Sample records for visible infrared solar-infrared

  1. Use Remote Sensing Data (selected visible and infrared spectrums...

    Broader source: Energy.gov (indexed) [DOE]

    Use Remote Sensing Data (selected visible and infrared spectrums) to locate high temperature ground anomalies in Colorado. Confirm heat flow potential with on-site surveys to drill...

  2. Use Remote Sensing Data (selected visible and infrared spectrums...

    Broader source: Energy.gov (indexed) [DOE]

    City - May 19, 2010 * Project Title - "Use Remote Sensing Data (selected visible and infrared spectrums) to locate high temperature ground anomalies in Colorado. Confirm heat flow...

  3. Comparison of Long-Wave Infrared Imaging and Visible/Near-Infrared Imaging of Vegetation for

    E-Print Network [OSTI]

    Lawrence, Rick L.

    Comparison of Long-Wave Infrared Imaging and Visible/Near-Infrared Imaging of Vegetation using spectral imaging. This has been accom- plished with both visible/near-infrared (Vis/NIR) sunlight reflection and long-wave infrared (LWIR) thermal emission. During a 4-week period in summer 2011

  4. Evaluation of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Moderate Resolution Imaging Spectrometer

    E-Print Network [OSTI]

    Evaluation of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Moderate Resolution the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and the Moderate Resolution Imaging Spectrometer (MODIS). Key goals were to assess the nature of these relationships as they varied between sensors

  5. Using Visible and Near Infrared Diffuse Reflectance Spectroscopy to Characterize and Classify Soil Profiles

    E-Print Network [OSTI]

    Wilke, Katrina Margarette

    2011-10-21T23:59:59.000Z

    USING VISIBLE AND NEAR INFRARED DIFFUSE REFLECTANCE SPECTROSCOPY TO CHARACTERIZE AND CLASSIFY SOIL PROFILES A Thesis by KATRINA MARGARETTE WILKE Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE August 2010 Major Subject: Soil Science USING VISIBLE AND NEAR INFRARED DIFFUSE REFLECTANCE SPECTROSCOPY TO CHARACTERIZE AND CLASSIFY SOIL PROFILES A Thesis...

  6. Combustion Control Using Infrared and Visible Light Devices

    E-Print Network [OSTI]

    Lewis, S. E.

    1981-01-01T23:59:59.000Z

    Economics and overall experience have acted against the installation of infrared carbon monoxide or carbon dioxide analyzers on smaller systems for air fuel ratio control. This paper discusses an interesting control signal which can be derived from...

  7. Mid-infrared second-order susceptibility of -quartz and its application to visible-infrared surface sum-frequency spectroscopy

    E-Print Network [OSTI]

    Richmond, Geraldine L.

    Mid-infrared second-order susceptibility of -quartz and its application to visible-infrared surface to elucidate the nonlinear susceptibility of any material in the mid-infrared region. Crystalline quartz-frequency spectroscopy which are expanding into the mid-IR with the increasing availability of widely tunable infrared

  8. Enhanced visible and near-infrared capabilities of the JET mirror-linked divertor spectroscopy system

    SciTech Connect (OSTI)

    Lomanowski, B. A., E-mail: b.a.lomanowski@durham.ac.uk; Sharples, R. M. [Centre for Advanced Instrumentation, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Meigs, A. G.; Conway, N. J.; Zastrow, K.-D.; Heesterman, P.; Kinna, D. [EURATOM/CCFE Fusion Association, Culham Science Center, Abingdon OX14 3DB (United Kingdom); Collaboration: JET-EFDA Team

    2014-11-15T23:59:59.000Z

    The mirror-linked divertor spectroscopy diagnostic on JET has been upgraded with a new visible and near-infrared grating and filtered spectroscopy system. New capabilities include extended near-infrared coverage up to 1875 nm, capturing the hydrogen Paschen series, as well as a 2 kHz frame rate filtered imaging camera system for fast measurements of impurity (Be II) and deuterium D?, D?, D? line emission in the outer divertor. The expanded system provides unique capabilities for studying spatially resolved divertor plasma dynamics at near-ELM resolved timescales as well as a test bed for feasibility assessment of near-infrared spectroscopy.

  9. Remote sensing of Greenland ice sheet using multispectral near-infrared and visible radiances

    E-Print Network [OSTI]

    Dozier, Jeff

    Remote sensing of Greenland ice sheet using multispectral near-infrared and visible radiances Petr microwave methods. The method should be useful for long-term monitoring of the melt area of the Greenland of MODIS retrievals of the western portion of the Greenland ice sheet over the period 2000 to 2006

  10. Combustion Control Using Infrared and Visible Light Devices

    E-Print Network [OSTI]

    Lewis, S. E.

    1981-01-01T23:59:59.000Z

    by the boiler controller, while other heat inputs and useful heat outputs which remain relatively constant can be entered on the control panel. Wasteful heat output such as stack losses are not to be included; only useful heat outputs such as space heating... to the boiler controller at the speed of light, time lag in the combustion analysis system is 78 7.69 6.41 5.13 3.85 2.56 1.28 reduced to nil. Thus, the infrared flame monitor 79 8.86' 7.59 6.33 5.06 3.80 2.S3 1.27 ing system is capable of holding...

  11. Comparison and detection of total and available soil carbon fractions using visible/near infrared diffuse reflectance spectroscopy

    E-Print Network [OSTI]

    Grunwald, Sabine

    . With the advent of visible/near-infrared-diffuse reflectance spectroscopy (VNIR-DRS) to infer on soil C fractionsComparison and detection of total and available soil carbon fractions using visible/near infrared diffuse reflectance spectroscopy D.V. Sarkhot a,1,2 , S. Grunwald a, , Y. Ge b,3 , C.L.S. Morgan c,4

  12. PPPL3301, Preprint: May 1998, UC426 Design Study of a Visible/Infrared Periscope for Intense Radiation

    E-Print Network [OSTI]

    PPPL­3301, Preprint: May 1998, UC­426 Design Study of a Visible/Infrared Periscope for Intense projected heating of the reflective optics themselves to several hundred degrees Celsius. Tests of beryllium regions during operation and infrared measurement of the surface temperature of the first wall structures

  13. PPPL-3301, Preprint: May 1998, UC-426 Design Study of a Visible/Infrared Periscope for Intense Radiation

    E-Print Network [OSTI]

    PPPL-3301, Preprint: May 1998, UC-426 Design Study of a Visible/Infrared Periscope for Intense projected heating of the reflective optics themselves to several hundred degrees Celsius. Tests of beryllium regions during operation and infrared measurement of the surface temperature of the first wall structures

  14. aerial color infrared: Topics by E-print Network

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

    Summary: Solar infrared colors provide powerful constraints on the stellar effective temperature scale, but to this purpose they must be measured with both accuracy and precision....

  15. Composition, Mineralogy, and Porosity of Multiple Asteroid Systems from Visible and Near-infrared Spectral Data

    E-Print Network [OSTI]

    Lindsay, Sean S; Emery, Joshua P; Enriquez, J Emilio; Assafin, Marcelo

    2014-01-01T23:59:59.000Z

    We provide a taxonomic and compositional characterization of Multiple Asteroid Systems (MASs) located in the main belt (MB) using visible and near-infrared (0.45-2.5 um) spectral data of 42 MB MASs. The mineralogical analysis is applied to determine meteorite analogs for the MASs, which, in turn, are applied to the MAS density measurements of Marchis et al. (2012) to estimate the system porosity. The macroporosities are used to evaluate the primary MAS formation hypotheses. The visible observing campaign includes 25 MASs obtained using the SOAR telescope with the Goodman High Throughput Spectrometer. The infrared observing campaign includes 34 MASs obtained using the NASA IRTF with the SpeX spectragraph. The MASs are classified using the Bus-DeMeo taxonomic system. We perform a NIR spectral band parameter analysis using a new analysis routine, the Spectral Analysis Routine for Asteroids (SARA). The SARA routine determines band centers, areas, and depths by utilizing the diagnostic absorption features near 1- ...

  16. Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-D

    SciTech Connect (OSTI)

    Lasnier, C. J., E-mail: lasnier@LLNL.gov; Allen, S. L.; Ellis, R. E.; Fenstermacher, M. E.; McLean, A. G.; Meyer, W. H.; Morris, K.; Seppala, L. G. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); Crabtree, K. [College of Optics, University of Arizona, Tucson, Arizona 85721 (United States); Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2014-11-15T23:59:59.000Z

    An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in diverted and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. Demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.

  17. A versatile femtosecond stimulated Raman spectroscopy setup with tunable pulses in the visible to near infrared

    SciTech Connect (OSTI)

    Zhu, Liangdong [Department of Physics, Oregon State University, Corvallis, Oregon 97331 (United States); Liu, Weimin [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States); Fang, Chong, E-mail: Chong.Fang@oregonstate.edu [Department of Physics, Oregon State University, Corvallis, Oregon 97331 (United States); Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)

    2014-07-28T23:59:59.000Z

    We demonstrate a versatile and efficient setup to perform femtosecond stimulated Raman spectroscopy (FSRS). Technical innovations are implemented to achieve the wavelength tunability for both the picosecond narrowband Raman pump pulse and femtosecond broadband Raman probe pulse. Using a simplified one-grating scheme in a home-built second harmonic bandwidth compressor followed by a two-stage noncollinear optical parametric amplifier, we tune the Raman pump pulse from ca. 480 to 750?nm. To generate the suitable Raman probe pulse in tandem, we rely on our recently demonstrated broadband up-converted multicolor array technique that readily provides tunable broadband laser sidebands across the visible to near-infrared range. This unique setup has unparalleled flexibility for conducting FSRS. We measure the ground-state Raman spectra of a cyclohexane standard using tunable pump-probe pairs at various wavelengths across the visible region. The best spectral resolution is ?12?cm{sup ?1}. By tuning the pump wavelength closer to the electronic absorption band of a photoacid pyranine in water, we observe the pre-resonantly enhanced Raman signal. The stimulated Raman gain of the 1627?cm{sup ?1} mode is increased by over 15 times.

  18. Summary Leaf reflectance at visible and near-infrared wavelengths (4001000 nm) is related primarily to pigmenta-

    E-Print Network [OSTI]

    Richardson, Andrew D.

    Summary Leaf reflectance at visible and near-infrared wavelengths (4001000 nm) is related physiology and relationships between plants and their growth environment. We studied reflectance of two co collected from 24 sites and white spruce from 30 sites. Overall, reflectance spectra of the two species were

  19. Comprehensive Pyrometry of Incandescent Multiwalled Carbon Nanotubes and Graphene in the Visible and Near Infrared

    E-Print Network [OSTI]

    Singer, Scott

    2012-01-01T23:59:59.000Z

    E. Pop, Infrared Microscopy of Joule Heating in Graphenenear infrared is attainable through gating and heating of

  20. Optical Temperature Sensor Using Infrared-to-Visible-Frequency Upconversion in Er This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Cao, Wenwu

    Optical Temperature Sensor Using Infrared-to-Visible-Frequency Upconversion in Er 3+ /Yb 3. 8 (2011) 087804 Optical Temperature Sensor Using Infrared-to-Visible-Frequency Upconversion in Er3 State University, University Park, Pennsylvania 16802, USA (Received 24 May 2011) An optical temperature

  1. REPRODUCING VISIBLE AND NEAR-INFRARED REFLECTANCE SPECTRA OF LUNAR ROCKS DIRECTLY FROM THEIR END-MEMBER SPECTRA: IMPORTANCE OF ILMENITE IN

    E-Print Network [OSTI]

    Hiroi, Takahiro

    REPRODUCING VISIBLE AND NEAR-INFRARED REFLECTANCE SPECTRA OF LUNAR ROCKS DIRECTLY FROM THEIR END as a solid foundation for lunar science and explo- ration. The visible and near-infrared spectroscopy, 15555, 70017, and 70035 have been prepared for analysis. Bidirectional reflectance spectra (0.28- 2.6 m

  2. CHARACTERISTIC SIZE OF FLARE KERNELS IN THE VISIBLE AND NEAR-INFRARED CONTINUA

    SciTech Connect (OSTI)

    Xu, Yan; Jing, Ju; Wang, Haimin [Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States); Cao, Wenda, E-mail: yx2@njit.edu [Big Bear Solar Observatory, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States)

    2012-05-01T23:59:59.000Z

    In this Letter, we present a new approach to estimate the formation height of visible and near-infrared emission of an X10 flare. The sizes of flare emission cores in three wavelengths are accurately measured during the peak of the flare. The source size is the largest in the G band at 4308 A and shrinks toward longer wavelengths, namely the green continuum at 5200 A and NIR at 15600 A, where the emission is believed to originate from the deeper atmosphere. This size-wavelength variation is likely explained by the direct heating model as electrons need to move along converging field lines from the corona to the photosphere. Therefore, one can observe the smallest source, which in our case is 0.''65 {+-} 0.''02 in the bottom layer (represented by NIR), and observe relatively larger kernels in upper layers of 1.''03 {+-} 0.''14 and 1.''96 {+-} 0.''27, using the green continuum and G band, respectively. We then compare the source sizes with a simple magnetic geometry to derive the formation height of the white-light sources and magnetic pressure in different layers inside the flare loop.

  3. Ground-based All-sky Mid-infrared and Visible Imagery for Purposes of Characterizing Cloud Properties

    SciTech Connect (OSTI)

    Klebe, Dimitri; Blatherwick, R. D.; Morris, Victor R.

    2014-02-24T23:59:59.000Z

    This paper describes the All Sky Infrared Visible Analyzer (ASIVA), a multi-purpose visible and infrared sky imaging and analysis instrument whose primary functionality is to provide radiometrically calibrated imagery in the mid-infrared (mid-IR) atmospheric window. This functionality enables the determination of diurnal hemispherical cloud fraction (HCF) and estimates of sky/cloud temperature from which one can derive estimates of cloud emissivity and cloud height. This paper describes the calibration methods and performance of the ASIVA instrument with particular emphasis on data products being developed for the meteorological community. Data presented here were collected during a field campaign conducted at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility from May 21 to July 27, 2009. The purpose of this campaign was to determine the efficacy of IR technology in providing reliable nighttime HCF data. Significant progress has been made in the analysis of the campaign data over the past several years and the ASIVA has proven to be an excellent instrument for determining HCF as well as several other important cloud properties.

  4. DERIVING THE DISTRIBUTION OF ORDINARY CHONDRITE (H, L, LL)-LIKE MATERIALS IN ASTEROIDS FROM THEIR VISIBLE AND NEAR-INFRARED REFLECTANCE SPECTROSCOPY. T.

    E-Print Network [OSTI]

    Hiroi, Takahiro

    THEIR VISIBLE AND NEAR-INFRARED REFLECTANCE SPECTROSCOPY. T. Hiroi1 , T. Nimura2,3 , Y. Ueda2 , S. Sasaki4 and near-infrared tele- scopic reflectance spectra of 53 S/A/R/V asteroids were taken from the 24-color [3 reflects their abundance in the main asteroid belt. The abundant S-type asteroids and less abundant Q

  5. Method And Apparatus For Examining A Tissue Using The Spectral Wing Emission Therefrom Induced By Visible To Infrared Photoexcitation.

    DOE Patents [OSTI]

    Alfano, Robert R. (3777 Independence Ave., Bronx, NY 10463); Demos, Stavros G. (3550 Pacific Ave., Apt. 304, Livermore, CA 94550); Zhang, Gang (3 Rieder Rd., Edison, NJ 08817)

    2003-12-16T23:59:59.000Z

    Method and an apparatus for examining a tissue using the spectral wing emission therefrom induced by visible to infrared photoexcitation. In one aspect, the method is used to characterize the condition of a tissue sample and comprises the steps of (a) photoexciting the tissue sample with substantially monochromatic light having a wavelength of at least 600 nm; and (b) using the resultant far red and near infrared spectral wing emission (SW) emitted from the tissue sample to characterize the condition of the tissue sample. In one embodiment, the substantially monochromatic photoexciting light is a continuous beam of light, and the resultant steady-state far red and near infrared SW emission from the tissue sample is used to characterize the condition of the tissue sample. In another embodiment, the substantially monochromatic photoexciting light is a light pulse, and the resultant time-resolved far red and near infrared SW emission emitted from the tissue sample is used to characterize the condition of the tissue sample. In still another embodiment, the substantially monochromatic photoexciting light is a polarized light pulse, and the parallel and perpendicular components of the resultant polarized time-resolved SW emission emitted from the tissue sample are used to characterize the condition of the tissue sample.

  6. Observation of enhanced visible and infrared emissions in photonic crystal thin-film light-emitting diodes

    SciTech Connect (OSTI)

    Cheung, Y. F.; Li, K. H.; Hui, R. S. Y.; Choi, H. W., E-mail: hwchoi@hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong)

    2014-08-18T23:59:59.000Z

    Photonic crystals, in the form of closed-packed nano-pillar arrays patterned by nanosphere lithography, have been formed on the n-faces of InGaN thin-film vertical light-emitting diodes (LEDs). Through laser lift-off of the sapphire substrate, the thin-film LEDs conduct vertically with reduced dynamic resistances, as well as reduced thermal resistances. The photonic crystal plays a role in enhancing light extraction, not only at visible wavelengths but also at infrared wavelengths boosting heat radiation at high currents, so that heat-induced effects on internal quantum efficiencies are minimized. The observations are consistent with predictions from finite-difference time-domain simulations.

  7. Soot scattering measurements in the visible and near-infrared spectrum

    SciTech Connect (OSTI)

    ZHU,JINYU; CHOI,MUN YOUNG; MULHOLLAND,GEORGE W.; GRITZO,LOUIS A.

    2000-02-08T23:59:59.000Z

    Scattering to extinction cross-section ratios, {rho}{sub se} were measured using the NIST Large Agglomerate Optics Facility for soot produced from ethene and acetylene laminar diffusion flames. Measurements were performed using light sources at 543.5 nm, 632.8 nm and 856 nm. The average scattering to extinction cross-section ratios for these wavelengths are equal to 0.246, 0.196, and 0.196 for ethene and 0.316, 0.230, and 0.239 for acetylene. The 856 nm measurements represent the longest wavelength for which accurate scattering measurements have been performed for soot. The size distribution and fractal properties of the two soots were determined to assess the effects of limited acceptance angle range, finite size of the sensor, and departure from cosine response on the uncertainty in the measurement of {rho}{sub se} The expanded relative uncertainty (95% confidence level) was found to be {+-}6% at the two visible wavelengths and {+-}8% at 856 nm. Both the magnitude and wavelength dependence of {rho}{sub se} for the present experiments are significantly different from those reported by Krishnan et al. for overfire soot produced using a turbulent flame. The results are compared with the predictions of fractal optics.

  8. Air-bridged photonic crystal slabs at visible and near-infrared wavelengths K. B. Crozier,1 Virginie Lousse,2,3 Onur Kilic,3 Sora Kim,3 Shanhui Fan,3 and Olav Solgaard3

    E-Print Network [OSTI]

    Air-bridged photonic crystal slabs at visible and near-infrared wavelengths K. B. Crozier,1 are demonstrated at visible and near-infrared wavelengths. We present experimental and theoretical studies useful filtering functions, such as all-pass transmission and flattop reflection.2 Third

  9. Dispersion properties and low infrared optical losses in epitaxial AlN on sapphire substrate in the visible and infrared range

    SciTech Connect (OSTI)

    Soltani, A., E-mail: ali.soltani@iemn.univ-lille1.fr; Stolz, A.; Gerbedoen, J.-C.; Rousseau, M.; Bourzgui, N.; De Jaeger, J.-C. [Institut d'lectronique, Microlectronique et Nanotechnologie, UMR-CNRS 8520, PRES Universit Lille Nord de France, Cit Scientifique, Avenue Poincar, CS 60069, 59652 Villeneuve d'Ascq Cedex (France); Charrier, J. [Fonctions Optiques pour les Technologies de l'informatiON, UMR-CNRS 6082, ENSSAT 6, rue de Kerampont, CS 80518, 22305 Lannion Cedex (France); Mattalah, M. [Laboratoire de Microlectronique, Universit Djilali Liabes, 22000 Sidi Bel Abbes (Algeria); Barkad, H. A. [Institut Universitaire Technologique Industriel, Universit de Djibouti, Avenue Georges Clmenceau, BP 1904 Djibouti (Djibouti); Mortet, V. [Institute of Physics of Academy of Sciences of Czech Republic, Fyzikln stav AV CR, v.v.i., Na Slovance 1999/2 (Czech Republic); BenMoussa, A. [Solar Terrestrial Center of Excellence, Royal Observatory of Belgium, Circular 3, B-1180 Brussels (Belgium)

    2014-04-28T23:59:59.000Z

    Optical waveguiding properties of a thick wurtzite aluminum nitride highly [002]-textured hetero-epitaxial film on (001) basal plane of sapphire substrate are studied. The physical properties of the film are determined by X-ray diffraction, atomic force microscopy, microRaman, and photocurrent spectroscopy. The refractive index and the thermo-optic coefficients are determined by m-lines spectroscopy using the classical prism coupling technique. The optical losses of this planar waveguide are also measured in the spectral range of 4501553?nm. The lower value of optical losses is equal to 0.7 dB/cm at 1553?nm. The optical losses due to the surface scattering are simulated showing that the contribution is the most significant at near infrared wavelength range, whereas the optical losses are due to volume scattering and material absorption in the visible range. The good physical properties and the low optical losses obtained from this planar waveguide are encouraging to achieve a wide bandgap optical guiding platform from these aluminum nitride thin films.

  10. ETA CARINAE ACROSS THE 2003.5 MINIMUM: ANALYSIS IN THE VISIBLE AND NEAR-INFRARED SPECTRAL REGION

    SciTech Connect (OSTI)

    Nielsen, K. E.; Kober, G. Vieira [Catholic University of America, Washington, DC 20064 (United States); Weis, K.; Bomans, D. J. [Astronomisches Institut, Ruhr-Universitaet Bochum, Universitaetsstrasse 150, D-44780 Bochum (Germany); Gull, T. R. [Astrophysics Science Division, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Stahl, O. [ZAH, Landessternwarte Heidelberg-Koenigstuhl, D-69117 Heidelberg (Germany)], E-mail: krister.nielsen@nasa.gov

    2009-04-15T23:59:59.000Z

    We present an analysis of the visible through near-infrared spectrum of Eta Carinae ({eta} Car) and its ejecta obtained during the '{eta} Car Campaign with the Ultraviolet and Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT)'. This is a part of larger effort to present a complete {eta} Car spectrum, and extends the previously presented analyses with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) in the UV (1240-3159 A) to 10,430 A. The spectrum in the mid- and near-UV is characterized by the ejecta absorption. At longer wavelengths, stellar wind features from the central source and narrow-emission lines from the Weigelt condensations dominate the spectrum. However, narrow absorption lines from the circumstellar shells are present. This paper provides a description of the spectrum between 3060 and 10,430 A, including line identifications of the ejecta absorption spectrum, the emission spectrum from the Weigelt condensations and the P Cygni stellar wind features. The high spectral resolving power of VLT/UVES enables equivalent width measurements of atomic and molecular absorption lines for elements with no transitions at the shorter wavelengths. However, the ground-based seeing and contributions of nebular-scattered radiation prevent direct comparison of measured equivalent widths in the VLT/UVES and HST/STIS spectra. Fortunately, HST/STIS and VLT/UVES have a small overlap in wavelength coverage which allows us to compare and adjust for the difference in scattered radiation entering the instruments' apertures. This paper provides a complete online VLT/UVES spectrum with line identifications and a spectral comparison between HST/STIS and VLT/UVES between 3060 and 3160 A.

  11. Solar and Infrared Radiation Station (SIRS) Handbook

    SciTech Connect (OSTI)

    Stoffel, T

    2005-07-01T23:59:59.000Z

    The Solar Infrared Radiation Station (SIRS) provides continuous measurements of broadband shortwave (solar) and longwave (atmospheric or infrared) irradiances for downwelling and upwelling components. The following six irradiance measurements are collected from a network of stations to help determine the total radiative flux exchange within the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility: Direct normal shortwave (solar beam) Diffuse horizontal shortwave (sky) Global horizontal shortwave (total hemispheric) Upwelling shortwave (reflected) Downwelling longwave (atmospheric infrared) Upwelling longwave (surface infrared)

  12. Thermo-mechanical analysis of ITER first mirrors and its use for the ITER equatorial visible/infrared wide angle viewing system optical design

    SciTech Connect (OSTI)

    Joanny, M.; Salasca, S.; Dapena, M.; Cantone, B.; Travere, J. M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Thellier, C.; Ferme, J. J. [THALES SESO, 13593 Aix-en-Provence Cedex 3 (France); Marot, L. [Department of Physics, University of Basel, 4056 Basel (Switzerland); Buravand, O. [Institut d'Optique Graduate School, 91127 Palaiseau (France); Perrollaz, G. [AMETRA, 13770 Venelles (France); Zeile, C. [INR, KIT, D-76344 Eggenstein-Leopoldshafen (Germany)

    2012-10-15T23:59:59.000Z

    ITER first mirrors (FMs), as the first components of most ITER optical diagnostics, will be exposed to high plasma radiation flux and neutron load. To reduce the FMs heating and optical surface deformation induced during ITER operation, the use of relevant materials and cooling system are foreseen. The calculations led on different materials and FMs designs and geometries (100 mm and 200 mm) show that the use of CuCrZr and TZM, and a complex integrated cooling system can limit efficiently the FMs heating and reduce their optical surface deformation under plasma radiation flux and neutron load. These investigations were used to evaluate, for the ITER equatorial port visible/infrared wide angle viewing system, the impact of the FMs properties change during operation on the instrument main optical performances. The results obtained are presented and discussed.

  13. PROSPECTING IN LATE-TYPE DWARFS: A CALIBRATION OF INFRARED AND VISIBLE SPECTROSCOPIC METALLICITIES OF LATE K AND M DWARFS SPANNING 1.5 dex

    SciTech Connect (OSTI)

    Mann, Andrew W.; Hilton, Eric J. [Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Dr, Honolulu, HI 96822 (United States); Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Gaidos, Eric [Department of Geology and Geophysics, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822 (United States); Lepine, Sebastien [Department of Astrophysics, American Museum of Natural History, New York, NY 10024 (United States)

    2013-02-01T23:59:59.000Z

    Knowledge of late K and M dwarf metallicities can be used to guide planet searches and constrain planet formation models. However, the determination of metallicities of late-type stars is difficult because visible wavelength spectra of their cool atmospheres contain many overlapping absorption lines, preventing the measurement of equivalent widths. We present new methods, and improved calibrations of existing methods, to determine metallicities of late K and M dwarfs from moderate resolution (1300 < R < 2000) visible and infrared spectra. We select a sample of 112 wide binary systems that contain a late-type companion to a solar-type primary star. Our sample includes 62 primary stars with previously published metallicities, as well as 50 stars with metallicities determined from our own observations. We use our sample to empirically determine which features in the spectrum of the companion are best correlated with the metallicity of the primary. We find {approx_equal}120 features in K and M dwarf spectra that are useful for predicting metallicity. We derive metallicity calibrations for different wavelength ranges, and show that it is possible to get metallicities reliable to <0.10 dex using either visible, J-, H-, or K-band spectra. We find that the most accurate metallicities derived from visible spectra requires the use of different calibrations for early-type (K5.5-M2) and late-type (M2-M6) dwarfs. Our calibrations are applicable to dwarfs with metallicities of -1.04 < [Fe/H] <+0.56 and spectral types from K7 to M5. Lastly, we use our sample of wide binaries to test and refine existing calibrations to determine M dwarf metallicities. We find that the {zeta} parameter, which measures the ratio of TiO can CaH bands, is correlated with [Fe/H] for super-solar metallicities, and {zeta} does not always correctly identify metal-poor M dwarfs. We also find that existing calibrations in the K and H bands are quite reliable for stars with [Fe/H] >-0.5, but are less useful for more metal-poor stars.

  14. Fabrication and testing of diamond-machined gratings in ZnSe, GaP, and bismuth germanate for the near infrared and visible

    SciTech Connect (OSTI)

    Kuzmenko, P J; Little, S L; Ikeda, Y; Kobayashi, N

    2008-06-22T23:59:59.000Z

    High quality immersion gratings for infrared applications have been demonstrated in silicon and germanium. To extend this technology to shorter wavelengths other materials must be investigated. We selected three materials, zinc selenide, gallium phosphide and bismuth germanate (Bi{sub 4}Ge{sub 3}O{sub 12}), based on high refractive index, good visible transmission and commercial availability in useful sizes. Crystal samples were diamond turned on an ultra-precision lathe to identify preferred cutting directions. Using this information we diamond-flycut test gratings over a range of feed rates to determine the optimal cutting conditions. For both ZnSe and GaP good surface quality was achieved at feed rates up to 1.0 cm/minute using a special compound angle diamond tool with negative rake angles on both cutting surfaces. The surface roughness of the groove facets was about 4 nm. A Zygo interferometer measured grating wavefront errors in reflection. For the ZnSe the RMS error was < {lambda}/20 at 633nm. More extensive testing was performed with a HeNe laser source and a cooled CCD camera. These measurements demonstrated high relative diffraction efficiency (> 80%), low random groove error (2.0 nm rms), and Rowland ghost intensities at < 0.1%. Preliminary tests on bismuth germanate show high tool wear.

  15. Spectroscopic Monitoring of Spent Nuclear Fuel Reprocessing Streams: An Evaluation of Spent Fuel Solutions via Raman, Visible, and Near-Infrared Spectroscopy

    SciTech Connect (OSTI)

    Bryan, Samuel A.; Levitskaia, Tatiana G.; Johnsen, Amanda M.; Orton, Christopher R.; Peterson, James M.

    2011-09-01T23:59:59.000Z

    The potential of using optical spectroscopic techniques, such as Raman and Visible/Near Infrared (Vis/NIR), for on-line process control and special nuclear materials accountability applications at a spent nuclear fuel reprocessing facility was evaluated. Availability of on-line real-time techniques that directly measure process concentrations of nuclear materials will enhance performance and proliferation resistance of the solvent extraction processes. Further, on-line monitoring of radiochemical streams will also improve reprocessing plant operation and safety. This report reviews current state of development of the spectroscopic on-line monitoring techniques for such solutions. To further examine applicability of optical spectroscopy for monitoring reprocessing solutions, segments of a spent nuclear fuel, with approximate burn-up values of 70 MWd/kgM, were dissolved in concentrated nitric acid and adjusted to varying final concentrations of HNO3. The resulting spent fuel solutions were batch-contacted with tributyl phosphate/dodecane organic solvent. The feed and equilibrium aqueous and loaded organic solutions were subjected to optical measurements. The obtained spectra showed the presence of the quantifiable Raman bands due to NO3- and UO22+ and Vis/NIR bands due to multiple species of Pu(IV), Pu(VI), Np(V), the Np(V)-U(VI) cation-cation complex, and Nd(III) in fuel solutions, justifying spectroscopic techniques as a promising methodology for monitoring spent fuel processing solutions in real-time. Quantitative evaluation of the fuel solution was performed based on spectroscopic measurements and compared to ICP-MS analysis.

  16. Variable waveband infrared imager

    DOE Patents [OSTI]

    Hunter, Scott R.

    2013-06-11T23:59:59.000Z

    A waveband imager includes an imaging pixel that utilizes photon tunneling with a thermally actuated bimorph structure to convert infrared radiation to visible radiation. Infrared radiation passes through a transparent substrate and is absorbed by a bimorph structure formed with a pixel plate. The absorption generates heat which deflects the bimorph structure and pixel plate towards the substrate and into an evanescent electric field generated by light propagating through the substrate. Penetration of the bimorph structure and pixel plate into the evanescent electric field allows a portion of the visible wavelengths propagating through the substrate to tunnel through the substrate, bimorph structure, and/or pixel plate as visible radiation that is proportional to the intensity of the incident infrared radiation. This converted visible radiation may be superimposed over visible wavelengths passed through the imaging pixel.

  17. Infrared floodlight

    DOE Patents [OSTI]

    Levin, Robert E. (S. Hamilton, MA); English, George J. (Reading, MA)

    1986-08-05T23:59:59.000Z

    An infrared floodlight assembly designed particularly for security purposes and including a heat-conducting housing, a lens secured to the housing to provide a closure therefor, and a floodlight located within (and surrounded by) the housing. The floodlight combines the use of a tungsten halogen light source and dichroic hot and cold mirrors for directing substantially only infrared radiation toward the assembly's forward lens. Visible radiation is absorbed by the housing's interior wall(s) and, optionally, by a filter located between the floodlight and lens. An optional means may be used within the floodlight to reflect all forward radiation back toward the paraboloidal hot mirror or, alternatively, to reflect only visible radiation in this direction. The dichroic hot and cold mirrors preferably each comprise a glass substrate having multiple layers of titanium dioxide and silicon dioxide thereon.

  18. Measurement of the specific surface area of snow using infrared reflectance in an integrating sphere at 1310 and 1550 nm

    E-Print Network [OSTI]

    Gallet, J.-C.; Domine, F.; Zender, C. S; Picard, G.

    2009-01-01T23:59:59.000Z

    Reflection of solar radiation by the Antarctic snow surface at ultraviolet, visible, and near-infrared

  19. The hydrogenation and dehydrogenation of C{sub 2}-C{sub 4} hydrocarbons on Pt(111) monitored in situ over 13 orders of magnitude in pressure with infrared-visible sum frequency generation

    SciTech Connect (OSTI)

    Cremer, P.S.

    1996-05-01T23:59:59.000Z

    The hydrogenation and dehydrogenation of ethylene, propylene, and isobutene were monitored in situ during heterogeneous catalysis over Pt(111) between 10{sup -10} Torr and 1000 Torr with infrared-visible sum frequency generation (SFG). SFG is a surface specific vibrational spectroscopy capable of achieving submonolayer sensitivity under reaction conditions in the presence of hundreds of Toff of reactants and products. Olefin dehydrogenation experiments were carried out with SFG under ultra high vacuum (UHV) conditions on the (111) crystal face of platinum Ethylene chemisorbed on Pt(111) below 230 K in the di-{sigma} bonded conformation (Pt-CH{sub 2}CH{sub 2}-Pt). Upon annealing the system to form the dehydrogenation product, ethylidyne (M=CCH{sub 3}), evidence was found for an ethylidene intermediate (M=CHCH{sub 3}) from its characteristic v{sub as}(CH{sub 3}) near 2960 cm{sup -1}. Hydrogenation of ethylene was carried out between 1 Toff and 700 Torr of H{sub 2} while the vibrational spectrum of surface species was monitored with SFG. Simultaneously, gas chromatography was used to obtain the turnover rate for the catalytic reaction, which could be correlated with the adsorbed intermediate concentration to determine the reaction rate per surface intermediate. Di-{sigma} bonded ethylene, {pi}-bonded ethylene, ethyl groups and ethylidyne resided on the surface during reaction. The mechanistic pathway for ethylene hydrogenation involved the stepwise hydrogenation of {pi}-bonded ethylene through an ethyl intermediate to ethane. The hydrogenation of propylene was carried out under the same conditions as ethylene. It was found that propylene hydrogenates from {pi}-bonded propylene through a 2-propyl intermediate to propane on Pt(111). The rate of reaction was approximately 50% slower than that of ethylene hydrogenation. Isobutene, however, was found to hydrogenate almost two order of magnitude slower than propylene on Pt(111).

  20. The Use of Infrared Technology To Detect Heat Loss

    E-Print Network [OSTI]

    Faulkner, K.

    1979-01-01T23:59:59.000Z

    Infrared refers to electro magnetic energy with a wave length longer than those of visible light. Researchers developed methods to quantify, focus and form real-time images to infrared energy. This spawned the development of infrared Thenrography...

  1. Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Lee Spangler; Ross Bricklemyer; David Brown

    2012-03-15T23:59:59.000Z

    There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficient soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as a rapid and inexpensive tool for intensively mapping soil texture and organic carbon (SOC). While lab-based VisNIR has been established as a viable technique for estimating various soil properties, few experiments have compared the predictive accuracy of on-the-go and lab-based VisNIR. Eight north central Montana wheat fields were intensively interrogated using on-the-go and lab-based VisNIR. Lab-based spectral data consistently provided more accurate predictions than on-the-go data. However, neither in situ nor lab-based spectroscopy yielded even semi-quantitative SOC predictions. There was little SOC variability to explain across the eight fields, and on-the-go VisNIR was not able to capture the subtle SOC variability in these Montana soils. With more variation in soil clay content compared to SOC, both lab and on-the-go VisNIR showed better explanatory power. There are several potential explanations for poor on-the-go predictive accuracy: soil heterogeneity, field moisture, consistent sample presentation, and a difference between the spatial support of on-the-go measurements and soil samples collected for laboratory analyses. Though the current configuration of a commercially available on-the-go VisNIR system allows for rapid field scanning, on-the-go soil processing (i.e. drying, crushing, and sieving) could improve soil carbon predictions. Laser-induced breakdown spectroscopy (LIBS) is an emerging elemental analysis technology with the potential to provide rapid, accurate and precise analysis of soil constituents, such as carbon, in situ across landscapes. The research team evaluated the accuracy of LIBS for measuring soil profile carbon in field-moist, intact soil cores simulating conditions that might be encountered by a probe-mounted LIBS instrument measuring soil profile carbon in situ. Over the course of three experiments, more than120 intact soil cores from eight north central Montana wheat fields and the Washington State University (WSU) Cook Agronomy Farm near Pullman, WA were interrogated with LIBS for rapid total carbon (TC), inorganic carbon (IC), and SOC determination. Partial least squares regression models were derived and independently validated at field- and regional scales. Researchers obtained the best LIBS validation predictions for IC followed by TC and SOC. Laser-induced breakdown spectroscopy is fundamentally an elemental analysis technique, yet LIBS PLS2 models appeared to discriminate IC from TC. Regression coefficients from initial models suggested a reliance upon stoichiometric relationships between carbon (247.8 nm) and other elements

  2. The visibility complex made visibly simple an introduction to 2D structures of visibility

    E-Print Network [OSTI]

    Durand, Frdo

    . Then a sweeping algorithm that can build the complex in O(mlog(n)) where n is the size of the visibility graph when a line becomes tangent to three objects. This is shown in the video. The complex is build usingThe visibility complex made visibly simple an introduction to 2D structures of visibility Fr

  3. ARM - Measurement - Visibility

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowbandheat flux ARM DatagovMeasurementsVisibility ARM Data

  4. Transparent, near-infrared organic photovoltaic solar cells for window and energy-scavenging applications

    E-Print Network [OSTI]

    Lunt, Richard R.

    We fabricate near-infrared absorbing organic photovoltaics that are highly transparent to visible light. By optimizing near-infrared optical-interference, we demonstrate power efficiencies of 1.30.1% with simultaneous ...

  5. Resonant Visible Light Modulation with Graphene

    E-Print Network [OSTI]

    Yu, Renwen; de Abajo, F Javier Garcia

    2015-01-01T23:59:59.000Z

    Fast modulation and switching of light at visible and near-infrared (vis-NIR) frequencies is of utmost importance for optical signal processing and sensing technologies. No fundamental limit appears to prevent us from designing wavelength-sized devices capable of controlling the light phase and intensity at gigaherts (and even terahertz) speeds in those spectral ranges. However, this problem remains largely unsolved, despite recent advances in the use of quantum wells and phase-change materials for that purpose. Here, we explore an alternative solution based upon the remarkable electro-optical properties of graphene. In particular, we predict unity-order changes in the transmission and absorption of vis-NIR light produced upon electrical doping of graphene sheets coupled to realistically engineered optical cavities. The light intensity is enhanced at the graphene plane, and so is its absorption, which can be switched and modulated via Pauli blocking through varying the level of doping. Specifically, we explor...

  6. Silicon-based visible and near-infrared optoelectric devices

    DOE Patents [OSTI]

    Carey, III, James Edward (Newton, MA); Mazur, Eric (Concord, MA)

    2011-12-20T23:59:59.000Z

    In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

  7. Silicon-based visible and near-infrared optoelectric devices

    DOE Patents [OSTI]

    Mazur, Eric (Concord, MA); Carey, III, James E. (Newton, MA)

    2010-08-24T23:59:59.000Z

    In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

  8. Silicon-based visible and near-infrared optoelectric devices

    DOE Patents [OSTI]

    Mazur, Eric (Concord, MA); Carey, III, James E. (Newton, MA)

    2011-02-08T23:59:59.000Z

    In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

  9. Silicon-based visible and near-infrared optoelectric devices

    DOE Patents [OSTI]

    Mazur, Eric; Carey, James Edward

    2013-12-10T23:59:59.000Z

    In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity great than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelenths, e.g., up to about 3.5 microns.

  10. Visible and near infrared reflectances measured from laboratory ice clouds

    E-Print Network [OSTI]

    Liou, K. N.

    ,aswellasuncertaintiesin data, validation by means of the independent in situ airborne and ground-based measurements that are co. Liou Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles the measured ice particle morphology. We demonstrate that laboratory scat- tering and reflectance data for thin

  11. Nowcasting of Thunderstorms from GOES Infrared and Visible V Lakshmanan

    E-Print Network [OSTI]

    Lakshmanan, Valliappa

    by clustering the pixels in the in- put images using spatial-contiguity-enhanced K-means clustering. Identified is used to nowcast the images. Comparison of the now- casts with the observed values at the corresponding

  12. Silicon-based visible and near-infrared optoelectric devices

    DOE Patents [OSTI]

    Carey, III, James Edward; Mazur, Eric

    2006-06-06T23:59:59.000Z

    In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

  13. Silicon-based visible and near-infrared optoelectric devices

    DOE Patents [OSTI]

    Mazur, Eric (Concord, MA); Carey, III, James Edward (Newton, MA)

    2009-03-17T23:59:59.000Z

    In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

  14. Fusion of Infrared and Visible Images for Face Recognition

    E-Print Network [OSTI]

    of IR imagery to facial occlusion caused by eyeglasses. Our experiments indicate that IR-based recognition performance degrades seriously when eyeglasses are present in the probe image of eyeglasses. Our fusion scheme is pixel-based, operates in the wavelet domain, and employs genetic algorithms

  15. ARM - Evaluation Product - Airborne Visible/Infrared Imaging Spectrometer

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006Datastreamstwrcam40m Documentation DataDatastreamsxsaprhsrhi1-min (NAVBE1M) Value Added Products(AVIRIS)

  16. Geothermal Exploration with Visible through Long Wave Infrared Imaging

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI Reference LibraryAdd to library WebWesternLondon,Valley, Nv |Data

  17. Geothermal Exploration with Visible through Long Wave Infrared...

    Open Energy Info (EERE)

    be mapped on the surface using the LWIR. Many of the aforementioned minerals have absorption features that overlap each other in other parts of the electromagnetic spectrum....

  18. ARM - Field Campaign - Solmirus' All Sky Infrared Visible Analyzer (ASIVA)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa- Polarization DiversityPolarizationgovCampaignsSmall Particles in Cirrus

  19. The multi-filter rotating shadowband radiometer (MFRSR) - precision infrared radiometer (PIR) platform in Fairbanks: Scientific objectives

    SciTech Connect (OSTI)

    Stamnes, K.; Leontieva, E. [Univ. of Alaska, Fairbanks (United States)

    1996-04-01T23:59:59.000Z

    The multi-filter rotating shadowband radiometer (MFRSR) and precision infrared radiometer (PIR) have been employed at the Geophysical Institute in Fairbanks to check their performance under arctic conditions. Drawing on the experience of the previous measurements in the Arctic, the PIR was equipped with a ventilator to prevent frost and moisture build-up. We adopted the Solar Infrared Observing Sytem (SIROS) concept from the Southern Great Plains Cloud and Radiation Testbed (CART) to allow implementation of the same data processing software for a set of radiation and meteorological instruments. To validate the level of performance of the whole SIROS prior to its incorporation into the North Slope of Alaska (NSA) Cloud and Radiation Testbed Site instrumental suite for flux radiatin measurements, the comparison between measurements and model predictions will be undertaken to assess the MFRSR-PIR Arctic data quality.

  20. FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS)

    E-Print Network [OSTI]

    Ohta, Shigemi

    FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS) Proposal Team: L INFORMATION · TECHNIQUE(S): Fourier transform infrared spectroscopy; Raman and visible spectroscopy; Diamond techniques combined with DACs; Laser heating techniques combined with DACs. · SOURCE: Large-gap (90 mm

  1. On the near infrared variability of chemically peculiar stars

    E-Print Network [OSTI]

    F. A. Catalano; F. Leone

    1998-05-06T23:59:59.000Z

    Some CP stars have recently been discovered by Catalano et al. (1991) to be variable also in the near infrared, although with smaller amplitudes than in the visible. Hence an observational campaign was started in which the infrared light variability of a number of CP2 and CP4 stars has been investigated at the ESO-La Silla Observatory in the bands J, H, and K. As a general result, infrared variations show the same behavior in all three filters but amplitudes are smaller than in the visible.

  2. 3D Visibility made visibly simple: an introduction to the Visibility Skeleton

    E-Print Network [OSTI]

    Durand, Frédo

    .g. lighting sim­ ulation), the limits of umbra and penumbra, etc. Previ­ ous approaches have used coarse visible from a vertex of the scene and the limits of umbra and penumbra between two polygons. 1 are the limits of umbra and penumbra together with back­ projections which encode the topological aspect

  3. Thermal Infrared Remote Sensing

    E-Print Network [OSTI]

    to us, like reflective ("nearreflective ("near--" infrared (0.7" infrared (0.7 -- 3.03.0 m)m) andand near-infrared far infrared ultraviolet Thermal Infrared refers to region o EM spectrum from ~3 - 14 m.landscape. IMPORTANT: NEARIMPORTANT: NEAR--INFRARED is short enough wavelength toINFRARED is short enough wavelength

  4. Development of SiGe arrays for visible-near IR imaging applications

    E-Print Network [OSTI]

    Sood, Ashok K.

    SiGe based focal plane arrays offer a low cost alternative for developing visible- near-infrared focal plane arrays that will cover the spectral band from 0.4 to 1.6 microns. The attractive features of SiGe based foal plane ...

  5. Characterization of sige-detector arrays for visible-NIR imaging sensor applications

    E-Print Network [OSTI]

    Sood, Ashok K.

    SiGe based focal plane arrays offer a low cost alternative for developing visible- near-infrared focal plane arrays that will cover the spectral band from 0.4 to 1.6 microns. The attractive features of SiGe based foal plane ...

  6. Smoke and Visible Emissions (New Mexico)

    Broader source: Energy.gov [DOE]

    This rule establishes controls on smoke and visible emissions from certain sources.This rule is not intended to preempt any more stringent controls on smoke and visible emissions provided in any...

  7. Evaluation of the Teledyne SIDECAR ASIC at cryogenic temperature using a visible hybrid H2RG focal plane array in 32 channel readout

    E-Print Network [OSTI]

    Liske, Jochen

    Evaluation of the Teledyne SIDECAR ASIC at cryogenic temperature using a visible hybrid H2RG focal, Hilo, HI 96720, USA ABSTRACT Teledyne Imaging Sensors (TIS) has developed a new CMOS device known of FPA drive electronics to operate visible and infrared imaging detectors with a fully digital interface

  8. Infrared retina

    DOE Patents [OSTI]

    Krishna, Sanjay (Albuquerque, NM); Hayat, Majeed M. (Albuquerque, NM); Tyo, J. Scott (Tucson, AZ); Jang, Woo-Yong (Albuquerque, NM)

    2011-12-06T23:59:59.000Z

    Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

  9. Spectroscopic Infrared Ellipsometry

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Spectroscopic Infrared Ellipsometry: Components, Calibration, and Application #12;CIP-DATA KONINKLIJKE BIBLIOTHEEK, DEN HAAG Boer, Johannes Henricus Wilhelmus Gerardus den Spectroscopic Infrared in Dutch. ISBN 90 386 0017 8 Subject headings: spectroscopy ellipsometry infrared. #12;Spectroscopic

  10. Thermal Infrared Remote Sensing

    E-Print Network [OSTI]

    Thermal Infrared Remote Sensing Thermal Infrared Remote Sensing #12;0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4 and x-ray Ultraviolet Infrared Microwave and radio waves Wavelength in meters (m) Electromagnetic.77 700 red limit 30k0.041 2.48 green500 near-infrared far infrared ultraviolet Thermal Infrare refers

  11. An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared

    E-Print Network [OSTI]

    Zheludev, Nikolay

    An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared Jun and modulating metamaterial proper- ties in the visible and near-infrared range remain major technological to electromechanically reconfigure the metamolecules and dramatically change the transmission and reflection spectra

  12. Visible Light Communications: Recent Activities in Japan

    E-Print Network [OSTI]

    L, James Jian-Qiang

    The Graduate School of System Design and Management, Keio University, Yokohama, Japan Smart Spaces: A Smart, visible light LEDs are beginning to be used in every home and office, which makes visible light LEDs ideal, and the market share of LED lighting will be more than 30 percent of total lighting market in 2016. Prediction

  13. Visible spectrometer utilizing organic thin film absorption

    E-Print Network [OSTI]

    Tiefenbruck, Laura C. (Laura Christine)

    2004-01-01T23:59:59.000Z

    In this thesis, I modeled and developed a spectrometer for the visible wavelength spectrum, based on absorption characteristics of organic thin films. The device uses fundamental principles of linear algebra to reconstruct ...

  14. Visible Spectrum Incandescent Selective Emitter

    SciTech Connect (OSTI)

    Sonsight Inc.

    2004-04-30T23:59:59.000Z

    The purpose of the work performed was to demonstrate the feasibility of a novel bi-layer selective emitter. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected part of the radiation spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature. The major research objectives involved answering the following questions: (1) What maximum VIS/NIR radiant power and emissivity ratios can be attained at 2650 K? (2) What is the observed emitter body life and how does its performance vary with time? (3) What are the design tradeoffs for a dual heating approach in which both an internally mounted heating coil and electrical resistance self-heating are used? (4) What are the quantitative improvements to be had from utilizing a bi-layer emitter body with a low emissivity inner layer and a partially transmissive outer layer? Two approaches to obtaining selective emissivity were investigated. The first was to utilize large optical scattering within an emitter material with a spectral optical absorption that is much greater within the visible spectrum than that within the NIR. With this approach, an optically thick emitter can radiate almost as if optically thin because essentially, scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. The performance of thin emitters was also investigated (for optically thin emitters, spectral emissivity is proportional to spectral absorptivity). These emitters were fabricated from thin mono-layer emitter rods as well as from bi-layer rods with a thin emitter layer mounted on a substrate core. With an initially estimated energy efficiency of almost three times that of standard incandescent bulbs, a number of energy, economic and environmental benefits such as less energy use and cost, reduced CO{sub 2} emissions, and no mercury contamination was initially projected. The work performed provided answers to a number of important questions. The first is that, with the investigated approaches, the maximum sustained emitter efficiencies are about 1.5 times that of a standard incandescent bulb. This was seen to be the case for both thick and thin emitters, and for both mono-layer and bi-layer designs. While observed VIS/NIR ratios represent improvements over standard incandescent bulbs, it does not appear sufficient to overcome higher cost (i.e. up to five times that of the standard bulb) and ensure commercial success. Another result is that high temperatures (i.e. 2650 K) are routinely attainable without platinum electrodes. This is significant for reducing material costs. A novel dual heating arrangement and insulated electrodes were used to attain these temperatures. Another observed characteristic of the emitter was significant grain growth soon after attaining operating temperatures. This is an undesirable characteristic that results in substantially less optical scattering and spectral selectivity, and which significantly limits emitter efficiencies to the values reported. Further work is required to address this problem.

  15. Emission of Visible Light by Hot Dense Metals

    E-Print Network [OSTI]

    More, R.M.

    2010-01-01T23:59:59.000Z

    HIFAN 1761 EMISSION OF VISIBLE LIGHT BY HOT DENSE METALS ByDE-AC52-07NA27344. HI FAN Emission of Visible Light by HotABSTRACT We consider the emission of visible light by hot

  16. Energy Department Announces Funding to Provide Better Visibility...

    Office of Environmental Management (EM)

    Announces Funding to Provide Better Visibility into the Health of the Nation's Electric Grid Energy Department Announces Funding to Provide Better Visibility into the Health of the...

  17. Infrared Thermography (IRT) Working Group

    Broader source: Energy.gov (indexed) [DOE]

    Infrared Thermography (IRT) Working Group Sco McWilliams U.S. Photovoltaic Manufacturing Consor;um (PVMC) Infrared Thermography Infrared Thermography (IRT) has been demonstrated...

  18. Relating productivity to visibility and lighting

    SciTech Connect (OSTI)

    Clear, R.; Berman, S.

    1982-01-01T23:59:59.000Z

    The problem of determining the appropriate light levels for visual tasks is a cost-benefit problem. Existing light level recommendations seriously underweight the importance of economic factors. Furthermore, the relative importance of the visibility factors in determining the optimal light levels appears inconsistent with the importance of these factors in determining visibility and visual performance. It is shown that calculations based on acuities give a lower limit of 100 to 200 lux for cost-effective light levels for office tasks. Upper limits are calculated from correlations of task performance to visibility levels. Visibility levels become progressively insensitive to luminance as luminance increases. Average power densities above 100 watts/m/sup 2/ are cost-effective only when visibility is very low. However, there is a 3-to-10 times larger increase in benefits from improving contrast or contrast sensitivity than from using more than 10 watts/m/sup 2/. Contrast or contrast sensitivity can be improved by using forms with larger print, using xerographic copy instead of carbon or mimeo, making sure office workers have the right eyeglasses, or even by transferring workers with visual problems to less visually demanding tasks. Once these changes are made it is no longer cost-effective to use more than 10 watts/m/sup 2/. This conclusion raises serious questions about recommendations that lead to greater than about 10 watts/m/sup 2/ of installed lighting for general office work.

  19. Infrared Surveys for AGN

    E-Print Network [OSTI]

    Harding E. Smith

    2002-03-06T23:59:59.000Z

    From the earliest extragalactic infrared studies AGN have shown themselves to be strong infrared sources and IR surveys have revealed new populations of AGN. I briefly review current motivations for AGN surveys in the infrared and results from previous IR surveys. The Luminous Infrared Galaxies, which in some cases house dust-enshrouded AGN, submillimeter surveys, and recent studies of the cosmic x-ray and infrared backgrounds suggest that there is a population of highly-obscured AGN at high redshift. ISO Surveys have begun to resolve the infrared background and may have detected this obscured AGN population. New infrared surveys, particularly the SIRTF Wide-area Infrared Extragalactic Legacy Survey (SWIRE), will detect this population and provide a platform for understanding the evolution of AGN, Starbursts and passively evolving galaxies in the context of large-scale structure and environment.

  20. Infrared Inspection Techniques

    E-Print Network [OSTI]

    Hill, A. B.; Bevers, D. V.

    1979-01-01T23:59:59.000Z

    Infrared scanning equipment has been used at Amoco's Texas City refinery since 1971 as an inspection tool. A camera scans the field of view and focuses the infrared radiation on a detector which converts the infrared signal to an electrical signal...

  1. Infrared Inspection Techniques

    E-Print Network [OSTI]

    Hill, A. B.; Bevers, D. V.

    1979-01-01T23:59:59.000Z

    Infrared scanning equipment has been used at Amoco's Texas City refinery since 1971 as an inspection tool. A camera scans the field of view and focuses the infrared radiation on a detector which converts the infrared signal to an electrical signal...

  2. Mid-Infrared Optical Frequency Combs based on Crystalline Microresonators

    E-Print Network [OSTI]

    Wang, C Y; Del'Haye, P; Schliesser, A; Hofer, J; Holzwarth, R; Hnsch, T W; Picqu, N; Kippenberg, T J

    2011-01-01T23:59:59.000Z

    The mid-infrared spectral range (\\lambda ~ 2 \\mu m to 20 \\mu m) is known as the "molecular fingerprint" region as many molecules have their highly characteristic, fundamental ro-vibrational bands in this part of the electromagnetic spectrum. Broadband mid-infrared spectroscopy therefore constitutes a powerful and ubiquitous tool for optical analysis of chemical components that is used in biochemistry, astronomy, pharmaceutical monitoring and material science. Optical frequency combs, i.e. broad spectral bandwidth coherent light sources consisting of equally spaced sharp lines, have revolutionized optical frequency metrology one decade ago. They now demonstrate dramatically improved acquisition rates, resolution and sensitivity for molecular spectroscopy mostly in the visible and near-infrared ranges. Mid-infrared frequency combs have therefore become highly desirable and recent progress in generating such combs by nonlinear frequency conversion has opened access to this spectral region. Here we report on a pr...

  3. Nanosecond-scale timing jitter in transition edge sensors at telecom and visible wavelengths

    E-Print Network [OSTI]

    Antia Lamas-Linares; Brice Calkins; Nathan A. Tomlin; Thomas Gerrits; Adriana E. Lita; Joern Beyer; Richard P. Mirin; Sae Woo Nam

    2012-09-25T23:59:59.000Z

    Transition edge sensors (TES) have the highest reported efficiencies (>98%) for detection of single photons in the visible and near infrared. Experiments in quantum information and foundations of physics that rely critically on this efficiency have started incorporating these detectors into con- ventional quantum optics setups. However, their range of applicability has been hindered by slow operation both in recovery time and timing jitter. We show here how a conventional tungsten-TES can be operated with jitter times of < 4 ns, well within the timing resolution necessary for MHz clocking of experiments, and providing an important practical simplification for experiments that rely on the simultaneous closing of both efficiency and locality loopholes.

  4. Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation into Ni-Silicate by Visible,

    E-Print Network [OSTI]

    Sparks, Donald L.

    into Ni-Silicate by Visible, Infrared and XANES Spectroscopy and Thermogravimetry A. C. Scheinost, R. G suggest either the formation of layered double hydroxides or of layer silicates. Desorption studies polymerization of SiO causes the formation of 1:1 or 2:1 Ni silicates, where the original Ni-Al hydroxide

  5. Visible-NIR, Electrical Impedance, pH, and CIE L*, a*, and b* Color Space Values to Predict Beef Tenderness

    E-Print Network [OSTI]

    Wiederhold, William

    2011-05-11T23:59:59.000Z

    Predicting tenderness in today's beef supply could be advantageous to packers and consumers. In this study (n = 1,137 carcasses), visible-near-infrared, electrical impedance, pH and Minolta CIE L*, a*, and b* color space values were examined...

  6. Infrared microscope inspection apparatus

    DOE Patents [OSTI]

    Forman, S.E.; Caunt, J.W.

    1985-02-26T23:59:59.000Z

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

  7. The visible Smith-Purcell radiation search

    SciTech Connect (OSTI)

    Fernow, R.C.; Kirk, H.G.; Ulc, S. Wang, X.

    1994-03-01T23:59:59.000Z

    We report here the results of an experiment at the Accelerator Test Facility at Brookhaven National Laboratory to search for the production of visible radiation from the Smith-Purcell effect using a 3 MeV electron beam. After running the experiment under a variety of conditions we were unable to isolate a definite signal from Smith-Parcell effect. Any Smith-Purcell signal present in the measured radiation was less than 10% of the background signal.

  8. State visibility in Q-bit space

    E-Print Network [OSTI]

    A. F. Kracklauer

    2007-03-04T23:59:59.000Z

    We study by comparison the structure of singlet type states in Q-bit space in the light of quantum and classical paradigms. It is shown that only the classical paradigm implies a variation in the visibility of correlation coefficients, that has been observed in fact in experiments. We conclude that Q-bit space in not a appropriate venue for an EPR test of quantum completeness.

  9. Visible-wavelength semiconductor lasers and arrays

    DOE Patents [OSTI]

    Schneider, Jr., Richard P. (Albuquerque, NM); Crawford, Mary H. (Albuquerque, NM)

    1996-01-01T23:59:59.000Z

    A visible semiconductor laser. The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1.lambda.) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%.

  10. Seeing solar on campus : a visible photovoltaic installation on campus

    E-Print Network [OSTI]

    Guarda, Daniel Jair Alves

    2006-01-01T23:59:59.000Z

    This paper presents a methodology for selecting a site on the MIT campus for a visible solar photovoltaic installation. Visibility, solar exposure, advertising potential, aesthetics, interactivity and direct or important ...

  11. Investigation of the photoactivity of pristine and mixed phase N-doped titania under visible and solar irradiation

    SciTech Connect (OSTI)

    Das, Barnali [Solar and Energy Materials Laboratory, Department of Energy, Tezpur University, Tezpur, Assam 784028 (India); Nair, Ranjith G. [Solar and Energy Materials Laboratory, Department of Energy, Tezpur University, Tezpur, Assam 784028 (India); Department of Physics, National Institute of Technology-Silchar, Silchar, Assam 788010 (India); Rajbongshi, Bijumani [Solar and Energy Materials Laboratory, Department of Energy, Tezpur University, Tezpur, Assam 784028 (India); Samdarshi, S.K., E-mail: drsksamdarshi@rediffmail.com [Solar and Energy Materials Laboratory, Department of Energy, Tezpur University, Tezpur, Assam 784028 (India)

    2013-09-15T23:59:59.000Z

    Nitrogen doped titania nano-particles were synthesized by solgel method with an aim to investigate the impact of doping in titanium matrix and the titania phases on their photocatalytic activity under visible and solar irradiation. The structural, optical and chemical characterization of the prepared materials were done using X-ray diffraction analysis, scanning electron microscopy, UVvisible diffuse reflectance spectroscopy, photoluminescence spectroscopy, and Fourier transform infrared spectroscopy. The samples were calcined at different temperatures (200 C600 C) to obtain different phases. All the samples showed red-shift in the visible region attributable to the doping of nitrogen in the titania matrix. The samples calcined at low temperatures showed high photocatalytic activity compared to the high temperature samples. The enhancement in the visible light activity may be attributed to the large amount of nitrogen present in the surface region of the catalyst and reduced carrier recombination. Among the high temperature samples the high activity may be due to the presence of mixed phase as well. - Highlights: Pristine and mixed phases of N doped titania synthesized at different temperatures. High visible light photoactivity exhibited by pristine rutile phase and mixed phase. Role of surface N in rutile and matrix embedded N in other samples corroborated.

  12. A Model of Visible QCD Axion

    E-Print Network [OSTI]

    Fukuda, Hajime; Ibe, Masahiro; Yanagida, Tsutomu T

    2015-01-01T23:59:59.000Z

    We pursue a class of visible axion models where the axion mass is enhanced by strong dynamics in a mirrored copy of the Standard Model in the line of the idea put forward by Rubakov. In particular, we examine the consistency of the models with laboratory, astrophysical, and cosmological constraints. As a result, viable parameter regions are found, where the mass of the axion is of $O(100)$ MeV or above while the Peccei-Quinn breaking scale is at around $10^{3\\mbox{-}5}$ GeV.

  13. February 8th 2011 Visible light communications

    E-Print Network [OSTI]

    L, James Jian-Qiang

    400 350 300 250 200 150100 150 200 150 150 200 x y 0 LED Lamp 5 m x y 0 5 m 2.5 800 600 700 500 400 200 150100 150 200 150 150 200 x y 0 LED Lamp 5 m x y 0 5 m x y 0 LED Lamp 5 m x y 0 5 m 2.5 800 600 exchange RF Wireless channel PC or portable terminal Visible optical link LED solid state lighting unit #12

  14. A Model of Visible QCD Axion

    E-Print Network [OSTI]

    Hajime Fukuda; Keisuke Harigaya; Masahiro Ibe; Tsutomu T. Yanagida

    2015-05-07T23:59:59.000Z

    We pursue a class of visible axion models where the axion mass is enhanced by strong dynamics in a mirrored copy of the Standard Model in the line of the idea put forward by Rubakov. In particular, we examine the consistency of the models with laboratory, astrophysical, and cosmological constraints. As a result, viable parameter regions are found, where the mass of the axion is of $O(100)$ MeV or above while the Peccei-Quinn breaking scale is at around $10^{3\\mbox{-}5}$ GeV.

  15. Visible Light Solar Technologies | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin BaxinUmweltVillage ofInformationVineyardEnergyViridasVishVisible

  16. Infrared Supernova Remnants in the Spitzer GLIMPSE Field

    E-Print Network [OSTI]

    Ho-Gyu Lee

    2006-01-23T23:59:59.000Z

    We have searched for infrared emission from supernova remnants (SNRs) included in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) field. At the positions of 100 known SNRs, we made 3.6, 4.5, 5.8, and 8.0 um band images covering the radio continuum emitting area of each remnant. In-depth examinations of four band images based on the radio continuum images of SNRs result in the identification of sixteen infrared SNRs in the GLIMPSE field. Eight SNRs show distinct infrared emission in nearly all the four bands, and the other eight SNRs are visible in more than one band. We present four band images for all identified SNRs, and RGB-color images for the first eight SNRs. These images are the first high resolution (infrared region. The images typically show filamentary emission along the radio enhanced SNR boundaries. Most SNRs are well identified in the 4.5 and 5.8 um bands. We give a brief description of the infrared features of the identified SNRs.

  17. Tunable Transmittance of Near-infrared and Visible Light in Reconstruc...

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

    R. J. Mendelsberg and A. Llordes et al., "Dynamically Modulating the Surface Plasmon Resonance of Doped Semiconductor Nanocrystals", Nano Lett. 11, 4415 (2011). Primary...

  18. Mid-infrared electric field characterization using a visible charge-coupled-device-based

    E-Print Network [OSTI]

    Boyer, Edmond

    -based spectrometer. The spec- tral phase is also characterized by a variant of zero-added-phase spectral phase directly to molecular structure and dynamics and benefits from being free of the complications of excited doubling a pico- second mode-locked Nd:YAG laser. Highly stretched 800-nm pulses are readily available from

  19. Optical properties of metallic (III, Mn)V ferromagnetic semiconductors in the infrared to visible range

    E-Print Network [OSTI]

    Hankiewicz, EM; Jungwirth, T.; Dietl, T.; Timm, C.; Sinova, Jairo.

    2004-01-01T23:59:59.000Z

    , Phys. Rev. B 65, 201303(R) (2002). 11 K. W. Edmonds, P. Bogus?awski, K. Y. Wang, R. P. Campion, S. N. Novikov, N. R. S. Farley, B. L. Gallagher, C. T. Foxon, M. Sawicki, T. Dietl, M. B. Nardelli, and J. Bernholc, Phys. Rev. Lett. 92, 037201 (2004... of Complex Materials (Springer Verlag, Berlin, 2002). 21 T. Jungwirth, J. K?nig, J. Sinova, J. Ku?era, and A. H. Mac- Donald, Phys. Rev. B 66, 012402 (2002). 22 T. Jungwirth, J. Sinova, K. Wang, K. W. Edmonds, R. Campion, B. Gallagher, C. Foxon, Q. Niu...

  20. In situ characterization of soil properties using visible near-infrared diffuse reflectance spectroscopy

    E-Print Network [OSTI]

    Waiser, Travis Heath

    2007-09-17T23:59:59.000Z

    , organic C, and inorganic C. Water potential did not improve model predictions, nor did it correlate with the VNIR spectra; r2-values were below 0.31. These results show that DRS is an acceptable technique to measure selected soil properties in-situ...

  1. Comprehensive Pyrometry of Incandescent Multiwalled Carbon Nanotubes and Graphene in the Visible and Near Infrared

    E-Print Network [OSTI]

    Singer, Scott

    2012-01-01T23:59:59.000Z

    of 1990 (ITS-90). , Metrologia, vol. 27, p. 3, Mar. 1990. [Wavelength Pyrometry, Metrologia, vol. 17, p. 103, 1981. [

  2. Objective Assessment of the Information Content of Visible and Infrared Radiance Measurements for Cloud

    E-Print Network [OSTI]

    Stephens, Graeme L.

    such as the Advanced Very High Resolution Radiometer (AVHRR) aboard the Geostationary Operational Environmental the amount of solar energy that reaches the Earth's surface and the amount that is radiated back to space and, therefore, represent a critical factor governing global energy balance Liou (1986). Furthermore, clouds play

  3. Visible and Infra-red Light Emission in Boron-Doped Wurtzite Silicon Nanowires

    E-Print Network [OSTI]

    Fabbri, Filippo

    Silicon, the mainstay semiconductor in microelectronic circuitry, is considered unsuitable for optoelectronic applications owing to its indirect electronic band gap, which limits its efficiency as a light emitter. Here we ...

  4. Face recognition by fusing thermal infrared and visible imagery George Bebis a,

    E-Print Network [OSTI]

    Bebis, George

    by eyeglasses. Specifically, our experimental results illustrate that recognition performance in the IR spectrum degrades seriously when eyeglasses are present in the probe image but not in the gallery image and vice

  5. Mapping microphytobenthos biomass by non-linear inversion of visible-infrared hyperspectral images

    E-Print Network [OSTI]

    Combe, Jean-Philippe

    . Microphytobenthos is a microalgae forming a biofilm on the mudflat. Its spatial distribution is heterogeneous so in the case of Bourgneuf Bay, a macrotidal shellfish ecosystem with a large mudflat, where microphytobenthos

  6. Tunable Transmittance of Near-infrared and Visible Light in Reconstructed

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2,EHSS A-Z SiteManhattanPacific:Nanocrystal-in-Glass

  7. GROUND-BASED CLOUD IMAGES AND SKY RADIANCES IN THE VISIBLE AND NEAR INFRARED REGION FROM

    E-Print Network [OSTI]

    Shields, Janet

    the atmospheric heating rates as well as the amount of solar radiation including biologically effective UV preliminary comparisons with model calculations and cloud cover data both from another type of sky imager data are of specific importance to study the role of clouds on the radiation balance of the earth

  8. Cloud Properties Derived from Visible and Near-infrared Reflectance in the

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced. C o w l i t zManufacturing:DOE NationalCommittee of thePresence of

  9. Detecting Drizzle in Marine Warm Clouds Using Visible, Infrared, and Microwave Satellite Data

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration wouldDECOMPOSITIONPortalToDepthandCirrus-Overlapping-Water Clouds

  10. Infrared Emission from AGN

    E-Print Network [OSTI]

    D. B. Sanders

    1999-03-30T23:59:59.000Z

    Infrared observations of complete samples of active galactic nuclei (AGN) have shown that a substantial fraction of their bolometric luminosity is emitted at wavelengths ~8-1000microns. In radio-loud and Blazar-like objects much of this emission appears to be direct non-thermal synchrotron radiation. However, in the much larger numbers of radio-quiet AGN it is now clear that thermal dust emission is responsible for the bulk of radiation from the near-infrared through submillimeter wavelengths. Luminous infrared-selected AGN are often surrounded by powerful nuclear starbursts, both of which appear to be fueled by enormous supplies of molecular gas and dust funneled into the nuclear region during the strong interaction/merger of gas rich disks. All-sky surveys in the infrared show that luminous infrared AGN are at least as numerous as optically-selected AGN of comparable bolometric luminosity, suggesting that AGN may spend a substantial fraction of their lifetime in a dust-enshrouded phase. The space density of luminous infrared AGN at high redshift may be sufficient to account for much of the X-Ray background, and for a substantial fraction of the far-infrared background as well. These objects plausibly represent a major epoch in the formation of spheroids and massive black holes (MBH).

  11. DeMeo taxonomy : categorization of asteroids in the near-infrared

    E-Print Network [OSTI]

    DeMeo, Francesca E

    2007-01-01T23:59:59.000Z

    This work presents the DeMeo taxonomy, an asteroid taxonomy with 24 classes based on Principal Component Analysis of spectral data over the visible and near-infrared wavelengths, specifically the 0.45 to 2.45 micron range. ...

  12. Path-dependent human identification using a pyroelectric infrared sensor and Fresnel lens

    E-Print Network [OSTI]

    Pitsianis, Nikos P.

    Path-dependent human identification using a pyroelectric infrared sensor and Fresnel lens arrays) sensor whose visibility is modulated by a Fresnel lens array. The optimal element number of the lens," Proc. of IEEE. Signals, Systems and Computers 1, 843-838 (2001). 11. Fresnel Technologies Inc., http

  13. Visible-wavelength semiconductor lasers and arrays

    DOE Patents [OSTI]

    Schneider, R.P. Jr.; Crawford, M.H.

    1996-09-17T23:59:59.000Z

    The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1{lambda}) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%. 5 figs.

  14. Inverted cones grating for flexible metafilter at optical and infrared frequencies

    SciTech Connect (OSTI)

    Brckner, Jean-Baptiste; Le Rouzo, Judikal; Escoubas, Ludovic [Aix-Marseille Universit, IM2NP, CNRS-UMR 7334, Domaine Universitaire de Saint-Jrme, Service 231, 13397 Marseille Cedex 20 (France); Brissonneau, Vincent; Dubarry, Christophe [CEA-LITEN DTNM, 17 Avenue des Martyrs, 38054 Grenoble cedex 9 (France); Ferchichi, Abdelkerim; Gourgon, Ccile [LTM CNRS, Laboratoire des Technologies de la Microlectronique 17 Avenue des Martyrs, 38054 Grenoble cedex 9 (France); Berginc, Grard [Thales Optronique S.A., 2 Avenue Gay Lussac, 78990 Elancourt (France)

    2014-02-24T23:59:59.000Z

    By combining the antireflective properties from gradual changes in the effective refractive index and cavity coupling from cone gratings and the efficient optical behavior of a tungsten film, a flexible filter showing very broad antireflective properties from the visible to short wavelength infrared region and, simultaneously, a mirror-like behavior in the mid-infrared wavelength region and long-infrared wavelength region has been conceived. Nanoimprint technology has permitted the replication of inverted cone patterns on a large scale on a flexible polymer, afterwards coated with a thin tungsten film. This optical metafilter is of great interest in the stealth domain where optical signature reduction from the optical to short wavelength infrared region is an important matter. As it also acts as selective thermal emitter offering a good solar-absorption/infrared-emissivity ratio, interests are found as well for solar heating applications.

  15. Visible light surface emitting semiconductor laser

    DOE Patents [OSTI]

    Olbright, Gregory R. (Boulder, CO); Jewell, Jack L. (Bridgewater, NJ)

    1993-01-01T23:59:59.000Z

    A vertical-cavity surface-emitting laser is disclosed comprising a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. Specific embodiments of the invention for generating red, green, and blue radiation are described.

  16. Sustained water cleavage by visible light

    SciTech Connect (OSTI)

    Borgarello, E.; Kiwi, J.; Pelizzetti, E.; Visca, M.; Graetzel, M.

    1981-10-21T23:59:59.000Z

    Sustained cleavage of water by 4 quanta of visible light is achieved in aqueous solutions by using a bifunctional redox catalyst composed of Pt and RuO/sub 2/ cosupported by colloidal TiO/sub 2/ particles. A photochemical model system containing Ru(bpy)/sub 3//sup 2 +/ as a sensitizer and methyl viologen (MV/sup 2 +/) as an electron relay is used to test the effect of catalyst composition, sensitizer concentration, pH, and temperature on the efficiency of light-induced water decomposition. Electron relay free systems also exhibit high photoactivity. Direct band gap irradiation by uv light leads to efficient water cleavage in the absence of sensitizer and relay.

  17. Suppression of quantum decoherence via infrared-driven coherent exciton-plasmon coupling: Undamped field and Rabi oscillations

    SciTech Connect (OSTI)

    Sadeghi, S. M., E-mail: seyed.sadeghi@uah.edu [Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Nano and Micro Device Center, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Patty, K. D. [Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)

    2014-02-24T23:59:59.000Z

    We show that when a semiconductor quantum dot is in the vicinity of a metallic nanoparticle and driven by a mid-infrared laser field, its coherent dynamics caused by interaction with a visible laser field can become free of quantum decoherence. We demonstrate that this process, which can offer undamped Rabi and field oscillations, is the result of coherent normalization of the effective polarization dephasing time of the quantum dot (T{sub 2}{sup *}). This process indicates formation of infrared-induced coherently forced oscillations, which allows us to control the value of T{sub 2}{sup *} using the infrared laser. The results offer decay-free ultrafast modulation of the effective field experienced by the quantum dot when neither the visible laser field nor the infrared laser changes with time.

  18. Capturing All the Light: Panchromatic Visible Absorption for...

    Office of Science (SC) Website

    Capturing All the Light: Panchromatic Visible Absorption for Solar Photoconversion Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES...

  19. Packet loss visibility and packet prioritization in digital videos

    E-Print Network [OSTI]

    Kanumuri, Sandeep

    2006-01-01T23:59:59.000Z

    Performance comparison for videos with apparent compres-Prioritization in Digital Videos A Dissertation submitted inloss visibility, Packet Video Workshop, Irvine, December

  20. Near-infrared Hong-Ou-Mandel interference on a silicon quantum photonic circuit

    E-Print Network [OSTI]

    Xinan Xu; Zhenda Xie; Jiangjun Zheng; Junlin Liang; Tian Zhong; Mingbin Yu; Serdar Kocaman; Guo-Qiang Lo; Dim-Lee Kwong; Dirk R. Englund; Franco N. C. Wong; Chee Wei Wong

    2012-12-03T23:59:59.000Z

    Near-infrared Hong-Ou-Mandel quantum interference is observed in silicon nanophotonic directional couplers with raw visibilities on-chip at 90.5%. Spectrally-bright 1557-nm two-photon states are generated in a periodically-poled KTiOPO4 waveguide chip, serving as the entangled photon source and pumped with a self-injection locked laser, for the photon statistical measurements. Efficient four-port coupling in the communications C-band and in the high-index-contrast silicon photonics platform is demonstrated, with matching theoretical predictions of the quantum interference visibility. Constituents for the residual quantum visibility imperfection are examined, supported with theoretical analysis of the sequentially-triggered multipair biphoton contribution and techniques for visibility compensation, towards scalable high-bitrate quantum information processing and communications.

  1. A PHOTOMETRICALLY AND MORPHOLOGICALLY VARIABLE INFRARED NEBULA IN L483

    SciTech Connect (OSTI)

    Connelley, Michael S. [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States); Hodapp, Klaus W. [University of Hawaii Institute for Astronomy, 640 N. Aohoku Pl., Hilo, HI 96720 (United States); Fuller, Gary A. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)

    2009-03-15T23:59:59.000Z

    We present narrow and broad K-band observations of the Class 0/I source IRAS 18148-0440 that span 17 years. The infrared nebula associated with this protostar in the L483 dark cloud is both morphologically and photometrically variable on a timescale of only a few months. This nebula appears to be an infrared analog to other well known optically visible variable nebulae associated with young stars, such as Hubble's Variable Nebula. Along with Cepheus A, this is one of the first large variable nebulae to be found that is only visible in the infrared. The variability of this nebula is most likely due to changing illumination of the cloud rather than any motion of the structure in the nebula. Both morphological and photometric changes are observed on a timescale only a few times longer than the light crossing time of the nebula, suggesting very rapid intrinsic changes in the illumination of the nebula. Our narrowband observations also found that H{sub 2} knots are found nearly twice as far to the east of the source as to its west, and that H{sub 2} emission extends farther east of the source than the previously known CO outflow.

  2. Visible Inequality, Status Competition and Conspicuous Consumption: Evidence from India

    E-Print Network [OSTI]

    Bandyopadhyay, Antar

    Visible Inequality, Status Competition and Conspicuous Consumption: Evidence from India Punarjit representative micro data from India. I ...nd that a decrease in the level of visible inequality, ceteris paribus in one's social status due to parallel action of others. From a policy perspective, my ...ndings

  3. Infrared Thermometer (IRT) Handbook

    SciTech Connect (OSTI)

    VR Morris

    2006-10-30T23:59:59.000Z

    The Infrared Thermometer (IRT) is a ground-based radiation pyrometer that provides measurements of the equivalent blackbody brightness temperature of the scene in its field of view. The downwelling version has a narrow field of view for measuring sky temperature and for detecting clouds. The upwelling version has a wide field of view for measuring the narrowband radiating temperature of the ground surface.

  4. Fourier Transform Infrared Spectroscopy

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    FTIR - 1 Fourier Transform Infrared Spectroscopy FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL IN VODKA AND MOUTHWASH INTRODUCTION As a part has contained MTBE (methyl tert­butyl ether) as its primary oxygenate. However, there has been

  5. Visible Photoluminescence from Cubic (3C) Silicon Carbide Microdisks Coupled to High Quality Whispering Gallery Modes

    E-Print Network [OSTI]

    Marina Radulaski; Thomas M. Babinec; Kai Mller; Konstantinos G. Lagoudakis; Jingyuan Linda Zhang; Sonia Buckley; Yousif A. Kelaita; Kassem Alassaad; Gabriel Ferro; Jelena Vu?kovi?

    2014-12-08T23:59:59.000Z

    We present the design, fabrication and characterization of cubic (3C) silicon carbide microdisk resonators with high quality factor modes at visible and near infrared wavelengths (600 - 950 nm). Whispering gallery modes with quality factors as high as 2,300 and corresponding mode volumes V ~ 2 ({\\lambda}/n)^3 are measured using laser scanning confocal microscopy at room temperature. We obtain excellent correspondence between transverse-magnetic (TM) and transverse-electric (TE) polarized resonances simulated using Finite Difference Time Domain (FDTD) method and those observed in experiment. These structures based on ensembles of optically active impurities in 3C-SiC resonators could play an important role in diverse applications of nonlinear and quantum photonics, including low power optical switching and quantum memories.

  6. Tailoring Metallodielectric Structures for Super Resolution and Superguiding Applications in the Visible and Near IR Ranges

    E-Print Network [OSTI]

    De Ceglia, D; Cappeddu, M G; Centini, M; Akozbek, N; DOrazio, A; Haus, J W; Bloemer, M J; Scalora, M

    2008-01-01T23:59:59.000Z

    We discuss propagation effects in realistic, transparent, metallo-dielectric photonic band gap structures in the context of negative refraction and super-resolution in the visible and near infrared ranges. In the resonance tunneling regime, we find that for transverse-magnetic incident polarization, field localization effects contribute to a waveguiding phenomenon that makes it possible for the light to remain confined within a small fraction of a wavelength, without any transverse boundaries, due to the suppression of diffraction. This effect is related to negative refraction of the Poynting vector inside each metal layer, balanced by normal refraction inside the adjacent dielectric layer: The degree of field localization and material dispersion together determine the total momentum that resides within any given layer, and thus the direction of energy flow. We find that the transport of evanescent wave vectors is mediated by the excitation of quasi-stationary, low group velocity surface waves responsible for...

  7. The Infrared Ca II lines in Sunspot Umbrae

    E-Print Network [OSTI]

    Kollatschny, W; Wiehr, E; Fallipou, M A

    2012-01-01T23:59:59.000Z

    We present an empirical working model for sunspot umbrae which equally describes observed continuum intensities and line profiles. The wings of the infrared Ca II lines depend sensitively on the temperature gradient at -0.6 umbra and are thus insensitive to parasitic light. It is also shown that the infrared K I 7699 line is suitable for umbral spectroscopy since it is not seriously blended, its continuum is well defined and it is less influenced by parasitic light as compared to lines in the visible spectrum, due to the smaller umbal contrast. Calculations show that the umbral gradient dT/d(tau), required to fit the Ca II triplet lines, strongly conflicts with the observed profiles of K I 7699, NaD2 and Fe I 5434 (g=0), even when assuming vanishing Fe II lines for a maximum correction of parasitic light. It is shown that the discrepancy from the different line pr...

  8. Infrared Maximally Abelian Gauge

    E-Print Network [OSTI]

    Tereza Mendes; Attilio Cucchieri; Antonio Mihara

    2006-11-01T23:59:59.000Z

    The confinement scenario in Maximally Abelian gauge (MAG) is based on the concepts of Abelian dominance and of dual superconductivity. Recently, several groups pointed out the possible existence in MAG of ghost and gluon condensates with mass dimension 2, which in turn should influence the infrared behavior of ghost and gluon propagators. We present preliminary results for the first lattice numerical study of the ghost propagator and of ghost condensation for pure SU(2) theory in the MAG.

  9. Introduction Dust aerosols affect visibility, perturb the radiative energy balance

    E-Print Network [OSTI]

    Wang, Jun

    Sunphotometer and air temperature from ground observations. Model Flow Chart GOES-8 06/28/00 1145 UTC -90 -80Introduction Dust aerosols affect visibility, perturb the radiative energy balance of the earth

  10. Digital meteorological radar data compared with digital infrared data from a geostationary meteorological satellite

    E-Print Network [OSTI]

    Henderson, Rodney Stuart

    1979-01-01T23:59:59.000Z

    and infrared spectrums. The SEM in- eludes a magnetometer, a solar x ? ray telescope, and an energetic 22 particle monitor. The TTC includes equipment for S-band trans- mission and reception (ir. reduced bandwidth) of VISSR data, S-band transmission... the visible and infrared spectrums. Radiation is received by the VISSR's primary optics via a 45 object-space scan mirror. The mirror is an elliptically shaped plane mirror which is tilted about its minor axis to obtain the north- south scan steps. West...

  11. An Infrared Spectral Library for Atmospheric Environmental Monitoring...

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

    An Infrared Spectral Library for Atmospheric Environmental Monitoring. An Infrared Spectral Library for Atmospheric Environmental Monitoring. Abstract: Infrared (IR) spectroscopy...

  12. Infrared Transmissometer to Measure the Thickness of NbN Thin Films

    E-Print Network [OSTI]

    Sunter, Kristen A; Lang, Christopher I; Berggren, Karl K

    2015-01-01T23:59:59.000Z

    We present an optical setup that can be used to characterize the thicknesses of thin NbN films to screen samples for fabrication and to better model the performance of the resulting superconducting nanowire single photon detectors. The infrared transmissometer reported here is easy to use, gives results within minutes and is non-destructive. Thus, the thickness measurement can be easily integrated into the workflow of deposition and characterization. Comparison to a similar visible-wavelength transmissometer is provided.

  13. The first infrared beamline at the ALS: Design, construction, and initial commissioning

    SciTech Connect (OSTI)

    McKinney, W.R.; Hirschmugl, C.J.; Padmore, H.A.; Lauritzen, T.; Andresen, N.; Andronaco, G.; Patton, R.; Fong, M.

    1997-09-01T23:59:59.000Z

    The first Infrared (IR) Beamline at the Advanced Light Source (ALS), Beamline 1.4, is described. The design of the optical and mechanical systems are discussed, including choices and tradeoffs. The initial commissioning of the beamline is reported. The beamline, while designed primarily for IR microscopy and only initially instrumented for microscopy (with a Nicolet interferometer and microscope), will have the potential for surface science experiments at grazing incidence, and time-resolved visible spectroscopy.

  14. Frequency selective infrared sensors

    SciTech Connect (OSTI)

    Davids, Paul; Peters, David W

    2014-11-25T23:59:59.000Z

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  15. Frequency selective infrared sensors

    DOE Patents [OSTI]

    Davids, Paul; Peters, David W

    2013-05-28T23:59:59.000Z

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  16. Synchrotron infrared confocal microscope: Application to infrared 3D spectral imaging

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Synchrotron infrared confocal microscope: Application to infrared 3D spectral imaging F Jamme1, 2 coupled to an infrared microscope allows imaging at the so-called diffraction limit. Thus, numerous infrared beamlines around the world have been developed for infrared chemical imaging. Infrared microscopes

  17. A Novel Spectroscopic Ellipsometer in the Infrared

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    A Novel Spectroscopic Ellipsometer in the Infrared Proefschrift ter verkrijging van de graad van-Charles A novel spectroscopic ellipsometer in the infrared / by Jean-Charles Cigal. ­ Eindhoven : Technische / infraroodspectroscopie / siliciumoxide / botweefsel Subject headings: ellipsometers / infrared spectroscopy / silicon

  18. Can infrared gravitons screen $?$?

    E-Print Network [OSTI]

    Jaume Garriga; Takahiro Tanaka

    2007-09-04T23:59:59.000Z

    It has been suggested that infrared gravitons in de Sitter space may lead to a secular screening of the effective cosmological constant. This seems to clash with the naive expectation that the curvature scalar should stay constant due to the Heisenberg equation of motion. Here, we show that the tadpole correction to the local expansion rate, which has been used in earlier analyses as an indicator of a decaying effective $\\Lambda$, is not gauge invariant. On the other hand, we construct a gauge invariant operator which measures the renormalized curvature scalar smeared over an arbitrary window function, and we find that there is no secular screening of this quantity (to any given order in perturbation theory).

  19. Lateral conduction infrared photodetector

    DOE Patents [OSTI]

    Kim, Jin K. (Albuquerque, NM); Carroll, Malcolm S. (Albuquerque, NM)

    2011-09-20T23:59:59.000Z

    A photodetector for detecting infrared light in a wavelength range of 3-25 .mu.m is disclosed. The photodetector has a mesa structure formed from semiconductor layers which include a type-II superlattice formed of alternating layers of InAs and In.sub.xGa.sub.1-xSb with 0.ltoreq.x.ltoreq.0.5. Impurity doped regions are formed on sidewalls of the mesa structure to provide for a lateral conduction of photo-generated carriers which can provide an increased carrier mobility and a reduced surface recombination. An optional bias electrode can be used in the photodetector to control and vary a cut-off wavelength or a depletion width therein. The photodetector can be formed as a single-color or multi-color device, and can also be used to form a focal plane array which is compatible with conventional read-out integrated circuits.

  20. Asymptotics of the Infrared

    E-Print Network [OSTI]

    P. R. Crompton

    2005-04-17T23:59:59.000Z

    We follow recent formulations of dimensionally reduced loop operators for quantum field theories and exact representations of probabilistic lattice dynamics to identify a new scheme for the evaluation of partition function zeroes, allowing for the explicit analysis of quantum critical phenomena. This new approach gives partition function zeroes from a factored quantum loop operator basis and, as we show, constitutes an effective mapping of the renormalization group $\\beta$-function onto the noncommuting local operator basis of a countably finite Hilbert space. The Vafa-Witten theorem for CP-violation and related complex action problems of Euclidean Field theories are discussed, following recent treatments, and are shown to be natural consequences of the analyticity of the limiting distribution of these zeroes, and properties of vacuum regimes governed by a dominant quantum fluctuation in the vicinity of a renormalization group equation fixed point in the infrared.

  1. Algorithms for the Automatic Identification of MARFEs and UFOs in JET Database of Visible Camera Videos

    E-Print Network [OSTI]

    Algorithms for the Automatic Identification of MARFEs and UFOs in JET Database of Visible Camera Videos

  2. Synchrotron Infrared Unveils a Mysterious Microbial Community

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

    Synchrotron Infrared Unveils a Mysterious Microbial Community Synchrotron Infrared Unveils a Mysterious Microbial Community Print Tuesday, 22 January 2013 00:00 A cold sulfur...

  3. Interactive Visibility Culling in Complex Environments using Occlusion-Switches

    E-Print Network [OSTI]

    North Carolina at Chapel Hill, University of

    Categories and Subject Descriptors: I.3.5 [Com- puter Graphics]: Computational Geometry and Object ModelingInteractive Visibility Culling in Complex Environments using Occlusion-Switches Naga K. Govindaraju culling in complex 3D environments. An occlusion- switch consists of two GPUs (graphics processing units

  4. Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino

    E-Print Network [OSTI]

    Merlino, Robert L.

    Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino Department of Physics and Astronomy with their announcement that: "We find that a new type of sound wave, namely, the dust-acoustic waves, can appear" [1 and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some

  5. GLAO IN THE VISIBLE: THE SAM EXPERIENCE Andrei Tokovinina

    E-Print Network [OSTI]

    Tokovinin, Andrei A.

    -common-path errors were avoided. SAM can feed corrected images to its internal CCD detector, SAMI (4K4K CCDGLAO IN THE VISIBLE: THE SAM EXPERIENCE Andrei Tokovinina Cerro Tololo Interamerican Observatory, Casilla 603, La Serena, Chile Abstract. The SOAR adaptive module (SAM) is going through science

  6. Accepted Manuscript Visible Models for Interactive Pattern Recognition

    E-Print Network [OSTI]

    Nagy, George

    in interactive visual classification. The visible model of an object to be recognized is an abstraction classification, faster than unaided human classification, and that both machine and human performance improve Polytechnic Institute, Troy, NY 12180 USA. He is now with the National Library of Medicine, Bldg. 38A, Rm. 10S

  7. Resonator design for a visible wavelength free-electron laser (*)

    SciTech Connect (OSTI)

    Bhowmik, A.; Lordi, N. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.); Ben-Zvi, I.; Gallardo, J. (Brookhaven National Lab., Upton, NY (United States))

    1990-01-01T23:59:59.000Z

    Design requirements for a visible wavelength free-electron laser being developed at the Accelerator Test Facility at Brookhaven National Laboratory are presented along with predictions of laser performance from 3-D numerical simulations. The design and construction of the optical resonator, its alignment and control systems are also described. 15 refs., 8 figs., 4 tabs.

  8. Visibility Preprocessing with Occluder Fusion for Urban Walkthroughs

    E-Print Network [OSTI]

    in the umbra (shadow volume) with respect to a given area light source. In contrast to occlusion from a point: · The umbra with respect to a polygonal area light source is not only bounded by planes, but also by reguli, i. For visibility from a point, the joint umbra of many occluders is the union of the umbrae of the individual

  9. Industrial Use of Infrared Inspections

    E-Print Network [OSTI]

    Duch, A. A.

    1979-01-01T23:59:59.000Z

    operating load. - Pinpointing of the exact location of the problems. - The inspections will locate problems which will, in most cases, go unnoticed using conventional techniques. An infrared inspection will locate problem areas in the plant electrica1...

  10. The SNAP near infrared detectors

    E-Print Network [OSTI]

    2002-01-01T23:59:59.000Z

    it will detect Type Ia supernov between z = 1 and 1.7 andphotometry for all supernov. HgCdTe technology, with a cut-Keywords: Cosmology, Supernovae, Dark Energy, Near Infrared,

  11. Infrared Dry-peeling Technology for Tomatoes

    E-Print Network [OSTI]

    Infrared Dry-peeling Technology for Tomatoes Saves Energy Energy Efficiency Research Office PIER This research will use infrared heating technology for peeling tomatoes. Infrared dry peeling, a device, producing less wastewater and preserving product quality. Infrared drypeeling is expected to reduce

  12. High-power parametric conversion from near-infrared to short-wave infrared

    E-Print Network [OSTI]

    Dalang, Robert C.

    High-power parametric conversion from near-infrared to short-wave infrared Adrien Billat,1,* Steevy.billat@epfl.ch Abstract: We report the design of an all-fiber continuous wave Short-Wave Infrared source capable to output.4370) Nonlinear optics, fibers; (140.3070) Infrared and far-infrared lasers. References and links 1. M. N

  13. YET ANOTHER INFRARED ARCHIVE: RELEASE OF THE INFRARED TELESCOPE IN SPACE (IRTS) ARCHIVE DATA

    E-Print Network [OSTI]

    Yamamura, Issei

    1 YET ANOTHER INFRARED ARCHIVE: RELEASE OF THE INFRARED TELESCOPE IN SPACE (IRTS) ARCHIVE DATA I the near- and mid-infrared low resolu- tion spectral catalogues of point sources, and image maps in #12;ve wavelength bands in the far-infrared. The point source catalogues contains over 14 000 (near-infrared

  14. HIGH-RESOLUTION MID-INFRARED SPECTROSCOPY OF ULTRALUMINOUS INFRARED GALAXIES D. Farrah,1

    E-Print Network [OSTI]

    Galis, Frietson

    infrared emission. This initially provoked heated debate between a ``starburst'' camp and an ``activeHIGH-RESOLUTION MID-INFRARED SPECTROSCOPY OF ULTRALUMINOUS INFRARED GALAXIES D. Farrah,1 J. Bernard, 10Y37 m spectra of 53 ultraluminous infrared galaxies (ULIRGs), taken using the Infrared Spectrograph

  15. Dusty Infrared Galaxies: Sources of the Cosmic Infrared Background

    E-Print Network [OSTI]

    Guilaine Lagache; Jean-Loup Puget; Herve Dole

    2005-07-12T23:59:59.000Z

    The discovery of the Cosmic Infrared Background (CIB) in 1996, together with recent cosmological surveys from the mid-infrared to the millimeter have revolutionized our view of star formation at high redshifts. It has become clear, in the last decade, that a population of galaxies that radiate most of their power in the far-infrared (the so-called ``infrared galaxies'') contributes an important part of the whole galaxy build-up in the Universe. Since 1996, detailed (and often painful) investigations of the high-redshift infrared galaxies have resulted in the spectacular progress covered in this review. We outline the nature of the sources of the CIB including their star-formation rate, stellar and total mass, morphology, metallicity and clustering properties. We discuss their contribution to the stellar content of the Universe and their origin in the framework of the hierarchical growth of structures. We finally discuss open questions for a scenario of their evolution up to the present-day galaxies.

  16. Multipath Reflections Analysis on Indoor Visible Light Positioning System

    E-Print Network [OSTI]

    Gu, Wenjun; Kavehrad, Mohsen

    2015-01-01T23:59:59.000Z

    Visible light communication (VLC) has become a promising research topic in recent years, and finds its wide applications in indoor environments. Particularly, for location based services (LBS), visible light also provides a practical solution for indoor positioning. Multipath-induced dispersion is one of the major concerns for complex indoor environments. It affects not only the communication performance but also the positioning accuracy. In this paper, we investigate the impact of multipath reflections on the positioning accuracy of indoor VLC positioning systems. Combined Deterministic and Modified Monte Carlo (CDMMC) approach is applied to estimate the channel impulse response considering multipath reflections. Since the received signal strength (RSS) information is used for the positioning algorithm, the power distribution from one transmitter in a typical room configuration is first calculated. Then, the positioning accuracy in terms of root mean square error is obtained and analyzed.

  17. Hydrogen generation under visible light using nitrogen doped titania anodes

    SciTech Connect (OSTI)

    Lin, H.; Rumaiz, A.; Schulz, M.; Huang, C.P.; Sha, S. I.

    2010-06-16T23:59:59.000Z

    Hydrogen is among several energy sources that will be needed to replace the quickly diminishing fossil fuels. Free hydrogen is not available naturally on earth and the current processes require a fossil fuel, methane, to generate hydrogen. Electrochemical splitting of water on titania proposed by Fujishima suffers from low efficiency. The efficiency could be enhanced if full sun spectrum can be utilized. Using pulsed laser deposition technique we synthesized nitrogen doped titanium dioxide (TiO{sub 2-x}N{sub x}) thin films with improved visible light sensitivity. The photoactivity was found to be N concentration dependent. Hydrogen evolution was observed under visible light irradiation (wavelength > 390 nm) without the presence of any organic electron donor.

  18. Interference Visibility as a Witness of Entanglement and Quantum Correlation

    E-Print Network [OSTI]

    Lin Zhang; Arun Kumar Pati; Junde Wu

    2014-10-30T23:59:59.000Z

    In quantum information and communication one looks for the non-classical features like interference and quantum correlations to harness the true power of composite systems. We show how the concept akin to interference is, in fact, intertwined in a quantitative manner to entanglement and quantum correlation. In particular, we prove that the difference in the squared visibility for a density operator before and after a complete measurement, averaged over all unitary evolutions, is directly related to the quantum correlation measure based on the measurement disturbance. For pure and mixed bipartite states the unitary average of the squared visibility is related to entanglement measure. This may constitute direct detection of entanglement and quantum correlations with quantum interference setups. Furthermore, we prove that for a fixed purity of the subsystem state, there is a complementarity relation between the linear entanglement of formation and the measurement disturbance. This brings out a quantitative difference between two kinds of quantum correlations.

  19. Chaotic fluctuation of temperature on environmental interface exchanging energy by visible and infrared radiation, convection and conduction

    E-Print Network [OSTI]

    D. T. Miahilovi?; D. Kapor; M. Budin?evi?

    2007-02-02T23:59:59.000Z

    The concept of environmental interface is defined and analyzed from the point of view of the possible source of non-standard behaviour. The energy balance equation is written for the interface where all kinds of energy transfer occur. It is shown that under certain conditions, the discrete version of the equation for the temperature time rate turns in to the well-known logistic equation and the conditions for chaotic behaviour are studied. They are determined by the Lyapunov exponent. The realistic situation when the coefficients of the equation vary with time, is studied for the Earth-environment general system.

  20. Transmittance from visible to mid infra-red in AZO films grown by atomic layer deposition system

    E-Print Network [OSTI]

    Tanner, David B.

    found applications in thin film photovoltaics such as CdTe and CIGS based solar cells (Dhere et al for solar cells, flat panel displays, LCD electrodes, touch panel transparent contacts and IR win- dows Westgate a , D.I. Koukis b , D.J. Arenas c , D.B. Tanner b a Center for Autonomous Solar Power, Binghamton

  1. Infrared and Visible Image Fusion for Face Recognition Saurabh Singha, Aglika Gyaourovaa, George Bebisa, and Ioannis Pavlidisb

    E-Print Network [OSTI]

    Bebis, George

    imagery is very sensitive to facial occlusion caused by eyeglasses. In this paper, we propose fusing IR by eyeglasses. Two different fusion schemes have been investigated in this study: (1) image- based fusion to eyeglasses. Objects made of glass act as a temperature screen, completely hiding the parts located behind

  2. Multi-Sensor Fusion of Electro-Optic and Infrared Signals for High Resolution Visible Images: Part II

    E-Print Network [OSTI]

    of high resolution and low noise level, but they cannot reflect information about the temperature the properties of low resolution and high noise level, but IR images can reflect information about temperature variation of objects in the daytime via high-resolution EO images. The proposed novel framework

  3. Electrically injected visible vertical cavity surface emitting laser diodes

    DOE Patents [OSTI]

    Schneider, R.P.; Lott, J.A.

    1994-09-27T23:59:59.000Z

    Visible laser light output from an electrically injected vertical cavity surface emitting laser (VSCEL) diode is enabled by the addition of phase-matching spacer layers on either side of the active region to form the optical cavity. The spacer layers comprise InAlP which act as charge carrier confinement means. Distributed Bragg reflector layers are formed on either side of the optical cavity to act as mirrors. 5 figs.

  4. Reflection beamshifts of visible light due to graphene

    E-Print Network [OSTI]

    Hermosa, N

    2015-01-01T23:59:59.000Z

    I present theoretical calculations of reflection beamshifts, Goos-H\\"anchen and Imbert-Fedorov shifts, due to the presence of a monolayer graphene on a dielectric media when using a beam with wavelength in the visible range. Specifically, I look at beamshifts for different polarization states (p, s, $45^0$, $\\sigma^+$). The Goos-H\\"anchen shifts I calculated are in good agreement with results of a recent experiment. I will discuss other possible experimental routes to determine beamshifts in graphene.

  5. Visible light photon counters optimization for quantum information applications

    SciTech Connect (OSTI)

    Molina, J.; /Rio de Janeiro State U.; Estrada, J.; Bross, A.; /Fermilab; Ginther, G.; /Rochester U.; Buscher, V.; /Freiburg U.

    2006-10-01T23:59:59.000Z

    In this paper we describe the studies of the main parameters needed for optimal operation of Visible Light Photon Counters (VLPCs) when used in quantum information systems. The isolation of the single photon signal is analyzed through the definition of a contamination parameter. A compromise in the minimization of this parameter for temperature, bias voltage and dark count variation must be achieved and this depends on the experimental conditions.

  6. Visible Light Photoreduction of CO{sub 2} Using CdSe/Pt/TiO{sub 2} Heterostructured Catalysts

    SciTech Connect (OSTI)

    Wang, Congjun [Parsons Project Services, South Park, PA (United States); Thompson, Robert L. [Parsons Project Services, South Park, PA (United States); Baltrus, John [National Energy Technology Laboratory (NETL), Pittsburgh, PA, (United States); Matranga, Christopher [National Energy Technology Laboratory (NETL), Pittsburgh, PA, (United States)

    2010-08-01T23:59:59.000Z

    A series of CdSe quantum dot (QD)-sensitized TiO{sub 2} heterostructures have been synthesized, characterized, and tested for the photocatalytic reduction of CO{sub 2} in the presence of H{sub 2}O. Our results show that these heterostructured materials are capable of catalyzing the photoreduction of CO{sub 2} using visible light illumination (? > 420 nm) only. The effect of removing surfactant caps from the CdSe QDs by annealing and using a hydrazine chemical treatment have also been investigated. The photocatalytic reduction process is followed using infrared spectroscopy to probe the gas-phase reactants and gas chromatography to detect the products. Gas chromatographic analysis shows that the primary reaction product is CH{sub 4}, with CH{sub 3}OH, H{sub 2}, and CO observed as secondary products. Typical yields of the gas-phase products after visible light illumination (?>420 nm) were 48 ppm g{sup -1} h{sup -1} of CH{sub 4}, 3.3 ppm g{sup -1} h{sup -1} of CH{sub 3}OH (vapor), and trace amounts of CO and H{sub 2}.

  7. Near infrared detectors for SNAP

    SciTech Connect (OSTI)

    Schubnell, M.; Barron, N.; Bebek, C.; Brown, M.G.; Borysow, M.; Cole, D.; Figer, D.; Lorenzon, W.; Mostek, N.; Mufson, S.; Seshadri, S.; Smith, R.; Tarle, G.

    2006-05-23T23:59:59.000Z

    Large format (1k x 1k and 2k x 2k) near infrared detectors manufactured by Rockwell Scientific Center and Raytheon Vision Systems are characterized as part of the near infrared R&D effort for SNAP (the Super-Nova/Acceleration Probe). These are hybridized HgCdTe focal plane arrays with a sharp high wavelength cut-off at 1.7 um. This cut-off provides a sufficiently deep reach in redshift while it allows at the same time low dark current operation of the passively cooled detectors at 140 K. Here the baseline SNAP near infrared system is briefly described and the science driven requirements for the near infrared detectors are summarized. A few results obtained during the testing of engineering grade near infrared devices procured for the SNAP project are highlighted. In particular some recent measurements that target correlated noise between adjacent detector pixels due to capacitive coupling and the response uniformity within individual detector pixels are discussed.

  8. Germanium blocked impurity band far infrared detectors

    SciTech Connect (OSTI)

    Rossington, C.S.

    1988-04-01T23:59:59.000Z

    The infrared portion of the electromagnetic spectrum has been of interest to scientist since the eighteenth century when Sir William Herschel discovered the infrared as he measured temperatures in the sun's spectrum and found that there was energy beyond the red. In the late nineteenth century, Thomas Edison established himself as the first infrared astronomer to look beyond the solar system when he observed the star Arcturus in the infrared. Significant advances in infrared technology and physics, long since Edison's time, have resulted in many scientific developments, such as the Infrared Astronomy Satellite (IRAS) which was launched in 1983, semiconductor infrared detectors for materials characterization, military equipment such as night-vision goggles and infrared surveillance equipment. It is now planned that cooled semiconductor infrared detectors will play a major role in the ''Star Wars'' nuclear defense scheme proposed by the Reagan administration.

  9. Infrared extrapolations for atomic nuclei

    E-Print Network [OSTI]

    R. J. Furnstahl; G. Hagen; T. Papenbrock; K. A. Wendt

    2014-08-01T23:59:59.000Z

    Harmonic oscillator model-space truncations introduce systematic errors to the calculation of binding energies and other observables. We identify the relevant infrared scaling variable and give values for this nucleus-dependent quantity. We consider isotopes of oxygen computed with the coupled-cluster method from chiral nucleon-nucleon interactions at next-to-next-to-leading order and show that the infrared component of the error is sufficiently understood to permit controlled extrapolations. By employing oscillator spaces with relatively large frequencies, well above the energy minimum, the ultraviolet corrections can be suppressed while infrared extrapolations over tens of MeVs are accurate for ground-state energies. However, robust uncertainty quantification for extrapolated quantities that fully accounts for systematic errors is not yet developed.

  10. Lattice Simulations and Infrared Conformality

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

    Appelquist, Thomas; Fleming, George T.; Lin, Meifeng; Neil, Ethan T.; Schaich, David A.

    2011-09-01T23:59:59.000Z

    We examine several recent lattice-simulation data sets, asking whether they are consistent with infrared conformality. We observe, in particular, that for an SU(3) gauge theory with 12 Dirac fermions in the fundamental representation, recent simulation data can be described assuming infrared conformality. Lattice simulations include a fermion mass m which is then extrapolated to zero, and we note that this data can be fit by a small-m expansion, allowing a controlled extrapolation. We also note that the conformal hypothesis does not work well for two theories that are known or expected to be confining and chirally broken, and that it does work well for another theory expected to be infrared conformal.

  11. Lattice Simulations and Infrared Conformality

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

    Appelquist, Thomas; Fleming, George T.; Lin, Meifeng; Neil, Ethan T.; Schaich, David A.

    2011-09-01T23:59:59.000Z

    We examine several recent lattice-simulation data sets, asking whether they are consistent with infrared conformality. We observe, in particular, that for an SU(3) gauge theory with 12 Dirac fermions in the fundamental representation, recent simulation data can be described assuming infrared conformality. Lattice simulations include a fermion mass m which is then extrapolated to zero, and we note that this data can be fit by a small-m expansion, allowing a controlled extrapolation. We also note that the conformal hypothesis does not work well for two theories that are known or expected to be confining and chirally broken, and that itmoredoes work well for another theory expected to be infrared conformal.less

  12. Analysis of the High-Resolution Infrared Spectrum of Cyclopropane...

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

    the High-Resolution Infrared Spectrum of Cyclopropane. Analysis of the High-Resolution Infrared Spectrum of Cyclopropane. Abstract: The high resolution infrared spectrum of...

  13. Observation of two visible Dicke-superradiant transitions in atomic europium (*)

    E-Print Network [OSTI]

    Boyer, Edmond

    L-123 Observation of two visible Dicke-superradiant transitions in atomic europium (*) C visible pour les raies de l'europium 03BB = 557,7 nm et 03BB = 545,3 nm. Le caractre superradiant de report the first experimental evidence of visible superradiance for the europium lines at 03BB = 557.7 nm

  14. Dual-band infrared capabilities for imaging buried object sites

    SciTech Connect (OSTI)

    Del Grande, N.K.; Durbin, P.F.; Gorvad, M.R.; Perkins, D.E.; Clark, G.A.; Hernandez, J.E.; Sherwood, R.J.

    1993-04-02T23:59:59.000Z

    We discuss dual-band infrared (DBIR) capabilities for imaging buried object sizes. We identify physical features affecting thermal contrast needed to distinguish buried object sites from undisturbed sites or surface clutter. Apart from atmospheric transmission and system performance, these features include: object size, shape, and burial depth; ambient soil, disturbed soil and object site thermal diffusivity differences; surface temperature, emissivity, plant-cover, slope, albedo and roughness variations; weather conditions and measurement times. We use good instrumentation to measure the time-varying temperature differences between buried object sites and undisturbed soil sites. We compare near surface soil temperature differences with radiometric infrared (IR) surface temperature differences recorded at 4.7 {plus_minus} 0.4 {mu}m and at 10.6 {plus_minus} 1.0 {mu}m. By producing selective DBIR image ratio maps, we distinguish temperature-difference patterns from surface emissivity effects. We discuss temperature differences between buried object sites, filled hole site (without buried objects), cleared (undisturbed) soil sites, and grass-covered sites (with and without different types of surface clutter). We compare temperature, emissivity-ratio, visible and near-IR reflectance signatures of surface objects, leafy plants and sod. We discuss the physical aspects of environmental, surface and buried target features affecting interpretation of buried targets, surface objects and natural backgrounds.

  15. Real time infrared aerosol analyzer

    DOE Patents [OSTI]

    Johnson, Stanley A. (Countryside, IL); Reedy, Gerald T. (Bourbonnais, IL); Kumar, Romesh (Naperville, IL)

    1990-01-01T23:59:59.000Z

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

  16. Visible Y -junction diode laser with mixed coupling

    SciTech Connect (OSTI)

    van der Poel, C.J.; Opschoor, J.; Valster, A.; Drenten, R.R. (Philips Research Laboratories, P. O. Box 80 000, 5600 JA Eindhoven (The Netherlands)); Andre, J.P. (Laboratoires d'Electronique et de Physique Applique, 3 Avenue Descartes, 94450 Limeil-Brevannes (France))

    1990-07-15T23:59:59.000Z

    An experimental study and theoretical analysis of a phase-locked, visible, {lambda}=670 nm, 2-3 {ital Y}-junction semiconductor laser array are presented. In a ridgetype 2-3 {ital Y}-junction, AlInGaP/InGaP array, both in-phase and anti-phase array modes are observed to lase simultaneously. The experimental results are discussed in the framework of a model based on the beam propagation method. The influence of the presence of both interferometric and evanescent coupling on the array modes is analyzed.

  17. Quantitative nondestructive testing using Infrared Thermography

    E-Print Network [OSTI]

    Manohar, Arun

    2012-01-01T23:59:59.000Z

    steady, and selective heating scenarios. Infrared Physics &heating thermography and lock-in ther- mography to quantitative nondestructive evaluations. Infraredheating is very difficult to achieve in a practical scenario. The Infrared

  18. Infrared emitting device and method

    DOE Patents [OSTI]

    Kurtz, Steven R. (Albuquerque, NM); Biefeld, Robert M. (Albuquerque, NM); Dawson, L. Ralph (Albuquerque, NM); Howard, Arnold J. (Albuquerque, NM); Baucom, Kevin C. (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    An infrared emitting device and method. The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region. Examples have been set forth showing embodiments of the present invention as surface- and edge-emitting light emitting diodes (LEDs), an optically-pumped semiconductor laser, and an electrically-injected semiconductor diode laser. The light emission from each of the infrared emitting devices of the present invention is in the midwave infrared region of the spectrum from about 2 to 6 microns.

  19. Infrared Catastrophe for Nelson's Model

    E-Print Network [OSTI]

    Masao Hirokawa

    2005-11-08T23:59:59.000Z

    We mathematically study the infrared catastrophe for the Hamiltonian of Nelson's model when it has the external potential in a general class. For the model, we prove the pull-through formula on ground states in operator theory first. Based on this formula, we show both non-existence of any ground state and divergence of the total number of soft bosons.

  20. Sample rotating turntable kit for infrared spectrometers

    DOE Patents [OSTI]

    Eckels, Joel Del (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

    2008-03-04T23:59:59.000Z

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  1. Using Infrared Sensors to Follow an Infrared Beam Scott Sobieski, Thomas Richards, David Peacock,

    E-Print Network [OSTI]

    Kay, Jennifer S.

    Using Infrared Sensors to Follow an Infrared Beam Scott Sobieski, Thomas Richards, David Peacock, Computer Science Department The second robot follows the infrared beam from the first robot. These sensors infrared sensors produce a value between 0 and 255 depending on their distance from the emitting beam

  2. YET ANOTHER INFRARED ARCHIVE: RELEASE OF THE INFRARED TELESCOPE IN SPACE (IRTS) ARCHIVE DATA

    E-Print Network [OSTI]

    Yamamura, Issei

    1 YET ANOTHER INFRARED ARCHIVE: RELEASE OF THE INFRARED TELESCOPE IN SPACE (IRTS) ARCHIVE DATA I from 1.4 to 700 µm. Presently the archive includes the near- and mid-infrared low resolu- tion spectral catalogues of point sources, and image maps in five wavelength bands in the far-infrared. The point source

  3. IN-VIVO DIAGNOSIS OF CHEMICALLY INDUCED MELANOMA IN AN ANIMAL MODEL USING UV-VISIBLE AND NIR ELASTIC SCATTERING SPECTROSCOPY: PRELIMINARY TESTING.

    SciTech Connect (OSTI)

    C. A'AMAR; R. LEY; ET AL

    2001-01-01T23:59:59.000Z

    Elastic light scattering spectroscopy (ESS) has the potential to provide spectra that contain both morphological and chromophore information from tissue. We report on a preliminary study of this technique, with the hope of developing a method for diagnosis of highly-pigmented skin lesions, commonly associated with skin cancer. Four opossums were treated with dimethylbenz(a)anthracene to induce both malignant melanoma and benign pigmented lesions. Skin lesions were examined in vivo using both UV-visible and near infrared (NIR) ESS, with wavelength ranges of 330-900 nm and 900-1700 nm, respectively. Both portable systems used identical fiber-optic probe geometry throughout all of the measurements. The core diameters for illuminating and collecting fibers were 400 and 200 {micro}m, respectively, with center-to-center separation of 350 {micro}m. The probe was placed in optical contact with the tissue under investigation. Biopsies from lesions were analyzed by two standard histopathological procedures. Taking into account only the biopsied lesions, UV-visible ESS showed distinct spectral correlation for 11/13 lesions. The NIR-ESS correlated well with 12/13 lesions correctly. The results of these experiments showed that UV-visible and NIR-ESS have the potential to classify benign and malignant skin lesions, with encouraging agreement to that provided by standard histopathological examination. These initial results show potential for ESS based diagnosis of pigmented skin lesions, but further trials are required in order to substantiate the technique.

  4. Chapter VIII Automated Overlay of Infrared

    E-Print Network [OSTI]

    Hopgood, Adrian

    166 Chapter VIII Automated Overlay of Infrared and Visual Medical Images G. Schaefer Aston written permission of IGI Global is prohibited. AbstrAct Medical infrared imaging captures the temperature a useful diagnostic visualisation for the clinician. #12;167 Automated Overlay of Infrared and Visual

  5. Satellite Infrared Soundings From NOAA Spacecraft

    E-Print Network [OSTI]

    NOAA Tec / Satellite Infrared Soundings From NOAA Spacecraft #12;U.S. DEPARTMENT OF COMMERCE Infrared Soundings From NOAA Spacecraft L. M. McMillin D. Q. Wark J. M. Siomkajlo P. G. Abel A. Werbowetzki. E. Bittner C. M. Hayden #12;UDC 551.507.362.2:551.508.2:551.501.7:535-1 Physics Infrared radiation

  6. Infrared Catastrophe for Nelson's Model Masao Hirokawa

    E-Print Network [OSTI]

    Infrared Catastrophe for Nelson's Model Masao Hirokawa Department of Mathematics, Okayama University, 700­8530 Okayama, Japan Abstract We study the infrared catastrophe for Nelson's Hamiltonian general conditions. 1 Introduction The purpose of this study is to investigate the infrared catastrophe

  7. Enhancement of near-infrared absorption in graphene with metal gratings

    SciTech Connect (OSTI)

    Zhao, B.; Zhang, Z. M., E-mail: zhuomin.zhang@me.gatech.edu [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Zhao, J. M. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); School of Energy Science and Engineering, Harbin Institute of Technology, Harbin (China)

    2014-07-21T23:59:59.000Z

    Graphene has been demonstrated as a good candidate for ultrafast optoelectronic devices. However, graphene is essentially transparent in the visible and near infrared with an absorptivity of 2.3%, which has largely limited its application in photon detection. This Letter demonstrates that the absorptance in a monatomic graphene layer can be greatly enhanced to nearly 70%, thanks to the localized strong electric field resulting from magnetic resonances in deep metal gratings. Furthermore, the resonance frequency is essentially not affected by the additional graphene layer. The method presented here may benefit the design of next-generation graphene-based optical and optoelectronic devices.

  8. Visible light emitting vertical cavity surface emitting lasers

    DOE Patents [OSTI]

    Bryan, R.P.; Olbright, G.R.; Lott, J.A.; Schneider, R.P. Jr.

    1995-06-27T23:59:59.000Z

    A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of {lambda}/2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In{sub z}(Al{sub y}Ga{sub 1{minus}y}){sub 1{minus}z}P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m {lambda}/2n{sub eff} where m is an integer and n{sub eff} is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of {lambda}/n, typically within the green to red portion of the visible spectrum. 10 figs.

  9. Fiber optic interferometry: Statistics of visibility and closure phase

    E-Print Network [OSTI]

    E. Tatulli; A. Chelli

    2005-08-19T23:59:59.000Z

    Interferometric observations with three telescopes or more provide two observables: closure phase information together with visibilities measurements. When using single-mode interferometers, both observables have to be redefined in the light of the coupling phenomenon betwe en the incoming wavefront and the fiber. We introduce in this paper the estimator of both so-called modal visibility and modal closure phase. Then, we compute the statistics of the two observables in presence of partial correction by Adaptive Optics. From this theoretical analysis, data reduction process using classical least square minimization is investigated. In the framework of the AMBER instrument, the three beams recombiner of the VLTI, we simulate the observation of a single Gaussian source and we study the performances of the interferometer in terms of diameter measurements. We show that the observation is optimized, i.e. that the Signal to Noise Ratio (SNR) of the diameter is maximal, when the full width half maximum (FWHM) of the source is roughly 1/2 of the mean resolution of the interferometer. We finally point out that in the case of an observation with 3 telescopes, neglecting the correlation between the measurements leads to overestimate the SNR by a factor of $\\sqrt{2}$. We infer that in any cases, this value is an upper limit.

  10. Visible light emitting vertical cavity surface emitting lasers

    DOE Patents [OSTI]

    Bryan, Robert P. (Boulder, CO); Olbright, Gregory R. (Boulder, CO); Lott, James A. (Albuquerque, NM); Schneider, Jr., Richard P. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of .lambda./2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In.sub.z (Al.sub.y Ga.sub.1-y).sub.1-z P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m .lambda./2n.sub.eff where m is an integer and n.sub.eff is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of .lambda./n, typically within the green to red portion of the visible spectrum.

  11. Highlights: Optical/NIR Spectroscopy of Ultraluminous Infrared Galaxies

    E-Print Network [OSTI]

    S. Veilleux

    1999-03-14T23:59:59.000Z

    This paper reviews the results from recent optical and near-infrared spectroscopic studies of ultraluminous infrared galaxies.

  12. Infra-Red Surface-Plasmon-Resonance technique for biological studies

    E-Print Network [OSTI]

    V. Lirtsman; M. Golosovsky; D. Davidov

    2007-11-18T23:59:59.000Z

    We report on a Surface-Plasmon-Resonance (SPR) technique based on Fourier -Transform - Infra - Red (FTIR) spectrometer. In contrast to the conventional surface plasmon technique, operating at a fixed wavelength and a variable angle of incidence, our setup allows the wavelength and the angle of incidence to be varied simultaneously. We explored the potential of the SPR technique in the infrared for biological studies involving aqueous solutions. Using computer simulations, we found the optimal combination of parameters (incident angle, wavelength) for performing this task. Our experiments with physiologically important glucose concentrations in water and in human plasma verified our computer simulations. Importantly, we demonstrated that the sensitivity of the SPR technique in the infrared range is not lower and in fact is even higher than that for visible light. We emphasize the advantages of infra red SPR for studying glucose and other biological molecules in living cells.

  13. Mid-infrared response of reduced graphene oxide and its high-temperature coefficient of resistance

    SciTech Connect (OSTI)

    Liang, Haifeng, E-mail: hfliang2004@gmail.com [Key Laboratory of Optical Measurement and Thin Film of Shaanxi Province, Xian Technological University, Xian 710032 (China)

    2014-10-15T23:59:59.000Z

    Much effort has been made to study the formation mechanisms of photocurrents in graphene and reduced graphene oxide films under visible and near-infrared light irradiation. A built-in field and photo-thermal electrons have been applied to explain the experiments. However, much less attention has been paid to clarifying the mid-infrared response of reduced graphene oxide films at room temperature. Thus, mid-infrared photoresponse and annealing temperature-dependent resistance experiments were carried out on reduced graphene oxide films. A maximum photocurrent of 75 ?A was observed at room temperature, which was dominated by the bolometer effect, where the resistance of the films decreased as the temperature increased after they had absorbed light. The electrons localized in the defect states and the residual oxygen groups were thermally excited into the conduction band, forming a photocurrent. In addition, a temperature increase of 2 C for the films after light irradiation for 2 minutes was observed using absorption power calculations. This work details a way to use reduced graphene oxide films that contain appropriate defects and residual oxygen groups as bolometer-sensitive materials in the mid-infrared range.

  14. Ferroelectric infrared detector and method

    DOE Patents [OSTI]

    Lashley, Jason Charles (Sante Fe, NM); Opeil, Cyril P. (Chestnut Hill, MA); Smith, James Lawrence (Los Alamos, NM)

    2010-03-30T23:59:59.000Z

    An apparatus and method are provided for sensing infrared radiation. The apparatus includes a sensor element that is positioned in a magnetic field during operation to ensure a .lamda. shaped relationship between specific heat and temperature adjacent the Curie temperature of the ferroelectric material comprising the sensor element. The apparatus is operated by inducing a magnetic field on the ferroelectric material to reduce surface charge on the element during its operation.

  15. Multi-channel infrared thermometer

    DOE Patents [OSTI]

    Ulrickson, Michael A. (East Windsor, NJ)

    1986-01-01T23:59:59.000Z

    A device for measuring the two-dimensional temperature profile of a surface comprises imaging optics for generating an image of the light radiating from the surface; an infrared detector array having a plurality of detectors; and a light pipe array positioned between the imaging optics and the detector array for sampling, transmitting, and distributing the image over the detector surfaces. The light pipe array includes one light pipe for each detector in the detector array.

  16. Navajo Generating Station and Air Visibility Regulations: Alternatives and Impacts

    SciTech Connect (OSTI)

    Hurlbut, D. J.; Haase, S.; Brinkman, G.; Funk, K.; Gelman, R.; Lantz, E.; Larney, C.; Peterson, D.; Worley, C.; Liebsch, E.

    2012-01-01T23:59:59.000Z

    Pursuant to the Clean Air Act, the U.S. Environmental Protection Agency (EPA) announced in 2009 its intent to issue rules for controlling emissions from Navajo Generating Station that could affect visibility at the Grand Canyon and at several other national parks and wilderness areas. The final rule will conform to what EPA determines is the best available retrofit technology (BART) for the control of haze-causing air pollutants, especially nitrogen oxides. While EPA is ultimately responsible for setting Navajo Generating Station's BART standards in its final rule, it will be the U.S. Department of the Interior's responsibility to manage compliance and the related impacts. This study aims to assist both Interior and EPA by providing an objective assessment of issues relating to the power sector.

  17. Infrared emitting device and method

    DOE Patents [OSTI]

    Kurtz, S.R.; Biefeld, R.M.; Dawson, L.R.; Howard, A.J.; Baucom, K.C.

    1997-04-29T23:59:59.000Z

    The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region. Examples have been set forth showing embodiments of the present invention as surface- and edge-emitting light emitting diodes (LEDs), an optically-pumped semiconductor laser, and an electrically-injected semiconductor diode laser. The light emission from each of the infrared emitting devices of the present invention is in the midwave infrared region of the spectrum from about 2 to 6 microns. 8 figs.

  18. ARM: Shortwave Array Spectroradiometer-Hemispheric, VISible channel, low-sun angles [a0 data is uncalibrated

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Flynn, Connor

    Shortwave Array Spectroradiometer-Hemispheric, VISible channel, low-sun angles [a0 data is uncalibrated

  19. ARM: Shortwave Array Spectroradiometer-Hemispheric, VISible channel, high-sun angles [a0 data is uncalibrated

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Flynn, Connor

    Shortwave Array Spectroradiometer-Hemispheric, VISible channel, high-sun angles [a0 data is uncalibrated

  20. Visible light photocatalytic activity in nitrogen-doped TiO{sub 2} nanobelts

    SciTech Connect (OSTI)

    De Nyago Tafen; Lewis, James P. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Wang Jin; Wu Nianqiang [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, West Virginia 26506 (United States)

    2009-03-02T23:59:59.000Z

    We present a comprehensive experimental and theoretical study of the electronic properties and photocatalytic activity of nitrogen-doped anatase TiO{sub 2} nanobelts. UV-visible spectra show enhanced absorption in the visible light range for nitrogen-doped nanobelts compared to the pristine sample. The nitrogen-doped nanobelts exhibit improved photocatalytic activity compared to the pristine sample upon visible light irradiation. Furthermore, the incorporation of nitrogen introduces localized states in the band gap.

  1. Passive infrared bullet detection and tracking

    DOE Patents [OSTI]

    Karr, Thomas J. (Alamo, CA)

    1997-01-01T23:59:59.000Z

    An apparatus and method for passively detecting a projectile such as, for example, a bullet using a passive infrared detector. A passive infrared detector is focused onto a region in which a projectile is expected to be located. Successive images of infrared radiation in the region are recorded. Background infrared radiation present in the region is suppressed such that second successive images of infrared radiation generated by the projectile as the projectile passes through the region are produced. A projectile path calculator determines the path and other aspects of the projectile by using the second successive images of infrared radiation generated by the projectile. The present invention, in certain embodiments, also determines the origin of the path of the projectile and takes a photograph of the area surrounding the origin and/or fires at least one projectile at the area surrounding the origin of the path of the projectile.

  2. Passive infrared bullet detection and tracking

    DOE Patents [OSTI]

    Karr, T.J.

    1997-01-21T23:59:59.000Z

    An apparatus and method for passively detecting a projectile such as, for example, a bullet using a passive infrared detector. A passive infrared detector is focused onto a region in which a projectile is expected to be located. Successive images of infrared radiation in the region are recorded. Background infrared radiation present in the region is suppressed such that second successive images of infrared radiation generated by the projectile as the projectile passes through the region are produced. A projectile path calculator determines the path and other aspects of the projectile by using the second successive images of infrared radiation generated by the projectile. The present invention, in certain embodiments, also determines the origin of the path of the projectile and takes a photograph of the area surrounding the origin and/or fires at least one projectile at the area surrounding the origin of the path of the projectile. 9 figs.

  3. Infra-red signature neutron detector

    DOE Patents [OSTI]

    Bell, Zane William (Oak Ridge, TN) [Oak Ridge, TN; Boatner, Lynn Allen (Oak Ridge, TN) [Oak Ridge, TN

    2009-10-13T23:59:59.000Z

    A method of detecting an activator, the method including impinging with an activator a receptor material that includes a photoluminescent material that generates infrared radiation and generation a by-product of a nuclear reaction due to the activator impinging the receptor material. The method further includes generating light from the by-product via the Cherenkov effect, wherein the light activates the photoluminescent material so as to generate the infrared radiation. Identifying a characteristic of the activator based on the infrared radiation.

  4. Infrared regularization with vector mesons and baryons

    E-Print Network [OSTI]

    P. C. Bruns; Ulf-G. Meiner

    2008-08-23T23:59:59.000Z

    We extend the method of infrared regularization to spin-1 fields coupled to baryons. As an application, we discuss the axial form factor of the nucleon.

  5. Parameterization of Infrared Absorption in Midlatitude Cirrus Clouds

    SciTech Connect (OSTI)

    Sassen, Kenneth; Wang, Zhien; Platt, C.M.R.; Comstock, Jennifer M.

    2003-01-01T23:59:59.000Z

    Employing a new approach based on combined Raman lidar and millimeter-wave radar measurements and a parameterization of the infrared absorption coefficient {sigma}{sub a}(km{sup -1}) in terms of retrieved cloud microphysics, we derive a statistical relation between {sigma}{sub a} and cirrus cloud temperature. The relations {sigma}{sub a} = 0.3949 + 5.3886 x 10{sup -3} T + 1.526 x 10{sup -5} T{sup 2} for ambient temperature (T,{sup o}C), and {sigma}{sub a} = 0.2896 + 3.409 x 10{sup -3} T{sub m} for midcloud temperature (T{sub m}, {sup o}C), are found using a second order polynomial fit. Comparison with two {sigma}{sub a} versus T{sub m} relations obtained primarily from midlatitude cirrus using the combined lidar/infrared radiometer (LIRAD) approach reveals significant differences. However, we show that this reflects both the previous convention used in curve fitting (i. e., {sigma}{sub a} {yields} 0 at {approx} 80 C), and the types of clouds included in the datasets. Without such constraints, convergence is found in the three independent remote sensing datasets within the range of conditions considered valid for cirrus (i.e., cloud optical depth {approx} 3.0 and T{sub m} < {approx}20 C). Hence for completeness we also provide reanalyzed parameterizations for a visible extinction coefficient {sigma}{sub a} versus T{sub m} relation for midlatitude cirrus, and a data sample involving cirrus that evolved into midlevel altostratus clouds with higher optical depths.

  6. A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs

    E-Print Network [OSTI]

    Absil, O; Merand, A; Augereau, J -C; Foresto, V Coude du; Defrere, D; Kervella, P; Aufdenberg, J P; Desort, M; Ehrenreich, D; Lagrange, A -M; Montagnier, G; Olofsson, J; Brummelaar, T A ten; McAlister, H A; Sturmann, J; Sturmann, L; Turner, N H

    2008-01-01T23:59:59.000Z

    High-precision interferometric observations of six early-type main sequence stars known to harbour cold debris discs have been obtained in the near-infrared K band with the FLUOR instrument at the CHARA Array. The measured squared visibilities are compared to the expected visibility of the stellar photospheres based on theoretical photospheric models taking into account rotational distortion, searching for potential visibility reduction at short baselines due to circumstellar emission. Our observations bring to light the presence of resolved circumstellar emission around one of the six target stars (zeta Aql) at the 5 sigma level. The morphology of the emission source cannot be directly constrained because of the sparse spatial frequency sampling of our interferometric data. Using complementary adaptive optics observations and radial velocity measurements, we find that the presence of a low-mass companion is a likely origin for the excess emission. The potential companion has a K-band contrast of four magnitu...

  7. Compensated infrared absorption sensor for carbon dioxide and other infrared absorbing gases

    DOE Patents [OSTI]

    Owen, Thomas E.

    2005-11-29T23:59:59.000Z

    A gas sensor, whose chamber uses filters and choppers in either a semicircular geometry or annular geometry, and incorporates separate infrared radiation filters and optical choppers. This configuration facilitates the use of a single infrared radiation source and a single detector for infrared measurements at two wavelengths, such that measurement errors may be compensated.

  8. A distributed Approach for Access and Visibility Task under Ergonomic Constraints with a Manikin

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    A distributed Approach for Access and Visibility Task under Ergonomic Constraints with a Manikin, to assess an efficient path planner for a manikin for access and visibility task under ergonomic constraints a way to explore areas such as maintenance or ergonomics of the product that were traditionally ignored

  9. All-optical Fog Sensor for Determining the Fog Visibility Range in Optical Wireless Communication Links

    E-Print Network [OSTI]

    Haddadi, Hamed

    All-optical Fog Sensor for Determining the Fog Visibility Range in Optical Wireless Communication is to use an all optical based fog sensor to study the atmospheric visibility of fog and its constituents on the optical wireless communication (OWC) links in a controlled laboratory test-bid. The fog sensor measures

  10. Photocatalytic Oxidation of Aqueous Organic Contaminants by Semiconductors using Visible Light Radiation

    E-Print Network [OSTI]

    Meyers, Steven D.

    Photocatalytic Oxidation of Aqueous Organic Contaminants by Semiconductors using Visible Light semiconductor, InVO4, mechanically alloyed to TiO2, to shift photo-initiation into the visible range. 3, the ratio of semiconductors had no significant impact on the reaction rate. Long term goal - develop

  11. Increased Climate Variability Is More Visible Than Global Warming: A General

    E-Print Network [OSTI]

    Kreinovich, Vladik

    Increased Climate Variability Is More Visible Than Global Warming: A General System@utep.edu Abstract While global warming is a statistically confirmed long-term phenomenon, its most visible than the global warming itself. 1 Formulation of the Problem What is global warming. The term "global

  12. Hybrid optics for the visible produced by bulk casting of sol-gel glass using diamond-turned molds

    SciTech Connect (OSTI)

    Bernacki, B.E.; Miller, A.C.; Maxey, L.C.; Cunningham, J.P. [Oak Ridge National Lab., TN (United States); Moreshead, W.V.; Nogues, J.L.R. [Geltech Inc., Alachua, FL (United States)

    1995-07-01T23:59:59.000Z

    Recent combinations of diffractive and refractive functions in the same optical component allow designers additional opportunities to make systems more compact and enhance performance. This paper describes a research program for fabricating hybrid refractive/diffractive components from diamond-turned molds using the bulk casting of sol-gel silica glass. The authors use the complementary dispersive nature of refractive and diffractive optics to render two-color correction in a single hybrid optical element. Since diamond turning has matured as a deterministic manufacturing technology, techniques previously suitable only in the infrared are now being applied to components used at visible wavelengths. Thus, the marriage of diamond turning and sol-gel processes offers a cost-effective method for producing highly customized and specialized optical components in high quality silica glass. With the sol-gel casting method of replication, diamond-turned mold costs can be shared over many pieces. Diamond turning takes advantage of all of the available degrees of freedom in a single hybrid optical element: aspheric surface to eliminate spherical aberration, kinoform surface for control of primary chromatic aberration, and the flexibility to place the kinoform on non-planar surfaces for maximum design flexibility. The authors discuss the critical issues involved in designing the hybrid element, single point diamond-turning the mold, and fabrication in glass using the sol-gel process.

  13. Copper(II) imidazolate frameworks as highly efficient photocatalysts for reduction of CO{sub 2} into methanol under visible light irradiation

    SciTech Connect (OSTI)

    Li, Jingtian; Luo, Deliang; Yang, Chengju; He, Shiman; Chen, Shangchao; Lin, Jiawei; Zhu, Li; Li, Xin, E-mail: xinliscau@yahoo.com

    2013-07-15T23:59:59.000Z

    Three copper(II) imidazolate frameworks were synthesized by a hydrothermal (or precipitation) reaction. The catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, transmission electron microscopy (TEM), ultravioletvisible spectroscopy (UVvis), Fourier transform infrared spectra (FTIR), thermogravimetry (TG). Meanwhile, the photocatalytic activities of the samples for reduction of CO{sub 2} into methanol and degradation of methylene blue (MB) under visible light irradiation were also investigated. The results show that the as-prepared samples exhibit better photocatalytic activities for the reduction of carbon dioxide into methanol with water and degradation of MB under visible light irradiation. The orthorhombic copper(II) imidazolate frameworks with a band gap of 2.49 eV and green (G) color has the best photocatalytic activity for reduction of CO{sub 2} into methanol, 1712.7 ?mol/g over 5 h, which is about three times as large as that of monoclinic copper(II) imidazolate frameworks with a band gap 2.70 eV and blue (J) color. The degradation kinetics of MB over three photocatalysts fitted well to the apparent first-order rate equation and the apparent rate constants for the degradation of MB over G, J and P (with pink color) are 0.0038, 0.0013 and 0.0016 min{sup ?1}, respectively. The synergistic effects of smallest band gap and orthorhombic crystal phase structure are the critical factors for the better photocatalytic activities of G. Moreover, three frameworks can also be stable up to 250 C. The investigation of Cu-based zeolitic imidazolate frameworks maybe provide a design strategy for a new class of photocatalysts applied in degradation of contaminations, reduction of CO{sub 2}, and even water splitting into hydrogen and oxygen under visible light. - Graphical abstract: Carbon dioxide was reduced into methanol with water over copper(II) imidazolate frameworks under visible light irradiation. - Highlights: Three copper(II) imidazolate frameworks were first applied in the photo-reduction of CO{sub 2}. The photocatalytic activities of the frameworks depend on their band gap and phase structures. The photocatalytic activity of orthorhombic frameworks is 3 times that of monoclinic frameworks. The degradation kinetics of MB over three photocatalysts followed the first-order rate equation. The largest yield for reduction of CO{sub 2} into methanol on green framworks was 1712.7 ?mol/g over 5 h.

  14. Infrared fixed point in quantum Einstein gravity

    E-Print Network [OSTI]

    S. Nagy; J. Krizsan; K. Sailer

    2012-06-28T23:59:59.000Z

    We performed the renormalization group analysis of the quantum Einstein gravity in the deep infrared regime for different types of extensions of the model. It is shown that an attractive infrared point exists in the broken symmetric phase of the model. It is also shown that due to the Gaussian fixed point the IR critical exponent $\

  15. A CATALOG OF GALACTIC INFRARED CARBON STARS

    SciTech Connect (OSTI)

    Chen, P. S. [National Astronomical Observatories/Yunnan Observatory and Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 (China); Yang, X. H., E-mail: iraspsc@yahoo.com.cn, E-mail: yangxh@cqu.edu.cn [Department of Physics, Chongqing University, Chongqing 400044 (China)

    2012-02-15T23:59:59.000Z

    We collected almost all of the Galactic infrared carbon stars (IRCSs) from literature published up to the present to organize a catalog of 974 Galactic IRCSs in this paper. Some of their photometric properties in the near-, mid-, and far-infrared are discussed.

  16. Infrared Fiber Optics James A. Harrington

    E-Print Network [OSTI]

    1 Infrared Fiber Optics James A. Harrington Ceramic & Materials Engineering Rutgers University Piscataway, NJ 08854-8065 1. Introduction Infrared (IR) optical fibers may be defined as fiber optics IR fiber optics may logically be divided into three broad categories: glass, crystalline, and hollow

  17. Infrared scintillation yield in gaseous and liquid argon

    E-Print Network [OSTI]

    A. Buzulutskov; A. Bondar; A. Grebenuk

    2011-04-19T23:59:59.000Z

    The study of primary and secondary scintillations in noble gases and liquids is of paramount importance to rare-event experiments using noble gas media. In the present work, the scintillation yield in gaseous and liquid Ar has for the first time been measured in the near infrared (NIR) and visible region, both for primary and secondary (proportional) scintillations, using Geiger-mode avalanche photodiodes (G-APDs) and pulsed X-ray irradiation. The primary scintillation yield of the fast component was measured to be 17000 photon/MeV in gaseous Ar in the NIR, in the range of 690-1000 nm, and 510 photon/MeV in liquid Ar, in the range of 400-1000 nm. Proportional NIR scintillations (electroluminescence) in gaseous Ar have been also observed; their amplification parameter at 163 K was measured to be 13 photons per drifting electron per kV. Possible applications of NIR scintillations in high energy physics experiments are discussed.

  18. Near Infrared Spectroscopy for Burning Plasma Diagnostic Applications

    SciTech Connect (OSTI)

    Soukhanovskii, V A

    2008-06-18T23:59:59.000Z

    Ultraviolet and visible (UV-VIS, 200-750 nm) atomic spectroscopy of neutral and ion fuel species (H, D, T, Li) and impurities (e.g. He, Be, C, W) is a key element of plasma control and diagnosis on ITER and future magnetically confined burning plasma experiments (BPX). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window and optical fiber transmission under intense neutron and {gamma}-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000 nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can address machine protection and plasma control diagnostic tasks, as well as plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma facing component temperatures.

  19. Infrared Thermography Measurements of Window Thermal Test Specimen Surface Temperatures

    E-Print Network [OSTI]

    Infrared Thermography Measurements of Window Thermal Test Specimen Surface Temperatures Brent T Temperatures of Window Specimens: Infrared Thermography Laboratory Measurements Brent T. Griffith1 , Howdy and cold sides, respectively. Surface temperature maps were compiled using an infrared thermographic system

  20. OPTICAL DIFFERENCE FREQUENCY GENERATION OF FAR INFRARED RADIATION

    E-Print Network [OSTI]

    Morris, J.R.

    2010-01-01T23:59:59.000Z

    Absorption on Far-Infrared Generation IV. V. Comparison withIII CHAPTER IV. PHASE MATCHED FAR-INFRARED GENERATION BY THE1970). CHAPTER IV. PHASE MATCHED FAR-INFRARED GENERATION BY

  1. Polymer-Ceramic MEMS Bimorphs as Thermal Infrared Sensors

    E-Print Network [OSTI]

    Warren, Clinton Gregory

    2010-01-01T23:59:59.000Z

    in response to heating cause by infrared light. In order to70 Heating and cooling of infrared source as measured withto detect the heating and cooling of the infrared source,

  2. Zachar and Naik Principles of Infrared Thermography and

    E-Print Network [OSTI]

    Wisconsin-Milwaukee, University of

    Zachar and Naik 1 Principles of Infrared Thermography and Application for Assessment details the principles of infrared thermography from the underlying theoretical considerations to the physical constraints involved with performing the test. Infrared (IR) thermography testing may be conducted

  3. FY 2006 Infrared Photonics Final Report

    SciTech Connect (OSTI)

    Anheier, Norman C.; Allen, Paul J.; Bernacki, Bruce E.; Ho, Nicolas; Krishnaswami, Kannan; Qiao, Hong (Amy); Schultz, John F.

    2006-12-28T23:59:59.000Z

    Research done by the Infrared Photonics team at Pacific Northwest National Laboratory (PNNL) is focused on developing miniaturized integrated optics and optical fiber processing methods for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications by exploiting the unique optical and material properties of chalcogenide glass. PNNL has developed thin-film deposition capabilities, direct laser writing techniques, infrared photonic device demonstration, holographic optical element design and fabrication, photonic device modeling, and advanced optical metrologyall specific to chalcogenide glass. Chalcogenide infrared photonics provides a pathway to quantum cascade laser (QCL) transmitter miniaturization. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors that are particularly useful for nuclear nonproliferation missions.

  4. Infrared spectroscopy of ionic clusters

    SciTech Connect (OSTI)

    Price, J.M. (California Univ., Berkeley, CA (USA). Dept. of Chemistry Lawrence Berkeley Lab., CA (USA))

    1990-11-01T23:59:59.000Z

    This thesis describes new experiments wherein the infrared vibrational predissociation spectra of a number of mass-selected ionic cluster systems have been obtained and analyzed in the 2600 to 4000 cm{sup {minus}1} region. The species studied include: the hydrated hydronium ions, H{sub 3}O{sup +} (H{sub 2}O){sub 3 {minus}10}, ammoniated ammonium ions, NH{sub 4}{sup +}(NH{sub 3}){sub 1 {minus}10} and cluster ions involving both water and ammonia around an ammonium ion core, (mixed clusters) NH{sub 4}{sup +}(NH{sub 3}){sub n}(H{sub 2}O){sub m} (n+m=4). In each case, the spectra reveal well resolved structures that can be assigned to transitions arising from the vibrational motions of both the ion core of the clusters and the surrounding neutral solvent molecules. 154 refs., 19 figs., 8 tabs.

  5. FY 2005 Infrared Photonics Final Report

    SciTech Connect (OSTI)

    Anheier, Norman C.; Allen, Paul J.; Ho, Nicolas; Krishnaswami, Kannan; Johnson, Bradley R.; Sundaram, S. K.; Riley, Bradley M.; Martinez, James E.; Qiao, Hong (Amy); Schultz, John F.

    2005-12-01T23:59:59.000Z

    Research done by the Infrared Photonics team at Pacific Northwest National Laboratory (PNNL) is focused on developing miniaturized integrated optics for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications by exploiting the unique optical and material properties of chalcogenide glass. PNNL has developed thin-film deposition capabilities, direct laser writing techniques, infrared photonic device demonstration, holographic optical element design and fabrication, photonic device modeling, and advanced optical metrologyall specific to chalcogenide glass. Chalcogenide infrared photonics provides a pathway to quantum cascade laser (QCL) transmitter miniaturization. QCLs provide a viable infrared laser source for a new class of laser transmitters capable of meeting the performance requirements for a variety of national security sensing applications. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors that are particularly useful for nuclear nonproliferation missions. During FY 2005, PNNLs Infrared Photonics research team made measurable progress exploiting the extraordinary optical and material properties of chalcogenide glass to develop miniaturized integrated optics for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications. We investigated sulfur purification methods that will eventually lead to routine production of optical quality chalcogenide glass. We also discovered a glass degradation phenomenon and our investigation uncovered the underlying surface chemistry mechanism and developed mitigation actions. Key research was performed to understand and control the photomodification properties. This research was then used to demonstrate several essential infrared photonic devices, including LWIR single-mode waveguide devices and waveguide couplers. Optical metrology tools were also developed to characterize optical waveguide structures and LWIR optical components.

  6. The Quiescent Accretion Disk in IP Peg at Near-Infrared Wavelengths

    E-Print Network [OSTI]

    C. S. Froning; E. L. Robinson; William F. Welsh; Janet H. Wood

    1999-07-07T23:59:59.000Z

    We present near-infrared, H-band (1.45-1.85 microns) observations of the eclipsing dwarf nova, IP Peg, in quiescence. The light curves are composed of ellipsoidal variations from the late-type secondary star and emission from the accretion disk and the bright spot. The light curves have two eclipses: a primary eclipse of the accretion disk and the bright spot by the companion star, and a secondary eclipse of the companion star by the disk. The ellipsoidal variations of the secondary star were modeled and subtracted from the data. The resulting light curve shows a pronounced double-hump variation. The double-hump profile resembles those seen in the light curves of WZ Sge and AL Com and likely originates in the accretion disk. The primary eclipse was modeled using maximum entropy disk mapping techniques. The accretion disk has a flat intensity distribution and a cool brightness temperature (Tbr=3000 K) in the near-infrared. Superimposed on the face of the disk is the bright spot (Tbr=10,000 K); the position of the bright spot is different from the observed range of visible bright spot positions. The near-infrared accretion disk flux is dominated by optically thin emission. The secondary eclipse indicates the presence of some occulting medium in the disk, but the eclipse depth is too shallow to be caused by a fully opaque accretion disk.

  7. Enhanced visible-light absorption of mesoporous TiO2 by co-doping with transition-metal/nitrogen ions

    SciTech Connect (OSTI)

    Mathis, John [Embry-Riddle Aeronautical University; Bi, Zhonghe [ORNL; Bridges, Craig A [ORNL; Kidder, Michelle [ORNL; Paranthaman, Mariappan Parans [ORNL

    2013-01-01T23:59:59.000Z

    Titanium (IV) oxide, TiO2, has been the object of intense scrutiny for energy applications. TiO2 is inexpensive, non-toxic, and has excellent corrosion resistance when exposed to electrolytes. A major drawback preventing the widespread use TiO2 for photolysis is its relatively large band gap of ~3eV. Only light with wavelengths shorter than 400 nm, which is in the ultraviolet portion of the spectrum, has sufficient energy to be absorbed. Less than 14 percent of the solar irradiation reaching the earth s surface has energy exceeding this band gap. Adding dopants such as transition metals has long been used to reduce the gap and increase photocatalytic activity by accessing the visible part of the solar spectrum. The degree to which the band gap is reduced using transition metals depends in part on the overlap of the d-orbitals of the transition metals with the oxygen p-orbitals. Therefore, doping with anions such as nitrogen to modify the cation-anion orbital overlap is another approach to reduce the gap. Recent studies suggest that using a combination of transition metals and nitrogen as dopants is more effective at introducing intermediate states within the band gap, effectively narrowing it. Here we report the synthesis of mesoporous TiO2 spheres, co-doped with transition metals and nitrogen that exhibit a nearly flat absorbance response across the visible spectrum extending into the near infrared.

  8. Automated High-Pressure Titration System with In Situ Infrared...

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

    High-Pressure Titration System with In Situ Infrared Spectroscopic Detection. Automated High-Pressure Titration System with In Situ Infrared Spectroscopic Detection. Abstract: A...

  9. Analysis of Rotational Structure in the High-Resolution Infrared...

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

    Rotational Structure in the High-Resolution Infrared Spectrum and Assignment of Vibrational Fundamentals of Analysis of Rotational Structure in the High-Resolution Infrared...

  10. Infrared Thermography (IRT) Working Group | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Infrared Thermography (IRT) Working Group Infrared Thermography (IRT) Working Group Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado...

  11. Detection of Low Volatility Organic Analytes on Soils Using Infrared...

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

    Low Volatility Organic Analytes on Soils Using Infrared Reflection Spectroscopy. Detection of Low Volatility Organic Analytes on Soils Using Infrared Reflection Spectroscopy....

  12. Quantitative Infrared Intensity Studies of Vapor-PhaseGlyoxal...

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

    Infrared Intensity Studies of Vapor-Phase Glyoxal,Methylglyoxal, and 2,3-Butanedione (Diacetyl) with Quantitative Infrared Intensity Studies of Vapor-Phase Glyoxal,Methylglyoxal,...

  13. atmospheric infrared sounder: Topics by E-print Network

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

    Infrared Atmospheric Sounding Interferometer (IASI)Advanced Very High Resolution Radiometer (AVHRR Li, Jun 4 Ozone Profile Retrieval from an Advanced Infrared Sounder:...

  14. High Throughput Operando Studies using Fourier Transform Infrared...

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

    Throughput Operando Studies using Fourier Transform Infrared Imaging and Raman Spectroscopy. High Throughput Operando Studies using Fourier Transform Infrared Imaging and Raman...

  15. Identification of carbon sensitization for the visible-light photocatalytic titanium oxide

    SciTech Connect (OSTI)

    Chen, Y. J.; Jhan, G. Y.; Cai, G. L.; Lin, C. S.; Wong, M. S.; Ke, S.-C.; Lo, H. H.; Cheng, C. L.; Shyue, J.-J. [Department of Materials Science and Engineering, National Dong Hwa University, Shoufeng, Hualien 97401, Taiwan and Graduate Institute of Optoelectronics Engineering, Shoufeng, Hualien 97401, Taiwan (China); Department of Physics, National Dong Hwa University, Shoufeng, Hualien 97401, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan (China)

    2010-07-15T23:59:59.000Z

    The authors successfully synthesized titanium oxide (TiO{sub 2}) nanopowder with visible-light photocatalytic ability by low-pressure flat-flame metal organic chemical vapor condensation method. In order to confirm that carbon doping is a viable mechanism for the visible-light absorption of the powder prepared by this method, they modify the process by total exclusion of nitrogen usage to eliminate the nitrogen doping possibility. Since nitrogen is avoided in the process, the visible-light absorption cannot be due to nitrogen doping. They also found that the nanopowder formed has a single phase of anatase. Thus the nanopowder does not have anatase/rutile interface, and the authors can eliminate the possibility of visible-light absorption by the anatase/rutile interface. The visible-light absorption should thus be resort to the carbon doping. X-ray photoelectron spectroscopy studies show the presence of several carbon related bonds except Ti-C bond. This suggests that the carbon does not incorporate into the TiO{sub 2} crystal and should locate on the surface of the nanopowder. Thus the carbon species act as a visible-light sensitizer for the TiO{sub 2} as a photocatalyst. Among all carbon bonds the C-C bond is believed to be responsible for the light absorption, since all other carbon related bonds are not chromophores. The visible-light TiO{sub 2} photocatalysis induced by carbon doping is confirmed and explained.

  16. Assessing the potential visibility benefits of Clean Air Act Title IV emission reductions

    SciTech Connect (OSTI)

    Trexler, E.C. Jr. [USDOE, Washington, DC (United States); Shannon, J.D. [Argonne National Lab., IL (United States)

    1995-06-01T23:59:59.000Z

    Assessments are made of the benefits of the 1990 Clean Air Act Title IV (COVE), Phase 2, SO2 and NOX reduction provisions, to the visibility in typical eastern and western Class 1 areas. Probable bands of visibility impairment distribution curves are developed for Shenandoah National Park, Smoky Mountain National Park and the Grand Canyon National Park, based on the existing emissions, ``Base Case``, and for the COVE emission reductions, ``CAAA Case``. Emission projections for 2010 are developed with improved versions of the National Acid Precipitation Assessment Program emission projection models. Source-receptor transfer matrices created with the Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model are used with existing emission inventories and with the emission projections to calculate atmospheric concentrations of sulfate and nitrate at the receptors of interest for existing and projected emission scenarios. The Visibility Assessment Scoping Model (VASM) is then used to develop distributions of visibility impairment. VASM combines statistics of observed concentrations of particulate species and relative humidity with ASTRAP calculations of the relative changes in atmospheric sulfate and nitrate particulate concentrations in a Monte Carlo approach to produce expected distributions of hourly particulate concentrations and RH. Light extinction relationships developed in theoretical and field studies are then used to calculate the resulting distribution of visibility impairment. Successive Monte Carlo studies are carried out to develop sets of visibility impairment distributions with and without the COVE emission reductions to gain insight into the detectability of expected visibility improvements.

  17. Infrared-optical spectroscopy of transparent conducting perovskite (La,Ba)SnO{sub 3} thin films

    SciTech Connect (OSTI)

    Seo, Dongmin; Yu, Kwangnam; Jun Chang, Young; Choi, E. J., E-mail: echoi@uos.ac.kr [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of); Sohn, Egon; Hoon Kim, Kee [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-01-13T23:59:59.000Z

    We have performed optical transmission, reflection, spectroscopic ellipsometry, and Hall effect measurements on the electron-doped La{sub x}Ba{sub 1x}SnO{sub 3} (x?=?0.04) transparent thin films. From the infrared Drude response and plasma frequency analysis we determine the effective mass of the conducting electron m*?=?0.35m{sub 0}. In the visible-UV region the optical band gap shifts to high energy in (La,Ba)SnO{sub 3} by 0.18?eV compared with undoped BaSnO{sub 3} which, in the context of the Burstein-Moss analysis, is consistent with the infrared-m*. m* of BaSnO{sub 3} is compared with other existing transparent conducting oxides (TCO), and implication on search for high-mobility TCO compounds is discussed.

  18. The Infrared Luminosity of Galaxy Clusters

    E-Print Network [OSTI]

    Martin Giard; Ludovic Montier; Etienne Pointecouteau; Ellen Simmat

    2008-08-28T23:59:59.000Z

    The aim of this study is to quantify the infrared luminosity of clusters as a function of redshift and compare this with the X-ray luminosity. This can potentially constrain the origin of the infrared emission to be intracluster dust and/or dust heated by star formation in the cluster galaxies. We perform a statistical analysis of a large sample of galaxy clusters selected from existing databases and catalogues.We coadd the infrared IRAS and X-ray RASS images in the direction of the selected clusters within successive redshift intervals up to z = 1. We find that the total infrared luminosity is very high and on average 20 times higher than the X-ray luminosity. If all the infrared luminosity is to be attributed to emission from diffuse intracluster dust, then the IR to X-ray ratio implies a dust-to-gas mass abundance of 5e-4. However, the infrared luminosity shows a strong enhancement for 0.1 infrared luminosity that we measure is generated by the ongoing star formation in the member galaxies. From theoretical predictions calibrated on extinction measurements (dust mass abundance equal to 1e-5), we expect only a minor contribution, of a few percent, from intracluster dust.

  19. ISO and the Cosmic Infrared Background

    E-Print Network [OSTI]

    Herve Dole

    2002-12-12T23:59:59.000Z

    ISO observed, for the first time to such a high sensitivity level, the mid- and far-infrared universe. A Number of deep surveys were performed to probe the cosmological evolution of galaxies. In this review, I discuss and summarize results of mid-infrared ISOCAM and far-infrared ISOPHOT surveys, and show how our vision of the extragalactic infrared universe has become more accurate. In particular, ISO allowed us to resolve into sources a significant fraction of the Cosmic Infrared Background (CIB) in the mid-infrared, and to probe a fainter population in the far-infrared with the detection of the CIB fluctuations. Together with other wavelength data sets, the nature of ISO galaxies is now in the process of being understood. I also show that the high quality of the ISO data put strong constraints on the scenarios of galaxy evolution. This induced a burst in the development of models, yielding to a more coherent picture of galaxy evolution. I finally emphasize the potential of the ISO data archive in the field of observational cosmology, and describe the next steps, in particular the forthcoming cosmological surveys to be carried out by SIRTF.

  20. Using the visibility complex for radiosity computation Rachel Orti Fredo Durand Stephane Rivi`ere Claude Puech

    E-Print Network [OSTI]

    Boyer, Edmond

    to be strictly recomputed. In computational geometry, a data structure called the visibility complex has recentlyUsing the visibility complex for radiosity computation Rachel Orti Fredo Durand Stephane Rivi in those calculations. We propose the use of the visibility complex for radiosity calculations

  1. The gas-rich circumbinary disk of HR 4049. I. A detailed study of the mid-infrared spectrum

    SciTech Connect (OSTI)

    Malek, S. E.; Cami, J., E-mail: sarahemalek@gmail.com, E-mail: jcami@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada)

    2014-01-01T23:59:59.000Z

    We present a detailed analysis of the mid-infrared spectrum of the peculiar evolved object HR 4049. The full Spitzer-IRS high-resolution spectrum shows a wealth of emission with prominent features from CO{sub 2} and H{sub 2}O and possible contributions from HCN and OH. We model the molecular emission and find that it originates from a massive (M ? 8 10{sup 3} M {sub ?}), warm (T {sub ex} ? 500 K) and radially extended gas disk that is optically thick at infrared wavelengths. We also report less enrichment in {sup 17}O and {sup 18}O than previously found and a comparison of the Spitzer observations to earlier data obtained by the Short Wavelength Spectrometer on board the Infrared Space Observatory reveals that the CO{sub 2} flux has more than doubled in 10 yr time, indicating active and ongoing chemical evolution in the circumbinary disk. If the gas originates from interaction between the stellar wind and the dust, this suggests that the dust could be oxygen-rich in nature. The molecular gas plays a crucial role in the thermal properties of the circumbinary disk by allowing visible light to heat the dust and then trapping the infrared photons emitted by the dust. This results in higher temperatures and a more homogeneous temperature structure in the disk.

  2. Origin of photoactivity of oxygen-deficient TiO{sub 2} under visible light

    SciTech Connect (OSTI)

    Lo, H.-H.; Gopal, Neeruganti O.; Ke, S.-C. [Department of Physics and Nanotechnology Research Center, National Dong Hwa University, Hualien 974-01, Taiwan (China)

    2009-08-24T23:59:59.000Z

    As it is now well established that oxygen vacancies are spontaneously introduced during nitrogen doping of anatase TiO{sub 2}, there is a lively debate on whether nitrogen dopant or oxygen vacancy contributes to the visible light photoactivity of the doped catalyst. We showed that the coordinately unsaturated Ti site is integral to the visible light photoactivity in anatase oxygen-deficient TiO{sub 2} catalyst. Accordingly, oxygen vacancies may contribute to the visible light photoactivities in N-doped TiO{sub 2} and other nonmetallic ion-doped TiO{sub 2} as well. A redox active visible light photocatalyst has been developed based on oxygen-deficient structure in anatase TiO{sub 2}.

  3. Graviweak Unification in the Visible and Invisible Universe and Inflation from the Higgs Field False Vacuum

    E-Print Network [OSTI]

    C. R. Das; L. V. Laperashvili

    2014-09-16T23:59:59.000Z

    In the present paper we develop the self-consistent $Spin(4,4)$-invariant model of the unification of gravity with weak $SU(2)$ interactions in the assumption of the existence of visible and invisible sectors of the Universe. It was shown that the consequences of the multiple point principle predicting two degenerate vacua in the Standard Model (SM) suggest a theory of Inflation, in which the inflaton field $\\sigma$ starts trapped in a cold coherent state in the "false vacuum" of the Universe at the value of the Higgs field's VEV $v\\sim 10^{18}$ GeV (in the visible world). Then the inflations of the two Higgs doublet fields, visible $\\phi$ and mirror $\\phi'$, lead to the emergence of the SM vacua at the Electroweak scales with the Higgs boson VEVs $v_1\\approx 246$ GeV and $v'_1=\\zeta v_1$ (with $\\zeta \\sim 100$) in the visible and invisible worlds, respectively.

  4. Creating supply chain visibility : a case study on extending Intel's Unit Level Traceability to customers

    E-Print Network [OSTI]

    Kang, Annie

    2012-01-01T23:59:59.000Z

    In an effort to enable supply chain visibility for Intel products, the Customer Unit Level Traceability (ULT) Program was formed to help extend Intel's ULT capability to the customer level. Increased traceability of Intel ...

  5. Molecular Hydrogen in Infrared Cirrus

    E-Print Network [OSTI]

    Kristen Gillmon; J. Michael Shull

    2005-07-25T23:59:59.000Z

    We combine data from our recent FUSE survey of interstellar molecular hydrogen absorption toward 50 high-latitude AGN with COBE-corrected IRAS 100 micron emission maps to study the correlation of infrared cirrus with H2. A plot of the H2 column density vs. IR cirrus intensity shows the same transition in molecular fraction, f_H2, as seen with total hydrogen column density, N_H. This transition is usually attributed to H2 self-shielding, and it suggests that many diffuse cirrus clouds contain H2 in significant fractions, f_H2 = 1-30%. These clouds cover approximately 50% of the northern sky at latitudes b > 30 degrees, at temperature-corrected 100 micron intensities D_100 > 1.5 MJy/sr. The sheetlike cirrus clouds, with hydrogen densities n_H > 30 cm^-3, may be compressed by dynamical processes at the disk-halo interface, and they are conducive to H2 formation on grain surfaces. Exploiting the correlation between N(H2) and 100 micron intensity, we estimate that cirrus clouds at b > 30 contain approximately 3000 M_sun in H2. Extrapolated over the inner Milky Way, the cirrus may contain 10^7 M_sun of H2 and 10^8 M_sun in total gas mass. If elevated to 100 pc, their gravitational potential energy is ~10^53 erg.

  6. Uncooled infrared photon detector and multicolor infrared detection using microoptomechanical sensors

    DOE Patents [OSTI]

    Datskos, Panagiotis G. (Knoxville, TN); Rajic, Solobodan (Knoxville, TN); Datskou, Irene C. (Knoxville, TN)

    1999-01-01T23:59:59.000Z

    Systems and methods for infrared detection are described. An optomechanical photon detector includes a semiconductor material and is based on measurement of a photoinduced lattice strain. A multicolor infrared sensor includes a stack of frequency specific optomechanical detectors. The stack can include one, or more, of the optomechanical photon detectors that function based on the measurement of photoinduced lattice strain. The systems and methods provide advantages in that rapid, sensitive multicolor infrared imaging can be performed without the need for a cooling subsystem.

  7. The effects of air pollution on visibility at Edwards AFB, California

    E-Print Network [OSTI]

    Tongue, Jeffrey Scott

    1987-01-01T23:59:59.000Z

    THE EFFECTS OF AIR POLLUTION ON VISIBILITY AT EDWARDS AFB, CALIFORNIA A Thesis by JEFFREY SCOTT TONGUE Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... May 1987 Major Subject: Meteorology THE EFFECTS OF AIR POLLUTION ON VISIBILITY AT EDWARDS AFB, CALIFORNIA A Thesis by JEFFREY SCOTT TONGUE Approved as to style and content by: Walter K. Henry (Chairman of Committee) Kenneth C. Brundidge...

  8. Infrared Evolution Equations: Method and Applications

    E-Print Network [OSTI]

    B. I. Ermolaev; M. Greco; S. I. Troyan

    2007-04-03T23:59:59.000Z

    It is a brief review on composing and solving Infrared Evolution Equations. They can be used in order to calculate amplitudes of high-energy reactions in different kinematic regions in the double-logarithmic approximation.

  9. Infrared limit in external field scattering

    E-Print Network [OSTI]

    Andrzej Herdegen

    2012-05-17T23:59:59.000Z

    Scattering of electrons/positrons by external classical electromagnetic wave packet is considered in infrared limit. In this limit the scattering operator exists and produces physical effects, although the scattering cross-section is trivial.

  10. Rapid infrared heating of a surface

    DOE Patents [OSTI]

    Sikka, Vinod K. (Oak Ridge, TN); Blue, Craig A. (Concord, TN); Ohriner, Evan Keith (Knoxville, TN)

    2002-01-01T23:59:59.000Z

    High energy flux infrared heaters are used to treat an object having a surface section and a base section such that a desired characteristic of the surface section is physically, chemically, or phasically changed while the base section remains unchanged.

  11. Rapid infrared heating of a surface

    DOE Patents [OSTI]

    Sikka, Vinod K. (Oak Ridge, TN); Blue, Craig A. (Concord, TN); Ohriner, Evan Keith (Knoxville, TN)

    2001-01-01T23:59:59.000Z

    High energy flux infrared heaters are used to treat an object having a surface section and a base section such that a desired characteristic of the surface section is physically, chemically, or phasically changed while the base section remains unchanged.

  12. Science and applications of infrared semiconductor nanocrystals

    E-Print Network [OSTI]

    Geyer, Scott Mitchell

    2010-01-01T23:59:59.000Z

    In this work we study several applications of semiconductor nanocrystals (NCs) with infrared band gaps. In the first half, we explore the physics of two systems with applications in NC based photovoltaics. The physics of ...

  13. Rapid infrared heating of a surface

    DOE Patents [OSTI]

    Sikka, Vinod K.; Blue, Craig A.; Ohriner, Evan Keith

    2003-12-23T23:59:59.000Z

    High energy flux infrared heaters are used to treat an object having a surface section and a base section such that a desired characteristic of the surface section is physically, chemically, or phasically changed while the base section remains unchanged.

  14. The near infrared 12 1 electronic transition

    E-Print Network [OSTI]

    Maier, John Paul

    The near infrared 12 A00 2 X2 A0 1 electronic transition of B3 in a neon matrix Anton Batalov, Jan applying a double reflection technique. The light beam reflects from the metal surface of the substrate

  15. Applying near-infrared spectroscopy (nirs)

    E-Print Network [OSTI]

    Wruck, Eric Michael

    2005-08-29T23:59:59.000Z

    investigated. A recently developed optical imaging technique called near-infrared spectroscopy (NIRS) shows promise for being an acceptable alternative to invasive imaging techniques. NIRS measures correlates of neural activity by assessing hemoglobin...

  16. Synthesis and characterization of infrared quantum dots

    E-Print Network [OSTI]

    Harris, Daniel Kelly

    2014-01-01T23:59:59.000Z

    This thesis focuses on the development of synthetic methods to create application ready quantum dots (QDs) in the infrared for biological imaging and optoelectronic devices. I concentrated primarily on controlling the size ...

  17. Infrared Issues in Graviton Higgs Theory

    E-Print Network [OSTI]

    Srijit Bhattacharjee; Parthasarathi Majumdar

    2013-01-30T23:59:59.000Z

    We investigate the one-loop infrared behaviour of the effective potential in minimally coupled graviton Higgs theory in Minkowski background. The gravitational analogue of one loop Coleman Weinberg effective potential turns out to be complex, the imaginary part indicating an infrared instability. This instability is traced to a tachyonic pole in the graviton propagator for constant Higgs fields. Physical implications of this behaviour are studied. We also discuss physical differences between gauge theories coupled to Higgs fields and graviton Higgs theory.

  18. Infrared-laser spectroscopy, 1980-1983

    SciTech Connect (OSTI)

    McDowell, R.S.

    1983-01-01T23:59:59.000Z

    The review article used as a text for the Short Course on Infrared Laser Spectroscopy was completed in January 1980 and included only a few references after that date. There has ensued three years of progress, during which spectroscopy using tunable infrared lasers has become an increasingly used tool both for basic research and for analytical and industrial applications. The present paper, which follows closely the outline of the earlier review, updates the latter to early 1983. 238 references.

  19. Heat Loss Measurement Using Infrared Imaging

    E-Print Network [OSTI]

    Seeber, S. A.

    1983-01-01T23:59:59.000Z

    levels for objects seen in the CRT. (Radiance levels refer to the amount of infrared energy produced by an object.) The conversion of these radiance compari sons to temperatures and heat flows will be discussed below. Infrared images may be recorded... radiance level comparisons since colors may be associated with particular temperature ranges. Black and white images may be colorized during the inspection process. Alternatively, the black and white images may be stored on magnetic tape and color...

  20. Infrared finite coupling in Sudakov resummation

    E-Print Network [OSTI]

    Georges Grunberg

    2006-02-06T23:59:59.000Z

    New arguments are presented to emphasize the interest of the infrared finite coupling approach to power corrections in the context of Sudakov resummation. The more regular infrared behavior of some peculiar combinations of Sudakov anomalous dimensions, free of Landau singularities at large Nf, is pointed out. A general conflict between the infrared finite coupling and infrared renormalon approaches to power corrections is explained, and a possible resolution is proposed, which makes use of the arbitrariness of the choice of exponentiated constant terms. A simple ansatz for a 'universal' non-perturbative Sudakov effective coupling at large Nf follows naturally from these considerations. In this last version, a new result is presented: the striking emergence of an infrared finite perturbative effective coupling in the Drell-Yan process at large Nf (at odds with the infrared renormalon argument) within the framework of Sudakov resummation for eikonal cross sections of Laenen, Sterman and Vogelsang. Some suggestions for phenomenology at finite Nf, alternative to the shape function approach, are given.

  1. Infrared spectroscopic diagnostics for Active Galactic Nuclei

    E-Print Network [OSTI]

    Luigi Spinoglio

    2007-09-26T23:59:59.000Z

    Infrared spectroscopy in the mid- and far-infrared provides powerful diagnostics for studying the emission regions in active galaxies. The large variety of ionic fine structure lines can probe gas conditions in a variety of physical conditions, from highly ionized gas excited by photons originated by black hole accretion to gas photoionized by young stellar systems. The critical density and the ionization potential of these transitions allow to fully cover the density-ionization parameter space. Some examples of line ratios diagrams using both mid-infrared and far-infrared ionic fine structure lines are presented. The upcoming space observatory Herschel will be able to observe the far-infrared spectra of large samples of local active galaxies. Based on the observed near-to-far infrared emission line spectrum of the template galaxy NGC1068, are presented the predictions for the line fluxes expected for galaxies at high redshift. To observe spectroscopically large samples of distant galaxies, we will have to wait fot the future space missions, like SPICA and, ultimately, FIRI.

  2. Infrared phonon modes in multiferroic single-crystal FeTe2O5Br

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

    Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

    2013-06-01T23:59:59.000Z

    Reflection and transmission as a function of temperature (7300 K and 5300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

  3. Interaction of far-infrared and mid-infrared laser transitions in the ammonia laser

    SciTech Connect (OSTI)

    Nelson, L.Y.; Buchwald, M.I.; Jones, C.R.

    1980-01-01T23:59:59.000Z

    Mid-infrared laser emission in ammonia is usually observed on a P(J + 2) transition when a CO/sub 2/ laser is used to optically pump a near resonant R(J) absorption feature. However, by generating simultaneous FIR ammonia laser emission in the same optical cavity, mid-infrared emission is obtained exclusively on the P(J) transition.

  4. Raman Database Considerations for Near-Infrared Systems

    SciTech Connect (OSTI)

    Kunkel, Brenda M.; Su, Yin-Fong; Tonkyn, Russell G.; Stephan, Eric G.; Joly, Alan G.; Birnbaum, Jerome C.; Jarman, Kristin H.; Johnson, Timothy J.

    2011-12-21T23:59:59.000Z

    For Raman spectroscopy the ability to detect is often limited by the existence and quality of the reference library to which field spectra are compared. Developing such databases is often labor- and resource-intensive; typically the generated data are not transferred to other instruments. Still other considerations may exist for comparing data at visible and ultraviolet excitation wavelengths such as resonance enhancement. However, for the common near-infrared wavelengths of 785, 830, 960, 1047 and 1064 nm where this is normally of a lesser concern, it is logical to consider whether data can be ported from one spectrometer to another so as to obviate the expensive and time-consuming process of generating reference data for each system. The present experiment generated a list of 125 chemical and common substances and formed a database from their corresponding 1064 nm spectra. The same molecules were then measured using a 785 nm system the new spectra were treated as unknowns and compared to the 1064 nm database using a commercial search algorithm. We found that at least 108 of the 125 spectra recorded at 785 nm were correctly identified using the search algorithm. For the few that were incorrectly identified, in most cases the spectra were extremely similar or the 785 nm signal was degraded due to fluorescence, as would occur regardless of reference data. Our results indicate that if the spectrometers are properly calibrated on both their wavelength and intensity axes, foreign data recorded at a different NIR wavelength can be successfully used as reference libraries

  5. Infrared curing simulations of liquid composites molding

    SciTech Connect (OSTI)

    Nakouzi, S.; Pancrace, J.; Schmidt, F. M.; Le Maoult, Y.; Berthet, F. [Universite de Toulouse (France); INSA, UPS, Mines Albi, ISAE, ICA - Institut Clement Ader, Campus Jarlard, F-81013 Albi cedex 09 (France); Ecole des Mines Albi, Campus Jarlard, F-81013 Albi (France)

    2011-05-04T23:59:59.000Z

    Infrared radiation is an effective energy source to cure thermosetting polymers. Its usage is expected to reduce curing time in comparison with thermal heating and mold thermally regulated. In addition, because of the polymerization mechanism and instant on-off control of this power, an improvement in the final properties of the material is also expected. In this paper, we studied the infrared interaction with carbon (or glass) fibers reinforced epoxy matrix, where Liquid resin infusion (LRI) is used to manufacture the composite. Temperature of the composite is a key parameter that affects its mechanical properties and is controlled by the infrared emitters and the exothermic heat released from the polymerization. Radiative heat flux is computed using the in-lab developed software RAYHEAT. Then, the heat flux (or absorbed energy for glass fibers) is exported to the finite element based program COMSOLMULTIPHYSICS where heat balance equation is solved. This equation is coupled with the exothermic heat released during the curing process in order to predict the composite temperature versus time and degree of cure. Numerical simulations will be performed on planar parts (sheet shape) as well as curvilinear shapes. Experimental validations of the infrared curing carbon (glass)-epoxy composite system are presented in this paper Sheet surface temperature distribution are measured thanks to infrared camera. Kinetic parameters were estimated from differential scanning calorimeter (DSC) experimental data.

  6. Infrared instability from nonlinear QCD evolution

    E-Print Network [OSTI]

    R. Enberg; R. Peschanski

    2006-01-13T23:59:59.000Z

    Using the Balitsky-Kovchegov (BK) equation as an explicit example, we show that nonlinear QCD evolution leads to an instability in the propagation toward the infrared of the gluon transverse momentum distribution, if one starts with a state with an infrared cut-off. This effect takes the mathematical form of rapidly moving traveling wave solutions of the BK equation, which we investigate by numerical simulations. These traveling wave solutions are different from those governing the transition to saturation, which propagate towards the ultraviolet. The infrared wave speed, formally infinite for the leading order QCD kernel, is determined by higher order corrections. This mechanism could play a role in the rapid decrease of the mean free path in the Color Glass Condensate scenario for heavy ion collisions.

  7. Infrared light sources with semimetal electron injection

    DOE Patents [OSTI]

    Kurtz, Steven R. (Albuquerque, NM); Biefeld, Robert M. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    An infrared light source is disclosed that comprises a layered semiconductor active region having a semimetal region and at least one quantum-well layer. The semimetal region, formed at an interface between a GaAsSb or GalnSb layer and an InAsSb layer, provides electrons and holes to the quantum-well layer to generate infrared light at a predetermined wavelength in the range of 2-6 .mu.m. Embodiments of the invention can be formed as electrically-activated light-emitting diodes (LEDs) or lasers, and as optically-pumped lasers. Since the active region is unipolar, multiple active regions can be stacked to form a broadband or multiple-wavelength infrared light source.

  8. The Effect of Lunar-like Satellites on the Orbital Infrared Light Curves of Earth-analog Planets

    E-Print Network [OSTI]

    Nicholas A. Moskovitz; Eric Gaidos; Darren Williams

    2008-10-17T23:59:59.000Z

    We investigate the influence of lunar-like satellites on the infrared orbital light curves of Earth-analog extra-solar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet. We use an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of the Earth while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g. via spectroscopy or visible-wavelength detection of specular glint from a surface ocean) only the largest (approximately Mars-size) lunar-like satellites can be detected by light curve data from a TPF-like instrument (i.e. one that achieves a photometric signal-to-noise of 10-20 at infrared wavelengths). Non-detection of a lunar-like satellite can obfuscate the interpretation of a given system's infrared light curve so that it may resemble a single planet with high obliquity, different orbital longitude of vernal equinox relative to inferior conjunction and in some cases drastically different thermal characteristics. If the thermal properties of the planet are not independently established then the presence of a lunar-like satellite cannot be inferred from infrared data, thus demonstrating that photometric light curves alone can only be used for preliminary study of extra-solar Earth-like planets.

  9. Standard practice for visible penetrant testing using the Water-Washable process

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2010-01-01T23:59:59.000Z

    1.1 This practice describes procedures for visible liquid penetrant examination utilizing the water-washable process. It is a nondestructive practice for detecting discontinuities that are open to the surface such as cracks, seams, laps, cold shuts, laminations, isolated porosity, through leaks or lack of fusion and is applicable to in-process, final, and maintenance examination. This practice can be effectively used in the examination of nonporous, metallic materials, both ferrous and nonferrous, and of nonmetallic materials such as glazed or fully densified ceramics, and certain nonporous plastics, and glass. 1.2 This practice also provides the following references: 1.2.1 A reference by which visible penetrant examination procedures using the water-washable process can be reviewed to ascertain their applicability and completeness. 1.2.2 For use in the preparation of process specifications dealing with the visible, water-washable liquid penetrant examination of materials and parts. Agreement between the u...

  10. Standard practice for visible penetrant testing using Solvent-Removable process

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2010-01-01T23:59:59.000Z

    1.1 This practice covers procedures for visible penetrant examination utilizing the solvent-removable process. It is a nondestructive testing method for detecting discontinuities that are open to the surface such as cracks, seams, laps, cold shuts, laminations, isolated porosity, through leaks, or lack of fusion and is applicable to in-process, final, and maintenance examination. It can be effectively used in the examination of nonporous, metallic materials, both ferrous and nonferrous, and of nonmetallic materials such as glazed or fully densified ceramics and certain nonporous plastics and glass. 1.2 This practice also provides a reference: 1.2.1 By which a visible penetrant examination method using the solvent-removable process recommended or required by individual organizations can be reviewed to ascertain its applicability and completeness. 1.2.2 For use in the preparation of process specifications dealing with the visible, solvent-removable liquid penetrant examination of materials and parts. Agreeme...

  11. Spitzer Mid-Infrared Spectroscopy of 70um-Selected Distant Luminous Infrared Galaxies

    E-Print Network [OSTI]

    Kate Brand; Dan W. Weedman; Vandana Desai; Emeric Le Floc'h; Lee Armus; Arjun Dey; Jim R. Houck; Buell T. Jannuzi; Howard A. Smith; B. T. Soifer

    2007-09-20T23:59:59.000Z

    We present mid-infrared spectroscopy obtained with the Spitzer Space Telescope of a sample of 11 optically faint, infrared luminous galaxies selected from a Spitzer MIPS 70um imaging survey of the NDWFS Bootes field. These are the first Spitzer IRS spectra presented of distant 70um-selected sources. All the galaxies lie at redshifts 0.3infrared luminosities of L_IR~ 0.1-17 x 10^12 solar luminosities. Seven of the galaxies exhibit strong emission features attributed to polycyclic aromatic hydrocarbons (PAHs). The average IRS spectrum of these sources is characteristic of classical starburst galaxies, but with much larger infrared luminosities. The PAH luminosities of L(7.7) ~ 0.4 - 7 x 10^11 solar luminosities imply star formation rates of ~ 40 - 720 solar masses per year. Four of the galaxies show deep 9.7um silicate absorption features and no significant PAH emission features (6.2um equivalent widths infrared luminosities and low f70/f24 flux density ratios suggests that these sources have AGN as the dominant origin of their large mid-infrared luminosities, although deeply embedded but luminous starbursts cannot be ruled out. If the absorbed sources are AGN-dominated, a significant fraction of all far-infrared bright, optically faint sources may be dominated by AGN.

  12. High efficiency quasi-monochromatic infrared emitter

    SciTech Connect (OSTI)

    Brucoli, Giovanni; Besbes, Mondher; Benisty, Henri, E-mail: henri.benisty@institutoptique.fr; Greffet, Jean-Jacques [Laboratoire Charles Fabry, UMR 8501, Institut dOptique, CNRS, Universit Paris-Sud 11, 2, Avenue Augustin Fresnel, 91127 Palaiseau Cedex (France); Bouchon, Patrick; Hadar, Riad [Office National dtudes et de Recherches Arospatiales, Chemin de la Hunire, 91761 Palaiseau (France)

    2014-02-24T23:59:59.000Z

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  13. Infrared Mapping Helps Optimize Catalytic Reactions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News link toInfluence ofQuickdegreeInfraredInfrared

  14. Photocatalytic activity of nitrogen doped rutile TiO{sub 2} nanoparticles under visible light irradiation

    SciTech Connect (OSTI)

    Yang Songwang [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Gao Lian [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)], E-mail: liangaoc@online.sh.cn

    2008-07-01T23:59:59.000Z

    This work provides the design and synthesis of nitrogen doped rutile TiO{sub 2} nanoparticles working as efficient photocatalysts under visible light irradiation. Nitrogen doped rutile TiO{sub 2} nanoparticles are synthesized through the surface nitridation of rutile nanoparticles, which have been prepared in advance. The experimental results show that the nitrogen element is easily doped into the lattice of TiO{sub 2} nanoparticles and its doping amount increases with the decrease of nanocrystallite size. The photocatalytic activity of the nanoparticles under visible light irradiation is correlated not only with the amount of doped nitrogen element but also with the morphology and crystallinity of nanoparticles.

  15. Nitrogen-sensitized dual phase titanate/titania for visible-light driven phenol degradation

    SciTech Connect (OSTI)

    Cheng, Yu Hua; Subramaniam, Vishnu P.; Gong, Dangguo; Tang, Yuxin [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)] [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Highfield, James, E-mail: James_Highfield@ices.a-star.edu.sg [Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore)] [Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Pehkonen, Simo O. [Chemical Engineering Program, Masdar Institute of Science and Technology, PO Box 54224, Abu Dhabi (United Arab Emirates)] [Chemical Engineering Program, Masdar Institute of Science and Technology, PO Box 54224, Abu Dhabi (United Arab Emirates); Pichat, Pierre [Photocatalyse et Environnement, CNRS/Ecole Centrale de Lyon (STMS), 69134 Ecully Cedex (France)] [Photocatalyse et Environnement, CNRS/Ecole Centrale de Lyon (STMS), 69134 Ecully Cedex (France); Schreyer, Martin K. [Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore)] [Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Chen, Zhong, E-mail: aszchen@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)] [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2012-12-15T23:59:59.000Z

    A dual-phase material (DP-160) comprising hydrated titanate (H{sub 2}Ti{sub 3}O{sub 7}{center_dot}xH{sub 2}O) and anatase (TiO{sub 2}) was synthesized in a low-temperature one-pot process in the presence of triethylamine (TEA) as the N-source. The unique structure exhibits strong visible light absorption. The chromophore is linked to Ti-N bonds derived from both surface sensitization and sub-surface (bulk) doping. From transmission electron microscope (TEM) and textural studies by N{sub 2} physisorption, the composite exists as mesoporous particles with a grain size of {approx}20 nm and mean pore diameter of 3.5 nm, responsible for the high surface area ({approx}180 m{sup 2}/g). DP-160 demonstrated photocatalytic activity in the degradation of phenol under visible light ({lambda}>420 nm). The activity of the composite was further enhanced by a small addition (0.001 M) of H{sub 2}O{sub 2}, which also gave rise to some visible light activity in the control samples. This effect is believed to be associated with the surface peroxo-titanate complex. GC-MS analyses showed that the intermediate products of phenol degradation induced by visible light irradiation of DP-160 did not differ from those obtained by UV (band-gap) irradiation of TiO{sub 2}. The overall performance of the composite is attributed to efficient excitation via inter-band states (due to N-doping), surface sensitization, improved adsorptive properties of aromatic compounds due to the N-carbonaceous overlayer, and the presence of heterojunctions that are known to promote directional charge transfer in other mixed-phase titanias like Degussa P25. - graphical abstract: Nitrogen-sensitized dual phase titanate/titania photocatalyst showing extended visible light absorption and efficient photocatalytic degradation of phenol. Highlights: Black-Right-Pointing-Pointer Low temperature one-pot synthesis of visible light active dual phase photocatalyst. Black-Right-Pointing-Pointer The dual phase consists of nanoscale titanate and anatase titania phases. Black-Right-Pointing-Pointer The photocatalyst displays high activity in degrading phenol under visible light. Black-Right-Pointing-Pointer Mechanisms for the sensitization to visible light are considered.

  16. Atomic Entanglement vs Photonic Visibility for Quantum Criticality of Hybrid System

    E-Print Network [OSTI]

    M. X. Huo; Ying Li; Z. Song; C. P. Sun

    2007-02-12T23:59:59.000Z

    To characterize the novel quantum phase transition for a hybrid system consisting of an array of coupled cavities and two-level atoms doped in each cavity, we study the atomic entanglement and photonic visibility in comparison with the quantum fluctuation of total excitations. Analytical and numerical simulation results show the happen of quantum critical phenomenon similar to the Mott insulator to superfluid transition. Here, the contour lines respectively representing the atomic entanglement, photonic visibility and excitation variance in the phase diagram are consistent in the vicinity of the non-analytic locus of atomic concurrences.

  17. Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water...

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

    and Azimuth-Resolved Infrared Spectroscopy of Water on TiO2(110): Anisotropy and the Hydrogen-Bonding Network. Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water on...

  18. Study of ice cloud properties using infrared spectral data

    E-Print Network [OSTI]

    Garrett, Kevin James

    2009-05-15T23:59:59.000Z

    The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding...

  19. Application of Infrared Thermography in Building Energy Efficiency

    E-Print Network [OSTI]

    Shi, Y.; Chen, H.; Xu, Q.; I, D.; Wang, Z.; Fang, X.

    2006-01-01T23:59:59.000Z

    Based on experience, the paper introduces the key issues during the use of infrared thermography in building energy efficiency. In order to get a more useful thermal infrared spectrum, we must correct the operating apparatus and measure more...

  20. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

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

    Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Wednesday, 29 October 2008 00:00 Graphene-a single layer...

  1. Matching of Infrared Emitters with Textiles For Improved Energy Utilization

    E-Print Network [OSTI]

    Carr, W. W.; Williamson, V. A.; Johnson, M. R.; Do, B. T.

    1994-01-01T23:59:59.000Z

    The successful utilization of infrared radiation is dependent on the spectral characteristics of the material being processed and on how well the spectral output of the infrared source matches those of the material being heated. Very little bas been...

  2. Study of ice cloud properties using infrared spectral data

    E-Print Network [OSTI]

    Garrett, Kevin James

    2009-05-15T23:59:59.000Z

    The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding...

  3. Application of Infrared Thermography in Building Energy Efficiency

    E-Print Network [OSTI]

    Shi, Y.; Chen, H.; Xu, Q.; I, D.; Wang, Z.; Fang, X.

    2006-01-01T23:59:59.000Z

    Based on experience, the paper introduces the key issues during the use of infrared thermography in building energy efficiency. In order to get a more useful thermal infrared spectrum, we must correct the operating apparatus and measure more...

  4. Matching of Infrared Emitters with Textiles For Improved Energy Utilization

    E-Print Network [OSTI]

    Carr, W. W.; Williamson, V. A.; Johnson, M. R.; Do, B. T.

    The successful utilization of infrared radiation is dependent on the spectral characteristics of the material being processed and on how well the spectral output of the infrared source matches those of the material being heated. Very little bas been...

  5. Infrared Brightness Temperature of Mars, 1983-2103

    E-Print Network [OSTI]

    E. L. Wright

    2007-03-25T23:59:59.000Z

    The predicted infrared brightness temperature of Mars using the 1976 model of Wright is tabulated here for the period 1983 to 2103. This model was developed for far-infrared calibration, and is still being used for JCMT calibration.

  6. Infrared Optical Imaging Techniques for Gas Visualization and Measurement

    E-Print Network [OSTI]

    Safitri, Anisa

    2012-07-16T23:59:59.000Z

    Advancement in infrared imaging technology has allowed the thermal imaging to detect and visualize several gases, mostly hydrocarbon gases. In addition, infrared cameras could potentially be used as a non-contact temperature measurement for gas...

  7. A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs

    E-Print Network [OSTI]

    O. Absil; E. Di Folco; A. Merand; J. -C. Augereau; V. Coude du Foresto; D. Defrere; P. Kervella; J. P. Aufdenberg; M. Desort; D. Ehrenreich; A. -M. Lagrange; G. Montagnier; J. Olofsson; T. A. ten Brummelaar; H. A. McAlister; J. Sturmann; L. Sturmann; N. H. Turner

    2008-06-30T23:59:59.000Z

    High-precision interferometric observations of six early-type main sequence stars known to harbour cold debris discs have been obtained in the near-infrared K band with the FLUOR instrument at the CHARA Array. The measured squared visibilities are compared to the expected visibility of the stellar photospheres based on theoretical photospheric models taking into account rotational distortion, searching for potential visibility reduction at short baselines due to circumstellar emission. Our observations bring to light the presence of resolved circumstellar emission around one of the six target stars (zeta Aql) at the 5 sigma level. The morphology of the emission source cannot be directly constrained because of the sparse spatial frequency sampling of our interferometric data. Using complementary adaptive optics observations and radial velocity measurements, we find that the presence of a low-mass companion is a likely origin for the excess emission. The potential companion has a K-band contrast of four magnitudes, a most probable mass of about 0.6 Msun, and is expected to orbit between about 5.5 AU and 8 AU from its host star assuming a purely circular orbit. Nevertheless, by adjusting a physical debris disc model to the observed Spectral Energy Distribution of the zeta Aql system, we also show that the presence of hot dust within 10 AU from zeta Aql, producing a total thermal emission equal to 1.69 +- 0.31% of the photospheric flux in the K band, is another viable explanation for the observed near-infrared excess. Our re-interpretation of archival near- to far-infrared photometric measurements shows however that cold dust is not present around zeta Aql at the sensitivity limit of the IRS and MIPS instruments onboard Spitzer, and urges us to remove zeta Aql from the category of bona fide debris disc stars.

  8. Near-Infrared Adaptive Optics Imaging of the Central Regions of Nearby Sc Galaxies: I. M33

    E-Print Network [OSTI]

    T. J. Davidge

    1999-10-18T23:59:59.000Z

    Near-infrared images obtained with the Canada-France-Hawaii Telescope (CFHT) Adaptive Optics Bonnette (AOB) are used to investigate the stellar content within 18 arcsec of the center of the Local Group spiral galaxy M33. AGB stars with near-infrared spectral-energy distributions similar to those of giants in the solar neighborhood and Baade's Window are detected over most of the field. The bolometric luminosity function (LF) of these stars has a discontinuity near M_{bol} = -5.25, and comparisons with evolutionary tracks suggest that most of the AGB stars formed in a burst of star formation 1 - 3 Gyr in the past. The images are also used to investigate the integrated near-infrared photometric properties of the nucleus and the central light concentration. The nucleus is bluer than the central light concentration, in agreement with previous studies at visible wavelengths. The CO index of the central light concentration 0.5 arcsec from the galaxy center is 0.05, which corresponds to [Fe/H] = -1.2 for simple stellar systems. Hence, the central light concentration could not have formed from the chemically-enriched material that dominates the present-day inner disk of M33.

  9. Search for bright stars with infrared excess

    SciTech Connect (OSTI)

    Raharto, Moedji, E-mail: moedji@as.itb.ac.id [Astronomy Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24T23:59:59.000Z

    Bright stars, stars with visual magnitude smaller than 6.5, can be studied using small telescope. In general, if stars are assumed as black body radiator, then the color in infrared (IR) region is usually equal to zero. Infrared data from IRAS observations at 12 and 25?m (micron) with good flux quality are used to search for bright stars (from Bright Stars Catalogues) with infrared excess. In magnitude scale, stars with IR excess is defined as stars with IR color m{sub 12}?m{sub 25}>0; where m{sub 12}?m{sub 25}?=??2.5log(F{sub 12}/F{sub 25})+1.56, where F{sub 12} and F{sub 25} are flux density in Jansky at 12 and 25?m, respectively. Stars with similar spectral type are expected to have similar color. The existence of infrared excess in the same spectral type indicates the existence of circum-stellar dust, the origin of which is probably due to the remnant of pre main-sequence evolution during star formation or post AGB evolution or due to physical process such as the rotation of those stars.

  10. Infrared Scales and Factorization in QCD

    E-Print Network [OSTI]

    Aneesh V. Manohar

    2005-12-14T23:59:59.000Z

    Effective field theory methods are used to study factorization of the deep inelastic scattering cross-section. The cross-section is shown to factor in QCD, even though it does not factor in perturbation theory for some choices of the infrared regulator. Messenger modes are not required in soft-collinear effective theory for deep inelastic scattering as x -> 1.

  11. Infrared Quantum Dots** By Edward H. Sargent*

    E-Print Network [OSTI]

    and treat disease, harness new forms of energy, and visualize threats to our safety and environment depend of the telecommunications wave- length band spans 12001700 nm.[1] It is of interest to unite, in a single monolithic10 cm; solar and thermal photovoltaics for energy conversion; and infrared sensing and imaging based

  12. J. Opt. 15 (2013) 085101 (3pp) T Roy et al A meta-diffraction-grating for visible light

    E-Print Network [OSTI]

    Zheludev, Nikolay

    2013-01-01T23:59:59.000Z

    in the far infrared [5] and near-infrared [7] region of the spectrum while flat lenses designed from optical attracted substantial attention [3-9]. In particular anomalous refraction and reflection has been observed [3-8] are concerned with the infrared part of the spectrum, whereas here we experimentally

  13. Comparing local vs. global visible and near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) calibrations for the prediction of soil clay, organic C

    E-Print Network [OSTI]

    Lawrence, Rick L.

    ) calibrations for the prediction of soil clay, organic C and inorganic C Joel B. Sankey a, , David J. Brown b,1 samples for VisNIR-DRS predictions of soil clay content (clay), organic carbon content (SOC of Prediction (SEP)= 3.8, 6.7, and 26.2 g kg- 1 ]. This was similarly true for clay (SEP=95.3 and 102.5 g kg- 1

  14. Use of a region of the visible and near infrared spectrum to predict mechanical properties of wet wood and standing trees

    DOE Patents [OSTI]

    Meglen, Robert R. (Boulder, CO); Kelley, Stephen S. (Evergreen, CO)

    2003-01-01T23:59:59.000Z

    In a method for determining the dry mechanical strength for a green wood, the improvement comprising: (a) illuminating a surface of the wood to be determined with a reduced range of wavelengths in the VIS-NIR spectra 400 to 1150 nm, said wood having a green moisture content; (b) analyzing the surface of the wood using a spectrometric method, the method generating a first spectral data of a reduced range of wavelengths in VIS-NIR spectra; and (c) using a multivariate analysis technique to predict the mechanical strength of green wood when dry by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data of a reduced range of wavelengths in VIS-NIR spectra obtained from a reference wood having a green moisture content, the second spectral being correlated with a known mechanical strength analytical result obtained from the reference wood when dried and a having a dry moisture content.

  15. Strong visible and near infrared luminescence in undoped YAG single C. R. Varney, S. M. Reda, D. T. Mackay, M. C. Rowe, and F. A. Selim

    E-Print Network [OSTI]

    Collins, Gary S.

    impurities as confirmed by Glow Discharge Mass Spectrometry analysis. The 800 nm was only excited by high properties of rare-earth doped YAG crystals and their performance in laser and scintillation applications and the scintillation output is substantially decreased. Nevertheless, Undoped YAG crystals may have the potential

  16. Monolithically integrated near-infrared and mid-infrared detector array for spectral imaging

    E-Print Network [OSTI]

    Perera, A. G. Unil

    detector test results ensure the high quality of material suitable for near-infrared/QWIP dual-band focal. A CTIS records spatial and spectral information by imaging a scene through an optical relay system

  17. Transmissive infrared frequency selective surfaces and infrared antennas : final report for LDRD 105749.

    SciTech Connect (OSTI)

    Wendt, Joel Robert; Hadley, G. Ronald; Samora, Sally; Loui, Hung; Cruz-Cabrera, Alvaro Augusto; Davids, Paul; Kemme, Shanalyn A.; Basilio, Lorena I.; Johnson, William Arthur; Peters, David William

    2009-09-01T23:59:59.000Z

    Plasmonic structures open up new opportunities in photonic devices, sometimes offering an alternate method to perform a function and sometimes offering capabilities not possible with standard optics. In this LDRD we successfully demonstrated metal coatings on optical surfaces that do not adversely affect the transmission of those surfaces at the design frequency. This technology could be applied as an RF noise blocking layer across an optical aperture or as a method to apply an electric field to an active electro-optic device without affecting optical performance. We also demonstrated thin optical absorbers using similar patterned surfaces. These infrared optical antennas show promise as a method to improve performance in mercury cadmium telluride detectors. Furthermore, these structures could be coupled with other components to lead to direct rectification of infrared radiation. This possibility leads to a new method for infrared detection and energy harvesting of infrared radiation.

  18. Temporary Housing Mission Overview Temporary Housing is a highly visible mission.

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Temporary Housing Mission Overview Temporary Housing is a highly visible mission. Success requires teamwork (FEMA/COE/State/Local) and advanced planning. FEMA's steps to providing housing relief assistance (home repair limits, rental limits, self-help Manufactured Housing Units (MHU) on private sites

  19. Enhanced visibility of hydrogen atoms by neutron crystallography on fully deuterated myoglobin

    E-Print Network [OSTI]

    Ramakrishnan, Venki

    determined by x-ray crystallography except at very high resolution. The scattering of neutrons by hydrogenEnhanced visibility of hydrogen atoms by neutron crystallography on fully deuterated myoglobin Fong and structurally, direct visu- alization of them by using crystallography is difficult. Neutron crys- tallography

  20. Gain dispersion in Visible Light Photon Counters as a function of counting rate

    SciTech Connect (OSTI)

    Bross, A.; /Fermilab; Buscher, V.; /Freiburg U.; Estrada, J.; /Fermilab; Ginther, G.; /Rochester U.; Molina, J.; /Rio de Janeiro State U.

    2005-03-01T23:59:59.000Z

    We present measurements of light signals using Visible Light Photon Counters (VLPC), that indicate an increase in gain dispersion as the counting rate increases. We show that this dispersion can be understood on the basis of a recent observation of localized field reduction in VLPCs at high input rates.

  1. A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery

    E-Print Network [OSTI]

    A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery; published 30 January 2004. [1] Solar radiation assessment by satellite is constrained by physical Composition and Structure: Transmission and scattering of radiation; KEYWORDS: solar radiation, satellite

  2. Development of low dark current SiGe-detector arrays for visible-NIR imaging sensor

    E-Print Network [OSTI]

    Sood, Ashok K.

    SiGe based Focal Plane Arrays offer a low cost alternative for developing visible- NIR focal plane arrays that will cover the spectral band from 0.4 to 1.6 microns. The attractive features of SiGe based IRFPA's will take ...

  3. MRI-Visible Micellar Nanomedicine for Targeted Drug Delivery to Lung Cancer Cells

    E-Print Network [OSTI]

    Gao, Jinming

    MRI-Visible Micellar Nanomedicine for Targeted Drug Delivery to Lung Cancer Cells Jagadeesh Setti micelle (MFM) system that is encoded with a lung cancer-targeting peptide (LCP), and encapsulated. The LCP-encoded MFM showed significantly increased Rv 6-dependent cell targeting in H2009 lung cancer

  4. Infrared regular representation of the three dimensional massless Nelson model

    E-Print Network [OSTI]

    Infrared regular representation of the three dimensional massless Nelson model J#19;ozsef L this Gaussian measure space. KEYWORDS: Nelson's scalar #12;eld model, infrared regular representation, ground] of a spinless electron coupled to a scalar massless Bose #12;eld is infrared divergent in 3 space dimensions

  5. Infrared Observations of Soft GammaRay Repeaters

    E-Print Network [OSTI]

    Smith, Ian Andrew

    Infrared Observations of Soft Gamma­Ray Repeaters I. A. Smith Department of Space Physics been found for SGR 0525--66. This paper gives a brief overview of some recent and ongoing infrared observing programs. For a more detailed review article, see Smith (1997) [2]. INFRARED SPECTRA OF SGR 1806

  6. Near-infrared light scattering by particles in coastal waters

    E-Print Network [OSTI]

    Babin, Marcel

    Near-infrared light scattering by particles in coastal waters David Doxaran* , Marcel Babin extend over the near-infrared spectral region to up to 870 nm. The measurements were conducted in three in the near-infrared very closely matched a - spectral dependence, which is expected when the particle size

  7. INFRARED THERMAL IMAGING OF AUTOMOBILES: Identification of Cold Start Vehicles

    E-Print Network [OSTI]

    Denver, University of

    INFRARED THERMAL IMAGING OF AUTOMOBILES: Identification of Cold Start Vehicles Angela M. Monateri emitters, even thought they have no repairable fault. This study investigates the use of thermal infrared be differentiated from hot vehicles by infrared imaging, which can distinguish between: ·Hot and cold exhaust system

  8. Near-infrared spectroscopy of HD the barrier to linearity

    E-Print Network [OSTI]

    Oka, Takeshi

    Near-infrared spectroscopy of HD 3 above the barrier to linearity BY JENNIFER L. GOTTFRIED, transitions of HC 3 above the barrier to linearity have been observed. A highly sensitive near-infrared-adiabatic and radiative corrections is revealed. Keywords: HD 3 ; near-infrared spectroscopy; barrier to linearity 1

  9. Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells

    E-Print Network [OSTI]

    Schiff, Eric A.

    Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells Kai Zhu a,1 , E Solar, Toano, VA 23168, USA Abstract We report infrared depletion modulation spectra for near an infrared modulation spectroscopy technique that probes the optical spectra of dopants and defects

  10. Infrared-Based Screening System Oak Ridge National Laboratory

    E-Print Network [OSTI]

    Infrared-Based Screening System (IBSS) Oak Ridge National Laboratory managed by UT-Battelle, LLC underperforming or overworking components are identified. These thermal-based systems integrate infrared (IR) sensors or cameras, video images, and vehicle position sensors, and are generically known as infrared

  11. Molecular basis of infrared detection by Elena O. Gracheva1

    E-Print Network [OSTI]

    Newman, Eric A.

    , snakes detect infrared signals through a mechanism involving radiant heating of the pit organ, ratherARTICLES Molecular basis of infrared detection by snakes Elena O. Gracheva1 *, Nicholas T. Ingolia2 system for detecting infrared radiation, enabling them to generate a `thermal image' of predators or prey

  12. Infrared Temperature Sensing of Mechanically Loaded Specimens: Thermal Analysis

    E-Print Network [OSTI]

    Rabin, Yoed

    , not the instantaneous effect of heating within a single loading cycle. KEY WORDS--Infrared, temperature measurement, meInfrared Temperature Sensing of Mechanically Loaded Specimens: Thermal Analysis by Y. Rabin and D. Rittel ABSTRACT--Infrared temperature-sensing techniques have the major advantages of virtually

  13. Negligible Sample Heating from Synchrotron Infrared Beam Michael C. Martina

    E-Print Network [OSTI]

    Negligible Sample Heating from Synchrotron Infrared Beam Michael C. Martina , Nelly M. Tsvetkovab of Molecular and Cellular Biology, University of California at Davis, USA Infrared (IR) spectroscopy is one can now obtain diffraction-limited spot sizes with high signal intensity in an infrared microscope

  14. NDE of Concrete Structures Strengthened with FRP Using Infrared Thermography

    E-Print Network [OSTI]

    Entekhabi, Dara

    NDE of Concrete Structures Strengthened with FRP Using Infrared Thermography Monica A. STARNES the effectiveness of infrared thermography to estimate the width of subsurface flaws in fiber-reinforced polymer infrared thermography, i.e., not only detecting but also characterizing subsurface flaws. Finite element

  15. Quantum grid infrared photodetectors L. P. Rokhinson,a)

    E-Print Network [OSTI]

    Rokhinson, Leonid

    Quantum grid infrared photodetectors L. P. Rokhinson,a) C. J. Chen, and D. C. Tsui Department to as the quantum grid infrared photodetector QGIP . In an ideal structure, a grid pattern with very narrow to as the quantum grid infrared photodetector QGIP . This approach may produce a more uniform and optimized detector

  16. Application of External-Cavity Quantum Cascade Infrared Lasers to Nanosecond Time-Resolved Infrared Spectroscopy of Condensed-Phase Samples Following Pulse Radiolysis

    SciTech Connect (OSTI)

    Grills, D.C.; Cook, A.R.; Fujita, E.; George, M.W.; Miller, J.R.; Preses, J.M.; Wishart, J.F.

    2010-06-01T23:59:59.000Z

    Pulse radiolysis, utilizing short pulses of high-energy electrons from accelerators, is a powerful method for rapidly generating reduced or oxidized species and other free radicals in solution. Combined with fast time-resolved spectroscopic detection (typically in the ultraviolet/visible/near-infrared), it is invaluable for monitoring the reactivity of species subjected to radiolysis on timescales ranging from picoseconds to seconds. However, it is often difficult to identify the transient intermediates definitively due to a lack of structural information in the spectral bands. Time-resolved vibrational spectroscopy offers the structural specificity necessary for mechanistic investigations but has received only limited application in pulse radiolysis experiments. For example, time-resolved infrared (TRIR) spectroscopy has only been applied to a handful of gas-phase studies, limited mainly by several technical challenges. We have exploited recent developments in commercial external-cavity quantum cascade laser (EC-QCL) technology to construct a nanosecond TRIR apparatus that has allowed, for the first time, TRIR spectra to be recorded following pulse radiolysis of condensed-phase samples. Near single-shot sensitivity of DeltaOD <1 x 10(-3) has been achieved, with a response time of <20 ns. Using two continuous-wave EC-QCLs, the current apparatus covers a probe region from 1890-2084 cm(-1), and TRIR spectra are acquired on a point-by-point basis by recording transient absorption decay traces at specific IR wavelengths and combining these to generate spectral time slices. The utility of the apparatus has been demonstrated by monitoring the formation and decay of the one-electron reduced form of the CO(2) reduction catalyst, [Re(I)(bpy)(CO)(3)(CH(3)CN)](+), in acetonitrile with nanosecond time resolution following pulse radiolysis. Characteristic red-shifting of the nu(CO) IR bands confirmed that one-electron reduction of the complex took place. The availability of TRIR detection with high sensitivity opens up a wide range of mechanistic pulse radiolysis investigations that were previously difficult or impossible to perform with transient UV/visible detection.

  17. MID-INFRARED IRS SPECTROSCOPY OF NGC 7331: A FIRST LOOK AT THE SPITZER INFRARED NEARBY GALAXIES SURVEY (SINGS) LEGACY

    E-Print Network [OSTI]

    Draine, Bruce T.

    MID-INFRARED IRS SPECTROSCOPY OF NGC 7331: A FIRST LOOK AT THE SPITZER INFRARED NEARBY GALAXIES to 38 m using all modules of Spitzer's Infrared Spectrograph (IRS). A strong new dust emission feature with standard photodissociation region (PDR) models. Either additional PDR heating or shocks are required

  18. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

    SciTech Connect (OSTI)

    Shimonishi, Takashi [Department of Earth and Planetary Sciences, Graduate School of Science, Kobe University, Nada Kobe 657-8501 (Japan); Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ita, Yoshifusa [Astronomical Institute, Graduate School of Science, Tohoku University, 6-3 Aramaki Aoba, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Kawamura, Akiko [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kaneda, Hidehiro, E-mail: shimonishi@penguin.kobe-u.ac.jp [Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)

    2013-02-01T23:59:59.000Z

    We performed a near-infrared spectroscopic survey toward an area of {approx}10 deg{sup 2} of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R {approx} 20) spectra in 2-5 {mu}m for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 {mu}m, and 67% of the sources also have photometric data up to 24 {mu}m. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 {mu}m can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near-infrared. A large number of near-infrared spectral data provided by the survey possess scientific potential that can be applied to various studies. In this paper, we present the details of the spectroscopic survey and the catalog, and discuss its scientific applications.

  19. Dye Surface Coating Enables Visible Light Activation of TiO2 Nanoparticles Leading to Degradation of

    E-Print Network [OSTI]

    Brown, Eric

    Dye Surface Coating Enables Visible Light Activation of TiO2 Nanoparticles Leading to Degradation that an alizarin red S ~ARS! dye coating on TiO2 nanoparticles enables visible light activation coatings on TiO2 nanoparticles can serve to enhance imaging, by clearly showing that dye coatings on TiO2

  20. Penetration of UV-visible solar radiation in the global oceans: Insights from ocean color remote sensing

    E-Print Network [OSTI]

    Penetration of UV-visible solar radiation in the global oceans: Insights from ocean color remote 2013. [1] Penetration of solar radiation in the ocean is determined by the attenuation coefficient (Kd. Lewis, R. Arnone, and R. Brewin (2013), Penetration of UV-visible solar radiation in the global oceans

  1. Estimation of light penetration, and horizontal and vertical visibility in oceanic and coastal waters from surface reflectance

    E-Print Network [OSTI]

    Babin, Marcel

    Estimation of light penetration, and horizontal and vertical visibility in oceanic and coastal penetration, and horizontal and vertical visibility in oceanic and coastal waters from surface reflectance, J. The algorithms are found to be valid both in coastal and oceanic waters, and largely insensitive to regional

  2. Mid-Infrared Plasmonic Biosensing with Graphene

    E-Print Network [OSTI]

    Rodrigo, Daniel; Janner, Davide; Etezadi, Dordaneh; de Abajo, F Javier Garca; Pruneri, Valerio; Altug, Hatice

    2015-01-01T23:59:59.000Z

    Infrared spectroscopy is the technique of choice for chemical identification of biomolecules through their vibrational fingerprints. However, infrared light interacts poorly with nanometric size molecules. Here, we exploit the unique electro-optical properties of graphene to demonstrate a high-sensitivity tunable plasmonic biosensor for chemically-specific label-free detection of protein monolayers. The plasmon resonance of nanostructured graphene is dynamically tuned to selectively probe the protein at different frequencies and extract its complex refractive index. Additionally, the extreme spatial light confinement in graphene, up to two orders of magnitude higher than in metals, produces an unprecedentedly high overlap with nanometric biomolecules, enabling superior sensitivity in the detection of their refractive index and vibrational fingerprints. The combination of tunable spectral selectivity and enhanced sensitivity of graphene opens exciting prospects for biosensing.

  3. Quantification of UV-Visible and Laser Spectroscopic Techniques for Materials Accountability and Process Control

    SciTech Connect (OSTI)

    Czerwinski, Kenneth

    2013-09-13T23:59:59.000Z

    Ultravioletvisible spectroscopy (UVVisible) and time-resolved laser fluorescence spectroscopy (TRLFS) optical techniques can permit on-line analysis of actinide elements in a solvent extraction process in real time. These techniques have been used for measuring actinide speciation and concentration under laboratory conditions and are easily adaptable to multiple sampling geometries, such as dip probes, fiber-optic sample cells, and flow-through cell geometries. To fully exploit these techniques, researchers must determine the fundamental speciation of target actinides and the resulting influence on spectroscopic properties. Detection limits, process conditions, and speciation of key actinide components can be established and utilized in a range of areas, particularly those related to materials accountability and process control. Through this project, researchers will develop tools and spectroscopic techniques to evaluate solution extraction conditions and concentrations of U, Pu, and Cm in extraction processes, addressing areas of process control and materials accountability. The team will evaluate UV Visible and TRLFS for use in solvent extraction-based separations. Ongoing research is examining efficacy of UV-Visible spectroscopy to evaluate uranium and plutonium speciation under conditions found in the UREX process and using TRLFS to evaluate Cm speciation and concentration in the TALSPEAK process. A uranyl and plutonium nitrate UVVisible spectroscopy study met with success, which supports the utility and continued exploration of spectroscopic methods for evaluation of actinide concentrations and solution conditions for other aspects of the UREX+ solvent extraction scheme. This project will ex examine U and Pu absorbance in TRUEX and TALSPEAK, perform detailed examination of Cm in TRUEX and TALSPEAK, study U laser fluorescence, and apply project data to contactors. The team will also determine peak ratios as a function of solution concentrations for the UV-Visible spectroscopy studies. The use of TRLFS to examine Cm and U will provide data to evaluate lifetime, peak location, and peak ratios (mainly for U). The bases for the spectroscopic techniques have been investigated, providing fundamental evidence for the applications utility.

  4. Mid-Infrared Single Photon Counting

    E-Print Network [OSTI]

    Guilherme Temporao; Sebastien Tanzilli; Hugo Zbinden; Nicolas Gisin; Thierry Aellen; Marcella Giovannini; Jerome Faist

    2005-11-29T23:59:59.000Z

    We report a procedure to detect mid-infrared single photons at 4.65 um via a two-stage scheme based on Sum Frequency Generation, using a Periodically Poled Lithium Niobate (PPLN) nonlinear crystal and a Silicon Avalanche Photodiode. An experimental investigation shows that, in addition to a high timing resolution, this technique yields a detection sensitivity of 1.24 pW with 63mW of net pump power.

  5. Broadband Infrared Heterodyne Spectrometer: Final Report

    SciTech Connect (OSTI)

    Stevens, C G; Cunningham, C T; Tringe, J W

    2010-12-16T23:59:59.000Z

    This report summarizes the most important results of our effort to develop a new class of infrared spectrometers based on a novel broadband heterodyne design. Our results indicate that this approach could lead to a near-room temperature operation with performance limited only by quantum noise carried by the incoming signal. Using a model quantum-well infrared photodetector (QWIP), we demonstrated key performance features of our approach. For example, we directly measured the beat frequency signal generated by superimposing local oscillator (LO) light of one frequency and signal light of another through a spectrograph, by injecting the LO light at a laterally displaced input location. In parallel with the development of this novel spectrometer, we modeled a new approach to reducing detector volume though plasmonic resonance effects. Since dark current scales directly with detector volume, this ''photon compression'' can directly lead to lower currents. Our calculations indicate that dark current can be reduced by up to two orders of magnitude in an optimized ''superlens'' structure. Taken together, our spectrometer and dark current reduction strategies provide a promising path toward room temperature operation of a mid-wave and possibly long-wave infrared spectrometer.

  6. Visibility of cold atomic gases in optical lattices for finite temperatures

    SciTech Connect (OSTI)

    Hoffmann, Alexander [Arnold Sommerfeld Center, Ludwig Maximilian Universitaet, Theresienstrasse 37, 80333 Muenchen (Germany); Pelster, Axel [Fachbereich Physik, Universitaet Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg (Germany); Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany)

    2009-05-15T23:59:59.000Z

    In nearly all experiments with ultracold atoms time-of-flight pictures are the only data available. In this paper we present an analytical strong-coupling calculation for those time-of-flight pictures of bosons in a three-dimensional optical lattice in the Mott phase. This allows us to determine the visibility, which quantifies the contrast of peaks in the time-of-flight pictures, and we suggest how to use it as a thermometer.

  7. Volume-scalable high-brightness three-dimensional visible light source

    DOE Patents [OSTI]

    Subramania, Ganapathi; Fischer, Arthur J; Wang, George T; Li, Qiming

    2014-02-18T23:59:59.000Z

    A volume-scalable, high-brightness, electrically driven visible light source comprises a three-dimensional photonic crystal (3DPC) comprising one or more direct bandgap semiconductors. The improved light emission performance of the invention is achieved based on the enhancement of radiative emission of light emitters placed inside a 3DPC due to the strong modification of the photonic density-of-states engendered by the 3DPC.

  8. INFRARED SPECTRAL OBSERVATION OF EIGHT BL LAC OBJECTS FROM THE SPITZER INFRARED SPECTROGRAPH

    SciTech Connect (OSTI)

    Chen, P. S.; Shan, H. G., E-mail: iraspsc@yahoo.com.cn [National Astronomical Observatories/Yunnan Observatory and Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 (China)

    2011-05-01T23:59:59.000Z

    The Spitzer Infrared Spectrograph (IRS) low-resolution spectra for eight BL Lac objects are presented in this paper. It can be seen that the infrared spectrum of S5 0716+714 shows in the IRS region many emission features that would be from a nearby galaxy. It is also shown that, except for the silicate absorptions around 10 {mu}m for some sources, emission lines in the infrared spectra for the other seven BL Lac objects are indeed very weak or absent. In addition, ignoring the silicate feature, all spectra can be well fitted by a power-law distribution indicative of the emission mechanism of the synchrotron radiation for these BL Lac objects in the IRS region.

  9. Invited Article: An integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument

    SciTech Connect (OSTI)

    Khne, P., E-mail: kuehne@huskers.unl.edu; Schubert, M., E-mail: schubert@engr.unl.edu; Hofmann, T., E-mail: thofmann@engr.unl.edu [Department of Electrical Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Herzinger, C. M., E-mail: cherzinger@jawoollam.com; Woollam, J. A., E-mail: jwoollam@jawoollam.com [J. A. Woollam Co., Inc., 645 M Street, Suite 102, Lincoln, Nebraska 68508-2243 (United States)

    2014-07-15T23:59:59.000Z

    We report on the development of the first integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument, covering an ultra wide spectral range from 3 cm{sup ?1} to 7000 cm{sup ?1} (0.1210 THz or 0.4870 meV). The instrument comprises four sub-systems, where the magneto-cryostat-transfer sub-system enables the usage of the magneto-cryostat sub-system with the mid-infrared ellipsometer sub-system, and the far-infrared/terahertz ellipsometer sub-system. Both ellipsometer sub-systems can be used as variable angle-of-incidence spectroscopic ellipsometers in reflection or transmission mode, and are equipped with multiple light sources and detectors. The ellipsometer sub-systems are operated in polarizer-sample-rotating-analyzer configuration granting access to the upper left 3 3 block of the normalized 4 4 Mueller matrix. The closed cycle magneto-cryostat sub-system provides sample temperatures between room temperature and 1.4 K and magnetic fields up to 8 T, enabling the detection of transverse and longitudinal magnetic field-induced birefringence. We discuss theoretical background and practical realization of the integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument, as well as acquisition of optical Hall effect data and the corresponding model analysis procedures. Exemplarily, epitaxial graphene grown on 6H-SiC, a tellurium doped bulk GaAs sample and an AlGaN/GaN high electron mobility transistor structure are investigated. The selected experimental datasets display the full spectral, magnetic field and temperature range of the instrument and demonstrate data analysis strategies. Effects from free charge carriers in two dimensional confinement and in a volume material, as well as quantum mechanical effects (inter-Landau-level transitions) are observed and discussed exemplarily.

  10. Infrared Safety in Factorized Hard Scattering Cross-Sections

    E-Print Network [OSTI]

    Andrew Hornig; Christopher Lee; Grigory Ovanesyan

    2009-05-13T23:59:59.000Z

    The rules of soft-collinear effective theory can be used naively to write hard scattering cross-sections as convolutions of separate hard, jet, and soft functions. One condition required to guarantee the validity of such a factorization is the infrared safety of these functions in perturbation theory. Using e+e- angularity distributions as an example, we propose and illustrate an intuitive method to test this infrared safety at one loop. We look for regions of integration in the sum of Feynman diagrams contributing to the jet and soft functions where the integrals become infrared divergent. Our analysis is independent of an explicit infrared regulator, clarifies how to distinguish infrared and ultraviolet singularities in pure dimensional regularization, and demonstrates the necessity of taking zero-bins into account to obtain infrared-safe jet functions.

  11. Infrared Spectroscopy of Molecular Supernova Remnants

    E-Print Network [OSTI]

    William T. Reach; Jeonghee Rho

    2000-07-27T23:59:59.000Z

    We present Infrared Space Observatory spectroscopy of sites in the supernova remnants W28, W44, and 3C391, where blast waves are impacting molecular clouds. Atomic fine-structure lines were detected from C, N, O, Si, P, and Fe. The S(3) and S(9) lines of H2 were detected for all three remnants. The observations require both shocks into gas with moderate (~ 100 /cm3) and high (~10,000 /cm3) pre-shock densities, with the moderate density shocks producing the ionic lines and the high density shock producing the molecular lines. No single shock model can account for all of the observed lines, even at the order of magnitude level. We find that the principal coolants of radiative supernova shocks in moderate-density gas are the far-infrared continuum from dust grains surviving the shock, followed by collisionally-excited [O I] 63.2 and [Si II] 34.8 micron lines. The principal coolant of the high-density shocks is collisionally-excited H2 rotational and ro-vibrational line emission. We systematically examine the ground-state fine structure of all cosmically abundant elements, to explain the presence or lack of all atomic fine lines in our spectra in terms of the atomic structure, interstellar abundances, and a moderate-density, partially-ionized plasma. The [P II] line at 60.6 microns is the first known astronomical detection. There is one bright unidentified line in our spectra, at 74.26 microns. The presence of bright [Si II] and [Fe II] lines requires partial destruction of the dust. The required gas-phase abundance of Fe suggests 15-30% of the Fe-bearing grains were destroyed. The infrared continuum brightness requires ~1 Msun of dust survives the shock, suggesting about 1/3 of the dust mass was destroyed, in agreement with the depletion estimate and with theoretical models for dust destruction.

  12. Infrared Properties of Nearby Interacting Galaxies: from Spirals to ULIRGs

    E-Print Network [OSTI]

    V. Charmandaris

    2006-10-20T23:59:59.000Z

    I present a brief review of some of the mid-infrared properties of interacting galaxies as these were revealed using observations from the Infrared Space Observatory and Spitzer Space Telescope over the last decade. The variation of the infrared spectral energy distribution in interacting galaxies can be used as an extinction free tracer not only of the location of the star formation activity but also of the physical mechanism dominating their energy production.

  13. Doped carbon nanostructure field emitter arrays for infrared imaging

    DOE Patents [OSTI]

    Korsah, Kofi (Knoxville, TN) [Knoxville, TN; Baylor, Larry R (Farragut, TN) [Farragut, TN; Caughman, John B (Oak Ridge, TN) [Oak Ridge, TN; Kisner, Roger A (Knoxville, TN) [Knoxville, TN; Rack, Philip D (Knoxville, TN) [Knoxville, TN; Ivanov, Ilia N (Knoxville, TN) [Knoxville, TN

    2009-10-27T23:59:59.000Z

    An infrared imaging device and method for making infrared detector(s) having at least one anode, at least one cathode with a substrate electrically connected to a plurality of doped carbon nanostructures; and bias circuitry for applying an electric field between the anode and the cathode such that when infrared photons are adsorbed by the nanostructures the emitted field current is modulated. The detectors can be doped with cesium to lower the work function.

  14. UNIDENTIFIED INFRARED EMISSION BANDS: PAHs or MAONs?

    SciTech Connect (OSTI)

    Sun Kwok; Yong Zhang, E-mail: sunkwok@hku.hk [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong)

    2013-07-01T23:59:59.000Z

    We suggest that the carrier of the unidentified infrared emission (UIE) bands is an amorphous carbonaceous solid with mixed aromatic/aliphatic structures, rather than free-flying polycyclic aromatic hydrocarbon molecules. Through spectral fittings of the astronomical spectra of the UIE bands, we show that a significant amount of the energy is emitted by the aliphatic component, implying that aliphatic groups are an essential part of the chemical structure. Arguments in favor of an amorphous, solid-state structure rather than a gas-phase molecule as a carrier of the UIE are also presented.

  15. Nonperturbative infrared fixed point in sextet QCD

    E-Print Network [OSTI]

    Benjamin Svetitsky; Yigal Shamir; Thomas DeGrand

    2008-09-18T23:59:59.000Z

    The SU(3) gauge theory with fermions in the sextet representation is one of several theories of interest for technicolor models. We have carried out a Schrodinger functional (SF) calculation for the lattice theory with two flavors of Wilson fermions. We find that the discrete beta function changes sign when the SF renormalized coupling is in the neighborhood of g^2 = 2.0, showing a breakdown of the perturbative picture even though the coupling is weak. The most straightforward interpretation is an infrared-stable fixed point.

  16. Infrared Mapping Helps Optimize Catalytic Reactions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm)HydrogenRFPTri-Party AgreementInfrared Mapping Helps

  17. Infrared Mapping Helps Optimize Catalytic Reactions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News link toInfluence ofQuickdegreeInfrared

  18. Infrared Mapping Helps Optimize Catalytic Reactions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News link toInfluenceInfrared Mapping Helps Optimize

  19. Infrared Mapping Helps Optimize Catalytic Reactions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News link toInfluenceInfrared Mapping Helps

  20. Infrared near-field spectroscopy of trace explosives using an...

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

    spectroscopy of trace explosives using an external cavity quantum cascade laser. Infrared near-field spectroscopy of trace explosives using an external cavity quantum cascade...

  1. Infrared Spectroscopy and Optical Constants of Porous Amorphous...

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

    Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Infrared Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Abstract: Reflection-absorption...

  2. Thermal And-Or Near Infrared At Yellowstone Region (Hellman ...

    Open Energy Info (EERE)

    Yellowstone Caldera Geothermal Region Exploration Technique Thermal And-Or Near Infrared Activity Date Usefulness useful DOE-funding Unknown References Melanie J. Hellman,...

  3. An Infrared Spectral Database for Detection of Gases Emitted...

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

    Database for Detection of Gases Emitted by Biomass Burning. An Infrared Spectral Database for Detection of Gases Emitted by Biomass Burning. Abstract: We report the construction of...

  4. Detection of illegal drugs using passive infrared sensing

    SciTech Connect (OSTI)

    Bennett, C.L.; Carter, M.R.; Fields, D.J.

    1996-04-12T23:59:59.000Z

    This report summarizes results on experiments testing the feasibility of detecting illegal drugs using passive infrared spectroscopy in the 8-13 micrometer spectral band.

  5. algaas mid infrared: Topics by E-print Network

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

    populations of mid-infrared sources, probably reflecting differences in the intracluster media and recent dynamical evolution of these systems. J. E. Geach; Ian Smail; R. S....

  6. Mid-Infrared Emission from Elliptical Galaxies: Sensitivity to Stellar Age

    E-Print Network [OSTI]

    Pasquale Temi; Fabrizio Brighenti; William G. Mathews

    2005-11-10T23:59:59.000Z

    Mid-infrared observations (3.6 - 24 microns) of normal giant elliptical galaxies with the Spitzer space telescope are consistent with pure populations of very old stars with no evidence of younger stars. Most of the stars in giant elliptical galaxies are old but the mean stellar age determined from Balmer absorption in optical spectra can appear much younger due to a small admixture of younger stars. The mean stellar age can also be determined from the spectral energy distribution in the mid-infrared which decreases with time relative to the optical emission and shifts to shorter wavelengths. The observed flux ratios F_8um/F_3.6um and F_24um/F_3.6um for elliptical galaxies with the oldest Balmer line ages are lower than predicted by recent models of single stellar populations. For ellipticals with the youngest Balmer line ages in our sample, 3-5 Gyrs, the flux ratios F_24um/F_3.6um are identical to those of the oldest stars. When theoretical mid-IR spectra of old (12 Gyr) and young stellar populations are combined, errors in the F_24um/F_3.6um observations are formally inconsistent with a mass fraction of young stars that exceeds ~1%. This is less than the fraction of young stars expected in discussions of recent surveys of elliptical galaxies at higher redshifts. However, this inconsistancy between Balmer line ages and those inferred from mid-IR observations must be regarded as provisional until more accurate observations and theoretical spectra become available. Finally, there is no evidence to date that central disks or patches of dust commonly visible in optical images of elliptical galaxies contribute sensibly to the mid-IR spectrum.

  7. Detection of exposure damage in composite materials using Fourier transform infrared technology.

    SciTech Connect (OSTI)

    Roach, Dennis Patrick; Duvall, Randy L.

    2010-09-01T23:59:59.000Z

    Goal: to detect the subtle changes in laminate composite structures brought about by thermal, chemical, ultraviolet, and moisture exposure. Compare sensitivity of an array of NDI methods, including Fourier Transform Infrared Spectroscopy (FTIR), to detect subtle differences in composite materials due to deterioration. Inspection methods applied: ultrasonic pulse echo, through transmission ultrasonics, thermography, resonance testing, mechanical impedance analysis, eddy current, low frequency bond testing & FTIR. Comparisons between the NDI methods are being used to establish the potential of FTIR to provide the necessary sensitivity to non-visible, yet significant, damage in the resin and fiber matrix of composite structures. Comparison of NDI results with short beam shear tests are being used to relate NDI sensitivity to reduction in structural performance. Chemical analyses technique, which measures the infrared intensity versus wavelength of light reflected on the surface of a structure (chemical and physical information via this signature). Advances in instrumentation have resulted in hand-held portable devices that allow for field use (few seconds per scan). Shows promise for production quality assurance and in-service applications on composite aircraft structures (scarfed repairs). Statistical analysis on frequency spectrums produced by FTIR interrogations are being used to produce an NDI technique for assessing material integrity. Conclusions are: (1) Use of NDI to assess loss of composite laminate integrity brought about by thermal, chemical, ultraviolet, and moisture exposure. (2) Degradation trends between SBS strength and exposure levels (temperature and time) have been established for different materials. (3) Various NDI methods have been applied to evaluate damage and relate this to loss of integrity - PE UT shows greatest sensitivity. (4) FTIR shows promise for damage detection and calibration to predict structural integrity (short beam shear). (5) Detection of damage for medium exposure levels (possibly resin matrix degradation only) is more difficult and requires additional study. (6) These are initial results only - program is continuing with additional heat, UV, chemical and water exposure test specimens.

  8. CHAPTER 8CHAPTER 8CHAPTER 8:CHAPTER 8: Thermal InfraredThermal Infrared

    E-Print Network [OSTI]

    Gilbes, Fernando

    measurable temperature variations of 1/10,000 C.p In World War I, S. O. Hoffman could detect men at 120 m remote sensor data were collected by the U. S. Television IR Operational Satellite (TIROS) launched a Coastal Zone Color Scanner (CZCS) that included a thermal infrared sensor for monitoring sea

  9. Direct comparison of EUV and visible-light interferometries Kenneth A. Goldberg*a, Patrick Naulleaua, SangHun Leea,b, Chang Changa,b, Cynthia Bresloffc,

    E-Print Network [OSTI]

    Direct comparison of EUV and visible-light interferometries Kenneth A. Goldberg*a, Patrick? EUV imaging systems provide the first direct comparisons of visible-light and at-wavelength EUV-coated Schwarzschild objectives are discussed. Favorable agreement has been achieved between EUV and visible-light

  10. Infrared and ultraviolet problem for the Nelson model with variable coefficients

    E-Print Network [OSTI]

    Infrared and ultraviolet problem for the Nelson model with variable coefficients C. G´erard,1 , F of the Hamiltonian in the presence of the infrared problem, i.e. assuming that the boson mass tends to 0 at infinity state one usually speaks of the infrared problem or infrared divergence. The infrared problem arises

  11. $\\alpha$ Centauri A in the far infrared

    E-Print Network [OSTI]

    Liseau, R; Olofsson, G; Bryden, G; Marshall, J P; Ardila, D; Aran, A Bayo; Danchi, W C; del Burgo, C; Eiroa, C; Ertel, S; Fridlund, M C W; Krivov, A V; Pilbratt, G L; Roberge, A; Thbault, P; Wiegert, J; White, G J

    2012-01-01T23:59:59.000Z

    Chromospheres and coronae are common phenomena on solar-type stars. Understanding the energy transfer to these heated atmospheric layers requires direct access to the relevant empirical data. Study of these structures has, by and large, been limited to the Sun thus far. The region of the temperature reversal can be directly observed only in the far infrared and submm. We aim at the determination of the characteristics of the atmosphere in the region of the temperature minimum of the solar sister star alpha Cen A. For the nearby binary system alpha Centauri, stellar parameters are known with high accuracy from measurements. For the basic model parameters Teff, log g and [Fe/H], we interpolate in the grid of GAIA/PHOENIX stellar model atmospheres and compute the corresponding model for the G2 V star alpha Cen A. Comparison with photometric measurements shows excellent agreement between observed photospheric data in the optical and infrared. For longer wavelengths, the modelled spectral energy distribution is co...

  12. The Effect of Lunar-like Satellites on the Orbital Infrared Light Curves of Earth-analog Planets

    E-Print Network [OSTI]

    Moskovitz, Nicholas A; Williams, Darren

    2008-01-01T23:59:59.000Z

    We investigate the influence of lunar-like satellites on the infrared orbital light curves of Earth-analog extra-solar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet. We use an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of the Earth while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g. via spectroscopy or visible-wavelength detection of specular glint from a surface ocean) only the largest (approximately Mars-siz...

  13. region between x-rays and visible light, can be observed only by sensors above the Earth's

    E-Print Network [OSTI]

    Waliser, Duane E.

    was started on concepts for shielding the Starprobe spacecraft from heating during the close flyby when solar and infrared wave- lengths, to have a silicated surface. A radio- metric model of this Earth-crossing asteroid· Voyager observations of hot spots on the Jupiter moon 10 led to reexamination of Earth-based infrared

  14. Cancellation of Infrared divergences to all orders in LFQED

    E-Print Network [OSTI]

    Jai D. More; Anuradha Misra

    2014-05-06T23:59:59.000Z

    Coherent state approach has been proposed as an alternate way to deal with the true infrared divergences in light front field theory. We show that infrared divergences in fermion mass renormalization are eliminated to all orders in light front time ordered perturbation theory if one uses coherent state basis instead of the usual Fock basis to calculate the Hamiltonian matrix elements.

  15. Near-infrared spectroscopic tissue imaging for medical applications

    DOE Patents [OSTI]

    Demos; Stavros (Livermore, CA), Staggs; Michael C. (Tracy, CA)

    2006-03-21T23:59:59.000Z

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  16. Multivariate classification of infrared spectra of cell and tissue samples

    DOE Patents [OSTI]

    Haaland, David M. (Albuquerque, NM); Jones, Howland D. T. (Albuquerque, NM); Thomas, Edward V. (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    Multivariate classification techniques are applied to spectra from cell and tissue samples irradiated with infrared radiation to determine if the samples are normal or abnormal (cancerous). Mid and near infrared radiation can be used for in vivo and in vitro classifications using at least different wavelengths.

  17. active infrared systems: Topics by E-print Network

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

    active infrared systems First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Infrared spectroscopic...

  18. akari infrared observations: Topics by E-print Network

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

    akari infrared observations First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 The Infrared Astronomical...

  19. affecting thermal infrared: Topics by E-print Network

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

    affecting thermal infrared First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Thermal Infrared Remote...

  20. Apparatus and method for transient thermal infrared spectrometry

    DOE Patents [OSTI]

    McClelland, John F. (Ames, IA); Jones, Roger W. (Ames, IA)

    1991-12-03T23:59:59.000Z

    A method and apparatus for enabling analysis of a material (16, 42) by applying a cooling medium (20, 54) to cool a thin surface layer portion of the material and to transiently generate a temperature differential between the thin surface layer portion and the lower portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material. The altered thermal infrared emission spectrum of the material is detected by a spectrometer/detector (28, 50) while the altered thermal infrared emission spectrum is sufficiently free of self-absorption by the material of the emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation, so that the detected altered thermal infrared emission spectrum is indicative of the characteristics relating to the molecular composition of the material.

  1. akari infrared spectroscopy: Topics by E-print Network

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

    akari infrared spectroscopy First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Near-infrared and...

  2. Near-infrared spectroscopic tissue imaging for medical applications

    DOE Patents [OSTI]

    Demos, Stavros (Livermore, CA); Staggs, Michael C. (Tracy, CA)

    2006-12-12T23:59:59.000Z

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  3. Infrared Limit of Gluon Amplitudes at Strong Coupling

    E-Print Network [OSTI]

    Evgeny I. Buchbinder

    2007-07-27T23:59:59.000Z

    In this note, we propose that the infrared structure of gluon amplitudes at strong coupling can be fully extracted from a local consideration near cusps. This is consistent with field theory and correctly reproduces the infrared divergences of the four-gluon amplitude at strong coupling calculated recently by Alday and Maldacena.

  4. als infrared beamlines: Topics by E-print Network

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

    als infrared beamlines First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Noise reduction for the infrared...

  5. akari infrared camera: Topics by E-print Network

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

    akari infrared camera First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 The Infrared Camera (IRC) for...

  6. akari space infrared: Topics by E-print Network

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

    akari space infrared First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 The Infrared Astronomical Mission...

  7. Temperature profile of the infrared image Heat exchange between

    E-Print Network [OSTI]

    Jaehne, Bernd

    T Temperature profile of the infrared image Heat exchange between atmosphere and ocean References coefficient of heat in water determine the heat transfer velocity: *t Infrared images of the water surface: a-Karls-Universität Heidelberg www.uni-heidelberg.de Active controlled flux technique (ACFT) Continuous heat flux Periodic heat

  8. Synthesis and Evaluation of Polyhydroxylated Near-Infrared

    E-Print Network [OSTI]

    Larson-Prior, Linda

    Synthesis and Evaluation of Polyhydroxylated Near-Infrared Carbocyanine Molecular Probes Zongren achilefus@wustl.edu Received April 22, 2004 ABSTRACT A new near-infrared (NIR) fluorescent molecular probe as needlelike crystals directly from the reaction mixture by controlled heating of the mixture between 100

  9. Infrared Thermography User Group (IRUG) 2003 Meeting Proceedings

    SciTech Connect (OSTI)

    None

    2003-10-01T23:59:59.000Z

    Infrared thermography is a key component of predictive maintenance programs for fossil and nuclear utilities. EPRI's Technology for Equipment Assessment and Maintenance (TEAM) group and their Maintenance Management & Technology (MM&T) program supported the 13th Infrared Thermography Users' Group (IRUG) meeting, which was hosted and also supported by Progress Energy.

  10. OIL SPILL SENSOR USING MULTISPECTRAL INFRARED IMAGING VIA 1 MINIMIZATION

    E-Print Network [OSTI]

    Yin, Wotao

    OIL SPILL SENSOR USING MULTISPECTRAL INFRARED IMAGING VIA 1 MINIMIZATION Yingying Li , Wei Computational and Applied Mathematics, Rice University ABSTRACT Early detection of oil spill events is the key in detecting the early onset of a small-scale oil spill event. Based on an infrared oil-water contrast model

  11. Ultraluminous Infrared Galaxies and the Origin of QSOs

    E-Print Network [OSTI]

    D. B. Sanders

    2001-09-09T23:59:59.000Z

    We review the evidence which suggests that ultraluminous infrared galaxies (ULIGs) are the precursors of optically selected quasi-stellar objects (QSOs) and discuss additional data that suggests that the majority, if not all QSOs, may begin their lives in an intense infrared phase. Implications for the host galaxies of QSOs are discussed.

  12. A Panoramic Mid-infrared Survey of Two Distant Clusters

    E-Print Network [OSTI]

    Geach, J E; Ellis, Richard S; Moran, S M; Smith, G P; Treu, T; Kneib, J P; Edge, A C; Kodama, T; Smail, Ian

    2006-01-01T23:59:59.000Z

    (abridged) We present panoramic Spitzer MIPS 24um observations covering 9x9Mpc (25'x25') fields around two massive clusters, Cl0024+16 and MS0451-03, at z=0.39 and z=0.55. Our observations cover a very wide range of environments within these clusters, from high-density regions around the cores out to the turn-around radius. Cross-correlating the mid-infrared catalogs with deep optical and near-infrared imaging of these fields, we investigate the optical/near-infrared colors of the mid-infrared sources. We find excesses of mid-infrared sources with optical/near-infrared colors expected of cluster members in the two clusters and test this selection using spectroscopically confirmed 24um members. The much more significant excess is associated with Cl0024+16, whereas MS0451-03 has comparatively few mid-infrared sources. The mid-infrared galaxy population in Cl0024+16 appears to be associated with dusty star-forming galaxies (typically redder than the general cluster population by up to A_V~1-2 mags) rather than e...

  13. Infrared absorption spectra, radiative efficiencies, and global warming potentials

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Infrared absorption spectra, radiative efficiencies, and global warming potentials of newly.mdpi.com/journal/atmosphere Article Infrared Absorption Spectra, Radiative Efficiencies, and Global Warming Potentials of Newly of 600­1730 cm-1 . These spectra are then used to calculate the radiative efficiencies and global warming

  14. Development of nanosecond time-resolved infrared detection at the LEAF pulse radiolysis facility

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

    Grills, David C.; Farrington, Jaime A.; Layne, Bobby H.; Preses, Jack M.; Bernstein, Herbert J.; Wishart, James F.

    2015-04-01T23:59:59.000Z

    When coupled with transient absorption spectroscopy, pulse radiolysis, which utilizes high-energy electron pulses from an accelerator, is a powerful tool for investigating the kinetics and thermodynamics of a wide range of radiation-induced redox and electron transfer processes. The majority of these investigations detect transient species in the UV, visible, or near-IR spectral regions. Unfortunately, the often-broad and featureless absorption bands in these regions can make the definitive identification of intermediates difficult. Time-resolved vibrational spectroscopy would offer much improved structural characterization, but has received only limited application in pulse radiolysis. In this paper, we describe in detail the development of amoreunique nanosecond time-resolved infrared (TRIR) detection capability for condensed-phase pulse radiolysis on a new beam line at the LEAF facility of Brookhaven National Laboratory. The system makes use of a suite of high-power, continuous wave external-cavity quantum cascade lasers as the IR probe source, with coverage from 2330-1051 cm?. The response time of the TRIR detection setup is ?40 ns, with a typical sensitivity of ?100 OD after 4-8 signal averages using a dual-beam probe/reference normalization detection scheme. This new detection method has enabled mechanistic investigations of a range of radiation-induced chemical processes, some of which are highlighted here.less

  15. The gas-rich disk of HR 4049: A study of the infrared spectrum

    SciTech Connect (OSTI)

    Malek, Sarah E. [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Cami, Jan [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 Canada and SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94034 (United States)

    2014-05-02T23:59:59.000Z

    Here, we present a summary of our analyses of the mid-and near-infrared spectrum of the unusual evolved binary HR 4049. We f nd that the disk is massive (M > 8 10{sup ?3} M{sub ?}), warm and radially extended. We also report some enrichment in {sup 17}O and {sup 18}O and a comparison of observations from Spitzer-IRS to those obtained by ISO-SWS 10 years earlier reveals that the CO{sub 2} f ux has more than doubled in this time, indicating active and ongoing chemical evolution in the circumbinary disk. Given the high column densities of the gas in the disk, we expect that the molecular gas plays a crucial role in the thermal properties of the circumbinary disk by allowing visible light to heat the dust and then trapping the IR photons emitted by the dust. This will result in higher temperatures and a more homogeneous temperature structure in the disk. Finally, we estimate a mass for the primary in HR 4049 which is too low for the star to have experienced a typical evolutionary path.

  16. Development of nanosecond time-resolved infrared detection at the LEAF pulse radiolysis facility

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

    Grills, David C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Farrington, Jaime A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Layne, Bobby H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Preses, Jack M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bernstein, Herbert J. [Dowling College, Shirley, NY (United States); Wishart, James F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-04-01T23:59:59.000Z

    When coupled with transient absorption spectroscopy, pulse radiolysis, which utilizes high-energy electron pulses from an accelerator, is a powerful tool for investigating the kinetics and thermodynamics of a wide range of radiation-induced redox and electron transfer processes. The majority of these investigations detect transient species in the UV, visible, or near-IR spectral regions. Unfortunately, the often-broad and featureless absorption bands in these regions can make the definitive identification of intermediates difficult. Time-resolved vibrational spectroscopy would offer much improved structural characterization, but has received only limited application in pulse radiolysis. In this paper, we describe in detail the development of a unique nanosecond time-resolved infrared (TRIR) detection capability for condensed-phase pulse radiolysis on a new beam line at the LEAF facility of Brookhaven National Laboratory. The system makes use of a suite of high-power, continuous wave external-cavity quantum cascade lasers as the IR probe source, with coverage from 2330-1051 cm?. The response time of the TRIR detection setup is ?40 ns, with a typical sensitivity of ?100 OD after 4-8 signal averages using a dual-beam probe/reference normalization detection scheme. This new detection method has enabled mechanistic investigations of a range of radiation-induced chemical processes, some of which are highlighted here.

  17. Infrared non-destructive evaluation method and apparatus

    DOE Patents [OSTI]

    Baleine, Erwan; Erwan, James F; Lee, Ching-Pang; Stinelli, Stephanie

    2014-10-21T23:59:59.000Z

    A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

  18. The nearby eclipsing stellar system delta Velorum - I. Origin of the infrared excess from VISIR and NACO imaging

    E-Print Network [OSTI]

    Pierre Kervella; Frdric Thvenin; Monika Petr-Gotzens

    2008-11-11T23:59:59.000Z

    - Context: The triple stellar system delta Vel system presents a significant infrared excess, whose origin is still being debated. A large infrared bow shock has been discovered using Spitzer/MIPS observations. Although it appears as a significant contributor to the measured IR excess, the possibility exists that a circumstellar IR excess is present around the stars of the system. - Aims: The objective of the present VISIR and NACO observations is to identify whether one of the stars of the delta Vel system presents a circumstellar photometric excess in the thermal IR domain and to quantify it. - Methods: We observed delta Vel using the imaging modes of the ESO/VLT instruments VISIR (in BURST mode) and NACO to resolve the A-B system (0.6" separation) and obtain the photometry of each star. We also obtained one NACO photometry epoch precisely at the primary (annular) eclipse of delta Vel Aa by Ab. - Results: Our photometric measurements with NACO (2.17 mic), complemented by the existing visible photometry allowed us to reconstruct the spectral energy distribution of the three stars. We then compared the VISIR photometry (8.6-12.8 mic) to the expected photospheric emission from the three stars at the corresponding wavelengths. - Conclusions: We can exclude the presence of a circumstellar thermal infrared excess around delta Vel A or B down to a few percent level. This supports the conclusions of Gaspar et al. (2008) that the IR excess of delta Vel has an interstellar origin, although a cold circumstellar disk could still be present. In addition, we derive the spectral types of the three stars Aa, Ab, and B (respectively A2IV, A4V and F8V), and we estimate the age of the system around 400-500 Myr.

  19. Can a many-nucleon structure be visible in bremsstrahlung emission during $\\alpha$ decay?

    E-Print Network [OSTI]

    Maydanyuk, Sergei P; Zou, Li-Ping

    2015-01-01T23:59:59.000Z

    We analyze if the nucleon structure of the $\\alpha$ decaying nucleus can be visible in the experimental bremsstrahlung spectra of the emitted photons which accompany such a decay. We develop a new formalism of the bremsstrahlung model taking into account distribution of nucleons in the $\\alpha$ decaying nuclear system. We conclude the following: (1) After inclusion of the nucleon structure into the model the calculated bremsstrahlung spectrum is changed very slowly for a majority of the $\\alpha$ decaying nuclei. However, we have observed that visible changes really exist for the $^{106}{\\rm Te}$ nucleus ($Q_{\\alpha}=4.29$ MeV, $T_{1/2}$=70 mks) even for the energy of the emitted photons up to 1 MeV. This nucleus is a good candidate for future experimental study of this task. (2) Inclusion of the nucleon structure into the model increases the bremsstrahlung probability of the emitted photons. (3) We find the following tendencies for obtaining the nuclei, which have bremsstrahlung spectra more sensitive to the ...

  20. Fabrication and characterization of the source grating for visibility improvement of neutron phase imaging with gratings

    SciTech Connect (OSTI)

    Kim, Jongyul [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Nuclear and Quantum Engineering Department, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Lee, Kye Hong; Lim, Chang Hwy; Kim, Taejoo [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Ahn, Chi Won [Nano Fusion Technology Division, National Nanofab Center, Daejeon 305-701 (Korea, Republic of); Cho, Gyuseong [Nuclear and Quantum Engineering Department, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Lee, Seung Wook [School of Mechanical Engineering, Pusan National University, Pusan 609-735 (Korea, Republic of)

    2013-06-15T23:59:59.000Z

    The fabrication of gratings including metal deposition processes for highly neutron absorbing lines is a critical issue to achieve a good visibility of the grating-based phase imaging system. The source grating for a neutron Talbot-Lau interferometer is an array of Gadolinium (Gd) structures that are generally made by sputtering, photo-lithography, and chemical wet etching. However, it is very challenging to fabricate a Gd structure with sufficient neutron attenuation of approximately more than 20 {mu}m using a conventional metal deposition method because of the slow Gd deposition rate, film stress, high material cost, and so on. In this article, we fabricated the source gratings for neutron Talbot-Lau interferometers by filling the silicon structure with Gadox particles. The new fabrication method allowed us a very stable and efficient way to achieve a much higher Gadox filled structure than a Gd film structure, and is even more suitable for thermal polychromatic neutrons, which are more difficult to stop than cold neutrons. The newly fabricated source gratings were tested at the polychromatic thermal neutron grating interferometer system of HANARO at the Korea Atomic Energy Research Institute, and the visibilities and images from the neutron phase imaging system with the new source gratings were compared with those fabricated by a Gd deposition method.

  1. Surface photoelectric and visible light driven photocatalytic properties of zinc antimonate-based photocatalysts

    SciTech Connect (OSTI)

    Wu, Shaojun; Li, Guoqiang; Zhang, Yang [Key Laboratory of Photovoltaic Materials of Henan Province and School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute of Physics for Microsystems, Henan University, Kaifeng 475004 (China); Zhang, Weifeng, E-mail: wfzhang@henu.edu.cn [Key Laboratory of Photovoltaic Materials of Henan Province and School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute of Physics for Microsystems, Henan University, Kaifeng 475004 (China)

    2013-03-15T23:59:59.000Z

    Highlights: ? N-doped and pristine ZnSb{sub 2}O{sub 6} photocatalysts were synthesized by a facile method. ? N-doped ZnSb{sub 2}O{sub 6} shows a significant enhanced visible light photocatalytic activity. ? The N-doped ZnSb{sub 2}O{sub 6} shows the reduced surface photovoltage signals. - Abstract: The N-doped and pristine ZnSb{sub 2}O{sub 6} photocatalysts were synthesized by a facile method. The samples were characterized by X-ray diffraction (XRD), UVvis spectroscopy, surface photovoltage spectroscopy and scanning electron microscopy. The photocatalytic activities of the prepared samples were evaluated from the degradation of rhodamine B (RhB) under full arc and visible light irradiation of Xe lamp. The XRD and UVvis results indicated that the N-doping did not change the crystal structure, but decrease the band gap in comparison with the pristine one. The N-doped ZnSb{sub 2}O{sub 6} shows the reduced surface photovoltage signals and the significantly enhanced photocatalytic activity under two irradiation conditions.

  2. Systematic expansion for infrared oscillator basis extrapolations

    E-Print Network [OSTI]

    R. J. Furnstahl; S. N. More; T. Papenbrock

    2014-03-20T23:59:59.000Z

    Recent work has demonstrated that the infrared effects of harmonic oscillator basis truncations are well approximated by imposing a partial-wave Dirichlet boundary condition at a properly identified radius L. This led to formulas for extrapolating the corresponding energy E_L and other observables to infinite L and thus infinite basis size. Here we reconsider the energy for a two-body system with a Dirichlet boundary condition at L to identify and test a consistent and systematic expansion for E_L that depends only on observables. We also generalize the energy extrapolation formula to nonzero angular momentum, and apply it to the deuteron. Formulas given previously for extrapolating the radius are derived in detail.

  3. Oxidation of carbynes: Signatures in infrared spectra

    SciTech Connect (OSTI)

    Cinquanta, E., E-mail: eugenio.cinquanta@mdm.imm.cnr.it, E-mail: p.rudolf@rug.nl [CIMAINA, University of Milan, Via Celoria 16, 20133 Milano (Italy); Department of Materials Science, University of Milan Bicocca, Via Cozzi 53, 20125 Milano (Italy); Manini, N.; Caramella, L.; Onida, G. [European Theoretical Spectroscopy Facility (ETSF), Via Celoria 16, 20133 Milano (Italy); Physics Department, University of Milan, Via Celoria 16, 20133 Milano (Italy); Ravagnan, L.; Milani, P. [CIMAINA, University of Milan, Via Celoria 16, 20133 Milano (Italy); Physics Department, University of Milan, Via Celoria 16, 20133 Milano (Italy); Rudolf, P., E-mail: eugenio.cinquanta@mdm.imm.cnr.it, E-mail: p.rudolf@rug.nl [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

    2014-06-28T23:59:59.000Z

    We report and solidly interpret the infrared spectrum of both pristine and oxidized carbynes embedded in a pure-carbon matrix. The spectra probe separately the effects of oxidation on sp- and on sp{sup 2}-hybridized carbon, and provide information on the stability of the different structures in an oxidizing atmosphere. The final products are mostly short end-oxidized carbynes anchored with a double bond to sp{sup 2} fragments, plus an oxidized sp{sup 2} amorphous matrix. Our results have important implications for the realization of carbyne-based nano-electronics devices and highlight the active participation of carbynes in astrochemical reactions where they act as carbon source for the promotion of more complex organic species.

  4. Pigments which reflect infrared radiation from fire

    DOE Patents [OSTI]

    Berdahl, Paul H. (Oakland, CA)

    1998-01-01T23:59:59.000Z

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer (.mu.m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 .mu.m or, for cool smoky fires, about 2 .mu.m to about 16 .mu.m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 .mu.m to about 2 .mu.m and thin leafing aluminum flake pigments.

  5. Automated Spot Weld Inspection using Infrared Thermography

    SciTech Connect (OSTI)

    Chen, Jian [ORNL] [ORNL; Zhang, Wei [ORNL] [ORNL; Yu, Zhenzhen [ORNL] [ORNL; Feng, Zhili [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    An automated non-contact and non-destructive resistance spot weld inspection system based on infrared (IR) thermography was developed for post-weld applications. During inspection, a weld coupon was heated up by an auxiliary induction heating device from one side of the weld, while the resulting thermal waves on the other side were observed by an IR camera. The IR images were analyzed to extract a thermal signature based on normalized heating time, which was then quantitatively correlated to the spot weld nugget size. The use of normalized instead of absolute IR intensity was found to be useful in minimizing the sensitivity to the unknown surface conditions and environment interference. Application of the IR-based inspection system to different advanced high strength steels, thickness gauges and coatings were discussed.

  6. Mid-Infrared Spectra of Be Stars

    E-Print Network [OSTI]

    S. A. Rinehart; J. R. Houck; J. D. Smith

    1999-10-11T23:59:59.000Z

    We present the first medium-resolution ($R\\sim 600$) mid-infrared (8-13.3\\micron) spectra of 11 Be stars. A large number of lines are observed and identified in these spectra, including, as an example, 39 hydrogen recombination lines in the spectrum of $\\gamma$ Cas. In the majority of our spectra, all of the observed lines are attributable to hydrogen recombination. Two of the sources, $\\beta$ Lyr and MWC 349 also show emission from other species. Both of these objects show evidence of [Ne II] emission, and $\\beta$ Lyr also shows evidence of He I emission. We tabulate the effective line strength and line widths for the observed lines, and briefly discuss the physical implications of the observed line series. We also use a simple model of free-free emission to characterize the disks around these sources.

  7. Pigments which reflect infrared radiation from fire

    DOE Patents [OSTI]

    Berdahl, P.H.

    1998-09-22T23:59:59.000Z

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer ({micro}m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 {micro}m or, for cool smoky fires, about 2 {micro}m to about 16 {micro}m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 {micro}m to about 2 {micro}m and thin leafing aluminum flake pigments. 4 figs.

  8. A Panoramic Mid-infrared Survey of Two Distant Clusters

    E-Print Network [OSTI]

    J. E. Geach; Ian Smail; R. S. Ellis; S. M. Moran; G. P. Smith; T. Treu; J. -P. Kneib; A. C. Edge; T. Kodama

    2006-06-06T23:59:59.000Z

    (abridged) We present panoramic Spitzer MIPS 24um observations covering 9x9Mpc (25'x25') fields around two massive clusters, Cl0024+16 and MS0451-03, at z=0.39 and z=0.55. Our observations cover a very wide range of environments within these clusters, from high-density regions around the cores out to the turn-around radius. Cross-correlating the mid-infrared catalogs with deep optical and near-infrared imaging of these fields, we investigate the optical/near-infrared colors of the mid-infrared sources. We find excesses of mid-infrared sources with optical/near-infrared colors expected of cluster members in the two clusters and test this selection using spectroscopically confirmed 24um members. The much more significant excess is associated with Cl0024+16, whereas MS0451-03 has comparatively few mid-infrared sources. The mid-infrared galaxy population in Cl0024+16 appears to be associated with dusty star-forming galaxies (typically redder than the general cluster population by up to A_V~1-2 mags) rather than emission from dusty tori around active galactic nuclei (AGN) in early-type hosts. The inferred total-infrared star-formation rates in Cl0024+16 are typically >5x greater than those found from a similar Halpha survey, indicating significant obscured activity in the cluster population. We find evidence for strong evolution of the level of dust-obscured star-formation in dense environments out to z=0.5, analogous to the rise in fraction of optically-selected star-forming galaxies seen in clusters and the field out to similar redshifts. However, there are clearly significant cluster-to-cluster variations in the populations of mid-infrared sources, probably reflecting differences in the intracluster media and recent dynamical evolution of these systems.

  9. Mid-infrared ultra-short mode-locked fiber laser utilizing topological insulator Bi2Te3 nano-sheets as the saturable absorber

    E-Print Network [OSTI]

    Yin, Ke; Zheng, Xin; Yu, Hao; Cheng, Xiangai; Hou, Jing

    2015-01-01T23:59:59.000Z

    The newly-emergent two-dimensional topological insulators (TIs) have shown their unique electronic and optical properties, such as good thermal management, high nonlinear refraction index and ultrafast relaxation time. Their narrow energy band gaps predict their optical absorption ability further into the mid-infrared region and their possibility to be very broadband light modulators ranging from the visible to the mid-infrared region. In this paper, a mid-infrared mode-locked fluoride fiber laser with TI Bi2Te3 nano-sheets as the saturable absorber is presented. Continuous wave lasing, Q-switched and continuous-wave mode-locking (CW-ML) operations of the laser are observed sequentially by increasing the pump power. The observed CW-ML pulse train has a pulse repetition rate of 10.4 MHz, a pulse width of ~6 ps, and a center wavelength of 2830 nm. The maximum achievable pulse energy is 8.6 nJ with average power up to 90 mW. This work forcefully demonstrates the promising applications of two-dimensional TIs for ...

  10. Tunable infrared source employing Raman mixing

    DOE Patents [OSTI]

    Byer, Robert L. (Stanford, CA); Herbst, Richard L. (Menlo Park, CA)

    1980-01-01T23:59:59.000Z

    A tunable source of infrared radiation is obtained by irradiating an assemblage of Raman active gaseous atoms or molecules with a high intensity pumping beam of coherent radiation at a pump frequency .omega..sub.p to stimulate the generation of Stokes wave energy at a Stokes frequency .omega..sub.s and to stimulate the Raman resonant mode at the Raman mode frequency .omega..sub.R within the irradiated assemblage where the pump frequency .omega..sub.p minus the Stokes frequency .omega..sub.s is equal to the Raman mode frequency .omega..sub.R. The stimulated assemblage is irradiated with a tunable source of coherent radiation at a frequency .omega..sub.i to generate the output infrared radiation of the frequency .omega..sub.0 which is related to the Raman mode frequency .omega..sub.R and the input wave .omega..sub.i by the relation .omega..sub.0 =.omega..sub.i .+-..omega..sub.R. In one embodiment the interaction between the pump wave energy .omega..sub.p and the tunable input wave energy .omega..sub.i is collinear and the ratio of the phase velocity mismatch factor .DELTA.k to the electric field exponential gain coefficient T is within the range of 0.1 to 5. In another embodiment the pump wave energy .omega..sub.p and the tunable input wave energy .omega..sub.i have velocity vectors k.sub.p and k.sub.i which cross at an angle to each other to compensate for phase velocity mismatches in the medium. In another embodiment, the Stokes wave energy .omega..sub.s is generated by pump energy .omega..sub.p in a first Raman cell and .omega..sub.s, .omega..sub.i and .omega..sub.p are combined in a second Raman mixing cell to produce the output at .omega..sub.i.

  11. Characteristic evaluation of a near-infrared Fabry-Perot filter for the InfraRed Imaging Magnetograph (IRIM)

    E-Print Network [OSTI]

    Institute of Technology, Center for Solar-Terrestrial Research, 323 Martin Luther King Blvd., Newark, NJ 110, Kunming, Yunnan 650011, P. R. China ABSTRACT The InfraRed Imaging Magnetograph (IRIM) is a high solar two-dimensional narrow-band spectro-polarimeter working in the near infrared from 1.0 µm to 1.7 µm

  12. Spitzer Mid-Infrared Spectroscopy of Infrared Luminous Galaxies at z~2 I: the Spectra

    E-Print Network [OSTI]

    Lin Yan; Anna Sajina; Dario Fadda; Phil Choi; Lee Armus; George Helou; Harry Teplitz; David Frayer; Jason Surace

    2006-12-12T23:59:59.000Z

    We present the mid-infrared (MIR) spectra obtained with the Spitzer InfraRed Spectrograph (IRS) for a sample of 52 sources, selected as infrared luminous, z>1 candidates in the Extragalactic First Look Survey (XFLS). The sample selection criteria are f(24um) > 0.9mJy, nu fnu(24um)/nu fnu(8um) > 3.16 and nu fnu(24um)/nu fnu(0.7um) > 10. Of the 52 spectra, 47 (90%) produced measurable redshifts based solely on the mid-IR spectral features, with the majority (35/47=74%) at 1.5 1. Their $L_{1600\\AA}$ and $L_{\\rm IR}$ suggest that our sample is among the most luminous and most dust enshrouded systems of its epoch . Our study has revealed a significant population of dust enshrouded galaxies at z~2, whose enormous energy output, comparable to that of quasars, is generated by AGN as well as starburst. This IR luminous population has very little overlap with sub-mm and UV-selected populations (Abridged).

  13. Pushing The Sample-Size Limit Of Infrared Vibrational Nano-Spectroscop...

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

    The Sample-Size Limit Of Infrared Vibrational Nano-Spectroscopy: From Monolayer Towards Single molecule sensitivity. Pushing The Sample-Size Limit Of Infrared Vibrational...

  14. Strategies for Detecting Organic Liquids on Soils Using Mid-Infrared...

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

    Strategies for Detecting Organic Liquids on Soils Using Mid-Infrared Reflection Spectroscopy . Strategies for Detecting Organic Liquids on Soils Using Mid-Infrared Reflection...

  15. Discovery of Active Galactic Nuclei in Mid- and Far-Infrared Deep Surveys with ISO

    E-Print Network [OSTI]

    Yoshiaki Taniguchi

    2001-11-01T23:59:59.000Z

    We present a summary on the discovery of active galactic nuclei in mid- and far-infrared deep surveys with use of the Infrared Space Observatory.

  16. Mid-Infrared Observations of Normal Star-Forming Galaxies: The Infrared Space Observatory Key Project Sample

    E-Print Network [OSTI]

    Daniel A. Dale; Nancy A. Silbermann; George Helou

    2000-05-04T23:59:59.000Z

    We present mid-infrared maps and preliminary analysis for 61 galaxies observed with the ISOCAM instrument aboard the Infrared Space Observatory. Many of the general features of galaxies observed at optical wavelengths---spiral arms, disks, rings, and bright knots of emission---are also seen in the mid-infrared, except the prominent optical bulges are absent at 6.75 and 15 microns. In addition, the maps are quite similar at 6.75 and 15 microns, except for a few cases where a central starburst leads to lower 6.75/15 ratios in the inner region. We also present infrared flux densities and mid-infrared sizes for these galaxies. The mid-infrared color 6.75/15 shows a distinct trend with the far-infrared color 60/100. The quiescent galaxies in our sample (60/100 < 0.6) show 6.75/15 near unity, whereas this ratio drops significantly for galaxies with higher global heating intensity levels. Azimuthally-averaged surface brightness profiles indicate the extent to which the mid-infrared flux is centrally concentrated, and provide information on the radial dependence of mid-infrared colors. The galaxies are mostly well resolved in these maps: almost half of them have < 10% of their flux in the central resolution element. A comparison of optical and mid-infrared isophotal profiles indicates that the optical flux at 4400 Angstroms near the optical outskirts of the galaxies is approximately eight (seven) times that at 6.75 microns (15 microns), comparable with observations of the diffuse quiescent regions of the Milky Way.

  17. Synthesis and characterization of substitutional and interstitial nitrogen-doped titanium dioxides with visible light photocatalytic activity

    SciTech Connect (OSTI)

    Peng Feng [School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640 (China)], E-mail: cefpeng@scut.edu.cn; Cai Lingfeng; Yu Hao; Wang Hongjuan; Yang Jian [School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640 (China)

    2008-01-15T23:59:59.000Z

    Both substitutional and interstitial nitrogen-doped titanium dioxides (N-TiO{sub 2}) were prepared. Their surface states were clarified by XPS spectra of N 1s, O 1s and Ti 2p. The results of photocatalysis show that both substitutional and interstitial N impurities greatly enhance the photoactivity of TiO{sub 2} in visible light. Moreover, the visible light activity of interstitial N-doped TiO{sub 2} is higher than that of substitutional N-doped TiO{sub 2}. The microwave synthesis presented in this paper is a promising and practical method to produce interstitial nitrogen-doped photocatalysts with high visible light activity. - Graphical abstract: Both substitutional and interstitial N impurities can enhance the photoactivity of TiO{sub 2} in visible light; moreover, the visible light activity of interstitial N-doped TiO{sub 2} is higher than that of substitutional N-doped TiO{sub 2}.

  18. Infrared exponents of gluon and ghost propagators from Lattice QCD

    E-Print Network [OSTI]

    O. Oliveira; P. J. Silva

    2007-10-02T23:59:59.000Z

    The compatibility of the pure power law infrared solution of QCD Dyson-Schwinger equations (DSE) and lattice data for the gluon and ghost propagators in Landau gauge is discussed. For the gluon propagator, the lattice data is compatible with the DSE infrared solution with an exponent $\\kappa\\sim0.53$, measured using a technique that suppresses finite volume effects and allows to model these corrections to the lattice data. For the ghost propagator, the lattice data does not seem to follow the infrared DSE power law solution.

  19. Infrared Critical Exponents in Finite-Temperature Coulomb Gauge QCD

    E-Print Network [OSTI]

    Klaus Lichtenegger; Daniel Zwanziger

    2009-11-28T23:59:59.000Z

    We investigate the infrared critical exponents of Coulomb gauge Yang-Mills theory in the limit of very high temperature. This allows us to focus on one scale (the spatial momentum) since all but the lowest Matsubara frequency decouple from the deep infrared. From the first-order Dyson-Schwinger equations in a bare-vertex truncation we obtain infrared exponents which correspond to confining or overconfining (yet mathematically well-defined) solutions. For three spatial dimensions the exponents are close to what is expected for a linearly rising color-Coulomb potential.

  20. Broadband visible light source based on AllnGaN light emitting diodes

    SciTech Connect (OSTI)

    Crawford, Mary H.; Nelson, Jeffrey S.

    2003-12-16T23:59:59.000Z

    A visible light source device is described based on a light emitting diode and a nanocluster-based film. The light emitting diode utilizes a semiconductor quantum well structure between n-type and p-type semiconductor materials on the top surface a substrate such as sapphire. The nanocluster-based film is deposited on the bottom surface of the substrate and can be derived from a solution of MoS.sub.2, MoSe.sub.2, WS.sub.2, and WSe.sub.2 particles of size greater than approximately 2 nm in diameter and less than approximately 15 nm in diameter, having an absorption wavelength greater than approximately 300 nm and less than approximately 650 nm.

  1. Solvothermal synthesis of designed nonstoichiometric strontium titanate for efficient visible-light photocatalysis

    SciTech Connect (OSTI)

    Sulaeman, Uyi; Yin, Shu; Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

    2010-09-06T23:59:59.000Z

    SrTiO{sub 3} powders with various Sr/Ti atomic ratios were synthesized by microwave-assisted solvothermal reactions of SrCl{sub 2} and Ti(OC{sub 3}H{sub 7}){sub 4} in KOH aqueous solutions. The nanoparticles of perovskite type SrTiO{sub 3} structure with the particle size of 30-40 nm were synthesized. The photocatalytic activity was determined by deNO{sub x} ability using light emitting diode lamps of various wavelengths such as 627 nm (red), 530 nm (green), 445 nm (blue), and 390 nm (UV). The photocatalytic activity significantly changed depending on the Sr/Ti atomic ratio, i.e., the strontium rich sample (Sr/Ti atomic ratio>1) showed excellent visible light responsive photocatalytic activity for the oxidative destruction of NO.

  2. Bright and fast voltage reporters across the visible spectrum via electrochromic FRET (eFRET)

    E-Print Network [OSTI]

    Zou, Peng; Douglass, Adam D; Hochbaum, Daniel R; Brinks, Daan; Werley, Christopher A; Harrison, D Jed; Campbell, Robert E; Cohen, Adam E

    2014-01-01T23:59:59.000Z

    We present a palette of brightly fluorescent genetically encoded voltage indicators (GEVIs) with excitation and emission peaks spanning the visible spectrum, sensitivities from 6 - 10% Delta F/F per 100 mV, and half-maximal response times from 1 - 7 ms. A fluorescent protein is fused to an Archaerhodopsin-derived voltage sensor. Voltage-induced shifts in the absorption spectrum of the rhodopsin lead to voltage-dependent nonradiative quenching of the appended fluorescent protein. Through a library screen, we identified linkers and fluorescent protein combinations which reported neuronal action potentials in cultured rat hippocampal neurons with a single-trial signal-to-noise ratio from 6.6 to 11.6 in a 1 kHz imaging bandwidth at modest illumination intensity. The freedom to choose a voltage indicator from an array of colors facilitates multicolor voltage imaging, as well as combination with other optical reporters and optogenetic actuators.

  3. Ultrathin metal-semiconductor-metal resonator for angle invariant visible band transmission filters

    SciTech Connect (OSTI)

    Lee, Kyu-Tae; Seo, Sungyong; Yong Lee, Jae; Jay Guo, L., E-mail: guo@umich.edu [Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-06-09T23:59:59.000Z

    We present transmission visible wavelength filters based on strong interference behaviors in an ultrathin semiconductor material between two metal layers. The proposed devices were fabricated on 2?cm??2?cm glass substrate, and the transmission characteristics show good agreement with the design. Due to a significantly reduced light propagation phase change associated with the ultrathin semiconductor layer and the compensation in phase shift of light reflecting from the metal surface, the filters show an angle insensitive performance up to 70, thus, addressing one of the key challenges facing the previously reported photonic and plasmonic color filters. This principle, described in this paper, can have potential for diverse applications ranging from color display devices to the image sensors.

  4. Enhancement of the visibility of objects located below the surface of a scattering medium

    DOE Patents [OSTI]

    Demos, Stavros

    2013-11-19T23:59:59.000Z

    Techniques are provided for enhancing the visibility of objects located below the surface of a scattering medium such as tissue, water and smoke. Examples of such an object include a vein located below the skin, a mine located below the surface of the sea and a human in a location covered by smoke. The enhancement of the image contrast of a subsurface structure is based on the utilization of structured illumination. In the specific application of this invention to image the veins in the arm or other part of the body, the issue of how to control the intensity of the image of a metal object (such as a needle) that must be inserted into the vein is also addressed.

  5. UV-modulated one-dimensional photonic-crystal resonator for visible lights

    SciTech Connect (OSTI)

    Yang, S. Y.; Yang, P. H.; Liao, C. D.; Chieh, J. J.; Chen, Y. P.; Horng, H. E.; Hong, Chin-Yih; Yang, H. C. [Institute of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan (China); Department of Mechanical Engineering, Nan-kai Institute of Technology, Nantou County 542, Taiwan (China); Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

    2006-12-04T23:59:59.000Z

    The one-dimensional photonic-crystal (A/SiO{sub 2}){sub 6}/ZnO/(SiO{sub 2}/A){sub 6} resonators at visible lights are fabricated and characterized, where A may be ZnO or indium tin oxide. Owing to the absorption of ultraviolet (UV) light by the ZnO layers, the refractive index of ZnO layers is changed temporally. This fact led to a temporary shifting of the forbidden band and the resonant mode of the resonator under UV irradiation. Besides, via adjusting the thickness of the ZnO defect layer, the resonant wavelength is manipulated. These experimental data show good consistence with simulated results.

  6. Single-photon detection timing jitter in a visible light photon counter

    E-Print Network [OSTI]

    Burm Baek; Kyle S. McKay; Martin J. Stevens; Jungsang Kim; Henry H. Hogue; Sae Woo Nam

    2010-01-27T23:59:59.000Z

    Visible light photon counters (VLPCs) offer many attractive features as photon detectors, such as high quantum efficiency and photon number resolution. We report measurements of the single-photon timing jitter in a VLPC, a critical performance factor in a time-correlated single-photon counting measurement, in a fiber-coupled closed-cycle cryocooler. The measured timing jitter is 240 ps full-width-at-half-maximum at a wavelength of 550 nm, with a dark count rate of 25 000 counts per second. The timing jitter increases modestly at longer wavelengths to 300 ps at 1000 nm, and increases substantially at lower bias voltages as the quantum efficiency is reduced.

  7. A holographic bound on the total number of computations in the visible Universe

    E-Print Network [OSTI]

    Maurice H. P. M. van Putten

    2014-08-12T23:59:59.000Z

    Information and encoding are central to holographic imaging of matter and fields within a two-surface. We consider the probability of detection of particles inside star-like holographic screens defined by their propagators. Imaging a point particle of mass m hereby requires I = 2 pi mr in log2 bits on a spherical screen or radius r. Encoding the three hairs of mass, charge, angular momentum and radiation requires a minimum of four bits. This formulation leads directly to Reissner-Nordstrom black holes and extremal Kerr black holes for minimal screens, that envelope event horizons. Applied to the cosmological event horizon, the total number of computations in the visible Universe is found to be bounded by 10e121.

  8. A new list of thorium and argon spectral lines in the visible

    E-Print Network [OSTI]

    C. Lovis; F. Pepe

    2007-03-15T23:59:59.000Z

    Aims. We present a new list of thorium and argon emission lines in the visible obtained by analyzing high-resolution (R=110,000) spectra of a ThAr hollow cathode lamp. The aim of this new line list is to allow significant improvements in the quality of wavelength calibration for medium- to high-resolution astronomical spectrographs. Methods. We use a series of ThAr lamp exposures obtained with the HARPS instrument (High Accuracy Radial-velocity Planet Searcher) to detect previously unknown lines, perform a systematic search for blended lines and correct individual wavelengths by determining the systematic offset of each line relative to the average wavelength solution. Results. We give updated wavelengths for more than 8400 lines over the spectral range 3785-6915 A. The typical internal uncertainty on the line positions is estimated to be ~10 m/s (3.3 parts in 10^8 or 0.18 mA), which is a factor of 2-10 better than the widely used Los Alamos Atlas of the Thorium Spectrum (Palmer & Engleman 1983). The absolute accuracy of the global wavelength scale is the same as in the Los Alamos Atlas. Using this new line list on HARPS ThAr spectra, we are able to obtain a global wavelength calibration which is precise at the 20 cm/s level (6.7 parts in 10^10 or 0.0037 mA). Conclusions. Several research fields in astronomy requiring high-precision wavelength calibration in the visible (e.g. radial velocity planet searches, variability of fundamental constants) should benefit from using the new line list.

  9. Development and Quantification of UV-Visible and Laser Spectroscopic Techniques for Materials Accountability and Process Control

    SciTech Connect (OSTI)

    Ken Czerwinski; Phil Weck; Frederic Poineau

    2010-12-29T23:59:59.000Z

    Ultraviolet-Visible Spectroscopy (UV-Visible) and Time Resolved Laser Fluorescence Spectroscopy (TRLFS) optical techniques can permit on-line, real-time analysis of the actinide elements in a solvent extraction process. UV-Visible and TRLFS techniques have been used for measuring the speciation and concentration of the actinides under laboratory conditions. These methods are easily adaptable to multiple sampling geometries, such as dip probes, fiber-optic sample cells, and flow-through cell geometries. To fully exploit these techniques for GNEP applications, the fundamental speciation of the target actinides and the resulting influence on 3 spectroscopic properties must be determined. Through this effort detection limits, process conditions, and speciation of key actinide components can be establish and utilized in a range of areas of interest to GNEP, especially in areas related to materials accountability and process control.

  10. Visible light photocatalytic degradation of 4-chlorophenol using vanadium and nitrogen co-doped TiO{sub 2}

    SciTech Connect (OSTI)

    Jaiswal, R.; Kothari, D. C. [Department of Physics, University of Mumbai, Vidyanagari, Santacruz (E), Mumbai 400 098 (India); Patel, N.; Miotello, A. [Dipartimento di Fisica, Universita degli Studi di Trento, I-38123 Povo ( Trento) (Italy)

    2013-02-05T23:59:59.000Z

    Vanadium and Nitrogen were codoped in TiO{sub 2} photocatalyst by Sol-gel method to utilize visible light more efficiently for photocatalytic reactions. A noticeable shift of absorption edge to visible light region was obtained for the singly-doped namely V-TiO{sub 2}, N-TiO{sub 2} and codoped V-N-TiO{sub 2} samples in comparison with undoped TiO{sub 2}, with smallest band gap obtained with codoped-TiO{sub 2}. The photocatalytic activities for all TiO{sub 2} photocatalysts were tested by 4-chlorophenol (organic pollutant) degradation under visible light irradiation. It was found that codoped TiO{sub 2} exhibits the best photocatalytic activity, which could be attributed to the synergistic effect produced by V and N dopants.

  11. Ag@AgHPW as a plasmonic catalyst for visible-light photocatalytic degradation of environmentally harmful organic pollutants

    SciTech Connect (OSTI)

    Zhou, Wenhui; Cao, Minhua, E-mail: caomh@bit.edu.cn; Li, Na; Su, Shuangyue; Zhao, Xinyu; Wang, Jiangqiang; Li, Xianghua; Hu, Changwen

    2013-06-01T23:59:59.000Z

    Graphical abstract: Ag@Ag{sub x}H{sub 3?x}PW12O40 (Ag@AgHPW) nanoparticles (NPs), a new visible-light driven plasmonic photocatalyst, are prepared by a green photoreduction strategy without the addition of any surfactant, which show a high activity and stability for the degradation of methyl blue (MB) under visible light irradiation. - Highlights: A new visible-light driven photocatalyst Ag@Ag{sub x}H{sub 3?x}PW{sub 12}O{sub 40} was designed. The photocatalyst shows a high activity for the degradation of methyl blue. The high activity can be ascribed to the synergy of photoexcited AgHPW and Ag. - Abstract: Ag@Ag{sub x}H{sub 3?x}PW{sub 12}O{sub 40} (Ag@AgHPW) nanoparticles (NPs), a new visible-light driven plasmonic photocatalyst, are prepared by a green photoreduction strategy without the addition of any surfactant. They show strong absorption in the visible region because of the localized surface plasmon resonance (LSPR) of Ag NPs. This plasmonic photocatalyst shows a high activity and stability for the degradation of methyl blue (MB) under visible light irradiation, which could be attributed to the highly synergy of photoexcited Ag{sub x}H{sub 3?x}PW{sub 12}O{sub 40} (AgHPW) and plasmon-excited Ag NPs and the confinement effects at interfaces between polyoxometalates (POMs) and silver. POM anions have redox ability and high photocatalytic activity, whereas Ag NPs could effectively accelerate the separation of electrons and holes, both of which contribute to their high activity.

  12. Active infrared materials for beam steering.

    SciTech Connect (OSTI)

    Brener, Igal; Reno, John Louis; Passmore, Brandon Scott; Gin, Aaron V.; Shaner, Eric Arthur; Miao, Xiaoyu; Barrick, Todd A.

    2010-10-01T23:59:59.000Z

    The mid-infrared (mid-IR, 3 {micro}m -12 {micro}m) is a highly desirable spectral range for imaging and environmental sensing. We propose to develop a new class of mid-IR devices, based on plasmonic and metamaterial concepts, that are dynamically controlled by tunable semiconductor plasma resonances. It is well known that any material resonance (phonons, excitons, electron plasma) impacts dielectric properties; our primary challenge is to implement the tuning of a semiconductor plasma resonance with a voltage bias. We have demonstrated passive tuning of both plasmonic and metamaterial structures in the mid-IR using semiconductors plasmas. In the mid-IR, semiconductor carrier densities on the order of 5E17cm{sup -3} to 2E18cm{sup -3} are desirable for tuning effects. Gate control of carrier densities at the high end of this range is at or near the limit of what has been demonstrated in literature for transistor style devices. Combined with the fact that we are exploiting the optical properties of the device layers, rather than electrical, we are entering into interesting territory that has not been significantly explored to date.

  13. Infrared modified gravity with dynamical torsion

    SciTech Connect (OSTI)

    Nikiforova, V. [Physics Department, Moscow State University, Moscow, 119899 (Russian Federation); Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow, 117312 (Russian Federation); Randjbar-Daemi, S. [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34014, Trieste (Italy); Rubakov, V. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow, 117312 (Russian Federation)

    2009-12-15T23:59:59.000Z

    We continue the recent study of the possibility of constructing a consistent infrared modification of gravity by treating the vierbein and connection as independent dynamical fields. We present the generalized Fierz-Pauli equation that governs the propagation of a massive spin-2 mode in a model of this sort in the backgrounds of arbitrary torsionless Einstein manifolds. We show explicitly that the number of propagating degrees of freedom in these backgrounds remains the same as in flat space-time. This generalizes the recent result that the Boulware-Deser phenomenon does not occur in de Sitter and anti-de Sitter backgrounds. We find that, at least for weakly curved backgrounds, there are no ghosts in the model. We also discuss the interaction of sources in flat background. It is generally believed that the spinning matter is the only source of torsion. Our flat space study shows that this is not the case. We demonstrate that an ordinary conserved symmetric energy-momentum tensor can also generate torsion fields and thus excite massive spin-2 degrees of freedom.

  14. Infrared Sensitive Physics in QCD and in Electroweak Theory

    E-Print Network [OSTI]

    Marcello Ciafaloni

    2006-12-06T23:59:59.000Z

    I recall the main ideas about the treatment of QCD infrared physics, as developed in the late seventies, and I outline some novel applications of those ideas to Electroweak Theory.

  15. Infra-Red Process for Colour Fixation on Fabrics

    E-Print Network [OSTI]

    Biau, D.; Raymond, D. J.

    1983-01-01T23:59:59.000Z

    Infra-red radiations find wide application in industrial processes as heating, drying, stoving and forming. The results are often far better than those from the other techniques: convection oven, gas IR etc . They come from the electric IR specific...

  16. Infrared Optical Imaging Techniques for Gas Visualization and Measurement

    E-Print Network [OSTI]

    Safitri, Anisa

    2012-07-16T23:59:59.000Z

    modeling. In this research, infrared cameras have been used to visualize liquefied natural gas (LNG) plumes from LNG spills on water. The analyses of the thermograms showed that the apparent temperatures were different from the thermocouple measurement...

  17. Apparatus and method for transient thermal infrared emission spectrometry

    DOE Patents [OSTI]

    McClelland, John F. (Ames, IA); Jones, Roger W. (Ames, IA)

    1991-12-24T23:59:59.000Z

    A method and apparatus for enabling analysis of a solid material (16, 42) by applying energy from an energy source (20, 70) top a surface region of the solid material sufficient to cause transient heating in a thin surface layer portion of the solid material (16, 42) so as to enable transient thermal emission of infrared radiation from the thin surface layer portion, and by detecting with a spectrometer/detector (28, 58) substantially only the transient thermal emission of infrared radiation from the thin surface layer portion of the solid material. The detected transient thermal emission of infrared radiation is sufficiently free of self-absorption by the solid material of emitted infrared radiation, so as to be indicative of characteristics relating to molecular composition of the solid material.

  18. Arsenic Trisulfide on Lithium Niobate Devices for Infrared Integrated Optics

    E-Print Network [OSTI]

    Xia, Xin

    2012-07-16T23:59:59.000Z

    Arsenic trisulfide (As?S?) waveguide devices on lithium niobate substrates (LiNbO?) provide a set of compact and versatile means for guiding and manipulating optical modes in infrared integrated optical circuits, including the integrated trace gas...

  19. TeV Blazars and Cosmic Infrared Background Radiation

    E-Print Network [OSTI]

    F. A. Aharonian

    2001-12-13T23:59:59.000Z

    The recent developments in studies of TeV radiation from blazars are highlighted and the implications of these results for derivation of cosmologically important information about the cosmic infrared background radiation are discussed.

  20. Measuring absolute infrared spectral radiance with correlated photons: new arrangements

    E-Print Network [OSTI]

    Migdall, Alan

    metrologia Measuring absolute infrared spectral radiance with correlated photons: new arrangements must be created in pairs, the VIS channel is also stimulated. In this Metrologia, 1998, 35, 295-300 295

  1. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

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

    Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned...

  2. Airborne Infrared Target Tracking with the Nintendo Wii Remote Sensor

    E-Print Network [OSTI]

    Beckett, Andrew 1984-

    2012-11-12T23:59:59.000Z

    entirely. This research presents a solution to the target tracking problem which reliably provides automatic target detection and tracking with low expense and computational overhead by making use of the infrared sensor from a Nintendo Wii Remote Controller....

  3. Infra-Red Process for Colour Fixation on Fabrics

    E-Print Network [OSTI]

    Biau, D.; Raymond, D. J.

    1983-01-01T23:59:59.000Z

    Infra-red radiations find wide application in industrial processes as heating, drying, stoving and forming. The results are often far better than those from the other techniques: convection oven, gas IR etc . They come from the electric IR specific...

  4. In Situ Infrared Spectroscopic Study of Forsterite Carbonation...

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

    We employed in situ mid-infrared spectroscopy to follow the reaction of a model silicate mineral (forsterite, Mg2SiO4) for 24 hr with wet scCO2 at 50C and 180 atm, using...

  5. Wednesday, January 30, 2013 Infrared Trapping the "Greenhouse Effect"

    E-Print Network [OSTI]

    Toohey, Darin W.

    Wednesday, January 30, 2013 Infrared Trapping the "Greenhouse Effect" Goals to look is the same as a 1.8 degree F change. #12;Last time - Greenhouse effect demo Selective absorption. Greenhouse

  6. Engineering adenylate cyclases regulated by near-infrared window light

    E-Print Network [OSTI]

    Ryu, Min-Hyung

    Bacteriophytochromes sense light in the near-infrared window, the spectral region where absorption by mammalian tissues is minimal, and their chromophore, biliverdin IX?, is naturally present in animal cells. These properties ...

  7. Arsenic Trisulfide on Lithium Niobate Devices for Infrared Integrated Optics

    E-Print Network [OSTI]

    Xia, Xin

    2012-07-16T23:59:59.000Z

    Arsenic trisulfide (As?S?) waveguide devices on lithium niobate substrates (LiNbO?) provide a set of compact and versatile means for guiding and manipulating optical modes in infrared integrated optical circuits, including the integrated trace gas...

  8. advanced infrared focal: Topics by E-print Network

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

    present is the largest IR focal plane of the 21 st century. The work is being done by Raytheon Infrared Operations (RIO but better known as SBRC) by many of the same people who...

  9. Hadamard subtractions for infrared singularities in quantum field theory

    E-Print Network [OSTI]

    Burton, George Edmund C.

    2011-06-27T23:59:59.000Z

    Feynman graphs in perturbative quantum field theory are replete with infrared divergences caused by the presence of massless particles, how-ever these divergences are known to cancel order-by-order when all virtual and ...

  10. The Use of Infrared Technology To Detect Heat Loss

    E-Print Network [OSTI]

    Faulkner, K.

    1979-01-01T23:59:59.000Z

    . Some of todays more sophisticated infrared instruments are real-time and produce "heat-pictures". These are representations of objects with surface temperatures appearing as patterns upon objects....

  11. Probing correlated electron matter with infrared magneto- optics

    E-Print Network [OSTI]

    LaForge, Andrew David

    2009-01-01T23:59:59.000Z

    H. Kaddouri, S. Benet, Optics Comm. 204, 355361 (2002), [do not affect the magneto optics analysis. See F. Marsiglio,Matter with Infrared Magneto-Optics A dissertation submitted

  12. Infrared absorption spectra, radiative efficiencies, and global warming potentials

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Infrared absorption spectra, radiative efficiencies, and global warming potentials absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison. (1995) and combined with atmospheric lifetimes from the literature to determine global warming

  13. Infrared thermometry study of nanofluid pool boiling phenomena

    E-Print Network [OSTI]

    Gerardi, Craig

    Abstract Infrared thermometry was used to obtain first-of-a-kind, time- and space-resolved data for pool boiling phenomena in water-based nanofluids with diamond and silica nanoparticles at low concentration (<0.1 vol.%). ...

  14. absorption infrared spectroscopy: Topics by E-print Network

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

    absorption infrared spectroscopy First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Polarization...

  15. Infrared Study of the Molecular Orientation in Ultrathin Films of Behenic Acid Methyl Ester: Comparison between

    E-Print Network [OSTI]

    Pezolet, Michel

    Infrared Study of the Molecular Orientation in Ultrathin Films of Behenic Acid Methyl Ester-Blodgett transfer. The presence in the infrared spectra of several bands due to the methylene wagging and twisting and infrared spectroscopy have been developed to study these films. Infrared spectroscopy is particularly

  16. Atomic lines in infrared spectra for ultracool dwarfs

    E-Print Network [OSTI]

    Yu. Lyubchik; H. R. A. Jones; Ya. V. Pavlenko; S. Viti; J. C. Pickering; R. Blackwell-Whitehead

    2003-12-22T23:59:59.000Z

    We provide a set of atomic lines which are suitable for the description of ultracool dwarf spectra from 10000 to 25000 \\AA. This atomic linelist was made using both synthetic spectra calculations and existing atlases of infrared spectra of Arcturus and Sunspot umbra. We present plots, which show the comparison of synthetic spectra and observed Arcturus and Sunspot umbral spectra for all atomic lines likely to be observable in high resolution infrared spectra.

  17. Mid-Infrared Spectroscopic Diagnostics of Galactic Nuclei

    E-Print Network [OSTI]

    Vassilis Charmandaris; the Spitzer/IRS Instrument Team

    2006-07-13T23:59:59.000Z

    In this paper I summarize the science motivations, as well as a few mid-infrared spectroscopic methods used to identify the principal mechanisms of energy production in dust enshrouded galactic nuclei. The development of the various techniques is briefly discussed. Emphasis is given to the use of the data which are becoming available with the infrared spectrograph (IRS) on Spitzer, as well as the results which have been obtained by IRS over the past two years.

  18. Infrared cutoffs and the adiabatic limit in noncommutative spacetime

    E-Print Network [OSTI]

    Claus Doescher; Jochen Zahn

    2005-12-02T23:59:59.000Z

    We discuss appropriate infrared cutoffs and their adiabatic limit for field theories on the noncommutative Minkowski space in the Yang-Feldman formalism. In order to do this, we consider a mass term as interaction term. We show that an infrared cutoff can be defined quite analogously to the commutative case and that the adiabatic limit of the two-point function exists and coincides with the expectation, to all orders.

  19. The infrared and Raman spectra of N-alkyl ethylenimines

    E-Print Network [OSTI]

    Ashby, Theodore Leroy

    1968-01-01T23:59:59.000Z

    and Assi nments. . . . . . . . . . . . . . . , 5 A, Structural Considerations. . . . ~ . . . , . . . , 5 B, Assi"na ent of Spectra. . . . . . , . . . . . . . . . . 9 1, Yethod, 9 2. N-Yethyl Ethylenimine, . . . . , . . . . . . . 10 3. N-Ethyl... the Or ientation of the Principal Axes. Page 2. The Infrared Spectrum of I!-Yythyl Ethy- lenimine from 4000 to 50 cm . . . . . . . , . . . . 11 3. The Raman Spectrum of !! i~'. ethyl Ethylenimine. 13 4. The Infrared Spectrum of N-Ethyl Ethy- lenimine from...

  20. On the performance of infrared sensors in earth observations

    E-Print Network [OSTI]

    Johnson, Luther Franklin

    1972-01-01T23:59:59.000Z

    systems is depen- dent upon the radiative properties of targets in addition to constraints imposed by system components . The unclas- sified state-of-the-art of infrared system performance figures is reviewed to indicate the relevance to system... of unclassified infrared literature reveals in- frared systems applications in industry, medicine, and science. Indeed, any detection application is possible if a measurable variation in radiation is caused by the tar- get property of interest. Hudson [10] has...

  1. Fourier Transform Infrared Spectroscopy for Process Monitoring and Control

    E-Print Network [OSTI]

    Solomon, P. R.; Carangelo, M. D.; Carangelo, R. M.

    FOURIER TRANSFORM INFRARED SPECl'ROSCOPY FOR PROCESS MONITORING AND CONTROL Peter R. Solomon Martin D. Carangelo Robert M. Carangelo President Software Engineer Vice-President On-Line Technologies, Inc. On-Line Technologies, Inc. On... years, significant progress has been made in the applications and hardware for Fourier Transform Infrared (Ff?IR) spectroscopy. The applications of Fr-IR include: i) concentrations of multiple species and phases (gases, liquid, particles, surfaces...

  2. Infrared cutoffs and the adiabatic limit in noncommutative spacetime

    SciTech Connect (OSTI)

    Doescher, Claus; Zahn, Jochen [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Zentrum fuer Mathematische Physik, Universitaet Hamburg, Bundesstrasse 55, 20146 Hamburg (Germany)

    2006-02-15T23:59:59.000Z

    We discuss appropriate infrared cutoffs and their adiabatic limit for field theories on the noncommutative Minkowski space in the Yang-Feldman formalism. In order to do this, we consider a mass term as interaction term. We show that an infrared cutoff can be defined quite analogously to the commutative case and that the adiabatic limit of the two-point function exists and coincides with the expectation, to all orders.

  3. Exploring Infrared Properties of Giant Low Surface Brightness Galaxies

    E-Print Network [OSTI]

    Nurur Rahman; Justin H. Howell; George Helou; Joseph M. Mazzarella; Brent Buckalew

    2007-04-11T23:59:59.000Z

    Abridged: We present analysis of Spitzer Space Telescope observations of the three low surface brightness (LSB) optical giant galaxies Malin 1, UGC 6614 and UGC 9024. Mid- and far-infrared morphology, spectral energy distributions, and integrated colors are used to derive the dust mass, dust-to-gas mass ratio, total infrared luminosity, and star formation rate (SFR). The 8 micron images indicate that polycyclic aromatic hydrocarbon molecules are present in the central regions of all three metal-poor LSB galaxies. The diffuse optical disks of Malin 1 and UGC 9024 remain undetected at mid- and far-infrared wavelengths. The dustiest of the three LSB galaxies, UGC 6614, has infrared morphology that varies significantly with wavelength. The 8 and 24 micron emission is co-spatial with H\\alpha emission previously observed in the outer ring of UGC 6614. The estimated dust-to-gas ratios, from less than 10^{-3} to 10^{-2}, support previous indications that the LSB galaxies are relatively dust poor compared to the HSB galaxies. The total infrared luminosities are approximately 1/3 to 1/2 the blue band luminosities, suggesting that old stellar populations are the primary source of dust heating in these LSB objects. The SFR estimated from the infrared data ranges ~0.01-0.88 M_sun yr^{-1}, consistent with results from optical studies.

  4. Making the margin visible : out-of -school literacy practices among Mexican heritage English learners in an English-only district

    E-Print Network [OSTI]

    Burrows-Goodwill, Shivani Linda

    2009-01-01T23:59:59.000Z

    living room three distinct shelving areas were dedicated towas occupied by built-in shelving, filled with books andtwo bedrooms consists of shelving. The more visible shelving

  5. Femtosecond measurements of near-infrared pulse induced mid-infrared transmission modulation of quantum cascade lasers

    SciTech Connect (OSTI)

    Cai, Hong; Liu, Sheng [Department of Physics, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250 (United States); Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Lalanne, Elaine [Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Guo, Dingkai; Chen, Xing; Choa, Fow-Sen [Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Department of CSEE, UMBC, Baltimore, Maryland 21250 (United States); Wang, Xiaojun [AdTech Optics, Inc., City of Industry, California 91748 (United States); Johnson, Anthony M., E-mail: amj@umbc.edu [Department of Physics, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250 (United States); Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Department of CSEE, UMBC, Baltimore, Maryland 21250 (United States)

    2014-05-26T23:59:59.000Z

    We temporally resolved the ultrafast mid-infrared transmission modulation of quantum cascade lasers (QCLs) using a near-infrared pump/mid-infrared probe technique at room temperature. Two different femtosecond wavelength pumps were used with photon energy above and below the quantum well (QW) bandgap. The shorter wavelength pump modulates the mid-infrared probe transmission through interband transition assisted mechanisms, resulting in a high transmission modulation depth and several nanoseconds recovery lifetime. In contrast, pumping with a photon energy below the QW bandgap induces a smaller transmission modulation depth but much faster (several picoseconds) recovery lifetime, attributed to intersubband transition assisted mechanisms. The latter ultrafast modulation (>60?GHz) could provide a potential way to realize fast QCL based free space optical communication.

  6. Near-infrared induced optical quenching effects on mid-infrared quantum cascade lasers

    SciTech Connect (OSTI)

    Guo, Dingkai, E-mail: dingk1@umbc.edu; Talukder, Muhammad Anisuzzaman; Chen, Xing [Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Cai, Hong [Center of Advanced Studies in Photonics Research (CASPR), University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Johnson, Anthony M.; Choa, Fow-Sen [Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Center of Advanced Studies in Photonics Research (CASPR), University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Khurgin, Jacob B. [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2014-06-23T23:59:59.000Z

    In space communications, atmospheric absorption and Rayleigh scattering are the dominant channel impairments. Transmission using mid-infrared (MIR) wavelengths offers the benefits of lower loss and less scintillation effects. In this work, we report the telecom wavelengths (1.55??m and 1.3??m) induced optical quenching effects on MIR quantum cascade lasers (QCLs), when QCLs are operated well above their thresholds. The QCL output power can be near 100% quenched using 20?mW of near-infrared (NIR) power, and the quenching effect depends on the input NIR intensity as well as wavelength. Time resolved measurement was conducted to explore the quenching mechanism. The measured recovery time is around 14?ns, which indicates that NIR generated electron-hole pairs may play a key role in the quenching process. The photocarrier created local field and band bending can effectively deteriorate the dipole transition matrix element and quench the QCL. As a result, MIR QCLs can be used as an optical modulator and switch controlled by NIR lasers. They can also be used as converters to convert telecom optical signals into MIR optical signals.

  7. Infrared scaling solutions beyond the Landau gauge: The maximally Abelian gauge and Abelian infrared dominance

    E-Print Network [OSTI]

    Markus Q. Huber; Reinhard Alkofer; Kai Schwenzer

    2011-03-01T23:59:59.000Z

    Functional equations like exact renormalization group and Dyson-Schwinger equations have contributed to a better understanding of non-perturbative phenomena in quantum field theories in terms of the underlying Green functions. In Yang-Mills theory especially the Landau gauge has been used, as it is the most accessible gauge for these methods. The growing understanding obtained in this gauge allows to proceed to other gauges in order to obtain more information about the relation of different realizations of the confinement mechanism. In the maximally Abelian gauge first results are very encouraging as a variant of Abelian infrared dominance is found: The Abelian part of the gauge field propagator is enhanced at low momenta and thereby dominates the dynamics in the infrared. Its role is therefore similar to that of the ghost propagator in the Landau gauge, where one denotes the corresponding phenomenon as ghost dominance. Also the ambiguity of two different types of solutions (decoupling and scaling) exists in both gauges. Here we present how the two solutions are related in the maximally Abelian gauge. The intricacy of the system of functional equations in this gauge required the development of some new tools and methods as, for example, the automated derivation of the equations by the program DoFun. We also present results for linear covariant and ghost anti-ghost symmetric gauges.

  8. Axion Stars in the Infrared Limit

    E-Print Network [OSTI]

    Joshua Eby; Peter Suranyi; Cenalo Vaz; L. C. R. Wijewardhana

    2015-02-06T23:59:59.000Z

    Following Ruffini and Bonazzola, we use a quantized boson field to describe condensates of axions forming compact objects. Without substantial modifications, the method can only be applied to axions with decay constant, $f_a$, satisfying $\\delta=(f_a\\,/\\,M_P)^2\\ll 1$, where $M_P$ is the Planck mass. Similarly, the applicability of the Ruffini-Bonazzola method to axion stars also requires that the relative binding energy of axions satisfies $\\Delta=\\sqrt{1-(E_a\\,/\\,m_a)^2}\\ll1$, where $E_a$ and $m_a$ are the energy and mass of the axion. The simultaneous expansion of the equations of motion in $\\delta$ and $\\Delta$ leads to a simplified set of equations, depending only on the parameter, $\\lambda=\\sqrt{\\delta}\\,/\\,\\Delta$ in leading order of the expansions. Keeping leading order in $\\Delta$ is equivalent to the infrared limit, in which only relevant and marginal terms contribute to the equations of motion. The number of axions in the star is uniquely determined by $\\lambda$. Numerical solutions are found in a wide range of $\\lambda$. At small $\\lambda$ the mass and radius of the axion star rise linearly with $\\lambda$. While at larger $\\lambda$ the radius of the star continues to rise, the mass of the star, $M$, attains a maximum at $\\lambda_{\\rm max}\\simeq 0.58$. All stars are unstable for $\\lambda>\\lambda_{\\rm max}$ . We discuss the relationship of our results to current observational constraints on dark matter and the phenomenology of Fast Radio Bursts.

  9. Miniaturized Mid-Infrared Sensor Technologies

    SciTech Connect (OSTI)

    Kim, S; Young, C; Mizaikoff, B

    2007-08-16T23:59:59.000Z

    Fundamental vibrational and rotational modes associated with most inorganic and organic molecules are spectroscopically accessible within the mid-infrared (MIR; 3-20 {micro}m) regime of the electromagnetic spectrum. The interaction between MIR photons and organic molecules provides particularly sharp transitions, which - despite the wide variety of organic molecules - provide unique MIR absorption spectra reflecting the molecularly characteristic arrangement of chemical bonds within the probed molecules via the frequency position of the associated vibrational and rotational transitions. Given the inherent molecular selectivity and achievable sensitivity, MIR spectroscopy provides an ideal platform for optical sensing applications. Despite this potential, early MIR sensing applications were limited to localized applications due to the size of the involved instrumentation, and limited availability of appropriately compact MIR optical components including light sources, detectors, waveguides, and spectrometers. During the last decades, engineering advances in photonics and optical engineering have facilitated the translation of benchtop-style MIR spectroscopy into miniaturized optical sensing schemes providing a footprint compatible with portable instrumentation requirements for field deployable analytical tools. In this trend article, we will discuss recent advances and future strategies for miniaturizing MIR sensor technology. The Beer-Lambert law implies that achievable limit of detection (LOD) for any optical sensor system improves by increasing the interaction length between photons and target analyte species such as e.g., folding the optical path multiple times as in multi-pass gas phase sensing; however, this governing paradigm naturally leads to an increase in system dimensions. Hence, miniaturization of optical sensing system requires scaling down of each optical component, yet improving the performance of each optical element within a smaller form factor for overall at least maintaining, or ideally improving the achievable sensitivity.

  10. Infrared Spectroscopy of Discrete Uranyl Anion Complexes

    SciTech Connect (OSTI)

    Gary S. Groenewold; Anita K. Gianotto; Michael E. McIlwain; Michael J. Van Stipdonk; Michael Kullman; Travis J. Cooper; David T. Moore; Nick Polfer; Jos Oomens; Ivan Infante; Lucas Visscher; Bertrand Siboulet; Wibe A. de Jong

    2007-12-01T23:59:59.000Z

    The Free-Electron Laser for Infrared Experiments, FELIX, was used to study the wavelength-resolved multiphoton dissociation of discrete, gas phase uranyl (UO22+) complexes containing a single anionic ligand (A), with or without ligated solvent molecules (S). The apparent uranyl antisymmetric and symmetric stretching frequencies were measured for complexes with general formula [UO2A(S)n]+, where A was either hydroxide, methoxide or acetate, S was water, ammonia, acetone or acetonitrile, and n = 0-2. The values for the antisymmetric stretching frequency for uranyl ligated with only an anion ([UO2A]+) were as low or lower than measurements for [UO2]2+ ligated with as many as five strong neutral donor ligands, and are comparable to solution phase values. This result was surprising because initial DFT calculations using B3LYP predicted values that were 30 40 cm-1 higher, consistent with intuition but not with the data. Modification of the basis set and use of alternative functionals improved computational accuracy for the methoxide and acetate complexes, but calculated values for the hydroxide were greater than the measurement regardless of the computational method used. Attachment of a neutral donor ligand S to [UO2A]+ produced [UO2AS]+, which resulted only very modest changes to the uranyl frequency, and did not universally shift values lower. DFT calculations for [UO2AS]+ were in accord with trends in the data, and showed that attachment of the solvent was accommodated by weakening of the U-anion bond as well as the uranyl. When uranyl frequencies were compared for [UO2AS]+ species having different solvent neutrals, values decreased with increasing neutral nucleophilicity.

  11. Infrared phonon modes in multiferroic single-crystal FeTe2O5Br

    SciTech Connect (OSTI)

    Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

    2013-06-01T23:59:59.000Z

    Reflection and transmission as a function of temperature (7300 K and 5300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

  12. Self-heating in a GaN based heterostructure field effect transistor: Ultraviolet and visible Raman measurements and simulations

    E-Print Network [OSTI]

    Holtz, Mark

    Self-heating in a GaN based heterostructure field effect transistor: Ultraviolet and visible Raman online 8 December 2006 We report direct self-heating measurements for AlGaN/GaN heterostructure field density can be commensurately high, collisional energy loss from electrons to the crystal leads to self-heating

  13. Design and Synthesis of Visible Isotope-Coded Affinity Tags for the Absolute Quantification of Specific Proteins in Complex Mixtures

    E-Print Network [OSTI]

    Gelb, Michael

    for selective enrichment of tag peptides. Another cysteine peptide enrichment and isotope tagging scheme hasDesign and Synthesis of Visible Isotope-Coded Affinity Tags for the Absolute Quantification spectrometry is most useful when quantitative data is also obtained. We recently introduced isotope

  14. Optical Wireless based on High Brightness Visible LEDs Grantham Pang, Thomas Kwan, Hugh Liu, Chi-Ho Chan

    E-Print Network [OSTI]

    Pang, Grantham

    and encoded with audio or data signal. Hence, an LED indicator lamp or traffic light can become an information for incandescent lamps [3,4]. This advancement has led to the production of large- area full-color LED displaysOptical Wireless based on High Brightness Visible LEDs Grantham Pang, Thomas Kwan, Hugh Liu, Chi

  15. Distribution of unresolvable anisotropic microstructures revealed in visibility-contrast images using x-ray Talbot interferometry

    SciTech Connect (OSTI)

    Yashiro, Wataru; Harasse, Sebastien; Kawabata, Katsuyuki; Kuwabara, Hiroaki; Yamazaki, Takashi; Momose, Atsushi [Department of Advanced Materials Science, Graduate School of Frontier Sciences, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

    2011-09-01T23:59:59.000Z

    X-ray Talbot interferometry has been widely used as a technique for x-ray phase imaging and tomography. We propose a method using this interferometry for mapping distribution of parameters characterizing anisotropic microstructures, which are typically of the order of {mu}m in size and cannot be resolved by the imaging system, in a sample. The method uses reduction in fringe visibility, which is caused by such unresolvable microstructures, in moire images obtained using an interferometer. We applied the method to a chloroprene rubber sponge sample, which exhibited uniaxial anisotropy of reduced visibility. We measured the dependencies of reduced visibility on both the Talbot order and the orientation of the sample and obtained maps of three parameters and their anisotropies that characterize the unresolvable anisotropic microstructures in the sample. The maps indicated that the anisotropy of the sample's visibility contrast mainly originated from the anisotropy of the microstructure elements' average size. Our method directly provides structural information on unresolvable microstructures in real space, which is only accessible through the ultra-small-angle x-ray scattering measurements in reciprocal space, and is expected to be broadly applied to material, biological, and medical sciences.

  16. Bringing Visibility to Rural Users in Cote d'Ivoire Mariya Zheleva, Paul Schmitt, Morgan Vigil and Elizabeth Belding

    E-Print Network [OSTI]

    Belding-Royer, Elizabeth M.

    from Cote d'Ivoire with an emphasis on understanding how population density impacts the use of cellularBringing Visibility to Rural Users in Cote d'Ivoire Mariya Zheleva, Paul Schmitt, Morgan Vigil a cellular traffic dataset provided by Orange in Cote d'Ivoire with the goal of identifying distinctions

  17. Feedback-Driven Evolution of the Far-Infrared Spectral Energy Distributions of Luminous and Ultraluminous Infrared Galaxies

    E-Print Network [OSTI]

    Sukanya Chakrabarti; T. J. Cox; Lars Hernquist; Philip F. Hopkins; Brant Robertson; Tiziana Di Matteo

    2007-01-22T23:59:59.000Z

    We calculate infrared spectral energy distributions (SEDs) from simulations of major galaxy mergers and study the effect of AGN and starburst driven feedback on the evolution of the SED as a function of time. We use a self-consistent three-dimensional radiative equilibrium code to calculate the emergent SEDs and to make images. To facilitate a simple description of our findings, we describe our results in reference to an approximate analytic solution for the far-IR SED. We focus mainly on the luminous infrared galaxy (LIRG) and ultraluminous infrared galaxy (ULIRG) phases of evolution. We contrast the SEDs of simulations performed with AGN feedback to simulations performed with starburst driven wind feedback. We find that the feedback processes critically determine the evolution of the SED. Changing the source of illumination (whether stellar or AGN) has virtually no impact on the reprocessed far-infrared SED. We find that AGN feedback is particularly effective at dispersing gas and rapidly injecting energy into the ISM. The observational signature of such powerful feedback is a warm SED. In general, simulations performed with starburst driven winds have colder spectra and reprocess more of their emission into the infrared, resulting in higher infrared to bolometric luminosities compared to (otherwise equivalent) simulations performed with AGN feedback. We depict our results in IRAS bands, as well as in Spitzer's MIPS bands, and in Herschel's PACS bands.

  18. Spitzer Detection of PAH and Silicate Dust Features in the Mid-Infrared Spectra of z~2 Ultraluminous Infrared Galaxies

    E-Print Network [OSTI]

    Lin Yan; R. Chary; L. Armus; H. Teplitz; G. Helou; D. Frayer; D. Fadda; J. Surace; P. Choi

    2005-04-14T23:59:59.000Z

    We report the initial results from a Spitzer GO-1 program to obtain low resolution, mid-infrared spectra of infrared luminous galaxies at z~1-2. This paper presents the spectra of eight sources observed with the Spitzer InfraRed Spectrograph (IRS). Of the eight spectra, six have mid-IR spectral features, either emission from Polycyclic Aromatic Hydrocarbon (PAH) or silicate absorption. Based on these mid-IR features, the inferred six redshifts are in the range of 1.8-2.6. The remaining two spectra detect only strong continua, thus do not yield redshift information. Strong, multiple PAH emission features are detected in two sources, and weak PAH emission in another two. These data provide direct evidence that PAH molecules are present and directly observable in ULIRGs at z~2. The six sources with measured redshifts are dusty, infrared luminous galaxies at z~2 with estimated $L_{bol} \\sim 10^{13}L_\\odot$. Of the eight sources, two appear starburst dominated; two with only power law continua are probably type I QSOs; and the remaining four are likely composite systems containing a buried AGN and a starburst component. Since half of our sample are optically faint sources with R>25.5mag (Vega), our results demonstrate the potential of using mid-infrared spectroscopy, especially the Aromatic and silicate features produced by dust grains to directly probe optically faint and infrared luminous populations at high redshift.

  19. A multimodality vascular imaging phantom of an abdominal aortic aneurysm with a visible thrombus

    SciTech Connect (OSTI)

    Allard, Louise; Chayer, Boris; Qin Zhao [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Quebec H2L 2W5 (Canada); Soulez, Gilles [Department of Radiology, University of Montreal Hospital (CHUM), Quebec H2L 2M1 (Canada); Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Quebec H3T 1J4 (Canada); Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada); Roy, David [Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada); Cloutier, Guy [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Quebec H2L 2W5 (Canada); Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Quebec H3T 1J4 (Canada); Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada)

    2013-06-15T23:59:59.000Z

    Purpose: With the continuous development of new stent grafts and implantation techniques, it has now become technically feasible to treat abdominal aortic aneurysms (AAA) with challenging anatomy using endovascular repair with standard, fenestrated, or branched stent-grafts. In vitro experimentations are very useful to improve stent-graft design and conformability or imaging guidance for stent-graft delivery or follow-up. Vascular replicas also help to better understand the limitation of endovascular approaches in challenging anatomy and possibly improve surgical planning or training by practicing high risk clinical procedures in the laboratory to improve outcomes in the operating room. Most AAA phantoms available have a very basic anatomy, which is not representative of the clinical reality. This paper presents a method of fabrication of a realistic AAA phantom with a visible thrombus, as well as some mechanical properties characterizing such phantom. Methods: A realistic AAA geometry replica of a real patient anatomy taken from a multidetector computed tomography (CT) scan was manufactured. To demonstrate the multimodality imaging capability of this new phantom with a thrombus visible in magnetic resonance (MR) angiography, CT angiography (CTA), digital subtraction angiography (DSA), and ultrasound, image acquisitions with all these modalities were performed by using standard clinical protocols. Potential use of this phantom for stent deployment was also tested. A rheometer allowed defining hyperelastic and viscoelastic properties of phantom materials. Results: MR imaging measurements of SNR and CNR values on T1 and T2-weighted sequences and MR angiography indicated reasonable agreement with published values of AAA thrombus and abdominal components in vivo. X-ray absorption also lay within normal ranges of AAA patients and was representative of findings observed on CTA, fluoroscopy, and DSA. Ultrasound propagation speeds for developed materials were also in concordance with the literature for vascular and abdominal tissues. Conclusions: The mimicked abdominal tissues, AAA wall, and surrounding thrombus were developed to match imaging features of in vivo MR, CT, and ultrasound examinations. This phantom should be of value for image calibration, segmentation, and testing of endovascular devices for AAA endovascular repair.

  20. THE NUCLEAR INFRARED EMISSION OF LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Mason, R. E. [Gemini Observatory, Northern Operations Center, 670 N. A'ohoku Place, Hilo, HI 96720 (United States); Lopez-Rodriguez, E.; Packham, C. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, P.O. Box 112055, Gainesville, FL 32611 (United States); Alonso-Herrero, A. [Instituto de Fisica de Cantabria, CSIC-UC, Avenida de los Castros s/n, 39005 Santander (Spain); Levenson, N. A.; Radomski, J. [Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile); Ramos Almeida, C. [Instituto de Astrofisica de Canarias, C/Via Lactea, s/n, E-38205, La Laguna, Tenerife (Spain); Colina, L. [Departamento de Astrofisica, Centro de Astrobiologia (CSIC/INTA), Instituto Nacional de Tecnica Aeroespacial, Crta de Torrejon a Ajalvir, km 4, 28850 Torrejon de Ardoz, Madrid (Spain); Elitzur, M. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Aretxaga, I. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Aptdo. Postal 51 y 216, 72000 Puebla (Mexico); Roche, P. F. [Astrophysics, Department of Physics, University of Oxford, DWB, Keble Road, Oxford OX1 3RH (United Kingdom); Oi, N. [Department of Astronomy, School of Science, Graduate University for Advanced Studies (SOKENDAI), Mitaka, Tokyo 181-8588 (Japan)

    2012-07-15T23:59:59.000Z

    We present high-resolution mid-infrared (MIR) imaging, nuclear spectral energy distributions (SEDs), and archival Spitzer spectra for 22 low-luminosity active galactic nuclei (LLAGNs; L{sub bol} {approx}< 10{sup 42} erg s{sup -1}). Infrared (IR) observations may advance our understanding of the accretion flows in LLAGNs, the fate of the obscuring torus at low accretion rates, and, perhaps, the star formation histories of these objects. However, while comprehensively studied in higher-luminosity Seyferts and quasars, the nuclear IR properties of LLAGNs have not yet been well determined. We separate the present LLAGN sample into three categories depending on their Eddington ratio and radio emission, finding different IR characteristics for each class. (1) At the low-luminosity, low-Eddington-ratio (log L{sub bol}/L{sub Edd} < -4.6) end of the sample, we identify 'host-dominated' galaxies with strong polycyclic aromatic hydrocarbon bands that may indicate active (circum-)nuclear star formation. (2) Some very radio-loud objects are also present at these low Eddington ratios. The IR emission in these nuclei is dominated by synchrotron radiation, and some are likely to be unobscured type 2 AGNs that genuinely lack a broad-line region. (3) At higher Eddington ratios, strong, compact nuclear sources are visible in the MIR images. The nuclear SEDs of these galaxies are diverse; some resemble typical Seyfert nuclei, while others lack a well-defined MIR 'dust bump'. Strong silicate emission is present in many of these objects. We speculate that this, together with high ratios of silicate strength to hydrogen column density, could suggest optically thin dust and low dust-to-gas ratios, in accordance with model predictions that LLAGNs do not host a Seyfert-like obscuring torus. We anticipate that detailed modeling of the new data and SEDs in terms of accretion disk, jet, radiatively inefficient accretion flow, and torus components will provide further insights into the nuclear structures and processes of LLAGNs.

  1. MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS

    SciTech Connect (OSTI)

    Kospal, A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Abraham, P.; Kun, M.; Moor, A. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, 1525 Budapest (Hungary); Acosta-Pulido, J. A. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Dullemond, C. P. [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie der Universitaet Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg (Germany); Henning, Th.; Leinert, Ch. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Turner, N. J., E-mail: akospal@rssd.esa.int [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-08-01T23:59:59.000Z

    Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containing observations of 68 low- and intermediate-mass young stellar objects. The atlas consists of 2.5-11.6 {mu}m low-resolution spectra obtained with the ISOPHOT-S instrument on board the Infrared Space Observatory (ISO) between 1996 and 1998, as well as 5.2-14.5 {mu}m low-resolution spectra obtained with the Infrared Spectrograph instrument on board the Spitzer Space Telescope between 2004 and 2007. The observations were retrieved from the ISO and Spitzer archives and were post-processed interactively by our own routines. For those 47 objects where multi-epoch spectra were available, we analyze mid-infrared spectral variability on annual and/or decadal timescales. We identify 37 variable candidate sources. Many stars show wavelength-independent flux changes, possibly due to variable accretion rates. In several systems, all exhibiting 10 {mu}m silicate emission, the variability of the 6-8 {mu}m continuum, and the silicate feature exhibit different amplitudes. A possible explanation is variable shadowing of the silicate-emitting region by an inner disk structure of changing height or extra silicate emission from dust clouds in the disk atmosphere. Our results suggest that mid-infrared variability, in particular, the wavelength-dependent changes, is more ubiquitous than was known before. Interpreting this variability is a new possibility for exploring the structure of the disk and its dynamical processes.

  2. The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural

    E-Print Network [OSTI]

    Glotch, Timothy D.

    The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance. As such, they may have experienced shock heating produced by impacts and could have been significantly altered or melted. We characterized the effects of high temperatures on the mid-to-far-infrared (mid

  3. Mrk 609: resolving the circum-nuclear structure with near-infrared integral field spectroscopy

    E-Print Network [OSTI]

    J. Zuther; C. Iserlohe; J. -U. Pott; T. Bertram; S. Fischer; W. Voges; G. Hasinger; A. Eckart

    2007-04-16T23:59:59.000Z

    We present first results of near infrared J and H+K ESO-SINFONI integral field spectroscopy of the composite starburst/Seyfert 1.8 galaxy Mrk 609. The data were taken during the science verification period of SINFONI. We aim to investigate the morphology and excitation conditions within the central 2 kpc. Additional Nobeyama 45 m CO(1-0) data are presented, which we used to estimate the molecular gas mass. The source was selected from a sample of adaptive optics suitable, SDSS/ROSAT based, X-ray bright AGN with redshifts of 0.03 < z < 1. This sample allows for a detailed study of the NIR properties of the nuclear and host environments with high spectral and spatial resolution. Our NIR data reveal a complex emission-line morphology, possibly associated with a nuclear bar seen in the reconstructed continuum images. The detections of [SiVI] and a broad Pa alpha component are clear indicators for the presence of an accreting super-massive black hole at the center of Mrk 609. In agreement with previous observations we find that the circum-nuclear emission is not significantly extincted. The analysis of the high angular resolution rotational-vibrational molecular hydrogen and forbidden [FeII] emission reveals a LINER character of the nucleus. The large H_2 gas mass deduced from the CO(1-0) observation provides the fuel needed to feed the starburst and Seyfert activity in Mrk 609. High angular resolution imaging spectroscopy provides an ideal tool to resolve the nuclear and starburst contribution in active galaxies. We show that Mrk 609 exhibits LINER features, that appear to be hidden in larger aperture visible/NIR spectra.

  4. Are dust shell models well-suited to explain interferometric data of late-type stars in the near-infrared?

    E-Print Network [OSTI]

    P. Schuller; P. Salom; G. Perrin; B. Mennesson; G. Niccolini; P. de Laverny; S. Ridgway; V. Coud du Foresto; W. A. Traub; .

    2004-01-22T23:59:59.000Z

    Recently available near-infrared interferometric data on late-type stars show a strong increase of diameter for asymptotic giant branch (AGB) stars between the K (2.0 - 2.4 \\mu m) and L (3.4 - 4.1 \\mu m) bands. Aiming at an explanation of these findings, we chose the objects \\alpha Orionis (Betelgeuse), SW Virginis, and R Leonis, which are of different spectral types and stages of evolution, and which are surrounded by circumstellar envelopes with different optical thicknesses. For these stars, we compared observations with spherically symmetric dust shell models. Photometric and 11 \\mu m interferometric data were also taken into account to further constrain the models. -- [...] -- We conclude that AGB models comprising a photosphere and dust shell, although consistent with SED data and also interferometric data in K and at 11 \\mu m, cannot explain the visibility data in L; an additional source of model opacity, possibly related to a gas component, is needed in L to be consistent with the visibility data.

  5. ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Kouzuma, S. [School of International Liberal Studies, Chukyo University, Toyota 470-0393 (Japan); Yamaoka, H., E-mail: skouzuma@lets.chukyo-u.ac.jp, E-mail: yamaoka@phys.kyushu-u.ac.jp [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

    2012-03-01T23:59:59.000Z

    We present the properties of the ensemble variability V for nearly 5000 near-infrared active galactic nuclei (AGNs) selected from the catalog of Quasars and Active Galactic Nuclei (13th Edition) and the SDSS-DR7 quasar catalog. From three near-infrared point source catalogs, namely, Two Micron All Sky Survey (2MASS), Deep Near Infrared Survey (DENIS), and UKIDSS/LAS catalogs, we extract 2MASS-DENIS and 2MASS-UKIDSS counterparts for cataloged AGNs by cross-identification between catalogs. We further select variable AGNs based on an optimal criterion for selecting the variable sources. The sample objects are divided into subsets according to whether near-infrared light originates by optical emission or by near-infrared emission in the rest frame; and we examine the correlations of the ensemble variability with the rest-frame wavelength, redshift, luminosity, and rest-frame time lag. In addition, we also examine the correlations of variability amplitude with optical variability, radio intensity, and radio-to-optical flux ratio. The rest-frame optical variability of our samples shows negative correlations with luminosity and positive correlations with rest-frame time lag (i.e., the structure function, SF), and this result is consistent with previous analyses. However, no well-known negative correlation exists between the rest-frame wavelength and optical variability. This inconsistency might be due to a biased sampling of high-redshift AGNs. Near-infrared variability in the rest frame is anticorrelated with the rest-frame wavelength, which is consistent with previous suggestions. However, correlations of near-infrared variability with luminosity and rest-frame time lag are the opposite of these correlations of the optical variability; that is, the near-infrared variability is positively correlated with luminosity but negatively correlated with the rest-frame time lag. Because these trends are qualitatively consistent with the properties of radio-loud quasars reported by some previous studies, most of our sample objects are probably radio-loud quasars. Finally, we also discuss the negative correlations seen in the near-infrared SFs.

  6. EARLY SCIENCE WITH SOFIA, THE STRATOSPHERIC OBSERVATORY FOR INFRARED ASTRONOMY

    SciTech Connect (OSTI)

    Young, E. T.; Becklin, E. E.; De Buizer, J. M.; Andersson, B.-G.; Casey, S. C.; Helton, L. A. [SOFIA Science Center, Universities Space Research Association, NASA Ames Research Center, MS 232, Moffett Field, CA 94035 (United States); Marcum, P. M.; Roellig, T. L.; Temi, P. [NASA Ames Research Center, MS 232, Moffett Field, CA 94035 (United States); Herter, T. L. [Astronomy Department, 202 Space Sciences Building, Cornell University, Ithaca, NY 14853-6801 (United States); Guesten, R. [Max-Planck Institut fuer Radioastronomie, Auf dem Huegel 69, Bonn (Germany); Dunham, E. W. [Lowell Observatory, 1400 W. Mars Hill Rd., Flagstaff AZ 86001 (United States); Backman, D.; Burgdorf, M. [SOFIA Science Center, NASA Ames Research Center, MS 211-1, Moffett Field, CA 94035 (United States); Caroff, L. J.; Erickson, E. F. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Davidson, J. A. [School of Physics, The University of Western Australia (M013), 35 Stirling Highway, Crawley WA 6009 (Australia); Gehrz, R. D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States); Harper, D. A. [Yerkes Observatory, University of Chicago, 373 W. Geneva St., Williams Bay, WI (United States); Harvey, P. M. [Astronomy Department, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); and others

    2012-04-20T23:59:59.000Z

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an airborne observatory consisting of a specially modified Boeing 747SP with a 2.7 m telescope, flying at altitudes as high as 13.7 km (45,000 ft). Designed to observe at wavelengths from 0.3 {mu}m to 1.6 mm, SOFIA operates above 99.8% of the water vapor that obscures much of the infrared and submillimeter. SOFIA has seven science instruments under development, including an occultation photometer, near-, mid-, and far-infrared cameras, infrared spectrometers, and heterodyne receivers. SOFIA, a joint project between NASA and the German Aerospace Center Deutsches Zentrum fuer Luft und-Raumfahrt, began initial science flights in 2010 December, and has conducted 30 science flights in the subsequent year. During this early science period three instruments have flown: the mid-infrared camera FORCAST, the heterodyne spectrometer GREAT, and the occultation photometer HIPO. This Letter provides an overview of the observatory and its early performance.

  7. Far-infrared optical and dielectric response of ZnS measured by terahertz time-domain spectroscopy

    E-Print Network [OSTI]

    Far-infrared optical and dielectric response of ZnS measured by terahertz time-domain spectroscopy material in the infrared and far-infrared region.1 It plays a vital role in being used as infrared windows the frequency-dependent optical properties and complex di- electric response of ZnS over a broad far-infrared

  8. ULTRALUMINOUS INFRARED GALAXIES IN THE WISE AND SDSS SURVEYS

    SciTech Connect (OSTI)

    Su, Shanshan; Kong, Xu; Li, Jinrong [Center for Astrophysics, University of Science and Technology of China, Hefei 230026 (China); Fang, Guanwen, E-mail: sushan@mail.ustc.edu.cn, E-mail: xkong@ustc.edu.cn [Institute for Astronomy and History of Science and Technology, Dali University, Yunnan 671003 (China)

    2013-11-20T23:59:59.000Z

    In this paper, we present a large catalog of 419 Ultraluminous infrared galaxies (ULIRGs), carefully selected from the Wide-field Infrared Survey Explorer mid-infrared data and the Sloan Digital Sky Survey eighth data release, and classify them into three subsamples, based on their emission line properties: H II-like ULIRGs, Seyfert 2 ULIRGs, and composite ULIRGs. We apply our new efficient spectral synthesis technique, which is based on mean field approach to Bayesian independent component analysis (MF-ICA) method, to the galaxy integrated spectra. We also analyze the stellar population properties, including percentage contribution, stellar age, and stellar mass, for these three types of ULIRGs, and explore the evolution among them. We find no significant difference between the properties of stellar populations in ULIRGs with or without active galactic nucleus components. Our results suggest that there is no evolutionary link among these three type ULIRGs.

  9. Nanofocusing of mid-infrared electromagnetic waves on graphene monolayer

    SciTech Connect (OSTI)

    Qiu, Weibin, E-mail: wbqiu@hqu.edu.cn, E-mail: wqiu@semi.ac.cn [College of Information Science and Engineering, National Huaqiao University, Xiamen 361021, Fujian (China); Institute of Semiconductors, Chinese Academy of Science, 100083 Beijing (China); Liu, Xianhe; Zhao, Jing; He, Shuhong; Ma, Yuhui; Wang, Jia-Xian [College of Information Science and Engineering, National Huaqiao University, Xiamen 361021, Fujian (China); Pan, Jiaoqing [Institute of Semiconductors, Chinese Academy of Science, 100083 Beijing (China)

    2014-01-27T23:59:59.000Z

    Nanofocusing of mid-infrared (MIR) electromagnetic waves on graphene monolayer with gradient chemical potential is investigated with numerical simulation. On an isolated freestanding monolayer graphene sheet with spatially varied chemical potential, the focusing spot sizes of frequencies between 44 THz and 56 THz can reach around 1.6?nm and the intensity enhancement factors are between 2178 and 654. For 56 THz infrared, a group velocity as slow as 510{sup ?5} times of the light speed in vacuum is obtained at the focusing point. When the graphene sheet is placed on top of an aluminum oxide substrate, the focusing spot size of 56 THz infrared reduces to 1.1?nm and the intensity enhancement factor is still as high as 220. This structure offers an approach for focusing light in the MIR regime beyond the diffraction limit without complicated device geometry engineering.

  10. Infrared finite ghost propagator in the Feynman gauge

    E-Print Network [OSTI]

    A. C. Aguilar; J. Papavassiliou

    2007-12-05T23:59:59.000Z

    We demonstrate how to obtain from the Schwinger-Dyson equations of QCD an infrared finite ghost propagator in the Feynman gauge. The key ingredient in this construction is the longitudinal form factor of the non-perturbative gluon-ghost vertex, which, contrary to what happens in the Landau gauge, contributes non-trivially to the gap equation of the ghost. The detailed study of the corresponding vertex equation reveals that in the presence of a dynamical infrared cutoff this form factor remains finite in the limit of vanishing ghost momentum. This, in turn, allows the ghost self-energy to reach a finite value in the infrared, without having to assume any additional properties for the gluon-ghost vertex, such as the presence of massless poles. The implications of this result and possible future directions are briefly outlined.

  11. Infrared structure of e+e- --> 3 jets at NNLO

    E-Print Network [OSTI]

    A. Gehrmann-De Ridder; T. Gehrmann; E. W. N. Glover; G. Heinrich

    2008-11-25T23:59:59.000Z

    We describe the calculation of the next-to-next-to-leading order (NNLO) QCD corrections to three-jet production and related event shape observables in electron-positron annihilation. Infrared singularities due to double real radiation at tree level and single real radiation at one loop are subtracted from the full QCD matrix elements using antenna functions, which are then integrated analytically and added to the two loop contribution. Using this antenna subtraction method, we obtain numerically finite contributions from five-parton and four-parton processes, and observe an explicit analytic cancellation of infrared poles in the four-parton and three-parton contributions. All contributions are implemented in a flexible parton-level event generator programme, allowing the numerical computation of any infrared-safe observable related to three-jet final states to NNLO accuracy.

  12. Infrared Singularities and Soft Gluon Resummation with Massive Partons

    E-Print Network [OSTI]

    A. Ferroglia; M. Neubert; B. D. Pecjak; L. L. Yang

    2010-06-24T23:59:59.000Z

    Infrared divergences of QCD scattering amplitudes can be derived from an anomalous dimension matrix, which is also an essential ingredient for the resummation of large logarithms due to soft gluon emissions. We report a recent analytical calculation of the anomalous dimension matrix with both massless and massive partons at two-loop level, which describes the two-loop infrared singularities of any scattering amplitudes with an arbitrary number of massless and massive partons, and also enables soft gluon resummation at next-to-next-to-leading-logarithmic order. As an application, we calculate the infrared poles in the q qbar -> t tbar and gg -> t tbar scattering amplitudes at two-loop order.

  13. High speed infrared radiation thermometer, system, and method

    DOE Patents [OSTI]

    Markham, James R. (Middlefield, CT)

    2002-01-01T23:59:59.000Z

    The high-speed radiation thermometer has an infrared measurement wavelength band that is matched to the infrared wavelength band of near-blackbody emittance of ceramic components and ceramic thermal barrier coatings used in turbine engines. It is comprised of a long wavelength infrared detector, a signal amplifier, an analog-to-digital converter, an optical system to collect radiation from the target, an optical filter, and an integral reference signal to maintain a calibrated response. A megahertz range electronic data acquisition system is connected to the radiation detector to operate on raw data obtained. Because the thermometer operates optimally at 8 to 12 .mu.m, where emittance is near-blackbody for ceramics, interferences to measurements performed in turbine engines are minimized. The method and apparatus are optimized to enable mapping of surface temperatures on fast moving ceramic elements, and the thermometer can provide microsecond response, with inherent self-diagnostic and calibration-correction features.

  14. Nanoscale spatially resolved infrared spectra from single microdroplets

    E-Print Network [OSTI]

    Mller, Thomas; Kulik, Andrzej J; Shimanovich, Ulyana; Mason, Thomas O; Knowles, Tuomas P J; Dietler, Giovanni

    2014-01-01T23:59:59.000Z

    Droplet microfluidics has emerged as a powerful platform allowing a large number of individual reactions to be carried out in spatially distinct microcompartments. Due to their small size, however, the spectroscopic characterisation of species encapsulated in such systems remains challenging. In this paper, we demonstrate the acquisition of infrared spectra from single microdroplets containing aggregation-prone proteins. To this effect, droplets are generated in a microfluidic flow-focussing device and subsequently deposited in a square array onto a ZnSe prism using a micro stamp. After drying, the solutes present in the droplets are illuminated locally by an infrared laser through the prism, and their thermal expansion upon absorption of infrared radiation is measured with an atomic force microscopy tip, granting nanoscale resolution. Using this approach, we resolve structural differences in the amide bands of the spectra of monomeric and aggregated lysozyme from single microdroplets with picolitre volume.

  15. Molecular Gas Distribution in Double-Nucleus Ultraluminous Infrared Galaxies

    E-Print Network [OSTI]

    A. S. Evans; J. A. Surace; J. M. Mazzarella; D. B Sanders

    1999-12-22T23:59:59.000Z

    Millimeter (CO) observations of 5 double-nucleus ultraluminous infrared galaxy (ULIG) mergers are presented. With nuclear separations of 3-5 kpc, these galaxies are in the ``intermediate'' stages of the merger process. A preliminary comparison of the distribution of molecular gas (the likely fuel source for both starbursts and active galactic nuclei: AGN) shows a tendency for molecular gas to be associated with the AGN nucleus of ULIGs with ``warm'', Seyfert-like infrared colors ($f_{25 microns}/f_{60 microns} >~ 0.20) and associated with both stellar nuclei of ULIGs with ``cool'' infrared colors (f_{25 microns} /f_{60 microns} < 0.2). Studies of ULIGs with a wide range of nuclear separations using the high resolution and increased sensitivity of ALMA will provide a larger statistical sample with which the gas distribution, molecular gas masses, and densities can be determined as a function of the evolutionary stage, starburst and AGN activity, and lookback time.

  16. Apparatus for generating coherent infrared energy of selected wavelength

    DOE Patents [OSTI]

    Stevens, Charles G. (Danville, CA)

    1985-01-01T23:59:59.000Z

    A tunable source (11) of coherent infrared energy includes a heat pipe (12) having an intermediate region (24) at which cesium (22) is heated to vaporizing temperature and end regions (27, 28) at which the vapor is condensed and returned to the intermediate region (24) for reheating and recirculation. Optical pumping light (43) is directed along the axis of the heat pipe (12) through a first end window (17) to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window (18). A porous walled tubulation (44) extends along the axis of the heat pipe (12) and defines a region (46) in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light (43). Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light (43).

  17. Space-Based Thermal Infrared Studies of Asteroids

    E-Print Network [OSTI]

    Mainzer, A; Trilling, D

    2015-01-01T23:59:59.000Z

    Large-area surveys operating at mid-infrared wavelengths have proven to be a valuable means of discovering and characterizing minor planets. Through the use of radiometric models, it is possible to derive physical properties such as diameters, albedos, and thermal inertia for large numbers of objects. Modern detector array technology has resulted in a significant improvement in spatial resolution and sensitivity compared with previous generations of space-based infrared telescopes, giving rise to a commensurate increase in the number of objects that have been observed at these wavelengths. Space-based infrared surveys of asteroids therefore offer an effective means of rapidly gathering information about small body populations' orbital and physical properties. The AKARI, WISE/NEOWISE, Spitzer, and Herschel missions have significantly increased the number of minor planets with well-determined diameters and albedos.

  18. Temperature dependence of the threshold current for InGaAlP visible laser diodes

    SciTech Connect (OSTI)

    Ishikawa, M.; Shiozawa, H.; Itaya, K.; Hatakoshi, G.; Uematsu, Y. (Research and Development Center, Toshiba Corp., Saiwai-ku, Kawasaki 210 (JP))

    1991-01-01T23:59:59.000Z

    The temperature dependence of the threshold current for InGaAlP visible light laser diodes is investigated from the aspect of gain-current characteristics. The cavity length dependence of light output power versus current characteristic was evaluated for a 40 {mu}m width InGaP-InBaAlP broad-stripe laser in the temperature range between {minus} 70 and 90{degrees} C, which had about a 670 nm oscillation wavelength at room temperature. The threshold-current density dependence on the cavity length shows that a linear-gain approximation is suitable for this system. A minimum threshold-current density at 860 A/cm{sup 2} was achieved at room temperature with a cavity length of 1160 {mu}m, which is the lowest value ever reported for this material. The linear-gain parameters {beta} and {ital J}{sub 0} depended on the temperature with the characteristic temperature of about 200 K, which is considered to be the intrinsic characteristic temperature of the threshold current for this active-layer material. The internal quantum efficiency, derived from the cavity length dependence of the differential quantum efficiency, decreased in the temperature range higher than {minus}10{degrees} C, which affected the excess threshold-current increase and the decrease in the characteristic temperature at this temperature range. The theoretical calculation, considering a one-dimensional band structure model, showed that this excess increase of the threshold current was found to be attributed to the electron overflow current into the p-type cladding layer.

  19. Synthesis and magnetic characterization of magnetite obtained by monowavelength visible light irradiation

    SciTech Connect (OSTI)

    Lin, Yulong [Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001 (China) [Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017 (China); Wei, Yu, E-mail: weiyu@mail.hebtu.edu.cn [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050016 (China)] [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050016 (China); Sun, Yuhan, E-mail: yhsun@sxicc.ac.cn [Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001 (China)] [Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001 (China); Wang, Jing [School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017 (China)] [School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017 (China)

    2012-03-15T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Magnetite was synthesized under monowavelength LED irradiation at room temperature. Black-Right-Pointing-Pointer Different wavelength irradiations led to distinctive characteristics of magnetite. Black-Right-Pointing-Pointer Particle sizes of magnetite were controlled by different irradiation wavelengths. Black-Right-Pointing-Pointer Wavelength affects the magnetic characteristics of magnetite. -- Abstract: Magnetite (Fe{sub 3}O{sub 4}) nanoparticles were controllably synthesized by aerial oxidation Fe{sup II}EDTA solution under different monowavelength light-emitting diode (LED) lamps irradiation at room temperature. The results of the X-ray diffraction (XRD) spectra show the formation of magnetite nanoparticle further confirmed by Fourier transform infrared spectroscope (FTIR) and the difference in crystallinity of as-prepared samples. Fe{sub 3}O{sub 4} particles are nearly spherical in shape based on transmission electron microscopy (TEM). Average crystallite sizes of magnetite can be controlled by different irradiation light wavelengths from XRD and TEM: 50.1, 41.2, and 20.3 nm for red, green, and blue light irradiation, respectively. The magnetic properties of Fe{sub 3}O{sub 4} samples were investigated. Saturation magnetization values of magnetic nanoparticles were 70.1 (sample M-625), 65.3 (sample M-525), and 58.2 (sample M-460) emu/g, respectively.

  20. Infrared problem and spatially local observables in electrodynamics

    E-Print Network [OSTI]

    Andrzej Herdegen

    2007-11-14T23:59:59.000Z

    An algebra previously proposed as an asymptotic field structure in electrodynamics is considered in respect of localization properties of fields. Fields are 'spatially local' -- localized in regions resulting as unions of two intersecting (solid) lightcones: a future- and a past-lightcone. This localization remains in concord with the usual idealizations connected with the scattering theory. Fields thus localized naturally include infrared characteristics normally placed at spacelike infinity and form a structure respecting Gauss law. When applied to the description of the radiation of an external classical current the model is free of 'infrared catastrophe'.

  1. Antenna-coupled microcavities for enhanced infrared photo-detection

    SciTech Connect (OSTI)

    Nga Chen, Yuk; Todorov, Yanko, E-mail: yanko.todorov@univ-paris-diderot.fr; Askenazi, Benjamin; Vasanelli, Angela; Sirtori, Carlo [Laboratoire Matriaux et Phnomnes Quantiques, Universit Paris Diderot, Sorbonne Paris Cit, CNRS-UMR 7162, 75013 Paris (France); Biasiol, Giorgio [IOM CNR, Laboratorio TASC, Area Science Park, I-34149 Trieste (Italy); Colombelli, Raffaele [Institut d'Electronique Fondamentale, Universit Paris Sud, CNRS-UMR 8622, F-91405 Orsay (France)

    2014-01-20T23:59:59.000Z

    We demonstrate mid-infrared detectors embedded into an array of double-metal nano-antennas. The antennas act as microcavities that squeeze the electric field into thin semiconductor layers, thus enhancing the detector responsivity. Furthermore, thanks to the ability of the antennas to gather photons from an area larger than the device's physical dimensions, the dark current is reduced without hindering the photo-generation rate. In these devices, the background-limited performance is improved with a consequent increase of the operating temperature. Our results illustrate how the antenna-coupled microcavity concept can be applied to enhance the performances of infrared opto-electronic devices.

  2. Infrared behavior of QCD from the Dyson-Schwinger formalism

    E-Print Network [OSTI]

    Christian S. Fischer

    2008-10-14T23:59:59.000Z

    We discuss the properties of two different types of infrared solutions of Landau gauge Yang-Mills theory and argue for one of these (the 'scaling solution'). We furthermore clarify the status of previously obtained results from DSEs on a four-torus. Including quarks we discuss a relation between confinement and dynamical chiral symmetry breaking based on the scaling solution of Yang-Mills theory. An infrared singularity in the quark-gluon vertex allows for a solution of the $U_A$(1) problem along the lines of a mechanism suggested by Kogut and Susskind long ago.

  3. Infrared self-consistent solutions of bispinor QED3

    E-Print Network [OSTI]

    Tomasz Radozycki

    2013-01-25T23:59:59.000Z

    Quantum electrodynamics in three dimensions in the bispinor formulation is considered. It is shown that the Dyson-Schwinger equations for fermion and boson propagators may be self-consistently solved in the infrared domain if on uses the Salam's vertex function. The parameters defining the behavior of the propagators are found numerically for different values of coupling constant and gauge parameter. For weak coupling the approximated analytical solutions are obtained. The renormalized gauge boson propagator (transverse part) is shown in the infrared domain to be practically gauge independent.

  4. Near-Infrared Photometric Analyses of White Dwarf Stars

    E-Print Network [OSTI]

    P. -E. Tremblay; P. Bergeron

    2006-11-29T23:59:59.000Z

    We review the available near- and mid- infrared photometry data sets for white dwarfs from the Two Micron All-Sky Survey (2MASS) Point Source Catalog and the Spitzer Space Telescope. These data sets have been widely used to search for white dwarfs with an infrared excess as well as to characterize the atmosphere of cool white dwarfs. We evaluate the reliability of the 2MASS photometry by performing a statistical comparison with published JHK CIT magnitudes, and by carrying out a detailed model atmosphere analysis of the available photometry. We then present a critical examination of various results published in the literature including data from the Spitzer Space Telescope.

  5. Improving the Infra-red of Holographic Descriptions of QCD

    E-Print Network [OSTI]

    Nick Evans; Andrew Tedder; Tom Waterson

    2007-01-03T23:59:59.000Z

    A surprisingly good holographic description of QCD can be obtained from naive five dimensional gauge theory on a truncated AdS space. We seek to improve the infra-red description of QCD in such models by using a more sophisticated metric and an action derived from string theory duals of chiral symmetry breaking. Our metric is smooth into the infra-red and the chiral condensate is a prediction of the dynamics. The theory reproduces QCD meson data at the 10% level.

  6. On the performance of infrared sensors in earth observations

    E-Print Network [OSTI]

    Johnson, Luther Franklin

    1972-01-01T23:59:59.000Z

    ON THE PERFORMANCE OF INFRARED SENSORS IN EARTH OBSERVATIONS A Thesis by LUTHER FRANKLIN JOHNSON III Submitted to the Graduate College of Texas A(M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... Augus t 19 72 Major Subject: Electrical Engineering ON THE PERFORMANCE O'F INFRARED SENSORS IN EARTH OBSERVATIONS A Thesis by LUTHER FRANKLIN JOHNSON III Approved as to style and content by: r rman o ommr t Hea o Depart ent Mem er em er, em er...

  7. Infrared absorption spectroscopy and chemical kinetics of free radicals

    SciTech Connect (OSTI)

    Curl, R.F.; Glass, G.P. [Rice Univ., Houston, TX (United States)

    1993-12-01T23:59:59.000Z

    This research is directed at the detection, monitoring, and study of chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. During the last year, infrared kinetic spectroscopy using excimer laser flash photolysis and color-center laser probing has been employed to study the high resolution spectrum of HCCN, the rate constant of the reaction between ethynyl (C{sub 2}H) radical and H{sub 2} in the temperature region between 295 and 875 K, and the recombination rate of propargyl (CH{sub 2}CCH) at room temperature.

  8. A local infrared perspective to deeper ISO surveys

    E-Print Network [OSTI]

    D. M. Alexander; H. Aussel

    2000-02-09T23:59:59.000Z

    We present new techniques to produce IRAS 12 micron samples of galaxies and stars. We show that previous IRAS 12 micron samples are incompatible for detailed comparison with ISO surveys and review their problems. We provide a stellar infrared diagnostic diagram to distinguish galaxies from stars without using longer wavelength IRAS colour criteria and produce complete 12 micron samples of galaxies and stars. This new technique allows us to estimate the contribution of non-dusty galaxies to the IRAS 12 micron counts and produce a true local mid-infrared extragalactic sample compatible with ISO surveys. We present our initial analysis and results.

  9. Final LDRD report : enhanced spontaneous emission rate in visible III-nitride LEDs using 3D photonic crystal cavities.

    SciTech Connect (OSTI)

    Fischer, Arthur Joseph; Subramania, Ganapathi S.; Coley, Anthony J.; Lee, Yun-Ju; Li, Qiming; Wang, George T.; Luk, Ting Shan; Koleske, Daniel David; Fullmer, Kristine Wanta

    2009-09-01T23:59:59.000Z

    The fundamental spontaneous emission rate for a photon source can be modified by placing the emitter inside a periodic dielectric structure allowing the emission to be dramatically enhanced or suppressed depending on the intended application. We have investigated the relatively unexplored realm of interaction between semiconductor emitters and three dimensional photonic crystals in the visible spectrum. Although this interaction has been investigated at longer wavelengths, very little work has been done in the visible spectrum. During the course of this LDRD, we have fabricated TiO{sub 2} logpile photonic crystal structures with the shortest wavelength band gap ever demonstrated. A variety of different emitters with emission between 365 nm and 700 nm were incorporated into photonic crystal structures. Time-integrated and time-resolved photoluminescence measurements were performed to measure changes to the spontaneous emission rate. Both enhanced and suppressed emission were demonstrated and attributed to changes to the photonic density of states.

  10. Optical near-field induced visible response photoelectrochemical water splitting on nanorod TiO{sub 2}

    SciTech Connect (OSTI)

    Thu Hac Huong Le; Mawatari, Kazuma; Pihosh, Yuriy; Kitamori, Takehiko [Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656 (Japan); Kawazoe, Tadashi; Yatsui, Takashi; Ohtsu, Motoichi [Department of Electrical Engineering and Information Systems, Graduate School of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656 (Japan); Tosa, Masahiro [Micro-Nano Component Materials Group, Materials Engineering Laboratory, National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba, Ibaraki 305-0047 (Japan)

    2011-11-21T23:59:59.000Z

    Here we report a way to induce the visible response of non-doped TiO{sub 2} in the photocatalytic electrochemical water splitting, which is achieved by utilizing the optical near-field (ONF) generated on nanorod TiO{sub 2}. The visible response is attributed to the ONF-induced phonon-assisted excitation process, in which TiO{sub 2} is excited by sub-bandgap photons via phonon energy. Our approach directly gets involved in the excitation process without chemical modification of materials; accordingly it is expected to have few drawbacks on the photocatalytic performance. This study may offer another perspective on the development of solar harvesting materials.

  11. High Spatial Resolution KAO Far-Infrared Observations of the Central Regions of Infrared-Bright Galaxies

    E-Print Network [OSTI]

    Beverly J. Smith; P. M. Harvey

    1996-05-06T23:59:59.000Z

    We present new high spatial resolution Kuiper Airborne Observatory 50 micron and/or 100 micron data for 11 infrared-bright galaxies. We also tabulate previously published KAO data for 11 other galaxies, along with the IRAS data for the bulges of M 31 and M 81. We find that L(FIR)/L(B) and L(FIR)/L(H) correlate with CO (1 - 0) intensity and tau(100). Galaxies with optical or near-infrared signatures of OB stars in their central regions have higher values of I(CO) and tau(100), as well as higher far-infrared surface brightnesses and L(FIR)/L(B) and L(FIR)/L(H) ratios. L(FIR)/L(H(alpha)) does not correlate strongly with CO and tau(100). These results support a scenario in which OB stars dominate dust heating in the more active galaxies and older stars are important in quiescent bulges.

  12. Novel visible-light-driven photocatalyst. Poly(p-phenylene)-catalyzed photoreductions of water, carbonyl compounds, and olefins

    SciTech Connect (OSTI)

    Shibata, Takuya; Kabumoto, Akira; Shiragami, Tsutomu; Ishitani, Osamu; Pac, Chyongjin; Yanagida, Shozo (Osaka Univ. (Japan))

    1990-03-08T23:59:59.000Z

    The insoluble yellow powder of poly(p-phenylene) (PPP) prepared by nickel-catalyzed polycondensation of the Grignard reagent from 1,4-dibromobenzene shows photocatalytic activity under visible light toward water, carbonyl compounds, and olefins. Water is photoreduced to H{sub 2} in the presence of amines as sacrificial electron donors. The H{sub 2} evolution is enhanced 3-20 times by noble-metal deposition, in which Ru deposition is the most effective.

  13. Nitrogen stabilized reactive sputtering of optimized TiO{sub 2-x} photocatalysts with visible light reactivity

    SciTech Connect (OSTI)

    Chen, Le; Graham, Michael E.; Gray, Kimberly A. [Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

    2009-07-15T23:59:59.000Z

    Photoreactive and visible light responsive nonstoichiometric mixed-phase titania was prepared by reactive direct current magnetron sputtering. Trace amounts of nitrogen were added for process stabilization without being incorporated into the films. Based on the CO{sub 2} photoreduction tests and structural and optical characterization, the influence of the trace nitrogen on the sputtered nonstoichiometric TiO{sub 2} was studied and was compared to nitrogen-doped titania.

  14. Analysis of the empirical relations between visible solar radiation, the solar altitude and the transparency of the atmosphere

    E-Print Network [OSTI]

    Garcia Occhipinti, Antonio

    1965-01-01T23:59:59.000Z

    ANALYSIS OF THE EMPIRICAL RELATIONS BETWEEN VISUAL SOLAR RADIATION, THE SOLAR ALTITUDE AND THE TRANSPARENCY OF THE ATMOSPHERE A Thesis A. Garcia Occhipinti Submitted to the Graduate College of the Texas ARM Untverstty in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January 1965 Major Subject: Oceanography ANALYSIS OF THE EMPIRICAL RELATIONS BETWEEN VISIBLE SOLAR RADIATION, THE SOLAR ALTITUDE AND THE TRANSPARENCY OF THE ATMOSPHERE A Thesis A. Garcia Occhipinti...

  15. Infrared 3-4 Micron Spectroscopy of Infrared Luminous Galaxies with Possible Signatures of Obscured Active Galactic Nuclei

    E-Print Network [OSTI]

    Masatoshi Imanishi

    2006-02-10T23:59:59.000Z

    We present the results of infrared 2.8-4.1 micron (L-band) spectroscopy of nearby infrared luminous galaxies with possible signatures of dust-obscured active galactic nuclei (AGNs) in data at other wavelengths. The samples are chosen to include sources with a radio excess relative to far-infrared emission, strong absorption features in mid-infrared 5-11.5 micron spectra, unusually weak [CII] 158 micron emission relative to the far-infrared continuum, and radio galaxies classified optically as narrow-line objects. Our aim is to investigate whether the signatures of possible obscured AGNs can be detected in our L-band spectra, based on the strengths of emission and absorption features. Six of nine observed sources clearly show 3.3 micron polycyclic aromatic hydrocarbon (PAH) emission features, a good starburst indicator. An absorption feature at 3.1 micron due to ice-covered dust is detected in IRAS 04154+1755 and IRAS 17208-0014. The signature of a bare carbonaceous dust absorption feature at 3.4 micron is seen in NGC 1377. Our L-band spectra reveal strong signatures of obscured AGNs in all three optical Seyfert 2 galaxies (IRAS 04154+1755, Cygnus A, and 3C 234), and two galaxies classified optically as non-Seyferts (NGC 828 and NGC 1377). Among the remaining optical non-Seyferts, IRAS 17208-0014 might also show a buried AGN signature, whereas no explicit AGN evidence is seen in the L-band spectra of the mid-infrared absorption-feature source IRAS 15250+3609, and two weak [CII] emitters IC 860 and CGCG 1510.8+0725.

  16. Facile synthesis of novel Ag/AgI/BiOI composites with highly enhanced visible light photocatalytic performances

    SciTech Connect (OSTI)

    Cao, Jing, E-mail: caojing@mail.ipc.ac.cn [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Zhao, Yijie; Lin, Haili; Xu, Benyan [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); Chen, Shifu, E-mail: chshifu@chnu.edu.cn [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China)

    2013-10-15T23:59:59.000Z

    Novel Ag/AgI/BiOI composites were controllably synthesized via a facile ion-exchange followed by photoreduction strategy by using hierarchical BiOI microflower as substrate. The as-prepared Ag/AgI/BiOI composites were studied by X-ray powder diffractometer (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), BrunauerEmmettTeller (BET) surface area analyzer and UVvis diffuse reflectance spectroscopy (DRS). Under visible light (?>420 nm), Ag/AgI/BiOI displayed highly enhanced photocatalytic activities for degradation of methyl orange (MO) compared to the pure hierarchical BiOI, which was mainly ascribed to the highly efficient separation of electrons and holes through the closely contacted interfaces in the Ag/AgI/BiOI ternary system. - Graphical abstract: Ag/AgI/BiOI displayed excellent photocatalytic activities for methyl orange degradation under visible light, which was mainly ascribed to the highly efficient separation of electrons and holes through Z-scheme pathway. Display Omitted - Highlights: Novel Ag/AgI/BiOI composites were successfully synthesized. Ag/AgI/BiOI displayed higher visible light activities than those of pure BiOI and AgI. O{sub 2}{sup ?} and h{sup +}, especially O{sub 2}{sup ?}, dominated the photodegradation process of MO. A Z-scheme pattern was adopted for Ag/AgI/BiOI activity enhancement.

  17. Crystallographic Dependence of Visible-light Photoactivity in Epitaxial TiO2?xNx Anatase and Rutile

    SciTech Connect (OSTI)

    Ohsawa, Takeo; Lyubinetsky, Igor; Du, Yingge; Henderson, Michael A.; Shutthanandan, V.; Chambers, Scott A.

    2009-02-03T23:59:59.000Z

    Nitrogen-doped TiO2 materials have been shown to exhibit visible-light photoactivity, but the operative mechanism(s) are not well understood. Here we use structurally and compositionally well-defined epitaxial films of TiO2?xNx anatase (001) and rutile (110) (x~0.02) to show a qualitative difference between the visible-light activities for the two polymorphs. Holes generated by visible light at N sites in anatase (001) readily diffuse to the surface and oxidize adsorbed trimethyl acetate while the same in rutile (110) remain trapped in the bulk. In light of the low doping densities that can be achieved in phase-pure material, conventional wisdom suggests that holes should be trapped at N sites in both polymorphs. Although the detailed mechanism is not yet understood, these results suggest that the hole hopping probability is much higher along the [001] direction in N-doped anatase than along the [110] direction in N-doped rutile.

  18. Visible Light Photocatalysis with Nitrogen-Doped Titanium Dioxide Nanoparticles Prepared by Plasma Assisted Chemical Vapor Deposition

    SciTech Connect (OSTI)

    Buzby,S.; Barakat, M.; Lin, H.; Ni, C.; Rykov, S.; Chen, J.; Shah, S.

    2006-01-01T23:59:59.000Z

    Nitrogen-doped TiO{sub 2} nanoparticles were synthesized via plasma assisted metal organic chemical vapor deposition. Nitrogen dopant concentration was varied from 0 to 1.61 at. %. The effect of nitrogen ion doping on visible light photocatalysis has been investigated. Samples were analyzed by various analytical techniques such as x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy, and near-edge x-ray absorption fine structure. Titanium tetraisopropoxide was used as the titanium precursor, while rf-plasma-decomposed ammonia was used as the source for nitrogen doping. The N-doped TiO{sub 2} nanoparticles were deposited on stainless steel mesh under a flow of Ar and O2 gases at 600 {sup o}C in a tube reactor. The photocatalytic activity of the prepared N-doped TiO{sub 2} samples was tested by the degradation of 2-chlorophenol (2-CP) in an aqueous solution using a visible lamp equipped with an UV filter. The efficiency of photocatalytic oxidation of 2-CP was measured using high performance liquid chromatography. Results obtained revealed the formation of N-doped TiO{sub 2} samples as TiO{sub 2-x}N{sub x}, and a corresponding increase in the visible light photocatalytic activity.

  19. Inhibition of uracil-DNA glycosylase increases SCEs in BrdU-treated and visible light-irradiated cells

    SciTech Connect (OSTI)

    Maldonado, A.; Hernandez, P.; Gutierrez, C.

    1985-11-01T23:59:59.000Z

    The authors have approached the study of the ability of different types of lesions produced by DNA-damaging agents to develop sister-chromatid exchanges (SCEs) by analyzing SCE levels observed in Allium cepa L cells with BrdU-substituted DNA and exposed to visible light (VL), an irradiation which produces uracil residues in DNA after debromination of bromouracil and enhances SCE levels but only above a certain dose. They have partially purified an uracil-DNA glycosylase activity from A. cepa L root meristem cells, which removes uracil from DNA, the first step in the excision repair of this lesion. This enzyme was inhibited in vitro by 6-amino-uracil and uracil but not by thymine. When cells exposed to VL, at a dose that did not produce per se an SCE increase, were immediately post-treated with these inhibitors of uracil-DNA glycosylase, a significant increase in SCE levels was obtained. Moreover, SCE levels in irradiated cells dropped to control level when a short holding time elapsed between exposure to VL and the beginning of post-treatment with the inhibitor. Thus, our results showed that inhibitors of uracil-DNA glycosylase enhanced SCE levels in cells with unifilarly BrdU-substituted DNA exposed to visible light; and indicated the existence of a very rapid repair of SCE-inducing lesions produced by visible light irradiation of cells with unifilarly BrdU-containing DNA.

  20. Broadband three-photon near-infrared quantum cutting in Tm{sup 3+} singly doped YVO{sub 4}

    SciTech Connect (OSTI)

    Wang, Y. Z.; Yu, D. C.; Lin, H. H.; Ye, S.; Peng, M. Y.; Zhang, Q. Y., E-mail: qyzhang@scut.edu.cn [State Key Laboratory of Luminescence Materials and Devices, and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641 (China)

    2013-11-28T23:59:59.000Z

    An efficient three-photon near-infrared (NIR) quantum cutting (QC) is reported in Tm{sup 3+} singly doped YVO{sub 4} polycrystalline phosphors, where an optimized content of Tm{sup 3+} is determined to be 1.0?mol. %. Upon the absorption of a visible photon around 473?nm, three NIR photons emitting at 1180, 1479, and 1800?nm can be obtained efficiently by the sequential three-step radiative transitions of Tm{sup 3+}. The underlying mechanisms are analyzed in terms of the steady and dynamic fluorescence spectra measurements. Internal quantum yield is calculated to be 161.8% as a theoretical value when luminescence quenching due to defect species can be overcome. In addition, the broadband ultraviolet (UV)-excited [VO{sub 4}]{sup 3?} can strongly sensitize the {sup 1}G{sub 4} level of Tm{sup 3+} in the wavelength range likely from 250 to 360?nm, greatly increasing the UV photo-response and NIR fluorescent intensity of Tm{sup 3+}. The further development of this broadband three-photon NIR QC material would explore the new route to improve the photo-response of novel photoelectronic devices, particularly in 250360?nm.