children in Early Childhood Classrooms</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gadzikowski, Ann</p> <p>2013-01-01</p> <p>Nearly every group of children includes at least one exceptionally <span class="hlt">bright</span> child. From the especially creative child to the child who has already mastered learning outcomes to the "twice exceptional" child, exceptionally <span class="hlt">bright</span> children have a wide range of talents and behaviors. This book will help you understand what it means to be…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21448743','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21448743"><span id="translatedtitle">MAGNETIC <span class="hlt">BRIGHT</span> POINTS IN THE QUIET SUN</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sanchez Almeida, J.; Bonet, J. A.; Viticchie, B.</p> <p>2010-05-20</p> <p>We present a visual determination of the number of <span class="hlt">bright</span> points (BPs) existing in the quiet Sun, which are structures though to trace intense kG magnetic concentrations. The measurement is based on a 0.''1 angular resolution G-band movie obtained with the Swedish Solar Telescope at the solar disk center. We find 0.97 BPs Mm{sup -2}, which is a factor 3 larger than any previous estimate. It corresponds to 1.2 BPs per solar granule. Depending on the details of the segmentation, the BPs cover between 0.9% and 2.2% of the solar surface. Assuming their field strength to be 1.5 kG, the detected BPs contribute to the solar magnetic flux with an unsigned flux density between 13 G and 33 G. If network and inter-network regions are counted separately, they contain 2.2 BPs Mm{sup -2} and 0.85 BPs Mm{sup -2}, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AAS...22524307L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AAS...22524307L"><span id="translatedtitle">Dark Skies, <span class="hlt">Bright</span> Kids Year 6</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liss, Sandra; Troup, Nicholas William; Johnson, Kelsey E.; Barcos-Munoz, Loreto D.; Beaton, Rachael; Bittle, Lauren; Borish, Henry J.; Burkhardt, Andrew; Corby, Joanna; Dean, Janice; Hancock, Danielle; King, Jennie; Prager, Brian; Romero, Charles; Sokal, Kimberly R.; Stierwalt, Sabrina; Wenger, Trey; Zucker, Catherine</p> <p>2015-01-01</p> <p>Now entering our sixth year of operation, Dark Skies, <span class="hlt">Bright</span> Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in central Virginia through fun, hands-on activities that introduce basic Astronomy concepts beyond Virginia's Standards of Learning. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.DSBK has amassed over 15,000 contact hours since 2009 and we continue to broaden our impact. One important step we have taken in the past year is to establish a graduate student led assessment program to identify and implement directed learning goals for DSBK outreach. The collection of student workbooks, observations, and volunteer surveys indicates broad scale success for the program both in terms of student learning and their perception of science. The data also reveal opportunities to improve our organizational and educational practices to maximize student achievement and overall volunteer satisfaction for DSBK's future clubs and outreach endeavors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7636E..3AZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7636E..3AZ"><span id="translatedtitle">High <span class="hlt">brightness</span> EUV light source modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zakharov, Sergey V.; Choi, Peter; Zakharov, Vasily S.</p> <p>2010-04-01</p> <p>EUV source for actinic mask metrology, particularly for defect inspection, requires extremely high <span class="hlt">brightness</span>. The selfabsorption of radiation limits the in-band EUV radiance of the source plasma and the etendue constraint limits the usable power of a conventional single unit EUV source. Theoretical study and numerical modelling has been carried out to address fundamental issues in tin and xenon plasmas and to optimize the performance of EUV sources. The highly ionized xenon plasma in the presence of fast electrons demonstrates the enhanced radiance. Theoretical models and robust modelling tools are being further developed under an international collaboration project FIRE in the frame of the EU FP7 IAPP program. NANO-UV is delivering a new generation of EUV light source with an intrinsic photon collector. Extensive numerical modelling has provided basic numbers to select the optimal regimes for tin and xenon based source operation. From these designs, a family of specially configured multiplexed source structures is being introduced to address the mask metrology needs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20884478','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20884478"><span id="translatedtitle">Chromatic variations suppress suprathreshold <span class="hlt">brightness</span> variations.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kingdom, Frederick A A; Bell, Jason; Gheorghiu, Elena; Malkoc, Gokhan</p> <p>2010-01-01</p> <p>Most objects in natural scenes are suprathreshold in both color (chromatic) and luminance contrast. How salient is each dimension? We have developed a novel method employing a stimulus similar to that used by B. C. Regan and J. D. Mollon (1997) who studied the relative saliencies of the two chromatic cardinal directions. Our stimuli consist of left- and right-oblique modulations of color and/or luminance defined within a lattice of circles. In the "separated" condition, the two modulations were presented separately as forced-choice pairs, and the task was to indicate which was more salient. In the "combined" condition, the two orthogonal-in-orientation modulations were added, and the task was to indicate the more salient orientation. The ratio of color to luminance contrast at the PSE was calculated for both conditions. Across color directions, 48% more luminance contrast relative to color contrast was required to achieve a PSE in the "combined" compared to the "separated" condition. A second experiment showed that the PSE difference was due to the luminance being masked by the color, rather than due to superior color grouping. We conclude that suprathreshold <span class="hlt">brightness</span> variations are masked by suprathreshold color variations. PMID:20884478</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23383886','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23383886"><span id="translatedtitle">Antilensing: the <span class="hlt">bright</span> side of voids.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bolejko, Krzysztof; Clarkson, Chris; Maartens, Roy; Bacon, David; Meures, Nikolai; Beynon, Emma</p> <p>2013-01-11</p> <p>More than half of the volume of our Universe is occupied by cosmic voids. The lensing magnification effect from those underdense regions is generally thought to give a small dimming contribution: objects on the far side of a void are supposed to be observed as slightly smaller than if the void were not there, which together with conservation of surface <span class="hlt">brightness</span> implies net reduction in photons received. This is predicted by the usual weak lensing integral of the density contrast along the line of sight. We show that this standard effect is swamped at low redshifts by a relativistic Doppler term that is typically neglected. Contrary to the usual expectation, objects on the far side of a void are brighter than they would be otherwise. Thus the local dynamics of matter in and near the void is crucial and is only captured by the full relativistic lensing convergence. There are also significant nonlinear corrections to the relativistic linear theory, which we show actually underpredicts the effect. We use exact solutions to estimate that these can be more than 20% for deep voids. This remains an important source of systematic errors for weak lensing density reconstruction in galaxy surveys and for supernovae observations, and may be the cause of the reported extra scatter of field supernovae located on the edge of voids compared to those in clusters. PMID:23383886</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5869126','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5869126"><span id="translatedtitle">Improved <span class="hlt">brightness</span> of the ATA injector</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weir, J.T.; Caporaso, G.J.; Chambers, F.W.; Kalibjian, R.; Kallman, J.; Paul, A.C.; Prono, D.S.; Slominski, M.E.</p> <p>1985-10-01</p> <p>Studies of the ATA injector using the low density plasma cathode (flashboard cathode) have shown that the <span class="hlt">brightness</span> of the injector was being limited by the non-uniform emission of the cathode surface. To avoid this difficulty, we rearranged the cathode-anode geometry to accommodate field shaping surfaces and a field emission cathode. Computer simulations of the cathode-anode geometry using the EBQ code led us to try a 5.5 cm radius cathode with an A-K gap of about 13 cm. There was no grid used during the experiment. The cathode was surrounded by a Pierce correcting shroud and the typical gap voltage was about 2.5 MeV. Our initial tests of the field emission cathodes were done using a woven carbon yarn that was laced through a fine mesh screen and then trimmed to a uniform height. Using these ''tufted'' cathodes, it was easy to vary the number of emission sites per square centimeter. We also varied the geometry of these cathodes by giving the screen a slight convex shape so that the center of the cathode was about 1 cm closer to the anode plane than the edge of the cathode. At the suggestion of R. Adler of MRC, we also tested commerically available velvet cloth. This was done by epoxying the cloth to the cathode surface using a conducting silver epoxy. We tested the velvet cathodes in both the flat and convex configurations to compare with the tufted carbon yarn cathodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatNa..10..676K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatNa..10..676K"><span id="translatedtitle"><span class="hlt">Bright</span> visible light emission from graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Young Duck; Kim, Hakseong; Cho, Yujin; Ryoo, Ji Hoon; Park, Cheol-Hwan; Kim, Pilkwang; Kim, Yong Seung; Lee, Sunwoo; Li, Yilei; Park, Seung-Nam; Shim Yoo, Yong; Yoon, Duhee; Dorgan, Vincent E.; Pop, Eric; Heinz, Tony F.; Hone, James; Chun, Seung-Hyun; Cheong, Hyeonsik; Lee, Sang Wook; Bae, Myung-Ho; Park, Yun Daniel</p> <p>2015-08-01</p> <p>Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics. In particular, the strong light-matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators and plasmonic devices. In addition, electrically biased graphene on SiO2 substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here, we report the observation of <span class="hlt">bright</span> visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced. Hot electrons (˜2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/874615','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/874615"><span id="translatedtitle">High output lamp with high <span class="hlt">brightness</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kirkpatrick, Douglas A.; Bass, Gary K.; Copsey, Jesse F.; Garber, Jr., William E.; Kwong, Vincent H.; Levin, Izrail; MacLennan, Donald A.; Roy, Robert J.; Steiner, Paul E.; Tsai, Peter; Turner, Brian P.</p> <p>2002-01-01</p> <p>An ultra <span class="hlt">bright</span>, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26076467','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26076467"><span id="translatedtitle"><span class="hlt">Bright</span> visible light emission from graphene.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Young Duck; Kim, Hakseong; Cho, Yujin; Ryoo, Ji Hoon; Park, Cheol-Hwan; Kim, Pilkwang; Kim, Yong Seung; Lee, Sunwoo; Li, Yilei; Park, Seung-Nam; Yoo, Yong Shim; Yoon, Duhee; Dorgan, Vincent E; Pop, Eric; Heinz, Tony F; Hone, James; Chun, Seung-Hyun; Cheong, Hyeonsik; Lee, Sang Wook; Bae, Myung-Ho; Park, Yun Daniel</p> <p>2015-08-01</p> <p>Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics. In particular, the strong light-matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators and plasmonic devices. In addition, electrically biased graphene on SiO2 substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here, we report the observation of <span class="hlt">bright</span> visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced. Hot electrons (∼2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications. PMID:26076467</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25192187','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25192187"><span id="translatedtitle">Ultra-<span class="hlt">bright</span> alkylated graphene quantum dots.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Feng, Lan; Tang, Xing-Yan; Zhong, Yun-Xin; Liu, Yue-Wen; Song, Xue-Huan; Deng, Shun-Liu; Xie, Su-Yuan; Yan, Jia-Wei; Zheng, Lan-Sun</p> <p>2014-11-01</p> <p>Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-<span class="hlt">bright</span> PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The photocatalytic rate is ca. 5.9 times higher than that of pure P25, indicating that AGQDs could harness the visible spectrum of sunlight for energy conversion or environmental therapy. PMID:25192187</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060048198','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060048198"><span id="translatedtitle">Solar CIV Vacuum-<span class="hlt">Ultraviolet</span> Fabry-Perot Interferometers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gary, G. Allen; West, Edward A.; Rees, David; McKay, Jack A.; Zukic, Maumer; Herman, Peter</p> <p>2006-01-01</p> <p>Aims: A tunable, high spectral resolution, high effective finesse, vacuum <span class="hlt">ultraviolet</span> (VUV) Fabry-Perot interferometer (PPI) is designed for obtaining narrow-passband images, magnetograms, and Dopplergrams of the transition region emission line of CIV (155 nm). Methods: The integral part of the CIV narrow passband filter package (with a 2-10 pm FWHM) consists of a multiple etalon system composed of a tunable interferometer that provides high-spectral resolution and a static low-spectral resolution interferometer that allows a large effective free spectral range. The prefilter for the interferometers is provided by a set of four mirrors with dielectric high-reflective coatings. A tunable interferometer, a VUV piezoelectric-control etalon, has undergone testing using the surrogate F2 eximer laser line at 157 nm for the CIV line. We present the results of the tests with a description of the overall concept for a complete narrow-band CIV spectral filter. The static interferometer of the filter is envisioned as being hudt using a set of fixed MgF2 plates. The four-mirror prefilter is designed to have dielectric multilayer n-stacks employing the design concept used in the <span class="hlt">Ultraviolet</span> Imager of NASA's Polar Spacecraft. A dual etalon system allows the effective free spectral range to be commensurate with the prefilter profile. With an additional etalon, a triple etalon system would allow a spectrographic resolution of 2 pm. The basic strategy has been to combine the expertise of spaceflight etalon manufacturing with VUV coating technology to build a VUV FPI which combines the best attributes of imagers and spectrographs into a single compact instrument. Results. Spectro-polarimetry observations of the transition region CIV emission can be performed to increase the understanding of the magnetic forces, mass motion, evolution, and energy release within the solar atmosphere at the base of the corona where most of the magnetic field is approximately force-free. The 2D imaging</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012tisd.book..361D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012tisd.book..361D"><span id="translatedtitle">PBS Nanodots for <span class="hlt">Ultraviolet</span> Radiation Nanosensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dekhtyar, Yu.; Romanova, M.; Anischenko, A.; Sudnikovich, A.; Polyaka, N.; Reisfeld, R.; Saraidarov, T.; Polyakov, B.</p> <p></p> <p>PbS nanodots embedded in a zirconium oxide nanofilm were explored as possible <span class="hlt">ultraviolet</span> (UV) sensors for nanodosimetry purposes. The nanodots were excited by <span class="hlt">ultraviolet</span> photons to get emission of weak electrons. The emitted charge correlated to UV exposure indicates that PbS nanodots have potential for use as UV sensors for nanodosimetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=270365','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=270365"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> light-an FDA approved technology</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p><span class="hlt">Ultraviolet</span> Light (254 nm) is a U.S. Food and Drug Administration approved nonthermal intervention technology that can be used for decontamination of food and food contact surfaces. <span class="hlt">Ultraviolet</span> light is a green technology that leaves no chemical residues. Results from our laboratory indicate that ex...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820000154&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2528ultraviolet%2Bradiation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820000154&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2528ultraviolet%2Bradiation%2529"><span id="translatedtitle">Clear Film Protects Against <span class="hlt">Ultraviolet</span> Radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gupta, A.; Yavrouian, A.</p> <p>1983-01-01</p> <p>Acrylic film contains screeing agent filtering <span class="hlt">ultraviolet</span> radiation up to 380 nanometers in wavelength but passes other components of Sunlight. Film used to protect such materials as rubber and plastics degraded by <span class="hlt">ultraviolet</span> light. Used as protective cover on outdoor sheets or pipes made of such materials as polyethylene or polypropylene and on solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=image+AND+processing&pg=2&id=EJ938874','ERIC'); return false;" href="http://eric.ed.gov/?q=image+AND+processing&pg=2&id=EJ938874"><span id="translatedtitle">Pen Ink as an <span class="hlt">Ultraviolet</span> Dosimeter</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Downs, Nathan; Turner, Joanna; Parisi, Alfio; Spence, Jenny</p> <p>2008-01-01</p> <p>A technique for using highlighter ink as an <span class="hlt">ultraviolet</span> dosimeter has been developed for use by secondary school students. The technique requires the students to measure the percentage of colour fading in ink drawn onto strips of paper that have been exposed to sunlight, which can be calibrated to measurements of the <span class="hlt">ultraviolet</span> irradiance using…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25930008','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25930008"><span id="translatedtitle">Near-<span class="hlt">ultraviolet</span> laser diodes for brilliant <span class="hlt">ultraviolet</span> fluorophore excitation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Telford, William G</p> <p>2015-12-01</p> <p>Although multiple lasers are now standard equipment on most modern flow cytometers, <span class="hlt">ultraviolet</span> (UV) lasers (325-365 nm) remain an uncommon excitation source for cytometry. Nd:YVO4 frequency-tripled diode pumped solid-state lasers emitting at 355 nm are now the primary means of providing UV excitation on multilaser flow cytometers. Although a number of UV excited fluorochromes are available for flow cytometry, the cost of solid-state UV lasers remains prohibitively high, limiting their use to all but the most sophisticated multilaser instruments. The recent introduction of the brilliant <span class="hlt">ultraviolet</span> (BUV) series of fluorochromes for cell surface marker detection and their importance in increasing the number of simultaneous parameters for high-dimensional analysis has increased the urgency of including UV sources in cytometer designs; however, these lasers remain expensive. Near-UV laser diodes (NUVLDs), a direct diode laser source emitting in the 370-380 nm range, have been previously validated for flow cytometric analysis of most UV-excited probes, including quantum nanocrystals, the Hoechst dyes, and 4',6-diamidino-2-phenylindole. However, they remain a little-used laser source for cytometry, despite their significantly lower cost. In this study, the ability of NUVLDs to excite the BUV dyes was assessed, along with their compatibility with simultaneous brilliant violet (BV) labeling. A NUVLD emitting at 375 nm was found to excite most of the available BUV dyes at least as well as a UV 355 nm source. This slightly longer wavelength did produce some unwanted excitation of BV dyes, but at sufficiently low levels to require minimal additional compensation. NUVLDs are compact, relatively inexpensive lasers that have higher power levels than the newest generation of small 355 nm lasers. They can, therefore, make a useful, cost-effective substitute for traditional UV lasers in multicolor analysis involving the BUV and BV dyes. PMID:25930008</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22342178','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22342178"><span id="translatedtitle">A closer look at the fluctuations in the <span class="hlt">brightness</span> of SN 2009IP during its late 2012 eruption</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martin, J. C.; Hambsch, F.-J.; Margutti, R.; Soderberg, A.; Tan, T. G.; Curtis, I.</p> <p>2015-01-01</p> <p>The supernova (SN) impostor SN 2009ip has re-brightened several times since its initial discovery in 2009 August. During its last outburst in late 2012 September, it reached a peak <span class="hlt">brightness</span> of m{sub v} ∼13.5 (M{sub v} brighter than −18), causing some to speculate that it had undergone a terminal core-collapse SN. Relatively high-cadence multi-wavelength photometry of the post-peak decline revealed bumps in <span class="hlt">brightness</span> infrequently observed in other SNe IIn. These bumps occurred synchronously in all <span class="hlt">ultraviolet</span> (UV) and optical bands with amplitudes of 0.1–0.4 mag at intervals of 10–30 days. Episodic continuum brightening and dimming in the UV and optical with these characteristics is not easily explained within the context of models that have been proposed for the late September 2012 outburst of SN 2009ip. We also present evidence that the post-peak fluctuations in <span class="hlt">brightness</span> occur at regular intervals and raise more questions about their origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AJ....149....9M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AJ....149....9M"><span id="translatedtitle">A Closer Look At the Fluctuations in the <span class="hlt">Brightness</span> of Sn 2009ip During Its Late 2012 Eruption</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martin, J. C.; Hambsch, F.-J.; Margutti, R.; Tan, T. G.; Curtis, I.; Soderberg, A.</p> <p>2015-01-01</p> <p>The supernova (SN) impostor SN 2009ip has re-brightened several times since its initial discovery in 2009 August. During its last outburst in late 2012 September, it reached a peak <span class="hlt">brightness</span> of mv ˜13.5 (Mv brighter than -18), causing some to speculate that it had undergone a terminal core-collapse SN. Relatively high-cadence multi-wavelength photometry of the post-peak decline revealed bumps in <span class="hlt">brightness</span> infrequently observed in other SNe IIn. These bumps occurred synchronously in all <span class="hlt">ultraviolet</span> (UV) and optical bands with amplitudes of 0.1-0.4 mag at intervals of 10-30 days. Episodic continuum brightening and dimming in the UV and optical with these characteristics is not easily explained within the context of models that have been proposed for the late September 2012 outburst of SN 2009ip. We also present evidence that the post-peak fluctuations in <span class="hlt">brightness</span> occur at regular intervals and raise more questions about their origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27043058','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27043058"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> safety assessments of insect light traps.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sliney, David H; Gilbert, David W; Lyon, Terry</p> <p>2016-06-01</p> <p>Near-<span class="hlt">ultraviolet</span> (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and <span class="hlt">ultraviolet</span> insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous <span class="hlt">ultraviolet</span> emissions. A variety of UV "Black-light" ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to <span class="hlt">ultraviolet</span> radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic <span class="hlt">ultraviolet</span> safety standards for ILT products. PMID:27043058</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4867860','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4867860"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> safety assessments of insect light traps</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sliney, David H.; Gilbert, David W.; Lyon, Terry</p> <p>2016-01-01</p> <p>ABSTRACT Near-<span class="hlt">ultraviolet</span> (UV-A: 315–400 nm), “black-light,” electric lamps were invented in 1935 and <span class="hlt">ultraviolet</span> insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous <span class="hlt">ultraviolet</span> emissions. A variety of UV “Black-light” ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to <span class="hlt">ultraviolet</span> radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic <span class="hlt">ultraviolet</span> safety standards for ILT products. PMID:27043058</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EPJP..127..148S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EPJP..127..148S"><span id="translatedtitle">Addendum to: The <span class="hlt">brightness</span> temperature of Mercury at 150 and 240 GHz. The <span class="hlt">brightness</span> temperature of Mars at millimetre wavelengths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sabbatini, L.; Pizzo, L.; Dall'Oglio, G.</p> <p>2012-12-01</p> <p>We present new measurements of Mars at 1.25 and 2mm of wavelength, in addition to the previous ones performed on Mercury and already published in our paper "The <span class="hlt">brightness</span> temperature of Mercury at 150 and 240GHz". A brief description of the observational strategy is given, and <span class="hlt">brightness</span> temperature of the planet is reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.9044E..0YH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.9044E..0YH"><span id="translatedtitle">Detection of latent fingerprints by <span class="hlt">ultraviolet</span> spectral imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Wei; Xu, Xiaojing; Wang, Guiqiang</p> <p>2013-12-01</p> <p>Spectral imaging technology research is becoming more popular in the field of forensic science. <span class="hlt">Ultraviolet</span> spectral imaging technology is an especial part of the full spectrum of imaging technology. This paper finished the experiment contents of the <span class="hlt">ultraviolet</span> spectrum imaging method and image acquisition system based on <span class="hlt">ultraviolet</span> spectral imaging technology. <span class="hlt">Ultraviolet</span> spectral imaging experiments explores a wide variety of <span class="hlt">ultraviolet</span> reflectance spectra of the object material curve and its <span class="hlt">ultraviolet</span> spectrum of imaging modalities, can not only gives a reference for choosing <span class="hlt">ultraviolet</span> wavelength to show the object surface potential traces of substances, but also gives important data for the <span class="hlt">ultraviolet</span> spectrum of imaging technology development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983A%26A...120..223S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983A%26A...120..223S"><span id="translatedtitle">The <span class="hlt">ultraviolet</span> reddening of Be stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schild, R.</p> <p>1983-04-01</p> <p>The UV extinction of several <span class="hlt">bright</span> Be stars is examined in light of Schild's (1978) demonstration of their intrinsic (B-V) color excess. Stars possessing this excess are found not to have the 0.22-micron bump associated with Bless and Savage's (1972) interstellar reddening law. The <span class="hlt">bright</span> Be stars studied are HD 30076, HD 58011, HD 63462, and HD 105435.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MNRAS.436.3464K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MNRAS.436.3464K"><span id="translatedtitle">Spatial distributions of core-collapse supernovae in infrared-<span class="hlt">bright</span> galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kangas, T.; Mattila, S.; Kankare, E.; Kotilainen, J. K.; Väisänen, P.; Greimel, R.; Takalo, A.</p> <p>2013-12-01</p> <p>We have measured the correlation between the locations of core-collapse supernovae (CCSNe) and host galaxy light in the Hα line, near <span class="hlt">ultraviolet</span> (NUV), R band and Ks band to constrain the progenitors of CCSNe using pixel statistics. Our sample consists of 86 CCSNe in 57 infrared (IR)-<span class="hlt">bright</span> galaxies, of which many are starbursts and 10 are luminous infrared galaxies (LIRGs). We also analyse the radial distribution of CCSNe in these galaxies, and determine power-law and exponential fits to CCSN surface density profiles. To probe differences between the SN population of these galaxies and normal spiral galaxies, our results were compared to previous similar studies with samples dominated by normal spiral galaxies where possible. We obtained a normalized scale length of 0.23^{+0.03}_{-0.02} R25 for the surface density of CCSNe in IR-<span class="hlt">bright</span> galaxies; less than that derived for CCSNe in a galaxy sample dominated by normal spiral galaxies (0.29 ± 0.01). This reflects a more centrally concentrated population of massive stars in IR-<span class="hlt">bright</span> galaxies. Furthermore, this centralization is dominated by a central excess of Type Ibc/IIb SNe. This may be due to a top-heavy initial mass function and/or an enhanced close binary fraction in regions of enhanced star formation. Type Ic SNe are most strongly correlated with Hα light and NUV-<span class="hlt">bright</span> regions, reflecting the shortest lifetime and thus highest mass for Type Ic progenitors. Previous studies with samples dominated by normal spiral galaxies have indicated a lower Ibc-Hα correlation than our results do, which may be due to the central excess of Type Ibc/IIb SNe in our sample. The difference between Types II and Ib is insignificant, suggesting that progenitor mass is not the dominant factor in determining if a SN is of Type Ib or II. Similar differences in correlation can be seen in the Ks band (which in these galaxies is dominated by red supergiants and thus also traces recent star formation), with Type Ibc/IIb SNe tracing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AAS...22124602S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AAS...22124602S&link_type=ABSTRACT"><span id="translatedtitle">Dark Skies, <span class="hlt">Bright</span> Kids! Year 4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sokal, Kimberly R.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R.; Borish, J.; Crawford, S. B.; Corby, J.; Damke, G.; Dean, J.; Dorsey, G.; Jackson, L.; Liss, S.; Oza, A.; Peacock, S.; Prager, B.; Romero, C.; Sivakoff, G. R.; Walker, L.; Whelan, D. G.; Zucker, C.</p> <p>2013-01-01</p> <p>Aiming to engage young children's natural excitement and curiosity, the outreach group Dark Skies, <span class="hlt">Bright</span> Kids (DSBK) brings a hands-on approach to astronomy to elementary schools in Virginia. We hope to enhance children's view and understanding of science while exploring the Universe using fun activities. DSBK focuses on rural and underserved schools in Albemarle County and offers a semester-long astronomy club for third through fifth grade students. We believe regular interactions foster personal relationships between students and volunteers that encourage a life-long interest in science. In our fourth year of hosting clubs, we returned to Ivy Creek Elementary School, where we saw wonderful responses from a special group of students with `low-incidence' disabilities. DSBK has grown to realize a broader reach beyond local astronomy clubs; we hope to ignite a spark of interest in astronomy and science more widely- in more children, their families, and their teachers. We also hosted the Second Annual Central Virginia Star Party with an open invitation to the community to encourage families to enjoy astronomy together. Throughout the year, DSBK now holds 'one-off' programs (akin to astronomy field days) for elementary schools and children's groups throughout Virginia. Furthermore, we are in the final stages of a project to create two bilingual astronomy books called "Snapshots of the Universe", in Spanish and French with English translations. This art book will be made available online and we are working to get a copy in every elementary school in the state. DSBK has begun to reach out to elementary school teachers in order to provide them with useful and engaging classroom material. We have adapted our volunteer-created activities into useful and ready-to-use lessons, available online. After improvements based on research through interactions and feedback from teachers, we have explicitly identified the learning goals in terms of Virginia's Standards of Learning</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AAS...21934707W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AAS...21934707W&link_type=ABSTRACT"><span id="translatedtitle">Dark Skies, <span class="hlt">Bright</span> Kids! Year 3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whelan, David G.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R. L.; Borish, J.; Corby, J. F.; Dorsey, G.; Gugliucci, N. E.; Prager, B. J.; Ries, P. A.; Romero, C. E.; Sokal, K. R.; Tang, X.; Walker, L. M.; Yang, A. J.; Zasowski, G.</p> <p>2012-01-01</p> <p>Dark Skies, <span class="hlt">Bright</span> Kids! (DSBK) is a program that brings astronomy education to elementary schools throughout central Virginia. In a relaxed, out-of-classroom atmosphere, we are able to foster the innate curiosity that young students have about science and the world around them. We target schools that are under-served due to their rural locale or special needs students, demonstrating that science is a fun and creative process to a segment of the population that might not otherwise be exposed to astronomy. Families are included in the learning experience during semi-annual `star parties'. Since last January, we have expanded the breadth and depth of our educational capabilities. We have developed new programs for use in our digital planetarium. We held the first Central Virginia Star Party, providing an atmosphere where local children from multiple schools were able to share their love for astronomy. Local government and University officials were also invited so that they could experience our focused science outreach. Most recently, we have become part of Ivy Creek School's Club Day activities, bringing our program to a new segment of the elementary school system in Albemarle County: those that have `low-incidence' disabilities, requiring special attention. We continue to develop a curriculum for after-school programs that functions as either a series of one-time activities or several months of focused outreach at one school. Many of these activities are provided on our website, http://www.astro.virginia.edu/dsbk/, for the wider astronomical community, including the new planetarium work. We have extended our book project to include two bilingual astronomy books called `Snapshots of the Universe,' one in Spanish and English, the other in French and English. These books introduce young people to some of the many wonders of the Universe through art and captions developed by DSBK volunteers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IAUS..304..403P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IAUS..304..403P"><span id="translatedtitle">Optical microvariability of <span class="hlt">bright</span> type 2 quasars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Polednikova, Jana; Ederoclite, Alessandro; Cepa, Jordi; de Diego Onsurbe, José Antonio; González-Serrano, José Ignacio</p> <p>2014-07-01</p> <p>We present results from a project focused on searching optical microvariabilty (also known as ``intra-night'' variability) in type 2 - obscured - quasars. Optical microvariability can be described as very small changes in the flux, typically in the order of hundredths of magnitude, which can be observed on timescales of hours. Such studies have been so far conducted for samples of blazars and type 1, unobscured, AGNs, where the optical microvariability was detected with success. We have focused on obscured targets which would pose a challenge to the AGN standard model. In the present work, however, we have observed a sample of three <span class="hlt">bright</span> (g mag < 17) type 2 quasar, based on the catalog of type 2 quasars from SDSS of Reyes et al. (2008). The observations were carried out with the 1.5 meter telescope at San Pedro Martir observatory in Mexico. The sample was observed during an observation period of four days in Johnsons V filter, resulting in at least two continuous intervals of observations per target during the observational run. We have obtained differential light curves for our sources as well as for the comparison stars. They were analyzed using one-way analysis of variance statistical test (ANOVA), which has been repeatedly used in the past for studies of unobscured targets. Based on the results from the statistical analysis, we show that at least two out of three observed targets appear to be variable on time scales of hours. So far, this is the first study which confirmed existence of optical microvariability in type 2 quasars.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AAS...21715805C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AAS...21715805C"><span id="translatedtitle">Dark Skies, <span class="hlt">Bright</span> Kids: Year 2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carlberg, Joleen K.; Johnson, K.; Lynch, R.; Walker, L.; Beaton, R.; Corby, J.; de Messieres, G.; Drosback, M.; Gugliucci, N.; Jackson, L.; Kingery, A.; Layman, S.; Murphy, E.; Richardson, W.; Ries, P.; Romero, C.; Sivakoff, G.; Sokal, K.; Trammell, G.; Whelan, D.; Yang, A.; Zasowski, G.</p> <p>2011-01-01</p> <p>The Dark Skies, <span class="hlt">Bright</span> Kids (DSBK) outreach program brings astronomy education into local elementary schools in central Virginia's Southern Albemarle County through an after-school club. Taking advantage of the unusually dark night skies in the rural countryside, DSBK targets economically disadvantaged schools that tend to be underserved due to their rural locale. The goals of DSBK are to foster children's natural curiosity, demonstrate that science is a fun and creative process, challenge students' conceptions of what a scientist is and does, and teach some basic astronomy. Furthermore, DSBK works to assimilate families into students' education by holding family observing nights at the school. Now in its third semester, DSBK has successfully run programs at two schools with very diverse student populations. Working with these students has helped us to revise our activities and to create new ones. A by-product of our work has been the development of lesson plans, complete with learning goals and detailed instructions, that we make publically available on our website. This year we are expanding our repertoire with our new planetarium, which allows us to visualize topics in novel ways and supplements family observing on cloudy nights. The DSBK volunteers have also created a bilingual astronomy artbook --- designed, written, and illustrated by UVa students --- that we will publish and distribute to elementary schools in Virginia. Our book debuted at the last AAS winter meeting, and since then it has been extensively revised and updated with input from many individuals, including parents, professional educators, and a children's book author. Because the club is currently limited to serving a few elementary schools, this book will be part of our efforts to broaden our impact by bringing astronomy to schools we cannot go to ourselves and reaching out to Spanish-speaking communities at the same time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982EOSTr..63..577K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982EOSTr..63..577K"><span id="translatedtitle">Impact of snow on surface <span class="hlt">brightness</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kukla, George J.; Brown, Jeffrey A.</p> <p></p> <p>The snow-covered land surface has different albedo than the snow-free surface, depending primarily on the type and density of the vegetation, the relief, and the continuity and age of the snow blanket. This is clearly demonstrated by the winter mosaic of east central Asia shown on the front cover. It is a section of a larger composite assembled from cloud-free satellite images to portray the land surface under continuous snow cover. The mosaic is a valuable tool for distinguishing (from remote positions) snow from clouds and for charting snow cover where illumination is poor. It also can be used to determine relative sensitivity of surface albedo to the occurrence of snow.Segments with a minimum of clouds along the orbital subtrack were selected from the transparencies of the Defense Meteorological Satellite Program (DMSP). Satellite sensors record in the spectral band 0.4-1.2 µm. The satellite is in polar orbit at a mean altitude of 830 km (450 nm) and crosses the equator at approximately local noon. The spatial resolution along the orbital subtrack is about 0.6 km [Dickinson et al., 1974]. The mosaic is assembled from imagery taken between mid-January and mid-February of 1979. The original hard-copy transparencies (on loan from the DMSP library) were reproduced as contact negatives to preserve detail.The snow cover marks the land surface with a characteristic signature that depends on the distribution, density, and type of vegetation; relief; presence of water bodies; distribution and type of land use, etc. This signature can be readily utilized, among others, to distinguish snow-covered land from clouds and from snow-free land [Barnes et al., 1974; Lillesand et al., 1982]. We have compared the <span class="hlt">brightness</span> fields in the imagery with the vegetation density and land-use patterns charted in the World Forestry Atlas [Wiebecke, 1971].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IAUS..284..237M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IAUS..284..237M"><span id="translatedtitle">Multiwavelength data for <span class="hlt">bright</span> active galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mickaelian, Areg M.; Abrahamyan, Hayk V.; Paronyan, Gurgen M.; Harutyunyan, Gohar S.</p> <p>2012-08-01</p> <p>The spectral energy distribution (SED) gives a complete picture of the radiation of space objects and may result in correct classifications compared to those based only on optical (or other local) spectra. This is especially crucial for active galaxies, both AGN and Starbursts (SB). For this, multiwavelength (MW) data are needed taken from available surveys and catalogs. We have cross-correlated the Catalogue of quasars and active galaxies with all-sky or large-area MW catalogues, such as X-ray ROSAT (BSC and FSC), UV GALEX (MIS and AIS), optical APM, MAPS, USNO-B1.0, GSC 2.3.2, and SDSS DR8, NIR 2MASS, MIR/FIR WISE, IRAS (PSC and FSC) and AKARI (IRC and FIS), radio GB6, NVSS, FIRST, and WENSS. We have established accurate positions and photometry for a few thousands of objects that appeared in the catalog with poor data, as well as achieved the best astrometric and photometric data for all objects. This allowed correct cross-correlations and establishing correct MW data for these objects. As a result, we obtained 34 photometric points from X-rays to radio and using VO tools built SEDs for some 10,000 <span class="hlt">bright</span> objects. Some data from other surveys were also used, such as Chandra, XMM, Spitzer, etc. All objects were grouped into several forms of SED and were compared to the known optical classes given in the catalog (QSO, BLL, Sy1, Sy1.2-1.9, Sy2, LINER, SB, and HII). This allowed reveal obscured AGN, as well as find previously misclassified objects. A homogeneous classification for these objects was established. The first part of this project is presented; establishment of accurate positions and photometry and cross-correlations with MW catalogs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AAS...22344404P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AAS...22344404P"><span id="translatedtitle">Dark Skies, <span class="hlt">Bright</span> Kids! Year 5</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prager, Brian; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R.; Bittle, L.; Borish, H.; Burkhardt, A.; Corby, J.; Damke, G.; Dean, J.; Dorsey, G.; Graninger, D.; Lauck, T.; Liss, S.; Oza, A.; Peacock, S.; Romero, C.; Sokal, K. R.; Stierwalt, S.; Walker, L.; Wenger, T.; Zucker, C.</p> <p>2014-01-01</p> <p>Our public outreach group Dark Skies, <span class="hlt">Bright</span> Kids! (DSBK) fosters science literacy in Virginia by bringing a hands-on approach to astronomy that engages children's natural excitement and curiosity. We are an entirely volunteer-run group based out of the Department of Astronomy at the University of Virginia and we enthusiastically utilize astronomy as a 'gateway science.' We create long-term relationships with students during an 8 to 10 week long, after-school astronomy club at under served elementary schools in neighboring counties, and we visited 3 different schools in 2013. Additionally, we organize and participate in science events throughout the community. The fifth year of DSBK was marked by surpassing 10,000 contact hours in Spring 2013 Semester and by ringing in the fall semester with our biggest, most successful star party to date. We hosted the Third Annual Central Virginia Star Party, free and open to the community to encourage families to enjoy astronomy together. Nearly four hundred people of all ages attended, double the number from previous years. Joining with local astronomical societies, we offered an enlightening and exciting night with resources rarely accessible to the public, such as an IR camera and a portable planetarium. With numerous telescopes pointed at the sky, and a beautifully clear night with views of the Milky Way, the International Space Station, and numerous meteors, the star party was a fantastic opportunity to introduce many of our guests to the natural wonders of our night sky and enjoy some of the darkest skies on the eastern seaboard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ap%26SS.355....1F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ap%26SS.355....1F"><span id="translatedtitle">Far <span class="hlt">ultraviolet</span> nighttime ionospheric photometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Liping; Peng, Ruyi; Shi, Entao; Peng, Jilong; Wang, Tianfang; Jiang, Fang; Jia, Nan; Li, Xiaoyin; Wang, Yongmei</p> <p>2015-01-01</p> <p>Far <span class="hlt">Ultraviolet</span> Nighttime Ionopsheric Photometer (FNIP) is a newly-designed instrument for low earth orbit missions, observing the earth night airglow nadir at OI 135.6 nm emission produced by ionospheric O++e recombination and receiving the horizontal information on nighttime ionosphere with a spatial resolution of about 1.6∘×3.8∘. This simple, highly robust instrument excludes OI 130.4 nm emission and Herzberg oxygen bands with lower power and approximately achieves a sensitivity of about 400 counts/s/Rayleigh at 135.6 nm with stray light less than 2 %. Some tests of the instrument have been conducted and the results will be discussed in the end.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930029560&hterms=ageing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dageing','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930029560&hterms=ageing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dageing"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> spectroscopy of cometary comae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feldman, Paul D.</p> <p>1991-01-01</p> <p>During the past decade, vacuum <span class="hlt">ultraviolet</span> spectra of over 30 comets have been obtained with the IUE satellite observatory. With few exceptions, the spectra of these comets appear to be similar, with OH and H produced by the photodissociation of water being the dominant species and emissions of C, O, S, CS and CO2(+) usually present. Although signs of variabiity of many kinds in comet spectra appear, the evidence from the UV observations suggests that all comets have the same basic chemical composition and that observed differences are due to evolution and ageing processes. During the 1985-86 apparition of Comet Halley, spectra were also obtained by other spacecraft and by sounding rocket instruments, including a long-slit imaging spectrograph.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790038545&hterms=Photobiology&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPhotobiology','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790038545&hterms=Photobiology&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPhotobiology"><span id="translatedtitle">Cloud effects on <span class="hlt">ultraviolet</span> photoclimatology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Green, A. E. S.; Spinhirne, J. D.</p> <p>1978-01-01</p> <p>The purpose of this study is to quantify for the needs of photobiology the influence of clouds upon the <span class="hlt">ultraviolet</span> spectral irradiance reaching the ground. Towards this end, analytic formulas are developed which approximately characterize the influence of clouds upon total solar radiation. These may be used in conjunction with a solar pyranometer to assign an effective visual optical depth for the cloud cover. A formula is also developed which characterizes the influence of the optical depth of clouds upon the UV spectral irradiance in the 280-340 nm region. Thus total solar energy observations to assign cloud optical properties can be used to calculate the UV spectral irradiance at the ground in the presence of these clouds. As incidental by-products of this effort, convenient formulas are found for the direct and diffuse components of total solar energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010foan.book..387P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010foan.book..387P"><span id="translatedtitle"><span class="hlt">Ultraviolet</span>, Visible, and Fluorescence Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Penner, Michael H.</p> <p></p> <p>Spectroscopy in the <span class="hlt">ultraviolet</span>-visible (UV-Vis) range is one of the most commonly encountered laboratory techniques in food analysis. Diverse examples, such as the quantification of macrocomponents (total carbohydrate by the phenol-sulfuric acid method), quantification of microcomponents, (thiamin by the thiochrome fluorometric procedure), estimates of rancidity (lipid oxidation status by the thiobarbituric acid test), and surveillance testing (enzyme-linked immunoassays), are presented in this text. In each of these cases, the analytical signal for which the assay is based is either the emission or absorption of radiation in the UV-Vis range. This signal may be inherent in the analyte, such as the absorbance of radiation in the visible range by pigments, or a result of a chemical reaction involving the analyte, such as the colorimetric copper-based Lowry method for the analysis of soluble protein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880019324','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880019324"><span id="translatedtitle">International <span class="hlt">ultraviolet</span> explorer observatory operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1986-01-01</p> <p>This volume contains the Final Report for the International <span class="hlt">Ultraviolet</span> Explorer (IUE) Observatory Operations contract, NAS5-28787. The report summarizes the activities of the IUE Observatory over the 13-month period from November 1985 through November 1986 and is arranged in sections according to the functions specified in the Statement of Work (SOW) of the contract. In order to preserve numerical correspondence between the technical SOW elements specified by the contract and the sections of this report, project management activities (SOW element 0.0.) are reported here in Section 7, following the reports of technical SOW elements 1.0 through 6.0. Routine activities have been summarized briefly whenever possible; statistical compilations, reports, and more lengthy supplementary material are contained in the Appendices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985Icar...62..305B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985Icar...62..305B"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> reflectance properties of asteroids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butterworth, P. S.; Meadows, A. J.</p> <p>1985-05-01</p> <p>An analysis of the UV spectra of 28 asteroids obtained with the Internal <span class="hlt">Ultraviolet</span> Explorer (IUE) satellite is presented. The spectra lie within the range 2100-3200 A. The results are examined in terms of both asteroid classification and of current ideas concerning the surface mineralogy of asteroids. For all the asteroids examined, UV reflectivity declines approximately linearly toward shorter wavelengths. In general, the same taxonomic groups are seen in the UV as in the visible and IR, although there is some evidence for asteroids with anomalous UV properties and for UV subclasses within the S class. No mineral absorption features are reported of strength similar to the strongest features in the visible and IR regions, but a number of shallow absorptions do occur and may provide valuable information on the surface composition of many asteroids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840027157&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840027157&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">The <span class="hlt">ultraviolet</span> astronomy mission: Columbus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, R.</p> <p>1984-01-01</p> <p>An <span class="hlt">ultraviolet</span> astronomy mission (Columbus) is described. It exploits the spectral region between 900 and 1200A, which is extremely rich in containing the Lyman lines of hydrogen and deuterium and the Lyman band of their molecules, together with the resonance lines of many important ions. High resolving power and high sensitivity provide a unique capability for studying the brightest members of neighboring galaxies, the HeI and HeII absorption systems in quasars out to a red shift of 2, and the halos of intervening galaxies. Complementary focal plane instruments are planned in order to allow observations to longer (2000A) and shorter (100A) wavelengths. This wide coverage embraces the resonance lines of all the cosmically abundant elements and a wide range of temperature zones up to 100 million K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950025399','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950025399"><span id="translatedtitle">Global <span class="hlt">Ultraviolet</span> Imager (GUVI) investigation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christensen, Andrew B.</p> <p>1995-01-01</p> <p>This report covers the activities performed under NAS5-32572. The results of those activities are included in this Final Report. TIMED Science Objectives: (1) To determine the temperature, density, and wind structure of the MLTI (mixed layer thermal inertia), including the seasonal and latitudinal variations; and (2) To determine the relative importance of the various radiative, chemical, electrodynamical, and dynamical sources and sinks of energy for the thermal structure of the MLTI. GUVI Science Goals: (1) Determine the spatial and temporal variations of temperature and constituent densities in the lower thermosphere; and (2) Determine the importance of auroral energy sources and solar EUV (extreme <span class="hlt">ultraviolet</span>) to the energy balance of the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17676122','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17676122"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> characterization of integrating spheres.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shaw, Ping-Shine; Li, Zhigang; Arp, Uwe; Lykke, Keith R</p> <p>2007-08-01</p> <p>We have studied the performance of polytetrafluoroethylene integrating spheres in the <span class="hlt">ultraviolet</span> (UV) region with wavelengths as short as 200 nm. Two techniques were used for this study; first, the spectral throughput of an integrating sphere irradiated by a deuterium lamp was analyzed by a monochromator. Second, a UV laser beam was directed into an integrating sphere, and spectrally dispersed laser induced fluorescence was studied. Significant absorption and fluorescence features were observed in the UV region and attributed to the contamination in the integrating sphere. We demonstrate that integrating spheres are easily contaminated by environmental pollutants such as polycyclic aromatic hydrocarbons emitted from engine exhaust. Baking of the contaminated integrating sphere can reverse some but not all of the effects caused by contaminants. The implications for using integrating spheres for UV measurement are discussed. PMID:17676122</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ApOpt..46.5119S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ApOpt..46.5119S"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> characterization of integrating spheres</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shaw, Ping-Shine; Li, Zhigang; Arp, Uwe; Lykke, Keith R.</p> <p>2007-08-01</p> <p>We have studied the performance of polytetrafluoroethylene integrating spheres in the <span class="hlt">ultraviolet</span> (UV) region with wavelengths as short as 200 nm. Two techniques were used for this study; first, the spectral throughput of an integrating sphere irradiated by a deuterium lamp was analyzed by a monochromator. Second, a UV laser beam was directed into an integrating sphere, and spectrally dispersed laser induced fluorescence was studied. Significant absorption and fluorescence features were observed in the UV region and attributed to the contamination in the integrating sphere. We demonstrate that integrating spheres are easily contaminated by environmental pollutants such as polycyclic aromatic hydrocarbons emitted from engine exhaust. Baking of the contaminated integrating sphere can reverse some but not all of the effects caused by contaminants. The implications for using integrating spheres for UV measurement are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22167109','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22167109"><span id="translatedtitle">THE <span class="hlt">ULTRAVIOLET</span> RADIATION ENVIRONMENT AROUND M DWARF EXOPLANET HOST STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>France, Kevin; Froning, Cynthia S.; Stocke, John T.; Bushinsky, Rachel; Linsky, Jeffrey L.; Roberge, Aki; Tian, Feng; Desert, Jean-Michel; Mauas, Pablo; Vieytes, Mariela; Walkowicz, Lucianne M.</p> <p>2013-02-15</p> <p>The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. <span class="hlt">Ultraviolet</span> photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis exists for understanding the <span class="hlt">ultraviolet</span> spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both far-UV (FUV) and near-UV (NUV) wavelengths. The combined FUV+NUV spectra are publicly available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No 'UV-quiet' M dwarfs are observed. The <span class="hlt">bright</span> stellar Ly{alpha} emission lines are reconstructed, and we find that the Ly{alpha} line fluxes comprise {approx}37%-75% of the total 1150-3100 A flux from most M dwarfs; {approx}>10{sup 3} times the solar value. We develop an empirical scaling relation between Ly{alpha} and Mg II emission, to be used when interstellar H I attenuation precludes the direct observation of Ly{alpha}. The intrinsic unreddened flux ratio is F(Ly{alpha})/F(Mg II) = 10 {+-} 3. The F(FUV)/F(NUV) flux ratio, a driver for abiotic production of the suggested biomarkers O{sub 2} and O{sub 3}, is shown to be {approx}0.5-3 for all M dwarfs in our sample, >10{sup 3} times the solar ratio. For the four stars with moderate signal-to-noise Cosmic Origins Spectrograph time-resolved spectra, we find UV emission line variability with amplitudes of 50%-500% on 10{sup 2}-10{sup 3} s timescales. This effect should be taken into account in future UV transiting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130013639','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130013639"><span id="translatedtitle">The <span class="hlt">Ultraviolet</span> Radiation Environment around M Dwarf Exoplanet Host Stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>France, Kevin; Froning, Cynthia S.; Linsky, Jeffrey L.; Roberge, Aki; Stocke, John T.; Tian, Feng; Bushinsky, Rachel; Desert, Jean-Michel; Mauas, Pablo; Mauas, Pablo; Walkowicz, Lucianne M.</p> <p>2013-01-01</p> <p>The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. <span class="hlt">Ultraviolet</span> photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis exists for understanding the <span class="hlt">ultraviolet</span> spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both far-UV (FUV) and near-UV (NUV) wavelengths. The combined FUV+NUV spectra are publicly available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No "UV-quiet" M dwarfs are observed. The <span class="hlt">bright</span> stellar Lyman-alpha emission lines are reconstructed, and we find that the Lyman-alpha line fluxes comprise approximately 37%-75% of the total 1150-3100 A flux from most M dwarfs; approximately greater than 10(exp3) times the solar value. We develop an empirical scaling relation between Lyman-alpha and Mg II emission, to be used when interstellar H I attenuation precludes the direct observation of Lyman-alpha. The intrinsic unreddened flux ratio is F(Lyman-alpha)/F(Mg II) = 10(exp3). The F(FUV)/F(NUV) flux ratio, a driver for abiotic production of the suggested biomarkers O2 and O3, is shown to be approximately 0.5-3 for all M dwarfs in our sample, greather than 10(exp3) times the solar ratio. For the four stars with moderate signal-to-noise Cosmic Origins Spectrograph time-resolved spectra, we find UV emission line variability with amplitudes of 50%.500% on 10(exp2)-10(exp3) s timescales. This effect should be taken</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015Natur.520..205B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015Natur.520..205B&link_type=ABSTRACT"><span id="translatedtitle">Four-wave mixing experiments with extreme <span class="hlt">ultraviolet</span> transient gratings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bencivenga, F.; Cucini, R.; Capotondi, F.; Battistoni, A.; Mincigrucci, R.; Giangrisostomi, E.; Gessini, A.; Manfredda, M.; Nikolov, I. P.; Pedersoli, E.; Principi, E.; Svetina, C.; Parisse, P.; Casolari, F.; Danailov, M. B.; Kiskinova, M.; Masciovecchio, C.</p> <p>2015-04-01</p> <p>Four-wave mixing (FWM) processes, based on third-order nonlinear light-matter interactions, can combine ultrafast time resolution with energy and wavevector selectivity, and enable the exploration of dynamics inaccessible by linear methods. The coherent and multi-wave nature of the FWM approach has been crucial in the development of advanced technologies, such as silicon photonics, subwavelength imaging and quantum communications. All these technologies operate at optical wavelengths, which limits the spatial resolution and does not allow the probing of excitations with energy in the electronvolt range. Extension to shorter wavelengths--that is, the extreme <span class="hlt">ultraviolet</span> and soft-X-ray ranges--would allow the spatial resolution to be improved and the excitation energy range to be expanded, as well as enabling elemental selectivity to be achieved by exploiting core resonances. So far, FWM applications at such wavelengths have been prevented by the absence of coherent sources of sufficient <span class="hlt">brightness</span> and of suitable experimental set-ups. Here we show how transient gratings, generated by the interference of coherent extreme-<span class="hlt">ultraviolet</span> pulses delivered by the FERMI free-electron laser, can be used to stimulate FWM processes at suboptical wavelengths. Furthermore, we have demonstrated the possibility of observing the time evolution of the FWM signal, which shows the dynamics of coherent excitations as molecular vibrations. This result opens the way to FWM with nanometre spatial resolution and elemental selectivity, which, for example, would enable the investigation of charge-transfer dynamics. The theoretical possibility of realizing these applications has already stimulated ongoing developments of free-electron lasers: our results show that FWM at suboptical wavelengths is feasible, and we hope that they will enable advances in present and future photon sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21464751','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21464751"><span id="translatedtitle">THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE <span class="hlt">ULTRAVIOLET</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brown, Peter J.; Roming, Peter W. A.; Ciardullo, Robin; Gronwall, Caryl; Hoversten, Erik A.; Pritchard, Tyler; Milne, Peter; Bufano, Filomena; Mazzali, Paolo; Elias-Rosa, Nancy; Filippenko, Alexei V.; Li Weidong; Foley, Ryan J.; Hicken, Malcolm; Kirshner, Robert P.; Gehrels, Neil; Holland, Stephen T.; Immler, Stefan; Phillips, Mark M.; Still, Martin</p> <p>2010-10-01</p> <p>We examine the absolute magnitudes and light-curve shapes of 14 nearby (redshift z = 0.004-0.027) Type Ia supernovae (SNe Ia) observed in the <span class="hlt">ultraviolet</span> (UV) with the Swift <span class="hlt">Ultraviolet</span>/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way extinction law and one for the Large Magellanic Cloud that has been modified by circumstellar scattering. We find very different behavior in the near-UV filters (uvw1{sub rc} covering {approx}2600-3300 A after removing optical light, and u {approx} 3000-4000 A) compared to a mid-UV filter (uvm2 {approx}2000-2400 A). The uvw1{sub rc} - b colors show a scatter of {approx}0.3 mag while uvm2-b scatters by nearly 0.9 mag. Similarly, while the scatter in colors between neighboring filters is small in the optical and somewhat larger in the near-UV, the large scatter in the uvm2 - uvw1 colors implies significantly larger spectral variability below 2600 A. We find that in the near-UV the absolute magnitudes at peak <span class="hlt">brightness</span> of normal SNe Ia in our sample are correlated with the optical decay rate with a scatter of 0.4 mag, comparable to that found for the optical in our sample. However, in the mid-UV the scatter is larger, {approx}1 mag, possibly indicating differences in metallicity. We find no strong correlation between either the UV light-curve shapes or the UV colors and the UV absolute magnitudes. With larger samples, the UV luminosity might be useful as an additional constraint to help determine distance, extinction, and metallicity in order to improve the utility of SNe Ia as standardized candles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22364772','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22364772"><span id="translatedtitle">THE MYSTERY OF THE COSMIC DIFFUSE <span class="hlt">ULTRAVIOLET</span> BACKGROUND RADIATION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Henry, Richard Conn; Murthy, Jayant; Overduin, James; Tyler, Joshua E-mail: jmurthy@yahoo.com E-mail: 97tyler@cardinalmail.cua.edu</p> <p>2015-01-01</p> <p>The diffuse cosmic background radiation in the Galaxy Evolution Explorer far-<span class="hlt">ultraviolet</span> (FUV, 1300-1700 Å) is deduced to originate only partially in the dust-scattered radiation of FUV-emitting stars: the source of a substantial fraction of the FUV background radiation remains a mystery. The radiation is remarkably uniform at both far northern and far southern Galactic latitudes and increases toward lower Galactic latitudes at all Galactic longitudes. We examine speculation that this might be due to interaction of the dark matter with the nuclei of the interstellar medium, but we are unable to point to a plausible mechanism for an effective interaction. We also explore the possibility that we are seeing radiation from <span class="hlt">bright</span> FUV-emitting stars scattering from a ''second population'' of interstellar grains—grains that are small compared with FUV wavelengths. Such grains are known to exist, and they scatter with very high albedo, with an isotropic scattering pattern. However, comparison with the observed distribution (deduced from their 100 μm emission) of grains at high Galactic latitudes shows no correlation between the grains' location and the observed FUV emission. Our modeling of the FUV scattering by small grains also shows that there must be remarkably few such ''smaller'' grains at high Galactic latitudes, both north and south; this likely means simply that there is very little interstellar dust of any kind at the Galactic poles, in agreement with Perry and Johnston. We also review our limited knowledge of the cosmic diffuse background at <span class="hlt">ultraviolet</span> wavelengths shortward of Lyα—it could be that our ''second component'' of the diffuse FUV background persists shortward of the Lyman limit and is the cause of the reionization of the universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AAS...22334821B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AAS...22334821B&link_type=ABSTRACT"><span id="translatedtitle">PULSE: the Palomar <span class="hlt">Ultraviolet</span> Laser for the Study of Exoplanets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bottom, Michael; Dekany, R.; Bowler, B. P.; Baranec, C.; Burruss, R.</p> <p>2014-01-01</p> <p>PULSE is a project to augment the currently operating 5.1-m Hale PALM-3000 exoplanet adaptive optics system with an <span class="hlt">ultraviolet</span> Rayleigh laser and associated wavefront sensor. By using a <span class="hlt">bright</span> (U ~ 7) <span class="hlt">ultraviolet</span> laser to measure the high spatial and temporal order turbulence near the telescope aperture, where it dominates, one can extend the faintness limit of natural guide stars needed by PALM-3000. Initial simulations indicate that very-high infrared contrast ratios and good visible-light adaptive optics performance will be achieved by such an upgraded system on stars as faint as mV = 16-17 using an optimized low-order NGS sensor. This will enable direct imaging searches for, and subsequent characterization of, companions around cool, low-mass stars for the first time, as well as routine visible-light imaging twice as sharp as HST for fainter targets. PULSE will reuse the laser and wavefront sensor technology developed for the automated Robo-AO laser system currently operating at the Palomar 60-inch telescope, as well as take advantage of pending optimization of low-order NGS wavefront sensing and planned new interfaces to the PALM-3000 real-time reconstruction computer. PULSE will dramatically extend the AO sky coverage of the telescope from 1% to 50%. More specifically, this will boost the yield from a number of operational exoplanet instruments at Palomar including PHARO, a NIR imager, spectrograph, and coronagraph; a fiber nulling interferometer; and Project 1640, a coronagraph and IFS. Two additional funded instruments expected to benefit from PULSE in the coming years are the SDC; a NIR/visible self-calibrating vector vortex coronagraph, and DARKNESS; an energy-resolving, photon counting MKIDS camera.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6596038','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6596038"><span id="translatedtitle">Far-<span class="hlt">ultraviolet</span> spectroscopy of Comet Halley (1986 VI)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dymond, K.F.</p> <p>1989-01-01</p> <p>Far-<span class="hlt">ultraviolet</span> spectra were obtained of Comet Halley (1986 III) on 26 February 1986 and on 13 March 1986 using an imaging spectrograph launched aboard a sounding rocket. Most of the far-<span class="hlt">ultraviolet</span> emissions are excited by fluorescence with solar line emission; therefore, the fluorescence excitation rates have been re-evaluated as functions of heliocentric velocity using high-resolution solar fluxes and the latest values for the oscillator strengths. The spectra are analyzed with particular emphasis placed on identifying the weak features present. The upper limits on the production rates of OCS and CS{sub 2} determined from upper limits placed on sulfur emissions are found to be consistent with production rates inferred by other observers. The upper limits on the <span class="hlt">brightness</span> of the H{sub 2} {lambda}1608 emission have been used to place upper limits on the column density of H{sub 2} in the coma. These upper limits are {approx equal}3 times the column densities determined by models that assume that H{sub 2} is produced solely by photodissociation of H{sub 2}O. The presence of the O I {lambda}1356 emission in the comet spectra is evidence of the importance of electron impact processes in the inner coma, since this emission is probably excited from the ground state of neutral oxygen by electron impact. The spatial distribution of the CO Fourth Positive Band emissions and the C I {lambda}1561 and C I {lambda}1657 emissions are examined. The shapes of the C emission profiles cannot be adequately described by models which assume that C is produced by photodissociation of CO and other carbon bearing species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17395237','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17395237"><span id="translatedtitle">The lowest spatial frequency channel determines <span class="hlt">brightness</span> perception.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perna, A; Morrone, M C</p> <p>2007-05-01</p> <p>This study investigates the role played by individual spatial scales in determining the apparent <span class="hlt">brightness</span> of greyscale patterns. We measured the perceived difference in <span class="hlt">brightness</span> across an edge in the presence of notch filtering and high-pass filtering for two stimulus configurations, one that elicits the perception of transparency and one that appears opaque. For both stimulus configurations, the apparent <span class="hlt">brightness</span> of the surfaces delimited by the border decreased monotonically with progressive (ideal) high-pass filtering, with a critical cut-off at 1 c/deg. Using two octave ideal notch filtering, the maximum detrimental effect on apparent <span class="hlt">brightness</span> was observed at about 1c/deg. Critical frequencies for apparent <span class="hlt">brightness</span> did not vary with contrast, viewing distance, or surface size, suggesting that apparent <span class="hlt">brightness</span> is determined by the channel tuned at 1 c/deg. Modelling the data with the local energy model [Morrone, M. C., & Burr, D. C. (1988). Feature detection in human vision: a phase dependent energy model. Proceedings of the Royal Society (London), B235, 221-245] at 1c/deg confirmed the suggestion that this channel mediates apparent <span class="hlt">brightness</span> for both opaque and transparent borders, with no need for pooling or integration across spatial channels. PMID:17395237</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4476568','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4476568"><span id="translatedtitle">Quantitative <span class="hlt">Brightness</span> Analysis of Fluorescence Intensity Fluctuations in E. Coli</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hur, Kwang-Ho; Mueller, Joachim D.</p> <p>2015-01-01</p> <p>The <span class="hlt">brightness</span> measured by fluorescence fluctuation spectroscopy specifies the average stoichiometry of a labeled protein in a sample. Here we extended <span class="hlt">brightness</span> analysis, which has been mainly applied in eukaryotic cells, to prokaryotic cells with E. coli serving as a model system. The small size of the E. coli cell introduces unique challenges for applying <span class="hlt">brightness</span> analysis that are addressed in this work. Photobleaching leads to a depletion of fluorophores and a reduction of the <span class="hlt">brightness</span> of protein complexes. In addition, the E. coli cell and the point spread function of the instrument only partially overlap, which influences intensity fluctuations. To address these challenges we developed MSQ analysis, which is based on the mean Q-value of segmented photon count data, and combined it with the analysis of axial scans through the E. coli cell. The MSQ method recovers <span class="hlt">brightness</span>, concentration, and diffusion time of soluble proteins in E. coli. We applied MSQ to measure the <span class="hlt">brightness</span> of EGFP in E. coli and compared it to solution measurements. We further used MSQ analysis to determine the oligomeric state of nuclear transport factor 2 labeled with EGFP expressed in E. coli cells. The results obtained demonstrate the feasibility of quantifying the stoichiometry of proteins by <span class="hlt">brightness</span> analysis in a prokaryotic cell. PMID:26099032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016pimo.conf..148L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016pimo.conf..148L&link_type=ABSTRACT"><span id="translatedtitle">Easy way to estimate meteor <span class="hlt">brightness</span> on TV frames</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leonov, V. A.; Bagrov, A. V.</p> <p>2016-01-01</p> <p>The traditional method of the meteor <span class="hlt">brightness</span> measurements claims that the meteor <span class="hlt">brightness</span> is equal to the stellar magnitude of a star that looks like a meteor in the brightest point of its track. This rule was convenient for the comparison of meteor observations by different observers and for the analysis of the <span class="hlt">brightness</span> distributions of meteors from observed showers. This traditional method suffers from systematic errors, particularly those that arise from using stellar <span class="hlt">brightness</span> measured in specific spectral wave bands different from the observer's ones, but mainly due to neglecting the influence of the meteor angular velocity on the real meteor <span class="hlt">brightness</span>. To get a proper estimate of the meteor <span class="hlt">brightness</span> that is a measure of the ground meteor illumination in the non-systematic units, an observer must take into account that the effective exposition of a meteor image in any resolution element of its track is a few times shorter than the corresponding exposition of a star image in the same frame. We propose a very simple method for improved estimations of meteor <span class="hlt">brightness</span> by applying a correction to the meteor stellar magnitude obtained within the traditional framework.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015DPS....4710304L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015DPS....4710304L&link_type=ABSTRACT"><span id="translatedtitle">Photometric Properties of Ceres and the Occator <span class="hlt">Bright</span> Spots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jian-Yang; Le Corre, Lucille; Reddy, Vishnu; Sykes, Mark V.; Nathues, Andreas; Pieters, Carle M.; Ciarniello, Mauro; Turrini, Diego; McFadden, Lucy A.; Raymond, Carol A.; Russell, Christopher T.</p> <p>2015-11-01</p> <p>Dawn discovered several extremely <span class="hlt">bright</span> spots on Ceres, the most prominent of which is located inside the Occator crater that is at least 4-5 times brighter than the average Ceres. Interestingly, these <span class="hlt">bright</span> spots are located in relatively young craters that are at the longitudes corresponding to the maximum water vapor observed by the Herschel Space Observatory, suggesting possible correlation with water sublimation on Ceres. We used the multi-color imaging data collected by the Dawn Framing Camera to analyze the global photometric properties of Ceres and the <span class="hlt">bright</span> spots, especially those located inside the Occator crater. Our objectives are to determine the albedo and other light scattering properties of the <span class="hlt">bright</span> spots on Ceres in the visible wavelengths, in order to characterize their physical properties and find clues about their composition and possible formation mechanisms and the correlation with water sublimation. The overall geometric albedo of Ceres’ global surface is 0.09-0.10, consistent with previous studies. The Hapke roughness parameter is about 20°, close to many other asteroids, rather than 44° as reported earlier. Correspondingly, the phase function of Ceres is less backscattering than previously modeled. In contrast, the geometric albedo of the <span class="hlt">bright</span> spots inside the Occator crater is 0.4-0.5, and the single scattering albedo is 0.7-0.8, brighter than Vesta’s global albedo but much darker than many icy satellites in the outer solar system. The Hapke roughness of the <span class="hlt">bright</span> spots is much higher than Ceres average, suggesting relatively loose deposit of materials rather than more coherent or tightly packed materials. The phase function of <span class="hlt">bright</span> spots material is relatively more forward scattering than average Ceres, possibly correlated to stronger multiple scattering due to high albedo resulting from more transparent materials. The highest resolution images as of late-August 2015 show fine structures within the Occator <span class="hlt">bright</span> spots. We</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22011988','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22011988"><span id="translatedtitle">FAR-<span class="hlt">ULTRAVIOLET</span> CONTINUUM EMISSION: APPLYING THIS DIAGNOSTIC TO THE CHROMOSPHERES OF SOLAR-MASS STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Linsky, Jeffrey L.; Bushinsky, Rachel; Ayres, Tom; France, Kevin; Fontenla, Juan</p> <p>2012-01-20</p> <p>The far-<span class="hlt">ultraviolet</span> (FUV) continuum flux is recognized as a very sensitive diagnostic of the temperature structure of the Sun's lower chromosphere. Until now analysis of the available stellar FUV data has shown that solar-type stars must also have chromospheres, but quantitative analyses of stellar FUV continua require far higher quality spectra and comparison with new non-LTE chromosphere models. We present accurate far-<span class="hlt">ultraviolet</span> (FUV, 1150-1500 A) continuum flux measurements for solar-mass stars, made feasible by the high throughput and very low detector background of the Cosmic Origins Spectrograph on the Hubbble Space Telescope. We show that the continuum flux can be measured above the detector background even for the faintest star in our sample. We find a clear trend of increasing continuum <span class="hlt">brightness</span> temperature at all FUV wavelengths with decreasing rotational period, which provides an important measure of magnetic heating rates in stellar chromospheres. Comparison with semiempirical solar flux models shows that the most rapidly rotating solar-mass stars have FUV continuum <span class="hlt">brightness</span> temperatures similar to the brightest faculae seen on the Sun. The thermal structure of the brightest solar faculae therefore provides a first-order estimate of the thermal structure and heating rate for the most rapidly rotating solar-mass stars in our sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7382E..3XY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7382E..3XY"><span id="translatedtitle">Corona solar blind <span class="hlt">ultraviolet</span> image detecting method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yin, Li-min; Tang, Wen-qing; Zhang, Yu</p> <p>2009-07-01</p> <p>Corona is one of important reasons of electrical energy loss in the electric power. According to incomplete statistics, corona loss electrical energy has achieved two thousands and fifty millions kW.h in our nation every year. Sometimes corona also can have some disturbance to radio and communication. Therefore to discover and examine corona promptly has the extremely vital significance for conserving energy and realizing high quality communication. <span class="hlt">Ultraviolet</span> image detecting technology is a preferred corona detection method in electric power. It may realize all-weather reliable survey to corona. The solar blind <span class="hlt">ultraviolet</span> signal discharged by corona is quite weak. Moreover the <span class="hlt">ultraviolet</span> image quality has been affected seriously by the detection system noise. A corona solar blind <span class="hlt">ultraviolet</span> image processing method is proposed in this paper. <span class="hlt">Ultraviolet</span> image has so small target, low contrast image, district characteristic and real-time demand that it is processed by multi-scale <span class="hlt">ultraviolet</span> morphology filter technology based on mathematics morphology in this paper. Results show that the method can stretch image contrast, enhance target and weaken noise. The algorithm is easy to deal in parallel and it can be realized easily by hardware. It will be accurately demarcated when the condition of device need to be absolutely measured. The paper proposes a kind of mathematics morphology algorithm. Solar blind <span class="hlt">ultraviolet</span> image will be further processed according to temperature and humidity in order to remove the infection of corona discharge demarcation and solve correct demarcation question when equipment condition need to be absolutely measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860063274&hterms=bangalore&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbangalore','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860063274&hterms=bangalore&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbangalore"><span id="translatedtitle">Solar coronal <span class="hlt">bright</span> points observed with the VLA</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Habbal, S. R.; Ronan, R. S.; Withbroe, G. L.; Shevgaonkar, R. K.; Kundu, M. R.</p> <p>1986-01-01</p> <p>The first observations of solar coronal <span class="hlt">bright</span> points made at 20-cm wavelength with the VLA are reported. The <span class="hlt">brightness</span> temperature of the sources observed varies between 1 and 5 x 10 to the 5th K. The observations indicate that significant fluctuations in the <span class="hlt">brightness</span> temperature as well as in the spatial extent of these sources can occur over a few minutes. These fluctuations are shown to be due to density and temperature fluctuations at transition region heights combined with either plasma motions along magnetic field lines or changes in magnetic field topology, or both.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=GL-2002-001200&hterms=orange+history&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dorange%2Bhistory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=GL-2002-001200&hterms=orange+history&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dorange%2Bhistory"><span id="translatedtitle">HUBBLE FINDS MANY <span class="hlt">BRIGHT</span> CLOUDS ON URANUS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>A recent Hubble Space Telescope view reveals Uranus surrounded by its four major rings and by 10 of its 17 known satellites. This false-color image was generated by Erich Karkoschka using data taken on August 8, 1998, with Hubble's Near Infrared Camera and Multi-Object Spectrometer. Hubble recently found about 20 clouds - nearly as many clouds on Uranus as the previous total in the history of modern observations. The orange-colored clouds near the prominent <span class="hlt">bright</span> band circle the planet at more than 300 mph (500 km/h), according to team member Heidi Hammel (MIT). One of the clouds on the right-hand side is brighter than any other cloud ever seen on Uranus. The colors in the image indicate altitude. Team member Mark Marley (New Mexico State University) reports that green and blue regions show where the atmosphere is clear and sunlight can penetrate deep into Uranus. In yellow and grey regions the sunlight reflects from a higher haze or cloud layer. Orange and red colors indicate very high clouds, such as cirrus clouds on Earth. The Hubble image is one of the first images revealing the precession of the brightest ring with respect to a previous image [LINK to PRC97-36a]. Precession makes the fainter part of the ring (currently on the upper right-hand side) slide around Uranus once every nine months. The fading is caused by ring particles crowding and hiding each other on one side of their eight-hour orbit around Uranus. The blue, green and red components of this false-color image correspond to exposures taken at near-infrared wavelengths of 0.9, 1.1, and 1.7 micrometers. Thus, regions on Uranus appearing blue, for example, reflect more sunlight at 0.9 micrometer than at the longer wavelengths. Apparent colors on Uranus are caused by absorption of methane gas in its atmosphere, an effect comparable to absorption in our atmosphere which can make distant clouds appear red. Credit: Erich Karkoschka (University of Arizona) and NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=10476&hterms=ultraviolet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dultraviolet','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=10476&hterms=ultraviolet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dultraviolet"><span id="translatedtitle">STEREO's Extreme <span class="hlt">UltraViolet</span> Imager (EUVI)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p>At a pixel resolution of 2048x2048, the STEREO EUVI instrument provides views of the Sun in <span class="hlt">ultraviolet</span> light that rivals the full-disk views of SOHO/EIT. This image is through the 171 Angstrom (<span class="hlt">ultraviolet</span>) filter which is characteristic of iron ions (missing eight and nine electrons) at 1 million degrees. There is a short data gap in the latter half of the movie that creates a freeze and then jump in the data view. This is a movie of the Sun in 171 Angstrom <span class="hlt">ultraviolet</span> light. The time frame is late January, 2007</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900023720&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528ultraviolet%2Bradiation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900023720&hterms=ultraviolet+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528ultraviolet%2Bradiation%2529"><span id="translatedtitle">Measurements of the diffuse <span class="hlt">ultraviolet</span> radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fix, John D.; Craven, John D.; Frank, Louis A.</p> <p>1989-01-01</p> <p>The imaging instrumentation on the Dynamics Explorer 1 satellite has been used to measure the intensity of the diffuse <span class="hlt">ultraviolet</span> radiation on two great circles about the sky. It is found that the isotropic component of the diffuse <span class="hlt">ultraviolet</span> radiation (possibly of extragalactic origin) has an intensity of 530 + or - 80 units (a unit is 1 photon per sq cm s A sr) at a wavelength of 150 nm. The Galactic component of the diffuse <span class="hlt">ultraviolet</span> radiation has a dependence on Galactic latitude which requires strongly forward scattering particles if it is produced by dust above the Galactic plane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985PhDT.......136B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985PhDT.......136B"><span id="translatedtitle">Spectroscopy of the Far and Extreme <span class="hlt">Ultraviolet</span> Dayglow.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bowers, Charles W.</p> <p></p> <p>We have designed, built and flown in a sounding rocket payload a spectrograph with (DBLTURN) 2 (ANGSTROM) resolution from 850 (ANGSTROM) to 1850 (ANGSTROM) obtaining the highest resolution, broad wavelength coverage UV dayglow spectrum to date. This instrument utilizes a newly developed photon counting detector consisting of an <span class="hlt">ultraviolet</span>-to -visible-light image intensifier with two microchannel plates in a tandem arrangement followed by a phosphor coated on the face of a fiber optics output bundle. Light generated in the phosphor by electron pulses produced by the MCP stack is transmitted to a Reticon (1024S) photodiode array with 1024 independent photodiodes. The broad light pulses generated by the intensifier were detected by the photodiode array. This flight data was transmitted to the ground and centroided, recovering the spectrograph resolution of (DBLTURN) 2 (ANGSTROM). The vacuum spectrograph contains an osmium coated, holographic f/2 concave diffraction grating, baffled to f/4 for flight. A movable slit wheel mechanism provides a vacuum seal, which is broken during flight as the entrance slit is moved into position. The UV dayglow spectrum obtained is presented and tentative identification of most of the emission features is made. A relatively <span class="hlt">bright</span> emission line at 1173 (ANGSTROM) is identified as arising from the OI 3s' ('3)D('0) - 2p('4) ('1)D transition and is well resolved from adjacent NI emission features. Enhanced emission from this line is expected by the radiative entrapment of photons from the strong, optically thick 989 (ANGSTROM) emission feature. The simultaneous observations of the 989 (ANGSTROM) and 1173 (ANGSTROM) emissions allows comparison with model predictions of the variation with altitude of these related features (Meier, 1982). This comparison is consistent with the radiative entrapment model showing a decrease in 989 (ANGSTROM) emission and an increase in 1173 (ANGSTROM) emission at lower altitudes. The data are also consistent</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/az0590.photos.363917p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/az0590.photos.363917p/"><span id="translatedtitle">Detail of <span class="hlt">Bright</span> Angel stone vault, containing condenser, Hoffman condensation ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Detail of <span class="hlt">Bright</span> Angel stone vault, containing condenser, Hoffman condensation pump, Jennings vacuum heating pump, and misc. pipes and valves. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/az0590.photos.363916p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/az0590.photos.363916p/"><span id="translatedtitle">Perspective of <span class="hlt">Bright</span> Angel stone vault, view south, with HAER ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Perspective of <span class="hlt">Bright</span> Angel stone vault, view south, with HAER field team measuring (Michael Lee and Dominic Duran foreground, Christopher Marston rear). - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002989','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002989"><span id="translatedtitle">Visible Color and Photometry of <span class="hlt">Bright</span> Materials on Vesta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schroder, S. E.; Li, J. Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.</p> <p>2012-01-01</p> <p>The Dawn Framing Camera (FC) collected images of the surface of Vesta at a pixel scale of 70 m in the High Altitude Mapping Orbit (HAMO) phase through its clear and seven color filters spanning from 430 nm to 980 nm. The surface of Vesta displays a large diversity in its <span class="hlt">brightness</span> and colors, evidently related to the diverse geology [1] and mineralogy [2]. Here we report a detailed investigation of the visible colors and photometric properties of the apparently <span class="hlt">bright</span> materials on Vesta in order to study their origin. The global distribution and the spectroscopy of <span class="hlt">bright</span> materials are discussed in companion papers [3, 4], and the synthesis results about the origin of Vestan <span class="hlt">bright</span> materials are reported in [5].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980STIN...8025619G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980STIN...8025619G"><span id="translatedtitle"><span class="hlt">Brightness</span> temperature measurements for high-energy jet propagation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glenn, H. D.</p> <p>1980-01-01</p> <p>The use of fiber optics to measure times of arrival and <span class="hlt">brightness</span> temperature profiles for high-energy gas jets is described. Voitenko compressors were used to produce high-energy air and oxygen jets through steel pipes 2 cm i.d. and 350 cm in length containing air initially at 0.02 Torr or less. Reduction of the time-of-arrival data indicated that velocities for the various identified jet components ranged between 2.40 and 7.95 cm/microsec. The fiber optics emplacement design and <span class="hlt">brightness</span> temperature calibration procedure are described. Maximum <span class="hlt">brightness</span> temperatures of 93,000 and 136,000 K were measured for air and oxygen jets, respectively, as they started down the exit pipes. <span class="hlt">Brightness</span> temperature profiles were obtained to 50 microsec behind the jet front. The results suggest that delayed entrainment of wall material was the predominant factor in reducing pressures and temperatures in the slower components of the jet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/az0590.photos.363911p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/az0590.photos.363911p/"><span id="translatedtitle">South and west elevations of <span class="hlt">Bright</span> Angel boiler house. Red ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>South and west elevations of <span class="hlt">Bright</span> Angel boiler house. Red Horse log cabin visible in background. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/az0590.photos.363915p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/az0590.photos.363915p/"><span id="translatedtitle"><span class="hlt">Bright</span> Angel stone vault, with HAER field team members Dominic ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p><span class="hlt">Bright</span> Angel stone vault, with HAER field team members Dominic Duran, Christopher Marston, and Michael Lee (l to r). - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/az0590.photos.363905p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/az0590.photos.363905p/"><span id="translatedtitle">Yellow steam and electrical pipes across from <span class="hlt">Bright</span> Angel Lodge. ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Yellow steam and electrical pipes across from <span class="hlt">Bright</span> Angel Lodge. Note control valve to right of control box, view E. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title21-vol8/pdf/CFR-2014-title21-vol8-sec878-4630.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title21-vol8/pdf/CFR-2014-title21-vol8-sec878-4630.pdf"><span id="translatedtitle">21 CFR 878.4630 - <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-04-01</p> <p>... <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders. (a) Identification. An <span class="hlt">ultraviolet</span> lamp for dermatologic disorders is a device (including a fixture) intended to provide <span class="hlt">ultraviolet</span> radiation of the body to... 21 Food and Drugs 8 2014-04-01 2014-04-01 false <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders....</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol8/pdf/CFR-2012-title21-vol8-sec880-6500.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol8/pdf/CFR-2012-title21-vol8-sec880-6500.pdf"><span id="translatedtitle">21 CFR 880.6500 - Medical <span class="hlt">ultraviolet</span> air purifier.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-04-01</p> <p>... to <span class="hlt">ultraviolet</span> radiation. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical <span class="hlt">ultraviolet</span> air purifier. 880.6500 Section... Miscellaneous Devices § 880.6500 Medical <span class="hlt">ultraviolet</span> air purifier. (a) Identification. A medical <span class="hlt">ultraviolet</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title21-vol8/pdf/CFR-2014-title21-vol8-sec880-6500.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title21-vol8/pdf/CFR-2014-title21-vol8-sec880-6500.pdf"><span id="translatedtitle">21 CFR 880.6500 - Medical <span class="hlt">ultraviolet</span> air purifier.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-04-01</p> <p>... to <span class="hlt">ultraviolet</span> radiation. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical <span class="hlt">ultraviolet</span> air purifier. 880.6500 Section... Miscellaneous Devices § 880.6500 Medical <span class="hlt">ultraviolet</span> air purifier. (a) Identification. A medical <span class="hlt">ultraviolet</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title21-vol8/pdf/CFR-2010-title21-vol8-sec878-4630.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title21-vol8/pdf/CFR-2010-title21-vol8-sec878-4630.pdf"><span id="translatedtitle">21 CFR 878.4630 - <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-04-01</p> <p>... <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders. (a) Identification. An <span class="hlt">ultraviolet</span> lamp for dermatologic disorders is a device (including a fixture) intended to provide <span class="hlt">ultraviolet</span> radiation of the body to... 21 Food and Drugs 8 2010-04-01 2010-04-01 false <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title21-vol8/pdf/CFR-2011-title21-vol8-sec878-4630.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title21-vol8/pdf/CFR-2011-title21-vol8-sec878-4630.pdf"><span id="translatedtitle">21 CFR 878.4630 - <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-04-01</p> <p>... <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders. (a) Identification. An <span class="hlt">ultraviolet</span> lamp for dermatologic disorders is a device (including a fixture) intended to provide <span class="hlt">ultraviolet</span> radiation of the body to... 21 Food and Drugs 8 2011-04-01 2011-04-01 false <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title21-vol8/pdf/CFR-2013-title21-vol8-sec878-4630.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title21-vol8/pdf/CFR-2013-title21-vol8-sec878-4630.pdf"><span id="translatedtitle">21 CFR 878.4630 - <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-04-01</p> <p>... <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders. (a) Identification. An <span class="hlt">ultraviolet</span> lamp for dermatologic disorders is a device (including a fixture) intended to provide <span class="hlt">ultraviolet</span> radiation of the body to... 21 Food and Drugs 8 2013-04-01 2013-04-01 false <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title21-vol8/pdf/CFR-2013-title21-vol8-sec880-6500.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title21-vol8/pdf/CFR-2013-title21-vol8-sec880-6500.pdf"><span id="translatedtitle">21 CFR 880.6500 - Medical <span class="hlt">ultraviolet</span> air purifier.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-04-01</p> <p>... to <span class="hlt">ultraviolet</span> radiation. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical <span class="hlt">ultraviolet</span> air purifier. 880.6500 Section... Miscellaneous Devices § 880.6500 Medical <span class="hlt">ultraviolet</span> air purifier. (a) Identification. A medical <span class="hlt">ultraviolet</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol8/pdf/CFR-2012-title21-vol8-sec878-4630.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol8/pdf/CFR-2012-title21-vol8-sec878-4630.pdf"><span id="translatedtitle">21 CFR 878.4630 - <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-04-01</p> <p>... <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders. (a) Identification. An <span class="hlt">ultraviolet</span> lamp for dermatologic disorders is a device (including a fixture) intended to provide <span class="hlt">ultraviolet</span> radiation of the body to... 21 Food and Drugs 8 2012-04-01 2012-04-01 false <span class="hlt">Ultraviolet</span> lamp for dermatologic disorders....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950053210&hterms=catalogue&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcatalogue','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950053210&hterms=catalogue&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcatalogue"><span id="translatedtitle">Catalogue of Galactic globular-cluster surface-<span class="hlt">brightness</span> profiles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Trager, S. C.; King, Ivan R.; Djorgovski, S.</p> <p>1995-01-01</p> <p>We present a catalogue of surface-<span class="hlt">brightness</span> profiles (SBPs) of 125 Galactic globular clusters, the largest such collection ever gathered. The SPBs are constructed from generally inhomogeneous data, but are based heavily on the Berkeley Global Cluster Survey of Djorgovski & King. All but four of the SBPs have photometric zero points. We derive central surface <span class="hlt">brightness</span>, King-model concentrations, core radii, half-light, and other fraction-of-light radii where data permit, and we briefly discuss their use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT.........6O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT.........6O"><span id="translatedtitle">Structural, electrical and optical characterization of high <span class="hlt">brightness</span> phosphor-free white light emitting diodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Omiya, Hiromasa</p> <p></p> <p>Much interest currently exists in GaN and related materials for applications such as light-emitting devices operating in the amber to <span class="hlt">ultraviolet</span> range. Solid-state lighting (SSL) using these materials is widely being investigated worldwide, especially due to their high-energy efficiency and its impact on environmental issues. A new approach for solid-state lighting uses phosphor-free white light emitting diodes (LEDs) that consist of blue, green, and red quantum wells (QW), all in a single device. This approach leads to improved color rendering, and directionality, compared to the conventional white LEDs that use yellow phosphor on blue or <span class="hlt">ultraviolet</span> emitters. Improving the <span class="hlt">brightness</span> of these phosphor-free white LEDs should enhance and accelerate the development of SSL technology. The main objective of the research reported in this dissertation is to provide a comprehensive understanding of the nature of the multiple quantum wells used in phosphor-free white LEDs. This dissertation starts with an introduction to lighting history, the fundamental concepts of nitride semiconductors, and the evolution of LED technology. Two important challenges in LED technology today are metal-semiconductor contacts and internal piezoelectric fields present in quantum well structures. Thus, the main portion of this dissertation consists of three parts dealing with metal-semiconductor interfaces, single quantum well structures, and multiple quantum well devices. Gold-nickel alloys are widely used as contacts to the p-region of LEDs. We have performed a detailed study for its evolution under standard annealing steps. The atomic arrangement of gold at its interface with GaN gives a clear explanation for the improved ohmic contact performance. We next focus on the nature of InGaN QWs. The dynamic response of the QWs was studied with electron holography and time-resolved cathodoluminescence. Establishing the correlation between energy band structure and the light emission spectra</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=30747&keyword=color+AND+terms&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=59400504&CFTOKEN=60220136','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=30747&keyword=color+AND+terms&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=59400504&CFTOKEN=60220136"><span id="translatedtitle">AUTOMATION OF AN <span class="hlt">ULTRAVIOLET</span>-VISIBLE SPECTROMETER</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This report is an overview of the functional description and major features of an automated <span class="hlt">ultraviolet</span>-visible spectrometer system intended for environmental measurements application. As such, it defines functional specifications and requirements which are divided into the chlor...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6832636','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6832636"><span id="translatedtitle">Inactivation of mitochondrial ATPase by <span class="hlt">ultraviolet</span> light</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chavez, E.; Cuellar, A.</p> <p>1984-05-01</p> <p>The present work describes experiments that show that far-<span class="hlt">ultraviolet</span> irradiation induce the inhibition of ATPase activity in both membrane-bound and soluble F1. It was also found that <span class="hlt">ultraviolet</span> light promotes the release of tightly bound adenine nucleotides from F1-ATPase. Experiments carried out with submitochondrial particles indicate that succinate partially protects against these effects of <span class="hlt">ultraviolet</span> light. Titration of sulfhydryl groups in both irradiated submitochondrial particles and soluble F1-ATPase indicates that a conformational change induced by photochemical modifications of amino acid residues appears involved in the inactivation of the enzyme. Finally, experiments are described which show that the tyrosine residue located in the active site of F1-ATPase is modified by <span class="hlt">ultraviolet</span> irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NatCC...4..434W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NatCC...4..434W&link_type=ABSTRACT"><span id="translatedtitle">Solar <span class="hlt">ultraviolet</span> radiation in a changing climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williamson, Craig E.; Zepp, Richard G.; Lucas, Robyn M.; Madronich, Sasha; Austin, Amy T.; Ballaré, Carlos L.; Norval, Mary; Sulzberger, Barbara; Bais, Alkiviadis F.; McKenzie, Richard L.; Robinson, Sharon A.; Häder, Donat-P.; Paul, Nigel D.; Bornman, Janet F.</p> <p>2014-06-01</p> <p>The projected large increases in damaging <span class="hlt">ultraviolet</span> radiation as a result of global emissions of ozone-depleting substances have been forestalled by the success of the Montreal Protocol. New challenges are now arising in relation to climate change. We highlight the complex interactions between the drivers of climate change and those of stratospheric ozone depletion, and the positive and negative feedbacks among climate, ozone and <span class="hlt">ultraviolet</span> radiation. These will result in both risks and benefits of exposure to <span class="hlt">ultraviolet</span> radiation for the environment and human welfare. This Review synthesizes these new insights and their relevance in a world where changes in climate as well as in stratospheric ozone are altering exposure to <span class="hlt">ultraviolet</span> radiation with largely unknown consequences for the biosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040122041&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040122041&hterms=ultraviolet+astronomy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">Astronomy and the Extreme <span class="hlt">Ultraviolet</span> Explorer satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bowyer, S.</p> <p>1994-01-01</p> <p>The extreme <span class="hlt">ultraviolet</span> wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is fortunately located in a region of low extreme <span class="hlt">ultraviolet</span> opacity. The Extreme <span class="hlt">Ultraviolet</span> Explorer, launched in June 1992, has surveyed the sky in this wave band and has detected a wide variety of astronomical sources at considerable distances, including some extragalactic objects. Studies in the extreme <span class="hlt">ultraviolet</span> band have already begun to increase our understanding of the contents of the universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014apn6.confE..63N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014apn6.confE..63N"><span id="translatedtitle">Low-mass companions to <span class="hlt">Bright</span> Giants</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niedzielski, A.; Wolszczan, A.; Nowak, G.; Adamów, M.; Deka, B.; Górecka, M.; Kowalik, K.</p> <p>2014-04-01</p> <p> systems evolution - the main goal of PTPS. The sample was optimized for HET and HRS. It contains relatively <span class="hlt">bright</span> stars with V in the range of 9-12 mag, randomly distributed over the northern hemisphere. After 2-3 epochs or precise RV HET observations all stars with amplitudes exceeding the HET/HRS PSF FWHM - 5 km s-1 (SB1) or below 5?ERV - ˜ 20-50 m s (single) were rejected from further monitoring. Stars with significant cross-correlation profile variations were identified as SB2 and also excluded. All remaining 300 stars are systematically monitored in search for low-mass companions. Over a dozen stars with planetary-mass companions have already been discovered (Niedzielski et al. 2007, 2009a, b; Gettel et al. 2012a, b; Nowak et al. 2013). Here I will present our new results concerning the most luminous giants with log(L/LSun)> 2, presumably post Horizontal Branch stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140005769','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140005769"><span id="translatedtitle">Global View of the <span class="hlt">Bright</span> Material on Vesta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zambon, F.; DeSanctis, C.; Schroeder, S.; Tosi, F.; Li, J.-Y.; Longobardo, A.; Ammannito, E.; Blewett, D. T.; Palomba, E.; Capaccioni, F.; Frigeri, A.; Capria, M. T.; Fonte, S.; Mittlefehldt, D. W.; Nathues, A.; Pieters, C.; Russell, C. T.; Raymond, C. A.</p> <p>2014-01-01</p> <p>At 525 km in mean diameter, Vesta is the second-most massive and one of the brightest asteroids of the main-belt. Here we give a global view of the <span class="hlt">bright</span> material (BM) units on Vesta. We classified the BMs according to the normal visual albedo. The global albedo map of Vesta allows to be divided the surface into three principal types of terrains: <span class="hlt">bright</span> regions, dark regions and intermediate regions. The distribution of <span class="hlt">bright</span> regions is not uniform. The mid-southern latitudes contain the most <span class="hlt">bright</span> areas, while the northern hemisphere is poor in <span class="hlt">bright</span> regions. The analysis of the spectral parameters and the normal visual albedo show a dependence between albedo and the strength (depth) of ferrous iron absorption bands, strong bands correspond with high albedo units. Vesta's average albedo is 0.38, but there are <span class="hlt">bright</span> material whose albedo can exceed 0.50. Only the E-Type asteroids have albedos comparable to those of the BMs on Vesta. The Dawn mission observed a large fraction of Vesta's surface at high spatial resolution, allowing a detailed study of the morphology and mineralogy of it. In particular, reflectance spectra provided by the Visible and InfraRed spectrometer (VIR), confirmed that Vesta's mineralogy is dominated by pyroxenes. All Vesta spectra show two strong absorption bands at approx 0.9 and 1.9 micron, typical of the pyroxenes and associated with the howardite, eucrite and diogenite (HED) meteorites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23969460','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23969460"><span id="translatedtitle">An observational correlation between stellar <span class="hlt">brightness</span> variations and surface gravity.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bastien, Fabienne A; Stassun, Keivan G; Basri, Gibor; Pepper, Joshua</p> <p>2013-08-22</p> <p>Surface gravity is a basic stellar property, but it is difficult to measure accurately, with typical uncertainties of 25 to 50 per cent if measured spectroscopically and 90 to 150 per cent if measured photometrically. Asteroseismology measures gravity with an uncertainty of about 2 per cent but is restricted to relatively small samples of <span class="hlt">bright</span> stars, most of which are giants. The availability of high-precision measurements of <span class="hlt">brightness</span> variations for more than 150,000 stars provides an opportunity to investigate whether the variations can be used to determine surface gravities. The Fourier power of granulation on a star's surface correlates physically with surface gravity: if <span class="hlt">brightness</span> variations on timescales of hours arise from granulation, then such variations should correlate with surface gravity. Here we report an analysis of archival data that reveals an observational correlation between surface gravity and root mean squared <span class="hlt">brightness</span> variations on timescales of less than eight hours for stars with temperatures of 4,500 to 6,750 kelvin, log surface gravities of 2.5 to 4.5 (cgs units) and overall <span class="hlt">brightness</span> variations of less than three parts per thousand. A straightforward observation of optical <span class="hlt">brightness</span> variations therefore allows a determination of the surface gravity with a precision of better than 25 per cent for inactive Sun-like stars at main-sequence to giant stages of evolution. PMID:23969460</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013214','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013214"><span id="translatedtitle">Synthesizing SMOS Zero-Baselines with Aquarius <span class="hlt">Brightness</span> Temperature Simulator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Colliander, A.; Dinnat, E.; Le Vine, D.; Kainulainen, J.</p> <p>2012-01-01</p> <p>SMOS [1] and Aquarius [2] are ESA and NASA missions, respectively, to make L-band measurements from the Low Earth Orbit. SMOS makes passive measurements whereas Aquarius measures both passive and active. SMOS was launched in November 2009 and Aquarius in June 2011.The scientific objectives of the missions are overlapping: both missions aim at mapping the global Sea Surface Salinity (SSS). Additionally, SMOS mission produces soil moisture product (however, Aquarius data will eventually be used for retrieving soil moisture too). The consistency of the <span class="hlt">brightness</span> temperature observations made by the two instruments is essential for long-term studies of SSS and soil moisture. For resolving the consistency, the calibration of the instruments is the key. The basis of the SMOS <span class="hlt">brightness</span> temperature level is the measurements performed with the so-called zero-baselines [3]; SMOS employs an interferometric measurement technique which forms a <span class="hlt">brightness</span> temperature image from several baselines constructed by combination of multiple receivers in an array; zero-length baseline defines the overall <span class="hlt">brightness</span> temperature level. The basis of the Aquarius <span class="hlt">brightness</span> temperature level is resolved from the <span class="hlt">brightness</span> temperature simulator combined with ancillary data such as antenna patterns and environmental models [4]. Consistency between the SMOS zero-baseline measurements and the simulator output would provide a robust basis for establishing the overall comparability of the missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010037596','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010037596"><span id="translatedtitle">The Influence of Microphysical Cloud Parameterization on Microwave <span class="hlt">Brightness</span> Temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Skofronick-Jackson, Gail M.; Gasiewski, Albin J.; Wang, James R.; Zukor, Dorothy J. (Technical Monitor)</p> <p>2000-01-01</p> <p>The microphysical parameterization of clouds and rain-cells plays a central role in atmospheric forward radiative transfer models used in calculating passive microwave <span class="hlt">brightness</span> temperatures. The absorption and scattering properties of a hydrometeor-laden atmosphere are governed by particle phase, size distribution, aggregate density., shape, and dielectric constant. This study identifies the sensitivity of <span class="hlt">brightness</span> temperatures with respect to the microphysical cloud parameterization. Cloud parameterizations for wideband (6-410 GHz observations of baseline <span class="hlt">brightness</span> temperatures were studied for four evolutionary stages of an oceanic convective storm using a five-phase hydrometeor model in a planar-stratified scattering-based radiative transfer model. Five other microphysical cloud parameterizations were compared to the baseline calculations to evaluate <span class="hlt">brightness</span> temperature sensitivity to gross changes in the hydrometeor size distributions and the ice-air-water ratios in the frozen or partly frozen phase. The comparison shows that, enlarging the rain drop size or adding water to the partly Frozen hydrometeor mix warms <span class="hlt">brightness</span> temperatures by up to .55 K at 6 GHz. The cooling signature caused by ice scattering intensifies with increasing ice concentrations and at higher frequencies. An additional comparison to measured Convection and Moisture LA Experiment (CAMEX 3) <span class="hlt">brightness</span> temperatures shows that in general all but, two parameterizations produce calculated T(sub B)'s that fall within the observed clear-air minima and maxima. The exceptions are for parameterizations that, enhance the scattering characteristics of frozen hydrometeors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009A%26A...495..639G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009A%26A...495..639G"><span id="translatedtitle">The <span class="hlt">brightness</span> temperature of Mercury at mm-wavelengths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Greve, A.; Thum, C.; Moreno, R.; Yan, N.</p> <p>2009-02-01</p> <p>We present observations of Mercury made with the IRAM 30-m telescope at 3, 2 and 1.3 mm wavelength (90, 150 and 230 GHz) during the years 1985-2005; we derive from these data the disk-averaged <span class="hlt">brightness</span> temperatures. The observations at 3 mm combined with those by Epstein & Andrew allow a separation of the data into 40° wide longitude intervals and by this an investigation of the disk-averaged <span class="hlt">brightness</span> temperature with Mercury's longitude. From the new mm-wavelength data, and data taken from the literature, we derive the disk-averaged <span class="hlt">brightness</span> temperature as a function of wavelength. On Mercury's night side a significant decrease in <span class="hlt">brightness</span> temperature occurs towards shorter wavelengths. We use the three surface models (A,B,C) discussed by Mitchell & de Pater and calculate for the cool and hot surface region the corrresponding diurnal variation of the disk-averaged <span class="hlt">brightness</span> temperature at 90 GHz. For the same models we calculate the variation of the disk-averaged <span class="hlt">brightness</span> temperature with wavelength between 1.3 mm and 37 mm, on Mercury's midnight side and noon side. Although the scatter in the observations is large, there seems to be a marginally better agreement with model B and A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUSM..SH41B09D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUSM..SH41B09D"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Spectroscopy of Coronal Jets Within the Fast Solar Wind</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dobrzycka, D.; Cranmer, S. R.; Raymond, J. C.; Biesecker, D. A.; Gurman, J. B.</p> <p>2001-05-01</p> <p>The coronal jets are spectacular dynamic events originating from different structures in the solar corona. We present UVCS/SOHO observations of polar coronal jets. They appear to originate near flaring <span class="hlt">ultraviolet</span> <span class="hlt">bright</span> points within polar coronal holes that are source regions of the fast solar wind. UVCS recorded the jets as a significant enhancement in the integrated intensities of the strongest coronal emission lines: mostly H~I Lyα and O~VI λ λ 1032,1037. A number of detected jets are correlated with the EIT Fe~XII 195~Å and LASCO C2 white-light events. Typically, the observed H~I Lyα enhancement was up to a factor of 1.3-1.7 over the ambient corona and lasted for 20-30 minutes. The narrow profiles of the emission lines indicate that the material in the jets is cooler than the underlying corona. We modeled the observable properties of the jets to get estimates on jet plasma conditions. We discuss the model results, the initial electron temperature and the heating rate required to reproduce the observed O~VI ionization state. We also discuss connection of the polar jets to the fast solar wind. This work is supported by the National Aeronautics and Space Administration under grant NAG5--7822 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the ESA PRODEX program (Swiss contribution).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6490291','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6490291"><span id="translatedtitle">Sunscreens for delay of <span class="hlt">ultraviolet</span> induction of skin tumors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wulf, H.C.; Poulsen, T.; Brodthagen, H.; Hou-Jensen, K.</p> <p>1982-08-01</p> <p>Sunscreens with different sun protection factors (SPFs) have been tested for their capability of delaying or preventing actinic damage and skin cancer development in groups of hairless, pigmented mice exposed to artificial <span class="hlt">ultraviolet</span> (UV) light of increasing intensity. The dose delivered was less than or equal to 1 minimal erythema dose (MED) in the group of untreated mice, so that the mice to which sunscreens were applied never obtained a sunburn after UV exposure. The quality of UV light was similar to <span class="hlt">bright</span> midday sun at a latitude of 56 degrees (city of Copenhagen). Tumorigenesis was demonstrated to be delayed corresponding to the SPF claimed by the manufacturer, but almost all of the UV-irradiated mice developed skin tumors. Histologic examination revealed actinic degeneration and tumors of squamous cell type with marked variation in differentiation. Metastases to lymph nodes and lungs were found in only 10%. Toxic reactions, such as eczematous-like skin reactions, dark coloring, and amyloidosis, were observed predominantly in the group treated with the sunscreen of highest SPF value. Long-term investigations seem to be necessary to unveil these problems--in particular, the specific SPF value, in sunscreens, that should be recommended to the public for prevention or delay of actinic damage and/or cancer development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750016522','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750016522"><span id="translatedtitle">The rocket <span class="hlt">ultraviolet</span> spectrum of the planetary nebula NGC 7027</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bohlin, R. C.; Marionni, P. A.; Stecher, T. P.</p> <p>1975-01-01</p> <p>An <span class="hlt">ultraviolet</span> spectrum of NGC 7027 was obtained with a rocket-borne telescope. The observed fluxes are given on an absolute basis and upper limits are given for the strongest predicted lines which were not observed. The extinction correction was made on the basis of the observed and calculated line ratios for the hydrogenic recombination line of He 2 at 1640A to H beta. The extinction is in agreement with ground based determinations. When corrected for extinction the C 4 resonance line at 1549A is in good agreement with the intensity calculated from models, but the C 3 intercombination line at 1909A is a factor of ten too <span class="hlt">bright</span>. The addition of dielectronic recombination to the models sufficiently changes the C 3 concentration to reduce the discrepancy to a factor of four. The abundance of carbon is assumed to be 2 x 0.0001 that of hydrogen. Using carbon abundances for the sun, this discrepancy disappears and there must be attenuation in the C 4 line. Since the optical depth is approximately 10,000 at the line center, no appreciable number of absorbing grains can exist in the C 4 producing region of the nebula.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARC46005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARC46005B"><span id="translatedtitle">Extreme-<span class="hlt">ultraviolet</span> ultrafast ARPES at high repetition rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buss, Jan; Wang, He; Xu, Yiming; Stoll, Sebastian; Zeng, Lingkun; Ulonska, Stefan; Denlinger, Jonathan; Hussain, Zahid; Jozwiak, Chris; Lanzara, Alessandra; Kaindl, Robert</p> <p></p> <p>Time- and angle-resolved photoemission spectroscopy (trARPES) represents a powerful approach to resolve the electronic structure and quasiparticle dynamics in complex materials, yet is often limited in either momentum space (incident photon energy), probe sensitivity (pulse repetition rate), or energy resolution. We demonstrate a novel table-top trARPES setup that combines a <span class="hlt">bright</span> 50-kHz source of narrowband, extreme <span class="hlt">ultraviolet</span> (XUV) pulses at 22.3 eV with UHV photoemission instrumentation to sensitively access dynamics for a large momentum space. The output of a high-power Ti:sapphire amplifier is split to provide the XUV probe and intense photoexcitation (up to mJ/cm2) . A vacuum beamline delivers spectral and flux characterization, differential pumping, as well as XUV beam steering and toroidal refocusing onto the sample with high incident flux of 3x1011 ph/s. Photoemission studies are carried out in a customized UHV chamber equipped with a hemispherical analyzer (R4000), six-axis sample cryostat, and side chambers for sample loading, storage and preparation. An ARPES energy resolution down to 70 meV with the direct XUV output is demonstrated. We will discuss initial applications of this setup including Fermi surface mapping and trARPES of complex materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3843830','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3843830"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> vision in birds: the importance of transparent eye media</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lind, Olle; Mitkus, Mindaugas; Olsson, Peter; Kelber, Almut</p> <p>2014-01-01</p> <p><span class="hlt">Ultraviolet</span> (UV)-sensitive visual pigments are widespread in the animal kingdom but many animals, for example primates, block UV light from reaching their retina by pigmented lenses. Birds have UV-sensitive (UVS) visual pigments with sensitivity maxima around 360–373 nm (UVS) or 402–426 nm (violet-sensitive, VS). We describe how these pigments are matched by the ocular media transmittance in 38 bird species. Birds with UVS pigments have ocular media that transmit more UV light (wavelength of 50% transmittance, λT0.5, 323 nm) than birds with VS pigments (λT0.5, 358 nm). Yet, visual models predict that colour discrimination in <span class="hlt">bright</span> light is mostly dependent on the visual pigment (UVS or VS) and little on the ocular media. We hypothesize that the precise spectral tuning of the ocular media is mostly relevant for detecting weak UV signals, e.g. in dim hollow-nests of passerines and parrots. The correlation between eye size and UV transparency of the ocular media suggests little or no lens pigmentation. Therefore, only small birds gain the full advantage from shifting pigment sensitivity from VS to UVS. On the other hand, some birds with VS pigments have unexpectedly low UV transmission of the ocular media, probably because of UV blocking lens pigmentation. PMID:24258716</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9286E..0NL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9286E..0NL"><span id="translatedtitle">Design of high-<span class="hlt">brightness</span> TEM00-mode solar-pumped laser for renewable material processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, D.; Almeida, J.</p> <p>2014-08-01</p> <p>The conversion of sunlight into laser light by direct solar pumping is of ever-increasing importance because broadband, temporally constant, sunlight is converted into laser light, which can be a source of narrowband, collimated, rapidly pulsed, radiation with the possibility of obtaining extremely high <span class="hlt">brightness</span> and intensity. Nonlinear processes, such as harmonic generation, might be used to obtain broad wavelength coverage, including the <span class="hlt">ultraviolet</span> wavelengths, where the solar flux is very weak. The direct excitation of large lasers by sunlight offers the prospect of a drastic reduction in the cost of coherent optical radiation for high average power materials processing. This renewable laser has a large potential for many applications such as high-temperature materials processing, renewable magnesium-hydrogen energy cycle and so on. We propose here a scalable TEM00 mode solar laser pumping scheme, which is composed of four firststage 1.13 m diameter Fresnel lenses with its respective folding mirrors mounted on a two-axis automatic solar tracker. Concentrated solar power at the four focal spots of these Fresnel lenses are focused individually along a common 3.5 mm diameter, 70 mm length Nd:YAG rod via four pairs of second-stage fused-silica spherical lenses and third-stage 2D-CPCs (Compound Parabolic Concentrator), sitting just above the laser rod which is also double-pass pumped by four V-shaped pumping cavities. Distilled water cools both the rod and the concentrators. 15.4 W TEM00 solar laser power is numerically calculated, corresponding to 6.7 times enhancement in laser beam <span class="hlt">brightness</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26252685','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26252685"><span id="translatedtitle">Generation of <span class="hlt">Bright</span>, Spatially Coherent Soft X-Ray High Harmonics in a Hollow Waveguide Using Two-Color Synthesized Laser Pulses.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Cheng; Stein, Gregory J; Hong, Kyung-Han; Lin, C D</p> <p>2015-07-24</p> <p>We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser pulses, optimized such that highest harmonic yields are emitted from each atom. Optimization of the gas pressure and waveguide configuration has enabled us to produce <span class="hlt">bright</span> and spatially coherent harmonics extending from the extreme <span class="hlt">ultraviolet</span> to soft x rays. Our study on the interplay among waveguide mode, atomic dispersion, and plasma effect uncovers how dynamic phase matching is accomplished and how an optimized waveform is maintained when optimal waveguide parameters (radius and length) and gas pressure are identified. Our analysis should help laboratory development in the generation of high-flux <span class="hlt">bright</span> coherent soft x rays as tabletop light sources for applications. PMID:26252685</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850041298&hterms=magnitude&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dmagnitude','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850041298&hterms=magnitude&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dmagnitude"><span id="translatedtitle">A medium-<span class="hlt">bright</span> quasar sample - New quasar surface densities in the magnitude range from 16.4 to 17.65 for B</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mitchell, K. J.; Warnock, A., III; Usher, P. D.</p> <p>1984-01-01</p> <p>A new medium-<span class="hlt">bright</span> quasar sample (MBQS) is constructed from spectroscopic observations of 140 <span class="hlt">bright</span> objects selected for varying degrees of blue and <span class="hlt">ultraviolet</span> excess (B-UVX) in five Palomar 1.2 m Schmidt fields. The MBQS contains 32 quasars with B less than 17.65 mag. The new integral surface densities in the B range from 16.45 to 17.65 mag are approximately 40 percent (or more) higher than expected. The MBQS and its redshift distribution increase the area of the Hubble diagram covered by complete samples of quasars. The general spectroscopic results indicate that the three-color classification process used to catalog the spectroscopic candidates (1) has efficiently separated the intrinsically B-UVX stellar objects from the Population II subdwarfs and (2) has produced samples of B-UVX objects which are more complete than samples selected by (U - B) color alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.115d3901J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.115d3901J"><span id="translatedtitle">Generation of <span class="hlt">Bright</span>, Spatially Coherent Soft X-Ray High Harmonics in a Hollow Waveguide Using Two-Color Synthesized Laser Pulses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Cheng; Stein, Gregory J.; Hong, Kyung-Han; Lin, C. D.</p> <p>2015-07-01</p> <p>We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser pulses, optimized such that highest harmonic yields are emitted from each atom. Optimization of the gas pressure and waveguide configuration has enabled us to produce <span class="hlt">bright</span> and spatially coherent harmonics extending from the extreme <span class="hlt">ultraviolet</span> to soft x rays. Our study on the interplay among waveguide mode, atomic dispersion, and plasma effect uncovers how dynamic phase matching is accomplished and how an optimized waveform is maintained when optimal waveguide parameters (radius and length) and gas pressure are identified. Our analysis should help laboratory development in the generation of high-flux <span class="hlt">bright</span> coherent soft x rays as tabletop light sources for applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3445124','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3445124"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Light and Skin Cancer in Athletes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Harrison, Shannon C.; Bergfeld, Wilma F.</p> <p>2009-01-01</p> <p>The incidence of melanoma and nonmelanoma skin cancers is increasing worldwide. <span class="hlt">Ultraviolet</span> light exposure is the most important risk factor for cutaneous melanoma and nonmelanoma skin cancers. Nonmelanoma skin cancer includes basal cell carcinoma and squamous cell carcinoma. Constitutive skin color and genetic factors, as well as immunological factors, play a role in the development of skin cancer. <span class="hlt">Ultraviolet</span> light also causes sunburn and photoaging damage to the skin. PMID:23015891</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/981695','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/981695"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Behavior of N = 8 supergravity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dixon, Lance J.; /SLAC</p> <p>2010-06-07</p> <p>In these lectures the author describes the remarkable <span class="hlt">ultraviolet</span> behavior of N = 8 supergravity, which through four loops is no worse than that of N = 4 super-Yang-Mills theory (a finite theory). I also explain the computational tools that allow multi-loop amplitudes to be evaluated in this theory - the KLT relations and the unitarity method - and sketch how <span class="hlt">ultraviolet</span> divergences are extracted from the amplitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012muls.conf....1D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012muls.conf....1D"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Behavior of {N} = 8 Supergravity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dixon, Lance J.</p> <p>2012-12-01</p> <p>In these lectures I describe the remarkable <span class="hlt">ultraviolet</span> behavior of {N} = 8 supergravity, which through four loops is no worse than that of {N} = 4 super-Yang-Mills theory (a finite theory). I also explain the computational tools that allow multi-loop amplitudes to be evaluated in this theory - the KLT relations and the unitarity method - and sketch how <span class="hlt">ultraviolet</span> divergences are extracted from the amplitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750004674','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750004674"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> stellar spectrophotometry from a balloon platform</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kondo, Y.; Wells, C.</p> <p>1974-01-01</p> <p>A 40 centimeter diameter aperture, balloon-borne telescope and <span class="hlt">ultraviolet</span> spectrometer is described and selected scientific results are briefly reviewed. The general configuration of the 0.4 angstrom resolution instrument is shown and the utilization of servo-controlled secondary mirror, image dissector detector, and special mirror coatings are discussed. An outlook for astronomical research in the mid-<span class="hlt">ultraviolet</span> from balloon-borne telescopes is presented together with future development plans for JSC's balloon-borne payload.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5888..128K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5888..128K"><span id="translatedtitle">Polarization measurements in the vacuum <span class="hlt">ultraviolet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kobayashi, K.; West, E. A.; Noble, M.</p> <p>2005-08-01</p> <p>This paper will describe the Vacuum <span class="hlt">Ultraviolet</span> (VUV) polarization testing of the Solar <span class="hlt">Ultraviolet</span> Magnetograph (SUMI) optics. SUMI is being develop for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization properties of the VUV calibration polarizers, the instrumental polarization of the VUV chamber, SUMI's toroidal varied-line-space gratings and the SUMI polarimeter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950009617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950009617"><span id="translatedtitle">Dust near luminous <span class="hlt">ultraviolet</span> stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Henry, Richard C.</p> <p>1993-01-01</p> <p>This report describes research activities related to the Infrared Astronomical Satellite (IRAS) sky survey. About 745 luminous stars were examined for the presence of interstellar dust heated by a nearby star. The 'cirrus' discovered by IRAS is thermal radiation from interstellar dust at moderate and high galactic latitudes. The IRAS locates the dust which must (at some level) scatter <span class="hlt">ultraviolet</span> starlight, although it was expected that thermal emission would be found around virtually every star, most stars shown no detectable emission. And the emission found is not uniform. It is not that the star is embedded in 'an interstellar medium', but rather what is found are discrete clouds that are heated by starlight. An exception is the dearth of clouds near the very hottest stars, implying that the very hottest stars play an active role with respect to destroying or substantially modifying the dust clouds over time. The other possibility is simply that the hottest stars are located in regions lacking in dust, which is counter-intuitive. A bibliography of related journal articles is attached.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6181','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6181"><span id="translatedtitle">Masks for extreme <span class="hlt">ultraviolet</span> lithography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cardinale, G; Goldsmith, J; Kearney, P A; Larson, C; Moore, C E; Prisbrey, S; Tong, W; Vernon, S P; Weber, F; Yan, P-Y</p> <p>1998-09-01</p> <p>In extreme <span class="hlt">ultraviolet</span> lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20883261','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20883261"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> radiation and skin cancer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Narayanan, Deevya L; Saladi, Rao N; Fox, Joshua L</p> <p>2010-09-01</p> <p>Skin cancer is the most common type of cancer in fair-skinned populations in many parts of the world. The incidence, morbidity and mortality rates of skin cancers are increasing and, therefore, pose a significant public health concern. <span class="hlt">Ultraviolet</span> radiation (UVR) is the major etiologic agent in the development of skin cancers. UVR causes DNA damage and genetic mutations, which subsequently lead to skin cancer. A clearer understanding of UVR is crucial in the prevention of skin cancer. This article reviews UVR, its damaging effects on the skin and its relationship to UV immunosuppression and skin cancer. Several factors influence the amount of UVR reaching the earth's surface, including ozone depletion, UV light elevation, latitude, altitude, and weather conditions. The current treatment modalities utilizing UVR (i.e. phototherapy) can also predispose to skin cancers. Unnecessary exposure to the sun and artificial UVR (tanning lamps) are important personal attributable risks. This article aims to provide a comprehensive overview of skin cancer with an emphasis on carefully evaluated statistics, the epidemiology of UVR-induced skin cancers, incidence rates, risk factors, and preventative behaviors & strategies, including personal behavioral modifications and public educational initiatives. PMID:20883261</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994SPIE.2134B..92S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994SPIE.2134B..92S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> radiation cataract: dose dependence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Soderberg, Per G.; Loefgren, Stefan</p> <p>1994-07-01</p> <p>Current safety limits for cataract development after acute exposure to <span class="hlt">ultraviolet</span> radiation (UVR) are based on experiments analyzing experimental data with a quantal, effect-no effect, dose-response model. The present study showed that intensity of forward light scattering is better described with a continuous dose-response model. It was found that 3, 30 and 300 kJ/m2UVR300nm induces increased light scattering within 6 h. For all three doses the intensity of forward light scattering was constant after 6 h. The intensity of forward light scattering was proportional to the log dose of UVR300nm. There was a slight increase of the intensity of forward light scattering on the contralateral side in animals that received 300 kJ/m2. Altogether 72 Sprague-Dawley male rats were included. Half of the rats were exposed in vivo on one side to UVR300nm. The other half was kept as a control group, receiving the same treatment as exposed rats but without delivery of UVR300nm to the eye. Subgroups of the rats received either of the three doses. Rats were sacrificed at varying intervals after the exposure. The lenses were extracted and the forward light scattering was estimated. It is concluded that intensity of forward light scattering in the lens after exposure to UVR300nm should be described with a continuous dose-reponse model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860003801','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860003801"><span id="translatedtitle">Survey of <span class="hlt">ultraviolet</span> shuttle glow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spear, K. A.; Uckler, G. J.; Tobiska, K.</p> <p>1985-01-01</p> <p>The University of Colorado Get Away Special (GAS) project utilizes the efforts of its students to place experiments on the shuttle. The objective of one experiment, the shuttle glow study, is to conduct a general survey of emissions in the <span class="hlt">ultraviolet</span> near vehicle surfaces. An approximate wavelength range of 1900 to 3000 A will be scanned to observe predominant features. Special emphasis will be placed on studying the band structure of NO near 2000 A and the Mg+ line at 2800 A. The spectrometer, of Ebert-Faste 1/8-meter design, will perform the experiment during spacecraft night. It will be oriented such that the optical axis points to the cargo bay zenith. In order to direct the field-of-view of the instrument onto the shuttle vertical stabilizer (tail), a mirror assembly is employed. The mirror system has been designed to rotate through 7.5 degrees of arc using 10 positions resulting in a spatial resolution of 30 x 3 cm, with the larger dimension corresponding to the horizontal direction. Such a configuration can be attained from the forwardmost position in the cargo bay. Each spatial position will be subjected to a full spectral scan with a resolution on the order of 10 A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/2203439','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/2203439"><span id="translatedtitle">Human exposure to <span class="hlt">ultraviolet</span> radiation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Diffey, B L</p> <p>1990-03-01</p> <p>Although the sun remains the main source of <span class="hlt">ultraviolet</span> radiation (UVR) exposure in humans, the advent of artificial UVR sources has increased the opportunity for both intentional and unintentional exposure. Intentional exposure is most often to tan the skin. People living in less sunny climates can now maintain a year-round tan by using sunbeds and solaria emitting principally UVA radiation. Another reason for intentional exposure to artificial UVR is treatment of skin diseases, notably psoriasis. Unintentional exposure is normally the result of occupation. Outdoor workers, such as farmers, receive three to four times the annual solar UV exposure of indoor workers. Workers in many industries, eg, photoprinting or hospital phototherapy departments, may be exposed to UVR from artificial sources. One group particularly at risk is electric arc welders, where inadvertent exposure is so common that the terms "arc eye" or "welders flash" are often used to describe photokeratitis. In addition to unavoidable exposure to natural UVR, the general public is exposed to low levels of UVR from sources such as fluorescent lamps used for indoor lighting and shops and restaurants where UVA lamps are often used in traps to attract flying insects. PMID:2203439</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Sci...350.1225P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Sci...350.1225P"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> surprise: Efficient soft x-ray high-harmonic generation in multiply ionized plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Popmintchev, Dimitar; Hernández-García, Carlos; Dollar, Franklin; Mancuso, Christopher; Pérez-Hernández, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieszka; Becker, Andreas; Plaja, Luis; Murnane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio</p> <p>2015-12-01</p> <p>High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Because of reduced quantum diffusion of the radiating electron wave function, the emission from each species is highest when a short-wavelength <span class="hlt">ultraviolet</span> driving laser is used. However, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle <span class="hlt">ultraviolet</span> lasers in waveguides that can generate <span class="hlt">bright</span> beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high <span class="hlt">ultraviolet</span> refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth-limited pulse trains of ~100 attoseconds.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1234578','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1234578"><span id="translatedtitle">The <span class="hlt">Ultraviolet</span> Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieskzka; Becker, Andreas; Plaja, Luis; Muranane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio</p> <p>2015-12-04</p> <p>High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength <span class="hlt">ultraviolet</span> driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle <span class="hlt">ultraviolet</span> lasers in waveguides that can generate <span class="hlt">bright</span> beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high <span class="hlt">ultraviolet</span> refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1234578-ultraviolet-surprise-efficient-soft-ray-high-harmonic-generation-multiply-ionized-plasmas','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1234578-ultraviolet-surprise-efficient-soft-ray-high-harmonic-generation-multiply-ionized-plasmas"><span id="translatedtitle">The <span class="hlt">Ultraviolet</span> Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; et al</p> <p>2015-12-04</p> <p>High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength <span class="hlt">ultraviolet</span> driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle <span class="hlt">ultraviolet</span> lasers in waveguides that can generate <span class="hlt">bright</span> beams inmore » the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high <span class="hlt">ultraviolet</span> refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AAS...22313801M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AAS...22313801M"><span id="translatedtitle">SPINR Sounding Rocket Measurements of Far-<span class="hlt">Ultraviolet</span> Dust Scattering Properties in Orion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mendillo, Christopher; Cook, T.; Chakrabarti, S.; Gordon, K. D.</p> <p>2014-01-01</p> <p>Wide-field observations of the Orion OB stellar association were performed in the far-<span class="hlt">ultraviolet</span> using the Spectrograph for Photometric Imaging with Numeric Reconstruction (SPINR) sounding rocket. These observations reveal the diffuse signature of starlight scattering off interstellar dust grains. The spectral-imaging data were used along with a three-dimensional radiative transfer model to measure the dust scattering parameters: the grain albedo (a) and the scattering asymmetry (g). The measured parameters are consistent with previous measurements made toward Orion. A sharp increase in albedo was measured at ~1330 Å. This feature is not explained by current grain models. The constructed three-dimensional model of Orion includes a two-component dust distribution. The foreground distribution is responsible for the small amount of visible reddening measured toward the <span class="hlt">bright</span> stars in the Orion constellation. The background distribution represents the Orion Molecular Cloud, which dominates observations of dust emission in the infrared. This model was used to show that backscattered light from the molecular cloud alone cannot produce the observed scattered light distribution. The foreground dust, though optically thin in the visible, significantly contributes to the scattered light in the far-<span class="hlt">ultraviolet</span>. This suggests that observations of Orion in the infrared and far-<span class="hlt">ultraviolet</span> may probe entirely different dust populations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........22T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........22T"><span id="translatedtitle">Studying Laser-Induced Spin Currents Using Ultrafast Extreme <span class="hlt">Ultraviolet</span> Light</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turgut, Emrah</p> <p></p> <p>Next-generation magnetic-memory devices and heat-assisted magnetic-recording applications will require a better understanding of magnetic multilayers and their interactions with optical-laser pulses. In this thesis, by combining the advantages of ultrabroad-band extreme-<span class="hlt">ultraviolet</span> light including ultrafast time resolution, element selectivity and tabletop easy access, I report three findings in the study of ultrafast magnetization dynamics in itinerant ferromagnets. First, I experimentally prove that the transverse magneto-optical Kerr response with extreme-<span class="hlt">ultraviolet</span> light has a purely magnetic origin and that our experimental technique is an artifact-free ultrafast magnetic probe. Second, I demonstrate the first ultrafast magnetization enhancement driven by ultrafast spin currents in Ni/Ru/Fe multilayers. Third, I engineer the sample system by choosing either insulating or spin-scattering spacer layers between the Ni and Fe magnetic layers and by structural ordering. Then, I control the competition between ultrafast spin-flip scattering and superdiffusive spin-current mechanisms; either of these processes may to be the dominant mechanism in ultrafast demagnetization. Finally, I report two continuing experiments that are promising for future ultrafast magnetization studies with extreme-<span class="hlt">ultraviolet</span> sources. These experiments are resonant-magnetic small-angle-scattering and the generation of <span class="hlt">bright</span> circularly polarized high harmonics accompanied by a demonstration of the first x-ray magnetic circular dichroism with a tabletop system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000hpdl.conf..225B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000hpdl.conf..225B&link_type=ABSTRACT"><span id="translatedtitle">Properties and Frequency Conversion of High-<span class="hlt">Brightness</span> Diode-Laser Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boller, Klaus-Jochen; Beier, Bernard; Wallenstein, Richard</p> <p></p> <p>An overview of recent developments in the field of high-power, high-<span class="hlt">brightness</span> diode-lasers, and the optically nonlinear conversion of their output into other wavelength ranges, is given. We describe the generation of continuous-wave (CW) laser beams at power levels of several hundreds of milliwatts to several watts with near-perfect spatial and spectral properties using Master-Oscillator Power-Amplifier (MOPA) systems. With single- or double-stage systems, using amplifiers of tapered or rectangular geometry, up to 2.85 W high-<span class="hlt">brightness</span> radiation is generated at wavelengths around 810nm with AlGaAs diodes. Even higher powers, up to 5.2W of single-frequency and high spatial quality beams at 925nm, are obtained with InGaAs diodes. We describe the basic properties of the oscillators and amplifiers used. A strict proof-of-quality for the diode radiation is provided by direct and efficient nonlinear optical conversion of the diode MOPA output into other wavelength ranges. We review recent experiments with the highest power levels obtained so far by direct frequency doubling of diode radiation. In these experiments, 100mW single-frequency <span class="hlt">ultraviolet</span> light at 403nm was generated, as well as 1W of single-frequency blue radiation at 465nm. Nonlinear conversion of diode radiation into widely tunable infrared radiation has recently yielded record values. We review the efficient generation of widely tunable single-frequency radiation in the infrared with diode-pumped Optical Parametric Oscillators (OPOs). With this system, single-frequency output radiation with powers of more than 0.5W was generated, widely tunable around wavelengths of <!- MATH 2.1 mu mathrm{m} -> 2.1,m and <!- MATH 1.65 mu mathrm{m} -> 1.65,m and with excellent spectral and spatial quality. These developments are clear indicators of recent advances in the field of high-<span class="hlt">brightness</span> diode-MOPA systems, and may emphasize their future central importance for applications within a vast range of optical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23933245','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23933245"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> resources over Northern Eurasia.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chubarova, Natalia; Zhdanova, Yekaterina</p> <p>2013-10-01</p> <p>We propose a new climatology of UV resources over Northern Eurasia, which includes the assessments of both detrimental (erythema) and positive (vitamin D synthesis) effects of <span class="hlt">ultraviolet</span> radiation on human health. The UV resources are defined by using several classes and subclasses - UV deficiency, UV optimum, and UV excess - for 6 different skin types. To better quantifying the vitamin D irradiance threshold we accounted for an open body fraction S as a function of effective air temperature. The spatial and temporal distribution of UV resources was estimated by radiative transfer (RT) modeling (8 stream DISORT RT code) with 1×1° grid and monthly resolution. For this purpose special datasets of main input geophysical parameters (total ozone content, aerosol characteristics, surface UV albedo, UV cloud modification factor) have been created over the territory of Northern Eurasia. The new approaches were used to retrieve aerosol parameters and cloud modification factor in the UV spectral region. As a result, the UV resources were obtained for clear-sky and mean cloudy conditions for different skin types. We show that the distribution of UV deficiency, UV optimum and UV excess is regulated by various geophysical parameters (mainly, total ozone, cloudiness and open body fraction) and can significantly deviate from latitudinal dependence. We also show that the UV optimum conditions can be simultaneously observed for people with different skin types (for example, for 4-5 skin types at the same time in spring over Western Europe). These UV optimum conditions for different skin types occupy a much larger territory over Europe than that over Asia. PMID:23933245</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000STIN...0010579L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000STIN...0010579L"><span id="translatedtitle">Modeling <span class="hlt">Ultraviolet</span> Emissions Near Io</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Linker, Jon A.</p> <p>2000-10-01</p> <p>In this report, we describe work awarded to Science Applications International Corporation, for the period 6/l/99 to 5/31/00. During this time period, we have investigated the interaction of Io, Jupiter's innermost Galilean satellite, with the Io plasma torus, and the role this interaction plays in producing <span class="hlt">ultraviolet</span> (UV) emissions from neutral oxygen and sulfur. Io, the innermost of Jupiter's Galilean satellites, plays a unique role in the jovian magnetosphere. Neutral material that escapes from Io is ionized to form the lo torus, a dense, heavy-ion plasma that corotates with Jupiter and interacts with Io. Io supplies not only the torus, but is a major source of plasma for the entire magnetosphere. Ionization and charge-exchange of neutrals near lo strongly influences the plasma interaction, and Io's neutral atmosphere plays an important role in the generation of currents that couple Io to Jupiter. There have been no in situ measurements of the neutral density near Io, but remote observations of neutrals near lo have been performed for many years. Recent observations from the Hubble Space Telescope (HST) have shown detailed structure in UV emissions from neutral species near Io. Electron-impact of the neutrals by the Io torus plasma is the primary mechanism responsible for exciting these emissions. Previously, we have modeled the Io plasma environment using three-dimensional magnetohydrodynamic (MHD) simulations, and we have shown that the interaction between Io and the plasma torus plays an important role in producing the morphology of the observed emissions. In the past year, we have extended these studies to use both UV observations and Galileo particle and field measurements to investigate the Io interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=AS16-123-19657&hterms=Middle+earth&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMiddle%2Bearth','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=AS16-123-19657&hterms=Middle+earth&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMiddle%2Bearth"><span id="translatedtitle">Earth, photographed in far-<span class="hlt">ultraviolet</span> light with the <span class="hlt">ultraviolet</span> camera</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1972-01-01</p> <p>The Earth, photographed in far-<span class="hlt">ultraviolet</span> light (1304 Angstrom) by Astronaut John W. Young, Apollo 16 commander, with the <span class="hlt">ultraviolet</span> camera. The auroral belts 13 degrees either side of the magnetic equator can be seen crossing each other on the middle of the right side of the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015533','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015533"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Spectroscopy of Asteroid(4) Vesta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Li, Jian-Yang; Bodewits, Dennis; Feaga, Lori M.; Landsman, Wayne; A'Hearn, Michael F.; Mutchler, Max J.; Russell, Christopher T.; McFadden, Lucy A.; Raymond, Carol A.</p> <p>2011-01-01</p> <p>We report a comprehensive review of the UV-visible spectrum and rotational lightcurve of Vesta combining new observations by Hubble Space Telescope and Swift with archival International <span class="hlt">Ultraviolet</span> Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm arc derived by carefully comparing these observations from various instruments at different times and observing geometries. Vesta has a rotationally averaged geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673 nm, and 0.30 at 950 nm. The linear spectral slope in the <span class="hlt">ultraviolet</span> displays a sharp minimum ncar sub-Earth longitude of 20deg, and maximum in the eastern hemisphere. This is completely consistent with the distribution of the spectral slope in the visible wavelength. The uncertainty of the measurement in the <span class="hlt">ultraviolet</span> is approx.20%, and in the visible wavelengths better than 10%. The amplitude of Vesta's rotational lightcurves is approx.10% throughout the range of wavelengths we observed, but is smaller at 950 nm (approx.6%) ncar the 1-micron mafic band center. Contrary to earlier reports, we found no evidence for any difference between the phasing of the <span class="hlt">ultraviolet</span> and visible/ncar-infrared lightcurves with respect to sub-Earth longitude. Vesta's average spectrum between 220 and 950 nm can well be described by measured reflectance spectra of fine particle howardite-like materials of basaltic achondrite meteorites. Combining this with the in-phase behavior of the <span class="hlt">ultraviolet</span>, visible. and ncar-infrared lightcurves, and the spectral slopes with respect to the rotational phase, we conclude that there is no global <span class="hlt">ultraviolet</span>/visible reversal on Vesta. Consequently, this implies lack of global space weathering on Vesta. Keyword,: Asteroid Vesta; Spectrophotometry; Spectroscopy; <span class="hlt">Ultraviolet</span> observations; Hubble Space Telescope observations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.105f3303W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.105f3303W"><span id="translatedtitle">High performance organic integrated device with <span class="hlt">ultraviolet</span> photodetective and electroluminescent properties consisting of a charge-transfer-featured naphthalimide derivative</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Hanyu; Zhou, Jie; Wang, Xu; Lu, Zhiyun; Yu, Junsheng</p> <p>2014-08-01</p> <p>A high performance organic integrated device (OID) with <span class="hlt">ultraviolet</span> photodetective and electroluminescent (EL) properties was fabricated by using a charge-transfer-featured naphthalimide derivative of 6-{3,5-bis-[9-(4-t-butylphenyl)-9H-carbazol-3-yl]-phenoxy}-2-(4-t-butylphenyl)-benzo[de]isoquinoline-1,3-dione (CzPhONI) as the active layer. The results showed that the OID had a high detectivity of 1.5 × 1011 Jones at -3 V under the UV-350 nm illumination with an intensity of 0.6 mW/cm2, and yielded an exciplex EL light emission with a maximum <span class="hlt">brightness</span> of 1437 cd/m2. Based on the energy band diagram, both the charge transfer feature of CzPhONI and matched energy level alignment were responsible for the dual <span class="hlt">ultraviolet</span> photodetective and EL functions of OID.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ascl.soft08011E&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ascl.soft08011E&link_type=ABSTRACT"><span id="translatedtitle">PROFFIT: Analysis of X-ray surface-<span class="hlt">brightness</span> profiles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eckert, Dominique</p> <p>2016-08-01</p> <p>PROFFIT analyzes X-ray surface-<span class="hlt">brightness</span> profiles for data from any X-ray instrument. It can extract surface-<span class="hlt">brightness</span> profiles in circular or elliptical annuli, using constant or logarithmic bin size, from the image centroid, the surface-<span class="hlt">brightness</span> peak, or any user-given center, and provides surface-<span class="hlt">brightness</span> profiles in any circular or elliptical sectors. It offers background map support to extract background profiles, can excise areas using SAO DS9-compatible (ascl:0003.002) region files to exclude point sources, provides fitting with a number of built-in models, including the popular beta model, double beta, cusp beta, power law, and projected broken power law, uses chi-squared or C statistic, and can fit on the surface-<span class="hlt">brightness</span> or counts data. It has a command-line interface similar to HEASOFT’s XSPEC (ascl:9910.005) package, provides interactive help with a description of all the commands, and results can be saved in FITS, ROOT or TXT format.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/3695799','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/3695799"><span id="translatedtitle"><span class="hlt">Bright</span> artificial light subsensitizes a central muscarinic mechanism.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dilsaver, S C; Majchrzak, M J</p> <p>1987-12-14</p> <p>Supersensitivity of a muscarinic mechanism is implicated in the pathophysiology of depression. <span class="hlt">Bright</span> artificial light is efficacious in the treatment of Seasonal Affective Disorder (SAD). We studied the effect of constant <span class="hlt">bright</span> light (11,500 lux) on the sensitivity of adult, male rats to oxotremorine, 1.5 mg/kg ip, using a repeated measures design. Oxotremorine challenges were proceeded by the injection of methylscopolamine, 1 mg/kg ip, by 30 minutes. Temperature was telemetrically measured every 10 minutes for 120 minutes starting 10 minutes after the injection of oxotremorine. Prior to and after 7 continuous days of exposure to <span class="hlt">bright</span> light, the sample exhibited a hypothermic response of 2.50 +/- 0.48 degrees C (mean +/- SEM) and 0.29 +/- 0.31 degrees C (mean +/- SEM), respectively (p less than 0.0014). All 7 animals exhibited blunting to the thermic response to oxotremorine. <span class="hlt">Bright</span> light also blocked the capacity of amitriptyline to supersensitize a central muscarinic mechanism. Exposure to light at an intensity of 300 lux for 7 days had no effect on the thermic response to oxotremorine. These data are consistent with the hypotheses that the biology of depression involves supersensitivity of central muscarinic mechanisms and that the effects of <span class="hlt">bright</span> artificial light are not the consequence of shifting circadian rhythms. PMID:3695799</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3864689','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3864689"><span id="translatedtitle">Counting unstained, confluent cells by modified <span class="hlt">bright</span>-field microscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Drey, L. Louis; Graber, Michael C.; Bieschke, Jan</p> <p>2013-01-01</p> <p>We present a very simple procedure yielding high-contrast images of adherent, confluent cells such as human neuroblastoma (SH-EP) cells by ordinary <span class="hlt">bright</span>-field microscopy. Cells are illuminated through a color filter and a pinhole aperture placed between the condenser and the cell culture surface. Refraction by each cell body generates a sharp, <span class="hlt">bright</span> spot when the image is defocused. The technique allows robust, automatic cell counting from a single <span class="hlt">bright</span>-field image in a wide range of focal positions; it does this via free, readily available image-analysis tools. Contrast may be enhanced by swelling cell bodies by brief incubation in PBS. The procedure was benchmarked against manual counting and automated counting of fluorescently labeled cell nuclei.. Counts from day-old and freshly seeded plates were compared in a range of densities, from sparse to densely overgrown. On average <span class="hlt">bright</span>-field images produced the same counts as fluorescent images, with less than 5% error. This method will allow routine cell counting using a plain <span class="hlt">bright</span>-field microscope, absent cell-line modification or cell staining. PMID:23834382</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930017558','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930017558"><span id="translatedtitle">Oxygen abundances in low surface-<span class="hlt">brightness</span> galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roennback, Jari</p> <p>1993-01-01</p> <p>Recent theories predict that some protogalaxies, in low-density environments of the field, are contracting and interacting so slowly that global star formation can be delayed until today. These systems should be gas rich and have low surface-<span class="hlt">brightness</span>. Blue compact galaxies (BCG's) and other compact HII region galaxies currently experiencing a burst of star formation are good candidates of truly young galaxies (in the sense that global star formation recently has been initiated). If they really are young, they ought to have a recent phase when their <span class="hlt">brightness</span> was much lower than in the bursting phase. No claims of observations of such proto-BCG's exist. Observations of galaxies in their juvenile phases would undoubtedly be of great interest, e.g. the determination of the primordial helium abundance would improve. A proper place to search for young nearby galaxies could be among blue low surface-<span class="hlt">brightness</span> galaxies (BLSBG's) in the local field. The study of low surface-<span class="hlt">brightness</span> galaxies (LSBG's) as a group began relatively recently. They are galaxies with extraordinary properties both as individuals and as a group. A few years ago we started an optical study of a sample of BLSBG's selected from the ESO/Uppsala catalogue. Results of spectroscopic observations obtained on a subsample - 8 galaxies - of our selection are reported. The HII region oxygen chemical abundances and its relation to the blue absolute magnitude and surface-<span class="hlt">brightness</span> is investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21305043','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21305043"><span id="translatedtitle"><span class="hlt">ULTRAVIOLET</span> SPECTRA OF THE C-2003K7 COMET: EVIDENCE FOR DUST SUBLIMATION IN Si AND C LINES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ciaravella, A.; Raymond, J. C.; Giordano, S.</p> <p>2010-04-10</p> <p>UV spectra of the <span class="hlt">bright</span> sungrazing comet C-2003K7 detected at 2.37 R {sub sun} above the Sun surface by the <span class="hlt">Ultraviolet</span> Coronagraph Spectrometer (UVCS) during the daily synoptic scan show <span class="hlt">bright</span> lines of H I Ly{alpha}, Si III {lambda} 1206, and C III {lambda} 977. The derived outgassing rate is an order of magnitude larger than those of the other sungrazers observed by UVCS. Analysis of the spectra suggests that the comet broke apart into smaller pieces before it reached the UVCS slit. The observations provide lower and upper limits to the values of the Si III/C III ratio, in the range 8-22. The ratio indicates a larger abundance of silicates in the cometary dust as compared to organic refractory materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22370145','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22370145"><span id="translatedtitle">The effect of surface <span class="hlt">brightness</span> dimming in the selection of high-z galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Calvi, V.; Stiavelli, M.; Bradley, L.; Pizzella, A.; Kim, S.</p> <p>2014-12-01</p> <p>Cosmological surface <span class="hlt">brightness</span> (SB) dimming of the form (1 + z){sup –4} affects all sources. The strong dependence of SB dimming on redshift z suggests the presence of a selection bias when searching for high-z galaxies, i.e., we tend to detect only those galaxies with a high SB. However, unresolved knots of emission are not affected by SB dimming, thus providing a way to test the clumpiness of high-z galaxies. Our strategy relies on the comparison of the total flux detected for the same source in surveys characterized by different depth. For all galaxies, deeper images permit the better investigation of low-SB features. Cosmological SB dimming makes these low-SB features hard to detect when going to higher and higher redshifts. We used the GOODS and HUDF Hubble Space Telescope legacy data sets to study the effect of SB dimming on low-SB features of high-z galaxies and compare it to the prediction for smooth sources. We selected a sample of Lyman-break galaxies at z ∼ 4 (i.e., B {sub 435}-band dropouts) detected in all of the data sets and found no significant trend when comparing the total magnitudes measured from images with different depth. Through Monte Carlo simulations we derived the expected trend for galaxies with different SB profiles. The comparison to the data hints at a compact distribution for most of the rest-frame <span class="hlt">ultraviolet</span> light emitted from high-z galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013cos..rept....5D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013cos..rept....5D&link_type=ABSTRACT"><span id="translatedtitle">Second COS FUV Lifetime Position: Verification of FUV <span class="hlt">Bright</span> Object Aperture (BOA) Operations (FCAL4)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Debes, John H.</p> <p>2013-05-01</p> <p>As part of the calibration of the second lifetime position on the Cosmic Origins Spectrograph (COS) far-<span class="hlt">ultraviolet</span> (FUV) detectors, observations of the external target, G191-B2B, were obtained with the G130M, G160M, and G140L gratings in combi- nation with the <span class="hlt">Bright</span> Object Aperture. The observations were designed to verify the performance of these spectroscopic modes by reproducing similar observations taken during the SM4 Servicing Mission Observatory Verification (SMOV) of COS. These observations allowed for a detailed determination of the spatial location and profile of the spectra from the three gratings, as well as a determination of the spectral resolution of the G130M grating prior to and after the lifetime move. In general, the negligi- ble differences which exist between the two lifetime positions can be attributed to slight differences in the optical path. In particular, the spectral resolution appears to be slightly improved. The stability of the absolute and relative flux calibration was investigated for G130M as well using STIS echelle data of G191-B2B. We determine that the COS ab- solute flux calibration with the BOA is accurate to 10%, and flux calibrated data are reproducible at the 1-2% level since SMOV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27299915','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27299915"><span id="translatedtitle"><span class="hlt">Bright</span> UV Single Photon Emission at Point Defects in h-BN.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bourrellier, Romain; Meuret, Sophie; Tararan, Anna; Stéphan, Odile; Kociak, Mathieu; Tizei, Luiz H G; Zobelli, Alberto</p> <p>2016-07-13</p> <p>To date, quantum sources in the <span class="hlt">ultraviolet</span> (UV) spectral region have been obtained only in semiconductor quantum dots. Color centers in wide bandgap materials may represent a more effective alternative. However, the quest for UV quantum emitters in bulk crystals faces the difficulty of combining an efficient UV excitation/detection optical setup with the capability of addressing individual color centers in potentially highly defective materials. In this work we overcome this limit by employing an original experimental setup coupling cathodoluminescence within a scanning transmission electron microscope to a Hanbury-Brown-Twiss intensity interferometer. We identify a new extremely <span class="hlt">bright</span> UV single photon emitter (4.1 eV) in hexagonal boron nitride. Hyperspectral cathodoluminescence maps show a high spatial localization of the emission (∼80 nm) and a typical zero-phonon line plus phonon replica spectroscopic signature, indicating a point defect origin, most likely carbon substitutional at nitrogen sites. An additional nonsingle-photon broad emission may appear in the same spectral region, which can be attributed to intrinsic defects related to electron irradiation. PMID:27299915</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...796..102C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...796..102C"><span id="translatedtitle">The Effect of Surface <span class="hlt">Brightness</span> Dimming in the Selection of High-z Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calvi, V.; Stiavelli, M.; Bradley, L.; Pizzella, A.; Kim, S.</p> <p>2014-12-01</p> <p>Cosmological surface <span class="hlt">brightness</span> (SB) dimming of the form (1 + z)-4 affects all sources. The strong dependence of SB dimming on redshift z suggests the presence of a selection bias when searching for high-z galaxies, i.e., we tend to detect only those galaxies with a high SB. However, unresolved knots of emission are not affected by SB dimming, thus providing a way to test the clumpiness of high-z galaxies. Our strategy relies on the comparison of the total flux detected for the same source in surveys characterized by different depth. For all galaxies, deeper images permit the better investigation of low-SB features. Cosmological SB dimming makes these low-SB features hard to detect when going to higher and higher redshifts. We used the GOODS and HUDF Hubble Space Telescope legacy data sets to study the effect of SB dimming on low-SB features of high-z galaxies and compare it to the prediction for smooth sources. We selected a sample of Lyman-break galaxies at z ~ 4 (i.e., B 435-band dropouts) detected in all of the data sets and found no significant trend when comparing the total magnitudes measured from images with different depth. Through Monte Carlo simulations we derived the expected trend for galaxies with different SB profiles. The comparison to the data hints at a compact distribution for most of the rest-frame <span class="hlt">ultraviolet</span> light emitted from high-z galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016QuEle..46..473V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016QuEle..46..473V&link_type=ABSTRACT"><span id="translatedtitle">High <span class="hlt">brightness</span> EUV sources based on laser plasma at using droplet liquid metal target</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vinokhodov, A. Yu; Krivokorytov, M. S.; Sidelnikov, Yu V.; Krivtsun, V. M.; Medvedev, V. V.; Koshelev, K. N.</p> <p>2016-05-01</p> <p>We present the study of a source of extreme <span class="hlt">ultraviolet</span> (EUV) radiation based on laser plasma generated due to the interaction of radiation from a nanosecond Nd : YAG laser with a liquidmetal droplet target consisting of a low-temperature eutectic indium–tin alloy. The generator of droplets is constructed using a commercial nozzle and operates on the principle of forced capillary jet decomposition. Long-term spatial stability of the centre-of-mass position of the droplet with the root-mean-square deviation of ~0.5 μm is demonstrated. The use of a low-temperature working substance instead of pure tin increases the reliability and lifetime of the droplet generator. For the time- and space-averaged power density of laser radiation on the droplet target 4 × 1011 W cm-2 and the diameter of radiating plasma ~80 μm, the mean efficiency of conversion of laser energy into the energy of EUV radiation at 13.5 +/- 0.135 nm equal to 2.3% (2π sr)-1 is achieved. Using the doublepulse method, we have modelled the repetitively pulsed regime of the source operation and demonstrated the possibility of its stable functioning with the repetition rate up to 8 kHz for the droplet generation repetition rate of more than 32 kHz, which will allow the source <span class="hlt">brightness</span> to be as large as ~0.96 kW (mm2 sr)-1.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6381E..0BY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6381E..0BY"><span id="translatedtitle">Hyperspectral <span class="hlt">bright</span> greenish-yellow fluorescence (BGYF) imaging of aflatoxin contaminated corn kernels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Haibo; Hruska, Zuzana; Brown, Robert L.; Cleveland, Thomas E.</p> <p>2006-10-01</p> <p>Aflatoxin contaminated corn poses a serious threat to both domestic animals and humans, because of its carcinogenic properties. Traditionally, corn kernels have been examined for evidence of <span class="hlt">bright</span> greenish-yellow fluorescence (BGYF), which is an indication of possible presence of Aspergillus flavus, one of the aflatoxin producing strains of fungi, when illuminated with a high-intensity <span class="hlt">ultra-violet</span> light. The BGYF test is typically the first step that leads to an in-depth chemical analysis for possible aflatoxin contamination. The objective of the present study was to analyze hyperspectral BGYF response of corn kernels under UVA excitation. The target corn samples were collected from a commercial corn field in 2005 and showed abundant BGYF response. The BGYF positive kernels were manually picked out and imaged under a visible near-infrared hyperspectral imaging system under UV radiation with excitation wavelength centered at 365 nm. Initial results exhibited strong emission spectra with peaks centered from 500 nm to 515 nm wavelength range for BGYF positive kernels. Aflatoxin levels on the BGYF positive and negative corn kernels (used as control) were measured subsequently with high performance liquid chromatography. The mean aflatoxin concentration level was 5114 ppb for the BGYF positive and undetectable for the normal kernels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016QuEle..46..473V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016QuEle..46..473V"><span id="translatedtitle">High <span class="hlt">brightness</span> EUV sources based on laser plasma at using droplet liquid metal target</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vinokhodov, A. Yu; Krivokorytov, M. S.; Sidelnikov, Yu V.; Krivtsun, V. M.; Medvedev, V. V.; Koshelev, K. N.</p> <p>2016-05-01</p> <p>We present the study of a source of extreme <span class="hlt">ultraviolet</span> (EUV) radiation based on laser plasma generated due to the interaction of radiation from a nanosecond Nd : YAG laser with a liquidmetal droplet target consisting of a low-temperature eutectic indium–tin alloy. The generator of droplets is constructed using a commercial nozzle and operates on the principle of forced capillary jet decomposition. Long-term spatial stability of the centre-of-mass position of the droplet with the root-mean-square deviation of ~0.5 μm is demonstrated. The use of a low-temperature working substance instead of pure tin increases the reliability and lifetime of the droplet generator. For the time- and space-averaged power density of laser radiation on the droplet target 4 × 1011 W cm-2 and the diameter of radiating plasma ~80 μm, the mean efficiency of conversion of laser energy into the energy of EUV radiation at 13.5 ± 0.135 nm equal to 2.3% (2π sr)-1 is achieved. Using the doublepulse method, we have modelled the repetitively pulsed regime of the source operation and demonstrated the possibility of its stable functioning with the repetition rate up to 8 kHz for the droplet generation repetition rate of more than 32 kHz, which will allow the source <span class="hlt">brightness</span> to be as large as ~0.96 kW (mm2 sr)-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SSRv..158..365G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SSRv..158..365G"><span id="translatedtitle">Large-scale <span class="hlt">Bright</span> Fronts in the Solar Corona: A Review of "EIT waves"</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gallagher, Peter T.; Long, David M.</p> <p>2011-07-01</p> <p>"EIT waves" are large-scale coronal <span class="hlt">bright</span> fronts (CBFs) that were first observed in 195 Å images obtained using the Extreme-<span class="hlt">ultraviolet</span> Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory ( SOHO). Commonly called "EIT waves", CBFs typically appear as diffuse fronts that propagate pseudo-radially across the solar disk at velocities of 100-700 km s-1 with front widths of 50-100 Mm. As their speed is greater than the quiet coronal sound speed ( c s ≤200 km s-1) and comparable to the local Alfvén speed ( v A ≤1000 km s-1), they were initially interpreted as fast-mode magnetoacoustic waves (vf=(cs2 + vA2)^{1/2}). Their propagation is now known to be modified by regions where the magnetosonic sound speed varies, such as active regions and coronal holes, but there is also evidence for stationary CBFs at coronal hole boundaries. The latter has led to the suggestion that they may be a manifestation of a processes such as Joule heating or magnetic reconnection, rather than a wave-related phenomena. While the general morphological and kinematic properties of CBFs and their association with coronal mass ejections have now been well described, there are many questions regarding their excitation and propagation. In particular, the theoretical interpretation of these enigmatic events as magnetohydrodynamic waves or due to changes in magnetic topology remains the topic of much debate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...585A.100B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...585A.100B"><span id="translatedtitle">DR Tauri: Temporal variability of the <span class="hlt">brightness</span> distribution in the potential planet-forming region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brunngräber, R.; Wolf, S.; Ratzka, Th.; Ober, F.</p> <p>2016-01-01</p> <p>Aims: We investigate the variability of the <span class="hlt">brightness</span> distribution and the changing density structure of the protoplanetary disk around DR Tau, a classical T Tauri star. DR Tau is known for its peculiar variations from the <span class="hlt">ultraviolet</span> (UV) to the mid-infrared (MIR). Our goal is to constrain the temporal variation of the disk structure based on photometric and MIR interferometric data. Methods: We observed DR Tau with the MID-infrared Interferometric instrument (MIDI) at the Very Large Telescope Interferometer (VLTI) at three epochs separated by about nine years, two months, respectively. We fit the spectral energy distribution and the MIR visibilities with radiative transfer simulations. Results: We are able to reproduce the spectral energy distribution as well as the MIR visibility for one of the three epochs (third epoch) with a basic disk model. We were able to reproduce the very different visibility curve obtained nine years earlier with a very similar baseline (first epoch), using the same disk model with a smaller scale height. The same density distribution also reproduces the observation made with a higher spatial resolution in the second epoch, i.e. only two months before the third epoch. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under the programs 074.C-0342(A) and 092.C-0726(A,B).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014MNRAS.444.2580B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014MNRAS.444.2580B&link_type=ABSTRACT"><span id="translatedtitle">The XMM-Newton <span class="hlt">Bright</span> Survey sample of absorbed quasars: X-ray and accretion properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ballo, L.; Severgnini, P.; Della Ceca, R.; Caccianiga, A.; Vignali, C.; Carrera, F. J.; Corral, A.; Mateos, S.</p> <p>2014-11-01</p> <p>Although absorbed quasars are extremely important for our understanding of the energetics of the Universe, the main physical parameters of their central engines are still poorly known. In this work, we present and study a complete sample of 14 quasars (QSOs) that are absorbed in the X-rays (column density NH > 4 × 1021 cm-2 and X-ray luminosity L 2-10 keV > 1044 ergs-1; XQSO2) belonging to the XMM-Newton <span class="hlt">Bright</span> Serendipitous Survey (XBS). From the analysis of their <span class="hlt">ultraviolet</span>-to-mid-infrared spectral energy distribution, we can separate the nuclear emission from the host galaxy contribution, obtaining a measurement of the fundamental nuclear parameters, like the mass of the central supermassive black hole and the value of Eddington ratio, λ Edd. Comparing the properties of XQSO2s with those previously obtained for the X-ray unabsorbed QSOs in the XBS, we do not find any evidence that the two samples are drawn from different populations. In particular, the two samples span the same range in Eddington ratios, up to λ Edd ˜ 0.5; this implies that our XQSO2s populate the `forbidden region' in the so-called `effective Eddington limit paradigm'. A combination of low grain abundance, presence of stars inwards of the absorber, and/or anisotropy of the disc emission can explain this result.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21562486','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21562486"><span id="translatedtitle">DISCOVERY OF A <span class="hlt">BRIGHT</span>, EXTREMELY LOW MASS WHITE DWARF IN A CLOSE DOUBLE DEGENERATE SYSTEM</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vennes, S.; Kawka, A.; Nemeth, P.; Thorstensen, J. R.; Skinner, J. N.; Pigulski, A.; Steslicki, M.; Kolaczkowski, Z.; Srodka, P.</p> <p>2011-08-10</p> <p>We report the discovery of a <span class="hlt">bright</span> (V {approx} 13.7), extremely low mass white dwarf in a close double degenerate system. We originally selected GALEX J171708.5+675712 for spectroscopic follow-up among a group of white dwarf candidates in an <span class="hlt">ultraviolet</span>-optical reduced proper-motion diagram. The new white dwarf has a mass of 0.18 M{sub sun} and is the primary component of a close double degenerate system (P = 0.246137 days, K{sub 1} = 288 km s{sup -1}) comprising a fainter white dwarf secondary with M{sub 2} {approx} 0.9 M{sub sun}. Light curves phased with the orbital ephemeris show evidence of relativistic beaming and weaker ellipsoidal variations. The light curves also reveal secondary eclipses (depth {approx}8 mmag) while the primary eclipses appear partially compensated by the secondary gravitational deflection and are below detection limits. Photospheric abundance measurements show a nearly solar composition of Si, Ca, and Fe (0.1-1 sun), while the normal kinematics suggest a relatively recent formation history. Close binary evolutionary scenarios suggest that extremely low mass white dwarfs form via a common-envelope phase and possible Roche lobe overflow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AIPC.1119...97W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AIPC.1119...97W&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Bright</span> and Not-So-<span class="hlt">Bright</span> Prospects for Women in Physics in China-Beijing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Ling-An; Yang, Zhongqin; Ma, Wanyun</p> <p>2009-04-01</p> <p>Science in China-Beijing is enjoying a healthy increase in funding year by year, so the prospects for physicists are also <span class="hlt">bright</span>. However, employment discrimination against women, formerly unthinkable, is becoming more and more explicit as the country evolves toward a market economy. Some recruitment notices bluntly state that only men will be considered, or impose restrictions upon potential female candidates. Female associate professors in many institutions are forced to retire at age 55, compared with 60 for men. This double-pinching discrimination against both younger and older women threatens to lead to a "pincer" effect, more serious than the "scissors" effect. Indeed, the ratio of senior-level women physicists in general has dropped significantly in recent years in China. Ironically, the number of female students applying for graduate studies is on the rise, as it is becoming increasingly difficult for them to compete with men in the job market with just an undergraduate degree. The Chinese Physical Society has made certain efforts to promote the image of women physicists, but it will take time and effort to reverse the trend.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22413398','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22413398"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> radiation therapy and UVR dose models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grimes, David Robert</p> <p>2015-01-15</p> <p><span class="hlt">Ultraviolet</span> radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to <span class="hlt">ultraviolet</span> (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative <span class="hlt">ultraviolet</span> dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for <span class="hlt">ultraviolet</span> phototherapy are also examined, and the need for an accurate computational dose estimation method in <span class="hlt">ultraviolet</span> phototherapy is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050169997','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050169997"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Views of Enceladus, Tethys, and Dione</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hansen, C. J.; Hendrix, A. R.</p> <p>2005-01-01</p> <p>The Cassini <span class="hlt">Ultraviolet</span> Imaging Spectrograph (UVIS) has collected <span class="hlt">ultraviolet</span> observations of many of Saturn's icy moons since Cassini's insertion into orbit around Saturn. We will report on results from Enceladus, Tethys and Dione, orbiting in the Saturn system at distances of 3.95, 4.88 and 6.26 Saturn radii, respectively. Icy satellite science objectives of the UVIS include investigations of surface age and evolution, surface composition and chemistry, and tenuous exospheres. We address these objectives by producing albedo maps, and reflection and emission spectra, and observing stellar occultations. UVIS has four channels: EUV: Extreme <span class="hlt">Ultraviolet</span> (55 nm to 110 nm), FUV: Far <span class="hlt">Ultraviolet</span> (110 to 190 nm), HSP: High Speed Photometer, and HDAC: Hydrogen-Deuterium Absorption Cell. The EUV and FUV spectrographs image onto a 2-dimensional detector, with 64 spatial rows by 1024 spectral columns. To-date we have focused primarily on the far <span class="hlt">ultraviolet</span> data acquired with the low resolution slit width (4.8 angstrom spectral resolution). Additional information is included in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8507288','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8507288"><span id="translatedtitle">[Health effects of <span class="hlt">ultraviolet</span> radiation].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ohnaka, T</p> <p>1993-01-01</p> <p>Exposure to <span class="hlt">ultraviolet</span> radiation (UVR) occurs from both natural and artificial sources. The main natural source is the sun. On the other hand, artificial UVR sources are widely used in industry and also used in hospitals, laboratories, etc. because of their germicidal properties. They are even used for cosmetic purposes. UVR can be classified into three regions according to its wavelength: as UVA (320-400nm), UVB (320-280nm) and UVC (280-200nm). The UVC has the greatest health effect on humans among the three. The sun radiates a wide range of spectrum of electromagnetic radiation including the UVR, however the radiation below 290 nm in wavelength does not reach the surface of the earth for effective absorption by the stratospheric ozone layer. As a result, UVR from a natural source consists of only UVA and a part of UVB. On the other hand, artificial UVR sources include UVC region and have serious effects on the human body, especially on the skin and eyes. The health effects of UVR on humans can be beneficial or detrimental, depending on the amount and form of UVR, as well as on the skin type of the individual exposed. It has been acknowledged that a long period of UVR deficiency may have harmful effects on the human body, such as the development of vitamin D deficiency and rickets in children due to a disturbance in the phosphorus and calcium metabolism. Appropriate measures to increase the amount of exposure to UVR, especially to UVB radiation by the use of sun bathing, the exposure to artificial UVR sources, etc. have shown to prevent disease states caused by UVR deficiency. The harmful effects of UVR consist of erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancer is commonly produced by UVR. In this review, various states of UV from solar radiation and the degree of exposure to UVR are introduced. The benefits and harmful health effects of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012amos.confE..68J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012amos.confE..68J"><span id="translatedtitle">Daytime Sky <span class="hlt">Brightness</span> Modeling of Haleakala along the GEO Belt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jim, K.,; Gibson, B.; Pier, E.</p> <p>2012-09-01</p> <p>We model the <span class="hlt">brightness</span> of the daytime sky along the GEO belt, as seen from Haleakala, from 0.3 to 5 microns using MODTRAN. A model near summer solstice and near vernal equinox will illustrate how the sky <span class="hlt">brightness</span> changes with season. Our goal is to determine the sky background radiance and transmission as a function of wavelength for imaging applications during the daytime. The sky <span class="hlt">brightness</span> varies throughout a modeled day, and this is shown using a set of look angles toward the geosynchronous belt. We compare our results using radiosonde and real weather data recorded at the summit on two dates, one near the vernal equinox and one near the summer solstice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7042656','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7042656"><span id="translatedtitle">High <span class="hlt">brightness</span> sources for MeV microprobe applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Read, P.M.; Alton, G.D.; Maskrey, J.T.</p> <p>1987-01-01</p> <p>State of the art MeV ion microprobe facilities are now approaching current density limitations on targets imposed by the fundamental nature of conventional gaseous ion sources. With a view to addressing this problem efforts are under way which have the ultimate objective of developing high <span class="hlt">brightness</span> Li liquid metal ion sources suitable for MeV ion microprobe applications. Prototype Li/sup +/ and Ga/sup +/ liquid metal ion sources have been designed, fabricated and are undergoing preliminary testing. This paper describes the first total emittance and <span class="hlt">brightness</span> measurements of a Ga liquid metal ion source. The effect of the geometry of the ion extraction system is investigated and the <span class="hlt">brightness</span> data are compared to those of a radio frequency ion source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160002400','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160002400"><span id="translatedtitle"><span class="hlt">Bright</span> Stuff on Ceres = Sulfates and Carbonates on CI Chondrites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zolensky, Michael; Chan, Queenie H. S.; Gounelle, Matthieu; Fries, Marc</p> <p>2016-01-01</p> <p>Recent reports of the DAWN spacecraft's observations of the surface of Ceres indicate that there are <span class="hlt">bright</span> areas, which can be explained by large amounts of the Mg sulfate hexahydrate (MgSO4•6(H2O)), although the identification appears tenuous. There are preliminary indications that water is being evolved from these <span class="hlt">bright</span> areas, and some have inferred that these might be sites of contemporary hydro-volcanism. A heat source for such modern activity is not obvious, given the small size of Ceres, lack of any tidal forces from nearby giant planets, probable age and presumed bulk composition. We contend that observations of chondritic materials in the lab shed light on the nature of the <span class="hlt">bright</span> spots on Ceres</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AstBu..70..379K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AstBu..70..379K"><span id="translatedtitle">New low surface <span class="hlt">brightness</span> dwarf galaxies detected around nearby spirals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karachentsev, I. D.; Riepe, P.; Zilch, T.; Blauensteiner, M.; Elvov, M.; Hochleitner, P.; Hubl, B.; Kerschhuber, G.; Küppers, S.; Neyer, F.; Pölzl, R.; Remmel, P.; Schneider, O.; Sparenberg, R.; Trulson, U.; Willems, G.; Ziegler, H.</p> <p>2015-10-01</p> <p>We conduct a survey of low surface <span class="hlt">brightness</span> (LSB) satellite galaxies around the Local Volume massive spirals using long exposures with small amateur telescopes. We identified 27 low and very low surface <span class="hlt">brightness</span> objects around the galaxies NGC672, 891, 1156, 2683, 3344, 4258, 4618, 4631, and 5457 situated within 10 Mpc from us, and found nothing new around NGC2903, 3239, 4214, and 5585. Assuming that the dwarf candidates are the satellites of the neighboring luminous galaxies, their absolute magnitudes are in the range of -8.6 > M B > -13.3, their effective diameters are 0.4-4.7 kpc, and the average surface <span class="hlt">brightness</span> is 26ṃ1/□″. The mean linear projected separation of the satellite candidates from the host galaxies is 73 kpc. Our spectroscopic observations of two LSB dwarfs with the Russian 6-meter telescope confirm their physical connection to the host galaxies NGC891 and NGC2683.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ASPC..499...13C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ASPC..499...13C"><span id="translatedtitle">On the Triggering Mechanisms of <span class="hlt">Bright</span> Submillimeter Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, C.-C.; ALESS and ALMA-S2CLS Consortia</p> <p>2015-12-01</p> <p>The understanding of the physical processes that cause the extreme star formation in <span class="hlt">bright</span> submillimeter galaxies provides essential constraints to models of galaxy formation and evolution. The outstanding issue of whether the high star formation rate of up to 1000 M⊙ yr-1 in <span class="hlt">bright</span> submillimeter galaxies is triggered by rapidly evolving major merger events, or a consequence of violent disk instability, is still under debated. Here I present recent work on the measurements of size and morphology of the stellar distributions on a sample of ALMA-detected SMGs in ECDF-S field. Combined with the measurements of the size and morphology of the dust distributions, our results favour the scenario that most <span class="hlt">bright</span> submillimeter galaxies are going through the processes of major merger.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19757961','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19757961"><span id="translatedtitle">Spatial filtering versus anchoring accounts of <span class="hlt">brightness</span>/lightness perception in staircase and simultaneous <span class="hlt">brightness</span>/lightness contrast stimuli.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blakeslee, Barbara; Reetz, Daniel; McCourt, Mark E</p> <p>2009-01-01</p> <p>J. Cataliotti and A. Gilchrist (1995) reported that, consistent with anchoring theory, the lightness of a black step in a reflectance staircase was not altered by moving a white step from a remote to an adjacent location. Recently, E. Economou, S. Zdravkovic, and A. Gilchrist (2007) reported data supporting three additional predictions of the anchoring model (A. Gilchrist et al., 1999): 1) equiluminant incremental targets in staircase simultaneous lightness contrast stimuli appeared equally light; 2) the simultaneous lightness contrast effect was due mainly to the lightening of the target on the black surround; and 3) the strength of lightness induction was greatest for darker targets. We investigated similar stimuli using <span class="hlt">brightness</span>/lightness matching and found, contrary to these reports, that: 1) the relative position of the steps in a luminance staircase significantly influenced their <span class="hlt">brightness</span>/lightness; 2) equiluminant incremental targets in staircase simultaneous <span class="hlt">brightness</span>/lightness contrast stimuli did not all appear equally <span class="hlt">bright</span>/light; 3) an asymmetry due to a greater brightening/lightening of the target on the black surround was not general; and 4) darker targets produced larger effects only when plotted on a log scale. In addition, the ODOG model (B. Blakeslee & M. E. McCourt, 1999) did an excellent job of accounting for <span class="hlt">brightness</span>/lightness matching in these stimuli. PMID:19757961</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...589A...6K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...589A...6K"><span id="translatedtitle">The possible origin of facular <span class="hlt">brightness</span> in the solar atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kostik, R.; Khomenko, E.</p> <p>2016-05-01</p> <p>This paper studies the dependence of the Ca ii H line core <span class="hlt">brightness</span> on the strength and inclination of the photospheric magnetic field, and on the parameters of convective and wave motions in a facular region at the center of the solar disc. We use three simultaneous data sets that were obtained at the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife): (1) spectra of Ba ii 4554 Å line, registered with the instrument TESOS to measure the variations of intensity and velocity through the photosphere up to the temperature minimum; (2) spectropolarimetric data in Fe i 1.56 μm lines (registered with the instrument TIP II) to measure photospheric magnetic fields; (3) filtergrams in Ca ii H that give information about <span class="hlt">brightness</span> fluctuations in the chromosphere. The results show that the Ca ii H <span class="hlt">brightness</span> in the facula strongly depends on the power of waves with periods in the 5-min range, which propagate upwards, and also on the phase shift between velocity oscillations at the bottom photosphere and around the temperature minimum height that is measured from Ba ii line. The Ca ii H <span class="hlt">brightness</span> is maximum at locations where the phase shift between temperature and velocity oscillations lies within 0°-100°. There is an indirect influence of convective motions on the Ca ii H <span class="hlt">brightness</span>. The higher the amplitude of convective velocities is and the greater the height is where they change their direction of motion, the brighter the facula. In summary, our results lead to conclusions that facular regions appear <span class="hlt">bright</span> not only because of the Wilson depression in magnetic structures, but also owing to real heating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/960964','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/960964"><span id="translatedtitle"><span class="hlt">Bright</span> and dark excitons in semiconductor carbon nanotubes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tretiak, Sergei</p> <p>2008-01-01</p> <p>We report electronic structure calculations of finite-length semiconducting carbon nanotubes using the time dependent density functional theory (TD-DFT) and the time dependent Hartree Fock (TD-HF) approach coupled with semiempirical AM1 and ZINDO Hamiltonians. We specifically focus on the energy splitting, relative ordering, and localization properties of the optically active (<span class="hlt">bright</span>) and optically forbidden (dark) states from the lowest excitonic band of the nanotubes. These excitonic states are very important in competing radiative and non-radiative processes in these systems. Our analysis of excitonic transition density matrices demonstrates that pure DFT functionals overdelocalize excitons making an electron-hole pair unbound; consequently, excitonic features are not presented in this method. In contrast, the pure HF and A111 calculations overbind excitons inaccurately predicting the lowest energy state as a <span class="hlt">bright</span> exciton. Changing AM1 with ZINDO Hamiltonian in TD-HF calculations, predicts the <span class="hlt">bright</span> exciton as the second state after the dark one. However, in contrast to AM1 calculations, the diameter dependence of the excitation energies obtained by ZINDO does not follow the experimental trends. Finally, the TD-DFT approach incorporating hybrid functions with a moderate portion of the long-range HF exchange, such as B3LYP, has the most generality and predictive capacity providing a sufficiently accurate description of excitonic structure in finite-size nanotubes. These methods characterize four important lower exciton bands. The lowest state is dark, the upper band is <span class="hlt">bright</span>, and the two other dark and nearly degenerate excitons lie in-between. Although the calculated energy splittings between the lowest dark and the <span class="hlt">bright</span> excitons are relatively large ({approx}0.1 eV), the dense excitonic manifold below the <span class="hlt">bright</span> exciton allows for fast non-radiative relaxation leasing to the fast population of the lowest dark exciton. This rationalizes the low</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004NewA...10...91K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004NewA...10...91K"><span id="translatedtitle">An observational model of the zodiacal light <span class="hlt">brightness</span> distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwon, S. M.; Hong, S. S.; Weinberg, J. L.</p> <p>2004-12-01</p> <p>The zodiacal light (ZL) has been newly derived from photo-polarimetric nightsky observations at Mt. Haleakala, Hawaii on the night of 21/22 August, 1968. The resulting ZL <span class="hlt">brightness</span> map has spatial resolution 2° × 2° and covers most of the sky that can be reached from the ground, extending ecliptic longitude over 30°⩽ Λ- Λ⊙⩽330° and latitude -90°⩽ β⩽90°. By utilizing a semi-empirical method for correcting the atmospheric diffuse light and an improved technique for making individual star subtraction, we have reduced the relative uncertainty in the ZL <span class="hlt">brightness</span> from the previous level of ˜20% down to ˜10%, which helps to reveal small scale structures in the observed <span class="hlt">brightness</span> distribution. Since the primary data base employed in our reduction was restricted to the observations over a single night, the resulting map demonstrates asymmetries in the ZL <span class="hlt">brightness</span> distribution over the morning and evening sides and also over the northern and southern ecliptic hemispheres. From these asymmetries we were able to locate the plane of maximum density of interplanetary dust particles at inclination i≃2° and longitude of ascending node Ω≃80°. To improve and homogenize the sky coverage the primary data base was then supplemented with observations on six additional nights, four in August and two in February of the same year. By folding the ZL <span class="hlt">brightness</span> in the northern and southern hemispheres and also in the morning and evening sides upon each other, we have constructed an observational model of the ZL <span class="hlt">brightness</span> in 2° intervals of ecliptic coordinates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740047866&hterms=Temperature+wavelength&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DTemperature%2Bwavelength','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740047866&hterms=Temperature+wavelength&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DTemperature%2Bwavelength"><span id="translatedtitle">Absolute <span class="hlt">brightness</span> temperature measurements at 2.1-mm wavelength</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ulich, B. L.</p> <p>1974-01-01</p> <p>Absolute measurements of the <span class="hlt">brightness</span> temperatures of the Sun, new Moon, Venus, Mars, Jupiter, Saturn, and Uranus, and of the flux density of DR21 at 2.1-mm wavelength are reported. Relative measurements at 3.5-mm wavelength are also preented which resolve the absolute calibration discrepancy between The University of Texas 16-ft radio telescope and the Aerospace Corporation 15-ft antenna. The use of the <span class="hlt">bright</span> planets and DR21 as absolute calibration sources at millimeter wavelengths is discussed in the light of recent observations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870049345&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870049345&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">Voyager observations of the azimuthal <span class="hlt">brightness</span> variations in Saturn's rings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Franklin, F. A.; Cook, A. F., II; Barrey, R. T. F.; Roff, C. A.; Hunt, G. E.; De Rueda, H. B.</p> <p>1987-01-01</p> <p>The present Voyagers I and II measurements of Saturn A ring azimuthal <span class="hlt">brightness</span> variations in reflected light are noted to be in general agreement with earth-based measurements. Voyager images of the rings in light transmitted through them also indicate the presence of these <span class="hlt">brightness</span> variations, but with greater amplitude and an about 65-deg phase discrepancy with those seen in reflection. These differences in photometric behavior are qualitatively accounted for in terms of the widespread presence of particle wakes in the A ring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8241E..0GD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8241E..0GD"><span id="translatedtitle">Record-<span class="hlt">brightness</span> laser-diode bars for fiber coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dogan, M.; Pathak, R.; Ellison, S.; Eppich, H.; Campbell, G.; Vignati, J.; Jacob, J. H.; Lang, K. D.; Chin, R. H.; Knapczyk, M. T.; Sun, W.; Fulghum, S. F.; Chin, A. K.</p> <p>2012-03-01</p> <p>High <span class="hlt">brightness</span>, laser-diode bars are required for efficient coupling into small-core optical-fibers. Record power and <span class="hlt">brightness</span> results were achieved using 20% fill-factor, 980nm, 1cm-wide, 4mm cavity-length bars. Lifetimes of single bars, operated CW at 200W and 20°C, exceed 1000hr. Due to superb thermal management, the power conversion efficiency (PCE) exceeds 60% at 200W output power. Similar lifetime and PCE were obtained for a 3-bar stack emitting 600W output power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...589A..46S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...589A..46S"><span id="translatedtitle">Are solar <span class="hlt">brightness</span> variations faculae- or spot-dominated?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shapiro, A. I.; Solanki, S. K.; Krivova, N. A.; Yeo, K. L.; Schmutz, W. K.</p> <p>2016-04-01</p> <p>Context. Regular spaceborne measurements have revealed that solar <span class="hlt">brightness</span> varies on multiple timescales, variations on timescales greater than a day being attributed to a surface magnetic field. Independently, ground-based and spaceborne measurements suggest that Sun-like stars show a similar, but significantly broader pattern of photometric variability. Aims: To understand whether the broader pattern of stellar variations is consistent with the solar paradigm, we assess relative contributions of faculae and spots to solar magnetically-driven <span class="hlt">brightness</span> variability. We investigate how the solar <span class="hlt">brightness</span> variability and its facular and spot contributions depend on the wavelength, timescale of variability, and position of the observer relative to the ecliptic plane. Methods: We performed calculations with the SATIRE model, which returns solar <span class="hlt">brightness</span> with daily cadence from solar disc area coverages of various magnetic features. We took coverages as seen by an Earth-based observer from full-disc SoHO/MDI and SDO/HMI data and projected them to mimic out-of-ecliptic viewing by an appropriate transformation. Results: Moving the observer away from the ecliptic plane increases the amplitude of 11-year variability as it would be seen in Strömgren (b + y)/2 photometry, but decreases the amplitude of the rotational <span class="hlt">brightness</span> variations as it would appear in Kepler and CoRoT passbands. The spot and facular contributions to the 11-year solar variability in the Strömgren (b + y)/2 photometry almost fully compensate each other so that the Sun appears anomalously quiet with respect to its stellar cohort. Such a compensation does not occur on the rotational timescale. Conclusions: The rotational solar <span class="hlt">brightness</span> variability as it would appear in the Kepler and CoRoT passbands from the ecliptic plane is spot-dominated, but the relative contribution of faculae increases for out-of-ecliptic viewing so that the apparent <span class="hlt">brightness</span> variations are faculae-dominated for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20776966','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20776966"><span id="translatedtitle">Friction and Diffusion of Matter-Wave <span class="hlt">Bright</span> Solitons</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sinha, Subhasis; Brand, Joachim; Cherny, Alexander Yu.; Kovrizhin, Dmitry</p> <p>2006-01-27</p> <p>We consider the motion of a matter-wave <span class="hlt">bright</span> soliton under the influence of a cloud of thermal particles. In the ideal one-dimensional system, the scattering process of the quasiparticles with the soliton is reflectionless; however, the quasiparticles acquire a phase shift. In the realistic system of a Bose-Einstein condensate confined in a tight waveguide trap, the transverse degrees of freedom generate an extra nonlinearity in the system which gives rise to finite reflection and leads to dissipative motion of the soliton. We calculate the velocity and temperature-dependent frictional force and diffusion coefficient of a matter-wave <span class="hlt">bright</span> soliton immersed in a thermal cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016A%26A...589A..46S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016A%26A...589A..46S&link_type=ABSTRACT"><span id="translatedtitle">Are solar <span class="hlt">brightness</span> variations faculae- or spot-dominated?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shapiro, A. I.; Solanki, S. K.; Krivova, N. A.; Yeo, K. L.; Schmutz, W. K.</p> <p>2016-05-01</p> <p>Context. Regular spaceborne measurements have revealed that solar <span class="hlt">brightness</span> varies on multiple timescales, variations on timescales greater than a day being attributed to a surface magnetic field. Independently, ground-based and spaceborne measurements suggest that Sun-like stars show a similar, but significantly broader pattern of photometric variability. Aims: To understand whether the broader pattern of stellar variations is consistent with the solar paradigm, we assess relative contributions of faculae and spots to solar magnetically-driven <span class="hlt">brightness</span> variability. We investigate how the solar <span class="hlt">brightness</span> variability and its facular and spot contributions depend on the wavelength, timescale of variability, and position of the observer relative to the ecliptic plane. Methods: We performed calculations with the SATIRE model, which returns solar <span class="hlt">brightness</span> with daily cadence from solar disc area coverages of various magnetic features. We took coverages as seen by an Earth-based observer from full-disc SoHO/MDI and SDO/HMI data and projected them to mimic out-of-ecliptic viewing by an appropriate transformation. Results: Moving the observer away from the ecliptic plane increases the amplitude of 11-year variability as it would be seen in Strömgren (b + y)/2 photometry, but decreases the amplitude of the rotational <span class="hlt">brightness</span> variations as it would appear in Kepler and CoRoT passbands. The spot and facular contributions to the 11-year solar variability in the Strömgren (b + y)/2 photometry almost fully compensate each other so that the Sun appears anomalously quiet with respect to its stellar cohort. Such a compensation does not occur on the rotational timescale. Conclusions: The rotational solar <span class="hlt">brightness</span> variability as it would appear in the Kepler and CoRoT passbands from the ecliptic plane is spot-dominated, but the relative contribution of faculae increases for out-of-ecliptic viewing so that the apparent <span class="hlt">brightness</span> variations are faculae-dominated for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910044057&hterms=baumert&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbaumert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910044057&hterms=baumert&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbaumert"><span id="translatedtitle">The microwave <span class="hlt">brightness</span> temperature spectrum of the quiet sun</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zirin, H.; Baumert, B. M.; Hurford, G. J.</p> <p>1991-01-01</p> <p>New measurements of the microwave <span class="hlt">brightness</span> temperature spectrum of the center of the quiet sun, acquired at Owens Valley over several months during the 1986-1987 sunspot minimum, are reported. The resulting <span class="hlt">brightness</span> temperature spectra are consistent with previous data, but exhibit much less frequency-to-frequency scatter. The corona is fitted well by an optically thin source at temperature of 10 to the 6th k, scale height H = 5 x 10 to the 9th, and density of 3.2 x 10 to the 8th/cu cm, and the chromosphere, an optically thick source at around 11,000 k.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9086E..0CE','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9086E..0CE"><span id="translatedtitle">High-<span class="hlt">brightness</span> displays in integrated weapon sight systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Edwards, Tim; Hogan, Tim</p> <p>2014-06-01</p> <p>In the past several years Kopin has demonstrated the ability to provide ultra-high <span class="hlt">brightness</span>, low power display solutions in VGA, SVGA, SXGA and 2k x 2k display formats. This paper will review various approaches for integrating high <span class="hlt">brightness</span> overlay displays with existing direct view rifle sights and augmenting their precision aiming and targeting capability. Examples of overlay display systems solutions will be presented and discussed. This paper will review significant capability enhancements that are possible when augmenting the real-world as seen through a rifle sight with other soldier system equipment including laser range finders, ballistic computers and sensor systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1234332','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1234332"><span id="translatedtitle">A <span class="hlt">bright</span> PPKTP waveguide source of polarization entangled photons</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fanto, Michael; Tison, Christoper C.; Holwand, Gregory A; Preble, Dr. Stefan F; Alsing, Paul; Smith IV, Amos M</p> <p>2015-01-01</p> <p>The need for <span class="hlt">bright</span> efficient sources of entangled photons has been a subject of tremendous research over the last decade. Researchers have been working to increase the <span class="hlt">brightness</span> and purity to help overcome the spontaneous nature of the sources. Periodic poling has been implemented to allow for the use of crystals that would not normally satisfy the phase matching conditions. Utilizing periodic poling and single mode waveguide confinement of the pump field has yielded extremely large effective nonlinearities in sources easily producing millions of photon pairs. Here we will demonstrate these large nonlinearity effects in a periodically poled potassium titanyl phosphate (PPKTP) waveguide as well as characterizing the source purity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760013996','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760013996"><span id="translatedtitle">Far <span class="hlt">ultraviolet</span> excitation processes in comets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feldman, P. D.; Opal, C. B.; Meier, R. R.; Nicolas, K. R.</p> <p>1976-01-01</p> <p>Recent observations of atomic oxygen and carbon in the far <span class="hlt">ultraviolet</span> spectrum of comet Kohoutek have demonstrated the existence of these atomic species in the cometary coma. However, in order to identify the source of their origin, it is necessary to relate the observed <span class="hlt">ultraviolet</span> flux to the atomic production rate. Analyses of observed OI wavelength 1304 and CI wavelength 1657 A multiplets have been carried out using high resolution solar spectra. Also examined is the possibility of observing <span class="hlt">ultraviolet</span> fluorescence from molecules such as CO and H2, as well as resonance scattering either from atomic ions for which there are strong corresponding solar lines (CII) or from atoms for which there is an accidental wavelength coincidence (SI).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA04279&hterms=light+years&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlight%2Byears','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA04279&hterms=light+years&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlight%2Byears"><span id="translatedtitle">GALEX 1st Light Near <span class="hlt">Ultraviolet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2003-01-01</p> <p><p/>This image was taken on May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered during the missions 'first light' milestone, and shows celestial objects in the constellation Hercules. The objects shown represent those detected by the camera's near <span class="hlt">ultraviolet</span> channel over a 5-minute period. The radial streaks at the edge of the image are due to stars reflecting from the near <span class="hlt">ultraviolet</span> detector window. <p/>The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. <p/>The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the <span class="hlt">ultraviolet</span> and determine the history of star formation in the universe over the last 10 billion years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/872688','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/872688"><span id="translatedtitle">Photoresist composition for extreme <span class="hlt">ultraviolet</span> lithography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Felter, T. E.; Kubiak, G. D.</p> <p>1999-01-01</p> <p>A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme <span class="hlt">ultraviolet</span> (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme <span class="hlt">ultraviolet</span> radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods. A photoresist composition for extreme <span class="hlt">ultraviolet</span> radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AJ....121.1395W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AJ....121.1395W"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> Signposts of Resonant Dynamics in the Starburst-ringed SAB Galaxy M94 (NGC 4736)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waller, William H.; Fanelli, Michael N.; Keel, William C.; Bohlin, Ralph; Collins, Nicholas R.; Madore, Barry F.; Marcum, Pamela M.; Neff, Susan G.; O'Connell, Robert W.; Offenberg, Joel D.; Roberts, Morton S.; Smith, Andrew M.; Stecher, Theodore P.</p> <p>2001-03-01</p> <p>The dynamic orchestration of star-birth activity in the starburst-ringed galaxy M94 (NGC 4736) is investigated using images from the <span class="hlt">Ultraviolet</span> Imaging Telescope (UIT; far-<span class="hlt">ultraviolet</span> [FUV] band), Hubble Space Telescope (HST; near-<span class="hlt">ultraviolet</span> [NUV] band), Kitt Peak 0.9 m telescope (Hα, R, and I bands), and Palomar 5 m telescope (B band), along with spectra from the International <span class="hlt">Ultraviolet</span> Explorer (IUE) and the Lick 1 m telescope. The wide-field UIT image shows FUV emission from (1) an elongated nucleus, (2) a diffuse inner disk, where Hα is observed in absorption, (3) a <span class="hlt">bright</span> inner ring of H II regions at the perimeter of the inner disk (R=48"=1.1 kpc), and (4) two 500 pc size knots of hot stars exterior to the ring on diametrically opposite sides of the nucleus (R=130"=2.9 kpc). The HST Faint Object Camera image resolves the NUV emission from the nuclear region into a <span class="hlt">bright</span> core and a faint 20" long ``minibar'' at a position angle of 30°. Optical and IUE spectroscopy of the nucleus and diffuse inner disk indicates a ~107-108 yr old stellar population from low-level star-birth activity blended with some LINER activity. Analysis of the Hα-, FUV-, NUV-, B-, R-, and I-band emissions, along with other observed tracers of stars and gas in M94, indicates that most of the star formation is being orchestrated via ring-bar dynamics, involving the nuclear minibar, inner ring, oval disk, and outer ring. The inner starburst ring and bisymmetric knots at intermediate radius, in particular, argue for bar-mediated resonances as the primary drivers of evolution in M94 at the present epoch. Similar processes may be governing the evolution of the ``core-dominated'' galaxies that have been observed at high redshift. The gravitationally lensed ``Pretzel Galaxy'' (0024+1654) at a redshift of ~1.5 provides an important precedent in this regard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002873','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002873"><span id="translatedtitle">Extremely Low Passive Microwave <span class="hlt">Brightness</span> Temperatures Due to Thunderstorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cecil, Daniel J.</p> <p>2015-01-01</p> <p>Extreme events by their nature fall outside the bounds of routine experience. With imperfect or ambiguous measuring systems, it is appropriate to question whether an unusual measurement represents an extreme event or is the result of instrument errors or other sources of noise. About three weeks after the Tropical Rainfall Measuring Mission (TRMM) satellite began collecting data in Dec 1997, a thunderstorm was observed over northern Argentina with 85 GHz <span class="hlt">brightness</span> temperatures below 50 K and 37 GHz <span class="hlt">brightness</span> temperatures below 70 K (Zipser et al. 2006). These values are well below what had previously been observed from satellite sensors with lower resolution. The 37 GHz <span class="hlt">brightness</span> temperatures are also well below those measured by TRMM for any other storm in the subsequent 16 years. Without corroborating evidence, it would be natural to suspect a problem with the instrument, or perhaps an irregularity with the platform during the first weeks of the satellite mission. Automated quality control flags or other procedures in retrieval algorithms could treat these measurements as errors, because they fall outside the expected bounds. But the TRMM satellite also carries a radar and a lightning sensor, both confirming the presence of an intense thunderstorm. The radar recorded 40+ dBZ reflectivity up to about 19 km altitude. More than 200 lightning flashes per minute were recorded. That same storm's 19 GHz <span class="hlt">brightness</span> temperatures below 150 K would normally be interpreted as the result of a low-emissivity water surface (e.g., a lake, or flood waters) if not for the simultaneous measurements of such intense convection. This paper will examine records from TRMM and related satellite sensors including SSMI, AMSR-E, and the new GMI to find the strongest signatures resulting from thunderstorms, and distinguishing those from sources of noise. The lowest <span class="hlt">brightness</span> temperatures resulting from thunderstorms as seen by TRMM have been in Argentina in November and December. For</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930050438&hterms=modtran&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmodtran','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930050438&hterms=modtran&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmodtran"><span id="translatedtitle"><span class="hlt">Ultraviolet</span> O2 transmittance - AURIC implementation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, G. P.; Hall, L. A.; Minschwaner, K.; Yoshino, K.; Betchley, C.; Conant, J. A.</p> <p>1993-01-01</p> <p>A new spectrally precise approach to Schumann-Runge synthesis has been devised, employing nine (9) different spectral arrays containing polynomial coefficients. The coefficients were fit to calculated cross sections obtained from a detailed Schumann-Runge model that incorporates the most recent high resolution spectroscopic data for a temperature range between 130 and 500K. This large data base is being used to reexamine the existing parameterizations of UV transmission and photolysis. In addition, it is now possible to extend atmospheric radiance codes further into the <span class="hlt">ultraviolet</span>. Initial implementation has been accomplished for the MODTRAN code as part of the eventual development of AURIC, the Atmospheric <span class="hlt">Ultraviolet</span> Radiance Integrated Code.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890000511&hterms=pH+substances&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DpH%2Bsubstances','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890000511&hterms=pH+substances&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DpH%2Bsubstances"><span id="translatedtitle">Ozone/<span class="hlt">Ultraviolet</span>-Photo-Oxidation Reactor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Swartz, Ari Ben; Agthe, Richard E.</p> <p>1989-01-01</p> <p>Experimental chemical-processing system destroys waste hydrazine in water by use of ozone in <span class="hlt">ultraviolet</span>-photo-oxidation reactor. New process reduces concentrations of hydrazines and intermediate decomposition products in effluent liquid and gas to below limit of detectability. Liquid sprayed in reaction chamber past <span class="hlt">ultraviolet</span> lamps, against flow of oxygen and ozone. Hydrazines and intermediate decomposition products oxidized to harmless substances. Effectiveness and speed of process depends on maintenance of circulating liquid at correct pH, determines lower limit of oxidation by ozone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930039417&hterms=ultraviolet+astronomy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528ultraviolet%2Bastronomy%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930039417&hterms=ultraviolet+astronomy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528ultraviolet%2Bastronomy%2529"><span id="translatedtitle">Far and extreme <span class="hlt">ultraviolet</span> astronomy with ORFEUS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kraemer, G.; Barnstedt, J.; Eberhard, N.; Grewing, M.; Gringel, W.; Haas, C.; Kaelble, A.; Kappelmann, N.; Petrik, J.; Appenzeller, I.</p> <p>1990-01-01</p> <p>ORFEUS (Orbiting and Retrievable Far and Extreme <span class="hlt">Ultraviolet</span> Spectrometer) is a 1 m normal incidence telescope for spectroscopic investigations of cosmic sources in the far and extreme <span class="hlt">ultraviolet</span> spectral range. The instrument will be integrated into the freeflyer platform ASTRO-SPAS. ORFEUS-SPAS is scheduled with STS ENDEAVOUR in September 1992. We describe the telescope with its two spectrometer and their capabilities i.e., spectral range, resolution and overall sensitivity. The main classes of objects to be observed with the instrument are discussed and two examples of simulated spectra for the white dwarf HZ43 and an O9-star in LMC are shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFM.P13E..02R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFM.P13E..02R&link_type=ABSTRACT"><span id="translatedtitle">The <span class="hlt">Ultraviolet</span> Spectrograph on the Europa Mission (Europa-UVS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Retherford, K. D.; Gladstone, R.; Greathouse, T. K.; Steffl, A.; Davis, M. W.; Feldman, P. D.; McGrath, M. A.; Roth, L.; Saur, J.; Spencer, J. R.; Stern, S. A.; Pope, S.; Freeman, M. A.; Persyn, S. C.; Araujo, M. F.; Cortinas, S. C.; Monreal, R. M.; Persson, K. B.; Trantham, B. J.; Versteeg, M. H.; Walther, B. C.</p> <p>2015-12-01</p> <p>NASA's Europa multi-flyby mission is designed to provide a diversity of measurements suited to enrich our understanding of the potential habitability of this intriguing ocean world. The Europa mission's <span class="hlt">Ultraviolet</span> Spectrograph, Europa-UVS, is the sixth in a series of successful <span class="hlt">ultraviolet</span> imaging spectrographs (Rosetta-Alice, New Horizons Pluto-Alice, LRO-LAMP) and, like JUICE-UVS (now under Phase B development), is largely based on the most recent of these to fly, Juno-UVS. Europa-UVS observes photons in the 55-210 nm wavelength range, at moderate spectral and spatial resolution along a 7.5° slit. Three distinct apertures send light to the off-axis telescope mirror feeding the long-slit spectrograph: i) a main entrance airglow port is used for most observations (e.g., airglow, aurora, surface mapping, and stellar occultations); ii) a high-spatial-resolution port consists of a small hole in an additional aperture door, and is used for detailed observations of <span class="hlt">bright</span> targets; and iii) a separate solar port allows for solar occultations, viewing at a 60° offset from the nominal payload boresight. Photon event time-tagging (pixel list mode) and programmable spectral imaging (histogram mode) allow for observational flexibility and optimal science data management. As on Juno-UVS, the effects of penetrating electron radiation on electronic parts and data quality are mitigated through contiguous shielding, filtering of pulse height amplitudes, management of high-voltage settings, and careful use of radiation-hard parts. The science goals of Europa-UVS are to: 1) Determine the composition & chemistry, source & sinks, and structure & variability of Europa's atmosphere, from equator to pole; 2) Search for and characterize active plumes in terms of global distribution, structure, composition, and variability; 3) Explore the surface composition & microphysics and their relation to endogenic & exogenic processes; and 4) Investigate how energy and mass flow in the Europa</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340013','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340013"><span id="translatedtitle">The <span class="hlt">ultraviolet</span> attenuation law in backlit spiral galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Keel, William C.; Manning, Anna M.; Holwerda, Benne W.; Lintott, Chris J.; Schawinski, Kevin E-mail: ammanning@bama.ua.edu E-mail: Twitter@BenneHolwerda E-mail: Twitter@chrislintott E-mail: Twitter@kevinschawinski</p> <p>2014-02-01</p> <p>The effective extinction law (attenuation behavior) in galaxies in the emitted <span class="hlt">ultraviolet</span> (UV) regime is well known only for actively star-forming objects and combines effects of the grain properties, fine structure in the dust distribution, and relative distributions of stars and dust. We use Galaxy Evolution Explorer, XMM Optical Monitor, and Hubble Space Telescope (HST) data to explore the UV attenuation in the outer parts of spiral disks which are backlit by other UV-<span class="hlt">bright</span> galaxies, starting with the candidate list of pairs provided by Galaxy Zoo participants. New optical images help to constrain the geometry and structure of the target galaxies. Our analysis incorporates galaxy symmetry, using non-overlapping regions of each galaxy to derive error estimates on the attenuation measurements. The entire sample has an attenuation law across the optical and UV that is close to the Calzetti et al. form; the UV slope for the overall sample is substantially shallower than found by Wild et al., which is a reasonable match to the more distant galaxies in our sample but not to the weighted combination including NGC 2207. The nearby, <span class="hlt">bright</span> spiral NGC 2207 alone gives an accuracy almost equal to the rest of our sample, and its outer arms have a very low level of foreground starlight. Thus, this widespread, fairly 'gray' law can be produced from the distribution of dust alone, without a necessary contribution from differential escape of stars from dense clouds. Our results indicate that the extrapolation needed to compare attenuation between backlit galaxies at moderate redshifts from HST data, and local systems from Sloan Digital Sky Survey and similar data, is mild enough to allow the use of galaxy overlaps to trace the cosmic history of dust in galaxies. For NGC 2207, HST data in the near-UV F336W band show that the covering factor of clouds with small optical attenuation becomes a dominant factor farther into the UV, which opens the possibility that widespread</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........33J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........33J"><span id="translatedtitle">Plasmonic enhancement of <span class="hlt">ultraviolet</span> fluorescence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiao, Xiaojin</p> <p></p> <p>Plasmonics relates to the interaction between electromagnetic radiation and conduction electrons at metallic interfaces or in metallic nanostructures. Surface plasmons are collective electron oscillations at a metal surface, which can be manipulated by shape, texture and material composition. Plasmonic applications cover a broad spectrum from visible to near infrared, including biosensing, nanolithography, spectroscopy, optoelectronics, photovoltaics and so on. However, there remains a gap in this activity in the <span class="hlt">ultraviolet</span> (UV, < 400 nm), where significant opportunity exists for both fundamental and application research. Motivating factors in the study of UV Plasmonics are the direct access to biomolecular resonances and native fluorescence, resonant Raman scattering interactions, and the potential for exerting control over photochemical reactions. This dissertation aims to fill in the gap of Plasmonics in the UV with efforts of design, fabrication and characterization of aluminium (Al) and magnesium (Mg) nanostructures for the application of label-free bimolecular detection via native UV fluorescence. The first contribution of this dissertation addresses the design of Al nanostructures in the context of UV fluorescence enhancement. A design method that combines analytical analysis with numerical simulation has been developed. Performance of three canonical plasmonic structures---the dipole antenna, bullseye nanoaperture and nanoaperture array---has been compared. The optimal geometrical parameters have been determined. A novel design of a compound bullseye structure has been proposed and numerically analyzed for the purpose of compensating for the large Stokes shift typical of UV fluorescence. Second, UV lifetime modification of diffusing molecules by Al nanoapertures has been experimentally demonstrated for the first time. Lifetime reductions of ~3.5x have been observed for the high quantum yield (QY) laser dye p-terphenyl in a 60 nm diameter aperture with 50</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26375576','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26375576"><span id="translatedtitle">Surface Emitting, High Efficiency Near-Vacuum <span class="hlt">Ultraviolet</span> Light Source with Aluminum Nitride Nanowires Monolithically Grown on Silicon.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, S; Djavid, M; Mi, Z</p> <p>2015-10-14</p> <p>To date, it has remained challenging to realize electrically injected light sources in the vacuum <span class="hlt">ultraviolet</span> wavelength range (∼200 nm or shorter), which are important for a broad range of applications, including sensing, surface treatment, and photochemical analysis. In this Letter, we have demonstrated such a light source with molecular beam epitaxially grown aluminum nitride (AlN) nanowires on low cost, large area Si substrate. Detailed angle dependent electroluminescence studies suggest that, <span class="hlt">albeit</span> the light is TM polarized, the dominant light emission direction is from the nanowire top surface, that is, along the c axis, due to the strong light scattering effect. Such an efficient surface emitting device was not previously possible using conventional c-plane AlN planar structures. The AlN nanowire LEDs exhibit an extremely large electrical efficiency (>85%), which is nearly ten times higher than the previously reported AlN planar devices. Our detailed studies further suggest that the performance of AlN nanowire LEDs is predominantly limited by electron overflow. This study provides important insight on the fundamental emission characteristics of AlN nanowire LEDs and also offers a viable path to realize an efficient surface emitting near-vacuum <span class="hlt">ultraviolet</span> light source through direct electrical injection. PMID:26375576</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. Their policies may differ from this site.</small> </div> </center> <div id="footer-wrapper"> <div class="footer-content"> <div id="footerOSTI" class=""> <div class="row"> <div class="col-md-4 text-center col-md-push-4 footer-content-center"><small><a href="http://www.science.gov/disclaimer.html">Privacy and Security</a></small> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center col-md-pull-4 footer-content-left"> <img src="http://www.osti.gov/images/DOE_SC31.png" alt="U.S. Department of Energy" usemap="#doe" height="31" width="177"><map style="display:none;" name="doe" id="doe"><area shape="rect" coords="1,3,107,30" href="http://www.energy.gov" alt="U.S. Deparment of Energy"><area shape="rect" coords="114,3,165,30" href="http://www.science.energy.gov" alt="Office of Science"></map> <a ref="http://www.osti.gov" style="margin-left: 15px;"><img src="http://www.osti.gov/images/footerimages/ostigov53.png" alt="Office of Scientific and Technical Information" height="31" width="53"></a> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center footer-content-right"> <a href="http://www.osti.gov/nle"><img src="http://www.osti.gov/images/footerimages/NLElogo31.png" alt="National Library of Energy" height="31" width="79"></a> <a href="http://www.science.gov"><img src="http://www.osti.gov/images/footerimages/scigov77.png" alt="science.gov" height="31" width="98"></a> <a href="http://worldwidescience.org"><img src="http://www.osti.gov/images/footerimages/wws82.png" alt="WorldWideScience.org" height="31" width="90"></a> </div> </div> </div> </div> </div> <p><br></p> </div><!-- container --> </body> </html>