National Library of Energy BETA

Sample records for aerosol optical properties

  1. ARM - Measurement - Aerosol optical properties

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

    : Aerosol optical properties The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter...

  2. ARM - Field Campaign - MASRAD - Aerosol Optical Properties

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

    govCampaignsMASRAD - Aerosol Optical Properties Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation Aerosol and Drizzle...

  3. Optical Properties of Mixed Black Carbon, Inorganic and Secondary Organic Aerosols

    SciTech Connect (OSTI)

    Paulson, S E

    2012-05-30

    Summarizes the achievements of the project, which are divided into four areas: 1) Optical properties of secondary organic aerosols; 2) Development and of a polar nephelometer to measure aerosol optical properties and theoretical approaches to several optical analysis problems, 3) Studies on the accuracy of measurements of absorbing carbon by several methods, and 4) Environmental impacts of biodiesel.

  4. Characterizing Aerosol Distributions and Optical Properties Using the NASA Langley High Spectral Resolution Lidar

    SciTech Connect (OSTI)

    Hostetler, Chris; Ferrare, Richard

    2013-02-14

    The objective of this project was to provide vertically and horizontally resolved data on aerosol optical properties to assess and ultimately improve how models represent these aerosol properties and their impacts on atmospheric radiation. The approach was to deploy the NASA Langley Airborne High Spectral Resolution Lidar (HSRL) and other synergistic remote sensors on DOE Atmospheric Science Research (ASR) sponsored airborne field campaigns and synergistic field campaigns sponsored by other agencies to remotely measure aerosol backscattering, extinction, and optical thickness profiles. Synergistic sensors included a nadir-viewing digital camera for context imagery, and, later in the project, the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). The information from the remote sensing instruments was used to map the horizontal and vertical distribution of aerosol properties and type. The retrieved lidar parameters include profiles of aerosol extinction, backscatter, depolarization, and optical depth. Products produced in subsequent analyses included aerosol mixed layer height, aerosol type, and the partition of aerosol optical depth by type. The lidar products provided vertical context for in situ and remote sensing measurements from other airborne and ground-based platforms employed in the field campaigns and was used to assess the predictions of transport models. Also, the measurements provide a data base for future evaluation of techniques to combine active (lidar) and passive (polarimeter) measurements in advanced retrieval schemes to remotely characterize aerosol microphysical properties. The project was initiated as a 3-year project starting 1 January 2005. It was later awarded continuation funding for another 3 years (i.e., through 31 December 2010) followed by a 1-year no-cost extension (through 31 December 2011). This project supported logistical and flight costs of the NASA sensors on a dedicated aircraft, the subsequent analysis and archival of the data, and the presentation of results in conferences, workshops, and publications. DOE ASR field campaigns supported under this project included - MAX-Mex /MILAGRO (2006) - TexAQS 2006/GoMACCS (2006) - CHAPS (2007) - RACORO (2009) - CARE/CalNex (2010) In addition, data acquired on HSRL airborne field campaigns sponsored by other agencies were used extensively to fulfill the science objectives of this project and the data acquired have been made available to other DOE ASR investigators upon request.

  5. Ultraviolet high-spectral-resolution Doppler lidar for measuring wind field and aerosol optical properties

    SciTech Connect (OSTI)

    Imaki, Masaharu; Kobayashi, Takao

    2005-10-01

    An ultraviolet incoherent Doppler lidar that incorporates the high-spectral-resolution (HSR) technique has been developed for measuring the wind field and aerosol optical properties in the troposphere. An injection seeded and tripled Nd:YAG laser at an ultraviolet wavelength of 355 nm was used in the lidar system. The HRS technique can resolve the aerosol Mie backscatter and the molecular Rayleigh backscatter to derive the signal components. By detecting the Mie backscatter, a great increase in the Doppler filter sensitivity was realized compared to the conventional incoherent Doppler lidars that detected the Rayleigh backscatter. The wind velocity distribution in a two-dimensional cross section was measured. By using the HSR technique, multifunction and absolute value measurements were realized for aerosol extinction, and volume backscatter coefficients; the laser beam transmittance, the lidar ratio, and the backscatter ratio are derived from these measurements.

  6. Lidar Measurements of the Vertical Distribution of Aerosol Optical and Physical Properties over Central Asia

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

    Chen, Boris B.; Sverdlik, Leonid G.; Imashev, Sanjar A.; Solomon, Paul A.; Lantz, Jeffrey; Schauer, James J.; Shafer, Martin M.; Artamonova, Maria S.; Carmichael, Gregory R.

    2013-01-01

    The vertical structure of aerosol optical and physical properties was measured by Lidar in Eastern Kyrgyzstan, Central Asia, from June 2008 to May 2009. Lidar measurements were supplemented with surface-based measurements of PM 2.5 and PM 10 mass and chemical composition in both size fractions. Dust transported into the region is common, being detected 33% of the time. The maximum frequency occurred in the spring of 2009. Dust transported to Central Asia comes from regional sources, for example, Taklimakan desert and Aral Sea basin, and from long-range transport, for example, deserts of Arabia, Northeast Africa, Iran, and Pakistan. Regionalmore » sources are characterized by pollution transport with maximum values of coarse particles within the planetary boundary layer, aerosol optical thickness, extinction coefficient, integral coefficient of aerosol backscatter, and minimum values of the Ångström exponent. Pollution associated with air masses transported over long distances has different characteristics during autumn, winter, and spring. During winter, dust emissions were low resulting in high values of the Ångström exponent (about 0.51) and the fine particle mass fraction (64%). Dust storms were more frequent during spring with an increase in coarse dust particles in comparison to winter. The aerosol vertical profiles can be used to lower uncertainty in estimating radiative forcing.« less

  7. Investigations of the Absorption Properties of Near-Ground Aerosol by the Methods of Optical-Acoustic Spectrometry and Diff...

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

    Investigations of the Absorption Properties of Near-Ground Aerosol by the Methods of Optical-Acoustic Spectrometry and Diffuse Extinction V. S. Kozlov, M. V. Panchenko, A. B. Tikhomirov, and B. A. Tikhomirov Institute of Atmospheric Optics Tomsk, Russia Introduction Aerosol absorption is an important factor in the formation of non-selective radiation extinction in the visible wavelength range, and plays a great role in solving many radiative and climatic problems. The principal absorbing

  8. Measurement and Modeling of Vertically Resolved Aerosol Optical Properties and Radiative Fluxes Over the ARM SGP Site During the May 2003 Aerosol IOP

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

    Measurement and Modeling of Vertically Resolved Aerosol Optical Properties and Radiative Fluxes Over the ARM SGP Site During the May 2003 Aerosol IOP B. Schmid and J. Redemann Bay Area Environmental Research Institute National Aeronautics and Space Administration Ames Research Center Moffett Field, California W. P. Arnott Desert Research Institute Reno, Nevada A. Bucholtz and J. Reid Naval Research Laboratory Monterey, California P. Colarco Earth System Science Interdisciplinary Center

  9. ARM - AOS Aerosol Properties Plots

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

    ViewersAOS Aerosol Properties Plots XDC Data Viewers Aerosol Properties Plots SGP AMF NSA (BRW) AOS Aerosol Properties Plots These plots are designed to provide a quick look at the measured aerosol properties or review current station operations. Be aware that they are raw unedited data. Do not quote and cite. Aerosol Properties Plots SGP AMF NSA (BRW)

  10. Preliminary Results of in-situ Measurements of Aerosol Optical...

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

    of Aerosol Optical and Water Uptake Properties from the ARM Mobile Facility in Niger Jefferson, Anne NOAA CMDL Ogren, John NOAACMDL Category: Field Campaigns The second...

  11. ARM - Measurement - Aerosol optical depth

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

    depth ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol optical depth A measure of how much light aerosols prevent from passing through a column of atmosphere. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including

  12. ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    1998-03-01

    10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  13. ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  14. ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  15. ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  16. Effect of Aerosol Humidification on the Column Aerosol Optical Thickness

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

    over the ARM Southern Great Plains Site Effect of Aerosol Humidification on the Column Aerosol Optical Thickness over the ARM Southern Great Plains Site Li, Zhanqing University of Maryland Jeong, Myeong-Jae University of Maryland Category: Aerosols This study investigates the aerosol humidification effect (AHE) using seventy profiles of the aerosol scattering and absorption coefficients at high (~85%) and low (~40%) relative humidity (RH) levels obtained over the Southern Great Plains (SGP)

  17. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

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

    Sivaraman, Chitra; Flynn, Connor

    2010-12-15

    10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  18. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

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

    Sivaraman, Chitra; Flynn, Connor

    10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  19. Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

    SciTech Connect (OSTI)

    Richard A. Ferrare; David D. Turner

    2011-09-01

    Project goals: (1) Use the routine surface and airborne measurements at the ARM SGP site, and the routine surface measurements at the NSA site, to continue our evaluations of model aerosol simulations; (2) Determine the degree to which the Raman lidar measurements of water vapor and aerosol scattering and extinction can be used to remotely characterize the aerosol humidification factor; (3) Use the high temporal resolution CARL data to examine how aerosol properties vary near clouds; and (4) Use the high temporal resolution CARL and Atmospheric Emitted Radiance Interferometer (AERI) data to quantify entrainment in optically thin continental cumulus clouds.

  20. ARM - PI Product - Niamey Aerosol Optical Depths

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

    Aerosol Optical Depths ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Niamey Aerosol Optical Depths MFRSR irradiance data collected during the ACRF AMF deployment in Niamey, Niger have been used to derive AOD for five wavelength channels of the MFRSR. These data have been corrected to adjust for filter drift over the course of the campaign and contamination due to forward scattering as a result of

  1. ARM - Field Campaign - MASRAD: Marine Aerosol Properties

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

    govCampaignsMASRAD: Marine Aerosol Properties Campaign Links AMF Point Reyes Website Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA....

  2. Emerging Technology for Measuring Atmospheric Aerosol Properties

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

    Technology for Measuring Atmospheric Aerosol Properties Bruce Gandrud Greg Kok Droplet Measurement Technologies Darrel Baumgardner Centro de Ciencias de la Atmósfera Universidad Nacional Autónoma de México Acknowledgements * The DMT staff * Bob Bluth and Haflidi Jonsson * Pat Arnott * Greg Roberts and Thanos Nenes * Dave Fahey, Shuka Schwarz and Ru-Shan Gao * NSF, NASA, ONR, NOAA and DOE Introducing Droplet Measurement Technologies * Founded in 1987 * Specializing in aerosol and cloud

  3. Hyperspectral Aerosol Optical Depths from TCAP Flights

    SciTech Connect (OSTI)

    Shinozuka, Yohei; Johnson, Roy R.; Flynn, Connor J.; Russell, P. B.; Schmid, Beat; Redemann, Jens; Dunagan, Stephen; Kluzek, Celine D.; Hubbe, John M.; Segal-Rosenheimer, Michal; Livingston, J. M.; Eck, T.; Wagener, Richard; Gregory, L.; Chand, Duli; Berg, Larry K.; Rogers, Ray; Ferrare, R. A.; Hair, John; Hostetler, Chris A.; Burton, S. P.

    2013-11-13

    4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research), the worlds first hyperspectral airborne tracking sunphotometer, acquired aerosol optical depths (AOD) at 1 Hz during all July 2012 flights of the Two Column Aerosol Project (TCAP). Root-mean square differences from AERONET ground-based observations were 0.01 at wavelengths between 500-1020 nm, 0.02 at 380 and 1640 nm and 0.03 at 440 nm in four clear-sky fly-over events, and similar in ground side-by-side comparisons. Changes in the above-aircraft AOD across 3-km-deep spirals were typically consistent with integrals of coincident in situ (on DOE Gulfstream 1 with 4STAR) and lidar (on NASA B200) extinction measurements within 0.01, 0.03, 0.01, 0.02, 0.02, 0.02 at 355, 450, 532, 550, 700, 1064 nm, respectively, despite atmospheric variations and combined measurement uncertainties. Finer vertical differentials of the 4STAR measurements matched the in situ ambient extinction profile within 14% for one homogeneous column. For the AOD observed between 350-1660 nm, excluding strong water vapor and oxygen absorption bands, estimated uncertainties were ~0.01 and dominated by (then) unpredictable throughput changes, up to +/-0.8%, of the fiber optic rotary joint. The favorable intercomparisons herald 4STARs spatially-resolved high-frequency hyperspectral products as a reliable tool for climate studies and satellite validation.

  4. Investigation of Absorption Properties of Submicron Aerosol in the Troposphere Over West Siberia

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

    Investigation of Absorption Properties of Submicron Aerosol in the Troposphere Over West Siberia M. V. Panchenko, V. S. Kozlov, and V. P. Shmargunov Institute of Atmospheric Optics Tomsk, Russia Introduction Improving radiative climate models for the cloudless atmosphere depends largely on the correct way to simulate single-scattering albedo of atmospheric aerosol. Solving this problem requires performing detailed experiments on the study of the aerosol absorption characteristics in the

  5. Aerosol Optical Depth Value-Added Product Report

    SciTech Connect (OSTI)

    Koontz, A; Hodges, G; Barnard, J; Flynn, C; Michalsky, J

    2013-03-17

    This document describes the process applied to retrieve aerosol optical depth (AOD) from multifilter rotating shadowband radiometers (MFRSR) and normal incidence multifilter radiometers (NIMFR) operated at the ARM Climate Research Facility’s ground-based facilities.

  6. ARM - Field Campaign - Cirrus Clouds and Aerosol Properties Campaign

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

    govCampaignsCirrus Clouds and Aerosol Properties Campaign ARM Data Discovery Browse Data Related Campaigns Vaisala Laser Ceilometer CL51 Demonstration 2013.11.14, Winston, SGP...

  7. ARM AOS Processing Status and Aerosol Intensive Properties VAP

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

    AOS Processing Status and Aerosol Intensive Properties VAP A. S. Koontz and C. J. Flynn Pacific Northwest National Laboratory Richland, Washington J. A. Ogren, E. Andrews, and P....

  8. Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

    SciTech Connect (OSTI)

    Turner, David, D.; Ferrare, Richard, A.

    2011-07-06

    The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.

  9. Quantifying Aerosol Direct Effects from Broadband Irradiance and Spectral Aerosol Optical Depth Observations

    SciTech Connect (OSTI)

    Creekmore, Torreon N.; Joseph, Everette; Long, Charles N.; Li, Siwei

    2014-05-16

    We outline a methodology using broadband and spectral irradiances to quantify aerosol direct effects on the surface diffuse shortwave (SW) irradiance. Best Estimate Flux data span a 13 year timeframe at the Department of Energy Atmospheric Radiation Measurement Program’s Southern Great Plains (SGP) site. Screened clear-sky irradiances and aerosol optical depth (AOD), for solar zenith angles ≤ 65°, are used to estimate clear-sky diffuse irradiances. We validate against detected clear-sky observations from SGP’s Basic Radiation System (BRS). BRS diffuse irradiances were in accordance with estimates, producing a root-mean-square error and mean bias errors of 4.0 W/m2 and -1.4 W/m2, respectively. Absolute differences show 99% of estimates within ±10 W/m2 (10%) of the mean BRS observations. Clear-sky diffuse estimates are used to derive quantitative estimates of aerosol radiative effects, represented as the aerosol diffuse irradiance (ADI). ADI is the contribution of diffuse SW to global SW, attributable to scattering of atmospheric transmission by natural plus anthropogenic aerosols. Estimated slope for the ADI as a function of AOD indicates an increase of ~22 W/m2 in diffuse SW for every 0.1 increase in AOD. Such significant increases in the diffuse fraction could possibly increase photosynthesis. Annual mean ADI is 28.2 W/m2, and heavy aerosol loading at SGP provides up to a maximum increase of 120 W/m2 in diffuse SW over background conditions. With regard to seasonal variation, the mean diffuse forcings are 17.2, 33.3, 39.0, and 23.6 W/m2 for winter, spring, summer, and fall, respectively.

  10. Connecting Organic Aerosol Climate-Relevant Properties to Chemical Mechanisms of Sources and Processing

    SciTech Connect (OSTI)

    Thornton, Joel

    2015-01-26

    The research conducted on this project aimed to improve our understanding of secondary organic aerosol (SOA) formation in the atmosphere, and how the properties of the SOA impact climate through its size, phase state, and optical properties. The goal of this project was to demonstrate that the use of molecular composition information to mechanistically connect source apportionment and climate properties can improve the physical basis for simulation of SOA formation and properties in climate models. The research involved developing and improving methods to provide online measurements of the molecular composition of SOA under atmospherically relevant conditions and to apply this technology to controlled simulation chamber experiments and field measurements. The science we have completed with the methodology will impact the simulation of aerosol particles in climate models.

  11. Analysis of Langley optical depth data, with aerosol and gas...

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

    Columbia University - NASAGISS Lacis, Andrew NASAGoddard Institute for Space Studies Carlson, Barbara NASAGoddard Institute for Space Studies Category: Aerosols Bimodal aerosol...

  12. ARM: 10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

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

    Chitra Sivaraman; Connor Flynn

    1998-03-01

    10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

  13. ARM: 10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

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

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

  14. Aerosol optical hygroscopicity measurements during the 2010 CARES campaign

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

    Atkinson, D. B.; Radney, J. G.; Lum, J.; Kolesar, K. R.; Cziczo, D. J.; Pekour, M. S.; Zhang, Q.; Setyan, A.; Zelenyuk, A.; Cappa, C. D.

    2015-04-17

    Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter γ, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GFs) at 85% relative humidity and the dimensionless hygroscopicity parameter κ for oxygenated organic aerosol (OA) and for supermicron particles (defined heremore » as particles with aerodynamic diameters between 1 and 2.5 microns), yielding κ = 0.1–0.15 and 0.9–1.0, respectively. The derived range of oxygenated OA κ values are in line with previous observations. The relatively large values for supermicron particles is consistent with substantial contributions of sea-salt-containing particles in this size range. Analysis of time-dependent variations in the supermicron particle hygroscopicity suggest that atmospheric processing, specifically chloride displacement by nitrate and the accumulation of secondary organics on supermicron particles, can lead to substantial depression of the observed GF.« less

  15. Cloud Properties Working Group Low Clouds Update

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

    radiative fluxes, and Optical properties and radiative fluxes, and Associated aerosol prop. & atmospheric state Associated aerosol prop. & atmospheric state Long Long - - term...

  16. Aerosol Properties from Multi-spectral and Multi-angular Aircraft 4STAR Observations: Expected Advantages and Challenges

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Flynn, Connor J.; Redemann, Jens; Schmid, Beat; Russell, P. B.; Sinyuk, Alexander

    2012-11-01

    The airborne Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) is developed to retrieve aerosol microphysical and optical properties from multi-angular and multi-spectral measurements of sky radiance and direct-beam sun transmittance. The necessarily compact design of the 4STAR may cause noticeable apparent enhancement of sky radiance at small scattering angles. We assess the sensitivity of expected 4STAR-based aerosol retrieval to such enhancement by applying the operational AERONET retrieval code and constructed synthetic 4STARlike data. Also, we assess the sensitivity of the broadband fluxes and the direct aerosol radiative forcing to uncertainties in aerosol retrievals associated with the sky radiance enhancement. Our sensitivity study results suggest that the 4STARbased aerosol retrieval has limitations in obtaining detailed information on particle size distribution and scattering phase function. However, these limitations have small impact on the retrieved bulk optical parameters, such as the asymmetry factor (up to 4%, or 0.02) and single-scattering albedo (up to 2%, or 0.02), and the calculated direct aerosol radiative forcing (up to 6%, or 2 Wm-2).

  17. Aerosol optical hygroscopicity measurements during the 2010 CARES Campaign

    SciTech Connect (OSTI)

    Atkinson, D. B.; Radney, J. G.; Lum, J.; Kolesar, K. R.; Cziczo, Daniel J.; Pekour, Mikhail S.; Zhang, Qi; Setyan, Ari; Zelenyuk, Alla; Cappa, Christopher

    2015-01-01

    Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 CARES study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter ?, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GF) at 85% relative humidity and the dimensionless hygroscopicity parameter ? for oxygenated organic aerosol (OA) and for supermicron particles, yielding ? = 0.10.15 and 0.91.0, respectively. The derived range of oxygenated OA ? values are in line with previous observations. The relatively large values for supermicron particles is consistent with substantial contributions of sea salt-containing particles in this size range. Analysis of time-dependent variations in the supermicron particle hygroscopicity suggest that atmospheric processing, specifically chloride displacement by nitrate and the accumulation of secondary organics on supermicron particles, can lead to substantial depression of the observed GF.

  18. Aerosol optical hygroscopicity measurements during the 2010 CARES Campaign

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

    Atkinson, D. B.; Radney, J. G.; Lum, J.; Kolesar, K. R.; Cziczo, D. J.; Pekour, M. S.; Zhang, Q.; Setyan, A.; Zelenyuk, A.; Cappa, C. D.

    2014-12-10

    Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 CARES study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter γ, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GF) at 85% relative humidity and the dimensionless hygroscopicity parameter κ for oxygenated organic aerosol (OA) and for supermicron particles, yielding κ = 0.1–0.15 and 0.9–1.0, respectively. Themore » derived range of oxygenated OA κ values are in line with previous observations. The relatively large values for supermicron particles is consistent with substantial contributions of sea salt-containing particles in this size range. Analysis of time-dependent variations in the supermicron particle hygroscopicity suggest that atmospheric processing, specifically chloride displacement by nitrate and the accumulation of secondary organics on supermicron particles, can lead to substantial depression of the observed GF.« less

  19. Direct Aerosol Forcing Uncertainty

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

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  20. Aerosol Observing System (AOS) Handbook

    SciTech Connect (OSTI)

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earths radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  1. CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-05-27

    Carbonaceous aerosol components, which include black carbon (BC), urban primary organic aerosols (POA), biomass burning aerosols, and secondary organic aerosols (SOA) from both urban and biogenic precursors, have been previously shown to play a major role in the direct and indirect radiative forcing of climate. The primary objective of the CARES 2010 intensive field study is to investigate the evolution of carbonaceous aerosols of different types and their effects on optical and cloud formation properties.

  2. Wave like signatures in aerosol optical depth and associated radiative impacts over the central Himalayan region

    SciTech Connect (OSTI)

    Shukla, K. K.; Phanikumar, D. V.; Kumar, Niranjan; Reddy, Kishore; Kotamarthi, Veerabhadra R.; Newsom, Rob K.; Ouarda, Taha B.

    2015-10-01

    In this study, we present a case study on 16 October 2011 to show the first observational evidence of the influence of short period gravity waves in aerosol transport during daytime over the central Himalayan region. The Doppler lidar data has been utilized to address the daytime boundary layer evolution and related aerosol dynamics over the site. Mixing layer height is estimated by wavelet covariance transform method and found to be ~ 0.7 km, AGL. Aerosol optical depth observations during daytime revealed an asymmetry showing clear enhancement during afternoon hours as compared to forenoon. Interestingly, Fourier and wavelet analysis of vertical velocity and attenuated backscatter showed similar 50-90 min short period gravity wave signatures during afternoon hours. Moreover, our observations showed that gravity waves are dominant within the boundary layer implying that the daytime boundary layer dynamics is playing a vital role in transporting the aerosols from surface to the top of the boundary layer. Similar modulations are also evident in surface parameters like temperature, relative humidity and wind speed indicating these waves are associated with the dynamical aspects over Himalayan region. Finally, time evolution of range-23 height indicator snapshots during daytime showed strong upward velocities especially during afternoon hours implying that convective processes through short period gravity waves plays a significant role in transporting aerosols from the nearby valley region to boundary layer top over the site. These observations also establish the importance of wave induced daytime convective boundary layer dynamics in the lower Himalayan region.

  3. Advanced optical measurements for characterizing photophysical properties

    Office of Scientific and Technical Information (OSTI)

    of single nanoparticles. (Technical Report) | SciTech Connect Technical Report: Advanced optical measurements for characterizing photophysical properties of single nanoparticles. Citation Details In-Document Search Title: Advanced optical measurements for characterizing photophysical properties of single nanoparticles. Formation of complex nanomaterials would ideally involve single-pot reaction conditions with one reactive site per nanoparticle, resulting in a high yield of incrementally

  4. DOE/SC-ARM/TR-129 Aerosol Optical Depth Value-Added Product

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

    9 Aerosol Optical Depth Value-Added Product A Koontz C Flynn G Hodges J Michalsky J Barnard March 2013 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use

  5. ARM - Measurement - Hydrometeor optical properties

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

    scattering and absorption cross-sections, and backscatter fraction. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  6. ARM - Cumulus Humilis Aerosol Processing Study (CHAPS)

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

    Study (CHAPS) Campaign Details News Field Participants Resources Status and Actions ARM Data Discovery Browse Data Cumulus Humilis Aerosol Processing Study (CHAPS) Summer 2007 ASP Field Campaign The primary goal of the CHAPS campaign is to characterize and contrast freshly emitted aerosols above, within and below fields of cumulus humilis (or fair-weather cumulus). These observations will be used to examine the aerosol optical properties and cloud nucleating properties from both below-cloud and

  7. Development of RAMS-CMAQ to Simulate Aerosol Optical Depth and Aerosol Direct Radiative Forcing and Its Application to East Asia

    SciTech Connect (OSTI)

    Han, Xiao; Zhang, Meigen; Liu, Xiaohong; Ghan, Steven J.; Xin, Jin-Yuan; Wang, Li-Li

    2009-11-16

    The air quality modeling system RAMS (Regional Atmospheric Modeling System)-CMAQ (Models-3 Community Multi-scale Air Quality) is developed to simulate the aerosol optical depth (AOD) and aerosol direct forcing (DF). The aerosol-specific extinction, single scattering albedo, and asymmetry factor are parameterized based on Mie theory taking into account the aerosol size distribution, composition, refractive index, and water uptake of solution particles. A two-stream solar radiative model considers all gaseous molecular absorption, Rayleigh scattering, and aerosols and clouds. RAMSCMAQ is applied to simulate all major aerosol concentrations (e.g., sulfate, nitrate, ammonium, organic carbon, black carbon, fine soil, and sea salt) and AOD and DF over East Asia in 2005. To evaluate its performance, the simulated AOD values were compared with ground-based in situ measurements. The comparison shows that RAMSCMAQ performed well in most of the model domain and generally captured the observed variations. High AOD values (0.2?1.0) mainly appear in the Sichuan Basin as well as in central and southeastern China. The geographic distribution of DF generally follows the AOD distribution patterns, and the DF at the top-of-the-atmosphere is less than ?25 and ?20 W m?2 in clear-sky and all-sky over the Sichuan Basin. Both AOD and DF exhibit seasonal variations with lower values in July and higher ones in January. The DF could obviously be impacted by high cloud fractions.

  8. Posters Ship-Based Measurements of Cloud Optical Properties

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

    the optical properties of MBL clouds using measurements taken on the NOAA research vessel Malcom Baldrige. We seek the relationship between optical depth and liquid water because...

  9. Optical Properties of the Charge-Density-Wave Polychalcogenide...

    Office of Scientific and Technical Information (OSTI)

    Optical Properties of the Charge-Density-Wave Polychalcogenide Compounds R2Te5 (RNd, Sm and Gd) Citation Details In-Document Search Title: Optical Properties of the...

  10. OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR

    Office of Scientific and Technical Information (OSTI)

    NANOSTRUCTURES (Journal Article) | SciTech Connect OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES Citation Details In-Document Search Title: OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES This chapter provides an overview of some recent research activities on the study of optical and dynamic properties of semiconductor nanomaterials. The emphasis is on unique aspects of these properties in nanostructures as compared to bulk

  11. Thermo-optical Properties of Nanofluids

    SciTech Connect (OSTI)

    Ortega, Maria Alejandra; Echevarria, Lorenzo; Rodriguez, Luis; Castillo, Jimmy; Fernandez, Alberto

    2008-04-15

    In this work, we report thermo-optical properties of nanofluids. Spherical gold nanoparticles obtained by laser ablation in condensed media were characterized using thermal lens spectroscopy in SDS-water solution pumping at 532 nm with a 10 ns pulsed laser-Nd-YAG system. Nanoparticles obtained by laser ablation were stabilized in the time by surfactants (Sodium Dodecyl-Sulfate or SDS) in different molar concentrations. The morphology and size of the gold nanoparticles were determined by transmission electron microscopy (TEM). The plasmonic resonance bands in gold nanoparticles are responsible of the light optical absorption of this wavelength. The position of the absorption maximum and width band in the UV-Visible spectra is given by the morphological characteristics of these systems. The thermo-optical constant such as thermal diffusion, thermal conductivity and dn/dT are functions of nanoparticles sizes and dielectric constant of the media. The theoretical model existents do not describe completely this relations because is not possible separate the contributions due to nanoparticles size, factor form and dielectric constant. The thermal lens signal obtained is also dependent of nanoparticles sizes. This methodology can be used in order to evaluate nanofluids and characterizing nanoparticles in different media. These results are expected to have an impact in bioimaging, biosensors and other technological applications such as cooler system.

  12. FY 2010 Fourth Quarter Report: Evaluation of the Dependency of Drizzle Formation on Aerosol Properties

    SciTech Connect (OSTI)

    Lin, W; McGraw, R; Liu, Y; Wang, J; Vogelmann, A; Daum, PH

    2010-10-01

    Metric for Quarter 4: Report results of implementation of composite parameterization in single-column model (SCM) to explore the dependency of drizzle formation on aerosol properties. To better represent VOCALS conditions during a test flight, the Liu-Duam-McGraw (LDM) drizzle parameterization is implemented in the high-resolution Weather Research and Forecasting (WRF) model, as well as in the single-column Community Atmosphere Model (CAM), to explore this dependency.

  13. Global Distribution and Climate Forcing of Marine Organic Aerosol - Part 2: Effects on Cloud Properties and Radiative Forcing

    SciTech Connect (OSTI)

    Gantt, Brett; Xu, Jun; Meskhidze, N.; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

    2012-07-25

    A series of simulations with the Community Atmosphere Model version 5 (CAM5) with a 7-mode Modal Aerosol Model were conducted to assess the changes in cloud microphysical properties and radiative forcing resulting from marine organic aerosols. Model simulations show that the anthropogenic aerosol indirect forcing (AIF) predicted by CAM5 is decreased in absolute magnitude by up to 0.09 Wm{sup -2} (7 %) when marine organic aerosols are included. Changes in the AIF from marine organic aerosols are associated with small global increases in low-level incloud droplet number concentration and liquid water path of 1.3 cm{sup -3} (1.5 %) and 0.22 gm{sup -2} (0.5 %), respectively. Areas especially sensitive to changes in cloud properties due to marine organic aerosol include the Southern Ocean, North Pacific Ocean, and North Atlantic Ocean, all of which are characterized by high marine organic emission rates. As climate models are particularly sensitive to the background aerosol concentration, this small but non-negligible change in the AIF due to marine organic aerosols provides a notable link for ocean-ecosystem marine low-level cloud interactions and may be a candidate for consideration in future earth system models.

  14. Techniques and Methods Used to Determine the Aerosol Best Estimate...

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

    I: Aerosol Optical Properties. J. Geophys. Res., 109, D06208, doi:10.10292003JD004025. Daniel, J. S., and coauthors, 2002: Cloud liquid water and ice measurements from...

  15. Automated retrieval of cloud and aerosol properties from the ARM Raman lidar, part 1: feature detection

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Newsom, Rob K.; Turner, David D.; Comstock, Jennifer M.

    2015-11-01

    A Feature detection and EXtinction retrieval (FEX) algorithm for the Atmospheric Radiation Measurement (ARM) program’s Raman lidar (RL) has been developed. Presented here is part 1 of the FEX algorithm: the detection of features including both clouds and aerosols. The approach of FEX is to use multiple quantities— scattering ratios derived using elastic and nitro-gen channel signals from two fields of view, the scattering ratio derived using only the elastic channel, and the total volume depolarization ratio— to identify features using range-dependent detection thresholds. FEX is designed to be context-sensitive with thresholds determined for each profile by calculating the expected clear-sky signal and noise. The use of multiple quantities pro-vides complementary depictions of cloud and aerosol locations and allows for consistency checks to improve the accuracy of the feature mask. The depolarization ratio is shown to be particularly effective at detecting optically-thin features containing non-spherical particles such as cirrus clouds. Improve-ments over the existing ARM RL cloud mask are shown. The performance of FEX is validated against a collocated micropulse lidar and observations from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite over the ARM Darwin, Australia site. While we focus on a specific lidar system, the FEX framework presented here is suitable for other Raman or high spectral resolution lidars.

  16. OPTICAL PROPERTIES OF A MECHANICALLY POLISHED AND AIR-EQUILIBRATED...

    Office of Scientific and Technical Information (OSTI)

    POLISHED AND AIR-EQUILIBRATED 111 UO2 SURFACE BY RAMAN AND ELLIPSOMETRIC SPECTROSCOPY Citation Details In-Document Search Title: OPTICAL PROPERTIES OF A MECHANICALLY...

  17. Optical diffraction properties of multimicrogratings (Journal...

    Office of Scientific and Technical Information (OSTI)

    Publisher: Optical Society of America Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text ...

  18. ARM - Measurement - Aerosol backscattered radiation

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

    RLPROF : Raman LIDAR Vertical Profiles UW-AIR : University of Washington Airborne Aerosol Instruments Value-Added Products AIP : Aerosol Intensive Properties (Process) AIP1OGREN :...

  19. Determines the Thermal and Optical Properties of Fenestration Systems

    Energy Science and Technology Software Center (OSTI)

    1995-01-27

    WINDOW4.1 computes the thermal properties of windows and other fenestration elements used in typical residential and commercial buildings. Manufactures, specifiers, architects, consumers, and the energy code specialists all need to know these properties (U-values, Solar Heat Gain Coefficients, optical properties). The use of this program to calculate these properties is typically much more cost effective than laboratory test procedures. Properties of complete window systems are based on libraries (or user input) component data.

  20. Coupling Between Oceanic Upwelling and Cloud-aerosol Properties at the AMF Point Reyes Site

    SciTech Connect (OSTI)

    Dunn, M.; Jensen, M.; Miller, M.; Kollias, P.; Bartholomew, M. J.; Turner, D.; Andrews, E.; Jefferson, A.; Daum, P.

    2008-03-10

    Cloud microphysical properties measured at the ARM Mobile Facility site located on the northern coast of California near Point Reyes, during the 2005 Marine Stratus Radiation, Aerosol and Drizzle experiment, were analyzed to determine their relationship to the coastal sea surface temperature (SST) which was characterized using measurements acquired from a National Oceanic and Atmospheric Administration offshore buoy. An increase in SST resulting from a relaxation of upwelling, occurring in the eastern Pacific Ocean off the coast of California in summer is observed to strongly correlate with nearby ground measured cloud microphysical properties and cloud condensation nuclei (CCN) concentrations. Correlations between these atmospheric and oceanic features provide insight into the interplay between the ocean and cloud radiative properties. We present evidence of this robust correlation and examine the factors controlling these features. The marine boundary layer is in direct contact with the sea surface and is strongly influenced by SST. Moisture and vertical motion are crucial ingredients for cloud development and so we examine the role of SST in providing these key components to the atmosphere. Although upwelling of cold subsurface waters is conventionally thought to increase aerosols in the region, thus increasing clouds, here we observed a relaxation of upwelling associated with changes in the structure of marine stratus clouds. As upwelling relaxes, the SST get warmer, thick clouds with high liquid water paths are observed and persist for a few days. This cycle is repeated throughout the summer upwelling season. A concomitant cyclic increase and decrease of CCN concentration is also observed. Forcing mechanisms and large-scale atmospheric features are discussed. Marine stratocumulus clouds are a critical component of the earth's radiation budget and this site provides an excellent opportunity to study the influence of SST on these clouds.

  1. Optical and infrared properties of glancing angle deposited nanostructured

    Office of Scientific and Technical Information (OSTI)

    tungsten films (Journal Article) | SciTech Connect Optical and infrared properties of glancing angle deposited nanostructured tungsten films Citation Details In-Document Search Title: Optical and infrared properties of glancing angle deposited nanostructured tungsten films Authors: Ungaro, Craig [1] ; Shah, Ankit [1] ; Kravchenko, Ivan I [2] ; Hensley, Dale K [2] ; Gray, Stephen K. [3] ; Gupta, Mool C. [1] + Show Author Affiliations University of Virginia, Charlottesville ORNL Argonne

  2. ARM - Publications: Science Team Meeting Documents: A decade long aerosol

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

    and cloud statistics and aerosol indirect effect at the ARM SGP site A decade long aerosol and cloud statistics and aerosol indirect effect at the ARM SGP site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Twelve-year data of MFRSR and MWR have been used to derive aerosol and cloud optical properties at the ARM SGP. Diurnal, monthly, seasonal and

  3. Aerosol Extinction Profiles

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

    and Thermodynamic Responses to Uncertainty in Aerosol Extinction Profiles For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Aerosol radiative effects are of great importance for climate simulations over South Asia. For quantifying aerosol direct radiative effect, aerosol optical depth (AOD) and single scattering albedo (SSA) are often compared with observations. These comparisons have revealed large AOD underestimation and

  4. Distinct optical properties of relativistically degenerate matter

    SciTech Connect (OSTI)

    Akbari-Moghanjoughi, M.

    2014-06-15

    In this paper, we use the collisional quantum magnetohydrodynamic (CQMHD) model to derive the transverse dielectric function of a relativistically degenerate electron fluid and investigate various optical parameters, such as the complex refractive index, the reflection and absorption coefficients, the skin-depth and optical conductivity. In this model we take into accounts effects of many parameters such as the atomic-number of the constituent ions, the electron exchange, electron diffraction effect and the electron-ion collisions. Study of the optical parameters in the solid-density, the warm-dense-matter, the big-planetary core, and the compact star number-density regimes reveals that there are distinct differences between optical characteristics of the latter and the former cases due to the fundamental effects of the relativistic degeneracy and other quantum mechanisms. It is found that in the relativistic degeneracy plasma regime, such as found in white-dwarfs and neutron star crusts, matter possess a much sharper and well-defined step-like reflection edge beyond the x-ray electromagnetic spectrum, including some part of gamma-ray frequencies. It is also remarked that the magnetic field intensity only significantly affects the plasma reflectivity in the lower number-density regime, rather than the high density limit. Current investigation confirms the profound effect of relativistic degeneracy on optical characteristics of matter and can provide an important plasma diagnostic tool for studying the physical processes within the wide scope of quantum plasma regimes be it the solid-density, inertial-confined, or astrophysical compact stars.

  5. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian (Port Jefferson, NY); Kulkarni, Pramod (Port Jefferson Station, NY)

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  6. Nanodiamonds: Their Structure and Optical Properties

    SciTech Connect (OSTI)

    Raty, J.-Y.; van Buuren, T.; Galli, G.

    2002-05-14

    Nanometer sized diamond is a constituent of diverse systems ranging from interstellar dusts and meteorites [1] to carbonaceous residues of detonations [2] and diamond-like films [3-5]. Many of the properties of bulk diamond have been well understood for decades, those of nanodiamond are mostly unexplored. We present a combined theoretical and experimental study showing that diamond has unique properties not only as a bulk material but also at the nanoscale, where size reduction and surface reconstruction effects are fundamentally different from those found, e.g. in Si and Ge.

  7. The Two-Column Aerosol Project (TCAP) Science Plan

    SciTech Connect (OSTI)

    Berkowitz, CM; Berg, LK; Cziczo, DJ; Flynn, CJ; Kassianov, EI; Fast, JD; Rasch, PJ; Shilling, JE; Zaveri, RA; Zelenyuk, A; Ferrare, RA; Hostetler, CA; Cairns, B; Russell, PB; Ervens, B

    2011-07-27

    The Two-Column Aerosol Project (TCAP) field campaign will provide a detailed set of observations with which to (1) perform radiative and cloud condensation nuclei (CCN) closure studies, (2) evaluate a new retrieval algorithm for aerosol optical depth (AOD) in the presence of clouds using passive remote sensing, (3) extend a previously developed technique to investigate aerosol indirect effects, and (4) evaluate the performance of a detailed regional-scale model and a more parameterized global-scale model in simulating particle activation and AOD associated with the aging of anthropogenic aerosols. To meet these science objectives, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will deploy the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) on Cape Cod, Massachusetts, for a 12-month period starting in the summer of 2012 in order to quantify aerosol properties, radiation, and cloud characteristics at a location subject to both clear and cloudy conditions, and clean and polluted conditions. These observations will be supplemented by two aircraft intensive observation periods (IOPs), one in the summer and a second in the winter. Each IOP will deploy one, and possibly two, aircraft depending on available resources. The first aircraft will be equipped with a suite of in situ instrumentation to provide measurements of aerosol optical properties, particle composition and direct-beam irradiance. The second aircraft will fly directly over the first and use a multi-wavelength high spectral resolution lidar (HSRL) and scanning polarimeter to provide continuous optical and cloud properties in the column below.

  8. Carbonaceous Aerosols and Radiative Effects Study (CARES), g1-aircraft, sedlacek sp2

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

    Sedlacek, Art

    The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume.

  9. Carbonaceous Aerosols and Radiative Effects Study (CARES), g1-aircraft, sedlacek sp2

    SciTech Connect (OSTI)

    Sedlacek, Art

    2011-08-30

    The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume.

  10. ARM - Evaluation Product - Cloud Optical Properties from MFRSR Using Min

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

    Algorithm ProductsCloud Optical Properties from MFRSR Using Min Algorithm ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Cloud Optical Properties from MFRSR Using Min Algorithm Like the operational VAP run at other sites, MFRSRCLDOD is based on the algorithm by Min and Harrison (1996). Users are

  11. Optical properties of colloidal germanium nanocrystals

    SciTech Connect (OSTI)

    WILCOXON,JESS P.; PROVENCIO,PAULA P.; SAMARA,GEORGE A.

    2000-05-01

    Highly crystalline germanium (Ge) nanocrystals in the size range 2--10 nm were grown in inverse micelles and purified and size-separated by high pressure liquid chromatography with on-line optical and electrical diagnostics. The nanocrystals retain the diamond structure of bulk Ge down to at least 2.0 nm (containing about 150 Ge atoms). The background- and impurity-free extinction and photoluminescence (PL) spectra of these nanocrystals revealed rich structure which was interpreted in terms of the bandstructure of Ge shifted to higher energies by quantum confinement. The shifts ranged from {minus}0.1 eV to over 1 eV for the various transitions. PL in the range 350--700 nm was observed from nanocrystals 2--5 nm in size. The 2.0 nm nanocrystals yielded the most intense PL (at 420 nm) which is believed to be intrinsic and attributed to direct recombination at {Gamma}. Excitation at high energy (250 nm) populates most of the conduction bands resulting in competing recombination channels and the observed broad PL spectra.

  12. Optical techniques for determining dynamic material properties

    SciTech Connect (OSTI)

    Paisley, D.L.; Stahl, D.B.

    1996-12-31

    Miniature plates are laser-launched with a 10-Joule Nd:YAG for one-dimensional (1-D) impacts on to target materials much like gas gun experiments and explosive plane wave plate launch. By making the experiments small, flyer plates (3 mm diameter x 50 micron thick) and targets (10 mm diameter x 200 micron thick), 1-D impact experiments can be performed in a standard laser-optical laboratory with minimum confinement and collateral damage. The laser-launched plates do not require the traditional sabot on gas guns nor the explosives needed for explosive planewave lenses, and as a result are much more amenable to a wide variety of materials and applications. Because of the small size very high pressure gradients can be generated with relative ease. The high pressure gradients result in very high strains and strain rates that are not easily generated by other experimental methods. The small size and short shock duration (1 - 20 ns) are ideal for dynamically measuring bond strengths of micron-thick coatings. Experimental techniques, equipment, and dynamic material results are reported.

  13. Optical Properties of Moderately-Absorbing Organic and Mixed Organic/Inorganic Particles at Very High Humidities

    SciTech Connect (OSTI)

    Bond, Tami C; Rood, Mark J; Brem, Benjamin T; Mena-Gonzalez, Francisco C; Chen, Yanju

    2012-04-16

    Relative humidity (RH) affects the water content of an aerosol, altering its ability to scatter and absorb light, which is important for aerosol effects on climate and visibility. This project involves in situ measurement and modeling of aerosol optical properties including absorption, scattering and extinction at three visible wavelengths (467, 530, 660 nm), for organic carbon (OC) generated by pyrolysis of biomass, ammonium sulfate and sodium chloride, and their mixtures at controlled RH conditions. Novel components of this project include investigation of: (1) Changes in all three of these optical properties at scanned RH conditions; (2) Optical properties at RH values up to 95%, which are usually extrapolated instead of measured; and (3) Examination of aerosols generated by the pyrolysis of wood, which is representative of primary atmospheric organic carbon, and its mixture with inorganic aerosol. Scattering and extinction values were used to determine light absorption by difference and single scattering albedo values. Extensive instrumentation development and benchmarking with independently measured and modeled values were used to obtain and evaluate these new results. The single scattering albedo value for a dry absorbing polystyrene microsphere benchmark agreed within 0.02 (absolute value) with independently published results at 530 nm. Light absorption by a nigrosin (sample light-absorbing) benchmark increased by a factor of 1.24 +/-0.06 at all wavelengths as RH increased from 38 to 95%. Closure modeling with Mie theory was able to reproduce this increase with the linear volume average (LVA) refractive index mixing rule for this water soluble compound. Absorption by biomass OC aerosol increased by a factor of 2.1 +/- 0.7 and 2.3 +/- 1.2 between 32 and 95% RH at 467 nm and 530 nm, but there was no detectable absorption at 660 nm. Additionally, the spectral dependence of absorption by OC that was observed with filter measurements was confirmed qualitatively in situ at 467 and 530 nm. Closure modeling with the dynamic effective medium approximation (DEMA) refractive index model was able to capture the increasing absorption trend with RH indicating that the droplets were heterogeneously mixed while containing dispersed insoluble absorbing material within those droplets. Seven other refractive index mixing models including LVA did not adequately describe the measurements for OC. Mixing the biomass OC aerosol with select mass fractions of ammonium sulfate ranging from 25 to 36% and sodium chloride ranging from 21 to 30% resulted in an increase in light scattering and extinction with RH and inorganic mass fraction. However, no detectable difference in light absorption behavior in comparison to pure biomass OC was observed. The main finding of this research is a measured increase in absorption with increasing RH, which is currently not represented in radiative transfer models even though biomass burning produces most of the primary OC aerosol in the atmosphere.

  14. Optical system properties of a reconfigurable MEMS interconnect.

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect system properties of a reconfigurable MEMS interconnect. Citation Details In-Document Search Title: Optical system properties of a reconfigurable MEMS interconnect. No abstract prepared. Authors: Spahn, Olga Blum ; Grossetete, Grant David ; Gass, Fawn Renee ; Kemme, Shanalyn A. ; Dagel, Daryl James Publication Date: 2002-12-01 OSTI Identifier: 913215 Report Number(s): SAND2003-0020C TRN: US200802%%382 DOE Contract Number: AC04-94AL85000 Resource Type:

  15. Method for quantifying optical properties of the human lens

    DOE Patents [OSTI]

    Loree, deceased, Thomas R. (late of Albuquerque, NM); Bigio, Irving J. (Los Alamos, NM); Zuclich, Joseph A. (San Antonio, TX); Shimada, Tsutomu (Los Alamos, NM); Strobl, Karlheinz (Fiskdale, MA)

    1999-01-01

    Method for quantifying optical properties of the human lens. The present invention includes the application of fiberoptic, OMA-based instrumentation as an in vivo diagnostic tool for the human ocular lens. Rapid, noninvasive and comprehensive assessment of the optical characteristics of a lens using very modest levels of exciting light are described. Typically, the backscatter and fluorescence spectra (from about 300- to 900-nm) elicited by each of several exciting wavelengths (from about 300- to 600-nm) are collected within a few seconds. The resulting optical signature of individual lenses is then used to assess the overall optical quality of the lens by comparing the results with a database of similar measurements obtained from a reference set of normal human lenses having various ages. Several metrics have been identified which gauge the optical quality of a given lens relative to the norm for the subject's chronological age. These metrics may also serve to document accelerated optical aging and/or as early indicators of cataract or other disease processes.

  16. Method for quantifying optical properties of the human lens

    DOE Patents [OSTI]

    Loree, T.R.; Bigio, I.J.; Zuclich, J.A.; Shimada, Tsutomu; Strobl, K.

    1999-04-13

    A method is disclosed for quantifying optical properties of the human lens. The present invention includes the application of fiberoptic, OMA-based instrumentation as an in vivo diagnostic tool for the human ocular lens. Rapid, noninvasive and comprehensive assessment of the optical characteristics of a lens using very modest levels of exciting light are described. Typically, the backscatter and fluorescence spectra (from about 300- to 900-nm) elicited by each of several exciting wavelengths (from about 300- to 600-nm) are collected within a few seconds. The resulting optical signature of individual lenses is then used to assess the overall optical quality of the lens by comparing the results with a database of similar measurements obtained from a reference set of normal human lenses having various ages. Several metrics have been identified which gauge the optical quality of a given lens relative to the norm for the subject`s chronological age. These metrics may also serve to document accelerated optical aging and/or as early indicators of cataract or other disease processes. 8 figs.

  17. Lanthanides-clay nanocomposites: Synthesis, characterization and optical properties

    SciTech Connect (OSTI)

    Celedon, Salvador; Quiroz, Carolina; Gonzalez, Guillermo; Sotomayor Torres, Clivia M.; Benavente, Eglantina

    2009-05-06

    Complexes of Europium(III) and Terbium(III) with 2,2-bipyridine and 1,10-phenanthroline were inserted into Na-bentonite by ion exchange reactions at room temperature. The products display interlaminar distances and stoichiometries in agreement with the ion exchange capacity and the interlayer space available in the clay. The optical properties of the intercalates, being qualitatively similar to those of the free complexes, are additionally improved with respect to exchange processes with the medium, especially in a moist environment. The protection again hydrolysis, together with the intensity of the optical transition {sup 5}D{sub 0}-{sup 5}F{sub 2} observed in the nanocomposite, makes these products promising for the development of novel optical materials.

  18. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

    1988-01-01

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  19. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

  20. Optical Adhesive Property Study Kansas City Division P. D. Sundvold

    Office of Scientific and Technical Information (OSTI)

    Optical Adhesive Property Study Kansas City Division P. D. Sundvold KCP-613-5631 Published January 1996 Topical Report Approved for public release; distribution is unlimited. Prepared Under Contract Number DE-AC04-76-DP00613 for the &lliedSig nal United States Department of Energy A E R O S P A C E DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their

  1. Optical method for determining the mechanical properties of a material

    DOE Patents [OSTI]

    Maris, Humphrey J. (Barrington, RI); Stoner, Robert J. (Duxbury, MA)

    1998-01-01

    Disclosed is a method for characterizing a sample, comprising the steps of: (a) acquiring data from the sample using at least one probe beam wavelength to measure, for times less than a few nanoseconds, a change in the reflectivity of the sample induced by a pump beam; (b) analyzing the data to determine at least one material property by comparing a background signal component of the data with data obtained for a similar delay time range from one or more samples prepared under conditions known to give rise to certain physical and chemical material properties; and (c) analyzing a component of the measured time dependent reflectivity caused by ultrasonic waves generated by the pump beam using the at least one determined material property. The first step of analyzing may include a step of interpolating between reference samples to obtain an intermediate set of material properties. The material properties may include sound velocity, density, and optical constants. In one embodiment, only a correlation is made with the background signal, and at least one of the structural phase, grain orientation, and stoichiometry is determined.

  2. Optical method for determining the mechanical properties of a material

    DOE Patents [OSTI]

    Maris, H.J.; Stoner, R.J.

    1998-12-01

    Disclosed is a method for characterizing a sample, comprising the steps of: (a) acquiring data from the sample using at least one probe beam wavelength to measure, for times less than a few nanoseconds, a change in the reflectivity of the sample induced by a pump beam; (b) analyzing the data to determine at least one material property by comparing a background signal component of the data with data obtained for a similar delay time range from one or more samples prepared under conditions known to give rise to certain physical and chemical material properties; and (c) analyzing a component of the measured time dependent reflectivity caused by ultrasonic waves generated by the pump beam using the at least one determined material property. The first step of analyzing may include a step of interpolating between reference samples to obtain an intermediate set of material properties. The material properties may include sound velocity, density, and optical constants. In one embodiment, only a correlation is made with the background signal, and at least one of the structural phase, grain orientation, and stoichiometry is determined. 14 figs.

  3. Climate implications of carbonaceous aerosols: An aerosol microphysical study using the GISS/MATRIX climate model

    SciTech Connect (OSTI)

    Bauer, Susanne E.; Menon, Surabi; Koch, Dorothy; Bond, Tami; Tsigaridis, Kostas

    2010-04-09

    Recently, attention has been drawn towards black carbon aerosols as a likely short-term climate warming mitigation candidate. However the global and regional impacts of the direct, cloud-indirect and semi-direct forcing effects are highly uncertain, due to the complex nature of aerosol evolution and its climate interactions. Black carbon is directly released as particle into the atmosphere, but then interacts with other gases and particles through condensation and coagulation processes leading to further aerosol growth, aging and internal mixing. A detailed aerosol microphysical scheme, MATRIX, embedded within the global GISS modelE includes the above processes that determine the lifecycle and climate impact of aerosols. This study presents a quantitative assessment of the impact of microphysical processes involving black carbon, such as emission size distributions and optical properties on aerosol cloud activation and radiative forcing. Our best estimate for net direct and indirect aerosol radiative forcing change is -0.56 W/m{sup 2} between 1750 and 2000. However, the direct and indirect aerosol effects are very sensitive to the black and organic carbon size distribution and consequential mixing state. The net radiative forcing change can vary between -0.32 to -0.75 W/m{sup 2} depending on these carbonaceous particle properties. Assuming that sulfates, nitrates and secondary organics form a coating shell around a black carbon core, rather than forming a uniformly mixed particles, changes the overall net radiative forcing from a negative to a positive number. Black carbon mitigation scenarios showed generally a benefit when mainly black carbon sources such as diesel emissions are reduced, reducing organic and black carbon sources such as bio-fuels, does not lead to reduced warming.

  4. OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR...

    Office of Scientific and Technical Information (OSTI)

    of optical nanomaterials are discussed towards the end of the chapter, including solar energy conversion, optical sensing of chemicals and biochemicals, solid state...

  5. Simulation of aerosol direct radiative forcing with RAMS-CMAQ in East Asia

    SciTech Connect (OSTI)

    Han, Xiao; Zhang, Meigen; Han, Zhiewi; Xin, Jin-Yuan; Liu, Xiaohong

    2011-11-14

    The air quality modeling system RAMS-CMAQ is developed to assess aerosol direct radiative forcing by linking simulated meteorological parameters and aerosol mass concentration with the aerosol optical properties/radiative transfer module in this study. The module is capable of accounting for important factors that affect aerosol optical properties and radiative effect, such as incident wave length, aerosol size distribution, water uptake, and internal mixture. Subsequently, the modeling system is applied to simulate the temporal and spatial variations in mass burden, optical properties, and direct radiative forcing of diverse aerosols, including sulfate, nitrate, ammonium, black carbon, organic carbon, dust, and sea salt over East Asia throughout 2005. Model performance is fully evaluated using various observational data, including satellite monitoring of MODIS and surface measurements of EANET (Acid Deposition Monitoring Network), AERONET (Aerosol Robotic Network), and CSHNET (Chinese Sun Hazemeter Network). The correlation coefficients of the comparisons of daily average mass concentrations of sulfate, PM2.5, and PM10 between simulations and EANET measurements are 0.70, 0.61, and 0.64, respectively. It is also determined that the modeled aerosol optical depth (AOD) is in congruence with the observed results from the AERONET, the CSHNET, and the MODIS. The model results suggest that the high AOD values ranging from 0.8 to 1.2 are mainly distributed over the Sichuan Basin as well as over central and southeastern China, in East Asia. The aerosol direct radiative forcing patterns generally followed the AOD patterns. The strongest forcing effect ranging from -12 to -8 W m-2 was mainly distributed over the Sichuan Basin and the eastern China's coastal regions in the all-sky case at TOA, and the forcing effect ranging from -8 to -4 W m-2 could be found over entire eastern China, Korea, Japan, East China Sea, and the sea areas of Japan

  6. Optical Properties of ZnO-Alloyed Nanocrystalline Films

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

    Che, Hui; Huso, Jesse; Morrison, John L.; Thapa, Dinesh; Huso, Michelle; Yeh, Wei Jiang; Tarun, M. C.; McCluskey, M. D.; Bergman, Leah

    2012-01-01

    ZnO is emore » merging as one of the materials of choice for UV applications. It has a deep excitonic energy level and a direct bandgap of ~3.4 eV. Alloying ZnO with certain atomic constituents adds new optical and electronic functionalities to ZnO. This paper presents research on M g x Z n 1 − x O and Z n S 1 − x O x nanocrystalline flexible films, which enable tunable optical properties in the deep-UV and in the visible range. The ZnO and Mg 0 .3 Zn 0 .7 O films were found to have bandgaps at 3.35 and 4.02 eV, respectively. The photoluminescence of the Mg 0 .3 Zn 0 .7 O exhibited a bandedge emission at 3.95 eV, and at lower energy 3.38 eV due to the limited solubility inherent to these alloys. ZnS 0 .76 O 0 .24 and ZnS 0 .16 O 0 .84 were found to have bandgaps at 3.21 and 2.65 eV, respectively. The effect of nitrogen doping on ZnS 0 .16 O 0 .84 is discussed in terms of the highly lattice mismatched nature of these alloys and the resulting valence-band modification.« less

  7. Constraining the atmospheric composition of the day-night terminators of HD 189733b: Atmospheric retrieval with aerosols

    SciTech Connect (OSTI)

    Lee, Jae-Min; Irwin, Patrick G. J.; Fletcher, Leigh N.; Barstow, Joanna K.; Heng, Kevin

    2014-07-01

    A number of observations have shown that Rayleigh scattering by aerosols dominates the transmission spectrum of HD 189733b at wavelengths shortward of 1 ?m. In this study, we retrieve a range of aerosol distributions consistent with transmission spectroscopy between 0.3-24 ?m that were recently re-analyzed by Pont et al. To constrain the particle size and the optical depth of the aerosol layer, we investigate the degeneracies between aerosol composition, temperature, planetary radius, and molecular abundances that prevent unique solutions for transit spectroscopy. Assuming that the aerosol is composed of MgSiO{sub 3}, we suggest that a vertically uniform aerosol layer over all pressures with a monodisperse particle size smaller than about 0.1 ?m and an optical depth in the range 0.002-0.02 at 1 ?m provides statistically meaningful solutions for the day/night terminator regions of HD 189733b. Generally, we find that a uniform aerosol layer provide adequate fits to the data if the optical depth is less than 0.1 and the particle size is smaller than 0.1 ?m, irrespective of the atmospheric temperature, planetary radius, aerosol composition, and gaseous molecules. Strong constraints on the aerosol properties are provided by spectra at wavelengths shortward of 1 ?m as well as longward of 8 ?m, if the aerosol material has absorption features in this region. We show that these are the optimal wavelengths for quantifying the effects of aerosols, which may guide the design of future space observations. The present investigation indicates that the current data offer sufficient information to constrain some of the aerosol properties of HD189733b, but the chemistry in the terminator regions remains uncertain.

  8. Magneto-optic properties of uranium-based compounds

    SciTech Connect (OSTI)

    Kirby, R.D.; Shen, J.X.; Woollam, J.A.; Sellmyer, D.J. )

    1991-04-15

    Uranium-based compounds often show interesting magnetic properties and large polar Kerr rotations. Because of this, the wavelength and temperature dependencies of the polar Kerr rotation in several uranium-based compounds, including UMn{sub 2}Ge{sub 2}, UFe{sub 2}, and UGa{sub 2}, have been investigated. The Mn moments order ferromagnetically in UMn{sub 2}Ge{sub 2} below 380 K, and while the U moments do not order ferromagnetically until the temperature is below 150 K. The measurements presented here show that the size of the Kerr rotation increases from 0.05{degree} at room temperature to 0.15{degree} when the U moments are ordered. The wavelength dependence of the Kerr rotation between 500 and 1000 nm is rather weak. UGa{sub 2} orders ferromagnetically at 130 K, and a Kerr rotation of 0.2{degree} at 85 K and 632.8 nm can be measured, with the rotation increasing to 0.4{degree} at 1000 nm. UFe{sub 2} orders ferromagnetically at 180 K, and the Kerr rotation (85 K, 632.8 nm) is 0.17{degree}. These magnetic and optical properties are discussed in terms of the electronic states of uranium.

  9. Niamey Aerosol Optical Depths

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

    Flynn, Connor

    2008-10-01

    MFRSR irradiance data collected during the ACRF AMF deployment in Niamey, Niger have been used to derive AOD for five wavelength channels of the MFRSR. These data have been corrected to adjust for filter drift over the course of the campaign and contamination due to forward scattering as a result of large dust particles in the atmosphere around Niamey.

  10. Laboratory Experiments and Instrument Intercomparison Studies of Carbonaceous Aerosol Particles

    SciTech Connect (OSTI)

    Davidovits, Paul

    2015-10-20

    Aerosols containing black carbon (and some specific types of organic particulate matter) directly absorb incoming light, heating the atmosphere. In addition, all aerosol particles backscatter solar light, leading to a net-cooling effect. Indirect effects involve hydrophilic aerosols, which serve as cloud condensation nuclei (CCN) that affect cloud cover and cloud stability, impacting both atmospheric radiation balance and precipitation patterns. At night, all clouds produce local warming, but overall clouds exert a net-cooling effect on the Earth. The effect of aerosol radiative forcing on climate may be as large as that of the greenhouse gases, but predominantly opposite in sign and much more uncertain. The uncertainties in the representation of aerosol interactions in climate models makes it problematic to use model projections to guide energy policy. The objective of our program is to reduce the uncertainties in the aerosol radiative forcing in the two areas highlighted in the ASR Science and Program Plan. That is, (1) addressing the direct effect by correlating particle chemistry and morphology with particle optical properties (i.e. absorption, scattering, extinction), and (2) addressing the indirect effect by correlating particle hygroscopicity and CCN activity with particle size, chemistry, and morphology. In this connection we are systematically studying particle formation, oxidation, and the effects of particle coating. The work is specifically focused on carbonaceous particles where the uncertainties in the climate relevant properties are the highest. The ongoing work consists of laboratory experiments and related instrument inter-comparison studies both coordinated with field and modeling studies, with the aim of providing reliable data to represent aerosol processes in climate models. The work is performed in the aerosol laboratory at Boston College. At the center of our laboratory setup are two main sources for the production of aerosol particles: (a) two well-characterized source of soot particles and (b) a flow reactor for controlled OH and/or O3 oxidation of relevant gas phase species to produce well-characterized SOA particles. After formation, the aerosol particles are subjected to physical and chemical processes that simulate aerosol growth and aging. A suite of instruments in our laboratory is used to characterize the physical and chemical properties of aerosol particles before and after processing. The Time of Flight Aerosol Mass Spectrometer (ToF-AMS) together with a Scanning Mobility Particle Sizer (SMPS) measures particle mass, volume, density, composition (including black carbon content), dynamic shape factor, and fractal dimension. The–ToF-AMS was developed at ARI with Boston College participation. About 120 AMS instruments are now in service (including 5 built for DOE laboratories) performing field and laboratory studies world-wide. Other major instruments include a thermal denuder, two Differential Mobility Analyzers (DMA), a Cloud Condensation Nuclei Counter (CCN), a Thermal desorption Aerosol GC/MS (TAG) and the new Soot Particle Aerosol Mass Spectrometer (SP-AMS). Optical instrumentation required for the studies have been brought to our laboratory as part of ongoing and planned collaborative projects with colleagues from DOE, NOAA and university laboratories. Optical instruments that will be utilized include a Photoacoustic Spectrometer (PAS), a Cavity Ring Down Aerosol Extinction Spectrometer (CRD-AES), a Photo Thermal Interferometer (PTI), a new 7-wavelength Aethalometer and a Cavity Attenuated Phase Shift Extinction Monitor (CAPS). These instruments are providing aerosol absorption, extinction and scattering coefficients at a range of atmospherically relevant wavelengths. During the past two years our work has continued along the lines of our original proposal. We report on 12 completed and/or continuing projects conducted during the period 08/14 to 0814/2015. These projects are described in 17 manuscripts published in refereed journals.

  11. Metal colloids and quantum dots: linear and nonlinear optical properties

    SciTech Connect (OSTI)

    Henderson, Don O.

    1997-05-12

    Nanophase materials have found a wide application in a variety of technological areas which include ultrafast optical switching high density information storage and retrieval, electronics, and catalysts, to mention a few. Nanocrystal science has also drawn considerable interest from the fundamental perspective engaging physicists, chemists, and material scientists into this area of rapidly expanding and challenging research. Basic questions concerning how matter evolves from atomic like behavior to molecular and onto bulk lie at the center nanocrystal research. In addition, because of the high surface to volume ratio of the nanocrystals, the interaction potential between a nanocrystal and its surrounding environment becomes an important issue in determining its properties. While significant progress has been made in nanocrystal research, there are many problems concerned with their fabrication. In particular, the difficulty of incorporating nanocrystals into a matrix that is appropriate for ultimate device development has hindered some aspects of nanocrystal research. Ion implantation is a method that is now established as a technique for fabricating metal and semiconductor nanocrystals. It is highly versatile in that one may select nearly any host material for incorporating the nanocrystals of interest. The flexibility of being able to select the host matrix is also interesting from the point of view that it opens the opportunity to investigate matrix-nanocrystal interactions. We summarize in the following sections results on metal and semiconductor nanocrystals formed by ion implantation into dielectric hosts.

  12. Science Overview Document Indirect and Semi-Direct Aerosol Campaign (ISDAC) April 2008

    SciTech Connect (OSTI)

    SJ Ghan; B Schmid; JM Hubbe; CJ Flynn; A Laskin; AA Zelenyuk; DJ Czizco; CN Long; G McFarquhar; J Verlinde; J Harrington; JW Strapp; P Liu; A Korolev; A McDonald; M Wolde; A Fridlind; T Garrett; G Mace; G Kok; S Brooks; D Collins; D Lubin; P Lawson; M Dubey; C Mazzoleni; M Shupe; S Xie; DD Turner; Q Min; EJ Mlawer; D Mitchell

    2007-11-01

    The ARM Climate Research Facilitys (ACRF) Aerial Vehicle Program (AVP) will deploy an intensive cloud and aerosol observing system to the ARM North Slope of Alaska (NSA) locale for a five week Indirect and Semi-Direct Aerosol Campaign (ISDAC) during period 29 March through 30 April 2008. The deployment period is within the International Polar Year, thus contributing to and benefiting from the many ancillary observing systems collecting data synergistically. We will deploy the Canadian National Research Council Convair 580 aircraft to measure temperature, humidity, total particle number, aerosol size distribution, single particle composition, concentrations of cloud condensation nuclei and ice nuclei, optical scattering and absorption, updraft velocity, cloud liquid water and ice contents, cloud droplet and crystal size distributions, cloud particle shape, and cloud extinction. In addition to these aircraft measurements, ISDAC will deploy two instruments at the ARM site in Barrow: a spectroradiometer to retrieve cloud optical depth and effective radius, and a tandem differential mobility analyzer to measure the aerosol size distribution and hygroscopicity. By using many of the same instruments used during Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004, we will be able to contrast the arctic aerosol and cloud properties during the fall and spring transitions. The aerosol measurements can be used in cloud models driven by objectively analyzed boundary conditions to test whether the cloud models can simulate the aerosol influence on the clouds. The influence of aerosol and boundary conditions on the simulated clouds can be separated by running the cloud models with all four combinations of M-PACE and ISDAC aerosol and boundary conditions: M-PACE aerosol and boundary conditions, M-PACE aerosol and ISDAC boundary conditions, ISDAC aerosol and M-PACE boundary conditions, and ISDAC aerosol and boundary conditions. ISDAC and M-PACE boundary conditions are likely to be very different because of the much more extensive ocean water during M-PACE. The uniformity of the surface conditions during ISDAC greatly simplifies the objective analysis (surface fluxes and precipitation are very weak), so that it can largely rely on the European Centre for Medium-Range Weather Forecasts analysis. The aerosol measurements can also be used as input to the cloud models and to evaluate the aerosol retrievals. By running the cloud models with and without solar absorption by the aerosols, we can determine the semidirect effect of the aerosol on the clouds.

  13. An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a

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

    Decade of Observations at a Mid-Continental Site An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a Decade of Observations at a Mid-Continental Site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Category: Aerosols Continuing observations of aerosol and cloud optical property have been made using MFRSR and MWR at the ARM SGP site since

  14. Collaborative research. Study of aerosol sources and processing at the GVAX Pantnagar Supersite

    SciTech Connect (OSTI)

    Worsnop, Doug; Volkamer, Rainer

    2012-08-13

    The Two Column Aerosol Project (TCAP) investigated uncertainties in the aerosol direct effect in the northern hemisphere mid-latitudes. The University of Colorado 2D-MAX-DOAS and LED-CE-DOAS instruments were collocated with DOE’s Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) and Mobile Aerosol Observing System (MAOS) during the TCAP-1 campaign at Cape Cod, MA (1 July to 13 August 2012). We have performed atmospheric radiation closure studies to evaluate the use of a novel parameter, i.e., the Raman Scattering Probability (RSP). We have performed first measurements of RSP almucantar scans, and measure RSP in spectra of scattered solar photons at 350nm and 430nm. Radiative Transfer Modelling of RSP demonstrate that the RSP measurement is maximally sensitive to infer even extremely low aerosol optical depth (AOD < 0.01) reliably by DOAS at low solar relative azimuth angles. We further assess the role of elevated aerosol layers on near surface observations of oxygen collision complexes, O 2-O2. Elevated aerosol layers modify the near surface absorption of O2-O2 and RSP. The combination of RSP and O2-O2 holds largely unexplored potential to better constrain elevated aerosol layers and measure column aerosol optical properties such as aerosol effective radius, extinction, aerosol phase functions and refractive indices. The TCAP deployment also provides a time series of reactive trace gas vertical profiles, i.e., nitrogen dioxide (NO2) and glyoxal (C2H2O2), which are measured simultaneously with the aerosol optical properties by DOAS. NO2 is an important precursor for ozone (O3) that modifies oxidative capacity. Glyoxal modifies oxidative capacity and is a source for brown carbon by forming secondary organic aerosol (SOA) via multiphase reactions in aerosol and cloud water. We have performed field measurements of these gases during TCAP, and conducted laboratory experiments to quantify for the first time the Setschenow salting constant, KS, of glyoxal in sulfate aerosols. Knowledge about KS is prerequisite to predict how increasing sulfate concentrations since pre-industrial times have modified the formation of SOA from biogenic gases in atmospheric models.

  15. OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR...

    Office of Scientific and Technical Information (OSTI)

    towards the end of the chapter, including solar energy conversion, optical sensing of chemicals and biochemicals, solid state lighting, photocatalysis, and photoelectrochemistry. ...

  16. Optical diffractionn properties of multi-microgratings (Journal...

    Office of Scientific and Technical Information (OSTI)

    OSTI Identifier: 1185603 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Journal Article Resource Relation: Journal Name: Applied Optics; Journal Volume: 54; Journal...

  17. Synthesis, electronic and optical properties of Si nanostructures

    SciTech Connect (OSTI)

    Dinh, L.N.

    1996-09-01

    Silicon and silicon oxide nanostructures have been deposited on solid substrates, in an ultra high vacuum (UHV) chamber, by laser ablation or thermal vaporization. Laser ablation followed by substrate post annealing produced Si clusters with average size of a few nanometers, on highly oriented pyrolytic graphite (HOPG) surfaces. This technique, which is based on surface diffusion, is limited to the production of less than one layer of clusters on a given surface. The low coverage of Si clusters and the possibility of nonradiative decay of excitation in the Si cores to the HOPG substrates in these samples rendered them unsuitable for many optical measurements. Thermal vaporization of Si in an Ar buffer gas, on the contrary, yielded multilayer coverage of Si nanoclusters with a fairly narrow size distribution of about 2 nm, full width at half maximum (FWHM). As a result, further study was performed only on Si nanoclusters synthesized by thermal vaporization in a buffer gas. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) revealed that these nanoclusters were crystalline. However, during synthesis, if oxygen was the buffer gas, a network of amorphous Si oxide nanostructures (an-SiO{sub x}) with occasional embedded Si dots was formed. All samples showed strong infrared and/or visible photoluminescence (PL) with varying decay times from nanoseconds to microseconds depending on synthesis conditions. There were differences in PL spectra for hydrogen and oxygen passivated nc-Si, while many common PL properties between oxygen passivated nc-Si and an SiO{sub x} were observed. The observed experimental results can be best explained by a model involving absorption between quantum confined states in the Si cores and emission for which the decay times are very sensitive to surface and/or interface states.

  18. Structural and optical properties of ZnO and ZnO:Fe nanoparticles under

    Office of Scientific and Technical Information (OSTI)

    dense electronic excitations (Journal Article) | SciTech Connect Structural and optical properties of ZnO and ZnO:Fe nanoparticles under dense electronic excitations Citation Details In-Document Search Title: Structural and optical properties of ZnO and ZnO:Fe nanoparticles under dense electronic excitations We report on the changes in structural, morphological, and optical properties of sol-gel derived ZnO and ZnO:Fe nanoparticles due to dense electronic excitations produced by heavy ion

  19. AERONET: The Aerosol Robotic Network

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

    AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html

  20. Optical Properties of the Charge-Density-Wave Polychalcogenide...

    Office of Scientific and Technical Information (OSTI)

    the rare-earth polychalcogenide Rsub 2Tesub 5 (R Nd, Sm and Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption spectrum we extract the...

  1. Structural and optical properties of ZnO and ZnO:Fe nanoparticles...

    Office of Scientific and Technical Information (OSTI)

    We report on the changes in structural, morphological, and optical properties of sol-gel derived ZnO and ZnO:Fe nanoparticles due to dense electronic excitations produced by heavy ...

  2. Influence of Elastic and Surface Strains on the Optical Properties of

    Office of Scientific and Technical Information (OSTI)

    Semiconducting Core-Shell Nanoparticles (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Influence of Elastic and Surface Strains on the Optical Properties of Semiconducting Core-Shell Nanoparticles Citation Details In-Document Search This content will become publicly available on July 6, 2016 Title: Influence of Elastic and Surface Strains on the Optical Properties of Semiconducting Core-Shell Nanoparticles Authors: Mangeri, John ; Heinonen, Olle ;

  3. OPTICAL PROPERTIES OF A MECHANICALLY POLISHED AND AIR-EQUILIBRATED [111]

    Office of Scientific and Technical Information (OSTI)

    UO2 SURFACE BY RAMAN AND ELLIPSOMETRIC SPECTROSCOPY (Conference) | SciTech Connect Conference: OPTICAL PROPERTIES OF A MECHANICALLY POLISHED AND AIR-EQUILIBRATED [111] UO2 SURFACE BY RAMAN AND ELLIPSOMETRIC SPECTROSCOPY Citation Details In-Document Search Title: OPTICAL PROPERTIES OF A MECHANICALLY POLISHED AND AIR-EQUILIBRATED [111] UO2 SURFACE BY RAMAN AND ELLIPSOMETRIC SPECTROSCOPY Optical constants of a [111] UO{sub 2} surface, aged in air, were measured in the range from .8 and 5 eV

  4. Influence of sputtering power on the optical properties of ITO thin films

    SciTech Connect (OSTI)

    K, Aijo John; M, Deepak T, Manju; Kumar, Vineetha V.

    2014-10-15

    Tin doped indium oxide films are widely used in transparent conducting coatings such as flat panel displays, crystal displays and in optical devices such as solar cells and organic light emitting diodes due to the high electrical resistivity and optical transparency in the visible region of solar spectrum. The deposition parameters have a commendable influence on the optical and electrical properties of the thin films. In this study, ITO thin films were prepared by RF magnetron sputtering. The properties of the films prepared under varying sputtering power were compared using UV- visible spectrophotometry. Effect of sputtering power on the energy band gap, absorption coefficient and refractive index are investigated.

  5. Fiber optic spectroscopic digital imaging sensor and method for flame properties monitoring

    DOE Patents [OSTI]

    Zelepouga, Serguei A.; Rue, David M.; Saveliev, Alexei V.

    2011-03-15

    A system for real-time monitoring of flame properties in combustors and gasifiers which includes an imaging fiber optic bundle having a light receiving end and a light output end and a spectroscopic imaging system operably connected with the light output end of the imaging fiber optic bundle. Focusing of the light received by the light receiving end of the imaging fiber optic bundle by a wall disposed between the light receiving end of the fiber optic bundle and a light source, which wall forms a pinhole opening aligned with the light receiving end.

  6. CARES: Carbonaceous Aerosol and Radiative Effects Study Operations Plan

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-07-12

    The CARES field campaign is motivated by the scientific issues described in the CARES Science Plan. The primary objectives of this field campaign are to investigate the evolution and aging of carbonaceous aerosols and their climate-affecting properties in the urban plume of Sacramento, California, a mid-size, mid-latitude city that is located upwind of a biogenic volatile organic compound (VOC) emission region. Our basic observational strategy is to make comprehensive gas, aerosol, and meteorological measurements upwind, within, and downwind of the urban area with the DOE G-1 aircraft and at strategically located ground sites so as to study the evolution of urban aerosols as they age and mix with biogenic SOA precursors. The NASA B-200 aircraft, equipped with the High Spectral Resolution Lidar (HSRL), digital camera, and the Research Scanning Polarimeter (RSP), will be flown in coordination with the G-1 to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties, and to provide the vertical context for the G-1 and ground in situ measurements.

  7. Effects of Ocean Ecosystem on Marine Aerosol-Cloud Interaction

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

    Meskhidze, Nicholas; Nenes, Athanasios

    2010-01-01

    Using smore » atellite data for the surface ocean, aerosol optical depth (AOD), and cloud microphysical parameters, we show that statistically significant positive correlations exist between ocean ecosystem productivity, the abundance of submicron aerosols, and cloud microphysical properties over different parts of the remote oceans. The correlation coefficient for remotely sensed surface chlorophyll a concentration ([Chl- a ]) and liquid cloud effective radii over productive areas of the oceans varies between − 0.2 and − 0.6 . Special attention is given to identifying (and addressing) problems from correlation analysis used in the previous studies that can lead to erroneous conclusions. A new approach (using the difference between retrieved AOD and predicted sea salt aerosol optical depth, AOD diff ) is developed to explore causal links between ocean physical and biological systems and the abundance of cloud condensation nuclei (CCN) in the remote marine atmosphere. We have found that over multiple time periods, 550 nm AOD diff (sensitive to accumulation mode aerosol, which is the prime contributor to CCN) correlates well with [Chl- a ] over the productive waters of the Southern Ocean. Since [Chl- a ] can be used as a proxy of ocean biological productivity, our analysis demonstrates the role of ocean ecology in contributing CCN, thus shaping the microphysical properties of low-level marine clouds.« less

  8. Efficacy of Aerosol-Cloud Interactions Under Varying Meteorological Conditions: Southern Great Plains Vs. Pt. Reyes

    SciTech Connect (OSTI)

    Dunn, M.; Schwartz, S.; Kim, B.-G.; Miller, M.; Liu, Y.; Min, Q.

    2008-03-10

    Several studies have demonstrated that cloud dynamical processes such as entrainment mixing may be the primary modulator of cloud optical properties in certain situations. For example, entrainment of dry air alters the cloud drop size distribution by enhancing drop evaporation. However, the effect of entrainment mixing and other forms or turbulence is still quite uncertain. Although these factors and aerosol-cloud interactions should be considered together when evaluating the efficacy of aerosol indirect effects, the underlying mechanisms appear to be dependent upon each other. In addition, accounting for them is impossible with the current understanding of aerosol indirect effect. Therefore, careful objective screening and analysis of observations are needed to determine the extent to which mixing related properties affect cloud optical properties, apart from the aerosol first indirect effect. This study addresses the role of aerosol-cloud interactions in the context of varying meteorological conditions based on ARM data obtained at the Southern Great Plains (SGP) site in Oklahoma and at Pt. Reyes, California. Previous analyses of the continental stratiform clouds at the SGP site have shown that the thicker clouds of high liquid water path (LWP) tend to contain sub adiabatic LWPs. These sub adiabatic LWPs, which result from active mixing processes, correspond to a lower susceptibility of the clouds to aerosol-cloud interactions, and, hence, to reduced aerosol indirect effects. In contrast, the consistently steady and thin maritime stratus clouds observed at Pt. Reyes are much closer to adiabatic. These clouds provide an excellent benchmark for the study of the aerosol influence on modified marine clouds relative to continental clouds, since they form in a much more homogeneous meteorological environment than those at the continental site.

  9. Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

    SciTech Connect (OSTI)

    Zaveri, Rahul A.; Shaw, William J.; Cziczo, D. J.; Schmid, Beat; Ferrare, R.; Alexander, M. L.; Alexandrov, Mikhail; Alvarez, R. J.; Arnott, W. P.; Atkinson, D.; Baidar, Sunil; Banta, Robert M.; Barnard, James C.; Beranek, Josef; Berg, Larry K.; Brechtel, Fred J.; Brewer, W. A.; Cahill, John F.; Cairns, Brian; Cappa, Christopher D.; Chand, Duli; China, Swarup; Comstock, Jennifer M.; Dubey, Manvendra K.; Easter, Richard C.; Erickson, Matthew H.; Fast, Jerome D.; Floerchinger, Cody; Flowers, B. A.; Fortner, Edward; Gaffney, Jeffrey S.; Gilles, Mary K.; Gorkowski, K.; Gustafson, William I.; Gyawali, Madhu S.; Hair, John; Hardesty, Michael; Harworth, J. W.; Herndon, Scott C.; Hiranuma, Naruki; Hostetler, Chris A.; Hubbe, John M.; Jayne, J. T.; Jeong, H.; Jobson, Bertram T.; Kassianov, Evgueni I.; Kleinman, L. I.; Kluzek, Celine D.; Knighton, B.; Kolesar, K. R.; Kuang, Chongai; Kubatova, A.; Langford, A. O.; Laskin, Alexander; Laulainen, Nels S.; Marchbanks, R. D.; Mazzoleni, Claudio; Mei, F.; Moffet, Ryan C.; Nelson, Danny A.; Obland, Michael; Oetjen, Hilke; Onasch, Timothy B.; Ortega, Ivan; Ottaviani, M.; Pekour, Mikhail S.; Prather, Kimberly A.; Radney, J. G.; Rogers, Ray; Sandberg, S. P.; Sedlacek, Art; Senff, Christoph; Senum, Gunar; Setyan, Ari; Shilling, John E.; Shrivastava, ManishKumar B.; Song, Chen; Springston, S. R.; Subramanian, R.; Suski, Kaitlyn; Tomlinson, Jason M.; Volkamer, Rainer M.; Wallace, Hoyt A.; Wang, J.; Weickmann, A. M.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zelenyuk, Alla; Zhang, Qi

    2012-08-22

    Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites - one within the Sacramento urban area and another about 40 km to the northeast in the foothills area - were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and 'aged' urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: a) the scientific background and motivation for the study, b) the operational and logistical information pertinent to the execution of the study, c) an overview of key observations and initial results from the aircraft and ground-based sampling platforms, and d) a roadmap of planned data analyses and focused modeling efforts that will facilitate the integration of new knowledge into improved representations of key aerosol processes in climate models.

  10. Properties of optically selected supernova remnant candidates in M33

    SciTech Connect (OSTI)

    Lee, Jong Hwan; Lee, Myung Gyoon, E-mail: leejh@astro.snu.ac.kr, E-mail: mglee@astro.snu.ac.kr [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-10-01

    Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/H? and round morphology in the continuum-subtracted H? and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, ? = 2.38 0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/H?) of the remnants has two concentrations at [S II]/H? ? 0.55 and ?0.8, as in M31. Interestingly, L {sub X} (and L {sub 20cm}) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.

  11. Modeling optical properties of silicon clusters by first principles: From a few atoms to large nanocrystals

    SciTech Connect (OSTI)

    Nurbawono, Argo; Liu, Shuanglong; Zhang, Chun

    2015-04-21

    Time dependent density functional tight binding (TDDFTB) method is implemented with sparse matrix techniques and improved parallelization algorithms. The method is employed to calculate the optical properties of various Si nanocrystals (NCs). The calculated light absorption spectra of small Si NCs from TDDFTB were found to be comparable with many body perturbation methods utilizing planewave basis sets. For large Si NCs (more than a thousand atoms) that are beyond the reach of conventional approaches, the TDDFTB method is able to produce reasonable results that are consistent with prior experiments. We also employed the method to study the effects of surface chemistry on the optical properties of large Si NCs. We learned that the optical properties of Si NCs can be manipulated with small molecule passivations such as methyl, hydroxyl, amino, and fluorine. In general, the shifts and profiles in the absorption spectra can be tuned with suitably chosen passivants.

  12. Ab initio study of the structural, electronic and optical properties of ZnTe compound

    SciTech Connect (OSTI)

    Bahloul, B.; Deghfel, B.; Amirouche, L.; Bounab, S.; Bentabet, A.; Bouhadda, Y.; Fenineche, N.

    2015-03-30

    Structural, electronic and optical properties of ZnTe compound were calculated using Density Functional Theory (DFT) based on the pseudopotentials and planewaves (PP-PW) method as implemented in the ABINIT computer code, where the exchangecorrelation functional is approximated using the local density approximation (LDA) and the generalized gradient approximation (GGA). The obtained results from either LDA or GGa calculation for lattice parameter, energy band gap and optical parameters, such as the fundamental absorption edge, the peaks observed in the imaginary part of the dielectric function, the macroscopic dielectric constants and the optical dielectric constant, are compared with the available theoretical results and experimental data.

  13. Determining biological tissue optical properties via integrating sphere spatial measurements

    DOE Patents [OSTI]

    Baba, Justin S. (Knoxville, TN); Letzen, Brian S. (Coral Springs, FL)

    2011-01-11

    An optical sample is mounted on a spatial-acquisition apparatus that is placed in or on an enclosure. An incident beam is irradiated on a surface of the sample and the specular reflection is allowed to escape from the enclosure through an opening. The spatial-acquisition apparatus is provided with a light-occluding slider that moves in front of the sample to block portions of diffuse scattering from the sample. As the light-occluding slider moves across the front of the sample, diffuse light scattered into the area of the backside of the light-occluding slider is absorbed by back side surface of the light-occluding slider. By measuring a baseline diffuse reflectance without a light-occluding slider and subtracting measured diffuse reflectance with a light-occluding slider therefrom, diffuse reflectance for the area blocked by the light-occluding slider can be calculated.

  14. Optical Properties of CdSe Nanoparticle Assemblies

    SciTech Connect (OSTI)

    Huser, T; Gerion, D; Zaitseva, N; Krol, D M; Leon, F R

    2003-11-24

    We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.

  15. Magneto-optical properties of biogenic photonic crystals in algae

    SciTech Connect (OSTI)

    Iwasaka, M.; Mizukawa, Y.

    2014-05-07

    In the present study, the effects of strong static magnetic fields on the structural colors of the cell covering crystals on a microalgae, coccolithophore, were investigated. The coccolithophore, Emiliania huxleyi, generates a precise assembly of calcite crystals called coccoliths by biomineralization. The coccoliths attached to the cells exhibited structural colors under side light illumination, and the colors underwent dynamic transitions when the magnetic fields were changed between 0?T and 5?T, probably due to diamagnetically induced changes of their inclination under the magnetic fields. The specific light-scattering property of individual coccoliths separated from the cells was also observed. Light scattering from a condensed suspension of coccoliths drastically decreased when magnetic fields of more than 4?T were applied parallel to the direction of observation. The magnetically aligned cell-covering crystals of the coccolithophores exhibited the properties of both a photonic crystal and a minimum micromirror.

  16. Study on third-order nonlinear optical properties of 4-methylsulfanyl chalcone derivatives using picosecond pulses

    SciTech Connect (OSTI)

    D'silva, E.D.; Podagatlapalli, G. Krishna; Venugopal Rao, S.; Dharmaprakash, S.M.

    2012-11-15

    Graphical abstract: Photograph and schematic representation of Z-scan experimental setup used to investigate third order nonlinear properties of the chalcone materials. Highlights: ? Br and NO{sub 2} substituted chalcone derivatives were exposed to picosecond laser pulses. ? Third-order nonlinear optical (NLO) properties were investigated. ? Compounds show promising third-order and optical limiting properties. ? These materials found suitable for electrical and optical applications. -- Abstract: In this paper we present results from the experimental study of third-order nonlinear optical (NLO) properties of three molecules of Br and NO{sub 2} substituted chalcone derivatives namely (2E)-1-(4-bromophenyl)-3-[4(methylsulfanyl)phenyl]prop-2-en-1-one (4Br4MSP), (2E)-1-(3-bromophenyl)-3-[4-(methylsulfanyl) phenyl]prop-2-en-1-one (3Br4MSP) and (2E)-3[4(methylsulfanyl) phenyl]-1-(4-nitrophenyl)prop-2-en-1-one (4N4MSP). The NLO properties have been investigated by Z-scan technique using 2 ps laser pulses at 800 nm. The nonlinear refractive indices, nonlinear absorption coefficient, and the magnitude of third-order susceptibility have been determined. The values obtained are of the order of 10{sup ?7} cm{sup 2}/GW, 10{sup ?3} cm/GW and 10{sup ?14} esu respectively. The molecular second hyperpolarizability for the chalcone derivatives is of the order of 10{sup ?32} esu. The coupling factor, excited state cross section, ground state cross section etc. were determined. The optical limiting (OL) property was studied. The results suggest that the nonlinear properties investigated for present chalcones are comparable with some of the reported chalcone derivatives and can be desirable for NLO applications.

  17. Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds"? (DOE/SC00002354)

    SciTech Connect (OSTI)

    Paul J. DeMott, Anthony J. Prenni; Sonia M. Kreidenweis

    2012-09-28

    Clouds play an important role in weather and climate. In addition to their key role in the hydrologic cycle, clouds scatter incoming solar radiation and trap infrared radiation from the surface and lower atmosphere. Despite their importance, feedbacks involving clouds remain as one of the largest sources of uncertainty in climate models. To better simulate cloud processes requires better characterization of cloud microphysical processes, which can affect the spatial extent, optical depth and lifetime of clouds. To this end, we developed a new parameterization to be used in numerical models that describes the variation of ice nuclei (IN) number concentrations active to form ice crystals in mixed-phase (water droplets and ice crystals co-existing) cloud conditions as these depend on existing aerosol properties and temperature. The parameterization is based on data collected using the Colorado State University continuous flow diffusion chamber in aircraft and ground-based campaigns over a 14-year period, including data from the DOE-supported Mixed-Phase Arctic Cloud Experiment. The resulting relationship is shown to more accurately represent the variability of ice nuclei distributions in the atmosphere compared to currently used parameterizations based on temperature alone. When implemented in one global climate model, the new parameterization predicted more realistic annually averaged cloud water and ice distributions, and cloud radiative properties, especially for sensitive higher latitude mixed-phase cloud regions. As a test of the new global IN scheme, it was compared to independent data collected during the 2008 DOE-sponsored Indirect and Semi-Direct Aerosol Campaign (ISDAC). Good agreement with this new data set suggests the broad applicability of the new scheme for describing general (non-chemically specific) aerosol influences on IN number concentrations feeding mixed-phase Arctic stratus clouds. Finally, the parameterization was implemented into a regional cloud-resolving model to compare predictions of ice crystal concentrations and other cloud properties to those observed in two intensive case studies of Arctic stratus during ISDAC. Our implementation included development of a prognostic scheme of ice activation using the IN parameterization so that the most realistic treatment of ice nuclei, including their budget (gains and losses), was achieved. Many cloud microphysical properties and cloud persistence were faithfully reproduced, despite a tendency to under-predict (by a few to several times) ice crystal number concentrations and cloud ice mass, in agreement with some other studies. This work serves generally as the basis for improving predictive schemes for cloud ice crystal activation in cloud and climate models, and more specifically as the basis for such a scheme to be used in a Multi-scale Modeling Format (MMF) that utilizes a connected system of cloud-resolving models on a global grid in an effort to better resolve cloud processes and their influence on climate.

  18. A Study of the Optical Properties of Ice Crystals with Black Carbon Inclusions

    SciTech Connect (OSTI)

    Arienti, Marco; Yang, Xiaoyuan; Kopacz, Adrian M; Geier, Manfred

    2015-09-01

    The report focu ses on the modification of the optical properties of ice crystals due to atmospheric black car bon (BC) contamination : the objective is to advance the predictive capabilities of climate models through an improved understanding of the radiative properties of compound particles . The shape of the ice crystal (as commonly found in cirrus clouds and cont rails) , the volume fraction of the BC inclusion , and its location inside the crystal are the three factors examined in this study. In the multiscale description of this problem, where a small absorbing inclusion modifies the optical properties of a much la rger non - absorbing particle, state - of - the - art discretization techniques are combined to provide the best compromise of flexibility and accuracy over a broad range of sizes .

  19. A simple growth method for Nb?O? films and their optical properties

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

    Dash, J. K.; Kisslinger, K.; Chen, L.; Topka, Michael R.; Dinolfo, Peter H.; Zhang, L. H.; Lu, T. -M.; Wang, G. -C.

    2015-04-13

    A simple method for the synthesis of Nb?O? films of thicknesses ranging from tens to several hundreds of nanometers on amorphous silicon dioxide or quartz substrates is presented. Nb?O? films were formed by annealing the sputter deposited Nb films under an Ar flow and without oxygen plasma in a quartz tube within a furnace at 850 C. The structural, compositional, optical, and vibrational properties were characterized by grazing incidence X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet visible spectroscopy, and Raman scattering. Each of the Nb?O? films is polycrystalline with an orthorhombic crystal structure. We observed vibrational modes includingmorelongitudinal optical, transverse optical, and triply degenerate modes, and measured the indirect optical band gap to be ~3.65 eV. The transmittance spectrum of the ~20 nm thick Nb?O? film shows over 90% transmittance below the band gap energy in the visible wavelength range and decreases to less than 20% in the ultraviolet regime. The optical properties of the films in the UV-vis range show potential applications as UV detectors.less

  20. A simple growth method for Nb2O5 films and their optical properties

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

    Dash, J. K.; Chen, L.; Topka, Michael R.; Dinolfo, Peter H.; Zhang, L. H.; Kisslinger, K.; Lu, T. -M.; Wang, G. -C.

    2015-04-13

    A simple method for the synthesis of Nb₂O₅ films of thicknesses ranging from tens to several hundreds of nanometers on amorphous silicon dioxide or quartz substrates is presented. Nb₂O₅ films were formed by annealing the sputter deposited Nb films under an Ar flow and without oxygen plasma in a quartz tube within a furnace at 850 °C. The structural, compositional, optical, and vibrational properties were characterized by grazing incidence X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet visible spectroscopy, and Raman scattering. Each of the Nb₂O₅ films is polycrystalline with an orthorhombic crystal structure. We observed vibrational modes includingmore » longitudinal optical, transverse optical, and triply degenerate modes, and measured the indirect optical band gap to be ~3.65 eV. The transmittance spectrum of the ~20 nm thick Nb₂O₅ film shows over 90% transmittance below the band gap energy in the visible wavelength range and decreases to less than 20% in the ultraviolet regime. As a result, the optical properties of the films in the UV-vis range show potential applications as UV detectors.« less

  1. Cloud Optical Properties from the Multifilter Shadowband Radiometer (MFRSRCLDOD): An ARM Value-Added Product

    SciTech Connect (OSTI)

    Turner, DD; McFarlane, SA; Riihimaki, L; Shi, Y; Lo, C; Min, Q

    2014-02-01

    The microphysical properties of clouds play an important role in studies of global climate change. Observations from satellites and surface-based systems have been used to infer cloud optical depth and effective radius. Min and Harrison (1996) developed an inversion method to infer the optical depth of liquid water clouds from narrow band spectral Multifilter Rotating Shadowband Radiometer (MFRSR) measurements (Harrison et al. 1994). Their retrieval also uses the total liquid water path (LWP) measured by a microwave radiometer (MWR) to obtain the effective radius of the warm cloud droplets. Their results were compared with Geostationary Operational Environmental Satellite (GOES) retrieved values at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site (Min and Harrison 1996). Min et al. (2003) also validated the retrieved cloud optical properties against in situ observations, showing that the retrieved cloud effective radius agreed well with the in situ forward scattering spectrometer probe observations. The retrieved cloud optical properties from Min et al. (2003) were used also as inputs to an atmospheric shortwave model, and the computed fluxes were compared with surface pyranometer observations.

  2. ARM - Evaluation Product - Aerosol Modeling Testbed

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

    and satellite aerosol optical depth data is included to supplement and enhance the value of the CARES data. The software that is provided in AMT extracts model output from...

  3. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

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

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; Chi, X.; Krüger, M. L.; Shiraiwa, M.; Förster, J. -D.; Pöschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; et al

    2015-03-16

    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water solublemore » fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34% in the accumulation vs. ~ 47% in the coarse mode. The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5–99.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ~ 70%, while efflorescence occurred at different humidities, i.e., at ~ 35% RH for submicron particles vs. ~ 50% RH for supermicron particles. This ~ 15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments. The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5–99.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv, ws value related to the water soluble (ws) fraction was estimated to be ~ 0.15 for the accumulation mode and ~ 0.36 for the coarse mode, respectively. The obtained κv, ws for the accumulation mode is in good agreement with earlier data reported for remote sites in the Amazon rain forest (κv ≈ 0.15) and a Colorado boreal forest (κv ≈ 0.16). We used the Zdanovskii–Stokes–Robinson (ZSR) mixing rule to predict the chemical composition dependent hygroscopicity, κv, p. The obtained κv, p values overestimate the experimental FDHA-KIM-derived κv, ws by factors of 1.8 and 1.5 for the accumulation and coarse modes, respectively. This divergence can be partly explained by incomplete dissolution of the hygroscopic inorganic compounds resulting from kinetic limitations due to a sparingly soluble organic coating. The TEM and STXM-NEXAFS results indicate that aged submicron (>300 nm) and supermicron aerosol particles possess core-shell structures with an inorganic core, and are enriched in organic carbon at the mixed particle surface. The direct FDHA kinetic studies provide a bulk diffusion coefficient of water of ~ 10−12 cm2 s−1 indicating a semi-solid state of the organic-rich phase leading to kinetic limitations of water uptake and release during hydration and dehydration cycles. Overall the present ZOTTO data set, obtained in the growing season, has revealed a strong influence of organic carbon on the hygroscopic properties of the ambient aerosols. The sparingly soluble organic coating controls hygroscopic growth, phase transitions, and microstructural rearrangement processes. The observed kinetic limitations can strongly influence the outcome of experiments performed on multi-second time scales, such as the commonly applied HTDMA (Hygroscopicity Tandem Differential Mobility Analyzer) and CCNC (Cloud Condensation Nuclei Counter) measurements.« less

  4. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

    SciTech Connect (OSTI)

    Mikhailov, E. F.; Mironov, G. N.; Phlker, C.; Chi, X.; Krger, M. L.; Shiraiwa, M.; Frster, J. -D.; Pschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; Weigand, M.; Kilcoyne, A. L. D.; Andreae, M. O.

    2015-03-16

    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61 N; 89 E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water soluble fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34% in the accumulation vs. ~ 47% in the coarse mode.

    The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 599.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ~ 70%, while efflorescence occurred at different humidities, i.e., at ~ 35% RH for submicron particles vs. ~ 50% RH for supermicron particles. This ~ 15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments.

    The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 599.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, ?v, was calculated. The ?v, ws value related to the water soluble (ws) fraction was estimated to be ~ 0.15 for the accumulation mode and ~ 0.36 for the coarse mode, respectively. The obtained ?v, ws for the accumulation mode is in good agreement with earlier data reported for remote sites in the Amazon rain forest (?v ≈ 0.15) and a Colorado boreal forest (?v ≈ 0.16).

    We used the ZdanovskiiStokesRobinson (ZSR) mixing rule to predict the chemical composition dependent hygroscopicity, ?v, p. The obtained ?v, p values overestimate the experimental FDHA-KIM-derived ?v, ws by factors of 1.8 and 1.5 for the accumulation and coarse modes, respectively. This divergence can be partly explained by incomplete dissolution of the hygroscopic inorganic compounds resulting from kinetic limitations due to a sparingly soluble organic coating. The TEM and STXM-NEXAFS results indicate that aged submicron (>300 nm) and supermicron aerosol particles possess core-shell structures with an inorganic core, and are enriched in organic carbon at the mixed particle surface. The direct FDHA kinetic studies provide a bulk diffusion coefficient of water of ~ 10?12 cm2 s?1 indicating a semi-solid state of the organic-rich phase leading to kinetic limitations of water uptake and release during hydration and dehydration cycles. Overall the present ZOTTO data set, obtained in the growing season, has revealed a strong influence of organic carbon on the hygroscopic properties of the ambient aerosols. The sparingly soluble organic coating controls hygroscopic growth, phase transitions, and microstructural rearrangement processes. The observed kinetic limitations can strongly influence the outcome of experiments performed on multi-second time scales, such as the commonly applied HTDMA (Hygroscopicity Tandem Differential Mobility Analyzer

  5. Optical properties of transparent glassceramics containing lithiummica nanocrystals: Crystallization effect

    SciTech Connect (OSTI)

    Khani, V.; Alizadeh, P.; Shakeri, M.S.

    2013-09-01

    Graphical abstract: Optical properties of transparent Li{sub 2}OMgOAl{sub 2}O{sub 3}SiO{sub 2}F glasses containing lithiummica nanocrystals are studied and crystallization condition has been evaluated and optimized to produce transparent glassceramics. Crystallization temperatures were determined by differential thermal analysis and crystalline phases were identified and quantified by X-ray diffraction. Scanning electron microscopy was used for morphological variations and UVvis absorption spectroscopy for comparative analysis of transparency. In order to investigate the optical properties of transparent glassceramics, optical band gap, Fermi energy level and Urbach energy are calculated. The results of the investigation illustrate that band gap is reduced with increases in crystallization time and temperature. Enhanced orderliness in the arrangement of atoms might be regarded as possible reasons for the above changes. - Highlights: The optimum temperature and time of crystallization were determined. Limica nanocrystals with size of <30 nm were formed using a two-step heat-treatment. Optical band gap and Fermi energy of nanocrystalline materials decreased with increasing of crystallization temperature and time. Urbach band tailing was decreased with increasing of crystallization condition. - Abstract: Optical properties of transparent Li{sub 2}OMgOAl{sub 2}O{sub 3}SiO{sub 2}F glasses containing lithiummica nanocrystals were studied. The crystallization condition of these glasses was evaluated and optimized to produce transparent glassceramics. Crystallization temperatures were determined by differential thermal analysis and crystalline phases were identified and quantified by X-ray diffraction. Scanning electron microscopy was used to detect morphological changes and UVvis absorption spectroscopy was used for comparative analysis of transparency. In order to investigate the optical properties of the transparent glassceramics, optical band gap, Fermi energy level and Urbach energy were calculated. The results of the investigation illustrate that the band gap is reduced with increases in crystallization time and temperature. Enhanced orderliness in the arrangement of atoms might be regarded as possible reasons for the above changes.

  6. Detecting Cirrus-Overlapping-Water Clouds and Retrieving their Optical Properties Using MODIS Data

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

    Cirrus-Overlapping-Water Clouds and Retrieving their Optical Properties Using MODIS Data F.-L. Chang and Z. Li Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland Z. Li Department of Meteorology University of Maryland College Park, Maryland Introduction Different methods have been proposed to detect multilayer clouds using passive remote sensing data. Baum et al. (1995) used the CO 2 -slicing technique applied to the High Resolution Infrared Radiation

  7. Aerosol characterization study using multi-spectrum remote sensing measurement techniques.

    SciTech Connect (OSTI)

    Glen, Crystal Chanea; Sanchez, Andres L.; Lucero, Gabriel Anthony; Schmitt, Randal L.; Johnson, Mark S.; Tezak, Matthew Stephen; Servantes, Brandon Lee

    2013-09-01

    A unique aerosol flow chamber coupled with a bistatic LIDAR system was implemented to measure the optical scattering cross sections and depolarization ratio of common atmospheric particulates. Each of seven particle types (ammonium sulfate, ammonium nitrate, sodium chloride, potassium chloride, black carbon and Arizona road dust) was aged by three anthropogenically relevant mechanisms: 1. Sulfuric acid deposition, 2. Toluene ozonolysis reactions, and 3. m-Xylene ozonolysis reactions. The results of pure particle scattering properties were compared with their aged equivalents. Results show that as most particles age under industrial plume conditions, their scattering cross sections are similar to pure black carbon, which has significant impacts to our understanding of aerosol impacts on climate. In addition, evidence emerges that suggest chloride-containing aerosols are chemically altered during the organic aging process. Here we present the direct measured scattering cross section and depolarization ratios for pure and aged atmospheric particulates.

  8. Hydrothermal synthesis of nanostructured zinc oxide and study of their optical properties

    SciTech Connect (OSTI)

    Moulahi, A.; Sediri, F.; Gharbi, N.

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Nanostructured ZnO were successfully obtained by a hydrothermal route. Black-Right-Pointing-Pointer Inorganic precursor and molar ratio are key factors for morphology and particle size. Black-Right-Pointing-Pointer Optical properties were also studied. -- Abstract: Nanostructured ZnO (nanorods, nanoshuttles) have been synthesized by hydrothermal approach using ZnCl{sub 2} or Zn(NO{sub 3}){sub 2}{center_dot}6H{sub 2}O as zinc sources and cetyltrimethylammonium bromide as structure-directing agent. Techniques X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible absorption, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy have been used to characterize the structure, morphology and composition of the nanostructured zinc oxide. The optical properties of the as-obtained materials were also studied and showing that it is possible to apply the ZnO nanoshuttles and nanorods on the UV filter, photocatalysis, and special optical devices.

  9. Synthesis, characterization and optical properties of hybrid PVAZnO nanocomposite: A composition dependent study

    SciTech Connect (OSTI)

    Hemalatha, K.S. [Department of Physics, Bangalore University, Bangalore 560 056, Karnataka (India); Department of Physics, Maharani's Science College for Women, Palace Road, Bangalore 560 001, Karnataka (India); Rukmani, K., E-mail: rukmani9909@yahoo.co.in [Department of Physics, Bangalore University, Bangalore 560 056, Karnataka (India); Suriyamurthy, N. [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Nagabhushana, B.M. [Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, Karnataka (India)

    2014-03-01

    Graphical abstract: - Highlights: ZnO nanoparticles were prepared by solution combustion method. PVAZnO nanocomposites were synthesized by solution casting method. Doped and undoped films were characterized using different techniques. Red shift in optical band gap was observed in Nanocomposite films with respect to nano ZnO. Photoluminescence intensity was found to be optimum for PVA10 mol% ZnO nanocomposite film. - Abstract: Nanocomposites of poly vinyl alcohol (PVA) and ZnO have been synthesized using the solution casting technique for different concentrations of nano ZnO powder prepared by low temperature solution combustion method. The formation of polymer nanocomposite and changes in the structural and micro structural properties of the materials were investigated by X-ray diffraction, Energy dispersive X ray spectroscopy and optical microscopy techniques (FTIR and UVVisible). The surface morphology of PVAZnO nanocomposite films were elucidated using Scanning Electron Microscopy. The optical absorption spectrum of nano ZnO shows blue shift in the optical band gap energy with respect to characteristic bulk ZnO at room temperature, whereas PVAZnO hybrid films show red shift with respect to nano ZnO. The photoluminescence studies show that the intensity of the blue emission (470 nm) varies with change in concentration of ZnO with an optimum intensity observed at 10 mol% of ZnO.

  10. Tuning optical properties of transparent conducting barium stannate by dimensional reduction

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

    Li, Yuwei; Zhang, Lijun; Ma, Yanming; Singh, David J.

    2015-01-30

    We report calculations of the electronic structure and optical properties of doped n-type perovskite BaSnO3 and layered perovskites. While doped BaSnO3 retains its transparency for energies below the valence to conduction band onset, the doped layered compounds exhibit below band edge optical conductivity due to transitions from the lowest conduction band. This gives absorption in the visible for Ba2SnO4. It is important to minimize this phase in transparent conducting oxide (TCO) films. Ba3Sn2O7 and Ba4Sn3O10 have strong transitions only in the red and infrared, respectively. Thus, there may be opportunities for using these as wavelength filtering TCO.

  11. Effect of hydrogenation on the electrical and optical properties of GaSb

    SciTech Connect (OSTI)

    Dutta, P.S.; Bhat, H.L.; Kumar, V.

    1996-12-31

    The effect of hydrogen plasma treatment on the optical and electrical properties of Gallium Antimonide bulk single crystals is presented. Plasma exposure gives rise to a layer of defects on the surface. These defects introduce multiple trap levels in the band gap from which a slow emission of carriers is observed during the capacitance-voltage measurements. On removal of the defect layer by controlled etching, the effects of hydrogen passivation are seen. The results of optical measurements indicate that passivation of shallow acceptors is more efficient than that of the donors and in general the passivation efficiency depends on the doping level. Passivation of deep levels and extended defects like grain boundaries and dislocations has also been observed. The thermal stability of the passivated deep level and extended defects is higher than that of the shallow level.

  12. Electronic and optical properties of single excitons and biexcitons in type-II quantum dot nanocrystals

    SciTech Connect (OSTI)

    Koc, Fatih; Sahin, Mehmet E-mail: mehsahin@gmail.com

    2014-05-21

    In this study, a detailed investigation of the electronic and optical properties (i.e., binding energies, absorption wavelength, overlap of the electron-hole wave functions, recombination oscillator strength, etc.) of an exciton and a biexciton in CdTe/CdSe core/shell type-II quantum dot heterostructures has been carried out in the frame of the single band effective mass approximation. In order to determine the electronic properties, we have self-consistently solved the Poisson-Schrdinger equations in the Hartree approximation. We have considered all probable Coulomb interaction effects on both energy levels and also on the corresponding wave functions for both single exciton and biexciton. In addition, we have taken into account the quantum mechanical exchange-correlation effects in the local density approximation between same kinds of particles for biexciton. Also, we have examined the effect of the ligands and dielectric mismatch on the electronic and optical properties. We have used a different approximation proposed by Sahin and Koc [Appl. Phys. Lett. 102, 183103 (2013)] for the recombination oscillator strength of the biexciton for bound and unbound cases. The results obtained have been presented comparatively as a function of the shell thicknesses and probable physical reasons in behind of the results have been discussed in a detail.

  13. Doping of TiO 2 Polymorphs for Altered Optical and Photocatalytic Properties

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

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; Sohlberg, Karl

    2009-01-01

    Tmore » his paper reviews recent investigations of the influence of dopants on the optical properties of TiO 2 polymorphs. The common undoped polymorphs of TiO 2 are discussed and compared. The results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of the TiO 2 electronic structure, which is supported with first-principles calculations.« less

  14. Doping ofTiO2Polymorphs for Altered Optical and Photocatalytic Properties

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

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; Sohlberg, Karl

    2009-01-01

    This paper reviews recent investigations of the influence of dopants on the optical properties ofTiO2polymorphs. The common undoped polymorphs ofTiO2are discussed and compared. The results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of theTiO2electronic structure, which is supported with first-principles calculations.

  15. ARM - Measurement - Aerosol concentration

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

    CSPHOT : Cimel Sunphotometer CPC : Condensation Particle Counter HTDMA : Humidified Tandem Differential Mobility Analyzer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights)...

  16. ARM - AIP1OGREN: AOS Intensive Properties

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

    govDataAIP1OGREN: AOS Intensive Properties AIP1OGREN: AOS Intensive Properties The aip1ogren value-added product produces aerosol intensive properties from Aerosol Observing Station data. Information Last Updated: October 2008 General Description The aip1ogren value-added product (VAP) computes several aerosol intensive properties. It requires as input calibrated, corrected, aerosol extensive properties (scattering and absorption coefficients, primarily) from the Aerosol Observing Station (AOS).

  17. ARM - Field Campaign - Two-Column Aerosol Project (TCAP): Winter...

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

    on atmospheric particulate matter. The effect of aerosol properties such as size, morphology and composition on cloud droplet formation has been studied theoretically as well as...

  18. Tuning the Optical Properties of Mesoporous TiO2 Films by Nanoscale Engineering

    SciTech Connect (OSTI)

    Schwenzer, Birgit; Wang, Liang; Swensen, James S.; Padmaperuma, Asanga B.; Silverman, Gary; Korotkov, Roman; Gaspar, Daniel J.

    2012-07-03

    Introducing mesoscale pores into spincoated titanium dioxide films, prepared by spincoating different sol-gel precursor solutions on silicon substrates and subsequent annealing at 350 C, 400 C or 450 C, respectively, affects several optical properties of the material. The change in refractive index observed for different mesoporous anatase films directly correlates with changes in pore size, but is also in a more complex manner influenced by the film thickness and the density of pores within the films. Additionally, the band gap of the films is blueshifted by the stress the introduction of pores exerts on the inorganic matrix. The differently sized pores were templated by Pluronic{reg_sign} block copolymers in the solgel solutions and tuned by employing different annealing temperatures for the film preparation. This study focused on elucidating the effect different templating materials (F127 and P123) have on the pore size of the final mesoporous titania film, and on understanding the relation of varying polymer concentration (taking P123 as an example) in the sol-gel solution to the pore concentration and size in the resultant titania film. Titania thin film samples or corresponding titanium dioxide powders were characterized by X-ray diffraction, nitrogen adsorption, ellipsometery, UV/Vis spectrometry and other techniques to understand the interplay between mesoporosity and optical properties.

  19. Initial Assessment of the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR)-Based Aerosol Retrieval: Sensitivity Study

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Flynn, Connor J.; Redemann, Jens; Schmid, Beat; Russell, P. B.; Sinyuk, Alexander

    2012-10-24

    The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) being developed for airborne measurements will offer retrievals of aerosol microphysical and optical properties from multi-angular and multi-spectral measurements of sky radiance and direct-beam sun transmittance. In this study, we assess the expected accuracy of the 4STAR-based aerosol retrieval and its sensitivity to major sources of anticipated perturbations in the 4STAR measurements by adapting a theoretical approach previously developed for the AERONET measurements. The major anticipated perturbations are (1) an apparent enhancement of sky radiance at small scattering angles associated with the necessarily compact design of the 4STAR and (2) and an offset (i.e. uncertainty) of sky radiance calibration independent of scattering angle. The assessment is performed through application of the operational AERONET aerosol retrieval and constructed synthetic 4STAR-like data. Particular attention is given to the impact of these perturbations on the upwelling and downwelling broadband fluxes and the direct aerosol radiative forcing at the bottom and top of the atmosphere. The results from this study suggest that limitations in the accuracy of 4STAR-retrieved particle size distributions and scattering phase functions have diminished impact on the accuracy of retrieved bulk microphysical parameters, permitting quite accurate retrievals of properties including the effective radius (up to 10%, or 0.03), and the radiatively important optical properties, such as the asymmetry factor (up to 4%, or 0.02) and single-scattering albedo (up to 6%, or 0.04). Also, the obtained results indicate that the uncertainties in the retrieved aerosol optical properties are quite small in the context of the calculated fluxes and direct aerosol radiative forcing (up to 15%, or 3 Wm-2).

  20. Aerosol Characterization Data from the Asian Pacific Regional Aerosol Characterization Project (ACE-Asia)

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

    The Aerosol Characterization Experiments (ACE) were designed to increase understanding of how atmospheric aerosol particles affect the Earth's climate system. These experiments integrated in-situ measurements, satellite observations, and models to reduce the uncertainty in calculations of the climate forcing due to aerosol particles and improve the ability of models to predict the influences of aerosols on the Earth's radiation balance. ACE-Asia was the fourth in a series of experiments organized by the International Global Atmospheric Chemistry (IGAC) Program (A Core Project of the International Geosphere Biosphere Program). The Intensive Field Phase for ACE-Asia took place during the spring of 2001 (mid-March through early May) off the coast of China, Japan and Korea. ACE-Asia pursued three specific objectives: 1) Determine the physical, chemical, and radiative properties of the major aerosol types in the Eastern Asia and Northwest Pacific region and investigate the relationships among these properties. 2) Quantify the physical and chemical processes controlling the evolution of the major aerosol types and in particular their physical, chemical, and radiative properties. 3) Develop procedures to extrapolate aerosol properties and processes from local to regional and global scales, and assess the regional direct and indirect radiative forcing by aerosols in the Eastern Asia and Northwest Pacific region [Edited and shortened version of summary at http://data.eol.ucar.edu/codiac/projs?ACE-ASIA]. The Ace-Asia collection contains 174 datasets.

  1. Brush-Coated Nanoparticle Polymer Thin Films: structure-mechanical-optical properties

    SciTech Connect (OSTI)

    Green, Peter F.

    2015-01-13

    Executive Summary Our work was devoted to understanding the structure and properties of a class of thin film polymer nanocomposites (PNCs). PNCs are composed of polymer hosts into which nanoparticles (metallic nanoparticles, quantum dots, nanorods, C60, nanotubes) are incorporated. PNCs exhibit a diverse range of functional properties (optical, electronic, mechanical, biomedical, structural), determined in part by the chemical composition of the polymer host and the type of nanoparticle. The properties PNCs rely not only on specific functional, size-dependent, behavior of the nanoparticles, but also on the dispersion, and organizational order in some cases, inter-nanoparticle separation distances, and on relative interactions between the nanoparticles and the host. Therefore the scientific challenges associated with understanding the interrelations between the structure and function/properties of PNCs are far more complex than may be understood based only on the knowledge of the compositions of the constituents. The challenges of understanding the structure-function behavior of PNCs are further compounded by the fact that control of the dispersion of the nanoparticles within the polymer hosts is difficult; one must learn how to disperse inorganic particles within an organic host. The goal of this proposal was to develop an understanding of the connection between the structure and the thermal (glass transition), mechanical and optical properties of a specific class of PNCs. Specifically PNCs composed of polymer chain grafted gold nanoparticles within polymer hosts. A major objective was to understand how to develop basic principles that enable the fabrication of functional materials possessing optimized morphologies and combinations of materials properties. Accomplishments: We developed: (1) fundamental principles that enabled the creation of thin film PNCs possessing more complex morphologies of homopolymers and block copolymer micellar systems [1-6]; (2) a new understanding of physical phenomena associated with the structure of PNC systems and the glass transition and dynamics [7-11], including surface dynamics [12, 13]; designed PNCs to understand the connection between structure and specific optical responses of the material [14, 15]; electrorheological phenomena [16-18]; coarsening/aggregation phenomena [19, 20]; directed assembly [21] and elastic mechanical properties of thin supported films [22]. We established procedures to design and control the spatial distribution of gold nanoparticles (Au-NP), onto which polystyrene (PS) chains were end-grafted, within thin film PS hosts.[1-3] We explained how enthalpic and entropic interactions between the grafted layers and the polymer host chains, the nanoparticle (NP) sizes and shapes determine the spatial distribution of NPs within the host (i.e.: the morphology). In brief, the chemistries of the grafted chains and the polymer hosts, the degrees of polymerization of grafted and host chains (N and P, respectively), and the surface grafting densities ? influence the thermodynamic interactions. Thin films are unique: the external interfaces (substrate and free surface) profoundly influence the spatial distribution of NPs within the PNC. For example, thin films are thermodynamically less stable than their bulk analogs due to the preferential attraction between the brush-coated nanoparticles and the external interfaces (i.e.: the free surface/polymer interface and the polymer/substrate interface). We investigated the organization of the brush-coated nanoparticles within a host composed on block copolymer micelles in a homopolymer [4, 5]. Block copolymers, composed of a polymer of type A that is bonded covalently to another polymer of type B (A-b-B) are known to form micelles within homopolymers A or B. A micelle is composed of an inner core of the A component of the copolymer and an outer corona of the B-component, that resides within homopolymer B, which serves as the host. If the host is the A homopolymer then the core of the micelle is composed of the B component of the co

  2. Optical properties of strain-free AlN nanowires grown by molecular beam epitaxy on Si substrates

    SciTech Connect (OSTI)

    Wang, Q.; Zhao, S.; Connie, A. T.; Shih, I.; Mi, Z.; Gonzalez, T.; Andrews, M. P.; Du, X. Z.; Lin, J. Y.; Jiang, H. X.

    2014-06-02

    The optical properties of catalyst-free AlN nanowires grown on Si substrates by molecular beam epitaxy were investigated. Such nanowires are nearly free of strain, with strong free exciton emission measured at room temperature. The photoluminescence intensity is significantly enhanced, compared to previously reported AlN epilayer. Moreover, the presence of phonon replicas with an energy separation of ?100?meV was identified to be associated with the surface-optical phonon rather than the commonly reported longitudinal-optical phonon, which is further supported by the micro-Raman scattering experiments.

  3. Thermal properties of the optically transparent pore-free nanostructured yttria-stabilized zirconia

    SciTech Connect (OSTI)

    Ghosh, S.; Teweldebrhan, D.; Morales, J. R.; Garay, J. E.; Balandin, A. A.

    2009-12-01

    The authors report results of investigation of thermal conductivity of nanocrystalline yttria-stabilized zirconia. The optically transparent pore-free bulk samples were prepared via the spark plasma sintering process to ensure homogeneity. Thermal conductivity K was measured by two different techniques. It was found that the pore-free nanostructured bulk zirconia is an excellent thermal insulator with the room-temperature Kapprox1.7-2.0 W/m K. It was also shown that the 'phonon-hopping' model can accurately describe specifics of K dependence on temperature and the grain size. The obtained results are important for optimization of zirconia properties for specific applications in advanced electronics and coatings.

  4. Optimization of the optical properties of nanostructured silicon surfaces for solar cell applications

    SciTech Connect (OSTI)

    Zhou, Di; Pennec, Y.; Djafari-Rouhani, B.; Lambert, Y.; Deblock, Y.; Stiévenard, D.; Cristini-Robbe, O.; Xu, T.; Faucher, M.

    2014-04-07

    Surface nanostructuration is an important challenge for the optimization of light trapping in solar cell. We present simulations on both the optical properties and the efficiency of micro pillars—MPs—or nanocones—NCs—silicon based solar cells together with measurements on their associated optical absorption. We address the simulation using the Finite Difference Time Domain method, well-adapted to deal with a periodic set of nanostructures. We study the effect of the period, the bottom diameter, the top diameter, and the height of the MPs or NCs on the efficiency, assuming that one absorbed photon induces one exciton. This allows us to give a kind of abacus involving all the geometrical parameters of the nanostructured surface with regard to the efficiency of the associated solar cell. We also show that for a given ratio of the diameter over the period, the best efficiency is obtained for small diameters. For small lengths, MPs are extended to NCs by changing the angle between the bottom surface and the vertical face of the MPs. The best efficiency is obtained for an angle of the order of 70°. Finally, nanostructures have been processed and allow comparing experimental results with simulations. In every case, a good agreement is found.

  5. Morphology Of Diesel Soot Residuals From Supercooled Water Droplets And Ice Crystals: Implications For Optical Properties

    SciTech Connect (OSTI)

    China, Swarup; Kulkarni, Gourihar; Scarnatio, Barbara; Sharma, Noopur; Pekour, Mikhail S.; Shilling, John E.; Wilson, Jacqueline M.; Zelenyuk, Alla; Chand, Duli; Liu, Shang; Aiken, Allison; Dubey, Manvendra K.; Laskin, Alexander; Zaveri, Rahul A.; Mazzoleni, Claudio

    2015-11-04

    Freshly emitted soot particles are fractal-like aggregates, but atmospheric processing often transforms their morphology. Morphology of soot particles plays an important role in determining their optical properties, life cycle and hence their effect on Earths radiative balance. However, little is known about the morphology of soot particles that participated in cold cloud processes. Here we report results from laboratory experiments that simulate cold cloud processing of diesel soot particles by allowing them to form supercooled droplets and ice crystals at -20 and -40C, respectively. Electron microscopy revealed that soot residuals from ice crystals were more compact (roundness~0.55) than those from supercooled droplets (roundness ~0.45), while nascent soot particles were the least compact (roundness~0.41). Optical simulations using the discrete dipole approximation showed that the more compact structure enhances soot single scattering albedo by a factor up to 1.4, thereby reducing the top-of-the-atmosphere direct radiative forcing by ~63%. These results underscore that climate models should consider the morphological evolution of soot particles due to cold cloud processing to improve the estimate of direct radiative forcing of soot.

  6. Synthesis, optical properties, and microstructure of semiconductor nanocrystals formed by ion implantation

    SciTech Connect (OSTI)

    Budai, J.D.; White, C.W.; Withrow, S.P.; Zuhr, R.A.; Zhu, J.G.

    1996-12-01

    High-dose ion implantation, followed by annealing, has been shown to provide a versatile technique for creating semiconductor nanocrystals encapsulated in the surface region of a substrate material. The authors have successfully formed nanocrystalline precipitates from groups IV (Si, Ge, SiGe), III-V (GaAs, InAs, GaP, InP, GaN), and II-VI (CdS, CdSe, CdS{sub x}Se{sub 1{minus}x}, CdTe, ZnS, ZnSe) in fused silica, Al{sub 2}O{sub 3} and Si substrates. Representative examples will be presented in order to illustrate the synthesis, microstructure, and optical properties of the nanostructured composite systems. The optical spectra reveal blue-shifts in good agreement with theoretical estimates of size-dependent quantum-confinement energies of electrons and holes. When formed in crystalline substrates, the nanocrystal lattice structure and orientation can be reproducibly controlled by adjusting the implantation conditions.

  7. Atmospheric Radiation Measurement (ARM) Data from Shouxian, China for the Study of Aerosol Indirect Effects in China

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

    In a complex ARM Mobile Facility (AMF) deployment, monitoring data was collected at four locations in China during 2008. The various sites are located in regions with different climate regimes and with high aerosol loadings of different optical, physical, and chemical properties. Measurements obtained at all the AMF sites during the 8-month deployment in China will help scientists to validate satellite-based findings, understand the mechanisms of the aerosol indirect effects in the region, and examine the roles of aerosols in affecting regional climate and atmospheric circulation, with a special focus on the impact of the East Asian monsoon system. As with other collections from the ARM Mobile Facility, the datasets are available from the ARM Archive. The ARM Archive physically resides at the Oak Ridge National Laboratory.

  8. Structural, electronic and optical properties of La{sub x}Sc{sub 1-x}Sb alloys

    SciTech Connect (OSTI)

    Ghezali, M.

    2015-03-30

    We present calculations of the structural, electronic and optic properties of LaxSc1-xSb ternary alloys for 0?x?1, by using the first principle full potential linear muffin-tin orbital (FPLMTO) method based on the local density approximation (LDA). the lattice constant, bulk modulus, electronic band structures, density of state and optical properties such as dielectric functions, refractive index and extinction coefficient are calculated and discussed for (x=0.25, 0.5 and 0.75). Our results agree well with the available data in the literature.

  9. East Asian Studies of Tropospheric Aerosols and their Impact on Regional Climate (EAST-AIRC): An Overview

    SciTech Connect (OSTI)

    Li, Zhanqing; Li, C.; Chen, H.; Tsay, S. C.; Holben, B. N.; Huang, J.; Li, B.; Maring, H.; Qian, Yun; Shi, Guangyu; Xia, X.; Yin, Y.; Zheng, Y.; Zhuang, G.

    2011-02-01

    As the most populated region of the world, Asia is a major source of aerosols with potential large impact over vast downstream areas. Papers published in this special section describe the variety of aerosols observed in China and their effects and interactions with the regional climate as part of the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate (EAST-AIRC). The majority of the papers are based on analyses of observations made under three field projects, namely, the Atmospheric Radiation Measurements (ARM) Mobile Facility mission in China (AMF10 China), the East Asian Study of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE), and the Atmospheric Aerosols of China and their Climate Effects (AACCE). The former two are US-China collaborative projects and the latter is a part of the China’s National Basic Research program (or often referred to as “973 project”). Routine meteorological data of China are also employed in some studies. The wealth of general and specialized measurements lead to extensive and close-up investigations of the optical, physical and chemical properties of anthropogenic, natural, and mixed aerosols; their sources, formation and transport mechanisms; horizontal, vertical and temporal variations; direct and indirect effects and interactions with the East Asian monsoon system. Particular efforts are made to advance our understanding of the mixing and interaction between dust and anthropogenic pollutants during transport. Several modeling studies were carried out to simulate aerosol impact on radiation budget, temperature, precipitation, wind and atmospheric circulation, fog, etc. In addition, impacts of the Asian monsoon system on aerosol loading are also simulated.

  10. Project Overview: Cumulus Humilis Aerosol Processing Study (CHAPS): Proposed Summer 2007 ASP Field Campaign

    SciTech Connect (OSTI)

    Berkowitz, Carl M.; Berg, Larry K.; Ogren, J. A.; Hostetler, Chris A.; Ferrare, Richard

    2006-05-18

    This white paper presents the scientific motivation and preliminary logistical plans for a proposed ASP field campaign to be carried out in the summer of 2007. The primary objective of this campaign is to use the DOE Gulfstream-1 aircraft to make measurements characterizing the chemical, physical and optical properties of aerosols below, within and above large fields of fair weather cumulus and to use the NASA Langley Research Centers High Spectral Resolution Lidar (HSRL) to make independent measurements of aerosol backscatter and extinction profiles in the vicinity of these fields. Separate from the science questions to be addressed by these observations will be information to add in the development of a parameterized cumulus scheme capable of including multiple cloud fields within a regional or global scale model. We will also be able to compare and contrast the cloud and aerosol properties within and outside the Oklahoma City plume to study aerosol processes within individual clouds. Preliminary discussions with the Cloud and Land Surface Interaction Campaign (CLASIC) science team have identified overlap between the science questions posed for the CLASIC Intensive Operation Period (IOP) and the proposed ASP campaign, suggesting collaboration would benefit both teams.

  11. Optical Properties and Wave Propagation in Semiconductor-Based Two-Dimensional Photonic Crystals

    SciTech Connect (OSTI)

    Mario Agio

    2002-12-31

    This work is a theoretical investigation on the physical properties of semiconductor-based two-dimensional photonic crystals, in particular for what concerns systems embedded in planar dielectric waveguides (GaAs/AlGaAs, GaInAsP/InP heterostructures, and self-standing membranes) or based on macro-porous silicon. The photonic-band structure of photonic crystals and photonic-crystal slabs is numerically computed and the associated light-line problem is discussed, which points to the issue of intrinsic out-of-lane diffraction losses for the photonic bands lying above the light line. The photonic states are then classified by the group theory formalism: each mode is related to an irreducible representation of the corresponding small point group. The optical properties are investigated by means of the scattering matrix method, which numerically implements a variable-angle-reflectance experiment; comparison with experiments is also provided. The analysis of surface reflectance proves the existence of selection rules for coupling an external wave to a certain photonic mode. Such rules can be directly derived from symmetry considerations. Lastly, the control of wave propagation in weak-index contrast photonic-crystal slabs is tackled in view of designing building blocks for photonic integrated circuits. The proposed designs are found to comply with the major requirements of low-loss propagation, high and single-mode transmission. These notions are then collected to model a photonic-crystal combiner for an integrated multi-wavelength-source laser.

  12. The structural, electrical, and optical properties of hydrogenated chromium-doped CdO films

    SciTech Connect (OSTI)

    Dakhel, A.A.; Hamad, H.

    2013-12-15

    Cadmium oxide thin films doped with different amounts of chromium and annealed in hydrogen atmosphere have been grown on glass substrates by means of physical vapour deposition (PVD) method. The structural, electrical, and optical properties of the prepared Cr-doped CdO (CdO:CrH) films were systematically studied. The structural investigations show that the incorporated Cr ions mainly occupied locations in interstitial positions of CdO lattice. The bandgap engineer by Cr incorporation and hydrogenation were studied. The variations of the electrical parameters of CdO:CrH films with Cr incorporation and hydrogenation were investigated. It was established that among the investigated samples, the largest mobility and conductivity were measured with 1.5%:CrH film. Therefore, hydrogenated CdO:Cr films can be effectively used in different applications of near infrared-transparent-conducting-oxide (NIR-TCO). - Graphical abstract: Optoelectronic properties of synthesised chromium-doped CdO thin films. It was established that the largest mobility (53.4 cm{sup 2}/V.s) and conductivity (2136.8 S/cm) were measured in 1.5%:CrH doped CdO film. Therefore, such films can be effectively used in near infrared-transparent-conducting-oxide (NIR-TCO). - Highlights: The properties of CdO films annealed in H{sub 2} gas were systematically studied. Cr{sup 3+} ions most likely occupied interstitial locations in CdO lattice and as donors. Improvement of conductivity parameters with Cr doping and H annealing. Bandgap narrowing observed with Cd-doping.

  13. WRF-Chem Simulations of Aerosols and Anthropogenic Aerosol Radiative Forcing in East Asia

    SciTech Connect (OSTI)

    Gao, Yi; Zhao, Chun; Liu, Xiaohong; Zhang, Meigen; Leung, Lai-Yung R.

    2014-08-01

    This study aims to provide a first comprehensive evaluation of WRF-Chem for modeling aerosols and anthropogenic aerosol radiative forcing (RF) over East Asia. Several numerical experiments were conducted from November 2007 to December 2008. Comparison between model results and observations shows that the model can generally reproduce the observed spatial distributions of aerosol concentration, aerosol optical depth (AOD) and single scattering albedo (SSA) from measurements at different sites, including the relatively higher aerosol concentration and AOD over East China and the relatively lower AOD over Southeast Asia, Korean, and Japan. The model also depicts the seasonal variation and transport of pollutions over East Asia. Particulate matter of 10 um or less in the aerodynamic diameter (PM10), black carbon (BC), sulfate (SO42-), nitrate (NO3-) and ammonium (NH4+) concentrations are higher in spring than other seasons in Japan due to the pollutant transport from polluted area of East Asia. AOD is high over Southwest and Central China in winter, spring and autumn and over North China in summer while is low over South China in summer due to monsoon precipitation. SSA is lowest in winter and highest in summer. The model also captures the dust events at the Zhangye site in the semi-arid region of China. Anthropogenic aerosol RF is estimated to range from -5 to -20 W m-2 over land and -20 to -40 W m-2 over ocean at the top of atmosphere (TOA), 5 to 30 W m-2 in the atmosphere (ATM) and -15 to -40 W m-2 at the bottom (BOT). The warming effect of anthropogenic aerosol in ATM results from BC aerosol while the negative aerosol RF at TOA is caused by scattering aerosols such as SO4 2-, NO3 - and NH4+. Positive BC RF at TOA compensates 40~50% of the TOA cooling associated with anthropogenic aerosol.

  14. Method and apparatus for measuring the intensity and phase of one or more ultrashort light pulses and for measuring optical properties of materials

    DOE Patents [OSTI]

    Trebino, Rick P. (Livermore, CA); DeLong, Kenneth W. (Livermore, CA)

    1996-01-01

    The intensity and phase of one or more ultrashort light pulses are obtained using a non-linear optical medium. Information derived from the light pulses is also used to measure optical properties of materials. Various retrieval techniques are employed. Both "instantaneously" and "non-instantaneously" responding optical mediums may be used.

  15. MAGIC Cloud Properties from Zenith Radiance Data Final Campaign Summary

    SciTech Connect (OSTI)

    Chiu, J. -Y.C.; Gregory, L.; Wagener, R.

    2016-01-01

    Cloud droplet size and optical depth are the most fundamental properties for understanding cloud formation, dissipation and interactions with aerosol and drizzle. They are also a crucial determinant of Earth’s radiative and water-energy balances. However, these properties are poorly predicted in climate models. As a result, the response of clouds to climate change is one of the major sources of uncertainty in climate prediction.

  16. ARM - Measurement - Aerosol scattering

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

    : Nephelometer PASS : Photoacoustic Soot Spectrometer RL : Raman Lidar TDMA : Tandem Differential Mobility Analyzer Field Campaign Instruments AMT : Aerosol Modeling...

  17. Solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  18. Solid aerosol generator

    DOE Patents [OSTI]

    Prescott, Donald S. (Shelley, ID); Schober, Robert K. (Midwest City, OK); Beller, John (Idaho Falls, ID)

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  19. Improved solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  20. A simple growth method for Nb2O5 films and their optical properties

    SciTech Connect (OSTI)

    Dash, J. K.; Chen, L.; Topka, Michael R.; Dinolfo, Peter H.; Zhang, L. H.; Kisslinger, K.; Lu, T. -M.; Wang, G. -C.

    2015-04-13

    A simple method for the synthesis of Nb?O? films of thicknesses ranging from tens to several hundreds of nanometers on amorphous silicon dioxide or quartz substrates is presented. Nb?O? films were formed by annealing the sputter deposited Nb films under an Ar flow and without oxygen plasma in a quartz tube within a furnace at 850 C. The structural, compositional, optical, and vibrational properties were characterized by grazing incidence X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet visible spectroscopy, and Raman scattering. Each of the Nb?O? films is polycrystalline with an orthorhombic crystal structure. We observed vibrational modes including longitudinal optical, transverse optical, and triply degenerate modes, and measured the indirect optical band gap to be ~3.65 eV. The transmittance spectrum of the ~20 nm thick Nb?O? film shows over 90% transmittance below the band gap energy in the visible wavelength range and decreases to less than 20% in the ultraviolet regime. As a result, the optical properties of the films in the UV-vis range show potential applications as UV detectors.

  1. Effect of 200 keV Ar{sup +} implantation on optical and electrical properties of polyethyleneterepthalate (PET)

    SciTech Connect (OSTI)

    Kumar, Rajiv Goyal, Meetika Sharma, Ambika; Aggarwal, Sanjeev; Sharma, Annu; Kanjilal, D.

    2015-05-15

    In the present paper we have discussed the effect of 200 keV Ar{sup +} ions on the electrical and optical properties of PET samples. PET samples were implanted with 200 keV Ar{sup +} ions to various doses ranging from 110{sup 15} to 110{sup 17} Ar{sup +} cm{sup 2}. The changes in the electrical and optical properties of pristine and implanted PET specimens have been studied by using Keithley electrometer and UV-Visible absorption spectroscopy. The electrical conductivity has found to be increased with increasing ion dose. The optical studies have revealed the drastic alterations in optical band gap from 3.63 eV to 1.48 eV and also increase in number of carbon atoms per cluster from 215 to 537. Further, the change in the electrical conductivity and optical band gap has also been correlated with the formation of conductive islands in the implanted layers of PET.

  2. Evaluating Clouds, Aerosols, and their Interactions in Three Global Climate Models using COSP and Satellite Observations

    SciTech Connect (OSTI)

    Ban-Weiss, George; Jin, Ling; Bauer, S.; Bennartz, Ralph; Liu, Xiaohong; Zhang, Kai; Ming, Yi; Guo, Huan; Jiang, Jonathan

    2014-09-23

    Accurately representing aerosol-cloud interactions in global climate models is challenging. As parameterizations evolve, it is important to evaluate their performance with appropriate use of observations. In this work we compare aerosols, clouds, and their interactions in three climate models (AM3, CAM5, ModelE) to MODIS satellite observations. Modeled cloud properties were diagnosed using the CFMIP Observations Simulator Package (COSP). Cloud droplet number concentrations (N) were derived using the same algorithm for both satellite-simulated model values and observations. We find that aerosol optical depth tau simulated by models is similar to observations. For N, AM3 and CAM5 capture the observed spatial pattern of higher values in near-coast versus remote ocean regions, though modeled values in general are higher than observed. In contrast, ModelE simulates lower N in most near-coast versus remote regions. Aerosol- cloud interactions were computed as the sensitivity of N to tau for marine liquid clouds off the coasts of South Africa and Eastern Asia where aerosol pollution varies in time. AM3 and CAM5 are in most cases more sensitive than observations, while the sensitivity for ModelE is statistically insignificant. This widely used sensitivity could be subject to misinterpretation due to the confounding influence of meteorology on both aerosols and clouds. A simple framework for assessing the N tau sensitivity at constant meteorology illustrates that observed sensitivity can change from positive to statistically insignificant when including the confounding influence of relative humidity. Satellite simulated values of N were compared to standard model output and found to be higher with a bias of 83 cm-3.

  3. Structural, thermodynamic and optical properties of MgF{sub 2} studied from first-principles theory

    SciTech Connect (OSTI)

    Ramesh Babu, K.; Bheema Lingam, Ch.; Auluck, S.; Tewari, Surya P.; Vaitheeswaran, G.

    2011-02-15

    A detailed theoretical study of structural, electronic, elastic, thermodynamic and optical properties of rutile type MgF{sub 2} has been carried out by means of first-principles Density Functional Theory (DFT) calculations using plane wave pseudo-potentials within the local density approximation and generalized-gradient approximation for the exchange and correlation functionals. The calculated ground state properties and elastic constants agree quite well with experimental values. From the calculated elastic constants we conclude that MgF{sub 2} is relatively hard when compared to other alkaline-earth fluorides and ductile in nature. The thermodynamic properties such as heat capacity, entropy, free energy, phonon density of states and Debye temperatures are calculated at various temperatures from the lattice dynamical data obtained through the quasi-harmonic Debye model. From free energy and entropy it is found that the system is thermodynamically stable up to 1200 K. The imaginary part of the calculated dielectric function {epsilon}{sub 2}({omega}) could reproduce the six prominent peaks which are observed in experiment. From the calculated {epsilon}({omega}), other optical properties such as refractive index, reflectivity and electron energy-loss spectrum are obtained up to the photon energy range of 30 eV. -- Graphical abstract: The calculated imaginary part {epsilon}{sub 2}({omega}) of the complex dielectric function {epsilon}({omega}) of MgF{sub 2} as a function of photon energy is shown. The calculated {epsilon}{sub 2}({omega}) could reproduce the major peaks observed in experiment. All the peaks observed are corresponds to interband transitions from 'p' states of Fluorine in valence band to the 's' states of Mg in conduction band. Display Omitted Research highlights: > Structural and bonding properties. > Optical properties. > Single and polycrystalline elastic properties. > Thermodynamic properties.

  4. Aerosol remote sensing in polar regions

    SciTech Connect (OSTI)

    Tomasi, Claudio; Kokhanovsky, Alexander A.; Lupi, Angelo; Ritter, Christoph; Smirnov, Alexander; O'Neill, Norman T.; Stone, Robert S.; Holben, Brent N.; Nyeki, Stephan; Mazzola, Mauro; Lanconelli, Christian; Vitale, Vito; Stebel, Kerstin; Aaltonen, Veijo; de Leeuw, Gerrit; Rodriguez, Edith; Herber, Andreas B.; Radionov, Vladimir F.; Zielinski, Tymon; Petelski, Tomasz; Sakerin, Sergey M.; Kabanov, Dmitry M.; Xue, Yong; Mei, Linlu; Istomina, Larysa; Wagener, Richard; McArthur, Bruce; Sobolewski, Piotr S.; Kivi, Rigel; Courcoux, Yann; Larouche, Pierre; Broccardo, Stephen; Piketh, Stuart J.

    2015-01-01

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness ?(?) at visible and near-infrared wavelengths, from which best-fit values of ngstrm's exponent ? were calculated. Analysing these data, the monthly mean values of ?(0.50 ?m) and ? and the relative frequency histograms of the daily mean values of both parameters were determined for winterspring and summerautumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of ? versus ?(0.50 ?m) showed: (i) a considerable increase in ?(0.50 ?m) for the Arctic aerosol from summer to winterspring, without marked changes in ?; and (ii) a marked increase in ?(0.50 ?m) passing from the Antarctic Plateau to coastal sites, whereas ? decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of ?(?) and ? at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-lesund. Satellite-based MODIS, MISR, and AATSR retrievals of ?(?) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surfaceatmosphere system over polar regions.

  5. Structural, optical and ethanol sensing properties of Cu-doped SnO{sub 2} nanowires

    SciTech Connect (OSTI)

    Johari, Anima Sharma, Manish; Johari, Anoopshi; Bhatnagar, M. C.

    2014-04-24

    In present work, one-dimensional nanostructure of Cu-doped Tin oxide (SnO{sub 2}) was synthesized by using thermal evaporation method in a tubular furnace under Nitrogen (N{sub 2}) ambience. The growth was carried out at atmospheric pressure. SEM and TEM images reveal the growth of wire-like nanostructures of Cu-doped SnO{sub 2} on Si substrate. The XRD analysis confirms that the synthesized SnO{sub 2} nanowires have tetragonal rutile structure with polycrystalline nature and X-ray diffraction pattern also showed that Cu gets incorporated into the SnO{sub 2} lattice. EDX spectra confirm the doping of Cu into SnO{sub 2} nanowires and atomic fraction of Cu in nanowires is ? 0.5 at%. The Vapor Liquid Solid (VLS) growth mechanism for Cu-doped SnO{sub 2} nanowires was also confirmed by EDX spectra. The optical properties of as grown Cu-doped SnO{sub 2} nanowires were studied by using UV-vis spectra which concludes the band gap of about 3.7 eV. As synthesized single Cu-doped SnO{sub 2} nanowire based gas sensor exhibit relatively good performance to ethanol gas. This sensing behaviour offers a suitable application of the Cu-doped SnO{sub 2} nanowire sensor for detection of ethanol gas.

  6. Structural and optical properties of chromium doped zinc oxide nanoparticles synthesized by sol-gel method

    SciTech Connect (OSTI)

    Naqvi, Syed Mohd. Adnan; Irshad, Kashif; Soleimani, Hassan E-mail: noorhana-yahya@petronas.com.my; Yahya, Noorhana E-mail: noorhana-yahya@petronas.com.my

    2014-10-24

    Nanosized Cr-doped ZnO nano particles were synthesized by facile sol-gel auto combustion method. The structural and optical properties of Cr-doped ZnO nanoparticles have been investigated by XRD and UV-Vis spectroscopy at room temperature for 0% to 8% concentration. X-ray diffraction analysis reveals that the Cr-doped ZnO crystallizes in a single phase polycrystalline nature with wurtzite lattice. With every % of doping, the peaks are shifting scarcely and doping of Cr is possible up to 7%. After that, the last peak vanishes, that signifies its structure is transmuted from 8% doping. The average crystallite size decreases with increase in Cr concentration (i.e. 28.9 nm for 0% to 25.8 nm for 8%). The UV-Vis spectra of the nanoparticles betoken an incrementation in the band gap energy from 3.401, 3.415, 3.431, 3.437,3.453, 3.514,3.521, 3.530 and 3.538 eV respectively, for 0,1, 2, 3, 4, 5, 6, 7 and 8 % doping concentration.

  7. ZnO and MgZnO Nanocrystalline Flexible Films: Optical and Material Properties

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

    Huso, Jesse; Morrison, John L.; Che, Hui; Sundararajan, Jency P.; Yeh, Wei Jiang; McIlroy, David; Williams, Thomas J.; Bergman, Leah

    2011-01-01

    An emore » merging material for flexible UV applications is Mg x Zn 1 − x O which is capable of tunable bandgap and luminescence in the UV range of ~3.4 eV–7.4 eV depending on the composition x . Studies on the optical and material characteristics of ZnO and Mg 0.3 Zn 0.7 O nanocrystalline flexible films are presented. The analysis indicates that the ZnO and Mg 0.3 Zn 0.7 O have bandgaps of 3.34 eV and 4.02 eV, respectively. The photoluminescence (PL) of the ZnO film was found to exhibit a structural defect-related emission at ~3.316 eV inherent to the nanocrystalline morphology. The PL of the Mg 0.3 Zn 0.7 O film exhibits two broad peaks at 3.38 eV and at 3.95 eV that are discussed in terms of the solubility limit of the ZnO-MgO alloy system. Additionally, external deformation of the film did not have a significant impact on its properties as indicated by the Raman LO-mode behavior, making these films attractive for UV flexible applications.« less

  8. Pencil-like zinc oxide micro/nano-scale structures: Hydrothermal synthesis, optical and photocatalytic properties

    SciTech Connect (OSTI)

    Moulahi, A.; Sediri, F.

    2013-10-15

    Graphical abstract: - Highlights: Zinc oxide micro/nanopencils have been synthesized hydrothermally. Photocatalytic activity has been evaluated by the degradation of methylene blue under UV light irradiation. ZnO nanopencils exhibit much higher photocatalytic activity than the commercial ZnO. - Abstract: Zinc oxide micro/nanopencils have been successfully synthesized by hydrothermal process using zinc acetate and diamines as structure-directing agents. The morphology, the structure, the crystallinity and the composition of the materials were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The optical properties of synthesized ZnO were investigated by UVvis spectroscopy. The photocatalytic activity of the material has been evaluated by the degradation of methylene blue under UV irradiation. As a result, after the lapse of 150 min, around 82% bleaching was observed, with ZnO nanopencils yielding more photodegradation compared to that of commercial ZnO (61%)

  9. Three-dimensional photonic crystal fluorinated tin oxide (FTO) electrodes : synthesis and optical and electrical properties.

    SciTech Connect (OSTI)

    Yang, Z.; Gao, S.; Li, W.; Vlasko-Vlasov, V.; Welp, U.; Kwok, W.-K.; Xu, T.

    2011-04-01

    Photovoltaic (PV) schemes often encounter a pair of fundamentally opposing requirements on the thickness of semiconductor layer: a thicker PV semiconductor layer provides enhanced optical density, but inevitably increases the charge transport path length. An effective approach to solve this dilemma is to enhance the interface area between the terminal electrode, i.e., transparent conducting oxide (TCO) and the semiconductor layer. As such, we report a facile, template-assisted, and solution chemistry-based synthesis of 3-dimensional inverse opal fluorinated tin oxide (IO-FTO) electrodes. Synergistically, the photonic crystal structure possessed in the IO-FTO exhibits strong light trapping capability. Furthermore, the electrical properties of the IO-FTO electrodes are studied by Hall effect and sheet resistance measurement. Using atomic layer deposition method, an ultrathin TiO{sub 2} layer is coated on all surfaces of the IO-FTO electrodes. Cyclic voltammetry study indicates that the resulting TiO{sub 2}-coated IO-FTO shows excellent potentials as electrodes for electrolyte-based photoelectrochemical solar cells.

  10. Electro-optical and dielectric properties of CdSe quantum dots and 6CHBT liquid crystals composites

    SciTech Connect (OSTI)

    Singh, U. B.; Pandey, M. B.; Dhar, R; Pandey, A. S.; Kumar, S.; Dabrowski, R.

    2014-11-15

    We have prepared the composites of a room temperature nematic liquid crystal namely 4-(trans-4-n-hexylcyclohexyl) isothiocyanatobenzoate (6CHBT) and Cadmium Selenide Quantum Dots (CdSe-QDs) and investigated their electro-optical and dielectric properties. Effect of dispersion of CdSe-QDs on various electro-optical and display parameters of host liquid crystalline material have been studied. Physical parameters, such as switching threshold voltage and splay elastic constant have been altered drastically for composites. Dispersion of QDs in a liquid crystals medium destabilizes nematic ordering of the host and decreases the nematic-to-isotropic transition temperature.

  11. The electronic and optical properties of Eu/Si-codoped anatase TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Lin Yanming; Jiang Zhenyi; Zhang Xiaodong; Hu Xiaoyun; Fan Jun

    2012-03-05

    The electronic and optical properties of Eu/Si-codoped anatase TiO{sub 2} are investigated using the density functional theory. The calculated results show that the synergistic effects of Eu/Si codoping can effectively extend the optical absorption edge, which can lead to higher visible-light photocatalytic activities than pure anatase TiO{sub 2}. To verify the reliability of our calculated results, nanocrystalline Eu/Si-codoped TiO{sub 2} is prepared by a sol-gel-solvothermal method, and the experimental results also indicate that the codoping sample exhibits better absorption performance and higher photocatalytic activities than pure TiO{sub 2}.

  12. Some Results of Joint Measurements of Aerosol Extinction of Solar Radiation on Horizontal and Slant Paths

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

    Results of Joint Measurements of Aerosol Extinction of Solar Radiation on Horizontal and Slant Paths S. M. Sakerin, D. M. Kabanov, Yu. A. Pkhalagov, and V. N. Uzhegov Institute of Atmospheric Optics Tomsk, Russia Introduction It's a well-known fact that the contribution atmospheric aerosol makes in the total extinction of radiation in calculations and models of radiation must be considered; the quantitative measure of this contribution is the aerosol optical thickness of the atmosphere. The

  13. Optical devices having flakes suspended in a host fluid to provide a flake/fluid system providing flakes with angularly dependent optical properties in response to an alternating current electric field due to the dielectric properties of the system

    DOE Patents [OSTI]

    Kosc, Tanya Z.; Marshall, Kenneth L.; Jacobs, Stephen D.

    2006-05-09

    Optical devices utilizing flakes (also called platelets) suspended in a host fluid have optical characteristics, such as reflective properties, which are angular dependent in response to an AC field. The reflectivity may be Bragg-like, and the characteristics are obtained through the use of flakes of liquid crystal material, such as polymer liquid crystal (PLC) materials including polymer cholesteric liquid crystal (PCLC) and polymer nematic liquid crystal (PNLC) material or birefringent polymers (BP). The host fluid may be propylene carbonate, poly(ethylene glycol) or other fluids or fluid mixtures having fluid conductivity to support conductivity in the flake/host system. AC field dependent rotation of 90.degree. can be obtained at rates and field intensities dependent upon the frequency and magnitude of the AC field. The devices are useful in providing displays, polarizers, filters, spatial light modulators and wherever switchable polarizing, reflecting, and transmission properties are desired.

  14. Influence of baking method and baking temperature on the optical properties of ZnO thin films

    SciTech Connect (OSTI)

    Ng, Zi-Neng; Chan, Kah-Yoong

    2015-04-24

    In this work, sol-gel spin coating technique was utilised to coat ZnO thin films on glass substrates. During the intermediate 3 minutes baking process, either hotplate or convection oven was employed to bake the samples. The temperature for the baking process was varied from 150°C to 300°C for both instruments. Avantes Optical Spectrophotometer was used to characterise the optical property. The optical transmittances of hotplate-baked and oven-baked samples showed different trends with increasing baking temperatures, ranging from below 50% transmittance to over 90% transmittance in the visible range of wavelength. The difference in baking mechanisms using hotplate and convection oven will be discussed in this paper.

  15. Electronic and optical properties of TiCoSb under different pressures

    SciTech Connect (OSTI)

    Xu Bin; Zhang Jing; Liang Jianchu; Gao Guoying; Yi Lin

    2012-08-15

    The electronic structure and optical properties of TiCoSb are studied by the first-principles calculation. It is found that the band gaps increase with the pressure increasing. It is noted that the increase of the band gap is due to the electrons of Ti 3d and Co 3d of the valence band (VB) shifting away from the Fermi level. Our calculation indicates that TiCoSb has the large density of state near the Fermi level; moreover, the changes of the density of states near the Fermi level mainly are caused by Ti 3d and Co 3d under the different pressures. It is noted that the absorption edge increases with an increase of pressure. As pressure increases, the static dielectric constants {epsilon}{sub 1}(0) decrease. All peaks of the imaginary part of the dielectric function {epsilon}{sub 2}({omega}) move towards higher energies within increasing pressure. - Graphical abstract: The first peak positions of the absorption spectrum increase and shift the high energy with an increase of pressure. The buleshift of the absorption edge could be observed. Highlights: Black-Right-Pointing-Pointer It is noted that the increase of the band gap is due to the electrons of Ti 3d and Co 3d of VB moving away from the Fermi level. Black-Right-Pointing-Pointer It is noted that the absorption edge increases with an increase of pressure. Black-Right-Pointing-Pointer As pressure increases, the static dielectric constant {epsilon}{sub 1}(0) decreases. Black-Right-Pointing-Pointer All peaks of the imaginary part of the dielectric function {epsilon}{sub 2}({omega}) move to wards higher energies within creasing pressure.

  16. Comparative studies of optical and elastic properties of ZrO{sub 2} thin films prepared under normal and oblique incidence deposition geometries

    SciTech Connect (OSTI)

    Sarkar, P. Tokas, R. B. Jena, S. Thakur, S. Sahoo, N. K.

    2014-04-24

    Oblique angle deposited optical thin films have attracted recent researchers interest because of their attractive optical, micro-structural, mechanical properties and more importantly because of their great potential in achieving tunability in refractive index. These properties in turn make it important in case of designing different optical devices. In the present work, ZrO{sub 2} thin films have been deposited on fused silica substrate by electron beam evaporation technique in normal as well as oblique angle deposition configurations. Optical properties, especially refractive index of the films have been estimated by fitting the measured transmission spectra with suitable theoretical dispersion models. Atomic force microscopy has been employed to characterize morphological properties of samples. The elastic properties of both the films are estimated by Atomic Force Acoustic Microscopy, a new and highly sensitive technique for thin films.

  17. Growth mechanism and optical properties of Ti thin films deposited onto fluorine-doped tin oxide glass substrate

    SciTech Connect (OSTI)

    Einollahzadeh-Samadi, Motahareh; Dariani, Reza S.

    2015-03-15

    In this work, a detailed study of the influence of the thickness on the morphological and optical properties of titanium (Ti) thin films deposited onto rough fluorine-doped tin oxide glass by d.c. magnetron sputtering is carried out. The films were characterized by several methods for composition, crystallinity, morphology, and optical properties. Regardless of the deposition time, all the studied Ti films of 400, 1500, 2000, and 2500?nm in thickness were single crystalline in the ?-Ti phase and also very similar to each other with respect to composition. Using the atomic force microscopy (AFM) technique, the authors analyzed the roughness evolution of the Ti films characteristics as a function of the film thickness. By applying the dynamic scaling theory to the AFM images, a steady growth roughness exponent ??=?0.72??0.02 and a dynamic growth roughness exponent ??=?0.22??0.02 were determined. The value of ? and ? are consistent with nonlinear growth model incorporating random deposition with surface diffusion. Finally, measuring the reflection spectra of the samples by a spectrophotometer in the spectral range of 3001100?nm allowed us to investigate the optical properties. The authors observed the increments of the reflection of Ti films with thickness, which by employing the effective medium approximation theory showed an increase in thickness followed by an increase in the volume fraction of metal.

  18. A New Approach to Modeling Aerosol Effects on East Asian Climate: Parametric Uncertainties Associated with Emissions, Cloud Microphysics and their Interactions

    SciTech Connect (OSTI)

    Yan, Huiping; Qian, Yun; Zhao, Chun; Wang, Hailong; Wang, Minghuai; Yang, Ben; Liu, Xiaohong; Fu, Qiang

    2015-09-16

    In this study, we adopt a parametric sensitivity analysis framework that integrates the quasi-Monte Carlo parameter sampling approach and a surrogate model to examine aerosol effects on the East Asian Monsoon climate simulated in the Community Atmosphere Model (CAM5). A total number of 256 CAM5 simulations are conducted to quantify the model responses to the uncertain parameters associated with cloud microphysics parameterizations and aerosol (e.g., sulfate, black carbon (BC), and dust) emission factors and their interactions. Results show that the interaction terms among parameters are important for quantifying the sensitivity of fields of interest, especially precipitation, to the parameters. The relative importance of cloud-microphysics parameters and emission factors (strength) depends on evaluation metrics or the model fields we focused on, and the presence of uncertainty in cloud microphysics imposes an additional challenge in quantifying the impact of aerosols on cloud and climate. Due to their different optical and microphysical properties and spatial distributions, sulfate, BC, and dust aerosols have very different impacts on East Asian Monsoon through aerosol-cloud-radiation interactions. The climatic effects of aerosol do not always have a monotonic response to the change of emission factors. The spatial patterns of both sign and magnitude of aerosol-induced changes in radiative fluxes, cloud, and precipitation could be different, depending on the aerosol types, when parameters are sampled in different ranges of values. We also identify the different cloud microphysical parameters that show the most significant impact on climatic effect induced by sulfate, BC and dust, respectively, in East Asia.

  19. Aerodynamic Focusing Of High-Density Aerosols

    SciTech Connect (OSTI)

    Ruiz, D. E.; Fisch, Nathaniel

    2014-02-24

    High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

  20. Structural characterization and novel optical properties of defect chalcopyrite ZnGa{sub 2}Te{sub 4} thin films

    SciTech Connect (OSTI)

    Fouad, S.S.; Sakr, G.B.; Yahia, I.S.; Basset, D.M. Abdel

    2011-11-15

    Highlights: {yields} Preparation and characterization of ZnGa{sub 2}Te{sub 4} in powder and thin film forms. {yields} Structure properties such as XRD and EDX. {yields} Optical constant of the as-deposited ZnGa{sub 2}Te{sub 4} for the first time. {yields} Extraction of the optical parameters of the studied films. -- Abstract: Stoichiometric thin film samples of the ternary ZnGa{sub 2}Te{sub 4} defect chalcopyrite compound were prepared and characterized by X-ray diffraction technique. The elemental chemical composition of the prepared bulk material as well as of the as-deposited film was determined by energy-dispersive X-ray spectrometry. ZnGa{sub 2}Te{sub 4} thin films were deposited, by conventional thermal evaporation technique onto highly cleaned glass substrates. The X-ray and electron diffraction studies revealed that the as-deposited and the annealed ZnGa{sub 2}Te{sub 4} films at annealing temperature t{sub a} {<=} 548 K are amorphous, while those annealed at t{sub a} {>=} 573 K (for 1 h), are polycrystalline. The optical properties of the as-deposited films have been investigated for the first time at normal incidence in the spectral range from 500 to 2500 nm. The refractive index dispersion in the transmission and low absorption region is adequately described by the Wemple-DiDomenico single oscillator model, whereby, the values of the oscillator parameters have been calculated. The analysis of the optical absorption coefficient revealed an in-direct optical transition with energy of 1.33 eV for the as-deposited sample. This work suggested that ZnGa{sub 2}Te{sub 4} is a good candidate in solar cell devices as an absorbing layer.

  1. ARM - Measurement - Aerosol extinction

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

    extinction ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol extinction The removal of radiant energy from an incident beam by the process of aerosol absorption and/or scattering. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available

  2. ARM - Measurement - Aerosol image

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

    image ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol image Images of aerosols from which one can derive characteristics such as size and shape. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those

  3. Two-Column Aerosol Project

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

    Column Aerosol Project Tiny particles in the sky known as "aerosols" come in many forms-dust, soot, and sea salt, for example. Depending on the type of aerosol, it can either...

  4. Particulate Matter Aerosols

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

    The study of atmospheric aerosols is important because of its adverse effects on health, air quality, visibility, cultural heritage, and Earth's radiation balance. Techniques that...

  5. ARM - Measurement - Aerosol composition

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

    quality assurance purposes. ARM Instruments PILS : Particle Into Liquid Sampler TDMA : Tandem Differential Mobility Analyzer Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass...

  6. Optical and electronic properties of delafossite CuBO{sub 2}p-type transparent conducting oxide

    SciTech Connect (OSTI)

    Ruttanapun, Chesta E-mail: krchesta@kmitl.ac.th

    2013-09-21

    CuBO{sub 2} delafossite was prepared by solid state reaction and calcined/sintered at 1005?C. The optical properties of this p-type transparent conducting oxide were investigated. Its crystal structure, morphology, composition, oxygen decomposition, and optical and electronic properties were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, thermal gravimetric analysis (TGA), ultraviolet-visible-near-infrared (UV-VIS-NIR) and fluorescence spectroscopies, Seebeck coefficient, and electrical conductivity measurements. CuBO{sub 2} delafossite possesses a hexagonal space group R3{sup }m. TGA indicated a weight loss of 10%, which was attributed to excess oxygen. The positive Seebeck coefficient confirmed p-type behavior. Emission at 355?nm indicated a direct band type transition, and the UV-VIS-NIR spectrum indicated an optical direct gap of 3.6?eV. Activation energies for carrier production and electrical conduction were 0.147 and 0.58?eV, respectively, indicating the thermal activation of carriers. CuBO{sub 2} delafossite is a p-type transparent conducting oxide with a wide band gap and may have potential in industrial p-type electrodes.

  7. Investigation of optical limiting properties of Aluminium nanoparticles prepared by pulsed laser ablation in different carrier media

    SciTech Connect (OSTI)

    Kuladeep, Rajamudili; Jyothi, L.; Narayana Rao, D.; Prakash, P.; Mayank Shekhar, S.; Durga Prasad, M.

    2013-12-28

    In this communication, we carried out the systematic investigation of nonlinear absorption and scattering properties of Aluminium nanoparticles (Al NPs) in various polar and non-polar solvents. Al NPs were synthesized with pulsed Nd:YAG laser operated at 1064 nm by ablating Al target in polar and non-polar liquid environment like chloroform, chlorobenzene, toluene, benzene, and carbon tetrachloride. Synthesized Al NPs colloids of various solvents differ in appearance and UV-Vis extinction spectra exhibit absorption in the UV region. The characterization of Al NPs performed by Transmission electron microscopy (TEM) studies reveal that NPs are made up of a well crystallized Al inner part (bright zone) embedded with an amorphous metal Al shell (dark region). Growth, aggregation, and precipitation mechanisms which influence the optical properties and stability of NPs are found to be related to the dipole moment of the surrounding liquid environment. The nonlinear absorption and scattering studies are performed by open aperture Z-scan technique with 532 nm under nanosecond pulse excitation. The Z-scan measurements are fitted theoretically to estimate both two-photon absorption (TPA) and nonlinear scattering (NLS) coefficients. In polar solvents like chlorobenzene, chloroform synthesized Al NPs exhibited higher TPA, NLS coefficient values, and lower optical limiting threshold values in comparison with partially polar solvent like toluene and non-polar solvents like benzene and carbontetrachloride. These results indicate the potential use of Al NPs as a versatile optical limiting material.

  8. A theoretical analysis of the optical absorption properties in one-dimensional InAs/GaAs quantum dot superlattices

    SciTech Connect (OSTI)

    Kotani, Teruhisa; Birner, Stefan; Lugli, Paolo; Hamaguchi, Chihiro

    2014-04-14

    We present theoretical investigations of miniband structures and optical properties of InAs/GaAs one-dimensional quantum dot superlattices (1D-QDSLs). The calculation is based on the multi-band kp theory, including the conduction and valence band mixing effects, the strain effect, and the piezoelectric effect; all three effects have periodic boundary conditions. We find that both the electronic and optical properties of the 1D-QDSLs show unique states which are different from those of well known single quantum dots (QDs) or quantum wires. We predict that the optical absorption spectra of the 1D-QDSLs strongly depend on the inter-dot spacing because of the inter-dot carrier coupling and changing strain states, which strongly influence the conduction and valence band potentials. The inter-miniband transitions form the absorption bands. Those absorption bands can be tuned from almost continuous (closely stacked QD case) to spike-like shape (almost isolated QD case) by changing the inter-dot spacing. The polarization of the lowest absorption peak for the 1D-QDSLs changes from being parallel to the stacking direction to being perpendicular to the stacking direction as the inter-dot spacing increases. In the case of closely stacked QDs, in-plane anisotropy, especially [110] and [11{sup }0] directions also depend on the inter-dot spacing. Our findings and predictions will provide an additional degree of freedom for the design of QD-based optoelectronic devices.

  9. Radiative and thermodynamic responses to aerosol extinction profiles during the pre-monsoon month over South Asia

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

    Feng, Y.; Kotamarthi, V. R.; Coulter, R.; Zhao, C.; Cadeddu, M.

    2015-06-19

    Aerosol radiative effects and thermodynamic responses over South Asia are examined with a version of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) for March 2012. Model results of Aerosol Optical Depth (AOD) and extinction profiles are analyzed and compared to satellite retrievals and two ground-based lidars located in the northern India. The WRF-Chem model is found to underestimate the AOD during the simulated pre-monsoon month and about 83 % of the model low-bias is due to aerosol extinctions below ~2 km. Doubling the calculated aerosol extinctions below 850 hPa generates much better agreement with the observed AODmore » and extinction profiles averaged over South Asia. To separate the effect of absorption and scattering properties, two runs were conducted: in one run (Case I), the calculated scattering and absorption coefficients were increased proportionally, while in the second run (Case II) only the calculated aerosol scattering coefficient was increased. With the same AOD and extinction profiles, the two runs produce significantly different radiative effects over land and oceans. On the regional mean basis, Case I generates 48 % more heating in the atmosphere and 21 % more dimming at the surface than Case II. Case I also produces stronger cooling responses over the land from the longwave radiation adjustment and boundary layer mixing. These rapid adjustments offset the stronger radiative heating in Case I and lead to an overall lower-troposphere cooling up to -0.7 K day−1, which is smaller than that in Case II. Over the ocean, direct radiative effects dominate the heating rate changes in the lower atmosphere lacking such surface and lower atmosphere adjustments due to fixed sea surface temperature, and the strongest atmospheric warming is obtained in Case I. Consequently, atmospheric dynamics (boundary layer heights and meridional circulation) and thermodynamic processes (water vapor and cloudiness) are shown to respond differently between Case I and Case II underlying the importance of determining the exact portion of scattering or absorbing aerosols that lead to the underestimation of aerosol optical depth in the model. In addition, the model results suggest that both direct radiative effect and rapid thermodynamic responses need to be quantified for understanding aerosol radiative impacts.« less

  10. Radiative and thermodynamic responses to aerosol extinction profiles during the pre-monsoon month over South Asia

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

    Feng, Y.; Kotamarthi, V. R.; Coulter, R.; Zhao, C.; Cadeddu, M.

    2015-06-19

    Aerosol radiative effects and thermodynamic responses over South Asia are examined with a version of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) for March 2012. Model results of Aerosol Optical Depth (AOD) and extinction profiles are analyzed and compared to satellite retrievals and two ground-based lidars located in the northern India. The WRF-Chem model is found to underestimate the AOD during the simulated pre-monsoon month and about 83 % of the model low-bias is due to aerosol extinctions below ~2 km. Doubling the calculated aerosol extinctions below 850 hPa generates much better agreement with the observed AODmoreand extinction profiles averaged over South Asia. To separate the effect of absorption and scattering properties, two runs were conducted: in one run (Case I), the calculated scattering and absorption coefficients were increased proportionally, while in the second run (Case II) only the calculated aerosol scattering coefficient was increased. With the same AOD and extinction profiles, the two runs produce significantly different radiative effects over land and oceans. On the regional mean basis, Case I generates 48 % more heating in the atmosphere and 21 % more dimming at the surface than Case II. Case I also produces stronger cooling responses over the land from the longwave radiation adjustment and boundary layer mixing. These rapid adjustments offset the stronger radiative heating in Case I and lead to an overall lower-troposphere cooling up to -0.7 K day?1, which is smaller than that in Case II. Over the ocean, direct radiative effects dominate the heating rate changes in the lower atmosphere lacking such surface and lower atmosphere adjustments due to fixed sea surface temperature, and the strongest atmospheric warming is obtained in Case I. Consequently, atmospheric dynamics (boundary layer heights and meridional circulation) and thermodynamic processes (water vapor and cloudiness) are shown to respond differently between Case I and Case II underlying the importance of determining the exact portion of scattering or absorbing aerosols that lead to the underestimation of aerosol optical depth in the model. In addition, the model results suggest that both direct radiative effect and rapid thermodynamic responses need to be quantified for understanding aerosol radiative impacts.less

  11. Radiative and thermodynamic responses to aerosol extinction profiles during the pre-monsoon month over South Asia

    SciTech Connect (OSTI)

    Feng, Y.; Kotamarthi, V. R.; Coulter, R.; Zhao, C.; Cadeddu, M.

    2015-06-19

    Aerosol radiative effects and thermodynamic responses over South Asia are examined with a version of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) for March 2012. Model results of Aerosol Optical Depth (AOD) and extinction profiles are analyzed and compared to satellite retrievals and two ground-based lidars located in the northern India. The WRF-Chem model is found to underestimate the AOD during the simulated pre-monsoon month and about 83 % of the model low-bias is due to aerosol extinctions below ~2 km. Doubling the calculated aerosol extinctions below 850 hPa generates much better agreement with the observed AOD and extinction profiles averaged over South Asia. To separate the effect of absorption and scattering properties, two runs were conducted: in one run (Case I), the calculated scattering and absorption coefficients were increased proportionally, while in the second run (Case II) only the calculated aerosol scattering coefficient was increased. With the same AOD and extinction profiles, the two runs produce significantly different radiative effects over land and oceans. On the regional mean basis, Case I generates 48 % more heating in the atmosphere and 21 % more dimming at the surface than Case II. Case I also produces stronger cooling responses over the land from the longwave radiation adjustment and boundary layer mixing. These rapid adjustments offset the stronger radiative heating in Case I and lead to an overall lower-troposphere cooling up to -0.7 K day?1, which is smaller than that in Case II. Over the ocean, direct radiative effects dominate the heating rate changes in the lower atmosphere lacking such surface and lower atmosphere adjustments due to fixed sea surface temperature, and the strongest atmospheric warming is obtained in Case I. Consequently, atmospheric dynamics (boundary layer heights and meridional circulation) and thermodynamic processes (water vapor and cloudiness) are shown to respond differently between Case I and Case II underlying the importance of determining the exact portion of scattering or absorbing aerosols that lead to the underestimation of aerosol optical depth in the model. In addition, the model results suggest that both direct radiative effect and rapid thermodynamic responses need to be quantified for understanding aerosol radiative impacts.

  12. Optical and electrical properties of Mg-doped AlN nanowires grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Connie, Ashfiqua Tahseen; Zhao, Songrui; Sadaf, Sharif Md.; Shih, Ishiang; Mi, Zetian; Du, Xiaozhang; Lin, Jingyu; Jiang, Hongxing

    2015-05-25

    In this paper, the optical and electrical properties of Mg-doped AlN nanowires are discussed. At room temperature, with the increase of Mg-doping concentration, the Mg-acceptor energy level related optical transition can be clearly measured, which is separated about 0.6?eV from the band-edge transition, consistent with the Mg activation energy in AlN. The electrical conduction measurements indicate an activation energy of 23?meV at 300?K450?K temperature range, which is significantly smaller than the Mg-ionization energy in AlN, suggesting the p-type conduction being mostly related to hopping conduction. The free hole concentration of AlN:Mg nanowires is estimated to be on the order of 10{sup 16?}cm{sup ?3}, or higher.

  13. Ellipsometric characterization and density-functional theory analysis of anisotropic optical properties of single-crystal ?-SnS

    SciTech Connect (OSTI)

    Banai, R. E.; Brownson, J. R. S.; Burton, L. A.; Walsh, A.; Choi, S. G. To, B.; Hofherr, F.; Sorgenfrei, T.; Crll, A.

    2014-07-07

    We report on the anisotropic optical properties of single-crystal tin monosulfide (SnS). The components ?{sub a}, ?{sub b}, and ?{sub c} of the pseudodielectric-function tensor (?)=(??)+i(??) spectra are taken from 0.73 to 6.45 eV by spectroscopic ellipsometry. The measured (?) spectra are in a good agreement with the results of the calculated dielectric response from hybrid density functional theory. The (?) spectra show the direct band-gap onset and a total of eight above-band-gap optical structures that are associated with the interband-transition critical points (CPs). We obtain accurate CP energies by fitting analytic CP expressions to second-energy-derivatives of the (?) data. Their probable electronic origins and implications for photovoltaic applications are discussed.

  14. ULTRA-HIGH TEMPERATURE SENSORS BASED ON OPTICAL PROPERTY MODULATION AND VIBRATION-TOLERANT INTERFEROMETRY

    SciTech Connect (OSTI)

    Nabeel A. Riza

    2005-07-22

    The goals of the first six months of this project were to begin laying the foundations for both the SiC front-end optical chip fabrication techniques for high pressure gas species sensing as well as the design, assembly, and test of a portable high pressure high temperature calibration test cell chamber for introducing gas species. This calibration cell will be used in the remaining months for proposed first stage high pressure high temperature gas species sensor experimentation and data processing. All these goals have been achieved and are described in detail in the report. Both design process and diagrams for the mechanical elements as well as the optical systems are provided. Photographs of the fabricated calibration test chamber cell, the optical sensor setup with the calibration cell, the SiC sample chip holder, and relevant signal processing mathematics are provided. Initial experimental data from both the optical sensor and fabricated test gas species SiC chips is provided. The design and experimentation results are summarized to give positive conclusions on the proposed novel high temperature high pressure gas species detection optical sensor technology.

  15. The influence of Cd doping on the microstructure and optical properties of nanocrystalline copper ferrite thin films

    SciTech Connect (OSTI)

    El-Hagary, M.; Matar, A.; Shaaban, E.R.; Emam-Ismail, M.

    2013-06-01

    Highlights: ? The structural and optical properties of Cu{sub 1?x}Cd{sub x}Fe{sub 2}O{sub 4} thin films were studied. ? The micro structural parameters of the films have been determined. ? The room temperature reflectance and transmittance data are analyzed. ? The refractive index and energy gap are determined. ? The single oscillator parameters were calculated. - Abstract: Nanocrystalline thin films of mixed CuCd ferrites, Cu{sub 1?x}Cd{sub x}Fe{sub 2}O{sub 4} (x = 0, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9 and 1), were deposited by electron beam evaporation technique. The films were annealed at 450 C for 1 h. The effect of Cd doping on the structural and optical properties of the deposited films has been investigated by using X-ray diffraction (XRD) and optical spectrophotometry. XRD patterns of the annealed films show spinal cubic structure. The lattice parameter was found to increase with the increase of cadmium concentration. The crystallite size of the films was found to vary from 8 nm to 30 nm. The optical transition was found to be direct and indirect transitions with energy gaps decrease from 2.466 (x = 0) to 2.00 (x = 1) eV and from 2.148 (x = 0) to 1.824 (x = 1) eV, respectively. The refractive index dispersion of the films was found to increase with Cd content and discussed in terms of the WempleDiDomenico single oscillator model.

  16. Portable Aerosol Contaminant Extractor

    DOE Patents [OSTI]

    Carlson, Duane C. (N. Augusta, SC); DeGange, John J. (Aiken, SC); Cable-Dunlap, Paula (Waynesville, NC)

    2005-11-15

    A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

  17. Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

    DOE Patents [OSTI]

    Pipino, Andrew C. R. (Gaithersburg, MD); Hudgens, Jeffrey W. (Rockville, MD)

    1999-08-24

    An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

  18. Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

    DOE Patents [OSTI]

    Pipino, Andrew Charles Rule (Gaithersburg, MD)

    1999-11-16

    An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

  19. Systems and methods for optically measuring properties of hydrocarbon fuel gases

    DOE Patents [OSTI]

    Adler-Golden, Steven (Newtonville, MA); Bernstein, Lawrence S. (Lexington, MA); Bien, Fritz (Concord, MA); Gersh, Michael E. (Bedford, MA); Goldstein, Neil (Belmont, MA)

    1998-10-13

    A system and method for optical interrogation and measurement of a hydrocarbon fuel gas includes a light source generating light at near-visible wavelengths. A cell containing the gas is optically coupled to the light source which is in turn partially transmitted by the sample. A spectrometer disperses the transmitted light and captures an image thereof. The image is captured by a low-cost silicon-based two-dimensional CCD array. The captured spectral image is processed by electronics for determining energy or BTU content and composition of the gas. The innovative optical approach provides a relatively inexpensive, durable, maintenance-free sensor and method which is reliable in the field and relatively simple to calibrate. In view of the above, accurate monitoring is possible at a plurality of locations along the distribution chain leading to more efficient distribution.

  20. Systems and methods for optically measuring properties of hydrocarbon fuel gases

    DOE Patents [OSTI]

    Adler-Golden, S.; Bernstein, L.S.; Bien, F.; Gersh, M.E.; Goldstein, N.

    1998-10-13

    A system and method for optical interrogation and measurement of a hydrocarbon fuel gas includes a light source generating light at near-visible wavelengths. A cell containing the gas is optically coupled to the light source which is in turn partially transmitted by the sample. A spectrometer disperses the transmitted light and captures an image thereof. The image is captured by a low-cost silicon-based two-dimensional CCD array. The captured spectral image is processed by electronics for determining energy or BTU content and composition of the gas. The innovative optical approach provides a relatively inexpensive, durable, maintenance-free sensor and method which is reliable in the field and relatively simple to calibrate. In view of the above, accurate monitoring is possible at a plurality of locations along the distribution chain leading to more efficient distribution. 14 figs.

  1. Mid infrared optical properties of Ge/Si quantum dots with different doping level

    SciTech Connect (OSTI)

    Sofronov, A. N.; Firsov, D. A.; Vorobjev, L. E.; Shalygin, V. A.; Panevin, V. Yu.; Vinnichenko, M. Ya.; Tonkikh, A. A.; Danilov, S. N.

    2013-12-04

    Optical characterization of the Ge/Si quantum dots using equilibrium and photo-induced absorption spectroscopy in the mid-infrared spectral range was performed in this work. Equilibrium absorption spectra were measured in structures with various doping levels for different light polarizations. Photo-induced absorption spectra measured in undoped structure under interband optical excitation of non-equilibrium charge carriers demonstrate the same features as doped sample in equilibrium conditions. Hole energy spectrum was determined from the analysis of experimental data.

  2. Study of in-duct spray drying using condensation aerosol

    SciTech Connect (OSTI)

    Chen, W.J.R.; Chang, S.M.; Adikesavalu, R. )

    1992-06-01

    Sulfur removal efficiency of in-duct spray drying is limited by sorbent content and surface properties of the sorbent-water aerosol. It was the purpose of this study to improve the sulfur removal efficiency for in-duct spray drying by injecting condensation aerosol instead of conventional dispersion aerosol. The program was composed of three phases. In Phase I, a novel pulsed fluid bed feeder was developed and was used to feed hydrated lime for subsequent experiments. A small condensation aerosol generator was then built, which produces a lime-water condensation aerosol by condensing steam on lime particles. The results show that novel lime-water aerosols less than 10 microns were generated. The central task in Phase II was to simulate experimentally in-duct spray drying using condensation aerosols and compare the results with those using dispersion aerosols reported in the literature. A small entrained-flow reactor was constructed to simulate an in-duct spray dryer. The condensation aerosol was then introduced to the reactor at various approach to saturation temperature, calcium/sulfur stoichiometry and sulfur dioxide concentration for desulfurization study. The results show that we have improved the sulfur removal efficiency for in-duct spray drying to 90 percent or above. Thus we have met and exceeded the stated project goal of 70 percent sulfur removal. A comprehensive computer code was employed to calculate sulfur removal efficiency in Phase III.

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

    SciTech Connect (OSTI)

    Soltani, A. Stolz, A.; Gerbedoen, J.-C.; Rousseau, M.; Bourzgui, N.; De Jaeger, J.-C.; Charrier, J.; Mattalah, M.; Barkad, H. A.; Mortet, V.

    2014-04-28

    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.

  4. Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds

    SciTech Connect (OSTI)

    McFarquhar, Greg; Ghan, Steven J.; Verlinde, J.; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Mengistu; Brooks, Sarah D.; Cziczo, Daniel J.; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor J.; Gultepe, Ismail; Hubbe, John M.; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. R.; Liu, Peter S.; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, A. M.; Moffet, Ryan C.; Morrison, H.; Ovchinnikov, Mikhail; Shupe, Matthew D.; Turner, David D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matthew; Glen, Andrew

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic boundary layer in the vicinity of Barrow, Alaska was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) sponsored by the Department of Energy Atmospheric Radiation Measurement (ARM) and Atmospheric Science Programs. The primary aim of ISDAC was to examine indirect effects of aerosols on clouds that contain both liquid and ice water. The experiment utilized the ARM permanent observational facilities at the North Slope of Alaska (NSA) in Barrow. These include a cloud radar, a polarized micropulse lidar, and an atmospheric emitted radiance interferometer as well as instruments specially deployed for ISDAC measuring aerosol, ice fog, precipitation and spectral shortwave radiation. The National Research Council of Canada Convair-580 flew 27 sorties during ISDAC, collecting data using an unprecedented 42 cloud and aerosol instruments for more than 100 hours on 12 different days. Data were obtained above, below and within single-layer stratus on 8 April and 26 April 2008. These data enable a process-oriented understanding of how aerosols affect the microphysical and radiative properties of arctic clouds influenced by different surface conditions. Observations acquired on a heavily polluted day, 19 April 2008, are enhancing this understanding. Data acquired in cirrus on transit flights between Fairbanks and Barrow are improving our understanding of the performance of cloud probes in ice. Ultimately the ISDAC data will be used to improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and to determine the extent to which long-term surface-based measurements can provide retrievals of aerosols, clouds, precipitation and radiative heating in the Arctic.

  5. Aerosol Retrievals from ARM SGP MFRSR Data

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

    Alexandrov, Mikhail

    2008-01-15

    The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous measurements of the solar direct normal and diffuse horizontal irradiances at six wavelengths (nominally 415, 500, 615, 673, 870, and 940 nm) at short intervals (20 sec for ARM instruments) throughout the day. Time series of spectral optical depth are derived from these measurements. Besides water vapor at 940 nm, the other gaseous absorbers within the MFRSR channels are NO2 (at 415, 500, and 615 nm) and ozone (at 500, 615, and 670 nm). Aerosols and Rayleigh scattering contribute atmospheric extinction in all MFRSR channels. Our recently updated MFRSR data analysis algorithm allows us to partition the spectral aerosol optical depth into fine and coarse modes and to retrieve the fine mode effective radius. In this approach we rely on climatological amounts of NO2 from SCIAMACHY satellite retrievals and use daily ozone columns from TOMS.

  6. Electronic structure and optical properties of ?-(Fe1-xVx)2O3 solid-solution thin films

    SciTech Connect (OSTI)

    Chamberlin, Sara E.; Nayyar, Iffat H.; Kaspar, Tiffany C.; Sushko, Petr; Chambers, Scott A.

    2015-01-26

    We have examined the effect of V doping on the electronic and optical properties of hematite (?-Fe2O3) by means of ?-(Fe1-xVx)2O3 (0 ? x ? ~0.5) epitaxial films and theoretical modeling. The conductivity is enhanced by several orders of magnitude as x is increased, and this enhancement is manifested in x-ray photoelectron spectra by a growing Doniach-Sunjic tail on the O 1s peak, as well as by increasing intensity at the Fermi level in valence band spectra. Optical absorption shows a reduction in direct band gap by as much as 0.64 eV for x = 0.53 (Eg = 1.46 eV) relative to that of ?-Fe2O3 (Eg = 2.10 eV). Detailed understanding of the character of the optical transitions in the alloys is achieved using first-principles calculations of the ground and excited states. These calculations reveal that V doping results in localized, occupied V 3d states which are hybridized with Fe states and located at approximately mid-gap in ? Fe2O3. The lowest energy transitions involve electronic excitations from occupied V 3d orbitals to unoccupied Fe 3d* orbitals.

  7. Synthesis and evaluation of optical and electrochemical properties of a new conjugated polymer containing substituted thiophene and non-conjugation linkers

    SciTech Connect (OSTI)

    R, Prashanth Kumar K D, Udayakumar; K, Siji Narendran N; K, Chandrasekharan

    2014-10-15

    Conjugated polymers have been developed in a variety of applied fields owing to their promising optoelectronic properties. These are pursuing considerable interest as opto-electrical material because of their chemical stability and processability. This paper describes the synthesis and study of electro-optical properties of a new donoracceptor polymer composed of substituted thiophene and 4,4?-propane-2,2-diyldiphenol units as electron rich moieties and 1,3,4-oxadiazole unit as electron deficient moiety. The optical properties of the polymer are studied using UV-visible absorption spectroscopy and fluorescent emission spectroscopy. From the electrochemical data, HOMO and LUMO energy levels of the polymer are calculated.

  8. Effects of graphene oxide concentration on optical properties of ZnO/RGO nanocomposites and their application to photocurrent generation

    SciTech Connect (OSTI)

    Azarang, Majid, E-mail: azarangmajid@gmail.com, E-mail: azarang@phys.usb.ac.ir [Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Physics, University of Sistan and Baluchestan, 98135-674 Zahedan (Iran, Islamic Republic of); Shuhaimi, Ahmad; Sookhakian, M. [Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Yousefi, Ramin, E-mail: Yousefi.ramin@gmail.com, E-mail: raminyousefi@iaumis.ac.ir [Department of Physics, Masjed-Soleiman Branch, Islamic Azad University (I.A.U), Masjed-Soleiman (Iran, Islamic Republic of)

    2014-08-28

    The effects of different concentrations of graphene oxide (GO) on the structure and optical properties of ZnO nanoparticles (NPs) were investigated. The nanocomposites were synthesized via the sol-gel method in a gelatin medium. X-ray diffraction patterns (XRD) and Fourier transform infrared spectroscopy indicated that the GO sheets were reduced and changed to reduced GO (RGO) during the calcination of the nanocomposites at 400?C. In addition, the XRD patterns of the NPs indicated a hexagonal (wurtzite) structure for all the products. Microscopic studies showed that the NPs were decorated and dispersed on the RGO sheets very well. However, these studies revealed that the RGO concentration had an effect on the crystal growth process for the ZnO NPs. Furthermore, these studies showed that the NPs could be grown with a single crystal quality in an optimum RGO concentration. According to the XRD results that were obtained from pure ZnO NPs, the calcinations temperature was decreased by the RGO. UVvis and room temperature photoluminescence studies showed that the optical properties of the ZnO/RGO nanocomposite were affected by the RGO concentration. Finally, the obtained ZnO/RGO nanocomposite was used to generate a photocurrent. Observations showed that the photocurrent intensity of the nanocomposite was significantly increased by increasing the RGO, with an optimum RGO concentration.

  9. Structural and optical properties of CdO thin films deposited by RF magnetron sputtering technique

    SciTech Connect (OSTI)

    Kumar, G. Anil Reddy, M. V. Ramana; Reddy, Katta Narasimha

    2014-04-24

    Cadmium oxide (CdO) thin films were deposited on glass substrate by r.f. magnetron sputtering technique using a high purity (99.99%) Cd target of 2-inch diameter and 3 mm thickness in an Argon and oxygen mixed atmosphere with sputtering power of 50W and sputtering pressure of 210{sup ?2} mbar. The prepared films were characterized by X-ray diffraction (XRD), optical spectroscopy and scanning electron microscopy (SEM). The XRD analysis reveals that the films were polycrystalline with cubic structure. The visible range transmittance was found to be over 70%. The optical band gap increased from 2.7 eV to2.84 eV with decrease of film thickness.

  10. Optical properties of {gamma}- and {alpha}-Ce by spectroscopic ellipsometry

    SciTech Connect (OSTI)

    Joo Yull, Rhee

    1992-07-20

    A rotating analyzer type ellipsometer with an ultra high vacuum sample chamber was built. The dielectric functions of {gamma}- and {alpha}-Ce were measured in the energy range from 1.5 to 5.4 eV to investigate the role of the 4f electron in the isostructural phase transition. {gamma}- and {alpha}-Ce were made by evaporation of Ce on sapphire substrates at room temperature and 25 K. All measurements were performed inside a UHV chamber at pressures lower than l {times} 10{sup {minus}10}Torr. The measured dielectric functions showed a thickness dependence. The thicker sample has the smaller optical conductivities. Both overlayer thickness and void fraction increase as sample thickness increases. Repeating cooling-heating-cooling or heating-cooling-heating cycles causes the sample surface to become rougher but the relative volume fractions of both phases and the void fraction in the bulk remain unchanged. The optical conductivity increases upon entering the a-phase but the number of electrons per atom, N{sub eff}/N{sub A}, contributing to the optical conductivity does not change. The valence electrons lose oscillator strength in the above energy range due to volume collapse. This reduces N{sub eff}/NA but the increased 4f-sd valence band hybridization exactly compensates the reduced oscillator strength. Therefore the net effects of the {gamma}{yields}{alpha} isostructural phase transition are an increase of optical conductivity and constancy of N{sub eff}/N{sub A}.

  11. Structural and optical properties of DC reactive magnetron sputtered zinc aluminum oxide thin films

    SciTech Connect (OSTI)

    Kumar, B. Rajesh; Rao, T. Subba

    2014-10-15

    Highly transparent conductive Zinc Aluminum Oxide (ZAO) thin films have been deposited on glass substrates using DC reactive magnetron sputtering method. The thin films were deposited at 200 C and post-deposition annealing from 15 to 90 min. XRD patterns of ZAO films exhibit only (0 0 2) diffraction peak, indicating that they have c-axis preferred orientation perpendicular to the substrate. Scanning electron microscopy (SEM) is used to study the surface morphology of the films. The grain size obtained from SEM images of ZAO thin films are found to be in the range of 20 - 26 nm. The minimum resistivity of 1.74 10{sup ?4} ? cm and an average transmittance of 92% are obtained for the thin film post annealed for 30 min. The optical band gap of ZAO thin films increased from 3.49 to 3.60 eV with the increase of annealing time due to Burstein-Moss effect. The optical constants refractive index (n) and extinction coefficient (k) were also determined from the optical transmission spectra.

  12. ARM - Measurement - Aerosol absorption

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

    absorption ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol absorption The...

  13. Monodisperse aerosol generator

    DOE Patents [OSTI]

    Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  14. Aerosol remote sensing in polar regions

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

    Tomasi, Claudio; Kokhanovsky, Alexander A.; Lupi, Angelo; Ritter, Christoph; Smirnov, Alexander; O'Neill, Norman T.; Stone, Robert S.; Holben, Brent N.; Nyeki, Stephan; Wehrli, Christoph; et al

    2015-01-01

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness τ(λ) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent α were calculated. Analysing these data, the monthly mean values of τ(0.50 μm) and α and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of α versus τ(0.50 μm) showed: (i)more » a considerable increase in τ(0.50 μm) for the Arctic aerosol from summer to winter–spring, without marked changes in α; and (ii) a marked increase in τ(0.50 μm) passing from the Antarctic Plateau to coastal sites, whereas α decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of τ(λ) and α at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of τ(λ) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions.« less

  15. Thermal and Optical Properties of Low-E Storm Windows and Panels

    SciTech Connect (OSTI)

    Culp, Thomas D.; Widder, Sarah H.; Cort, Katherine A.

    2015-07-17

    Installing low-emissivity (low-E) storm windows and panels over existing windows has been identified as a cost-effective new approach for improving the energy efficiency of existing buildings where window replacement is impractical or too expensive. As such, it is desirable to characterize the key energy performance properties of low-E storm windows and panels when installed over different types of existing primary windows. this paper presents the representative U-factors, solar heat gain coefficients (SGHCs) and visible transmittance properties of the combined assemblies of various storm windows and panel types installed over different primary windows.

  16. Structure and optical properties of a noncentrosymmetric borate RbSr{sub 4}(BO{sub 3}){sub 3}

    SciTech Connect (OSTI)

    Xia, M.J.; Li, R.K.

    2013-01-15

    A new noncentrosymmetric borate, RbSr{sub 4}(BO{sub 3}){sub 3} (abbreviated as RSBO), has been grown from Rb{sub 2}O--B{sub 2}O{sub 3}--RbF flux and its crystal structure was determined by single crystal x-ray diffraction. It crystallizes in space group Ama2 with cell parameters of a=11.128(10) A, b=12.155(15) A, c=6.952(7) A, Z=4. The basic structural units are isolated planar BO{sub 3} groups. Second harmonic generation (SHG) test of the title compound by the Kurtz-Perry method shows that RSBO can be phase matchable with an effective SHG coefficient about two-thirds as large as that of KH{sub 2}PO{sub 4} (KDP). Finally, based on the anionic group approximation, the optical properties of the title compound are compared with those of the structure-related apatite-like compounds with the formula 'A{sub 5}(TO{sub n}){sub 3}X'. - Graphical abstract: RbSr{sub 4}(BO{sub 3}){sub 3} and some other borate NLO compounds, namely Ca{sub 5}(BO{sub 3}){sub 3}F RCa{sub 4}(BO{sub 3}){sub 3}O (R=Y or Gd) and Na{sub 3}La{sub 2}(BO{sub 3}){sub 3} can be viewed as the derivatives of apatite. They have similar formula composed of five cations and three anion groups (we call them 5/3 structures). The detailed SHG coefficients and optical properties of the apatite-like NLO crystals were compared and summarized. Highlights: Black-Right-Pointing-Pointer A new noncentrosymmetric borate RbSr{sub 4}(BO{sub 3}){sub 3} was grown from flux. Black-Right-Pointing-Pointer The RbSr{sub 4}(BO{sub 3}){sub 3} can be viewed as a derivative of the apatite-like structure. Black-Right-Pointing-Pointer The structure and its relationship to the optical properties of RbSr{sub 4}(BO{sub 3}){sub 3} are compared with other NLO crystals with apatite-like structures. Black-Right-Pointing-Pointer The basic structural units are the planar BO{sub 3} groups in the structure. Black-Right-Pointing-Pointer Second harmonic generation (SHG) test shows that RbSr{sub 4}(BO{sub 3}){sub 3} can be phase matchable with an effective SHG coefficient about two-thirds as large as that of KH{sub 2}PO{sub 4}.

  17. GCM parameterization of radiative forcing by Pinatubo aerosols

    SciTech Connect (OSTI)

    Lacis, A.A.; Mishchenko, M.I.

    1996-12-31

    This paper addresses the question of whether the general circulation model (GCM) parameterization of volcanic aerosol forcing can be adequately described in terms of just two physical aerosol parameters: (1) the aerosol column optical thickness and (2) the effective radius of the aerosol size distribution. Data recorded from the eruption of Mt. Pinatubo in the Philippines in June 1991 was analyzed to attempt to answer this question. The spatial distribution of the particle size showed considerable variability and was found to increase steadily following the eruption. The time evolution of the Pinatubo aerosol particle size distribution as derived from satellite data differed significantly, particularly in the early phases of the eruption, from that assumed in the initial GCM simulation of the Pinatubo eruption. A bimodal distribution was used to examine the possibility that the actual size distribution of the volcanic aerosol was multimodal. However, results suggested that in most cases the aerosol size distribution was essentially monomodal in nature. Results from the radiative model used in the calculations are also presented. 11 refs., 6 figs.

  18. The Radiative Role of Free Tropospheric Aerosols and Marine Clouds over the Central North Atlantic

    SciTech Connect (OSTI)

    Mazzoleni, Claudio; Kumar, Sumit; Wright, Kendra; Kramer, Louisa; Mazzoleni, Lynn; Owen, Robert; Helmig, Detlev

    2014-12-09

    The scientific scope of the project was to exploit the unique location of the Pico Mountain Observatory (PMO) located in the summit caldera of the Pico Volcano in Pico Island in the Azores, for atmospheric studies. The observatory, located at 2225m a.s.l., typically samples free tropospheric aerosols laying above the marine low-level clouds and long-range transported from North America. The broad purpose of this research was to provide the scientific community with a better understanding of fundamental physical processes governing the effects of aerosols on radiative forcing and climate; with the ultimate goal of improving our abilities to understand past climate and to predict future changes through numerical models. The project was 'exploratory' in nature, with the plan to demonstrate the feasibility of deploying for the first time, an extensive aerosol research package at PMO. One of the primary activities was to test the deployment of these instruments at the site, to collect data during the 2012 summer season, and to further develop the infrastructure and the knowledge for performing novel research at PMO in follow-up longer-term aerosol-cloud studies. In the future, PMO could provide an elevated research outpost to support the renewed DOE effort in the Azores that was intensified in 2013 with the opening of the new sea-level ARM-DOE Eastern North Atlantic permanent facility at Graciosa Island. During the project period, extensive new data sets were collected for the planned 2012 season. Thanks to other synergistic activities and opportunities, data collection was then successfully extended to 2013 and 2014. Highlights of the scientific findings during this project include: a) biomass burning contribute significantly to the aerosol loading in the North Atlantic free troposphere; however, long-range transported black carbon concentrations decreased substantially in the last decade. b) Single black carbon particles analyzed off-line at the electron microscope were often very compacted, suggesting cloud processing and exhibiting different optical properties from fresh emissions. In addition, black carbon was found to be sometimes mixed with mineral dust, affecting its optical properties and potential forcing. c) Some aerosols collected at PMO acted as ice nuclei, potentially contributing to cirrus cloud formation during their transport in the upper free troposphere. Identified good ice nuclei were often mineral dust particles. d) The free tropospheric aerosols studied at PMO have relevance to low level marine clouds due, for example, to synoptic subsidence entraining free tropospheric aerosols into the marine boundary layer. This has potentially large consequences on cloud condensation nuclei concentrations and compositions in the marine boundary layer; therefore, having an effect on the marine stratus clouds, with potentially important repercussions on the radiative forcing. The scientific products of this project currently include contributions to two papers published in the Nature Publishing group (Nature Communications and Scientific Reports), one paper under revision for Atmospheric Chemistry and Physics, one in review in Geophysical Research Letters and one recently submitted to Atmospheric Chemistry and Physics Discussion. In addition, four manuscripts are in advanced state of preparation. Finally, twenty-eight presentations were given at international conferences, workshops and seminars.

  19. Optical properties of Pr-doped BaY{sub 2}F{sub 8}

    SciTech Connect (OSTI)

    Andrade, Adriano B. Mello, Ana C. S. de; Valerio, Mrio E. G.; Rezende, Marcos V. dos S.; Baldochi, Sonia L.

    2014-08-07

    Crystalline samples of Pr-doped BaY{sub 2}F{sub 8} (BaYF) were prepared by zone melting technique. The pure phase obtained was identified by X-ray diffraction measurement. Optical absorption result was evaluated and it showed that the formation of the absorption bands can be connected to color centers generated by radiation in the matrix. Radioluminescence emission measurements after excitation by X-ray showed that the material exhibited components responsible for long lasting phosphorescence. Short decay times were also evaluated, the measurements showed a fast component around 70?ns associated to the 4f{sup 1}5d{sup 1} ? 4f{sup 2} transition of the Pr{sup 3+} ion. The Thermoluminescence (TL) results indicate the presence of two trapping centers.

  20. Optical properties of MX chain materials: An extended Peierls-Hubbard model

    SciTech Connect (OSTI)

    Bishop, A.R.; Batistic, I.; Gammel, J.T.; Saxena, A.

    1991-01-01

    We describe theoretical modeling of both pure (MX) and mixed-halide (MX{sub x}X{prime}{sub 1-x}) halogen (X)-bridged transition metal (M) linear chain complexes in terms of an extended Peierls-Hubbard, tight-binding Hamiltonian with 3/4-filling of two-bands. Both inter- and intra-site electron-phonon coupling are included. Electronic (optical absorption), lattice dynamic (IR, Raman) and spin (ESR) signatures are obtained for the ground states, localized excited states produced by impurities, doping or photo-excitation -- excitons, polarons, bipolarons, solitons; and the edge states (which occur in mixed-halide crystals, e.g. PtCl{sub x}Br{sub 1-x}). Adiabatic molecular dynamics is used to explore photodecay channels in pure and impure systems for ground states as well as in the presence of pre-existing polaronic states. 12 refs., 3 figs., 1 tab.

  1. Structural and optical properties of self-assembled chains of plasmonic nanocubes

    SciTech Connect (OSTI)

    Klinkova, Anna; Gang, Oleg; Therien-Aubin, Heloise; Ahmed, Aftab; Nykypanchuk, Dmytro; Choueiri, Rachelle M.; Gagnon, Brandon; Muntyanu, Anastasiya; Walker, Gilbert C.; Kumacheva, Eugenia

    2014-10-10

    Solution-based linear self-assembly of metal nanoparticles offers a powerful strategy for creating plasmonic polymers, which, so far, have been formed from spherical nanoparticles and nanorods. Here, we report linear solution-based self-assembly of metal nanocubes (NCs), examine the structural characteristics of the NC chains and demonstrate their advanced optical characteristics. Predominant face-to-face assembly of large NCs coated with short polymer ligands led to a larger volume of hot spots in the chains, a nearly uniform E-field enhancement in the gaps between co-linear NCs and a new coupling mode for NC chains, in comparison with chains of nanospheres with similar dimensions, composition and surface chemistry. The NC chains exhibited a stronger surface enhanced Raman scattering (SERS) signal, in comparison with linear assemblies of nanospheres. The experimental results were in agreement with finite difference time domain (FDTD) simulations.

  2. Nonlinear-optical and structural properties of nanocrystalline silicon carbide films

    SciTech Connect (OSTI)

    Brodyn, M. S.; Volkov, V. I. Lyakhovetskii, V. R.; Rudenko, V. I.; Puzilkov, V. M.; Semenov, A. V.

    2012-02-15

    The aim of this study is to investigate the nonlinearity of refraction in nanostructured silicon carbide films depending on their structural features (synthesis conditions for such films, substrate temperature during their deposition, concentration of the crystalline phase in the film, Si/C ratio of atomic concentrations in the film, and size of SiC nanocrystals formed in the film). The corresponding dependences are obtained, as well as the values of nonlinear-optical third-order susceptibility {chi}{sup (3)}({omega}; {omega}, -{omega}, {omega}) for various silicon polytypes (3C, 21R, and 27R) which exceed the value of {chi}{sup (3)} in bulk silicon carbide single crystals by four orders of magnitude.

  3. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

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

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited undermore » higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.« less

  4. Structural and optical properties of self-assembled chains of plasmonic nanocubes

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

    Klinkova, Anna; Gang, Oleg; Therien-Aubin, Heloise; Ahmed, Aftab; Nykypanchuk, Dmytro; Choueiri, Rachelle M.; Gagnon, Brandon; Muntyanu, Anastasiya; Walker, Gilbert C.; Kumacheva, Eugenia

    2014-10-10

    Solution-based linear self-assembly of metal nanoparticles offers a powerful strategy for creating plasmonic polymers, which, so far, have been formed from spherical nanoparticles and nanorods. Here, we report linear solution-based self-assembly of metal nanocubes (NCs), examine the structural characteristics of the NC chains and demonstrate their advanced optical characteristics. Predominant face-to-face assembly of large NCs coated with short polymer ligands led to a larger volume of hot spots in the chains, a nearly uniform E-field enhancement in the gaps between co-linear NCs and a new coupling mode for NC chains, in comparison with chains of nanospheres with similar dimensions, compositionmore » and surface chemistry. The NC chains exhibited a stronger surface enhanced Raman scattering (SERS) signal, in comparison with linear assemblies of nanospheres. The experimental results were in agreement with finite difference time domain (FDTD) simulations.« less

  5. Effect of CaF{sub 2} addition on optical properties of barium phosphate glasses

    SciTech Connect (OSTI)

    Kumar, N. Manoj Rao, G. Venkateswara Akhila, B. E. Shashikala, H. D.

    2014-04-24

    Ternary barium phosphate glasses, (50?X)BaO?XCaF{sub 2}?50P{sub 2}O{sub 5} have been prepared by adding 0-10 mol% of CaF{sub 2} to binary barium phosphate glasses. The amorphous nature of the prepared glasses was confirmed by X-ray diffraction technique. The UV-Visible absorption spectra have been recorded, optical band gap energy Eopt and Urbach energy Etail were determined. Shift in Eopt and Etail with increase in concentration of CaF{sub 2} is noted. FTIR analysis was carried out to investigate the short and intermediate-range orders in glasses. Shift of (P-O-P) band to higher wave number with the substitution of BaO with CaF{sub 2} shows the shortening of the phosphate chains. Hardness and density of glass samples were measured and correlated with the composition of glasses.

  6. Structural and optical properties of Sb{sub 2}S{sub 3} nanocrystals in glass

    SciTech Connect (OSTI)

    Mishra, Rakesh K. Kashyap, Raman Vedeshwar, A. G. Tandon, R. P.

    2014-04-24

    In this work conventional solid state precipitation method is adopted to fabricate Sb{sub 2}S{sub 3} nanocrystals in glass. The glass composition is optimized for proper host glass matrix to grow antimony trisulphide semiconductor quantum dots. The dot size is modified by heat treatment of glass samples in the temperature range from 550C to 700C for various time durations. Structural studies are carried out by X-ray diffraction and transmission electron microscopy and nanoparticles with size ranges from 8 nm to 70 nm are obtained. Quantum dots so grown were further characterized by optical absorption spectroscopy and a blue shift is observed for absorption edge energy that conform the quantum confinement effect.

  7. Optical, electrical and surface properties of annealed CdO:Mg thin films prepared by spray pyrolysis

    SciTech Connect (OSTI)

    Karakaya, Seniye E-mail: oozbas@ogu.edu.tr; Ozbas, Omer E-mail: oozbas@ogu.edu.tr

    2013-12-16

    The use of transparent conducting oxides in optoelectronic and photovoltaic devices has encouraged research on this field in recent years. Especially, cadmium oxide is a promising material for solar cell application but also for photodiodes and gas sensors. Mg doped CdO (CdO:Mg) films have been prepared on glass substrates by the ultrasonic spray pyrolysis (USP) technique. After the production, the films have been annealed in air atmosphere at 475C and half hour. Results on surface, optical and electrical properties of the films as a function of the thermal annealing have been reported. Thicknesses of the films have been determined by the filmetrics thin film measurement system. Transmission and absorbance spectra have been taken by UV-vis spectrophotometer. Atomic Force Microscopy (AFM) analysis indicates that the roughness of the surface decreases upon increasing Mg concentration. The minimum resistivity value of the films was 210{sup ?3} ? cm.

  8. Optical properties of chromium and neodymium in zirconium-barium-lanthanum-aluminum fluoride glass. Final report, October 1987-September 1988

    SciTech Connect (OSTI)

    Hanson, F.E.; Caspers, H.H.

    1993-08-01

    The optical properties are reported of chromium and neodymium doped in zirconium-barium-lanthanum-aluminum fluoride glass (ZBLA). The fluorescence of Cr(3+) and of co-doped Cr(3+), Nd(3+) glasses is investigated. Fluorescence decay rates of Cr(3+) and Nd(3+) are measured at various temperatures, and the excitation transfer efficiency between Cr(3+) and Nd(3+) is determined. The absorption spectrum of Nd(3+):ZBLA is characterized in terms of the Judd-Ofelt model of crystal field-induced electric-dipole transitions. The three phenomenological intensity parameters for Nd(3+) in ZBLA glass Omega sub 2,4,6, are compared to those obtained for Nd(3+) in Y3Al5Ol2, Gd3S2Al3Ol2, and LHG-8 glass.

  9. Multicycle rapid thermal annealing optimization of Mg-implanted GaN: Evolution of surface, optical, and structural properties

    SciTech Connect (OSTI)

    Greenlee, Jordan D.; Feigelson, Boris N.; Anderson, Travis J.; Hite, Jennifer K.; Mastro, Michael A.; Eddy, Charles R.; Hobart, Karl D.; Kub, Francis J.; Tadjer, Marko J.

    2014-08-14

    The first step of a multi-cycle rapid thermal annealing process was systematically studied. The surface, structure, and optical properties of Mg implanted GaN thin films annealed at temperatures ranging from 900 to 1200?C were investigated by Raman spectroscopy, photoluminescence, UV-visible spectroscopy, atomic force microscopy, and Nomarski microscopy. The GaN thin films are capped with two layers of in-situ metal organic chemical vapor deposition -grown AlN and annealed in 24 bar of N{sub 2} overpressure to avoid GaN decomposition. The crystal quality of the GaN improves with increasing annealing temperature as confirmed by UV-visible spectroscopy and the full widths at half maximums of the E{sub 2} and A{sub 1} (LO) Raman modes. The crystal quality of films annealed above 1100?C exceeds the quality of the as-grown films. At 1200?C, Mg is optically activated, which is determined by photoluminescence measurements. However, at 1200?C, the GaN begins to decompose as evidenced by pit formation on the surface of the samples. Therefore, it was determined that the optimal temperature for the first step in a multi-cycle rapid thermal anneal process should be conducted at 1150?C due to crystal quality and surface morphology considerations.

  10. Structural and optical properties of (Ag,Cu)(In,Ga)Se{sub 2} polycrystalline thin film alloys

    SciTech Connect (OSTI)

    Boyle, J. H.; Shafarman, W. N.; Birkmire, R. W.; McCandless, B. E.

    2014-06-14

    The structural and optical properties of pentenary alloy (Ag,Cu)(In,Ga)Se{sub 2} polycrystalline thin films were characterized over the entire compositional range at a fixed (Cu?+?Ag)/(In?+?Ga) ratio. Films deposited at 550?C on bare and molybdenum coated soda-lime glass by elemental co-evaporation in a single-stage process with constant incident fluxes exhibit single phase chalcopyrite structure, corresponding to 122 spacegroup (I-42d) over the entire compositional space. Unit cell refinement of the diffraction patterns show that increasing Ag substitution for Cu, the refined a{sub o} lattice constant, (Ag,Cu)-Se bond length, and anion displacement increase in accordance with the theoretical model proposed by Jaffe, Wei, and Zunger. However, the refined c{sub o} lattice constant and (In,Ga)-Se bond length deviated from theoretical expectations for films with mid-range Ag and Ga compositions and are attributed to influences from crystallographic bond chain ordering or cation electronegativity. The optical band gap, derived from transmission and reflection measurements, widened with increasing Ag and Ga content, due to influences from anion displacement and cation electronegativity, as expected from theoretical considerations for pseudo-binary chalcopyrite compounds.

  11. Multishell Au/Ag/SiO2 nanorods with tunable optical properties as single particle orientation and rotational tracking probes

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

    Chen, Kuangcai; Lin, Chia -Cheng; Vela, Javier; Fang, Ning

    2015-04-07

    In this study, three-layer core–shell plasmonic nanorods (Au/Ag/SiO2–NRs), consisting of a gold nanorod core, a thin silver shell, and a thin silica layer, were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of the hybridmore » nanorods on synthetic lipid bilayers and on live cell membranes were obtained with millisecond temporal resolution using a scientific complementary metal-oxide-semiconductor camera. The results demonstrate that the as-synthesized hybrid nanorods are promising imaging probes with improved sensitivity and good biocompatibility for single plasmonic particle tracking experiments in biological systems.« less

  12. ARM - Field Campaign - In-situ Aerosol Profiles (Cessna Aerosol...

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

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : In-situ Aerosol Profiles (Cessna Aerosol Flights) 2000.03.01 - 2007.10.31 Lead...

  13. Optical and Physical Properties from Primary On-Road Vehicle ParticleEmissions And Their Implications for Climate Change

    SciTech Connect (OSTI)

    Strawa, A.W.; Kirchstetter, T.W.; Hallar, A.G.; Ban-Weiss, G.A.; McLaughlin, J.P.; Harley, R.A.; Lunden, M.M.

    2009-01-23

    During the summers of 2004 and 2006, extinction and scattering coefficients of particle emissions inside a San Francisco Bay Area roadway tunnel were measured using a combined cavity ring-down and nephelometer instrument. Particle size distributions and humidification were also measured, as well as several gas phase species. Vehicles in the tunnel traveled up a 4% grade at a speed of approximately 60 km h{sup -1}. The traffic situation in the tunnel allows the apportionment of emission factors between light duty gasoline vehicles and diesel trucks. Cross-section emission factors for optical properties were determined for the apportioned vehicles to be consistent with gas phase and particulate matter emission factors. The absorption emission factor (the absorption cross-section per mass of fuel burned) for diesel trucks (4.4 {+-} 0.79 m{sup 2} kg{sup -1}) was 22 times larger than for light-duty gasoline vehicles (0.20 {+-} 0.05 m{sup 2} kg{sup -1}). The single scattering albedo of particles - which represents the fraction of incident light that is scattered as opposed to absorbed - was 0.2 for diesel trucks and 0.3 for light duty gasoline vehicles. These facts indicate that particulate matter from motor vehicles exerts a positive (i.e., warming) radiative climate forcing. Average particulate mass absorption efficiencies for diesel trucks and light duty gasoline vehicles were 3.14 {+-} 0.88 m{sup 2} g{sub PM}{sup -1} and 2.9 {+-} 1.07 m{sup 2} g{sub PM}{sup -1}, respectively. Particle size distributions and optical properties were insensitive to increases in relative humidity to values in excess of 90%, reinforcing previous findings that freshly emitted motor vehicle particulate matter is hydrophobic.

  14. Organic Aerosol Component (OACOMP) Value-Added Product Report

    SciTech Connect (OSTI)

    Fast, J; Zhang, Q; Tilp, A; Shippert, T; Parworth, C; Mei, F

    2013-08-23

    Significantly improved returns in their aerosol chemistry data can be achieved via the development of a value-added product (VAP) of deriving OA components, called Organic Aerosol Components (OACOMP). OACOMP is primarily based on multivariate analysis of the measured organic mass spectral matrix. The key outputs of OACOMP are the concentration time series and the mass spectra of OA factors that are associated with distinct sources, formation and evolution processes, and physicochemical properties.

  15. Electronic and optical properties of TaO{sub 1-x}N{sub 1+x}-based alloys

    SciTech Connect (OSTI)

    Al-Aqtash, Nabil; Apostol, Florin; Mei, Wai-Ning; Sabirianov, Renat F.; Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588

    2013-02-15

    TaON is considered as a potential candidate as a visible-light responsive photocatalyst. We report the results of ab initio studies of electronic structure of TaON-based alloys. Specifically, we show that the position of conduction and valence band can be modified by varying the oxygen and nitrogen concentrations in TaO{sub 1-x}N{sub 1+x}. We find that the band gap decreases monotonically with the increase of N/O ratio. The band gap energy is decreased in monoclinic TaON from near 2.3 eV to just over 1.7 eV (i.e., by 35%) when N/O ratio is increased from 3/5 to 5/3. Our calculations show that the band gap reduces in a series of experimentally fabricated alloys ZrTa{sub 3}O{sub 5}N{sub 3}{yields}TaON{yields}YTa{sub 7}O{sub 7}N{sub 8}. The band gap reduction is mostly associated with the change in the position of the valence band due to the hybridization of N 2p states, while the conduction band consisting mostly of Ta 5d-states is not sensitive to N content. The calculated optical absorption spectra show reduction in the optical band gap with increasing N/O ratio. - Graphical abstract: Band gap energy of TaO{sub 1-x}N{sub 1+x} as a function of N/O ratio. Highlights: Black-Right-Pointing-Pointer The electronic and optical properties of TaON-based alloys are studied using DFT. Black-Right-Pointing-Pointer The position of conduction and valence bands can be modified by varying N/O ratio. Black-Right-Pointing-Pointer The band gap decreases monotonically with the increase of N/O ratio in TaO{sub 1-x}N{sub 1+x}. Black-Right-Pointing-Pointer The band gap reduces in a series of fabricated alloys ZrTa{sub 3}O{sub 5}N{sub 3}{yields}TaON{yields}YTa{sub 7}O{sub 7}N{sub 8}. Black-Right-Pointing-Pointer The optical band gap decreases with the increase of N/O ratio.

  16. Development of an aerosol microphysical module: Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS)

    SciTech Connect (OSTI)

    Matsui, H.; Koike, Makoto; Kondo, Yutaka; Fast, Jerome D.; Takigawa, M.

    2014-09-30

    Number concentrations, size distributions, and mixing states of aerosols are essential parameters for accurate estimation of aerosol direct and indirect effects. In this study, we developed an aerosol module, designated Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS), that can represent these parameters explicitly by considering new particle formation (NPF), black carbon (BC) aging, and secondary organic aerosol (SOA) processes. A two-dimensional bin representation is used for particles with dry diameters from 40 nm to 10 m to resolve both aerosol size (12 bins) and BC mixing state (10 bins) for a total of 120 bins. The particles with diameters from 1 to 40 nm are resolved using an additional 8 size bins to calculate NPF. The ATRAS module was implemented in the WRF-chem model and applied to examine the sensitivity of simulated mass, number, size distributions, and optical and radiative parameters of aerosols to NPF, BC aging and SOA processes over East Asia during the spring of 2009. BC absorption enhancement by coating materials was about 50% over East Asia during the spring, and the contribution of SOA processes to the absorption enhancement was estimated to be 10 20% over northern East Asia and 20 35% over southern East Asia. A clear north-south contrast was also found between the impacts of NPF and SOA processes on cloud condensation nuclei (CCN) concentrations: NPF increased CCN concentrations at higher supersaturations (smaller particles) over northern East Asia, whereas SOA increased CCN concentrations at lower supersaturations (larger particles) over southern East Asia. Application of ATRAS to East Asia also showed that the impact of each process on each optical and radiative parameter depended strongly on the process and the parameter in question. The module can be used in the future as a benchmark model to evaluate the accuracy of simpler aerosol models and examine interactions between NPF, BC aging, and SOA processes under different meteorological conditions and emissions.

  17. Laboratory Experiments and Instrument Development for the Study of Atmospheric Aerosols

    SciTech Connect (OSTI)

    Davidovits, Paul

    2011-12-10

    Soot particles are generated by incomplete combustion of fossil and biomass fuels. Through direct effects clear air aerosols containing black carbon (BC) such as soot aerosols, absorb incoming light heating the atmosphere, while most other aerosols scatter light and produce cooling. Even though BC represents only 1-2% of the total annual emissions of particulate mass to the atmosphere, it has been estimated that the direct radiative effect of BC is the second-most important contributor to global warming after absorption by CO2. Ongoing studies continue to underscore the climate forcing importance of black carbon. However, estimates of the radiative effects of black carbon on climate remain highly uncertain due to the complexity of particles containing black carbon. Quantitative measurement of BC is challenging because BC often occurs in highly non-spherical soot particles of complex morphology. Freshly emitted soot particles are typically fractal hydrophobic aggregates. The aggregates consist of black carbon spherules with diameters typically in the range of about 15-40 nm, and they are usually coated by adsorbed polyaromatic hydrocarbons (PAHs) produced during combustion. Diesel-generated soot particles are often emitted with an organic coating composed primarily of lubricating oil and unburned fuel, as well as well as PAH compounds. Sulfuric acid has also been detected in diesel and aircraft-emitted soot particles. In the course of aging, these particle coatings may be substantially altered by chemical reactions and/or the deposition of other materials. Such processes transform the optical and CCN properties of the soot aerosols in ways that are not yet well understood. Our work over the past seven years consisted of laboratory research, instrument development and characterization, and field studies with the central focus of improving our understanding of the black carbon aerosol climate impacts. During the sixth year as well as during this seventh year (no-cost extension period) of our grant, we extended our studies to perform experiments on the controlled production and characterization of secondary organic aerosol.

  18. Nonlinear optical properties of bulk cuprous oxide using single beam Z-scan at 790?nm

    SciTech Connect (OSTI)

    Serna, J.; Rueda, E.; Garca, H.

    2014-11-10

    The two-photon absorption (TPA) coefficient ? and the nonlinear index of refraction n{sub 2} for bulk cuprous oxide (Cu{sub 2}O) direct gap semiconductor single crystal have been measured by using a balance-detection Z-scan single beam technique, with an excellent signal to noise ratio. Both coefficients were measured at 790?nm using a 65 fs laser pulse at a repetition rate of 90.9?MHz, generated by a Ti:Sapphire laser oscillator. The experimental values for ? were explained by using a model that includes allowed-allowed, forbidden-allowed, and forbidden-forbidden transitions. It was found that the forbidden-forbidden transition is the dominant mechanism, which is consistent with the band structure of Cu{sub 2}O. The low value for ? found in bulk, as compared with respect to thin film, is explained in terms of the structural change in thin films that result in opposite parities of the conduction and valence band. The n{sub 2} is also theoretically calculated by using the TPA dispersion curve and the Kramers-Kronig relations for nonlinear optics.

  19. Study on structural, optical properties of solvothermally synthesized Ni doped CdS nanorods

    SciTech Connect (OSTI)

    Kaur, Kamaldeep Verma, N. K.

    2015-05-15

    Undoped and alkali metal i.e Ni doped CdS nanorods (Cd{sub x}Ni{sub 1-x}S) with (x = 0.0, 0.3,) has been synthesized by using a convenient solvothermal technique. In order to confirm the structure of the synthesized nanorods X-ray diffraction (XRD) has been done which reveals the formation of hexagonal phase of the dilute magnetic semiconducting nanorods having size of undoped 27.79nm and doped 17.49nm. Energy dispersive X-ray analysis depicts the presence of elements Cd, Ni and S in their stoichiometric ratio. Optical behavior of undoped and doped nanorods has been investigated. UV-visible spectra show the blue shift in the band gap, as compared to the bulk CdS which may be due the quantum confinement occurs in the nanostructures. Morphological analysis has been done with the help of Transmission electron microscope which confirms the polycrystalline nature of the synthesized nanorods.

  20. ARM - Measurement - Aerosol effective radius

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

    effective radius ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol effective radius Aerosol effective radius is the ratio of the third and second moments of the number size distribution of aerosol particles. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for

  1. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model Third Quarter 2008

    SciTech Connect (OSTI)

    JH Mather; DA Randall; CJ Flynn

    2008-06-30

    In 2008, the Atmospheric Radiation Measurement (ARM) Program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the metrics will deal with a decade-long control simulation using geodesic grid-coupled climate model. For ARM, the metrics will deal with observations associated with the 2006 deployment of the ARM Mobile Facility (AMF) to Niamey, Niger. Specifically, ARM has been asked to deliver data products for Niamey that describe cloud, aerosol, and dust properties. This report describes the aerosol optical depth (AOD) product.

  2. Microstructure, optical property, and electronic band structure of cuprous oxide thin films

    SciTech Connect (OSTI)

    Park, Jun-Woo; Jang, Hyungkeun; Kim, Sung; Choi, Suk-Ho; Lee, Hosun; Kang, Joongoo; Wei, Su-Huai

    2011-11-15

    Cuprous oxide (Cu{sub 2}O) thin films were grown via radio frequency sputtering deposition at various temperatures. The dielectric functions and luminescence properties of the Cu{sub 2}O thin films were measured using spectroscopic ellipsometry and photoluminescence, respectively. High-energy peaks were observed in the photoluminescence spectra. Several critical points (CPs) were found using second derivative spectra of the dielectric functions and the standard critical point model. The electronic band structure and the dielectric functions were calculated using density functional theory, and the CP energies were estimated to compare with the experimental data. We identified the high-energy photoluminescence peaks to quasi-direct transitions which arose from the granular structures of the Cu{sub 2}O thin films.

  3. Highly stable aerosol generator

    DOE Patents [OSTI]

    DeFord, Henry S. (Kennewick, WA); Clark, Mark L. (Kennewick, WA)

    1981-01-01

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

  4. Highly stable aerosol generator

    DOE Patents [OSTI]

    DeFord, H.S.; Clark, M.L.

    1981-11-03

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

  5. Optical properties database for high performance glazings. Task 12: Building energy analysis and design tools for solar applications, Subtask A.1: High-performance glazing

    SciTech Connect (OSTI)

    Reilly, S.; Selkowitz, S.; Winkelmann, F.

    1992-06-30

    The framework used for the data is described; maintain and updating the database is addressed; and covers extensions of the database are covered. The appendices include the glass library (Appendix A) and the glazing system library (Appendix B) which for the foundation of the optical property database, and a spectral data reporting format (Appendix C).

  6. First principles treatment of structural, optical, and thermoelectric properties of Li{sub 7}MnN{sub 4} as electrode for a Li secondary battery

    SciTech Connect (OSTI)

    Khan, Wilayat; Reshak, A.H.

    2015-01-15

    The electronic structure, electronic charge density and linear optical properties of the metallic Li{sub 7}MnN{sub 4} compound, having cubic symmetry, are calculated using the full potential linearized augmented plane wave (FP-LAPW) method. The calculated band structure and density of states using the local density, generalized gradient and EngelVosko approximations, depict the metallic nature of the cubic Li{sub 7}MnN{sub 4} compound. The bands crossing the Fermi level in the calculated band structure are mainly from the Mn-d states with small support of N-p states. In addition, the Mn-d states at the Fermi level enhance the density of states, which is very useful for the electronic transport properties. The valence electronic charge density depicts strong covalent bond between Mn and two N atoms and polar covalent bond between Mn and Li atoms. The frequency dependent linear optical properties like real and imaginary part of the dielectric function, optical conductivity, reflectivity and energy loss function are calculated on the basis of the computed band structure. Both intra-band and inter-band transitions contribute to the calculated optical parameters. Using the BoltzTraP code, the thermoelectric properties like electrical and thermal conductivity, Seebeck coefficient, power coefficient and heat capacity of the Li{sub 7}MnN{sub 4} are also calculated as a function of temperature and studied.

  7. Implementing marine organic aerosols into the GEOS-Chem model

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

    Gantt, B.; Johnson, M. S.; Crippa, M.; Prévôt, A. S. H.; Meskhidze, N.

    2015-03-17

    Marine-sourced organic aerosols (MOAs) have been shown to play an important role in tropospheric chemistry by impacting surface mass, cloud condensation nuclei, and ice nuclei concentrations over remote marine and coastal regions. In this work, an online marine primary organic aerosol emission parameterization, designed to be used for both global and regional models, was implemented into the GEOS-Chem (Global Earth Observing System Chemistry) model. The implemented emission scheme improved the large underprediction of organic aerosol concentrations in clean marine regions (normalized mean bias decreases from -79% when using the default settings to -12% when marine organic aerosols are added). Modelmore » predictions were also in good agreement (correlation coefficient of 0.62 and normalized mean bias of -36%) with hourly surface concentrations of MOAs observed during the summertime at an inland site near Paris, France. Our study shows that MOAs have weaker coastal-to-inland concentration gradients than sea-salt aerosols, leading to several inland European cities having >10% of their surface submicron organic aerosol mass concentration with a marine source. The addition of MOA tracers to GEOS-Chem enabled us to identify the regions with large contributions of freshly emitted or aged aerosol having distinct physicochemical properties, potentially indicating optimal locations for future field studies.« less

  8. Implementing marine organic aerosols into the GEOS-Chem model

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

    Gantt, B.; Johnson, M. S.; Crippa, M.; Prévôt, A. S. H.; Meskhidze, N.

    2014-09-09

    Marine organic aerosols (MOA) have been shown to play an important role in tropospheric chemistry by impacting surface mass, cloud condensation nuclei, and ice nuclei concentrations over remote marine and coastal regions. In this work, an online marine primary organic aerosol emission parameterization, designed to be used for both global and regional models, was implemented into the GEOS-Chem model. The implemented emission scheme improved the large underprediction of organic aerosol concentrations in clean marine regions (normalized mean bias decreases from -79% when using the default settings to -12% when marine organic aerosols are added). Model predictions were also in goodmore » agreement (correlation coefficient of 0.62 and normalized mean bias of -36%) with hourly surface concentrations of MOA observed during the summertime at an inland site near Paris, France. Our study shows that MOA have weaker coastal-to-inland concentration gradients than sea-salt aerosols, leading to several inland European cities having > 10% of their surface submicron organic aerosol mass concentration with a marine source. The addition of MOA tracers to GEOS-Chem enabled us to identify the regions with large contributions of freshly-emitted or aged aerosol having distinct physicochemical properties, potentially indicating optimal locations for future field studies.« less

  9. Structural, thermal, optical properties and simulation of white light of titanium-tungstate-tellurite glasses doped with dysprosium

    SciTech Connect (OSTI)

    Jyothi, L. [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Upender, G. [Glass Science and Technology Section, Glass Division, CSIR-CGCRI, Kolkata 700032 (India); Kuladeep, R. [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Rao, D. Narayana, E-mail: dnrsp@uohyd.ernet.in [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-02-01

    Graphical abstract: CIE coordinate diagram of different concentrations of the Dy{sup 3+}-doped TTWD glasses with coordinates in the white light region. - Highlights: Radiative lifetime of {sup 4}F{sub 9/2} level of Dy{sup 3+} ions is longer in the tellurite glass. Quantum efficiency is found to be high. These glasses are suitable materials for generating white light. - Abstract: Structural, thermal, optical properties and simulation of white light of Dy{sup 3+}-doped tellurite glasses of composition TTWD: (75 ? x)TeO{sub 2} ? 10TiO{sub 2} ? 15WO{sub 3} ? xDy{sub 2}O{sub 3} (x = 0, 0.1, 0.5, 1.0 and 2.0 mol%) were investigated. Raman spectra revealed that the glass contains TeO{sub 4}, TeO{sub 3}, WO{sub 4} and WO{sub 6} units. Differential scanning calorimetry (DSC) measurements were carried out to measure the glass transition temperature of all the glasses. From the optical absorption spectra, luminescence spectra and using the JuddOfelt (JO) analysis, we estimated the radiative transition probabilities, emission cross-sections, branching ratios and radiative lifetimes. The decay curves at lower concentrations are exponential while they show a non-exponential behavior at higher concentrations (?0.5 mol%) due to energy transfer processes. The effective lifetime for the {sup 4}F{sub 9/2} level decreases with increase in Dy{sub 2}O{sub 3} concentration for the glasses under investigation. The non-exponential decay curves could fit well to the InokutiHirayama (IH) model with S = 6, indicating that the nature of interaction responsible for energy transfer is of dipoledipole type. Simulation of white light is examined with varying concentration and the results indicate that these glasses are suitable for white light emitting diode applications.

  10. Balance of optical, structural, and electrical properties of textured liquid phase crystallized Si solar cells

    SciTech Connect (OSTI)

    Preidel, V. Amkreutz, D.; Haschke, J.; Wollgarten, M.; Rech, B.; Becker, C.

    2015-06-14

    Liquid phase crystallized Si thin-film solar cells on nanoimprint textured glass substrates exhibiting two characteristic, but distinct different surface structures are presented. The impact of the substrate texture on light absorption, the structural Si material properties, and the resulting solar cell performance is analyzed. A pronounced periodic substrate texture with a vertical feature size of about 1 μm enables excellent light scattering and light trapping. However, it also gives rise to an enhanced Si crystal defect formation deteriorating the solar cell performance. In contrast, a random pattern with a low surface roughness of 45 nm allows for the growth of Si thin films being comparable to Si layers on planar reference substrates. Amorphous Si/crystalline Si heterojunction solar cells fabricated on the low-roughness texture exhibit a maximum open circuit voltage of 616 mV and internal quantum efficiency peak values exceeding 90%, resulting in an efficiency potential of 13.2%. This demonstrates that high quality crystalline Si thin films can be realized on nanoimprint patterned glass substrates by liquid phase crystallization inspiring the implementation of tailor-made nanophotonic light harvesting concepts into future liquid phase crystallized Si thin film solar cells on glass.

  11. Synthesis and optical properties of cadmium selenide quantum dots for white light-emitting diode application

    SciTech Connect (OSTI)

    Xu, Xianmei; Wang, Yilin; Gule, Teri; Luo, Qiang [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Zhou, Liya, E-mail: zhouliyatf@163.com [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Gong, Fuzhong [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China)

    2013-03-15

    Highlights: ? Stable CdSe QDs were synthesized by the one-step and two-level process respectively. ? The fabricated white LEDs show good white balance. ? CdSe QDs present well green to yellow band luminescence. ? CdSe QDs displayed a broad excitation band. - Abstract: Yellow light-emitting cadmium selenide quantum dots were synthesized using one-step and two-step methods in an aqueous medium. The structural luminescent properties of these quantum dots were investigated. The obtained cadmium selenide quantum dots displayed a broad excitation band suitable for blue or near-ultraviolet light-emitting diode applications. White light-emitting diodes were fabricated by coating the cadmium selenide samples onto a 460 nm-emitting indium gallium nitrite chip. Both samples exhibited good white balance. Under a 20 mA working current, the white light-emitting diode fabricated via the one-step and two-step methods showed Commission Internationale de lclairage coordinates at (0.27, 0.23) and (0.27, 0.33), respectively, and a color rendering index equal to 41 and 37, respectively. The one-step approach was simpler, greener, and more effective than the two-step approach. The one-step approach can be enhanced by combining cadmium selenide quantum dots with proper phosphors.

  12. Research on the electronic and optical properties of polymer and other organic molecular thin films

    SciTech Connect (OSTI)

    1997-02-01

    The main goal of the work is to find materials and methods of optimization of organic layered electroluminescent cells and to study such properties of polymers and other organic materials that can be used in various opto-electronic devices. The summary of results obtained during the first year of work is presented. They are: (1) the possibility to produce electroluminescent cells using a vacuum deposition photoresist technology for commercial photoresists has been demonstrated; (2) the idea to replace the polyaryl polymers by other polymers with weaker hole conductivity for optimization of electroluminescent cells with ITO-Al electrodes has been suggested. The goal is to obtain amorphous processable thin films of radiative recombination layers in electroluminescent devices; (3) procedures of preparation of high-quality vacuum-deposited poly (p-phenylene) (PPP) films on various substrates have been developed; (4) it was found for the first time that the fluorescence intensity of PPP films depends on the degree of polymerization; (5) the role of interfaces between organic compounds, on one side, and metals or semiconductors, on the other side, has been studied and quenching of the fluorescence caused by semiconductor layer in thin sandwiches has been observed; (6) studies of the dynamics of photoexcitations revealed the exciton self-trapping in quasi-one-dimensional aggregates; and (7) conditions for preparation of highly crystalline fullerene C{sub 60} films by vacuum deposition have been found. Composites of C{sub 60} with conjugated polymers have been prepared.

  13. One ARM, Two Columns and a Whole Lot of Aerosols | Department of Energy

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

    ARM, Two Columns and a Whole Lot of Aerosols One ARM, Two Columns and a Whole Lot of Aerosols July 25, 2012 - 5:49pm Addthis This observatory is part of an air particles research initiative at Cape Cod National Seashore in Massachusetts, and includes dozens of sophisticated instruments that take continuous ground-based measurements of clouds, aerosols, and other atmospheric properties. | Photo courtesy of the ARM Climate Research Facility. This observatory is part of an air particles research

  14. Ganges Valley Aerosol Experiment: Science and Operations Plan

    SciTech Connect (OSTI)

    Kotamarthi, VR

    2010-06-21

    The Ganges Valley region is one of the largest and most rapidly developing sections of the Indian subcontinent. The Ganges River, which provides the region with water needed for sustaining life, is fed primarily by snow and rainfall associated with Indian summer monsoons. Impacts of changes in precipitation patterns, temperature, and the flow of the snow-fed rivers can be immense. Recent satellite-based measurements have indicated that the upper Ganges Valley has some of the highest persistently observed aerosol optical depth values. The aerosol layer covers a vast region, extending across the Indo-Gangetic Plain to the Bay of Bengal during the winter and early spring of each year. The persistent winter fog in the region is already a cause of much concern, and several studies have been proposed to understand the economic, scientific, and societal dimensions of this problem. During the INDian Ocean EXperiment (INDOEX) field studies, aerosols from this region were shown to affect cloud formation and monsoon activity over the Indian Ocean. This is one of the few regions showing a trend toward increasing surface dimming and enhanced mid-tropospheric warming. Increasing air pollution over this region could modify the radiative balance through direct, indirect, and semi-indirect effects associated with aerosols. The consequences of aerosols and associated pollution for surface insolation over the Ganges Valley and monsoons, in particular, are not well understood. The proposed field study is designed for use of (1) the ARM Mobile Facility (AMF) to measure relevant radiative, cloud, convection, and aerosol optical characteristics over mainland India during an extended period of 912 months and (2) the G-1 aircraft and surface sites to measure relevant aerosol chemical, physical, and optical characteristics in the Ganges Valley during a period of 612 weeks. The aerosols in this region have complex sources, including burning of coal, biomass, and biofuels; automobile emissions; and dust. The extended AMF deployment will enable measurements under different regimes of the climate and aerosol abundancein the wet monsoon period with low aerosol loading; in the dry, hot summer with aerosols dispersed throughout the atmospheric column; and in the cool, dry winter with aerosols confined mostly to the boundary later and mid-troposphere. Each regime, in addition, has its own distinct radiative and atmospheric dynamic drivers. The aircraft operational phase will assist in characterizing the aerosols at times when they have been observed to be at the highest concentrations. A number of agencies in India will collaborate with the proposed field study and provide support in terms of planning, aircraft measurements, and surface sites. The high concentration of aerosols in the upper Ganges Valley, together with hypotheses involving several possible mechanisms with direct impacts on the hydrologic cycle of the region, gives us a unique opportunity to generate data sets that will be useful both in understanding the processes at work and in providing answers regarding the effects of aerosols on climate in a region where the perturbation is the highest.

  15. Syntheses, Structure, Magnetism, and Optical Properties of Lutetium-based Interlanthanide Selenides

    SciTech Connect (OSTI)

    Booth, Corwin H; Jin, Geng Bang; Choi, Eun Sang; Guertin, Robert P.; Brooks, James S.; Booth, Corwin H.; Albrecht-Schmitt, Thomas E.

    2007-10-01

    Ln{sub 3}LuSe{sub 6} (Ln = La, Ce), {beta}-LnLuSe{sub 3} (Ln = Pr, Nd), and Ln{sub x}Lu{sub 4-x}Se{sub 6} (Ln = Sm, Gd; x = 1.82, 1.87) have been synthesized using a Sb{sub 2}Se{sub 3} flux at 1000 C. Ln{sub 3}LuSe{sub 6} (Ln = La, Ce) adopt the U{sub 3}ScS{sub 6}-type three-dimensional structure, which is constructed from two-dimensional {infinity}{sup 2} [Ln{sub 3}Se{sub 6}]{sup 3-} slabs with the gaps between these slabs filled by octahedrally coordinated Lu{sup 3+} ions. The series of {beta}-LnLuSe{sub 3} (Ln = Pr, Nd) are isotypic with UFeS{sub 3}. Their structures include layers formed from LuSe6 octahedra that are separated by eight-coordinate larger Ln{sup 3+} ions in bicapped trigonal prismatic environments. Sm{sub 1.82}Lu{sub 2.18}Se{sub 6} and Gd{sub 1.87}Lu{sub 2.13}Se{sub 6} crystallize in the disordered F-Ln{sub 2}S{sub 3} type structure with the eight-coordinate bicapped trigonal prismatic Ln(1) ions residing in the one-dimensional channels formed by three different double chains via edge and corner sharing. These double chains are constructed from Ln(2)Se{sub 7} monocapped trigonal prisms, Ln(3)Se{sub 6} octahedra, and Ln(4)S{sub 6} octahedra, respectively. The magnetic susceptibilities of {beta}-PrLuSe{sub 3} and {beta}-NdLuSe{sub 3} follow the Curie-Weiss law. Sm{sub 1.82}Lu{sub 2.18}Se{sub 6} shows van Vleck paramagnetism. Magnetic measurements show that Gd{sub 1.87}Lu{sub 2.13}Se{sub 6} undergoes an antiferromagnetic transition around 4 K. Ce{sub 3}LuSe{sub 6} exhibits ferromagnetic ordering below 5 K. The optical band gaps for La{sub 3}LuSe{sub 6}, Ce{sub 3}LuSe{sub 6}, {beta}- PrLuSe{sub 3}, {beta}-NdLuSe{sub 3}, Sm{sub 1.82}Lu{sub 2.18}Se{sub 6}, and Gd{sub 1.87}Lu{sub 2.13}Se{sub 6} are 1.26, 1.10, 1.56, 1.61, 1.51, and 1.56 eV, respectively.

  16. Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data

    SciTech Connect (OSTI)

    Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

    2012-03-28

    In this DOE project the improvements to parameterization of marine primary organic matter (POM) emissions, hygroscopic properties of marine POM, marine isoprene derived secondary organic aerosol (SOA) emissions, surfactant effects, new cloud droplet activation parameterization have been implemented into Community Atmosphere Model (CAM 5.0), with a seven mode aerosol module from the Pacific Northwest National Laboratory (PNNL)???¢????????s Modal Aerosol Model (MAM7). The effects of marine aerosols derived from sea spray and ocean emitted biogenic volatile organic compounds (BVOCs) on microphysical properties of clouds were explored by conducting 10 year CAM5.0-MAM7 model simulations at a grid resolution 1.9???????°????????2.5???????° with 30 vertical layers. Model-predicted relationship between ocean physical and biological systems and the abundance of CCN in remote marine atmosphere was compared to data from the A-Train satellites (MODIS, CALIPSO, AMSR-E). Model simulations show that on average, primary and secondary organic aerosol emissions from the ocean can yield up to 20% increase in Cloud Condensation Nuclei (CCN) at 0.2% Supersaturation, and up to 5% increases in droplet number concentration of global maritime shallow clouds. Marine organics were treated as internally or externally mixed with sea salt. Changes associated with cloud properties reduced (absolute value) the model-predicted short wave cloud forcing from -1.35 Wm-2 to -0.25 Wm-2. By using different emission scenarios, and droplet activation parameterizations, this study suggests that addition of marine primary aerosols and biologically generated reactive gases makes an important difference in radiative forcing assessments. All baseline and sensitivity simulations for 2001 and 2050 using global-through-urban WRF/Chem (GU-WRF) were completed. The main objective of these simulations was to evaluate the capability of GU-WRF for an accurate representation of the global atmosphere by exploring the most accurate configuration of physics options in GWRF for global scale modeling in 2001 at a horizontal grid resolution of 1???????° x 1???????°. GU-WRF model output was evaluated using observational datasets from a variety of sources including surface based observations (NCDC and BSRN), model reanalysis (NCEP/ NCAR Reanalysis and CMAP), and remotely-sensed data (TRMM) to evaluate the ability of GU-WRF to simulate atmospheric variables at the surface as well as aloft. Explicit treatment of nanoparticles produced from new particle formation in GU-WRF/Chem-MADRID was achieved by expanding particle size sections from 8 to 12 to cover particles with the size range of 1.16 nm to 11.6 ???????µm. Simulations with two different nucleation parameterizations were conducted for August 2002 over a global domain at a 4???????º by 5???????º horizontal resolution. The results are evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as satellite and reanalysis data. We have also explored the relationship between ???¢????????clean marine???¢??????? aerosol optical properties and ocean surface wind speed using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses

  17. Synthesis, characterization and optical properties of NH{sub 4}Dy(PO{sub 3}){sub 4}

    SciTech Connect (OSTI)

    Chemingui, S.; Ferhi, M. Horchani-Naifer, K.; Férid, M.

    2014-09-15

    Polycrystalline powders of NH{sub 4}Dy(PO{sub 3}){sub 4} polyphosphate have been grown by the flux method. This compound was found to be isotopic with NH{sub 4}Ce(PO{sub 3}){sub 4} and RbHo(PO{sub 3}){sub 4}. It crystallizes in the monoclinic space group P2{sub 1/n} with unit cell parameters a=10.474(6) Å, b=9.011(4) Å, c=10.947(7) Å and β=106.64(3)°. The title compound has been transformed to triphosphate Dy(PO{sub 3}){sub 3} after calcination at 800 °C. Powder X-ray diffraction, infrared and Raman spectroscopies and the differential thermal analysis have been used to identify these materials. The spectroscopic properties have been investigated through absorption, excitation, emission spectra and decay curves of Dy{sup 3+} ion in both compounds at room temperature. The emission spectra show the characteristic emission bands of Dy{sup 3+} in the two compounds, before and after calcination. The integrated emission intensity ratios of the yellow to blue (I{sub Y}/I{sub B}) transitions and the chromaticity properties have been determined from emission spectra. The decay curves are found to be double-exponential. The non-exponential behavior of the decay rates was related to the resonant energy transfer as well as cross-relaxation between the donor and acceptor Dy{sup 3+} ions. The determined properties have been discussed as function of crystal structure of both compounds. They reveal that NH{sub 4}Dy(PO{sub 3}){sub 4} is promising for white light generation but Dy(PO{sub 3}){sub 3} is potential candidates in field emission display (FED) and plasma display panel (PDP) devices. - Graphical abstract: The CIE color coordinate diagrams showing the chromatic coordinates of Dy{sup 3+} luminescence in NH{sub 4}Dy(PO{sub 3}){sub 4} and Dy(PO{sub 3}){sub 3}. - Highlights: • The polycrystalline powders of NH{sub 4}Dy(PO{sub 3}){sub 4} and Dy(PO{sub 3}){sub 3} are synthesized. • The obtained powders are characterized. • The spectroscopic properties of Dy{sup 3+} ion are investigated. • Results are discussed as function of crystal structure and chemical composition. • The usefulness of NH{sub 4}Dy(PO{sub 3}){sub 4} and Dy(PO{sub 3}){sub 3} in optical devices is revealed.

  18. COLLABORATIVE RESEARCH: Study of Aerosol Sources and Processing at the GVAX Pantnagar Supersite

    SciTech Connect (OSTI)

    Worsnop, Douglas R.

    2014-07-28

    This project funded the participation of scientists from seven research groups, running more than thirty instruments, in the Winter Intensive Operating Period (January-February 2012) of the Clean Air for London (ClearfLo) campaign at a rural site in Detling, UK, 45 km southeast of central London. The primary science questions for the ClearfLo Winter IOP were, 1) what is the urban increment of particulate matter (PM) and other pollutants in the greater London area, and, 2) what is the contribution of solid fuel use for home heating to wintertime PM? An additional motivation for the Detling measurements was the question of whether coatings on black carbon particles enhance absorption. The following four key accomplishments have been identified so far: 1) Chemical, physical and optical characterization of PM from local and regional sources (Figures 2, 4, 5 and 6). 2) Measurement of urban increment in particulate matter and gases in London (Figure 3). 3) Measurement of optical properties and chemical composition of coatings on black carbon containing particles indicates absorption enhancement. 4) First deployment of chemical ionization instrument (MOVI-CI-TOFMS) to measure both particle-phase and gas-phase organic acids. (See final report from Joel Thornton, University of Washington, for details.) Analysis of the large dataset acquired in Detling is ongoing and will yield further key accomplishments. These measurements of urban and rural aerosol properties will contribute to improved modeling of regional aerosol emissions, and of atmospheric aging and removal. The measurement of absorption enhancement by coatings on black carbon will contribute to improved modeling of the direct radiative properties of PM.

  19. Investigation of size dependent structural and optical properties of thin films of CdSe quantum dots

    SciTech Connect (OSTI)

    Sharma, Madhulika; Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay, Powai, Mumbai 400076 ; Sharma, A.B.; Mishra, N.; Pandey, R.K.

    2011-03-15

    Research highlights: {yields} CdSe q-dots have been synthesized using simple chemical synthesis route. {yields} Thin film of CdSe quantum dots exhibited self-organized growth. {yields} Size dependent blue shift observed in the absorption edge of CdSe nanocrystallites. {yields} PL emission band corresponds to band edge luminescence and defect luminescence. {yields} Organized growth led to enhancement in luminescence yield of smaller size Q-dots. -- Abstract: Cadmium selenide (CdSe) quantum dots were grown on indium tin oxide substrate using wet chemical technique for possible application as light emitting devices. The structural, morphological and luminescence properties of the as deposited thin films of CdSe Q-dot have been investigated, using X-ray diffraction, transmission electron microscopy, atomic force microscopy and optical and luminescence spectroscopy. The quantum dots have been shown to deposit in an organized array on ITO/glass substrate. The as grown Q-dots exhibited size dependent blue shift in the absorption edge. The effect of quantum confinement also manifested as a blue shift of photoluminescence emission. It is shown that the nanocrystalline CdSe exhibits intense photoluminescence as compared to the large grained polycrystalline CdSe films.

  20. Structural and optical properties of InGaNGaN nanowire heterostructures grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Limbach, F.; Gotschke, T.; Stoica, T.; Calarco, R.; Sutter, E.; Ciston, J.; Cusco, R.; Artus, L.; Kremling, S.; Ho?fling, S.; Worschech, L.; Gru?tzmacher, D.

    2011-01-01

    InGaN/GaN nanowire (NW) heterostructures grown by plasma assisted molecular beam epitaxy were studied in comparison to their GaN and InGaN counterparts. The InGaN/GaN heterostructure NWs are composed of a GaN NW, a thin InGaN shell, and a multifaceted InGaN cap wrapping the top part of the GaN NW. High-resolution transmission electron microscopy (HRTEM) images taken from different parts of a InGaN/GaN NW show a wurtzite structure of the GaN core and the epitaxial InGaN shell around it, while additional crystallographic domains are observed whithin the InGaN cap region. Large changes in the lattice parameter along the wire, from pure GaN to higher In concentration demonstrate the successful growth of a complex InGaN/GaN NW heterostructure. Photoluminescence (PL) spectra of these heterostructure NW ensembles show rather broad and intense emission peak at 2.1 eV. However, ?-PL spectra measured on single NWs reveal a reduced broadening of the visible luminescence. The analysis of the longitudinal optical phonon Raman peak position and its shape reveal a variation in the In content between 20% and 30%, in agreement with the values estimated by PL and HRTEM investigations. The reported studies are important for understanding of the growth and properties of NW heterostructures suitable for applications in optoelectronics and photovoltaics.

  1. Glancing angle deposition of SiO{sub 2} thin film microstructures: Investigations of optical and morphological properties

    SciTech Connect (OSTI)

    Tokas, R. B. E-mail: tokasstar@gmail.com; Jena, S. E-mail: tokasstar@gmail.com; Sarkar, P. E-mail: tokasstar@gmail.com; Thakur, S. E-mail: tokasstar@gmail.com; Sahoo, N. K. E-mail: tokasstar@gmail.com

    2014-04-24

    In present work, the optical and the morphological properties of micro-structured SiO{sub 2} thin films fabricated by using glancing angle deposition (GLAD) technique has been carried out. The results are compared with the normally deposited SiO{sub 2} films for the gained advantages. The influence of the glancing angle on the refractive index of porous SiO{sub 2} film was investigated by the spectral transmission measurement in 400950 nm wavelength regimes. The refractive index has been found to be 1.14@532 nm for the porous SiO{sub 2} film deposited at a glancing angle of 85. The density and surface qualities of these samples were primarily investigated by using grazing angle X-ray reflectivity (GIXR) and atomic force microscope (AFM) measurements. Results indicate a substantial decrease in film density and refractive index and increase in surface roughness and grain size for GLAD SiO{sub 2} compared to normally deposited SiO{sub 2} films.

  2. Effects of hydrogen on the optical properties of ZnCdO/ZnO quantum wells grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Buyanova, I. A.; Wang, X. J.; Chen, W. M.; Pozina, G.; Lim, W.; Norton, D. P.; Pearton, S. J.; Osinsky, A.; Dong, J. W.; Hertog, B.

    2008-06-30

    Temperature-dependent cw- and time-resolved photoluminescence (PL), as well as optically detected magnetic resonance (ODMR) measurements are employed to evaluate effects of deuterium (2H) doping on optical properties of ZnCdO/ZnO quantum well structures grown by molecular beam epitaxy. It is shown that incorporation of {sup 2}H from a remote plasma causes a substantial improvement in radiative efficiency of the investigated structures. Based on transient PL measurements, the observed improvements are attributed to efficient passivation by hydrogen of competing nonradiative recombination centers via defects. This conclusion is confirmed from the ODMR studies.

  3. Ab initio density functional theory investigation of the structural, electronic and optical properties of Ca{sub 3}Sb{sub 2} in hexagonal and cubic phases

    SciTech Connect (OSTI)

    Arghavani Nia, Borhan; Sedighi, Matin; Shahrokhi, Masoud; Moradian, Rostam

    2013-11-15

    A density functional theory study of structural, electronical and optical properties of Ca{sub 3}Sb{sub 2} compound in hexagonal and cubic phases is presented. In the exchangecorrelation potential, generalized gradient approximation (PBE-GGA) has been used to calculate lattice parameters, bulk modulus, cohesive energy, dielectric function and energy loss spectra. The electronic band structure of this compound has been calculated using the above two approximations as well as another form of PBE-GGA, proposed by Engle and Vosko (EV-GGA). It is found that the hexagonal phase of Ca{sub 3}Sb{sub 2} has an indirect gap in the ??N direction; while in the cubic phase there is a direct-gap at the ? point in the PBE-GGA and EV-GGA. Effects of applying pressure on the band structure of the system studied and optical properties of these systems were calculated. - Graphical abstract: A density functional theory study of structural, electronic and optical properties of Ca{sub 3}Sb{sub 2} compound in hexagonal and cubic phases is presented. Display Omitted - Highlights: Physical properties of Ca{sub 3}Sb{sub 2} in hexagonal and cubic phases are investigated. It is found that the hexagonal phase is an indirect gap semiconductor. Ca{sub 3}Sb{sub 2} is a direct-gap semiconductor at the ? point in the cubic phase. By increasing pressure the semiconducting band gap and anti-symmetry gap are decreased.

  4. Assessing the Effects of Anthropogenic Aerosols on Pacific Storm Track Using a Multiscale Global Climate Model

    SciTech Connect (OSTI)

    Wang, Yuan; Wang, Minghuai; Zhang, Renyi; Ghan, Steven J.; Lin, Yun; Hu, Jiaxi; Pan, Bowen; Levy, Misti; Jiang, Jonathan; Molina, Mario J.

    2014-05-13

    Atmospheric aerosols impact weather and global general circulation by modifying cloud and precipitation processes, but the magnitude of cloud adjustment by aerosols remains poorly quantified and represents the largest uncertainty in estimated forcing of climate change. Here we assess the impacts of anthropogenic aerosols on the Pacific storm track using a multi-scale global aerosol-climate model (GCM). Simulations of two aerosol scenarios corresponding to the present day and pre-industrial conditions reveal long-range transport of anthropogenic aerosols across the north Pacific and large resulting changes in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths. Shortwave and longwave cloud radiative forcing at the top of atmosphere are changed by - 2.5 and + 1.3 W m-2, respectively, by emission changes from pre-industrial to present day, and an increased cloud-top height indicates invigorated mid-latitude cyclones. The overall increased precipitation and poleward heat transport reflect intensification of the Pacific storm track by anthropogenic aerosols. Hence, this work provides for the first time a global perspective of the impacts of Asian pollution outflows from GCMs. Furthermore, our results suggest that the multi-scale modeling framework is essential in producing the aerosol invigoration effect of deep convective clouds on the global scale.

  5. Ganges Valley Aerosol Experiment

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

    Ganges Valley Aerosol Experiment In northeastern India, the fertile land around the Ganges River supports several hundred million people. This river, the largest in India, is fed by monsoon rains and runoff from the nearby Himalayan Mountains. Through an intergovernmental agreement with India, the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility deployed its portable laboratory, the ARM Mobile Facility (AMF), to Nainital, India, in June 2011. During

  6. Cantera Aerosol Dynamics Simulator

    Energy Science and Technology Software Center (OSTI)

    2004-09-01

    The Cantera Aerosol Dynamics Simulator (CADS) package is a general library for aerosol modeling to address aerosol general dynamics, including formation from gas phase reactions, surface chemistry (growth and oxidation), bulk particle chemistry, transport by Brownian diffusion, thermophoresis, and diffusiophoresis with linkage to DSMC studies, and thermal radiative transport. The library is based upon Cantera, a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. The method uses a discontinuous galerkinmore » formulation for the condensation and coagulation operator that conserves particles, elements, and enthalpy up to round-off error. Both O-D and 1-D time dependent applications have been developed with the library. Multiple species in the solid phase are handled as well. The O-D application, called Tdcads (Time Dependent CADS) is distributed with the library. Tdcads can address both constant volume and constant pressure adiabatic homogeneous problems. An extensive set of sample problems for Tdcads is also provided.« less

  7. ARM Cloud Aerosol Precipitation Experiment

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

    Aerosol Precipitation Experiment a NOAA ship in the Pacific Ocean and on a DOE- sponsored plane over land and sea. These researchers will study: (1) water sources, evolution and structure of atmospheric rivers over the Pacific Ocean (2) long range transport of aerosols over the Pacific Ocean between Hawaii and the U.S. West Coast, and how aerosols interact with atmospheric rivers (3) the point where atmospheric rivers make landfall on the U.S. West Coast, especially how clouds form where

  8. Aerosol mass spectrometry systems and methods

    DOE Patents [OSTI]

    Fergenson, David P.; Gard, Eric E.

    2013-08-20

    A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

  9. ARM - Surface Aerosol Observing System

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

    2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Surface Aerosol Observing System The ARM Mobile Facility (AMF) is...

  10. Effect of 8 MeV electron beam irradiation on the structural and optical properties of CeO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Babitha, K.K.; Priyanka, K.P.; Sreedevi, A.; Ganesh, S.; Varghese, Thomas

    2014-12-15

    The effect of 8 MeV electron beam irradiation on the structural and optical properties of cerium oxide nanoparticles was investigated. Ceria nanoparticles were synthesized by chemical precipitation method, and characterized by X-ray diffraction, transmission electron microscopy, ultravioletvisible, photoluminescence and Raman spectroscopy. Ultravioletvisible absorption spectra, photoluminescence and Raman spectra of beam irradiated samples were modified, and shifted to blue region, which were attributed to quantum size effect. Systematic observations found that nonstoichiometry, defects and size reduction caused by beam irradiation have great influence on optical band gap, blue shift, photoluminescence and Raman band modifications. Moreover, electron beam irradiation is a suitable technique to enhance the structural and optical properties of nanoceria by controlling the particle size, which may lead to potentially useful technological applications. - Highlights: Investigated effect of beam irradiation on CeO{sub 2} nanoparticles Beam irradiation caused size reduction and surface modification. It increases microstrain, decreases d-spacing and broadens XRD peaks. It also modifies optical band gap, absorption, PL and Raman bands.

  11. Annealing temperature and barrier thickness effect on the structural and optical properties of silicon nanocrystals/SiO₂ superlattices

    SciTech Connect (OSTI)

    López-Vidrier, J. Hernández, S.; López-Conesa, L.; Peiró, F.; Garrido, B.; Hiller, D.; Gutsch, S.; Zacharias, M.; Estradé, S.

    2014-10-07

    The effect of the annealing temperature and the SiO₂ barrier thickness of silicon nanocrystal (NC)/SiO₂ superlattices (SLs) on their structural and optical properties is investigated. Energy-filtered transmission electron microscopy (TEM) revealed that the SL structure is maintained for annealing temperatures up to 1150 °C, with no variation on the nanostructure morphology for different SiO₂ barrier thicknesses. Nevertheless, annealing temperatures as high as 1250 °C promote diffusion of Si atoms into the SiO₂ barrier layers, which produces larger Si NCs and the loss of the NC size control expected from the SL approach. Complementary Raman scattering measurements corroborated these results for all the SiO₂ and Si-rich oxynitride layer thicknesses. In addition, we observed an increasing crystalline fraction up to 1250 °C, which is related to a decreasing contribution of the suboxide transition layer between Si NCs and the SiO₂ matrix due to the formation of larger NCs. Finally, photoluminescence measurements revealed that the emission of the superlattices exhibits a Gaussian-like lineshape with a maximum intensity after annealing at 1150 °C, indicating a high crystalline degree in good agreement with Raman results. Samples submitted to higher annealing temperatures display a progressive emission broadening, together with an increase in the central emission wavelength. Both effects are related to a progressive broadening of the size distribution with a larger mean size, in agreement with TEM observations. On the other hand, whereas the morphology of the Si NCs is unaffected by the SiO₂ barrier thickness, the emission properties are slightly modified. These observed modifications in the emission lineshape allow monitoring the precipitation process of Si NCs in a direct non-destructive way. All these experimental results evidence that an annealing temperature of 1150 °C and 1-nm SiO₂ barrier can be reached whilst preserving the SL structure, being thus the optimal structural SL parameters for their use in optoelectronics.

  12. Impact of defects on the electrical transport, optical properties and failure mechanisms of GaN nanowires.

    SciTech Connect (OSTI)

    Armstrong, Andrew M.; Aubry, Sylvie; Shaner, Eric Arthur; Siegal, Michael P.; Li, Qiming; Jones, Reese E.; Westover, Tyler; Wang, George T.; Zhou, Xiao Wang; Talin, Albert Alec; Bogart, Katherine Huderle Andersen; Harris, C. Thomas; Huang, Jian Yu

    2010-09-01

    We present the results of a three year LDRD project that focused on understanding the impact of defects on the electrical, optical and thermal properties of GaN-based nanowires (NWs). We describe the development and application of a host of experimental techniques to quantify and understand the physics of defects and thermal transport in GaN NWs. We also present the development of analytical models and computational studies of thermal conductivity in GaN NWs. Finally, we present an atomistic model for GaN NW electrical breakdown supported with experimental evidence. GaN-based nanowires are attractive for applications requiring compact, high-current density devices such as ultraviolet laser arrays. Understanding GaN nanowire failure at high-current density is crucial to developing nanowire (NW) devices. Nanowire device failure is likely more complex than thin film due to the prominence of surface effects and enhanced interaction among point defects. Understanding the impact of surfaces and point defects on nanowire thermal and electrical transport is the first step toward rational control and mitigation of device failure mechanisms. However, investigating defects in GaN NWs is extremely challenging because conventional defect spectroscopy techniques are unsuitable for wide-bandgap nanostructures. To understand NW breakdown, the influence of pre-existing and emergent defects during high current stress on NW properties will be investigated. Acute sensitivity of NW thermal conductivity to point-defect density is expected due to the lack of threading dislocation (TD) gettering sites, and enhanced phonon-surface scattering further inhibits thermal transport. Excess defect creation during Joule heating could further degrade thermal conductivity, producing a viscous cycle culminating in catastrophic breakdown. To investigate these issues, a unique combination of electron microscopy, scanning luminescence and photoconductivity implemented at the nanoscale will be used in concert with sophisticated molecular-dynamics calculations of surface and defect-mediated NW thermal transport. This proposal seeks to elucidate long standing material science questions for GaN while addressing issues critical to realizing reliable GaN NW devices.

  13. Structural and optical properties of InGaN--GaN nanowire heterostructures grown by molecular beam epitaxy

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

    Limbach, F.; Gotschke, T.; Stoica, T.; Calarco, R.; Sutter, E.; Ciston, J.; Cusco, R.; Artus, L.; Kremling, S.; Hofling, S.; et al

    2011-01-01

    InGaN/GaN nanowire (NW) heterostructures grown by plasma assisted molecular beam epitaxy were studied in comparison to their GaN and InGaN counterparts. The InGaN/GaN heterostructure NWs are composed of a GaN NW, a thin InGaN shell, and a multifaceted InGaN cap wrapping the top part of the GaN NW. High-resolution transmission electron microscopy (HRTEM) images taken from different parts of a InGaN/GaN NW show a wurtzite structure of the GaN core and the epitaxial InGaN shell around it, while additional crystallographic domains are observed whithin the InGaN cap region. Large changes in the lattice parameter along the wire, from pure GaNmore » to higher In concentration demonstrate the successful growth of a complex InGaN/GaN NW heterostructure. Photoluminescence (PL) spectra of these heterostructure NW ensembles show rather broad and intense emission peak at 2.1 eV. However, μ-PL spectra measured on single NWs reveal a reduced broadening of the visible luminescence. The analysis of the longitudinal optical phonon Raman peak position and its shape reveal a variation in the In content between 20% and 30%, in agreement with the values estimated by PL and HRTEM investigations. The reported studies are important for understanding of the growth and properties of NW heterostructures suitable for applications in optoelectronics and photovoltaics.« less

  14. Structural and optical properties of InGaNGaN nanowire heterostructures grown by molecular beam epitaxy

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

    Limbach, F.; Gotschke, T.; Stoica, T.; Calarco, R.; Sutter, E.; Ciston, J.; Cusco, R.; Artus, L.; Kremling, S.; Ho?fling, S.; et al

    2011-01-01

    InGaN/GaN nanowire (NW) heterostructures grown by plasma assisted molecular beam epitaxy were studied in comparison to their GaN and InGaN counterparts. The InGaN/GaN heterostructure NWs are composed of a GaN NW, a thin InGaN shell, and a multifaceted InGaN cap wrapping the top part of the GaN NW. High-resolution transmission electron microscopy (HRTEM) images taken from different parts of a InGaN/GaN NW show a wurtzite structure of the GaN core and the epitaxial InGaN shell around it, while additional crystallographic domains are observed whithin the InGaN cap region. Large changes in the lattice parameter along the wire, from pure GaNmoreto higher In concentration demonstrate the successful growth of a complex InGaN/GaN NW heterostructure. Photoluminescence (PL) spectra of these heterostructure NW ensembles show rather broad and intense emission peak at 2.1 eV. However, ?-PL spectra measured on single NWs reveal a reduced broadening of the visible luminescence. The analysis of the longitudinal optical phonon Raman peak position and its shape reveal a variation in the In content between 20% and 30%, in agreement with the values estimated by PL and HRTEM investigations. The reported studies are important for understanding of the growth and properties of NW heterostructures suitable for applications in optoelectronics and photovoltaics.less

  15. A Global Climatology of Single-Layer and Overlapped Clouds and their Optical Properties Developed Using a New Algorithm Applied to Terra/MODIS Data

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

    Global Climatology of Single-Layer and Overlapped Clouds and their Optical Properties Developed Using a New Algorithm Applied to Terra/MODIS Data F.-L. Chang and Z. Li Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland Z. Li Department of Meteorology University of Maryland College Park, Maryland Introduction To date, weather satellites are the only tool to measure cloud and climate variables on a global scale, an objective addressed by the International

  16. Atmospheric Science Program Cumulus Humilis Aerosol Processing...

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

    aerosols - within and around them. Aerosols - particularly those associated with human activity - are thought to be changing the brightness, the lifetime, the amount of...

  17. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion...

  18. About EffectiveŽ Height of the Aerosol Atmosphere in Visible and IR Wavelength Range

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

    "Effective" Height of the Aerosol Atmosphere in Visible and IR Wavelength Range V. N. Uzhegov, D. M. Kabanov, M. V. Panchenko, Yu. A. Pkhalagov, and S. M. Sakerin Institute of Atmospheric Optics Tomsk, Russia Introduction Aerosol component of the atmosphere is one of the important factors affecting the radiation budget of the space - atmosphere - underlying surface system in visible and infrared (IR) wavelength ranges. It is extremely important to take into account the contribution of

  19. Influence of the Electronic Structure and Optical Properties of CeO2 and UO2 for Characterization with UV-Laser Assisted Atom Probe Tomography

    SciTech Connect (OSTI)

    Billy Valderrama; H.B. Henderson; C. Yablinsky; J. Gan; T.R. Allen; M.V. Manuel

    2015-09-01

    Oxide materials are used in numerous applications such as thermal barrier coatings, nuclear fuels, and electrical conductors and sensors, all applications where nanometer-scale stoichiometric changes can affect functional properties. Atom probe tomography can be used to characterize the precise chemical distribution of individual species and spatially quantify the oxygen to metal ratio at the nanometer scale. However, atom probe analysis of oxides can be accompanied by measurement artifacts caused by laser-material interactions. In this investigation, two technologically relevant oxide materials with the same crystal structure and an anion to cation ratio of 2.00, pure cerium oxide (CeO2) and uranium oxide (UO2) are studied. It was determined that electronic structure, optical properties, heat transfer properties, and oxide stability strongly affect their evaporation behavior, thus altering their measured stoichiometry, with thermal conductance and thermodynamic stability being strong factors.

  20. Electronic structure and optical properties of Ag{sub 3}PO{sub 4} photocatalyst calculated by hybrid density functional method

    SciTech Connect (OSTI)

    Liu, J. J.; Fu, X. L.; Chen, S. F.; Zhu, Y. F.

    2011-11-07

    The electronic structure and optical properties of Ag{sub 3}PO{sub 4} were studied by hybrid density functional theory. The results indicated that the band gap is 2.43 eV, which agrees well with the experimental value of 2.45 eV. The conduction bands of Ag{sub 3}PO{sub 4} are mainly attributable to Ag 5s and 5p states, while the valence bands are dominated by O 2p and Ag 4d states. The highest valence band edge potential was 2.67 V (vs. normal hydrogen electrode), which has enough driving force for photocatalytic water oxidation and pollutants degradation. The optical absorption spectrum showed that Ag{sub 3}PO{sub 4} is a visible light response photocatalyst.

  1. Electronic and optical properties of pure and modified diamondoids studied by many-body perturbation theory and time-dependent density functional theory

    SciTech Connect (OSTI)

    Demján, Tamás; Vörös, Márton; Palummo, Maurizia; Gali, Adam

    2014-08-14

    Diamondoids are small diamond nanoparticles (NPs) that are built up from diamond cages. Unlike usual semiconductor NPs, their atomic structure is exactly known, thus they are ideal test-beds for benchmarking quantum chemical calculations. Their usage in spintronics and bioimaging applications requires a detailed knowledge of their electronic structure and optical properties. In this paper, we apply density functional theory (DFT) based methods to understand the electronic and optical properties of a few selected pure and modified diamondoids for which accurate experimental data exist. In particular, we use many-body perturbation theory methods, in the G{sub 0}W{sub 0} and G{sub 0}W{sub 0}+BSE approximations, and time-dependent DFT in the adiabatic local density approximation. We find large quasiparticle gap corrections that can exceed thrice the DFT gap. The electron-hole binding energy can be as large as 4 eV but it is considerably smaller than the GW corrections and thus G{sub 0}W{sub 0}+BSE optical gaps are about 50% larger than the Kohn-Sham (KS) DFT gaps. We find significant differences between KS time-dependent DFT and GW+BSE optical spectra on the selected diamondoids. The calculated G{sub 0}W{sub 0} quasiparticle levels agree well with the corresponding experimental vertical ionization energies. We show that nuclei dynamics in the ionization process can be significant and its contribution may reach about 0.5 eV in the adiabatic ionization energies.

  2. Thermoelectric, electronic, optical and chemical bonding properties of Ba{sub 2}PrRuO{sub 6}: At temperature 7 K and 150 K

    SciTech Connect (OSTI)

    Reshak, A.H.; Khan, Wilayat

    2015-01-15

    Highlights: DFT-FPLAPW method used for calculating the electronic structure. The Fermi surface of BPRO (7 K and 150 K) is also calculated. The complex dielectric function has been calculated. Thermoelectric properties were also calculated using BoltzTraP code. Power factor shows that both compounds are good thermoelectric materials at 600 K. - Abstract: We present first principles calculations of the band structure, density of states, electronic charge density, Fermi surface and optical properties of Ba{sub 2}PrRuO{sub 6} single crystals at two different temperatures. The atomic positions were optimized by minimizing the forces acting on the atoms. We have employed the full potential linear augmented plane wave method within local density approximation, generalized gradient approximation and EngelVosko generalized gradient approximation to treat the exchange correlation potential. The calculation shows that the compound is superconductor with strong hybridization near the Fermi energy level. Fermi surface is composed of two sheets. The calculated electronic specific heat capacities indicate, very close agreement with the experimental one. The bonding features of the compounds are analyzed using the electronic charge density in the (1 0 0) and (010) crystallographic planes. The dispersion of the optical constants was calculated and discussed. The thermoelectric properties are also calculated using the BoltzTrap code.

  3. Effect of arsenic on the optical properties of GaSb-based type II quantum wells with quaternary GaInAsSb layers

    SciTech Connect (OSTI)

    Janiak, F. Motyka, M.; S?k, G.; Dyksik, M.; Ryczko, K.; Misiewicz, J.; Weih, R.; Hfling, S.; Kamp, M.; Patriarche, G.

    2013-12-14

    Optical properties of molecular beam epitaxially grown type II W shaped GaSb/AlSb/InAs/GaIn(As)Sb/InAs/AlSb/GaSb quantum wells (QWs) designed for the active region of interband cascade lasers have been investigated. Temperature dependence of Fourier-transformed photoluminescence and photoreflectance was employed to probe the effects of addition of arsenic into the original ternary valence band well of GaInSb. It is revealed that adding arsenic provides an additional degree of freedom in terms of band alignment and strain tailoring and allows enhancing the oscillator strength of the active type II transition. On the other hand, however, arsenic incorporation apparently also affects the structural and optical material quality via generating carrier trapping states at the interfaces, which can deteriorate the radiative efficiency. These have been evidenced in several spectroscopic features and are also confirmed by cross-sectional transmission electron microscopy images. While arsenic incorporation into type II QWs is a powerful heterostructure engineering tool for optoelectronic devices, a compromise has to be found between ideal band structure properties and high quality morphological properties.

  4. Carbonaceous Aerosols and Radiative Effects Study

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

    Carbonaceous Aerosols and Radiative Effects Study Science Objective This field campaign is designed to increase scientific knowledge about the evolution of black carbon, primary organic aerosols (POA), and secondary organic aerosols (SOA) from both man-made and biogenic sources. Black carbon and primary organic aerosols are emitted directly into the atmosphere through diesel and gasoline vehicle exhaust, as well as during meat cooking and biomass burning; secondary organic aerosols are formed

  5. ARM - Campaign Instrument - drum-aerosol

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

    govInstrumentsdrum-aerosol Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Drum Aerosol Sampler (DRUM-AEROSOL) Instrument Categories Aerosols Campaigns Aerosol IOP [ Download Data ] Southern Great Plains, 2003.05.01 - 2003.05.31 Primary Measurements Taken The following measurements are those considered scientifically relevant. Refer to the datastream (netcdf) file headers for the list of all available measurements, including

  6. eDPS Aerosol Collection

    SciTech Connect (OSTI)

    Venzie, J.

    2015-10-13

    The eDPS Aerosol Collection project studies the fundamental physics of electrostatic aerosol collection for national security applications. The interpretation of aerosol data requires understanding and correcting for biases introduced from particle genesis through collection and analysis. The research and development undertaken in this project provides the basis for both the statistical correction of existing equipment and techniques; as well as, the development of new collectors and analytical techniques designed to minimize unwanted biases while improving the efficiency of locating and measuring individual particles of interest.

  7. Development of Aerosol Models for Radiative Flux Calculations at ARM Sites

    SciTech Connect (OSTI)

    Ogren, John A.; Dutton, Ellsworth G.; McComiskey, Allison C.

    2006-09-30

    The direct radiative forcing (DRF) of aerosols, the change in net radiative flux due to aerosols in non-cloudy conditions, is an essential quantity for understanding the human impact on climate change. Our work has addressed several key issues that determine the accuracy, and identify the uncertainty, with which aerosol DRF can be modeled. These issues include the accuracy of several radiative transfer models when compared to measurements and to each other in a highly controlled closure study using data from the ARM 2003 Aerosol IOP. The primary focus of our work has been to determine an accurate approach to assigning aerosol properties appropriate for modeling over averaged periods of time and space that represent the observed regional variability of these properties. We have also undertaken a comprehensive analysis of the aerosol properties that contribute most to uncertainty in modeling aerosol DRF, and under what conditions they contribute the most uncertainty. Quantification of these issues enables the community to better state accuracies of radiative forcing calculations and to concentrate efforts in areas that will decrease uncertainties in these calculations in the future.

  8. Stratospheric aerosol geoengineering

    SciTech Connect (OSTI)

    Robock, Alan

    2015-03-30

    The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 510 times the rates from gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.

  9. Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) Science Plan

    SciTech Connect (OSTI)

    Fast, JD; Berg, LK

    2015-12-01

    Cumulus convection is an important component in the atmospheric radiation budget and hydrologic cycle over the Southern Great Plains and over many regions of the world, particularly during the summertime growing season when intense turbulence induced by surface radiation couples the land surface to clouds. Current convective cloud parameterizations contain uncertainties resulting in part from insufficient coincident data that couples cloud macrophysical and microphysical properties to inhomogeneities in boundary layer and aerosol properties. The Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) campaign is designed to provide a detailed set of measurements that are needed to obtain a more complete understanding of the life cycle of shallow clouds by coupling cloud macrophysical and microphysical properties to land surface properties, ecosystems, and aerosols. HI-SCALE consists of 2, 4-week intensive observational periods, one in the spring and the other in the late summer, to take advantage of different stages and distribution of “greenness” for various types of vegetation in the vicinity of the Atmospheric Radiation and Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site as well as aerosol properties that vary during the growing season. Most of the proposed instrumentation will be deployed on the ARM Aerial Facility (AAF) Gulfstream 1 (G-1) aircraft, including those that measure atmospheric turbulence, cloud water content and drop size distributions, aerosol precursor gases, aerosol chemical composition and size distributions, and cloud condensation nuclei concentrations. Routine ARM aerosol measurements made at the surface will be supplemented with aerosol microphysical properties measurements. The G-1 aircraft will complete transects over the SGP Central Facility at multiple altitudes within the boundary layer, within clouds, and above clouds.

  10. X-shaped Electro-Optic Chromophore with Remarkably Blue-Shifted Optical Absorption. Synthesis, Characterization, Linear/Nonlinear Optical Properties, Self-Assembly, and Thin Film Microstructural Characteristics

    SciTech Connect (OSTI)

    Kang,H.; Evmenenko, G.; Dutta, P.; Clays, K.; Song, K.; Marks, T.

    2006-01-01

    A novel type of 'X-shaped' two-dimensional electro-optic (EO) chromophore with extended conjugation has been synthesized and characterized. This chromophore is found to exhibit a remarkably blue-shifted optical maximum (357 nm in CH{sub 2}Cl{sub 2}) while maintaining a very large first hyperpolarizability ({beta}). Hyper-Rayleigh Scattering (HRS) measurements at 800 nm provide a {beta}{sub zzz} value of 1840 x 10{sup -30} esu. Self-assembled thin films of this chromophore were fabricated via a layer-by-layer chemisorptive siloxane-based approach. The chromophoric multilayers have been characterized by transmission optical spectroscopy, advancing contact angle measurements, synchrotron X-ray reflectivity, atomic force microscopy, and angle-dependent polarized second harmonic generation spectroscopy. The self-assembled chromophoric films exhibit a dramatically blue-shifted optical maximum (325 nm) while maintaining a large EO response ({chi}({sup 2}){sub 333} {approx} 232 pm/V at 1064 nm; r{sub 33} {approx} 45 pm/V at 1310 nm). This work demonstrates an attractive approach to developing EO materials offering improved nonlinearity-transparency trade-offs.

  11. Transport of anthropogenic and biomass burning aerosols from Europe to the Arctic during spring 2008

    SciTech Connect (OSTI)

    Marelle, L.; Raut, Jean-Christophe; Thomas, J. L.; Law, K. S.; Quennehen, Boris; Ancellet, G.; Pelon, J.; Schwarzenboeck, A.; Fast, Jerome D.

    2015-04-10

    During the POLARCAT-France airborne campaign in April 2008, pollution originating from anthropogenic and biomass burning emissions was measured in the European Arctic. We compare these aircraft measurements with simulations using the WRF-Chem model to investigate model representation of aerosols transported from Europe to the Arctic. Modeled PM2.5 is evaluated using European Monitoring and Evaluation Programme (EMEP) measurements in source regions and POLARCAT aircraft measurements in the Scandinavian Arctic. Total PM2.5 agrees well with the measurements, although the model overestimates nitrate and underestimates organic carbon in source regions. Using WRF-Chem in combination with the Lagrangian model FLEXPART-WRF, we find that during the campaign the research aircraft sampled two different types of European plumes: mixed anthropogenic and fire plumes from eastern Europe and Russia transported below 2 km, and anthropogenic plumes from central Europe uplifted by warm conveyor belt circulations to 56 km. Both modeled plume types had undergone significant wet scavenging (> 50% PM10) during transport. Modeled aerosol vertical distributions and optical properties below the aircraft are evaluated in the Arctic using airborne lidar measurements. Model results show that the pollution event transported aerosols into the Arctic (> 66.6 N) for a 4-day period. During this 4-day period, biomass burning emissions have the strongest influence on concentrations between 2.5 and 3 km altitudes, while European anthropogenic emissions influence aerosols at both lower (~ 1.5 km) and higher altitudes (~ 4.5 km). As a proportion of PM2.5, modeled black carbon and SO4= concentrations are more enhanced near the surface in anthropogenic plumes. The European plumes sampled during the POLARCAT-France campaign were transported over the region of springtime snow cover in northern Scandinavia, where they had a significant local atmospheric warming effect. We find that, during this transport event, the average modeled top-of-atmosphere (TOA) shortwave direct and semi-direct radiative effect (DSRE) north of 60 N over snow and ice-covered surfaces reaches +0.58 W m?2, peaking at +3.3 W m?2 at noon over Scandinavia and Finland.

  12. Transport of anthropogenic and biomass burning aerosols from Europe to the Arctic during spring 2008

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

    Marelle, L.; Raut, Jean-Christophe; Thomas, J. L.; Law, K. S.; Quennehen, Boris; Ancellet, G.; Pelon, J.; Schwarzenboeck, A.; Fast, Jerome D.

    2015-04-10

    During the POLARCAT-France airborne campaign in April 2008, pollution originating from anthropogenic and biomass burning emissions was measured in the European Arctic. We compare these aircraft measurements with simulations using the WRF-Chem model to investigate model representation of aerosols transported from Europe to the Arctic. Modeled PM2.5 is evaluated using European Monitoring and Evaluation Programme (EMEP) measurements in source regions and POLARCAT aircraft measurements in the Scandinavian Arctic. Total PM2.5 agrees well with the measurements, although the model overestimates nitrate and underestimates organic carbon in source regions. Using WRF-Chem in combination with the Lagrangian model FLEXPART-WRF, we find that duringmore » the campaign the research aircraft sampled two different types of European plumes: mixed anthropogenic and fire plumes from eastern Europe and Russia transported below 2 km, and anthropogenic plumes from central Europe uplifted by warm conveyor belt circulations to 5–6 km. Both modeled plume types had undergone significant wet scavenging (> 50% PM10) during transport. Modeled aerosol vertical distributions and optical properties below the aircraft are evaluated in the Arctic using airborne lidar measurements. Model results show that the pollution event transported aerosols into the Arctic (> 66.6° N) for a 4-day period. During this 4-day period, biomass burning emissions have the strongest influence on concentrations between 2.5 and 3 km altitudes, while European anthropogenic emissions influence aerosols at both lower (~ 1.5 km) and higher altitudes (~ 4.5 km). As a proportion of PM2.5, modeled black carbon and SO4= concentrations are more enhanced near the surface in anthropogenic plumes. The European plumes sampled during the POLARCAT-France campaign were transported over the region of springtime snow cover in northern Scandinavia, where they had a significant local atmospheric warming effect. We find that, during this transport event, the average modeled top-of-atmosphere (TOA) shortwave direct and semi-direct radiative effect (DSRE) north of 60° N over snow and ice-covered surfaces reaches +0.58 W m−2, peaking at +3.3 W m−2 at noon over Scandinavia and Finland.« less

  13. Property

    Energy Savers [EERE]

    ER-B-98-07 AUDIT REPORT PERSONAL PROPERTY AT THE OAK RIDGE OPERATIONS OFFICE AND THE OFFICE OF SCIENTIFIC AND TECHNICAL INFORMATION U.S. DEPARTMENT OF ENERGY OFFICE OF INSPECTOR GENERAL OFFICE OF AUDIT SERVICES APRIL 1998 Page 10 DEPARTMENT OF ENERGY Washington, DC 20585 April 6, 1998 MEMORANDUM FOR THE MANAGER, OAK RIDGE OPERATIONS OFFICE AND THE DIRECTOR, OFFICE OF SCIENTIFIC AND TECHNICAL INFORMATION FROM: Terry L. Brendlinger Eastern Regional Audit Office Office of Inspector General SUBJECT:

  14. ARM Aerosol Working Group Meeting

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

    Report ARM STM 2008 Norfolk, VA Connor Flynn for B Schmid and AWG Members AWG Instruments * Raman Lidar - SGP * Micropulse Lidars - all sites * Aerosol Sampling - SGP, NSA, AMF - scattering, absorption, number, size distribution, hygroscopicity, CCN, composition (major ions). * In situ Aerosol Profile (Cessna) - scattering, absorption, number, hygroscopicity, * Radiometers: - MFRSR, NIMFR, RSS, Cimel, AERI, SWS AWG-related Field Campaigns * Recent Past: - MASRAD (Marine Stratus Radiation,

  15. Electronic structure and optical properties of ?-(Fe{sub 1-x}V{sub x}){sub 2}O{sub 3} solid-solution thin films

    SciTech Connect (OSTI)

    Chamberlin, S. E.; Nayyar, I. H.; Kaspar, T. C.; Sushko, P. V.; Chambers, S. A.

    2015-01-26

    We have examined the effect of V doping on the electronic and optical properties of epitaxial hematite (?-Fe{sub 2}O{sub 3}) thin films, by employing several characterization techniques and computational modeling. The conductivity of ?-(Fe{sub 1-x}V{sub x}){sub 2}O{sub 3} (0???x????0.5) is enhanced by several orders of magnitude as x is increased, as evidenced by electrical resistivity measurements and x-ray photoelectron spectroscopy core-level and valence-band spectra. Optical absorption shows a reduction in the direct band gap by as much as 0.64?eV for x?=?0.53 (E{sub g}?=?1.46?eV) relative to that of ?-Fe{sub 2}O{sub 3} (E{sub g}?=?2.10?eV). Detailed understanding of the character of the optical transitions in the alloys is achieved using first-principles calculations of the ground and excited states. These calculations reveal that V doping results in occupied V 3d orbitals hybridized with Fe orbitals and located at approximately mid-gap in ?-Fe{sub 2}O{sub 3}. The lowest energy transitions involve charge transfer from occupied V 3d to unoccupied Fe 3d* orbitals. With a low band gap and high conductivity, ?-(Fe{sub 1-x}V{sub x}){sub 2}O{sub 3} is a promising material for photovoltaic and photoelectrochemical applications.

  16. Structural and optical properties of Sn{sub 1?x}Fe{sub x}O{sub 2} thin films prepared by flash evaporation technique

    SciTech Connect (OSTI)

    Kuppan, M. Kaleemulla, S. Rao, N. Madhusudhana Krishna, N. Sai Begam, M. Rigana

    2014-04-24

    Sn{sub 1?x}Fe{sub X}O{sub 2} (x = 0, 0.05) thin films were prepared on glass substrate using the flash evaporation technique. The samples were annealed at 773 K for 2 hrs in air atmosphere. A systematic study was carried out on the structural and optical properties of the as deposited and annealed thin films. From the X-ray diffraction analysis it was found that the Sn{sub 1?x}Fe{sub X}O{sub 2} films deposited at 623 K were amorphous in nature and the Sn{sub 1?x}Fe{sub X}O{sub 2} films annealed at 773 K exhibited the tetragonal structure of the SnO{sub 2}. The optical band gap of the SnO{sub 2} thin films was found to be as 3.17 eV whereas the optical band gap of the Sn{sub 1?x}Fe{sub X}O{sub 2} films was found to be as 3.01 eV after air annealing.

  17. Evaluation of Black Carbon Estimations in Global Aerosol Models

    SciTech Connect (OSTI)

    Koch, D.; Schulz, M.; Kinne, Stefan; McNaughton, C. S.; Spackman, J. R.; Balkanski, Y.; Bauer, S.; Berntsen, T.; Bond, Tami C.; Boucher, Olivier; Chin, M.; Clarke, A. D.; De Luca, N.; Dentener, F.; Diehl, T.; Dubovik, O.; Easter, Richard C.; Fahey, D. W.; Feichter, J.; Fillmore, D.; Freitag, S.; Ghan, Steven J.; Ginoux, P.; Gong, S.; Horowitz, L.; Iversen, T.; Kirkevag, A.; Klimont, Z.; Kondo, Yutaka; Krol, M.; Liu, Xiaohong; Miller, R.; Montanaro, V.; Moteki, N.; Myhre, G.; Penner, J.; Perlwitz, Ja; Pitari, G.; Reddy, S.; Sahu, L.; Sakamoto, H.; Schuster, G.; Schwarz, J. P.; Seland, O.; Stier, P.; Takegawa, Nobuyuki; Takemura, T.; Textor, C.; van Aardenne, John; Zhao, Y.

    2009-11-27

    We evaluate black carbon (BC) model predictions from the AeroCom model intercomparison project by considering the diversity among year 2000 model simulations and comparing model predictions with available measurements. These model-measurement intercomparisons include BC surface and aircraft concentrations, aerosol absorption optical depth (AAOD) from AERONET and OMI retrievals and BC column estimations based on AERONET. In regions other than Asia, most models are biased high compared to surface concentration measurements. However compared with (column) AAOD or BC burden retreivals, the models are generally biased low. The average ratio of model to retrieved AAOD is less than 0.7 in South American and 0.6 in African biomass burning regions; both of these regions lack surface concentration measurements. In Asia the average model to observed ratio is 0.6 for AAOD and 0.5 for BC surface concentrations. Compared with aircraft measurements over the Americas at latitudes between 0 and 50N, the average model is a factor of 10 larger than observed, and most models exceed the measured BC standard deviation in the mid to upper troposphere. At higher latitudes the average model to aircraft BC is 0.6 and underestimate the observed BC loading in the lower and middle troposphere associated with springtime Arctic haze. Low model bias for AAOD but overestimation of surface and upper atmospheric BC concentrations at lower latitudes suggests that most models are underestimating BC absorption and should improve estimates for refractive index, particle size, and optical effects of BC coating. Retrieval uncertainties and/or differences with model diagnostic treatment may also contribute to the model-measurement disparity. Largest AeroCom model diversity occurred in northern Eurasia and the remote Arctic, regions influenced by anthropogenic sources. Changing emissions, aging, removal, or optical properties within a single model generated a smaller change in model predictions than the range represented by the full set of AeroCom models. Upper tropospheric concentrations of BC mass from the aircraft measurements are suggested to provide a unique new benchmark to test scavenging and vertical dispersion of BC in global models.

  18. Determination of the optical properties of La2-xBaxCuO₄ for several dopings, including the anomalous x=1/8 phase

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

    Homes, C. C.; Hücker, M.; Li, Q.; Xu, Z. J.; Wen, J. S.; Gu, G. D.; Tranquada, J. M.

    2012-04-11

    The optical properties of single crystals of the high-temperature superconductor La2-xBaxCuO₄ have been measured over a wide frequency and temperature range for light polarized in the a-b planes and along the c axis. Three different Ba concentrations have been examined, x=0.095 with a critical temperature Tc=32 K, x=0.125 where the superconductivity is dramatically weakened with Tc≅2.4 K, and x=0.145 with Tc≅24 K. The in-plane behavior of the optical conductivity for these materials at high temperature is described by a Drude-like response with a scattering rate that decreases with temperature. Below Tc in the x=0.095 and 0.145 materials there is amore » clear signature of the formation of a superconducting state in the optical properties allowing the superfluid density (ρs0) and the penetration depth to be determined. In the anomalous 1/8 phase, some spectral weight shifts from lower to higher frequency (≳300 cm⁻¹) on cooling below the spin-ordering temperature Tso≅42 K, associated with the onset of spin-stripe order; we discuss alternative interpretations in terms of a conventional density-wave gap versus the response to pair-density-wave superconductivity. The two dopings for which a superconducting response is observed both fall on the universal scaling line ρs0/8≅4.4σdcTc, which is consistent with the observation of strong dissipation within the a-b planes. The optical properties for light polarized along the c axis reveal an insulating character dominated by lattice vibrations, superimposed on a weak electronic background. No Josephson plasma edge is observed in the low-frequency reflectance along the c axis for x=1/8; however, sharp plasma edges are observed for x=0.095 and 0.145 below Tc.« less

  19. Structural and optical properties of Ag-doped copper oxide thin films on polyethylene napthalate substrate prepared by low temperature microwave annealing

    SciTech Connect (OSTI)

    Das, Sayantan; Alford, T. L.

    2013-06-28

    Silver doped cupric oxide thin films are prepared on polyethylene naphthalate (flexible polymer) substrates. Thin films Ag-doped CuO are deposited on the substrate by co-sputtering followed by microwave assisted oxidation of the metal films. The low temperature tolerance of the polymer substrates led to the search for innovative low temperature processing techniques. Cupric oxide is a p-type semiconductor with an indirect band gap and is used as selective absorption layer solar cells. X-ray diffraction identifies the CuO phases. Rutherford backscattering spectrometry measurements confirm the stoichiometry of each copper oxide formed. The surface morphology is determined by atomic force microscopy. The microstructural properties such as crystallite size and the microstrain for (-111) and (111) planes are calculated and discussed. Incorporation of Ag led to the lowering of band gap in CuO. Consequently, it is determined that Ag addition has a strong effect on the structural, morphological, surface, and optical properties of CuO grown on flexible substrates by microwave annealing. Tauc's plot is used to determine the optical band gap of CuO and Ag doped CuO films. The values of the indirect and direct band gap for CuO are found to be 2.02 eV and 3.19 eV, respectively.

  20. Synthesis and investigation of optical properties of TOPO-capped CuInS{sub 2} semiconductor nanocrystal in the presence of different solvent

    SciTech Connect (OSTI)

    Asgary, Saeid; Mirabbaszadeh, Kavoos; Nayebi, Payman; Emadi, Hamid

    2014-03-01

    Graphical abstract: - Highlights: TOPO-capped CuInS{sub 2} nanoparticles were synthesized by injection method. Pure CuInS{sub 2} nanoparticle was obtained by injection in 200 C. The size, shape and optical properties of products were controlled. Nanoparticles with size smaller than 10 nm and wurtzite phase was obtained. The absorption and PL spectra of CuInS{sub 2} nanoparticles were tunable. - Abstract: In this work, synthesis of CuInS{sub 2} semiconductor nanoparticles by thermolysis of a mixed solution of CuAc, In(Ac){sub 3} and DDT in coordinating solvent and trioctylphosphine oxide (TOPO) as ligand was developed. CuInS{sub 2} nanoparticles with size of ?10 nm and nanorods were obtained and optical properties controlled by adjusting the reaction parameters such as temperature and time. Also the shape of nanoparticles was controlled by various solvents elaborately. The as-prepared nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), UVvis absorption, and photoluminescence (PL) spectroscopy. With the use of different solvent different morphology obtained. In the presence of oleylamine/octadecene rectangle-like nanorods obtained while with the use of oleic acid sphere-like nanoparticles achieved.

  1. Optical modeling and electrical properties of cadmium oxide nanofilms: Developing a metaheuristic calculation process model

    SciTech Connect (OSTI)

    Abdolahzadeh Ziabari, Ali; Refahi Sheikhani, A. H.; Nezafat, Reza Vatani; Haghighidoust, Kasra Monsef

    2015-04-07

    Cadmium oxide thin films were deposited onto glass substrates by solgel dip-coating method and annealed in air. The normal incidence transmittance of the films was measured by a spectrophotometer. D.C electrical parameters such as carrier concentration and mobility were analyzed by Hall Effect measurements. A combination of ForouhiBloomer and standard Drude model was used to simulate the optical constants and thicknesses of the films from transmittance data. The transmittance spectra of the films in the visible domain of wavelengths were successfully fitted by using the result of a hybrid particle swarm optimization method and genetic algorithm. The simulated transmittance is in good accordance with the measured spectrum in the whole measurement wavelength range. The electrical parameters obtained from the optical simulation are well consistent with those measured electrically by Hall Effect measurements.

  2. X-ray Vision for Aerosol Scientists: LCLS Snapshots of Soot (Narrated)

    ScienceCinema (OSTI)

    None

    2014-06-03

    This short conceptual animation depicts how scientists can now simultaneously capture fractal morphology (structure), chemical composition and nanoscale imagery of individual aerosol particles in flight. These particles, known as "PM2.5" because they are smaller than 2.5 microns in diameter, affect climate by interacting with sunlight and impact human health by entering the lungs. The single LCLS laser pulses travel to the Atomic, Molecular and Optical Sciences (AMO) laboratory in the Near Experimental Hall. As we zoom in, we see deep inside a simplified aerosol inlet, where the complex fractal structure of the soot particles, each one completely unique, is shown. Individual soot particles are then delivered into the pulses of the LCLS beam, which destroys them. X-rays are scattered to the detector before the particle is destroyed, giving information about the morphology of the particle. Ion fragments released in the explosion are sent into a mass spectrometer, which measures their mass-to-charge ratio -- giving scientists information about the chemical composition of the particle. Many different particles are analyzed in this manner, allowing scientists to probe variations in the particles due to changes in their environment before being sent through the aerosol inlet. The final visual of aerosols emitted from a factory is representative of the goal that such LCLS aerosol dynamics experiments can provide critical feedback into modeling and understanding combustion, aerosol processes in manufacturing or aerosol effects on climate change.

  3. Impact of biomass burning aerosol on the monsoon circulation transition over Amazonia

    SciTech Connect (OSTI)

    Zhang, Y.; Fu, Rong; Yu, Hongbin; Qian, Yun; Dickinson, Robert; Silva Dias, Maria Assuncao F.; da Silva Dias, Pedro L.; Fernandes, Katia

    2009-05-30

    Ensemble simulations of a regional climate model (RegCM3) forced by aerosol radiative forcing suggest that biomass burning aerosols can work against the seasonal monsoon circulation transition, thus re-enforce the dry season rainfall pattern for Southern Amazonia. Strongly absorbing smoke aerosols warm and stabilize the lower troposphere within the smoke center in southern Amazonia (where aerosol optical depth > 0.3). These changes increase the surface pressure in the smoke center, weaken the southward surface pressure gradient between northern and southern Amazonia, and consequently induce an anomalous moisture divergence in the smoke center and an anomalous convergence occurs in northwestern Amazonia (5S-5N, 60W-40 70W). The increased atmospheric thermodynamic stability, surface pressure, and divergent flow in Southern Amazonia may inhibit synoptic cyclonic activities propagated from extratropical South America, and re-enforce winter-like synoptic cyclonic activities and rainfall in southeastern Brazil, Paraguay and northeastern Argentina.

  4. XrayOpticsConstants

    Energy Science and Technology Software Center (OSTI)

    2005-06-20

    This application (XrayOpticsConstants) is a tool for displaying X-ray and Optical properties for a given material, x-ray photon energy, and in the case of a gas, pressure. The display includes fields such as the photo-electric absorption attenuation length, density, material composition, index of refraction, and emission properties (for scintillator materials).

  5. Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations and Indirect Aerosol Effects

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

    Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations, and Indirect Aerosol Effects P. H. Daum and Y. Liu Brookhaven National Laboratory Upton, New York Introduction Most studies of the effect of aerosols on cloud radiative properties have considered only changes in the cloud droplet concentration, neglecting changes in the spectral shape of the cloud droplet size distribution. However, it has been shown that that the spectral dispersion of the cloud droplet size distribution

  6. Single-step in-situ synthesis and optical properties of ZnSe nanostructured dielectric nanocomposites

    SciTech Connect (OSTI)

    Dey, Chirantan; Rahaman Molla, Atiar; Tarafder, Anal; Karmakar, Basudeb; Kr Mishra, Manish; De, Goutam; Goswami, Madhumita; Kothiyal, G. P.

    2014-04-07

    This work provides the evidence of visible red photoluminescent light emission from ZnSe nanocrystals (NCs) grown within a dielectric (borosilicate glass) matrix synthesized by a single step in-situ technique for the first time and the NC sizes were controlled by varying only the concentration of ZnSe in glass matrix. The ZnSe NCs were investigated by UV-Vis optical absorption spectroscopy, Raman spectroscopy, and transmission electron microscopy (TEM). The sizes of the ZnSe NCs estimated from the TEM images are found to alter in the range of 2–53 nm. Their smaller sizes of the NCs were also calculated by using the optical absorption spectra and the effective mass approximation model. The band gap enlargements both for carrier and exciton confinements were evaluated and found to be changed in the range of 0–1.0 eV. The Raman spectroscopic studies showed blue shifted Raman peaks of ZnSe at 295 and 315 cm{sup −1} indicating phonon confinement effect as well as compressive stress effect on the surface atoms of the NCs. Red photoluminescence in ZnSe-glass nanocomposite reveals a broad multiple-peak structure due to overlapping of emission from NC size related electron-hole recombination (∼707 nm) and emissions from defects to traps, which were formed due to Se and Zn vacancies signifying potential application in photonics.

  7. Optical and carrier transport properties of graphene oxide based crystalline-Si/organic Schottky junction solar cells

    SciTech Connect (OSTI)

    Khatri, I.; Tang, Z.; Hiate, T.; Liu, Q.; Ishikawa, R.; Ueno, K.; Shirai, H.

    2013-12-21

    We investigated the graphene oxide (GO) based n-type crystalline silicon (c-Si)/conductive poly(ethylene dioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) Schottky junction devices with optical characterization and carrier transport measurement techniques. The optical transmittance in the UV region decreased markedly for the films with increasing the concentration of GO whereas it increased markedly in the visible-infrared regions. Spectroscopic ellipsometry revealed that the ordinary and extraordinary index of refraction increased with increasing the concentration of GO. The hole mobility also increased from 1.14 for pristine film to 1.85 cm{sup 2}/V s for the 1215?wt. % GO modified film with no significant increases of carrier concentration. The highest conductivity was found for a 15?wt. % GO modified PEDOT:PSS film: the c-Si/PEDOT:PSS:GO device using this sample exhibited a relatively high power conversion efficiency of 11.04%. In addition, the insertion of a 23?nm-thick GO thin layer at the c-Si/PEDOT:PSS interface suppressed the carrier recombination efficiency of dark electron and photo-generated hole at the anode, resulting in the increased photovoltaic performance. This study indicates that the GO can be good candidates for hole transporting layer of c-Si/PEDOT:PSS Schottky junction solar cell.

  8. Microstructural, magnetic, and optical properties of the self-assembled (III{sub 1-x}Mn{sub x})V quantum structure

    SciTech Connect (OSTI)

    Jeon, H. C.; Lee, S. J.; Kang, T. W.

    2010-01-04

    Diluted magnetic semiconductor (DMS) materials have attracted much attention because of the interest in both investigations of fundamental physical properties and promising applications for various spintronic devices. Among many DMS structures, (III{sub 1-x}Mn{sub x})V ferromagnetic semiconductor quantum structures have been particularly attractive due to their potential applications in spintronic devices and they have combined properties of both III-V semiconductors and Mn ferromagnetic compounds, and the excellent advantages derived by utilizing mature III-V based heterostructure technology. Even though not many papers have been reported on the formation of one layer of (III{sub 1-x}Mn{sub x})V Quantum structure-Quantum Dots(QDs) and Quantum Wires(Q-Wire), systematic studies concerning microstructural, magnetic, and optical properties of the (III{sub 1-x}Mn{sub x})V quantum structure have been more attractive because of the interest in promising applications in optoelectronic devices, such as spin injection lasers and spin switching devices.

  9. Electronic and optical properties of layered RE{sub 2}Ti{sub 2}O{sub 7} (RE = Ce and Pr) from first principles

    SciTech Connect (OSTI)

    Sayede, A.; Khenata, R.; Chahed, A.; Benhelal, O.

    2013-05-07

    We have studied the structural and electronic properties of Ce{sub 2}Ti{sub 2}O{sub 7} (CeTO) and Pr{sub 2}Ti{sub 2}O{sub 7} (PrTO) by first-principles density functional theory calculations. The computed structural parameters are in fairly good agreement with the available experimental findings. Band structure calculations using the GGA+U approach predict an insulating ground state for the herein studied compounds. The insulating band gaps of 2.00 eV and 2.83 eV are found for CeTO and PrTO, respectively. The analysis of the density of states reveals that the strongly localized RE 4f levels act as charge-trapping sites, predicting a lower photocatalytic activity for CeTO. We have also calculated the optical properties for both CeTO and PrTO. Based on these properties, it is predicted that these titanates are insensitive to ultra-violet radiation, while they are more sensitive to frequencies of the radiation in visible and early UV regions.

  10. Aerosol Remote Sealing System - Energy Innovation Portal

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

    Aerosol Remote Sealing System Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing SummaryMark Modera and Francois Remi Carrie from Berkeley National Laboratory have developed a rapid, economical technique to seal duct and other enclosed systems by means of an internally injected aerosol. DescriptionBerkeley National Laboratory's aerosol compound seals holes in enclosed systems and is effective even after bends and junctions. A unique, in situ aerosol

  11. ARM - PI Product - Direct Aerosol Forcing Uncertainty

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

    ProductsDirect Aerosol Forcing Uncertainty ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Direct Aerosol Forcing Uncertainty Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement

  12. Aerosol Oxidation Speeds Up in Smoggy Air

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

    Aerosol Oxidation Speeds Up in Smoggy Air Aerosol Oxidation Speeds Up in Smoggy Air Print Wednesday, 17 February 2016 11:37 Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those

  13. ARM - Measurement - Aerosol particle size distribution

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

    AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer HTDMA : Humidified Tandem Differential Mobility Analyzer SMPS : Scanning mobility particle sizer TDMA : Tandem...

  14. Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior

    SciTech Connect (OSTI)

    UC Davis; Cappa, Christopher D.; Wilson, Kevin R.

    2010-10-28

    Vacuum Ultraviolet (VUV) photoionization mass spectrometry has been used to measure the evolution of chemical composition for two distinct organic aerosol types as they are passed through a thermodenuder at different temperatures. The two organic aerosol types considered are primary lubricating oil (LO) aerosol and secondary aerosol from the alpha-pinene + O3 reaction (alphaP). The evolution of the VUV mass spectra for the two aerosol types with temperature are observed to differ dramatically. For LO particles, the spectra exhibit distinct changes with temperature in which the lower m/z peaks, corresponding to compounds with higher vapor pressures, disappear more rapidly than the high m/z peaks. In contrast, the alphaP aerosol spectrum is essentially unchanged by temperature even though the particles experience significant mass loss due to evaporation. The variations in the LO spectra are found to be quantitatively in agreement with expectations from absorptive partitioning theory whereas the alphaP spectra suggest that the evaporation of alphaP derived aerosol appears to not be governed by partitioning theory. We postulate that this difference arises from the alphaP particles existing as in a glassy state instead of having the expected liquid-like behavior. To reconcile these observations with decades of aerosol growth measurements, which indicate that OA formation is described by equilibrium partitioning, we present a conceptual model wherein the secondary OA is formed and then rapidly converted from an absorbing form to a non-absorbing form. The results suggest that although OA growth may be describable by equilibrium partitioning theory, the properties of organic aerosol once formed may differ significantly from the properties determined in the equilibrium framework.

  15. Fibre optics: Forty years later

    SciTech Connect (OSTI)

    Dianov, Evgenii M

    2010-01-31

    This paper presents a brief overview of the state of the art in fibre optics and its main applications: optical fibre communications, fibre lasers and fibre sensors for various physical property measurements. The future of fibre optics and the status of this important area of the modern technology in Russia are discussed. (fiber optics)

  16. ARM - Field Campaign - Aerosol IOP

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

    govCampaignsAerosol IOP Campaign Links Science Plan (PDF document) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Aerosol IOP 2003.05.01 - 2003.05.31 Lead Scientist : Richard Ferrare Data Availability The IOP participants examined the individual instrument data to assess data quality, and to initiate other data analyses. Authorized participants can read reports of planning and debrief meetings,

  17. Real time infrared aerosol analyzer

    DOE Patents [OSTI]

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

    1990-01-01

    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.

  18. Study of in-duct spray drying using condensation aerosol. Final report, June 16, 1990--June 15, 1992

    SciTech Connect (OSTI)

    Chen, W.J.R.; Chang, S.M.; Adikesavalu, R.

    1992-06-01

    Sulfur removal efficiency of in-duct spray drying is limited by sorbent content and surface properties of the sorbent-water aerosol. It was the purpose of this study to improve the sulfur removal efficiency for in-duct spray drying by injecting condensation aerosol instead of conventional dispersion aerosol. The program was composed of three phases. In Phase I, a novel pulsed fluid bed feeder was developed and was used to feed hydrated lime for subsequent experiments. A small condensation aerosol generator was then built, which produces a lime-water condensation aerosol by condensing steam on lime particles. The results show that novel lime-water aerosols less than 10 microns were generated. The central task in Phase II was to simulate experimentally in-duct spray drying using condensation aerosols and compare the results with those using dispersion aerosols reported in the literature. A small entrained-flow reactor was constructed to simulate an in-duct spray dryer. The condensation aerosol was then introduced to the reactor at various approach to saturation temperature, calcium/sulfur stoichiometry and sulfur dioxide concentration for desulfurization study. The results show that we have improved the sulfur removal efficiency for in-duct spray drying to 90 percent or above. Thus we have met and exceeded the stated project goal of 70 percent sulfur removal. A comprehensive computer code was employed to calculate sulfur removal efficiency in Phase III.

  19. Ab initio study on the effect of structural relaxation on the electronic and optical properties of P-doped Si nanocrystals

    SciTech Connect (OSTI)

    Pi, Xiaodong; Ni, Zhenyi; Yang, Deren E-mail: christophe.delerue@isen.fr; Delerue, Christophe E-mail: christophe.delerue@isen.fr

    2014-11-21

    In contrast to the conventional doping of bulk silicon (Si), the doping of Si nanocrystals (NCs) that are often smaller than 5 nm in diameter may lead to serious structural changes. Since the electronic and optical properties of Si NCs are intimately associated with their structures, it is critical to understand how doping impacts the structures of Si NCs. By means of ab initio calculation we now compare 1.4 nm phosphorus (P)-doped Si NCs without structural relaxation and those with structural relaxation. Structural changes induced by structural relaxation are manifested by the stretching and compressing of bonds and apparent variations in bond angles. With the increase of the concentration of P structural changes induced by structural relaxation become more serious. It is found that structural relaxation makes differences in the energy-level schemes of P-doped Si NCs. Structural relaxation also causes the binding energy of an electron in a P-doped Si NC to more significantly increase as the concentration of P increases. With the increase of the concentration of P structural relaxation leads to more pronounced changes in the optical absorption of P-doped Si NCs.

  20. Effect of ZnO seed layer on the morphology and optical properties of ZnO nanorods grown on GaN buffer layers

    SciTech Connect (OSTI)

    Nandi, R. Mohan, S. Major, S. S.; Srinivasa, R. S.

    2014-04-24

    ZnO nanorods were grown by chemical bath deposition on sputtered, polycrystalline GaN buffer layers with and without ZnO seed layer. Scanning electron microscopy and X-ray diffraction show that the ZnO nanorods on GaN buffer layers are not vertically well aligned. Photoluminescence spectrum of ZnO nanorods grown on GaN buffer layer, however exhibits a much stronger near-band-edge emission and negligible defect emission, compared to the nanorods grown on ZnO buffer layer. These features are attributed to gallium incorporation at the ZnO-GaN interface. The introduction of a thin (25 nm) ZnO seed layer on GaN buffer layer significantly improves the morphology and vertical alignment of ZnO-NRs without sacrificing the high optical quality of ZnO nanorods on GaN buffer layer. The presence of a thick (200 nm) ZnO seed layer completely masks the effect of the underlying GaN buffer layer on the morphology and optical properties of nanorods.

  1. Electrical and optical properties of Mn-doped Hg{sub 3}In{sub 2}Te{sub 6} crystals

    SciTech Connect (OSTI)

    Grushka, O. G. Chupyra, S. M.; Mysliuk, O. M.; Bilichuk, S. V.; Koziarskyi, D. P.

    2013-09-15

    The effect of Mn impurities on the properties of Hg{sub 3}In{sub 2}Te{sub 6} crystals is studied by electrical and optical measurements. It is shown that, despite the high dopant concentration (1 Multiplication-Sign 10{sup 19} cm{sup -3}), the electron concentration remains the same as that in an undoped crystal ({approx}10{sup 13} cm{sup -3} at 300 K). At the same time, narrowing of the band gap from 0.74 to 0.7 eV is observed. From an analysis of the absorption spectra, it is found that the absorption edge is formed by optical transitions involving density-of-states (DoS) tails and that two acceptor- and donor-type impurity bands are formed in the band gap. The two bands are described by a Gaussian distribution of the DoS, with an energy gap between the peaks of E{sub 0} = E{sub d}{sup 0} - E{sub a}{sup 0} = 0.4 eV. The total donor and acceptor concentration N{sub d} + N{sub a} and the degree of compensation K = N{sub a}/N{sub d} {yields} 1 are determined. Such compensation is responsible for pinning of the Fermi level near the middle of the band gap and for quasi-intrinsic conductivity at temperatures T {>=} 300 K.

  2. Multishell Au/Ag/SiO2 nanorods with tunable optical properties as single particle orientation and rotational tracking probes

    SciTech Connect (OSTI)

    Chen, Kuangcai; Lin, Chia -Cheng; Vela, Javier; Fang, Ning

    2015-04-07

    In this study, three-layer coreshell plasmonic nanorods (Au/Ag/SiO2NRs), consisting of a gold nanorod core, a thin silver shell, and a thin silica layer, were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of the hybrid nanorods on synthetic lipid bilayers and on live cell membranes were obtained with millisecond temporal resolution using a scientific complementary metal-oxide-semiconductor camera. The results demonstrate that the as-synthesized hybrid nanorods are promising imaging probes with improved sensitivity and good biocompatibility for single plasmonic particle tracking experiments in biological systems.

  3. A comparative study of structural and optical properties of Cu{sub 2}ZnSnS{sub 4} nanocrystals for photovotaic applications

    SciTech Connect (OSTI)

    Ghosh, Anima Thangavel, R.; Rajagopalan, M.

    2014-04-24

    The Cu{sub 2}ZnSnS{sub 4} (CZTS) nanocrystals were successfully synthesized by hot injection method. The synthesized nanocrystals were characterized by the X-ray diffraction (XRD) and UVvisible spectrometer. X-ray diffraction studies reveal polycrystalline films exhibiting kesterite structures with preferential orientation along (112) direction. From UV studies revealed that the CZTS nanocrystals band gap was tuned between 1.6 eV (for 1 hour, stirring) and 1.4 eV (for 2 hours stirrer) and its compared, structural and optical properties of CZTS by density functional theory based on Wien2K (FP-LAPW) simulation employing a combined Tran-Blaha modified Becke-Johnson (TB-MBJ) potential with scissor corrections. From this calculation, it was found that the compound is in direct nature. The estimated lattice constant and bandgap value is in good agreement with earlier reported results. The optical band-gap energy of the CZTS nanocrystals is 1.4 eV, which is quite close to the optimum value for solar cell.

  4. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model Fourth Quarter 2008

    SciTech Connect (OSTI)

    JH Mather; DA Randall; CJ Flynn

    2008-09-30

    In 2008, the Atmospheric Radiation Measurement (ARM) Program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the metrics will deal with a decade-long control simulation using geodesic grid-coupled climate model. For ARM, the metrics will deal with observations associated with the 2006 deployment of the ARM Mobile Facility (AMF) to Niamey, Niger. Specifically, ARM has been asked to deliver data products for Niamey that describe cloud, aerosol, and dust properties. The first quarter milestone was the initial formulation of the algorithm for retrieval of these properties. The second quarter milestone included the time series of ARM-retrieved cloud properties and a year-long CCPP control simulation. The third quarter milestone included the time series of ARM-retrieved aerosol optical depth and a three-year CCPP control simulation. This final fourth quarter milestone includes the time-series of aerosol and dust properties and a decade-long CCPP control simulation.

  5. ARM - Field Campaign - Fall 1997 Aerosol IOP

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

    govCampaignsFall 1997 Aerosol IOP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Fall 1997 Aerosol IOP 1997.09.15 - 1997.10.05 Lead Scientist : Stephen Schwartz For data sets, see below. Summary The Aerosol IOP was highlighted by the Gulfstream-1 aircraft flying clear-sky aerosol missions over the Central Facility to study the effect of aerosol loading on clear sky radiation fields, with weather

  6. ARM - Evaluation Product - Organic Aerosol Component VAP

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

    ProductsOrganic Aerosol Component VAP ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Organic Aerosol Component VAP Organic aerosol (OA, i.e., the organic fraction of particles) accounts for 10-90% of the fine aerosol mass globally and is a key determinant of aerosol radiative forcing. But atmospheric OA

  7. Zn-doped and undoped SnO{sub 2} nanoparticles: A comparative structural, optical and LPG sensing properties study

    SciTech Connect (OSTI)

    Mishra, R.K.; Sahay, P.P.

    2012-12-15

    Graphical abstract: The X-ray diffraction (XRD) analyses confirm that all the materials prepared are polycrystalline SnO{sub 2} possessing tetragonal rutile structure. On Zn-doping, the crystallite size has been found to decrease from 25 nm (undoped sample) to 13 nm (1 at% Zn-doped sample). Display Omitted Highlights: ? Zn-doped SnO{sub 2} nanoparticles show smaller crystallite size (1117 nm). ? Optical band gap in SnO{sub 2} nanoparticles increases on Zn-doping. ? 2 at% Zn-doped sample show minimum room temperature resistivity. ? LPG response of the Zn-doped SnO{sub 2} nanoparticles increases considerably. ? 1 at% Zn-doped sample shows maximum response (87%) at 300 C to 1 vol% concentration. -- Abstract: SnO{sub 2} nanoparticles were prepared by the co-precipitation method with SnCl{sub 4}5H{sub 2}O as the starting material and Zn(CH{sub 3}COO){sub 2}2H{sub 2}O as the source of dopant. All the materials prepared have been found to be polycrystalline SnO{sub 2} possessing tetragonal rutile structure with crystallite sizes in the range 1125 nm. Optical analyses reveal that for the SnO{sub 2} nanoparticles, both undoped and Zn-doped, direct transition occurs with the bandgap energies in the range 3.053.41 eV. Variation in the room temperature resistivity of the SnO{sub 2} nanoparticles as a function of dopant concentration has been explained on the basis of two competitive processes: (i) replacement of Sn{sup 4+} ion by an added Zn{sup 2+} ion, and (ii) ionic compensation of Zn{sup 2+} by the formation of oxygen vacancies. Among all the samples examined for LPG sensing, the 1 at% Zn-doped sample exhibits fast and maximum response (?87%) at 300 C for 1 vol% concentration of LPG in air.

  8. Apparatus and method for qualitative and quantitative measurements of optical properties of turbid media using frequency-domain photon migration

    DOE Patents [OSTI]

    Tromberg, B.J.; Tsay, T.T.; Berns, M.W.; Svaasand, L.O.; Haskell, R.C.

    1995-06-13

    Optical measurements of turbid media, that is media characterized by multiple light scattering, is provided through an apparatus and method for exposing a sample to a modulated laser beam. The light beam is modulated at a fundamental frequency and at a plurality of integer harmonics thereof. Modulated light is returned from the sample and preferentially detected at cross frequencies at frequencies slightly higher than the fundamental frequency and at integer harmonics of the same. The received radiance at the beat or cross frequencies is compared against a reference signal to provide a measure of the phase lag of the radiance and modulation ratio relative to a reference beam. The phase and modulation amplitude are then provided as a frequency spectrum by an array processor to which a computer applies a complete curve fit in the case of highly scattering samples or a linear curve fit below a predetermined frequency in the case of highly absorptive samples. The curve fit in any case is determined by the absorption and scattering coefficients together with a concentration of the active substance in the sample. Therefore, the curve fitting to the frequency spectrum can be used both for qualitative and quantitative analysis of substances in the sample even though the sample is highly turbid. 14 figs.

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

    SciTech Connect (OSTI)

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

    2014-03-28

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

  10. Apparatus and method for qualitative and quantitative measurements of optical properties of turbid media using frequency-domain photon migration

    DOE Patents [OSTI]

    Tromberg, Bruce J.; Tsay, Tsong T.; Berns, Michael W.; Svaasand, Lara O.; Haskell, Richard C.

    1995-01-01

    Optical measurements of turbid media, that is media characterized by multiple light scattering, is provided through an apparatus and method for exposing a sample to a modulated laser beam. The light beam is modulated at a fundamental frequency and at a plurality of integer harmonics thereof. Modulated light is returned from the sample and preferentially detected at cross frequencies at frequencies slightly higher than the fundamental frequency and at integer harmonics of the same. The received radiance at the beat or cross frequencies is compared against a reference signal to provide a measure of the phase lag of the radiance and modulation ratio relative to a reference beam. The phase and modulation amplitude are then provided as a frequency spectrum by an array processor to which a computer applies a complete curve fit in the case of highly scattering samples or a linear curve fit below a predetermined frequency in the case of highly absorptive samples. The curve fit in any case is determined by the absorption and scattering coefficients together with a concentration of the active substance in the sample. Therefore, the curve fitting to the frequency spectrum can be used both for qualitative and quantitative analysis of substances in the sample even though the sample is highly turbid.

  11. The synthesis and optical property of solid-state-prepared YAG:Ce phosphor by a spray-drying method

    SciTech Connect (OSTI)

    Lee, H.-M.; Cheng, C.-C.; Huang, C.-Y.

    2009-05-06

    Ce{sup 3+}-activated yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}:Ce, YAG:Ce) powder as luminescent phosphor was synthesized by the solid-state reaction method. The phase identification, microstructure and photoluminescent properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), absorption spectrum and photoluminescence (PL) analysis. Spherical phosphor particle is considered better than irregular-shaped particle to improve PL property and application, so this phosphor was granulated into a sphere-like shape by a spray-drying device. After calcinating at 1500 deg. C for 0, 4, and 8 h, the product was identified as YAG and CeO{sub 2} phases. The CeO{sub 2} phase content is decreased by increasing the calcination time or decreasing the Ce{sup 3+} doping content. The product showed higher emission intensity resulted from more Ce{sup 3+} content and larger grain size. The product with CeO{sub 2} was found to have lower emission intensity. This paper presents the crystal structures of Rietveld refinement results of powder XRD data.

  12. Optical Properties of InGaAsN: A New 1eV Bandgap Material System

    SciTech Connect (OSTI)

    Allerman, A.A.; Fritz, I.J.; Jones, E.D.; Kurtz, S.R.; Modine, N.A.; Tozer, S.T.; Wei, X.; Wright, A.F.

    1999-01-25

    InGaAsN is a new semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the bandgap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low temperature photohnninescence energy of the material for pressures between ambient and 110 kbar. We describe a simple, density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low concentration alloys. The theoretically predicted pressure dependence of the bandgap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for the strongly non-linear pressure dependence of the bandgap that, surprisingly, does not involve a nitrogen impurity band. Addhionally, conduction-band mass measurements, measured by three different techniques, will be described and finally, the magnetoluminescence determined pressure coefficient for the conduction-band mass is measured.

  13. ESO VERY LARGE TELESCOPE OPTICAL SPECTROSCOPY OF BL LACERTAE OBJECTS. IV. NEW SPECTRA AND PROPERTIES OF THE FULL SAMPLE

    SciTech Connect (OSTI)

    Landoni, M.; Treves, A.; Barattini, M.; Falomo, R.; Sbarufatti, B.; Decarli, R.; Kotilainen, J.

    2013-04-15

    We present the last chapter of a spectroscopy program aimed at deriving the redshift or a lower limit to the redshift of BL Lac objects using medium-resolution spectroscopy. Here we report new spectra for 33 BL Lac object candidates obtained in 2008-2009, confirming the BL Lac nature of 25 sources and obtaining new redshifts for 5 objects. These new observations are combined with our previous data in order to construct a homogeneous sample of {approx}70 BL Lac objects with high-quality spectroscopy. All these spectra can be accessed at the Web site http://www.oapd.inaf.it/zbllac/. The average spectrum, beaming properties of the full sample, discussion of intervening systems, and future perspectives are addressed.

  14. Cirrus Microphysical Properties from Stellar Aureole Measurements, Phase I

    SciTech Connect (OSTI)

    DeVore, J. G.; Kristl, J. A.; Rappaport, S. A.

    2012-04-20

    While knowledge of the impact of aerosols on climate change has improved significantly due to the routine, ground-based, sun photometer measurements of aerosols made at AERONET sites world-wide, the impact of cirrus clouds remains much less certain because they occur high in the atmosphere and are more difficult to measure. This report documents work performed on a Phase I SBIR project to retrieve microphysical properties of cirrus ice crystals from stellar aureole imagery. The Phase I work demonstrates that (1) we have clearly measured stellar aureole profiles; (2) we can follow the aureole profiles out to ~1/4 degree from stars (~1/2 degree from Jupiter); (3) the stellar aureoles from cirrus have very distinctive profiles, being flat out to a critical angle, followed by a steep power-law decline with a slope of ~-3; (4) the profiles are well modeled using exponential size distributions; and (5) the critical angle in the profiles is ~0.12 degrees, (6) indicating that the corresponding critical size ranges from ~150 to ~200 microns. The stage has been set for a Phase II project (1) to proceed to validating the use of stellar aureole measurements for retrieving cirrus particle size distributions using comparisons with optical property retrievals from other, ground-based instruments and (2) to develop an instrument for the routine, automatic measurement of thin cirrus microphysical properties.

  15. Transpiration purged optical probe

    DOE Patents [OSTI]

    2004-01-06

    An optical apparatus for clearly viewing the interior of a containment vessel by applying a transpiration fluid to a volume directly in front of the external surface of the optical element of the optical apparatus. The fluid is provided by an external source and transported by means of an annular tube to a capped end region where the inner tube is perforated. The perforation allows the fluid to stream axially towards the center of the inner tube and then axially away from an optical element which is positioned in the inner tube just prior to the porous sleeve. This arrangement draws any contaminants away from the optical element keeping it free of contaminants. In one of several embodiments, the optical element can be a lens, a viewing port or a laser, and the external source can provide a transpiration fluid having either steady properties or time varying properties.

  16. Comparative study of optical and structural properties of electrospun 1-dimensional CaYAl{sub 3}O{sub 7}:Eu{sup 3+} nanofibers and bulk phosphor

    SciTech Connect (OSTI)

    Yim, Chul Jin; Unithrattil, Sanjith; Chung, Woon Jin; Im, Won Bin

    2014-09-15

    We report the optical and structural studies of Eu{sup 3+}-doped 1-dimensional CaYAl{sub 3}O{sub 7} nano-fiber phosphor. CaYAl{sub 3}O{sub 7}:Eu{sup 3+} phosphors were synthesized by electrospinning technique and the pristine nano-fibers were annealed at 900 C to form well crystallized uniform fibers. Under ultraviolet excitation, the CaYAl{sub 3}O{sub 7}:Eu{sup 3+} exhibited red emission, due to transitions in the 4f states of Eu{sup 3+}. In order to explore the difference between the quantum efficiency of nano-fiber and bulk CaYAl{sub 3}O{sub 7}:Eu{sup 3+} phosphor, detailed structural and optical analyses were carried out. The structural analysis of the CaYAl{sub 3}O{sub 7}:Eu{sup 3+} nano-fibers indicates that the structural environment surrounding the dopant Eu{sup 3+} ion was more unstable in nano-fiber when compared to a bulk sample. Decay curves for both the samples when fitted with double exponential decay model indicate that the nano-fiber has shorter decay time, arising from the larger contribution from the non-radiative decay, due to defect levels introduced in the host lattice. - Highlights: Synthesis of red nano-phosphor through electrospinning Luminescence properties of bulk and nano-phosphors are compared. Inferior emission intensity of the nano-phosphor is analyzed using MEM. Charge cloud around nano-phosphor was found to be oblique.

  17. Zinc concentration effect on structural, optical and electrical properties of Cd{sub 1?x}Zn{sub x}Se thin films

    SciTech Connect (OSTI)

    Akaltun, Yunus; Y?ld?r?m, M. Ali; Ate?, Aytun; Y?ld?r?m, Muhammet

    2012-11-15

    Highlights: ? Cd{sub 1?x}Zn{sub x}Se thin films were deposited using SILAR method. ? The electron effective mass, refractive index, dielectric constant values were calculated by using the energy bandgap values as a function of the zinc concentration (x). ? The resistivity and activation energy changed as a function of the zinc concentration (x). -- Abstract: Cd{sub 1?x}Zn{sub x}Se thin films with different compositions (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were deposited on glass substrates using successive ionic layer adsorption and reaction (SILAR) method at room temperature and ambient pressure. The zinc concentration (x) effect on the structural, morphological, optical and electrical properties of Cd{sub 1?x}Zn{sub x}Se thin films were investigated. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies showed that all the films exhibited polycrystalline nature and were covered well on glass substrates. The energy dispersive X-ray (EDAX) analysis confirmed nearly stoichiometric deposition of the films. The energy bandgap values were changed from 1.99 to 2.82 eV depending on the zinc concentration. Bowing parameter was calculated as 0.08 eV. The electron effective mass (m{sub e}*/m{sub o}), refractive index (n), optical static and high frequency dielectric constants (?{sub o}, ?{sub ?}) values were calculated by using the energy bandgap values as a function of the zinc concentration. The resistivity values of the films changed between 10{sup 5} and 10{sup 7} ? cm with increasing zinc concentration at room temperature.

  18. Morphology-dependent optical absorption and conduction properties of photoelectrochemical photocatalysts for H{sub 2} production: A case study

    SciTech Connect (OSTI)

    Huda, Muhammad N.; Turner, John A.

    2010-06-15

    Efficient photoelectrochemical H{sub 2} production by solar irradiation depends not only on the photocatalyst's band gap and its band-edge positions but also on the detailed electronic nature of the bands, such as the localization or delocalization of the band edges and their orbital characteristics. These determine the carrier transport properties, reactivity, light absorption strength, etc. and significantly impact the material's efficiency as a photoconverter. The localization or delocalization of the band edges may arise either due to the orbital nature of the bands or the structural morphology of the material. A recent experimental report on a photocatalyst based on s/p orbitals showed very poor performance for H{sub 2} production despite the delocalized nature of the s/p bands as compared to the d-bands of transition metal oxides. It is then important to examine whether this poor performance is inherent to these materials or rather arises from some experimental limitations. A theoretical analysis by first-principle methods is well suited to shed light on this question.

  19. Aerosol indirect effects -- general circulation model intercomparison and evaluation with satellite data

    SciTech Connect (OSTI)

    Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E.; Gettelman, Andrew; Lohmann, Ulrike; Bellouin, Nicolas; Boucher, Olivier; Sayer, Andrew M.; Thomas, Gareth E.; McComiskey, Allison; Feingold, Graham; Hoose, Corinna; Kristjansson, Jon Egill; Liu, Xiaohong; Balkanski, Yves; Donner, Leo J.; Ginoux, Paul A.; Stier, Philip; Feichter, Johann; Sednev, Igor; Bauer, Susanne E.; Koch, Dorothy; Grainger, Roy G.; Kirkevag, Alf; Iversen, Trond; Seland, Oyvind; Easter, Richard; Ghan, Steven J.; Rasch, Philip J.; Morrison, Hugh; Lamarque, Jean-Francois; Iacono, Michael J.; Kinne, Stefan; Schulz, Michael

    2009-04-10

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterizes aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (Ta) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (Nd) compares relatively well to the satellite data at least over the ocean. The relationship between Ta and liquid water path is simulated much too strongly by the models. It is shown that this is partly related to the representation of the second aerosol indirect effect in terms of autoconversion. A positive relationship between total cloud fraction (fcld) and Ta as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld - Ta relationship, our results indicate that none can be identified as unique explanation. Relationships similar to the ones found in satellite data between Ta and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - Ta relationship show a strong positive correlation between Ta and fcld The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of Ta, and parameterisation assumptions such as a lower bound on Nd. Nevertheless, the strengths of the statistical relationships are good predictors for the aerosol forcings in the models. An estimate of the total short-wave aerosol forcing inferred from the combination of these predictors for the modelled forcings with the satellite-derived statistical relationships yields a global annual mean value of -1.5+-0.5 Wm-2. An alternative estimate obtained by scaling the simulated clear- and cloudy-sky forcings with estimates of anthropogenic Ta and satellite-retrieved Nd - Ta regression slopes, respectively, yields a global annual mean clear-sky (aerosol direct effect) estimate of -0.4+-0.2 Wm-2 and a cloudy-sky (aerosol indirect effect) estimate of -0.7+-0.5 Wm-2, with a total estimate of -1.2+-0.4 Wm-2.

  20. ARM - Mobile Aerosol Observing System

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

    FacilitiesMobile Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 MAOS Data Operations AMF Fact Sheet Images Contacts AMF Deployments McMurdo Station, Antarctica, 2015-2016 Pearl Harbor, Hawaii, to San Francisco, California, 2015 Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011

  1. Aerosol Oxidation Speeds Up in Smoggy Air

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

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  2. Aerosol Oxidation Speeds Up in Smoggy Air

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

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  3. Aerosol Oxidation Speeds Up in Smoggy Air

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

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  4. Researchers Model Impact of Aerosols Over California

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

    Researchers Model Impact of Aerosols Over California Researchers Model Impact of Aerosols Over California Research may clarify the effectiveness of regional pollution controls May 28, 2013 Contact: Linda Vu, lvu@lbl.gov, (510) 495-2404 LosAngelesSmogv1.jpg Smog over downtown Los Angeles. Aerosols are microscopic particles-like dust, pollen and soot-that ubiquitously float around in our atmosphere. Despite their tiny stature, these particles can have a huge impact on human health, climate and the

  5. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  6. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  7. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  8. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Composition and Reactions of Atmospheric Aerosol Particles Print Wednesday, 29 June 2005 00:00 Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the

  9. Aerosol Oxidation Speeds Up in Smoggy Air

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

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  10. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  11. Composition and Reactions of Atmospheric Aerosol Particles

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

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  12. ARM - Campaign Instrument - aerosol-tower-eml

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

    govInstrumentsaerosol-tower-eml Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : EML Tower based Aerosol Measurements (AEROSOL-TOWER-EML) Instrument Categories Aerosols Campaigns Remote Cloud Sensing (RCS) Field Evaluation [ Download Data ] Southern Great Plains, 1994.04.01 - 1994.05.31 Primary Measurements Taken The following measurements are those considered scientifically relevant. Refer to the datastream (netcdf) file

  13. A comparative study of optical absorption and photocatalytic properties of nanocrystalline single-phase anatase and rutile TiO{sub 2} doped with transition metal cations

    SciTech Connect (OSTI)

    Kernazhitsky, L.; Shymanovska, V.; Gavrilko, T.; Naumov, V.; Kshnyakin, V.; Khalyavka, T.

    2013-02-15

    The effect of nanocrystalline TiO{sub 2} doping with transition metal cations (Cu{sup 2+}, Fe{sup 3+}, Co{sup 2+}, Cr{sup 3+}) on their optical absorption and photocatalytic properties was investigated. The obtained metal-doped TiO{sub 2} samples were characterized by X-ray diffraction, scanning electron microscopy, and UV-vis absorption spectroscopy. It is shown that doping effect on anatase (A) and rutile (R) properties is quite different, being much stronger and complicated on A than on R. Contrary to doped R, doped A revealed a significant red shift of the absorption edge along with the band gap narrowing. Photocatalytic activity of anatase increases upon doping in the order: AR/Co>R/Cu>R/Fe>R/Cr, indicating the inhibitory effect of impurity cations. This fact correlates with the decrease in the UV absorption of the doped rutile in the region of the Hg-lamp irradiation at 4.88 eV. - Graphical abstract: A red shift of the absorption edge of nanocrystalline single-phase anatase after doping with transition metal cations. Highlights: Black-Right-Pointing-Pointer Single-phase anatase and rutile powders surface-doped with transition metal cations. Black-Right-Pointing-Pointer Absorption edge and band gap of rutile do not change with surface doping. Black-Right-Pointing-Pointer Band gap of surface-doped anatase reduces being the lowest for A/Fe. Black-Right-Pointing-Pointer The surface-doping improves photocatalytic activity of anatase. Black-Right-Pointing-Pointer The surface-doping inhibits photocatalytic activity of rutile.

  14. Composition and Reactions of Atmospheric Aerosol Particles

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

    high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while...

  15. Composition and Reactions of Atmospheric Aerosol Particles

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

    will help climate scientists refine the computer models used to predict climate change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and...

  16. Composition and Reactions of Atmospheric Aerosol Particles

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

    results will help climate scientists refine the computer models used to predict climate change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and...

  17. Composition and Reactions of Atmospheric Aerosol Particles

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

    refine the computer models used to predict climate change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and household cleaning products, but a...

  18. The LANL Cloud-Aerosol Model

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

    that incorporates two unique aspects in its formulation. First, the model employs a nonlinear solver that requires cloud-aerosol parameterizations be smooth or contain reasonable...

  19. Influence of As{sub 4} flux on the growth kinetics, structure, and optical properties of InAs/GaAs quantum dots

    SciTech Connect (OSTI)

    Garcia, A.; Mateo, C. M.; Defensor, M.; Salvador, A.; Hui, H. K.; Boothroyd, C. B.; Philpott, E.

    2007-10-01

    We report the effects of variations in As{sub 4} growth flux on the evolution of molecular beam epitaxy grown InAs quantum dots (QDs) and their structures and optical properties. For InAs QDs grown under As-stable conditions, evaluated through photoluminescence and atomic force microscopy (AFM) measurements, it is evident that QD size increases with As{sub 4} pressure along with improvement in size uniformity. Furthermore, transmission electron microscopy measurements for InAs layers of critical thicknesses ({approx}1.7 ML) showed decreasing QD density with increasing As{sub 4} pressure accompanied by a strong reduction in photoluminescence (PL) integral intensity. These show that high As{sub 4} fluxes suppress InAs QD formation while the decreasing PL intensity seems to indicate cluster formation that features nonradiative recombination. AFM measurements show larger and denser QDs for samples grown at higher As{sub 4} pressures. These are explained on the basis of adatom condensation during surface cooling and the influence of As{sub 4} pressure on indium incorporation.

  20. OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

    SciTech Connect (OSTI)

    Kawabata, K. S.; Akitaya, H.; Itoh, R.; Moritani, Y. [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yamanaka, M. [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); Maeda, K.; Nogami, D. [Department of Astronomy, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Ui, T.; Kawabata, M.; Mori, K.; Takaki, K.; Ueno, I.; Chiyonobu, S.; Harao, T.; Matsui, R.; Miyamoto, H.; Nagae, O. [Department of Physical Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Nomoto, K.; Suzuki, N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Tanaka, M., E-mail: kawabtkj@hiroshima-u.ac.jp [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

    2014-11-01

    We present optical and near-infrared multi-band linear polarimetry of the highly reddened Type Ia supernova (SN) 2014J that appeared in M82. SN 2014J exhibits large polarization at shorter wavelengths, e.g., 4.8% in the B band, which decreases rapidly at longer wavelengths, while the position angle of the polarization remains at approximately 40 over the observed wavelength range. These polarimetric properties suggest that the observed polarization is likely predominantly caused by the interstellar dust within M82. Further analysis shows that the polarization peaks at a wavelengths much shorter than those obtained for the Galactic dust. The wavelength dependence of the polarization can be better described by an inverse power law rather than by the Serkowski law for Galactic interstellar polarization. These points suggest that the nature of the dust in M82 may be different from that in our Galaxy, with polarizing dust grains having a mean radius of <0.1 ?m.

  1. Controllable growth and optical properties of InP and InP/InAs nanostructures on the sidewalls of GaAs nanowires

    SciTech Connect (OSTI)

    Yan, Xin; Zhang, Xia Li, Junshuai; Cui, Jiangong; Ren, Xiaomin

    2014-12-07

    The growth and optical properties of InP and InP/InAs nanostructures on GaAs nanowires are investigated. InP quantum well and quantum dots (QDs) are formed on the sidewalls of GaAs nanowires successively with increasing the deposition time of InP. The GaAs/InP nanowire heterostructure exhibits a type-II band alignment. The wavelength of the InP quantum well is in the range of 857892?nm at 77?K, which means that the quantum well is nearly fully strained. The InP quantum dot, which has a bow-shaped cross section, exhibits dislocation-free pure zinc blende structure. Stranski-Krastanow InAs quantum dots are subsequently formed on the GaAs/InP nanowire core-shell structure. The InAs quantum dots are distributed over the middle part of the nanowire, indicating that the In atoms contributing to the quantum dots mainly come from the vapor rather than the substrate. The longest emission wavelength obtained from the InAs QDs is 1039?nm at 77?K. The linewidth is as narrow as 46.3?meV, which is much narrower than those on planar InP substrates and wurtzite InP nanowires, suggesting high-crystal-quality, phase-purity, and size-uniformity of quantum dots.

  2. The effects of Si-doped prelayers on the optical properties of InGaN/GaN single quantum well structures

    SciTech Connect (OSTI)

    Davies, M. J. Dawson, P.; Massabuau, F. C.-P.; Oliver, R. A.; Kappers, M. J.; Humphreys, C. J.

    2014-09-01

    In this paper, we report on the effects of including Si-doped (In)GaN prelayers on the low temperature optical properties of a blue-light emitting InGaN/GaN single quantum well. We observed a large blue shift of the photoluminescence peak emission energy and significant increases in the radiative recombination rate for the quantum well structures that incorporated Si-doped prelayers. Simulations of the variation of the conduction and valence band energies show that a strong modification of the band profile occurs for the quantum wells on Si-doped prelayers due to an increase in strength of the surface polarization field. The enhanced surface polarization field opposes the built-in field across the quantum well and thus reduces this built-in electric field. This reduction of the electric field across the quantum well reduces the Quantum Confined Stark Effect and is responsible for the observed blue shift and the change in the recombination dynamics.

  3. THE INFLUENCE OF BENZENE AS A TRACE REACTANT IN TITAN AEROSOL ANALOGS

    SciTech Connect (OSTI)

    Trainer, Melissa G.; Sebree, Joshua A.; Heidi Yoon, Y.; Tolbert, Margaret A.

    2013-03-20

    Benzene has been detected in Titan's atmosphere by Cassini instruments, with concentrations ranging from sub-ppb in the stratosphere to ppm in the ionosphere. Sustained levels of benzene in the haze formation region could signify that it is an important reactant in the formation of Titan's organic aerosol. To date, there have not been laboratory investigations to assess the influence of benzene on aerosol properties. We report a laboratory study on the chemical composition of organic aerosol formed from C{sub 6}H{sub 6}/CH{sub 4}/N{sub 2} via far ultraviolet irradiation (120-200 nm). The compositional results are compared to those from aerosol generated by a more ''traditional Titan'' mixture of CH{sub 4}/N{sub 2}. Our results show that even a trace amount of C{sub 6}H{sub 6} (10 ppm) has significant impact on the chemical composition and production rates of organic aerosol. There are several pathways by which photolyzed benzene may react to form larger molecules, both with and without the presence of CH{sub 4}, but many of these reaction mechanisms are only beginning to be explored for the conditions at Titan. Continued work investigating the influence of benzene in aerosol growth will advance understanding of this previously unstudied reaction system.

  4. Laboratory Studies of Processing of Carbonaceous Aerosols by Atmospheric Oxidants/Hygroscopicity and CCN Activity of Secondary & Processed Primary Organic Aerosols

    SciTech Connect (OSTI)

    Ziemann, P.J.; Arey, J.; Atkinson, R.; Kreidenweis, S.M.; Petters, M.D.

    2012-06-13

    The atmosphere is composed of a complex mixture of gases and suspended microscopic aerosol particles. The ability of these particles to take up water (hygroscopicity) and to act as nuclei for cloud droplet formation significantly impacts aerosol light scattering and absorption, and cloud formation, thereby influencing air quality, visibility, and climate in important ways. A substantial, yet poorly characterized component of the atmospheric aerosol is organic matter. Its major sources are direct emissions from combustion processes, which are referred to as primary organic aerosol (POA), or in situ processes in which volatile organic compounds (VOCs) are oxidized in the atmosphere to low volatility reaction products that subsequent condense to form particles that are referred to as secondary organic aerosol (SOA). POA and VOCs are emitted to the atmosphere from both anthropogenic and natural (biogenic) sources. The overall goal of this experimental research project was to conduct laboratory studies under simulated atmospheric conditions to investigate the effects of the chemical composition of organic aerosol particles on their hygroscopicity and cloud condensation nucleation (CCN) activity, in order to develop quantitative relationships that could be used to more accurately incorporate aerosol-cloud interactions into regional and global atmospheric models. More specifically, the project aimed to determine the products, mechanisms, and rates of chemical reactions involved in the processing of organic aerosol particles by atmospheric oxidants and to investigate the relationships between the chemical composition of organic particles (as represented by molecule sizes and the specific functional groups that are present) and the hygroscopicity and CCN activity of oxidized POA and SOA formed from the oxidation of the major classes of anthropogenic and biogenic VOCs that are emitted to the atmosphere, as well as model hydrocarbons. The general approach for this project was to carry out reactions of representative anthropogenic and biogenic VOCs and organic particles with ozone (O3), and hydroxyl (OH), nitrate (NO3), and chlorine (Cl) radicals, which are the major atmospheric oxidants, under simulated atmospheric conditions in large-volume environmental chambers. A combination of on-line and off-line analytical techniques were used to monitor the chemical and physical properties of the particles including their hygroscopicity and CCN activity. The results of the studies were used to (1) improve scientific understanding of the relationships between the chemical composition of organic particles and their hygroscopicity and CCN activity, (2) develop an improved molecular level theoretical framework for describing these relationships, and (3) establish a large database that is being used to develop parameterizations relating organic aerosol chemical properties and SOA sources to particle hygroscopicity and CCN activity for use in regional and global atmospheric air quality and climate models.

  5. ARM - Field Campaign - Aerosol and Cloud Experiments in the Eastern...

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

    horizontal variabilities of aerosol, trace gases, cloud, drizzle, and atmospheric thermodynamics are critically needed for understanding and quantifying the budget of MBL aerosol,...

  6. The Indirect and Semi-Direct Aerosol Campaign

    SciTech Connect (OSTI)

    Ghan, Steve

    2014-03-24

    Research projects like the Indirect and Semi-Direct Aerosol Campaign, or ISDAC, increase our knowledge of atmospheric aerosol particles and cloud physics.

  7. ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects...

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

    govCampaignsCarbonaceous Aerosol and Radiative Effects Study (CARES) Campaign Links CARES Website ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and...

  8. ARM - Field Campaign - Carbonaceous Aerosol and Radiation Effects...

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

    Photo-Acoustic Aerosol Light Absorption and Scattering Campaign Links ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiative Effects Study (CARES)...

  9. The Indirect and Semi-Direct Aerosol Campaign

    ScienceCinema (OSTI)

    Ghan, Steve

    2014-06-12

    Research projects like the Indirect and Semi-Direct Aerosol Campaign, or ISDAC, increase our knowledge of atmospheric aerosol particles and cloud physics.

  10. Optical and magneto-optical studies of martensitic transformation in

    Office of Scientific and Technical Information (OSTI)

    Ni-Mn-Ga magnetic shape memory alloys (Journal Article) | SciTech Connect Optical and magneto-optical studies of martensitic transformation in Ni-Mn-Ga magnetic shape memory alloys Citation Details In-Document Search Title: Optical and magneto-optical studies of martensitic transformation in Ni-Mn-Ga magnetic shape memory alloys Optical and magneto-optical properties of single crystal of Ni{sub 50.1}Mn{sub 28.4}Ga{sub 21.5} magnetic shape memory alloy during its transformation from

  11. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    SciTech Connect (OSTI)

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  12. Linear and nonlinear optical properties of GaAs/Al{sub x}Ga{sub 1?x}As/GaAs/Al{sub y}Ga{sub 1?y}As multi-shell spherical quantum dot

    SciTech Connect (OSTI)

    Emre Kavruk, Ahmet E-mail: aekavruk@gmail.com; Koc, Fatih; Sahin, Mehmet E-mail: mehsahin@gmail.com

    2013-11-14

    In this work, the optical properties of GaAs/Al{sub x}Ga{sub 1?x}As/GaAs/Al{sub y}Ga{sub 1?y}As multi-shell quantum dot heterostructure have been studied as a function of Al doping concentrations for cases with and without a hydrogenic donor atom. It has been observed that the absorption coefficient strength and/or resonant absorption wavelength can be adjusted by changing the Al content of inner-barrier and/or outer-barrier regions. Besides, it has been shown that the donor atom has an important effect on the control of the electronic and optical properties of the structure. The results have been presented as a function of the Al contents of the inner-barrier x and outer-barrier y regions and probable physical reasons have been discussed.

  13. Large-Scale Spray Releases: Additional Aerosol Test Results

    SciTech Connect (OSTI)

    Daniel, Richard C.; Gauglitz, Phillip A.; Burns, Carolyn A.; Fountain, Matthew S.; Shimskey, Rick W.; Billing, Justin M.; Bontha, Jagannadha R.; Kurath, Dean E.; Jenks, Jeromy WJ; MacFarlan, Paul J.; Mahoney, Lenna A.

    2013-08-01

    One of the events postulated in the hazard analysis for the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak event involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids that behave as a Newtonian fluid. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and in processing facilities across the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNLs test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are mostly absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale testing. The small-scale testing and resultant data are described in Mahoney et al. (2012b), and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the relevant physical properties projected for actual WTP process streams.

  14. Small-Scale Spray Releases: Additional Aerosol Test Results

    SciTech Connect (OSTI)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, G. N.; Mahoney, Lenna A.; Tran, Diana N.; Burns, Carolyn A.; Kurath, Dean E.

    2013-08-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNLs test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are largely absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale. The small-scale testing and resultant data are described in Mahoney et al. (2012b) and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the relevant physical properties projected for actual WTP process streams.

  15. Crooker named Optical Society Fellow

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

    Crooker named Optical Society Fellow Crooker named Optical Society Fellow The society recognized Crooker for "the development and application of magneto-optical spectroscopies to colloidal quantum dots and to electron spin transport and noise in semiconductors." January 23, 2014 Scott Crooker Scott Crooker Crooker's research focuses on the development of ultra-sensitive optical techniques to measure the static and dynamic properties of electron spins and magnetization in semiconductor

  16. The bonding, charge distribution, spin ordering, optical, and elastic properties of four MAX phases Cr{sub 2}AX (A = Al or Ge, X = C or N): From density functional theory study

    SciTech Connect (OSTI)

    Li, Neng; Mo, Yuxiang; Ching, Wai-Yim

    2013-11-14

    In this work, we assess a full spectrum of properties (chemical bonding, charge distribution, spin ordering, optical, and elastic properties) of Cr{sub 2}AC (A = Al, Ge) and their hypothetical nitride counterparts Cr{sub 2}AN (A = Al, Ge) based on density functional theory calculations. The calculated total energy values indicate that a variety of spin ordering of these four compounds depending on interlayer-interactions between M-A and M-X within the sublattice, which is supported by bonding analysis. MAX phase materials are discovered to possess exotic magnetic properties which indicates that these materials could serve as promising candidates for novel layered magnetic materials for various electronic and spintronic applications. Further analysis of optical properties for two polarization vectors of Cr{sub 2}AX shows that the reflectivity is high in the visible-ultraviolet region up to ∼15 eV suggesting Cr{sub 2}AX as a promising candidate for use as a coating material. The elastic coefficients (C{sub ij}) and bulk mechanical properties [bulk modulus (K), shear modulus (G), Young's modulus (E), Poisson's ratio (η), and Pugh ratio (G/K)] of these four Cr{sub 2}AX compounds are also calculated and analyzed, which pave the way to predict or design new MAX phases that are less brittle or tougher by having a lower G/K value or higher η.

  17. Aerosol indirect effects ? general circulation model intercomparison and evaluation with satellite data

    SciTech Connect (OSTI)

    Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E.; Gettelman, Andrew; Lohmann, Ulrike; Bellouin, Nicolas; Boucher, Olivier; Sayer, Andrew M.; Thomas, Gareth E.; McComiskey, Allison; Feingold, Graham; Hoose, Corinna; Kristansson, Jon Egill; Liu, Xiaohong; Balkanski, Yves; Donner, Leo J.; Ginoux, Paul A.; Stier, Philip; Grandey, Benjamin; Feichter, Johann; Sednev, Igor; Bauer, Susanne E.; Koch, Dorothy; Grainger, Roy G.; Kirkevag, Alf; Iversen, Trond; Seland, Oyvind; Easter, Richard; Ghan, Steven J.; Rasch, Philip J.; Morrison, Hugh; Lamarque, Jean-Francois; Iacono, Michael J.; Kinne, Stefan; Schulz, Michael

    2010-03-12

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth ({tau}{sub a}) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (N{sub d}) compares relatively well to the satellite data at least over the ocean. The relationship between {tau}{sub a} and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (f{sub cld}) and {tau}{sub a} as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong f{sub cld} - {tau}{sub a} relationship, our results indicate that none can be identified as a unique explanation. Relationships similar to the ones found in satellite data between {tau}{sub a} and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - {tau}{sub a} relationship show a strong positive correlation between {tau}{sub a} and f{sub cld} The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of {tau}{sub a}, and parameterization assumptions such as a lower bound on N{sub d}. Nevertheless, the strengths of the statistical relationships are good predictors for the aerosol forcings in the models. An estimate of the total short-wave aerosol forcing inferred from the combination of these predictors for the modelled forcings with the satellite-derived statistical relationships yields a global annual mean value of -1.5 {+-} 0.5 Wm{sup -2}. In an alternative approach, the radiative flux perturbation due to anthropogenic aerosols can be broken down into a component over the cloud-free portion of the globe (approximately the aerosol direct effect) and a component over the cloudy portion of the globe (approximately the aerosol indirect effect). An estimate obtained by scaling these simulated clear- and cloudy-sky forcings with estimates of anthropogenic {tau}{sub a} and satellite-retrieved Nd - {tau}{sub a} regression slopes, respectively, yields a global, annual-mean aerosol direct effect estimate of -0.4 {+-} 0.2 Wm{sup -2} and a cloudy-sky (aerosol indirect effect) estimate of -0.7 {+-} 0.5 Wm{sup -2}, with a total estimate of -1.2 {+-} 0.4 Wm{sup -2}.

  18. Incorporating an advanced aerosol activation parameterization into WRF-CAM5: Model evaluation and parameterization intercomparison

    SciTech Connect (OSTI)

    Zhang, Yang; Zhang, Xin; Wang, Kai; He, Jian; Leung, Lai-Yung R.; Fan, Jiwen; Nenes, Athanasios

    2015-07-22

    Aerosol activation into cloud droplets is an important process that governs aerosol indirect effects. The advanced treatment of aerosol activation by Fountoukis and Nenes (2005) and its recent updates, collectively called the FN series, have been incorporated into a newly developed regional coupled climate-air quality model based on the Weather Research and Forecasting model with the physics package of the Community Atmosphere Model version 5 (WRF-CAM5) to simulate aerosol-cloud interactions in both resolved and convective clouds. The model is applied to East Asia for two full years of 2005 and 2010. A comprehensive model evaluation is performed for model predictions of meteorological, radiative, and cloud variables, chemical concentrations, and column mass abundances against satellite data and surface observations from air quality monitoring sites across East Asia. The model performs overall well for major meteorological variables including near-surface temperature, specific humidity, wind speed, precipitation, cloud fraction, precipitable water, downward shortwave and longwave radiation, and column mass abundances of CO, SO2, NO2, HCHO, and O3 in terms of both magnitudes and spatial distributions. Larger biases exist in the predictions of surface concentrations of CO and NOx at all sites and SO2, O3, PM2.5, and PM10 concentrations at some sites, aerosol optical depth, cloud condensation nuclei over ocean, cloud droplet number concentration (CDNC), cloud liquid and ice water path, and cloud optical thickness. Compared with the default Abdul-Razzack Ghan (2000) parameterization, simulations with the FN series produce ~107113% higher CDNC, with half of the difference attributable to the higher aerosol activation fraction by the FN series and the remaining half due to feedbacks in subsequent cloud microphysical processes. With the higher CDNC, the FN series are more skillful in simulating cloud water path, cloud optical thickness, downward shortwave radiation, shortwave cloud forcing, and precipitation. The model evaluation identifies several areas of provements including emissions and their vertical allocation as well as model formulations such as aerosol formation, cloud droplet nucleation, and ice nucleation.

  19. ARM - Field Campaign - Two-Column Aerosol Project (TCAP)

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

    govCampaignsTwo-Column Aerosol Project (TCAP) Campaign Links TCAP website ARM Data Discovery Browse Data Related Campaigns Two-Column Aerosol Project (TCAP): Field Evaluation of Real-time Cloud OD Sensor TWST 2013.04.15, Scott, AMF Two-Column Aerosol Project (TCAP): Winter Aerosol Effects on Cloud Formation 2013.02.04, Cziczo, AMF Two-Column Aerosol Project (TCAP): CU GMAX-DOAS Deployment 2012.07.15, Volkamer, AMF Two-Column Aerosol Project (TCAP): Aerosol Light Extinction Measurements

  20. Final Optics

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

    Final Optics Schematic layout of NIF's final optics assembly (FOA). The suite of optics for one beamline is on the right. The final optics assemblies (FOAs) are the last element of the main laser system and the first of the target area systems. Each FOA contains four integrated optics modules (IOMs) that incorporate beam conditioning, frequency conversion, focusing, diagnostic sampling, and debris shielding capabilities into a single compact assembly. These optics are shown in the figure at

  1. Large-Scale Spray Releases: Initial Aerosol Test Results

    SciTech Connect (OSTI)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.; Kurath, Dean E.; Adkins, Harold E.; Billing, Justin M.; Burns, Carolyn A.; Davis, James M.; Enderlin, Carl W.; Fischer, Christopher M.; Jenks, Jeromy WJ; Lukins, Craig D.; MacFarlan, Paul J.; Shutthanandan, Janani I.; Smith, Dennese M.

    2012-12-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. The round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width × length) 0.3 × 5 to 2.74 × 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the large size of some of the WTP equipment. The purpose of this report is to present the experimental results and analyses for the aerosol measurements obtained in the large-scale test stand. The report includes a description of the simulants used and their properties, equipment and operations, data analysis methodology, and test results. The results of tests investigating the role of slurry particles in plugging of small breaches are reported in Mahoney et al. 2012a. The results of the aerosol measurements in the small-scale test stand are reported in Mahoney et al. (2012b).

  2. Small-Scale Spray Releases: Initial Aerosol Test Results

    SciTech Connect (OSTI)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2012-11-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. The round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width × length) 0.3 × 5 to 2.74 × 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the large size of some of the WTP equipment. This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the aerosol measurements in the large-scale test stand are reported in Schonewill et al. (2012) along with an analysis of the combined results from both test scales.

  3. Small-Scale Spray Releases: Initial Aerosol Test Results

    SciTech Connect (OSTI)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2013-05-29

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and net generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of antifoam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. For the combination of both test stands, the round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width × length) 0.3 × 5 to 2.74 × 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the much larger flow rates and equipment that would be required. This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the aerosol measurements in the large-scale test stand are reported in Schonewill et al. (2012) along with an analysis of the combined results from both test scales.

  4. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

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

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; et al

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore » and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

  5. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    SciTech Connect (OSTI)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, Christine; Mann, Julia; O Connor, Ewan; Hogan, Robin; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palinkonda, Rabindra; Albrecht, Bruce; Hannay, Cecile; Lin, Yanluan

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.

  6. Fiber optic fluid detector

    DOE Patents [OSTI]

    Angel, S. Michael (Livermore, CA)

    1989-01-01

    Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

  7. Fiber optic fluid detector

    DOE Patents [OSTI]

    Angel, S.M.

    1987-02-27

    Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

  8. Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

    SciTech Connect (OSTI)

    Gaffney, Jeffrey

    2012-12-12

    This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

  9. Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

    SciTech Connect (OSTI)

    Steiner, A. L.; Tawfik, A. B.; Shalaby, A.; Zakey, A. S.; Abdel Wahab, M. M.; Salah, Z.; Solmon, F.; Sillman, S.; Zaveri, Rahul A.

    2014-04-16

    An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation, and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.

  10. Long-Term Measurements of Submicrometer Aerosol

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

    non-refractory submicron particulate matter (NR-PM1) including organic aerosol (OA), sulfate (SO 4 2- ), nitrate (NO 3 - ), ammonium (NH 4 + ), and chloride (Cl-). In this study,...

  11. ARM - Field Campaign - Aerosol Lidar Validation Experiment -...

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

    govCampaignsAerosol Lidar Validation Experiment - ALIVE Campaign Links ALIVE Website ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below...

  12. Study of Aerosol Indirect Effects in China

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

    Aerosol Indirect Effects in China In 2008, the U.S. Department of Energy (DOE)'s Atmospheric Radiation Measurement (ARM) Climate Research Facility is providing the ARM Mobile...

  13. Aerosol fabrication methods for monodisperse nanoparticles

    DOE Patents [OSTI]

    Jiang, Xingmao; Brinker, C Jeffrey

    2014-10-21

    Exemplary embodiments provide materials and methods for forming monodisperse particles. In one embodiment, the monodisperse particles can be formed by first spraying a nanoparticle-containing dispersion into aerosol droplets and then heating the aerosol droplets in the presence of a shell precursor to form core-shell particles. By removing either the shell layer or the nanoparticle core of the core-shell particles, monodisperse nanoparticles can be formed.

  14. Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect (OSTI)

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

    2003-01-28

    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  15. Parameterizations of Cloud Microphysics and Indirect Aerosol Effects

    SciTech Connect (OSTI)

    Tao, Wei-Kuo

    2014-05-19

    1. OVERVIEW Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al., 2000]. Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 1999]. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd, 2005]. Recently, a detailed spectral-bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep tropical clouds in the west Pacific warm pool region and summertime convection over a mid-latitude continent with different concentrations of CCN: a low "clean" concentration and a high "dirty" concentration. The impact of atmospheric aerosol concentration on cloud and precipitation will be investigated. 2. MODEL DESCRIPTION AND CASE STUDIES 2.1 GCE MODEL The model used in this study is the 2D version of the GCE model. Modeled flow is anelastic. Second- or higher-order advection schemes can produce negative values in the solution. Thus, a Multi-dimensional Positive Definite Advection Transport Algorithm (MPDATA) has been implemented into the model. All scalar variables (potential temperature, water vapor, turbulent coefficient and all five hydrometeor classes) use forward time differencing and the MPDATA for advection. Dynamic variables, u, v and w, use a second-order accurate advection scheme and a leapfrog time integration (kinetic energy semi-conserving method). Short-wave (solar) and long-wave radiation as well as a subgrid-scale TKE turbulence scheme are also included in the model. Details of the model can be found in Tao and Simpson (1993) and Tao et al. (2003). 2.2 Microphysics (Bin Model) The formulation of the explicit spectral-bin microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (cloud droplets and raindrops), and six types of ice particles: pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail. Each type is described by a special size distribution function containing 33 categories (bins). Atmospheric aerosols are also described using number density size-distribution functions (containing 33 bins). Droplet nucleation (activation) is derived from the analytical calculation of super-saturation, which is used to determine the sizes of aerosol particles to be activated and the corresponding sizes of nucleated droplets. Primary nucleation of each type of ice crystal takes place within certain temperature ranges. A detailed description of these explicitly parameterized processes can be found in Khain and Sednev (1996) and Khain et al. (1999, 2001). 2.3 Case Studies Three cases, a tropical oceanic squall system observed during TOGA COARE (Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, which occurred over the Pacific Ocean warm pool from November 1992 to February 1993), a midlatitude continental squall system observed during PRESTORM (Preliminary Regional Experiment for STORM-Central, which occurred in Kansas and Oklahoma during May-June 1985), and mid-afternoon convection observed during CRYSTAL-FACE (Cirrus Regional Study of Tropical Anvils and Cirrus Layers – Florida Area Cumulus Experiment, which occurred in Florida during July 2002), will be used to examine the impact of aerosols on deep, precipitating systems. 3. SUMMARY of RESULTS • For all three cases, higher CCN produces smaller cloud droplets and a narrower spectrum. Dirty conditions delay rain formation, increase latent heat release above the freezing level, and enhance vertical velocities at higher altitude for all cases. Stronger updrafts, deeper mixed-phase regions, and more ice particles are simulated with higher CCN in good agreement with observations. • In all cases, rain reaches the ground early with lower CCN. Rain suppression is also evident in all three cases with high CCN in good agreement with observations (Rosenfeld, 1999, 2000 and others). Rain suppression, however, only occurs during the first hour of simulation. This result suggests that microphysical processes dominate the impact of aerosols on precipitation in the early stage of precipitation development. • During the mature stage of the simulations, the effect of increasing aerosol concentration ranges from rain suppression in the PRESTORM case to little effect on surface rainfall in the CRYSTAL-FACE case to rain enhancement in the TOGA COARE case. • The model results suggest that evaporative cooling is a key process in determining whether higher CCN reduces or enhances precipitation. Cold pool strength can be enhanced by stronger evaporation. When cold pool interacts with the near surface wind shear, the low-level convergence can be stronger, facilitating secondary cloud formation and more vigorous precipitation processes. Evaporative cooling is more than two times stronger at low levels with higher CCN for the TOGA COARE case during the early stages of precipitation development. However, evaporative cooling is slightly stronger at lower levels with lower CCN for the PRESTORM case. The early formation of rain in the clean environment could allow for the formation of an earlier and stronger cold pool compared to a dirty environment. PRESTORM has a very dry environment and both large and small rain droplets can evaporate. Consequently, the cold pool is relatively weaker, and the system is relatively less intense with higher CCN. • Sensitivity tests are conducted to determine the impact of ice processes on aerosol-precipitation interaction. The results suggested that ice processes are crucial for suppressing precipitation due to high CCN for the PRESTORM case. More and smaller ice particles are generated in the dirty case and transported to the trailing stratiform region. This reduces the heavy convective rain and contributes to the weakening of the cold pool. Warm rain processes dominate the TOGA COARE case. Therefore, ice processes only play a secondary role in terms of aerosol-precipitation interaction. • Two of the three cloud systems presented in this paper formed a line structure (squall system). A 2D simulation, therefore, gives a good approximation to such a line of convective clouds. Since the real atmosphere is 3D, further 3D cloud-resolving simulations are needed to address aerosol-precipitation interactions. 4. REFERENCES Tao, W.-K., X. Li, A. Khain, T. Matsui, S. Lang, and J. Simpson, 2007: The role of atmospheric aerosol concentration on deep convective precipitation: Cloud-resolving model simulations. J. Geophy. Res., 112, D24S18, doi:10.1029/2007JD008728. All other references can be found in above paper. 5. Acknowledgements The GCE model is mainly supported by the NASA Headquarters Atmospheric Dynamics and Thermodynamics Program and the NASA Tropical Rainfall Measuring Mission (TRMM). The research was also supported by the Office of Science (BER), U. S. Department of Energy/Atmospheric Radiation Measurement (DOE/ARM) Interagency. The authors acknowledge NASA Goddard Space Flight Center for computer time used in this research.

  16. Optical microspectrometer

    DOE Patents [OSTI]

    Sweatt, William C.; Christenson, Todd R.

    2004-05-25

    An optical microspectrometer comprises a grism to disperse the spectra in a line object. A single optical microspectrometer can be used to sequentially scan a planar object, such as a dye-tagged microchip. Because the optical microspectrometer is very compact, multiple optical microspectrometers can be arrayed to provide simultaneous readout across the width of the planar object The optical microspectrometer can be fabricated with lithographic process, such as deep X-ray lithography (DXRL), with as few as two perpendicular exposures.

  17. The First Aerosol Indirect Effect: Beyond Twomey

    SciTech Connect (OSTI)

    Liu, Y.; Dunn, M.; Daum, P.

    2008-03-10

    The traditional first aerosol indirect effect or the Twomey effect involves several fundamental assumptions. Some of the assumptions (e.g., constant liquid water content) are explicitly stated in studies of the Twomey effect whereas others are only implicitly embedded in the quantitative formulation. This work focuses on examining the implicit assumptions. In particular, we will show that anthropogenic pollution not only increases aerosol loading and droplet concentrations but also alters the relative dispersions of both the aerosol and subsequent droplet size distributions. The indirect effects resulting from the two altered relative dispersions (aerosol dispersion effect and droplet dispersion effect) are likely opposite in sign and proportional in magnitude to the conventional Twomey effect. This result suggests that the outstanding problems of the Twomey effect (i.e., large uncertainty and overestimation reported in literature) may lie with violation of the constant spectral shapes of aerosol and droplet size distributions implicitly assumed in evaluation of the Twomey effect, and therefore, further progress in understanding and quantification of the first aerosol indirect effect demands moving beyond the traditional paradigm originally conceived by Twomey.

  18. Molecular Characterization of Brown Carbon (BrC) Chromophores in Secondary Organic Aerosol Generated From Photo-Oxidation of Toluene

    SciTech Connect (OSTI)

    Lin, Peng; Liu, Jiumeng; Shilling, John E.; Kathmann, Shawn M.; Laskin, Julia; Laskin, Alexander

    2015-09-28

    Atmospheric Brown carbon (BrC) is a significant contributor to light absorption and climate forcing. However, little is known about a fundamental relationship between the chemical composition of BrC and its optical properties. In this work, light-absorbing secondary organic aerosol (SOA) was generated in the PNNL chamber from toluene photo-oxidation in the presence of NOx (Tol-SOA). Molecular structures of BrC components were examined using nanospray desorption electrospray ionization (nano-DESI) and liquid chromatography (LC) combined with UV/Vis spectroscopy and electrospray ionization (ESI) high-resolution mass spectrometry (HRMS). The chemical composition of BrC chromophores and the light absorption properties of toluene SOA (Tol-SOA) depend strongly on the initial NOx concentration. Specifically, Tol-SOA generated under high-NOx conditions (defined here as initial NOx/toluene of 5/1) appears yellow and mass absorption coefficient of the bulk sample (MACbulk@365nm = 0.78 m2 g-1) is nearly 80 fold higher than that measured for the Tol-SOA sample generated under low-NOx conditions (NOx/toluene < 1/300). Fifteen compounds, most of which are nitrophenols, are identified as major BrC chromophores responsible for the enhanced light absorption of Tol-SOA material produced in the presence of NOx. The integrated absorbance of these fifteen chromophores accounts for 40-60% of the total light absorbance by Tol-SOA at wavelengths between 300 nm and 500 nm. The combination of tandem LC-UV/Vis-ESI/HRMS measurements provides an analytical platform for predictive understanding of light absorption properties by BrC and their relationship to the structure of individual chromophores. General trends in the UV/vis absorption by plausible isomers of the BrC chromophores were evaluated using theoretical chemistry calculations. The molecular-level understanding of BrC chemistry is helpful for better understanding the evolution and behavior of light absorbing aerosols in the atmosphere.

  19. Microsoft PowerPoint - Berkowitz_etal_AGU2011_poster_TCAP_ver3...

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

    Climatology of aerosol optical properties near the New England coast: preparation for the Two Column Aerosol Program (TCAP) field campaign Carl Berkowitz, Duli Chand*, Larry Berg,...

  20. ARM Aerosol Working Group Meeting

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

    series of retrieved dust properties, based on results from the AMF deployment in Niger, Africa. Lidar data survey Lidar profiles: fully-corrected MPL attenuated backscatter...

  1. H I, CO, and Planck/IRAS dust properties in the high latitude cloud complex, MBM 53, 54, 55 and HLCG 92 – 35. Possible evidence for an optically thick H I envelope around the CO clouds

    SciTech Connect (OSTI)

    Fukui, Yasuo; Okamoto, Ryuji; Kaji, Ryohei; Yamamoto, Hiroaki; Torii, Kazufumi; Hayakawa, Takahiro; Tachihara, Kengo; Okuda, Takeshi; Ohama, Akio; Kuroda, Yutaka; Kuwahara, Toshihisa; Dickey, John M.

    2014-11-20

    We present an analysis of the H I and CO gas in conjunction with the Planck/IRAS submillimeter/far-infrared dust properties toward the most outstanding high latitude clouds MBM 53, 54, 55 and HLCG 92 – 35 at b = –30° to – 45°. The CO emission, dust opacity at 353 GHz (τ{sub 353}), and dust temperature (T {sub d}) show generally good spatial correspondence. On the other hand, the correspondence between the H I emission and the dust properties is less clear than in CO. The integrated H I intensity W{sub H} {sub I} and τ{sub 353} show a large scatter with a correlation coefficient of ∼0.6 for a T {sub d} range from 16 K to 22 K. We find, however, that W{sub H} {sub I} and τ{sub 353} show better correlation for smaller ranges of T {sub d} every 0.5 K, generally with a correlation coefficient of 0.7-0.9. We set up a hypothesis that the H I gas associated with the highest T {sub d} ≥ 21.5 K is optically thin, whereas the H I emission is generally optically thick for T {sub d} lower than 21.5 K. We have determined a relationship for the optically thin H I gas between atomic hydrogen column density and τ{sub 353}, N{sub H} {sub I} (cm{sup −2})=(1.5×10{sup 26})⋅τ{sub 353}, under the assumption that the dust properties are uniform and we have applied this to estimate N{sub H} {sub I} from τ{sub 353} for the whole cloud. N{sub H} {sub I} was then used to solve for T {sub s} and τ{sub H} {sub I} over the region. The result shows that the H I is dominated by optically thick gas having a low spin temperature of 20-40 K and a density of 40-160 cm{sup –3}. The H I envelope has a total mass of ∼1.2 × 10{sup 4} M {sub ☉}, an order of magnitude larger than that of the CO clouds. The H I envelope properties derived by this method do not rule out a mixture of H I and H{sub 2} in the dark gas, but we present indirect evidence that most of the gas mass is in the atomic state.

  2. Lead phosphate glass compositions for optical components

    DOE Patents [OSTI]

    Sales, Brian C. (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN)

    1987-01-01

    A lead phosphate glass to which has been added indium oxide or scandium oe to improve chemical durability and provide a lead phosphate glass with good optical properties.

  3. System for testing optical fibers

    DOE Patents [OSTI]

    Golob, John E. [Olathe, KS; Looney, Larry D. [Los Alamos, NM; Lyons, Peter B. [Los Alamos, NM; Nelson, Melvin A. [Santa Barbara, CA; Davies, Terence J. [Santa Barbara, CA

    1980-07-15

    A system for measuring a combination of optical transmission properties of fiber optic waveguides. A polarized light pulse probe is injected into one end of the optical fiber. Reflections from discontinuities within the fiber are unpolarized whereas reflections of the probe pulse incident to its injection remain polarized. The polarized reflections are prevented from reaching a light detector whereas reflections from the discontinuities reaches the detector.

  4. Optical probe

    DOE Patents [OSTI]

    Hencken, Kenneth (Pleasanton, CA); Flower, William L. (Livermore, CA)

    1999-01-01

    A compact optical probe is disclosed particularly useful for analysis of emissions in industrial environments. The instant invention provides a geometry for optically-based measurements that allows all optical components (source, detector, rely optics, etc.) to be located in proximity to one another. The geometry of the probe disclosed herein provides a means for making optical measurements in environments where it is difficult and/or expensive to gain access to the vicinity of a flow stream to be measured. Significantly, the lens geometry of the optical probe allows the analysis location within a flow stream being monitored to be moved while maintaining optical alignment of all components even when the optical probe is focused on a plurality of different analysis points within the flow stream.

  5. Saharan dust as a causal factor of hemispheric asymmetry in aerosols and cloud cover over the tropical Atlantic Ocean

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

    Kishcha, Pavel; Da Sliva, Arlindo; Starobinets, Boris; Long, Charles N.; Kalashnikova, Olga; Alpert, Pinhas

    2015-07-09

    Meridional distribution of aerosol optical thickness (AOT) over the tropical Atlantic Ocean (30°N – 30°S) was analyzed to assess seasonal variations of meridional AOT asymmetry. Ten-year MERRA Aerosol Reanalysis (MERRAero) data (July 2002 – June 2012) confirms that the Sahara desert emits a significant amount of dust into the atmosphere over the Atlantic Ocean. Only over the Atlantic Ocean did MERRAero show that desert dust dominates other aerosol species and is responsible for meridional aerosol asymmetry between the tropical North and South Atlantic. Over the 10-year period under consideration, both MISR measurements and MERRAero data showed a pronounced meridional AOTmore » asymmetry. The meridional AOT asymmetry, characterized by the hemispheric ratio (RAOT) of AOT averaged separately over the North and over the South Atlantic, was about 1.7. Seasonally, meridional AOT asymmetry over the Atlantic was the most pronounced between March and July, when dust presence is maximal (RAOT ranged from 2 to 2.4). There was no noticeable meridional aerosol asymmetry in total AOT from September to October. During this period the contribution of carbonaceous aerosols to total AOT in the South Atlantic was comparable to the contribution of dust aerosols to total AOT in the North Atlantic. During the same 10-year period, MODIS cloud fraction (CF) data showed that there was no noticeable asymmetry in meridional CF distribution in different seasons (the hemispheric ratio of CF ranged from 1.0 to 1.2). MODIS CF data illustrated significant cloud cover (CF of 0.7 – 0.9) with limited precipitation ability along the Saharan Air Layer.« less

  6. Saharan dust as a causal factor of hemispheric asymmetry in aerosols and cloud cover over the tropical Atlantic Ocean

    SciTech Connect (OSTI)

    Kishcha, Pavel; Da Sliva, Arlindo; Starobinets, Boris; Long, Charles N.; Kalashnikova, Olga; Alpert, Pinhas

    2015-07-09

    Meridional distribution of aerosol optical thickness (AOT) over the tropical Atlantic Ocean (30°N – 30°S) was analyzed to assess seasonal variations of meridional AOT asymmetry. Ten-year MERRA Aerosol Reanalysis (MERRAero) data (July 2002 – June 2012) confirms that the Sahara desert emits a significant amount of dust into the atmosphere over the Atlantic Ocean. Only over the Atlantic Ocean did MERRAero show that desert dust dominates other aerosol species and is responsible for meridional aerosol asymmetry between the tropical North and South Atlantic. Over the 10-year period under consideration, both MISR measurements and MERRAero data showed a pronounced meridional AOT asymmetry. The meridional AOT asymmetry, characterized by the hemispheric ratio (RAOT) of AOT averaged separately over the North and over the South Atlantic, was about 1.7. Seasonally, meridional AOT asymmetry over the Atlantic was the most pronounced between March and July, when dust presence is maximal (RAOT ranged from 2 to 2.4). There was no noticeable meridional aerosol asymmetry in total AOT from September to October. During this period the contribution of carbonaceous aerosols to total AOT in the South Atlantic was comparable to the contribution of dust aerosols to total AOT in the North Atlantic. During the same 10-year period, MODIS cloud fraction (CF) data showed that there was no noticeable asymmetry in meridional CF distribution in different seasons (the hemispheric ratio of CF ranged from 1.0 to 1.2). MODIS CF data illustrated significant cloud cover (CF of 0.7 – 0.9) with limited precipitation ability along the Saharan Air Layer.

  7. Optical keyboard

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY); Feichtner, John D. (Fiddletown, CA); Phillips, Thomas E. (San Diego, CA)

    2001-01-01

    An optical keyboard includes an optical panel having optical waveguides stacked together. First ends of the waveguides define an inlet face, and opposite ends thereof define a screen. A projector transmits a light beam outbound through the waveguides for display on the screen as a keyboard image. A light sensor is optically aligned with the inlet face for sensing an inbound light beam channeled through the waveguides from the screen upon covering one key of the keyboard image.

  8. Metasurface optical antireflection coating

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

    Zhang, Boyang; Hendrickson, Joshua; Nader, Nima; Chen, Hou -Tong; Guo, Junpeng

    2014-12-15

    Light reflection at the boundary of two different media is one of the fundamental phenomena in optics, and reduction of reflection is highly desirable in many optical systems. Traditionally, optical antireflection has been accomplished using single- or multiple-layer dielectric films and graded index surface structures in various wavelength ranges. However, these approaches either impose strict requirements on the refractive index matching and film thickness, or involve complicated fabrication processes and non-planar surfaces that are challenging for device integration. Here, we demonstrate an antireflection coating strategy, both experimentally and numerically, by using metasurfaces with designer optical properties in the mid-wave infrared.more » Our results show that the metasurface antireflection is capable of eliminating reflection and enhancing transmission over a broad spectral band and a wide incidence angle range. The demonstrated antireflection technique has no requirement on the choice of materials and is scalable to other wavelengths.« less

  9. Aerosol beam-focus laser-induced plasma spectrometer device

    DOE Patents [OSTI]

    Cheng, Meng-Dawn (Oak Ridge, TN)

    2002-01-01

    An apparatus for detecting elements in an aerosol includes an aerosol beam focuser for concentrating aerosol into an aerosol beam; a laser for directing a laser beam into the aerosol beam to form a plasma; a detection device that detects a wavelength of a light emission caused by the formation of the plasma. The detection device can be a spectrometer having at least one grating and a gated intensified charge-coupled device. The apparatus may also include a processor that correlates the wavelength of the light emission caused by the formation of the plasma with an identity of an element that corresponds to the wavelength. Furthermore, the apparatus can also include an aerosol generator for forming an aerosol beam from bulk materials. A method for detecting elements in an aerosol is also disclosed.

  10. ARM - Field Campaign - Two-Column Aerosol Project (TCAP): Aerial...

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

    govCampaignsTwo-Column Aerosol Project (TCAP): Aerial Campaign ARM Data Discovery Browse Data Related Campaigns Two-Column Aerosol Project (TCAP) 2012.07.01, Berg, AMF Comments? We...

  11. Apparatus for rapid measurement of aerosol bulk chemical composition

    DOE Patents [OSTI]

    Lee, Yin-Nan E. (East Setauket, NY); Weber, Rodney J. (Atlanta, GA)

    2003-01-01

    An apparatus and method for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution are provided. The apparatus includes a modified particle size magnifier for producing activated aerosol particles and a collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical methods. The method provided for on-line measurement of chemical composition of aerosol particles includes exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

  12. Apparatus for rapid measurement of aerosol bulk chemical composition

    DOE Patents [OSTI]

    Lee, Yin-Nan E.; Weber, Rodney J.; Orsini, Douglas

    2006-04-18

    An apparatus for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution is provided. The apparatus includes an enhanced particle size magnifier for producing activated aerosol particles and an enhanced collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical means. Methods for on-line measurement of chemical composition of aerosol particles are also provided, the method including exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; and flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

  13. Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report

    SciTech Connect (OSTI)

    2013-10-18

    This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing sedimentation. In addition to the known indirect effects (glaciation, riming and thermodynamic), new indirect effects were discovered and quantified due to responses of sedimentation, aggregation and coalescence in glaciated clouds to changing aerosol conditions. In summary, the change in horizontal extent of the glaciated clouds ('lifetime indirect effects'), especially of ice-only clouds, was seen to be of higher importance in regulating aerosol indirect effects than changes in cloud properties ('cloud albedo indirect effects').

  14. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    SciTech Connect (OSTI)

    Keene, William C.; Long, Michael S.

    2013-05-20

    This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry??s MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of marine aerosol production on the microphysical properties of aerosol populations and clouds over the ocean and the corresponding direct and indirect effects on radiative transfer; (2) atmospheric burdens of reactive halogen species and their impacts on O3, NOx, OH, DMS, and particulate non-sea-salt SO42-; and (3) the global production and influences of marine-derived particulate organic carbon. The model reproduced major characteristics of the marine aerosol system and demonstrated the potential sensitivity of global, decadal-scale climate metrics to multiphase marine-derived components of Earth??s troposphere. Due to the combined computational burden of the coupled system, the currently available computational resources were the limiting factor preventing the adequate statistical analysis of the overall impact that multiphase chemistry might have on climate-scale radiative transfer and climate.

  15. Long-term Measurements of Submicrometer Aerosol Chemistry at the Southern Great Plains (SGP) Using an Aerosol Chemical Speciation Monitor (ACSM)

    SciTech Connect (OSTI)

    Parworth, Caroline; Fast, Jerome D.; Mei, Fan; Shippert, Timothy R.; Sivaraman, Chitra; Tilp, Alison; Watson, Thomas; Zhang, Qi

    2015-04-01

    In this study the long-term trends of non-refractory submicrometer aerosol (NR-PM1) composition and mass concentration measured by an Aerosol Chemical Speciation Monitor (ACSM) at the U.S. Department of Energy’s Southern Great Plains (SGP) site are discussed. Over the period of 19 months (Nov. 20, 2010 – June 2012) highly time resolved (~30 min.) NR-PM1 data was recorded. Using this dataset the value-added product (VAP) of deriving organic aerosol components (OACOMP) is introduced. With this VAP, multivariate analysis of the measured organic mass spectral matrix can be performed on long term data to return organic aerosol (OA) factors that are associated with distinct sources, evolution processes, and physiochemical properties. Three factors were obtained from this VAP including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a biomass burning OA (BBOA) factor. Back trajectory analyses were performed to investigate possible sources of major NR-PM1 species at the SGP site. Organics dominated NR-PM1 mass concentration for the majority of the study with the exception of winter, when nitrate increased due to transport of precursor species from surrounding urban and agricultural areas and also due to cooler temperatures. Sulfate mass concentrations showed little seasonal variation with mixed regional and local sources. In the spring BBOA emissions increased and were mainly associated with local fires. Isoprene and carbon monoxide emission rates were computed by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) to represent the spatial distribution of biogenic and anthropogenic sources, respectively. From this model there is evidence to support that biogenic emissions from the southeast contribute to SOA formation at the SGP site during the summer.

  16. Structural, optical and ethanol gas sensing properties of In{sub 2}O{sub 3} and Dy{sup 3+}:In{sub 2}O{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Anand, Kanica Thangaraj, R. Kohli, Nipin Singh, Ravi Chand

    2014-04-24

    This paper reports the structural, optical and ethanol gas sensing properties of In{sub 2}O{sub 3} and 5% Dy{sup 3+}doped In{sub 2}O{sub 3} nanoparticles. The simple cost-effective hydrolysis assisted co-precipitation method was adopted. Synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible spectroscopy (UV-vis) techniques. XRD revealed that synthesized nanoparticles have cubic bixbyite phase. The lattice parameter, strain and crystallite size have been calculated by using the Williamson-Hall plots. UV-vis spectroscopy showed the red shift in the optical band gap due to Dy{sup 3+} doping in In{sub 2}O{sub 3} nanoparticles. For ethanol gas sensing properties, the nanoparticles were applied as thick film onto alumina substrate and tested at different operating temperatures. The results showed that the optimum operating temperature of both the gas sensors is 300C. At optimum operating temperature, the response of In{sub 2}O{sub 3} and Dy{sup 3+}:In{sub 2}O{sub 3} gas sensor towards 250 ppm ethanol was found to be 9.65 and 37.80. The investigations revealed that the addition of Dy{sup 3+} as a dopant enhanced the sensing response of In{sub 2}O{sub 3} nanoparticles appreciably.

  17. A Multi-Chamber System for Analyzing the Outgassing, Deposition,and Associated Optical Degradation Properties of Materials in a Vacuum

    SciTech Connect (OSTI)

    Singal, Jack; Schindler, Rafe; Chang, Chihway; Czodrowski, Patrick; Kim, Peter; /KIPAC, Menlo Park /SLAC /Stanford U.

    2009-12-11

    We report on the Camera Materials Test Chamber, a multi-vessel apparatus which analyzes the outgassing consequences of candidate materials for use in the vacuum cryostat of a new telescope camera. The system measures the outgassing products and rates of samples of materials at different temperatures, and collects films of outgassing products to measure the effects on light transmission in six optical bands. The design of the apparatus minimizes potential measurement errors introduced by background contamination.

  18. Aerosol can puncture device test report

    SciTech Connect (OSTI)

    Leist, K.J.

    1994-10-01

    This test report documents the evaluation of an aerosol can puncture device to replace a system currently identified for use in the WRAP-1 facility. The new system is based upon a commercially available puncture device, as recommended by WHC Fire Protection. With modifications found necessary through the testing program, the Aerosol Can Puncture Device was found able to puncture and drain aerosol cans without incident. Modifications include the addition of a secondary collection bottle and the modification of the can puncture needle. In the course of testing, a variety of absorbents were tested to determine their performance in immobilizing drained fluids. The visibility of the puncture with Non-Destructive Examination techniques were also reviewed.

  19. Aerosol Radiative Effects and Single-Scattering Properties in...

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

    Institution of Oceanography University of California San Diego, California M. A. Miller, M. J. Bartholomew, and R. M. Reynolds Brookhaven National Laboratory Upton, New York...

  20. Apparatus for sampling and characterizing aerosols

    DOE Patents [OSTI]

    Dunn, Patrick F. (Downers Grove, IL); Herceg, Joseph E. (Naperville, IL); Klocksieben, Robert H. (Park Forest, IL)

    1986-01-01

    Apparatus for sampling and characterizing aerosols having a wide particle size range at relatively low velocities may comprise a chamber having an inlet and an outlet, the chamber including: a plurality of vertically stacked, successive particle collection stages; each collection stage includes a separator plate and a channel guide mounted transverse to the separator plate, defining a labyrinthine flow path across the collection stage. An opening in each separator plate provides a path for the aerosols from one collection stage to the next. Mounted within each collection stage are one or more particle collection frames.

  1. Characterization of Ambient Aerosols in Mexico City during the MCMA-2003 Campaign with Aerosol Mass Spectrometry. Results from the CENICA Supersite

    SciTech Connect (OSTI)

    Salcedo, D.; Onasch, Timothy B.; Dzepina, K.; Canagaratna, M. R.; Zhang, Q.; Huffman, A. J.; DeCarlo, Peter; Jayne, J. T.; Mortimer, P.; Worsnop, Douglas R.; Kolb, C. E.; Johnson, Kirsten S.; Zuberi, Bilal M.; Marr, L.; Volkamer, Rainer M.; Molina, Luisa; Molina, Mario J.; Cardenas, B.; Bernabe, R.; Marquez, C.; Gaffney, Jeffrey S.; Marley, Nancy A.; Laskin, Alexander; Shutthanandan, V.; Xie, YuLong; Brune, W. H.; Lesher, R.; Shirley, T.; Jiminez, J. L.

    2006-03-24

    An Aerodyne Aerosol Mass Spectrometer (AMS) was deployed at the CENICA Supersite, while another was deployed in the Aerodyne Mobile Laboratory (AML) during the Mexico City Metropolitan Area field study (MCMA-2003) from March 29-May 4, 2003 to investigate particle concentrations, sources, and processes. This is the first of a series of papers reporting the AMS results from this campaign. The AMS provides real time information on mass concentration and composition of the non-refractory species in particulate matter less than 1 ?m (NR PM1) with high time and size resolution. For the first time, we report field results from a beam width probe, which was used to study the shape and mixing state of the particles and to quantify potential losses of irregular particles due to beam broadening inside the AMS. Data from this probe show that no significant amount of irregular particles was lost due to excessive beam broadening. A comparison of the CENICA and AML AMSs measurements is presented, being the first published intercomparison between two quadrupole AMSs. The speciation, and mass concentrations reported by the two AMSs compared well. In order to account for the refractory material in the aerosol, we also present measurements of Black Carbon (BC) using an aethalometer and an estimate of the aerosol soil component obtained from PIXE analysis of filters. Comparisons of (AMS + BC + soil) mass concentration with other collocated particle instruments (a LASAIR Optical Particle Counter, a Tapered Element Oscillating Microbalance (TEOM) and a DustTrack Aerosol Monitor) are also presented. The comparisons show that the (AMS + BC + soil) mass concentration during MCMC-2003 is a good approximation to the total PM??? mass concentration.

  2. Surrogate/spent fuel sabotage aerosol ratio testing:phase 1 summary and results.

    SciTech Connect (OSTI)

    Vigil, Manuel Gilbert; Sorenson, Ken Bryce; Lange, F. , Germany); Nolte, O. (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Koch, W. (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Dickey, Roy R.; Yoshimura, Richard Hiroyuki; Molecke, Martin Alan; Autrusson, Bruno (Institut de Radioprotection et de Surete Nucleaire , France); Young, F. I.; Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und reaktorsicherheit , Germany)

    2005-10-01

    This multinational test program is quantifying the aerosol particulates produced when a high energy density device (HEDD) impacts surrogate material and actual spent fuel test rodlets. The experimental work, performed in four consecutive test phases, has been in progress for several years. The overall program provides needed data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This program also provides significant political benefits in international cooperation for nuclear security related evaluations. The spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC), and supported by both the U.S. Department of Energy and Nuclear Regulatory Commission. This report summarizes the preliminary, Phase 1 work performed in 2001 and 2002 at Sandia National Laboratories and the Fraunhofer Institute, Germany, and documents the experimental results obtained, observations, and preliminary interpretations. Phase 1 testing included: performance quantifications of the HEDD devices; characterization of the HEDD or conical shaped charge (CSC) jet properties with multiple tests; refinement of the aerosol particle collection apparatus being used; and, CSC jet-aerosol tests using leaded glass plates and glass pellets, serving as representative brittle materials. Phase 1 testing was quite important for the design and performance of the following Phase 2 test program and test apparatus.

  3. Long-term measurements of submicrometer aerosol chemistry at the Southern Great Plains (SGP) using an Aerosol Chemical Speciation Monitor (ACSM)

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

    Parworth, Caroline; Tilp, Alison; Fast, Jerome; Mei, Fan; Shippert, Tim; Sivaraman, Chitra; Watson, Thomas; Zhang, Qi

    2015-04-01

    In this study the long-term trends of non-refractory submicrometer aerosol (NR-PM1) composition and mass concentration measured by an Aerosol Chemical Speciation Monitor (ACSM) at the Atmospheric Radiation Measurement (ARM) program's Southern Great Plains (SGP) site are discussed. NR-PM1 data was recorded at ~30 min intervals over a period of 19 months between November 2010 and June 2012. Positive Matrix Factorization (PMF) was performed on the measured organic mass spectral matrix using a rolling window technique to derive factors associated with distinct sources, evolution processes, and physiochemical properties. The rolling window approach also allows us to capture the dynamic variations ofmore » the chemical properties in the organic aerosol (OA) factors over time. Three OA factors were obtained including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a biomass burning OA (BBOA) factor. Back trajectory analyses were performed to investigate possible sources of major NR-PM1 species at the SGP site. Organics dominated NR-PM1 mass concentration for the majority of the study with the exception of winter, when ammonium nitrate increases due to transport of precursor species from surrounding urban and agricultural areas and also due to cooler temperatures. Sulfate mass concentrations have little seasonal variation with mixed regional and local sources. In the spring BBOA emissions increase and are mainly associated with local fires. Isoprene and carbon monoxide emission rates were obtained by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the 2011 U.S. National Emissions Inventory to represent the spatial distribution of biogenic and anthropogenic sources, respectively. The combined spatial distribution of isoprene emissions and air mass trajectories suggest that biogenic emissions from the southeast contribute to SOA formation at the SGP site during the summer.« less

  4. Long-term measurements of submicrometer aerosol chemistry at the Southern Great Plains (SGP) using an Aerosol Chemical Speciation Monitor (ACSM)

    SciTech Connect (OSTI)

    Parworth, Caroline; Tilp, Alison; Fast, Jerome; Mei, Fan; Shippert, Tim; Sivaraman, Chitra; Watson, Thomas; Zhang, Qi

    2015-04-01

    In this study the long-term trends of non-refractory submicrometer aerosol (NR-PM1) composition and mass concentration measured by an Aerosol Chemical Speciation Monitor (ACSM) at the Atmospheric Radiation Measurement (ARM) program's Southern Great Plains (SGP) site are discussed. NR-PM1 data was recorded at ~30 min intervals over a period of 19 months between November 2010 and June 2012. Positive Matrix Factorization (PMF) was performed on the measured organic mass spectral matrix using a rolling window technique to derive factors associated with distinct sources, evolution processes, and physiochemical properties. The rolling window approach also allows us to capture the dynamic variations of the chemical properties in the organic aerosol (OA) factors over time. Three OA factors were obtained including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a biomass burning OA (BBOA) factor. Back trajectory analyses were performed to investigate possible sources of major NR-PM1 species at the SGP site. Organics dominated NR-PM1 mass concentration for the majority of the study with the exception of winter, when ammonium nitrate increases due to transport of precursor species from surrounding urban and agricultural areas and also due to cooler temperatures. Sulfate mass concentrations have little seasonal variation with mixed regional and local sources. In the spring BBOA emissions increase and are mainly associated with local fires. Isoprene and carbon monoxide emission rates were obtained by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the 2011 U.S. National Emissions Inventory to represent the spatial distribution of biogenic and anthropogenic sources, respectively. The combined spatial distribution of isoprene emissions and air mass trajectories suggest that biogenic emissions from the southeast contribute to SOA formation at the SGP site during the summer.

  5. Two Hundred Fifty Years of Aerosols and Climate: The End of the Age of Aerosols

    SciTech Connect (OSTI)

    Smith, Steven J.; Bond, Tami C.

    2014-01-20

    Carbonaceous and sulfur aerosols have a substantial global and regional influence on climate in addition to their impact on health and ecosystems. The magnitude of this influence has changed substantially over the past and is expected to continue to change into the future. An integrated picture of the changing climatic influence of black carbon, organic carbon and sulfate over the period 1850 through 2100, focusing on uncertainty, is presented using updated historical inventories and a coordinated set of emission projections. While aerosols have had a substantial impact on climate over the past century, by the end of the 21st century aerosols will likely be only a minor contributor to radiative forcing due to increases in greenhouse gas forcing and a global decrease in pollutant emissions. This outcome is even more certain under a successful implementation of a policy to limit greenhouse gas emissions as low-carbon energy technologies that do not emit appreciable aerosol or SO2 are deployed.

  6. HIghMass-high H I mass, H I-rich galaxies at z ? 0 sample definition, optical and H? imaging, and star formation properties

    SciTech Connect (OSTI)

    Huang, Shan; Matsushita, Satoki; Haynes, Martha P.; Giovanelli, Riccardo; Hallenbeck, Gregory; Jones, Michael G.; Adams, Elizabeth A. K.; Brinchmann, Jarle; Chengalur, Jayaram N.; Hunt, Leslie K.; Masters, Karen L.; Saintonge, Amelie; Spekkens, Kristine

    2014-09-20

    We present first results of the study of a set of exceptional H I sources identified in the 40% ALFALFA extragalactic H I survey catalog ?.40 as both being H I massive (M{sub HI}>10{sup 10} M{sub ?}) and having high gas fractions for their stellar masses: the HIghMass galaxy sample. We analyze UV- and optical-broadband and H? images to understand the nature of their relatively underluminous disks in optical and to test whether their high gas fractions can be tracked to higher dark matter halo spin parameters or late gas accretion. Estimates of their star formation rates (SFRs) based on spectral energy distribution fitting agree within uncertainties with the H? luminosity inferred current massive SFRs. The H II region luminosity functions, parameterized as dN/dlog L?L {sup ?}, have standard slopes at the luminous end (? ? 1). The global SFRs demonstrate that the HIghMass galaxies exhibit active ongoing star formation (SF) with moderate SF efficiency but, relative to normal spirals, a lower integrated SFR in the past. Because the SF activity in these systems is spread throughout their extended disks, they have overall lower SFR surface densities and lower surface brightness in the optical bands. Relative to normal disk galaxies, the majority of HIghMass galaxies have higher H? equivalent widths and are bluer in their outer disks, implying an inside-out disk growth scenario. Downbending double exponential disks are more frequent than upbending disks among the gas-rich galaxies, suggesting that SF thresholds exist in the downbending disks, probably as a result of concentrated gas distribution.

  7. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, V.J.; Johnson, S.A.

    1999-08-03

    A vapor sample detection method is described where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample. 13 figs.

  8. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, Vincent J. (Downers Grove, IL); Johnson, Stanley A. (Countryside, IL)

    1999-01-01

    A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

  9. Raman Lidar Measurements of Aerosols and Water Vapor During the May 2003 Aerosol IOP

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

    Raman Lidar Measurements of Aerosols and Water Vapor During the May 2003 Aerosol IOP R. A. Ferrare National Aeronautics and Space Administration Langley Research Center Hampton, Virginia D. D. Turner Pacific Northwest National Laboratory Richland, Washington M. Clayton Science Applications International Corporation National Aeronautics and Space Administration Langley Research Center Hampton, Virginia B. S. Schmid and J. Redemann BAER/NASA Ames Research Institute Moffett Field, California D.

  10. Radiological/biological/aerosol removal system

    DOE Patents [OSTI]

    Haslam, Jeffery J

    2015-03-17

    An air filter replacement system for existing buildings, vehicles, arenas, and other enclosed airspaces includes a replacement air filter for replacing a standard air filter. The replacement air filter has dimensions and air flow specifications that allow it to replace the standard air filter. The replacement air filter includes a filter material that removes radiological or biological or aerosol particles.

  11. Influence of growth temperature on electrical, optical, and plasmonic properties of aluminum:zinc oxide films grown by radio frequency magnetron sputtering

    SciTech Connect (OSTI)

    Dondapati, Hareesh; Santiago, Kevin; Pradhan, A. K.

    2013-10-14

    We have investigated the responsible mechanism for the observation of metallic conductivity at room temperature and metal-semiconductor transition (MST) at lower temperatures for aluminum-doped zinc oxide (AZO) films. AZO films were grown on glass substrates by radio-frequency magnetron sputtering with varying substrate temperatures (T{sub s}). The films were found to be crystalline with the electrical resistivity close to 1.1 10{sup ?3} ? cm and transmittance more than 85% in the visible region. The saturated optical band gap of 3.76 eV was observed for the sample grown at T{sub s} of 400 C, however, a slight decrease in the bandgap was noticed above 400 C, which can be explained by BursteinMoss effect. Temperature dependent resistivity measurements of these highly conducting and transparent films showed a MST at ?110 K. The observed metal-like and metal-semiconductor transitions are explained by taking into account the Mott phase transition and localization effects due to defects. All AZO films demonstrate crossover in permittivity from positive to negative and low loss in the near-infrared region, illustrating its applications for plasmonic metamaterials, including waveguides for near infrared telecommunication region. Based on the results presented in this study, the low electrical resistivity and high optical transmittance of AZO films suggested a possibility for the application in the flexible electronic devices, such as transparent conducting oxide film on LEDs, solar cells, and touch panels.

  12. PARAMETERIZATIONS FOR THE KELVIN (SURFACE TENSION) EFFECT ON...

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

    EQUILIBRIUM RADIUS AND ASSOCIATED OPTICAL PROPERTIES OF A HYGROSCOPIC AEROSOL PARTICLE Lewis, Ernie Brookhaven National Laboratory Schwartz, Stephen Brookhaven National...

  13. Hybrid Pd/Fe{sub 3}O{sub 4} nanowires: Fabrication, characterization, optical properties and application as magnetically reusable catalyst for the synthesis of N-monosubstituted ureas under ligand-free conditions

    SciTech Connect (OSTI)

    Nasrollahzadeh, Mahmoud; Azarian, Abbas; Ehsani, Ali; Sajadi, S.Mohammad; Babaei, Ferydon

    2014-07-01

    Highlights: Preparation of Pd/Fe{sub 3}O{sub 4} nanowires as magnetically reusable catalysts. The optical properties of the catalyst were studied using Gans theory. N-arylation of benzylurea and in situ hydrogenolysis of 1-benzyl-3-arylureas. - Abstract: This paper reports the synthesis and use of Pd/Fe{sub 3}O{sub 4} nanowires, as magnetically separable catalysts for ligand-free amidation coupling reactions of aryl halides with benzylurea under microwave irradiation. Then, the in situ hydrogenolysis of the products was performed to afford the N-monosubstituted ureas from good to excellent yields. This method has the advantages of high yields, simple methodology and easy work up. The catalyst can be recovered by using a magnet and reused several times without significant loss of its catalytic activity. The catalyst was characterized using the powder XRD, SEM, EDS and UVvis spectroscopy. Experimental absorbance spectra was compared with results from the Gans theory.

  14. Study of optical properties of asymmetric bipolar pulse DC magnetron sputtered Ta{sub 2}O{sub 5} thin film as a function of oxygen content in deposition ambient

    SciTech Connect (OSTI)

    Haque, S. Maidul Shinde, D. D. Misal, J. S.; Bhattacharyya, D.; Sahoo, N. K.

    2014-04-24

    Tantalum penta-oxide thin films have been deposited by reactive sputtering technique using asymmetric bipolar pulsed DC source at various oxygen percentage viz. 0 to 50 %. The optical properties of the films have been studied by spectroscopic ellipsometry measurements. It has been observed that compact films with low void fraction, high refractive index and band gap can be obtained by the above technique with oxygen percentage in the range of 3040%. The films deposited with zero or very low oxygen content have high deposition rate and yield metal rich films with large voids, defects, low band gap and high refractive index. Similarly films deposited with >40% oxygen content again contain voids and defects due to the presence of large amount of gas molecules in the sputtering ambient.

  15. Airborne aerosol in situ measurements during TCAP: A closure study of total scattering

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

    Kassianov, Evgueni; Sedlacek, Arthur; Berg, Larry K.; Pekour, Mikhail; Barnard, James; Chand, Duli; Flynn, Connor; Ovchinnikov, Mikhail; Schmid, Beat; Shilling, John; et al

    2015-07-31

    We present a framework for calculating the total scattering of both non-absorbing and absorbing aerosol at ambient conditions from aircraft data. Our framework is developed emphasizing the explicit use of chemical composition data for estimating the complex refractive index (RI) of particles, and thus obtaining improved ambient size spectra derived from Optical Particle Counter (OPC) measurements. The feasibility of our framework for improved calculations of total scattering is demonstrated using three types of data collected by the U.S. Department of Energy’s (DOE) aircraft during the Two-Column Aerosol Project (TCAP). Namely, these data types are: (1) size distributions measured by amore » suite of OPC’s; (2) chemical composition data measured by an Aerosol Mass Spectrometer and a Single Particle Soot Photometer; and (3) the dry total scattering coefficient measured by a integrating nephelometer and scattering enhancement factor measured with a humidification system. We demonstrate that good agreement (~10%) between the observed and calculated scattering can be obtained under ambient conditions (RH < 80%) by applying chemical composition data for the RI-based correction of the OPC-derived size spectra. We also demonstrate that ignoring the RI-based correction or using non-representative RI values can cause a substantial underestimation (~40%) or overestimation (~35%) of the calculated scattering, respectively.« less

  16. Airborne aerosol in situ measurements during TCAP: A closure study of total scattering

    SciTech Connect (OSTI)

    Kassianov, Evgueni; Sedlacek, Arthur; Berg, Larry K.; Pekour, Mikhail; Barnard, James; Chand, Duli; Flynn, Connor; Ovchinnikov, Mikhail; Schmid, Beat; Shilling, John; Tomlinson, Jason; Fast, Jerome

    2015-07-31

    We present a framework for calculating the total scattering of both non-absorbing and absorbing aerosol at ambient conditions from aircraft data. Our framework is developed emphasizing the explicit use of chemical composition data for estimating the complex refractive index (RI) of particles, and thus obtaining improved ambient size spectra derived from Optical Particle Counter (OPC) measurements. The feasibility of our framework for improved calculations of total scattering is demonstrated using three types of data collected by the U.S. Department of Energy’s (DOE) aircraft during the Two-Column Aerosol Project (TCAP). Namely, these data types are: (1) size distributions measured by a suite of OPC’s; (2) chemical composition data measured by an Aerosol Mass Spectrometer and a Single Particle Soot Photometer; and (3) the dry total scattering coefficient measured by a integrating nephelometer and scattering enhancement factor measured with a humidification system. We demonstrate that good agreement (~10%) between the observed and calculated scattering can be obtained under ambient conditions (RH < 80%) by applying chemical composition data for the RI-based correction of the OPC-derived size spectra. We also demonstrate that ignoring the RI-based correction or using non-representative RI values can cause a substantial underestimation (~40%) or overestimation (~35%) of the calculated scattering, respectively.

  17. Influence of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} content on the structure of erbium-doped borosilicate glasses and on their physical, thermal, optical and luminescence properties

    SciTech Connect (OSTI)

    Bourhis, Kevin; Massera, Jonathan; Petit, Laeticia; Ihalainen, Heikki; Fargues, Alexandre; Cardinal, Thierry; Hupa, Leena; Hupa, Mikko; Dussauze, Marc; Rodriguez, Vincent; Boussard-Plédel, Catherine; Bureau, Bruno; Roiland, Claire; Ferraris, Monica

    2015-03-15

    Highlights: • Reorganization of the glass structure induced by the addition of P{sub 2}O{sub 5} or Al{sub 2}O{sub 3}. • Emission properties related to the presence of P or Al in the Er{sup 3+} coordination shell. • Declustering observed upon addition of P{sub 2}O{sub 5}. • No declustering upon addition of Al{sub 2}O{sub 3}. - Abstract: The effect of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} addition in Er-doped borosilicate glasses on the physical, thermal, optical, and luminescence properties is investigated. The changes in these glass properties are related to the glass structure modifications induced by the addition of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3}, which were probed by FTIR, {sup 11}B MAS NMR and X-ray photoelectron spectroscopies. Variations of the polymerization degree of the silicate tetrahedra and modifications in the {sup [3]}B/{sup [4]}B ratio are explained by a charge compensation mechanism due to the formation of AlO{sub 4}, PO{sub 4} groups and the formation of Al-O-P linkages in the glass network. From the absorption and luminescence properties of the Er{sup 3+} ions at 980 nm and 1530 nm, declustering is suspected for the highest P{sub 2}O{sub 5} concentrations while for the highest Al{sub 2}O{sub 3} concentrations no declustering is observed.

  18. Zenith Radiance Retrieval of Cloud Properties

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

    retrievals of cloud properties from the AMF/COPS campaign Preliminary retrievals of cloud properties from the AMF/COPS campaign Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC The cloud optical properties of interest are: The cloud optical properties of interest are: * Cloud optical depth τ - the great unknown * Radiative cloud

  19. Fiber optic coupled optical sensor

    DOE Patents [OSTI]

    Fleming, Kevin J. (Albuquerque, NM)

    2001-01-01

    A displacement sensor includes a first optical fiber for radiating light to a target, and a second optical fiber for receiving light from the target. The end of the first fiber is adjacent and not axially aligned with the second fiber end. A lens focuses light from the first fiber onto the target and light from the target onto the second fiber.

  20. Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations

    SciTech Connect (OSTI)

    Turner, David D.

    2003-06-01

    A novel new approach to retrieve cloud microphysical properties from mixed-phase clouds is presented. This algorithm retrieves cloud optical depth, ice fraction, and the effective size of the water and ice particles from ground-based, high-resolution infrared radiance observations. The theoretical basis is that the absorption coefficient of ice is stronger than that of liquid water from 10-13 mm, whereas liquid water is more absorbing than ice from 16-25 um. However, due to strong absorption in the rotational water vapor absorption band, the 16-25 um spectral region becomes opaque for significant water vapor burdens (i.e., for precipitable water vapor amounts over approximately 1 cm). The Arctic is characterized by its dry and cold atmosphere, as well as a preponderance of mixed-phase clouds, and thus this approach is applicable to Arctic clouds. Since this approach uses infrared observations, cloud properties are retrieved at night and during the long polar wintertime period. The analysis of the cloud properties retrieved during a 7 month period during the Surface Heat Budget of the Arctic (SHEBA) experiment demonstrates many interesting features. These results show a dependence of the optical depth on cloud phase, differences in the mode radius of the water droplets in liquid-only and mid-phase clouds, a lack of temperature dependence in the ice fraction for temperatures above 240 K, seasonal trends in the optical depth with the clouds being thinner in winter and becoming more optically thick in the late spring, and a seasonal trend in the effective size of the water droplets in liquid-only and mixed-phase clouds that is most likely related to aerosol concentration.

  1. A study on dependence of the structural, optical and electrical properties of cadmium lead sulphide thin films on Cd/Pb ratio

    SciTech Connect (OSTI)

    Nair, Sinitha B. E-mail: anithakklm@gmail.com; Abraham, Anitha E-mail: anithakklm@gmail.com; Philip, Rachel Reena; Pradeep, B.; Shripathi, T. E-mail: vganesancsr@gmail.com; Ganesan, V. E-mail: vganesancsr@gmail.com

    2014-10-15

    Cadmium Lead Sulphide thin films with systematic variation in Cd/Pb ratio are prepared at 333K by CBD, adjusting the reagent-molarity, deposition time and pH. XRD exhibits crystalline-amorphous transition as Cd% exceeds Pb%. AFM shows agglomeration of crystallites of size ?505 nm. EDAX assess the composition whereas XPS ascertains the ternary formation, with binding energies of Pb4f{sub 7/2} and 4f{sub 5/2}, Cd3d{sub 5/2} and 3d{sub 3/2} and S2p at 137.03, 141.606, 404.667, 412.133 and 160.218 eV respectively. The optical absorption spectra reveal the variance in the direct allowed band gaps, from 1.57eV to 2.42 eV as Cd/Pb ratio increases from 0.2 to 2.7, suggesting possibility of band gap engineering in the n-type films.

  2. Stackable differential mobility analyzer for aerosol measurement

    DOE Patents [OSTI]

    Cheng, Meng-Dawn; Chen, Da-Ren

    2007-05-08

    A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for charging to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.

  3. Total aerosol effect: forcing or radiative flux perturbation?

    SciTech Connect (OSTI)

    Lohmann, Ulrike; Storelvmo, Trude; Jones, Andy; Rotstayn, Leon; Menon, Surabi; Quaas, Johannes; Ekman, Annica; Koch, Dorothy; Ruedy, Reto

    2009-09-25

    Uncertainties in aerosol forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of rain formation. Traditionally these feedbacks were not included in estimates of total aerosol forcing. Here we argue that they should be included because these feedbacks act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases) the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP), that takes these fast feedbacks and interactions into account. Thus we propose replacing the direct and indirect aerosol forcing in the IPCC forcing chart with RFP estimates. This implies that it is better to evaluate the total anthropogenic aerosol effect as a whole.

  4. Climate Engineering with Stratospheric Aerosols and Associated Engineering Parameters

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.

    2013-02-12

    Climate engineering with stratospheric aerosols, an idea inspired by large volcaniceruptions, could cool the Earths surface and thus alleviate some of the predicted dangerous impacts of anthropogenic climate change. However, the effectiveness of climate engineering to achieve a particular climate goal, and any associated side effects, depend on certain aerosol parameters and how the aerosols are deployed in the stratosphere. Through the examples of sulfate and black carbon aerosols, this paper examines "engineering" parameters-aerosol composition, aerosol size, and spatial and temporal variations in deployment-for stratospheric climate engineering. The effects of climate engineering are sensitive to these parameters, suggesting that a particle could be found ordesigned to achieve specific desired climate outcomes. This prospect opens the possibility for discussion of societal goals for climate engineering.

  5. Indirect and Semi-Direct Aerosol Campaign

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

    Campaign For the month of April, researchers are descending on and above Barrow, Alaska, to obtain data from the atmosphere that will help them understand the impacts that aerosols have on Arctic clouds and climate. Scientists sponsored by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility are using a heavily instrumented aircraft to collect data from the sky, while instruments based at surface sites in Barrow and Atqasuk, Alaska, are obtaining

  6. Indirect and Semi-Direct Aerosol Campaign

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

    Campaign (ISDAC) The Influence of Arctic Aerosol on Clouds PIs: Steve Ghan, Greg McFarquhar, Hans Verlinde ARM AVP: Beat Schmid, Greg McFarquhar, John Hubbe, Debbie Ronfeld In situ measurements: Sarah Brooks, Don Collins, Dan Cziczo, Manvendra Dubey, Greg Kok, Alexei Korolev, Alex Laskin, Paul Lawson, Peter Liu, Claudio Mazzoleni, Ann-Marie McDonald, Greg McFarquhar, Walter Strapp, Alla Zelenyuk Retrievals: Connor Flynn, Dan Lubin, Mengistu Wolde, David Mitchell, Matthew Shupe, David Turner

  7. A New Assessment of the Aerosol First Indirect Effect

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

    New Assessment of the Aerosol First Indirect Effect Shao, Hongfei Florida State University Liu, Guosheng Florida State University Category: Aerosols The aerosol first indirect effect is known to cool the Earth radiatively. However, its magnitude is very uncertain; large discrepancies exist among the observed values published in the literature. In this study, we first survey the published values of those parameters used for describing the first indirect effect. By analyzing the discrepancies

  8. Aerosol Simulations by LLNL IMPACT and Comparisons with Field Measurements

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

    Simulations by LLNL IMPACT and Comparisons with Field Measurements C. C. Chuang, D. Bergman, J. Dignon, and P. Connell Lawrence Livermore National Laboratory Livermore, California Introduction The first step needed to assess aerosol climate effects is to provide the global concentrations and vertical profiles of different aerosol components. These distributions cannot be easily obtained from satellite retrievals or field measurements but are key to estimating the magnitude of aerosol forcing. A

  9. Discrimination between thin cirrus and and tropospheric aerosol using

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

    multiple measurements from Darwin ARCS Discrimination between thin cirrus and and tropospheric aerosol using multiple measurements from Darwin ARCS Mitchell, Ross CSIRO Category: Aerosols Thin cirrus cloud occurs frequently in the tropics, and is often difficult to distinguish from tropospheric aerosol on the basis of temporal variations in ground based measurements, since both can be rather spatially uniform. In this study we investigate their discrimination by combining data from three

  10. Importance of Iron Mineralogy to Aerosol Solubility: Potential Effects of

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

    Aerosol Source on Ocean Photosynthesis Importance of Iron Mineralogy to Aerosol Solubility: Potential Effects of Aerosol Source on Ocean Photosynthesis figure 1 Figure 1. Dust storm blowing glacial dusts from the Copper River Basin of southeast Alaska into the North Pacific Ocean, which depends on this and other external iron sources to support its biological communities. (Image: NASA MODIS satellite image, Nov. 1, 2006. http://earthobservatory.nasa.gov/IOTD/view.php?id=7094) Iron is one of

  11. Toward a Minimal Representation of Aerosols in Climate Models: Description

    Office of Scientific and Technical Information (OSTI)

    and Evaluation in the Community Atmosphere Model CAM5 (Journal Article) | SciTech Connect Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5 Citation Details In-Document Search Title: Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5 A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the

  12. Building America Webinar: Sealing of Home Enclosures with Aerosol Particles

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

    | Department of Energy Sealing of Home Enclosures with Aerosol Particles Building America Webinar: Sealing of Home Enclosures with Aerosol Particles This webinar was presented by research team Building Industry Research Alliance (BIRA), and provided information about a project that uses existing aerosol duct sealing technology to seal the entire building enclosure in order to achieve greater airtightness and energy and cost savings. File webinar_bira_20111014.wmv More Documents &

  13. ARM - Measurement - Cloud optical depth

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

    optical depth ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud optical depth Amount of light cloud droplets or ice particles prevent from passing through a column of atmosphere. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

  14. Core Perylene Diimide Designs via Direct Bay and Ortho (Poly)trifluoromethylation: Synthesis, Isolation, X-ray Structures, Optical and Electronic Properties

    SciTech Connect (OSTI)

    Clikeman, Tyler T.; Bukovsky, Eric V.; Wang, Xue B.; Chen, Yu-Sheng; Rumbles, Garry; Strauss, Steven H.; Boltalina, Olga V.

    2015-10-01

    We developed an efficient solvent- and catalyst-free direct polytrifluoromethylation of solid perylene-3,4,9,10-tetracarboxylic dianhydride that produced a new family of (poly)perfluoroalkyl bay and ortho substituted PDIs with two different imide substituents. Direct hydrogen substitution with CN group led to the synthesis of a cyanated perfluoroalkyl PDI derivative for the first time. Absorption, steady-state and time-resolved emission, X-ray diffraction, electrochemical, and gas-phase electron affinity data allowed for systematic studies of substitution effects at bay, ortho, and imide positions in the new PDIs. Solid-state packing showed remarkable variations in the intermolecular interactions that are important for charge transport and photophysical properties. Analysis of the electrochemical data for 143 electron poor PDIs, including newly reported compounds, revealed some general trends and peculiar effects of electron withdrawing group substitution at all three positions.

  15. Evolution of structural and optical properties of photocatalytic Fe doped TiO{sub 2} thin films prepared by RF magnetron sputtering

    SciTech Connect (OSTI)

    Nair, Prabitha B. Maneeshya, L. V. Justinvictor, V. B. Daniel, Georgi P. Joy, K. Thomas, P. V.

    2014-01-28

    Undoped and Fe doped TiO{sub 2} thin films have been prepared by RF magnetron sputtering. Pure TiO{sub 2} thin film exhibited an amorphous-like nature. With increase in iron concentration (00.1 at%), the films exhibited better crystallization to anatase phase . Red shift of absorption edge was observed in the UV-vis transmittance spectra . At higher Fe concentration (0.5 at%), onset of phase transformation to rutile is noticed. Photocatalytic properties of pure and 0.1 at% Fe doped TiO{sub 2} thin films were investigated by degradation of methylene blue in UV light, visible light and light from Hg vapor lamp. 70% degradation of methylene blue was observed in the presence of Fe doped film in comparison with 3% degradation in presence of pure TiO{sub 2} film when irradiated using visible light for 2 h.

  16. Light Absorption of Primary Organic Aerosol Paper Named ACS Editors...

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

    Absorption of Primary Organic Aerosol Paper Named ACS Editors' Choice For original submission and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights...

  17. Parameterizing the Mixing State of Complex Submicron Aerosols...

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

    DA Knopf, MK Gilles, and RC Moffet. 2015. "Chemical imaging of ambient aerosol particles: Observational constraints on mixing state parameterization." Journal of Geophysical...

  18. Building America Webinar: Sealing of Home Enclosures with Aerosol...

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

    Sealing of Home Enclosures with Aerosol Particles This webinar was presented by research team Building Industry Research Alliance (BIRA), and provided information about a project...

  19. ARM - Field Campaign - Azores: Clouds, Aerosol and Precipitation...

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

    Campaigns Azores: Above-Cloud Radiation Budget near Graciosa Island 2010.04.15, Miller, AMF Azores: Extension to Clouds, Aerosol and Precipitation in the Marine Boundary...

  20. ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects...

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

    of representative organic aerosols within the boundary layer. By combining a SMPS and a dual column CCN counter, the size-resolved CCN concentrations were measured. This allowed...

  1. Clouds, Aerosols and Precipitation in the Marine Boundary Layer...

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

    Framework, extend to investigation of aerosol-cloud interactions in models - Ensemble Kalman Filter (DART) Satellite activities with CAP-MBL Minnis: CAP-MBL subset MBL depth,...

  2. ARM - Field Campaign - Carbonaceous Aerosol and Radiation Effects...

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

    - Surface Meteorological Sounding Campaign Links ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiative Effects Study (CARES) 2010.06.02, Zaveri, AAF...

  3. ARM - Field Campaign - Indirect and Semi-Direct Aerosol Campaign...

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

    govCampaignsIndirect and Semi-Direct Aerosol Campaign (ISDAC) Campaign Links ISDAC Website ARM Data Discovery Browse Data Related Campaigns Parameterization of Extinction...

  4. Analysis of Aerosol Indirect Effects in California Coastal Stratus...

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

    Andrew Brookhaven National Laboratory Andrews, Betsy NOAACMDL Ogren, John NOAACMDL Turner, David University of Wisconsin-Madison Category: Field Campaigns Impacts of aerosol...

  5. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds...

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

    relevant to DOE's goals in understanding the impact of clouds and aerosols on climate change. TWST contributes significantly to the body of data used for extracting cloud...

  6. Toward a Minimal Representation of Aerosols in Climate Models...

    Office of Scientific and Technical Information (OSTI)

    Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5 Citation Details In-Document Search Title: Toward a Minimal ...

  7. The Radiative Role of Free Tropospheric Aerosols and Marine Clouds...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: The Radiative Role of Free Tropospheric Aerosols and Marine Clouds over the Central North Atlantic Citation Details In-Document Search Title: The Radiative Role...

  8. ARM - Publications: Science Team Meeting Documents: The SGP Aerosol...

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

    The SGP Aerosol Best-Estimate Value-Added Procedure and Its Impact on the BBHRP Project Turner, David Pacific Northwest National Laboratory Sivaraman, Chitra Pacific Northwest...

  9. About the Rhythms of Variability of the Submicron Aerosol Characterist...

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

    of the distribution of the aerosol characteristics were considered. The periodograms (Fourier spectra of the discrete data set) were calculated for all data arrays using...

  10. The AeroCom evaluation and intercomparison of organic aerosol in global models

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

    Tsigaridis, K.; Daskalakis, N.; Kanakidou, M.; Adams, P. J.; Artaxo, P.; Bahadur, R.; Balkanski, Y.; Bauer, S. E.; Bellouin, N.; Benedetti, A.; et al

    2014-10-15

    This paper evaluates the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations. Thirty-one global chemistry transport models (CTMs) and general circulation models (GCMs) have participated in this intercomparison, in the framework of AeroCom phase II. The simulation of OA varies greatly between models in terms of the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used (2 to 62), the complexity of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemicalmore » and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom experiments, mainly due to the increasing complexity of the SOA parameterization in models, and the implementation of new, highly uncertain, OA sources. Diversity of over one order of magnitude exists in the modeled vertical distribution of OA concentrations that deserves a dedicated future study. Furthermore, although the OA / OC ratio depends on OA sources and atmospheric processing, and is important for model evaluation against OA and OC observations, it is resolved only by a few global models. The median global primary OA (POA) source strength is 56 Tg a–1 (range 34–144 Tg a−1) and the median SOA source strength (natural and anthropogenic) is 19 Tg a–1 (range 13–121 Tg a−1). Among the models that take into account the semi-volatile SOA nature, the median source is calculated to be 51 Tg a–1 (range 16–121 Tg a−1), much larger than the median value of the models that calculate SOA in a more simplistic way (19 Tg a–1; range 13–20 Tg a–1, with one model at 37 Tg a−1). The median atmospheric burden of OA is 1.4 Tg (24 models in the range of 0.6–2.0 Tg and 4 between 2.0 and 3.8 Tg), with a median OA lifetime of 5.4 days (range 3.8–9.6 days). In models that reported both OA and sulfate burdens, the median value of the OA/sulfate burden ratio is calculated to be 0.77; 13 models calculate a ratio lower than 1, and 9 models higher than 1. For 26 models that reported OA deposition fluxes, the median wet removal is 70 Tg a–1 (range 28–209 Tg a−1), which is on average 85% of the total OA deposition. Fine aerosol organic carbon (OC) and OA observations from continuous monitoring networks and individual field campaigns have been used for model evaluation. At urban locations, the model–observation comparison indicates missing knowledge on anthropogenic OA sources, both strength and seasonality. The combined model–measurements analysis suggests the existence of increased OA levels during summer due to biogenic SOA formation over large areas of the USA that can be of the same order of magnitude as the POA, even at urban locations, and contribute to the measured urban seasonal pattern. Global models are able to simulate the high secondary character of OA observed in the atmosphere as a result of SOA formation and POA aging, although the amount of OA present in the atmosphere remains largely underestimated, with a mean normalized bias (MNB) equal to –0.62 (–0.51) based on the comparison against OC (OA) urban data of all models at the surface, –0.15 (+0.51) when compared with remote measurements, and –0.30 for marine locations with OC data. The mean temporal correlations across all stations are low when compared with OC (OA) measurements: 0.47 (0.52) for urban stations, 0.39 (0.37) for remote stations, and 0.25 for marine stations with OC data. The combination of high (negative) MNB and higher correlation at urban stations when compared with the low MNB and lower correlation at remote sites suggests that knowledge about the processes that govern aerosol processing, transport and removal, on top of their sources, is important at the remote stations. There is no clear change in model skill with increasing model complexity with regard to OC or OA mass concentration. As a result, the complexity is needed in models in order to distinguish between anthropogenic and natural OA as needed for climate mitigation, and to calculate the impact of OA on climate accurately.« less

  11. Effects of sulfate aerosol on the central Pennsylvania surface shortwave radiation budget. Master's thesis

    SciTech Connect (OSTI)

    Guimond, P.W.

    1994-12-01

    Surface radiation measurements are taken simultaneously with measurements of meteorological variables including temperature, pressure, relative humidity, and visibility to evaluate the impact of sulfate haze on the surface radiation budget. A relationship is sought between flux losses due only to aerosol and relative humidity, visibility or both, with the goal of facilitating parameterization of sulfate hazes by climate modelers. At the same time, a rotating shadowband radiometer (RSR) is compared with a more costly sun photometer to determine the feasibility of substituting the former for the latter in future research. It is found that depletion of surface radiation due to aerosol is typically ten to twenty percent of initial insolation, and that the losses can be correlated with zenith angle, relative humidity and optical depth. In the case of flux loss as a function of optical depth, the two are related in a nearly linear fashion. It is also discovered that the RSR has a predictable error owing to a wider field of view than the sun photometer, and can be used as a replacement for the former by correcting for the error.

  12. The AeroCom Evaluation and Intercomparison of Organic Aerosol in Global Models

    SciTech Connect (OSTI)

    Tsigaridis, Kostas; Daskalakis, N.; Kanakidou, M.; Adams, P. J.; Artaxo, Paulo; Bahadur, R.; Balkanski, Y.; Bauer, S.; Bellouin, N.; Benedetti, Angela; Bergman, T.; Berntsen, T.; Beukes, J. P.; Bian, Huisheng; Carslaw, K. S.; Chin, M.; Curci, Gabriele; Diehl, Thomas; Easter, Richard C.; Ghan, Steven J.; Gong, S.; Hodzic, Alma; Hoyle, Christopher R.; Iversen, T.; Jathar, S.; Jimenez, J. L.; Kaiser, J. W.; Kirkevag, A.; Koch, Dorothy; Kokkola, H.; Lee, Y. H.; Lin, G.; Liu, Xiaohong; Luo, Gan; Ma, Xiaoyan; Mann, G. W.; Mihalopoulos, Nikos; Morcrette, J. -J.; Muller, J. F.; Myhre, G.; Myriokefalitakis, S.; Ng, Nga L.; O'Donell, D.; Penner, J. E.; Pozzoli, L.; Pringle, K. J.; Russell, Lynn; Schulz, M.; Sciare, J.; Seland, O.; Shindell, Drew; Sillman, S.; Skeie, R. B.; Spracklen, D. V.; Stavrakou, T.; Steenrod, Stephen D.; Takemura, T.; Tiitta, P.; Tilmes, S.; Tost, H.; van Noije, T.; van Zyl, P. G.; von Salzen, Knut; Yu, Fangqun; Wang, Zaizi; Wang, Zhilli; Zaveri, Rahul A.; Zhang, Hua; Zhang, Kai; Zhang, Qi; Zhang, Xiaoye

    2014-10-15

    This paper evaluates the current status of global modeling of the organic aerosol (OA) occurrence in the troposphere and analyzes the differences calculated between models as well as between models and observations. Thirty-one global chemistry/transport and general circulation models have participated in this intercomparison, in the framework of AeroCom phase II. The simulation of OA varies greatly between models in terms of the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used (2 to 62), the complexity of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemical and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom experiments, mainly due to the increasing complexity of the SOA parameterization in models, and the implementation of new, highly uncertain, OA sources. Diversity of over an order of magnitude exists in the modeled vertical distribution of OA that deserves a dedicated future study. Furthermore, although the OA/OC ratio depends on OA sources and atmospheric processing and is important for model evaluation against OA and OC observations, it is resolved only by few global models. The median global primary OA source strength is 56 Tg a-1 (range 34 - 144 Tg a-1) and the median secondary OA source strength (natural and anthropogenic) is 19 Tg a-1 (range 13-121 Tg a-1). Among the models that take into account the semi-volatile SOA nature, the median source is calculated to be 51 Tg a-1 (range 16-121 Tg a-1), much larger than the median value of the models that calculate SOA in a more simplistic way (19 Tg a-1; range 13-20 Tg a-1, with one model at 37 Tg a-1). The median atmospheric burden of OA is 1.4 Tg (24 models in the range of 0.6-2.0 Tg and 4 between 2.4-3.8 Tg) with a median OA lifetime of 5.4 days (range 3.8-9.6 days). In models that reported both OA and sulfate burdens, the median value of the OA/sulfate burden ratio of is calculated to be 0.77; 13 models calculate a ratio lower than 1, and 9 models higher than 1. For 26 models that reported OA deposition fluxes, the median wet removal is 70 Tg a-1 (range 28-209 Tg a-1), which is on average 85% of the total OA deposition.

  13. Optical analyzer

    DOE Patents [OSTI]

    Hansen, A.D.

    1987-09-28

    An optical analyzer wherein a sample of particulate matter, and particularly of organic matter, which has been collected on a quartz fiber filter is placed in a combustion tube, and light from a light source is passed through the sample. The temperature of the sample is raised at a controlled rate and in a controlled atmosphere. The magnitude of the transmission of light through the sample is detected as the temperature is raised. A data processor, differentiator and a two pen recorder provide a chart of the optical transmission versus temperature and the rate of change of optical transmission versus temperature signatures (T and D) of the sample. These signatures provide information as to physical and chemical processes and a variety of quantitative and qualitative information about the sample. Additional information is obtained by repeating the run in different atmospheres and/or different rates or heating with other samples of the same particulate material collected on other filters. 7 figs.

  14. Optical coupler

    DOE Patents [OSTI]

    Majewski, Stanislaw; Weisenberger, Andrew G.

    2004-06-15

    In a camera or similar radiation sensitive device comprising a pixilated scintillation layer, a light guide and an array of position sensitive photomultiplier tubes, wherein there exists so-called dead space between adjacent photomultiplier tubes the improvement comprising a two part light guide comprising a first planar light spreading layer or portion having a first surface that addresses the scintillation layer and optically coupled thereto at a second surface that addresses the photomultiplier tubes, a second layer or portion comprising an array of trapezoidal light collectors defining gaps that span said dead space and are individually optically coupled to individual position sensitive photomultiplier tubes. According to a preferred embodiment, coupling of the trapezoidal light collectors to the position sensitive photomultiplier tubes is accomplished using an optical grease having about the same refractive index as the material of construction of the two part light guide.

  15. Optical memory

    DOE Patents [OSTI]

    Mao, Samuel S; Zhang, Yanfeng

    2013-07-02

    Optical memory comprising: a semiconductor wire, a first electrode, a second electrode, a light source, a means for producing a first voltage at the first electrode, a means for producing a second voltage at the second electrode, and a means for determining the presence of an electrical voltage across the first electrode and the second electrode exceeding a predefined voltage. The first voltage, preferably less than 0 volts, different from said second voltage. The semiconductor wire is optically transparent and has a bandgap less than the energy produced by the light source. The light source is optically connected to the semiconductor wire. The first electrode and the second electrode are electrically insulated from each other and said semiconductor wire.

  16. Optical switch

    DOE Patents [OSTI]

    Reedy, R.P.

    1987-11-10

    An optical switching device is provided whereby light from a first glass fiber or a second glass fiber may be selectively transmitted into a third glass fiber. Each glass fiber is provided with a focusing and collimating lens system. In one mode of operation, light from the first glass fiber is reflected by a planar mirror into the third glass fiber. In another mode of operation, light from the second glass fiber passes directly into the third glass fiber. The planar mirror is attached to a rotatable table which is rotated to provide the optical switching. 3 figs.

  17. Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics

    SciTech Connect (OSTI)

    Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

    2013-10-01

    Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

  18. Ge{sub 1-y}Sn{sub y} (y = 0.01-0.10) alloys on Ge-buffered Si: Synthesis, microstructure, and optical properties

    SciTech Connect (OSTI)

    Senaratne, C. L.; Kouvetakis, J.; Gallagher, J. D.; Jiang, Liying; Smith, D. J.; Menndez, J.; Aoki, Toshihiro

    2014-10-07

    Novel hydride chemistries are employed to deposit light-emitting Ge{sub 1-y}Sn{sub y} alloys with y ? 0.1 by Ultra-High Vacuum Chemical Vapor Deposition (UHV-CVD) on Ge-buffered Si wafers. The properties of the resultant materials are systematically compared with similar alloys grown directly on Si wafers. The fundamental difference between the two systems is a fivefold (and higher) decrease in lattice mismatch between film and virtual substrate, allowing direct integration of bulk-like crystals with planar surfaces and relatively low dislocation densities. For y ? 0.06, the CVD precursors used were digermane Ge?H? and deuterated stannane SnD?. For y ? 0.06, the Ge precursor was changed to trigermane Ge?H?, whose higher reactivity enabled the fabrication of supersaturated samples with the target film parameters. In all cases, the Ge wafers were produced using tetragermane Ge?H?? as the Ge source. The photoluminescence intensity from Ge{sub 1y}Sn{sub y}/Ge films is expected to increase relative to Ge{sub 1y}Sn{sub y}/Si due to the less defected interface with the virtual substrate. However, while Ge{sub 1y}Sn{sub y}/Si films are largely relaxed, a significant amount of compressive strain may be present in the Ge{sub 1y}Sn{sub y}/Ge case. This compressive strain can reduce the emission intensity by increasing the separation between the direct and indirect edges. In this context, it is shown here that the proposed CVD approach to Ge{sub 1y}Sn{sub y}/Ge makes it possible to approach film thicknesses of about 1 ?m, for which the strain is mostly relaxed and the photoluminescence intensity increases by one order of magnitude relative to Ge{sub 1y}Sn{sub y}/Si films. The observed strain relaxation is shown to be consistent with predictions from strain-relaxation models first developed for the Si{sub 1x}Ge{sub x}/Si system. The defect structure and atomic distributions in the films are studied in detail using advanced electron-microscopy techniques, including aberration corrected STEM imaging and EELS mapping of the average diamondcubic lattice.

  19. Method of dispersing particulate aerosol tracer

    DOE Patents [OSTI]

    O'Holleran, Thomas P. (Belleville, MI)

    1988-01-01

    A particulate aerosol tracer which comprises a particulate carrier of sheet silicate composition having a particle size up to one micron, and a cationic dopant chemically absorbed in solid solution in the carrier. The carrier is preferably selected from the group consisting of natural mineral clays such as bentonite, and the dopant is selected from the group consisting of rare earth elements and transition elements. The tracers are dispersed by forming an aqueous salt solution with the dopant present as cations, dispersing the carriers in the solution, and then atomizing the solution under heat sufficient to superheat the solution droplets at a level sufficient to prevent reagglomeration of the carrier particles.

  20. Effect of Tb{sup 3+} concentration on the optical and vibrational properties of YBO{sub 3} tri-doped with Eu{sup 3+}, Ce{sup 3+}, and Tb{sup 3+}

    SciTech Connect (OSTI)

    Sohal, S.; Hassanzadeh, E.; Huang, J. Y. [Department of Physics, Texas Tech University and Nano Tech Center, Lubbock, Texas 79409 (United States); Nazari, M.; Holtz, M., E-mail: mark.holtz@txstate.edu [Department of Physics, Texas State University, San Marcos, Texas 78666 (United States); Zhang, X.; Chaudhuri, J. [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States); Kuryatkov, V. V. [Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States); Hope-Weeks, L. J. [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-05-14

    Structural and optical studies are reported of yttrium orthoborate YBO{sub 3} when tri-doped with Eu{sup 3+}, Ce{sup 3+}, and Tb{sup 3+}, focusing on the role of terbium concentration. Incorporation of Tb{sup 3+} affects emission properties for photoluminescence (PL) excited by near ultraviolet light. For constant cerium and europium concentrations, increasing the Tb{sup 3+} results in diminished PL from the Ce{sup 3+} and Tb{sup 3+} color centers. Simultaneously, the PL excitation bands related to both Ce{sup 3+} and Tb{sup 3+} increase in intensity for red emission from the Eu{sup 3+}. Results are consistent with a Ce{sup 3+}???(Tb{sup 3+}){sub n}???Eu{sup 3+} energy transfer scheme, where (Tb{sup 3+}){sub n} denotes a chain incorporating n terbium ions. A high red to orange PL intensity ratio is obtained, ranging from 1.34 to 2.09. Raman vibrational bands show a systematic change, with Tb{sup 3+} concentration, in the B{sub 3}O{sub 9} ring terminal oxygen bending mode coordinated with the yttrium site where dopant ions substitute. The structural changes are interpreted as variations in the local neighborhood of these sites in the YBO{sub 3}:Ce{sup 3+},Tb{sup 3+},Eu{sup 3+} crystal structure.

  1. FirstOPTIC Software Package for Parabolic Trough Evaluation ...

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

    properties of system components. Optical performance is often evaluated using either a simple but low-accuracy analytical probability-approximation method, or an accurate but...

  2. Chemical distribution in high-solids paint overspray aerosols

    SciTech Connect (OSTI)

    D'Arcy, J.B.; Chan, T.L. )

    1990-03-01

    The chemical composition of high-solids basecoat paint overspray aerosols was determined as a function of particle size. Detailed information on the chemical composition of the overspray aerosols is important in health hazard evaluation since the composition and distribution within the airborne particles may differ significantly from the bulk paint material. This study was conducted in a typical down-draft paint booth equipped with air-atomized spray painting equipment. A fixed paint target was used to simulate typical overspray generation conditions and the aerosols were collected isokinetically with a seven-stage cascade impactor for size-fractionated analysis. The overspray aerosol from six paints consisted of organic paint binders with varying amounts of inorganic species as pigments or luster enhancers. These overspray aerosols had mass median aerodynamic diameters (MMAD) ranging from 2.9 to 9.7 microns. The size-fractionated paint samples collected on the impaction stages were analyzed by energy dispersive X-ray spectrometry on a scanning electron microscope (SEM-EDXRS) to identify the metallic elements. Atomic absorption spectrometry was used to determine the mass distribution of aluminum and iron as indicators of nonuniform distribution. Three of the aerosols containing aluminum were found to have bimodal distributions with most aluminum distributions having cumulative MMADs larger than the total aerosol. Iron in the aerosols was bimodal for three of the paints with all samples having an overall iron MMAD less than or equal to the overspray aerosol MMAD. Analysis using ultraviolet spectrometry revealed that the organic compounds present in the size-fractionated particulate samples consisted of a single, polydispersed mode with an MMAD similar to that of the total overspray aerosol.

  3. Optical temperature sensor using thermochromic semiconductors

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-01-01

    Optical thermometry is a growing technological field which exploits the ability of certain materials to change their optical properties with temperature. A subclass of such materials are those which change their color as a reversible and reproducible function of temperature. These materials are thermochromic. This invention is a composition to measure temperature utilizing thermochromic semiconductors.

  4. Laboratory Investigation of Contact Freezing and the Aerosol to Ice Crystal Transformation Process

    SciTech Connect (OSTI)

    Shaw, Raymond A.

    2014-10-28

    This project has been focused on the following objectives: 1. Investigations of the physical processes governing immersion versus contact nucleation, specifically surface-induced crystallization; 2. Development of a quadrupole particle trap with full thermodynamic control over the temperature range 0 to 40 C and precisely controlled water vapor saturation ratios for continuous, single-particle measurement of the aerosol to ice crystal transformation process for realistic ice nuclei; 3. Understanding the role of ice nucleation in determining the microphysical properties of mixed-phase clouds, within a framework that allows bridging between laboratory and field measurements.

  5. CARES Helps Explain Secondary Organic Aerosols

    SciTech Connect (OSTI)

    Zaveri, Rahul

    2014-03-28

    What happens when urban man-made pollution mixes with what we think of as pristine forest air? To know more about what this interaction means for the climate, the Carbonaceous Aerosol and Radiative Effects Study, or CARES, field campaign was designed in 2010. The sampling strategy during CARES was coordinated with CalNex 2010, another major field campaign that was planned in California in 2010 by the California Air Resources Board (CARB), the National Oceanic and Atmospheric Administration (NOAA), and the California Energy Commission (CEC). "We found two things. When urban pollution mixes with forest pollutions we get more secondary organic aerosols," said Rahul Zaveri, FCSD scientist and project lead on CARES. "SOAs are thought to be formed primarily from forest emissions but only when they interact with urban emissions. The data is saying that there will be climate cooling over the central California valley because of these interactions." Knowledge gained from detailed analyses of data gathered during the CARES campaign, together with laboratory experiments, is being used to improve existing climate models.

  6. Asthmatic responses to airborne acid aerosols

    SciTech Connect (OSTI)

    Ostro, B.D.; Lipsett, M.J.; Wiener, M.B.; Selner, J.C. )

    1991-06-01

    Controlled exposure studies suggest that asthmatics may be more sensitive to the respiratory effects of acidic aerosols than individuals without asthma. This study investigates whether acidic aerosols and other air pollutants are associated with respiratory symptoms in free-living asthmatics. Daily concentrations of hydrogen ion (H+), nitric acid, fine particulates, sulfates and nitrates were obtained during an intensive air monitoring effort in Denver, Colorado, in the winter of 1987-88. A panel of 207 asthmatics recorded respiratory symptoms, frequency of medication use, and related information in daily diaries. We used a multiple regression time-series model to analyze which air pollutants, if any, were associated with health outcomes reported by study participants. Airborne H+ was found to be significantly associated with several indicators of asthma status, including moderate or severe cough and shortness of breath. Cough was also associated with fine particulates, and shortness of breath with sulfates. Incorporating the participants' time spent outside and exercise intensity into the daily measure of exposure strengthened the association between these pollutants and asthmatic symptoms. Nitric acid and nitrates were not significantly associated with any respiratory symptom analyzed. In this population of asthmatics, several outdoor air pollutants, particularly airborne acidity, were associated with daily respiratory symptoms.

  7. CARES Helps Explain Secondary Organic Aerosols

    ScienceCinema (OSTI)

    Zaveri, Rahul

    2014-06-02

    What happens when urban man-made pollution mixes with what we think of as pristine forest air? To know more about what this interaction means for the climate, the Carbonaceous Aerosol and Radiative Effects Study, or CARES, field campaign was designed in 2010. The sampling strategy during CARES was coordinated with CalNex 2010, another major field campaign that was planned in California in 2010 by the California Air Resources Board (CARB), the National Oceanic and Atmospheric Administration (NOAA), and the California Energy Commission (CEC). "We found two things. When urban pollution mixes with forest pollutions we get more secondary organic aerosols," said Rahul Zaveri, FCSD scientist and project lead on CARES. "SOAs are thought to be formed primarily from forest emissions but only when they interact with urban emissions. The data is saying that there will be climate cooling over the central California valley because of these interactions." Knowledge gained from detailed analyses of data gathered during the CARES campaign, together with laboratory experiments, is being used to improve existing climate models.

  8. Method and apparatus for aerosol particle absorption spectroscopy

    DOE Patents [OSTI]

    Campillo, Anthony J.; Lin, Horn-Bond

    1983-11-15

    A method and apparatus for determining the absorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of electromagnetic energy which is scanned through the region of the spectrum which is of interest. Particles exposed to the heating beam which have absorption bands within the band width of the heating beam absorb energy from the beam. The particles are also illuminated by light of a wave length such that the light is scattered by the particles. The absorption spectra of the particles can thus be determined from an analysis of the scattered light since the absorption of energy by the particles will affect the way the light is scattered. Preferably the heating beam is modulated to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light will also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an interferometer and the scattered light reflects the Fourier Transform of the absorption spectra.

  9. ARM: 10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  10. ARM: 2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  11. ARM: 1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  12. ARM: 10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Newsom, Rob; Goldsmith, John

    1998-03-01

    10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  13. ARM: 10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  14. ARM: 10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  15. ARM: 2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Sivaraman, Chitra; Flynn, Connor

    2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  16. ARM: 1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

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

    Chitra Sivaraman; Connor Flynn

    1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  17. Sandia Energy - Quantum Optics

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

    Quantum Optics Home Energy Research EFRCs Solid-State Lighting Science EFRC Quantum Optics Quantum OpticsTara Camacho-Lopez2015-03-30T16:37:03+00:00 Quantum Optics with a Single...

  18. Quantum Optics

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

    Quantum Optics - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced Nuclear

  19. Optical analyzer

    DOE Patents [OSTI]

    Hansen, Anthony D. (Berkeley, CA)

    1989-01-01

    An optical analyzer (10) wherein a sample (19) of particulate matter, and particularly of organic matter, which has been collected on a quartz fiber filter (20) is placed in a combustion tube (11), and light from a light source (14) is passed through the sample (19). The temperature of the sample (19) is raised at a controlled rate and in a controlled atmosphere. The magnitude of the transmission of light through the sample (19) is detected (18) as the temperature is raised. A data processor (23), differentiator (28) and a two pen recorder (24) provide a chart of the optical transmission versus temperature and the rate of change of optical transmission versus temperature signatures (T and D) of the sample (19). These signatures provide information as to physical and chemical processes and a variety of quantitative and qualitative information about the sample (19). Additional information is obtained by repeating the run in different atmospheres and/or different rates of heating with other samples of the same particulate material collected on other filters.

  20. Fire aerosol experiment and comparisons with computer code predictions

    SciTech Connect (OSTI)

    Gregory, W.S.; Nichols, B.D.; White, B.W.; Smith, P.R.; Leslie, I.H.; Corkran, J.R.

    1988-01-01

    Los Alamos National Laboratory, in cooperation with New Mexico State University, has carried on a series of tests to provide experimental data on fire-generated aerosol transport. These data will be used to verify the aerosol transport capabilities of the FIRAC computer code. FIRAC was developed by Los Alamos for the US Nuclear Regulatory Commission. It is intended to be used by safety analysts to evaluate the effects of hypothetical fires on nuclear plants. One of the most significant aspects of this analysis deals with smoke and radioactive material movement throughout the plant. The tests have been carried out using an industrial furnace that can generate gas temperatures to 300/degree/C. To date, we have used quartz aerosol with a median diameter of about 10 ..mu..m as the fire aerosol simulant. We also plan to use fire-generated aerosols of polystyrene and polymethyl methacrylate (PMMA). The test variables include two nominal gas flow rates (150 and 300 ft/sup 3//min) and three nominal gas temperatures (ambient, 150/degree/C, and 300/degree/C). The test results are presented in the form of plots of aerosol deposition vs length of duct. In addition, the mass of aerosol caught in a high-efficiency particulate air (HEPA) filter during the tests is reported. The tests are simulated with the FIRAC code, and the results are compared with the experimental data. 3 refs., 10 figs., 1 tab.