National Library of Energy BETA

Sample records for investigating extreme ultraviolet

  1. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  2. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the Richard P. FeynmanInventorsInvestigating

  3. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  4. Extreme ultraviolet lithography machine

    DOE Patents [OSTI]

    Tichenor, Daniel A. (Castro Valley, CA); Kubiak, Glenn D. (Livermore, CA); Haney, Steven J. (Tracy, CA); Sweeney, Donald W. (San Ramon, CA)

    2000-01-01

    An extreme ultraviolet 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.

  5. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (Livermore, CA); Kubiak, Glenn D. (Livermore, CA)

    1999-01-01

    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 ultraviolet (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 ultraviolet 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.

  6. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (727 Clara St., Livermore, Alameda County, CA 94550); Kubiak, G. D. (475 Maple St., Livermore, Alameda County, CA 94550)

    2000-01-01

    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 ultraviolet (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 ultraviolet 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.

  7. Spectral investigations of photoionized plasmas induced in atomic and molecular gases using nanosecond extreme ultraviolet (EUV) pulses

    SciTech Connect (OSTI)

    Bartnik, A.; Fiedorowicz, H.; Wachulak, P. [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland)

    2014-07-15

    In this paper, results of spectral investigations of low temperature photoionized plasmas, created by irradiation of gases with intense pulses of extreme ultraviolet (EUV) radiation from a laser-produced plasma (LPP) source, are presented. The LPP source was based on a double-stream KrXe/He gas-puff target irradiated with 4?ns/0.8?J/10?Hz Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region ????10–12?nm; however, spectrally integrated intensity at longer wavelengths was also significant. The EUV beam was focused on a gas stream, injected into a vacuum chamber synchronously with the EUV pulses. Irradiation of gases resulted in formation of photoionized plasmas emitting radiation in the EUV range. Radiation spectra, measured for plasmas produced in various gases, are dominated by emission lines, originating from single charged ions. Significant differences in spectral intensities and distributions between plasmas created in neon and molecular gases were observed.

  8. Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Solar Dynamics Observatory/ EVE Extreme Ultraviolet Variability Experiment Frequently Asked and model solar extreme ultraviolet irradiance variations due to solar flares, solar rotation, and solar and structure of the Sun. What is solar variability? Solar radiation varies on all time scales ranging from

  9. Photoresist composition for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (Alameda County, CA); Kubiak, G. D. (Alameda County, CA)

    1999-01-01

    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 ultraviolet (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 ultraviolet 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 ultraviolet radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.

  10. Comparing Vacuum and Extreme Ultraviolet Radiation for Postionization of Laser Desorbed Neutrals from Bacterial Biofilms and Organic Fullerene

    E-Print Network [OSTI]

    Gaspera, Gerald L.

    2011-01-01

    Laboratory, USA Comparing Vacuum and Extreme Ultravioletradiation, extreme ultraviolet, vacuum ultravioletAbstract Vacuum and extreme ultraviolet radiation from 8 -

  11. THORIUM-BASED MIRRORS IN THE EXTREME ULTRAVIOLET Nicole Farnsworth

    E-Print Network [OSTI]

    Hart, Gus

    THORIUM-BASED MIRRORS IN THE EXTREME ULTRAVIOLET by Nicole Farnsworth Submitted to Brigham Young Ultraviolet and Thorium-based Mirrors . . . 1 1.2 Project Background the Optical Constants of Thorium Oxide 34 3.1 Reflectance and Transmittance Measurements

  12. Method for generating extreme ultraviolet with mather-type plasma accelerators for use in Extreme Ultraviolet Lithography

    DOE Patents [OSTI]

    Hassanein, Ahmed (Bolingbrook, IL); Konkashbaev, Isak (Bolingbrook, IL)

    2006-10-03

    A device and method for generating extremely short-wave ultraviolet electromagnetic wave uses two intersecting plasma beams generated by two plasma accelerators. The intersection of the two plasma beams emits electromagnetic radiation and in particular radiation in the extreme ultraviolet wavelength. In the preferred orientation two axially aligned counter streaming plasmas collide to produce an intense source of electromagnetic radiation at the 13.5 nm wavelength. The Mather type plasma accelerators can utilize tin, or lithium covered electrodes. Tin, lithium or xenon can be used as the photon emitting gas source.

  13. Xe capillary target for laser-plasma extreme ultraviolet source

    SciTech Connect (OSTI)

    Inoue, Takahiro; Okino, Hideyasu; Nica, Petru Edward; Amano, Sho; Miyamoto, Shuji; Mochizuki, Takayasu

    2007-10-15

    A cryogenic Xe jet system with an annular nozzle has been developed in order to continuously fast supply a Xe capillary target for generating a laser-plasma extreme ultraviolet (EUV) source. The cooling power of the system was evaluated to be 54 W, and the temperature stability was {+-}0.5 K at a cooling temperature of about 180 K. We investigated experimentally the influence of pressure loss inside an annular nozzle on target formation by shortening the nozzle length. Spraying caused by cavitation was mostly suppressed by mitigating the pressure loss, and a focused jet was formed. Around a liquid-solid boundary, a solid-Xe capillary target (100/70 {mu}m {phi}) was formed with a velocity of {<=}0.01 m/s. Laser-plasma EUV generation was tested by focusing a Nd:YAG laser beam on the target. The results suggested that an even thinner-walled capillary target is required to realize the inertial confinement effect.

  14. Condenser for ring-field deep-ultraviolet and extreme-ultraviolet lithography

    DOE Patents [OSTI]

    Chapman, Henry N. (Livermore, CA); Nugent, Keith A. (North Fitzroy, AU)

    2001-01-01

    A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror which is illuminated by a collimated beam at grazing incidence. The ripple plate comprises a plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

  15. Condenser for ring-field deep ultraviolet and extreme ultraviolet lithography

    DOE Patents [OSTI]

    Chapman, Henry N. (Livermore, CA); Nugent, Keith A. (North Fitzroy, AU)

    2002-01-01

    A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror which is illuminated by a collimated or converging beam at grazing incidence. The ripple plate comprises a flat or curved plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

  16. High numerical aperture projection system for extreme ultraviolet projection lithography

    DOE Patents [OSTI]

    Hudyma, Russell M. (San Ramon, CA)

    2000-01-01

    An optical system is described that is compatible with extreme ultraviolet radiation and comprises five reflective elements for projecting a mask image onto a substrate. The five optical elements are characterized in order from object to image as concave, convex, concave, convex, and concave mirrors. The optical system is particularly suited for ring field, step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width which effectively minimizes dynamic distortion. The present invention allows for higher device density because the optical system has improved resolution that results from the high numerical aperture, which is at least 0.14.

  17. Broadband extreme ultraviolet probing of transient gratings in vanadium dioxide

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sistrunk, Emily; Lawrence Livermore National Lab.; Grilj, Jakob; Ecole Polytechnique Federal de Lausanne; Jeong, Jaewoo; Samant, Mahesh G.; Gray, Alexander X.; Temple Univ. Philadelphia, PA; Dürr, Hermann A.; Parkin, Stuart S. P.; et al

    2015-02-11

    Nonlinear spectroscopy in the extreme ultraviolet (EUV) and soft x-ray spectral range offers the opportunity for element selective probing of ultrafast dynamics using core-valence transitions (Mukamel et al., Acc. Chem. Res. 42, 553 (2009)). We demonstrate a step on this path showing core-valence sensitivity in transient grating spectroscopy with EUV probing. We study the optically induced insulator-to-metal transition (IMT) of a VO? film with EUV diffraction from the optically excited sample. The VO? exhibits a change in the 3p-3d resonance of V accompanied by an acoustic response. Due to the broadband probing we are able to separate the two features.

  18. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C. (Livermore, CA); Wall, Mark A. (Stockton, CA)

    2001-01-01

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  19. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    EUV lithography relies on specialized lenses made of curved mirrors with reflective coatings called multilayers to print patterns with high resolution. One special flat mirror...

  20. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with SEMATECH, an international semiconductor industry consortium, to create a unique Fresnel zone-plate microscope on Advanced Light Source Beamline 11.3.2 called the SEMATECH...

  1. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  2. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the Richard P. FeynmanInventors

  3. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the Richard P.

  4. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenryInhibitingInteractivePGAS and HybridBetoniCenter for

  5. Carbon contamination of extreme ultraviolet (EUV) mask and its effect on imaging

    E-Print Network [OSTI]

    Fan, Yu-Jen

    2009-01-01

    induced carbon contamination of extreme ultraviolet optics."potential LWR due to the contamination topography may be anet aI. , "Accelerated contamination testing of EUV masks."

  6. Method for the protection of extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Grunow, Philip A.; Clift, Wayne M.; Klebanoff, Leonard E.

    2010-06-22

    A coating for the protection of optical surfaces exposed to a high energy erosive plasma. A gas that can be decomposed by the high energy plasma, such as the xenon plasma used for extreme ultraviolet lithography (EUVL), is injected into the EUVL machine. The decomposition products coat the optical surfaces with a protective coating maintained at less than about 100 .ANG. thick by periodic injections of the gas. Gases that can be used include hydrocarbon gases, particularly methane, PH.sub.3 and H.sub.2S. The use of PH.sub.3 and H.sub.2S is particularly advantageous since films of the plasma-induced decomposition products S and P cannot grow to greater than 10 .ANG. thick in a vacuum atmosphere such as found in an EUVL machine.

  7. Broadband extreme ultraviolet probing of transient gratings in vanadium dioxide

    SciTech Connect (OSTI)

    Sistrunk, Emily [SLAC National Acceleraor Laboratory, Menlo Park, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Grilj, Jakob [SLAC National Acceleraor Laboratory, Menlo Park, CA (United States); Ecole Polytechnique Federal de Lausanne (Switzerland); Jeong, Jaewoo [IBM Almaden Research Center, San Jose, CA (United States); Samant, Mahesh G. [IBM Almaden Research Center, San Jose, CA (United States); Gray, Alexander X. [SLAC National Acceleraor Laboratory, Menlo Park, CA (United States); Temple Univ. Philadelphia, PA (United States); Dürr, Hermann A. [SLAC National Acceleraor Laboratory, Menlo Park, CA (United States); Parkin, Stuart S. P. [IBM Almaden Research Center, San Jose, CA (United States); Max Planck Inst. of Microstructure Physics, Halle (Germany); Gühr, Markus [SLAC National Acceleraor Laboratory, Menlo Park, CA (United States)

    2015-01-01

    Nonlinear spectroscopy in the extreme ultraviolet (EUV) and soft x-ray spectral range offers the opportunity for element selective probing of ultrafast dynamics using core-valence transitions (Mukamel et al., Acc. Chem. Res. 42, 553 (2009)). We demonstrate a step on this path showing core-valence sensitivity in transient grating spectroscopy with EUV probing. We study the optically induced insulator-to-metal transition (IMT) of a VO? film with EUV diffraction from the optically excited sample. The VO? exhibits a change in the 3p-3d resonance of V accompanied by an acoustic response. Due to the broadband probing we are able to separate the two features.

  8. THE EXTREME-ULTRAVIOLET EMISSION FROM SUN-GRAZING COMETS

    SciTech Connect (OSTI)

    Bryans, P.; Pesnell, W. D.

    2012-11-20

    The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory has observed two Sun-grazing comets as they passed through the solar atmosphere. Both passages resulted in a measurable enhancement of extreme-ultraviolet (EUV) radiance in several of the AIA bandpasses. We explain this EUV emission by considering the evolution of the cometary atmosphere as it interacts with the ambient solar atmosphere. Molecules in the comet rapidly sublimate as it approaches the Sun. They are then photodissociated by the solar radiation field to create atomic species. Subsequent ionization of these atoms produces a higher abundance of ions than normally present in the corona and results in EUV emission in the wavelength ranges of the AIA telescope passbands.

  9. Graphene defect formation by extreme ultraviolet generated photoelectrons

    SciTech Connect (OSTI)

    Gao, A., E-mail: a.gao@utwente.nl; Lee, C. J.; Bijkerk, F. [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands and XUV Optics Group, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands)

    2014-08-07

    We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy lower than 80?eV. After e-beam irradiation, it is found that the D peak, I(D), appears in the Raman spectrum, indicating defect formation in graphene. The evolution of I(D)/I(G) follows the amorphization trajectory with increasing irradiation dose, indicating that graphene goes through a transformation from microcrystalline to nanocrystalline and then further to amorphous carbon. Further, irradiation of graphene with increased water partial pressure does not significantly change the Raman spectra, which suggests that, in the extremely low energy range, e-beam induced chemical reactions between residual water and graphene are not the dominant mechanism driving defect formation in graphene. Single layer graphene, partially suspended over holes was irradiated with EUV radiation. By comparing with the Raman results from e-beam irradiation, it is concluded that the photoelectrons, especially those from the valence band, contribute to defect formation in graphene during irradiation.

  10. Four-mirror extreme ultraviolet (EUV) lithography projection system

    DOE Patents [OSTI]

    Cohen, Simon J (Pleasonton, CA); Jeong, Hwan J (Los Altos, CA); Shafer, David R (Fairfield, CT)

    2000-01-01

    The invention is directed to a four-mirror catoptric projection system for extreme ultraviolet (EUV) lithography to transfer a pattern from a reflective reticle to a wafer substrate. In order along the light path followed by light from the reticle to the wafer substrate, the system includes a dominantly hyperbolic convex mirror, a dominantly elliptical concave mirror, spherical convex mirror, and spherical concave mirror. The reticle and wafer substrate are positioned along the system's optical axis on opposite sides of the mirrors. The hyperbolic and elliptical mirrors are positioned on the same side of the system's optical axis as the reticle, and are relatively large in diameter as they are positioned on the high magnification side of the system. The hyperbolic and elliptical mirrors are relatively far off the optical axis and hence they have significant aspherical components in their curvatures. The convex spherical mirror is positioned on the optical axis, and has a substantially or perfectly spherical shape. The spherical concave mirror is positioned substantially on the opposite side of the optical axis from the hyperbolic and elliptical mirrors. Because it is positioned off-axis to a degree, the spherical concave mirror has some asphericity to counter aberrations. The spherical concave mirror forms a relatively large, uniform field on the wafer substrate. The mirrors can be tilted or decentered slightly to achieve further increase in the field size.

  11. High photon flux table-top coherent extreme ultraviolet source

    E-Print Network [OSTI]

    Hädrich, Steffen; Rothhardt, Jan; Krebs, Manuel; Hoffmann, Armin; Pronin, Oleg; Pervak, Vladimir; Limpert, Jens; Tünnermann, Andreas

    2014-01-01

    High harmonic generation (HHG) enables extreme ultraviolet radiation with table-top setups. Its exceptional properties, such as coherence and (sub)-femtosecond pulse durations, have led to a diversity of applications. Some of these require a high photon flux and megahertz repetition rates, e.g. to avoid space charge effects in photoelectron spectroscopy. To date this has only been achieved with enhancement cavities. Here, we establish a novel route towards powerful HHG sources. By achieving phase-matched HHG of a megahertz fibre laser we generate a broad plateau (25 eV - 40 eV) of strong harmonics, each containing more than $10^{12}$ photons/s, which constitutes an increase by more than one order of magnitude in that wavelength range. The strongest harmonic (H25, 30 eV) has an average power of 143 $\\mu$W ($3\\cdot10^{13}$ photons/s). This concept will greatly advance and facilitate applications in photoelectron or coincidence spectroscopy, coherent diffractive imaging or (multidimensional) surface science.

  12. AN EXTREME-ULTRAVIOLET WAVE ASSOCIATED WITH A SURGE

    SciTech Connect (OSTI)

    Zheng, Ruisheng; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Hong, Junchao; Yang, Bo; Yang, Dan

    2013-02-10

    Taking advantage of the high temporal and spatial resolution observations from the Solar Dynamics Observatory, we present an extreme-ultraviolet (EUV) wave associated with a surge on 2010 November 13. Due to the magnetic flux cancelation, some surges formed in the source active region (AR). The strongest surge produced our studied event. The surge was deflected by the nearby loops that connected to another AR, and disrupted the overlying loops that slowly expanded and eventually evolved into a weak coronal mass ejection (CME). The surge was likely associated with the core of the CME. The EUV wave happened after the surge deflected. The wave departed far from the flare center and showed a close location relative to the deflected surge. The wave propagated in a narrow angular extent, mainly in the ejection direction of the surge. The close timing and location relations between the EUV wave and the surge indicate that the wave was closely associated with the CME. The wave had a velocity of 310-350 km s{sup -1}, while the speeds of the surge and the expanding loops were about 130 and 150 km s{sup -1}, respectively. All of the results suggest that the EUV wave was a fast-mode wave and was most likely triggered by the weak CME.

  13. Silicon nitride zoneplates and packaging for extreme ultraviolet instruments

    E-Print Network [OSTI]

    Anderson, Erik H.

    2014-01-01

    nitride zoneplates and packaging for extreme ultravioletphase. IV. MECHANICAL PACKAGING WITH BALLS AND GROOVESoverall efficiency. Packaging using kinematic configurations

  14. Combined effects of prepulsing and target geometry on efficient extreme ultraviolet

    E-Print Network [OSTI]

    Harilal, S. S.

    for Materials Under Extreme Environment School of Nuclear Engineering West Lafayette, Indiana 47907-2017 E-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3609043] Subject terms: nanolithography; extreme ultraviolet materials can significantly reduce their lifetime, and as a result, the efficiency and the economy

  15. Carbon contamination and oxidation of Au surfaces under extreme ultraviolet radiation: An x-ray photoelectron spectroscopy study

    E-Print Network [OSTI]

    Harilal, S. S.

    Carbon contamination and oxidation of Au surfaces under extreme ultraviolet radiation: An x 2012) Extreme ultraviolet (EUV) radiation-induced carbon contamination and oxidation of Au surfaces modification during EUV exposure. XPS analysis showed that total carbon contamination (C 1s peak

  16. Generation of intense continuum extreme-ultraviolet radiation by many-cycle

    E-Print Network [OSTI]

    Loss, Daniel

    LETTERS Generation of intense continuum extreme-ultraviolet radiation by many-cycle laser fields P in ultrashort pulse engineering have recently led to the breakthroughs of the generation of attosecond (10-18 s) pulse trains1­7 and isolated pulses8­11 . Although trains of multiple pulses can be generated through

  17. Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography source

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography 2009; published online 10 December 2009 A CO2 laser system with flexible parameters was developed 1010 W/cm2 . Utilizing this CO2 MOPA laser system, high conversion efficiency from laser to in-band 2

  18. Low-cost method for producing extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Folta, James A. (Livermore, CA); Montcalm, Claude (Fort Collins, CO); Taylor, John S. (Livermore, CA); Spiller, Eberhard A. (Mt. Kisco, NY)

    2003-11-21

    Spherical and non-spherical optical elements produced by standard optical figuring and polishing techniques are extremely expensive. Such surfaces can be cheaply produced by diamond turning; however, the roughness in the diamond turned surface prevent their use for EUV lithography. These ripples are smoothed with a coating of polyimide before applying a 60 period Mo/Si multilayer to reflect a wavelength of 134 .ANG. and have obtained peak reflectivities close to 63%. The savings in cost are about a factor of 100.

  19. Method for plasma formation for extreme ultraviolet lithography-theta pinch

    DOE Patents [OSTI]

    Hassanein, Ahmed (Naperville, IL); Konkashbaev, Isak (Bolingbrook, IL); Rice, Bryan (Hillsboro, OR)

    2007-02-20

    A device and method for generating extremely short-wave ultraviolet electromagnetic wave, utilizing a theta pinch plasma generator to produce electromagnetic radiation in the range of 10 to 20 nm. The device comprises an axially aligned open-ended pinch chamber defining a plasma zone adapted to contain a plasma generating gas within the plasma zone; a means for generating a magnetic field radially outward of the open-ended pinch chamber to produce a discharge plasma from the plasma generating gas, thereby producing a electromagnetic wave in the extreme ultraviolet range; a collecting means in optical communication with the pinch chamber to collect the electromagnetic radiation; and focusing means in optical communication with the collecting means to concentrate the electromagnetic radiation.

  20. Extreme ultraviolet emission and confinement of tin plasmas in the presence of a magnetic field

    SciTech Connect (OSTI)

    Roy, Amitava E-mail: aroy@barc.gov.in; Murtaza Hassan, Syed; Harilal, Sivanandan S.; Hassanein, Ahmed; Endo, Akira; Mocek, Tomas

    2014-05-15

    We investigated the role of a guiding magnetic field on extreme ultraviolet (EUV) and ion emission from a laser produced Sn plasma for various laser pulse duration and intensity. For producing plasmas, planar slabs of pure Sn were irradiated with 1064?nm, Nd:YAG laser pulses with varying pulse duration (5–15?ns) and intensity. A magnetic trap was fabricated with the use of two neodymium permanent magnets which provided a magnetic field strength ?0.5?T along the plume expansion direction. Our results indicate that the EUV conversion efficiency do not depend significantly on applied axial magnetic field. Faraday Cup ion analysis of Sn plasma show that the ion flux reduces by a factor of ?5 with the application of an axial magnetic field. It was found that the plasma plume expand in the lateral direction with peak velocity measured to be ?1.2?cm/?s and reduced to ?0.75?cm/?s with the application of an axial magnetic field. The plume expansion features recorded using fast photography in the presence and absence of 0.5?T axial magnetic field are simulated using particle-in-cell code. Our simulation results qualitatively predict the plasma behavior.

  1. Influence of laser pulse duration on extreme ultraviolet and ion emission features from tin plasmas

    SciTech Connect (OSTI)

    Roy, A., E-mail: roy@fzu.cz, E-mail: aroy@barc.gov.in [HiLASE Project, Department of Diode-Pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic); School of Nuclear Engineering and Center for Materials Under Extreme Environment (CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States); Harilal, S. S.; Polek, M. P.; Hassan, S. M.; Hassanein, A. [School of Nuclear Engineering and Center for Materials Under Extreme Environment (CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States)] [School of Nuclear Engineering and Center for Materials Under Extreme Environment (CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States); Endo, A. [HiLASE Project, Department of Diode-Pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic)] [HiLASE Project, Department of Diode-Pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic)

    2014-03-15

    We investigated the role of laser pulse duration and intensity on extreme ultraviolet (EUV) generation and ion emission from a laser produced Sn plasma. For producing plasmas, planar slabs of pure Sn were irradiated with 1064?nm Nd:YAG laser pulses with varying pulse duration (5–20?ns) and intensity. Experimental results performed at CMUXE indicate that the conversion efficiency (CE) of the EUV radiation strongly depend on laser pulse width and intensity, with a maximum CE of ?2.0% measured for the shortest laser pulse width used (5?ns). Faraday Cup ion analysis of Sn plasma showed that the ion flux kinetic profiles are shifted to higher energy side with the reduction in laser pulse duration and narrower ion kinetic profiles are obtained for the longest pulse width used. However, our initial results showed that at a constant laser energy, the ion flux is more or less constant regardless of the excitation laser pulse width. The enhanced EUV emission obtained at shortest laser pulse duration studied is related to efficient laser-plasma reheating supported by presence of higher energy ions at these pulse durations.

  2. Overlying extreme-ultraviolet arcades preventing eruption of a filament observed by AIA/SDO

    SciTech Connect (OSTI)

    Chen, Huadong; Ma, Suli; Zhang, Jun

    2013-11-20

    Using the multi-wavelength data from the Atmospheric Imaging Assembly/Solar Dynamic Observatory (AIA/SDO) and the Sun Earth Connection Coronal and Heliospheric Investigation/Solar Terrestrial Relations Observatory (SECCHI/STEREO), we report a failed filament eruption in NOAA AR 11339 on 2011 November 3. The eruption was associated with an X1.9 flare, but without any coronal mass ejection (CME), coronal dimming, or extreme ultraviolet (EUV) waves. Some magnetic arcades above the filament were observed distinctly in EUV channels, especially in the AIA 94 Ĺ and 131 Ĺ wavebands, before and during the filament eruption process. Our results show that the overlying arcades expanded along with the ascent of the filament at first until they reached a projected height of about 49 Mm above the Sun's surface, where they stopped. The following filament material was observed to be confined by the stopped EUV arcades and not to escape from the Sun. After the flare, a new filament formed at the low corona where part of the former filament remained before its eruption. These results support that the overlying arcades play an important role in preventing the filament from successfully erupting outward. We also discuss in this paper the EUV emission of the overlying arcades during the flare. It is rare for a failed filament eruption to be associated with an X1.9 class flare, but not with a CME or EUV waves. Therefore, this study also provides valuable insight into the triggering mechanism of the initiation of CMEs and EUV waves.

  3. Passivating overcoat bilayer for multilayer reflective coatings for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Montcalm, Claude (Livermore, CA); Stearns, Daniel G. (Los Altos, CA); Vernon, Stephen P. (Pleasanton, CA)

    1999-01-01

    A passivating overcoat bilayer is used for multilayer reflective coatings for extreme ultraviolet (EUV) or soft x-ray applications to prevent oxidation and corrosion of the multilayer coating, thereby improving the EUV optical performance. The overcoat bilayer comprises a layer of silicon or beryllium underneath at least one top layer of an elemental or a compound material that resists oxidation and corrosion. Materials for the top layer include carbon, palladium, carbides, borides, nitrides, and oxides. The thicknesses of the two layers that make up the overcoat bilayer are optimized to produce the highest reflectance at the wavelength range of operation. Protective overcoat systems comprising three or more layers are also possible.

  4. Improving Ramsey spectroscopy in the extreme-ultraviolet region with a random-sampling approach

    SciTech Connect (OSTI)

    Eramo, R.; Bellini, M. [Istituto Nazionale di Ottica (INO-CNR), Largo E. Fermi 6, I-50125 Florence (Italy); European Laboratory for Non-linear Spectroscopy (LENS), I-50019 Sesto Fiorentino, Florence (Italy); Corsi, C.; Liontos, I. [European Laboratory for Non-linear Spectroscopy (LENS), I-50019 Sesto Fiorentino, Florence (Italy); Cavalieri, S. [European Laboratory for Non-linear Spectroscopy (LENS), I-50019 Sesto Fiorentino, Florence (Italy); Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy)

    2011-04-15

    Ramsey-like techniques, based on the coherent excitation of a sample by delayed and phase-correlated pulses, are promising tools for high-precision spectroscopic tests of QED in the extreme-ultraviolet (xuv) spectral region, but currently suffer experimental limitations related to long acquisition times and critical stability issues. Here we propose a random subsampling approach to Ramsey spectroscopy that, by allowing experimentalists to reach a given spectral resolution goal in a fraction of the usual acquisition time, leads to substantial improvements in high-resolution spectroscopy and may open the way to a widespread application of Ramsey-like techniques to precision measurements in the xuv spectral region.

  5. Compact multi-bounce projection system for extreme ultraviolet projection lithography

    DOE Patents [OSTI]

    Hudyma, Russell M. (San Ramon, CA)

    2002-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four optical elements providing five reflective surfaces for projecting a mask image onto a substrate. The five optical surfaces are characterized in order from object to image as concave, convex, concave, convex and concave mirrors. The second and fourth reflective surfaces are part of the same optical element. The optical system is particularly suited for ring field step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width, which effectively minimizes dynamic distortion.

  6. Rare-earth plasma extreme ultraviolet sources at 6.5-6.7 nm

    SciTech Connect (OSTI)

    Otsuka, Takamitsu; Higashiguchi, Takeshi; Yugami, Noboru; Yatagai, Toyohiko [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Kilbane, Deirdre; White, John; Dunne, Padraig; O'Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Jiang, Weihua [Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 (Japan); Endo, Akira [Forschungszentrum Dresden, Bautzner Landstrs. 400, D-01328 Dresden (Germany)

    2010-09-13

    We have demonstrated a laser-produced plasma extreme ultraviolet source operating in the 6.5-6.7 nm region based on rare-earth targets of Gd and Tb coupled with a Mo/B{sub 4}C multilayer mirror. Multiply charged ions produce strong resonance emission lines, which combine to yield an intense unresolved transition array. The spectra of these resonant lines around 6.7 nm (in-band: 6.7 nm {+-}1%) suggest that the in-band emission increases with increased plasma volume by suppressing the plasma hydrodynamic expansion loss at an electron temperature of about 50 eV, resulting in maximized emission.

  7. Optimizing laser produced plasmas for efficient extreme ultraviolet and soft X-ray light sources

    SciTech Connect (OSTI)

    Sizyuk, Tatyana; Hassanein, Ahmed [Center for Materials under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-08-15

    Photon sources produced by laser beams with moderate laser intensities, up to 10{sup 14?}W/cm{sup 2}, are being developed for many industrial applications. The performance requirements for high volume manufacture devices necessitate extensive experimental research supported by theoretical plasma analysis and modeling predictions. We simulated laser produced plasma sources currently being developed for several applications such as extreme ultraviolet lithography using 13.5%?±?1% nm bandwidth, possibly beyond extreme ultraviolet lithography using 6.× nm wavelengths, and water-window microscopy utilizing 2.48?nm (La-?) and 2.88?nm (He-?) emission. We comprehensively modeled plasma evolution from solid/liquid tin, gadolinium, and nitrogen targets as three promising materials for the above described sources, respectively. Results of our analysis for plasma characteristics during the entire course of plasma evolution showed the dependence of source conversion efficiency (CE), i.e., laser energy to photons at the desired wavelength, on plasma electron density gradient. Our results showed that utilizing laser intensities which produce hotter plasma than the optimum emission temperatures allows increasing CE for all considered sources that, however, restricted by the reabsorption processes around the main emission region and this restriction is especially actual for the 6.×?nm sources.

  8. Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources

    DOE Patents [OSTI]

    Kublak, G.D.; Richardson, M.C.

    1996-11-19

    Method and apparatus for producing extreme ultraviolet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10{sup 11}--10{sup 12} watts/cm{sup 2}) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10--30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle. 5 figs.

  9. Ionization avalanching in clusters ignited by extreme-ultraviolet driven seed electrons

    E-Print Network [OSTI]

    Schütte, Bernd; Mermillod-Blondin, Alexandre; Vrakking, Marc J J; Rouzée, Arnaud; Fennel, Thomas

    2015-01-01

    We study the ionization dynamics of Ar clusters exposed to ultrashort near-infrared (NIR) laser pulses for intensities well below the threshold at which tunnel ionization could ignite the nanoplasma formation. We find that the emission of highly charged ions up to Ar$^{8+}$ can be switched on with unit contrast by generating only a few seed electrons with an ultrashort extreme ultraviolet (XUV) pulse prior to the NIR field. Molecular dynamics simulations can explain the experimental observations and predict a generic scenario where efficient heating via inverse bremsstrahlung and NIR avalanching are followed by resonant collective nanoplasma heating. The temporally and spatially well-controlled injection of the XUV seed electrons opens new routes for controlling avalanching and heating phenomena in nanostructures and solids, with implications for both fundamental and applied laser-matter science.

  10. Colliding laser-produced plasmas as targets for laser-generated extreme ultraviolet sources

    SciTech Connect (OSTI)

    Cummins, T.; O'Gorman, C.; Dunne, P.; Sokell, E.; O'Sullivan, G. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Hayden, P., E-mail: patrick.hayden@physics.org [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); School of Physical Sciences and National Centre for Plasma Science and Technology, Dublin City University, Glasnevin, Dublin 9 (Ireland)

    2014-07-28

    Colliding plasmas produced by neodymium-doped yttrium aluminium garnet (Nd:YAG) laser illumination of tin wedge targets form stagnation layers, the physical parameters of which can be controlled to optimise coupling with a carbon dioxide (CO{sub 2}) heating laser pulse and subsequent extreme ultraviolet (EUV) production. The conversion efficiency (CE) of total laser energy into EUV emission at 13.5?nm?±?1% was 3.6%. Neglecting both the energy required to form the stagnation layer and the EUV light produced before the CO{sub 2} laser pulse is incident results in a CE of 5.1% of the CO{sub 2} laser energy into EUV light.

  11. Extreme Ultraviolet Imaging of Three-dimensional Magnetic Reconnection in a Solar Eruption

    E-Print Network [OSTI]

    Sun, J Q; Ding, M D; Guo, Y; Priest, E R; Parnell, C E; Edwards, S J; Zhang, J; Chen, P F; Fang, C

    2015-01-01

    Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively. It is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions (3D) using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet (EUV) images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from $\\sim$1 to $\\ge$5 MK. Shortly afterwards, warm flare loops ($\\sim$3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magneti...

  12. Enhancement of laser plasma extreme ultraviolet emission by shockwave-laser interaction

    SciTech Connect (OSTI)

    Bruijn, Rene de; Koshelev, Konstantin N.; Zakharov, Serguei V.; Novikov, Vladimir G.; Bijkerk, Fred [FOM Institute for Plasma Physics Rijnhuizen, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); EPPRA SAS, 16 Avenue de Quebec, Silic 706 Courtaboeuf, 91961 Villebon-sur-Yvette (France) and TRINITI RF SRC, Troitsk (Russian Federation); KIAM RAS, Miusskaya square 4, Moscow, 125047 (Russian Federation); FOM Institute for Plasma Physics Rijnhuizen, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2005-04-15

    A double laser pulse heating scheme has been applied to generate plasmas with enhanced emission in the extreme ultraviolet (EUV). The plasmas were produced by focusing two laser beams (prepulse and main pulse) with a small spatial separation between the foci on a xenon gas jet target. Prepulses with ps-duration were applied to obtain high shockwave densities, following indications of earlier published results obtained using ns prepulses. EUV intensities around 13.5 nm and in the range 5-20 nm were recorded, and a maximum increase in intensity exceeding 2 was measured at an optimal delay of 140 ns between prepulse and main pulse. The gain in intensity is explained by the interaction of the shockwave produced by the prepulse with the xenon in the beam waist of the main pulse. Extensive simulation was done using the radiative magnetohydrodynamic code Z{sup *}.

  13. Tabletop Nanometer Extreme Ultraviolet Imaging in an Extended Reflection Mode using Coherent Fresnel Ptychography

    E-Print Network [OSTI]

    Seaberg, Matthew D; Gardner, Dennis F; Shanblatt, Elisabeth R; Murnane, Margaret M; Kapteyn, Henry C; Adams, Daniel E

    2013-01-01

    We demonstrate high resolution extreme ultraviolet (EUV) coherent diffractive imaging in the most general reflection geometry by combining ptychography with tilted plane correction. This method makes it possible to image extended surfaces at any angle of incidence. Refocused light from a tabletop coherent high harmonic light source at 29 nm illuminates a nanopatterned surface at 45 degree angle of incidence. The reconstructed image contains quantitative amplitude and phase (in this case pattern height) information, comparing favorably with both scanning electron microscope and atomic force microscopy images. In the future, this approach will enable imaging of complex surfaces and nanostructures with sub-10 nm-spatial resolution and fs-temporal resolution, which will impact a broad range of nanoscience and nanotechnology including for direct application in actinic inspection in support of EUV lithography.

  14. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    E-Print Network [OSTI]

    Gehman, V M; Rielage, K; Hime, A; Sun, Y; Mei, D -M; Maassen, J; Moore, D

    2011-01-01

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  15. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    E-Print Network [OSTI]

    V. M. Gehman; S. R. Seibert; K. Rielage; A. Hime; Y. Sun; D. -M. Mei; J. Maassen; D. Moore

    2011-09-22

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  16. Optimization of extreme ultraviolet photons emission and collection in mass-limited laser produced plasmas for lithography application

    E-Print Network [OSTI]

    Harilal, S. S.

    Optimization of extreme ultraviolet photons emission and collection in mass-limited laser produced in DPP or with pre-pulsing in LPP provide wide area for optimization in regards to conversion efficiency and collection as well as calculating photons source location and size. We optimized several parameters of dual

  17. PUBLISHED ONLINE: 31 MARCH 2013 | DOI: 10.1038/NPHYS2590 Extreme-ultraviolet light generation in

    E-Print Network [OSTI]

    Loss, Daniel

    generation in plasmonic nanostructures M. Sivis1 , M. Duwe1 , B. Abel2 and C. Ropers1 * Strong-harmonic generation. However, there is growing tension between the great promise held by extreme-ultraviolet and attosecond-pulse generation on the nanoscale, and the lack of successful implementations. Here, we address

  18. Efficient 13.5 nm extreme ultraviolet emission from Sn plasma irradiated by a long CO2 laser pulse

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    Efficient 13.5 nm extreme ultraviolet emission from Sn plasma irradiated by a long CO2 laser pulse 17 April 2008; accepted 4 June 2008; published online 23 June 2008 The effect of pulse duration on in with pulse durations from 25 to 110 ns. Employing a long pulse, for example, 110 ns, in a CO2 laser system

  19. THE HIGH-RESOLUTION EXTREME-ULTRAVIOLET SPECTRUM OF N{sub 2} BY ELECTRON IMPACT

    SciTech Connect (OSTI)

    Heays, A. N.; Ajello, J. M.; Aguilar, A.; Lewis, B. R.; Gibson, S. T.

    2014-04-01

    We have analyzed high-resolution (FWHM = 0.2 Ĺ) extreme-ultraviolet (EUV, 800-1350 Ĺ) laboratory emission spectra of molecular nitrogen excited by an electron impact at 20 and 100 eV under (mostly) optically thin, single-scattering experimental conditions. A total of 491 emission features were observed from N{sub 2} electronic-vibrational transitions and atomic N I and N II multiplets and their emission cross sections were measured. Molecular emission was observed at vibrationally excited ground-state levels as high as v'' = 17, from the a {sup 1}? {sub g} , b {sup 1}? {sub u} , and b'{sup 1}? {sub u} {sup +} excited valence states and the Rydberg series c'{sub n} {sub +1} {sup 1}? {sub u} {sup +}, c{sub n} {sup 1}? {sub u} , and o{sub n} {sup 1}? {sub u} for n between 3 and 9. The frequently blended molecular emission bands were disentangled with the aid of a sophisticated and predictive quantum-mechanical model of excited states that includes the strong coupling between valence and Rydberg electronic states and the effects of predissociation. Improved model parameters describing electronic transition moments were obtained from the experiment and allowed for a reliable prediction of the vibrationally summed electronic emission cross section, including an extrapolation to unobserved emission bands and those that are optically thick in the experimental spectra. Vibrationally dependent electronic excitation functions were inferred from a comparison of emission features following 20 and 100 eV electron-impact collisional excitation. The electron-impact-induced fluorescence measurements are compared with Cassini Ultraviolet Imaging Spectrograph observations of emissions from Titan's upper atmosphere.

  20. JET ROTATION INVESTIGATED IN THE NEAR-ULTRAVIOLET WITH THE HUBBLE SPACE TELESCOPE IMAGING SPECTROGRAPH

    SciTech Connect (OSTI)

    Coffey, Deirdre; Ray, Thomas P.; Rigliaco, Elisabetta; Bacciotti, Francesca; Eisloeffel, Jochen

    2012-04-20

    We present results of the second phase of our near-ultraviolet investigation into protostellar jet rotation using the Hubble Space Telescope Imaging Spectrograph. We obtain long-slit spectra at the base of five T Tauri jets to determine if there is a difference in radial velocity between the jet borders which may be interpreted as a rotation signature. These observations are extremely challenging and push the limits of current instrumentation, but have the potential to provide long-awaited observational support for the magnetocentrifugal mechanism of jet launching in which jets remove angular momentum from protostellar systems. We successfully detect all five jet targets (from RW Aur, HN Tau, DP Tau, and CW Tau) in several near-ultraviolet emission lines, including the strong Mg II doublet. However, only RW Aur's bipolar jet presents a sufficiently high signal-to-noise ratio to allow for analysis. The approaching jet lobe shows a difference of 10 km s{sup -1} in a direction which agrees with the disk rotation sense, but is opposite to previously published optical measurements for the receding jet. The near-ultraviolet difference is not found six months later, nor is it found in the fainter receding jet. Overall, in the case of RW Aur, differences are not consistent with a simple jet rotation interpretation. Indeed, given the renowned complexity and variability of this system, it now seems likely that any rotation signature is confused by other influences, with the inevitable conclusion that RW Aur is not suited to a jet rotation study.

  1. An analysis of ultraviolet spectra of Extreme Helium Stars and new clues to their origins

    E-Print Network [OSTI]

    Pandey, G; Jeffery, C S; Rao, N K; Pandey, Gajendra; Lambert, David L.

    2006-01-01

    Abundances of about 18 elements including the heavy elements Y and Zr are determined from Hubble Space Telescope Space Telescope Imaging Spectrograph ultraviolet spectra of seven extreme helium stars (EHes): LSE 78, BD+10 2179, V1920 Cyg, HD 124448, PV Tel, LS IV -1 2, and FQ Aqr. New optical spectra of the three stars -- BD+10 2179, V1920 Cyg, and HD 124448 were analysed. The abundance analyses is done using LTE line formation and LTE model atmospheres especially constructed for these EHe stars. The stellar parameters derived from an EHe's UV spectrum are in satisfactory agreement with those derived from its optical spectrum. Adopted abundances for the seven EHes are from a combination of the UV and optical analyses. Published results for an additional ten EHes provide abundances obtained in a nearly uniform manner for a total of 17 EHes, the largest sample on record. The initial metallicity of an EHe is indicated by the abundance of elements from Al to Ni; Fe is adopted to be the representative of initial m...

  2. Soft x ray/extreme ultraviolet images of the solar atmosphere with normal incidence multilayer optics

    SciTech Connect (OSTI)

    Lindblom, J.F.

    1990-01-01

    The first high resolution Soft X-Ray/Extreme Ultraviolet (XUV) images of the Sun with normal incidence multilayer optics were obtained by the Standford/MSFC Rocket X-Ray Spectroheliograph on 23 Oct. 1987. Numerous images at selected wavelengths from 8 to 256 A were obtained simultaneously by the diverse array of telescopes flown on-board the experiment. These telescopes included single reflection normal incidence multilayer systems (Herschelian), double reflection multilayer systems (Cassegrain), a grazing incidence mirror system (Wolter-Schwarzschild), and hybrid systems using normal incidence multilayer optics in conjunction with the grazing incidence primary (Wolter-Cassegrain). Filters comprised of approximately 1700{Angstrom} thick aluminum supported on a nickel mesh were used to transmit the soft x ray/EUV radiation while preventing the intense visible light emission of the Sun from fogging the sensitive experimental T-grain photographic emulsions. These systems yielded high resolution soft x ray/EUV images of the solar corona and transition region, which reveal magnetically confined loops of hot solar plasma, coronal plumes, polar coronal holes, supergranulation, and features associated with overlying cool prominences. The development, testing, and operation of the experiments, and the results from the flight are described. The development of a second generation experiment, the Multi-Spectral Solar Telescope Array, which is scheduled to fly in the summer of 1990, and a recently approved Space Station experiment, the Ultra-High Resolution XUV Spectroheliograph, which is scheduled to fly in 1996 are also described.

  3. THE EXTREME ULTRAVIOLET DEFICIT AND MAGNETICALLY ARRESTED ACCRETION IN RADIO-LOUD QUASARS

    SciTech Connect (OSTI)

    Punsly, Brian

    2014-12-20

    The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Ĺ and ?580 Ĺ is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Ĺ and 580 Ĺ in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large-scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of <2.8 M (in geometrized units) for rapidly rotating black holes and <5.5 M for modestly rotating black holes.

  4. ACTIVE REGION MOSS: DOPPLER SHIFTS FROM HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS

    SciTech Connect (OSTI)

    Tripathi, Durgesh [Inter-University Centre for Astronomy and Astrophysics, Pune University Campus, Pune 411007 (India); Mason, Helen E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Klimchuk, James A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-07-01

    Studying the Doppler shifts and the temperature dependence of Doppler shifts in moss regions can help us understand the heating processes in the core of the active regions. In this paper, we have used an active region observation recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode on 2007 December 12 to measure the Doppler shifts in the moss regions. We have distinguished the moss regions from the rest of the active region by defining a low-density cutoff as derived by Tripathi et al. in 2010. We have carried out a very careful analysis of the EIS wavelength calibration based on the method described by Young et al. in 2012. For spectral lines having maximum sensitivity between log T = 5.85 and log T = 6.25 K, we find that the velocity distribution peaks at around 0 km s{sup -1} with an estimated error of 4-5 km s{sup -1}. The width of the distribution decreases with temperature. The mean of the distribution shows a blueshift which increases with increasing temperature and the distribution also shows asymmetries toward blueshift. Comparing these results with observables predicted from different coronal heating models, we find that these results are consistent with both steady and impulsive heating scenarios. However, the fact that there are a significant number of pixels showing velocity amplitudes that exceed the uncertainty of 5 km s{sup -1} is suggestive of impulsive heating. Clearly, further observational constraints are needed to distinguish between these two heating scenarios.

  5. Tin removal from extreme ultraviolet collector optics by inductively coupled plasma reactive ion etching

    SciTech Connect (OSTI)

    Shin, H.; Srivastava, S. N.; Ruzic, D. N. [Center for Plasma Material Interactions, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2008-05-15

    Tin (Sn) has the advantage of delivering higher conversion efficiency compared to other fuel materials (e.g., Xe or Li) in an extreme ultraviolet (EUV) source, a necessary component for the leading next generation lithography. However, the use of a condensable fuel in a lithography system leads to some additional challenges for maintaining a satisfactory lifetime of the collector optics. A critical issue leading to decreased mirror lifetime is the buildup of debris on the surface of the primary mirror that comes from the use of Sn in either gas discharge produced plasma (GDPP) or laser produced plasma (LPP). This leads to a decreased reflectivity from the added material thickness and increased surface roughness that contributes to scattering. Inductively coupled plasma reactive ion etching with halide ions is one potential solution to this problem. This article presents results for etch rate and selectivity of Sn over SiO{sub 2} and Ru. The Sn etch rate in a chlorine plasma is found to be much higher (of the order of hundreds of nm/min) than the etch rate of other materials. A thermally evaporated Sn on Ru sample was prepared and cleaned using an inductively coupled plasma etching method. Cleaning was confirmed using several material characterization techniques. Furthermore, a collector mock-up shell was then constructed and etching was performed on Sn samples prepared in a Sn EUV source using an optimized etching recipe. The sample surface before and after cleaning was analyzed by atomic force microscopy, x-ray photoelectron spectroscopy, and Auger electron spectroscopy. The results show the dependence of etch rate on the location of Sn samples placed on the collector mock-up shell.

  6. A chain of winking (oscillating) filaments triggered by an invisible extreme-ultraviolet wave

    SciTech Connect (OSTI)

    Shen, Yuandeng; Tian, Zhanjun; Zhao, Ruijuan; Ichimoto, Kiyoshi; Ishii, Takako T.; Shibata, Kazunari

    2014-05-10

    Winking (oscillating) filaments have been observed for many years. However, observations of successive winking filaments in one event have not yet been reported. In this paper, we present the observations of a chain of winking filaments and a subsequent jet that are observed right after the X2.1 flare in AR11283. The event also produced an extreme-ultraviolet (EUV) wave that has two components: an upward dome-like wave (850 km s{sup –1}) and a lateral surface wave (554 km s{sup –1}) that was very weak (or invisible) in imaging observations. By analyzing the temporal and spatial relationships between the oscillating filaments and the EUV waves, we propose that all the winking filaments and the jet were triggered by the weak (or invisible) lateral surface EUV wave. The oscillation of the filaments last for two or three cycles, and their periods, Doppler velocity amplitudes, and damping times are 11-22 minutes, 6-14 km s{sup –1}, and 25-60 minutes, respectively. We further estimate the radial component magnetic field and the maximum kinetic energy of the filaments, and they are 5-10 G and ?10{sup 19} J, respectively. The estimated maximum kinetic energy is comparable to the minimum energy of ordinary EUV waves, suggesting that EUV waves can efficiently launch filament oscillations on their path. Based on our analysis results, we conclude that the EUV wave is a good agent for triggering and connecting successive but separated solar activities in the solar atmosphere, and it is also important for producing solar sympathetic eruptions.

  7. HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS OF THE TEMPERATURE STRUCTURE OF THE QUIET CORONA

    SciTech Connect (OSTI)

    Brooks, David H.; Warren, Harry P. [Space Science Division, Code 7673, Naval Research Laboratory, Washington, DC 20375 (United States); Williams, David R. [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); Watanabe, Tetsuya, E-mail: dhbrooks@ssd5.nrl.navy.mi [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2009-11-10

    We present a differential emission measure (DEM) analysis of the quiet solar corona on disk using data obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode. We show that the expected quiet-Sun DEM distribution can be recovered from judiciously selected lines, and that their average intensities can be reproduced to within 30%. We present a subset of these selected lines spanning the temperature range log T = 5.6-6.4 K that can be used to derive the DEM distribution reliably, including a subset of iron lines that can be used to derive the DEM distribution free of the possibility of uncertainties in the elemental abundances. The subset can be used without the need for extensive measurements, and the observed intensities can be reproduced to within the estimated uncertainty in the pre-launch calibration of EIS. Furthermore, using this subset, we also demonstrate that the quiet coronal DEM distribution can be recovered on size scales down to the spatial resolution of the instrument (1'' pixels). The subset will therefore be useful for studies of small-scale spatial inhomogeneities in the coronal temperature structure, for example, in addition to studies requiring multiple DEM derivations in space or time. We apply the subset to 45 quiet-Sun data sets taken in the period 2007 January to April, and show that although the absolute magnitude of the coronal DEM may scale with the amount of released energy, the shape of the distribution is very similar up to at least log T approx 6.2 K in all cases. This result is consistent with the view that the shape of the quiet-Sun DEM is mainly a function of the radiating and conducting properties of the plasma and is fairly insensitive to the location and rate of energy deposition. This universal DEM may be sensitive to other factors such as loop geometry, flows, and the heating mechanism, but if so they cannot vary significantly from quiet-Sun region to region.

  8. Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors

    DOE Patents [OSTI]

    Ruffner, J.A.

    1999-06-15

    A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet (DUV) and Extreme Ultra-Violet (EUV) wavelengths. The method results in a product with minimum feature sizes of less than 0.10 [micro]m for the shortest wavelength (13.4 nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R[sup 2] factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates. 15 figs.

  9. Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors

    DOE Patents [OSTI]

    Ruffner, Judith Alison (Albuquerque, NM)

    1999-01-01

    A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet ("DUV") and Extreme Ultra-Violet ("EUV") wavelengths. The method results in a product with minimum feature sizes of less than 0.10-.mu.m for the shortest wavelength (13.4-nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R.sup.2 factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates.

  10. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trap

    SciTech Connect (OSTI)

    Beiersdorfer, P.; Magee, E. W.; Brown, G. V.; Träbert, E.; Widmann, K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hell, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Dr. Remeis-Sternwarte and ECAP, Universität Erlangen-Nürnberg, 96049 Bamberg (Germany)

    2014-11-15

    A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Ĺ to above 300 Ĺ. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 ?m wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Ĺ above 100 Ĺ, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.

  11. Effects of the dynamics of droplet-based laser-produced plasma on angular extreme ultraviolet emission profile

    SciTech Connect (OSTI)

    Giovannini, Andrea Z.; Abhari, Reza S.

    2014-05-12

    The emission distribution of extreme ultraviolet (EUV) radiation from droplet targets is dependent on the dynamics of the laser-produced plasma. The EUV emission is measured on a 2% bandwidth centered at 13.5?nm (in-band). The targets of the laser are small (sub-50 ?m) tin droplets, and the in-band emission distribution is measured for different laser irradiances and droplet sizes at various angular positions. Larger droplets lead to a faster decay of EUV emission at larger angles with respect to the laser axis. A decrease in laser irradiance has the opposite effect. The measurements are used together with an analytical model to estimate plume dynamics. Additionally, the model is used to estimate EUV emission distribution for a desired droplet diameter and laser irradiance.

  12. Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources

    DOE Patents [OSTI]

    Kublak, Glenn D. (124 Turquoise Way, Livermore, Alameda County, CA 94550); Richardson, Martin C. (CREOL

    1996-01-01

    Method and apparatus for producing extreme ultra violet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10.sup.11 -10.sup.12 watts/cm.sup.2) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10-30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle.

  13. Quantitative analysis of electron energy loss spectra and modelling of optical properties of multilayer systems for extreme ultraviolet radiation regime

    SciTech Connect (OSTI)

    Gusenleitner, S.; Hauschild, D.; Reinert, F.; Handick, E.

    2014-03-28

    Ruthenium capped multilayer coatings for use in the extreme ultraviolet (EUV) radiation regime have manifold applications in science and industry. Although the Ru cap shall protect the reflecting multilayers, the surface of the heterostructures suffers from contamination issues and surface degradation. In order to get a better understanding of the effects of these impurities on the optical parameters, reflection electron energy loss spectroscopy (REELS) measurements of contaminated and H cleaned Ru multilayer coatings were taken at various primary electron beam energies. Experiments conducted at low primary beam energies between 100?eV and 1000?eV are very surface sensitive due to the short inelastic mean free path of the electrons in this energy range. Therefore, influences of the surface condition on the above mentioned characteristics can be appraised. In this paper, it can be shown that carbon and oxide impurities on the mirror surface decrease the transmission of the Ru cap by about 0.75% and the overall reflectance of the device is impaired as the main share of the non-transmitted EUV light is absorbed in the contamination layer.

  14. DIFFRACTION, REFRACTION, AND REFLECTION OF AN EXTREME-ULTRAVIOLET WAVE OBSERVED DURING ITS INTERACTIONS WITH REMOTE ACTIVE REGIONS

    SciTech Connect (OSTI)

    Shen Yuandeng; Liu Yu; Zhao Ruijuan; Tian Zhanjun; Su Jiangtao; Li Hui; Ichimoto, Kiyoshi; Shibata, Kazunari

    2013-08-20

    We present observations of the diffraction, refraction, and reflection of a global extreme-ultraviolet (EUV) wave propagating in the solar corona. These intriguing phenomena are observed when the wave interacts with two remote active regions, and together they exhibit properties of an EUV wave. When the wave approached AR11465, it became weaker and finally disappeared in the active region, but a few minutes later a new wavefront appeared behind the active region, and it was not concentric with the incoming wave. In addition, a reflected wave was also simultaneously observed on the wave incoming side. When the wave approached AR11459, it transmitted through the active region directly and without reflection. The formation of the new wavefront and the transmission could be explained with diffraction and refraction effects, respectively. We propose that the different behaviors observed during the interactions may be caused by different speed gradients at the boundaries of the two active regions. We find that the EUV wave formed ahead of a group of expanding loops a few minutes after the start of the loops' expansion, which represents the initiation of the associated coronal mass ejection (CME). Based on these results, we conclude that the EUV wave should be a nonlinear magnetosonic wave or shock driven by the associated CME, which propagated faster than the ambient fast mode speed and gradually slowed down to an ordinary linear wave. Our observations support the hybrid model that includes both fast wave and slow non-wave components.

  15. MAGNETIC RECONNECTION: FROM 'OPEN' EXTREME-ULTRAVIOLET LOOPS TO CLOSED POST-FLARE ONES OBSERVED BY SDO

    SciTech Connect (OSTI)

    Zhang, Jun; Yang, Shuhong; Li, Ting; Zhang, Yuzong; Li, Leping [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Jiang, Chaowei, E-mail: zjun@nao.cas.cn, E-mail: shuhongyang@nao.cas.cn, E-mail: liting@nao.cas.cn, E-mail: yuzong@nao.cas.cn, E-mail: lepingli@nao.cas.cn, E-mail: cwjiang@spaceweather.ac.cn [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-10-10

    We employ Solar Dynamics Observatory observations and select three well-observed events including two flares and one extreme-ultraviolet (EUV) brightening. During the three events, the EUV loops clearly changed. One event was related to a major solar flare that took place on 2012 July 12 in active region NOAA AR 11520. 'Open' EUV loops rooted in a facula of the AR deflected to the post-flare loops and then merged with them while the flare ribbon approached the facula. Meanwhile, 'open' EUV loops rooted in a pore disappeared from top to bottom as the flare ribbon swept over the pore. The loop evolution was similar in the low-temperature channels (e.g., 171 Ĺ) and the high-temperature channels (e.g., 94 Ĺ). The coronal magnetic fields extrapolated from the photospheric vector magnetograms also show that the fields apparently 'open' prior to the flare become closed after it. The other two events were associated with a B1.1 flare on 2010 May 24 and an EUV brightening on 2013 January 03, respectively. During both of these two events, some 'open' loops either disappeared or darkened before the formation of new closed loops. We suggest that the observations reproduce the picture predicted by the standard magnetic reconnection model: 'open' magnetic fields become closed due to reconnection, manifesting as a transformation from 'open' EUV loops to closed post-flare ones.

  16. NON-POTENTIAL FIELDS IN THE QUIET SUN NETWORK: EXTREME-ULTRAVIOLET AND MAGNETIC FOOTPOINT OBSERVATIONS

    SciTech Connect (OSTI)

    Chesny, D. L.; Oluseyi, H. M.; Orange, N. B.

    2013-11-20

    The quiet Sun (QS) magnetic network is known to contain dynamics which are indicative of non-potential fields. Non-potential magnetic fields forming ''S-shaped'' loop arcades can lead to the breakdown of static activity and have only been observed in high temperature X-ray coronal structures—some of which show eruptive behavior. Thus, analysis of this type of atmospheric structuring has been restricted to large-scale coronal fields. Here we provide the first identification of non-potential loop arcades exclusive to the QS supergranulation network. High-resolution Atmospheric Imaging Assembly data from the Solar Dynamics Observatory have allowed for the first observations of fine-scale ''S-shaped'' loop arcades spanning the network. We have investigated the magnetic footpoint flux evolution of these arcades from Heliospheric and Magnetic Imager data and find evidence of evolving footpoint flux imbalances accompanying the formation of these non-potential fields. The existence of such non-potentiality confirms that magnetic field dynamics leading to the build up of helicity exist at small scales. QS non-potentiality also suggests a self-similar formation process between the QS network and high temperature corona and the existence of self-organized criticality (SOC) in the form of loop-pair reconnection and helicity dissipation. We argue that this type of behavior could lead to eruptive forms of SOC as seen in active region (AR) and X-ray sigmoids if sufficient free magnetic energy is available. QS magnetic network dynamics may be considered as a coronal proxy at supergranular scales, and events confined to the network can even mimic those in coronal ARs.

  17. Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources

    SciTech Connect (OSTI)

    Aquila, Andrew Lee

    2009-05-21

    The development of multilayer optics for extreme ultraviolet (EUV) radiation has led to advancements in many areas of science and technology, including materials studies, EUV lithography, water window microscopy, plasma imaging, and orbiting solar physics imaging. Recent developments in femtosecond and attosecond EUV pulse generation from sources such as high harmonic generation lasers, combined with the elemental and chemical specificity provided by EUV radiation, are opening new opportunities to study fundamental dynamic processes in materials. Critical to these efforts is the design and fabrication of multilayer optics to transport, focus, shape and image these ultra-fast pulses This thesis describes the design, fabrication, characterization, and application of multilayer optics for EUV femtosecond and attosecond scientific studies. Multilayer mirrors for bandwidth control, pulse shaping and compression, tri-material multilayers, and multilayers for polarization control are described. Characterization of multilayer optics, including measurement of material optical constants, reflectivity of multilayer mirrors, and metrology of reflected phases of the multilayer, which is critical to maintaining pulse size and shape, were performed. Two applications of these multilayer mirrors are detailed in the thesis. In the first application, broad bandwidth multilayers were used to characterize and measure sub-100 attosecond pulses from a high harmonic generation source and was performed in collaboration with the Max-Planck institute for Quantum Optics and Ludwig- Maximilians University in Garching, Germany, with Professors Krausz and Kleineberg. In the second application, multilayer mirrors with polarization control are useful to study femtosecond spin dynamics in an ongoing collaboration with the T-REX group of Professor Parmigiani at Elettra in Trieste, Italy. As new ultrafast x-ray sources become available, for example free electron lasers, the multilayer designs described in this thesis can be extended to higher photon energies, and such designs can be used with those sources to enable new scientific studies, such as molecular bonding, phonon, and spin dynamics.

  18. Extreme ultraviolet reflector

    DOE Patents [OSTI]

    Newnam, Brian E. (Los Alamos, NM)

    1990-01-01

    A multi-faceted mirror forms a retroreflector for a resonator loop in a free electron laser (FEL) operating in the XUV (.lambda.=10-100 nm). The number of facets is determined by the angle-of-incidence needed to obtain total external reflectance (TER) from the facet surface and the angle through which the FEL beam is to be turned. Angles-of-incidence greater than the angle for TER may be used to increase the area of the beam incident on the surface and reduce energy absorption density. Suitable surface films having TER in the 10-100 nm range may be formed from a variety of materials, including Al, single-crystal Si, Ag, and Rh. One of the facets is formed as an off-axis conic section to collimate the output beam with minimum astigmatism.

  19. Study of extreme-ultraviolet emission and properties of a coronal streamer from PROBA2/SWAP, HINODE/EIS and Mauna Loa Mk4 observations

    SciTech Connect (OSTI)

    Goryaev, F.; Slemzin, V.; Vainshtein, L. [P.N. Lebedev Physical Institute of the RAS (LPI), Moscow 119991 (Russian Federation); Williams, David R., E-mail: goryaev_farid@mail.ru [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Surrey, RH5 6NT (United Kingdom)

    2014-02-01

    Wide-field extreme-ultraviolet (EUV) telescopes imaging in spectral bands sensitive to 1 MK plasma on the Sun often observe extended, ray-like coronal structures stretching radially from active regions to distances of 1.5-2 R {sub ?}, which represent the EUV counterparts of white-light streamers. To explain this phenomenon, we investigated the properties of a streamer observed on 2010 October 20 and 21, by the PROBA2/SWAP EUV telescope together with the Hinode/EIS (HOP 165) and the Mauna Loa Mk4 white-light coronagraph. In the SWAP 174 Ĺ band comprising the Fe IX-Fe XI lines, the streamer was detected to a distance of 2 R {sub ?}. We assume that the EUV emission is dominated by collisional excitation and resonant scattering of monochromatic radiation coming from the underlying corona. Below 1.2 R {sub ?}, the plasma density and temperature were derived from the Hinode/EIS data by a line-ratio method. Plasma conditions in the streamer and in the background corona above 1.2 R {sub ?} from the disk center were determined by forward-modeling the emission that best fit the observational data in both EUV and white light. It was found that the plasma in the streamer above 1.2 R {sub ?} is nearly isothermal, with a temperature of T = 1.43 ± 0.08 MK. The hydrostatic scale-height temperature determined from the evaluated density distribution was significantly higher (1.72 ± 0.08 MK), which suggests the existence of outward plasma flow along the streamer. We conclude that, inside the streamer, collisional excitation provided more than 90% of the observed EUV emission, whereas, in the background corona, the contribution of resonance scattering became comparable with that of collisions at R ? 2 R {sub ?}.

  20. EVIDENCE FOR THE WAVE NATURE OF AN EXTREME ULTRAVIOLET WAVE OBSERVED BY THE ATMOSPHERIC IMAGING ASSEMBLY ON BOARD THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect (OSTI)

    Shen Yuandeng; Liu Yu

    2012-07-20

    Extreme-ultraviolet (EUV) waves have been found for about 15 years. However, significant controversy remains over their physical natures and origins. In this paper, we report an EUV wave that was accompanied by an X1.9 flare and a partial halo coronal mass ejection (CME). Using high temporal and spatial resolution observations taken by the Solar Dynamics Observatory and the Solar-TErrestrial RElations Observatory, we are able to investigate the detailed kinematics of the EUV wave. We find several arguments that support the fast-mode wave scenario. (1) The speed of the EUV wave (570 km s{sup -1}) is higher than the sound speed of the quiet-Sun corona. (2) Significant deceleration of the EUV wave (-130 m s{sup -2}) is found during its propagation. (3) The EUV wave resulted in the oscillations of a loop and a filament along its propagation path, and a reflected wave from the polar coronal hole is also detected. (4) Refraction or reflection effect is observed when the EUV wave was passing through two coronal bright points. (5) The dimming region behind the wavefront stopped to expand when the wavefront started to become diffuse. (6) The profiles of the wavefront exhibited a dispersive nature, and the magnetosonic Mach number of the EUV wave derived from the highest intensity jump is about 1.4. In addition, triangulation indicates that the EUV wave propagated within a height range of about 60-100 Mm above the photosphere. We propose that the EUV wave observed should be a nonlinear fast-mode magnetosonic wave that propagated freely in the corona after it was driven by the CME expanding flanks during the initial period.

  1. Gas-phase study of the reactivity of optical coating materials with hydrocarbons by use of a desktop-size extreme-ultraviolet laser

    SciTech Connect (OSTI)

    Heinbuch, Scott; Rocca, Jorge J. [Department of Electrical and Computer Engineering, Colorado State University, 1320 Campus Delivery, Fort Collins, Colorado 80523-1320 (United States); National Science Foundation, Engineering Research Center for Extreme Ultraviolet Science and Technology, Colorado State University, 1320 Campus Delivery, Fort Collins, Colorado 80523-1320 (United States); Dong Feng; Bernstein, Elliot R. [National Science Foundation, Engineering Research Center for Extreme Ultraviolet Science and Technology, Colorado State University, 1320 Campus Delivery, Fort Collins, Colorado 80523-1320 (United States); Department of Chemistry, Colorado State University, 1872 Campus Delivery, Fort Collins, Colorado 80523-1872 (United States)

    2008-07-15

    The reactivity of prospective capping-layer extreme-ultraviolet (EUV) mirror materials with hydrocarbons is studied in the gas phase by use of mass spectroscopy of metal-oxide clusters. We report the results of chemistry studies for Si{sub m}, Ti{sub m}, Hf{sub m}, and Zr{sub m}O{sub n} metal-oxide clusters in which the reaction products were ionized with little or no fragmentation by 26.5 eV photons from a desktop-size 46.9 nm Ne-like Ar laser. Hf and Zr oxides are found to be much less reactive than Si or Ti oxides in the presence of EUV light. The results are relevant to the design of EUV mirror capping layers that are resistant to carbon contamination.

  2. Temporal characterization of a time-compensated monochromator for high-efficiency selection of extreme-ultraviolet pulses generated by high-order harmonics

    SciTech Connect (OSTI)

    Poletto, L.; Villoresi, P.; Benedetti, E.; Ferrari, F.; Stagira, S.; Sansone, G.; Nisoli, M.

    2008-07-15

    Ultrafast extreme-ultraviolet pulses are spectrally selected by a time-delay-compensated grating monochromator. The intrinsic very short duration of the pulses is obtained by exploiting the high-order harmonic generation process. The temporal characterization of the harmonic pulses is obtained using a cross-correlation method: pulses as short as 8 fs are measured at the output of the monochromator in the case of the 23rd harmonic. This value is in agreement with the expected duration of such pulses, indicating that the influence of the monochromator is negligible. The photon flux has been measured with a calibrated photodiode, pointing out the good efficiency of the monochromator, derived by the exploitation for the two gratings of the conical diffraction mounting.

  3. Viscometric Investigation of Intramolecular Hydrogen Bonding Cohesional Entanglement in Extremely Dilute

    E-Print Network [OSTI]

    Wu, Chi

    1997; accepted 2 June 1997 ABSTRACT: An investigation of influence of cryogenic treatment on extremely indicated that the viscosity of the solution is related to N, the times of the freezing and thawing cycle, and the temperature for freezing. Undergoing a treatment of freezing and thawing, the viscosity of the solution

  4. Investigating the effective range of vacuum ultraviolet-mediated breakdown in high-power microwave metamaterials

    SciTech Connect (OSTI)

    Liu, Chien-Hao, E-mail: cliu82@wisc.edu; Neher, Joel D., E-mail: jdneher@wisc.edu; Booske, John H., E-mail: booske@engr.wisc.edu; Behdad, Nader, E-mail: behdad@wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 (United States)

    2014-10-14

    Metamaterials and periodic structures operating under high-power excitations are susceptible to breakdown. It was recently demonstrated that a localized breakdown created in a given region of a periodic structure can facilitate breakdown in other regions of the structure where the intensity of the incident electromagnetic fields may not be high enough to cause breakdown under normal circumstances. It was also demonstrated that this phenomenon is due to the generation of vacuum ultraviolet radiation at the location of the initial discharge, which propagates to the neighboring regions (e.g., other unit cells in a periodic structure) and facilitates the generation of a discharge at a lower incident power level. In this paper, we present the results of an experimental study conducted to determine the effective range of this physical phenomenon for periodic structures that operate in air and in pure nitrogen gas at atmospheric pressure levels. It is demonstrated that when breakdown is induced in a periodic structure using a high-power pulse with a frequency of 9.382 GHz, duration of 0.8 ?s, and peak power level of 25 kW, this phenomenon is highly likely to happen in radii of approximately 16–17 mm from the location of the initial discharge under these test conditions. The results of this study are significant in designing metamaterials and periodic structures for high-power microwave applications as they suggest that a localized discharge created in such a periodic structure with a periodicity less than 16–17 mm can spread over a large surface and result in a distributed discharge.

  5. Space-resolved extreme ultraviolet spectroscopy free of high-energy neutral particle noise in wavelength range of 10–130 Ĺ on the large helical device

    SciTech Connect (OSTI)

    Huang, Xianli; Morita, Shigeru; Oishi, Tetsutarou; Goto, Motoshi; National Institute for Fusion Science, Toki 509-5292 Gifu ; Dong, Chunfeng

    2014-04-15

    A flat-field space-resolved extreme ultraviolet (EUV) spectrometer system working in wavelength range of 10–130 Ĺ has been constructed in the Large Helical Device (LHD) for profile measurements of bremsstrahlung continuum and line emissions of heavy impurities in the central column of plasmas, which are aimed at studies on Z{sub eff} and impurity transport, respectively. Until now, a large amount of spike noise caused by neutral particles with high energies (?180 keV) originating in neutral beam injection has been observed in EUV spectroscopy on LHD. The new system has been developed with an aim to delete such a spike noise from the signal by installing a thin filter which can block the high-energy neutral particles entering the EUV spectrometer. Three filters of 11 ?m thick beryllium (Be), 3.3 ?m thick polypropylene (PP), and 0.5 ?m thick polyethylene terephthalate (PET: polyester) have been examined to eliminate the spike noise. Although the 11 ?m Be and 3.3 ?m PP filters can fully delete the spike noise in wavelength range of ? ? 20 Ĺ, the signal intensity is also reduced. The 0.5 ?m PET filter, on the other hand, can maintain sufficient signal intensity for the measurement and the spike noise remained in the signal is acceptable. As a result, the bremsstrahlung profile is successfully measured without noise at 20 Ĺ even in low-density discharges, e.g., 2.9 × 10{sup 13} cm{sup ?3}, when the 0.5 ?m PET filter is used. The iron n = 3–2 L? transition array consisting of FeXVII to FeXXIV is also excellently observed with their radial profiles in wavelength range of 10–18 Ĺ. Each transition in the L? array can be accurately identified with its radial profile. As a typical example of the method a spectral line at 17.62 Ĺ is identified as FeXVIII transition. Results on absolute intensity calibration of the spectrometer system, pulse height and noise count analyses of the spike noise between holographic and ruled gratings and wavelength response of the used filters are also presented with performance of the present spectrometer system.

  6. SECONDARY WAVES AND/OR THE 'REFLECTION' FROM AND 'TRANSMISSION' THROUGH A CORONAL HOLE OF AN EXTREME ULTRAVIOLET WAVE ASSOCIATED WITH THE 2011 FEBRUARY 15 X2.2 FLARE OBSERVED WITH SDO/AIA AND STEREO/EUVI

    SciTech Connect (OSTI)

    Olmedo, Oscar; Vourlidas, Angelos; Zhang Jie; Cheng Xin

    2012-09-10

    For the first time, the kinematic evolution of a coronal wave over the entire solar surface is studied. Full Sun maps can be made by combining images from the Solar Terrestrial Relations Observatory satellites, Ahead and Behind, and the Solar Dynamics Observatory, thanks to the wide angular separation between them. We study the propagation of a coronal wave, also known as the 'Extreme Ultraviolet Imaging Telescope' wave, and its interaction with a coronal hole (CH) resulting in secondary waves and/or reflection and transmission. We explore the possibility of the wave obeying the law of reflection. In a detailed example, we find that a loop arcade at the CH boundary cascades and oscillates as a result of the extreme ultraviolet (EUV) wave passage and triggers a wave directed eastward that appears to have reflected. We find that the speed of this wave decelerates to an asymptotic value, which is less than half of the primary EUV wave speed. Thanks to the full Sun coverage we are able to determine that part of the primary wave is transmitted through the CH. This is the first observation of its kind. The kinematic measurements of the reflected and transmitted wave tracks are consistent with a fast-mode magnetohydrodynamic wave interpretation. Eventually, all wave tracks decelerate and disappear at a distance. A possible scenario of the whole process is that the wave is initially driven by the expanding coronal mass ejection and subsequently decouples from the driver and then propagates at the local fast-mode speed.

  7. Investigating the observed sensitivities of air-quality extremes to meteorological drivers via quantile regression

    E-Print Network [OSTI]

    Cooley, D.

    Air pollution variability is strongly dependent on meteorology. However, quantifying the impacts of changes in regional climatology on pollution extremes can be difficult due to the many non-linear and competing meteorological ...

  8. Investigating Operating System Noise in Extreme-Scale High-Performance Computing Systems using Simulation

    SciTech Connect (OSTI)

    Engelmann, Christian

    2013-01-01

    Hardware/software co-design for future-generation high-performance computing (HPC) systems aims at closing the gap between the peak capabilities of the hardware and the performance realized by applications (application-architecture performance gap). Performance profiling of architectures and applications is a crucial part of this iterative process. The work in this paper focuses on operating system (OS) noise as an additional factor to be considered for co-design. It represents the first step in including OS noise in HPC hardware/software co-design by adding a noise injection feature to an existing simulation-based co-design toolkit. It reuses an existing abstraction for OS noise with frequency (periodic recurrence) and period (duration of each occurrence) to enhance the processor model of the Extreme-scale Simulator (xSim) with synchronized and random OS noise simulation. The results demonstrate this capability by evaluating the impact of OS noise on MPI_Bcast() and MPI_Reduce() in a simulated future-generation HPC system with 2,097,152 compute nodes.

  9. Investigation of exposure to Extremely Low Frequency (ELF) magnetic and electric fields: Ongoing animal studies

    SciTech Connect (OSTI)

    Anderson, L.E.

    1994-03-01

    There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the nervous system, altered behavioral responses, some of which are related to sensing the presence of the field, and changes in endogenous biological rhythms. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in bone growth and fracture repair, reproduction and development, and immune system function. A major current emphasis in laboratory research is to determine whether or not the reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Three major challenges exist for ongoing research: (1) knowledge about the mechanisms underlying observed bioeffects is incomplete, (2) researchers do not as yet understand what physical aspects of exposure produce biological responses, and (3) health consequences resulting from ELF exposure are unknown. Although no animal studies clearly demonstrate deleterious effects of ELF fields, several are suggestive of potential health impacts. From the perspective of laboratory animal studies, this paper will discuss biological responses to ELF magnetic and/or electric field exposures.

  10. The Extreme Ultraviolet and X-Ray Sun in Time: High-Energy Evolutionary Tracks of a Solar-Like Star

    E-Print Network [OSTI]

    Tu, Lin; Güdel, Manuel; Lammer, Helmut

    2015-01-01

    Aims. We aim to describe the pre-main sequence and main-sequence evolution of X-ray and extreme-ultaviolet radiation of a solar mass star based on its rotational evolution starting with a realistic range of initial rotation rates. Methods. We derive evolutionary tracks of X-ray radiation based on a rotational evolution model for solar mass stars and the rotation-activity relation. We compare these tracks to X-ray luminosity distributions of stars in clusters with different ages. Results. We find agreement between the evolutionary tracks derived from rotation and the X-ray luminosity distributions from observations. Depending on the initial rotation rate, a star might remain at the X-ray saturation level for very different time periods, approximately from 10 Myr to 300 Myr for slow and fast rotators, respectively. Conclusions. Rotational evolution with a spread of initial conditions leads to a particularly wide distribution of possible X-ray luminosities in the age range of 20 to 500 Myrs, before rotational co...

  11. Flows and Non-thermal Velocities in Solar Active Regions Observed with the Extreme-ultraviolet Imaging Spectrometer on Hinode: A Tracer of Active Region Sources of Heliospheric Magnetic Fields?

    E-Print Network [OSTI]

    G. A. Doschek; H. P. Warren; J. T. Mariska; K. Muglach; J. L. Culhane; H. Hara; T Watanabe

    2008-07-17

    From Doppler velocity maps of active regions constructed from spectra obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft we observe large areas of outflow (20-50 km/s) that can persist for at least a day. These outflows occur in areas of active regions that are faint in coronal spectral lines formed at typical quiet Sun and active region temperatures. The outflows are positively correlated with non-thermal velocities in coronal plasmas. The bulk mass motions and non-thermal velocities are derived from spectral line centroids and line widths, mostly from a strong line of Fe XII at 195.12 Angstroms. The electron temperature of the outflow regions estimated from an Fe XIII to Fe XII line intensity ratio is about 1.2-1.4 MK. The electron density of the outflow regions derived from a density sensitive intensity ratio of Fe XII lines is rather low for an active region. Most regions average around 7E10+8 cm(-3), but there are variations on pixel spatial scales of about a factor of 4. We discuss results in detail for two active regions observed by EIS. Images of active regions in line intensity, line width, and line centroid are obtained by rastering the regions. We also discuss data from the active regions obtained from other orbiting spacecraft that support the conclusions obtained from analysis of the EIS spectra. The locations of the flows in the active regions with respect to the longitudinal photospheric magnetic fields suggest that these regions might be tracers of long loops and/or open magnetic fields that extend into the heliosphere, and thus the flows could possibly contribute significantly to the solar wind.

  12. Extreme Ultraviolet Spectroscopy of the Solar Corona

    E-Print Network [OSTI]

    Del Zanna, Giulio

    range of spectroscopic diagnostic tech- niques to determine the temperature distribution, densities a factor of 2 lower than in the quiet sun, with much lower emission measures at temperatures above 106 K been used to infer the temperature structure and the element abundances. The importance of including

  13. Investigating the Influence of Anthropogenic Forcing on Observed Mean and Extreme Sea Level Pressure Trends over the Mediterranean Region

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barkhordarian, Armineh

    2012-01-01

    We investigate whether the observed mean sea level pressure (SLP) trends over the Mediterranean region in the period from 1975 to 2004 are significantly consistent with what 17 models projected as response of SLP to anthropogenic forcing (greenhouse gases and sulphate aerosols, GS). Obtained results indicate that the observed trends in mean SLP cannot be explained by natural (internal) variability. Externally forced changes are detectable in all seasons, except spring. The large-scale component (spatial mean) of the GS signal is detectable in all the 17 models in winter and in 12 of the 17 models in summer. However, the small-scalemore »component (spatial anomalies about the spatial mean) of GS signal is only detectable in winter within 11 of the 17 models. We also show that GS signal has a detectable influence on observed decreasing (increasing) tendency in the frequencies of extremely low (high) SLP days in winter and that these changes cannot be explained by internal climate variability. While the detection of GS forcing is robust in winter and summer, there are striking inconsistencies in autumn, where analysis points to the presence of an external forcing, which is not GS forcing.« less

  14. Investigating nearby star-forming galaxies in the ultraviolet with HST/COS spectroscopy. I. Spectral analysis and interstellar abundance determinations

    SciTech Connect (OSTI)

    James, B. L.; Aloisi, A.; Sohn, S. T.; Wolfe, M. A. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Heckman, T., E-mail: bjames@ast.cam.ac.uk [The Johns Hopkins University, Baltimore, MD 21218 (United States)

    2014-11-10

    This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of nine nearby star-forming galaxies. The goal is to assess the (in)homogeneities of the multiphase ISM in galaxies where the bulk of metals can be hidden in the neutral phase, yet the metallicity is inferred from the ionized gas in the H II regions. The sample, spanning a wide range in physical properties, is to date the best suited to investigate the metallicity behavior of the neutral gas at redshift z = 0. ISM absorption lines were detected against the far-ultraviolet spectra of the brightest star-forming region(s) within each galaxy. Here we report on the observations, data reduction, and analysis of these spectra. Column densities were measured by a multicomponent line-profile fitting technique, and neutral-gas abundances were obtained for a wide range of elements. Several caveats were considered, including line saturation, ionization corrections, and dust depletion. Ionization effects were quantified with ad hoc CLOUDY models reproducing the complex photoionization structure of the ionized and neutral gas surrounding the UV-bright sources. An 'average spectrum of a redshift z = 0 star-forming galaxy' was obtained from the average column densities of unsaturated profiles of neutral-gas species. This template can be used as a powerful tool for studies of the neutral ISM at both low and high redshift.

  15. Reflective optical imaging system for extreme ultraviolet wavelengths

    DOE Patents [OSTI]

    Viswanathan, V.K.; Newnam, B.E.

    1993-05-18

    A projection reflection optical system has two mirrors in a coaxial, four reflection configuration to reproduce the image of an object. The mirrors have spherical reflection surfaces to provide a very high resolution of object feature wavelengths less than 200 [mu]m, and preferably less than 100 [mu]m. An image resolution of features less than 0.05-0.1 [mu]m, is obtained over a large area field; i.e., 25.4 mm [times] 25.4 mm, with a distortion less than 0.1 of the resolution over the image field.

  16. Reflective optical imaging system for extreme ultraviolet wavelengths

    DOE Patents [OSTI]

    Viswanathan, Vriddhachalam K. (Los Alamos, NM); Newnam, Brian E. (Los Alamos, NM)

    1993-01-01

    A projection reflection optical system has two mirrors in a coaxial, four reflection configuration to reproduce the image of an object. The mirrors have spherical reflection surfaces to provide a very high resolution of object feature wavelengths less than 200 .mu.m, and preferably less than 100 .mu.m. An image resolution of features less than 0.05-0.1 .mu.m, is obtained over a large area field; i.e., 25.4 mm .times.25.4 mm, with a distortion less than 0.1 of the resolution over the image field.

  17. PROMINENCE PLASMA DIAGNOSTICS THROUGH EXTREME-ULTRAVIOLET ABSORPTION

    SciTech Connect (OSTI)

    Landi, E.; Reale, F.

    2013-07-20

    In this paper, we introduce a new diagnostic technique that uses EUV and UV absorption to determine the electron temperature and column emission measure, as well as the He/H relative abundance of the absorbing plasma. If a realistic assumption on the geometry of the latter can be made and a spectral code such as CHIANTI is used, then this technique can also yield the absorbing plasma hydrogen and electron density. This technique capitalizes on the absorption properties of hydrogen and helium at different wavelength ranges and temperature regimes. Several cases where this technique can be successfully applied are described. This technique works best when the absorbing plasma is hotter than 15,000 K. We demonstrate this technique on AIA observations of plasma absorption during a coronal mass ejection eruption. This technique can be easily applied to existing observations of prominences and cold plasmas in the Sun from almost all space missions devoted to the study of the solar atmosphere, which we list.

  18. SPECTRUM OF THE EXTREME ULTRAVIOLET NIGHTGLOW AS MEASURED BY EURD

    E-Print Network [OSTI]

    Korpela, Eric J.

    extremo para la Radiaci´on Difusa, a collaboration of the Spanish Instituto Nacional de T to minimize possible contamination of scattered solar radi- ation at these wavelengths. The observations

  19. Type B Accident Investigation Board Report on the June 2002 High Radiation Dose to Extremities in Building 151, Lawrence Livermore National Laboratory

    Broader source: Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by Camille Yuan-Soo Hoo, Manager of the U.S. Department of Energy, Oakland Operations Office.

  20. Ultraviolet selective silicon photodiode 

    E-Print Network [OSTI]

    Chintapalli, Koteswara Rao

    1992-01-01

    (' silicon surfa&(& that n&ost of t h&) phologeneraied hole-el( & tron pairs are k&st by surface rccornbinai ion before being nolle&. trxl hy a pr). jun?i, ion. The major cause of surl'a&. e re?omhination is probably due Io lifetim(. shortening ol' Lhe...Luation degrades by &legr(es during (xposure Io high-cncrgy photo(&s such as in ultraviolet light. The second approa?h is a S&:hottky-b))rricr Iype. ol' photodiodc consisting of a iranspar()nt, thin metal film [I I]. ln I. his d(vi?e, ii, is dif%?ult to a...

  1. Ultraviolet radiation induced discharge laser

    DOE Patents [OSTI]

    Gilson, Verle A. (Livermore, CA); Schriever, Richard L. (Livermore, CA); Shearer, James W. (Livermore, CA)

    1978-01-01

    An ultraviolet 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 ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

  2. Single-crystalline aluminum film for ultraviolet plasmonic nanolasers

    E-Print Network [OSTI]

    Chou, Bo-Tsun; Wu, Yen-Mo; Chung, Yi-Chen; Hsueh, Wei-Jen; Lin, Shih-Wei; Lu, Tien-Chang; Lin, Tzy-Rong; Lin, Sheng-Di

    2015-01-01

    Plasmonic devices have advanced significantly in the past decade. Being one of the most intriguing devices, plamonic nanolasers plays an important role in biomedicine, chemical sensor, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly in ultraviolet regime, are extremely sensitive to metal and interface quality, which renders the development of ultraviolet plasmonics. Here, by addressing the material issues, we demonstrate a low threshold, high characteristic temperature metal-oxide-semiconductor ZnO nanolaser working at room temperature. The template for ZnO nanowires consists of a flat single-crystalline aluminum film grown by molecular beam epitaxy and an ultra-smooth Al2O3 spacer layer prepared by atomic layer deposition. By effectively reducing surface plasmon scattering loss and metal intrinsic absorption loss, the high-quality metal film and sharp interfaces between layers boost the device performance. Our work paves the way for future applicati...

  3. PULSE: The Palomar Ultraviolet Laser for the Study of Exoplanets

    E-Print Network [OSTI]

    Baranec, Christoph; Burruss, Rick S; Bowler, Brendan P; van Dam, Marcos; Riddle, Reed; Shelton, J Christopher; Truong, Tuan; Roberts, Jennifer; Milburn, Jennifer; Tesch, Jonathan

    2014-01-01

    The Palomar Ultraviolet Laser for the Study of Exoplanets (PULSE) will dramatically expand the science reach of PALM-3000, the facility high-contrast extreme adaptive optics system on the 5-meter Hale Telescope. By using an ultraviolet laser to measure the dominant high spatial and temporal order turbulence near the telescope aperture, one can increase the limiting natural guide star magnitude for exquisite correction from mV < 10 to mV < 16. Providing the highest near-infrared Strehl ratios from any large telescope laser adaptive optics system, PULSE uniquely enables spectroscopy of low-mass and more distant young exoplanet systems, essential to formulating a complete picture of exoplanet populations.

  4. Nanowire Ultraviolet Photodetectors and Optical By Hannes Kind, Haoquan Yan, Benjamin Messer,

    E-Print Network [OSTI]

    Yang, Peidong

    of a Nd:YAG laser was used as the UV light source. Neutral density filters were used to change the incident UV light power. It was found that the photoresponse (Ipc) can be expressed by a simple power law is extremely sensitive to ultraviolet light exposure. The light-induced conductivity increase allows us

  5. Impact of externally forced changes on temperature extremes 

    E-Print Network [OSTI]

    Morak, Simone

    2013-07-01

    This thesis investigates changes in temperature extremes between 1950-2005, analysing gridded data sets of observations and climate model simulations. It focuses on changes in the frequency of extreme temperatures occurring ...

  6. Sandia Energy - Extreme Conditions Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Extreme Conditions Modeling Home Stationary Power Energy Conversion Efficiency Water Power Technology Development Extreme Conditions Modeling Extreme Conditions ModelingAshley...

  7. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

    SciTech Connect (OSTI)

    Brown, Peter J., E-mail: pbrown@physics.tamu.edu [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States)

    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.

  8. Ultraviolet Completion of Flavour Models

    E-Print Network [OSTI]

    Ivo de Medeiros Varzielas; Luca Merlo

    2010-11-30

    Effective Flavour Models do not address questions related to the nature of the fundamental renormalisable theory at high energies. We study the ultraviolet completion of Flavour Models, which in general has the advantage of improving the predictivity of the effective models. In order to illustrate the important features we provide minimal completions for two known A4 models. We discuss the phenomenological implications of the explicit completions, such as lepton flavour violating contributions that arise through the exchange of messenger fields.

  9. Wafer chamber having a gas curtain for extreme-UV lithography

    DOE Patents [OSTI]

    Kanouff, Michael P. (Livermore, CA); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2001-01-01

    An EUVL device includes a wafer chamber that is separated from the upstream optics by a barrier having an aperture that is permeable to the inert gas. Maintaining an inert gas curtain in the proximity of a wafer positioned in a chamber of an extreme ultraviolet lithography device can effectively prevent contaminants from reaching the optics in an extreme ultraviolet photolithography device even though solid window filters are not employed between the source of reflected radiation, e.g., the camera, and the wafer. The inert gas removes the contaminants by entrainment.

  10. The dangers of extremes

    E-Print Network [OSTI]

    Donald Marolf

    2010-05-17

    While extreme black hole spacetimes with smooth horizons are known at the level of mathematics, we argue that the horizons of physical extreme black holes are effectively singular. Test particles encounter a singularity the moment they cross the horizon, and only objects with significant back-reaction can fall across a smooth (now non-extreme) horizon. As a result, classical interior solutions for extreme black holes are theoretical fictions that need not be reproduced by any quantum mechanical model. This observation suggests that significant quantum effects might be visible outside extreme or nearly extreme black holes. It also suggests that the microphysics of such black holes may be very different from that of their Schwarzschild cousins.

  11. Mechanical Performance Extreme Conditions

    E-Print Network [OSTI]

    Mechanical Performance ­ Extreme Conditions METALS This project provides property data, metrology information using the image correlation technique. With this instrument, high strain rate mechanical testing

  12. Microgap ultra-violet detector

    DOE Patents [OSTI]

    Wuest, C.R.; Bionta, R.M.

    1994-09-20

    A microgap ultra-violet 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.

  13. Microgap ultra-violet detector

    DOE Patents [OSTI]

    Wuest, Craig R. (Danville, CA); Bionta, Richard M. (Livermore, CA)

    1994-01-01

    A microgap ultra-violet 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.

  14. Extremely Large EUV Late Phase of Solar Flares

    E-Print Network [OSTI]

    Liu, Kai; Zhang, Jie; Cheng, Xin; Liu, Rui; Shen, Chenglong

    2015-01-01

    The second peak in the Fe XVI 33.5 nm line irradiance observed during solar flares by Extreme ultraviolet Variability Experiment (EVE) is known as Extreme UltraViolet (EUV) late phase. Our previous paper (Liu et al. 2013) found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different from the post flare loops (PFLs), and we also proposed that a long cooling process without additional heating could explain the late phase. In this paper, we define the extremely large late phase because it not only has a bigger peak in the warm 33.5 irradiance profile, but also releases more EUV radiative energy than the main phase. Through detailedly inspecting the EUV images from three point-of-view, it is found that, besides the later phase loop arcades, the more contribution of the extremely large late phase is from a hot structure that fails to erupt. This hot structure is identified as a flux rope, which is quickly energized by the flare reconnection...

  15. DETERMINING OPTICAL CONSTANTS OF URANIUM NITRIDE THIN FILMS IN THE EXTREME

    E-Print Network [OSTI]

    Hart, Gus

    deposition and characterization of reactively-sputtered uranium nitride thin films. I also report opticalDETERMINING OPTICAL CONSTANTS OF URANIUM NITRIDE THIN FILMS IN THE EXTREME ULTRAVIOLET (1.6-35 NM.1 Application 1 1.2 Optical Constants 2 1.3 Project Focus 7 2 Uranium Nitride Thin Films 8 2.1 Sputtering 8 2

  16. Onsite Wastewater Treatment Systems: Ultraviolet Light Disinfection 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2008-10-02

    Some onsite wastewater treatment systems include a disinfection component. This publication explains how homeowners can disinfect wastewater with ultraviolet light, what the components of such a system are, what factors affect the performance of a...

  17. Ultraviolet laser calibration of drift chambers

    E-Print Network [OSTI]

    Elliott, Grant (Grant Andrew)

    2006-01-01

    We demonstrate the use of a focused ultraviolet laser as a track calibration source in drift chambers, and specifically in a small time projection chamber (TPC). Drift chambers such as TPCs reconstruct the trajectories of ...

  18. Conference Program Extremism in

    E-Print Network [OSTI]

    Meyers, Steven D.

    Department of History, USF The phenomenal rise of the Islamic State in Iraq and Syria, also known as ISIS, has created a profound national security threat to the United States. However, ISIS is only one aspect of a much broader and important phenomenon in the Islamic world, namely extremism. The purpose

  19. Ultraviolet Behavior of N = 8 supergravity

    SciTech Connect (OSTI)

    Dixon, Lance J.

    2010-06-07

    In these lectures the author describes the remarkable ultraviolet 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 ultraviolet divergences are extracted from the amplitudes.

  20. Extreme Value Theory, Extreme Temperatures, and demonstration of extRemes

    E-Print Network [OSTI]

    Gilleland, Eric

    Center for Atmospheric Research, Boulder, Colorado, U.S.A. http://www.ral.ucar.edu/staff/ericg Third on Extreme Value Analysis (EVA) Motivation Central Limit Theorem Extremal Types Theorem Normal (light tail on Extreme Value Analysis (EVA) Extremal Types Theorem Let X1, . . . , Xn be a sequence of independent

  1. Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

    E-Print Network [OSTI]

    Ahmed, Musahid

    2008-01-01

    Physical Chemistry Vacuum-ultraviolet (VUV) photoionizationPhysical Chemistry Vacuum-ultraviolet (VUV) photoionizationwe report on the vacuum-ultraviolet (VUV) photoionization of

  2. Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

    E-Print Network [OSTI]

    Kostko, Oleg

    2008-01-01

    Vacuum-ultraviolet (VUV) photoionization of small methanolwe report on the vacuum-ultraviolet (VUV) photoionization ofionization with tunable vacuum- ultraviolet synchrotron

  3. ULTRAVIOLET NUMBER COUNTS OF GALAXIES FROM SWIFT ULTRAVIOLET/OPTICAL TELESCOPE DEEP IMAGING OF THE CHANDRA DEEP FIELD SOUTH

    SciTech Connect (OSTI)

    Hoversten, E. A.; Gronwall, C.; Koch, T. S.; Roming, P. W. A.; Siegel, M. H.; Berk, D. E. Vanden; Breeveld, A. A.; Curran, P. A.; Still, M.

    2009-11-10

    Deep Swift UV/Optical Telescope (UVOT) imaging of the Chandra Deep Field South is used to measure galaxy number counts in three near-ultraviolet (NUV) filters (uvw2: 1928 A, uvm2: 2246 A, and uvw1: 2600 A) and the u band (3645 A). UVOT observations cover the break in the slope of the NUV number counts with greater precision than the number counts by the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Galaxy Evolution Explorer, spanning a range 21 approx< m{sub AB} approx< 25. Model number counts confirm earlier investigations in favoring models with an evolving galaxy luminosity function.

  4. QCD in Extreme Environments

    E-Print Network [OSTI]

    John B. Kogut

    2002-08-30

    I review present challenges that QCD in extreme environments presents to lattice gauge theory. Recent data and impressions from RHIC are emphasized. Physical pictures of heavy ion wavefunctions, collisions and the generation of the Quark Gluon Plasma are discussed, with an eye toward engaging the lattice and its numerical methods in more interaction with the experimental and phenomenological developments. Controversial, but stimulating scenarios which can be confirmed or dismissed by lattice methods are covered. In the second half of the talk, several promising developments presented at the conference Lattice 2002 are reviewed.

  5. Surface photoconductivity of organosilicate glass dielectrics induced by vacuum-ultraviolet radiation

    SciTech Connect (OSTI)

    Zheng, H.; Nichols, M. T.; Pei, D.; Shohet, J. L.; Nishi, Y.

    2013-08-14

    The temporary increase in the electrical surface conductivity of low-k organosilicate glass (SiCOH) during exposure to vacuum-ultraviolet radiation (VUV) is investigated. To measure the photoconductivity, patterned “comb structures” are deposited on dielectric films and exposed to synchrotron radiation in the range of 8–25 eV, which is in the energy range of most plasma vacuum-ultraviolet radiation. The change in photo surface conductivity induced by VUV radiation may be beneficial in limiting charging damage of dielectrics by depleting the plasma-deposited charge.

  6. Precipitation extremes under climate change

    E-Print Network [OSTI]

    O'Gorman, Paul A

    2015-01-01

    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to...

  7. High-frequency surface acoustic wave propagation in nanaostructures characterized by coherent extreme ultraviolet beams

    E-Print Network [OSTI]

    Siemens, M.

    2009-01-01

    measurement of surface acoustic waves in thin metal filmsthe generation of surface acoustic waves of high frequency,”and S. M. Cherif, “Surface acoustic waves in the ghz range

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

    Office of Scientific and Technical Information (OSTI)

    Technial Information About OSTI Mission Organization Chart Achievements Alliances OSTI History Feedback DOE STI Program Scientific and Technical Information Program (STIP)...

  9. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell (218 Eastridge Dr., San Ramon, CA 94583-4905); Shafer, David (50 Drake La., Fairfield, CT 06430-2925)

    2001-01-01

    An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle of less than substantially 9.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 .mu.m.

  10. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell (315 Eastridge Dr., San Ramon, CA 94583-4905)

    2001-01-01

    An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first concave mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle of less than substantially 12.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 15.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 7 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 14 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than 16.0 .mu.m.

  11. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell (218 Eastridge Dr., San Ramon, CA 84583-4905)

    2000-01-01

    An all-refelctive optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first concave mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle less than substantially 12.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 15.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 7 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 14 .mu.m. Each of the six refelecting surfaces has an aspheric departure of less than 16.0 .mu.m.

  12. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell (218 Eastridge Dr., San Ramon, CA 94583-4905); Shafer, David R. (56 Drake La., Fairfield, CT 06430-2925)

    2001-01-01

    An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receive a chief ray at an incidence angle of less than substantially 9.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 .mu.m.

  13. Time dependent changes in extreme ultraviolet reflectivity of Ru mirrors from electron-induced surface chemistry

    E-Print Network [OSTI]

    Harilal, S. S.

    dissociation of residual hydrocarbons plays a dominant role in the presence of additional PEs, and thus reduces degradation.2 In fact, radiation induced carbon contamination and surface oxidation have been shown to drive that the adsorption and subsequent EUV-induced dissociation of water molecules on Ru surface affect mirror performance

  14. Hollow laser self-confined plasma for extreme ultraviolet lithography and other applications

    E-Print Network [OSTI]

    Harilal, S. S.

    low ~about 4%!, stacked multilayers, of which the reflection adds up, are used or bent crystals which

  15. Efficient laser-produced plasma extreme ultraviolet sources using grooved Sn targets

    E-Print Network [OSTI]

    Harilal, S. S.

    is to have a reliable, clean, and powerful light source at a wavelength near 13.5 nm. A laser-produced plasma A suitable LPP source will require a high conversion efficiency CE of the incident laser pulse energy to EUV-band CE is imperative, as this reduces the costs of production and own- ership for EUVL light source

  16. Ultrafast Strong-Field Vibrational Dynamics Studied by Femtosecond Extreme-Ultraviolet Transient Absorption Spectroscopy

    E-Print Network [OSTI]

    Hosler, Erik Robert

    2013-01-01

    Expansion of this technique to the attosecond regime may facilitate detection of correlated electronic and nuclear

  17. Ultrafast Strong-Field Vibrational Dynamics Studied by Femtosecond Extreme-Ultraviolet Transient Absorption Spectroscopy

    E-Print Network [OSTI]

    Hosler, Erik Robert

    2013-01-01

    dynamics. Tunnel ionization rate determinations are employed to model the pump, while electronic structure calculations

  18. Extreme-ultraviolet radiation transport in small scale length laser-produced tin plasmas

    E-Print Network [OSTI]

    Sequoia, Kevin Lamar Williams

    2009-01-01

    radiation heated sio2 aerogel plasma in "dog-bone" targetsspectra from Ti-doped aerogels. Journal of Quantitative

  19. Time-resolved visible and extreme ultraviolet spectroscopy of laser-produced tin plasma

    E-Print Network [OSTI]

    O'Shay, Joseph Fred

    2007-01-01

    application to inertial confinement fusion (ICF) [1], x-rayplasma [92 – 94], inertial confinement fusion [95], andconfinement of an expanding laser-produced plasma," Inertial Fusion

  20. Extreme-ultraviolet radiation transport in small scale length laser-produced tin plasmas

    E-Print Network [OSTI]

    Sequoia, Kevin Lamar Williams

    2009-01-01

    drive approach to inertial confinement fusion and the targetthe study of inertial confinement fusion [12, 13], soft X-

  1. Mitigation of fast ions from laser-produced Sn plasma for an extreme ultraviolet lithography source

    E-Print Network [OSTI]

    Tillack, Mark

    of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0438 and the Center for Energy Research of the reduction of fast ion energy from laser-produced Sn plasma by introducing a low energy prepulse. The energy candidates. Because of the availability of optics, most of the efforts focus on in-band 2% bandwidth 13.5 nm

  2. Mass-limited Sn target irradiated by dual laser pulses for an extreme ultraviolet lithography source

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    . However, at present, because of the high cost of the driving laser, the output power of the EUV light, and stable target supply is the key factor for lowering the critical requirements of the driving la- ser debris re- quires additional innovations for application to the practical EUV light source for HVM

  3. Enhancing extreme ultraviolet photons emission in laser produced plasmas for advanced lithography

    E-Print Network [OSTI]

    Harilal, S. S.

    subjected to laser beam energy with different intensities and laser wavelength to dual-beam lasers, i of vapor expansion rate, which can be produced as a result of droplet heating by pre-pulse laser energy, and the remaining part of the laser heats the plasma instead of inter- acting with the target. For obtaining

  4. Extreme ultraviolet laser-based table-top aerial image metrology of lithographic masks

    E-Print Network [OSTI]

    Rocca, Jorge J.

    masks," in 22nd Annual BACUS Symposium on Photomask Techology, (proceedings of SPIE, 2002), 0277­0786X

  5. Charge Carrier Dynamics in Transition Metal Oxides Studied by Femtosecond Transient Extreme Ultraviolet Absorption Spectroscopy

    E-Print Network [OSTI]

    Jiang, Chang-Ming

    2015-01-01

    Fabricated by Atomic Layer Deposition. Nanotechnology 2010,2 Nanotube Arrays via Atomic Layer Deposition for Improvedsputtering or atomic layer deposition technique to prepare

  6. UBIQUITOUS ROTATING NETWORK MAGNETIC FIELDS AND EXTREME-ULTRAVIOLET CYCLONES IN THE QUIET SUN

    SciTech Connect (OSTI)

    Zhang Jun; Liu Yang E-mail: yliu@sun.stanford.edu

    2011-11-01

    We present Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) observations of EUV cyclones in the quiet Sun. These cyclones are rooted in the rotating network magnetic fields (RNFs). Such cyclones can last several to more than 10 hr and, at the later phase, they are found to be associated with EUV brightenings (microflares) and even EUV waves. SDO Helioseismic and Magnetic Imager (HMI) observations show a ubiquitous presence of RNFs. Using HMI line-of-sight magnetograms on 2010 July 8, we find 388 RNFs in an area of 800 x 980 arcsec{sup 2} near the disk center where no active region is present. The sense of rotation shows a weak hemisphere preference. The unsigned magnetic flux of the RNFs is about 4.0 x 10{sup 21} Mx, or 78% of the total network flux. These observational phenomena at small scale reported in this Letter are consistent with those at large scale in active regions. The ubiquitous RNFs and EUV cyclones over the quiet Sun may suggest an effective way to heat the corona.

  7. Nanometer-scale ablation using focused, coherent extreme ultraviolet/soft x-ray light

    DOE Patents [OSTI]

    Menoni, Carmen S. (Fort Collins, CO); Rocca, Jorge J. (Fort Collins, CO); Vaschenko, Georgiy (San Diego, CA); Bloom, Scott (Encinitas, CA); Anderson, Erik H. (El Cerrito, CA); Chao, Weilun (El Cerrito, CA); Hemberg, Oscar (Stockholm, SE)

    2011-04-26

    Ablation of holes having diameters as small as 82 nm and having clean walls was obtained in a poly(methyl methacrylate) on a silicon substrate by focusing pulses from a Ne-like Ar, 46.9 nm wavelength, capillary-discharge laser using a freestanding Fresnel zone plate diffracting into third order is described. Spectroscopic analysis of light from the ablation has also been performed. These results demonstrate the use of focused coherent EUV/SXR light for the direct nanoscale patterning of materials.

  8. High resolution coherent diffractive imaging with a table-top extreme ultraviolet source

    SciTech Connect (OSTI)

    Vu Le, Hoang, E-mail: vuhoangle@swin.edu.au; Ba Dinh, Khuong; Hannaford, Peter; Van Dao, Lap [Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne 3122 (Australia)

    2014-11-07

    We demonstrate a resolution of 45?nm with a sample size down to 3??m × 3??m is achieved in a short exposure time of 2?s, from the diffraction pattern generated by a table-top high harmonic source at around 30?nm. By using a narrow-bandwidth focusing mirror, the diffraction pattern's quality is improved and the required exposure time is significantly reduced. In order to obtain a high quality of the reconstructed image, the ratio of the beam size to the sample size and the curvature of the focused beam need to be considered in the reconstruction process. This new experimental scheme is very promising for imaging sub-10?nm scale objects with a table-top source based on a small inexpensive femtosecond laser system.

  9. Extreme ultraviolet spectra of highly ionized Ge, Kr and Mo emitted by imploding plasmas

    SciTech Connect (OSTI)

    Goldsmith, S.; Feldman, U.; Cohen, L.; Behring, W.E.

    1984-01-01

    Spectra of highly ionized Ge, Kr and Mo in the spectral region of 10 to 80A were excited in laser-produced plasmas. The plasma was obtained by focusing the energy of the 24 laser beams of the University of Rochester Omega system on 0.4 mm diameter microballoon targets. The laser pulse duration was in the range of 0.87 to 1.09 ns, with total energy in the range of 1.8 to 2.2 kJ. The observed spectral lines include n = 2-2 transitions in the oxygen and fluorine isoelectronic sequences and n = 3 to 4 transitions in the sodium, magnesium and aluminum isoelectronic sequences. The present observations are compared with previous experimental and theoretical studies.

  10. Near-normal-incidence extreme-ultraviolet efficiency of a flat crystalline anisotropically etched blazed grating

    E-Print Network [OSTI]

    designs for high- resolution EUV spectroscopy in astrophysics where high efficiency in high orders produce more scattered light. Second, deviations in the groove profile from an ideal shape cause power.kowalski@nrl.navy.mil) is with the U.S. Naval Research Laboratory, Code 7655.3, 4555 Overlook Avenue, SW, Washington, D.C. 20375. R. K

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

    SciTech Connect (OSTI)

    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 Ĺ. 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.

  12. Ultraviolet-light-induced transformation of human primary cells

    SciTech Connect (OSTI)

    Sutherland, B.M.

    1981-01-01

    The development of model systems for probing the ultraviolet radiation induced oncogenic transformation of human skin cells is described. (ACR)

  13. Ultraviolet emissions from Gd3 + ions excited by energy transfer

    E-Print Network [OSTI]

    Cao, Wenwu

    Ultraviolet emissions from Gd3 + ions excited by energy transfer from Ho3 + ions Ying Yu October 2010 Accepted 28 October 2010 Available online 4 November 2010 Keywords: Ultraviolet emission Upconversion Energy transfer a b s t r a c t Ultraviolet (UV) upconversion (UC) emissions of Gd3+ ion were

  14. The Extreme Physics Explorer

    E-Print Network [OSTI]

    Martin Elvis

    2006-08-25

    Some tests of fundamental physics - the equation of state at supra-nuclear densities, the metric in strong gravity, the effect of magnetic fields above the quantum critical value - can only be measured using compact astrophysical objects: neutron stars and black holes. The Extreme Physics Explorer is a modest sized (~500 kg) mission that would carry a high resolution (R ~300) X-ray spectrometer and a sensitive X-ray polarimeter, both with high time resolution (~5 ?s) capability, at the focus of a large area (~5 sq.m), low resolution (HPD~1 arcmin) X-ray mirror. This instrumentation would enable new classes of tests of fundamental physics using neutron stars and black holes as cosmic laboratories.

  15. Microwave-driven ultraviolet light sources

    DOE Patents [OSTI]

    Manos, Dennis M. (Williamsburg, VA); Diggs, Jessie (Norfolk, VA); Ametepe, Joseph D. (Roanoke, VA)

    2002-01-29

    A microwave-driven ultraviolet (UV) light source is provided. The light source comprises an over-moded microwave cavity having at least one discharge bulb disposed within the microwave cavity. At least one magnetron probe is coupled directly to the microwave cavity.

  16. Bipolar charging of dust particles under ultraviolet radiation

    SciTech Connect (OSTI)

    Filippov, A. V. Babichev, V. N.; Fortov, V. E.; Gavrikov, A. V.; Pal', A. F.; Petrov, O. F.; Starostin, A. N.; Sarkarov, N. E.

    2011-05-15

    The photoemission charging of dust particles under ultraviolet radiation from a xenon lamp has been investigated. The velocities of yttrium dust particles with a work function of 3.3 eV and their charges have been determined experimentally; the latter are about 400-500 and about 100 elementary charges per micron of radius for the positively and negatively charged fractions, respectively. The dust particle charging and the dust cloud evolution in a photoemission cell after exposure to an ultraviolet radiation source under the applied voltage have been simulated numerically. The photoemission charging of dust particles has been calculated on the basis of nonlocal and local charging models. Only unipolar particle charging is shown to take place in a system of polydisperse dust particles with the same photoemission efficiency. It has been established that bipolar charging is possible in the case of monodisperse particles with different quantum efficiencies. Polydispersity in this case facilitates the appearance of oppositely charged particles in a photoemission plasma.

  17. Viability of Cladosporium herbarum spores under 157 nm laser and vacuum ultraviolet irradiation, low temperature (10 K) and vacuum

    SciTech Connect (OSTI)

    Sarantopoulou, E. Stefi, A.; Kollia, Z.; Palles, D.; Cefalas, A. C.; Petrou, P. S.; Bourkoula, A.; Koukouvinos, G.; Kakabakos, S.; Velentzas, A. D.

    2014-09-14

    Ultraviolet photons can damage microorganisms, which rarely survive prolonged irradiation. In addition to the need for intact DNA, cell viability is directly linked to the functionality of the cell wall and membrane. In this work, Cladosporium herbarum spore monolayers exhibit high viability (7%) when exposed to 157 nm laser irradiation (412 kJm?˛) or vacuum-ultraviolet irradiation (110–180 nm) under standard pressure and temperature in a nitrogen atmosphere. Spore viability can be determined by atomic-force microscopy, nano-indentation, mass, ?-Raman and attenuated reflectance Fourier-transform far-infrared spectroscopies and DNA electrophoresis. Vacuum ultraviolet photons cause molecular damage to the cell wall, but radiation resistance in spores arises from the activation of a photon-triggered signaling reaction, expressed via the exudation of intracellular substances, which, in combination with the low penetration depth of vacuum-ultraviolet photons, shields DNA from radiation. Resistance to phototoxicity under standard conditions was assessed, as was resistance to additional environmental stresses, including exposure in a vacuum, under different rates of change of pressure during pumping time and low (10 K) temperatures. Vacuum conditions were far more destructive to spores than vacuum-ultraviolet irradiation, and UV-B photons were two orders of magnitude more damaging than vacuum-ultraviolet photons. The viability of irradiated spores was also enhanced at 10 K. This work, in addition to contributing to the photonic control of the viability of microorganisms exposed under extreme conditions, including decontamination of biological warfare agents, outlines the basis for identifying bio-signaling in vivo using physical methodologies.

  18. Extreme hydrodynamic atmospheric loss near the critical thermal escape regime

    E-Print Network [OSTI]

    Erkaev, N V; Odert, P; Kulikov, Yu N; Kislyakova, K G

    2015-01-01

    By considering martian-like planetary embryos inside the habitable zone of solar-like stars we study the behavior of the hydrodynamic atmospheric escape of hydrogen for small values of the Jeans escape parameter $\\beta thermal energy. Our study is based on a 1-D hydrodynamic upper atmosphere model that calculates the volume heating rate in a hydrogen dominated thermosphere due to the absorption of the stellar soft X-ray and extreme ultraviolet (XUV) flux. We find that when the $\\beta$ value near the mesopause/homopause level exceeds a critical value of $\\sim$2.5, there exists a steady hydrodynamic solution with a smooth transition from subsonic to supersonic flow. For a fixed XUV flux, the escape rate of the upper atmosphere is an increasing function of the temperature at the lower boundary. Our model results indicate a crucial enhancement of the atmospheric escape rate, when the Jeans escape parameter $\\beta$ decr...

  19. A reflective optical transport system for ultraviolet Thomson...

    Office of Scientific and Technical Information (OSTI)

    A reflective optical transport system for ultraviolet Thomson scattering from electron plasma waves on OMEGA Citation Details In-Document Search Title: A reflective optical...

  20. Vacuum-ultraviolet photoreduction of graphene oxide: Electrical...

    Office of Scientific and Technical Information (OSTI)

    Vacuum-ultraviolet photoreduction of graphene oxide: Electrical conductivity of entirely reduced single sheets and reduced micro line patterns Citation Details In-Document Search...

  1. Lyalpha EMITTERS IN HIERARCHICAL GALAXY FORMATION. II. ULTRAVIOLET...

    Office of Scientific and Technical Information (OSTI)

    Lyalpha EMITTERS IN HIERARCHICAL GALAXY FORMATION. II. ULTRAVIOLET CONTINUUM LUMINOSITY FUNCTION AND EQUIVALENT WIDTH DISTRIBUTION Citation Details In-Document Search Title:...

  2. Multivariate Extremes Dependence Comparison Stochastic Tail Order Back to Multivariate Extremes Dependence Comparison of Multivariate

    E-Print Network [OSTI]

    Li, Haijun

    Multivariate Extremes Dependence Comparison Stochastic Tail Order Back to Multivariate Extremes Dependence Comparison of Multivariate Extremes Haijun Li Department of Mathematics Washington State University IWAP12, Jerusalem Haijun Li Dependence Comparison of Multivariate Extremes IWAP12, Jerusalem 1

  3. Ultraviolet Resonant Raman Enhancements in the Detection of Explosives

    SciTech Connect (OSTI)

    Short, B J; Carter, J C; Gunter, D; Hovland, P; Jagode, H; Karavanic, K; Marin, G; Mellor-Crummey, J; Moore, S; Norris, B; Oliker, L; Olschanowsky, C; Roth, P C; Schulz, M; Shende, S; Snavely, A; Spear, W

    2009-06-03

    Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (non-resonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, however, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided {approx}2000-fold enhancement at 244 nm and {approx}800-fold improvement at 229 nm while PETN showed a maximum of {approx}25-fold at 244 nm and {approx}190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as !4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

  4. Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of methylcyclohexane in the supersonic jet

    E-Print Network [OSTI]

    Kim, Sang Kyu

    Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of methylcyclohexane t Vacuum ultraviolet (VUV) mass-analyzed threshold ionization (MATI) spectrum of supersonically cooled the vacuum ultraviolet (VUV) laser source is particu- larly useful for molecular systems with no stable

  5. THE LONGITUDINAL PROPERTIES OF A SOLAR ENERGETIC PARTICLE EVENT INVESTIGATED USING MODERN SOLAR IMAGING

    SciTech Connect (OSTI)

    Rouillard, A. P.; Sheeley, N. R.; Tylka, A.; Vourlidas, A.; Rakowski, C.; Ng, C. K.; Cohen, C. M. S.; Mewaldt, R. A.; Mason, G. M.; Reames, D.; Savani, N. P.; StCyr, O. C.; Szabo, A.

    2012-06-10

    We use combined high-cadence, high-resolution, and multi-point imaging by the Solar-Terrestrial Relations Observatory (STEREO) and the Solar and Heliospheric Observatory to investigate the hour-long eruption of a fast and wide coronal mass ejection (CME) on 2011 March 21 when the twin STEREO spacecraft were located beyond the solar limbs. We analyze the relation between the eruption of the CME, the evolution of an Extreme Ultraviolet (EUV) wave, and the onset of a solar energetic particle (SEP) event measured in situ by the STEREO and near-Earth orbiting spacecraft. Combined ultraviolet and white-light images of the lower corona reveal that in an initial CME lateral 'expansion phase', the EUV disturbance tracks the laterally expanding flanks of the CME, both moving parallel to the solar surface with speeds of {approx}450 km s{sup -1}. When the lateral expansion of the ejecta ceases, the EUV disturbance carries on propagating parallel to the solar surface but devolves rapidly into a less coherent structure. Multi-point tracking of the CME leading edge and the effects of the launched compression waves (e.g., pushed streamers) give anti-sunward speeds that initially exceed 900 km s{sup -1} at all measured position angles. We combine our analysis of ultraviolet and white-light images with a comprehensive study of the velocity dispersion of energetic particles measured in situ by particle detectors located at STEREO-A (STA) and first Lagrange point (L1), to demonstrate that the delayed solar particle release times at STA and L1 are consistent with the time required (30-40 minutes) for the CME to perturb the corona over a wide range of longitudes. This study finds an association between the longitudinal extent of the perturbed corona (in EUV and white light) and the longitudinal extent of the SEP event in the heliosphere.

  6. Windmills and extreme 2-cells

    E-Print Network [OSTI]

    McCammond, Jon

    2009-01-01

    In this article we prove new results about the existence of 2-cells in disc diagrams which are extreme in the sense that they are attached to the rest of the diagram along a small connected portion of their boundary cycle. In particular, we establish conditions on a 2-complex X which imply that all minimal area disc diagrams over X with reduced boundary cycles have extreme 2-cells in this sense. The existence of extreme 2-cells in disc diagrams over these complexes leads to new results on coherence using the perimeter-reduction techniques we developed in an earlier article. Recall that a group is called coherent if all of its finitely generated subgroups are finitely presented. We illustrate this approach by showing that several classes of one-relator groups, small cancellation groups and groups with staggered presentations are collections of coherent groups.

  7. Polaritonic-to-Plasmonic Transition in Optically Resonant Bismuth Nanospheres for High-Contrast Switchable Ultraviolet Meta-Filters

    E-Print Network [OSTI]

    Cuadrado, Alexander; Serna, Rosalia

    2015-01-01

    In the quest aimed at unveiling alternative plasmonic elements overcoming noble metals for selected applications in photonics, we investigate by numerical simulations the near ultraviolet-to-near infrared optical response of solid and liquid Bi nanospheres embedded in a dielectric matrix. We also determine the resulting transmission contrast upon reversible solid-liquid phase transition to evaluate their potential for switchable optical filtering. The optical response of the solid (liquid) Bi nanospheres is ruled by localized polaritonic (plasmonic) resonances tunable by controlling the diameter. For a selected diameter between 20 nm and 50 nm, both solid and liquid nanospheres present a dipolar resonance inducing a strong peak extinction in the near ultraviolet, however at different photon energies. This enables a high transmission contrast at selected near ultraviolet photon energies. It is estimated that a two-dimensional assembly of 20 nm solid Bi nanospheres with a surface coverage of 28% will totally ex...

  8. Ultraviolet laser beam monitor using radiation responsive crystals

    DOE Patents [OSTI]

    McCann, Michael P. (Oliver Springs, TN); Chen, Chung H. (Knoxville, TN)

    1988-01-01

    An apparatus and method for monitoring an ultraviolet laser beam includes disposing in the path of an ultraviolet laser beam a substantially transparent crystal that will produce a color pattern in response to ultraviolet radiation. The crystal is exposed to the ultraviolet laser beam and a color pattern is produced within the crystal corresponding to the laser beam intensity distribution therein. The crystal is then exposed to visible light, and the color pattern is observed by means of the visible light to determine the characteristics of the laser beam that passed through crystal. In this manner, a perpendicular cross sectional intensity profile and a longitudinal intensity profile of the ultraviolet laser beam may be determined. The observation of the color pattern may be made with forward or back scattered light and may be made with the naked eye or with optical systems such as microscopes and television cameras.

  9. The Extremes Toolkit (extRemes) Weather and Climate Applications

    E-Print Network [OSTI]

    Gilleland, Eric

    · R is a language and environment for statistical computing and graphics. · It's Free! · Curiously with a high-level language capable of advanced statistical applications. · Available to a wide audience (not for Statistical Computing extRemes is written in and requires R, but does not require familiarity with R. About R

  10. Extreme Conditions Modeling Workshop Report

    SciTech Connect (OSTI)

    Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

  11. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  12. Extremophiles Microbial Life Under Extreme

    E-Print Network [OSTI]

    Benning, Liane G.

    were constructed from water-saturated precipitates from each site resulting in a total of 342 bacterial very low (no OTUs could be detected) to medium (9 OTUs) microbial activity. The most dominant Geothermal water Á Silica sinter Introduction Amongst terrestrial extreme environments, geothermal hot

  13. 1, 255285, 2005 Extreme climates

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , orography, and oceanic heat transport on extreme climates V. Romanova 1 , G. Lohmann 2,1 , and K. Grosfeld 2 to assess the possibility that land albedo, atmospheric CO2, orography and oceanic heat transport may cause5-covered Earth is the high land albedo in combination with initial temperatures set equal to the freezing point

  14. Extremal Higher Spin Black Holes

    E-Print Network [OSTI]

    Máximo Bańados; Alejandra Castro; Alberto Faraggi; Juan I. Jottar

    2015-11-30

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require nor implies the existence of supersymmetry, we exemplify its consequences in the context of sl(3|2) + sl(3|2) Chern-Simons theory. Remarkably, while as usual not all extremal solutions preserve supersymmetries, we find that the higher spin setup allows for non-extremal supersymmetric black hole solutions as well. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) + sl(3|2) Chern-Simons theory and two-dimensional CFTs with W_{(3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W_{(3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.

  15. Extremism

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street Lighting HostDISCLAIMERlinacSYNCHROTRONi

  16. Laser Makes New Shade of Ultraviolet (COSMIC Log on MSNBC.com...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cosmiclog.nbcnews.comnews201012285725603-laser-makes-new-shade-of-ultraviolet Submitted: Wednesday, December 29...

  17. New strategies for an extremely large telescope dedicated to extremely high contrast: The Colossus Project**

    E-Print Network [OSTI]

    Berdyugina, Svetlana

    New strategies for an extremely large telescope dedicated to extremely high contrast: The Colossus and adaptive optics and cophasing for the designing and for building such dedicated to extremely high contrast

  18. Coherent light scattering of ultraviolet light by avian feather barbs

    E-Print Network [OSTI]

    Prum, Richard O.; Andersson, Staffan; Torres, Rodolfo H.

    2003-04-05

    Ultraviolet (UV) structural colors of avian feathers are produced by the spongy medullary keratin of feather barbs, but various physical mechanisms have been hypothesized to produce those colors, including Rayleigh scattering, Mie scattering...

  19. Reduction of turkey hatching egg shell contamination with ultraviolet irradiation 

    E-Print Network [OSTI]

    Russo, Rebecca Ann

    2001-01-01

    The effects of ultraviolet light (UV) at 254 nm on indigenous eggshell surface aerobic bacteria, Salmonella, Escherichia coli, gram positive bacteria as well as inoculated Salmonella typhimurium chicken and E. coli O157:H7 were evaluated. Various...

  20. Subcutaneous and cutaneous melanins in Rhabdomys: complementary ultraviolet radiation shields

    E-Print Network [OSTI]

    Timm, Robert M.; Kermott, L. Henry

    1982-02-01

    We describe the pigmented tissue layer covering the skull of Rhabdomys pumilio and test the hypotheses that it is melanin and that it functions in absorption of ultraviolet solar radiation. The parietals were covered by a dark tissue layer...

  1. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    SciTech Connect (OSTI)

    Shin, Joong-Won, E-mail: jshin@govst.edu [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States) [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States); Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States); Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ?}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  2. Intense ultraviolet perturbations on aquatic primary producers

    E-Print Network [OSTI]

    Guimarais, Mayrene; Horvath, Jorge

    2010-01-01

    During the last decade, the hypothesis that one or more biodiversity drops in the Phanerozoic eon, evident in the geological record, might have been caused by the most powerful kind of stellar explosion so far known (Gamma Ray Bursts) has been discussed in several works. These stellar explosions could have left an imprint in the biological evolution on Earth and in other habitable planets. In this work we calculate the short-term lethality that a GRB would produce in the aquatic primary producers on Earth. This effect on life appears as a result of ultraviolet (UV) re-transmission in the atmosphere of a fraction of the gamma energy, resulting in an intense UV flash capable of penetrating ~ tens of meters in the water column in the ocean. We focus on the action of the UV flash on phytoplankton, as they are the main contributors to global aquatic primary productivity. Our results suggest that the UV flash could cause an hemispheric reduction of phytoplankton biomass in the upper mixed layer of the World Ocean o...

  3. Extreme Conditions Modeling Workshop Report

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvan Racah Evan-5 BeamlineGE,ExtracellularMoleculeExtreme

  4. Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

    SciTech Connect (OSTI)

    Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min; Lapidus, Alla; Copeland, Alex; Kim, Edwin; Land, Miriam; Mavrommatis, Konstantinos; Pitluck, Samuel; Richardson, Paul M.; Detter, Chris; Brettin, Thomas; Saunders, Elizabeth; Lai, Barry; Ravel, Bruce; Kemner, Kenneth M.; Wolf, Yuri I.; Sorokin, Alexander; Gerasimova, Anna V.; Gelfand, Mikhail S.; Fredrickson, James K.; Koonin, Eugene V.; Daly, Michael J.

    2007-07-24

    Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at itsoptimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to resistance; and strengthen the case for a role in survival of systems involved in manganese and iron homeostasis.

  5. Extreme hydro-meteorological events and their probabilities

    E-Print Network [OSTI]

    Beersma, Jules

    Extreme hydro-meteorological events and their probabilities Jules Beersma #12;Promotor: Prof. dr. A Onderzoekschool (BBOS) #12;Extreme hydro-meteorological events and their probabilities Extreme hydro

  6. Characterization of extreme precipitation within atmospheric river events over California

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jeon, S.; Prabhat,; Byna, S.; Gu, J.; Collins, W. D.; Wehner, M. F.

    2015-11-17

    Atmospheric rivers (ARs) are large, spatially coherent weather systems with high concentrations of elevated water vapor. These systems often cause severe downpours and flooding over the western coastal United States – and with the availability of more atmospheric moisture in the future under global warming we expect ARs to play an important role as potential causes of extreme precipitation changes. Therefore, we aim to investigate changes in extreme precipitation properties correlated with AR events in a warmer climate, which are large-scale meteorological patterns affecting the weather and climate of California. We have recently developed the TECA (Toolkit for Extrememore »Climate Analysis) software for automatically identifying and tracking features in climate data sets. Specifically, we can now identify ARs that make landfall on the western coast of North America. Based on this detection procedure, we can investigate the impact of ARs by exploring the spatial extent of AR precipitation using climate model (CMIP5) simulations and characterize spatial patterns of dependence for future projections between AR precipitation extremes under climate change within the statistical framework. Our results show that AR events in the future RCP (Representative Concentration Pathway)8.5 scenario (2076–2100) tend to produce heavier rainfall with higher frequency and longer days than events from the historical run (1981–2005). We also find that the dependence between extreme precipitation events has a shorter spatial range, within localized areas in California, under the high future emissions scenario than under the historical run.« less

  7. Extreme luminosity imaging conical spectrograph

    SciTech Connect (OSTI)

    Pikuz, S. A.; Shelkovenko, T. A.; Mitchell, M. D.; Chandler, K. M.; Douglass, J. D.; McBride, R. D.; Jackson, D. P.; Hammer, D. A.

    2006-10-15

    A new configuration for a two-dimensional (2D) imaging x-ray spectrograph based on a conically bent crystal is introduced: extreme luminosity imaging conical spectrograph (ELICS). The ELICS configuration has important advantages over spectrographs that are based on cylindrically and spherically bent crystals. The main advantages are that a wide variety of large-aperture crystals can be used, and any desired magnification in the spatial direction (the direction orthogonal to spectral dispersion) can be achieved by the use of different experimental arrangements. The ELICS can be set up so that the detector plane is almost perpendicular to the incident rays, a good configuration for time-resolved spectroscopy. ELICSs with mica crystals of 45x90 mm{sup 2} aperture have been successfully used for imaging on the XP and COBRA pulsed power generators, yielding spectra with spatial resolution in 2D of Z pinches and X pinches.

  8. Intensification of precipitation extremes with warming in a cloud resolving model

    E-Print Network [OSTI]

    Muller, Caroline

    A cloud-resolving model is used to investigate the effect of warming on high percentiles of precipitation (precipitation extremes) in the idealized setting of radiative-convective equilibrium. While this idealized setting ...

  9. The Near-Ultraviolet Continuum of Late-Type Stars

    E-Print Network [OSTI]

    Carlos Allende Prieto; David L. Lambert

    2000-01-28

    Analyses of the near-ultraviolet continuum of late-type stars have led to controversial results regarding the performance of state-of-the-art model atmospheres. The release of the homogeneous IUE final archive and the availability of the high-accuracy Hipparcos parallaxes provide an opportunity to revisit this issue, as accurate stellar distances make it possible to compare observed absolute fluxes with the predictions of model atmospheres. The near-UV continuum is highly sensitive to Teff and [Fe/H], and once the gravity is constrained from the parallax, these parameters may be derived from the analysis of low-dispersion "long-wavelength" (2000-3000 A) IUE spectra for stars previously studied by Alonso et al. (1996; A&AS 117, 227) using the Infrared Flux Method (IRFM). A second comparison is carried out against the stars spectroscopically investigated by Gratton et al. (1996; A&A 314, 191). It is shown that there is a good agreement between Teffs obtained from the IRFM and from the near-UV continuum, and a remarkable correspondence between observed and synthetic fluxes for stars with 4000 <= Teff <= 6000 K of any metallicity and gravity. These facts suggest that model atmospheres provide an adequate description of the near-UV continuum forming region and that the opacities involved are essentially understood. For cooler stars, the results of the IRFM are no longer reliable, as shown by Alonso et al., but the discrepancy noticed for stars hotter than 6000 K may reflect problems in the model atmospheres and/or the opacities at these higher temperatures.

  10. CHARACTERIZING ULTRAVIOLET AND INFRARED OBSERVATIONAL PROPERTIES FOR GALAXIES. I. INFLUENCES OF DUST ATTENUATION AND STELLAR POPULATION AGE

    SciTech Connect (OSTI)

    Mao Yewei; Kong Xu [Center for Astrophysics, University of Science and Technology of China, Hefei 230026 (China); Kennicutt, Robert C. Jr. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Hao, Cai-Na [Tianjin Astrophysics Center, Tianjin Normal University, Tianjin 300387 (China); Zhou Xu, E-mail: owen81@mail.ustc.edu.cn, E-mail: xkong@ustc.edu.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2012-09-20

    The correlation between infrared-to-ultraviolet luminosity ratio and ultraviolet color (or ultraviolet spectral slope), i.e., the IRX-UV (or IRX-{beta}) relation, found in studies of starburst galaxies is a prevalent recipe for correcting extragalactic dust attenuation. Considerable dispersion in this relation discovered for normal galaxies, however, complicates its usability. In order to investigate the cause of the dispersion and to have a better understanding of the nature of the IRX-UV relation, in this paper, we select five nearby spiral galaxies, and perform spatially resolved studies on each of the galaxies, with a combination of ultraviolet and infrared imaging data. We measure all positions within each galaxy and divide the extracted regions into young and evolved stellar populations. By means of this approach, we attempt to discover separate effects of dust attenuation and stellar population age on the IRX-UV relation for individual galaxies. In this work, in addition to dust attenuation, stellar population age is interpreted to be another parameter in the IRX-UV function, and the diversity of star formation histories is suggested to disperse the age effects. At the same time, strong evidence shows the need for more parameters in the interpretation of observational data, such as variations in attenuation/extinction law. Fractional contributions of different components to the integrated luminosities of the galaxies suggest that the integrated measurements of these galaxies, which comprise different populations, would weaken the effect of the age parameter on IRX-UV diagrams. The dependence of the IRX-UV relation on luminosity and radial distance in galaxies presents weak trends, which offers an implication of selective effects. The two-dimensional maps of the UV color and the infrared-to-ultraviolet ratio are displayed and show a disparity in the spatial distributions between the two galaxy parameters, which offers a spatial interpretation of the scatter in the IRX-UV relation.

  11. Replication of a Holographic Ion-etched Spherical Blazed Grating for use at Extreme-Ultraviolet Wavelengths: Efficiency

    SciTech Connect (OSTI)

    Kowalski,M.; Barbee, T.; Hunter, W.

    2006-01-01

    Using synchrotron radiation, we have measured the efficiency at an angle of incidence of 10 deg of a holographic ion-etched spherical blazed grating and three of its fourth-generation replicas. The measured efficiency profile of replicas 1 and 3 prior to multilayer coating oscillated from thin-film interference produced by the replicas' Al/Al2O3?/SiO2 structure. A Mo2C/Si multilayer coating was applied to the master grating and replicas 1 and 2. After coating, the maximum grating efficiency occurred in the -2nd order and the maximum values were 12.4% at 143.8 Angstroms for the master and 11.6% at 145.2 Angstroms for replicas 1 and 2. On the basis of measurements obtained after coating, the derived groove efficiency was 22.2% for the master, 19.4% for replica 1, and 19.3% for replica 2. The groove efficiency of the uncoated replica 3 was 24.3% at 142.5 Angstroms. We find that the replicas are reasonably faithful copies of the ion-etched master, and models based on measured atomic force microscope groove profiles are in general agreement with measured results. However, subtle issues remain regarding the widths of the peak order profile and the location of its maximum wavelength.

  12. Chemical Effect of Dry and Wet Cleaning of the Ru Protective Layer of the Extreme ultraviolet (EUV) Lithography Reflector

    E-Print Network [OSTI]

    Belau, Leonid

    2010-01-01

    Park, Physical Chemistry Chemical Y.B. He, et al. , JournalChemical Effect of Dry and Wet Cleaning of the Ru ProtectiveBerkeley, California 94720 Chemical Sciences Division,

  13. Tri-material multilayer coatings with high reflectivity and wide bandwidth for 25 to 50 nm extreme ultraviolet light

    E-Print Network [OSTI]

    Aquila, Andrew

    2010-01-01

    and testing ofEUV multilayer coatings for the AtmosphericTri-material multilayer coatings with high reflectivity andthe bandwidth of multilayer coatings. The simplest method to

  14. March 1, 2001 / Vol. 26, No. 5 / OPTICS LETTERS 259 Capping layers for extreme-ultraviolet multilayer

    E-Print Network [OSTI]

    . This is so because the native oxide layer thickness is a large proportion .30% of the total final layer to a higher R loss as a result of high E-field intensity within the native oxide layer, which invariably

  15. Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources

    E-Print Network [OSTI]

    Aquila, Andrew Lee

    2009-01-01

    multilayer optic depends on the photon energy or wavelengthedge. The photon energy (wavelength), along with the optics,energy. This method utilizes the interference at the surface of the optic

  16. Dynamics of laser-produced Sn-based plasmas for a monochromatic 13.5 nm extreme ultraviolet source

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    EUV spectrum. It was shown that for CO2 laser most of the laser energy deposition is localized around to monochromatic 13.5 nm EUV emission can be expected. It was found that 0.5% Sn- doped foam targets show an almost

  17. Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources

    E-Print Network [OSTI]

    Aquila, Andrew Lee

    2009-01-01

    Dispersion . . . . . . . . . . . . . 2.2.3 Optics for Pulse4.3.2 Optic Development . . . . . . . . .of EUV Multilayer Optics . . . . . 3.1.1 The Necessity of

  18. Ultrafast chemical dynamics of atoms and molecules studied by femtosecond time-resolved extreme ultraviolet transient absorption spectroscopy

    E-Print Network [OSTI]

    Lin, Ming-Fu

    2013-01-01

    increase rate of the green powers. The NIR powers of thedue to a decrease of the green power. Before sending anyposition, very low green power should be used to prevent

  19. Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources

    E-Print Network [OSTI]

    Aquila, Andrew Lee

    2009-01-01

    on how short an electromagnetic pulse can be. Derivation ofis essential for electromagnetic pulse measurements. In theof the electromagnetic spectrum. Visible light pulses can

  20. High-resolution tangential absolute extreme ultraviolet arrays for radiated power density measurements on NSTX-U

    SciTech Connect (OSTI)

    Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kozub, T. A.; LeBlanc, B. P.; Stratton, B. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Faust, I. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States)

    2014-11-15

    The radiated-power-density diagnostic on the equatorial midplane for the NSTX-U tokamak will be upgraded to measure the radial structure of the photon emissivity profile with an improved radial resolution. This diagnostic will enhance the characterization and studies of power balance, impurity transport, and MHD. The layout and response expected of the new system is shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation from high-Z impurities is also addressed.

  1. Extreme-ultraviolet spectral purity and magnetic ion debris mitigation by use of low-density tin targets

    E-Print Network [OSTI]

    Harilal, S S; Tillack, Mark S; O'Shay, Beau; Tao, Y; Paguio, R; Nikroo, A

    2006-01-01

    by the magnetic field due to confinement of the plumeconfinement 3 , application of electrostatic repeller fields 8,9 , and magnetic

  2. Probing temporal evolution of extreme ultraviolet assisted contamination on Ru mirror by x-ray photoelectron spectroscopy

    E-Print Network [OSTI]

    Harilal, S. S.

    Lafayette, Indiana 47907 B. Rice SEMATECH Inc., Albany, New York 12203 (Received 7 October 2011; accepted 4 concentration in the first 1 h followed by a slow but linear growth in the presence of EUV radiation. Further from plasma source to the mask and then to target wafer.5 However, Mo/Si MLM shows a very poor chemical

  3. Europium (Z=63) n=3-3 lines in the extreme ultraviolet: Na- through Si-like

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech(Journal(Patent)pressure in Ba ( Fe 1 - x Coproliferation

  4. Europium (Z=63) n=3-3 lines in the extreme ultraviolet: Na- through Si-like

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech(Journal(Patent)pressure in Ba ( Fe 1 - x Coproliferationions

  5. Enhanced Ultraviolet Cancellations in N = 5 Supergravity at Four Loop

    E-Print Network [OSTI]

    Zvi Bern; Scott Davies; Tristan Dennen

    2014-09-09

    We show that the four-loop four-point amplitudes of N = 5 supergravity are ultraviolet finite in four dimensions, contrary to expectations based on supersymmetry and duality-symmetry arguments. We explain why the diagrams of any covariant local formalism cannot manifestly exhibit the necessary cancellations for finiteness but instead require a new type of nontrivial ultraviolet cancellation that we call "enhanced cancellations". We also show that the three-loop four-point amplitudes in N = 4 and N = 5 supergravity theories display enhanced cancellations. To construct the loop integrand, we use the duality between color and kinematics. We apply standard methods for extracting ultraviolet divergences in conjunction with the FIRE5 integral reduction program to arrive at the four-loop results.

  6. Extreme Weather Events and Climate Change

    Broader source: Energy.gov [DOE]

    The presentation will review known variability in extreme weather such as excessive heat, cold waves, floods, droughts, hurricanes, severe thunderstorms and tornadoes. Projections and uncertainties...

  7. Extreme Scale Computing, Co-design

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Extreme Scale Computing, Co-design Informing system design, ensuring productive and efficient code Project Description To address the increasingly complex problems of the modern...

  8. Note on ultraviolet renormalization and ground state energy of the Nelson model

    E-Print Network [OSTI]

    Fumio Hiroshima

    2015-07-19

    Ultraviolet (UV) renormalization of the Nelson model in quantum field theory is considered. A relationship between a ultraviolet renormalization term and the ground state energy of the Hamiltonian with total momentum zero is studied by functional integrations.

  9. Extreme event statistics of daily rainfall: Dynamical systems approach

    E-Print Network [OSTI]

    G. Cigdem Yalcin; Pau Rabassa; Christian Beck

    2015-08-15

    We analyse the probability densities of daily rainfall amounts at a variety of locations on the Earth. The observed distributions of the amount of rainfall fit well to a q-exponential distribution with exponent q close to q=1.3. We discuss possible reasons for the emergence of this power law. On the contrary, the waiting time distribution between rainy days is observed to follow a near-exponential distribution. A careful investigation shows that a q-exponential with q=1.05 yields actually the best fit of the data. A Poisson process where the rate fluctuates slightly in a superstatistical way is discussed as a possible model for this. We discuss the extreme value statistics for extreme daily rainfall, which can potentially lead to flooding. This is described by Frechet distributions as the corresponding distributions of the amount of daily rainfall decay with a power law. On the other hand, looking at extreme event statistics of waiting times between rainy days (leading to droughts for very long dry periods) we obtain from the observed near-exponential decay of waiting times an extreme event statistics close to Gumbel distributions. We discuss superstatistical dynamical systems as simple models in this context.

  10. Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; et al

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologicallymore »important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.« less

  11. Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

    SciTech Connect (OSTI)

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; Jacobsen, Chris; Brody, James P.

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologically important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.

  12. Inhibition of Photosynthesis in Some Algae by Extreme-Red Light Author(s): Eugene Rabinowitch, Govindjee, Jan B. Thomas

    E-Print Network [OSTI]

    Govindjee

    Inhibition of Photosynthesis in Some Algae by Extreme-Red Light Author(s): Eugene Rabinowitch://www.jstor.org #12;Inhibition of Photosynthesis in Some Algae by Extreme"Red Light Abstract. Photosynthesis produced by far-red light (about 700 m,b) is reversibly inhibited in some algae by extreme-red light ( 750 m

  13. Could the Earth's surface Ultraviolet irradiance be blamed for the global warming? A new effect may exist

    E-Print Network [OSTI]

    Chen, Jilong; Zhao, Juan; Zheng, Yujun

    2014-01-01

    Whether natural factors could interpret the rise of the Earth's surface temperature is still controversial. Though numerous recent researches have reported apparent correlations between solar activity and the Earth's climate, solar activity has encountered a big problem when describing the rapid global warming after 1970s. Our investigation shows the good positive correlations between the Earth's surface Ultraviolet irradiance (280-400 nm) and the Earth's surface temperature both in temporal and spatial variations by analyzing the global surface Ultraviolet irradiance (280-400 nm) and global surface temperature data from 1980-1999. The rise of CO$_2$ cannot interpret the good positive correlations, and we could even get an opposite result to the good correlations when employing the rise of CO$_2$ to describe the relation between them. Based on the good positive correlations, we suggest a new effect, named "Highly Excited Water Vapor" (HEWV) effect, which can interpret how the Sun influences the Earth's surfac...

  14. Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study using data, J. A. (2012) Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study Access Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study using data

  15. Key issues of ultraviolet radiation of OH at high altitudes

    SciTech Connect (OSTI)

    Zhang, Yuhuai; Wan, Tian; Jiang, Jianzheng; Fan, Jing

    2014-12-09

    Ultraviolet (UV) emissions radiated by hydroxyl (OH) is one of the fundamental elements in the prediction of radiation signature of high-altitude and high-speed vehicle. In this work, the OH A{sup 2}?{sup +}?X{sup 2}? ultraviolet emission band behind the bow shock is computed under the experimental condition of the second bow-shock ultraviolet flight (BSUV-2). Four related key issues are discussed, namely, the source of hydrogen element in the high-altitude atmosphere, the formation mechanism of OH species, efficient computational algorithm of trace species in rarefied flows, and accurate calculation of OH emission spectra. Firstly, by analyzing the typical atmospheric model, the vertical distributions of the number densities of different species containing hydrogen element are given. According to the different dominating species containing hydrogen element, the atmosphere is divided into three zones, and the formation mechanism of OH species is analyzed in the different zones. The direct simulation Monte Carlo (DSMC) method and the Navier-Stokes equations are employed to compute the number densities of the different OH electronically and vibrationally excited states. Different to the previous work, the trace species separation (TSS) algorithm is applied twice in order to accurately calculate the densities of OH species and its excited states. Using a non-equilibrium radiation model, the OH ultraviolet emission spectra and intensity at different altitudes are computed, and good agreement is obtained with the flight measured data.

  16. THE LOCAL INTERSTELLAR ULTRAVIOLET RADIATION FIELD Richard Conn Henry1

    E-Print Network [OSTI]

    THE LOCAL INTERSTELLAR ULTRAVIOLET RADIATION FIELD Richard Conn Henry1 Center for Astrophysical 21218; henry@jhu.edu Received 2001 July 20; accepted 2002 January 16 ABSTRACT I have used the Hipparcos of the interstellar extinction, to create a model of the expected intensity and spectral dis- tribution of the local

  17. Extreme Nash Equilibria Martin Gairing1

    E-Print Network [OSTI]

    Mavronicolas, Marios

    Extreme Nash Equilibria Martin Gairing1 , Thomas L¨ucking1 , Marios Mavronicolas2 , Burkhard Monien the combinatorial structure and computational complexity of extreme Nash equilibria, ones that maximize or minimize, to con- trol the routing of its own assigned traffic. In a Nash equilibrium, each user routes its traffic

  18. Resolution dependence in modeling extreme weather events.

    SciTech Connect (OSTI)

    Taylor, J.; Larson, J.

    2001-04-13

    At Argonne National Laboratory we have developed a high performance regional climate modeling simulation capability based on the NCAR MM5v3.4. The regional climate simulation system at Argonne currently includes a Java-based interface to allow rapid selection and generation of initial and boundary conditions, a high-performance version of MM5v3.4 modified for long climate simulations on our 512-processor Beowulf cluster (Chiba City), an interactive Web-based analysis tool to facilitate analysis and collaboration via the Web, and an enhanced version of the CAVE5d software capable of working with large climate data sets. In this paper we describe the application of this modeling system to investigate the role of model resolution in predicting extreme events such as the ''Hurricane Huron'' event of 11-15 September 1996. We have performed a series of ''Hurricane Huron'' experiments at 80, 40, 20, and 10 km grid resolution over an identical spatiotemporal domain. We conclude that increasing model resolution leads to dramatic changes in the vertical structure of the simulated atmosphere producing significantly different representations of rainfall and other parameters critical to the assessment of impacts of climate change.

  19. Extreme wave impinging and overtopping 

    E-Print Network [OSTI]

    Ryu, Yong Uk

    2009-06-02

    This investigates the velocity fields of a plunging breaking wave impinging on a structure through measurements in a two-dimensional wave tank. As the wave breaks and overtops the structure, so-called green water is generated. The flow becomes multi...

  20. Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

    SciTech Connect (OSTI)

    Kostko, Oleg; Belau, Leonid; Wilson, Kevin R.; Ahmed, Musahid

    2008-04-24

    In this work, we report on the vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuum-ultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH+(n = 1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH n(H2O)H+ (n = 2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH+, (CH3OH)2+, (CH3OH)nH+ (n = 1-9), and (CH3OH)n(H2O)H+ (n = 2-9) as a function of photon energy. With an increasein the water content in the molecular beam, there is an enhancement of photoionization intensity for the methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  1. A Network Contention Model for the Extreme-scale Simulator

    SciTech Connect (OSTI)

    Engelmann, Christian [ORNL; Naughton, III, Thomas J [ORNL

    2015-01-01

    The Extreme-scale Simulator (xSim) is a performance investigation toolkit for high-performance computing (HPC) hardware/software co-design. It permits running a HPC application with millions of concurrent execution threads, while observing its performance in a simulated extreme-scale system. This paper details a newly developed network modeling feature for xSim, eliminating the shortcomings of the existing network modeling capabilities. The approach takes a different path for implementing network contention and bandwidth capacity modeling using a less synchronous and accurate enough model design. With the new network modeling feature, xSim is able to simulate on-chip and on-node networks with reasonable accuracy and overheads.

  2. Extreme events due to localisation of energy

    E-Print Network [OSTI]

    Colm Mulhern; Stephan Bialonski; Holger Kantz

    2015-01-09

    We study a one-dimensional chain of harmonically coupled units in an asymmetric anharmonic soft potential. Due to nonlinear localisation of energy, this system exhibits extreme events in the sense that individual elements of the chain show very large excitations. A detailed statistical analysis of extremes in this system reveals some unexpected properties, e.g., a pronounced pattern in the inter event interval statistics. We relate these statistical properties to underlying system dynamics, and notice that often when extreme events occur the system dynamics adopts (at least locally) an oscillatory behaviour, resulting in, for example, a quick succession of such events. The model therefore might serve as a paradigmatic model for the study of the interplay of nonlinearity, energy transport, and extreme events.

  3. International Migration and Extreme-Right Terrorism 

    E-Print Network [OSTI]

    Garcia, Blake Evan

    2015-05-04

    Is right-wing terrorism a response to rising immigration levels? I argue that influxes of immigrants into host states create a motive for violence to members of the extreme-right because it embodies an inherent threat to ...

  4. Extreme Balance of System Hardware Cost Reduction

    Broader source: Energy.gov [DOE]

    On September 1, 2011, DOE announced $42.4 million in funding over three years for the Extreme Balance of System Hardware Cost Reduction (BOS-X) funding opportunity. Part of the SunShot Systems...

  5. High extraction efficiency ultraviolet light-emitting diode

    DOE Patents [OSTI]

    Wierer, Jonathan; Montano, Ines; Allerman, Andrew A.

    2015-11-24

    Ultraviolet light-emitting diodes with tailored AlGaN quantum wells can achieve high extraction efficiency. For efficient bottom light extraction, parallel polarized light is preferred, because it propagates predominately perpendicular to the QW plane and into the typical and more efficient light escape cones. This is favored over perpendicular polarized light that propagates along the QW plane which requires multiple, lossy bounces before extraction. The thickness and carrier density of AlGaN QW layers have a strong influence on the valence subband structure, and the resulting optical polarization and light extraction of ultraviolet light-emitting diodes. At Al>0.3, thinner QW layers (<2.5 nm are preferred) result in light preferentially polarized parallel to the QW plane. Also, active regions consisting of six or more QWs, to reduce carrier density, and with thin barriers, to efficiently inject carriers in all the QWs, are preferred.

  6. Inorganic volumetric light source excited by ultraviolet light

    DOE Patents [OSTI]

    Reed, S.; Walko, R.J.; Ashley, C.S.; Brinker, C.J.

    1994-04-26

    The invention relates to a composition for the volumetric generation of radiation. The composition comprises a porous substrate loaded with a component capable of emitting radiation upon interaction with an exciting radiation. Preferably, the composition is an aerogel substrate loaded with a component, e.g., a phosphor, capable of interacting with exciting radiation of a first energy, e.g., ultraviolet light, to produce radiation of a second energy, e.g., visible light. 4 figures.

  7. Amplitudes and Ultraviolet Behavior of N = 8 Supergravity

    SciTech Connect (OSTI)

    Bern, Zvi; Carrasco, John Joseph; Dixon, Lance J.; Johansson, Henrik; Roiban, Radu; /Penn State U.

    2011-05-20

    In this contribution we describe computational tools that permit the evaluation of multi-loop scattering amplitudes in N = 8 supergravity, in terms of amplitudes in N = 4 super-Yang-Mills theory. We also discuss the remarkable ultraviolet behavior of N = 8 supergravity, which follows from these amplitudes, and is as good as that of N = 4 super-Yang-Mills theory through at least four loops.

  8. Durable Corrosion and Ultraviolet-Resistant Silver Mirror

    DOE Patents [OSTI]

    Jorgensen, G. J.; Gee, R.

    2006-01-24

    A corrosion and ultra violet-resistant silver mirror for use in solar reflectors; the silver layer having a film-forming protective polymer bonded thereto, and a protective shield overlay comprising a transparent multipolymer film that incorporates a UV absorber. The corrosion and ultraviolet resistant silver mirror retains spectral hemispherical reflectance and high optical clarity throughout the UV and visible spectrum when used in solar reflectors.

  9. Inorganic volumetric light source excited by ultraviolet light

    DOE Patents [OSTI]

    Reed, Scott (Albuquerue, NM); Walko, Robert J. (Albuquerue, NM); Ashley, Carol S. (Albuquerue, NM); Brinker, C. Jeffrey (Albuquerue, NM)

    1994-01-01

    The invention relates to a composition for the volumetric generation of radiation. The composition comprises a porous substrate loaded with a component capable of emitting radiation upon interaction with an exciting radiation. Preferably, the composition is an aerogel substrate loaded with a component, e.g., a phosphor, capable of interacting with exciting radiation of a first energy, e.g., ultraviolet light, to produce radiation of a second energy, e.g., visible light.

  10. Investigating the Ultraviolet Properties of Gravity with a Wilsonian Renormalization Group Equation

    E-Print Network [OSTI]

    Alessandro Codello; Roberto Percacci; Christoph Rahmede

    2013-08-27

    We review and extend in several directions recent results on the asymptotic safety approach to quantum gravity. The central issue in this approach is the search of a Fixed Point having suitable properties, and the tool that is used is a type of Wilsonian renormalization group equation. We begin by discussing various cutoff schemes, i.e. ways of implementing the Wilsonian cutoff procedure. We compare the beta functions of the gravitational couplings obtained with different schemes, studying first the contribution of matter fields and then the so-called Einstein-Hilbert truncation, where only the cosmological constant and Newton's constant are retained. In this context we make connection with old results, in particular we reproduce the results of the epsilon expansion and the perturbative one loop divergences. We then apply the Renormalization Group to higher derivative gravity. In the case of a general action quadratic in curvature we recover, within certain approximations, the known asymptotic freedom of the four-derivative terms, while Newton's constant and the cosmological constant have a nontrivial fixed point. In the case of actions that are polynomials in the scalar curvature of degree up to eight we find that the theory has a fixed point with three UV-attractive directions, so that the requirement of having a continuum limit constrains the couplings to lie in a three-dimensional subspace, whose equation is explicitly given. We emphasize throughout the difference between scheme-dependent and scheme-independent results, and provide several examples of the fact that only dimensionless couplings can have "universal" behavior.

  11. Non-extremal D-instantons

    E-Print Network [OSTI]

    E. Bergshoeff; A. Collinucci; U. Gran; D. Roest; S. Vandoren

    2004-12-28

    We construct the most general non-extremal deformation of the D-instanton solution with maximal rotational symmetry. The general non-supersymmetric solution carries electric charges of the SL(2,R) symmetry, which correspond to each of the three conjugacy classes of SL(2,R). Our calculations naturally generalise to arbitrary dimensions and arbitrary dilaton couplings. We show that for specific values of the dilaton coupling parameter, the non-extremal instanton solutions can be viewed as wormholes of non-extremal Reissner-Nordstr\\"om black holes in one higher dimension. We extend this result by showing that for other values of the dilaton coupling parameter, the non-extremal instanton solutions can be uplifted to non-extremal non-dilatonic p-branes in p+1 dimensions higher. Finally, we attempt to consider the solutions as instantons of (compactified) type IIB superstring theory. In particular, we derive an elegant formula for the instanton action. We conjecture that the non-extremal D-instantons can contribute to the R^8-terms in the type IIB string effective action.

  12. Non-extremal D-instantons

    E-Print Network [OSTI]

    Bergshoeff, E; Gran, U; Roest, D; Vandoren, S

    2004-01-01

    We construct the most general non-extremal deformation of the D-instanton solution with maximal rotational symmetry. The general non-supersymmetric solution carries electric charges of the $SL(2,\\mathbb{R})$ symmetry, which correspond to each of the three conjugacy classes of $SL(2,\\mathbb{R})$. Our calculations naturally generalise to arbitrary dimensions and arbitrary dilaton couplings. We show that for specific values of the dilaton coupling parameter, the non-extremal instanton solutions can be viewed as wormholes of non-extremal Reissner-Nordstr\\"om black holes in one higher dimension. We extend this result by showing that for other values of the dilaton coupling parameter, the non-extremal instanton solutions can be uplifted to non-extremal non-dilatonic p-branes in p+1 dimensions higher. Finally, we attempt to consider the solutions as instantons of (compactified) type IIB superstring theory. In particular, we derive an elegant formula for the instanton action. We conjecture that the non-extremal D-ins...

  13. Extremal Limits of Rotating Black Holes

    E-Print Network [OSTI]

    Laura Andrianopoli; Riccardo D'Auria; Antonio Gallerati; Mario Trigiante

    2013-05-30

    We consider non-extremal, stationary, axion-dilaton solutions to ungauged symmetric supergravity models, obtained by Harrison transformations of the non-extremal Kerr solution. We define a general algebraic procedure, which can be viewed as an Inonu-Wigner contraction of the Noether charge matrix associated with the effective D=3 sigma-model description of the solution, yielding, through different singular limits, the known BPS and non-BPS extremal black holes (which include the under-rotating non-BPS one). The non-extremal black hole can thus be thought of as "interpolating" among these limit-solutions. The algebraic procedure that we define generalizes the known Rasheed-Larsen limit which yielded, in the Kaluza-Klein theory, the first instance of under-rotating extremal solution. As an example of our general result, we discuss in detail the non-extremal solution in the T^3-model, with either (q_0, p^1) or (p^0, q_1) charges switched on, and its singular limits. Such solutions, computed in D=3 through the solution-generating technique, is completely described in terms of D=4 fields, which include the fully integrated vector fields.

  14. Bandgap measurements of low-k porous organosilicate dielectrics using vacuum ultraviolet irradiation

    SciTech Connect (OSTI)

    Zheng, H.; Shohet, J. L. [Plasma Processing and Technology Laboratory, Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, S. W. [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); Ryan, V. [GLOBALFOUNDRIES, Albany, New York 12203 (United States); Nishi, Y. [Stanford University, Stanford, California 94305 (United States)

    2014-02-10

    Vacuum ultraviolet (VUV) photoemission spectroscopy is used to investigate the effect of VUV radiation on porous organosilicate (SiCOH) dielectrics during plasma processing. By comparing photoemission spectroscopic results before and after VUV exposure, VUV irradiation with photon energies less than 9.0?eV was found to be beneficial in depleting accumulated charge in SiCOH films while VUV photons with higher energies did not have this effect. Moreover, VUV irradiation with 8.9?eV photons depletes the most charge. From this result, it can be concluded that 8.9?eV is the bandgap plus the electron affinity energy of SiCOH dielectrics.

  15. Injection locking of a high power ultraviolet laser diode for laser cooling of ytterbium atoms

    E-Print Network [OSTI]

    Toshiyuki Hosoya; Martin Miranda; Ryotaro Inoue; Mikio Kozuma

    2014-12-02

    We developed a high-power laser system at a wavelength of 399 nm for laser cooling of ytterbium atoms with ultraviolet laser diodes. The system is composed of an external cavity laser diode providing frequency stabilized output at a power of 40 mW and another laser diode for amplifying the laser power up to 220 mW by injection locking. The systematic method for optimization of our injection locking can also be applied to high power light sources at any other wavelengths. Our system, which does not depend on complex nonlinear frequency-doubling, has great importance for implementing transportable optical lattice clocks, and is also useful for investigations on condensed matter physics or quantum information processing using cold atoms.

  16. Extreme event statistics of daily rainfall: Dynamical systems approach

    E-Print Network [OSTI]

    Yalcin, G Cigdem; Beck, Christian

    2015-01-01

    We analyse the probability densities of daily rainfall amounts at a variety of locations on the Earth. The observed distributions of the amount of rainfall fit well to a q-exponential distribution with exponent q close to q=1.3. We discuss possible reasons for the emergence of this power law. On the contrary, the waiting time distribution between rainy days is observed to follow a near-exponential distribution. A careful investigation shows that a q-exponential with q=1.05 yields actually the best fit of the data. A Poisson process where the rate fluctuates slightly in a superstatistical way is discussed as a possible model for this. We discuss the extreme value statistics for extreme daily rainfall, which can potentially lead to flooding. This is described by Frechet distributions as the corresponding distributions of the amount of daily rainfall decay with a power law. On the other hand, looking at extreme event statistics of waiting times between rainy days (leading to droughts for very long dry periods) w...

  17. Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

    E-Print Network [OSTI]

    Makarova, Kira S.

    2008-01-01

    Deinococcus geothermalis: The Pool of Extreme RadiationDeinococcus geothermalis: The Pool of Extreme Radiationoriginally isolated from a hot pool at the Termi di Agnano,

  18. Evolution of extreme resistance to ionizing radiation via genetic...

    Office of Scientific and Technical Information (OSTI)

    DOE PAGES Search Results Published Article: Evolution of extreme resistance to ionizing radiation via genetic adaptation of DNA repair Title: Evolution of extreme resistance to...

  19. Tribal Energy System Vulnerabilities to Climate Change and Extreme...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    System Vulnerabilities to Climate Change and Extreme Weather Tribal Energy System Vulnerabilities to Climate Change and Extreme Weather This U.S. Department of Energy Office of...

  20. Extreme Temperature Energy Storage and Generation, for Cost and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Extreme Temperature Energy Storage and Generation, for Cost and Risk Reduction in Geothermal Exploration Extreme Temperature Energy Storage and Generation, for Cost and Risk...

  1. Ultraviolet number counts of galaxies from Swift UV/Optical Telescope deep imaging of the Chandra Deep Field South

    E-Print Network [OSTI]

    Hoversten, E A; Berk, D E Vanden; Koch, T S; Breeveld, A A; Curran, P A; Hinshaw, D A; Marshall, F E; Roming, P W A; Siegel, M H; Still, M

    2009-01-01

    Deep Swift UV/Optical Telescope (UVOT) imaging of the Chandra Deep Field South is used to measure galaxy number counts in three near ultraviolet (NUV) filters (uvw2: 1928 A, uvm2: 2246 A, uvw1: 2600 A) and the u band (3645 A). UVOT observations cover the break in the slope of the NUV number counts with greater precision than the number counts by the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) and the Galaxy Evolution Explorer (GALEX), spanning a range from 21 < m_AB < 25. Number counts models confirm earlier investigations in favoring models with an evolving galaxy luminosity function.

  2. Extreme Science (LBNL Science at the Theater)

    SciTech Connect (OSTI)

    Ajo-Franklin, Caroline; Klein, Spencer; Minor, Andrew; Torok, Tamas

    2012-02-27

    On Feb. 27, 2012 at the Berkeley Repertory Theatre, four Berkeley Lab scientists presented talks related to extreme science - and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel.

  3. The ultraviolet spectra of SO?ą? and SO?ą? near 2300 A 

    E-Print Network [OSTI]

    Kim, Sang Uk

    1966-01-01

    22 10 Isotope Shift of Bands in the 2300 S02 ~ 13 Vapor Pressure Curve of SO Correction Curve. A System of 24 33 INTRODUCTION SO has three absorption regions in the ultraviolet portion of its spectrum. They are located at 5900 ? 5400 A.... The emission spectrum lines of the iron arc were used as a 14 TABLE I CORRESPONDING PRESSURES AT DIFFERENT TEMPERATURES PLATL' NUMBER 3 Spectrograms Temperatures -100 C - 85'c - 70'0 - 65'c 50 C Pressures 22 mm 33 mm 43 mm 73 15 standard...

  4. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOE Patents [OSTI]

    Sze, Robert C. (Santa Fe, NM); Quigley, Gerard P. (Los Alamos, NM)

    1996-01-01

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source. A contamination-free VUV light source having a 225 cm.sup.2 emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm.sup.2 at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing.

  5. Graphene/GaN diodes for ultraviolet and visible photodetectors

    SciTech Connect (OSTI)

    Lin, Fang; Chen, Shao-Wen; Meng, Jie; Tse, Geoffrey; Fu, Xue-Wen; Xu, Fu-Jun [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Shen, Bo; Liao, Zhi-Min, E-mail: liaozm@pku.edu.cn, E-mail: yudp@pku.edu.cn; Yu, Da-Peng, E-mail: liaozm@pku.edu.cn, E-mail: yudp@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-08-18

    The Schottky diodes based on graphene/GaN interface are fabricated and demonstrated for the dual-wavelength photodetection of ultraviolet (UV) and green lights. The physical mechanisms of the photoelectric response of the diodes with different light wavelengths are different. For UV illumination, the photo-generated carriers lower the Schottky barrier and increase the photocurrent. For green light illumination, as the photon energy is smaller than the bandgap of GaN, the hot electrons excited in graphene via internal photoemission are responsible for the photoelectric response. Using graphene as a transparent electrode, the diodes show a ?mS photoresponse, providing an alternative route toward multi-wavelength photodetectors.

  6. Gamma Ray Burst Constraints on Ultraviolet Lorentz Invariance Violation

    E-Print Network [OSTI]

    Tina Kahniashvili; Grigol Gogoberidze; Bharat Ratra

    2006-10-20

    We present a unified general formalism for ultraviolet Lorentz invariance violation (LV) testing through electromagnetic wave propagation, based on both dispersion and rotation measure data. This allows for a direct comparison of the efficacy of different data to constrain LV. As an example we study the signature of LV on the rotation of the polarization plane of $\\gamma$-rays from gamma ray bursts in a LV model. Here $\\gamma$-ray polarization data can provide a strong constraint on LV, 13 orders of magnitude more restrictive than a potential constraint from the rotation of the cosmic microwave background polarization proposed by Gamboa, L\\'{o}pez-Sarri\\'{o}n, and Polychronakos (2006).

  7. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOE Patents [OSTI]

    Sze, R.C.; Quigley, G.P.

    1996-12-17

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

  8. Gamma ray bursts and extreme energy cosmic rays

    SciTech Connect (OSTI)

    Scarsi, Livio

    1998-06-15

    Extreme Energy Cosmic Ray particles (EECR) with E>10{sup 20} eV arriving on Earth with very low flux ({approx}1 particle/Km{sup 2}-1000yr) require for their investigation very large detecting areas, exceeding values of 1000 km{sup 2} sr. Projects with these dimensions are now being proposed: Ground Arrays ('Auger' with 2x3500 km{sup 2} sr) or exploiting the Earth Atmosphere as seen from space ('AIR WATCH' and OWL,'' with effective area reaching 1 million km{sup 2} sr). In this last case, by using as a target the 10{sup 13} tons of air viewed, also the high energy neutrino flux can be investigated conveniently. Gamma Rays Bursts are suggested as a possible source for EECR and the associated High Energy neutrino flux.

  9. Extremal Financial Risk Models and Portfolio Evaluation

    E-Print Network [OSTI]

    Zhang, Zhengjun

    Extremal Financial Risk Models and Portfolio Evaluation Zhengjun Zhang Department of Statistics assets. An important application of the proposed method is to calculate VaRs (Value at Risk) and evaluate, financial risk, portfolio evaluation. 2000 Mathematics Subject Classification: 60G70, 62G32, 62P20. 0 #12

  10. An Extremal N=2 Superconformal Field Theory

    E-Print Network [OSTI]

    Nathan Benjamin; Ethan Dyer; A. Liam Fitzpatrick; Shamit Kachru

    2015-06-30

    We provide an example of an extremal chiral ${\\cal N}=2$ superconformal field theory at $c=24$. The construction is based on a ${\\mathbb Z}_2$ orbifold of the theory associated to the $A_{1}^{24}$ Niemeier lattice. The statespace is governed by representations of the sporadic group $M_{23}$.

  11. Extremes in climate science Andreas Sterl (KNMI)

    E-Print Network [OSTI]

    Stoffelen, Ad

    (non-deterministic) influences: sun, volcanoes, anthropogenic effects (GHG emissions) => deterministic Sterl, PhysMathClim Climate change GHG concentrations increase => Temperature increases => other weather;31.01.2012, Utrecht Andreas Sterl, PhysMathClim EVT - 1 Extremes: tail of a distribution => few observations => tail

  12. Modelling Energy Markets with Extreme Thorsten Schmidt

    E-Print Network [OSTI]

    Schmidt, Thorsten

    . Besides this, due to the difficulty of storing electricity and inelastic demand, electricity spot prices approach to model spot prices of electricity. It uses a shot-noise model to capture extreme spikes typically arising in electricity markets. Moreover, the model easily accounts for seasonality and mean

  13. Changes in precipitation characteristics and extremes

    E-Print Network [OSTI]

    Allan, Richard P.

    Changes in precipitation characteristics and extremes Comparing Mediterranean to change Swiss characteristics Comparing Mediterranean to north-western European precipitation Master Thesis April 2012 Author precipitation 502) dvogel@student.ethz.ch Dr Richard Allan (University of Reading) Prof Dr Martin Wild (ETH

  14. Ultraviolet Free Electron Laser Facility preliminary design report

    SciTech Connect (OSTI)

    Ben-Zvi, I.

    1993-02-01

    This document, the Preliminary Design Report (PDR) for the Brookhaven Ultraviolet Free Electron Laser (UV FEL) facility, describes all the elements of a facility proposed to meet the needs of a research community which requires ultraviolet sources not currently available as laboratory based lasers. Further, for these experiments, the requisite properties are not extant in either the existing second or upcoming third generation synchrotron light sources. This document is the result of our effort at BNL to identify potential users, determine the requirements of their experiments, and to design a facility which can not only satisfy the existing need, but have adequate flexibility for possible future extensions as need dictates and as evolving technology allows. The PDR is comprised of three volumes. In this, the first volume, background for the development of the proposal is given, including descriptions of the UV FEL facility, and representative examples of the science it was designed to perform. Discussion of the limitations and potential directions for growth are also included. A detailed description of the facility design is then provided, which addresses the accelerator, optical, and experimental systems. Information regarding the conventional construction for the facility is contained in an addendum to volume one (IA).

  15. The far-ultraviolet spectra of "cool" PG1159 stars

    E-Print Network [OSTI]

    Werner, K; Kruk, J W

    2015-01-01

    We present a comprehensive study of Far Ultraviolet Spectroscopic Explorer (FUSE) spectra (912-1190 A) of two members of the PG1159 spectral class, which consists of hydrogen-deficient (pre-) white dwarfs with effective temperatures in the range Teff = 75,000-200,000 K. As two representatives of the cooler objects, we have selected PG1707+427 (Teff = 85,000 K) and PG1424+535 (Teff = 110,000 K), complementing a previous study of the hotter prototype PG1159-035 (Teff = 140,000 K). The helium-dominated atmospheres are strongly enriched in carbon and oxygen, therefore, their spectra are dominated by lines from C III-IV and O III-VI, many of which were never observed before in hot stars. In addition, lines of many other metals (N, F, Ne, Si, P, S, Ar, Fe) are detectable, demonstrating that observations in this spectral region are most rewarding when compared to the near-ultraviolet and optical wavelength bands. We perform abundance analyses of these species and derive upper limits for several undetected light and ...

  16. HST-COS observations of AGNs. II. Extended survey of ultraviolet composite spectra from 159 active galactic nuclei

    SciTech Connect (OSTI)

    Stevans, Matthew L. [Present address: Astronomy Department, University of Texas, Austin, TX 78712, USA. (United States); Shull, J. Michael [Also at Institute of Astronomy, Cambridge University, Cambridge CB3 OHA, UK. (United Kingdom); Danforth, Charles W.; Tilton, Evan M., E-mail: stevans@astro.as.utexas.edu, E-mail: michael.shull@colorado.edu, E-mail: charles.danforth@colorado.edu, E-mail: evan.tilton@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2014-10-10

    The ionizing fluxes from quasars and other active galactic nuclei (AGNs) are critical for interpreting their emission-line spectra and for photoionizing and heating the intergalactic medium. Using far-ultraviolet (FUV) spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), we directly measure the rest-frame ionizing continua and emission lines for 159 AGNs at redshifts 0.001 < z {sub AGN} < 1.476 and construct a composite spectrum from 475 to 1875 Ĺ. We identify the underlying AGN continuum and strong extreme ultraviolet (EUV) emission lines from ions of oxygen, neon, and nitrogen after masking out absorption lines from the H I Ly? forest, 7 Lyman-limit systems (N{sub H} {sub I}?10{sup 17.2} cm{sup –2}) and 214 partial Lyman-limit systems (14.5

  17. Accident Investigations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-03-04

    This Order prescribes organizational responsibilities, authorities, and requirements for conducting investigations of certain accidents occurring at DOE sites, facilities, areas, operations, and activities. Supersedes DOE O 225.1A. Cancels DOE G 225.1A-1.

  18. Correction of SOHO CELIAS/SEM EUV Measurements saturated by extreme solar flare events

    E-Print Network [OSTI]

    L. V. Didkovsky; D. L. Judge; A. R. Jones; S. Wieman; B. T. Tsurutani; D. McMullin

    2006-10-04

    The solar irradiance in the Extreme Ultraviolet (EUV) spectral bands has been observed with a 15 sec cadence by the SOHO Solar EUV Monitor (SEM) since 1995. During remarkably intense solar flares the SEM EUV measurements are saturated in the central (zero) order channel (0.1 -- 50.0 nm) by the flare soft X-ray and EUV flux. The first order EUV channel (26 -- 34 nm) is not saturated by the flare flux because of its limited bandwidth, but it is sensitive to the arrival of Solar Energetic Particles (SEP). While both channels detect nearly equal SEP fluxes, their contributions to the count rate is sensibly negligible in the zero order channel but must be accounted for and removed from the first channel count rate. SEP contribution to the measured SEM signals usually follows the EUV peak for the gradual solar flare events. Correcting the extreme solar flare SEM EUV measurements may reveal currently unclear relations between the flare magnitude, dynamics observed in different EUV spectral bands, and the measured Earth atmosphere response. A simple and effective correction technique based on analysis of SEM count-rate profiles, GOES X-ray, and GOES proton data has been developed and used for correcting EUV measurements for the five extreme solar flare events of July 14, 2000, October 28, November 2, November 4, 2003, and January 20, 2005. Although none of the 2000 and 2003 flare peaks were contaminated by the presence of SEPs, the January 20, 2005 SEPs were unusually prompt and contaminated the peak. The estimated accuracy of the correction is about 7.5% for large X-class events.

  19. Hopkins Ultraviolet Telescope Observations of Nova Circini 1995 and Nova Aquilae 1995

    E-Print Network [OSTI]

    Hopkins Ultraviolet Telescope Observations of Nova Circini 1995 and Nova Aquilae 1995 Bradford W 1995 and Nova Aql 1995 with the Hopkins Ultraviolet Telescope during the Astro­2 space shuttle mission in 1995 March. The spectra cover the wavelength range from 820 š A to 1840 š A with a spectral resolution

  20. Transporting container for an amputated extremity

    SciTech Connect (OSTI)

    Ammerman, S.W.

    1988-02-09

    A container assembly for transporting of an amputated extremity to a location for replantation is described comprising: an inner compartment adapted to receive an amputated extremity, the inner compartment being defined by a wall, an access opening providing access into the inner compartment, the access opening being closable; a completely closed outer compartment surrounding the inner compartment, the outer compartment abutting the wall; and cooling bags located within the outer compartment, Each cooling bag contains a pair of substances when mixed results in the production of a cooling affect. Each cooling bag contains chambers. The chambers are connected but separate. One of the substances is a granulized solid. The granulized solid is located within the separate chambers, whereby upon mixing occurring of the substances substantially even distribution of the cooling affect is obtained across the entire width of the inner compartment due to mixing between the substances occurring within each chamber.

  1. PREDICTING Ly? AND Mg II FLUXES FROM K AND M DWARFS USING GALAXY EVOLUTION EXPLORER ULTRAVIOLET PHOTOMETRY

    SciTech Connect (OSTI)

    Shkolnik, Evgenya L.; Rolph, Kristina A.; Peacock, Sarah; Barman, Travis S. E-mail: kristina.rolph@fandm.edu E-mail: barman@lpl.arizona.edu

    2014-11-20

    A star's ultraviolet (UV) emission can greatly affect the atmospheric chemistry and physical properties of closely orbiting planets with the potential for severe mass loss. In particular, the Ly? emission line at 1216 Ĺ, which dominates the far-ultraviolet (FUV) spectrum, is a major source of photodissociation of important atmospheric molecules such as water and methane. The intrinsic flux of Ly?, however, cannot be directly measured due to the absorption of neutral hydrogen in the interstellar medium and contamination by geocoronal emission. To date, reconstruction of the intrinsic Ly? line based on Hubble Space Telescope spectra has been accomplished for 46 FGKM nearby stars, 28 of which have also been observed by the Galaxy Evolution Explorer (GALEX). Our investigation provides a correlation between published intrinsic Ly? and GALEX far- and near-ultraviolet (NUV) chromospheric fluxes for K and M stars. The negative correlations between the ratio of the Ly? to the GALEX fluxes reveal how the relative strength of Ly? compared to the broadband fluxes weakens as the FUV and NUV excess flux increase. We also correlate GALEX fluxes with the strong NUV Mg II h+k spectral emission lines formed at lower chromospheric temperatures than Ly?. The reported correlations provide estimates of intrinsic Ly? and Mg II fluxes for the thousands of K and M stars in the archived GALEX all-sky surveys. These will constrain new stellar upper atmosphere models for cool stars and provide realistic inputs to models describing exoplanetary photochemistry and atmospheric evolution in the absence of UV spectroscopy.

  2. Chiral Gravity, Log Gravity and Extremal CFT

    E-Print Network [OSTI]

    Alexander Maloney; Wei Song; Andrew Strominger

    2009-03-26

    We show that the linearization of all exact solutions of classical chiral gravity around the AdS3 vacuum have positive energy. Non-chiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity-- the theory with logarithmically relaxed boundary conditions --has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic CFT. Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We normally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.

  3. Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of p-, m-, and o-difluorobenzenes. Ionization energies

    E-Print Network [OSTI]

    Kim, Myung Soo

    Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of p-, m-, and o been measured by vacuum ultraviolet mass-analyzed threshold ionization VUV-MATI spectroscopy. From use of monochromatic and tunable vacuum ultraviolet radia- tion which is not routinely available

  4. Vacuum-ultraviolet mass-analyzed threshold ionization spectra of iodobutane isomers: Conformer-specific ionization and ion-core

    E-Print Network [OSTI]

    Kim, Myung Soo

    Vacuum-ultraviolet mass-analyzed threshold ionization spectra of iodobutane isomers: Conformer-analyzed threshold ionization MATI spectra using coherent vacuum ultraviolet radiation have been obtained for t-photon MATI spectroscopy using a vacuum-ultraviolet VUV laser source generated by four-wave mixing in Kr gas.8

  5. Extremal unital completely positive normal maps and its symmetries

    E-Print Network [OSTI]

    Anilesh Mohari

    2015-07-30

    We consider the convex set of ( unital ) positive ( completely ) maps from a $C^*$ algebra $\\cla$ to a von-Neumann sub-algebra $\\clm$ of $\\clb(\\clh)$, the algebra of bounded linear operators on a Hilbert space $\\clh$ and study its extreme points via its canonical lifting to the convex set of ( unital ) positive ( complete ) normal maps from $\\hat{\\cla}$ to $\\clm$, where $\\hat{\\cla}$ is the universal enveloping von-Neumann algebra over $\\cla$. If $\\cla=\\clm$ and a ( complete ) positive operator $\\tau$ is a unique sum of a normal and a singular ( complete ) positive maps. Furthermore, a unital complete positive map is a unique convex combination of unital normal and singular complete positive maps. We used a duality argument to find a criteria for extremal elements in the convex set of unital completely positive maps having a given faithful normal invariant state. In our investigation, gauge symmetry in Stinespring representation and Kadison theorem on order isomorphism played an important role.

  6. Accident Investigations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-04-26

    To prescribe requirements for conducting investigations of certain accidents occurring at Department of Energy (DOE) operations and sites; to improve the environment, safety and health for DOE, contractors, and the public; and to prevent the recurrence of such accidents. Chg 2, 4-26-96

  7. Accident Investigations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-10-26

    To prescribe requirements for conducting investigations of certain accidents occurring at Department of Energy (DOE) operations and sites; to improve the environment , safety and health for DOE, contractors, and the public; and to prevent the recurrence of such accidents. Chg 1, 10-26-95. Cancels parts of DOE 5484.1

  8. Laser plasma formation assisted by ultraviolet pre-ionization

    SciTech Connect (OSTI)

    Yalin, Azer P., E-mail: ayalin@engr.colostate.edu; Dumitrache, Ciprian [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Wilvert, Nick [Sandia Laboratory, Albuquerque, New Mexico 87123 (United States); Joshi, Sachin [Cummins Inc., Columbus, Indiana 47201 (United States); Shneider, Mikhail N. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-10-15

    We present experimental and modeling studies of air pre-ionization using ultraviolet (UV) laser pulses and its effect on laser breakdown of an overlapped near-infrared (NIR) pulse. Experimental studies are conducted with a 266?nm beam (fourth harmonic of Nd:YAG) for UV pre-ionization and an overlapped 1064?nm NIR beam (fundamental of Nd:YAG), both having pulse duration of ?10?ns. Results show that the UV beam produces a pre-ionized volume which assists in breakdown of the NIR beam, leading to reduction in NIR breakdown threshold by factor of >2. Numerical modeling is performed to examine the ionization and breakdown of both beams. The modeled breakdown threshold of the NIR, including assist by pre-ionization, is in reasonable agreement with the experimental results.

  9. Paper II: Calibration of the Swift ultraviolet/optical telescope

    E-Print Network [OSTI]

    Breeveld, A A; Hoversten, E A; Koch, S; Landsman, W; Marshall, F E; Page, M J; Poole, T S; Roming, P; Smith, P J; Still, M; Yershov, V; Blustin, A J; Brown, P J; Gronwall, C; Holland, S T; Kuin, N P M; McGowan, K; Rosen, S; Boyd, P; Broos, P; Carter, M; Chester, M M; Hancock, B; Huckle, H; Immler, S; Ivanushkina, M; Kennedy, T; Mason, K O; Morgan, A N; Oates, S; de Pasquale, M; Schady, P; Siegel, M; Berk, D Vanden

    2010-01-01

    The Ultraviolet/Optical Telescope (UVOT) is one of three instruments onboard the Swift observatory. The photometric calibration has been published, and this paper follows up with details on other aspects of the calibration including a measurement of the point spread function with an assessment of the orbital variation and the effect on photometry. A correction for large scale variations in sensitivity over the field of view is described, as well as a model of the coincidence loss which is used to assess the coincidence correction in extended regions. We have provided a correction for the detector distortion and measured the resulting internal astrometric accuracy of the UVOT, also giving the absolute accuracy with respect to the International Celestial Reference System. We have compiled statistics on the background count rates, and discuss the sources of the background, including instrumental scattered light. In each case we describe any impact on UVOT measurements, whether any correction is applied in the st...

  10. Strong Ultraviolet Pulse From a Newborn Type Ia Supernova

    E-Print Network [OSTI]

    Cao, Yi; Howell, D Andrew; Gal-Yam, Avishay; Kasliwal, Mansi M; Valenti, Stefano; Johansson, J; Amanullah, R; Goobar, A; Sollerman, J; Taddia, F; Horesh, Assaf; Sagiv, Ilan; Cenko, S Bradley; Nugent, Peter E; Arcavi, Iair; Surace, Jason; Wo?niak, P R; Moody, Daniela I; Rebbapragada, Umaa D; Bue, Brian D; Gehrels, Neil

    2015-01-01

    Type Ia supernovae are destructive explosions of carbon oxygen white dwarfs. Although they are used empirically to measure cosmological distances, the nature of their progenitors remains mysterious, One of the leading progenitor models, called the single degenerate channel, hypothesizes that a white dwarf accretes matter from a companion star and the resulting increase in its central pressure and temperature ignites thermonuclear explosion. Here we report observations of strong but declining ultraviolet emission from a Type Ia supernova within four days of its explosion. This emission is consistent with theoretical expectations of collision between material ejected by the supernova and a companion star, and therefore provides evidence that some Type Ia supernovae arise from the single degenerate channel.

  11. An Internet Database of Ultraviolet Lightcurves for Seyfert Galaxies

    E-Print Network [OSTI]

    Jay P. Dunn; Brian Jackson; Rajesh P. Deo; Chris Farrington; Varendra Das; D. Michael Crenshaw

    2006-03-29

    Using the Multimission Archives at Space Telescope (MAST), we have extracted spectra and determined continuum light curves for 175 Seyfert Galaxies that have been observed with the International Ultraviolet Explorer (IUE) and the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST). To obtain the light curves as a function of Julian Date, we used fix bins in the object's rest frame, and measured small regions (between 30 and 60 Angstroms) of each spectrum's continuum flux in the range 1150 Angstroms to 3200 Angstroms. We provide access to the UV light curves and other basic information about the observations in tabular and graphical form via the Internet at http://www.chara.gsu.edu/PEGA/IUE/.

  12. Development of an Extreme Environment Materials Research Facility at Princeton

    SciTech Connect (OSTI)

    Cohen, A B; Tully, C G; Austin, R; Calaprice, F; McDonald, K; Ascione, G; Baker, G; Davidson, R; Dudek, L; Grisham, L; Kugel, H; Pagdon, K; Stevenson, T; Woolley, R

    2010-11-17

    The need for a fundamental understanding of material response to a neutron and/or high heat flux environment can yield development of improved materials and operations with existing materials. Such understanding has numerous applications in fields such as nuclear power (for the current fleet and future fission and fusion reactors), aerospace, and other research fields (e.g., high-intensity proton accelerator facilities for high energy physics research). A proposal has been advanced to develop a facility for testing various materials under extreme heat and neutron exposure conditions at Princeton. The Extreme Environment Materials Research Facility comprises an environmentally controlled chamber (48 m^3) capable of high vacuum conditions, with extreme flux beams and probe beams accessing a central, large volume target. The facility will have the capability to expose large surface areas (1 m^2) to 14 MeV neutrons at a fluence in excess of 10^13 n/s. Depending on the operating mode. Additionally beam line power on the order of 15-75 MW/m2 for durations of 1-15 seconds are planned... The multi-second duration of exposure can be repeated every 2-10 minutes for periods of 10-12 hours. The facility will be housed in the test cell that held the Tokamak Fusion Test Reactor (TFTR), which has the desired radiation and safety controls as well as the necessary loading and assembly infrastructure. The facility will allow testing of various materials to their physical limit of thermal endurance and allow for exploring the interplay between radiation-induced embrittlement, swelling and deformation of materials, and the fatigue and fracturing that occur in response to thermal shocks. The combination of high neutron energies and intense fluences will enable accelerated time scale studies. The results will make contributions for refining predictive failure modes (modeling) in extreme environments, as well as providing a technical platform for the development of new alloys, new materials, and the investigation of repair mechanisms. Effects on materials will be analyzed with in situ beam probes and instrumentation as the target is exposed to radiation, thermal fluxes and other stresses. Photon and monochromatic neutron fluxes, produced using a variable-energy (4-45 MeV) electron linac and the highly asymmetric electron-positron collisions technique used in high-energy physics research, can provide non-destructive, deep-penetrating structural analysis of materials while they are undergoing testing. The same beam lines will also be able to generate neutrons from photonuclear interactions using existing Bremsstrahlung and positrons on target quasi-monochromatic gamma rays. Other diagnostics will include infrared cameras, residual gas analyzer (RGA), and thermocouples; additional diagnostic capability will be added.

  13. Formation of emission line dots and extremely metal-deficient dwarfs from almost dark galaxies

    E-Print Network [OSTI]

    Bekki, Kenji

    2015-01-01

    Recent observations have discovered a number of extremely gas-rich very faint dwarf galaxies possibly embedded in low-mass dark matter halos. We investigate star formation histories of these gas-rich dwarf ("almost dark") galaxies both for isolated and interacting/merging cases. We find that although star formation rates (SFRs) are very low (systems with very low metallicities (Z/Z_sun<0.1), which can be identified as extremely metal-deficient ("XMD") dwarfs. These results imply that although there would exist ma...

  14. ORIGINAL ARTICLE Acupuncture for Upper-Extremity Rehabilitation in Chronic

    E-Print Network [OSTI]

    Schaechter, Judith D.

    ORIGINAL ARTICLE Acupuncture for Upper-Extremity Rehabilitation in Chronic Stroke: A Randomized. Acupuncture for upper- extremity rehabilitation in chronic stroke: a randomized sham- controlled study. Arch acci- dent; Hemiparesis; Muscle spasticity; Range of motion, artic- ular; Rehabilitation. © 2005

  15. Sensitivity of tropical precipitation extremes to climate change

    E-Print Network [OSTI]

    O'Gorman, Paul Ambrose

    Precipitation extremes increase in intensity over many regions of the globe in simulations of a warming climate1, 2, 3. The rate of increase of precipitation extremes in the extratropics is consistent across global climate ...

  16. DOE Zero Energy Ready Home Case Study: Green Extreme Homes &...

    Energy Savers [EERE]

    Green Extreme Homes & Carl Franklin Homes, Garland, TX DOE Zero Energy Ready Home Case Study: Green Extreme Homes & Carl Franklin Homes, Garland, TX DOE Zero Energy Ready Home Case...

  17. Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures

    SciTech Connect (OSTI)

    Verma, Jai Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep

    2014-01-13

    Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.

  18. FRG Approach to Nuclear Matter at Extreme Conditions

    E-Print Network [OSTI]

    Pósfay, Péter; Jakovác, Antal

    2015-01-01

    Functional renormalization group (FRG) is an exact method for taking into account the effect of quantum fluctuations in the effective action of the system. The FRG method applied to effective theories of nuclear matter yields equation of state which incorporates quantum fluctuations of the fields. Using the local potential approximation (LPA) the equation of state for Walecka-type models of nuclear matter under extreme conditions could be determined. These models can be tested by solving the corresponding Tolman--Oppenheimer--Volkov (TOV) equations and investigating the properties (mass and radius) of the corresponding compact star models. Here, we present the first steps on this way, we obtained a Maxwell construction within the FRG-based framework using a Walecka-type Lagrangian.

  19. Complete genome sequences for the anaerobic, extremely thermophilic...

    Office of Scientific and Technical Information (OSTI)

    Complete genome sequences for the anaerobic, extremely thermophilic plant biomass-degrading bacteria Caldicellulosiruptor hydrothermalis, Caldicellulosiruptor kristjanssonii,...

  20. Method for detection of extremely low concentration

    DOE Patents [OSTI]

    Andresen, Brian D. (Livermore, CA); Miller, Fred S. (Bethal Island, CA)

    2002-01-01

    An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.

  1. A Hierarchical Pattern Learning Framework for Forecasting Extreme Weather Events

    E-Print Network [OSTI]

    Ding, Wei

    . Frequent pattern-based data representations have been used in various studies for abstracting climaticA Hierarchical Pattern Learning Framework for Forecasting Extreme Weather Events Dawei Wang, Wei@cs.umb.edu Abstract--Extreme weather events, like extreme rainfalls, are severe weather hazards and also the triggers

  2. STATISTICS OF EXTREMES IN CLIMATE CHANGE Richard W. Katz

    E-Print Network [OSTI]

    Katz, Richard

    Covariates in extRemes (2) Climate Change Applications (2.1) Block maxima approach Simulated data from GEVSTATISTICS OF EXTREMES IN CLIMATE CHANGE Richard W. Katz Institute for Study of Society the application of the statistical theory of extreme values to climate, in general, and to climate change

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

    SciTech Connect (OSTI)

    Placco, Vinicius M. [Gemini Observatory, Hilo, HI 96720 (United States); Beers, Timothy C.; Smith, Verne V. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Roederer, Ian U. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Cowan, John J. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Frebel, Anna [Kavli Institute for Astrophysics and Space Research and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Filler, Dan; Ivans, Inese I. [Department of Physics and Astronomy, The University of Utah, Salt Lake City, UT 84112 (United States); Lawler, James E. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Schatz, Hendrik [JINA—Joint Institute for Nuclear Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556-5670 (United States); Sneden, Christopher [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Sobeck, Jennifer S. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Aoki, Wako, E-mail: vplacco@gemini.edu [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    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 ? (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 ? (Be) <–2.3, and lead, log ? (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.

  4. Method and apparatus for producing durationally short ultraviolet or x-ray laser pulses

    DOE Patents [OSTI]

    MacGowan, B.J.; Matthews, D.L.; Trebes, J.E.

    1987-05-05

    A method and apparatus is disclosed for producing ultraviolet or x- ray laser pulses of short duration. An ultraviolet or x-ray laser pulse of long duration is progressively refracted, across the surface of an opaque barrier, by a streaming plasma that is produced by illuminating a solid target with a pulse of conventional line focused high power laser radiation. The short pulse of ultraviolet or x-ray laser radiation, which may be amplified to high power, is separated out by passage through a slit aperture in the opaque barrier.

  5. Radiation stability of graphene under extreme conditions

    SciTech Connect (OSTI)

    Kumar, Sunil, E-mail: kumar.sunil092@gmail.com; Tripathi, Ambuj; Khan, Saif A.; Pannu, Compesh; Avasthi, Devesh K. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2014-09-29

    In this letter, we report radiation stability of graphene under extreme condition of high energy density generated by 150?MeV Au ion irradiation. The experiment reveals that graphene is radiation resistant for irradiation at 10{sup 14?}ions/cm{sup 2} of 150?MeV Au ions. It is significant to note that annealing effects are observed at lower fluences whereas defect production occurs at higher fluences but significant crystallinity is retained. Our results demonstrate applicability of graphene based devices in radiation environment and space applications.

  6. Extremely compliant and highly stretchable patterned graphene

    SciTech Connect (OSTI)

    Zhu, Shuze; Huang, Yinjun; Li, Teng, E-mail: LiT@umd.edu [Department of Mechanical Engineering and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28

    Graphene is intrinsically ultra-stiff in its plane. Its huge mechanical mismatch when interfacing with ultra-compliant biological tissues and elastomers (7–9 orders of magnitude difference in stiffness) poses significant challenge in its application to functional devices such as epidermal electronics and sensing prosthesis. We offer a feasible and promising solution to this significant challenge by suitably patterning graphene into a nanomesh. Through systematic coarse-grained simulations, we show that graphene nanomesh can be made extremely compliant with nearly zero stiffness up to about 20% elongation and then remain highly compliant up to about 50% elongation.

  7. Ultrahigh Energy Neutrals from Extreme Magnetic Flares

    E-Print Network [OSTI]

    David Eichler

    2003-03-20

    It is shown that bulk acceleration during reconnection of extremely strong magnetic fields near compact objects can accelerate ions to Lorentz factors of $\\sim 10^2 \\sigma^{3/5}$ under general conditions, where $\\sigma$, the magnetic energy per current-carrying proton rest energy, can approach $10^{15}$. For magnetar-type fields, neutrons and neutrinos can be generated at potentially detectable levels via hadron polarization. Ultrahigh energy photons can also be emitted and escorted from the high field region by Poynting flux.

  8. Extremely Low Temperature | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, AlabamaETEC GmbH JumpEllenville,PowerEvaporative CoolersExosunOpenExtremely Low

  9. Mesoscale Predictability of an Extreme Warm-Season Precipitation Event FUQING ZHANG, ANDREW M. ODINS, AND JOHN W. NIELSEN-GAMMON

    E-Print Network [OSTI]

    Mesoscale Predictability of an Extreme Warm-Season Precipitation Event FUQING ZHANG, ANDREW M Station, Texas (Manuscript received 22 November 2004, in final form 28 August 2005) ABSTRACT A mesoscale model is used to investigate the mesoscale predictability of an extreme precipitation event over central

  10. Testing the Molecular-Hydrogen Kennicutt-Schmidt Law in the Low-Density Environments of Extended Ultraviolet Disk Galaxies

    E-Print Network [OSTI]

    Watson, Linda C; Lisenfeld, Ute; Boeker, Torsten; Schinnerer, Eva

    2015-01-01

    Studying star formation beyond the optical radius of galaxies allows us to test empirical relations in extreme conditions with low average gas density and low molecular fraction. Previous studies discovered galaxies with extended ultraviolet (XUV) disks, which often contain star forming regions with lower Halpha-to-far-UV (FUV) flux ratios compared to inner disk star forming regions. However, most previous studies lack measurements of molecular gas, which is presumably the component of the interstellar medium out of which stars form. We analyzed published CO measurements and upper limits for fifteen star forming regions in the XUV or outer disk of three nearby spiral galaxies and a new CO upper limit from the IRAM 30 m telescope in one star forming region at r = 3.4 r_25 in the XUV disk of NGC 4625. We found that the star forming regions are in general consistent with the same molecular-hydrogen Kennicutt-Schmidt law that applies within the optical radius, independent of whether we used Halpha or FUV as the s...

  11. The formation of IRIS diagnostics. III. Near-ultraviolet spectra and images

    SciTech Connect (OSTI)

    Pereira, T. M. D.; Leenaarts, J.; De Pontieu, B.; Carlsson, M.; Uitenbroek, H. E-mail: jorritl@astro.uio.no E-mail: mats.carlsson@astro.uio.no

    2013-12-01

    The Mg II h and k lines are the prime chromospheric diagnostics of NASA's Interface Region Imaging Spectrograph (IRIS). In the previous papers of this series, we used a realistic three-dimensional radiative magnetohydrodynamics model to calculate the h and k lines in detail and investigated how their spectral features relate to the underlying atmosphere. In this work, we employ the same approach to investigate how the h and k diagnostics fare when taking into account the finite resolution of IRIS and different noise levels. In addition, we investigate the diagnostic potential of several other photospheric lines and near-continuum regions present in the near-ultraviolet (NUV) window of IRIS and study the formation of the NUV slit-jaw images. We find that the instrumental resolution of IRIS has a small effect on the quality of the h and k diagnostics; the relations between the spectral features and atmospheric properties are mostly unchanged. The peak separation is the most affected diagnostic, but mainly due to limitations of the simulation. The effects of noise start to be noticeable at a signal-to-noise ratio (S/N) of 20, but we show that with noise filtering one can obtain reliable diagnostics at least down to a S/N of 5. The many photospheric lines present in the NUV window provide velocity information for at least eight distinct photospheric heights. Using line-free regions in the h and k far wings, we derive good estimates of photospheric temperature for at least three heights. Both of these diagnostics, in particular the latter, can be obtained even at S/Ns as low as 5.

  12. THE NEAR-ULTRAVIOLET LUMINOSITY FUNCTION OF YOUNG, EARLY M-TYPE DWARF STARS

    SciTech Connect (OSTI)

    Ansdell, Megan; Baranec, Christoph; Gaidos, Eric; Mann, Andrew W.; Lépine, Sebastien; James, David; Buccino, Andrea; Mauas, Pablo; Petrucci, Romina; Law, Nicholas M.; Riddle, Reed

    2015-01-01

    Planets orbiting within the close-in habitable zones of M dwarf stars will be exposed to elevated high-energy radiation driven by strong magnetohydrodynamic dynamos during stellar youth. Near-ultraviolet (NUV) irradiation can erode and alter the chemistry of planetary atmospheres, and a quantitative description of the evolution of NUV emission from M dwarfs is needed when modeling these effects. We investigated the NUV luminosity evolution of early M-type dwarfs by cross-correlating the Lépine and Gaidos catalog of bright M dwarfs with the Galaxy Evolution Explorer (GALEX) catalog of NUV (1771-2831 Ĺ) sources. Of the 4805 sources with GALEX counterparts, 797 have NUV emission significantly (>2.5?) in excess of an empirical basal level. We inspected these candidate active stars using visible-wavelength spectra, high-resolution adaptive optics imaging, time-series photometry, and literature searches to identify cases where the elevated NUV emission is due to unresolved background sources or stellar companions; we estimated the overall occurrence of these ''false positives'' (FPs) as ?16%. We constructed an NUV luminosity function that accounted for FPs, detection biases of the source catalogs, and GALEX upper limits. We found the NUV luminosity function to be inconsistent with predictions from a constant star-formation rate and simplified age-activity relation defined by a two-parameter power law.

  13. Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

    SciTech Connect (OSTI)

    Ahmed, Musahid; Ahmed, Musahid; Wilson, Kevin R.; Belau, Leonid; Kostko, Oleg

    2008-05-12

    In this work we report on thevacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuumultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH + (n=1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH)n(H2O)H + (n=2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH +, (CH 3OH)2 +, (CH3OH)nH + (n=1-9), and (CH 3OH)n(H2O)H + (n=2-9 ) as a function of photon energy. With an increase in the water content in the molecular beam, there is an enhancement of photoionization intensity for methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  14. On the role of chemical reactions in initiating ultraviolet laser ablation in poly(methyl methacrylate)

    SciTech Connect (OSTI)

    Prasad, Manish; Conforti, Patrick F.; Garrison, Barbara J.

    2007-05-15

    The role of chemical reactions is investigated versus the thermal and mechanical processes occurring in a polymer substrate during irradiation by a laser pulse and subsequent ablation. Molecular dynamics simulations with an embedded Monte Carlo based reaction scheme were used to study ultraviolet ablation of poly(methyl methacrylate) at 157 nm. We discuss the onset of ablation, the mechanisms leading to ablation, and the role of stress relaxation of the polymer matrix during ablation. Laser induced heating and chemical decomposition of the polymer substrate are considered as ablation pathways. It is shown that heating the substrate can set off ablation via mechanical failure of the material only for very short laser pulses. For longer pulses, the mechanism of ejection is thermally driven limited by the critical number of bonds broken in the substrate. Alternatively, if the photon energy goes towards direct bond breaking, it initiates chemical reactions, polymer unzipping, and formation of gaseous products, leading to a nearly complete decomposition of the top layers of substrates. The ejection of small molecules has a hollowing out effect on the weakly connected substrates which can lead to lift-off of larger chunks. Excessive pressure buildup upon the creation of gaseous molecules does not lead to enhanced yield. The larger clusters are thermally ejected, and an entrainment of larger polymer fragments in gaseous molecules is not observed.

  15. Norathyriol Suppresses Skin Cancers Induced by Solar Ultraviolet Radiation by Targeting ERK Kinases

    SciTech Connect (OSTI)

    Li, Jixia; Malakhova, Margarita; Mottamal, Madhusoodanan; Reddy, Kanamata; Kurinov, Igor; Carper, Andria; Langfald, Alyssa; Oi, Naomi; Kim, Myoung Ok; Zhu, Feng; Sosa, Carlos P.; Zhou, Keyuan; Bode, Ann M.; Dong, Zigang

    2012-06-27

    Ultraviolet (UV) irradiation is the leading factor in the development of skin cancer, prompting great interest in chemopreventive agents for this disease. In this study, we report the discovery of norathyriol, a plant-derived chemopreventive compound identified through an in silico virtual screening of the Chinese Medicine Library. Norathyriol is a metabolite of mangiferin found in mango, Hypericum elegans, and Tripterospermum lanceolatum and is known to have anticancer activity. Mechanistic investigations determined that norathyriol acted as an inhibitor of extracellular signal-regulated kinase (ERK)1/2 activity to attenuate UVB-induced phosphorylation in mitogen-activated protein kinases signaling cascades. We confirmed the direct and specific binding of norathyriol with ERK2 through a cocrystal structural analysis. The xanthone moiety in norathyriol acted as an adenine mimetic to anchor the compound by hydrogen bonds to the hinge region of the protein ATP-binding site on ERK2. Norathyriol inhibited in vitro cell growth in mouse skin epidermal JB6 P+ cells at the level of G{sub 2}-M phase arrest. In mouse skin tumorigenesis assays, norathyriol significantly suppressed solar UV-induced skin carcinogenesis. Further analysis indicated that norathyriol mediates its chemopreventive activity by inhibiting the ERK-dependent activity of transcriptional factors AP-1 and NF-{kappa}B during UV-induced skin carcinogenesis. Taken together, our results identify norathyriol as a safe new chemopreventive agent that is highly effective against development of UV-induced skin cancer.

  16. Passive intrinsic-linewidth narrowing of ultraviolet extended-cavity diode laser by weak optical feedback

    E-Print Network [OSTI]

    Samutpraphoot, Polnop

    We present a simple method for narrowing the intrinsic Lorentzian linewidth of a commercial ultraviolet grating extended-cavity diode laser (TOPTICA DL Pro) using weak optical feedback from a long external cavity. We achieve ...

  17. Home ultraviolet light therapy for psoriasis: Why patients choose other options

    E-Print Network [OSTI]

    Dothard, Emily H.; Sandoval, Laura F.; Yentzer, Brad A.; Feldman, Steven R.

    2015-01-01

    of psoriasis [5]. A home light unit may therefore be theyou/your child for a home UV light device. I just need aboutFebruary 2015 Commentary Home ultraviolet light therapy for

  18. NEAR-ULTRAVIOLET PROPERTIES OF A LARGE SAMPLE OF TYPE Ia SUPERNOVAE...

    Office of Scientific and Technical Information (OSTI)

    SUPERNOVAE AS OBSERVED WITH THE Swift UVOT We present ultraviolet (UV) and optical photometry of 26 Type Ia supernovae (SNe Ia) observed from 2005 March to 2008 March with the...

  19. The far-ultraviolet UPS and downs of Alpha Centauri (Journal...

    Office of Scientific and Technical Information (OSTI)

    Centauri have yielded a detailed time history of far-ultraviolet (FUV: 1150-1700 ) emissions of the solarlike primary (A: G2 V) and the cooler but more active secondary (B: K1...

  20. MATING SYSTEM EVOLUTION, PLANT-POLLINATOR INTERACTIONS, AND FLORAL ULTRAVIOLET PATTERNING IN MIMULUS GUTTATUS

    E-Print Network [OSTI]

    Bodbyl-Roels, Sarah Ann

    2012-08-31

    speciation. In Chapter 4, I document within and among population variation in a cryptic floral trait, ultraviolet (UV) patterning. UV patterning is a visual stimulant for pollinators, but I found it in a selfing Mimulus species, suggesting that UV patterning...

  1. DETECTION OF NEUTRAL PHOSPHORUS IN THE NEAR-ULTRAVIOLET SPECTRA OF LATE-TYPE STARS

    E-Print Network [OSTI]

    Roederer, Ian U.

    We report the detection of several absorption lines of neutral phosphorus (P, Z = 15) in archival near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We ...

  2. Microbial Reduction on Eggshell Surfaces by the use of Hydrogen Peroxide and Ultraviolet Light 

    E-Print Network [OSTI]

    Gottselig, Steven Michael

    2011-10-21

    O2) in combination with ultraviolet light (UV) as an egg sanitization process on eggshell surfaces was studied. Preliminary experiments were conducted to develop an optimized methodology for eggshell disinfection that will be an effective...

  3. The development and application of a diode-laser-based ultraviolet absorption sensor for nitric oxide 

    E-Print Network [OSTI]

    Anderson, Thomas Nathan

    2004-09-30

    This thesis describes the development of a new type of sensor for nitric oxide (NO) that can be used in a variety of combustion diagnostics and control applications. The sensor utilizes the absorption of ultraviolet (UV) ...

  4. The lower extremity dexterity test as a measure of lower extremity dynamical capability

    E-Print Network [OSTI]

    Valero-Cuevas, Francisco

    Angeles, CA 90089-9006, United States b Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States c School of Applied Physiology the extent to which it is associated with lower extremity strength and anthropometry in healthy young adults

  5. Spatially Penalized Regression for Extremes Dependence Analysis and Prediction: Case of Precipitation Extremes

    E-Print Network [OSTI]

    Obradovic, Zoran

    Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA 3 School, and determine predictive power, under non-stationary climate. We have developed a data-dependent method Precipitation, Climate Change, Extremes Regression, Elastic Net, Sparse Modeling.. Permission to make digital

  6. Ultraviolet light absorbers having two different chromophors in the same molecule

    DOE Patents [OSTI]

    Vogl, O.; Li, S.

    1983-10-06

    This invention relates to novel ultraviolet light absorbers having two chromophors in the same molecule, and more particularly to benzotriazole substituted dihydroxybenzophenones and acetophenones. More particularly, this invention relates to 3,5-(di(2H-benzotriazole-2-yl))-2,4-dihydroxybenzophenone and 3,5-(di(2H-benzotriazole-2-yl))-2,4-dihydroxyacetophenone which are particularly useful as an ultraviolet light absorbers.

  7. Ultraviolet photodissociation of OCS: Product energy and angular distributions

    SciTech Connect (OSTI)

    McBane, G. C. [Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401 (United States); Schmidt, J. A.; Johnson, M. S. [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark); Schinke, R. [Max-Planck-Institut fuer Dynamik und Selbstorganisation (MPIDS), D-37077 Goettingen (Germany)

    2013-03-07

    The ultraviolet photodissociation of carbonyl sulfide (OCS) was studied using three-dimensional potential energy surfaces and both quantum mechanical dynamics calculations and classical trajectory calculations including surface hopping. The transition dipole moment functions used in an earlier study [J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys. 137, 054313 (2012)] were improved with more extensive treatment of excited electronic states. The new functions indicate a much larger contribution from the 1 {sup 1}A{sup Double-Prime} state ({sup 1}{Sigma}{sup -} in linear OCS) than was found in the previous work. The new transition dipole functions yield absorption spectra that agree with experimental data just as well as the earlier ones. The previously reported potential energy surfaces were also empirically modified in the region far from linearity. The resulting product state distributions P{sub v,j}, angular anisotropy parameters {beta}(j), and carbon monoxide rotational alignment parameters A{sub 0}{sup (2)}(j) agree reasonably well with the experimental results, while those computed from the earlier transition dipole and potential energy functions do not. The higher-j peak in the bimodal rotational distribution is shown to arise from nonadiabatic transitions from state 2 {sup 1}A{sup Prime} to the OCS ground state late in the dissociation.

  8. The Swift-UVOT ultraviolet and visible grism calibration

    E-Print Network [OSTI]

    Kuin, N P M; Breeveld, A A; Page, M J; James, C; Lamoureux, H; Mehdipour, M; Still, M; Yershov, V; Brown, P J; Carter, M; Mason, K O; Kennedy, T; Marshall, F; Roming, P W A; Siegel, M; Oates, S; Smith, P J; De Pasquale, M

    2015-01-01

    We present the calibration of the Swift UVOT grisms, of which there are two, providing low-resolution field spectroscopy in the ultraviolet and optical bands respectively. The UV grism covers the range 1700-5000 Angstrom with a spectral resolution of 75 at 2600 Angstrom for source magnitudes of u=10-16 mag, while the visible grism covers the range 2850-6600 Angstrom with a spectral resolution of 100 at 4000 Angstrom for source magnitudes of b=12-17 mag. This calibration extends over all detector positions, for all modes used during operations. The wavelength accuracy (1-sigma) is 9 Angstrom in the UV grism clocked mode, 17 Angstrom in the UV grism nominal mode and 22 Angstrom in the visible grism. The range below 2740 Angstrom in the UV grism and 5200 Angstrom in the visible grism never suffers from overlapping by higher spectral orders. The flux calibration of the grisms includes a correction we developed for coincidence loss in the detector. The error in the coincidence loss correction is less than 20%. The...

  9. Probing the Role of Carbon in the Interstellar Ultraviolet Extinction

    E-Print Network [OSTI]

    Mishra, Ajay

    2015-01-01

    We probe the role of carbon in the ultraviolet (UV) extinction by examining the relations between the amount of carbon required to be locked up in dust [C/H]_dust with the 2175 Angstrom extinction bump and the far-UV extinction rise, based on an analysis of the extinction curves along 16 Galactic sightlines for which the gas-phase carbon abundance is known and the 2175 Angstrom extinction bump exhibits variable strengths and widths. We derive [C/H]_dust from the Kramers-Kronig relation which relates the wavelength-integrated extinction to the total dust volume. This approach is less model-dependent since it does not require the knowledge of the detailed optical properties and size distribution of the dust. We also derive [C/H]_dust from fitting the observed UV/optical/near-infrared extinction with a mixture of amorphous silicate and graphite. We find that the carbon depletion [C/H]_dust tends to correlate with the strength of the 2175 Angstrom bump, while the abundance of silicon depleted in dust shows no cor...

  10. Matter Under Extreme Conditions: The Early Years

    E-Print Network [OSTI]

    Keeler, R Norris

    2010-01-01

    Extreme conditions in natural flows are examined, starting with a turbulent big bang. A hydro-gravitational-dynamics cosmology model is adopted. Planck-Kerr turbulence instability causes Planck-particle turbulent combustion. Inertial-vortex forces induce a non-turbulent kinetic energy cascade to Planck-Kolmogorov scales where vorticity is produced, overcoming 10^113 Pa Planck-Fortov pressures. The spinning, expanding fireball has a slight deficit of Planck antiparticles. Space and mass-energy powered by gluon viscous stresses expand exponentially at speeds >10^25 c. Turbulent temperature and spin fluctuations fossilize at scales larger than ct, where c is light speed and t is time. Because â??dark-energyâ?ť antigravity forces vanish when inflation ceases, and because turbulence produces entropy, the universe is closed and will collapse and rebound. Density and spin fossils of big bang turbulent mixing trigger structure formation in the plasma epoch. Fragmenting protosuperclustervoids and protoclustervoi...

  11. Left-Wing Extremism: The Current Threat

    SciTech Connect (OSTI)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  12. A Road Map to Extreme High Vacuum

    SciTech Connect (OSTI)

    Ganapati Rao Myneni

    2007-06-20

    Ultimate pressure of a well-designed vacuum system very much depends on pretreatments, processing and the procedures [1,2]. Until now much attention has been paid in minimizing hydrogen outgassing from the chamber material. However, procedures and processing deserves further scrutiny than hitherto given so far. For reducing the gas load, high sensitivity helium leak detection techniques with sensitivities better than 1× 10-12 Torr l/sec need to be used. Effects that are induced by vacuum instrumentation need to be reduced in order to obtain accurate pressure measurements. This presentation will discuss: clean assembly procedures, metal sponges for cryosorption pumping of hydrogen to extreme high vacuum, low cost surface diffusion barriers for reducing the hydrogen gas load, cascade pumping, sensitive helium leak detection techniques and the use of modified extractor and residual gas analyzers. Further, alternative back up pumping systems based on active NEG’s [3] for turbo molecular pumps will be presented.

  13. Monitoring Extreme-scale Lustre Toolkit

    SciTech Connect (OSTI)

    Brim, Michael J; Lothian, Josh

    2015-01-01

    We discuss the design and ongoing development of the Monitoring Extreme-scale Lustre Toolkit (MELT), a unified Lustre performance monitoring and analysis infrastructure that provides continuous, low-overhead summary information on the health and performance of Lustre, as well as on-demand, in-depth problem diagnosis and root-cause analysis. The MELT infrastructure leverages a distributed overlay network to enable monitoring of center-wide Lustre filesystems where clients are located across many network domains. We preview interactive command-line utilities that help administrators and users to observe Lustre performance at various levels of resolution, from individual servers or clients to whole filesystems, including job-level reporting. Finally, we discuss our future plans for automating the root-cause analysis of common Lustre performance problems.

  14. Near-horizon Extreme Kerr Magnetospheres

    E-Print Network [OSTI]

    Compčre, G

    2015-01-01

    Analytical solutions to force-free electrodynamics around black holes are fundamental to build simple models of accretion disk and jet dynamics. We present a (non-exhaustive) classification of complex highest weight solutions to the force-free equations in the near-horizon region of the extremal Kerr black hole. Bounds on the weights of solutions are derived from the finiteness of energy and the existence of a variational principle. Two classes of real magnetically dominated solutions, respectively axisymmetric and non-axisymmetric, are described which admit finite energy with respect to the asymptotically flat observer. Subtleties related to the velocity of light surface in the near-horizon region are discussed.

  15. Non-extremal fuzzballs and ergoregion emission

    E-Print Network [OSTI]

    Borun D. Chowdhury; Samir D. Mathur

    2008-10-23

    In the traditional picture of black holes Hawking radiation is created by pair creation from the vacuum at the horizon. In the fuzzball proposal, individual microstates do not have a horizon with the `vacuum' state in its vicinity. For a special family of non-extremal microstates it was recently found that emission occurs due to pair creation in an ergoregion, rather than at a horizon. In this paper we extend this result to a slightly larger class of microstates, again finding exact agreement between the emission in the gravity picture and the CFT dual. We write down an expression for emission from geometries with ergoregions, in terms of the leading falloff behavior of the wavefunctions in the fuzzball region. Finally, we describe another family of nonextremal microstates and find their ergoregion.

  16. Wavefront Control for Extreme Adaptive Optics

    SciTech Connect (OSTI)

    Poyneer, L A

    2003-07-16

    Current plans for Extreme Adaptive Optics systems place challenging requirements on wave-front control. This paper focuses on control system dynamics, wave-front sensing and wave-front correction device characteristics. It may be necessary to run an ExAO system after a slower, low-order AO system. Running two independent systems can result in very good temporal performance, provided specific design constraints are followed. The spatially-filtered wave-front sensor, which prevents aliasing and improves PSF sensitivity, is summarized. Different models of continuous and segmented deformable mirrors are studied. In a noise-free case, a piston-tip-tilt segmented MEMS device can achieve nearly equivalent performance to a continuous-sheet DM in compensating for a static phase aberration with use of spatial filtering.

  17. Recovery from ultraviolet-induced threshold voltage shift in indium gallium zinc oxide thin film transistors by positive gate bias

    SciTech Connect (OSTI)

    Liu, P.; Chen, T. P.; Li, X. D.; Wong, J. I.; Liu, Z.; Liu, Y.; Leong, K. C.

    2013-11-11

    The effect of short-duration ultraviolet (UV) exposure on the threshold voltage (V{sub th}) of amorphous indium gallium zinc oxide thin film transistors (TFTs) and its recovery characteristics were investigated. The V{sub th} exhibited a significant negative shift after UV exposure. The V{sub th} instability caused by UV illumination is attributed to the positive charge trapping in the dielectric layer and/or at the channel/dielectric interface. The illuminated devices showed a slow recovery in threshold voltage without external bias. However, an instant recovery can be achieved by the application of positive gate pulses, which is due to the elimination of the positive trapped charges as a result of the presence of a large amount of field-induced electrons in the interface region.

  18. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H. [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Fu, Yi-Keng; Chu, Mu-Tao [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan (China); Huang, Shyh-Jer, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States); Su, Yan-Kuin, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electronic Engineering, Kun-Shan University, Tainan 71003, Taiwan (China); Wang, Kang L. [Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States)

    2014-03-21

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL.

  19. Collateral Damage In Iraq and Capital Punishment in the U.S.: How the Public Makes Sense of Extreme Violence and Death

    E-Print Network [OSTI]

    Capps, Jason Scott

    2010-07-28

    Collateral Damage in Iraq and Capital Punishment in the U.S.: How the Public Makes Sense of Extreme Violence and Death This dissertation investigates the tendencies, attitudes, beliefs, ideologies, and narratives that citizens in the Pacific...

  20. Extreme Environment Silicon Carbide Hybrid Temperature & Pressure Optical Sensors

    SciTech Connect (OSTI)

    Nabeel Riza

    2010-09-01

    This final report contains the main results from a 3-year program to further investigate the merits of SiC-based hybrid sensor designs for extreme environment measurements in gas turbines. The study is divided in three parts. Part 1 studies the material properties of SiC such as temporal response, refractive index change with temperature, and material thermal response reversibility. Sensor data from a combustion rig-test using this SiC sensor technology is analyzed and a robust distributed sensor network design is proposed. Part 2 of the study focuses on introducing redundancy in the sensor signal processing to provide improved temperature measurement robustness. In this regard, two distinct measurement methods emerge. A first method uses laser wavelength sensitivity of the SiC refractive index behavior and a second method that engages the Black-Body (BB) radiation of the SiC package. Part 3 of the program investigates a new way to measure pressure via a distance measurement technique that applies to hot objects including corrosive fluids.

  1. The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). V. Ultraviolet diffuse emission and cirrus properties in the Virgo cluster direction

    E-Print Network [OSTI]

    Boissier, S; Voyer, E; Bianchi, S; Pappalardo, C; Guhathakurta, P; Heinis, S; Cortese, L; Duc, P -A; Cuillandre, J -C; Davies, J I; Smith, M W L

    2015-01-01

    CONTEXT: The Virgo direction has been observed at many wavelengths in the recent years, in particular in the ultraviolet with GALEX. The far ultraviolet (FUV) diffuse light detected by GALEX bears interesting information on the large scale distribution of Galactic dust, owing to the GALEX FUV band sensitivity and resolution. AIMS: We aim to characterise the ultraviolet large scale distribution of diffuse emission in the Virgo direction. A map of this emission may become useful for various studies by identifying regions where dust affects observations by either scattering light or absorbing radiation. METHODS: We construct mosaics of the FUV and near ultraviolet diffuse emission over a large sky region (RA 12 to 13 hours, DEC 0 to 20 degrees) surrounding the Virgo cluster, using all the GALEX available data in the area. We test for the first time the utilisation of the FUV diffuse light as a Galactic extinction E(B-V) tracer. RESULTS: The FUV diffuse light scattered on cirrus reveals details in their geometry....

  2. An investigation of symmetry in upper extremity strength during sagittal plane lifting tasks 

    E-Print Network [OSTI]

    Key, Wendy Ross

    1994-01-01

    effective in estimating the maximum acceptable weight for a lift (Aghazadeh and Ayoub, 1985). Biomechanical models consider many variables, including posture, gender, strength capabilities, coefficient of static friction, and anthropometry. In two...

  3. Self-organized micro-holes on titania based sol-gel films under continuous direct writing with a continuous wave ultraviolet laser

    SciTech Connect (OSTI)

    Bakhti, S.; Destouches, N.; Gamet, E.; Reynaud, S. [University of Lyon, F. 42023 Saint-Etienne (France) [University of Lyon, F. 42023 Saint-Etienne (France); CNRS, UMR 5516, Laboratoire Hubert Curien, 18 Rue Pr. Lauras F-42000 Saint-Etienne (France); University of Saint-Etienne, Jean Monnet, F-42000 Saint-Etienne (France); Balan, L. [Institut de Sciences des Materiaux de Mulhouse, CNRS UMR 7361, Universite de Haute Alsace, 15 rue Jean Starcky, 68057 Mulhouse (France)] [Institut de Sciences des Materiaux de Mulhouse, CNRS UMR 7361, Universite de Haute Alsace, 15 rue Jean Starcky, 68057 Mulhouse (France)

    2013-05-27

    The microstructuring of titania based sol-gel films is investigated by direct writing with a continuous wave ultraviolet laser beam emitting at 244 nm. Depending on the exposure conditions, the films exhibit a volume expansion, a volume shrinkage, a self-shaped delamination, or are damaged. This paper is mainly focused on the regime where spontaneous local delamination occurs, which corresponds to a narrow range of laser irradiances and writing speeds. In this regime, self-organized round-shape micro-holes opened on the substrate are generated.

  4. Nanodiamond dust and the far-ultraviolet quasar break

    E-Print Network [OSTI]

    L. Binette; G. Magris C.; Y. Krongold; C. Morisset; S. Haro-Corzo; J. A. de Diego; H. Mutschke; A. C. Andersen

    2005-05-29

    We explore the possibility that the steepening observed shortward of 1000A in the energy distribution of quasars may result from absorption by dust, being either intrinsic to the quasar environment or intergalactic. We find that a dust extinction curve consisting of nanodiamonds, composed of terrestrial cubic diamonds or with surface impurities as found in carbonaceous chondrite meteorites, such as Allende, is successful in reproducing the sharp break observed. The intergalactic dust model is partially successful in explaining the shape of the composite energy distribution, but must be discarded in the end, as the amount of crystalline dust required is unreasonable and would imply an improbable fine tuning among the dust formation processes. The alternative intrinsic dust model requires a mixture of both cubic diamonds and Allende nanodiamonds and provide a better fit of the UV break. The gas column densities implied are of the order 10^{20} cm^{-2} assuming solar metallicity for carbon and full depletion of carbon into dust. The absorption only occurs in the ultraviolet and is totally negligible in the visible. The minimum dust mass required is of the order ~ 0.003 r_{pc}^{2}M_o, where r_{pc} is the distance in parsec between the dust screen and the continuum source. The intrinsic dust model reproduces the flux {\\it rise} observed around 660A in key quasar spectra quite well. We present indirect evidence of a shallow continuum break near 670A (18.5 eV), which would be intrinsic to the quasar continuum.

  5. DISCOVERY AND CHARACTERIZATION OF AN EXTREMELY DEEP-ECLIPSING...

    Office of Scientific and Technical Information (OSTI)

    DISCOVERY AND CHARACTERIZATION OF AN EXTREMELY DEEP-ECLIPSING CATACLYSMIC VARIABLE: LSQ172554.8-643839 Citation Details In-Document Search Title: DISCOVERY AND CHARACTERIZATION OF...

  6. An extremal problem for a class of entire functions

    E-Print Network [OSTI]

    2015-09-26

    An extremal problem for a class of entire. functions. Alexandre Eremenko? and Peter Yuditskii†. May 29, 2008. Abstract. Soi f une fonction enti`ere de type ...

  7. Climate, extreme heat, and electricity demand in California

    E-Print Network [OSTI]

    Miller, N.L.

    2008-01-01

    warming and electricity demand: A study of California.Extreme Heat, and Electricity Demand in California Norman L.high temperature and electricity demand for air-conditioned

  8. LDRD symposium focuses on materials in extremes, big data, and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    LDRD symposium focuses on materials in extremes, big data, and energy use impacts | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission...

  9. Symmetry Lowering in Extreme-Electron-Density Perovskite Quantum Wells

    E-Print Network [OSTI]

    Zhang, Jack Y.; Hwang, Jinwoo; Raghavan, Santosh; Stemmer, Susanne

    2013-01-01

    in Extreme-Electron-Density Perovskite Quantum Wells Jack Y.in the ideal cubic perovskite structure. The insulatingan orthorhombic distorted perovskite (space group Pnma [17])

  10. Metabolically active eukaryotic communities in extremely acidic mine drainage

    E-Print Network [OSTI]

    Baker, Brett J; Lutz, M A; Dawson, S C; Bond, P L; Banfield, J F

    2004-01-01

    Microbial communities in acid mine drainage. FEMS Microbiol.Biogeochem- istry of acid mine drainage at Iron Mountain,in an extreme acid mine drainage environment. Appl. Environ.

  11. Predictability of extreme events in a branching diffusion model Abstract

    E-Print Network [OSTI]

    2010-01-15

    proverbial “straws in the wind” preceding a hurricane. The following ... including the extreme ones, a cascade process responsible for redistribution of energy (or.

  12. Constraining UV continuum slopes of active galactic nuclei with cloudy models of broad-line region extreme-ultraviolet emission lines

    SciTech Connect (OSTI)

    Moloney, Joshua [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Michael Shull, J., E-mail: joshua.moloney@colorado.edu, E-mail: michael.shull@colorado.edu [Also at Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK. (United Kingdom)

    2014-10-01

    Understanding the composition and structure of the broad-line region (BLR) of active galactic nuclei (AGNs) is important for answering many outstanding questions in supermassive black hole evolution, galaxy evolution, and ionization of the intergalactic medium. We used single-epoch UV spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope to measure EUV emission-line fluxes from four individual AGNs with 0.49 ? z ? 0.64, two AGNs with 0.32 ? z ? 0.40, and a composite of 159 AGNs. With the CLOUDY photoionization code, we calculated emission-line fluxes from BLR clouds with a range of density, hydrogen ionizing flux, and incident continuum spectral indices. The photoionization grids were fit to the observations using single-component and locally optimally emitting cloud (LOC) models. The LOC models provide good fits to the measured fluxes, while the single-component models do not. The UV spectral indices preferred by our LOC models are consistent with those measured from COS spectra. EUV emission lines such as N IV ?765, O II ?833, and O III ?834 originate primarily from gas with electron temperatures between 37,000 K and 55,000 K. This gas is found in BLR clouds with high hydrogen densities (n {sub H} ? 10{sup 12} cm{sup –3}) and hydrogen ionizing photon fluxes (?{sub H} ? 10{sup 22} cm{sup –2} s{sup –1}).

  13. Decomposition of catechol and carbonaceous residues on TiO2,,110...: A model system for cleaning of extreme ultraviolet lithography optics

    E-Print Network [OSTI]

    Diebold, Ulrike

    oxidize and/or become contaminated with residual carbon, which significantly low- ers the mirror electron yield and rapid contamination of the reflective optics. In prototype mir- ror systems, the deposits are predominantly composed of car- bon and hydrogen with oxygen as a minority species.2,3 Capping

  14. OBSERVATIONS AND MODELING OF THE EMERGING EXTREME-ULTRAVIOLET LOOPS IN THE QUIET SUN AS SEEN WITH THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect (OSTI)

    Chitta, L. P.; Van Ballegooijen, A. A.; DeLuca, E. E.; Kariyappa, R.; Hasan, S. S.; Hanslmeier, A.

    2013-05-01

    We used data from the Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) to study coronal loops at small scales, emerging in the quiet Sun. With HMI line-of-sight magnetograms, we derive the integrated and unsigned photospheric magnetic flux at the loop footpoints in the photosphere. These loops are bright in the EUV channels of AIA. Using the six AIA EUV filters, we construct the differential emission measure (DEM) in the temperature range 5.7-6.5 in log T (K) for several hours of observations. The observed DEMs have a peak distribution around log T Almost-Equal-To 6.3, falling rapidly at higher temperatures. For log T < 6.3, DEMs are comparable to their peak values within an order of magnitude. The emission-weighted temperature is calculated, and its time variations are compared with those of magnetic flux. We present two possibilities for explaining the observed DEMs and temperatures variations. (1) Assuming that the observed loops are composed of a hundred thin strands with certain radius and length, we tested three time-dependent heating models and compared the resulting DEMs and temperatures with the observed quantities. This modeling used enthalpy-based thermal evolution of loops (EBTEL), a zero-dimensional (0D) hydrodynamic code. The comparisons suggest that a medium-frequency heating model with a population of different heating amplitudes can roughly reproduce the observations. (2) We also consider a loop model with steady heating and non-uniform cross-section of the loop along its length, and find that this model can also reproduce the observed DEMs, provided the loop expansion factor {gamma} {approx} 5-10. More observational constraints are required to better understand the nature of coronal heating in the short emerging loops on the quiet Sun.

  15. Therapy-resistant psoriasis treated with alefacept and subsequent narrow band ultraviolet B phototherapy with total clearing of psoriasis

    E-Print Network [OSTI]

    Scheinfeld, Noah

    2005-01-01

    and ultraviolet B light for treatment of psoriasis.Presented at: International Psoriasis Symposium. June 18-22;B light for treatment of psoriasis. Poster Presented at:

  16. The Young and the Dustless: Interpreting Radio Observations of UltraViolet Luminous Galaxies

    E-Print Network [OSTI]

    Antara R. Basu-Zych; David Schiminovich; Benjamin D. Johnson; Charles Hoopes; Roderik Overzier; Marie A. Treyer; Timothy M. Heckman; Tom A. Barlow; Luciana Bianchi; Tim Conrow; Jose Donas; Karl G. Forster; Peter G. Friedman; Young-Wook Lee; Barry F. Madore; D. Christopher Martin; Bruno Milliard; Patrick Morrissey; Susan G. Neff; R. Michael Rich; Samir Salim; Mark Seibert; Todd A. Small; Alex S. Szalay; Ted K. Wyder; Suk Young Yi

    2007-07-12

    Ultraviolet Luminous Galaxies (UVLGs) have been identified as intensely star-forming, nearby galaxies. A subset of these, the supercompact UVLGs, are believed to be local analogs of high redshift Lyman Break Galaxies. Here we investigate the radio continuum properties of this important population for the first time. We have observed 42 supercompact UVLGs with the VLA, all of which have extensive coverage in the UV/optical by GALEX and SDSS. Our analysis includes comparison samples of multiwavelength data from the Spitzer First Look Survey and from the SDSS-Galex matched catalogs. In addition we have Spitzer MIPS data for 24 of our galaxies and find that they fall on the radio-FIR correlation of normal star-forming galaxies. We find that our galaxies have lower radio-to-UV ratios and lower Balmer decrements than other local galaxies with similar (high) star formation rates. Optical spectra show they have lower Dn(4000) and HdeltaA indices, higher Hbeta emission-line equivalents widths, and higher [OIII]5007/Hbeta emission-line ratios than normal star forming galaxies. Comparing these results to galaxy spectral evolution models we conclude that supercompact UVLGs are distinguished from normal star forming galaxies firstly by their high specific star formation rates. Moreover, compared to other types of galaxies with similar star formation rates, they have significantly less dust attenuation. In both regards they are similar to Lyman Break Galaxies. This suggests that the process that causes star formation in the supercompact UVLGs differs from other local star forming galaxies, but may be similar to Lyman Break Galaxies.

  17. Extreme Loads for an Offshore Wind Turbine using Statistical

    E-Print Network [OSTI]

    Manuel, Lance

    Extreme Loads for an Offshore Wind Turbine using Statistical Extrapolation from Limited Field Data,itiscommontoeithercarry out extensive simulation studies or undertake a field measurement campaign. At the Blyth offshore wind here is to estimate extreme loads for an offshore wind turbine for which the environmental and load

  18. Wind Extremes and Scales: Multifractal Insights and Empirical Evidence

    E-Print Network [OSTI]

    Lovejoy, Shaun

    17 Wind Extremes and Scales: Multifractal Insights and Empirical Evidence I. Tchiguirinskaia, D. Schertzer, S. Lovejoy, J.M. Veysseire Summary. An accurate assessment of wind extremes at various space-time scales (e.g. gusts, tempests, etc.) is of prime importance for a safe and efficient wind energy

  19. UN Millennium Development Goal 1 Eradicate Extreme Poverty and Hunger

    E-Print Network [OSTI]

    Gasch, Audrey P.

    UN Millennium Development Goal 1 Eradicate Extreme Poverty and Hunger QUICK FACTS The World Bank estimates that 1.4 bill people in developing countries were living in extreme poverty in 2005. Recent into absolute poverty. About 25% of children under

  20. Extreme Scale Computer Architecture: Energy Efficiency from the Ground Up

    E-Print Network [OSTI]

    Torrellas, Josep

    .... CPU module Board Cabinet #12;5 Low Voltage Operation · Vdd reduction is the best lever for energyExtreme Scale Computer Architecture: Energy Efficiency from the Ground Up Josep Torrellas, Automation & Test in Europe (DATE) March 2014 #12;1 · Extreme Scale computing: 100-1000x more capable

  1. PROBLEM APPLICATIONS: EXERCISE SESSION ON ANALYSES OF EXTREMES

    E-Print Network [OSTI]

    Katz, Richard

    statistical programming language R. #12;2 TUTORIAL: Part 1 INTRODUCTION TO EXTREMES TOOLKIT AND CLIMATE as covariate) #12;4 PREPARATION (if use own laptop) Statistical programming language R (open source): DownloadRemes package within R (No familiarity with extRemes assumed) RESOURCES R: The R Project for Statistical

  2. Extremely red stellar objects revealed by IPHAS

    E-Print Network [OSTI]

    N. J. Wright; R. Greimel; M. J. Barlow; J. E. Drew; M. -R. L. Cioni; A. A. Zijlstra; R. L. M. Corradi; E. A. González-Solares; P. Groot; J. Irwin; M. J. Irwin; A. Mampaso; R. A. H. Morris; D. Steeghs; Y. C. Unruh; N. Walton

    2008-11-04

    We present photometric analysis and follow-up spectroscopy for a population of extremely red stellar objects extracted from the point-source catalogue of the INT Photometric H-Alpha Survey (IPHAS) of the northern galactic plane. The vast majority of these objects have no previous identification. Analysis of optical, near- and mid-infrared photometry reveals that they are mostly highly-reddened asymptotic giant branch stars, with significant levels of circumstellar material. We show that the distribution of these objects traces galactic extinction, their highly reddened colours being a product of both interstellar and circumstellar reddening. This is the first time that such a large sample of evolved low-mass stars has been detected in the visual and allows optical counterparts to be associated with sources from recent infrared surveys. Follow-up spectroscopy on some of the most interesting objects in the sample has found significant numbers of S-type stars which can be clearly separated from oxygen-rich objects in the IPHAS colour-colour diagram. We show that this is due to the positions of different molecular bands relative to the narrow-band H-alpha filter used for IPHAS observations. The IPHAS (r' - H-alpha) colour offers a valuable diagnostic for identifying S-type stars. A selection method for identifying S-type stars in the galactic plane is briefly discussed and we estimate that over a thousand new objects of this type may be discovered, potentially doubling the number of known objects in this short but important evolutionary phase.

  3. Extreme seasonality of litter breakdown in an arctic spring-fed stream is driven by shredder phenology, not

    E-Print Network [OSTI]

    Benstead, Jon

    regimes. We used an alternative approach to investigate the importance of temperature by quantifying seasonal patterns in litter breakdown in an arctic spring-fed stream (Ivishak Spring, North Slope, Alaska) that experiences extreme seasonality in light availability and energy inputs while fluctuations in water

  4. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    SciTech Connect (OSTI)

    Sloan Roberts, F.; Anderson, Scott L. [Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112 (United States)] [Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112 (United States)

    2013-12-15

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a “soft” photoionization source for gas-phase mass spectrometry.

  5. Floriculture and Greenhouse Crops Utilization of ultraviolet-C (UV-C) irradiation on ornamental plants for disease

    E-Print Network [OSTI]

    Chen, Tsuhan

    Floriculture and Greenhouse Crops Utilization of ultraviolet-C (UV-C) irradiation on ornamental the effects of ultraviolet-C irradiation (UV-C) on commercially-valuable greenhouse ornamental plants UV lamps (Osram HNS OFR) have been suspended in the LIHREC greenhouses over greenhouse benches. Each

  6. Deep-Ultraviolet Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX, and RDX

    E-Print Network [OSTI]

    Asher, Sanford A.

    Deep-Ultraviolet Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX, and RDX Manash nitrate (NH4NO3), pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT), nitroamine (HMX. The ultraviolet (UV) resonance Raman/differential Raman cross-sections of NH4NO3, PETN, TNT, HMX, and RDX

  7. Re-evaluation of SO2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared satellite sensors

    E-Print Network [OSTI]

    Rose, William I.

    Re-evaluation of SO2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared Infrared Radiation Sounder/2) sensor, whose data sets have a higher temporal resolution, are also analyzed ultraviolet and infrared satellite sensors, Geochem. Geophys. Geosyst., 5, Q04001, doi:10.1029/ 2003GC000654

  8. Thermodynamics of the Near-Extremal NS5-brane

    E-Print Network [OSTI]

    T. Harmark; N. A. Obers

    2005-10-25

    We consider the thermodynamics of the near-extremal NS5-brane in type IIA string theory. The central tool we use is to map phases of six-dimensional Kaluza-Klein black holes to phases of near-extremal M5-branes with a transverse circle in eleven-dimensional supergravity. By S-duality these phases correspond to phases of the near-extremal type IIA NS5-brane. One of our main results is that in the canonical ensemble the usual near-extremal NS5-brane background, dual to a uniformly smeared near-extremal M5-brane, is subdominant to a new background of near-extremal M5-branes localized on the transverse circle. This new stable phase has a limiting temperature, which lies above the Hagedorn temperature of the usual NS5-brane phase. We discuss the limiting temperature and compare the different behavior of the NS5-brane in the canonical and microcanonical ensembles. We also briefly comment on the thermodynamics of near-extremal Dp-branes on a transverse circle.

  9. Prenatal Risk and Protective Factors for Childhood Cancer: Investigating the Effects of Ultraviolet Radiation, Pesticide Exposure, and Maternal Diet

    E-Print Network [OSTI]

    Lombardi, Christina

    2013-01-01

    study based on solar radiation data from NASA relying onwith data from the National Solar Radiation Database. Ourusing data from the National Solar Radiation Database from

  10. Vacuum-ultraviolet ionization spectroscopy of the jet-cooled RNA-base Kyo-Won Choi, Joo-Hee Lee and Sang Kyu Kim*

    E-Print Network [OSTI]

    Kim, Sang Kyu

    Vacuum-ultraviolet ionization spectroscopy of the jet-cooled RNA-base uracil Kyo-Won Choi, Joo accurately and precisely determined for the first time using a vacuum-ultraviolet mass-analyzed threshold be used for the clarification of the latter in this report. Here, we employ a vacuum-ultraviolet mass

  11. Lubricating bacteria model for the growth of bacterial colonies exposed to ultraviolet radiation

    SciTech Connect (OSTI)

    Zhang Shengli; Zhang Lei; Liang Run; Zhang Erhu; Liu Yachao; Zhao Shumin

    2005-11-01

    In this paper, we study the morphological transition of bacterial colonies exposed to ultraviolet radiation by modifying the bacteria model proposed by Delprato et al. Our model considers four factors: the lubricant fluid generated by bacterial colonies, a chemotaxis initiated by the ultraviolet radiation, the intensity of the ultraviolet radiation, and the bacteria's two-stage destruction rate with given radiation intensities. Using this modified model, we simulate the ringlike pattern formation of the bacterial colony exposed to uniform ultraviolet radiation. The following is shown. (1) Without the UV radiation the colony forms a disklike pattern and reaches a constant front velocity. (2) After the radiation is switched on, the bacterial population migrates to the edge of the colony and forms a ringlike pattern. As the intensity of the UV radiation is increased the ring forms faster and the outer velocity of the colony decreases. (3) For higher radiation intensities the total population decreases, while for lower intensities the total population increases initially at a small rate and then decreases. (4) After the UV radiation is switched off, the bacterial population grows both outward as well as into the inner region, and the colony's outer front velocity recovers to a constant value. All these results agree well with the experimental observations [Phys. Rev. Lett. 87, 158102 (2001)]. Along with the chemotaxis, we find that lubricant fluid and the two-stage destruction rate are critical to the dynamics of the growth of the bacterial colony when exposed to UV radiation, and these were not previously considered.

  12. Ultraviolet Spectroscopy of Protein Backbone Transitions in Aqueous Solution: Combined QM and MM Simulations

    E-Print Network [OSTI]

    Mukamel, Shaul

    Ultraviolet Spectroscopy of Protein Backbone Transitions in Aqueous Solution: Combined QM and MM (MM) calculations is developed to simulate the n f * and f * backbone transitions of proteins using a new algorithm, EHEF, which combines a molecular dynamics (MD) trajectory obtained with a MM

  13. NANODIAMOND DUST AND THE FAR-ULTRAVIOLET QUASAR BREAK Luc Binette,1

    E-Print Network [OSTI]

    Morisset, Christophe

    NANODIAMOND DUST AND THE FAR-ULTRAVIOLET QUASAR BREAK Luc Binette,1 Gladis Magris C.,2 Yair curve consisting of nanodiamonds, composed of terrestrial cubic diamonds or with surface impurities intrinsic dust model requires a mixture of both cubic diamonds and Allende nanodiamonds and provides

  14. First detection of an ultraviolet transition in an ionized polycyclic aromatic hydrocarbon

    E-Print Network [OSTI]

    ; accepted 3 May 1999 We report the first measurement of a polycyclic aromatic hydrocarbon cation electronicFirst detection of an ultraviolet transition in an ionized polycyclic aromatic hydrocarbon Xavier D of Physics. S0021-9606 99 02226-6 I. INTRODUCTION Polycyclic aromatic hydrocarbon PAH ions are prom- ising

  15. Global methane emission estimates from ultraviolet irradiation of terrestrial plant foliage

    E-Print Network [OSTI]

    Palmer, Paul

    of ultraviolet (UV) radiation-driven CH4 emissions from foliar pectin as a global CH4 source. · We combine source of UV-driven CH4 emissions and that other environmental stresses may also generate CH4 global warming potential 25 times that of CO2, and its current atmospheric concentration of 1.8 ppm makes

  16. Signatures of the Protein Folding Pathway in Two-Dimensional Ultraviolet Spectroscopy

    E-Print Network [OSTI]

    Mukamel, Shaul

    Signatures of the Protein Folding Pathway in Two-Dimensional Ultraviolet Spectroscopy Jun Jiang of the signals provides a quantitative marker of protein folding status, accessible by both theoretical calculations and experiments. SECTION: Biophysical Chemistry and Biomolecules Protein folding is an important

  17. EuroGeo4 Paper number 226 INSTALLATION AND ULTRAVIOLET EXPOSURE DAMAGE OF GEOTEXTILES

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    EuroGeo4 Paper number 226 1 INSTALLATION AND ULTRAVIOLET EXPOSURE DAMAGE OF GEOTEXTILES Benjamim, C-mail: zornberg@mail.utexas.edu) Abstract: A better understanding on the behavior of geotextile-reinforced soil material characterization program. Accordingly, eight prototype geotextile-reinforced soil structures were

  18. Non-thermal calcination by ultraviolet irradiation in the synthesis of microporous materials

    E-Print Network [OSTI]

    Parikh, Atul N.

    Non-thermal calcination by ultraviolet irradiation in the synthesis of microporous materials Atul N-directing agents in the synthesis of microporous materials. The method relies on the exposure of the sample. This method is applicable in making new materials from organic­inorganic pre- cursors and holds promise

  19. Geocomputation's future at the extremes: high performance computing and nanoclients

    E-Print Network [OSTI]

    Clarke, Keith

    Geocomputation's future at the extremes: high performance computing and nanoclients K.C. Clarke; High performance computing; Tractability; Geocom- putation E-mail address: kclarke@geog.ucsb.edu (K

  20. Monitoring and Understanding Trends in Extreme Storms: State of Knowledge

    E-Print Network [OSTI]

    Kunkel, Kenneth E.

    The state of knowledge regarding trends and an understanding of their causes is presented for a specific subset of extreme weather and climate types. For severe convective storms (tornadoes, hailstorms, and severe ...

  1. Extreme natural hazards: population growth, globalization and environmental change

    E-Print Network [OSTI]

    Huppert, Herbert

    in the affected countries, brought home to the world the realities of the danger. We live in times of increasing also be affecting the frequency of extreme weather events as well as the vulnerability of coastal areas

  2. Transition-metal-hydrogen systems at extreme conditions 

    E-Print Network [OSTI]

    Scheler, Thomas Herbert

    2013-07-01

    The application of extreme conditions offers a general route for the synthesis of materials under equilibrium conditions. By finely tuning the thermodynamic variables of pressure and temperature one can manipulate matter ...

  3. Calculation of Extreme Wave Loads on Coastal Highway Bridges 

    E-Print Network [OSTI]

    Meng, Bo

    2010-01-14

    Coastal bridges are exposed to severe wave, current and wind forces during a hurricane. Most coastal bridges are not designed to resist wave loads in such extreme situations, and there are no existing analytical methods to calculate wave loads...

  4. Performance and biocompatibility of extremely tough alginate/polyacrylamide hydrogels

    E-Print Network [OSTI]

    Suo, Zhigang

    National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20982 the further exploration of extremely tough alginate/PAAM IPN hydrogels as biomaterials. Ó 2013 Elsevier Ltd

  5. The development of an index for the proximal upper extremity 

    E-Print Network [OSTI]

    Walline, Erin Kurusz

    2006-08-16

    extremity constructs were proposed: a fatigue-based model and a compressive load-based model. The constructs incorporated lessons learned from the literature and results from the epidemiological study. Validation of the models was performed using data from...

  6. SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND...

    Office of Environmental Management (EM)

    @ E A R T H L I N K . N E T SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND CHARACTERISTICS AT NUCLEAR FACILITY SITES Categorization of Natural Hazard Phenomenon...

  7. New analogies between extreme QCD and cold atoms

    SciTech Connect (OSTI)

    Nishida, Yusuke

    2012-08-15

    We discuss two new analogies between extreme QCD and cold atoms. One is the analogue of 'hard probes' in cold atoms. The other is the analogue of 'quark-hadron continuity' in cold atoms.

  8. Mesoscale predictability of an extreme warm-season precipitation event 

    E-Print Network [OSTI]

    Odins, Andrew Michael

    2005-02-17

    During the period of June 29 through July 6, 2002, an extreme precipitation event occurred over Texas, resulting in catastrophic flooding. Operational forecasts performed poorly, neither predicting the copious amounts of ...

  9. SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND...

    Office of Environmental Management (EM)

    Review for the 10 Year Extreme Wind Update at the DOE Pantex Site DOE Standard 1020 - Natural Phenomena Hazard analysis and Design Criteria for DOE Facilities DOE-STD-1020-2012...

  10. Spectroscopic Investigations of Selected Cyclic and Bicyclic Molecules 

    E-Print Network [OSTI]

    McCann, Kathleen Rae

    2010-10-12

    fluorescence spectroscopy of jet-cooled molecules along with ultraviolet absorption spectroscopy. In recent years the group has investigated a number of bicyclic molecules containing the benzene ring including tetralin7 (TET) and 1,4-benzodioxan8 (14BZD.... stretch 3081 [3047] A? 26 35 Benzene stretch 756 722 2 2 C-H stretch [3072] [3028] 27 37 Benzene ring bend 712 682 3 3 C-H stretch 3060 R [3020] 28 39 Benzene ring bend 588 525 4 4 C-H stretch 3031 R [3005] 29 41 Sat. ring bend...

  11. Persisting cold extremes under 21st-century warming scenarios

    SciTech Connect (OSTI)

    Kodra, Evan A [ORNL; Steinhaeuser, Karsten J K [ORNL; Ganguly, Auroop R [ORNL

    2011-01-01

    Analyses of climate model simulations and observations reveal that extreme cold events are likely to persist across each land-continent even under 21st-century warming scenarios. The grid-based intensity, duration and frequency of cold extreme events are calculated annually through three indices: the coldest annual consecutive three-day average of daily maximum temperature, the annual maximum of consecutive frost days, and the total number of frost days. Nine global climate models forced with a moderate greenhouse-gas emissions scenario compares the indices over 2091 2100 versus 1991 2000. The credibility of model-simulated cold extremes is evaluated through both bias scores relative to reanalysis data in the past and multi-model agreement in the future. The number of times the value of each annual index in 2091 2100 exceeds the decadal average of the corresponding index in 1991 2000 is counted. The results indicate that intensity and duration of grid-based cold extremes, when viewed as a global total, will often be as severe as current typical conditions in many regions, but the corresponding frequency does not show this persistence. While the models agree on the projected persistence of cold extremes in terms of global counts, regionally, inter-model variability and disparity in model performance tends to dominate. Our findings suggest that, despite a general warming trend, regional preparedness for extreme cold events cannot be compromised even towards the end of the century.

  12. A Fast and Precise Indoor Localization Algorithm Based on an Online Sequential Extreme Learning Machine

    E-Print Network [OSTI]

    Zou, Han; Lu, Xiaoxuan; Jiang, Hao; Xie, Lihua

    2015-01-01

    C. -K. Extreme learning machine: Theory and applications.sequential extreme learning machine approach to WiFi basedloss and extreme learning machine. In Proceedings of the 1st

  13. Could the Earth's surface Ultraviolet irradiance be blamed for the global warming? (II) ----Ozone layer depth reconstruction via HEWV effect

    E-Print Network [OSTI]

    Chen, Jilong; Zheng, Yujun

    2014-01-01

    It is suggested by Chen {\\it et al.} that the Earth's surface Ultraviolet irradiance ($280-400$ nm) could influence the Earth's surface temperature variation by "Highly Excited Water Vapor" (HEWV) effect. In this manuscript, we reconstruct the developing history of the ozone layer depth variation from 1860 to 2011 based on the HEWV effect. It is shown that the reconstructed ozone layer depth variation correlates with the observational variation from 1958 to 2005 very well ($R=0.8422$, $P>99.9\\%$). From this reconstruction, we may limit the spectra band of the surface Ultraviolet irradiance referred in HEWV effect to Ultraviolet B ($280-320$ nm).

  14. Tuning the plasmon band number of aluminum nanorod within the ultraviolet-visible region by gold coating

    SciTech Connect (OSTI)

    Zhu, Jian E-mail: nanoptzhao@163.com; Li, Jian-Jun; Zhao, Jun-Wu E-mail: nanoptzhao@163.com

    2014-11-15

    The localized surface plasmon (LSP) properties of Al nanorod with Au coating have been investigated by using the quasi-static calculation. Because of the anisotropic plasmon splitting and the plasmon coupling between the Al and Au surfaces, the band number of LSP in the Al-Au core-shell nanorod could be tuned from 2 to 4 continuously in the ultraviolet-visible region. Due to the non-spherical symmetry and the dielectric polarization-induced plasmon energy fading, the Au coating-dependent plasmon shift and split are further affected by the aspect ratio and the dielectric surrounding. When the aspect ratio or the surrounding dielectric constant has a small value, the band number of LSP could only be tuned from 2 to 3. However, the band number of LSP could only be tuned from 3 to 4 when the aspect ratio or the surrounding dielectric constant has a large value. This tunable band number of LSP in the Au-coated Al nanorod provides potential application for multichannel plasmonic nanosensors.

  15. Extreme value statistics and the Pareto distribution in silicon photonics

    E-Print Network [OSTI]

    Borlaug, David; Jalali, Bahram

    2008-01-01

    L-shape probability distributions are extremely non-Gaussian distributions that have been surprisingly successful in describing the frequency of occurrence of extreme events, ranging from stock market crashes and natural disasters, the structure of biological systems, fractals, and optical rogue waves. In this paper, we show that fluctuations in stimulated Raman scattering in silicon, as well as in coherent anti-Stokes Raman scattering, can follow extreme value statistics and provide mathematical insight into the origin of this behavior. As an example of the experimental observations, we find that 16% of the Stokes pulses account for 84% of the pump energy transfer, an uncanny resemblance to the empirical Pareto principle or the 80/20 rule that describes important observation in socioeconomics.

  16. Intensification of hot extremes in the United States

    SciTech Connect (OSTI)

    Diffenbaugh, Noah [Stanford University; Ashfaq, Moetasim [ORNL

    2010-01-01

    Governments are currently considering policies that will limit greenhouse gas concentrations, including negotiation of an international treaty to replace the expiring Kyoto Protocol. Existing mitigation targets have arisen primarily from political negotiations, and the ability of such policies to avoid dangerous impacts is still uncertain. Using a large suite of climate model experiments, we find that substantial intensification of hot extremes could occur within the next 3 decades, below the 2 C global warming target currently being considered by policy makers. We also find that the intensification of hot extremes is associated with a shift towards more anticyclonic atmospheric circulation during the warm season, along with warm-season drying over much of the U.S. The possibility that intensification of hot extremes could result from relatively small increases in greenhouse gas concentrations suggests that constraining global warming to 2 C may not be sufficient to avoid dangerous climate change.

  17. The genealogy of extremal particles of Branching Brownian Motion

    E-Print Network [OSTI]

    Arguin, Louis-Pierre; Kistler, Nicola

    2010-01-01

    Branching Brownian Motion describes a system of particles which diffuse in space and split into offsprings according to a certain random mechanism. In virtue of the groundbreaking work by M. Bramson on the convergence of solutions of the Fisher-KPP equation to traveling waves, the law of the rightmost particle in the limit of large times is rather well understood. In this work, we address the full statistics of the extremal particles (first-, second-, third- etc. largest). In particular, we prove that in the large $t-$limit, such particles descend with overwhelming probability from ancestors having split either within a distance of order one from time $0$, or within a distance of order one from time $t$. The approach relies on characterizing, up to a certain level of precision, the paths of the extremal particles. As a byproduct, a heuristic picture of Branching Brownian Motion ``at the edge'' emerges, which sheds light on the still unknown limiting extremal process.

  18. Subsurface flow constructed wetland: treatment of domestic wastewater by gravel and tire chip media and ultraviolet disinfection of effluent 

    E-Print Network [OSTI]

    Richmond, Amanda Yvette

    2002-01-01

    spray application, wetland effluent must be disinfected (traditionally by chlorine). This study determines the treatment efficiency of SFCWs filled with gravel or tire chip media to treat domestic wastewater and the effectiveness of ultraviolet (UV...

  19. Quality and Sensory Attributes of Shell Eggs Sanitized with a Combination of Hydrogen Peroxide and Ultraviolet Light 

    E-Print Network [OSTI]

    Woodring, Kristy Senise

    2011-10-21

    Two experiments were conducted to evaluate the combination of hydrogen peroxide (H2O2) and ultraviolet light (UV) as an alternative eggshell sanitization procedure for shell egg processing. In each experiment, two cases of eggs (720 total) were...

  20. Ultraviolet and white photon avalanche upconversion in Ho{sup 3+}-doped nanophase glass ceramics

    SciTech Connect (OSTI)

    Lahoz, F.; Martin, I.R.; Calvilla-Quintero, J.M.

    2005-01-31

    Ho{sup 3+}-doped fluoride nanophase glass ceramics have been synthesized from silica-based oxyfluoride glass. An intense white emission light is observed by the naked eye under near infrared excitation at 750 nm. This visible upconversion is due to three strong emission bands in the primary color components, red, green, and blue. Besides, ultraviolet signals are also recorded upon the same excitation wavelength. The excitation mechanism of both the ultraviolet and the visible emissions is a photon avalanche process with a relatively low pump power threshold at about 20 mW. The total upconverted emission intensity has been estimated to increase by about a factor of 20 in the glass ceramic compared to the precursor glass, in which an avalanche type mechanism is not generated.

  1. Final LDRD report :ultraviolet water purification systems for rural environments and mobile applications.

    SciTech Connect (OSTI)

    Banas, Michael Anthony; Crawford, Mary Hagerott; Ruby, Douglas Scott; Ross, Michael P.; Nelson, Jeffrey Scott; Allerman, Andrew Alan; Boucher, Ray

    2005-11-01

    We present the results of a one year LDRD program that has focused on evaluating the use of newly developed deep ultraviolet LEDs in water purification. We describe our development efforts that have produced an LED-based water exposure set-up and enumerate the advances that have been made in deep UV LED performance throughout the project. The results of E. coli inactivation with 270-295 nm LEDs are presented along with an assessment of the potential for applying deep ultraviolet LED-based water purification to mobile point-of-use applications as well as to rural and international environments where the benefits of photovoltaic-powered systems can be realized.

  2. Improved energy efficiency by use of the new ultraviolet light radiation paint curing process

    SciTech Connect (OSTI)

    Grosset, A.M.; Su, W.-F.A.

    1984-08-01

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures is more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. The replacement of a conventional natural gas fired oven by an ultraviolet radiation curing line for paint curing could save quadrillions of joules per year for each finishing line. In this program sponsored by the U.S. Department of Energy, Office of Industrial Programs, two photoinduced polymerizations, via free radical or cationic mechanisms, were considered in the formulation of UV curable paints. The spectral output of radiation sources was chosen so as to complement the absorption spectra of pigments and photoactive agents; thus highly pigmented thick films could be cured fully by UV radiation. One coat enamels, topcoats, and primers have been developed which can be applied on three dimensional objects by spraying and can be cured by passing through a tunnel containing UV lamps.

  3. Ultraviolet and electron irradiation of DC-704 siloxane oil in zinc orthotitanate paint

    SciTech Connect (OSTI)

    Mossman, D.L.; Barsh, M.K.; Greenberg, S.A.

    1982-01-01

    Discrepancies exist between accelerated laboratory simulation and geosynchronous orbit flight data for zinc orthotitanate (ZOT) paint degradation. The effects of ultraviolet and electron irradiation on ZOT contaminated with DC-704 silicone oil are reported. In-situ solar absorptance and emittance changes for contaminated and clean specimens are discussed with reference to post-test surface morphology, determined by scanning electron microscope analysis. Features of the contaminated ZOT degradation kinetics correlate with orbital performance.

  4. Extreme high-head portables provide more pumping options

    SciTech Connect (OSTI)

    Fiscor, S.

    2006-10-15

    Three years ago, Godwin Pumps, one of the largest manufacturers of portable pumps, introduced its Extreme Duty High Lift (HL) series of pumps and more mines are finding unique applications for these pumps. The Extreme HL series is a range single-stage Dri-Prime pumps with heads up to 600 feet and flows up to 5,000 gallons per minute. The American Coal Co.'s Galatia mine, an underground longwall mine in southern Illinois, used an HL 160 to replace a multiple-staged centrifugal pump. It provided Galatia with 1,500 gpm at 465 ft. 3 photos.

  5. TECA: A Parallel Toolkit for Extreme Climate Analysis

    SciTech Connect (OSTI)

    Prabhat, Mr; Ruebel, Oliver; Byna, Surendra; Wu, Kesheng; Li, Fuyu; Wehner, Michael; Bethel, E. Wes

    2012-03-12

    We present TECA, a parallel toolkit for detecting extreme events in large climate datasets. Modern climate datasets expose parallelism across a number of dimensions: spatial locations, timesteps and ensemble members. We design TECA to exploit these modes of parallelism and demonstrate a prototype implementation for detecting and tracking three classes of extreme events: tropical cyclones, extra-tropical cyclones and atmospheric rivers. We process a modern TB-sized CAM5 simulation dataset with TECA, and demonstrate good runtime performance for the three case studies.

  6. Heats of vaporization of room temperature ionic liquids by tunable vacuum ultraviolet photoionization

    SciTech Connect (OSTI)

    Chambreau, Steven D.; Vaghjiani, Ghanshyam L.; To, Albert; Koh, Christine; Strasser, Daniel; Kostko, Oleg; Leone, Stephen R.

    2009-11-25

    The heats of vaporization of the room temperature ionic liquids (RTILs) N-butyl-N-methylpyrrolidinium bistrifluorosulfonylimide, N-butyl-N-methylpyrrolidinium dicyanamide, and 1-butyl-3-methylimidazolium dicyanamide are determined using a heated effusive vapor source in conjunction with single photon ionization by a tunable vacuum ultraviolet synchrotron source. The relative gas phase ionic liquid vapor densities in the effusive beam are monitored by clearly distinguished dissociative photoionization processes via a time-of-flight mass spectrometer at a tunable vacuum ultraviolet beamline 9.0.2.3 (Chemical Dynamics Beamline) at the Advanced Light Source synchrotron facility. Resulting in relatively few assumptions, through the analysis of both parent cations and fragment cations, the heat of vaporization of N-butyl-N-methylpyrrolidinium bistrifluorosulfonylimide is determined to be Delta Hvap(298.15 K) = 195+-19 kJ mol-1. The observed heats of vaporization of 1-butyl-3-methylimidazolium dicyanamide (Delta Hvap(298.15 K) = 174+-12 kJ mol-1) and N-butyl-N-methylpyrrolidinium dicyanamide (Delta Hvap(298.15 K) = 171+-12 kJ mol-1) are consistent with reported experimental values using electron impact ionization. The tunable vacuum ultraviolet source has enabled accurate measurement of photoion appearance energies. These appearance energies are in good agreement with MP2 calculations for dissociative photoionization of the ion pair. These experimental heats of vaporization, photoion appearance energies, and ab initio calculations corroborate vaporization of these RTILs as intact cation-anion ion pairs.

  7. EXTREME VALUE ANALYSIS FOR CLIMATE TIME SERIES Institute for Mathematics Applied to Geosciences

    E-Print Network [OSTI]

    Katz, Richard

    Extremes (3) Temporal Dependence / Scaling of Climate Extremes (4) Interpretation of Tail Behavior of floods: Design of dams Flood plain regulation ("100-year flood") #12;6 · Non-Stationarity -- Sources extremes) Sub-divide (e. g., separate analysis by month) #12;7 (2) Statistics of Climate Extremes · Tail

  8. WINDMILLS AND EXTREME 2CELLS JONATHAN P. MCCAMMOND 1 AND DANIEL T. WISE 2

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    WINDMILLS AND EXTREME 2­CELLS JONATHAN P. MCCAMMOND 1 AND DANIEL T. WISE 2 Abstract of a windmill, Section 3 uses windmills to prove that extreme 2­cells exist, and Section 4 uses extreme 2­cells by grants from NATEQ and NSERC. 1 #12; WINDMILLS AND EXTREME 2­CELLS 2 after suitable subdivisions

  9. The Extremes of the Extremes: Extraordinary Floods (Proceedings of a symposium held at Reykjavik, Iceland, July 2000). IAHS Publ. no. 271, 2002. 101

    E-Print Network [OSTI]

    Perfect, Ed

    , Iceland, July 2000). IAHS Publ. no. 271, 2002. 101 Recent extreme floods on Mars DEVON BURR Department

  10. QUENCHING DEPENDS ON MORPHOLOGIES: IMPLICATIONS FROM THE ULTRAVIOLET-OPTICAL RADIAL COLOR DISTRIBUTIONS IN GREEN VALLEY GALAXIES

    SciTech Connect (OSTI)

    Pan, Zhizheng; Lin, Weipeng; Li, Jinrong; Kong, Xu; Wang, Jing E-mail: linwp@shao.ac.cn

    2014-09-01

    In this Letter, we analyze the radial ultraviolet-optical color distributions in a sample of low redshift green valley galaxies, with the Galaxy Evolution Explorer (GALEX)+Sloan Digital Sky Survey (SDSS) images, to investigate how the residual recent star formation is distributed in these galaxies. We find that the dust-corrected u – r colors of early-type galaxies (ETGs) are flat out to R {sub 90}, while the colors monotonously turn blue when r > 0.5 R {sub 50} for late-type galaxies (LTGs). More than half of the ETGs are blue-cored and have remarkable positive NUV – r color gradients, suggesting that their star formations are centrally concentrated. The rest have flat color distributions out to R {sub 90}. The centrally concentrated star formation activity in a large portion of ETGs is confirmed by the SDSS spectroscopy, showing that ?50% of the ETGs have EW(H?) >6.0 Ĺ. Of the LTGs, 95% show uniform radial color profiles, which can be interpreted as a red bulge plus an extended blue disk. The links between the two kinds of ETGs, e.g., those objects having remarkable ''blue-cores'' and those having flat color gradients, are less known and require future investigations. It is suggested that the LTGs follow a general model by which quenching first occurs in the core regions, and then finally extend to the rest of the galaxy. Our results can be re-examined and have important implications for the IFU surveys, such as MaNGA and SAMI.

  11. INHIBITION OF PHOTOSYNTHESIS IN CERTAIN ALGAE BY EXTREME RED LIGHT

    E-Print Network [OSTI]

    Govindjee

    INHIBITION OF PHOTOSYNTHESIS IN CERTAIN ALGAE BY EXTREME RED LIGHT GOVINDJEE, EUGENE RABINOWITCH. INTRODUCTION It was shown in preceding papers (9, 10) that when the unicellular red alga Por- phyridium), these algae, when exposed to monochromatic light (bands isolated by a grating monochromator, band half

  12. The COS Stream Ciphers are Extremely Weak Steve Babbage

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    The COS Stream Ciphers are Extremely Weak Steve Babbage Vodafone Group R&D, Newbury, UK steve.babbage@vodafone.com Abstract: A new family of very fast stream ciphers called COS (for "crossing over system") has been. In this note we show that the COS ciphers are very weak indeed -- it requires negligible effort to reconstruct

  13. The COS Stream Ciphers are Extremely Weak Steve Babbage

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    The COS Stream Ciphers are Extremely Weak Steve Babbage Vodafone Group R&D, Newbury, UK steve.babbage@vodafone.com Abstract: A new family of very fast stream ciphers called COS (for ``crossing over system'') has been. In this note we show that the COS ciphers are very weak indeed --- it requires negligible effort to reconstruct

  14. Causal Analysis of the Unanticipated Extremity Exposure at HFEF

    SciTech Connect (OSTI)

    David E. James; Charles R. Posegate; Thomas P. Zahn; Alan G. Wagner

    2011-11-01

    This report covers the unintended extremity exposure to an operator while handling a metallurgical mount sample of irradiated fuel following an off-scale high beta radiation reading of the sample. The decision was made to continue working after the meter indicated high off-scale by the HPT Supervisor, which resulted in the operator at the next operation being exposed.

  15. Towards Understanding the Workspace of The Upper Extremities

    E-Print Network [OSTI]

    Abdel-Malek, Karim

    of a wrist undergoing rehabilitation. Keywords: Limb workspace, ergonomics, ranges of motion, shoulder, wrist largely based (e.g., AMA Guides to the Evaluation of Permanent Impairment [AMA 1997]). The reader is also extremity. (2) Quantify the full functional potential of a joint. (3) Select ergonomic postures reducing

  16. ITEP Webinar: Extreme Weather Events and Climate Change

    Broader source: Energy.gov [DOE]

    Attend this Institute for Tribal Environmental Professionals (ITEP) webinar and hear about the known variability in extreme weather such as excessive heat, cold waves, floods, droughts, hurricanes, severe thunderstorms and tornadoes. Projections and uncertainties of how these hazards might change due to global warming will be reviewed.

  17. Fitting In: Extreme Corporate Wellness and Organizational Communication 

    E-Print Network [OSTI]

    James, Eric Preston

    2014-07-31

    program known as CrossFit. I argue that a discourse of extreme corporate wellness furthers a social-Darwinian viewpoint of “survival of the fittest” not only in the workplace, but also in an employee’s personal and home life. This study combined...

  18. FAILURE OF GPS FUNCTIONING CAUSED BY EXTREME SOLAR RADIO EVENTS

    E-Print Network [OSTI]

    solar radio emission followed the flare exceeded power solar radio bursts (SRB) in all flares known tillFAILURE OF GPS FUNCTIONING CAUSED BY EXTREME SOLAR RADIO EVENTS E. L. Afraimovich1 , V. V. Demyanov1 , D. E. Gary2 , A. B. Ishin1 , and G. Ya. Smolkov1 1) Institute of Solar-Terrestrial Physics

  19. AIAA-2001-0044 Extreme Load Estimation for Wind Turbines

    E-Print Network [OSTI]

    AIAA-2001-0044 Extreme Load Estimation for Wind Turbines: Issues and Opportunities for Improved design load estimation procedures for wind turbines often do not accurately treat the statistical nature of loads. Current practice for wind turbine load analysis is reviewed. The authors

  20. Control of a Pneumatic Orthosis for Upper Extremity Stroke Rehabilitation

    E-Print Network [OSTI]

    Bobrow, James E.

    Control of a Pneumatic Orthosis for Upper Extremity Stroke Rehabilitation Eric T. Wolbrecht, John Leavitt, David J. Reinkensmeyer, and James E. Bobrow Abstract-- A key challenge in rehabilitation robotics rehabilitation of the arm. Pneumatic actuators can potentially help meet this challenge because of their high

  1. An Extreme Point Tabu Search Method for Data Mining

    E-Print Network [OSTI]

    Mitchell, John E.

    An Extreme Point Tabu Search Method for Data Mining Kristin P. Bennett \\Lambda Jennifer A. Blue error of all the decisions in the tree concurrently. Decision trees are ideal for data­mining because optimize existing decision trees. This capability can be used in data mining for avoiding overfitting

  2. HYDROGEN FLUORIDE Hydrogen Fluoride (HF) is an extremely

    E-Print Network [OSTI]

    Lance, Veronica P.

    HYDROGEN FLUORIDE Hydrogen Fluoride (HF) is an extremely corrosive clear and colorless liquid BE PROVIDED TO INDIVIDUALS WITH EXPOSURE TO HYDROGEN FLOURIDE www.ehs.columbia.edu/HFPolicy.html HF USE. Because hydrogen fluoride can penetrate natural rubber gloves you must use only neoprene or nitrile gloves

  3. REVIEW Open Access Climate change, air pollution and extreme events

    E-Print Network [OSTI]

    REVIEW Open Access Climate change, air pollution and extreme events leading to increasing dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor be explained only in changes occurred in the environment. Despite some differences in the air pollution profile

  4. BACKGROUND ON EXTREME VALUE THEORY WITH EMPHASIS ON CLIMATE APPLICATIONS

    E-Print Network [OSTI]

    Katz, Richard

    Threshold (9) Risk Communication (Under Stationarity) #12;4 (1) Traditional Statistical Methods · Fit models/distributions to all data -- Even if primary focus is on extremes · Statistical theory for averages -- Ubiquitous role distributions is too restrictive Statistical theory indicates possibility of "heavy" tails Data suggest evidence

  5. Extremal Fields and Neighboring Optimal Control of Constrained Systems 

    E-Print Network [OSTI]

    Harris, Matthew Wade

    2012-02-14

    this form, and so this work fills a void in the study of extremal fields and neighboring optimal control of constrained systems. Only first and second-order terms are written down, but the approach is systematic and higher order expressions can be found...

  6. Space based observations for monitoring extreme weather and climate events

    SciTech Connect (OSTI)

    Rao, P.K.

    1996-12-31

    Observations are essential for monitoring, understanding, and predicting the potential for extreme weather and climate events. These events occur on all time and spatial scales. Current NOAA operational satellites have a unique capability of providing many of the observations that are critical for monitoring these events. These observations and derived geophysical quantities can also be used for diagnostics and prediction purposes. Extreme weather conditions such as severe thunderstorms and flash floods, occur very quickly, may last for a short time, and create a considerable amount of damage. Advance warnings of the order of a few minutes are needed to alert the public so they may take adequate precautions. Some extreme weather conditions such as tropical storms (hurricanes) may last for days, and in order to predict the exact track, intensity of the storm and forecast the land fall, frequent observations are critical. Examples of satellite data that are obtained from the NOAA satellites are presented to demonstrate their ability to monitor the extreme weather phenomena. Examples of extreme climate conditions are droughts over continents and the annual depletion of ozone over the Antarctic. Data derived from NOAA satellites were used to monitor the severe drought over Texas and Southwestern U.S.A. in early 1996. Similar data are being used by other countries to monitor the drought in their regions. The development of the ozone hole over the Antarctic during the last fifteen years has been a major scientific and environmental concern. Data from NOAA operational satellites have been extensively used to show the yearly development and dissipation of the ozone hole during the Southern Hemisphere springtime.

  7. Science at the Theatre - Extreme Science - Promo Video

    SciTech Connect (OSTI)

    Klein, Spencer

    2012-01-01

    On Feb. 27 at 7 pm at the Berkeley Repertory Theatre, join four Berkeley Lab scientists as they discuss extreme science -- and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel. Go here for more information and to view videos of previous Science at the Theater events: http://www.lbl.gov/LBL-PID/fobl/

  8. On Thermodynamics and Phase Space of Near Horizon Extremal Geometries

    E-Print Network [OSTI]

    Hajian, Kamal

    2015-01-01

    Near Horizon Extremal Geometries (NHEG), are geometries which may appear in the near horizon region of the extremal black holes. These geometries have $SL(2,\\mathbb{R})\\!\\times\\!U(1)^n$ isometry, and constitute a family of solutions to the theory under consideration. In the first part of this report, their thermodynamic properties are reviewed, and their three universal laws are derived. In addition, at the end of the first part, the role of these laws in black hole thermodynamics is presented. In the second part of this thesis, we review building their classical phase space in the Einstein-Hilbert theory. The elements in the NHEG phase space manifold are built by appropriately chosen coordinate transformations of the original metric. These coordinate transformations are generated by some vector fields, dubbed "symplectic symmetry generators." To fully specify the phase space, we also need to identify the symplectic structure. In order to fix the symplectic structure, we use the formulation of Covariant Phase...

  9. Conceptual Design Report for the Extreme Ecosystems Test Chambers

    SciTech Connect (OSTI)

    C. Barnes; J. Beller; K. Caldwell; K. Croft; R. Cherry; W. Landman

    1998-12-01

    This conceptual design supports the creation of Extreme Ecosystems Test Chambers, which will replicate deep subsurface and subocean environments characterized by high pressure (2,000 psi) and subfreezing to high temperature (-4 to 300 degrees F) with differing chemical and saturation conditions. The design provides a system to support research and development that includes heat transfer, phase change issues in porous media, microbiology in extreme environments, and carbon sequestration and extraction. The initial system design is based on the research needs to support the commercial production of methane hydrates from subsurface sediments. The design provides for three pressure vessels: a Down Hole Test Vessel, a Vertical Multi-phase Test Vessel, and a Horizontal Multi-phase Test Vessel.

  10. Science at the Theatre - Extreme Science - Promo Video

    ScienceCinema (OSTI)

    Klein, Spencer

    2013-05-29

    On Feb. 27 at 7 pm at the Berkeley Repertory Theatre, join four Berkeley Lab scientists as they discuss extreme science -- and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel. Go here for more information and to view videos of previous Science at the Theater events: http://www.lbl.gov/LBL-PID/fobl/

  11. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    SciTech Connect (OSTI)

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

  12. Unambiguous discrimination of extremely similar states by a weak measurement

    E-Print Network [OSTI]

    Chang Qiao; Shengjun Wu; Zeng-Bing Chen

    2013-02-25

    In this paper, we propose a method to discriminate two extremely similar quantum states via a weak measurement. For the two states with equal prior probabilities, the optimum discrimination probability given by Ivanovic-Dieks-Peres limit can be achieved by our protocol with an appropriate choice of the interaction strength. However, compared with the conventional method for state discrimination, our approach shows the advantage of error-tolerance by achieving a better ratio of the success probability to the probability of error.

  13. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    SciTech Connect (OSTI)

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  14. Linear waves in the interior of extremal black holes I

    E-Print Network [OSTI]

    Gajic, Dejan

    2015-01-01

    We consider solutions to the linear wave equation in the interior region of extremal Reissner-Nordstr\\"om black holes. We show that, under suitable assumptions on the initial data, the solutions can be extended continuously beyond the Cauchy horizon and moreover, that their local energy is finite. This result is in contrast with previously established results for subextremal Reissner-Nordstr\\"om black holes, where the local energy was shown to generically blow up at the Cauchy horizon.

  15. New chaos indicators for systems with extremely small Lyapunov exponents

    E-Print Network [OSTI]

    Ken-ichi Okubo; Ken Umeno

    2015-03-18

    We propose new chaos indicators for systems with extremely small positive Lyapunov exponents. These chaos indicators can firstly detect a sharp transition between the Arnold diffusion regime and the Chirikov diffusion regime of the Froeschl\\'e map and secondly detect chaoticity in systems with zero Lyapunov exponent such as the Boole transformation and the $S$-unimodal function to characterize sub-exponential diffusions.

  16. Extremely red galaxies in the Phoenix Deep Survey

    E-Print Network [OSTI]

    A. M. Hopkins; J. Afonso; A. Georgakakis; M. Sullivan; B. Mobasher; L. E. Cram

    2003-09-04

    The Phoenix Deep Survey (PDS) is a multiwavelength survey based on deep 1.4 GHz radio observations used to identify a large sample of star forming galaxies to z=1. Here we present an exploration of the evolutionary constraints on the star-forming population imposed by the 1.4 GHz source counts, followed by an analysis of the average properties of extremely red galaxies in the PDS, by using the "stacking" technique.

  17. Total to Selective Extinction Ratios and Visual Extinctions from Ultraviolet Data

    E-Print Network [OSTI]

    Anna Geminale; Piotr Popowski

    2004-09-21

    We present determinations of the total to selective extinction ratio R_V and visual extinction A_V values for Milky Way stars using ultraviolet color excesses. We extend the analysis of Gnacinski and Sikorski (1999) by using non-equal weights derived from observational errors. We present a detailed discussion of various statistical errors. In addition, we estimate the level of systematic errors by considering different normalization of the extinction curve adopted by Wegner (2002). Our catalog of 782 R_V and A_V values and their errors is available in the electronic form on the World Wide Web.

  18. Vacuum ultraviolet and infrared spectra of condensed methyl acetate on cold astrochemical dust analogs

    SciTech Connect (OSTI)

    Sivaraman, B.; Nair, B. G.; Mason, N. J.; Lo, J.-I.; Cheng, B.-M.; Kundu, S.; Davis, D.; Prabhudesai, V.; Krishnakumar, E.; Raja Sekhar, B. N.

    2013-12-01

    Following the recent report of the first identification of methyl acetate (CH{sub 3}COOCH{sub 3}) in the interstellar medium (ISM), we have carried out vacuum ultraviolet (VUV) and infrared (IR) spectroscopy studies on methyl acetate from 10 K until sublimation in an ultrahigh vacuum chamber simulating astrochemical conditions. We present the first VUV and IR spectra of methyl acetate relevant to ISM conditions. Spectral signatures clearly showed molecular reorientation to have started in the ice by annealing the amorphous ice formed at 10 K. An irreversible phase change from amorphous to crystalline methyl acetate ice was found to occur between 110 K and 120 K.

  19. Cooperative effect of ultraviolet and near-infrared beams in laser-induced condensation

    SciTech Connect (OSTI)

    Matthews, M.; Henin, S.; Pomel, F.; Kasparian, J.; Wolf, J.-P.; Théberge, F.; Daigle, J.-F.; Lassonde, P.; Kieffer, J.-C.

    2013-12-23

    We demonstrate the cooperative effect of near infrared (NIR) and ultraviolet (UV) beams on laser-induced condensation. Launching a UV laser after a NIR pulse yields up to a 5-fold increase in the production of nanoparticles (25–300 nm) as compared to a single NIR beam. This cooperative effect exceeds the sum of those from the individual beams and occurs for delays up to 1 ?s. We attribute it to the UV photolysis of ozone created by the NIR pulses. The resulting OH radicals oxidize NO{sub 2} and volatile organic compounds, producing condensable species.

  20. Highly reproducible and reliable metal/graphene contact by ultraviolet-ozone treatment

    SciTech Connect (OSTI)

    Li, Wei [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Hacker, Christina A.; Cheng, Guangjun; Hight Walker, A. R.; Richter, Curt A.; Gundlach, David J., E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn [Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Liang, Yiran; Tian, Boyuan; Liang, Xuelei, E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn; Peng, Lianmao [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China)

    2014-03-21

    Resist residue from the device fabrication process is a significant source of contamination at the metal/graphene contact interface. Ultraviolet Ozone (UVO) treatment is proven here, by X-ray photoelectron spectroscopy and Raman measurement, to be an effective way of cleaning the metal/graphene interface. Electrical measurements of devices that were fabricated by using UVO treatment of the metal/graphene contact region show that stable and reproducible low resistance metal/graphene contacts are obtained and the electrical properties of the graphene channel remain unaffected.

  1. Construction and characterization of ultraviolet acousto-optic based femtosecond pulse shapers

    SciTech Connect (OSTI)

    Mcgrane, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Greenfield, Margo T [Los Alamos National Laboratory

    2008-01-01

    We present all the information necessary for construction and characterization of acousto optic pulse shapers, with a focus on ultraviolet wavelengths, Various radio-frequency drive configurations are presented to allow optimization via knowledgeable trade-off of design features. Detailed performance characteristics of a 267 nm acousto-optic modulator (AOM) based pulse shaper are presented, Practical considerations for AOM based pulse shaping of ultra-broad bandwidth (sub-10 fs) amplified femtosecond pulse shaping are described, with particular attention paid to the effects of the RF frequency bandwidth and optical frequency bandwidth on the spatial dispersion of the output laser pulses.

  2. Chemo-physical properties of renal capsules under ultraviolet-c exposure

    SciTech Connect (OSTI)

    Baghapour, Sh.; Parvin, P. Mokhtari, S.; Reyhani, A.; Mortazavi, S. Z.; Amjadi, A.

    2014-08-07

    The renal capsule tissue of lamb was irradiated with ultraviolet-C light and the treated samples were analyzed by uniaxial tensile test, dynamic mechanical analysis, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and contact angle measurements. It was shown that the skin cross-linking is dominant in low doses in accordance with the contact angle assessment. Conversely, the strong bulk degradation takes place at high doses. Similarly, the bulk cross-linking affects the mechanical tests as to enhance the stiffness at low doses, whereas strong degradation occurs at high doses that mainly arises from the strong bulk chain scission.

  3. Far-ultraviolet Observations of the North Ecliptic Pole with SPEAR

    E-Print Network [OSTI]

    Eric J. Korpela; Jerry Edelstein; Julia Kregenow; Kaori Nishikida; Kyoung-Wook Min; Dae-Hee Lee; Kwangsun Ryu; Wonyong Han; Uk-Won Nam; Jang-Hyun Park

    2006-01-26

    We present SPEAR/FIMS far-ultraviolet observations near the North Ecliptic Pole. This area, at b~30 degrees and with intermediate HI column, seems to be a fairly typical line of sight that is representative of general processes in the diffuse ISM. We detect a surprising number of emission lines of many elements at various ionization states representing gas phases from the warm neutral medium (WNM) to the hot ionized medium (HIM). We also detect fluorescence bands of H2, which may be due to the ubiquitous diffuse H2 previously observed in absorption.

  4. Global extreme events and their regional economic impact: 1996 update

    SciTech Connect (OSTI)

    Shen, S.

    1996-12-31

    The meaning of global warming and its relevance to everyday life is explained. Simple thermodynamics is used to predict an oscillatory nature of the change in climate due to global warming. The regional economic impacts of global extreme events are what mankind needs to focus on in government and private sector policy and planning. The economic impact of global warming has been tracked by the Extreme Event Index (EEI) established by the Global Warming International Center (GWIC). This review will update the overall trend and the components of the EEI from 1960 to 1996. The regional components of the global EEI have provided an excellent gauge for measuring the statistical vulnerability of any geographical locality in climate related economic disasters. The author further explains why we no longer fully understand the nature and magnitudes of common phenomena such as storms and wind speeds because of these extreme events, precipitation and temperature oscillations, atmospheric thermal unrest, as well as the further stratification of clouds, and changes in the absorptive properties of clouds. Hurricane strength winds are increasingly common even in continental areas. The author links the increase in duration of the El Nino to global warming, and further predicts a high public health risk as a result of the earth`s transition to another equilibrium state in its young history.

  5. Exascale Co-design for Modeling Materials in Extreme Environments

    SciTech Connect (OSTI)

    Germann, Timothy C.

    2014-07-08

    Computational materials science has provided great insight into the response of materials under extreme conditions that are difficult to probe experimentally. For example, shock-induced plasticity and phase transformation processes in single-crystal and nanocrystalline metals have been widely studied via large-scale molecular dynamics simulations, and many of these predictions are beginning to be tested at advanced 4th generation light sources such as the Advanced Photon Source (APS) and Linac Coherent Light Source (LCLS). I will describe our simulation predictions and their recent verification at LCLS, outstanding challenges in modeling the response of materials to extreme mechanical and radiation environments, and our efforts to tackle these as part of the multi-institutional, multi-disciplinary Exascale Co-design Center for Materials in Extreme Environments (ExMatEx). ExMatEx has initiated an early and deep collaboration between domain (computational materials) scientists, applied mathematicians, computer scientists, and hardware architects, in order to establish the relationships between algorithms, software stacks, and architectures needed to enable exascale-ready materials science application codes within the next decade. We anticipate that we will be able to exploit hierarchical, heterogeneous architectures to achieve more realistic large-scale simulations with adaptive physics refinement, and are using tractable application scale-bridging proxy application testbeds to assess new approaches and requirements. Such current scale-bridging strategies accumulate (or recompute) a distributed response database from fine-scale calculations, in a top-down rather than bottom-up multiscale approach.

  6. Extreme Adaptive Optics Testbed: High Contrast Measurements with a MEMS Deformable Mirror

    SciTech Connect (OSTI)

    Evans, J W; Morzinski, K; Reza, L; Severson, S; Poyneer, L; Macintosh, B; Dillon, D; Sommargren, G

    2005-08-16

    ''Extreme'' adaptive optics systems are optimized for ultra-high-contrast applications, such as ground-based extrasolar planet detection. The Extreme Adaptive Optics Testbed at UC Santa Cruz is being used to investigate and develop technologies for high-contrast imaging, especially wavefront control. We use a simple optical design to minimize wavefront error and maximize the experimentally achievable contrast. A phase shifting diffraction interferometer (PSDI) measures wavefront errors with sub-nm precision and accuracy for metrology and wavefront control. Previously, we have demonstrated RMS wavefront errors of <1.5 nm and a contrast of >10{sup 7} over a substantial region using a shaped pupil without a deformable mirror. Current work includes the installation and characterization of a 1024-actuator Micro-Electro-Mechanical-Systems (MEMS) deformable mirror, manufactured by Boston Micro-Machines for active wavefront control. Using the PSDI as the wavefront sensor we have flattened the deformable mirror to <1 nm within the controllable spatial frequencies and measured a contrast in the far field of >10{sup 6}. Consistent flattening required testing and characterization of the individual actuator response, including the effects of dead and low-response actuators. Stability and repeatability of the MEMS devices was also tested. Ultimately this testbed will be used to test all aspects of the system architecture for an extrasolar planet-finding AO system.

  7. Effects of plasma and vacuum-ultraviolet exposure on the mechanical properties of low-k porous organosilicate glass

    SciTech Connect (OSTI)

    Guo, X.; Shohet, J. L. [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Jakes, J. E. [Performance Enhanced Biopolymers, USDA Forest Service Forest Products Laboratory, Madison, Wisconsin 53726 (United States); Banna, S. [Applied Materials, Sunnyvale, California 94085 (United States); Nishi, Y. [Stanford University, Stanford, California 94305 (United States)

    2014-07-28

    The effects of plasma exposure and vacuum-ultraviolet (VUV) irradiation on the mechanical properties of low-k porous organosilicate glass (SiCOH) dielectric films were investigated. Nanoindentation measurements were made on SiCOH films before and after exposure to an electron-cyclotron-resonance plasma or a monochromatic synchrotron VUV beam, to determine the changes of film hardness, elastic modulus, and crack threshold due to these exposures. This permits the effects of ion bombardment and photon bombardment to be analyzed separately. The role of energetic ions was examined with a variety of inert plasma-exposure conditions. The role of VUV photons was analyzed as a function of synchrotron photon energy. It was found that both energetic ions and VUV photons with energies larger than the bond energy of the Si-O bond cause a significant increase in film hardness along with a smaller increase in elastic modulus and crack threshold. Differential Fourier transform infrared spectra and x-ray photoemission spectroscopy results show that the energetic ions affect the SiCOH properties mainly through physical bombardment, during which the ions transfer their momentum to the Si-O-Si backbone and transform them into more energetically stable Si-O-Si network structures. This results in the Si-O-Si network structures becoming densified. VUV photons assist reaction that increase the number of bridging O{sub 3}?Si-O-Si?O{sub 3} bonds and deplete nonbridging O{sub 3}?Si-O and C-Si?O{sub 3} bonds. This increased degree of cross linking in porous organosilicate dielectrics can substantially enhance their hardness and elastic modulus while showing no significant film shrinkage or densification.

  8. Laser Desorption Postionization Mass Spectrometry of Antibiotic-Treated Bacterial Biofilms using Tunable Vacuum Ultraviolet Radiation

    SciTech Connect (OSTI)

    Gasper, Gerald L.; Takahashi, Lynelle K.; Zhou, Jia; Ahmed, Musahid; Moore, Jerry F.; Hanley, Luke

    2010-08-04

    Laser desorption postionization mass spectrometry (LDPI-MS) with 8.0 ? 12.5 eV vacuum ultraviolet synchrotron radiation is used to single photon ionize antibiotics andextracellular neutrals that are laser desorbed both neat and from intact bacterial biofilms. Neat antibiotics are optimally detected using 10.5 eV LDPI-MS, but can be ionized using 8.0 eV radiation, in agreement with prior work using 7.87 eV LDPI-MS. Tunable vacuum ultraviolet radiation also postionizes laser desorbed neutrals of antibiotics and extracellular material from within intact bacterial biofilms. Different extracellular material is observed by LDPI-MS in response to rifampicin or trimethoprim antibiotic treatment. Once again, 10.5 eV LDPI-MS displays the optimum trade-off between improved sensitivity and minimum fragmentation. Higher energy photons at 12.5 eV produce significant parent ion signal, but fragment intensity and other low mass ions are also enhanced. No matrix is added to enhance desorption, which is performed at peak power densities insufficient to directly produce ions, thus allowing observation of true VUV postionization mass spectra of antibiotic treated biofilms.

  9. Detection of neutral phosphorus in the near-ultraviolet spectra of late-type stars

    SciTech Connect (OSTI)

    Roederer, Ian U. [Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109 (United States); Jacobson, Heather R.; Thanathibodee, Thanawuth; Frebel, Anna; Toller, Elizabeth, E-mail: iur@umich.edu [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2014-12-10

    We report the detection of several absorption lines of neutral phosphorus (P, Z = 15) in archival near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We derive phosphorus abundances or interesting upper limits in 14 late-type stars with metallicities spanning –3.8 < [Fe/H] <–0.1. Previously, phosphorus had only been studied in Galactic stars with –1.0 < [Fe/H] <+0.3. Iron lines reveal abundance offsets between the optical and ultraviolet regions, and we discuss and apply a correction factor to account for this offset. In stars with [Fe/H] >–1.0, the [P/Fe] ratio decreases toward the solar value with increasing metallicity, in agreement with previous observational studies. In stars with [Fe/H] <–1.0, ([P/Fe]) = +0.04 ± 0.10, which overlaps with the [P/Fe] ratios found in several high-redshift damped Lyman-? systems. This behavior hints at a primary origin in massive stars.

  10. Nuclear activity versus star formation: emission-line diagnostics at ultraviolet and optical wavelengths

    E-Print Network [OSTI]

    Feltre, Anna; Gutkin, Julia

    2015-01-01

    In the context of observations of the rest-frame ultraviolet and optical emission from distant galaxies, we explore the emission-line properties of photoionization models of active and inactive galaxies. Our aim is to identify new line-ratio diagnostics to discriminate between gas photoionization by active galactic nuclei (AGN) and star formation. We use a standard photoionization code to compute the emission from AGN narrow-line regions and compare this with calculations of the nebular emission from star-forming galaxies achieved using the same code. We confirm the appropriateness of widely used optical spectral diagnostics of nuclear activity versus star formation and explore new diagnostics at ultraviolet wavelengths. We find that combinations of a collisionally excited metal line or line multiplet, such as CIV 1548,1551, OIII]1661,1666, NIII]1750, [SiIII]1883+[SiIII]1892 and [CIII]1907+CIII]1909, with the HeII 1640 recombination line are individually good discriminants of the nature of the ionizing source...

  11. Differential effects of extreme drought on production and respiration: synthesis and modeling analysis

    E-Print Network [OSTI]

    Shi, Z.; Thomey, M. L.; Mowll, W.; Litvak, M.; Brunsell, Nathaniel A.; Collins, S. L.; Pockman, W. T.; Smith, M. D.; Knapp, A. K.; Luo, Y.

    2014-02-04

    Extremes in climate may severely impact ecosystem structure and function, with both the magnitude and rate of response differing among ecosystem types and processes. We conducted a modeling analysis of the effects of extreme ...

  12. U.S. Energy Sector Vulnerabilities to Climate Change and Extreme...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    U.S. Energy Sector Vulnerabilities to Climate Change and Extreme Weather U.S. Energy Sector Vulnerabilities to Climate Change and Extreme Weather This report-part of the...

  13. Freezing and extreme value statistics in a Random Energy Model with logarithmically correlated potential

    E-Print Network [OSTI]

    Yan V Fyodorov; Jean-Philippe Bouchaud

    2008-08-18

    We investigate some implications of the freezing scenario proposed by Carpentier and Le Doussal (CLD) for a random energy model (REM) with logarithmically correlated random potential. We introduce a particular (circular) variant of the model, and show that the integer moments of the partition function in the high-temperature phase are given by the well-known Dyson Coulomb gas integrals. The CLD freezing scenario allows one to use those moments for extracting the distribution of the free energy in both high- and low-temperature phases. In particular, it yields the full distribution of the minimal value in the potential sequence. This provides an explicit new class of extreme-value statistics for strongly correlated variables, manifestly different from the standard Gumbel class. -

  14. GTC optical imaging of extremely red 5C radio galaxies at high redshift

    E-Print Network [OSTI]

    Humphrey, A; Lagos, P

    2015-01-01

    We investigate the nature of seven unusual radio galaxies from the 5C catalogue that were previously known to have extremely red R-K colours, and for which emission lines were previously found to be weak or absent in their optical spectra. We present and discuss u, g, or r images of these radio galaxies, obtained using the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) at the Gran Telescopio Canarias (GTC). We have detected all seven targets in our g-band imaging. Their optical emission is extended, and we tentatively detect a radio-optical alignment effect in this sample. A subset of our sample (three sources) shows broad-band spectral energy distributions that flatten out near the wavelength range of the g-band, implying a dominant contribution there due to young stars and/or scattered or reprocessed radiation from the active nucleus.

  15. Extreme Synchrotron Blazars in Outburst: the Potentiality of INTEGRAL Imaging and Spectroscopy

    E-Print Network [OSTI]

    Elena Pian; Giuseppe Malaguti; Laura Maraschi; Gabriele Ghisellini; Giorgio G. C. Palumbo

    1998-11-10

    Only ~10 blazars have been detected in soft gamma-rays by OSSE and the PDS, often in flaring state. We investigate the impact of the imaging and spectral capabilities of the IBIS instrument on board INTEGRAL on the study of blazars. The objectives are: 1) to remove ambiguities in the identification of some blazars as soft gamma-ray emitters; 2) to determine the spectral shape of "extreme synchrotron" blazars, namely sources with high F_X/F_radio ratios, for which the synchrotron component peaks at far UV-soft X-ray frequencies. We expect that in these sources the synchrotron peak shifts to higher energies during outbursts, making them strong soft gamma-ray emitters, and therefore possible targets for INTEGRAL wide band X- and gamma-ray spectroscopy.

  16. Calculation of extremity neutron fluence-to-dose equivalent conversion factors 

    E-Print Network [OSTI]

    Wood-Zika, Annmarie Ruth

    1997-01-01

    -to-dose equivalent conversion factors to Los Alamos National Laboratory extremity dosimeter correction factors is performed....

  17. SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND CHARACTERISTICS AT NUCLEAR FACILITY SITES

    Broader source: Energy.gov [DOE]

    Summary of Revised Tornado, Hurricane and Extreme Straight Wind Characteristics at Nuclear Facility Sites BY: John D. Stevenson Consulting Engineer

  18. Basic Research Needs for Materials Under Extreme Environments. Report of the Basic Energy Sciences Workshop on Materials Under Extreme Environments, June 11-13, 2007

    SciTech Connect (OSTI)

    Wadsworth, J.; Crabtree, G. W.; Hemley, R. J.; Falcone, R.; Robertson, I.; Stringer, J.; Tortorelli, P.; Gray, G. T.; Nicol, M.; Lehr, J.; Tozer, S. W.; Diaz de la Rubia, T.; Fitzsimmons, T.; Vetrano, J. S.; Ashton, C. L.; Kitts, S.; Landson, C.; Campbell, B.; Gruzalski, G.; Stevens, D.

    2008-02-01

    To evaluate the potential for developing revolutionary new materials that will meet demanding future energy requirements that expose materials to environmental extremes.

  19. Room-temperature ultraviolet emission from an organic light-emitting diode C. F. Qiu, L. D. Wang, H. Y. Chen, M. Wong, and H. S. Kwok

    E-Print Network [OSTI]

    Room-temperature ultraviolet emission from an organic light-emitting diode C. F. Qiu, L. D. Wang, H Ultraviolet emission was obtained from N,N -diphenyl-N,N -bis 3-methylphenyl - 1,1 -bi phenyl -4,4 -diamine. Gallium nitride was used as a hole-blocking layer to contain the holes. A peak emission wavelength of 400

  20. Development of a coherent vacuum ultraviolet source at 104108 nm generated by four-wave sum frequency mixing in Hg vapor

    E-Print Network [OSTI]

    Kim, Myung Soo

    Development of a coherent vacuum ultraviolet source at 104­108 nm generated by four-wave sum-harmonic generation and four-wave mixing in a gas- eous nonlinear medium.8­11 Two tunable outputs from a pulsed dye ultraviolet VUV light source in the 104­108 nm range has been developed by utilizing four-wave sum frequency

  1. Electron density diagnostics for solar ultraviolet lines E. O'Shea (e.oshea@queensbelfast.ac.uk), T. O'Neill

    E-Print Network [OSTI]

    :4), in conjunction with observational data obtained with the Solar Ultraviolet Measurements of Emitted Radiation resolve these fea­ tures. However, with the Solar Ultraviolet Measurements of Emitted Radiation (sumer of this particular ratio in different solar regions and in testing the accuracy of the new atomic data discussed here

  2. EXTREMAL MODELS AND ENVIRONMENTAL APPLICATIONS Institute for Study of Society and Environment

    E-Print Network [OSTI]

    Katz, Richard

    in Extreme Value Theory (4) Interpretation of Tail Behavior (5) Complex Extreme Events (6) Risk Communication variables -- Engineering design Estimating return level of floods (Dams, flood plain definition) Estimating Extremes · Tail Behavior -- Shape parameter of GEV or GP distribution -- Bounded upper tail (i. e.,

  3. Statistics of extremes in hydrology Richard W. Katz a,*, Marc B. Parlange b

    E-Print Network [OSTI]

    Katz, Richard

    Statistics of extremes in hydrology Richard W. Katz a,*, Marc B. Parlange b , Philippe Naveau c Abstract The statistics of extremes have played an important role in engineering practice for water resources design and management. How recent developments in the statistical theory of extreme values can

  4. Notes and Discussion Vole Population Dynamics: Influence of Weather Extremes on Stoppage of

    E-Print Network [OSTI]

    Oli, Madan K.

    Notes and Discussion Vole Population Dynamics: Influence of Weather Extremes on Stoppage of Population Growth ABSTRACT.--Effects of 74 episodes of extreme weather on stoppage of population growth of extreme weather may have stopped population growth of only six M. ochrogaster fluctuations and of two M

  5. Numerical modeling of extreme rogue waves generated by directional energy focusing

    E-Print Network [OSTI]

    Grilli, Stéphan T.

    Numerical modeling of extreme rogue waves generated by directional energy focusing Christophe that contributes to the generation of extreme waves, also known as rogue waves, in the ocean. To simulate and analyze this phenomenon, we generate extreme waves in a 3D numerical wave tank (NWT), by specifying

  6. Detection and attribution of large spatiotemporal extreme events in Earth observation data

    E-Print Network [OSTI]

    Harmeling, Stefan

    and via which pathways climate extremes affect the state and functionality of terrestrial ecosystems and the associated biogeochemical cycles on a global scale. So far the impacts of climate extremes on the terrestrial- tects spatiotemporally contiguous extremes in Earth observations, and secondly infers the likely pathway

  7. WINDMILLS AND EXTREME 2-CELLS JONATHAN P. MCCAMMOND 1 AND DANIEL T. WISE 2

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    WINDMILLS AND EXTREME 2-CELLS JONATHAN P. MCCAMMOND 1 AND DANIEL T. WISE 2 Abstract of a windmill, Section 3 uses windmills to prove that extreme 2-cells exist, and Section 4 uses extreme 2-cells by NSF grant no. DMS-0101506 2 Research supported by grants from NATEQ and NSERC. 1 #12;WINDMILLS

  8. Properties of the extremely HI-massive galaxy HIZOA J0836-43

    E-Print Network [OSTI]

    Kraan-Korteweg, Renée C.

    Properties of the extremely HI-massive galaxy HIZOA J0836-43 Renée C.Kraan-Korteweg Astronomy@ast.uct.ac.za Little is known about the properties of extremely massive HI-galaxies. They are extremely scarce and are ­ according to hierarchical structure formation ­ only forming now (z HI SKA

  9. Extreme nonlinear optics of two-level systems

    SciTech Connect (OSTI)

    Tritschler, T.; Muecke, O. D.; Wegener, M.

    2003-09-01

    For Rabi frequencies comparable to, or even larger than, the transition frequency of a two-level system, the regime of extreme nonlinear optics is reached. Here, we give an overview of the radiated light intensity as a function of carrier frequency of light, transition frequency, Rabi frequency, spectrometer frequency, as well as of the shape and duration of the exciting optical pulses. The graphical representations reveal an amazing complexity and beauty of the nonlinear optical response. Analytical results within the ''square-wave approximation'' qualitatively reproduce many of the intricate features of the exact numerical calculations.

  10. Solidification at the High and Low Rate Extreme

    SciTech Connect (OSTI)

    Halim Meco

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt-pool oscillation may be the dominant factor governing the onset of unsteady thermal conditions accompanied by varying amounts of crystalline nucleation observed near the lower limit. At high quench-wheel velocities, the influence of these oscillations is minimal due to very short melt-pool residence times. However, microstructural evidence suggests that the entrapment of gas pockets at the wheel-metal interface plays a critical role in establishing the upper rate limit. An observed transition in wheel-side surface character with increasing melt-spinning rate supports this conclusion.

  11. Method for synthesizing extremely high-temperature melting materials

    DOE Patents [OSTI]

    Saboungi, Marie-Louise (Chicago, IL); Glorieux, Benoit (Perpignan, FR)

    2007-11-06

    The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as carbides and transition-metal, lanthanide and actinide oxides, using an aerodynamic levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

  12. Method For Synthesizing Extremely High-Temperature Melting Materials

    DOE Patents [OSTI]

    Saboungi, Marie-Louise (Chicago, IL); Glorieux, Benoit (Perpignan, FR)

    2005-11-22

    The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

  13. Analysis and Interpretation of Hard X-ray Emission fromthe Bullet...

    Office of Scientific and Technical Information (OSTI)

    in the Extreme Ultraviolet and Hard X-ray ranges have provided for more powerful tools for the investigation of this phenomenon. Detection of hard X-rays in the 20 to 100...

  14. Damage detection in mechanical structures using extreme value statistic.

    SciTech Connect (OSTI)

    Worden, K.; Allen, D. W. (David W.); Sohn, H. (Hoon); Farrar, C. R. (Charles R.)

    2002-01-01

    The first and most important objective of any damage identification algorithms is to ascertain with confidence if damage is present or not. Many methods have been proposed for damage detection based on ideas of novelty detection founded in pattern recognition and multivariate statistics. The philosophy of novelty detection is simple. Features are first extracted from a baseline system to be monitored, and subsequent data are then compared to see if the new features are outliers, which significantly depart from the rest of population. In damage diagnosis problems, the assumption is that outliers are generated from a damaged condition of the monitored system. This damage classification necessitates the establishment of a decision boundary. Choosing this threshold value is often based on the assumption that the parent distribution of data is Gaussian in nature. While the problem of novelty detection focuses attention on the outlier or extreme values of the data i.e. those points in the tails of the distribution, the threshold selection using the normality assumption weighs the central population of data. Therefore, this normality assumption might impose potentially misleading behavior on damage classification, and is likely to lead the damage diagnosis astray. In this paper, extreme value statistics is integrated with the novelty detection to specifically model the tails of the distribution of interest. Finally, the proposed technique is demonstrated on simulated numerical data and time series data measured from an eight degree-of-freedom spring-mass system.

  15. Geometric Constrained Variational Calculus. I. - Piecewise smooth extremals

    E-Print Network [OSTI]

    Enrico Massa; Danilo Bruno; Gianvittorio Luria; Enrico Pagani

    2015-03-30

    A geometric setup for constrained variational calculus is presented. The analysis deals with the study of the extremals of an action functional defined on piecewise differentiable curves, subject to differentiable, non-holonomic constraints. Special attention is paid to the tensorial aspects of the theory. As far as the kinematical foundations are concerned, a fully covariant scheme is developed through the introduction of the concept of infinitesimal control. The standard classification of the extremals into normal and abnormal ones is discussed, pointing out the existence of an algebraic algorithm assigning to each admissible curve a corresponding abnormality index, related to the co-rank of a suitable linear map. Attention is then shifted to the study of the first variation of the action functional. The analysis includes a revisitation of Pontryagin's equations and of the Lagrange multipliers method, as well as a reformulation of Pontryagin's algorithm in hamiltonian terms. The analysis is completed by a general result, concerning the existence of finite deformations with fixed endpoints.

  16. Devices useful for vacuum ultraviolet beam characterization including a movable stage with a transmission grating and image detector

    SciTech Connect (OSTI)

    Gessner, Oliver; Kornilov, Oleg A; Wilcox, Russell B

    2013-10-29

    The invention provides for a device comprising an apparatus comprising (a) a transmission grating capable of diffracting a photon beam into a diffracted photon output, and (b) an image detector capable of detecting the diffracted photon output. The device is useful for measuring the spatial profile and diffraction pattern of a photon beam, such as a vacuum ultraviolet (VUV) beam.

  17. Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of benzene: Vibrational analysis of C6H6

    E-Print Network [OSTI]

    Kim, Myung Soo

    Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of benzene: Vibrational analysis-photon spectra agrees with the previous suggestion that the geometry of benzene cation in the ground electronic. INTRODUCTION Benzene cation has been the focus of an intensive re- search effort, both experimental1

  18. Analytical model for the optical functions of amorphous semiconductors from the near-infrared to ultraviolet: Applications in thin film

    E-Print Network [OSTI]

    Deng, Xunming

    -infrared to ultraviolet: Applications in thin film photovoltaics A. S. Ferlauto, G. M. Ferreira, J. M. Pearce, C. R. Wronski, and R. W. Collinsa) Department of Physics, Materials Research Institute, and Center for Thin Film, it has numerous applications in the analysis and simulation of thin film a-Si:H based p-i-n and n

  19. Interaction of methanol and water on MgO,,100... studied by ultraviolet photoelectron and metastable impact electron spectroscopies

    E-Print Network [OSTI]

    Goodman, Wayne

    Interaction of methanol and water on MgO,,100... studied by ultraviolet photoelectron; accepted 27 October 1998 The coadsorption of methanol (CH3OH) and water (D2O) on the MgO 100 /Mo 100 photoelectron spectroscopy UPS HeI , and by thermal programmed desorption TPD . Methanol wets the MgO surface

  20. A close-up of the Sun (shown in ultraviolet light) reveals a mottled surface, bright flares,

    E-Print Network [OSTI]

    Christian, Eric

    #12;#12;A close-up of the Sun (shown in ultraviolet light) reveals a mottled surface, bright flares, and tongues of hot gas leaping into space. Though they look like burns in the face of the Sun, sunspots circle in the center of the photo--allows scientists to see the solar wind streaming away from the Sun

  1. THE ROLE OF POLYCYCLIC AROMATIC HYDROCARBONS IN ULTRAVIOLET EXTINCTION. I. PROBING SMALL MOLECULAR POLYCYCLIC AROMATIC HYDROCARBONS1

    E-Print Network [OSTI]

    THE ROLE OF POLYCYCLIC AROMATIC HYDROCARBONS IN ULTRAVIOLET EXTINCTION. I. PROBING SMALL MOLECULAR POLYCYCLIC AROMATIC HYDROCARBONS1 Geoffrey C. Clayton,2 Karl D. Gordon,3 F. Salama,4 L. J. Allamandola,4, with particular emphasis on a search for absorp- tion features produced by polycyclic aromatic hydrocarbons (PAHs

  2. Published in Proceedings of the XL2003 (Response of Structures to Extreme Loading) Conference, Toronto, August 2003. EFFICIENT MODELS FOR WIND TURBINE EXTREME LOADS

    E-Print Network [OSTI]

    Manuel, Lance

    , Toronto, August 2003. EFFICIENT MODELS FOR WIND TURBINE EXTREME LOADS USING INVERSE RELIABILITY K, USA ABSTRACT The reliability of wind turbines against extreme loads is the focus of this study loads for a 600kW three-bladed horizontal-axis wind turbine. Only operating loads ­ here, flapwise (out

  3. Electrically tunable selective reflection of light from ultraviolet to visible and infrared by heliconical cholesterics

    E-Print Network [OSTI]

    Xiang, Jie; Li, Quan; Paterson, Daniel A; Storey, John M D; Imrie, Corrie T; Lavrentovich, Oleg D

    2015-01-01

    Cholesteric liquid crystals with helicoidal molecular architecture are known for their ability to selectively reflect light with the wavelength that is determined by the periodicity of molecular orientations. Here we demonstrate that by using a cholesteric with oblique helicoidal(heliconical) structure, as opposed to the classic right-angle helicoid, one can vary the wavelength of selectively reflected light in a broad spectral range, from ultraviolet to visible and infrared (360-1520 nm for the same chemical composition) by simply adjusting the electric field applied parallel to the helicoidal axis. The effect exists in a wide temperature range (including the room temperatures) and thus can enable many applications that require dynamically controlled transmission and reflection of electromagnetic waves, from energy-saving smart windows to tunable organic lasers, reflective color display, and transparent see-through displays.

  4. Electrically tunable selective reflection of light from ultraviolet to visible and infrared by heliconical cholesterics

    E-Print Network [OSTI]

    Jie Xiang; Yannian Li; Quan Li; Daniel A. Paterson; John M. D. Storey; Corrie T. Imrie; Oleg D. Lavrentovich

    2015-03-30

    Cholesteric liquid crystals with helicoidal molecular architecture are known for their ability to selectively reflect light with the wavelength that is determined by the periodicity of molecular orientations. Here we demonstrate that by using a cholesteric with oblique helicoidal(heliconical) structure, as opposed to the classic right-angle helicoid, one can vary the wavelength of selectively reflected light in a broad spectral range, from ultraviolet to visible and infrared (360-1520 nm for the same chemical composition) by simply adjusting the electric field applied parallel to the helicoidal axis. The effect exists in a wide temperature range (including the room temperatures) and thus can enable many applications that require dynamically controlled transmission and reflection of electromagnetic waves, from energy-saving smart windows to tunable organic lasers, reflective color display, and transparent see-through displays.

  5. Accretion Rates for T Tauri Stars Using Nearly Simultaneous Ultraviolet and Optical Spectra

    E-Print Network [OSTI]

    Ingleby, Laura; Herczeg, Gregory; Blaty, Alex; Walter, Frederick; Ardila, David; Alexander, Richard; Edwards, Suzan; Espaillat, Catherine; Gregory, Scott G; Hillenbrand, Lynne; Brown, Alexander

    2013-01-01

    We analyze the accretion properties of 21 low mass T Tauri stars using a dataset of contemporaneous near ultraviolet (NUV) through optical observations obtained with the Hubble Space Telescope Imaging Spectrograph (STIS) and the ground based Small and Medium Aperture Research Telescope System (SMARTS), a unique dataset because of the nearly simultaneous broad wavelength coverage. Our dataset includes accreting T Tauri stars (CTTS) in Taurus, Chamaeleon I, $\\eta$ Chamaeleon and the TW Hydra Association. For each source we calculate the accretion rate by fitting the NUV and optical excesses above the photosphere, produced in the accretion shock, introducing multiple accretion components characterized by a range in energy flux (or density) for the first time. This treatment is motivated by models of the magnetospheric geometry and accretion footprints, which predict that high density, low filling factor accretion spots co-exist with low density, high filling factor spots. By fitting the UV and optical spectra wi...

  6. QUIET-SUN INTENSITY CONTRASTS IN THE NEAR-ULTRAVIOLET AS MEASURED FROM SUNRISE

    SciTech Connect (OSTI)

    Hirzberger, J.; Feller, A.; Riethmueller, T. L.; Schuessler, M.; Borrero, J. M.; Gandorfer, A.; Solanki, S. K.; Barthol, P.; Afram, N.; Unruh, Y. C.; Berdyugina, S. V.; Berkefeld, T.; Schmidt, W.; Bonet, J. A.; MartInez Pillet, V.; Knoelker, M.; Title, A. M.

    2010-11-10

    We present high-resolution images of the Sun in the near-ultraviolet spectral range between 214 nm and 397 nm as obtained from the first science flight of the 1 m SUNRISE balloon-borne solar telescope. The quiet-Sun rms intensity contrasts found in this wavelength range are among the highest values ever obtained for quiet-Sun solar surface structures-up to 32.8% at a wavelength of 214 nm. We compare the rms contrasts obtained from the observational data with theoretical intensity contrasts obtained from numerical magnetohydrodynamic simulations. For 388 nm and 312 nm the observations agree well with the numerical simulations whereas at shorter wavelengths discrepancies between observed and simulated contrasts remain.

  7. Ultraviolet Luminosity Density of the Universe During the Epoch of Reionization

    E-Print Network [OSTI]

    Mitchell-Wynne, Ketron; Gong, Yan; Ashby, Matthew; Dolch, Timothy; Ferguson, Henry; Finkelstein, Steven; Grogin, Norman; Kocevski, Dale; Koekemoer, Anton; Primack, Joel; Smidt, Joseph

    2015-01-01

    The spatial fluctuations of the extragalactic background light trace the total emission from all stars and galaxies in the Universe. A multi-wavelength study can be used to measure the integrated emission from first galaxies during reionization when the Universe was about 500 million years old. Here we report arcminute-scale spatial fluctuations in one of the deepest sky surveys with the Hubble Space Telescope in five wavebands between 0.6 and 1.6 $\\mu$m. We model-fit the angular power spectra of intensity fluctuation measurements to find the ultraviolet luminosity density of galaxies at $z$ > 8 to be $\\log \\rho_{\\rm UV} = 27.4^{+0.2}_{-1.2}$ erg s$^{-1}$ Hz$^{-1}$ Mpc$^{-3}$ $(1\\sigma)$. This level of integrated light emission allows for a significant surface density of fainter primeval galaxies that are below the point source detection level in current surveys.

  8. Dynamics of the solar chromosphere. V. High-frequency modulation in ultraviolet image sequences from TRACE

    E-Print Network [OSTI]

    A. G. de Wijn; R. J. Rutten; T. D. Tarbell

    2007-06-13

    We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from the Transition Region and Coronal Explorer (TRACE) mission which were taken with strict cadence regularity. The latter permits more reliable high-frequency diagnosis than in earlier work. Spatial Fourier power maps, spatially averaged coherence and phase-difference spectra, and spatio-temporal k-f decompositions all contain high-frequency features that at first sight seem of considerable intrinsic interest but actually are more likely to represent artifacts of different nature. Spatially averaged phase difference measurement provides the most sensitive diagnostic and indicates the presence of acoustic modulation up to f=20 mHz (periods down to 50 seconds) in internetwork areas.

  9. Tunable vacuum ultraviolet laser based spectrometer for angle resolved photoemission spectroscopy

    SciTech Connect (OSTI)

    Jiang, Rui; Mou, Daixiang; Wu, Yun; Huang, Lunan; Kaminski, Adam [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States) [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); McMillen, Colin D.; Kolis, Joseph [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States)] [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States); Giesber, Henry G.; Egan, John J. [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)] [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)

    2014-03-15

    We have developed an angle-resolved photoemission spectrometer with tunable vacuum ultraviolet laser as a photon source. The photon source is based on the fourth harmonic generation of a near IR beam from a Ti:sapphire laser pumped by a CW green laser and tunable between 5.3 eV and 7 eV. The most important part of the set-up is a compact, vacuum enclosed fourth harmonic generator based on potassium beryllium fluoroborate crystals, grown hydrothermally in the US. This source can deliver a photon flux of over 10{sup 14} photon/s. We demonstrate that this energy range is sufficient to measure the k{sub z} dispersion in an iron arsenic high temperature superconductor, which was previously only possible at synchrotron facilities.

  10. Swift-UVOT captures the earliest ultraviolet spectrum of a Gamma Ray Burst

    E-Print Network [OSTI]

    N. P. M. Kuin; W. B. Landsman; M. J. Page; P. Schady; M. Still; A. A. Breeveld; M. De Pasquale; P. J. Brown; M. Carter; C. James; P. A. Curran; A. Cucciara; C. Gronwall; S. T. Holland; E. A. Hoversten; S. Hunsberger; T. Kennedy; S. Koch; H. Lamoureux; F. E. Marshall; S. R. Oates; A. Parsons; D. Palmer; P. Roming; P. J. Smith

    2009-01-28

    We present the earliest ever ultraviolet spectrum of a gamma-ray burst (GRB) as observed with the Swift-UVOT. The GRB 081203A spectrum was observed for 50 seconds with the UV grism starting 251 seconds after the Swift-BAT trigger when the GRB was of u ~13.4 mag and still rising to its peak optical brightness. The UV grism spectrum shows a damped Ly-alpha line, Ly-beta, and the Lyman continuum break at a redshift z = 2.05 +/- 0.01. A model fit to the Lyman absorption implies log N(HI) = 22.0 +/- 0.2 cm-2, which is typical for GRB host galaxies with damped Ly-alpha absorbers. This observation of GRB 081203A demonstrates that for GRBs brighter than v ~14 mag and with 0.5 Swift-BAT trigger.

  11. Swift-UVOT captures the earliest ultraviolet spectrum of a Gamma Ray Burst

    E-Print Network [OSTI]

    Kuin, N P M; Page, M J; Schady, P; Still, M; Breeveld, A A; De Pasquale, M; Brown, P J; Carter, M; James, C; Curran, P A; Cucciara, A; Gronwall, C; Holland, S T; Hoversten, E; Hunsberger, S; Kennedy, T; Koch, S; Lamoureux, H; Marshall, F E; Oates, S R; Parsons, A; Palmer, D; Roming, P; Smith, P J

    2008-01-01

    We present the earliest ever ultraviolet spectrum of a gamma-ray burst (GRB) as observed with the Swift-UVOT. The spectrum of GRB 081203A was observed for 50 seconds with the UV grism starting 251 seconds after the Swift-BAT trigger when the GRB was of u ~13.4 mag and still rising to its peak optical brightness. The UV grism spectrum shows a damped Ly-alpha line, Ly-beta, and the Lyman continuum break at a redshift z = 2.05 +/- 0.01. A model fit to the Lyman absorption implies log N(HI) = 22.0 +/- 0.2 cm-2, which is typical for GRB host galaxies with damped Ly-alpha absorbers. This observation of GRB 081203A demonstrates that for GRBs brighter than v ~14 mag and with 0.5 Swift-BAT trigger.

  12. Origin of the Diffuse, Far Ultraviolet Emission in the Interarm Regions of M101

    E-Print Network [OSTI]

    Crocker, Alison F; Calzetti, Daniela; Holwerda, Benne Willem; Leitherer, Claus; Popescu, Cristina; Tuffs, R J

    2015-01-01

    We present images from the Solar Blind Channel on HST that resolve hundreds of far ultraviolet (FUV) emitting stars in two ~1 kpc$^2$ interarm regions of the grand-design spiral M101. The luminosity functions of these stars are compared with predicted distributions from simple star formation histories, and are best reproduced when the star formation rate has declined recently (past 10-50 Myr). This pattern is consistent with stars forming within spiral arms and then streaming into the interarm regions. We measure the diffuse FUV surface brightness after subtracting all of the detected stars, clusters and background galaxies. A residual flux is found for both regions which can be explained by a mix of stars below our detection limit and scattered FUV light. The amount of scattered light required is much larger for the region immediately adjacent to a spiral arm, a bright source of FUV photons.

  13. Ultraviolet stimulated electron source for use with low energy plasma instrument calibration

    E-Print Network [OSTI]

    Henderson, Kevin; Funsten, Herb; MacDonald, Elizabeth

    2011-01-01

    We report the development of a versatile, compact, low to medium energy electron source. A collimated, monoenergetic beam of electrons, up to 50 mm in diameter, is produced with energies ranging from 0.03 to 30 keV. A uniform electron beam profile is generated by illuminating a metal cathode plate with a near ultraviolet (UV) light emitting diode (LED). A parallel electric field accelerates the electrons away from the cathode plate towards a grounded grid. The beam intensity can be controlled from 10 - 10^9 electrons cm-2 s-1 and the angular divergence of the beam is less than 1 degree FWHM for energies greater than 1 keV.

  14. Ultraviolet stimulated electron source for use with low energy plasma instrument calibration

    SciTech Connect (OSTI)

    Henderson, Kevin; Harper, Ron; Funsten, Herb; MacDonald, Elizabeth [Space Science and Applications, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2012-07-15

    We have developed and demonstrated a versatile, compact electron source that can produce a mono-energetic electron beam up to 50 mm in diameter from 0.1 to 30 keV with an energy spread of <10 eV. By illuminating a metal cathode plate with a single near ultraviolet light emitting diode, a spatially uniform electron beam with 15% variation over 1 cm{sup 2} can be generated. A uniform electric field in front of the cathode surface accelerates the electrons into a beam with an angular divergence of <1 Degree-Sign at 1 keV. The beam intensity can be controlled from 10 to 10{sup 9} electrons cm{sup -2} s{sup -1}.

  15. Response to comments by Yuan Wang on “Trends of extreme precipitation in Eastern China and their possible causes”

    E-Print Network [OSTI]

    2015-01-01

    dependence of global precipitation extremes. Geo- phys. Res.2015: Trends of extreme precipitation in eastern China andon convective clouds and precipitation. Rev. Geophys. , 50,

  16. Far-ultraviolet observations of comet C/2001 Q4 (NEAT) with FIMS/SPEAR

    SciTech Connect (OSTI)

    Lim, Y.-M.; Min, K.-W. [Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Feldman, P. D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Han, W. [Korea Astronomy and Space Science Institute (KASI), 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Edelstein, J., E-mail: ymlim@kaist.ac.kr [Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States)

    2014-02-01

    We present the results of far-ultraviolet observations of comet C/2001 Q4 (NEAT) that were made with the Far-Ultraviolet Imaging Spectrograph on board the Korean satellite STSAT-1. The observations were conducted in two campaigns during its perihelion approach between 2004 May 8 and 15. Based on the scanning mode observations in the wavelength band of 1400-1700 Ĺ, we have constructed an image of the comet with an angular size of 5°×5°, which corresponds to the central coma region. Several important fluorescence emission lines were detected including S I multiplets at 1429 and 1479 Ĺ, C I multiplets at 1561 and 1657 Ĺ, and the CO A{sup 1}?-X{sup 1}?{sup +} Fourth Positive system; we have estimated the production rates of the corresponding species from the fluxes of these emission lines. The estimated production rate of CO was Q {sub CO} = (2.65 ± 0.63) × 10{sup 28} s{sup –1}, which is 6.2%-7.4% of the water production rate and is consistent with earlier predictions. The average carbon production rate was estimated to be Q{sub C} = ?1.59 × 10{sup 28} s{sup –1}, which is ?60% of the CO production rate. However, the observed carbon profile was steeper than that predicted using the two-component Haser model in the inner coma region, while it was consistent with the model in the outer region. The average sulfur production rate was Q{sub S} = (4.03±1.03) × 10{sup 27} s{sup –1}, which corresponds to ?1% of the water production rate.

  17. Investigation of Soap Powders

    E-Print Network [OSTI]

    Bragg, G.A.

    1913-01-01

    KU ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Investigation of Soap Powders 1913 by G. A. Bragg This work was digitized by the Scholarly Communications program staff in the KU Libraries’ Center for Digital... Scholarship. http://kuscholarworks.ku.edu Submitted to the School of Engineering of the University of Kansas in partial fulfillment of the requirements for the Degree of Bachelor of Science INVESTIGATION OF SOAP POWDERS. by G. A* Bragg. Presented...

  18. Molecular basis of the structural stability of a Top7-based scaffold at extreme pH and temperature conditions

    SciTech Connect (OSTI)

    Soares, Thereza A.; Boschek, Curt B.; Apiyo, David O.; Baird, Cheryl L.; Straatsma, TP

    2010-07-01

    The development of stable scaffolds that can tolerate environmental extremes has an immense potential for applications in industry and defense. Recently, we have engineered an eight-residue loop into the de novo designed Top7 protein, which specifically binds the glycoprotein CD4. The robust properties of the Top7, coupled with the ease in production, make it a robust scaffold to design novel functionalities for use under extreme environmental conditions. In the present work, a series of explicit-solvent molecular dynamics simulations are reported which investigates the effect of mutations and extreme conditions of temperature and pH on the structure, stability, and dynamics of the native and engineered Top7. These simulations indicate that i. The structural dynamics of the engineered and native Top7 in solution are equivalent under corresponding conditions of pH and temperature. Ensemble-averaged structures of the native and engineered Top7 maintain the overall tertiary structure pattern, albeit with loss of helical content when at low pH and high-temperature conditions. Mutations of residues E43A, D46A, E67A, E69A, EA81A along the ?-helices of the engineered Top7 did not lead to significant changes in the native fold under pH 2 and 400 K, suggesting that the helices can accommodate varying sequences. iii. The anti-parallel ?-sheet is the structural core responsible for the stability of the native and engineered Top7 and is well maintained under extreme pH and temperature conditions. These findings indicate that the insertion of an eight-residue loop into the structure of Top7 does not adversely affect the global fold or the structural stability of the Top7 scaffold.

  19. Theory of extreme correlations using canonical Fermions and path integrals

    SciTech Connect (OSTI)

    Shastry, B. Sriram, E-mail: sriram@physics.ucsc.edu

    2014-04-15

    The  t–J  model is studied using a novel and rigorous mapping of the Gutzwiller projected electrons, in terms of canonical electrons. The mapping has considerable similarity to the Dyson–Maleev transformation relating spin operators to canonical Bosons. This representation gives rise to a non Hermitian quantum theory, characterized by minimal redundancies. A path integral representation of the canonical theory is given. Using it, the salient results of the extremely correlated Fermi liquid (ECFL) theory, including the previously found Schwinger equations of motion, are easily rederived. Further, a transparent physical interpretation of the previously introduced auxiliary Greens function and the ‘caparison factor’, is obtained. The low energy electron spectral function in this theory, with a strong intrinsic asymmetry, is summarized in terms of a few expansion coefficients. These include an important emergent energy scale ?{sub 0} that shrinks to zero on approaching the insulating state, thereby making it difficult to access the underlying very low energy Fermi liquid behavior. The scaled low frequency ECFL spectral function, related simply to the Fano line shape, has a peculiar energy dependence unlike that of a Lorentzian. The resulting energy dispersion obtained by maximization is a hybrid of a massive and a massless Dirac spectrum E{sub Q}{sup ?}??Q??(?{sub 0}{sup 2}+Q{sup 2}), where the vanishing of Q, a momentum type variable, locates the kink minimum. Therefore the quasiparticle velocity interpolates between (??1) over a width ?{sub 0} on the two sides of Q=0, implying a kink there that strongly resembles a prominent low energy feature seen in angle resolved photoemission spectra (ARPES) of cuprate materials. We also propose novel ways of analyzing the ARPES data to isolate the predicted asymmetry between particle and hole excitations. -- Highlights: •Spectral function of the Extremely Correlated Fermi Liquid theory at low energy. •Electronic origin of low energy kinks in energy dispersion. •Non Hermitian representation of Gutzwiller projected electrons. •Analogy with Dyson–Maleev representation of spins. •Path integral formulation of extremely correlated electrons.

  20. TESTING THE APODIZED PUPIL LYOT CORONAGRAPH ON THE LABORATORY FOR ADAPTIVE OPTICS EXTREME ADAPTIVE OPTICS TESTBED

    SciTech Connect (OSTI)

    Thomas, Sandrine J.; Dillon, Daren; Gavel, Donald [Laboratory for Adaptive Optics, University of California/Lick Observatories, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Soummer, Remi [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Macintosh, Bruce [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 (United States); Sivaramakrishnan, Anand, E-mail: sthomas@ucolick.org, E-mail: dillon@ucolick.org, E-mail: gavel@ucolick.org, E-mail: soummer@stsci.edu, E-mail: macintosh1@mail.llnl.gov, E-mail: anand@amnh.org [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024 (United States)

    2011-10-15

    We present testbed results of the Apodized Pupil Lyot Coronagraph (APLC) at the Laboratory for Adaptive Optics (LAO). These results are part of the validation and tests of the coronagraph and of the Extreme Adaptive Optics (ExAO) for the Gemini Planet Imager (GPI). The apodizer component is manufactured with a halftone technique using black chrome microdots on glass. Testing this APLC (like any other coronagraph) requires extremely good wavefront correction, which is obtained to the 1 nm rms level using the microelectricalmechanical systems (MEMS) technology, on the ExAO visible testbed of the LAO at the University of Santa Cruz. We used an APLC coronagraph without central obstruction, both with a reference super-polished flat mirror and with the MEMS to obtain one of the first images of a dark zone in a coronagraphic image with classical adaptive optics using a MEMS deformable mirror (without involving dark hole algorithms). This was done as a complementary test to the GPI coronagraph testbed at American Museum of Natural History, which studied the coronagraph itself without wavefront correction. Because we needed a full aperture, the coronagraph design is very different from the GPI design. We also tested a coronagraph with central obstruction similar to that of GPI. We investigated the performance of the APLC coronagraph and more particularly the effect of the apodizer profile accuracy on the contrast. Finally, we compared the resulting contrast to predictions made with a wavefront propagation model of the testbed to understand the effects of phase and amplitude errors on the final contrast.

  1. Extremal black attractors in 8D maximal supergravity

    SciTech Connect (OSTI)

    Drissi, L. B [INANOTECH, Institute of Nanomaterials and Nanotechnology (Morocco); Hassani, F. Z; Jehjouh, H. [Lab/UFR-High Energy Physics, Faculty of Science, Rabat (Morocco) and GNPHE; Groupement National de Physique des Hautes Energies (Morocco); Saidi, E. H [INANOTECH, Institute of Nanomaterials and Nanotechnology (Morocco) and Lab/UFR-High Energy Physics; Faculty of Science, Rabat (Morocco); GNPHE, Groupement National de Physique des Hautes Energies (Morocco)

    2010-05-15

    Motivated by the new higher D-supergravity solutions on intersecting attractors obtained by Ferrara et al. in [Phys. Rev. D 79, 065031 (2009)], we focus in this paper on 8D maximal supergravity with moduli space (SL(3,R)/SO(3))x(SL(2,R)/SO(2)) and study explicitly the attractor mechanism for various configurations of extremal black p-branes (antibranes) with the typical near horizon geometries AdS{sub p+2}xS{sup m}xT{sup 6-p-m} and p=0, 1, 2, 3, 4; 2{<=}m{<=}6. Interpretations in terms of wrapped M2 and M5 branes of the 11D M-theory on 3-torus are also given.

  2. Lightlike shell solitons of extremal space-time film

    E-Print Network [OSTI]

    Chernitskii, Alexander A

    2015-01-01

    New exact solution class of Born -- Infeld type nonlinear scalar field model is obtained. The variational principle of this model has a specific form which is characteristic for extremal four-dimensional hypersurface or hyper film in five-dimensional space-time. Obtained solutions are singular solitons propagating with speed of light and having energy, momentum, and angular momentum which can be calculated for explicit conditions. The soliton singularity here is a moving two-dimensional surface or shell, where the model action density becomes zero. The lightlike soliton can have a set of tubelike shells with the appropriate cavities. A twisted lightlike soliton is considered. It is notable that its energy is proportional to its angular momentum in high-frequency approximation. A case with one tubelike cavity is considered. In this case the soliton shell is diffeomorphic to cylindrical surface with cuts by multifilar helix. The shell transverse size of the appropriate finite energy soliton can be converging to...

  3. Amplitude variations on the Extreme Adaptive Optics testbed

    SciTech Connect (OSTI)

    Evans, J; Thomas, S; Dillon, D; Gavel, D; Phillion, D; Macintosh, B

    2007-08-14

    High-contrast adaptive optics systems, such as those needed to image extrasolar planets, are known to require excellent wavefront control and diffraction suppression. At the Laboratory for Adaptive Optics on the Extreme Adaptive Optics testbed, we have already demonstrated wavefront control of better than 1 nm rms within controllable spatial frequencies. Corresponding contrast measurements, however, are limited by amplitude variations, including those introduced by the micro-electrical-mechanical-systems (MEMS) deformable mirror. Results from experimental measurements and wave optic simulations of amplitude variations on the ExAO testbed are presented. We find systematic intensity variations of about 2% rms, and intensity variations with the MEMS to be 6%. Some errors are introduced by phase and amplitude mixing because the MEMS is not conjugate to the pupil, but independent measurements of MEMS reflectivity suggest that some error is introduced by small non-uniformities in the reflectivity.

  4. The extreme vulnerability of interdependent spatially embedded networks

    E-Print Network [OSTI]

    Bashan, Amir; Buldyrev, Sergey V; Havlin, Shlomo

    2015-01-01

    Recent studies show that in interdependent networks a very small failure in one network may lead to catastrophic consequences. Above a critical fraction of interdependent nodes, even a single node failure can invoke cascading failures that may abruptly fragment the system, while below this "critical dependency" (CD) a failure of few nodes leads only to small damage to the system. So far, the research has been focused on interdependent random networks without space limitations. However, many real systems, such as power grids and the Internet, are not random but are spatially embedded. Here we analytically and numerically analyze the stability of systems consisting of interdependent spatially embedded networks modeled as lattice networks. Surprisingly, we find that in lattice systems, in contrast to non-embedded systems, there is no CD and \\textit{any} small fraction of interdependent nodes leads to an abrupt collapse. We show that this extreme vulnerability of very weakly coupled lattices is a consequence of t...

  5. Extremely strong tubular stacking of aromatic oligoamide macrocycles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kline, Mark A.; Wei, Xiaoxi; Horner, Ian J.; Liu, Rui; Chen, Shuang; Chen, Si; Yung, Ka Yi; Yamato, Kazuhiro; Cai, Zhonghou; Bright, Frank V.; et al

    2015-01-01

    As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of Kdimer > 1013 M-1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol-1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistentmore »tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3.« less

  6. Extremely strong tubular stacking of aromatic oligoamide macrocycles

    SciTech Connect (OSTI)

    Kline, Mark A.; Wei, Xiaoxi; Horner, Ian J.; Liu, Rui; Chen, Shuang; Chen, Si; Yung, Ka Yi; Yamato, Kazuhiro; Cai, Zhonghou; Bright, Frank V.; Zeng, Xiao Cheng; Gong, Bing

    2015-01-01

    As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of Kdimer > 1013 M-1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol-1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistent tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3.

  7. The Phoenix Deep Survey: Extremely Red Galaxies and Cluster Candidates

    E-Print Network [OSTI]

    Anthony G. Smith; Andrew M. Hopkins; Richard W. Hunstead; Samuel J. Schmidt; José Afonso; Antonis E. Georgakakis; Lawrence E. Cram; Bahram Mobasher; Mark Sullivan

    2008-04-24

    We present the results of a study of a sample of 375 Extremely Red Galaxies (ERGs) in the Phoenix Deep Survey, 273 of which constitute a subsample which is 80% complete to K_s = 18.5 over an area of 1160 arcmin^2. The angular correlation function for ERGs is estimated, and the association of ERGs with faint radio sources explored. We find tentative evidence that ERGs and faint radio sources are associated at z > 0.5. A new overdensity-mapping algorithm has been used to characterize the ERG distribution, and identify a number of cluster candidates, including a likely cluster containing ERGs at 0.5 4 criterion is more efficient than R - K_s > 5 at selecting dusty star-forming galaxies, rather than passively evolving ERGs.

  8. Deep Chandra, HST-COS, and Megacam Observations of the Phoenix Cluster: Extreme Star Formation and AGN Feedback on Hundred Kiloparsec Scales

    E-Print Network [OSTI]

    McDonald, M; van Weeren, R J; Applegate, D E; Bayliss, M; Bautz, M W; Benson, B A; Carlstrom, J E; Bleem, L E; Chatzikos, M; Edge, A C; Fabian, A C; Garmire, G P; Hlavacek-Larrondo, J; Jones-Forman, C; Mantz, A B; Miller, E D; Stalder, B; Veilleux, S; Zuhone, J A

    2015-01-01

    We present new ultraviolet, optical, and X-ray data on the Phoenix galaxy cluster (SPT-CLJ2344-4243). Deep optical imaging reveals previously-undetected filaments of star formation, extending to radii of ~50-100 kpc in multiple directions. Combined UV-optical spectroscopy of the central galaxy reveals a massive (2x10^9 Msun)), young (~4.5 Myr) population of stars, consistent with a time-averaged star formation rate of 610 +/- 50 Msun/yr. We report a strong detection of OVI(1032,1038) which appears to originate primarily in shock-heated gas, but may contain a substantial contribution (>1000 Msun/yr) from the cooling intracluster medium. We confirm the presence of deep X-ray cavities in the inner ~10 kpc, which are amongst the most extreme examples of radio-mode feedback detected to date, implying jet powers of 2-7 x10^45 erg/s. We provide evidence that the AGN inflating these cavities may have only recently transitioned from "quasar-mode" to "radio-mode", and may currently be insufficient to completely offset ...

  9. BAL QSOs AND EXTREME UFOs: THE EDDINGTON CONNECTION

    SciTech Connect (OSTI)

    Zubovas, Kastytis; King, Andrew

    2013-05-20

    We suggest a common physical origin connecting the fast, highly ionized winds (UFOs) seen in nearby active galactic nuclei (AGNs), and the slower and less ionized winds of broad absorption line (BAL) QSOs. The primary difference is the mass-loss rate in the wind, which is ultimately determined by the rate at which mass is fed toward the central supermassive black hole (SMBH) on large scales. This is below the Eddington accretion rate in most UFOs, and slightly super-Eddington in extreme UFOs such as PG1211+143, but ranges up to {approx}10-50 times this in BAL QSOs. For UFOs this implies black hole accretion rates and wind mass-loss rates which are at most comparable to Eddington, giving fast, highly ionized winds. In contrast, BAL QSO black holes have mildly super-Eddington accretion rates, and drive winds whose mass-loss rates are significantly super-Eddington, and so are slower and less ionized. This picture correctly predicts the velocities and ionization states of the observed winds, including the recently discovered one in SDSS J1106+1939. We suggest that luminous AGNs may evolve through a sequence from BAL QSO through LoBAL to UFO-producing Seyfert or quasar as their Eddington factors drop during the decay of a bright accretion event. LoBALs correspond to a short-lived stage in which the AGN radiation pressure largely evacuates the ionization cone, but before the large-scale accretion rate has dropped to the Eddington value. We show that sub-Eddington wind rates would produce an M-{sigma} relation lying above that observed. We conclude that significant SMBH mass growth must occur in super-Eddington phases, either as BAL QSOs, extreme UFOs, or obscured from direct observation.

  10. The Hawking cascade from a black hole is extremely sparse

    E-Print Network [OSTI]

    Finnian Gray; Sebastian Schuster; Alexander Van-Brunt; Matt Visser

    2015-06-12

    The Hawking flux from a black hole, (at least as seen from large distances), is extremely sparse and thin, with the average time between emission of successive Hawking quanta being hundreds of times larger than the natural timescale set by the energies of the emitted quanta. Some aspects of this result have been known for over 30 years, but have been largely forgotten, possibly because authors focussed mainly on the late-time high-temperature regime. We shall instead focus on the early-stage low-temperature regime, and shall both quantify and significantly extend these observations in a number of different ways. First we shall identify several natural dimensionless figures of merit, and thereby compare the mean time between emission of successive Hawking quanta to several quite natural timescales that can be associated with the emitted quanta, demonstrating that ratios of 300 or more are typical for emission of photons or gravitons from a Schwarzschild black hole. Furthermore these ratios are independent of the mass of the black hole as it slowly evolves. The situation for fermion emission (massless neutrinos) is actually worse. Second, we shall then show that the situation for Reissner-Nordstrom, Kerr, Kerr-Newman and "dirty" black holes is even worse. Third, we consider the effects of particle rest mass. Overall, the Hawking quanta are seen to be dribbling out of the black hole one at a time, in an extremely slow cascade of 3-body decays. This implies that the Hawking flux is subject to "shot noise". Observationally, the Planck spectrum of the Hawking flux can only be determined by collecting and integrating data over a very long time. We conclude by connecting these points back to various kinematic aspects of the Hawking evaporation process.

  11. Extreme multiplex spectroscopy at wide-field 4-m telescopes

    E-Print Network [OSTI]

    Robert Content; Tom Shanks

    2008-08-18

    We describe the design and science case for a spectrograph for the prime focus of classical 4-m wide-field telescopes that can deliver at least 4000 MOS slits over a 1 degree field. This extreme multiplex capability means that 25000 galaxy redshifts can be measured in a single night, opening up the possibilities for large galaxy redshift surveys out to z~0.7 and beyond for the purpose of measuring the Baryon Acoustic Oscillation (BAO) scale and for many other science goals. The design features four cloned spectrographs and exploits the exclusive possibility of tiling the focal plane of wide-field 4-m telescopes with CCDs for multi-object spectroscopic purposes. In ~200 night projects, such spectrographs have the potential to make galaxy redshift surveys of ~6 million galaxies over a wide redshift range and thus may provide a low-cost alternative to other survey routes such as WFMOS and SKA. Two of these extreme multiplex spectrographs are currently being designed for the AAT (NG1dF) and Calar Alto (XMS) 4-m class telescopes. NG2dF, a larger version for the AAT 2 degree field, would have 12 clones and at least 12000 slits. The clones use a transparent design including a grism in which all optics are smaller than the clone square subfield so that the clones can be tightly packed with little gaps between the contiguous fields. Only low cost glasses are used; the variations in chromatic aberrations between bands are compensated by changing one or two of the lenses adjacent to the grism. The total weight and length is smaller with a few clones than a unique spectrograph which makes it feasible to place the spectrograph at the prime focus.

  12. September 2009 INVESTIGATORS

    E-Print Network [OSTI]

    Varela, Carlos

    September 2009 SPONSORED PROJECTS GUIDE FOR PRINICIPAL INVESTIGATORS Cost Transfers Cost transfers to a project cannot be transferred to that project, even temporarily. Instead, use an Institute discretionary" or "to transfer to correct project" is not sufficient. Transfers of costs from one project to another

  13. Study Title: Principal Investigator

    E-Print Network [OSTI]

    Biederman, Irving

    Study Title: Principal Investigator: EXPERIMENTAL SUBJECT'S BILL OF RIGHTS You have been asked BE INFORMED ABOUT: 1. The nature and purpose of the study. 2. The procedures in the study and any drug or device to be used. 3. Discomforts and risks reasonably to be expected from the study. 4. Benefits

  14. A Microscale Exsolution Investigation

    E-Print Network [OSTI]

    Stanford University

    A Microscale Exsolution Investigation Markus Buchgraber, Anthony R. Kovscek Department of Energy-term storage security of the CO2 because the denser brine is less likely to move upwards towards shallower supplies, the risk is not zero. There are plausible mechanisms by which the CO2 laden brine could

  15. The use and calibration of read-out streaks to increase the dynamic range of the Swift Ultraviolet/Optical Telescope

    E-Print Network [OSTI]

    Page, M J; Breeveld, A A; Hancock, B; Holland, S T; Marshall, F E; Oates, S; Roming, P W A; Siegel, M H; Smith, P J; Carter, M; De Pasquale, M; Symeonidis, M; Yershov, V; Beardmore, A P

    2013-01-01

    The dynamic range of photon counting micro-channel-plate (MCP) intensified charged-coupled device (CCD) instruments such as the Swift Ultraviolet/Optical Telescope (UVOT) and the XMM-Newton Optical Monitor (XMM-OM) is limited at the bright end by coincidence loss, the superposition of multiple photons in the individual frames recorded by the CCD. Photons which arrive during the brief period in which the image frame is transferred for read out of the CCD are displaced in the transfer direction in the recorded images. For sufficiently bright sources, these displaced counts form read-out streaks. Using UVOT observations of Tycho-2 stars, we investigate the use of these read-out streaks to obtain photometry for sources which are too bright (and hence have too much coincidence loss) for normal aperture photometry to be reliable. For read-out-streak photometry, the bright-source limiting factor is coincidence loss within the MCPs rather than the CCD. We find that photometric measurements can be obtained for stars u...

  16. Electrical current leakage and open-core threading dislocations in AlGaN-based deep ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Moseley, Michael Allerman, Andrew; Crawford, Mary; Wierer, Jonathan J.; Smith, Michael; Biedermann, Laura

    2014-08-07

    Electrical current transport through leakage paths in AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) and their effect on LED performance are investigated. Open-core threading dislocations, or nanopipes, are found to conduct current through nominally insulating Al{sub 0.7}Ga{sub 0.3}N layers and limit the performance of DUV-LEDs. A defect-sensitive phosphoric acid etch reveals these open-core threading dislocations in the form of large, micron-scale hexagonal etch pits visible with optical microscopy, while closed-core screw-, edge-, and mixed-type threading dislocations are represented by smaller and more numerous nanometer-scale pits visible by atomic-force microscopy. The electrical and optical performances of DUV-LEDs fabricated on similar Si-doped Al{sub 0.7}Ga{sub 0.3}N templates are found to have a strong correlation to the density of these nanopipes, despite their small fraction (<0.1% in this study) of the total density of threading dislocations.

  17. Effect of ultraviolet radiation exposure on room-temperature hydrogen sensitivity of nanocrystalline doped tin oxide sensor incorporated into microelectromechanical systems device

    SciTech Connect (OSTI)

    Shukla, Satyajit; Agrawal, Rajnikant; Cho, Hyoung J.; Seal, Sudipta; Ludwig, Lawrence; Parish, Clyde [Advanced Materials Processing and Analysis Center (AMPAC) and Mechanical Materials Aerospace Engineering (MMAE) Department, Engineering 381, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); National Aeronautics and Space Administration (NASA), John F. Kennedy Space Center, Kennedy Space Center (KSC), Florida 32899 (United States)

    2005-03-01

    The effect of ultraviolet (UV) radiation exposure on the room-temperature hydrogen (H{sub 2}) sensitivity of nanocrystalline indium oxide (In{sub 2}O{sub 3})-doped tin oxide (SnO{sub 2}) thin-film gas sensor is investigated in this article. The present sensor is incorporated into microelectromechanical systems device using sol-gel dip-coating technique. The present sensor exhibits a very high sensitivity, as high as 65 000-110 000, at room temperature, for 900 ppm of H{sub 2} under the dynamic test condition without UV exposure. The H{sub 2} sensitivity is, however, observed to reduce to 200 under UV radiation, which is contrary to the literature data, where an enhanced room-temperature gas sensitivity has been reported under UV radiation. The observed phenomenon is attributed to the reduced surface coverage by the chemisorbed oxygen ions under UV radiation, which is in consonance with the prediction of the constitutive equation, proposed recently by the authors, for the gas sensitivity of nanocrystalline semiconductor oxide thin-film sensors.

  18. Studies of Ion Exchange Resin Integrity under Flowsheet Extremes: Part II

    SciTech Connect (OSTI)

    Nash, C.A.

    2002-12-19

    This task addressed four items related to SuperLig(R) 644 ion exchange resin stability under nominal to extreme conditions.

  19. A possible explanation of the clash for black hole entropy in the extremal limit

    E-Print Network [OSTI]

    Ru-Keng Su; Bin Wang; P. K. N. Yu; E. C. M. Young

    1997-11-24

    It is shown that the classical entropy of the extremal black hole depends on two different limits procedures. If we first take the extremal limit and then the boundary limit, the entropy is zero; if we do it the other way round, we get the Bekenstein-Hawking entropy. By means of the brick wall model, the quantum entropy of scalar field in the extremal black hole background has been calculated for the above two different limits procedures. A possible explanation which considers the quantum effect for the clash of black hole entropy in the extremal limit is given.

  20. On the use of Extreme Value Theory in analyses of continuum gamma decay

    SciTech Connect (OSTI)

    Garcia-Ruiz, R. F.; Cristancho, F.

    2010-08-04

    Extreme Value theory seems to be a promising tool for analysing experimental continuum gamma decay spectra in order to obtain physical parameters at high excitation energy.